The average B–O–T angles (B, O, and T denote boron, oxygen, and tetrahedrally coordinated atoms, respectively) are used as local geometric parameters for framework-incorporated B-sites within crystalline, borosilicate molecular sieves and are obtained from density-functional theory (DFT) calculations. The linear relationship between the B–O–T angles and the 11B NMR chemical shifts reported previously for smaller angles in minerals is shown here to extend to the larger angles more typical within crystalline molecular sieves. In total, the correlation can be employed to investigate tetrahedrally coordinated B atoms for the entire class of three-dimensional, crystalline borosilicates.
", "doi": "10.1021/acs.jpcc.4c02361", "issn": "1932-7447", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry C", "publication_date": "2024-06-13" }, { "id": "authors:j9b2v-drj26", "collection": "authors", "collection_id": "j9b2v-drj26", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230718-848518400.1", "type": "article", "title": "Exploring the boundaries of molecular sieve materials", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The Davis research program is focused on exploring and moving the boundaries of molecular sieve properties. Here, it is described how the program approached the investigation of: (i) extra-large pores and extra-large pore spaces, (ii) framework charge and (iii) enantiomerically enriched, powdered samples. Additionally, current work on item (iii), and site-specific placement of heteroatoms into the framework are discussed. The Corma research program also investigates a number of these areas, and some of the intersections with the Davis research program are provided.", "doi": "10.1016/j.micromeso.2023.112659", "issn": "1387-1811", "publisher": "Elsevier", "publication": "Microporous and Mesoporous Materials", "publication_date": "2023-08", "volume": "358", "pages": "Art. No. 112659" }, { "id": "authors:64aq7-c4t40", "collection": "authors", "collection_id": "64aq7-c4t40", "cite_using_url": "https://authors.library.caltech.edu/records/64aq7-c4t40", "type": "article", "title": "Synthesis and Characterization of Silicoaluminophosphate CIT-16P and Its Transformation to SAPO-17", "author": [ { "family_name": "Alshafei", "given_name": "Faisal H.", "orcid": "0000-0003-1808-1374", "clpid": "Alshafei-Faisal-H" }, { "family_name": "Kang", "given_name": "Jong Hun", "orcid": "0000-0002-4197-9070", "clpid": "Kang-Jong-Hun" }, { "family_name": "Cho", "given_name": "Sung June", "clpid": "Cho-Sung-June" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A silicoaluminophosphate molecular sieve, CIT-16P, is synthesized using butane-1,4-bis(quinuclidinium) [(C7H13N)-(CH2)4-(NC7H13)]2+ dihydroxide (DiQ-C4-(OH)2) as an organic structure-directing agent (OSDA). Upon the removal of the OSDA, either by thermal treatment in air at temperatures exceeding 490 °C or by extended ozone treatment at 150 °C, CIT-16P transforms to SAPO-17 (ERI topology). The structure solution of CIT-16P in its as-synthesized form is obtained using a Rietveld refinement of the powder X-ray diffraction pattern. The primary composite building units (CBUs) of CIT-16P are highly distorted cancrinite (can) CBUs that transform into stable can units of the ERI-type framework as a result of the OSDA removal. The distortion of can CBU is maintained without transformation by the presence of tightly bound DiQ-C4 dications in the as-synthesized form of CIT-16P. The transformed material is characterized and evaluated as a catalyst in the methanol-to-olefins (MTO) reaction. The catalytic behavior of the formed SAPO-17 (Si/T-atom = 0.022) (T = Si + Al + P) at 400 °C and WHSV of 1.3 h–1 produces elevated C3+ olefin products (i.e., propylene, butenes, and pentenes) in early stages of the reaction. However, as the reaction proceeds, the C3+ fraction decreases in favor of more ethylene.
", "doi": "10.1021/acs.inorgchem.2c04539", "issn": "0020-1669", "publisher": "American Chemical Society", "publication": "Inorganic Chemistry", "publication_date": "2023-04-17", "series_number": "15", "volume": "62", "issue": "15", "pages": "6065-6075" }, { "id": "authors:0jzen-gq598", "collection": "authors", "collection_id": "0jzen-gq598", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230420-614686900.15", "type": "article", "title": "Local Geometry of Tetrahedrally Coordinated Boron Correlates with \u00b9\u00b9B NMR Chemical Shifts in Borosilicate Minerals", "author": [ { "family_name": "Park", "given_name": "Youngkyu", "orcid": "0000-0001-7328-7565", "clpid": "Park-Youngkyu" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Chemical shifts from the \u00b9\u00b9B nuclear magnetic resonance (NMR) spectra of crystalline borosilicate minerals with highly ordered, tetrahedrally coordinated boron atoms (B) linearly correlate with the local geometric parameters related to the B\u2013O\u2013T angles (T denotes a tetrahedrally coordinated atom) obtained from single-crystal X-ray diffraction. The correlations between the \u00b9\u00b9B NMR chemical shifts and structural parameters are similar in functional form to the well-known correlations of \u00b2\u2079Si and \u00b2\u2077Al NMR chemical shifts with structural features of silicates and aluminosilicates, respectively. These correlations enable the use of \u00b9\u00b9B NMR chemical shifts to elucidate the local geometry of tetrahedrally coordinated B and aid in establishing B ordering among the crystallographic T-sites within crystalline borosilicates.", "doi": "10.1021/acs.jpcc.3c00614", "issn": "1932-7447", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry C", "publication_date": "2023-04-06", "series_number": "13", "volume": "127", "issue": "13", "pages": "6578-6585" }, { "id": "authors:1jy51-nfp84", "collection": "authors", "collection_id": "1jy51-nfp84", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221017-15547800.48", "type": "article", "title": "Carbon dioxide capture with zeotype materials", "author": [ { "family_name": "Fu", "given_name": "Donglong", "orcid": "0000-0002-5680-6279", "clpid": "Fu-Donglong" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The accumulation of carbon dioxide (CO\u2082) in the atmosphere has been recognized as one of the primary factors attributed to global warming. Various strategies have been proposed to mitigate the amount of atmospheric CO\u2082 such as its separation from emission streams with storage or utilization in fuels and chemicals. Zeolite-based materials (zeotype materials), a class of microporous solids with: (i) structural features of high surface area, chemical tunability and high stability, and (ii) a long history of global scale industrial use, have been extensively investigated for CO\u2082 capture. In this review, a comprehensive summary and discussion of the progress in the design and use of zeotype materials, e.g., cation and amine modifications, composites and templated carbons, for the capture of CO\u2082 is presented. The CO\u2082 adsorption mechanisms in these materials are described, and the factors that determine their performance are discussed. The application of zeotype materials for CO\u2082 capture under conditions such as post-combustion, indoor air cleaning and direct air capture are presented. Further, the mechanisms of water-zeolites interaction as well as their impacts on CO\u2082 adsorption performance are discussed. The review closes with a brief presentation on the challenges and opportunities for future research in the field.", "doi": "10.1039/d2cs00508e", "issn": "0306-0012", "publisher": "Royal Society of Chemistry", "publication": "Chemical Society Reviews", "publication_date": "2022-10", "series_number": "22", "volume": "51", "issue": "22", "pages": "9340-9370" }, { "id": "authors:dd3rg-n8m19", "collection": "authors", "collection_id": "dd3rg-n8m19", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221107-997760900.2", "type": "article", "title": "Exploring the boundaries of molecular sieve materials", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The Davis research program is focused on exploring and moving the boundaries of molecular sieve properties. Here, it is described how the program approached the investigation of: (i) extra-large pores and extra-large pore spaces, (ii) framework charge and (iii) enantiomerically enriched, powdered samples. Additionally, current work on item (iii), and site-specific placement of heteroatoms into the framework are discussed. The Corma research program also investigates a number of these areas, and some of the intersections with the Davis research program are provided.", "doi": "10.1016/j.micromeso.2022.112200", "issn": "1387-1811", "publisher": "Elsevier", "publication": "Microporous and Mesoporous Materials", "publication_date": "2022-10", "volume": "344", "pages": "Art. No. 112200" }, { "id": "authors:6s822-s1294", "collection": "authors", "collection_id": "6s822-s1294", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230525-771644200.2", "type": "article", "title": "Confinement effects facilitate low-concentration carbon dioxide capture with zeolites", "author": [ { "family_name": "Fu", "given_name": "Donglong", "orcid": "0000-0002-5680-6279", "clpid": "Fu-Donglong" }, { "family_name": "Park", "given_name": "Youngkyu", "orcid": "0000-0001-7328-7565", "clpid": "Park-Youngkyu" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Engineered systems designed to remove CO\u2082 from the atmosphere need better adsorbents. Here, we report on zeolite-based adsorbents for the capture of low-concentration CO\u2082. Synthetic zeolites with the mordenite (MOR)-type framework topology physisorb CO\u2082 from low concentrations with fast kinetics, low heat of adsorption, and high capacity. The MOR-type zeolites can have a CO\u2082 capacity of up to 1.15 and 1.05 mmol/g for adsorption from 400 ppm CO\u2082 at 30\u2009\u00b0C, measured by volumetric and gravimetric methods, respectively. A structure\u2013performance study demonstrates that Na\u207a cations in the O33 site located in the side-pocket of the MOR-type framework, that is accessed through a ring of eight tetrahedral atoms (either Si\u2074\u207a or Al\u00b3\u207a: eight-membered ring [8MR]), is the primary site for the CO\u2082 uptake at low concentrations. The presence of N\u2082 and O\u2082 shows negligible impact on CO\u2082 adsorption in MOR-type zeolites, and the capacity increases to \u223c2.0 mmol/g at subambient temperatures. By using a series of zeolites with variable topologies, we found the size of the confining pore space to be important for the adsorption of trace CO\u2082. The results obtained here show that the MOR-type zeolites have a number of desirable features for the capture of CO\u2082 at low concentrations.", "doi": "10.1073/pnas.2211544119", "pmcid": "PMC9522334", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2022-09-27", "series_number": "39", "volume": "119", "issue": "39", "pages": "e2211544119" }, { "id": "authors:xhx4p-mfs78", "collection": "authors", "collection_id": "xhx4p-mfs78", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220202-544177000", "type": "article", "title": "Structure Elucidation and Computationally Guided Synthesis of SSZ-43: A One-Dimensional 12-Ring Zeolite with Unique Sinusoidal Channels", "author": [ { "family_name": "Roslova", "given_name": "Maria", "clpid": "Roslova-Maria" }, { "family_name": "Cybulskis", "given_name": "Viktor J.", "clpid": "Cybulskis-Viktor-J" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Zones", "given_name": "Stacey I.", "orcid": "0000-0002-3128-6481", "clpid": "Zones-Stacey-I" }, { "family_name": "Zou", "given_name": "Xiaodong", "clpid": "Zou-Xiaodong" }, { "family_name": "Xie", "given_name": "Dan", "orcid": "0000-0003-2467-976X", "clpid": "Xie-Dan" } ], "abstract": "The structure of zeolite SSZ-43 was determined by 3D electron diffraction, synchrotron X-ray powder diffraction, and high-resolution transmission electron microscopy. The SSZ-43 framework forms one-dimensional, sinusoidal 12-ring channels from 5\u20746\u00b9 butterfly units commonly found in other zeolites, but with unique 6.5\u00d76.5 \u00c5 apertures and 12-ring 6.5\u00d78.9 \u00c5 windows perpendicular to the channels. SSZ-43 crystals are intergrowths of two polytypes: \u224890\u2009% orthorhombic polytype A with ABAB stacking of the 12-rings, and \u224810\u2009% monoclinic polytype B with ABCABC stacking. Molecular modeling performed on the idealized Si-SSZ-43 structure along with empirical relationships for zeolite selectivity in boron- and aluminum-containing synthesis gels were used in a combined approach to design new di-quaternary ammonium organic structure-directing agents (OSDAs). Experimental trials demonstrated that the new OSDAs produced SSZ-43 over a broader range of compositions than previous mono-quaternary OSDAs.", "doi": "10.1002/anie.202115087", "pmcid": "PMC9306729", "issn": "1433-7851", "publisher": "Wiley", "publication": "Angewandte Chemie International Edition", "publication_date": "2022-03-28", "series_number": "14", "volume": "61", "issue": "14", "pages": "Art. No. e202115087" }, { "id": "authors:d65qb-1y593", "collection": "authors", "collection_id": "d65qb-1y593", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211015-162637553", "type": "article", "title": "\u03b2-Cyclodextrin-containing polymer treatment of cutaneous lupus and influenza improves outcomes", "author": [ { "family_name": "Kelly", "given_name": "Linsley", "orcid": "0000-0001-7405-398X", "clpid": "Kelly-Linsley" }, { "family_name": "Olson", "given_name": "Lyra B.", "orcid": "0000-0003-2783-8244", "clpid": "Olson-Lyra-B" }, { "family_name": "Rempel", "given_name": "Rachel E.", "orcid": "0000-0002-6113-1659", "clpid": "Rempel-Rachel-E" }, { "family_name": "Everitt", "given_name": "Jeffrey I.", "orcid": "0000-0003-0273-6284", "clpid": "Everitt-Jeffrey-I" }, { "family_name": "Levine", "given_name": "Dana", "orcid": "0000-0002-5029-8664", "clpid": "Levine-Dana-J" }, { "family_name": "Nair", "given_name": "Smita K.", "orcid": "0000-0002-2983-3597", "clpid": "Nair-Smita-K" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Sullenger", "given_name": "Bruce A.", "orcid": "0000-0002-5113-5541", "clpid": "Sullenger-Bruce-A" } ], "abstract": "Nucleic acid (NA)-containing damage- and pathogen-associated molecular patterns (DAMPs and PAMPs, respectively) are implicated in numerous pathological conditions from infectious diseases to autoimmune disorders. Nucleic acid-binding polymers, including polyamidoamine (PAMAM) dendrimers, have demonstrated anti-inflammatory properties when administered to neutralize DAMPs/PAMPs. The PAMAM G3 variant has been shown to have beneficial effects in a cutaneous lupus erythematosus (CLE) murine model and improve survival of mice challenged with influenza. Unfortunately, the narrow therapeutic window of cationic PAMAM dendrimers makes their clinical development challenging. An alternative nucleic acid-binding polymer that has been evaluated in humans is a linear \u03b2-cyclodextrin-containing polymer (CDP). CDP's characteristics prompted us to evaluate its anti-inflammatory potential in CLE autoimmune and influenza infectious disease mouse models. We report that CDP effectively inhibits NA-containing DAMP-mediated activation of Toll-like receptors (TLRs) in cell culture, improves healing in lupus mice, and does not immunocompromise treated animals upon influenza infection but improves survival even when administered 3 days after infection. Finally, as anticipated, we observe limited toxicity in animals treated with CDP compared with PAMAM G3. Thus, CDP is a new anti-inflammatory agent that may be readily translated to the clinic to combat diseases associated with pathological NA-containing DAMPs/PAMPs.", "doi": "10.1016/j.ymthe.2021.10.003", "pmcid": "PMC8821959", "issn": "1525-0016", "publisher": "Cell Press", "publication": "Molecular Therapy", "publication_date": "2022-02-02", "series_number": "2", "volume": "30", "issue": "2", "pages": "845-854" }, { "id": "authors:m7tgv-ngs64", "collection": "authors", "collection_id": "m7tgv-ngs64", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211207-6364000", "type": "article", "title": "Zinc Containing Small-Pore Zeolites for Capture of Low Concentration Carbon Dioxide", "author": [ { "family_name": "Fu", "given_name": "Donglong", "orcid": "0000-0002-5680-6279", "clpid": "Fu-Donglong" }, { "family_name": "Park", "given_name": "Youngkyu", "orcid": "0000-0001-7328-7565", "clpid": "Park-Youngkyu" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The capture of low concentration CO\u2082 presents numerous challenges. Here, we report that zinc containing chabazite (CHA) zeolites can realize high capacity, fast adsorption kinetics, and low desorption energy when capturing ca. 400 ppm CO\u2082. Control of the state and location of the zinc ions in the CHA cage is critical to the performance. Zn\u00b2\u207a loaded onto paired anionic sites in the six-membered rings (6MRs) in the CHA cage are the primary sites to adsorb ca. 0.51 mmol CO\u2082/g-zeolite with Si/Al=ca. 7, a 17-fold increase compared to the parent H-form. The capacity is increased further to ca. 0.67 mmol CO\u2082/g-zeolite with Si/Al=ca. 2 due to more paired sites for zinc exchange. Zeolites with double six-membered rings (D6MRs) that orient 6MRs into the cages give enhanced uptakes for CO\u2082 adsorption with zinc exchange. The results reveal that zinc exchanged CHA and several other small pore, cage containing zeolites merit further investigation for the capture of low concentration CO\u2082.", "doi": "10.1002/anie.202112916", "issn": "1433-7851", "publisher": "Wiley", "publication": "Angewandte Chemie International Edition", "publication_date": "2022-01-26", "series_number": "5", "volume": "61", "issue": "5", "pages": "Art. No. e202112916" }, { "id": "authors:v8t8y-0v498", "collection": "authors", "collection_id": "v8t8y-0v498", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211206-463217289", "type": "article", "title": "Sulfonic Acid-Functionalized Zeolite Beta: Bronsted Acid Catalysts for Reactions Involving Liquid Water", "author": [ { "family_name": "Lusardi", "given_name": "Marcella", "orcid": "0000-0002-7002-4257", "clpid": "Lusardi-Marcella" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The utility of zeolites in biomass upgrading reactions can be limited in cases where stronger Bronsted acidity and/or hydrophobicity are required for effective catalysis. While sulfonated solids/sulfonic acid catalysts can be used in such cases, they forego the advantageous effects of confinement that are afforded by zeolites. Here, acidity, hydrophobicity, and confinement are integrated into a solid material by functionalizing the intrapore voids of zeolite Beta with phenethyl-sulfonic acid sites (PE-Betas). These PE-Betas, along with conventional H-Betas, mesoporous phenethyl-sulfonic acid-functionalized SiO\u2082 gel (PE-SiO\u2082), and commercial sulfonic acid catalysts (para-toluenesulfonic acid, Nafion NR50) are evaluated in the hydroxyalkylation/alkylation reaction of 2-methylfuran with acetone. The PE-Betas show superior turnover numbers (TON) due to the combination of high acid site strength and hydrophobicity that arises from the confined PE groups. Further, the hydrophobicity and TON over PE-Betas are invariant with acid site density, showing that these materials effectively decouple the active site density\u2013hydrophilicity relationship that is a fundamental limitation of conventional zeolites. These sulfonic acid-functionalized zeolites represent a distinct class of water-tolerant, strong Bronsted acid catalysts that may be well suited for a wide range of biomass upgrading reactions that generate stoichiometric amounts of liquid water.", "doi": "10.1021/acssuschemeng.1c06401", "issn": "2168-0485", "publisher": "American Chemical Society", "publication": "ACS Sustainable Chemistry & Engineering", "publication_date": "2021-12-20", "series_number": "50", "volume": "9", "issue": "50", "pages": "17120-17127" }, { "id": "authors:kzg3e-sra24", "collection": "authors", "collection_id": "kzg3e-sra24", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211201-161242469", "type": "article", "title": "Methanol-to-olefins catalysis on ERI-type molecular sieves: towards enhancing ethylene selectivity", "author": [ { "family_name": "Alshafei", "given_name": "Faisal H.", "orcid": "0000-0003-1808-1374", "clpid": "Alshafei-Faisal-H" }, { "family_name": "Park", "given_name": "Youngkyu", "clpid": "Park-Youngkyu" }, { "family_name": "Zones", "given_name": "Stacey I.", "orcid": "0000-0002-3128-6481", "clpid": "Zones-Stacey-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "ERI-type molecular sieves (SSZ-98, UZM-12, ERI-type zeolite, SAPO-17) are synthesized with varying Si/Al = 5\u20139 and Si/T-atoms = 0.034\u20130.12 using several organic structure-directing agents (OSDAs), and evaluated as catalysts for the methanol-to-olefins (MTO) reaction. SAPO-34 (Si/T-atoms = 0.089) and SSZ-13 (Si/Al = 15) are also prepared and tested for comparison. The ERI-type zeolites gave improved ethylene-to-propylene ratios (E/P = 1.1\u20131.9) over SSZ-13 (E/P = 0.82) and SAPO-34 (E/P = 0.85). The SAPO-17 samples produced an E/P of 0.7\u20131.1 and a generally high C\u2084+ fraction. The differences observed in the olefins product distributions between the zeolites with low framework Si/Al (E/P > 1.5) and SAPO-17 with low Si/T-atom < 0.1 (E/P \u2264 1 and high C\u2084+) are the result of slower maturation of aromatic hydrocarbon-pool (HP) species and the presence of aromatics with bulky alkyl-groups (C\u2083-C\u2084) in the SAPO-17 samples. The rapid formation of cyclic intermediates and the shift in their composition towards less-methylated ((CH\u2083)_(n\u22644)) methylbenzenes and methylnaphthalenes are found to be key to enhancing the ethylene selectivity in ERI-type molecular sieves.", "doi": "10.1016/j.jcat.2021.10.025", "issn": "0021-9517", "publisher": "Elsevier", "publication": "Journal of Catalysis", "publication_date": "2021-12", "volume": "404", "pages": "620-633" }, { "id": "authors:28da0-k5c41", "collection": "authors", "collection_id": "28da0-k5c41", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210226-075910480", "type": "article", "title": "Further Investigations of Racemic and Chiral Molecular Sieves of the STW Topology", "author": [ { "family_name": "Kang", "given_name": "Jong Hun", "orcid": "0000-0002-4197-9070", "clpid": "Kang-Jong-Hun" }, { "family_name": "McCusker", "given_name": "Lynne B.", "orcid": "0000-0003-0074-1733", "clpid": "McCusker-Lynne-B" }, { "family_name": "Deem", "given_name": "Michael W.", "orcid": "0000-0002-4298-3450", "clpid": "Deem-Michael-W" }, { "family_name": "Baerlocher", "given_name": "Christian", "orcid": "0000-0002-2427-0692", "clpid": "Baerlocher-Christian" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Large single crystals of pure-silica STW-type molecular sieves are prepared using 1,2,3,4,5-pentamethylimidazolium (12345PMI) and 2-ethyl-1,3,4-trimethylimidazolium (2E134TMI) as organic structure-directing agents (OSDAs) and \u03b1-amino acid additives. The effects of the amount and type of amino acid on the crystallization of pure-silica STW materials are investigated. Room-temperature single-crystal X-ray diffractometry shows that 12345PMI better fits the STW cage than 2E134TMI and is fully consistent with computed simulations. The synthesis of an enantioenriched R-STW-type molecular sieve having a Si/Ge ratio of 2.2 is achieved using a chiral, dicationic OSDA that contains two stereocenters. The conformation of the chiral OSDA in the chiral framework has been obtained from a Rietveld refinement using synchrotron powder diffraction data and is the first structure refinement of an enantioenriched, inorganic molecular sieve prepared from a pure, asymmetric OSDA.", "doi": "10.1021/acs.chemmater.0c04573", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2021-03-09", "series_number": "5", "volume": "33", "issue": "5", "pages": "1752-1759" }, { "id": "authors:5y2n2-jcc12", "collection": "authors", "collection_id": "5y2n2-jcc12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200518-150718789", "type": "article", "title": "Inhibition of interleukin-6 on matrix protein production by glomerular mesangial cells and its pathway involved", "author": [ { "family_name": "Chaudhari", "given_name": "Sarika", "clpid": "Chaudhari-S" }, { "family_name": "Shotorbani", "given_name": "Parisa Yazdizadeh", "clpid": "Shotorbani-P-Y" }, { "family_name": "Tao", "given_name": "Yu", "clpid": "Tao-Yu" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Mallet", "given_name": "Robert T.", "clpid": "Mallet-R-T" }, { "family_name": "Ma", "given_name": "Rong", "clpid": "Ma-Rong" } ], "abstract": "Activation of immunological pathways and disturbances of extracellular matrix (ECM) dynamics are important contributors to the pathogenesis of chronic kidney diseases. Glomerular mesangial cells (MCs) are critical for homeostasis of glomerular ECM dynamics. Interleukin-6 (IL-6) can act as a pro/anti-inflammatory agent relative to cell types and conditions. This study investigated whether IL-6 influences ECM protein production by MCs and the regulatory pathways involved. Experiments were carried out in cultured human MCs (HMCs) and in mice. We found that overexpression of IL-6 and its receptor decreased the abundance of fibronectin and collagen type IV in MCs. ELISA and immunoblot analysis demonstrated that thapsigargin [an activator of store-operated Ca\u00b2\u207a entry (SOCE)], but not the endoplasmic reticulum stress inducer tunicamycin, significantly increased IL-6 content. This thapsigargin effect was abolished by GSK-7975A, a selective inhibitor of SOCE, and by silencing Orai1 (the channel protein mediating SOCE). Furthermore, inhibition of NF-\u03baB pharmacologically and genetically significantly reduced SOCE-induced IL-6 production. Thapsigargin also stimulated nuclear translocation of the p65 subunit of NF-\u03baB. Moreover, MCs overexpressing IL-6 and its receptor in HMCs increased the content of the glucagon-like peptide-1 receptor (GLP-1R), and IL-6 inhibition of fibronectin was attenuated by the GLP-1R antagonist exendin 9\u201339. In agreement with the HMC data, specific knockdown of Orai1 in MCs using the targeted nanoparticle delivery system in mice significantly reduced glomerular GLP-1R levels. Taken together, our results suggest a novel SOCE/NF-\u03baB/IL-6/GLP-1R signaling pathway that inhibits ECM protein production by MCs.", "doi": "10.1152/ajprenal.00043.2020", "issn": "1931-857X", "publisher": "American Physiology Society", "publication": "American Journal of Physiology - Renal Physiology", "publication_date": "2020-06", "series_number": "6", "volume": "318", "issue": "6", "pages": "F1478-F1488" }, { "id": "authors:mwsj7-e5486", "collection": "authors", "collection_id": "mwsj7-e5486", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201019-151004940", "type": "article", "title": "Store-Operated Calcium Entry Upregulated IL6 Expression in Glomerular Mesangial Cells through NF-\u03baB Pathway", "author": [ { "family_name": "Chaudhari", "given_name": "Sarika", "clpid": "Chaudhari-S" }, { "family_name": "Shotorbani", "given_name": "Parisa Yazdizadeh", "clpid": "Shotorbani-P-Y" }, { "family_name": "Wei", "given_name": "Celine", "clpid": "Wei-Celine" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Ma", "given_name": "Rong", "clpid": "Ma-Rong" } ], "abstract": "Background: IL6 is a pleotropic cytokine and functions as a pro\u2010 as well as anti\u2010inflammatory mechanism depending on the cell type or the specific pathological environment. It is unclear if a particular signaling pathway confers IL6 with this property. Immunological and inflammatory mechanisms play a significant role in the development of diabetic nephropathy (DN). Locally produced cytokines/chemokines contributes to the early changes and histological impairment in DN. Glomerular mesangial cell (MC) is a major cell type in glomerulus to produce cytokines/chemokines in response to diabetes and a major contributor to mesangial expansion in DN. We have previously demonstrated that the Orai\u20101 mediated store\u2010operated calcium entry (SOCE) suppressed ECM protein production by MCs. The aim of this study was to determine whether and how SOCE in MCs regulated IL6 production by MCs. \n\nMethods: Orai1, the channel protein mediating SOCE in MCs was knocked down using the targeted nanoparticle\u2010siRNA delivery system in wild type C57BLKS/J mice at the age of 16 weeks. Immunohistochemistry was performed on the paraffin embedded kidney sections to examine glomerular IL6 expression. In cultured human MCs, the expression of IL6 was examined in culture media and whole cell lysates using ELISA and Western blot analysis, respectively in the presence of normal glucose (5 mM D\u2010glucose + 20 mM L\u2010glucose) with/without an activator (thapsigargin at 1 \u03bcM) or inhibitor (GSK\u20107975A 10 \u03bcM) of SOCE for 15 hrs. To determine the role of NF\u2010\u03baB in SOCE effects on IL6 production, human MCs were treated with an inhibitor of NF\u2010\u03baB, helenaline or siRNA against p65 subunit of NF\u2010\u03baB. Furthermore, the effect of SOCE on the nuclear translocation of p65 was examined by assessing abundance of nuclear p65 protein in response to activation and inhibition of SOCE. \n\nResults: The IL6 expression level was reduced in the glomeruli of the mice treated with nanoparticle/Orai1 siRNA for 2 weeks compared to that in the control mice. In cultured human MCs, thapsigargin significantly increased IL\u20106 level in supernatant media and in whole cell lysates of MCs, and this effect was attenuated by GSK 7975\u2010A, a selective inhibitor of SOCE. However, tunicamycin, an ER stress inducer did not alter the amount of IL6 as thapsigargin did. Treatment with helenaline, an inhibitor of NF\u2010\u03baB pathway, or knockdown of p65, a subunit of NF\u2010\u03baB significantly blunted the thapsigargin\u2010induced increase in IL6 protein abundance. Moreover, thapsigargin stimulated the nuclear translocation of p65 in human MCs. \n\nConclusion: Orai1\u2010mediated SOCE positively regulates IL6 production by MCs through activation of NF\u2010\u03baB pathway.", "doi": "10.1096/fasebj.2020.34.s1.02920", "issn": "0892-6638", "publisher": "Federation of American Societies for Experimental Biology", "publication": "FASEB Journal", "publication_date": "2020-04", "series_number": "S1", "volume": "34", "issue": "S1", "pages": "1" }, { "id": "authors:aw1av-jke75", "collection": "authors", "collection_id": "aw1av-jke75", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200122-141405997", "type": "article", "title": "Initiating a Research-Focused Academic Career in Chemical Engineering: Perspectives from Faculty at Different Career Stages", "author": [ { "family_name": "Cybulskis", "given_name": "Viktor J.", "clpid": "Cybulskis-V-J" }, { "family_name": "Gounder", "given_name": "Rajamani", "orcid": "0000-0003-1347-534X", "clpid": "Gounder-R" }, { "family_name": "Mojarad", "given_name": "Sarah", "clpid": "Mojarad-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Each fall, eager young researchers participate in the Meet the Faculty Candidates poster session at the AIChE Annual Meeting, and many more apply to tenure\u2010track faculty openings at academic institutions across the United States and throughout the world. These individuals embark on this journey with the eventual goal of becoming full professors. The process of initiating an academic career and developing a successful independent research program is an arduous journey that involves multiple stages. These stages include being hired into a faculty position, building an independent research program that involves recruiting students and can include constructing a laboratory, identifying research areas and specific problems to investigate, and establishing oneself as a scientific leader of a particular subject matter area within a broader community. Faculty candidates commonly seek advice from mentors or peers who have recently navigated the faculty interview and hiring processes to successfully obtain an academic position. Additionally, they often review the wealth of resources that are available on the Internet and in print. However, it can be daunting to sieve through this collective knowledge base to identify relevant information, as it invariably contains conflicting viewpoints and advice that may be subjective, generic to any research\u2010focused faculty position, or highly field specific.", "doi": "10.1002/aic.16927", "issn": "0001-1541", "publisher": "Wiley", "publication": "AIChE Journal", "publication_date": "2020-04", "series_number": "4", "volume": "66", "issue": "4", "pages": "Art. No. e16927" }, { "id": "authors:vn78y-09w62", "collection": "authors", "collection_id": "vn78y-09w62", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200224-124954330", "type": "article", "title": "Fluoride-free Synthesis of Germanosilicate CIT-13 and Its Inverse Sigma Transformation To Form CIT-14", "author": [ { "family_name": "Kang", "given_name": "Jong Hun", "orcid": "0000-0002-4197-9070", "clpid": "Kang-Jong-Hun" }, { "family_name": "Xie", "given_name": "Dan", "orcid": "0000-0003-2467-976X", "clpid": "Xie-Dan" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Germanium-containing, extra-large pore molecular sieve CIT-13 is synthesized without the use of fluoride. After the removal of occluded organics, CIT-13 obtained from fluoride-free preparation shows significant differences from CIT-13 samples prepared in the presence of fluoride. CIT-13 prepared using a fluoride-free method is able to undergo inverse sigma transformation to yield CIT-14 and transforms into a CIT-5-type germanosilicate much faster than Ge-CIT-13 of similar Si/Ge ratios from a fluoride-containing synthesis. A Rietveld-refined structure solution for CIT-14 reveals that this new molecular sieve possesses 12- and 8-membered ring channels. Results from \u00b9\u2079F magic-angle spinning (MAS) and \u00b9H\u2013\u00b2\u2079Si cross-polarized MAS nuclear magnetic resonance spectroscopy reveal that CIT-13 crystallized without fluoride has germanium siting which is different from CIT-13 synthesized in the presence of fluoride.", "doi": "10.1021/acs.chemmater.9b05072", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2020-03-10", "series_number": "5", "volume": "32", "issue": "5", "pages": "2014-2024" }, { "id": "authors:fk6jz-qns04", "collection": "authors", "collection_id": "fk6jz-qns04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200109-143243224", "type": "article", "title": "Nanoparticles containing a combination of a drug and an antibody for the treatment of breast cancer brain metastases", "author": [ { "family_name": "Wyatt", "given_name": "Emily A.", "orcid": "0000-0002-7534-0582", "clpid": "Wyatt-E-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "In women with human epidermal growth factor 2 (HER2)-positive breast cancer, the improved control of systemic disease with new therapies has unmasked brain metastases that historically would have remained clinically silent. The efficacy of therapeutic agents against brain metastases is limited by their inability to permeate the blood\u2013brain and blood\u2013tumor barriers (BBB and BTB) in therapeutic amounts. Here, we investigate the potential of mucic acid-based, targeted nanoparticles designed to transcytose the BBB/BTB to deliver a small molecule drug, camptothecin (CPT), and therapeutic antibody, Herceptin, to brain metastases in mice. Treatment with BBB-targeted combination CPT/Herceptin nanoparticles significantly inhibits tumor growth compared to free CPT/Herceptin and BBB-targeted nanoparticles carrying CPT alone. Though not as efficacious, BBB-targeted nanoparticles carrying only Herceptin also elicit considerable antitumor activity. These results demonstrate the potential of the targeted nanoparticle system for the delivery of an antibody alone or in combination with other drugs across the BBB/BTB to improve the therapeutic outcome.", "doi": "10.1021/acs.molpharmaceut.9b01167", "pmcid": "PMC7061347", "issn": "1543-8384", "publisher": "American Chemical Society", "publication": "Molecular Pharmaceutics", "publication_date": "2020-02-03", "series_number": "2", "volume": "17", "issue": "2", "pages": "717-721" }, { "id": "authors:gt851-tq180", "collection": "authors", "collection_id": "gt851-tq180", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191209-081001667", "type": "article", "title": "Carbonylation of Dimethyl Ether to Methyl Acetate over SSZ-13", "author": [ { "family_name": "Lusardi", "given_name": "Marcella", "orcid": "0000-0002-7002-4257", "clpid": "Lusardi-M" }, { "family_name": "Chen", "given_name": "Thomas T.", "clpid": "Chen-Thomas-T" }, { "family_name": "Kale", "given_name": "Matthew", "orcid": "0000-0002-3039-3111", "clpid": "Kale-M-J" }, { "family_name": "Kang", "given_name": "Jong Hun", "orcid": "0000-0002-4197-9070", "clpid": "Kang-Jong-Hun" }, { "family_name": "Neurock", "given_name": "Matthew", "clpid": "Neurock-M" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The small-pore zeolite with the chabazite framework topology, SSZ-13, is found to be an active catalyst in the carbonylation of dimethyl ether to methyl acetate (MA). The production of MA over SSZ-13 after 24 h on stream at 165 \u00b0C and 1 bar approaches that obtained from mordenite and is significantly higher than from ferrierite at comparable Si/Al of ca. 10. To understand the origin of the activity, SSZ-13 materials are synthesized with variable Si/Al, characterized via several techniques including multinuclear magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, and evaluated for their carbonylation activity. While MA production rates increase with decreasing Si/Al, the correlation is nonlinear due to the effect of Si/Al on the acid site distribution within different confining environments, and the associated impact of the latter on the rate-determining transition state barrier. Enhanced MA production rates trend with acid sites located at the eight-membered ring (8MR) that are increasingly populated as framework Al content increases. Density functional theory analyses of transition state energies as a function of active site location support the experimental findings, where the lowest apparent barriers are associated with the methoxy groups that orient within the plane of the 8MR window. This is due to an optimal charge stabilization of the cationic transition states with the negatively charged oxygens within the 8MR window. The effects of catalyst chemical composition, separate from framework topology, are also investigated using SAPO-34 (the silicoaluminophosphate analog of SSZ-13). Analyses of the \u00b9H MAS NMR signals and carbonylation activity suggest that the higher acid site strength of SSZ-13 compared to that of the SAPO material is required for effective Br\u00f8nsted acid catalysis of Koch-type carbonylation pathways.", "doi": "10.1021/acscatal.9b04307", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2020-01-03", "series_number": "1", "volume": "10", "issue": "1", "pages": "842-851" }, { "id": "authors:8cn9t-5f038", "collection": "authors", "collection_id": "8cn9t-5f038", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191122-112403919", "type": "article", "title": "Integration of thermochemical water splitting with CO\u2082 direct air capture", "author": [ { "family_name": "Brady", "given_name": "Casper", "clpid": "Brady-Casper" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Xu", "given_name": "Bingjun", "orcid": "0000-0002-2303-257X", "clpid": "Xu-Bingjun" } ], "abstract": "Renewable production of fuels and chemicals from direct air capture (DAC) of CO\u2082 is a highly desired goal. Here, we report the integration of the DAC of CO\u2082 with the thermochemical splitting of water to produce CO\u2082, H\u2082, O\u2082, and electricity. The produced CO\u2082 and H\u2082 can be converted to value-added chemicals via existing technologies. The integrated process uses thermal solar energy as the only energy input and has the potential to provide the dual benefits of combating anthropogenic climate change while creating renewable chemicals. A sodium\u2013manganese\u2013carbonate (Mn\u2013Na\u2013CO\u2082) thermochemical water-splitting cycle that simultaneously drives renewable H\u2082 production and DAC of CO\u2082 is demonstrated. An integrated reactor is designed and fabricated to conduct all steps of the thermochemical water-splitting cycle that produces close to stoichiometric amounts (\u223c90%) of H\u2082 and O\u2082 (illustrated with 6 consecutive cycles). The ability of the cycle to capture 75% of the \u223c400 ppm CO\u2082 from air is demonstrated also. A technoeconomic analysis of the integrated process for the renewable production of H\u2082, O\u2082, and electricity, as well as DAC of CO\u2082 shows that the proposed scheme of solar-driven H\u2082 production from thermochemical water splitting coupled with CO\u2082 DAC may be economically viable under certain circumstances.", "doi": "10.1073/pnas.1915951116", "pmcid": "PMC6911180", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2019-12-10", "series_number": "50", "volume": "116", "issue": "50", "pages": "25001-25007" }, { "id": "authors:pdd3h-dp529", "collection": "authors", "collection_id": "pdd3h-dp529", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191125-111539172", "type": "article", "title": "Transformation of Extra-Large Pore Germanosilicate CIT-13 Molecular Sieve into Extra-Large Pore CIT-5 Molecular Sieve", "author": [ { "family_name": "Kang", "given_name": "Jong Hun", "orcid": "0000-0002-4197-9070", "clpid": "Kang-Jong-Hun" }, { "family_name": "Xie", "given_name": "Dan", "orcid": "0000-0003-2467-976X", "clpid": "Xie-Dan" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The 14- and 10-membered ring germanosilicate Ge-CIT-13 (*CTH) is transformed into the 14-membered ring germanosilicate Ge-CIT-5 (CFI). The transformation can occur at room temperature but requires the presence of adsorbed water. The *CTH-to-CFI transformation involves rearrangement of germanium-rich double-4-ring units in *CTH to form double-zigzag chains in CFI. The rate of transformation is dependent on the germanium content of the starting Ge-CIT-13 and the humidity of the transforming atmosphere. Other germanosilicates\u2014UTL, IWW, and ITH\u2014do not show this type of transformation because of arrangements of Ge-sites within their d4r units and/or to spatial restrictions regarding the d4r unit arrangement within their interlayer regions. Ge-CIT-5 can be further transformed into 10-membered-ring CIT-15 using ammonium hydroxide solution as the delaminating agent. Postsynthetic alumination of Ge-CIT-5 yielded high-silica CFI-type aluminogermanosilicates having molar Si/Al ratios in the range of 14\u2013230, primarily depending on the acidity of the solution phase.", "doi": "10.1021/acs.chemmater.9b03675", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2019-12-10", "series_number": "23", "volume": "31", "issue": "23", "pages": "9777-9787" }, { "id": "authors:38kyw-rz902", "collection": "authors", "collection_id": "38kyw-rz902", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191023-160902739", "type": "article", "title": "Host immune response to anti-cancer camptothecin conjugated cyclodextrin-based polymers", "author": [ { "family_name": "Chen", "given_name": "Yi-Fan", "clpid": "Chen-Yi-Fan" }, { "family_name": "Wang", "given_name": "Yen-Hsin", "clpid": "Wang-Yen-Hsin" }, { "family_name": "Lei", "given_name": "Cing-Syuan", "clpid": "Lei-Cing-Syuan" }, { "family_name": "Changou", "given_name": "Chun A.", "clpid": "Changou-Chun-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Yen", "given_name": "Yun", "orcid": "0000-0003-0815-412X", "clpid": "Yen-Yun" } ], "abstract": "Introduction: Efficacy and safety are critical concerns when designing drug carriers. Nanoparticles are a particular type of carrier that has gained recent attention in cancer therapeutics. \n\nMethods: In this study, we assess the safety profile of IT-101, a nanoparticle formed by self-assembly of camptothecin (CPT) conjugated cyclodextrin-based polymers. IT-101 delivers CPT to target cancer cells in animal models of numerous human cancers and in humans. Previous data from preclinical and clinical trials indicate that IT-101 has no notable immunological side effects. However, there have been no published studies focused on evaluating the effects of IT-101 on host immune systems. \n\nResults: In this work, we demonstrate that IT-101 diminished initial host immune response following first injection of the nanopharmaceutical and induced NK cell activation and T cell proliferation upon further IT-101 exposure. Additionally, IT-101 could attenuate tumor growth more efficiently than CPT treatment only. \n\nConclusions: Drugs administration in whole-body circulation may lead to poorly bioavailable in central nervous system and often has toxic effects on peripheral tissues. Conjugated with cyclodextrin-based polymers not only reduce adverse effects but also modulate the immune responses to elevate drug efficacy. These immune responses may potentially facilitate actions of immune blockage, such as PD1/PDL1 in cancer treatment.", "doi": "10.1186/s12929-019-0583-0", "pmcid": "PMC6806548", "issn": "1423-0127", "publisher": "Springer", "publication": "Journal of Biomedical Science", "publication_date": "2019-10-23", "series_number": "1", "volume": "26", "issue": "1", "pages": "Art. No. 85" }, { "id": "authors:1ce00-zhg85", "collection": "authors", "collection_id": "1ce00-zhg85", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190812-141226810", "type": "conference_item", "title": "On the route to elucidating the relationships between zeolite structure and methanol-to-olefins reaction performance", "author": [ { "family_name": "Davis", "given_name": "Mark Edward", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The methanol-to-olefins (MTO) reaction produces high value-added light olefins from non-petroleum sources. Acidic zeotypes contg. cages bounded by 8-ring (small pore) windows can effectively catalyze the MTO reaction, since their cages can accommodate the necessary arom. intermediates while letting light olefin products escape. While progress on the understanding the reaction mechanisms of the MTO reaction continue, zeotype structure-MTO reaction property relationships are in their infancy. I discuss our recent work on elucidating how zeolite cage properties primarily det. reaction product distributions and our definition of the cage-defining ring that is well correlated to MTO product distributions. Addnl., I discuss how the acid site proximity and the shape of the cage can influence reaction lifetimes and coking amts. Overall, the goal is to understand desired properties of the zeotype catalyst to give a desired performance.", "publisher": "Caltech Library", "publication_date": "2019-08" }, { "id": "authors:01p7v-n8w22", "collection": "authors", "collection_id": "01p7v-n8w22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190812-135709922", "type": "conference_item", "title": "Investigation of the active Bronsted acid site for the DME carbonylation reaction in chabazite-type zeolites", "author": [ { "family_name": "Lusardi", "given_name": "Marcella", "orcid": "0000-0002-7002-4257", "clpid": "Lusardi-M" }, { "family_name": "Davis", "given_name": "Mark EDWARD", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Chabazite-type (CHA) zeolites (SSZ-13s) are active acid catalysts in the carbonylation of di-Me ether (DME), an important C-C bond forming reaction involved in the conversion of syngas derivs. to valuable chem. intermediates. We observe a max. in the formation rate of Me acetate, the target product, as a function of Si/Al in the SSZ-13s that cannot be explained from the standpoint of total acid site d. While the active sites for this reaction have been better studied in other zeolite topologies (MOR, FER), to date, the origin of activity in CHA remains unclear. To investigate this issue, we synthesized SSZ-13s with a range of Si/Al (5 < Si/Al < 75) to vary both Bronsted acid site d. and siting (e.g., paired vs. isolated), and evaluated the impact of these parameters on the DME carbonylation activity. Further, because the CHA structure has only one T-site, differentiating Bronsted acid sites via 1H NMR may be feasible. Three possible extraframework, monovalent cation sites exist. Only two of these sites are accessible by reactants, reducing the active Bronsted acid site candidates to the proton that sits in the 6-membered ring (MR) window, and the one oriented in the 8MR window. We detect three distinct resonances in the high-spin 1H NMR spectra on dehydrated SSZ-13s. From the reactivity and NMR analyses, coupled with divalent cation exchange expts. for specific titrn. of paired (framework Al sepd. by no more than 3 Si-O units) acid sites, we developed a model for the location of the active site in CHA. Given the unique framework topol. of CHA compared to other active, DME carbonylation zeolite topologies, this investigation provides further insights into this useful C-C bond forming reaction.", "publisher": "Caltech Library", "publication_date": "2019-08" }, { "id": "authors:1am3y-ek712", "collection": "authors", "collection_id": "1am3y-ek712", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190412-081340826", "type": "article", "title": "Cage-defining Ring: A Molecular Sieve Structural Indicator for Light Olefin Product Distribution from the Methanol-to-Olefins Reaction", "author": [ { "family_name": "Kang", "given_name": "Jong Hun", "orcid": "0000-0002-4197-9070", "clpid": "Kang-Jong-Hun" }, { "family_name": "Alshafei", "given_name": "Faisal H.", "clpid": "Alshafei-F-H" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The methanol-to-olefins (MTO) process produces high-value-added light olefins from nonpetroleum sources. Acidic zeotypes containing cages bounded by 8-ring (small-pore) windows can effectively catalyze the MTO reaction, since their cages can accommodate the necessary aromatic intermediates that produce the light olefin products that escape. While progress on the mechanisms of the MTO reaction continues, zeotype structure\u2013reaction property relationships have yet to be elucidated. Here, we report MTO reaction results from various small-pore, cage-containing silicoaluminophosphate/metalloaluminophosphates (SAPO/MAPOs) and zeolites under the same reaction conditions. The MTO behaviors of microporous materials having the following topologies are investigated: LEV, ERI, CHA, AFX, SFW, AEI, DDR, RTH, ITE, SAV, LTA, RHO, KFI, and UFI. The previous observation that light olefin product distributions from a series of small-pore, cage-containing zeolites can be classified into four structural categories is further supported by the results shown here from zeolite structures not investigated in the previous study and SAPO and MAPO materials with isostructural frameworks to all the zeolites. Additionally, these data reveal that light olefin product distributions are very similar over a given topology independent of framework composition. To develop a structure\u2013property relationship between the framework topology and the MTO light olefin product distribution, the concept of the cage-defining ring size is introduced. The cage-defining ring size is defined as the minimum number of tetrahedral atoms of the ring encircling the center of the framework cages in the molecular sieve topology. It is shown that the cage-defining ring size correlates with MTO light olefin product distribution.", "doi": "10.1021/acscatal.9b00746", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2019-07-05", "series_number": "7", "volume": "9", "issue": "7", "pages": "6012-6019" }, { "id": "authors:g4zdr-mx595", "collection": "authors", "collection_id": "g4zdr-mx595", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180806-125608962", "type": "article", "title": "Method of establishing breast cancer brain metastases affects brain uptake and efficacy of targeted, therapeutic nanoparticles", "author": [ { "family_name": "Wyatt", "given_name": "Emily A.", "orcid": "0000-0002-7534-0582", "clpid": "Wyatt-Emily-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "HER2\u2010targeted therapies effectively control systemic disease, but their efficacy against brain metastases is hindered by their low penetration of the blood\u2010brain and blood\u2010tumor barriers (BBB and BTB). We investigate brain uptake and antitumor efficacy of transferrin receptor (TfR)\u2010targeted, therapeutic nanoparticles designed to transcytose the BBB/BTB in three murine models. Two known models involving intracranial (IC) or intracardiac (ICD) injection of human breast cancer cells were employed, as was a third model developed here involving intravenous (IV) injection of the cells to form whole\u2010body tumors that eventually metastasize to the brain. We show the method of establishing brain metastases significantly affects therapeutic BBB/BTB penetration. Free drug accumulates and delays growth in IC\u2010 and ICD\u2010formed brain tumors, while non\u2010targeted nanoparticles show uptake and inhibition only in IC\u2010established metastases. TfR\u2010targeted nanoparticles accumulate and significantly delay growth in all three models, suggesting the IV model maintains a more intact BBB/BTB than the other models.", "doi": "10.1002/btm2.10108", "pmcid": "PMC6336738", "issn": "2380-6761", "publisher": "Wiley", "publication": "Bioengineering & Translational Medicine", "publication_date": "2019-01", "series_number": "1", "volume": "4", "issue": "1", "pages": "30-37" }, { "id": "authors:s4dxk-6ej97", "collection": "authors", "collection_id": "s4dxk-6ej97", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180918-090317825", "type": "article", "title": "A Thirty-Year Journey to the Creation of the First Enantiomerically Enriched Molecular Sieve", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "In 1987, our research on how to synthesize a chiral zeolite began. Finally, in 2017, my co-workers and I succeeded in preparing and characterizing the first enantiomerically enriched molecular sieve. Here, I recount how we initiated our work on synthesizing a chiral molecular sieve, the lessons learned from the many failures we had over the years, and what were some of the key advances that ultimately led to the successful synthesis and proof that we had in fact prepared an enantiomerically enriched molecular sieve. I have no doubts that numerous other chiral molecular sieves will now be elucidated and that clever applications of these materials will ultimately be realized.", "doi": "10.1021/acscatal.8b03080", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2018-11-02", "series_number": "11", "volume": "8", "issue": "11", "pages": "10082-10088" }, { "id": "authors:kfytr-jy369", "collection": "authors", "collection_id": "kfytr-jy369", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180828-102328472", "type": "article", "title": "The \"Holey\" Grail: Zeolites and Molecular Sieves: Mark E. Davis and Raul F. Lobo, New Members of Chemistry of Materials' 1k Club", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Lobo", "given_name": "Raul F.", "clpid": "Lobo-R-F" }, { "family_name": "Toro", "given_name": "Carlos", "clpid": "Toro-C" }, { "family_name": "Buriak", "given_name": "Jillian M.", "orcid": "0000-0002-9567-4328", "clpid": "Buriak-J-M" } ], "abstract": "As part of our continuing series of discussions with the authors of papers in Chemistry of Materials that have been cited more than 1000 times, we (CM) interviewed Prof. Mark E. Davis (MED) to talk about his 1992 review, \"Zeolite and molecular sieve synthesis\" (Figure 1).(1) The review has been consistently cited since publication through today (35\u201360 citations/year, without exception), underlining the relevance of the authors' perspective of the field, both of that time and into the future.(2) The enduring strength of the review lies partly with its thoughtful synopsis of the history of zeolites and textbook-like, highly readable definition and description of zeolites, followed by a detailed review of synthetic approaches. The review focused on what was known about molecular assembly to template the formation of these porous materials, an area that still has many open and unanswered questions. The papers citing this 1992 review would also serve as a very helpful introduction for new researchers to the evolution and present state-of-the-art of the field of zeolite and molecular sieve synthesis.", "doi": "10.1021/acs.chemmater.8b02658", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2018-08-28", "series_number": "16", "volume": "30", "issue": "16", "pages": "5519-5520" }, { "id": "authors:x7ynf-3mx33", "collection": "authors", "collection_id": "x7ynf-3mx33", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190812-144643336", "type": "book_section", "title": "Catalysis by Crystalline, Microporous Materials", "book_title": "Catalysis in Chemistry and Biology", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "contributor": [ { "family_name": "W\u00fcthrich", "given_name": "Kurt", "clpid": "W\u00fcthrich-K" }, { "family_name": "Grubbs", "given_name": "Robert H.", "clpid": "Grubbs-R-H" }, { "family_name": "de Bocarm\u00e9", "given_name": "Thierry Visart", "clpid": "de-Bocarm\u00e9-T-V" }, { "family_name": "De Wit", "given_name": "Anne", "clpid": "De-Wit-A" } ], "abstract": "The following sections are included: \n\nReaction pathways enabled by crystalline, microporous materials. \n\nExamples of recent contributions from M. E. Davis and collaborators. \n\nExamples of potential future developments with crystalline, microporous materials. \n\nReferences.", "doi": "10.1142/9789813237179_0021", "isbn": "9789813237162", "publisher": "World Scientific", "place_of_publication": "Hackensack, NJ", "publication_date": "2018-08", "pages": "137-140" }, { "id": "authors:d082f-z4c78", "collection": "authors", "collection_id": "d082f-z4c78", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190620-143428810", "type": "article", "title": "Improved chemotherapeutic delivery to brain metastases with targeted nanoparticles in preclinical breast cancer brain metastasis models", "author": [ { "family_name": "Wyatt", "given_name": "Emily A.", "orcid": "0000-0002-7534-0582", "clpid": "Wyatt-E-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Brain metastases present an increasing challenge to long-term survival for\nHER2-amplified breast cancer patients. While HER2 targeted therapies\neffectively control systemic metastases, they are largely ineffective against\nbrain metastases due to their inability to cross the blood-brain barrier. We\nhave recently demonstrated that brain uptake of targeted nanoparticles can\nbe increased by adding an acid-cleavable linkage between transferrin (Tf) and\nthe nanoparticle core [1]. Our lab has also developed a method for\nassembling targeted nanoparticles by complexing diol-containing polymerdrug\nconjugates and boronic acid-containing targeting agents [2]. Here, we\nreport the first efficacy results of targeted nanoparticles formed via this\nassembly strategy in a preclinical model of breast cancer brain metastasis.", "doi": "10.1158/1538-7445.AM2018-4641", "issn": "0008-5472", "publisher": "American Association for Cancer Research", "publication": "Cancer Research", "publication_date": "2018-07", "series_number": "13", "volume": "78", "issue": "13", "pages": "Art. No. 4641" }, { "id": "authors:8kc4x-ddw04", "collection": "authors", "collection_id": "8kc4x-ddw04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180510-135730797", "type": "article", "title": "Small-Pore Zeolites: Synthesis and Catalysis", "author": [ { "family_name": "Dusselier", "given_name": "Michiel", "orcid": "0000-0002-3074-2318", "clpid": "Dusselier-M" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "In the past decade or so, small-pore zeolites have received greater attention than large- and medium-pore molecular sieves that have historically dominated the literature. This is primarily due to the commercialization of two major catalytic processes, NOx exhaust removal and methanol conversion to light olefins, that take advantage of the properties of these materials with smaller apertures. Small-pore zeolites possess pores that are constructed of eight tetrahedral atoms (Si^(4+) and Al^(3+)), each time linked by a shared oxygen These eight-member ring pores (8MR) provide small molecules access to the intracrystalline void space, e.g., to NOx during car exhaust cleaning (NOx removal) or to methanol en route to its conversion into light olefins, while restricting larger molecule entrance and departure that is critical to overall catalyst performance. In total, there are forty-four structurally different small-pore zeolites. Forty-one of these zeolites can be synthesized, and the first synthetic zeolite (KFI, 1948) was in fact a small-pore material. Although the field of 8MR zeolite chemistry has expanded in many directions, the progress in synthesis is framework-specific, leaving insights and generalizations difficult to realize. This review first focuses on the relevant synthesis details of all 8MR zeolites and provides some generalized findings and related insights. Next, catalytic applications where 8MR zeolites either have been commercialized or have dominated investigations are presented, with the aim of providing structure\u2013activity relationships. The review ends with a summary that discusses (i) both synthetic and catalytic progress, (ii) a list of opportunities in the 8MR zeolite field, and (iii) a brief future outlook.", "doi": "10.1021/acs.chemrev.7b00738", "issn": "0009-2665", "publisher": "American Chemical Society", "publication": "Chemical Reviews", "publication_date": "2018-06-13", "series_number": "11", "volume": "118", "issue": "11", "pages": "5265-5329" }, { "id": "authors:xsz8r-q2b41", "collection": "authors", "collection_id": "xsz8r-q2b41", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180402-084148907", "type": "article", "title": "A Chromium Hydroxide/MIL-101(Cr) MOF Composite Catalyst and Its Use for the Selective Isomerization of Glucose to Fructose", "author": [ { "family_name": "Guo", "given_name": "Qiang", "clpid": "Guo-Qiang" }, { "family_name": "Ren", "given_name": "Limin", "clpid": "Ren-Limin" }, { "family_name": "Kumar", "given_name": "Prashant", "clpid": "Kumar-P" }, { "family_name": "Cybulskis", "given_name": "Viktor J.", "clpid": "Cybulskis-V-J" }, { "family_name": "Mkhoyan", "given_name": "K. Andre", "clpid": "Mkhoyan-K-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Tsapatsis", "given_name": "Michael", "orcid": "0000-0001-5610-3525", "clpid": "Tsapatsis-M" } ], "abstract": "A metal\u2013organic framework (MOF)\u2010based catalyst, chromium hydroxide/MIL\u2010101(Cr), was prepared by a one\u2010pot synthesis method. The combination of chromium hydroxide particles on and within Lewis acidic MIL\u2010101 accomplishes highly selective conversion of glucose to fructose in the presence of ethanol, matching the performance of optimized Sn\u2010containing Lewis acidic zeolites. Differently from zeolites, NMR spectroscopy studies with isotopically labeled molecules demonstrate that isomerization of glucose to fructose on this catalyst, proceeds predominantly via a proton transfer mechanism.", "doi": "10.1002/anie.201712818", "issn": "1433-7851", "publisher": "Wiley", "publication": "Angewandte Chemie International Edition", "publication_date": "2018-04-23", "series_number": "18", "volume": "57", "issue": "18", "pages": "4926-4930" }, { "id": "authors:j757d-y3y23", "collection": "authors", "collection_id": "j757d-y3y23", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180705-100512499", "type": "conference_item", "title": "Cis-trans isomerism and the role of dilution in organic structure direction to relevant zeolite catalysts AEI (SSZ-39) and GME (CIT-9)", "author": [ { "family_name": "Dusselier", "given_name": "Michiel", "orcid": "0000-0002-3074-2318", "clpid": "Dusselier-M" }, { "family_name": "Kang", "given_name": "Jong Hun", "orcid": "0000-0002-4197-9070", "clpid": "Kang-Jong-Hun" }, { "family_name": "Xie", "given_name": "Dan", "orcid": "0000-0003-2467-976X", "clpid": "Xie-Dan" }, { "family_name": "Davis", "given_name": "Mark", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolites are thriving as functional and stable materials in catalysis, sorption and even specialty applications. Besides their dominant presence in petrochem., their potential in the conversion of renewables and gaseous feedstock is huge (SCR, MTO, methane-partial oxidn.), and often a single framework excels at a specific task. Although novel structures are being reported frequently, for some structurally-relevant topologies, no effective synthetic aluminosilicate recipes are known. Natural or synthetic gmelinite (GME topol.) for example, is nearly always encountered with stacking faults (intergrowths) blocking the main channel and thus limiting porosity for application in catalysis. The search for fault-free synthetic GME has been going on for \u00b1 40 years, because the framework is a 3-dimensional large pore zeolite, with a promising 12x8x8 channel system for relevant hydrocarbon chemistries, e.g. hexane isomerization or reactions where mol. traffic control is vital (compare to LTL). Interestingly, the framework can be entirely constructed by linking d6r composite building units. Here, we present a new route for making GME zeolites, labeled CIT-9, based on the use of a simple org. structure directing agent (OSDA), with a remarkable cis-trans isomeric specificity. Only cis-N,N,3,5-tetramethylpiperidinium hydroxide leads to CIT-9, while the trans form leads to SSZ-39 of the AEI topol. AEI is an interesting cage-contg. zeolite with 8MR small-pore windows, and a documented excellent activity in SCR (Cu ions) and MTO (H+). The selectivity of synthesis also depends on the diln. of the synthesis suspension and thus the concn. of OSDA (selectivity to GME vs AEI in Figure 1) . The origin of both cis/trans and cage vs-channel selectivity is investigated and confirmed from mol. modeling. Finally, in the light of catalysis, the novel GME is studied with rotation electron diffraction and variable temp. XRD, to monitor its faulting and thermal stability. In short, the material is non-faulted, porous, and stable in its K-form. In a side note, the first methanol-to-olefin study with the other produced zeolite, SSZ-39 (AEI) is introduced as well.", "publisher": "Caltech Library", "publication_date": "2018-03" }, { "id": "authors:k62j1-kav22", "collection": "authors", "collection_id": "k62j1-kav22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180413-084049417", "type": "conference_item", "title": "Synthesis of chiral molecular sieves: A 30 year journey", "author": [ { "family_name": "Davis", "given_name": "Mark", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Recently, my co-workers and I synthesized an enantiomerically enriched, polycryst. mol. sieve that has the STW framework topol. My journey to prep. a chiral mol. sieve began 30 years ago, and in this presentation, I will chronicle the progress made from start to finish. Over that period of time, advances in synthetic methods, characterization techniques and computer simulations have greatly advanced, and all these advances were used to design, prep. and conclusively prove that an enantiomerically enriched, polycryst. mol. sieve was indeed\nobtained. Addnl., I will make a few comments about what may be possible with chiral mol. sieves in the near future.", "publisher": "Caltech Library", "publication_date": "2018-03" }, { "id": "authors:pvpzn-4t565", "collection": "authors", "collection_id": "pvpzn-4t565", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171208-092058527", "type": "article", "title": "Further studies on how the nature of zeolite cavities that are bounded by small pores influences the conversion of methanol to light olefins", "author": [ { "family_name": "Kang", "given_name": "Jong Hun", "orcid": "0000-0002-4197-9070", "clpid": "Kang-Jong-Hun" }, { "family_name": "Walter", "given_name": "Raimund", "clpid": "Walter-R" }, { "family_name": "Xie", "given_name": "Dan", "orcid": "0000-0003-2467-976X", "clpid": "Xie-Dan" }, { "family_name": "Davis", "given_name": "Tracy", "clpid": "Davis-T" }, { "family_name": "Chen", "given_name": "Cong-Yan", "clpid": "Chen-Cong-Yan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" } ], "abstract": "A series of small-pore zeolites are synthesized and investigated as catalysts for the methanol-to-olefins (MTO) reaction. Small-pore zeolites SSZ-13, SSZ-16, SSZ-27, SSZ-28, SSZ-52, SSZ-98, SSZ-99, SSZ-104, SSZ-105 and an ITQ-3-type material are synthesized, and the results from their use as catalytic materials in the MTO reaction compared to those obtained from SAPO-34. The production of propane that tends to correlate with catalytic material lifetime (higher initial propane yields lead to shorter lifetimes) declines with increasing Si/Al (as has been observed previously for SSZ-13), and a larger cage dimension leads to higher propane yields at a fixed Si/Al. Data from these materials and others reported previously, for example, SSZ-39 and Rho, that were tested at the same reaction conditions, revealed four different patterns of light olefin selectivities: 1)\u2005ethylene greater than propylene with low butene, for example, SSZ-17, SSZ-98, SSZ-105, 2)\u2005ethylene equal to propylene and low butene, for example, SAPO-34, SSZ-13, SSZ-16, SSZ-27, SSZ-52, SSZ-99, SSZ-104, 3)\u2005propylene greater than ethylene with butene similar to ethylene, for example, SSZ-28, SSZ-39, and 4)\u2005ethylene equal to propylene equal to butene, for example, Rho. No clear relationships between zeolite cage architecture and light olefin selectivity emerged from this investigation, although several trends are presented as suggestions for further study.", "doi": "10.1002/cphc.201701197", "issn": "1439-4235", "publisher": "Wiley", "publication": "ChemPhysChem", "publication_date": "2018-02-19", "series_number": "4", "volume": "19", "issue": "4", "pages": "412-419" }, { "id": "authors:yj81s-17a16", "collection": "authors", "collection_id": "yj81s-17a16", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180109-074115196", "type": "article", "title": "Pilot trial of CRLX101 in patients with advanced, chemotherapy-refractory gastroesophageal cancer", "author": [ { "family_name": "Chao", "given_name": "Joseph", "clpid": "Chao-Joseph" }, { "family_name": "Lin", "given_name": "James", "clpid": "Lin-James" }, { "family_name": "Frankel", "given_name": "Paul", "clpid": "Frankel-P-H" }, { "family_name": "Clark", "given_name": "Andrew J.", "clpid": "Clark-A-J" }, { "family_name": "Wiley", "given_name": "Devin T.", "clpid": "Wiley-D-T" }, { "family_name": "Garmey", "given_name": "Edward", "clpid": "Garmey-E-G" }, { "family_name": "Fakih", "given_name": "Marwan", "clpid": "Fakih-M" }, { "family_name": "Lim", "given_name": "Dean", "clpid": "Lim-Dean" }, { "family_name": "Chung", "given_name": "Vincent", "clpid": "Chung-Vincent" }, { "family_name": "Luevanos", "given_name": "Eloise", "clpid": "Luevanos-E" }, { "family_name": "Eliasof", "given_name": "Scott", "clpid": "Eliasof-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Yen", "given_name": "Yun", "orcid": "0000-0003-0815-412X", "clpid": "Yen-Yun" } ], "abstract": "Background: CRLX101 is an investigational nanoparticle-drug conjugate with a camptothecin payload. Preclinical evidence indicated preferential uptake in tumors, and tumor xenograft models demonstrate superiority of CRLX101 over irinotecan. A pilot trial was conducted at recommended phase 2 dosing (RP2D) using the bimonthly schedule to assess preferential uptake of CRLX101 in tumor vs. adjacent normal tissue in endoscopically accessible tumors in chemotherapy-refractory gastroesophageal cancer. Results from the biopsies were previously reported and herein we present the clinical outcomes.\nMethods: Patients initiated CRLX101 dosed at RP2D (15 mg/m^2) on days 1 and 15 of a 28-day cycle. Detection of preferential CRLX101 tumor uptake was the primary endpoint and objective response rate (ORR) was a secondary endpoint. With a sample size of ten patients, the study had 90% power to detect \u22651 responder if the true response rate is \u226521%.\nResults: Between Dec. 2012 and Dec. 2014, ten patients with chemotherapy-refractory (median 2 prior lines of therapy, range 1\u20134) gastric adenocarcinoma were enrolled. The median time-to-progression was 1.7 months. Best response was seen in one patient with stable disease (SD) for 8 cycles. Only \u2265 grade 3 drug-related toxicity occurred in one patient with grade 3 cardiac chest pain who was able to resume therapy after CRLX101 was reduced to 12 mg/m^2.\nConclusions: Bimonthly CRLX101 demonstrated minimal activity with SD as best response in this heavily pretreated population. Future efforts with CRLX101 in gastric cancer should focus on combination and more dose-intensive strategies given its favorable toxicity profile and evidence of preferential tumor uptake.", "doi": "10.21037/jgo.2017.08.10", "pmcid": "PMC5750185", "issn": "2078-6891", "publisher": "Society for Gastrointestinal Oncology", "publication": "Journal of Gastrointestinal Oncology", "publication_date": "2017-12", "series_number": "6", "volume": "8", "issue": "6", "pages": "962-969" }, { "id": "authors:9te3t-4tb55", "collection": "authors", "collection_id": "9te3t-4tb55", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171127-151753335", "type": "article", "title": "Future cancer research priorities in the USA: a Lancet Oncology Commission", "author": [ { "family_name": "Jaffee", "given_name": "Elizabeth M.", "clpid": "Jaffee-E-M" }, { "family_name": "Davis", "given_name": "Mark", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Heath", "given_name": "James", "orcid": "0000-0001-5356-4385", "clpid": "Heath-J-R" } ], "abstract": "We are in the midst of a technological revolution that is providing new insights into human biology and cancer. In this era of big data, we are amassing large amounts of information that is transforming how we approach cancer treatment and prevention. Enactment of the Cancer Moonshot within the 21st Century Cures Act in the USA arrived at a propitious moment in the advancement of knowledge, providing nearly US$2 billion of funding for cancer research and precision medicine. In 2016, the Blue Ribbon Panel (BRP) set out a roadmap of recommendations designed to exploit new advances in cancer diagnosis, prevention, and treatment. Those recommendations provided a high-level view of how to accelerate the conversion of new scientific discoveries into effective treatments and prevention for cancer. The US National Cancer Institute is already implementing some of those recommendations. As experts in the priority areas identified by the BRP, we bolster those recommendations to implement this important scientific roadmap. In this Commission, we examine the BRP recommendations in greater detail and expand the discussion to include additional priority areas, including surgical oncology, radiation oncology, imaging, health systems and health disparities, regulation and financing, population science, and oncopolicy. We prioritise areas of research in the USA that we believe would accelerate efforts to benefit patients with cancer. Finally, we hope the recommendations in this report will facilitate new international collaborations to further enhance global efforts in cancer control.", "doi": "10.1016/S1470-2045(17)30698-8", "issn": "1470-2045", "publisher": "Elsevier", "publication": "Lancet Oncology", "publication_date": "2017-11", "series_number": "11", "volume": "18", "issue": "11", "pages": "e653-e706" }, { "id": "authors:secg5-2e542", "collection": "authors", "collection_id": "secg5-2e542", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170831-132157296", "type": "article", "title": "CIT-9: a fault-free, gmelinite zeolite", "author": [ { "family_name": "Dusselier", "given_name": "Michiel", "orcid": "0000-0002-3074-2318", "clpid": "Dusselier-M" }, { "family_name": "Kang", "given_name": "Jong Hun", "orcid": "0000-0002-4197-9070", "clpid": "Kang-Jong-Hun" }, { "family_name": "Xie", "given_name": "Dan", "orcid": "0000-0003-2467-976X", "clpid": "Xie-Dan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A synthetic, fault-free gmelinite (GME) zeolite is prepared using a specific organic structure-directing agent (OSDA), cis-3,5-dimethylpiperidinium. The cis-isomers align in the main 12-membered ring (MR) channel of GME. Trans-isomer OSDA leads to the small-pore zeolite SSZ-39 with the OSDA in its cages. Data from N_2-physisorption and rotation electron diffraction provide evidence for the openness of the 12 MR channel in the GME 12\u00d78\u00d78 pore architecture and the absence of stacking faults, respectively. CIT-9 is hydrothermally stable when K^+-exchanged, while in the absence of exchange, the material transforms into an aluminous AFI-zeolite. The process of this phase-change was followed by in situ variable temperature powder X-ray diffraction. CIT-9 has the highest Si/Al ratio reported for GME, and along with its good porosity, opens the possibility of using GME in a variety of applications including catalysis.", "doi": "10.1002/anie.201707452", "issn": "1433-7851", "publisher": "Wiley", "publication": "Angewandte Chemie International Edition", "publication_date": "2017-10-16", "series_number": "43", "volume": "56", "issue": "43", "pages": "13475-13478" }, { "id": "authors:1ds23-nq785", "collection": "authors", "collection_id": "1ds23-nq785", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170628-070433726", "type": "article", "title": "Store Operated Calcium Entry Suppressed TGF-\u03b21/SMAD3 Signaling Pathway in Glomerular Mesangial Cells", "author": [ { "family_name": "Chaudhari", "given_name": "Sarika", "clpid": "Chaudhari-S" }, { "family_name": "Li", "given_name": "Weizu", "clpid": "Li-Weizu" }, { "family_name": "Wang", "given_name": "Yanxia", "clpid": "Wang-Yanxia" }, { "family_name": "Jiang", "given_name": "Hui", "clpid": "Jiang-Hui" }, { "family_name": "Ma", "given_name": "Yuhong", "clpid": "Ma-Yuhong" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Ma", "given_name": "Rong", "clpid": "Ma-Rong" } ], "abstract": "Our previous study demonstrated that the abundance of extracellular matrix proteins was suppressed by store-operated Ca^(2+) entry (SOCE) in mesangial cells (MCs). The present study was conducted to investigate the underlying mechanism focused on the transforming growth factor-\u03b21 (TGF-\u03b21)/Smad3 pathway, a critical pathway for ECM expansion in diabetic kidneys. We hypothesized that SOCE suppressed ECM protein expression by inhibiting this pathway in MCs. In cultured human MCs, we observed that TGF-\u03b21 (5 ng/ml for 15 h) significantly increased Smad3 phosphorylation, as evaluated by immunoblot. However, this response was markedly inhibited by thapsigargin (1 \u00b5M), a classical activator of store-operated Ca^(2+) channels. Consistently, both immunocytochemistry and immunoblot showed that TGF-\u03b21 significantly increased nuclear translocation of Smad3, which was prevented by pretreatment with thapsigargin. Importantly, the thapsigargin effect was reversed by lanthanum (La^(3+); 5 \u00b5M) and GSK-7975A (10 \u00b5M), both of which are selective blockers of store-operated Ca^(2+) channels. Furthermore, knockdown of Orai1, the pore-forming subunit of the store-operated Ca^(2+) channels, significantly augmented TGF-\u03b21-induced Smad3 phosphorylation. Overexpression of Orai1 augmented the inhibitory effect of thapsigargin on TGF-\u03b21-induced phosphorylation of Smad3. In agreement with the data from cultured MCs, in vivo knockdown of Orai1 specific to MCs using a targeted nanoparticle small interfering RNA delivery system resulted in a marked increase in abundance of phosphorylated Smad3 and in nuclear translocation of Smad3 in the glomerulus of mice. Taken together, our results indicate that SOCE in MCs negatively regulates the TGF-\u03b21/Smad3 signaling pathway.", "doi": "10.1152/ajprenal.00483.2016", "pmcid": "PMC5625109", "issn": "1931-857X", "publisher": "American Physiology Society", "publication": "American Journal of Physiology - Renal Physiology", "publication_date": "2017-09", "series_number": "3", "volume": "313", "issue": "3", "pages": "F729-F739" }, { "id": "authors:2hf6d-8mr48", "collection": "authors", "collection_id": "2hf6d-8mr48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170320-081110533", "type": "article", "title": "Negative regulation of Smad1 pathway and collagen IV expression by store-operated Ca^(2+) entry in glomerular mesangial cells", "author": [ { "family_name": "Wu", "given_name": "Peiwen", "clpid": "Wu-Peiwen" }, { "family_name": "Ren", "given_name": "Yuezhong", "clpid": "Ren-Yuezhong" }, { "family_name": "Ma", "given_name": "Yuhong", "clpid": "Ma-Yuhong" }, { "family_name": "Wang", "given_name": "Yanxia", "clpid": "Wang-Yanxia" }, { "family_name": "Jiang", "given_name": "Hui", "clpid": "Jiang-Hui" }, { "family_name": "Chaudhari", "given_name": "Sarika", "clpid": "Chaudhari-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Ma", "given_name": "Rong", "clpid": "Ma-Rong" } ], "abstract": "Collagen IV (Col IV) is a major component of expanded glomerular extracellular matrix in diabetic nephropathy and Smad1 is a key molecule regulating Col IV expression in mesangial cells (MCs). The present study was conducted to determine if Smad1 pathway and Col IV protein abundance were regulated by store-operated Ca^(2+) entry (SOCE). In cultured human MCs, pharmacological inhibition of SOCE significantly increased the total amount of Smad1 protein. Activation of SOCE blunted high-glucose-increased Smad1 protein content. Treatment of human MCs with ANG II at 1 \u00b5M for 15 min, high glucose for 3 days, or TGF-\u03b21 at 5 ng/ml for 30 min increased the level of phosphorylated Smad1. However, the phosphorylation of Smad1 by those stimuli was significantly attenuated by activation of SOCE. Knocking down Smad1 reduced, but expressing Smad1 increased, the amount of Col IV protein. Furthermore, activation of SOCE significantly attenuated high-glucose-induced Col IV protein production, and blockade of SOCE substantially increased the abundance of Col IV. To further verify those in vitro findings, we downregulated SOCE specifically in MCs in mice using small-interfering RNA (siRNA) against Orai1 (the channel protein mediating SOCE) delivered by the targeted nanoparticle delivery system. Immunohistochemical examinations showed that expression of both Smad1 and Col IV proteins was significantly greater in the glomeruli with positively transfected Orai1 siRNA compared with the glomeruli from the mice without Orai1 siRNA treatment. Taken together, our results indicate that SOCE negatively regulates the Smad1 signaling pathway and inhibits Col IV protein production in MCs.", "doi": "10.1152/ajprenal.00642.2016", "issn": "1931-857X", "publisher": "American Physiology Society", "publication": "American Journal of Physiology - Renal Physiology", "publication_date": "2017-06-04", "series_number": "6", "volume": "312", "issue": "6", "pages": "F1090-F1100" }, { "id": "authors:z7d4m-g6c56", "collection": "authors", "collection_id": "z7d4m-g6c56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170502-074819722", "type": "article", "title": "Enantiomerically enriched, polycrystalline molecular sieves", "author": [ { "family_name": "Brand", "given_name": "Stephen K.", "clpid": "Brand-Stephen-K" }, { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-Joel-E" }, { "family_name": "Deem", "given_name": "Michael W.", "orcid": "0000-0002-4298-3450", "clpid": "Deem-Michael-W" }, { "family_name": "Daeyaert", "given_name": "Frits", "clpid": "Daeyaert-Frits" }, { "family_name": "Ma", "given_name": "Yanhang", "clpid": "Ma-Yanhang" }, { "family_name": "Terasaki", "given_name": "Osamu", "clpid": "Terasaki-Osamu" }, { "family_name": "Orazov", "given_name": "Marat", "clpid": "Orazov-Marat" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolite and zeolite-like molecular sieves are being used in a large number of applications such as adsorption and catalysis. Achievement of the long-standing goal of creating a chiral, polycrystalline molecular sieve with bulk enantioenrichment would enable these materials to perform enantioselective functions. Here, we report the synthesis of enantiomerically enriched samples of a molecular sieve. Enantiopure organic structure directing agents are designed with the assistance of computational methods and used to synthesize enantioenriched, polycrystalline molecular sieve samples of either enantiomer. Computational results correctly predicted which enantiomer is obtained, and enantiomeric enrichment is proven by high-resolution transmission electron microscopy. The enantioenriched and racemic samples of the molecular sieves are tested as adsorbents and heterogeneous catalysts. The enantioenriched molecular sieves show enantioselectivity for the ring opening reaction of epoxides and enantioselective adsorption of 2-butanol (the R enantiomer of the molecular sieve shows opposite and approximately equal enantioselectivity compared with the S enantiomer of the molecular sieve, whereas the racemic sample of the molecular sieve shows no enantioselectivity).", "doi": "10.1073/pnas.1704638114", "pmcid": "PMC5441830", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2017-05-16", "series_number": "20", "volume": "114", "issue": "20", "pages": "5101-5106" }, { "id": "authors:kze6b-cg566", "collection": "authors", "collection_id": "kze6b-cg566", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161214-094030853", "type": "article", "title": "Structural and kinetic changes to small-pore Cu-zeolites after hydrothermal aging treatments and selective catalytic reduction of NO_x with ammonia", "author": [ { "family_name": "Albarracin-Caballero", "given_name": "Jonatan D.", "clpid": "Albarracin-Caballero-J-D" }, { "family_name": "Khurana", "given_name": "Ishant", "clpid": "Khurana-I" }, { "family_name": "Di Iorio", "given_name": "John R.", "clpid": "Di-Iorio-J-R" }, { "family_name": "Shih", "given_name": "Arthur J.", "clpid": "Shih-Arthur-J" }, { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-J-E" }, { "family_name": "Dusselier", "given_name": "Michiel", "orcid": "0000-0002-3074-2318", "clpid": "Dusselier-M" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Yezerets", "given_name": "Aleksey", "clpid": "Yezerets-A" }, { "family_name": "Miller", "given_name": "Jeffrey T.", "clpid": "Miller-J-T" }, { "family_name": "Ribeiro", "given_name": "Fabio H.", "clpid": "Ribeiro-F-H" }, { "family_name": "Gounder", "given_name": "Rajamani", "orcid": "0000-0003-1347-534X", "clpid": "Gounder-R" } ], "abstract": "Three small-pore, eight-membered ring (8-MR) zeolites of different cage-based topology (CHA, AEI, RTH), in their proton- and copper-exchanged forms, were first exposed to high temperature hydrothermal aging treatments (1073 K, 16 h, 10% (v/v) H_2O) and then to reaction conditions for low temperature (473 K) standard selective catalytic reduction (SCR) of NO_x with ammonia, in order to study the effect of zeolite topology on the structural and kinetic changes that occur to Cu-zeolites used in NO_x abatement. UV-visible spectra were collected to monitor changes to Cu structure and showed that band intensities for isolated, hydrated Cu^(2+) cations (\u223c12 500 cm^(\u22121)) remain constant after hydrothermal aging, but decrease in intensity upon subsequent exposure to low temperature SCR reaction conditions. Standard SCR rates (per Cu, 473 K), activation energies, and reaction orders are similar between Cu-AEI and Cu-CHA zeolites before and after hydrothermal aging, although rates are lower after hydrothermal aging as expected from the decreases in intensity of UV-visible bands for Cu^(2+) active sites. For Cu-RTH, rates are lower (by 2\u20133\u00d7) and apparent activation energies are lower (by \u223c2\u00d7) than for Cu-AEI or Cu-CHA. These findings suggest that the RTH framework imposes internal transport restrictions, effectively functioning as a one-dimensional framework during SCR catalysis. Hydrothermal aging of Cu-RTH results in complete deactivation and undetectable SCR rates, despite X-ray diffraction patterns and Ar micropore volumes (87 K) that remain unchanged after hydrothermal aging treatments and subsequent SCR exposure. These findings highlight some of the differences in low temperature SCR behavior among small-pore Cu-zeolites of different topology, and the beneficial properties conferred by double six-membered ring (D6R) composite building units. They demonstrate that deleterious structural changes to Cu sites occur after exposure to hydrothermal aging conditions and SCR reactants at low temperatures, likely reflecting the formation of inactive copper-aluminate domains. Therefore, the viability of Cu-zeolites for practical low temperature NO_x SCR catalysis cannot be inferred solely from assessments of framework structural integrity after hydrothermal aging treatments, but also require Cu active site and kinetic characterization after hydrothermally aged zeolites are exposed to low temperature SCR reaction conditions.", "doi": "10.1039/c6re00198j", "issn": "2058-9883", "publisher": "Royal Society of Chemistry", "publication": "Reaction Chemistry and Engineering", "publication_date": "2017-04-01", "series_number": "2", "volume": "2", "issue": "2", "pages": "168-179" }, { "id": "authors:bf9ja-rwn76", "collection": "authors", "collection_id": "bf9ja-rwn76", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170502-102605956", "type": "conference_item", "title": "Polymer-Based nanoparticle therapeutics", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "We have translated three polymer-based nanoparticles into the clinic for use as cancer therapeutics. One of these nanoparticle, exptl. therapeutics was the first to show functional RNA interference (RNAi) in humans. At this time, these nanoparticles have been investigated in over 10 different clin. trials. I will describe how we\ntranslated these nanoparticles from the lab. at Caltech into clin., exptl. therapeutics. In addn. to investigations of polymer-based nanoparticle therapeutics for cancer, we are now concg. on developing polymer-based nanoparticles that cross the blood-brain-barrier. Our recent efforts will be presented.", "publisher": "Caltech Library", "publication_date": "2017-04" }, { "id": "authors:9g7gj-p2n83", "collection": "authors", "collection_id": "9g7gj-p2n83", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170505-124940271", "type": "conference_item", "title": "Tweet, for science!: A social media course for scientists at Caltech tackling inreach and outreach online", "author": [ { "family_name": "Wilkins", "given_name": "Olivia", "orcid": "0000-0002-3191-5401", "clpid": "Wilkins-O-H" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Mojarad", "given_name": "Sarah", "clpid": "Mojarad-S" } ], "abstract": "The public places greater trust in scientists than in conventional media outlets for communicating science, and yet STEM topics are among the least represented areas on social media platforms. As technol. evolves, so do tools for online communication. Hence it is imperative that\nscientists develop and implement skills to use social media effectively. In Social Media for Scientists at the California Institute of Technol., students are introduced to how social media and science intersect and learn how to use social media for both inreach (engaging each other)\nand outreach (engaging general audiences). In the course, co-taught by a Chem. Engineering professor (Mark E. Davis) and a communications professional (Sarah Mojarad), students explore ethics, misinformation management, branding, and law through case studies, discussion boards, and various social media projects.", "publisher": "Caltech Library", "publication_date": "2017-04" }, { "id": "authors:yyfrr-26k55", "collection": "authors", "collection_id": "yyfrr-26k55", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170921-152404373", "type": "article", "title": "In Vivo Knockdown of I-mfa Using The Targeted Nanoparticle Delivery System Ameliorated Renal Injury in Diabetic Mice", "author": [ { "family_name": "Ma", "given_name": "Yuhong", "clpid": "Ma-Yuhong" }, { "family_name": "Li", "given_name": "Weizu", "clpid": "Li-Weizu" }, { "family_name": "Jiang", "given_name": "Hui", "clpid": "Jiang-Hui" }, { "family_name": "Wang", "given_name": "Yanxia", "clpid": "Wang-Yanxia" }, { "family_name": "Zuckerman", "given_name": "Jonathan", "clpid": "Zuckerman-J-E" }, { "family_name": "Davis", "given_name": "Mark", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Ma", "given_name": "Rong", "clpid": "Ma-Rong" } ], "abstract": "Accumulation of extracellular matrix (ECM) proteins in glomerulus is one of early features of diabetic nephropathy. Glomerular mesangial cell (MC) is the major source of ECM. Inhibitor of Myogenic Family isoform a (I-mfa) is a cytosolic protein interacting with components of Wnt/\u03b2-catenin pathway and of store-operated Ca^(2+) signaling pathway, both of which are involved in the development of diabetic nephropathy. The present study was carried out to determine if I-mfa in MCs contributed to renal injury in diabetic mice. Twelve male mice were randomly divided into 4 groups (3 mice each group): non-diabetes, diabetes, diabetes treated with scramble siRNA, and diabetes treated with siRNA against I-mfa. Diabetes was generated by multiple low-dose streptozotocin (STZ, 50 mg/kg) injections (intraperitoneal, once one day for 5 days) at an age of 6 weeks. Mice in group of non diabetes were injected with 10 mM citrate buffer (vehicle). Diabetes was indicated by a fasting blood glucose level of > 300 mg/dl. Scramble or I-mfa siRNA treatment started 24 weeks after STZ injection and the treatment lasted 2 weeks. All siRNAs (10 mg/kg body weight) were delivered by our recently established-targeted nanoparticle/siRNA delivery system which is glomerular mesangial cell specific. We found that STZ treatment significantly increased blood glucose level after 4 weeks of injection and reduced body weight 26 weeks after treatment. I-mfa siRNA treatment did not improve hyperglycemia, but lessened renal hypertrophy in STZ mice. Furthermore, diabetic mice showed significantly greater 24 hour urine output and this diabetic uresis was compromised by I-mfa siRNA treatment. Although knocking down I-mfa did not mitigate albuminuria, it lowered the level of blood urea nitrogen in diabetic mice. Consistent with the functional data, histological examination showed improved mesangial expansion and glomerular fibrosis in I-mfa siRNA-treated STZ mice. Immunohistochemical examination showed a significant reduction of protein abundance of glomerular fibronectin and collagen IV in the siRNA-treated diabetic mice. Taken together, our data indicate that I-mfa in MCs is involved in the development of diabetic kidney disease and thus, could be a potential therapeutic target for diabetic nephropathy.", "issn": "0892-6638", "publisher": "Federation of American Societies for Experimental Biology", "publication": "FASEB Journal", "publication_date": "2017-04", "series_number": "S1", "volume": "31", "issue": "S1", "pages": "Art. No. 716.3" }, { "id": "authors:qwg3y-8y518", "collection": "authors", "collection_id": "qwg3y-8y518", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160627-084015068", "type": "article", "title": "Steam-dealuminated, OSDA-free RHO and KFI-type zeolites as catalysts for the methanol-to-olefins reaction", "author": [ { "family_name": "Ji", "given_name": "Yuewei", "clpid": "Ji-Yuewei" }, { "family_name": "Birmingham", "given_name": "John", "clpid": "Birmingham-J" }, { "family_name": "Deimund", "given_name": "Mark A.", "clpid": "Deimund-M-A" }, { "family_name": "Brand", "given_name": "Stephen K.", "clpid": "Brand-S-K" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "RHO and KFI-type zeolites are synthesized in the absence of organic structure-directing agents (OSDAs), post-synthetically dealuminated via high temperature (600\u2013800 \u00b0C) steam treatments, and evaluated as catalysts for converting methanol-to-light olefins (MTO). The proton forms of the as-made zeolites deactivate rapidly when tested for the MTO reaction (conducted at 400 \u00b0C and atmospheric pressure) due to their high aluminum content. Steam treatments lead to improvements in olefin selectivities and catalyst lifetimes with samples steamed at 600 \u00b0C giving the best combination of lifetime and olefin selectivity. Zeolite characterizations by ^(27)Al NMR, ^(29)Si NMR and argon physisorption indicate that the steam treatments extract framework aluminum, leading to reductions in the total number of Br\u00f8nsted acid sites and the creation of mesopores that can facilitate transport of reactants. Poisoning of the acid sites external to the 8MR pores of the zeolites by treatments with trimethylphosphite results in longer catalyst lifetimes but do not affect the observed olefin selectivities, suggesting that olefins do not undergo secondary dimerization or methylation reactions at these sites.", "doi": "10.1016/j.micromeso.2016.06.012", "issn": "1387-1811", "publisher": "Elsevier", "publication": "Microporous and Mesoporous Materials", "publication_date": "2016-09-15", "volume": "232", "pages": "126-137" }, { "id": "authors:7wakz-n7q44", "collection": "authors", "collection_id": "7wakz-n7q44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160907-114638341", "type": "article", "title": "Synthesis and Characterization of CIT-13, a Germanosilicate Molecular Sieve with Extra-Large Pore Openings", "author": [ { "family_name": "Kang", "given_name": "Jong Hun", "orcid": "0000-0002-4197-9070", "clpid": "Kang-Jong-Hun" }, { "family_name": "Xie", "given_name": "Dan", "orcid": "0000-0003-2467-976X", "clpid": "Xie-Dan" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Smeets", "given_name": "Stef", "clpid": "Smeets-S" }, { "family_name": "McCusker", "given_name": "Lynne B.", "clpid": "McCusker-L-B" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The synthesis of the germanosilicate CIT-13, a molecular sieve that is the first to have a two-dimensional (2D) pore system possessing pores that are bounded by 14- and 10-rings, is accomplished using a family of monoquaternary, benzyl-imidazolium organic structure-directing agents (OSDAs) in aqueous media containing fluoride. CIT-13 is prepared using either hydrogen fluoride (HF) or ammonium fluoride (NH_4F). The structure refinement suggests that most of the Ge atoms are located in the d4r (double-4-rings) units, and that there are framework disorders in the arrangement of those d4r units. Other characterizations of CIT-13 such as ^(29)Si MAS NMR spectra, Ar-adsorption isotherms, and so forth are presented and compared to those of IM-12 (UTL), a previously reported germanosilicate with 14- and 12-ring pores.", "doi": "10.1021/acs.chemmater.6b02468", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2016-09-13", "series_number": "17", "volume": "28", "issue": "17", "pages": "6250-6259" }, { "id": "authors:y3dkz-vmk21", "collection": "authors", "collection_id": "y3dkz-vmk21", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160714-110754013", "type": "article", "title": "Methyl-ligated tin silsesquioxane catalyzed reactions of glucose", "author": [ { "family_name": "Brand", "given_name": "Stephen K.", "clpid": "Brand-S-K" }, { "family_name": "Josephson", "given_name": "Tyler R.", "clpid": "Josephson-T-R" }, { "family_name": "Labinger", "given_name": "Jay A.", "orcid": "0000-0002-1942-9232", "clpid": "Labinger-J-A" }, { "family_name": "Caratzoulas", "given_name": "Stavros", "clpid": "Caratzoulas-S" }, { "family_name": "Vlachos", "given_name": "Dionisios G.", "clpid": "Vlachos-D-G" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Tin-containing zeolite Beta (Sn-Beta) has been investigated as a catalyst for isomerizing aldohexoses into ketohexoses through a Lewis acid mediated hydride shift. Recent studies on the reactivities of Lewis base-doped and alkali-exchanged Sn-Beta samples have conclusively demonstrated that the \"open\" tin site performs the glucose isomerization reaction. With Lewis base doped Sn-Beta, glucose conversion is almost completely eliminated and product selectivity is shifted predominantly to mannose. These data suggest that glucose reactions may occur through pathways that do not involve the \"open\" site in Sn-Beta; albeit at significantly lower rates. To examine this possibility, reactions of glucose catalyzed by a homogeneous model of Sn-Beta that does not contain \"open\" sites, methyl-ligated tin silsesquioxane 1a, is experimentally and theoretically examined. 1a is an active glucose conversion catalyst selectively producing mannose, although the rates of reaction are far below those obtained from Sn-Beta. A hybrid quantum mechanical/molecular mechanics model is constructed, and the complete catalytic cycle is computationally examined, considering ring-opening, three distinct pathways for each hydride- and carbon-shift reaction, and ring-closing. The combined experimental and computational results suggest that there could be reaction pathways that involve Si\u2013O\u2013Sn cleavage that give much slower reaction rates than the open tin site in Sn-Beta.", "doi": "10.1016/j.jcat.2016.06.013", "issn": "0021-9517", "publisher": "Elsevier", "publication": "Journal of Catalysis", "publication_date": "2016-09", "volume": "341", "pages": "62-71" }, { "id": "authors:mhcb2-zyk22", "collection": "authors", "collection_id": "mhcb2-zyk22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160729-120515808", "type": "book_section", "title": "Chapter 8. Polymeric Nanoparticles and Cancer: Lessons Learnt from CRLX101", "book_title": "Nanomedicines", "author": [ { "family_name": "Gritli", "given_name": "Ismael", "clpid": "Gritli-I" }, { "family_name": "Garmey", "given_name": "Edward Graeme", "clpid": "Garmey-E-G" }, { "family_name": "Eliasof", "given_name": "Scott", "clpid": "Eliasof-S" }, { "family_name": "Tellez", "given_name": "Andres", "clpid": "Tellez-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Yun", "given_name": "Yen", "clpid": "Yun-Yen" } ], "contributor": [ { "family_name": "Braddock", "given_name": "Martin", "clpid": "Braddock-M" } ], "abstract": "CRLX101 (formerly IT-101) is a novel cyclodextrin-based polymer that self-assembles into nanoparticles. CRLX101 is covalently conjugated to the hydrophobic topoisomerase 1 (TOP1)-inhibitor camptothecin (CPT) resulting in stabilized structure and increased water solubility. Extensive preclinical studies of CRLX101 demonstrated delayed renal clearance and a prolonged plasma half-life. The nanoparticle passively accumulates in tumour tissue through the enhanced permeability and retention effect and slowly releases active CPT leading to enhanced TOP1 inhibition, potential hypoxia inducible factor-1\u03b1 (HIF-1\u03b1) effect, cancer stem cell targeting, and increased antitumour activity against multiple human tumour xenografts. More than 200 human cancer patients have been treated with CRLX101 in phase I/IIa and phase II clinical trials. In this chapter we explore a wide range of anti-cancer nanotherapeutic strategies to inhibit TOP1, HIF-1\u03b1 and cancer stem cells. Moreover, we discuss the therapeutic value of combining HIF-1\u03b1 inhibition with antiangiogenics. Finally, we return to CRLX101 and cover in detail the latest preclinical and clinical evaluations and discuss future directions.", "doi": "10.1039/9781782622536-00199", "isbn": "978-1-84973-947-4", "publisher": "Royal Society of Chemistry", "place_of_publication": "Cambridge, UK", "publication_date": "2016-04-28", "pages": "199-232" }, { "id": "authors:jtyzd-8tq13", "collection": "authors", "collection_id": "jtyzd-8tq13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160328-105032968", "type": "article", "title": "Synthesis of Germanosilicate Molecular Sieves from Mono- and Di-Quaternary Ammonium OSDAs Constructed from Benzyl Imidazolium Derivatives: Stabilization of Large Micropore Volumes Including New Molecular Sieve CIT-13", "author": [ { "family_name": "Boal", "given_name": "Ben W.", "clpid": "Boal-B-W" }, { "family_name": "Deem", "given_name": "Michael W.", "clpid": "Deem-M-W" }, { "family_name": "Xie", "given_name": "Dan", "orcid": "0000-0003-2467-976X", "clpid": "Xie-Dan" }, { "family_name": "Kang", "given_name": "Jong Hun", "orcid": "0000-0002-4197-9070", "clpid": "Kang-Jong-Hun" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" } ], "abstract": "A series of monoquaternary and diquarternary benzyl-imidazolium derivatives are prepared and used as organic structure direction agents (OSDAs) in germanosilicate syntheses. The goal of this work is to create new multidimensional large pore zeolites. For the OSDA made and tested, we looked for relationships based upon stereochemistry from the benzyl ring as part of each structure. Several known molecular sieves with the *BEA, BEC, IWS, or LTA topologies are obtained. Molecular modeling is carried out with the goal of understanding: (a) the product selectivity correlation with the OSDA and the zeolite obtained, and (b) why differential rates of crystallization are observed for isomers that lead to different zeolite products. Additionally, a new molecular sieve denoted CIT-13 is prepared and shown to possess intersecting 14- and 10-membered ring pores, which gives confidence to the soundness of this approach for OSDA construction to yield new multidimensional large pore zeolites. CIT-13 is the first molecular sieve to have this combination of pore sizes.", "doi": "10.1021/acs.chemmater.6b00031", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2016-04-12", "series_number": "7", "volume": "28", "issue": "7", "pages": "2158-2164" }, { "id": "authors:z65jc-dzb34", "collection": "authors", "collection_id": "z65jc-dzb34", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160512-084540662", "type": "article", "title": "Pillared Sn-MWW Prepared by a Solid-State-Exchange Method and its Use as a Lewis Acid Catalyst", "author": [ { "family_name": "Ren", "given_name": "Limin", "clpid": "Ren-Limin" }, { "family_name": "Guo", "given_name": "Qiang", "clpid": "Guo-Qiang" }, { "family_name": "Orazov", "given_name": "Marat", "clpid": "Orazov-M" }, { "family_name": "Xu", "given_name": "Dandan", "orcid": "0000-0002-0355-2906", "clpid": "Xu-Dandan" }, { "family_name": "Politi", "given_name": "Dorothea", "clpid": "Politi-D" }, { "family_name": "Kumar", "given_name": "Prashant", "clpid": "Kumar-P" }, { "family_name": "Alhassan", "given_name": "Saeed M.", "clpid": "Alhassan-S-M" }, { "family_name": "Mkhoyan", "given_name": "K. Andre", "clpid": "Mkhoyan-K-A" }, { "family_name": "Sidiras", "given_name": "Dimitrios", "clpid": "Sidiras-D" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Tsapatsis", "given_name": "Michael", "orcid": "0000-0001-5610-3525", "clpid": "Tsapatsis-M" } ], "abstract": "Pillared Sn-MWW (Sn-MWW(SP)-SSE) was prepared through a solid-state-exchange (SSE) route. The pillared structure was inherited from pillared B-MWW, and Sn was inserted in the framework by boron leaching and solid-state-exchange with tin tetrachloride pentahydrate. The Sn-MWW(SP)-SSE with framework Sn sites exhibits Lewis acidity and good catalytic performance for the Baeyer\u2013Villiger oxidation, and mono- and disaccharide isomerizations.", "doi": "10.1002/cctc.201600120", "issn": "1867-3880", "publisher": "Wiley", "publication": "ChemCatChem", "publication_date": "2016-04-06", "series_number": "7", "volume": "8", "issue": "7", "pages": "1274-1278" }, { "id": "authors:xsa9p-77p25", "collection": "authors", "collection_id": "xsa9p-77p25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160321-153715728", "type": "article", "title": "CRLX101 nanoparticles localize in human tumors and not in adjacent, nonneoplastic tissue after intravenous dosing", "author": [ { "family_name": "Clark", "given_name": "Andrew J.", "clpid": "Clark-Andrew-J" }, { "family_name": "Wiley", "given_name": "Devin T.", "clpid": "Wiley-Devin-T" }, { "family_name": "Zuckerman", "given_name": "Jonathan E.", "orcid": "0000-0002-8190-9210", "clpid": "Zuckerman-Jonathan-E" }, { "family_name": "Webster", "given_name": "Paul", "clpid": "Webster-Paul" }, { "family_name": "Chao", "given_name": "Joseph", "clpid": "Chao-Joseph" }, { "family_name": "Lin", "given_name": "James", "clpid": "Lin-James" }, { "family_name": "Yen", "given_name": "Yun", "orcid": "0000-0003-0815-412X", "clpid": "Yen-Yun" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Nanoparticle-based therapeutics are being used to treat patients with solid tumors. Whereas nanoparticles have been shown to preferentially accumulate in solid tumors of animal models, there is little evidence to prove that intact nanoparticles localize to solid tumors of humans when systemically administered. Here, tumor and adjacent, nonneoplastic tissue biopsies are obtained through endoscopic capture from patients with gastric, gastroesophageal, or esophageal cancer who are administered the nanoparticle CRLX101. Both the pre- and postdosing tissue samples adjacent to tumors show no definitive evidence of either the nanoparticle or its drug payload (camptothecin, CPT) contained within the nanoparticle. Similar results are obtained from the predosing tumor samples. However, in nine of nine patients that were evaluated, CPT is detected in the tumor tissue collected 24\u201348 h after CRLX101 administration. For five of these patients, evidence of the intact deposition of CRLX101 nanoparticles in the tumor tissue is obtained. Indications of CPT pharmacodynamics from tumor biomarkers such as carbonic anhydrase IX and topoisomerase I by immunohistochemistry show clear evidence of biological activity from the delivered CPT in the posttreatment tumors.", "doi": "10.1073/pnas.1603018113", "pmcid": "PMC4833237", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2016-04-05", "series_number": "14", "volume": "113", "issue": "14", "pages": "3850-3854" }, { "id": "authors:0jmt8-n2723", "collection": "authors", "collection_id": "0jmt8-n2723", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160202-100531931", "type": "article", "title": "Facile Synthesis, Characterization, and Catalytic Behavior of a Large-Pore Zeolite with the IWV Framework", "author": [ { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-J-E" }, { "family_name": "Chen", "given_name": "Cong-Yan", "clpid": "Chen-Cong-Yan" }, { "family_name": "Brand", "given_name": "Stephen K.", "clpid": "Brand-S-K" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Large-pore microporous materials are of great interest to process bulky hydrocarbon and biomass-derived molecules. ITQ-27 (IWV) has a two-dimensional pore system bounded by 12-membered rings (MRs) that lead to internal cross-sections containing 14\u2005MRs. Investigations into the catalytic behavior of aluminosilicate (zeolite) materials with this framework structure have been limited until now due to barriers in synthesis. The facile synthesis of aluminosilicate IWV in both hydroxide and fluoride media is reported herein using simple, diquaternary organic structure-directing agents (OSDAs) that are based on tetramethylimidazole. In hydroxide media, a zeolite product with Si/Al=14.8\u201323.2 is obtained, while in fluoride media an aluminosilicate product with Si/Al up to 82 is synthesized. The material produced in hydroxide media is tested for the hydroisomerization of n-hexane, and results from this test reaction suggest that the effective pore size of zeolites with the IWV framework structure is similar to but slightly larger than that of ZSM-12 (MTW), in fairly good agreement with crystallographic data.", "doi": "10.1002/chem.201504717", "issn": "0947-6539", "publisher": "John Wiley & Sons", "publication": "Chemistry: a European Journal", "publication_date": "2016-03-14", "series_number": "12", "volume": "22", "issue": "12", "pages": "4022-4029" }, { "id": "authors:g26x7-7gv91", "collection": "authors", "collection_id": "g26x7-7gv91", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160119-110838113", "type": "article", "title": "Catalysis by framework zinc in silica-based molecular sieves", "author": [ { "family_name": "Orazov", "given_name": "Marat", "clpid": "Orazov-Marat" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Microporous and mesoporous zincosilicates (e.g., CIT-6, VPI-8, Zn-MFI, and Zn-MCM-41) synthesized in the presence of alkali cations contain two broad types of Zn sites: one that is a dication analog of the monocation ion-exchangeable Al-site in aluminosilicates, while the other resembles isolated Zn sites on amorphous silica. The ratio of these sites varies, depending on the synthesis conditions of the zincosilicate. Post-synthetic strategies based on ion-exchange can alter the site distribution towards either population. Furthermore, post-synthetic introduction of isolated Zn sites of the latter type is possible for materials possessing silanol nests. Both types of sites behave as Lewis acid centers in probe-molecule IR spectroscopy, but have very different catalytic properties. Due to the unusually high adsorption energies of Lewis bases on such materials, Lewis acid catalysis is difficult at low temperatures and in solvents bearing Lewis basic functionality. However, at high temperatures, in hydrocarbon solvents, CIT-6 (Zn-beta) is able to selectively catalyze the Lewis-acid-catalyzed Diels\u2013Alder cycloaddition\u2013dehydration reactions of ethylene with methyl 5-(methoxymethyl)furan-2-carboxylate, a furan that can be derived quantitatively by partial oxidation of biomass-based 5-hydroxymethylfurfural. Additionally, zinc in silica-based molecular sieves is shown here to enable chemistries previously not accessible with framework Sn-, Ti- and Zr-based Lewis acid sites, e.g., the direct production of dimethyl terephthalate by Diels\u2013Alder cycloaddition\u2013dehydration reactions of ethylene and the dimethyl ester of furan-2,5-dicarboxilic acid.", "doi": "10.1039/C5SC03889H", "pmcid": "PMC5977500", "issn": "2041-6520", "publisher": "Royal Society of Chemistry", "publication": "Chemical Science", "publication_date": "2016-03", "series_number": "3", "volume": "7", "issue": "3", "pages": "2264-2274" }, { "id": "authors:h52kx-7q386", "collection": "authors", "collection_id": "h52kx-7q386", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160125-134417395", "type": "article", "title": "Effect of Heteroatom Concentration in SSZ-13 on the Methanol-to-Olefins Reaction", "author": [ { "family_name": "Deimund", "given_name": "Mark A.", "clpid": "Deimund-M-A" }, { "family_name": "Harrison", "given_name": "Luke", "clpid": "Harrison-L" }, { "family_name": "Lunn", "given_name": "Jonathan D.", "clpid": "Lunn-J-D" }, { "family_name": "Liu", "given_name": "Yu", "clpid": "Liu-Yu" }, { "family_name": "Malek", "given_name": "Andrzej", "orcid": "0000-0002-1608-9375", "clpid": "Malek-A" }, { "family_name": "Shayib", "given_name": "Ramzy", "clpid": "Shayib-R" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "SSZ-13 materials have been synthesized with varying amounts of Al to produce samples with different concentrations of Br\u00f8nsted acid sites, and consequently, these SSZ-13 materials contain increasing numbers of paired Al heteroatoms with increasing Al content. These materials were then characterized and tested as catalysts for the methanol-to-olefins (MTO) reaction at 400 \u00b0C and 100% methanol conversion under atmospheric pressure. A SAPO-34 sample was also synthesized and tested for comparison. SSZ-13 materials exhibited significant differences in MTO reactivity as Si/Al ratios varied. Reduced Al content (higher Si/Al ratio) and, consequently, fewer paired Al sites led to more stable light olefin selectivities, with a reduced initial transient period, lower initial propane selectivities, and longer catalyst lifetime. To further support the importance of paired Al sites in the formation of propane during this initial transient period, a series of experiments was conducted wherein an H-SSZ-13 sample was exchanged with Cu^(2+), steamed, and then back-exchanged to the H form. The H-SSZ-13 sample exhibited high initial propane selectivity, while the steamed H-SSZ-13, the Cu^(2+)-exchanged SSZ-13 sample, and the steamed Cu-SSZ-13 sample did not, as expected since steaming selectively removes paired Al sites and Cu^(2+) exchanges onto these sites. However, when it was back-exchanged to the proton form, the steamed Cu-SSZ-13 sample still exhibited the high initial alkane selectivity and transient period typical of the higher Al content materials. This is attributed to protection of paired Al sites during steaming via the Cu^(2+) cation. Post-reaction coke analyses reveal that the degree of methylation for each aromatic species increases with increasing Si/Al in SSZ-13. Further, SAPO-34 produces more polycyclic species than SSZ-13 samples. From these data, the paired Al site content appears to be correlated with both MTO reaction behavior and coke species formation in SSZ-13 samples.", "doi": "10.1021/acscatal.5b01450", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2016-02-05", "series_number": "2", "volume": "6", "issue": "2", "pages": "542-550" }, { "id": "authors:0zts3-kkj89", "collection": "authors", "collection_id": "0zts3-kkj89", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160707-082118111", "type": "article", "title": "Pilot trial of CRLX101 in patients (pts) with advanced, chemotherapy-refractory gastroesophageal cancer (GEC)", "author": [ { "family_name": "Chao", "given_name": "Joseph", "clpid": "Chao-Joseph" }, { "family_name": "Lin", "given_name": "James", "clpid": "Lin-James" }, { "family_name": "Frankel", "given_name": "Paul Henry", "clpid": "Frankel-P-H" }, { "family_name": "Clark", "given_name": "Andrew J.", "clpid": "Clark-A-J" }, { "family_name": "Wiley", "given_name": "Devin T.", "clpid": "Wiley-D-T" }, { "family_name": "Garmey", "given_name": "Edward Graeme", "clpid": "Garmey-E-G" }, { "family_name": "Fakih", "given_name": "Marwan", "clpid": "Fakih-M" }, { "family_name": "Lim", "given_name": "Dean", "clpid": "Lim-Dean" }, { "family_name": "Chung", "given_name": "Vincent M.", "clpid": "Chung-Vincent-M" }, { "family_name": "Luevanos", "given_name": "Eloise", "clpid": "Luevanos-E" }, { "family_name": "Eliasof", "given_name": "Scott", "clpid": "Eliasof-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Yen", "given_name": "Yun", "orcid": "0000-0003-0815-412X", "clpid": "Yen-Yun" } ], "abstract": "Background: Camptothecin (CPT) derivatives such as irinotecan have activity in 2nd-line therapy in advanced GEC with reported response rates of 0-15%. CRLX101 is an investigational nanoparticle-drug conjugate (NDC) with a CPT payload. Preclinical evidence indicates preferential uptake in tumors, and animal GEC xenograft models demonstrate superiority of CRLX101 over irinotecan. A pilot trial was conducted at recommended phase 2 dosing (RP2D) to assess preferential uptake of CRLX101 in tumor vs. adjacent normal tissue in endoscopically accessible tumors in patients with chemotherapy-refractory GEC. Data demonstrating preferential tumor uptake of CRLX101 has been presented separately and here we report on the clinical outcomes of patients enrolled. Methods: All pts initiated CRLX101 dosed intravenously at RP2D (15 mg/m2) on days 1 and 15 of a 28-day cycle until disease progression or intolerant toxicity. While detection of preferential CRLX101 tumor uptake was the primary endpoint, with 10 pts enrolled a secondary analysis could be performed with the study having 90% power to detect \u2265 1 responder if the true response rate is \u2265 21%. Responses were assessed using RECIST 1.1. Results: Between Dec. 2012 and Dec. 2014, 10 patients with chemotherapy-refractory (median 2 prior lines of therapy, range 1-4) GEC and adenocarcinoma histology were enrolled and evaluable for response and toxicity. The median time-to-progression was 1.9 mo (range 0.6-8.7 mo). Best response was seen in 1 pt with stable disease (SD) for 8 cycles. Only \u2265 grade 3 toxicities related to CRLX101 occurred in a single patient with grade 3 anemia and chest pain who was able to resume therapy without any further toxicity after CRLX101 was reduced to 12 mg/m2. Conclusions: CRLX101 demonstrated minimal activity with SD as best response in this heavily pretreated population. Future efforts with CRLX101 in advanced GEC should focus on combination strategies. Its favorable toxicity profile and evidence of preferential tumor uptake support further clinical research of combining CRLX101 with other targeted therapies such as anti-angiogenesis (ramucirumab) and/or immune checkpoint inhibitors. Clinical trial information: NCT01612546 Clinical trial information: NCT01612546.", "issn": "1527-7755", "publisher": "American Society of Clinical Oncology", "publication": "Journal of Clinical Oncology", "publication_date": "2016-02-01", "series_number": "4", "volume": "34", "issue": "4", "pages": "Art. No. 44" }, { "id": "authors:rnjrt-ra378", "collection": "authors", "collection_id": "rnjrt-ra378", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151109-101324263", "type": "article", "title": "Tin Silsesquioxanes as Models for the \"Open\" Site in Tin-Containing Zeolite Beta", "author": [ { "family_name": "Brand", "given_name": "Stephen K.", "clpid": "Brand-S-K" }, { "family_name": "Labinger", "given_name": "Jay A.", "orcid": "0000-0002-1942-9232", "clpid": "Labinger-J-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The use of biomass as a resource to produce value-added products has garnered significant interest as a means of reducing reliance on fossil fuels. This task is complicated by the complex, highly functionalized nature of abundant biomass derivatives, such as glucose. Tin-containing zeolite Beta (Sn-Beta) can selectively isomerize glucose to fructose through a 1,2-intramolecular hydride shift (1,2-HS) or selectively produce mannose through a 1,2-intramolecular carbon shift (1,2-CS) by titration of the silanol groups with sodium (Na-Sn-Beta). To understand the structure\u2013activity relationships between the conditions of the active sites in the zeolite, two molecular models (tin silsesquioxanes) of the tin sites in the zeolite were synthesized. Tin silsesquioxanes that contain an octahedral tin site with and without an adjacent silanol group selectively form fructose through a 1,2-HS and mannose through a 1,2-CS, respectively, and provide further evidence for the nature of the active sites in Sn-Beta.", "doi": "10.1002/cctc.201501067", "issn": "1867-3880", "publisher": "Wiley", "publication": "ChemCatChem", "publication_date": "2016-01-07", "series_number": "1", "volume": "8", "issue": "1", "pages": "121-124" }, { "id": "authors:n776y-gh144", "collection": "authors", "collection_id": "n776y-gh144", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160119-081421999", "type": "article", "title": "Commentary on Lo and Pisano's Proposal", "author": [ { "family_name": "Sharp", "given_name": "Phillip A.", "clpid": "Sharp-P-A" }, { "family_name": "Afeyan", "given_name": "Noubar", "clpid": "Afeyan-N" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Lerner", "given_name": "Josh", "clpid": "Lerner-J" } ], "abstract": "[no abstract]", "issn": "1532-9194", "publisher": "Sloan Management Review Association", "publication": "MIT Sloan Management Review", "publication_date": "2016-01", "series_number": "2", "volume": "57", "issue": "2", "pages": "54-57" }, { "id": "authors:63xqf-4nw52", "collection": "authors", "collection_id": "63xqf-4nw52", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151123-102043206", "type": "article", "title": "Clinical experiences with systemically administered siRNA-based therapeutics in cancer", "author": [ { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Small interfering RNA (siRNA)-based therapies are emerging as a promising new anticancer approach, and a small number of Phase I clinical trials involving patients with solid tumours have now been completed. Encouraging results from these pioneering clinical studies show that these new therapeutics can successfully and safely inhibit targeted gene products in patients with cancer, and have taught us important lessons regarding appropriate dosages and schedules. In this Review, we critically assess these Phase I studies and discuss their implications for future clinical trial design. Key challenges and future directions in the development of siRNA-containing anticancer therapeutics are also considered.", "doi": "10.1038/nrd4685", "issn": "1474-1776", "publisher": "Nature Publishing Group", "publication": "Nature Reviews Drug Discovery", "publication_date": "2015-12", "series_number": "12", "volume": "14", "issue": "12", "pages": "843-856" }, { "id": "authors:9whsq-k7x15", "collection": "authors", "collection_id": "9whsq-k7x15", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151124-135052333", "type": "article", "title": "The Engineering of Biology and Medicine", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Langer", "given_name": "Robert", "clpid": "Langer-Robert-M" } ], "abstract": "In celebration of the 100th Anniversary of PNAS, this Special Feature summarizes the enormous progress that has been made in the engineering of biology and medicine.", "doi": "10.1073/pnas.1517450112", "pmcid": "PMC4664332", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2015-11-24", "series_number": "47", "volume": "112", "issue": "47", "pages": "14423" }, { "id": "authors:q506h-w8524", "collection": "authors", "collection_id": "q506h-w8524", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160104-164055114", "type": "article", "title": "Facile Synthesis and Catalysis of Pure-Silica and Heteroatom LTA", "author": [ { "family_name": "Boal", "given_name": "Ben W.", "clpid": "Boal-B-W" }, { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-J-E" }, { "family_name": "Deimund", "given_name": "Mark A.", "clpid": "Deimund-M-A" }, { "family_name": "Deem", "given_name": "Michael W.", "clpid": "Deem-M-W" }, { "family_name": "Henling", "given_name": "Lawrence M.", "clpid": "Henling-L-M" }, { "family_name": "Brand", "given_name": "Stephen K.", "clpid": "Brand-S-K" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolite A (LTA) has many large-scale uses in separations and ion exchange applications. Because of the high aluminum content and lack of high-temperature stability, applications in catalysis, while highly desired, have been extremely limited. Herein, we report a robust method to prepare pure-silica, aluminosilicate (product Si/Al = 12\u201342), and titanosilicate LTA in fluoride media using a simple, imidazolium-based organic structure-directing agent. The aluminosilicate material is an active catalyst for the methanol-to-olefins reaction with higher product selectivities to butenes as well as C_5 and C_6 products than the commercialized silicoalumniophosphate or zeolite analogue that both have the chabazite framework (SAPO-34 and SSZ-13, respectively). The crystal structures of the as-made and calcined pure-silica materials were solved using single-crystal X-ray diffraction, providing information about the occluded organics and fluoride as well as structural information.", "doi": "10.1021/acs.chemmater.5b03579", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2015-11-24", "series_number": "22", "volume": "27", "issue": "22", "pages": "7774-7779" }, { "id": "authors:hf479-6sm06", "collection": "authors", "collection_id": "hf479-6sm06", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150325-074804965", "type": "article", "title": "Store-Operated Ca^(2+) Channels in Mesangial Cells Inhibit Matrix Protein Expression", "author": [ { "family_name": "Wu", "given_name": "Peiwen", "clpid": "Wu-Peiwen" }, { "family_name": "Wang", "given_name": "Yanxia", "clpid": "Wang-Yanxia" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Chaudhari", "given_name": "Sarika", "clpid": "Chaudhari-S" }, { "family_name": "Begg", "given_name": "Malcolm", "clpid": "Begg-M" }, { "family_name": "Ma", "given_name": "Rong", "clpid": "Ma-Rong" } ], "abstract": "Accumulation of extracellular matrix derived from glomerular mesangial cells is an early feature of diabetic nephropathy. Ca^(2+) signals mediated by store\u2013operated Ca^(2+) channels regulate protein production in a variety of cell types. The aim of this study was to determine the effect of store\u2013operated Ca^(2+) channels in mesangial cells on extracellular matrix protein expression. In cultured human mesangial cells, activation of store\u2013operated Ca^(2+) channels by thapsigargin significantly decreased fibronectin protein expression and collagen IV mRNA expression in a dose-dependent manner. Conversely, inhibition of the channels by 2-aminoethyl diphenylborinate significantly increased the expression of fibronectin and collagen IV. Similarly, overexpression of stromal interacting molecule 1 reduced, but knockdown of calcium release\u2013activated calcium channel protein 1 (Orai1) increased fibronectin protein expression. Furthermore, 2-aminoethyl diphenylborinate significantly augmented angiotensin II\u2013induced fibronectin protein expression, whereas thapsigargin abrogated high glucose\u2013 and TGF-\u03b21\u2013stimulated matrix protein expression. In vivo knockdown of Orai1 in mesangial cells of mice using a targeted nanoparticle siRNA delivery system resulted in increased expression of glomerular fibronectin and collagen IV, and mice showed significant mesangial expansion compared with controls. Similarly, in vivo knockdown of stromal interacting molecule 1 in mesangial cells by recombinant adeno\u2013associated virus\u2013encoded shRNA markedly increased collagen IV protein expression in renal cortex and caused mesangial expansion in rats. These results suggest that store\u2013operated Ca^(2+) channels in mesangial cells negatively regulate extracellular matrix protein expression in the kidney, which may serve as an endogenous renoprotective mechanism in diabetes.", "doi": "10.1681/ASN.2014090853", "pmcid": "PMC4625675", "issn": "1046-6673", "publisher": "American Society of Nephrology", "publication": "Journal of the American Society of Nephrology", "publication_date": "2015-11", "series_number": "11", "volume": "26", "issue": "11", "pages": "2691-2702" }, { "id": "authors:75v77-x6s40", "collection": "authors", "collection_id": "75v77-x6s40", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150922-110528268", "type": "article", "title": "Increased brain uptake of targeted nanoparticles by adding an acid-cleavable linkage between transferrin and the nanoparticle core", "author": [ { "family_name": "Clark", "given_name": "Andrew J.", "clpid": "Clark-Andrew-J" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Most therapeutic agents are excluded from entering the central nervous system by the blood\u2013brain barrier (BBB). Receptor mediated transcytosis (RMT) is a common mechanism used by proteins, including transferrin (Tf), to traverse the BBB. Here, we prepared Tf-containing, 80-nm gold nanoparticles with an acid-cleavable linkage between the Tf and the nanoparticle core to facilitate nanoparticle RMT across the BBB. These nanoparticles are designed to bind to Tf receptors (TfRs) with high avidity on the blood side of the BBB, but separate from their multidentate Tf\u2013TfR interactions upon acidification during the transcytosis process to allow release of the nanoparticle into the brain. These targeted nanoparticles show increased ability to cross an in vitro model of the BBB and, most important, enter the brain parenchyma of mice in greater amounts in vivo after systemic administration compared with similar high-avidity nanoparticles containing noncleavable Tf. In addition, we investigated this design with nanoparticles containing high-affinity antibodies (Abs) to TfR. With the Abs, the addition of the acid-cleavable linkage provided no improvement to in vivo brain uptake for Ab-containing nanoparticles, and overall brain uptake was decreased for all Ab-containing nanoparticles compared with Tf-containing ones. These results are consistent with recent reports of high-affinity anti-TfR Abs trafficking to the lysosome within BBB endothelium. In contrast, high-avidity, Tf-containing nanoparticles with the acid-cleavable linkage avoid major endothelium retention by shedding surface Tf during their transcytosis.", "doi": "10.1073/pnas.1517048112", "pmcid": "PMC4603510", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences", "publication_date": "2015-10-06", "series_number": "40", "volume": "112", "issue": "40", "pages": "12486-12491" }, { "id": "authors:6hmns-shd95", "collection": "authors", "collection_id": "6hmns-shd95", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150804-102104856", "type": "article", "title": "Synthesis of the RTH-type layer: the first small-pore, two dimensional layered zeolite precursor", "author": [ { "family_name": "Schmidt", "given_name": "Joel E.", "orcid": "0000-0002-0039-2863", "clpid": "Schmidt-Joel-E" }, { "family_name": "Xie", "given_name": "Dan", "orcid": "0000-0003-2467-976X", "clpid": "Xie-Dan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "There are several distinct two-dimensional zeolite building layers that can condense through different stacking arrangements of the layers to form various three-dimensional framework materials. All known building layers are dense layers in that they do not contain 8-membered ring (MR) or larger pores perpendicular to the two-dimensional layers. Herein, we report a new material (CIT-10) that consists of a two-dimensional layer (termed \"rth\" layer) that contains an 8 MR perpendicular to the layer. Calcination of CIT-10 forms pure-silica RTH (SSZ-50). CIT-10 can be pillared to form a new framework material with a three-dimensional pore system of 8 and 10 MRs, denoted CIT-11, that can be calcined to form a new microporous material, denoted CIT-12.", "doi": "10.1039/c5sc02325d", "pmcid": "PMC5950832", "issn": "2041-6520", "publisher": "Royal Society of Chemistry", "publication": "Chemical Science", "publication_date": "2015-10", "series_number": "10", "volume": "6", "issue": "10", "pages": "5955-5963" }, { "id": "authors:dsv28-1q023", "collection": "authors", "collection_id": "dsv28-1q023", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150914-125155730", "type": "article", "title": "Route to Renewable PET: Reaction Pathways and Energetics of Diels\u2013Alder and Dehydrative Aromatization Reactions Between Ethylene and Biomass-Derived Furans Catalyzed by Lewis Acid Molecular Sieves", "author": [ { "family_name": "Pacheco", "given_name": "Joshua J.", "clpid": "Pacheco-J-J" }, { "family_name": "Labinger", "given_name": "Jay A.", "orcid": "0000-0002-1942-9232", "clpid": "Labinger-J-A" }, { "family_name": "Sessions", "given_name": "Alex L.", "orcid": "0000-0001-6120-2763", "clpid": "Sessions-A-L" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Silica molecular sieves that have the zeolite beta topology and contain framework Lewis acid centers (e.g., Zr-\u03b2, Sn-\u03b2) are useful catalysts in the Diels\u2013Alder and dehydrative aromatization reactions between ethylene and various renewable furans for the production of biobased terephthalic acid precursors. Here, the main side products in the synthesis of methyl 4-(methoxymethyl)benzene carboxylate that are obtained by reacting ethylene with methyl 5-(methoxymethyl)-furan-2-carboxylate are identified, and an overall reaction pathway is proposed. Madon\u2013Boudart experiments using Zr-\u03b2 samples of varying Si/Zr ratios clearly indicate that there are no transport limitations to the rate of reaction for the synthesis of p-xylene from 2,5-dimethylfuran and ethylene and strongly suggest no mass transport limitations in the synthesis of methyl p-toluate from methyl 5-methyl-2-furoate and ethylene. Measured apparent activation energies for these reaction-limited systems are small (<10.5 kcal/mol), suggesting that apparent activation energies are derived from a collection of parameters and are not true activation energies for a single chemical step. In addition, 13C kinetic isotope effects (KIE) in the synthesis of MMBC and MPT measured by gas chromatography/isotope-ratio mass spectrometry in reactant-depletion experiments support the Madon\u2013Boudart result that these systems are not transport-limited and the KIE values agree with those previously reported for Diels\u2013Alder cycloadditions.", "doi": "10.1021/acscatal.5b01309", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2015-10", "series_number": "10", "volume": "5", "issue": "10", "pages": "5904-5913" }, { "id": "authors:prqmb-jj190", "collection": "authors", "collection_id": "prqmb-jj190", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150928-091254944", "type": "article", "title": "Methanol-to-Olefins Catalysis with Hydrothermally Treated Zeolite SSZ-39", "author": [ { "family_name": "Dusselier", "given_name": "Michiel", "orcid": "0000-0002-3074-2318", "clpid": "Dusselier-M" }, { "family_name": "Deimund", "given_name": "Mark A.", "clpid": "Deimund-M-A" }, { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-J-E" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolite SSZ-39 is evaluated for catalyzing the methanol-to-olefins (MTO) reaction. By steaming NH_4\u2013SSZ-39, Al can be removed from framework positions, resulting in an increase in framework-Si/AlT and thus a lowered active acid site density. The Si/Al_T ratios can be controlled by the steaming temperatures. SSZ-39 steamed at 750 \u00b0C, with preserved pore volume and morphology, is an excellent MTO catalyst, as high, stable olefin selectivities, long time-on-stream activity, and low alkane production are observed. Moreover, interesting propylene/ethylene/butylene ratios of 2.8/1/1.1 are obtained, likely related to the shape of the AEI cage. By Cu^(2+)-exchanging SSZ-39, evidence is provided to show that Al_T sites in close proximity (high AlT density) produce the unwanted effects (higher alkane-make and carbonaceous deposits) in nonsteamed materials during MTO.", "doi": "10.1021/acscatal.5b01577", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2015-10", "series_number": "10", "volume": "5", "issue": "10", "pages": "6078-6085" }, { "id": "authors:fek5r-34w58", "collection": "authors", "collection_id": "fek5r-34w58", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150917-135529579", "type": "article", "title": "Tandem catalysis for the production of alkyl lactates from ketohexoses at moderate temperatures", "author": [ { "family_name": "Orazov", "given_name": "Marat", "orcid": "0000-0003-1621-1331", "clpid": "Orazov-Marat" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Retro-aldol reactions have been implicated as the limiting steps in catalytic routes to convert biomass-derived hexoses and pentoses into valuable C_2, C_3, and C_4 products such as glycolic acid, lactic acid, 2-hydroxy-3-butenoic acid, 2,4-dihydroxybutanoic acid, and alkyl esters thereof. Due to a lack of efficient retro-aldol catalysts, most previous investigations of catalytic pathways involving these reactions were conducted at high temperatures (\u2265160 \u00b0C). Here, we report moderate-temperature (around 100 \u00b0C) retro-aldol reactions of various hexoses in aqueous and alcoholic media with catalysts traditionally known for their capacity to catalyze 1,2-intramolecular carbon shift (1,2-CS) reactions of aldoses, i.e., various molybdenum oxide and molybdate species, nickel(II) diamine complexes, alkali-exchanged stannosilicate molecular sieves, and amorphous TiO_2\u2013SiO_2 coprecipitates. Solid Lewis acid cocatalysts that are known to catalyze 1,2-intramolecular hydride shift (1,2-HS) reactions that enable the formation of \u03b1-hydroxy carboxylic acids from tetroses, trioses, and glycolaldehyde, but cannot readily catalyze retro-aldol reactions of hexoses and pentoses at these moderate temperatures, are shown to be compatible with the aforementioned retro-aldol catalysts. The combination of a distinct retro-aldol catalyst with a 1,2-HS catalyst enables lactic acid and alkyl lactate formation from ketohexoses at moderate temperatures (around 100 \u00b0C), with yields comparable to best-reported chemocatalytic examples at high temperature conditions (\u2265160 \u00b0C). The use of moderate temperatures enables numerous desirable features such as lower pressure and significantly less catalyst deactivation.", "doi": "10.1073/pnas.1516466112", "pmcid": "PMC4586831", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences", "publication_date": "2015-09-22", "series_number": "38", "volume": "112", "issue": "38", "pages": "11777-11782" }, { "id": "authors:vcyra-h3a24", "collection": "authors", "collection_id": "vcyra-h3a24", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150804-111519051", "type": "article", "title": "Self-Pillared, Single-Unit-Cell Sn-MFI Zeolite Nanosheets and Their Use for Glucose and Lactose Isomerization", "author": [ { "family_name": "Ren", "given_name": "Limin", "clpid": "Ren-Limin" }, { "family_name": "Guo", "given_name": "Qiang", "clpid": "Guo-Qiang" }, { "family_name": "Kumar", "given_name": "Prashant", "clpid": "Kumar-P" }, { "family_name": "Orazov", "given_name": "Marat", "clpid": "Orazov-M" }, { "family_name": "Xu", "given_name": "Dandan", "orcid": "0000-0002-0355-2906", "clpid": "Xu-Dandan" }, { "family_name": "Alhassan", "given_name": "Saeed M.", "clpid": "Alhassan-S-M" }, { "family_name": "Mkhoyan", "given_name": "K. Andre", "clpid": "Mkhoyan-K-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Tsapatsis", "given_name": "Michael", "orcid": "0000-0001-5610-3525", "clpid": "Tsapatsis-M" } ], "abstract": "Single-unit-cell Sn-MFI, with the detectable Sn uniformly distributed and exclusively located at framework sites, is reported for the first time. The direct, single-step, synthesis is based on repetitive branching caused by rotational intergrowths of single-unit-cell lamellae. The self-pillared, meso- and microporous zeolite is an active and selective catalyst for sugar isomerization. High yields for the conversion of glucose into fructose and lactose to lactulose are demonstrated.", "doi": "10.1002/anie.201505334", "issn": "1433-7851", "publisher": "Wiley", "publication": "Angewandte Chemie International Edition", "publication_date": "2015-09-07", "series_number": "37", "volume": "54", "issue": "37", "pages": "10848-10851" }, { "id": "authors:f4xx1-7sd16", "collection": "authors", "collection_id": "f4xx1-7sd16", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150910-091259402", "type": "patent", "title": "Click chemistry surface functionalization for resonant micro-cavity sensors", "author": [ { "family_name": "Armani", "given_name": "Andrea M.", "orcid": "0000-0001-9890-5104", "clpid": "Armani-Andrea-Martin" }, { "family_name": "Alabi", "given_name": "Akinleye C.", "clpid": "Alabi-A-C" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Flagan", "given_name": "Richard C.", "orcid": "0000-0001-5690-770X", "clpid": "Flagan-R-C" }, { "family_name": "Fraser", "given_name": "Scott E.", "orcid": "0000-0002-5377-0223", "clpid": "Fraser-S-E" } ], "abstract": "Micro-cavity resonant sensors have outer surfaces that are functionalized using click chemistry, e.g., involving a cycloaddition reaction of an alkyne functional group and an azide functional group. A first polymer linking element binds to an outer surface of the micro-cavity and has an azide functional group, which bonds to an alkyne functional group of a second polymer linking element as a result of a cycloaddition reaction. A functionalization element such as an antibody, antigen or protein for sensing a target molecule is bound to the second linking element.", "publisher": "U.S. Patent Office", "publication_date": "2015-08-25" }, { "id": "authors:ddv7t-rd879", "collection": "authors", "collection_id": "ddv7t-rd879", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150720-082143721", "type": "article", "title": "Cationic Mucic Acid Polymer-Based siRNA Delivery Systems", "author": [ { "family_name": "Pan", "given_name": "Dorothy W.", "clpid": "Pan-D-W" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Nanoparticle (NP) delivery systems for small interfering RNA (siRNA) that have good systemic circulation and high nucleic acid content are highly desired for translation into clinical use. Here, a family of cationic mucic acid-containing polymers is synthesized and shown to assemble with siRNA to form NPs. A cationic mucic acid polymer (cMAP) containing alternating mucic acid and charged monomers is synthesized. When combined with siRNA, cMAP forms NPs that require steric stabilization by poly(ethylene glycol) (PEG) that is attached to the NP surface via a 5-nitrophenylboronic acid linkage (5-nitrophenylboronic acid\u2013PEGm (5-nPBA\u2013PEGm)) to diols on mucic acid in the cMAP in order to inhibit aggregation in biological fluids. As an alternative, cMAP is covalently conjugated with PEG via two methods. First, a copolymer is prepared with alternating cMAP\u2013PEG units that can form loops of PEG on the surface of the formulated siRNA-containing NPs. Second, an mPEG\u2013cMAP\u2013PEGm triblock polymer is synthesized that could lead to a PEG brush configuration on the surface of the formulated siRNA-containing NPs. The copolymer and triblock polymer are able to form stable siRNA-containing NPs without and with the addition of 5-nPBA\u2013PEGm. Five formulations, (i) cMAP with 5-nPBA\u2013PEGm, (ii) cMAP\u2013PEG copolymer both (a) with and (b) without 5-nPBA\u2013PEGm, and (iii) mPEG\u2013cMAP\u2013PEGm triblock polymer both (a) with and (b) without 5-nPBA\u2013PEGm, are used to produce NPs in the 30\u201340 nm size range, and their circulation times are evaluated in mice using tail vein injections. The mPEG\u2013cMAP\u2013PEGm triblock polymer provides the siRNA-containing NP with the longest circulation time (5\u201310% of the formulation remains in circulation at 60 min postdosing), even when a portion of the excess cationic components used in the formulation is filtered away prior to injection. A NP formulation using the mPEG\u2013cMAP\u2013PEGm triblock polymer that is free of excess components could contain as much as ca. 30 wt % siRNA.", "doi": "10.1021/acs.bioconjchem.5b00324", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2015-08", "series_number": "8", "volume": "26", "issue": "8", "pages": "1791-1803" }, { "id": "authors:mhfme-gfk31", "collection": "authors", "collection_id": "mhfme-gfk31", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150701-133219784", "type": "article", "title": "Organic-Free Synthesis of CHA-Type Zeolite Catalysts for the Methanol-to-Olefins Reaction", "author": [ { "family_name": "Ji", "given_name": "Yuewei", "clpid": "Ji-Yuewei" }, { "family_name": "Deimund", "given_name": "Mark A.", "clpid": "Deimund-M-A" }, { "family_name": "Bhawe", "given_name": "Yashodhan", "clpid": "Bhawe-Y" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Chabazite (CHA)-type zeolites are prepared from the hydrothermal conversion of faujasite (FAU)-type zeolites, dealuminated by high-temperature steam treatments (500\u2013700 \u00b0C), and evaluated as catalysts for the methanol-to-olefins (MTO) reaction. The effects of temperature and partial pressure of water vapor during steaming are investigated. Powder X-ray diffraction (XRD) and Ar physisorption data show that the steam treatments cause partial structural collapse of the zeolite with the extent of degradation increasing with steaming temperature. ^(27)Al MAS NMR spectra of the steamed materials reveal the presence of tetrahedral, pentacoordinate, and octahedral aluminum. NH_3 and i-propylamine temperature-programmed desorption (TPD) demonstrate that steaming removes Br\u00f8nsted acid sites, while simultaneously introducing larger pores into the CHA materials that make the remaining acid sites more accessible. Acid washing the steamed CHA-type zeolites removes a significant portion of the extra-framework aluminum, producing an increase in the bulk Si/Al ratio as well as the adsorption volume. The proton form of the as-synthesized CHA (Si/Al = 2.4) rapidly deactivates when tested for MTO at a reaction temperature of 400 \u00b0C and atmospheric pressure. CHA samples steamed at 600 \u00b0C performed the best among the samples tested, showing increased olefin selectivities as well as catalyst lifetime compared to the unsteamed CHA. Both lifetime and C_2\u2013C_3 olefin selectivities are found to increase with increasing reaction temperature. At 450 \u00b0C, CHA steamed at 600 \u00b0C reached a combined C_2\u2013C_3 olefin selectivity of 74.2% at 100% methanol conversion, with conversion remaining above 80% for more than 130 min of time-on-stream (TOS) before deactivating. More stable time-on-stream behavior is observed for 600 \u00b0C-steamed CHA that underwent acid washing: conversion above 90% for more than 200 min of TOS at 450 \u00b0C with a maximum total C_2\u2013C_3 olefin selectivity of 71.4% at 100% conversion.", "doi": "10.1021/acscatal.5b00404", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2015-07", "series_number": "7", "volume": "5", "issue": "7", "pages": "4456-4465" }, { "id": "authors:ft6wz-6hd74", "collection": "authors", "collection_id": "ft6wz-6hd74", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150608-082630276", "type": "article", "title": "High-silica, heulandite-type zeolites prepared by direct synthesis and topotactic condensation", "author": [ { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-J-E" }, { "family_name": "Xie", "given_name": "Dan", "orcid": "0000-0003-2467-976X", "clpid": "Xie-Dan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "There are both natural minerals and synthetic zeolites that possess the HEU framework topology. These materials have a limited compositional range (Si/Al < 6), and the natural zeolites often contain a large amount of impurities such as Fe^(3+). The preparation of impurity-free HEU-type zeolites with higher Si/Al ratio could open many areas of application, particularly in catalysis. Here, we report the first high-silica HEU-type zeolite that can be prepared via two different procedures. In the first method high-silica HEU (denoted CIT-8) is prepared using a topotactic condensation mechanism (layered precursor denoted CIT-8P); CIT-8P is obtained from a low-water synthesis in fluoride media. CIT-8 prepared in this manner has a product Si/Al ratio of 9.8 \u00b1 0.7 and a micropore volume of 0.10 cm^3 g^(\u22121) (measured by nitrogen adsorption). The variable temperature powder X-ray diffraction shows that CIT-8 forms via topotactic condensation from CIT-8P along the b axis. Additionally, high-silica heulandite can be synthesized directly from a hydroxide-mediated reaction mixture (denoted CIT-8H), and has a Si/Al ratio of 6.4 \u00b1 0.3 and a micropore volume of 0.10 cm^3 g^(\u22121). Both synthesis methods produce zeolites that expand the compositional range of HEU-type zeolites. These synthetic methods allow for the addition of other heteroatoms, and titanium-containing CIT-8 is prepared as an illustrative example.", "doi": "10.1039/c5ta02354h", "issn": "2050-7488", "publisher": "Royal Society of Chemistry", "publication": "Journal of Materials Chemistry A", "publication_date": "2015-06-28", "series_number": "24", "volume": "3", "issue": "24", "pages": "12890-12897" }, { "id": "authors:ajk8w-75551", "collection": "authors", "collection_id": "ajk8w-75551", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150518-082421006", "type": "article", "title": "Synthesis of RTH-Type Zeolites Using a Diverse Library of Imidazolium Cations", "author": [ { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-J-E" }, { "family_name": "Deimund", "given_name": "Mark A.", "clpid": "Deimund-M-A" }, { "family_name": "Xie", "given_name": "Dan", "orcid": "0000-0003-2467-976X", "clpid": "Xie-Dan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "RTH-type zeolites are promising catalytic materials for applications that include the important methanol-to-olefins (MTO) and NO_x reduction reactions. Here, RTH-type zeolites are prepared using a wide-range of imidazolium-based, cationic organic structure directing agents (OSDAs), that greatly expand the methodologies and compositions that can be used to synthesize these materials. The abilities of the OSDAs to produce RTH-type zeolites agree well with results from molecular modeling studies of predicted stabilization energies of the OSDAs in the RTH framework. The RTH-type zeolites are stable to steaming up to 900 \u00b0C and are shown to be active MTO catalysts.", "doi": "10.1021/acs.chemmater.5b01003", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2015-05-26", "series_number": "10", "volume": "27", "issue": "10", "pages": "3756-3762" }, { "id": "authors:psaj4-k0752", "collection": "authors", "collection_id": "psaj4-k0752", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150420-092421971", "type": "article", "title": "Lack of in Vivo Antibody Dependent Cellular Cytotoxicity with Antibody Containing Gold Nanoparticles", "author": [ { "family_name": "Ahmed", "given_name": "Marya", "clpid": "Ahmed-Marya" }, { "family_name": "Pan", "given_name": "Dorothy W.", "clpid": "Pan-Dorothy-W" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Antibody-dependent cellular cytotoxicity (ADCC) is a cytolytic mechanism that can elicit in vivo antitumor effects and can play a significant role in the efficacy of antibody treatments for cancer. Here, we prepared cetuximab, panitumumab, and rituximab containing gold nanoparticles and investigated their ability to produce an ADCC effect in vivo. Cetuximab treatment of EGFR-expressing H1975 tumor xenografts showed significant tumor regression due to the ADCC activity of the antibody in vivo, while the control antibody, panitumumab, did not. However, all three antibody containing nanoparticles are not able to suppress tumor growth in the same in vivo mouse model. The antibody containing nanoparticles localized in the tumors and did not suppress the immune function of the animals, so the lack of tumor growth suppression of the cetuximab containing nanoparticle suggests that immobilizing antibodies onto a nanoparticle significantly decreases the ability of the antibody to promote an ADCC response.", "doi": "10.1021/acs.bioconjchem.5b00139", "pmcid": "PMC4445771", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2015-05", "series_number": "5", "volume": "26", "issue": "5", "pages": "812-816" }, { "id": "authors:qpyay-2bm23", "collection": "authors", "collection_id": "qpyay-2bm23", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150407-092610476", "type": "article", "title": "Upgrading Light Hydrocarbons: A Tandem Catalytic System for Alkane/Alkene Coupling", "author": [ { "family_name": "Labinger", "given_name": "Jay A.", "orcid": "0000-0002-1942-9232", "clpid": "Labinger-J-A" }, { "family_name": "Leitch", "given_name": "David C.", "clpid": "Leitch-D-C" }, { "family_name": "Bercaw", "given_name": "John E.", "clpid": "Bercaw-J-E" }, { "family_name": "Deimund", "given_name": "Mark A.", "clpid": "Deimund-M-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Light hydrocarbons, with relatively low fuel value, are abundant from several sources, including mixed alkane/alkene refinery byproduct streams. A tandem system consisting of a compatible combination of a homogeneous alkane dehydrogenation catalyst (known to be kinetically efficient but thermodynamically disfavored at low temperatures) with an olefin dimerization catalyst could effect the coupling of an alkane and alkene to produce a heavier, more valuable fuel molecule (C_nH_(2n+2) + CnH_(2n) = C_(2n)H_(4n+2)), a reaction that is thermodynamically favorable below 250 \u00b0C. We have demonstrated that coupling with a tandem homogeneous catalyst, consisting of a pincer-ligated iridium alkane dehydrogenation catalyst and an organometallic tantalum alkene dimerization catalyst; the combination couples 1-hexene/n-heptane to C_(13)/C_(14) products at temperatures ranging from 100 to 150 \u00b0C, operating with up to 90 % cooperativity. This particular combination generates alkene products rather than the desired alkanes, however, because the regioselectivity of the dimerization catalyst preferentially yields highly substituted alkenes that are not reactive towards hydrogen transfer. A complete cycle should be attainable by combining the dehydrogenation catalyst with an alternate dimerization catalyst that gives mostly linear and monosubstituted alkenes; we have synthesized a novel class of nickel-exchanged zincosilicates that exhibit the desired dimerization catalytic behavior.", "doi": "10.1007/s11244-015-0380-2", "issn": "1022-5528", "publisher": "Springer", "publication": "Topics in Catalysis", "publication_date": "2015-05", "series_number": "7-9", "volume": "58", "issue": "7-9", "pages": "494-501" }, { "id": "authors:ja3mg-qcx12", "collection": "authors", "collection_id": "ja3mg-qcx12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150515-114412556", "type": "article", "title": "The Effect of Adsorbed Molecule Gas-Phase Deprotonation Enthalpy on Ion Exchange in Sodium Exchanged Zeolites: An In Situ FTIR Investigation", "author": [ { "family_name": "Murphy", "given_name": "Brian", "clpid": "Murphy-B" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Xu", "given_name": "Bingjun", "orcid": "0000-0002-2303-257X", "clpid": "Xu-Bingjun" } ], "abstract": "Molecular-level understanding of the interactions between reactants and the surface of solid catalysts is of importance to the rational design of catalysts. Here, in situ transmission Fourier transform infrared spectroscopy is employed to investigate the ion exchange between the acidic hydrogen in organic molecules that have been adsorbed from the gas phase and sodium cations in zeolites. Organic compounds with functional groups common among key biomass-derived compounds are used as probe molecules. We demonstrate that ion exchange between acidic hydrogen in organic molecules and the sodium cations in zeolites with the FAU topology produces Br\u00f8nsted acid sites and the corresponding adsorbed salt species by identifying signature spectroscopic bands. Furthermore, the gas-phase deprotonation enthalpy (GPDE) of the organic compounds is identified as a key descriptor in determining the feasibility and extent of the exchange process. Molecules with GPDE below 1462 kJ/mol, e.g., m-cresol (1462 kJ/mol), propanoic acid (1454), acetic acid (1457), acrylic acid (1440) and trifluoroacetic acid (1357), show clear vibrational bands for Br\u00f8nsted acid sites and the corresponding sodium salts, while molecules with higher GPDE, such as trifluoroethanol (1513), ethanol (1586), and water (1622) do not. These data indicate that the degree of dissociation of the acidic hydrogen is a key element in the ion exchange. The generality of this process in zeolites is established by the observation of similar results on zeolites with differing topologies (FAU, MFI, *BEA, and MOR).", "doi": "10.1007/s11244-015-0383-z", "issn": "1022-5528", "publisher": "Springer", "publication": "Topics in Catalysis", "publication_date": "2015-05", "series_number": "7-9", "volume": "58", "issue": "7-9", "pages": "393-404" }, { "id": "authors:48z0q-r3t07", "collection": "authors", "collection_id": "48z0q-r3t07", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150406-150811375", "type": "article", "title": "Heterogeneous Catalysis for the Conversion of Sugars into Polymers", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The synthesis of commodity polymers from biomass presents interesting challenges and opportunities for new catalytic chemistries. Starting from glucose, reaction pathways to a variety of monomers for commodity polymers are presented. The first step for each pathway is the isomerization of glucose to fructose. This reaction can now be accomplished in aqueous media with hydrophobic, large pore molecular sieves that contain Lewis acid sites as catalysts. A typical catalyst is a pure-silica molecular sieve having the zeolite beta topology and containing a small amount of framework Sn^(4+) (Sn-Beta). Dehydration of fructose into 5-hydroxymethylfurfural (HMF) provides a convenient path that can lead to 2,5-furandicarboxylic acid (FDCA) for the synthesis of polyethylene furanoate (PEF) or purified terephthalic acid (PTA) (via Diels\u2013Alder reactions) for the synthesis of polyethylene terephthalate (PET). Recent progress on the dehydration of lactic acid could open new routes to acrylic acid and acrylonitrile that are used to produce polyacrylic acid and polyacrylonitrile, respectively, provided more selective catalysts for the retro-aldol deconstruction of fructose are developed.", "doi": "10.1007/s11244-015-0386-9", "issn": "1022-5528", "publisher": "Springer", "publication": "Topics in Catalysis", "publication_date": "2015-05", "series_number": "7-9", "volume": "58", "issue": "7-9", "pages": "405-409" }, { "id": "authors:6q0ed-brg58", "collection": "authors", "collection_id": "6q0ed-brg58", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150407-102201459", "type": "article", "title": "Solid State NMR Characterization of Sn-Beta Zeolites that Catalyze Glucose Isomerization and Epimerization", "author": [ { "family_name": "Hwang", "given_name": "Son-Jong", "orcid": "0000-0002-3210-466X", "clpid": "Hwang-Son-Jong" }, { "family_name": "Gounder", "given_name": "Rajamani", "orcid": "0000-0003-1347-534X", "clpid": "Gounder-R" }, { "family_name": "Bhawe", "given_name": "Yashodhan", "clpid": "Bhawe-Y" }, { "family_name": "Orazov", "given_name": "Marat", "clpid": "Orazov-M" }, { "family_name": "Bermejo-Deval", "given_name": "Ricardo", "clpid": "Bermejo-Deval-R" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "High resolution, multi-nuclear solid state nuclear magnetic resonance (NMR) characterizations are carried out in order to obtain insights into the structural features of Sn-beta zeolites that catalyze glucose isomerization or epimerization reactions in water and methanol solvents. In particular, we focus on investigating the local structural changes to catalytically-active framework Sn sites of different ^(119)Sn-labeled beta zeolites, including the calcined, dehydrated, rehydrated, and post-sugar isomerization catalysis forms. Magic angle spinning (MAS) and cross polarization MAS (either from ^1H or ^(19)F) ^(119)Sn NMR spectra provide evidence for changes to the local framework Sn coordination in the presence of water and sugar molecules, and provide insights into structural features of adsorbed intermediates that may be relevant in sugar isomerization reaction pathways.", "doi": "10.1007/s11244-015-0388-7", "issn": "1022-5528", "publisher": "Springer", "publication": "Topics in Catalysis", "publication_date": "2015-05", "series_number": "7-9", "volume": "58", "issue": "7-9", "pages": "435-440" }, { "id": "authors:paadr-9s978", "collection": "authors", "collection_id": "paadr-9s978", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150217-083232800", "type": "article", "title": "Triptycene Structure-Directing Agents in Aluminophosphate Synthesis", "author": [ { "family_name": "Boal", "given_name": "Ben W.", "clpid": "Boal-B-W" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The synthesis of aluminophosphates is investigated using a number of triptycene-based organic structure-directing agents (OSDA). These OSDAs are designed to synthesize extra-large pore and/or large cavity-containing molecular sieves. Starting from the hydrophobic triptycene molecule, OSDAs are prepared by introducing three amine-based centers that can be charged either by protonation in the acidic aluminophosphate reaction media or through quaternization. VPI-5 is synthesized using these tripytycene OSDAs, and the OSDAs are occluded inside the pores. This synthesis marks the first time VPI-5 has been made as a single phase with an OSDA occluded inside the framework of the as-made material that is not removed by simple washing with water or other solvents. Additionally, several other aluminophosphates with unknown structures are synthesized using these new OSDAs.", "doi": "10.1016/j.micromeso.2015.01.045", "issn": "1387-1811", "publisher": "Elsevier", "publication": "Microporous and Mesoporous Materials", "publication_date": "2015-05", "volume": "208", "pages": "203-211" }, { "id": "authors:5ee65-4ab04", "collection": "authors", "collection_id": "5ee65-4ab04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150406-092346931", "type": "article", "title": "Effect of Pore and Cage Size on the Formation of Aromatic Intermediates During the Methanol-to-Olefins Reaction", "author": [ { "family_name": "Deimund", "given_name": "Mark A.", "clpid": "Deimund-M-A" }, { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-J-E" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Six eight-membered-ring (8MR), microporous materials are synthesized and evaluated as catalysts for the methanol-to-olefins (MTO) reaction. The molecular sieves SSZ-13, SAPO-34, SAPO-39, MCM-35, ERS-7 and RUB-37 are investigated since they have 8MR access to the crystal interior but have differences in pore structure and cage size. The polymethylbenzene species that are the proposed reaction intermediates of the MTO reaction should only be able to form in materials with intra-molecular sieve void spaces of sufficient size to accommodate them. Thus, it is hypothesized that 8MR materials without adequately large pores or cages will be inactive for the MTO reaction. SSZ-13 and SAPO-34 (both with CHA framework topology) have interconnected 3-dimensional pore-and-cage systems sufficiently large for formation of the proposed reaction intermediates, while the other 8MR materials have intra-molecular sieve void spaces that are too small to allow formation of these species. The molecular sieves are tested as MTO catalysts at 400 \u00b0C, and only the molecular sieves with the CHA topology show MTO activity. Post-reaction analysis of the organic content of each solid material is accomplished by HF acid digestion with subsequent 1^H NMR analysis of the extracted hydrocarbon products to confirm the presence of aromatics in the 8MR materials with sufficiently large cages (those with CHA topology), and absence with materials that have smaller void spaces. These data provide further support for the necessity of polymethylbenzene species in the hydrocarbon pool for MTO activity.", "doi": "10.1007/s11244-015-0384-y", "issn": "1022-5528", "publisher": "Springer", "publication": "Topics in Catalysis", "publication_date": "2015-05", "series_number": "7-9", "volume": "58", "issue": "7-9", "pages": "416-423" }, { "id": "authors:b05ph-y7t59", "collection": "authors", "collection_id": "b05ph-y7t59", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150522-091501083", "type": "article", "title": "Influence of Organic Structure Directing Agent Isomer Distribution on the Synthesis of SSZ-39", "author": [ { "family_name": "Dusselier", "given_name": "Michiel", "orcid": "0000-0002-3074-2318", "clpid": "Dusselier-M" }, { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-J-E" }, { "family_name": "Moulton", "given_name": "Roger", "clpid": "Moulton-R" }, { "family_name": "Haymore", "given_name": "Barry", "clpid": "Haymore-B-L" }, { "family_name": "Hellums", "given_name": "Mark", "clpid": "Hellums-M" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The aluminosilicate molecular sieve with the AEI framework topology (SSZ-39) is currently of great interest for use in a number of important applications such as exhaust gas NO_x reduction and the methanol-to-olefins reaction. It is likely that advances in the synthesis of this molecular sieve will be needed for applications to proceed. Here, dimethylpiperidine based organic structure directing agents (OSDAs) are used to prepare SSZ-39, and the influence of diastereo- and structural isomeric mixtures on the synthesis of SSZ-39 is reported. Although differences in the rates of molecular sieve formation as well as preferential isomer incorporation occur, the synthesis of SSZ-39 is possible over a wide range of isomeric mixtures. These findings demonstrate that the synthesis of SSZ-39 can be accomplished with OSDA isomer mixtures that naturally occur from the synthesis of the organic precursors used to prepare the OSDAs.", "doi": "10.1021/acs.chemmater.5b00651", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2015-04-14", "series_number": "7", "volume": "27", "issue": "7", "pages": "2695-2702" }, { "id": "authors:9xs0d-90s44", "collection": "authors", "collection_id": "9xs0d-90s44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150421-094418904", "type": "article", "title": "Location of Ge and extra-framework species in the zeolite ITQ-24", "author": [ { "family_name": "Pinar", "given_name": "A. B.", "clpid": "Pinar-A-B" }, { "family_name": "McCusker", "given_name": "L. B.", "clpid": "McCusker-L-B" }, { "family_name": "Baerlocher", "given_name": "C.", "clpid": "Baerlocher-C" }, { "family_name": "Schmidt", "given_name": "J.", "clpid": "Schmidt-J" }, { "family_name": "Hwang", "given_name": "S.-J.", "orcid": "0000-0002-3210-466X", "clpid": "Hwang-Son-Jong" }, { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Zones", "given_name": "S. I.", "clpid": "Zones-S-I" } ], "abstract": "The germanosilicate ITQ-24 (IWR framework type) was synthesized in fluoride medium using 1,3,5-tris(1,2-dimethylimidazolium) benzene as the structure directing agent (SDA). A structure analysis of the as-synthesized ITQ-24 material using synchrotron powder diffraction data and difference electron density calculations have allowed the fluoride ions and the germanium atoms to be located and the conformation of the SDA to be determined. The benzyl ring is perpendicular to the b axis with the three imidazolium moieties forming a \"T-shaped\" arrangement. Ge atoms replace some of the Si in the double-4-ring (d4r) and in one of the single-4-rings (s4r). The other s4r contains only Si. Fluoride ions are in the d4r units. Initially, the space group Cmmm (highest possible symmetry) was assumed, but the framework geometry was strained. An independent evaluation of the symmetry using the powder charge flipping algorithm in Superflip led to a successful refinement with reasonable geometry and a refined composition of |[(C_6H_3)(C_7H_(10)N_2)_3]_2F_2|[Si_(40.2)Ge_(15.8)O_(112)] in the space group Pban.", "doi": "10.1039/C4DT03831B", "issn": "1477-9226", "publisher": "Royal Society of Chemistry", "publication": "Dalton Transactions", "publication_date": "2015-04-07", "series_number": "13", "volume": "44", "issue": "13", "pages": "6288-6295" }, { "id": "authors:k794a-sv217", "collection": "authors", "collection_id": "k794a-sv217", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150311-084546625", "type": "article", "title": "siRNA Delivery to the Glomerular Mesangium Using Polycationic Cyclodextrin Nanoparticles Containing siRNA", "author": [ { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Gale", "given_name": "Aaron", "clpid": "Gale-A" }, { "family_name": "Wu", "given_name": "Peiwen", "clpid": "Wu-Peiwen" }, { "family_name": "Ma", "given_name": "Rong", "clpid": "Ma-Rong" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "There is an urgent need for new therapies that can halt or reverse the course of chronic kidney disease with minimal side-effect burden on the patient. Small interfering RNA (siRNA) nanoparticles are new therapeutic entities in clinical development that could be useful for chronic kidney disease treatment because they combine the tissue-specific targeting properties of nanoparticles with the gene-specific silencing effects of siRNA. Recent reports have emerged demonstrating that the kidney, specifically the glomerulus, is a readily accessible site for nanoparticle targeting. Here, we explore the hypothesis that intravenously administered polycationic cyclodextrin nanoparticles containing siRNA (siRNA/CDP-NPs) can be used for delivery of siRNA to the glomerular mesangium. We demonstrate that siRNA/CDP-NPs localize to the glomerular mesangium with limited deposition in other areas of the kidney after intravenous injection. Additionally, we report that both mouse and human mesangial cells rapidly internalize siRNA/CDP-NPs in vitro and that nanoparticle uptake can be enhanced by attaching the targeting ligands mannose or transferrin to the nanoparticle surface. Lastly, we show knockdown of mesangial enhanced green fluorescent protein expression in a reporter mouse strain following iv treatment with siRNA/CDP-NPs. Altogether, these data demonstrate the feasibility of mesangial targeting using intravenously administered siRNA/CDP-NPs.", "doi": "10.1089/nat.2014.0505", "issn": "2159-3337", "publisher": "Mary Ann Liebert, Inc.", "publication": "Nucleic Acid Therapeutics", "publication_date": "2015-04-01", "series_number": "2", "volume": "25", "issue": "2", "pages": "53-64" }, { "id": "authors:7vbg0-3sf32", "collection": "authors", "collection_id": "7vbg0-3sf32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150202-095824189", "type": "article", "title": "CIT-7, a crystalline, molecular sieve with pores bounded by 8 and 10-membered rings", "author": [ { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-Joel-E" }, { "family_name": "Xie", "given_name": "Dan", "orcid": "0000-0003-2467-976X", "clpid": "Xie-Dan" }, { "family_name": "Rea", "given_name": "Thomas", "clpid": "Rea-Thomas" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A new crystalline molecular sieve, denoted CIT-7, is synthesized using an imidazolium-based diquaternary organic structure directing agent (OSDA). The framework structure is determined from a combination of rotation electron diffraction and synchrotron X-ray powder diffraction data. The structure has 10 crystallographically unique tetrahedral atoms (T-atoms) in the unit cell, and can be described as an ordered arrangement of the [4^(2)5^(4)6^(2)] mtw building unit and a previously unreported [4^(4)5^(2)] building unit. The framework contains a 2-dimensional pore system that is bounded by 10 T-atom rings (10-ring, 5.1 \u00c5 \u00d7 6.2 \u00c5 opening) that are connected with oval 8-rings (2.9 \u00c5 \u00d7 5.5 \u00c5 opening) through medium-sized cavities (~7.9 \u00c5) at the channel intersections. CIT-7 can be synthesized over a broad range of compositions including pure-silica and heteroatom, e.g., aluminosilicate and titanosilicate, containing variants.", "doi": "10.1039/C4SC03935A", "pmcid": "PMC5643978", "issn": "2041-6520", "publisher": "Royal Society of Chemistry", "publication": "Chemical Science", "publication_date": "2015-03-01", "series_number": "3", "volume": "6", "issue": "3", "pages": "1728-1734" }, { "id": "authors:3qkf9-9rc78", "collection": "authors", "collection_id": "3qkf9-9rc78", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150911-154803951", "type": "article", "title": "Nanoparticle therapeutics: from concept to clinic", "author": [ { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "We have translated two nanoparticle-based therapeutics into the clinic for\nuse as cancer therapeutics. These nanoparticles have been investigated in ca.\n10 clinical trials. I will describe how we translated these nanoparticles from\nthe laboratory at Caltech into clinical therapeutics. Lessons learned from\nthese translational and clinical experiences are accelerating our current\ntranslational efforts with nanoparticle-based therapeutics for cancer.", "doi": "10.2967/jnm565abs", "issn": "0161-5505", "publisher": "Society of Nuclear Medicine", "publication": "Journal of Nuclear Medicine", "publication_date": "2015-02", "series_number": "Suppl. 2", "volume": "56", "issue": "Suppl. 2", "pages": "23-24" }, { "id": "authors:3tk28-7p513", "collection": "authors", "collection_id": "3tk28-7p513", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141215-084344336", "type": "article", "title": "Facile Preparation of Aluminosilicate RTH across a Wide Composition Range Using a New Organic Structure-Directing Agent", "author": [ { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-J-E" }, { "family_name": "Deimund", "given_name": "Mark A.", "clpid": "Deimund-M-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "RTH type zeolite (aluminosilicate) is a potentially useful catalytic material that is limited by the inability to easily prepare the material over a wide composition range. Here, we report the use of pentamethylimidazolium to prepare aluminosilicate RTH across a wide range of compositions in both fluoride and hydroxide inorganic systems. RTH type zeolites are crystallized with a calcined product Si/Al of 7\u201327 from fluoride media and 6\u201359 from hydroxide media. The use of this new, simple organic structure-directing agent that can be prepared in one step allows for dramatic improvement in the compositional space where aluminosilicate RTH can be formed. RTH is tested as a catalyst for the methanol-to-olefins reaction and at complete conversion shows a high propylene/ethylene ratio of 3.9 at a propylene selectivity of 43%.", "doi": "10.1021/cm503625u", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2014-12-23", "series_number": "24", "volume": "26", "issue": "24", "pages": "7099-7105" }, { "id": "authors:81qrk-j5n58", "collection": "authors", "collection_id": "81qrk-j5n58", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140915-074106006", "type": "article", "title": "The synthesis of aluminophosphate and germanosilicate LTA using a triquaternary structure directing agent", "author": [ { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-J-E" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Xie", "given_name": "Dan", "clpid": "Xie-D" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The use of triquaternary organic structure directing agents (OSDAs) for the synthesis of microporous materials is relatively unexplored. Here a triquaternary OSDA prepared by reacting 1,2-dimethylimidazole with 1,3,5-tris(bromomethyl)benzene promotes the formation of LTA in the aluminophosphate or germanosilicate reaction chemistries.", "doi": "10.1016/j.micromeso.2014.08.051", "issn": "1387-1811", "publisher": "Elsevier", "publication": "Microporous and Mesoporous Materials", "publication_date": "2014-12", "volume": "200", "pages": "132-139" }, { "id": "authors:4h52v-5qd46", "collection": "authors", "collection_id": "4h52v-5qd46", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141027-132313969", "type": "article", "title": "Nickel-Exchanged Zincosilicate Catalysts for the Oligomerization of Propylene", "author": [ { "family_name": "Deimund", "given_name": "Mark A.", "clpid": "Deimund-M-A" }, { "family_name": "Labinger", "given_name": "Jay", "orcid": "0000-0002-1942-9232", "clpid": "Labinger-J-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Two nickel-containing zincosilicates (Ni-CIT-6 and Ni\u2013Zn-MCM-41) and two nickel-containing aluminosilicates (Ni-HiAl-BEA and Ni-USY) are synthesized and used as catalysts to oligomerize propylene into C_(3n) (C_6 and C_9) products. Both Ni-CIT-6 and Ni-HiAl-BEA have the *BEA topology and are investigated to assess the effects of framework zinc versus aluminum because the former gives two framework charges per atom, whereas the latter, only one. Ni-CIT-6 and Ni\u2013Zn-MCM-41 enable the comparison of a microporous to a mesoporous zincosilicate. Ni^2+ ion-exchanged into zeolite Y has been previously reported to oligomerize propylene and is used here for comparison. Reaction data are obtained at 180 and 250 \u00b0C, atmospheric pressure, and WHSV = 1.0 h^\u20131 in a feed stream of 85 mol % propylene (in inert). At these conditions, all catalysts are capable of oligomerizing propylene with steady-state conversions ranging from 3 to 16%. With the exception of Ni-HiAl-BEA, all catalysts have higher propylene conversions at 250 \u00b0C than at 180 \u00b0C. Both *BEA materials exhibit similar propylene conversions at each temperature, but Ni-HiAl-BEA is not as selective to C_3n products as Ni-CIT-6. Zincosilicates demonstrate higher average selectivities to C_3n products than the aluminosilicates at both reaction temperatures tested. Hexene products other than those expected by simple oligomerization are present, likely formed by double-bond isomerization catalyzed at acid sites. Additionally, both of the aluminosilicate materials catalyzed cracking reactions, forming non-C_3n products. The reduced acidity of the zincosilicates relative to the aluminosilicates likely accounts for higher C_(3n) product selectivity of the zincosilicates. Zincosilicates also exhibited higher linear-to-branched hexene isomer ratios (typically 1.0\u20131.5) when compared with the aluminosilicates, which had ratios on the order of 0.3. The mesoporous zincosilicate shows the best reaction behavior (including C_(3n) product selectivity: \u223c99% at both temperatures for Ni\u2013Zn-MCM-41) of the catalytic materials tested here.", "doi": "10.1021/cs501313z", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2014-11", "series_number": "11", "volume": "4", "issue": "11", "pages": "4189-4195" }, { "id": "authors:acnz7-pjg54", "collection": "authors", "collection_id": "acnz7-pjg54", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141113-125440628", "type": "article", "title": "Challenges of and Insights into Acid-Catalyzed Transformations of Sugars", "author": [ { "family_name": "Caratzoulas", "given_name": "Stavros", "clpid": "Caratzoulas-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Gorte", "given_name": "Raymond J.", "clpid": "Gorte-R-J" }, { "family_name": "Gounder", "given_name": "Rajamani", "orcid": "0000-0003-1347-534X", "clpid": "Gounder-R" }, { "family_name": "Lobo", "given_name": "Raul F.", "clpid": "Lobo-R-F" }, { "family_name": "Nikolakis", "given_name": "Vladimiros", "clpid": "Nikolakis-V" }, { "family_name": "Sandler", "given_name": "Stanley I.", "clpid": "Sandler-S-I" }, { "family_name": "Snyder", "given_name": "Mark A.", "clpid": "Snyder-M-A" }, { "family_name": "Tsapatsis", "given_name": "Michael", "orcid": "0000-0001-5610-3525", "clpid": "Tsapatsis-M" }, { "family_name": "Vlachos", "given_name": "Dionisios G.", "clpid": "Vlachos-D-G" } ], "abstract": "The selective transformation of hexose and pentose sugars to intermediate platform chemicals, such as furans, is an essential step in the conversion of cellulosic and hemicellulosic biomass to biofuels and biochemicals. Yet, many challenges in achieving commercially viable processes remain. In this feature article, we outline challenges that need to be overcome to enable these transformations. Then, we present the newly introduced acid-catalyzed isomerization of aldose sugars to ketose sugars via a class of solid Lewis acid catalysts (e.g., Sn-Beta, Ti-Beta). We elucidate mechanistic insights arising from subnanometer cooperativity and solvent effects that can be controlled to tune reaction pathways and selectivity and draw parallels between heterogeneous and homogeneous Lewis acid catalysts. Subsequently, we discuss fructose dehydration to 5-hydroxyl-methylfurfural (HMF) via homogeneous and heterogeneous Br\u00f8nsted acid-catalyzed chemistry. We show how fundamental insights arising from the combination of kinetics, spectroscopy, and multiscale simulations rationalize the improved yield of HMF in water\u2013organic cosolvents. The stability of heterogeneous Lewis acid catalysts under low pH enables tandem Br\u00f8nsted and Lewis acid-catalyzed reactions in a single pot that overcomes equilibrium limitations and gives a high HMF yield starting from sugar raw materials. Additionally, we provide an overview of multicomponent adsorption of biomass derivatives from solution in microporous materials and discuss how structure\u2013property relations can lead to superior micro- and micromesoporous carbon adsorbents for reactive adsorption toward high HMF yield. Finally, we provide an outlook for the field.", "doi": "10.1021/jp504358d", "issn": "1932-7447", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry C", "publication_date": "2014-10-09", "series_number": "40", "volume": "118", "issue": "40", "pages": "22815-22833" }, { "id": "authors:xvzrb-ncb60", "collection": "authors", "collection_id": "xvzrb-ncb60", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150604-145539780", "type": "article", "title": "Antitumor effects of an antibody (cetuximab)-targeted nanoparticle containing siRNA against EGFR", "author": [ { "family_name": "Pan", "given_name": "Dorothy W.", "clpid": "Pan-D-W" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Objective: Effective therapies for lung cancer that have mutated EGFR remain elusive. Because of the success of antibody-drug-conjugates, we are exploring the use of antibody targeted nanoparticles (NP) containing siRNA to produce multifunctional therapeutics. Here, we investigate the use of cetuximab (CTX) (commercial antibody to EGFR) targeted NPs containing siRNA against EGFR (sequence is for a region of the mRNA conserved in all types of mutations) in H1975 NSCLC xenografts. \nMethods: We synthesized a cationic mucic acid polymer by polymerizing a derivative of mucic acid, mucic acid ethylenediamine, with dimethyl suberimidate. This polycation can self-assemble with siRNA to form the NP. A methoxy polyethylene glycol (PEG) was modified to have a 5-nitrophenyl boronic acid (5-nPBA) moiety at one end to attach to diol groups on mucic acid and stabilize the NP. 5-nPBA-PEG with a carboxylic acid end group was conjugated to CTX to target the NP to EGFR receptors on the surface of cancer cells. These polymers were mixed with siRNA to form NPs, characterized by dynamic light scattering and cryo-transmission electron microscopy for size, and zeta potential measurements for surface charge. The NP was tested in vivo against tumors grown with H1975 NSCLC cells that contain the L858R and T790M mutations. NPs dosed iv (tail vein) at 9.3 mg/kg CTX targeting agent and 5 mg/kg siEGFR were injected twice a week for two weeks into nude mice with H1975 NSCLC xenografts and the anti-tumor effects compared to 9.3 mg/kg CTX (dosed iv tail vein) alone. \nResults: The CTX-targeted cMAP-siRNA NPs are ca. 40 nm in diameter as determined by both dynamic light scattering and cryo-TEM. The NPs' surface charge is slightly negative at -3.5 mV in 10 mM phosphate buffered at pH 7.4 (surrogate for extracellular conditions in vivo). When the NPs are in 1 mM KCl at pH 5.5 (surrogate for intracellular, endocytosis localization), the NP zeta potential is +1 mV indicating detachment of 5-nPBA-PEG from the NP at acidic pH. Thus, the NP is stabilized and targeted until it is endocytosed, where it disassembles to release the siRNA payload. We confirmed delivery of siEGFR to the tumor following two NP doses via a real-time PCR assay. In contrast to CTX treated mice that showed tumor growth delay but ultimately had tumors that grew to over 1000 mm^3, NP treated mice had tumors that remained below 200 mm^3 53 days following completion of 4 doses. \nConclusions: NPs containing full antibodies as targeting agents and siRNA payloads can be formulated into well defined, stable experimental therapeutics. The NP system used here has a pH-tunable 5-nPBA that allows for targeting and stabilizing the NP at a physiologic pH of 7.4. The targeting agent and PEG coating is able to detach from the NP at acidic pH like those found in endosomes, enabling the siRNA payload to escape and reach its site of action within the cell. These NPs produce significant tumor regression in vivo that is superior to CTX alone.", "doi": "10.1158/1538-7445.AM2014-4571", "issn": "0008-5472", "publisher": "American Association for Cancer Research", "publication": "Cancer Research", "publication_date": "2014-10-01", "series_number": "19 Suppleme", "volume": "74", "issue": "19 Suppleme", "pages": "Art. No. 4571" }, { "id": "authors:4cy38-zqt52", "collection": "authors", "collection_id": "4cy38-zqt52", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140505-152718789", "type": "article", "title": "Pharmacodynamic and Pharmacogenomic study of the nanoparticle conjugate of camptothecin CRLX101 for the treatment of cancer", "author": [ { "family_name": "Gaur", "given_name": "Shikha", "clpid": "Gaur-S" }, { "family_name": "Wang", "given_name": "Yafan", "clpid": "Wang-Yafan" }, { "family_name": "Kretzner", "given_name": "Leo", "clpid": "Kretzner-L" }, { "family_name": "Chen", "given_name": "Linling", "clpid": "Chen-Linling" }, { "family_name": "Yen", "given_name": "Terence", "clpid": "Yen-Terence" }, { "family_name": "Wu", "given_name": "Xiwei", "clpid": "Wu-Xiwei" }, { "family_name": "Yuan", "given_name": "Yate-Ching", "clpid": "Yuan-Yate-Ching" }, { "family_name": "Davis", "given_name": "Mark", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Yen", "given_name": "Yun", "orcid": "0000-0003-0815-412X", "clpid": "Yen-Yun" } ], "abstract": "CRLX101 is a nanopharmaceutical consisting of cyclodextrin-based polymer molecule and camptothecin. The CRLX101 nanoparticle is designed to concentrate and slowly release camptothecin in tumors over an extended period of time. Tumor biopsy and blood samples collected from patients with advanced solid malignancies before and after CRLX101 treatment are subjected to immunohistochemistry and pharmacogenomics. The expression of Topoisomerase-1, Ki-67, CaIX, CD31 and VEGF decreased after CRLX101 treatment. The expressions of these proteins are inversely proportional with survival duration of the patients. The Drug Metabolism Enzymes and Transporters (DMET) array shows an allele frequency in patients similar to global populations with none of the SNPs associated with toxicity. The results suggest that the observed lower toxicity is not likely be due to different genotypes in SNPs. CRLX101 demonstrates a promising anti-tumor activity in heavily pre-treated or treatment-refractory solid tumor malignancies presumably by inhibition of proliferation and angiogenesis correlating with tumor growth inhibition.", "doi": "10.1016/j.nano.2014.04.003", "issn": "1549-9634", "publisher": "Elsevier", "publication": "Nanomedicine-Nanotechnology Biology and Medicine", "publication_date": "2014-10", "series_number": "7", "volume": "10", "issue": "7", "pages": "1477-1486" }, { "id": "authors:pgxj4-8z757", "collection": "authors", "collection_id": "pgxj4-8z757", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140717-114522722", "type": "article", "title": "Correlating animal and human phase Ia/Ib clinical data with CALAA-01, a targeted, polymer-based nanoparticle containing siRNA", "author": [ { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Gritli", "given_name": "Ismael", "clpid": "Gritli-I" }, { "family_name": "Tolcher", "given_name": "Anthony", "clpid": "Tolcher-A" }, { "family_name": "Heidel", "given_name": "Jeremy D.", "clpid": "Heidel-J-D" }, { "family_name": "Lim", "given_name": "Dean", "clpid": "Lim-Dean" }, { "family_name": "Morgan", "given_name": "Robert", "clpid": "Morgan-R" }, { "family_name": "Chmielowski", "given_name": "Bartosz", "clpid": "Chmielowski-Bartosz" }, { "family_name": "Ribas", "given_name": "Antoni", "clpid": "Ribas-Antoni" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Yen", "given_name": "Yun", "orcid": "0000-0003-0815-412X", "clpid": "Yen-Yun" } ], "abstract": "Nanoparticle-based experimental therapeutics are currently being\ninvestigated in numerous human clinical trials. CALAA-01 is a targeted,\npolymer-based nanoparticle containing small interfering\nRNA (siRNA) and, to our knowledge, was the first RNA interference\n(RNAi)\u2013based, experimental therapeutic to be administered\nto cancer patients. Here, we report the results from the initial\nphase I clinical trial where 24 patients with different cancers were\ntreated with CALAA-01 and compare those results to data obtained\nfrom multispecies animal studies to provide a detailed example\nof translating this class of nanoparticles from animals to\nhumans. The pharmacokinetics of CALAA-01 in mice, rats, monkeys,\nand humans show fast elimination and reveal that the maximum\nconcentration obtained in the blood after i.v. administration\ncorrelates with body weight across all species. The safety profile of\nCALAA-01 in animals is similarly obtained in humans except that\nanimal kidney toxicities are not observed in humans; this could be\ndue to the use of a predosing hydration protocol used in the clinic.\nTaken in total, the animal models do appear to predict the behavior\nof CALAA-01 in humans.", "doi": "10.1073/pnas.1411393111", "pmcid": "PMC4128111", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2014-08-05", "series_number": "31", "volume": "111", "issue": "31", "pages": "11449-11454" }, { "id": "authors:zy2y7-gsa60", "collection": "authors", "collection_id": "zy2y7-gsa60", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140911-125859433", "type": "article", "title": "Synthesis of a Specified, Silica Molecular Sieve by Using Computationally Predicted Organic Structure-Directing Agents", "author": [ { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-J-E" }, { "family_name": "Deem", "given_name": "Michael W.", "clpid": "Deem-M-W" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Crystalline molecular sieves are used in numerous applications, where the properties exploited for each technology are the direct consequence of structural features. New materials are typically discovered by trial and error, and in many cases, organic structure-directing agents (OSDAs) are used to direct their formation. Here, we report the first successful synthesis of a specified molecular sieve through the use of an OSDA that was predicted from a recently developed computational method that constructs chemically synthesizable OSDAs. Pentamethylimidazolium is computationally predicted to have the largest stabilization energy in the STW framework, and is experimentally shown to strongly direct the synthesis of pure-silica STW. Other OSDAs with lower stabilization energies did not form STW. The general method demonstrated here to create STW may lead to new, simpler OSDAs for existing frameworks and provide a way to predict OSDAs for desired, theoretical frameworks.", "doi": "10.1002/anie.201404076", "issn": "1433-7851", "publisher": "Wiley", "publication": "Angewandte Chemie International Edition", "publication_date": "2014-08-04", "series_number": "32", "volume": "53", "issue": "32", "pages": "8372-8374" }, { "id": "authors:g9s2q-zxp09", "collection": "authors", "collection_id": "g9s2q-zxp09", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140811-125156249", "type": "conference_item", "title": "New route to glucose-derived terephthalic acid using zeolite catalysts", "author": [ { "family_name": "Pacheco", "given_name": "Joshua J.", "clpid": "Pacheco-J-J" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A new series of zeolite-catalyzed Diels-Alder cycloaddn. and dehydrative aromatization reactions between oxygenated furan dienes and ethylene are reported. It is found that pure Lewis-acid zeolites (Sn-BEA) are catalysts for the conversion of 5-substituted furoic acid derivs. and ethylene to 4-substituted benzoic acid derivs. For example, the diene, Me 5-(methoxymethyl)-furan-2-carboxylate, is converted to the dehydrated Diels-Alder product upon reaction with high-pressure (1000 psig) ethylene at 190\u00b0C (selectivity can be over 50%). The arom. product of this reaction, Me 4-(methoxymethyl)benzoate, can be used to produce terephthalic acid or its diester via oxidn. This new reaction pathway opens a completely new route for the prodn. of terephthalic acid starting from glucose-derived HMF (5-hydroxymethyl-2-furfural) and ethylene, and avoids any costly redn. steps.", "publisher": "Caltech Library", "publication_date": "2014-08" }, { "id": "authors:zt47t-zsr18", "collection": "authors", "collection_id": "zt47t-zsr18", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140623-111830392", "type": "article", "title": "Active Sites in Sn-Beta for Glucose Isomerization to Fructose and Epimerization to Mannose", "author": [ { "family_name": "Bermejo-Deval", "given_name": "Ricardo", "clpid": "Bermejo-Deval-R" }, { "family_name": "Orazov", "given_name": "Marat", "clpid": "Orazov-M" }, { "family_name": "Gounder", "given_name": "Rajamani", "orcid": "0000-0003-1347-534X", "clpid": "Gounder-R" }, { "family_name": "Hwang", "given_name": "Son-Jong", "orcid": "0000-0002-3210-466X", "clpid": "Hwang-Son-Jong" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Framework Lewis acidic tin sites in hydrophobic, pure-silica molecular sieves with the zeolite beta topology (Sn-Beta) have been reported previously to predominantly catalyze glucose\u2212fructose isomerization via 1,2 intramolecular hydride shift in water and glucose\u2013mannose epimerization via 1,2 intramolecular carbon shift in methanol. Here, we show that alkali-free Sn-Beta predominantly isomerizes glucose to fructose via 1,2 intramolecular hydride shift in both water and methanol. Increasing extents of postsynthetic Na+ exchange onto Sn-Beta, however, progressively shifts the reaction pathway toward glucose\u2013mannose epimerization via 1,2 intramolecular carbon shift. Na^+ remains exchanged onto silanol groups proximal to Sn centers during reaction in methanol solvent, leading to nearly exclusive selectivity toward epimerization. In contrast, decationation occurs with increasing reaction time in aqueous solvent and gradually shifts the reaction selectivity to isomerization at the expense of epimerization. Decationation and the concomitant selectivity changes are mitigated by the addition of NaCl to the aqueous reaction solution. Preadsorption of ammonia onto Sn-Beta leads to near complete suppression of infrared and ^(119)Sn nuclear magnetic resonance spectroscopic signatures attributed to open Sn sites and of glucose\u2212fructose isomerization pathways in water and methanol. These data provide evidence that Lewis acidic open Sn sites with either proximal silanol groups or Na-exchanged silanol groups are respectively the active sites for glucose\u2013fructose isomerization and glucose\u2013mannose epimerization.", "doi": "10.1021/cs500466j", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2014-07-03", "series_number": "7", "volume": "4", "issue": "7", "pages": "2288-2297" }, { "id": "authors:4yp3m-dfs35", "collection": "authors", "collection_id": "4yp3m-dfs35", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140602-151610855", "type": "article", "title": "Synthesis of terephthalic acid via Diels-Alder reactions with ethylene and oxidized variants of 5-hydroxymethylfurfural", "author": [ { "family_name": "Pacheco", "given_name": "Joshua J.", "clpid": "Pacheco-J-J" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Terephthalic acid (PTA), a monomer in the synthesis of polyethylene terephthalate (PET), is obtained by the oxidation of petroleum-derived p-xylene. There is significant interest in the synthesis of renewable, biomass-derived PTA. Here, routes to PTA starting from oxidized products of 5-hydroxymethylfurfural (HMF) that can be produced from biomass are reported. These routes involve Diels-Alder reactions with ethylene and avoid the hydrogenation of HMF to 2,5-dimethylfuran. Oxidized derivatives of HMF are reacted with ethylene over solid Lewis acid catalysts that do not contain strong Br\u00f8nsted acids to synthesize intermediates of PTA and its equally important diester, dimethyl terephthalate (DMT). The partially oxidized HMF, 5-(hydroxymethyl)furoic acid (HMFA), is reacted with high pressure ethylene over a pure-silica molecular sieve containing framework tin (Sn-Beta) to produce the Diels-Alder dehydration product, 4-(hydroxymethyl)benzoic acid (HMBA), with 31% selectivity at 61% HMFA conversion after 6 h at 190 \u00b0C. If HMFA is protected with methanol to form methyl 5-(methoxymethyl)furan-2-carboxylate (MMFC), MMFC can react with ethylene in the presence of Sn-Beta for 2 h to produce methyl 4-(methoxymethyl)benzenecarboxylate (MMBC) with 46% selectivity at 28% MMFC conversion or in the presence of a pure-silica molecular sieve containing framework zirconium (Zr-Beta) for 6 h to produce MMBC with 81% selectivity at 26% MMFC conversion. HMBA and MMBC can then be oxidized to produce PTA and DMT, respectively. When Lewis acid containing mesoporous silica (MCM-41) and amorphous silica, or Br\u00f8nsted acid containing zeolites (Al-Beta), are used as catalysts, a significant decrease in selectivity/yield of the Diels-Alder dehydration product is observed.", "doi": "10.1073/pnas.1408345111", "pmcid": "PMC4060660", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2014-06-10", "series_number": "23", "volume": "111", "issue": "23", "pages": "8363-8367" }, { "id": "authors:xv15v-2p715", "collection": "authors", "collection_id": "xv15v-2p715", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150312-082057691", "type": "article", "title": "Spinel metal oxide-alkali carbonate-based, low-temperature thermochemical cycles for water splitting", "author": [ { "family_name": "Xu", "given_name": "Bingjun", "orcid": "0000-0002-2303-257X", "clpid": "Xu-Bingjun" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Bhawe", "given_name": "Yashodhan", "clpid": "Bhawe-Y" } ], "abstract": "Thermochem. cycles that split water into stoichiometric amts. of hydrogen and oxygen below 1000\u00b0C are highly desirable,\nbecause they can convert the waste heat from nuclear power plants into chem. energy in the form of hydrogen. We report a\nmanganese-based thermochem. cycle with the highest operating temp. of 850\u00b0C that is completely recyclable and does not\ninvolve toxic or corrosive components. The thermochem. cycle includes the following 4 steps: (1) thermal treatment of a\nphys. mixt. of Na_2CO_3 and Mn_3O_4 to produce MnO, CO_2, and alpha-NaMnO_2 at 850\u00b0C, (2) oxidn. of MnO in the presence of\nNa_2CO_3 bywater to produce H_2, CO_2 and alpha-NaMnO_2 at 850\u00b0C, (3) Na+ extn. from alpha-NaMnO_2 by its suspension in aq.\nsolns. in the presence of bubbling CO_2 at 80\u00b0C, and (4) recovery of Mn_3O_4 by thermally reducing the sodium ion extd. solid\nproduced in step (3) at 850\u00b0C. The shuttling of Na+ into and out of the manganese oxides in the hydrogen and oxygen\nevolution steps, resp., provides the key thermodn. driving forces, and allows for the cycle to be closed at temps. below 1000\u00b0C.\nThe prodn. of hydrogen and oxygen is fully reproducible for at least 5 cycles.", "issn": "0065-7727", "publisher": "American Chemical Society", "publication": "Abstracts of Papers of the American Chemical Society", "publication_date": "2014-03-16", "volume": "247", "pages": "91-CATL" }, { "id": "authors:4mw08-dqe23", "collection": "authors", "collection_id": "4mw08-dqe23", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140728-075122200", "type": "conference_item", "title": "Award Address (Gabor A. Somorjai Award for Creative Research in Catalysis sponsored by the Gabor A. and Judith K. Somorjai Endowment Fund). New heterogeneous catalysts for converting sugars in aqueous media", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The isomerization of glucose into fructose is a large-scale reaction for the prodn. of high-fructose corn syrup, and recently, is\nbeing considered as an intermediate step in the possible route of biomass to fuels and chems. Here, it is shown that a large\npore zeolite that contains tin (Sn-Beta) is able to isomerize glucose to fructose in aq. media with high activity and selectivity.\nSpecifically, a 10 wt% glucose soln. contg. a catalytic amt. of Sn-Beta (1:50 Sn:glucose molar ratio) gives product yields of\napprox. 46% (wt./wt.) glucose, 31% (wt./wt.) fructose, and 9% (wt./wt.) mannose after 30 and 12 min of reaction at 383 K and\n413 K, resp. This reactivity is achieved also when a 45wt% glucose soln. is converted. The Sn-Beta catalyst can be used for\nmultiple cycles, and the reaction stops when the solid is removed, clearly indicating that the catalysis is occurring\nheterogeneously. With isotopically labeled glucose, it is demonstrated that the isomerization reaction catalyzed by Sn-Beta in\nwater proceeds by way of an intramol. hydride shift, confirming that framework tin centers in Sn-Beta act as Lewis acids in aq.\nmedia. The active site is shown to be Sn that has three bonds to framework oxygen atoms, and reaction rates are strongly\ndependent on the hydrophobicity of the mol. sieve. The Sn-Beta catalyst is able to perform the isomerization reaction in highly\nacidic, aq. environments with equiv. activity and product distribution as in media without added acid. This enables Sn-Beta to\ncouple isomerizations with other acid-catalyzed reactions, including hydrolysis/isomerization or isomerization/dehydration\nreaction sequences, including starch to fructose and glucose to 5-hydroxymethylfurfural (HMF). Modifications of Sn-Beta (and\nTi-Beta) have expanded the types of reactions that can be catalyzed. Some of those reactions include the conversion of glucose\nto mannose, glucose to sorbose and lactose to lactulose.", "publisher": "Caltech Library", "publication_date": "2014-03" }, { "id": "authors:yf45z-0wk18", "collection": "authors", "collection_id": "yf45z-0wk18", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140505-160524389", "type": "conference_item", "title": "Synthesis and characterization of high-silica LTA produced by direct synthesis using a combination of organic SDAs", "author": [ { "family_name": "Schmidt", "given_name": "Joel E.", "clpid": "Schmidt-J-E" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Recent years have seen resurgence in 8-ring, large cage microporous materials for NO_x conversion, sepns.,\nmethanol-to-olefins reactions, and biomass applications. Systems that are currently being investigated include\nAFX, CHA, LEV and other 8-ring systems. Another promising framework for these applications could be LTA,\nwhich has 8-ring pores and LTA cages (are 11.4 \u00c5 in diam.). Zeolite A is unsuitable for these applications as\nconventional LTA synthesis results in a material with Si/Al=1. Tetramethylammonium cations can be used to\nobtain LTA with ca. Si/Al=3, but these materials are not suitable for the aforementioned applications due to\npoor hydrothermal stability and pore blockage due to cations. Corma and co-workers first reported the\nsynthesis of germanosilicate, pure-silica and aluminosilicate LTA using a supramol. self-assembling org. SDA\nin 2004, denoted ITQ-29. This material showed great promise for applications in sepns., catalysis and low\ndielec. const. membranes. We have recently discovered a facile route to produce LTA using a combination of\norg. SDAs that do not require a supramol. assembly of the orgs. We will describe the synthetic procedure and\nthe properties of materials formed.", "publisher": "Caltech Library", "publication_date": "2014-03" }, { "id": "authors:w8sm5-cbr31", "collection": "authors", "collection_id": "w8sm5-cbr31", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140506-085307639", "type": "conference_item", "title": "Upgrading light hydrocarbons: A tandem catalytic system for alkane/alkene coupling", "author": [ { "family_name": "Labinger", "given_name": "Jay A.", "orcid": "0000-0002-1942-9232", "clpid": "Labinger-J-A" }, { "family_name": "Leitch", "given_name": "David C.", "clpid": "Leitch-D-C" }, { "family_name": "Bercaw", "given_name": "John E.", "clpid": "Bercaw-J-E" }, { "family_name": "Deimund", "given_name": "Mark A.", "clpid": "Deimund-M-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Light hydrocarbons, with relatively low fuel value, are abundant from several sources, including mixed\nalkane/alkene refinery byproduct streams. A tandem system consisting of a compatible combination of a\nhomogeneous alkane dehydrogenation catalyst (known to be kinetically efficient but thermodynamically\ndisfavored at low temps.) with an olefin dimerization catalyst could effect the coupling of an alkane and\nalkene to produce a heavier, more valuable fuel mol. (CnH2n+2 + CnH2n = C2nH4n+2), a reaction that is\nthermodynamically favorable below 250 \u00b0C. We have demonstrated that a homogeneous soln. of the pincerligated\niridium complex t-Bu4[PCP]IrH4 along with Cp*TaCl2(C2H4) couples 1-hexene/n-heptane to C13/C14\nproducts, operating with up to 90% cooperativity. Combining the dehydrogenation catalyst with a\nheterogeneous dimerization catalyst offers a promising approach to a practical process; our progress towards\nthat target will be reported.", "publisher": "Caltech Library", "publication_date": "2014-03" }, { "id": "authors:07msj-4j096", "collection": "authors", "collection_id": "07msj-4j096", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140506-085532422", "type": "conference_item", "title": "Solid state NMR characterization of Sn-Beta catalysts", "author": [ { "family_name": "Hwang", "given_name": "Son-Jong", "orcid": "0000-0002-3210-466X", "clpid": "Hwang-Son-Jong" }, { "family_name": "Orazov", "given_name": "Marat", "clpid": "Orazov-M" }, { "family_name": "Gounder", "given_name": "Raj", "orcid": "0000-0003-1347-534X", "clpid": "Gounder-R" }, { "family_name": "Bermejo-Deval", "given_name": "Ricardo", "clpid": "Bermejo-Deval-R" }, { "family_name": "Bhawe", "given_name": "Yashodhan", "clpid": "Bhawe-Y" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "High-resoln. multi-nuclear solid state NMR characterization has been performed to obtain insight into the\nmechanism of glucose reactions with Sn-beta zeolites. Glucose isomerization or epimerization reactions in\nwater and non-aq. environments were examd. thoroughly, and correlations between catalyst structural changes\nand reaction selectivity were the primary focus in this study. In particular, we investigated local structural\nchanges around the catalytically active Sn sites of ^(119)Sn-labeled beta zeolite in different states, including in\ntheir as synthesized form, after calcination in flowing air, after adsorption of sugar mols., and after performing\ncatalytic reaction cycles. Magic angle spinning (MAS) and cross polarization (CP) (either from ^1H or ^(19)F) MAS\n^(119)Sn NMR spectra provided insight into changes in local Sn coordination in the framework of zeolite beta\nunder various conditions. Other NMR results, including ^(13)C NMR of adsorbed glucose or methanol, and ^(19)For\n^(29)Si NMR of zeolite framework, will be used in interpretations of the catalytic reaction mechanisms.", "publisher": "Caltech Library", "publication_date": "2014-03" }, { "id": "authors:a4pj0-66s60", "collection": "authors", "collection_id": "a4pj0-66s60", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140303-111555814", "type": "article", "title": "Zeolites from a Materials Chemistry Perspective", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolites and zeolite-like materials are continually\nfinding new applications. Because of the uniformity of these solids, the expression of macroscale materials properties that are controlled by the materials chemistry at the atomic/molecular scale are achievable. In this Perspective, I discuss the following areas of current interest in zeolites and zeolite-like materials that rely on\nmanipulation of the materials chemistry for their preparation and provide new opportunities for application: (i) exploitation of organic structure-directing agents (SDAs) for new materials, (ii) the synthesis of zeolites without SDAs, (iii) the synthesis of very hydrophobic materials, (iv) conversions of two-dimensional (2D) to 3D materials and vice versa, (v) hierarchically organized\nmaterials, (vi) chiral materials, and (vii) direction of tetrahedral atoms to specific framework positions.", "doi": "10.1021/cm401914u", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2014-01-14", "series_number": "1", "volume": "26", "issue": "1", "pages": "239-245" }, { "id": "authors:dbapx-w7d77", "collection": "authors", "collection_id": "dbapx-w7d77", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140220-100357901", "type": "article", "title": "Monosaccharide and disaccharide isomerization over Lewis acid sites in hydrophobic and hydrophilic molecular sieves", "author": [ { "family_name": "Gounder", "given_name": "Rajamani", "orcid": "0000-0003-1347-534X", "clpid": "Gounder-R" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Lewis acid sites isolated within low-defect, hydrophobic molecular sieves (Sn-Beta-F, Ti-Beta-F) catalyze monosaccharide (glucose\u2013fructose) and disaccharide (lactose\u2013lactulose) aldose\u2013ketose isomerization reactions in liquid water at initial turnover rates (per total metal atom; 373 K) that are, respectively, \u223c10\u201330 and \u223c10^3\u201310^4 factors higher than sites isolated within highly defective, hydrophilic molecular sieves (Ti-Beta-OH) or amorphous co-precipitated oxides (TiO_(2)\u2013SiO_(2)). Glucose-H2/glucose-D2 kinetic isotope effects of \u223c2 (at 373 K) for intramolecular C2\u2013C1 hydride shift isomerization to fructose indicate that glucose transport to active sites within Ti-Beta-F or Ti-Beta-OH does not limit turnover rates in liquid water or methanol, in spite of dramatic differences in the volumetric occupation of hydrophobic and hydrophilic void spaces by physisorbed solvent molecules. Glucose isomerization turnover rates (per total Ti; 373 K) in liquid water are first-order in aqueous glucose concentration (at least up to 1.5% (w/w)). The mechanistic interpretation of measured first-order isomerization rate constants indicates that they reflect free energies of kinetically relevant isomerization transition states relative to two bound solvent molecules, which adsorb competitively with sugars at Lewis acid sites and are the most abundant surface intermediates during steady-state catalysis. The lower isomerization rate constants on Ti centers in highly defective environments, in part, reflect stronger coordination of solvent molecules to Ti centers via additional hydrogen bonding interactions with proximal surface hydroxyl groups. The direct measurement of glucose isomerization rate constants in the liquid phase provides a rigorous and quantitative description of the catalytic differences prevalent among Lewis acidic silica-based solids with hydrophobic or hydrophilic properties, and their interpretation using a mechanism-based rate equation provides further clarity into the inhibition of catalytic turnovers at Lewis acid sites by solvent coordination.", "doi": "10.1016/j.jcat.2013.06.016", "issn": "0021-9517", "publisher": "Elsevier", "publication": "Journal of Catalysis", "publication_date": "2013-12", "volume": "308", "pages": "176-188" }, { "id": "authors:vnq79-71v37", "collection": "authors", "collection_id": "vnq79-71v37", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131212-125225083", "type": "article", "title": "Targeting Therapeutics to the Glomerulus With Nanoparticles", "author": [ { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Nanoparticles are an enabling technology for the creation of tissue-/cell-specific therapeutics that have been investigated extensively as targeted therapeutics for cancer. The kidney, specifically the glomerulus, is another accessible site for nanoparticle delivery that has been relatively overlooked as a target organ. Given the medical need for the development of more potent, kidney-targeted therapies, the use of nanoparticle-based therapeutics may be one such solution to this problem. Here, we review the literature on nanoparticle targeting of the glomerulus. Specifically, we provide a broad overview of nanoparticle-based therapeutics and how the unique structural characteristics of the glomerulus allow for selective, nanoparticle targeting of this area of the kidney. We then summarize literature examples of nanoparticle delivery to the glomerulus and elaborate on the appropriate nanoparticle design criteria for glomerular targeting. Finally, we discuss the behavior of nanoparticles in animal models of diseased glomeruli and review examples of nanoparticle therapeutic approaches that have shown promise in animal models of glomerulonephritic disease.", "doi": "10.1053/j.ackd.2013.06.003", "issn": "1548-5595", "publisher": "National Kidney Foundation", "publication": "Advances in Chronic Kidney Disease", "publication_date": "2013-11", "series_number": "6", "volume": "20", "issue": "6", "pages": "500-507" }, { "id": "authors:0re2b-av166", "collection": "authors", "collection_id": "0re2b-av166", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131011-092434485", "type": "article", "title": "Correlating preclinical animal studies and human clinical trials of a multifunctional, polymeric nanoparticle", "author": [ { "family_name": "Eliasof", "given_name": "Scott", "clpid": "Eliasof-S" }, { "family_name": "Lazarus", "given_name": "Douglas", "clpid": "Lazarus-D" }, { "family_name": "Peters", "given_name": "Christian G.", "clpid": "Peters-C-G" }, { "family_name": "Case", "given_name": "Roy I.", "clpid": "Case-R-I" }, { "family_name": "Cole", "given_name": "Roderic O.", "clpid": "Cole-R-O" }, { "family_name": "Hwang", "given_name": "Jungyeon", "clpid": "Hwang-Jungyeon" }, { "family_name": "Schluep", "given_name": "Thomas", "clpid": "Schluep-T" }, { "family_name": "Chao", "given_name": "Joseph", "clpid": "Chao-Joseph" }, { "family_name": "Lin", "given_name": "James", "clpid": "Lin-James" }, { "family_name": "Yen", "given_name": "Yun", "orcid": "0000-0003-0815-412X", "clpid": "Yen-Yun" }, { "family_name": "Han", "given_name": "Han", "clpid": "Han-Han" }, { "family_name": "Wiley", "given_name": "Devin T.", "clpid": "Wiley-D-T" }, { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Nanoparticles are currently being investigated in a number of human clinical trials. As information on how nanoparticles function in humans is difficult to obtain, animal studies that can be correlative to human behavior are needed to provide guidance for human clinical trials. Here, we report correlative studies on animals and humans for CRLX101, a 20- to 30-nm-diameter, multifunctional, polymeric nanoparticle containing camptothecin (CPT). CRLX101 is currently in phase 2 clinical trials, and human data from several of the clinical investigations are compared with results from multispecies animal studies. The pharmacokinetics of polymer-conjugated CPT (indicative of the CRLX101 nanoparticles) in mice, rats, dogs, and humans reveal that the area under the curve scales linearly with milligrams of CPT per square meter for all species. Plasma concentrations of unconjugated CPT released from CRLX101 in animals and humans are consistent with each other after accounting for differences in serum albumin binding of CPT. Urinary excretion of polymer-conjugated CPT occurs primarily within the initial 24 h after dosing in animals and humans. The urinary excretion dynamics of polymer-conjugated and unconjugated CPT appear similar between animals and humans. CRLX101 accumulates into solid tumors and releases CPT over a period of several days to give inhibition of its target in animal xenograft models of cancer and in the tumors of humans. Taken in total, the evidence provided from animal models on the CRLX101 mechanism of action suggests that the behavior of CRLX101 in animals is translatable to humans.", "doi": "10.1073/pnas.1309566110", "pmcid": "PMC3773776", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2013-09-10", "series_number": "37", "volume": "110", "issue": "37", "pages": "15127-15132" }, { "id": "authors:8ny3y-pkm13", "collection": "authors", "collection_id": "8ny3y-pkm13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131016-132316656", "type": "conference_item", "title": "Sugar rearrangements mediated by Lewis acidic molecular sieves in liquid media", "author": [ { "family_name": "Gounder", "given_name": "Rajamani", "orcid": "0000-0003-1347-534X", "clpid": "Gounder-R" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Monosaccharide and disaccharide isomerization and epimerization reactions are catalyzed by Lewis acidic sites\n(M = Sn, Ti, Zr) isolated in silica-based heterogeneous solids, with selectivity and stereochem. specificity that are\ninaccessible to sugar rearrangements involving enolate intermediates catalyzed by bases. Such selectivity and\nspecificity reflect the ability of electrophilic Lewis acid centers to coordinate with oxygenated sugar functional\ngroups and to subsequently mediate intramol. rearrangements of specific H and C atoms, the mechanistic\ndetails of which are probed using D and ^(13)C isotopically-labeled reactants. Here, we discuss recent progress in\nunderstanding the influence of: (i) heteroatom and solvent identity on active site structures and reaction\nmechanisms and (ii) the surrounding silicate environments on the turnover rates of sugar reactions. For\nexample, glucose isomerization to fructose is mediated by Lewis acidic Ti sites isolated within hydrophobic\nand hydrophilic environments provided by cryst. mol. sieves with the Beta topol. and by amorphous silica.\nMeasured first-order rate consts. (per total Ti atom; 373 K), detd. from batch reactor studies under conditions of\nstrict kinetic control, are an order of magnitude higher in liq. water for hydrophobic than for hydrophilic solids.\nMechanistic interpretation of these rate consts. indicates that the environments surrounding Ti centers influence\nfree energy differences between isomerization transition states and two bound solvent mols. that adsorb\ncompetitively at Lewis sites and are most abundant surface intermediates during catalysis. Similar roles of\nhydrophobic pockets confining Lewis centers are found in heterogeneous, homogeneous and enzymic active\nsites that mediate sugar reactions. These findings help clarify the mechanistic details and site requirements for\nsugar conversion on heterogeneous Lewis acid solids, and also provide guidance for active site structural\nmodification to promote desired reaction pathways and thus to develop new heterogeneous catalysts for\nselective sugar conversion in liq. media.", "publisher": "Caltech Library", "publication_date": "2013-09" }, { "id": "authors:x7d1d-09q94", "collection": "authors", "collection_id": "x7d1d-09q94", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130913-103602906", "type": "article", "title": "Beyond shape selective catalysis with zeolites: Hydrophobic void spaces in zeolites enable catalysis in liquid water", "author": [ { "family_name": "Gounder", "given_name": "Rajamani", "orcid": "0000-0003-1347-534X", "clpid": "Gounder-R" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolites confine active sites within void spaces of molecular dimension. The size and shape of these voids can be tuned by changing framework topology, which can influence catalytic reactivity and selectivity via coupled reaction-transport phenomena that exploit differences in transport properties among reactants and/or products that differ in size and shape. The polarity and solvating properties of intrazeolite void environments can be tuned by changing chemical composition and structure, ranging from hydrophobic defect-free pure-silica surfaces to silica surfaces containing hydrophilic defect sites and/or heteroatoms. Here, we discuss how the polarity of zeolite voids influences catalytic reactivity and selectivity via the partitioning of reactant, product, and solvent molecules between intrazeolitic locations and external fluid phases. These findings provide a conceptual basis for developing selective catalytic processes in aqueous media using hydrophobic zeolites that are able to adsorb organic reactants while excluding liquid water from internal void spaces.", "doi": "10.1002/aic.14016", "issn": "0001-1541", "publisher": "Wiley", "publication": "AIChE Journal", "publication_date": "2013-09", "series_number": "9", "volume": "59", "issue": "9", "pages": "3349-3358" }, { "id": "authors:00wsx-j3f73", "collection": "authors", "collection_id": "00wsx-j3f73", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130826-150219730", "type": "article", "title": "First-in-human phase 1/2a trial of CRLX101, a cyclodextrin-containing polymer-camptothecin nanopharmaceutical in patients with advanced solid tumor malignancies", "author": [ { "family_name": "Weiss", "given_name": "Glen J.", "clpid": "Weiss-G-J" }, { "family_name": "Choi", "given_name": "Chung Hang J.", "clpid": "Choi-C-H-J" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Patients with advanced solid malignancies were enrolled to an open-label, single-arm, dose-escalation study, in which CRLX101 was administered intravenously over 60 min among two dosing schedules, initially weekly at 6, 12, and 18 mg/m^2 and later bi-weekly at 12, 15, and 18 mg/m^2. The maximum tolerated dose (MTD) was determined at 15 mg/m^2 bi-weekly, and an expansion phase 2a study was completed. Patient samples were obtained for pharmacokinetic (PK) and pharmacodynamic (PD) assessments. Response was evaluated per RECIST criteria v1.0 every 8 weeks. Sixty-two patients (31 male; median age 63 years, range 39\u201379) received treatment. Bi-weekly dosing was generally well tolerated with myelosuppression being the dose-limiting toxicity. Among all phase 1/2a patients receiving the MTD (n\u2009=\u200944), most common grade 3/4 adverse events were neutropenia and fatigue. Evidence of systemic plasma exposure to both the polymer-conjugated and unconjugated CPT was observed in all treated patients. Mean elimination unconjugated CPT T_(max) values ranged from 17.7 to 24.5 h, and maximum plasma concentrations and areas under the curve were generally proportional to dose for both polymer-conjugated and unconjugated CPT. Best overall response was stable disease in 28 patients (64 %) treated at the MTD and 16 (73 %) of a subset of NSCLC patients. Median progression-free survival (PFS) for patients treated at the MTD was 3.7 months and for the subset of NSCLC patients was 4.4 months. These combined phase 1/2a data demonstrate encouraging safety, pharmacokinetic, and efficacy results. Multinational phase 2 clinical development of CRLX101 across multiple tumor types is ongoing.", "doi": "10.1007/s10637-012-9921-8", "issn": "0167-6997", "publisher": "Springer Verlag", "publication": "Investigational New Drugs", "publication_date": "2013-08", "series_number": "4", "volume": "31", "issue": "4", "pages": "986-1000" }, { "id": "authors:wgr52-4tj88", "collection": "authors", "collection_id": "wgr52-4tj88", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130809-092706142", "type": "article", "title": "Single-Antibody, Targeted Nanoparticle Delivery of Camptothecin", "author": [ { "family_name": "Han", "given_name": "Han", "clpid": "Han-Han" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "We have developed a new method for assembling targeted nanoparticles that utilizes the complexation between targeting agents that contain boronic acids and polymer\u2013drug conjugates that possess diols. Here, we report the first in vivo, antitumor results of a nanoparticle formed via this new assembly methodology. A nanoparticle consisting of a mucic acid polymer conjugate of camptothecin (CPT), MAP\u2013CPT, and containing on average one Herceptin antibody is investigated in nude mice bearing HER2 overexpressing BT-474 human breast cancer tumors. Nontargeted MAP\u2013CPT and antibody-containing MAP\u2013CPT nanoparticles of ca. 30\u201340 nm diameter and slightly negative zeta potential show prolonged in vivo circulation and similar biodistributions after intravenous tail vein injections in mice. The maximum tolerated dose (MTD) of the nontargeted and Herceptin-containing MAP\u2013CPT nanoparticles is found to be 10 and 8 mg of CPT/kg, respectively, in mice. Mice bearing BT-474 human breast tumors treated with nontargeted MAP\u2013CPT nanoparticles at 8 mg of CPT/kg show significant tumor growth inhibition (mean tumor volume of 63 mm3) when compared to irinotecan at 80 mg/kg (mean tumor volume of 575 mm3) and CPT at 8 mg/kg (mean tumor volume of 808 mm3) at the end of the study. Herceptin antibody treatment at 5.9 mg/kg results in complete tumor regressions in 5 out of 8 mice, with a mean tumor volume of 60 mm3 at the end of the study. Mice treated with MAP\u2013CPT nanoparticles at 1 mg of CPT/kg do not show tumor inhibition. However, all mice receiving administrations of MAP\u2013CPT nanoparticles (1 mg of CPT/kg) that contain on average a single Herceptin molecule per nanoparticle (5.9 mg of Herceptin equivalent/kg) show complete tumor regression by the end of the study. These results demonstrate that the antitumor efficacy of nanoparticles carrying anticancer drugs can be enhanced by incorporating on average a single antibody.", "doi": "10.1021/mp300702x", "pmcid": "PMC3795804", "issn": "1543-8384", "publisher": "American Chemical Society", "publication": "Molecular Pharmaceutics", "publication_date": "2013-07", "series_number": "7", "volume": "10", "issue": "7", "pages": "2558-2567" }, { "id": "authors:5wfc3-c3339", "collection": "authors", "collection_id": "5wfc3-c3339", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130903-155918546", "type": "article", "title": "Titanium-Beta Zeolites Catalyze the Stereospecific Isomerization of D-Glucose to L-Sorbose via Intramolecular C5\u2013C1 Hydride Shift", "author": [ { "family_name": "Gounder", "given_name": "Rajamani", "orcid": "0000-0003-1347-534X", "clpid": "Gounder-R" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Pure-silica zeolite beta containing Lewis acidic framework Ti^(4+) centers (Ti-Beta) is shown to catalyze the isomerization of D-glucose to L-sorbose via an intramolecular C5\u2013C1 hydride shift. Glucose\u2013sorbose isomerization occurs in parallel to glucose\u2013fructose isomerization on Ti-Beta in both water and methanol solvents, with fructose formed as the predominant product in water and sorbose as the predominant product in methanol (at 373 K) at initial times and over the course of >10 turnovers. Isotopic tracer studies demonstrate that ^(13)C and D labels placed respectively at the C1 and C2 positions of glucose are retained respectively at the C6 and C5 positions of sorbose, consistent with its formation via an intramolecular C5\u2013C1 hydride shift isomerization mechanism. This direct Lewis acid-mediated pathway for glucose\u2013sorbose isomerization appears to be unprecedented among heterogeneous or biological catalysts and sharply contrasts indirect base-mediated glucose\u2013sorbose isomerization via 3,4-enediol intermediates or via retro-aldol fragmentation and recombination of sugar fragments. Measured first-order glucose\u2013sorbose isomerization rate constants (per total Ti; 373 K) for Ti-Beta in methanol are similar for glucose and glucose deuterated at the C2 position (within a factor of ~1.1), but are a factor of ~2.3 lower for glucose deuterated at each carbon position, leading to H/D kinetic isotope effects expected for kinetically relevant intramolecular C5\u2013C1 hydride shift steps. Optical rotation measurements show that isomerization of D-(+)-glucose (92% enantiomeric purity) with Ti-Beta in water (373 K) led to the formation of L-(\u2212)-sorbose (73% enantiomeric purity) and D-(\u2212)-fructose (87% enantiomeric purity) as the predominant stereoisomers, indicating that stereochemistry is preserved at carbon centers not directly involved in intramolecular C5\u2013C1 or C2\u2013C1 hydride shift steps, respectively. This new Lewis acid-mediated rearrangement of glucose to sorbose does not appear to have a metalloenzyme analog.", "doi": "10.1021/cs400273c", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2013-07", "series_number": "7", "volume": "3", "issue": "7", "pages": "1469-1476" }, { "id": "authors:5zve7-v7q30", "collection": "authors", "collection_id": "5zve7-v7q30", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130805-094119782", "type": "article", "title": "Transcytosis and brain uptake of transferrin-containing nanoparticles by tuning avidity to transferrin receptor", "author": [ { "family_name": "Wiley", "given_name": "Devin T.", "clpid": "Wiley-D-T" }, { "family_name": "Webster", "given_name": "Paul", "clpid": "Webster-P" }, { "family_name": "Gale", "given_name": "Aaron", "clpid": "Gale-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Receptor-mediated transcytosis across the blood\u2013brain barrier (BBB) may be a useful way to transport therapeutics into the brain. Here we report that transferrin (Tf)-containing gold nanoparticles can reach the brain parenchyma from systemic administration in mice through a receptor-mediated transcytosis pathway. This transport is aided by tuning the nanoparticle avidity to Tf receptor (TfR), which is correlated with nanoparticle size and total amount of Tf decorating the nanoparticle surface. Nanoparticles of both 45 nm and 80 nm diameter reach the brain parenchyma, and their accumulation there (visualized by silver enhancement light microscopy in combination with transmission electron microscopy imaging) is observed to be dependent on Tf content (avidity); nanoparticles with large amounts of Tf remain strongly attached to brain endothelial cells, whereas those with less Tf are capable of both interacting with TfR on the luminal side of the BBB and detaching from TfR on the brain side of the BBB. The requirement of proper avidity for nanoparticles to reach the brain parenchyma is consistent with recent behavior observed with transcytosing antibodies that bind to TfR.", "doi": "10.1073/pnas.1307152110", "pmcid": "PMC3666717", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2013-05-21", "series_number": "21", "volume": "110", "issue": "21", "pages": "8662-8667" }, { "id": "authors:f78ea-hp802", "collection": "authors", "collection_id": "f78ea-hp802", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130712-102141329", "type": "article", "title": "Spinel Metal Oxide-Alkali Carbonate-Based, Low-Temperature Thermochemical Cycles for Water Splitting and CO_2 Reduction", "author": [ { "family_name": "Xu", "given_name": "Bingjun", "orcid": "0000-0002-2303-257X", "clpid": "Xu-Bingjun" }, { "family_name": "Bhawe", "given_name": "Yashodhan", "clpid": "Bhawe-Y" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A manganese oxide-based, thermochemical cycle for water splitting below 1000 \u00b0C has recently been reported. The cycle involves the shuttling of Na+ into and out of manganese oxides via the consumption and formation of sodium carbonate, respectively. Here, we explore the combinations of three spinel metal oxides and three alkali carbonates in thermochemical cycles for water splitting and CO_2 reduction. Hydrogen evolution and CO_2 reduction reactions of metal oxides with a given alkali carbonate occur in the following order of decreasing activity: Fe_(3)O_4 > Mn_(3)O_4 > Co_(3)O_4, whereas the reactivity of a given metal oxide with alkali carbonates declines as Li_(2)CO_3 > Na_(2)CO_3 > K_(2)CO_3. While hydrogen evolution and CO_2 reduction reactions occur at a lower temperature on the combinations with the more reactive metal oxide and alkali carbonate, higher thermal reduction temperatures and more difficult alkali ion extractions are observed for the combinations of the more reactive metal oxides and alkali carbonates. Thus, for a thermochemical cycle to be closed at low temperatures, all three reactions of hydrogen evolution (CO_2 reduction), alkali ion extraction, and thermal reduction must proceed within the specified temperature range. Of the systems investigated here, only the Na_(2)CO_3/Mn_(3)O_4 combination satisfies these criteria with a maximum operating temperature (850 \u00b0C) below 1000 \u00b0C.", "doi": "10.1021/cm3038747", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2013-05-14", "series_number": "9", "volume": "25", "issue": "9", "pages": "1564-1571" }, { "id": "authors:3rt7m-d5516", "collection": "authors", "collection_id": "3rt7m-d5516", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130523-162341580", "type": "article", "title": "Targeted Nanoparticles Assembled via Complexation of Boronic-Acid-Containing Targeting Moieties to Diol-Containing Polymers", "author": [ { "family_name": "Han", "given_name": "Han", "clpid": "Han-Han" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The delivery of therapeutics via nanoscaled vehicles for solid cancer treatment can be enhanced by the incorporation of a targeting capability. Here, we describe a new method for assembling a targeted nanoparticle that utilizes the reversible covalent complexation between boronic acids and diols to achieve a targeted nanoparticle for the delivery of the anticancer drug camptothecin (CPT). CPT is conjugated to a biocompatible, hydrophilic copolymer of mucic acid and PEG (MAP). When this polymer\u2013drug conjugate is placed in water, it self-assembles into MAP\u2013CPT nanoparticles of ca. 30 nm (diameter) and slightly negative zeta potential. The antibody Herceptin is attached to a boronic acid via a polyethylene glycol (PEG) spacer, and this boronic acid-containing targeting moiety is complexed with the diol-containing MAP to form a targeted MAP\u2013CPT nanoparticle. The addition of Herceptin targeting agent to the MAP\u2013CPT nanoparticles yields targeted MAP\u2013CPT nanoparticles with increased nanoparticle size to ca. 40 nm (diameter). The main mechanisms of CPT release from MAP\u2013CPT nanoparticles are found by in vitro analysis to be hydrolysis and nanoparticle disruption by fat. Cellular uptake of nanoparticles is enhanced by 70% compared to nontargeted version by the incorporation of a single Herceptin antibody targeting agent per nanoparticle. This single Herceptin antibody targeted MAP\u2013CPT nanoparticle system carries ca. 60 CPT molecules per nanoparticle and shows prolonged plasma circulation with an elimination half-life of 21.2 h and AUC value of 2766 \u03bcg.h/mL at a 10 mg CPT/kg tail vein injection in mice.", "doi": "10.1021/bc300640j", "pmcid": "PMC3656490", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2013-04-17", "series_number": "4", "volume": "24", "issue": "4", "pages": "669-677" }, { "id": "authors:rfwmd-qys24", "collection": "authors", "collection_id": "rfwmd-qys24", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130124-161852094", "type": "article", "title": "Effect of Cage Size on the Selective Conversion of Methanol to Light Olefins", "author": [ { "family_name": "Bhawe", "given_name": "Yashodhan", "clpid": "Bhawe-Y" }, { "family_name": "Moliner-Marin", "given_name": "Manuel", "clpid": "Moliner-Marin-M" }, { "family_name": "Lunn", "given_name": "Jonathan D.", "clpid": "Lunn-J-D" }, { "family_name": "Liu", "given_name": "Yu", "clpid": "Liu-Yu" }, { "family_name": "Malek", "given_name": "Andrzej", "orcid": "0000-0002-1608-9375", "clpid": "Malek-A" }, { "family_name": "Davis", "given_name": "Mark", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolites that contain eight-membered ring pores but different cavity geometries (LEV, CHA, and AFX structure types) are synthesized at similar Si/Al ratios and crystal sizes. These materials are tested as catalysts for the selective conversion of methanol to light olefins. At 400 \u00b0C, atmospheric pressure, and 100% conversion of methanol, the ethylene selectivity decreases as the cage size increases. Variations in the Si/Al ratio of the LEV and CHA show that the maximum selectivity occurs at Si/Al = 15\u201318. Because lower Si/Al ratios tend to produce faster deactivation rates and poorer selectivities, reactivity comparisons between frameworks are performed with solids having a ratio Si/Al = 15\u201318. With LEV and AFX, the data are the first from materials with this high Si/Al. At similar Si/Al and primary crystallite size, the propylene selectivity for the material with the CHA structure exceeds those from either the LEV or AFX structure. The AFX material gives the shortest reaction lifetime, but has the lowest amount of carbonaceous residue after reaction. Thus, there appears to be an intermediate cage size for maximizing the production of light olefins and propylene selectivities equivalent to or exceeding ethylene selectivities.", "doi": "10.1021/cs300558x", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2012-12-07", "series_number": "12", "volume": "2", "issue": "12", "pages": "2490-2495" }, { "id": "authors:gx8mn-nss72", "collection": "authors", "collection_id": "gx8mn-nss72", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130124-084012360", "type": "article", "title": "Framework and Extraframework Tin Sites in Zeolite Beta React Glucose Differently", "author": [ { "family_name": "Bermejo-Deval", "given_name": "Ricardo", "clpid": "Bermejo-Deval-R" }, { "family_name": "Gounder", "given_name": "Rajamani", "orcid": "0000-0003-1347-534X", "clpid": "Gounder-R" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Here, we show that framework tin sites in pure silica zeolite Beta (Sn-Beta) can isomerize glucose to fructose by a Lewis acid-mediated intramolecular hydride shift in aqueous solvent, but not in methanol solvent. Mechanistic studies using isotopically labeled (^(2)H, ^(13)C) glucose reactants show that in methanol, Sn-Beta instead epimerizes glucose to mannose by a Lewis acid-mediated intramolecular carbon shift mechanism known as the Bilik reaction. We also provide evidence that extraframework tin sites located within the hydrophobic channels of zeolite Beta can isomerize glucose to fructose in both water and methanol solvent, but through a base-catalyzed proton-transfer mechanism. SnO_2 particles located at external zeolite crystal surfaces or supported on amorphous silica catalyze isomerization in methanol but not in water, suggesting that contact with bulk water inhibits isomerization at SnO_2 surfaces. ^(119)Sn MAS NMR spectroscopy was used to unambiguously identify framework Sn sites, which give resonances for octahedral Sn (\u2212685 to \u2212700 ppm) in hydrated Sn-Beta that disappear upon dehydration, with the concomitant appearance of resonances for tetrahedral Sn (\u2212425 to \u2212445 ppm). In sharp contrast, spectra of hydrated samples containing extraframework SnO_2 show resonances for octahedral Sn centered at \u2212604 ppm that do not change upon dehydration. These findings demonstrate that aldose\u2013ketose isomerization reactivity on Sn-zeolite samples cannot be ascribed to the presence of framework Sn sites in the absence of isotopic labeling studies. They also indicate that any Sn-zeolite samples that initially convert glucose to fructose, instead of mannose, in methanol solvent contain Sn species that are structurally different from framework Sn centers.", "doi": "10.1021/cs300474x", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2012-12", "series_number": "12", "volume": "2", "issue": "12", "pages": "2705-2713" }, { "id": "authors:fdv3m-ht482", "collection": "authors", "collection_id": "fdv3m-ht482", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121018-110927602", "type": "article", "title": "Fighting cancer with nanoparticle medicines - The nanoscale matters", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Papyrus writings from 1600\u20131500 BC describe cancer and the attempts at treatment. Centuries later, cancer remains a devastating disease. Given the long history of difficulties in developing cancer therapies, why is there excitement about nanoparticle medicine (nanomedicines) for fighting cancer? This article describes the current understanding of why these engineered, nano-sized medicines, which are highly multifunctional chemical systems, have the potential to provide revolutionary ways to treat cancer. This point is illustrated by physical insights at the nanoscale that allow for the development of nanoparticles that can function in both animals and humans. The human data show how we have translated two independent nanoparticle cancer therapeutics from laboratory curiosities to experimental therapeutics in human clinical trials.", "doi": "10.1557/mrs.2012.202", "issn": "0883-7694", "publisher": "Cambridge University Press", "publication": "MRS Bulletin", "publication_date": "2012-09", "series_number": "9", "volume": "37", "issue": "9", "pages": "828-835" }, { "id": "authors:se9ma-f7c28", "collection": "authors", "collection_id": "se9ma-f7c28", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120724-104817503", "type": "article", "title": "Preclinical study of the cyclodextrin-polymer conjugate of camptothecin CRLX101 for the treatment of gastric cancer", "author": [ { "family_name": "Gaur", "given_name": "Shikha", "clpid": "Gaur-S" }, { "family_name": "Chen", "given_name": "Linling", "clpid": "Chen-Linling" }, { "family_name": "Yen", "given_name": "Terence", "clpid": "Yen-Terence" }, { "family_name": "Wang", "given_name": "Yafan", "clpid": "Wang-Yafan" }, { "family_name": "Zhou", "given_name": "Bingsen", "clpid": "Zhou-Bingsen" }, { "family_name": "Davis", "given_name": "Mark", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Yen", "given_name": "Yun", "orcid": "0000-0003-0815-412X", "clpid": "Yen-Yun" } ], "abstract": "Camptothecin showed remarkable anticancer activity in animal models of cancer but was restricted in clinical use for its adverse toxicity in patients. The preclinical efficacy of CRLX101, a nanoparticle (NP) assembly containing cyclodextrin-based polymer and camptothecin was evaluated by in vitro cytotoxicity in gastric cancer cell lines and in vivo antitumor effects in human gastric cancer cell line BGC823 xenografts. Treated tumor sections were analyzed for presence of NPs and compared with vehicle control tumors for hypoxia and angiogenesis. Gastric cancer cell lines showed high in vitro cytotoxicity for CRLX101 and also showed strong antitumor activity in vivo. Electron micrographs revealed the intracellular presence of NPs in close proximity to vesicles. A significant decrease in expressions of carbonic anhydrase, VEGF, and CD31 proteins in treated tumors indicated an inhibition of hypoxia and angiogenesis. The results provide preclinical data for gastric adenocarcinoma.\nFrom the Clinical Editor:\nThis study describes a nanoparticle assembly containing cyclodextrin-based polymer and camptothecin, resulting in increased bioavailability of camptothecin, an effective but toxic anti-cancer agent. The antitumor effects and safety profile were demonstrated in a gastric carcinoma cell line.", "doi": "10.1016/j.nano.2011.09.007", "issn": "1549-9634", "publisher": "Elsevier", "publication": "Nanomedicine-Nanotechnology Biology and Medicine", "publication_date": "2012-07", "series_number": "5", "volume": "8", "issue": "5", "pages": "721-730" }, { "id": "authors:9d26h-j8708", "collection": "authors", "collection_id": "9d26h-j8708", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120723-125206829", "type": "article", "title": "Metalloenzyme-like catalyzed isomerizations of sugars by Lewis acid zeolites", "author": [ { "family_name": "Bermejo-Deval", "given_name": "Ricardo", "clpid": "Bermejo-Deval-R" }, { "family_name": "Assary", "given_name": "Rajeev S.", "orcid": "0000-0002-9571-3307", "clpid": "Assary-R-S" }, { "family_name": "Nikolla", "given_name": "Eranda", "orcid": "0000-0002-8172-884X", "clpid": "Nikolla-E" }, { "family_name": "Moliner", "given_name": "Manuel", "orcid": "0000-0002-5440-716X", "clpid": "Moliner-Manuel" }, { "family_name": "Rom\u00e1n-Leshkov", "given_name": "Yuriy", "orcid": "0000-0002-0025-4233", "clpid": "Rom\u00e1n-Leshkov-Y" }, { "family_name": "Hwang", "given_name": "Son-Jong", "orcid": "0000-0002-3210-466X", "clpid": "Hwang-Son-Jong" }, { "family_name": "Palsdottir", "given_name": "Arna", "clpid": "Palsdottir-A" }, { "family_name": "Silverman", "given_name": "Dorothy", "clpid": "Silverman-D" }, { "family_name": "Lobo", "given_name": "Raul F.", "clpid": "Lobo-R-F" }, { "family_name": "Curtiss", "given_name": "Larry A.", "orcid": "0000-0001-8855-8006", "clpid": "Curtiss-L-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Isomerization of sugars is used in a variety of industrially relevant processes and in glycolysis. Here, we show that hydrophobic zeolite beta with framework tin or titanium Lewis acid centers isomerizes sugars, e.g., glucose, via reaction pathways that are analogous to those of metalloenzymes. Specifically, experimental and theoretical investigations reveal that glucose partitions into the zeolite in the pyranose form, ring opens to the acyclic form in the presence of the Lewis acid center, isomerizes into the acyclic form of fructose, and finally ring closes to yield the furanose product. The zeolite catalysts provide processing advantages over metalloenzymes such as an ability to work at higher temperatures and in acidic conditions that allow for the isomerization reaction to be coupled with other important conversions.", "doi": "10.1073/pnas.1206708109", "pmcid": "PMC3382492", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2012-06-19", "series_number": "25", "volume": "109", "issue": "25", "pages": "9727-9732" }, { "id": "authors:1zqmv-t3y13", "collection": "authors", "collection_id": "1zqmv-t3y13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120626-150146846", "type": "article", "title": "Low-temperature, manganese oxide-based, thermochemical water splitting cycle", "author": [ { "family_name": "Xu", "given_name": "Bingjun", "orcid": "0000-0002-2303-257X", "clpid": "Xu-Bingjun" }, { "family_name": "Bhawe", "given_name": "Yashodhan", "clpid": "Bhawe-Y" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Thermochemical cycles that split water into stoichiometric amounts of hydrogen and oxygen below 1,000\u2009\u00b0C, and do not involve toxic or corrosive intermediates, are highly desirable because they can convert heat into chemical energy in the form of hydrogen. We report a manganese-based thermochemical cycle with a highest operating temperature of 850\u2009\u00b0C that is completely recyclable and does not involve toxic or corrosive components. The thermochemical cycle utilizes redox reactions of Mn(II)/Mn(III) oxides. The shuttling of Na+ into and out of the manganese oxides in the hydrogen and oxygen evolution steps, respectively, provides the key thermodynamic driving forces and allows for the cycle to be closed at temperatures below 1,000\u2009\u00b0C. The production of hydrogen and oxygen is fully reproducible for at least five cycles.", "doi": "10.1073/pnas.1206407109", "pmcid": "PMC3386106", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2012-06-12", "series_number": "24", "volume": "109", "issue": "24", "pages": "9260-9264" }, { "id": "authors:cbsf7-ec123", "collection": "authors", "collection_id": "cbsf7-ec123", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120702-142250235", "type": "article", "title": "Systemic delivery of siRNA nanoparticles targeting RRM2 suppresses head and neck tumor growth", "author": [ { "family_name": "Rahman", "given_name": "Mohammad Aminur", "clpid": "Rahman-M-A" }, { "family_name": "Amin", "given_name": "A. R. M. Ruhul", "clpid": "Amin-A-R-M-R" }, { "family_name": "Wang", "given_name": "Xu", "clpid": "Wang-Xu" }, { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Choi", "given_name": "Chung Hang J.", "clpid": "Choi-Chung-Hang-J" }, { "family_name": "Zhou", "given_name": "Bingsen", "clpid": "Zhou-Bingsen" }, { "family_name": "Wang", "given_name": "Dongsheng", "clpid": "Wang-Dongsheng" }, { "family_name": "Nannapaneni", "given_name": "Sreenivas", "clpid": "Nannapaneni-S" }, { "family_name": "Koenig", "given_name": "Lydia", "clpid": "Koenig-L" }, { "family_name": "Chen", "given_name": "Zhengjia", "clpid": "Chen-Zhenglia" }, { "family_name": "Chen", "given_name": "Zhuo (Georgia)", "clpid": "Chen-Zhuo-Georgia" }, { "family_name": "Yen", "given_name": "Yun", "orcid": "0000-0003-0815-412X", "clpid": "Yen-Yun" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Shin", "given_name": "Dong M.", "clpid": "Shin-Dong-M" } ], "abstract": "Systemic delivery of siRNA to solid tumors remains challenging. In this study, we investigated the systemic delivery of a siRNA nanoparticle targeting ribonucleotide reductase subunit M2 (RRM2), and evaluated its intratumoral kinetics, efficacy and mechanism of action. Knockdown of RRM2 by an RNAi mechanism strongly inhibited cell growth in head and neck squamous cell carcinoma (HNSCC) and non-small cell lung cancer (NSCLC) cell lines. In a mouse xenograft model of HNSCC, a single intravenous injection led to the accumulation of intact nanoparticles in the tumor that disassembled over a period of at least 3 days, leading to target gene knockdown lasting at least 10 days. A four-dose schedule of siRNA nanoparticle delivering RRM2 siRNA targeted to HNSCC tumors significantly reduced tumor progression by suppressing cell proliferation and inducing apoptosis. These results show promise for the use of RRM2 siRNA-based therapy for HNSCC and possibly NSCLC.", "doi": "10.1016/j.jconrel.2012.01.045", "pmcid": "PMC3348392", "issn": "0168-3659", "publisher": "Elsevier", "publication": "Journal of Controlled Release", "publication_date": "2012-05-10", "series_number": "3", "volume": "159", "issue": "3", "pages": "384-392" }, { "id": "authors:twbet-ddk65", "collection": "authors", "collection_id": "twbet-ddk65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120314-154828359", "type": "article", "title": "Polycation-siRNA nanoparticles can disassemble at the kidney glomerular basement membrane", "author": [ { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Choi", "given_name": "Chung Hang J.", "clpid": "Choi-Chung-Hang-J" }, { "family_name": "Han", "given_name": "Han", "clpid": "Han-Han" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Despite being engineered to avoid renal clearance, many cationic polymer (polycation)-based siRNA nanoparticles that are used for systemic delivery are rapidly eliminated from the circulation. Here, we show that a component of the renal filtration barrier\u2014the glomerular basement membrane (GBM)\u2014can disassemble cationic cyclodextrin-containing polymer (CDP)-based siRNA nanoparticles and, thereby, facilitate their rapid elimination from circulation. Using confocal and electron microscopies, positron emission tomography, and compartment modeling, we demonstrate that siRNA nanoparticles, but not free siRNA, accumulate and disassemble in the GBM. We also confirm that the siRNA nanoparticles do not disassemble in blood plasma in vitro and in vivo. This clearance mechanism may affect any nanoparticles that assemble primarily by electrostatic interactions between cationic delivery components and anionic nucleic acids (or other therapeutic entities).", "doi": "10.1073/pnas.1200718109", "pmcid": "PMC3286910", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2012-02-21", "series_number": "8", "volume": "109", "issue": "8", "pages": "3137-3142" }, { "id": "authors:h6yef-ehx17", "collection": "authors", "collection_id": "h6yef-ehx17", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150910-084810058", "type": "patent", "title": "Click chemistry surface functionalization for resonant micro-cavity sensors", "author": [ { "family_name": "Armani", "given_name": "Andrea M.", "orcid": "0000-0001-9890-5104", "clpid": "Armani-Andrea-Martin" }, { "family_name": "Alabi", "given_name": "Akinleye C.", "clpid": "Alabi-A-C" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Flagan", "given_name": "Richard C.", "orcid": "0000-0001-5690-770X", "clpid": "Flagan-R-C" }, { "family_name": "Fraser", "given_name": "Scott E.", "orcid": "0000-0002-5377-0223", "clpid": "Fraser-S-E" } ], "abstract": "Micro-cavity resonant sensors have outer surfaces that are functionalized using click chemistry, e.g., involving a cycloaddition reaction of an alkyne functional group and an azide functional group. A first polymer linking element binds to an outer surface of the micro-cavity and has an azide functional group, which bonds to an alkyne functional group of a second polymer linking element as a result of a cycloaddition reaction. A functionalization element such as an antibody, antigen or protein for sensing a target molecule is bound to the second linking element.", "publisher": "U.S. Patent Office", "publication_date": "2012-01-10" }, { "id": "authors:4034v-fxb73", "collection": "authors", "collection_id": "4034v-fxb73", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111129-073030662", "type": "article", "title": "Activation of Carbonyl-Containing Molecules with Solid Lewis Acids in Aqueous Media", "author": [ { "family_name": "Rom\u00e1n-Leshkov", "given_name": "Yuriy", "orcid": "0000-0002-0025-4233", "clpid": "Rom\u00e1n-Leshkov-Y" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Current interest in reacting carbonyl-containing molecules in aqueous media is primarily due to the growing emphasis on conversion of biomass to fuels and chemicals. Recently, solid Lewis acids have been shown to perform catalytic reactions with carbonyl-containing molecules such as sugars in aqueous media. Here, catalysis mediated by Lewis acids is briefly discussed, Lewis acid solids that perform catalysis in aqueous media are then described, and the review is concluded with a few comments on the outlook for the future.", "doi": "10.1021/cs200411d", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2011-11", "series_number": "11", "volume": "1", "issue": "11", "pages": "1566-1580" }, { "id": "authors:bm7p8-zjw67", "collection": "authors", "collection_id": "bm7p8-zjw67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111111-103608380", "type": "article", "title": "Reply to Perris, Borghese, and Magro", "author": [ { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Ribas", "given_name": "Antoni", "clpid": "Ribas-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Pitfalling in nanomedical targeting of melanoma: a 'clinical' case of misdelivered RNAi - Reply", "doi": "10.1111/j.1755-148X.2011.00897.x", "issn": "1755-1471", "publisher": "Blackwell", "publication": "Pigment Cell and Melanoma Research", "publication_date": "2011-10", "series_number": "5", "volume": "24", "issue": "5", "pages": "983-985" }, { "id": "authors:vydsz-0q411", "collection": "authors", "collection_id": "vydsz-0q411", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110506-112052601", "type": "article", "title": "Targeting kidney mesangium by nanoparticles of defined size", "author": [ { "family_name": "Choi", "given_name": "Chung Hang J.", "clpid": "Choi-Chung-Hang-J" }, { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Webster", "given_name": "Paul", "clpid": "Webster-P" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Nanoparticles are being investigated for numerous medical applications and are showing potential as an emerging class of carriers for drug delivery. Investigations on how the physicochemical properties (e.g., size, surface charge, shape, and density of targeting ligands) of nanoparticles enable their ability to overcome biological barriers and reach designated cellular destinations in sufficient amounts to elicit biological efficacy are of interest. Despite proven success in nanoparticle accumulation at cellular locations and occurrence of downstream therapeutic effects (e.g., target gene inhibition) in a selected few organs such as tumor and liver, reports on effective delivery of engineered nanoparticles to other organs still remain scarce. Here, we show that nanoparticles of ~75 \u00b1 25-nm diameters target the mesangium of the kidney. These data show the effects of particle diameter on targeting the mesangium of the kidney. Because many diseases originate from this area of the kidney, our findings establish design criteria for constructing nanoparticle-based therapeutics for targeting diseases that involve the mesangium of the kidney.", "doi": "10.1073/pnas.1103573108", "pmcid": "PMC3080986", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2011-04-19", "series_number": "16", "volume": "108", "issue": "16", "pages": "6656-6661" }, { "id": "authors:ys99d-gv619", "collection": "authors", "collection_id": "ys99d-gv619", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110505-113943118", "type": "article", "title": "\"One-Pot\" Synthesis of 5-(Hydroxymethyl)furfural from Carbohydrates using Tin-Beta Zeolite", "author": [ { "family_name": "Nikolla", "given_name": "Eranda", "orcid": "0000-0002-8172-884X", "clpid": "Nikolla-E" }, { "family_name": "Rom\u00e1n-Leshkov", "given_name": "Yuriy", "orcid": "0000-0002-0025-4233", "clpid": "Rom\u00e1n-Leshkov-Y" }, { "family_name": "Moliner", "given_name": "Manuel", "orcid": "0000-0002-5440-716X", "clpid": "Moliner-Manuel" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Conversion of carbohydrates to 5-(hydroxymethyl)furfural (HMF) may provide a step forward toward achieving a renewable biomass-based chemicals and fuels platform. Recently, we reported that a tin-containing, high-silica molecular sieve with the zeolite beta topology (Sn-Beta) can efficiently catalyze the isomerization of glucose to fructose in aqueous media at low pH. Herein, we describe the combination of Sn-Beta with acid catalysts in a one vessel, biphasic reactor system to synthesize HMF from carbohydrates such as glucose, cellobiose, and starch with high efficiency. HMF selectivities over 70% were obtained using this \"one-pot\" biphasic water/tetrahydrofuran (THF) reactor system. The key to successfully achieving the conversions/selectivities reported is that Sn-Beta is able to convert glucose to fructose at pH near 1 and in saturated aqueous salt solutions.", "doi": "10.1021/cs2000544", "issn": "2155-5435", "publisher": "American Chemical Society", "publication": "ACS Catalysis", "publication_date": "2011-04-01", "series_number": "4", "volume": "1", "issue": "4", "pages": "408-410" }, { "id": "authors:2c71x-cjk38", "collection": "authors", "collection_id": "2c71x-cjk38", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110303-143355838", "type": "article", "title": "Impact of Controlling the Site Distribution of Al Atoms on Catalytic Properties in Ferrierite-Type Zeolites", "author": [ { "family_name": "Rom\u00e1n-Leshkov", "given_name": "Yuriy", "orcid": "0000-0002-0025-4233", "clpid": "Rom\u00e1n-Leshkov-Y" }, { "family_name": "Moliner", "given_name": "Manuel", "orcid": "0000-0002-5440-716X", "clpid": "Moliner-Manuel" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolites with the ferrierite (FER) topology are synthesized using a combination of tetramethylammonium\n(TMA) cations with differently sized cyclic amines (pyrrolidine (Pyr), hexamethyleneimine (HMI), and 1,4-\ndiazabicyclo[2.2.2]octane (DAB)). Using these organic structure-directing agents (SDAs), low Si/Al ratios\nand concentrated synthesis mixtures favor the crystallization of FER materials. Increasing the size of the\ncyclic amine or decreasing the aluminum content leads to the crystallization of other phases or the creation\nof excessive amounts of connectivity defects. TMA cations play a decisive role in the synthesis of the FER\nmaterials, and their presence allows the use of HMI to synthesize FER. Proton MAS NMR is used to quantify\nthe accessibility of pyridine to acid sites in these FER samples, where it is found that the FER + HMI + TMA\nsample contains only 27% acid sites in the 8-MR channels, whereas FER + Pyr and FER + Pyr + TMA\ncontain 89% and 84%, respectively. The constraint index (CI) test and the carbonylation of dimethyl ether\n(DME) with carbon monoxide are used as probe reactions to evaluate how changes in the aluminum distribution\nin these FER samples affect their catalytic behavior. Results show that the use of Pyr as an SDA results in\nthe selective population of acid sites in the 8-MR channels, whereas the use of HMI generates FER zeolites\nwith an increased concentration of acid sites in the 10-MR channels.", "doi": "10.1021/jp106247g", "issn": "1932-7447", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry C", "publication_date": "2011-02-03", "series_number": "4", "volume": "115", "issue": "4", "pages": "1096-1102" }, { "id": "authors:z17hj-cag39", "collection": "authors", "collection_id": "z17hj-cag39", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110215-084538493", "type": "article", "title": "siRNA Knockdown of Ribonucleotide Reductase Inhibits Melanoma Cell Line Proliferation Alone or Synergistically with Temozolomide", "author": [ { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Hsueh", "given_name": "Teli", "clpid": "Hsueh-T" }, { "family_name": "Koya", "given_name": "Richard C.", "clpid": "Koya-R-C" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Ribas", "given_name": "Antoni", "clpid": "Ribas-A" } ], "abstract": "Systemically delivered small interfering RNA (siRNA) therapies for cancer have begun clinical development. The effects of siRNA-mediated knockdown of ribonucleotide reductase subunit-2 (RRM2), a rate-limiting enzyme in cell replication, were investigated in malignant melanoma, a cancer with a paucity of effective treatment options. A panel of human melanoma cell lines was transfected with siRNA to induce the knockdown of RRM2. Sequence-specific, siRNA-mediated inhibition of RRM2 effectively blocked cell proliferation and induced G1/S-phase cell cycle arrest. This effect was independent of the activating oncogenic mutations in the tested cell lines. Synergistic inhibition of melanoma cell proliferation was achieved using the combination of siRNA targeting RRM2 and temozolomide, an analog of the current standard of care for melanoma chemotherapy. In conclusion, siRNA-mediated RRM2 knockdown significantly inhibits proliferation of melanoma cell lines with different oncogenic mutations with synergistic enhancement in combination with temozolomide.", "doi": "10.1038/jid.2010.310", "issn": "0022-202X", "publisher": "Nature Publishing Group", "publication": "Journal of Investigative Dermatology", "publication_date": "2011-02", "series_number": "2", "volume": "131", "issue": "2", "pages": "453-460" }, { "id": "authors:3vk2r-se003", "collection": "authors", "collection_id": "3vk2r-se003", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110223-093924933", "type": "article", "title": "Clinical Developments in Nanotechnology for Cancer Therapy", "author": [ { "family_name": "Heidel", "given_name": "Jeremy D.", "clpid": "Heidel-J-D" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Nanoparticle approaches to drug delivery for cancer offer exciting and potentially \"game-changing\" ways to improve patient care and quality of life in numerous ways, such as reducing off-target toxicities by more selectively directing drug molecules to intracellular targets of cancer cells. Here, we focus on technologies being investigated clinically and discuss numerous types of therapeutic molecules that have been incorporated within nanostructured entities such as nanoparticles. The impacts of nanostructured therapeutics on efficacy and safety, including parameters like pharmacokinetics and biodistribution, are described for several drug molecules.\nAdditionally, we discuss recent advances in the understanding of ligand-based targeting of nanoparticles, such as on receptor avidity and selectivity.", "doi": "10.1007/s11095-010-0178-7", "issn": "0724-8741", "publisher": "Springer", "publication": "Pharmaceutical Research", "publication_date": "2011-02", "series_number": "2", "volume": "28", "issue": "2", "pages": "187-199" }, { "id": "authors:2yxg1-sbh28", "collection": "authors", "collection_id": "2yxg1-sbh28", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171025-152210869", "type": "patent", "title": "Molecular sieves for improved hydrocarbon traps", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Okubo", "given_name": "Tatsuya", "clpid": "Okubo-Tatsuya" } ], "abstract": "Molecular sieves and the use of such materials as hydrocarbon traps, particularly for reducing the emissions associated with the combustion of hydrocarbon fuels are described. Specifically, the use of molecular sieves such as zeolites as adsorbents for hydrocarbon gases, especially exhaust gases such as are formed during the combustion of hydrocarbons, and more particularly to the adsorption of hydrocarbon gases formed during the cold start operation of an internal combustion engine is described. In one embodiment, a method of treating exhaust gas that comprises a hydrocarbon combustion product is provided, the method comprising contacting the exhaust gas with a CON topology molecular sieve for a time period effective to facilitate adsorption of the hydrocarbon combustion product by the molecular sieve; passing a purge gas through the molecular sieve to remove adsorbed hydrocarbon combustion product; and contacting the purge gas containing the removed hydrocarbon combustion product with a hydrocarbon conversion catalyst.", "publisher": "U.S. Patent Office", "publication_date": "2010-12-28" }, { "id": "authors:zg3ry-fxr16", "collection": "authors", "collection_id": "zg3ry-fxr16", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120815-152834973", "type": "conference_item", "title": "Polymer nanoparticle-based cancer therapeutics: from concept to clinic", "author": [ { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Nanoparticle-based therapeutics contg. either small mol. anti-cancer agents (IT-101; entered Phase II) or siRNA\n(CALAA-01; in Phase I) are described. The key component in each nanoparticle is a cyclodextrin-contg. polymer that\nendows it with multifunctional behavior. Relationships between nanoparticle design and function in animal models are\nillustrated. Results from clin. trials are presented so show how nanoparticle-based therapeutics can provide interesting\nbehavior in humans.", "publisher": "Caltech Library", "publication_date": "2010-12" }, { "id": "authors:q5zvd-qfa30", "collection": "authors", "collection_id": "q5zvd-qfa30", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120816-073317087", "type": "conference_item", "title": "Tin-containing zeolites are highly active catalysts for the isomerization of glucose in water", "author": [ { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Moliner", "given_name": "M.", "orcid": "0000-0002-5440-716X", "clpid": "Moliner-Manuel" }, { "family_name": "Rom\u00e1n-Leshkov", "given_name": "Y.", "orcid": "0000-0002-0025-4233", "clpid": "Rom\u00e1n-Leshkov-Y" } ], "abstract": "The isomerization of glucose into fructose is a large-scale reaction for the prodn. of high-fructose corn syrup (HFCS;\nreaction performed by enzyme catalysts), and recently, is being considered as an intermediate step in the possible route\nof biomass to fuels and chems. Here, we show that a large pore zeolite that contains tin (Sn-Beta) is able to isomerize\nglucose to fructose in aq. media with high activity and selectivity. For example, a 10 wt% glucose soln. contg. a catalytic\namt. of Sn-Beta (1:50 Sn:glucose molar ratio) gives product yields of approx. 46% (wt./wt.) glucose, 31% (wt./wt.)\nfructose, and 9% (wt./wt.) mannose after 30 and 12 min of reaction at 383 K and 413 K, resp. The properties of the large\npore zeolite greatly influence the reaction behavior as the reaction does not proceed with a medium pore zeolite, and the\nisomerization activity is considerably lower when the metal centers are incorporated in ordered mesoporous silica (MCM-\n41). The Sn-Beta catalyst can be used for multiple cycles, and the reaction stops when the solid is removed, clearly\nindicating that the catalysis is occurring heterogeneously. Addnl., the Sn-Beta catalyst is able to perform the\nisomerization reaction in highly acidic, aq. environments with equiv. activity and product distribution as in media without\nadded acid. This enables Sn-Beta to couple isomerizations with other acid-catalyzed reactions, including\nhydrolysis/isomerization or isomerization/dehydration reaction sequences (starch to fructose and glucose to 5-\nhydroxymethylfurfural (HMF) demonstrated here). Details of the catalyst prepn. and reaction mechanism will be\npresented as well as discussions on how this new catalyst system could be integrated into larger reaction networks.", "publisher": "Caltech Library", "publication_date": "2010-12" }, { "id": "authors:p72fh-apq94", "collection": "authors", "collection_id": "p72fh-apq94", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101221-084907268", "type": "article", "title": "Mechanism of Glucose Isomerization Using a Solid Lewis Acid Catalyst in Water", "author": [ { "family_name": "Rom\u00e1n-Leshkov", "given_name": "Yuriy", "orcid": "0000-0002-0025-4233", "clpid": "Rom\u00e1n-Leshkov-Y" }, { "family_name": "Moliner", "given_name": "Manuel", "orcid": "0000-0002-5440-716X", "clpid": "Moliner-Manuel" }, { "family_name": "Labinger", "given_name": "Jay A.", "orcid": "0000-0002-1942-9232", "clpid": "Labinger-J-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "^1H and ^(13)C\u2005NMR spectroscopy on isotopically labeled glucose reveals that in the presence of tin-containing zeolite Sn-Beta, the isomerization reaction of glucose in water proceeds by way of an intramolecular hydride shift (see scheme) rather than proton transfer. This is the first mechanistic demonstration of Sn-Beta acting as a Lewis acid in a purely aqueous environment.", "doi": "10.1002/anie.201004689", "issn": "1433-7851", "publisher": "Wiley", "publication": "Angewandte Chemie International Edition", "publication_date": "2010-11-15", "series_number": "47", "volume": "49", "issue": "47", "pages": "8954-8957" }, { "id": "authors:7fkt9-1zz13", "collection": "authors", "collection_id": "7fkt9-1zz13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100409-142845517", "type": "article", "title": "Imidazolium structure directing agents in zeolite synthesis: Exploring guest/host relationships in the synthesis of SSZ-70", "author": [ { "family_name": "Archer", "given_name": "Raymond H.", "clpid": "Archer-R-H" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The synthesis of high-silica molecular sieve SSZ-70 is investigated using a variety of imidazolium structure directing agents (SDAs) that are designed to explore the nature of the guest (SDA)/host (SSZ-70) interactions. The SDAs are symmetric 1,3-disubstituted imidazoliums that span a wide range of hydrophobicity from 1,3-dimethylimidazolium (\u03a3(C + N) = 7) to 1,3-bis(2,6-diisopropylphenyl)imidazolium (\u03a3(C + N) = 29). Reactions with fluoride or hydroxide as mineralizing agent are investigated in pure-silica, borosilicate, and aluminosilicate inorganic compositions. The original borosilicate synthesis is extended to pure-silica and aluminosilicate compositions using five SDAs. The five SDAs span \u03a3(C + N) = 13 (1,3-bis(isobutyl)imidazolium) to \u03a3(C + N) = 19 (1,3-bis(cycloheptyl)imidazolium and 1,3-bis(norborn-2-yl)imidazolium) and four contain cycloalkyl groups. Thirteen screening reaction conditions (total of 160 syntheses) produced 11 different known molecular sieves.", "doi": "10.1016/j.micromeso.2009.11.018", "issn": "1387-1811", "publisher": "Elsevier", "publication": "Microporous and Mesoporous Materials", "publication_date": "2010-05", "series_number": "1-3", "volume": "130", "issue": "1-3", "pages": "255-265" }, { "id": "authors:ghhbe-g7h71", "collection": "authors", "collection_id": "ghhbe-g7h71", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100412-094056315", "type": "article", "title": "Pure-silica LTA, CHA, STT, ITW, and -SVR thin films and powders for low-k applications", "author": [ { "family_name": "Hunt", "given_name": "Heather K.", "clpid": "Hunt-H-K" }, { "family_name": "Lew", "given_name": "Christopher M.", "clpid": "Lew-C-M" }, { "family_name": "Sun", "given_name": "Minwei", "clpid": "Sun-Minwei" }, { "family_name": "Yan", "given_name": "Yushan", "clpid": "Yan-Yushan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The fluoride-mediated synthesis of pure-silica zeolite thin films with the STT and SSZ-74 (-SVR) topologies on surface-modified (1 0 0) Si wafers is reported. The films are prepared using the vapor phase transport of the fluoride mineralizing agent, a method used previously to synthesize thin films of the pure-silica zeolite topologies LTA, CHA, and ITW. The STT and -SVR films are polycrystalline, intergrown, continuous, and well-adhered to their substrates. The films are characterized by a combination of techniques, including X-ray diffraction and field emission scanning electron microscopy. The LTA, STT, -SVR, CHA, and ITW powders and films are investigated for low dielectric constant (low-k) material applications. The films are evaluated via parallel-plate capacitance measurements using an LCR meter; however, consistent k-values are not obtained due to variable film thicknesses and imperfectly parallel metal\u2013insulator\u2013metal structures. This variability is a limitation of the mechanical polishing equipment available, rather than the films themselves. Using a Time-Domain Reflectometer, combined with a transmission line, at various frequencies, the k-values of the powdered zeolites are determined. All the zeolites investigated, except STT, give k-values lower than those predicted from their structures using the Bruggeman effective medium model that has been commonly employed and found able to predict dielectric constants for amorphous silicas.", "doi": "10.1016/j.micromeso.2009.10.011", "issn": "1387-1811", "publisher": "Elsevier", "publication": "Microporous and Mesoporous Materials", "publication_date": "2010-05", "series_number": "1-3", "volume": "130", "issue": "1-3", "pages": "49-55" }, { "id": "authors:jt28b-qn598", "collection": "authors", "collection_id": "jt28b-qn598", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100513-094810982", "type": "article", "title": "Hybrid Organic\u2212Inorganic Solids That Show Shape Selectivity", "author": [ { "family_name": "Rom\u00e1n-Leshkov", "given_name": "Yuriy", "clpid": "Romn-Leshkov-Y" }, { "family_name": "Moliner", "given_name": "Manuel", "clpid": "Moliner-M" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Hybrid organic\u2212inorganic solids featuring millimolar/gram concentrations of intracrystalline organic moieties and shape-selectivity are synthesized. Pure-silica zeolite beta crystals are coated with zirconia and treated in aqueous sodium hydroxide to create defects and mesoporosity within the crystalline structure. Aminopropyl organic groups are subsequently grafted onto the generated intracrystalline silanol groups. After grafting, characterization data indicate a high organic concentration localized primarily within the intracrystalline voids. Specifically, thermogravimetric analysis shows an organic loading of 0.7 mmol of NH_2/g, ^(29)Si solid-state nuclear magnetic resonance (NMR) spectra display a quantitative decrease in Q^3 silicon atoms with a corresponding resharpening of the Q^4 resonances, and N_2 adsorption data show a decrease in micropore volume to 0.10 cm^3/g. Knoevenagel condensation reactions are catalyzed by the aminopropyl-functionalized materials using differently sized aldehydes and the results show that the zirconia-protected functionalized solid have shape selective properties.", "doi": "10.1021/cm100108e", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2010-04-27", "series_number": "8", "volume": "22", "issue": "8", "pages": "2646-2652" }, { "id": "authors:p0vb7-0sv43", "collection": "authors", "collection_id": "p0vb7-0sv43", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100512-143356133", "type": "article", "title": "Physicochemical Properties and Catalytic Behavior of the Molecular Sieve SSZ-70", "author": [ { "family_name": "Archer", "given_name": "Raymond H.", "clpid": "Archer-R-H" }, { "family_name": "Carpenter", "given_name": "John R.", "clpid": "Carpenter-J-R" }, { "family_name": "Hwang", "given_name": "Son-Jong", "orcid": "0000-0002-3210-466X", "clpid": "Hwang-Son-Jong" }, { "family_name": "Burton", "given_name": "Allen W.", "clpid": "Burton-A-W" }, { "family_name": "Chen", "given_name": "Cong-Yan", "clpid": "Chen-Cong-Yan" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "SSZ-70 is synthesized using 1,3-bis(isobutyl)imidazolium, 1,3-bis(cyclohexyl)imidazolium, and 1,3-bis(cycloheptyl)imidazolium structure directing agents (SDAs), and the solids obtained are characterized by powder X-ray diffraction (XRD), ^(29)Si magic angle spinning nuclear magnetic resonance (MAS NMR), electron microscopy, nitrogen and hydrocarbon adsorption, and thermogravimetric analyses. The physicochemical properties of SSZ-70 show that it is a new molecular sieve that has similarities to MWW-type materials. The catalytic behavior of SSZ-70 is evaluated through the use of the constraint index (CI) test. Distinct differences in the reactivity between Al-SSZ-70 and SSZ-25 (MWW) are observed and are the consequences of the structural differences between these two molecular sieves.", "doi": "10.1021/cm9035677", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2010-04-27", "series_number": "8", "volume": "22", "issue": "8", "pages": "2563-2572" }, { "id": "authors:798w7-pyq25", "collection": "authors", "collection_id": "798w7-pyq25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100512-155357114", "type": "article", "title": "Evidence of RNAi in humans from systemically administered siRNA via targeted nanoparticles", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Zuckerman", "given_name": "Jonathan E.", "clpid": "Zuckerman-J-E" }, { "family_name": "Choi", "given_name": "Chung Hang J.", "clpid": "Choi-Chung-Hang-J" }, { "family_name": "Seligson", "given_name": "David", "clpid": "Seligson-D" }, { "family_name": "Tolcher", "given_name": "Anthony", "clpid": "Tolcher-A" }, { "family_name": "Alabi", "given_name": "Christopher A.", "orcid": "0000-0003-2654-018X", "clpid": "Alabi-C-A" }, { "family_name": "Yen", "given_name": "Yun", "orcid": "0000-0003-0815-412X", "clpid": "Yen-Yun" }, { "family_name": "Heidel", "given_name": "Jeremy D.", "clpid": "Heidel-J-D" }, { "family_name": "Ribas", "given_name": "Antoni", "clpid": "Ribas-Antoni" } ], "abstract": "Therapeutics that are designed to engage RNA interference (RNAi) pathways have the potential to provide new, major ways of imparting therapy to patients. Long, double-stranded RNAs were first shown to mediate RNAi in Caenorhabditis elegans, and the potential use of RNAi for human therapy has been demonstrated by the finding that small interfering RNAs (siRNAs; approximately 21-base-pair double-stranded RNA) can elicit RNAi in mammalian cells without producing an interferon response. We are at present conducting the first in-human phase I clinical trial involving the systemic administration of siRNA to patients with solid cancers using a targeted, nanoparticle delivery system. Here we provide evidence of inducing an RNAi mechanism of action in a human from the delivered siRNA. Tumour biopsies from melanoma patients obtained after treatment show the presence of intracellularly localized nanoparticles in amounts that correlate with dose levels of the nanoparticles administered (this is, to our knowledge, a first for systemically delivered nanoparticles of any kind). Furthermore, a reduction was found in both the specific messenger RNA (M2 subunit of ribonucleotide reductase (RRM2)) and the protein (RRM2) levels when compared to pre-dosing tissue. Most notably, we detect the presence of an mRNA fragment that demonstrates that siRNA-mediated mRNA cleavage occurs specifically at the site predicted for an RNAi mechanism from a patient who received the highest dose of the nanoparticles. Together, these data demonstrate that siRNA administered systemically to a human can produce a specific gene inhibition (reduction in mRNA and protein) by an RNAi mechanism of action.", "doi": "10.1038/nature08956", "pmcid": "PMC2855406", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2010-04-15", "series_number": "7291", "volume": "464", "issue": "7291", "pages": "1067-1071" }, { "id": "authors:jsj2h-qxw82", "collection": "authors", "collection_id": "jsj2h-qxw82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100521-093201116", "type": "article", "title": "Tin-containing zeolites are highly active catalysts for the isomerization of glucose in water", "author": [ { "family_name": "Moliner", "given_name": "Manuel", "orcid": "0000-0002-5440-716X", "clpid": "Moliner-Manuel" }, { "family_name": "Rom\u00e1n-Leshkov", "given_name": "Yuriy", "orcid": "0000-0002-0025-4233", "clpid": "Rom\u00e1n-Leshkov-Y" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The isomerization of glucose into fructose is a large-scale reaction for the production of high-fructose corn syrup (HFCS; reaction performed by enzyme catalysts) and recently is being considered as an intermediate step in the possible route of biomass to fuels and chemicals. Here, it is shown that a large-pore zeolite that contains tin (Sn-Beta) is able to isomerize glucose to fructose in aqueous media with high activity and selectivity. Specifically, a 10% (wt/wt) glucose solution containing a catalytic amount of Sn-Beta (1\u223650 Sn:glucose molar ratio) gives product yields of approximately 46% (wt/wt) glucose, 31% (wt/wt) fructose, and 9% (wt/wt) mannose after 30 min and 12 min of reaction at 383 K and 413 K, respectively. This reactivity is achieved also when a 45 wt% glucose solution is used. The properties of the large-pore zeolite greatly influence the reaction behavior because the reaction does not proceed with a medium-pore zeolite, and the isomerization activity is considerably lower when the metal centers are incorporated in ordered mesoporous silica (MCM-41). The Sn-Beta catalyst can be used for multiple cycles, and the reaction stops when the solid is removed, clearly indicating that the catalysis is occurring heterogeneously. Most importantly, the Sn-Beta catalyst is able to perform the isomerization reaction in highly acidic, aqueous environments with equivalent activity and product distribution as in media without added acid. This enables Sn-Beta to couple isomerizations with other acid-catalyzed reactions, including hydrolysis/isomerization or isomerization/dehydration reaction sequences [starch to fructose and glucose to 5-hydroxymethylfurfural (HMF) demonstrated here].", "doi": "10.1073/pnas.1002358107", "pmcid": "PMC2852018", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2010-04-06", "series_number": "14", "volume": "107", "issue": "14", "pages": "6164-6168" }, { "id": "authors:12ssj-rfm67", "collection": "authors", "collection_id": "12ssj-rfm67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100125-095643851", "type": "article", "title": "Pure-silica zeolite thin films by vapor phase transport of fluoride for low-k applications", "author": [ { "family_name": "Hunt", "given_name": "Heather K.", "clpid": "Hunt-H-K" }, { "family_name": "Lew", "given_name": "Christopher M.", "clpid": "Lew-Christopher-M" }, { "family_name": "Sun", "given_name": "Minwei", "clpid": "Sun-Minwei" }, { "family_name": "Yan", "given_name": "Yushan", "clpid": "Yan-Yushan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A new method to synthesize pure-silica zeolite films is presented. Specifically, this method uses fluoridemediated\nsyntheses that involve the vapor phase transport of the mineralizing agent, fluoride, to crystallize\na precursor film deposited by dip-coating techniques to obtain thin films of pure-silica zeolites with\nLTA, CHA, and ITW topologies. The films are characterized by a combination of X-ray diffraction, field\nemission scanning electron microscopy, and X-ray energy dispersive analyses. The films are polycrystalline,\nintergrown, continuous and well-adhered to their substrates. The usefulness of these thin films as\nlow-k materials, that are needed to reduce cross-talk noise and energy dissipation between transistors\nin an integrated circuit, is demonstrated via evaluation of the pure-silica LTA film. The LTA topology\nhas the lowest framework density (FD = 14.2) of the 19 known pure-silica zeolites, and theoretically\ncould have the lowest dielectric constant. The average dielectric constants of the LTA films are calculated\nfrom capacitance measurements at a frequency of 1 MHz with metal\u2013insulator\u2013metal structures on lowresistivity\nsilicon substrates, and yield an average k = 1.69, well within the ultra low-k material requirements (k between 2.3 and 2.6).", "doi": "10.1016/j.micromeso.2009.07.023", "issn": "1387-1811", "publisher": "Elsevier", "publication": "Microporous and Mesoporous Materials", "publication_date": "2010-03", "series_number": "1-3", "volume": "128", "issue": "1-3", "pages": "12-18" }, { "id": "authors:fkxrp-9fa12", "collection": "authors", "collection_id": "fkxrp-9fa12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100217-134833200", "type": "article", "title": "Mechanism of active targeting in solid tumors with transferrin-containing gold nanoparticles", "author": [ { "family_name": "Choi", "given_name": "Chung Hang J.", "clpid": "Choi-Chung-Hang-J" }, { "family_name": "Alabi", "given_name": "Christopher A.", "orcid": "0000-0003-2654-018X", "clpid": "Alabi-C-A" }, { "family_name": "Webster", "given_name": "Paul", "clpid": "Webster-P" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "PEGylated gold nanoparticles are decorated with various amounts of human transferrin (Tf) to give a series of Tf-targeted particles with near-constant size and electrokinetic potential. The effects of Tf content on nanoparticle tumor targeting were investigated in mice bearing s.c. Neuro2A tumors. Quantitative biodistributions of the nanoparticles 24 h after i.v. tail-vein injections show that the nanoparticle accumulations in the tumors and other organs are independent of Tf. However, the nanoparticle localizations within a particular organ are influenced by the Tf content. In tumor tissue, the content of targeting ligands significantly influences the number of nanoparticles localized within the cancer cells. In liver tissue, high Tf content leads to small amounts of the nanoparticles residing in hepatocytes, whereas most nanoparticles remain in nonparenchymal cells. These results suggest that targeted nanoparticles can provide greater intracellular delivery of therapeutic agents to the cancer cells within solid tumors than their nontargeted analogs.", "doi": "10.1073/pnas.0914140107", "pmcid": "PMC2824286", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2010-01-19", "series_number": "3", "volume": "107", "issue": "3", "pages": "1235-1240" }, { "id": "authors:2tw2d-pvz32", "collection": "authors", "collection_id": "2tw2d-pvz32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100225-080357989", "type": "article", "title": "Further investigations on Constraint Index testing of zeolites that contain cages", "author": [ { "family_name": "Carpenter", "given_name": "John R.", "clpid": "Carpenter-J-R" }, { "family_name": "Yehb", "given_name": "Sheila", "clpid": "Yehb-S" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolites such as SSZ-25 and SSZ-35 exhibit Constraint Indexes (CI) lower than expected. Two hypotheses for the origin of the lower CI values are that partial cages on the external surface of the zeolites significantly contribute to the overall conversions and that the large cages within the crystalline structures provide less steric hinderence at the active site than would be expected from the size of the pores. The effect of external surface activity is observed by comparing the as-synthesized materials to those passivated via dealumination with ammonium hexafluorosilicate. The external surface dealumination is verified by XPS and by the reduction in reactivity toward isopropanol dehydration observed from materials still containing their SDAs. The external surface of calcined zeolites is shown to have little influence on the CI value. Cage accessibility is investigated by comparisons of structures having larger cages to those that do not and by following the time dependent behavior of the CI values for these materials. The presence of large cages in the zeolites is shown to lower the CI values below those expected from the pore sizes, and the time dependence of the CI value can provide insight into the existence of these larger cage structures.", "doi": "10.1016/j.jcat.2009.10.016", "issn": "0021-9517", "publisher": "Elsevier", "publication": "Journal of Catalysis", "publication_date": "2010-01-01", "series_number": "1", "volume": "269", "issue": "1", "pages": "64-70" }, { "id": "authors:v17km-b4668", "collection": "authors", "collection_id": "v17km-b4668", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091211-112153607", "type": "article", "title": "Design and development of IT-101, a cyclodextrin-containing polymer conjugate of camptothecin", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "IT-101 (Insert Therapeutics-101) is a linear, cyclodextrin-containing polymer conjugate of camptothecin (CPT). When formulated properly, the polymer conjugate self-assembles into nanoparticles of ca. 30 nm diameter and near neutral zeta potential. The nanoparticles show long circulation half-lives in animals and humans and localize in tumors. The nanoparticles enter the tumor cells and slowly release the CPT causing them to disassemble into individual polymer chains that are sufficiently small to be cleared renally. IT-101 is currently being investigated in human clinical trials. Here, the design and development of IT-101 is described with emphasis on features distinguishing it from other polymer-containing therapeutics.", "doi": "10.1016/j.addr.2009.05.005", "issn": "0169-409X", "publisher": "Elsevier", "publication": "Advanced Drug Delivery Reviews", "publication_date": "2009-11-12", "series_number": "13", "volume": "61", "issue": "13", "pages": "1189-1192" }, { "id": "authors:m5adg-96f38", "collection": "authors", "collection_id": "m5adg-96f38", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091125-114131522", "type": "article", "title": "A biodegradable filament for controlled drug delivery", "author": [ { "family_name": "Mack", "given_name": "Brendan C.", "clpid": "Mack-B-C" }, { "family_name": "Wright", "given_name": "Kenneth W.", "clpid": "Wright-K-W" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Biodegradable filaments (diameters of 250\u2013300 \u03bcm) for the controlled delivery of dexamethasone or levofloxacin are described. Filaments are prepared by wet-spinning solutions of poly(lactide-co-glycolide) (PLGA) and drug dissolved in dimethyl sulfoxide (DMSO) into a coagulation bath of water. Compositional analyses of the filaments by independent measurements of drug, DMSO, water, and polymer give drug loadings up to 40% of filament mass and drug retention (drug in filament per drug in solution) greater than 40%. Drug release kinetics, and thermal and mechanical properties, of the filaments are reported. Three filaments with levofloxacin contents of 46 \u00b1 2, 85 \u00b1 4, and 36 \u00b1 2 \u03bcg/cm (denoted 506-L1, 506-L2, and 506-L3, respectively) are implanted in the conjunctiva of New Zealand white rabbits. The time dependent, in-vivo tear concentrations of levofloxacin from filament implants in New Zealand white rabbit eyes are in general agreement with the results from the in-vitro release profiles, with one of the filaments (506-L1) showing effective levels of levofloxacin in the tears for 6 days. The filaments are generally well tolerated by the rabbits. Filament failure occurs at 6\u20138 days within the rabbit eyes, essentially the same time to failure observed from in-vitro mechanical properties testing results.", "doi": "10.1016/j.jconrel.2009.06.020", "issn": "0168-3659", "publisher": "Elsevier", "publication": "Journal of Controlled Release", "publication_date": "2009-11-03", "series_number": "3", "volume": "139", "issue": "3", "pages": "205-211" }, { "id": "authors:5h1v4-h7v47", "collection": "authors", "collection_id": "5h1v4-h7v47", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091020-133220333", "type": "article", "title": "Insights into the Nature of Synergistic Effects in Proton-Conducting 4,4\u22121H,1H-Bitriazole-Poly(ethylene oxide) Composites", "author": [ { "family_name": "Alabi", "given_name": "Christopher A.", "orcid": "0000-0003-2654-018X", "clpid": "Alabi-C-A" }, { "family_name": "Chen", "given_name": "Zhongwei", "clpid": "Chen-Zhongwei" }, { "family_name": "Yan", "given_name": "Yushan S.", "clpid": "Yan-Yushan-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A nitrogen-containing heterocycle (NCH), 4,4-1H-1H-bi-1,2,3-triazole (bitriazole), capable of mimicking the hydrogen bonding of water in the solid state is synthesized and its ability to conduct protons in the presence of poly(ethylene oxides) under anhydrous conditions is investigated. Bitriazole is shown to have sufficient thermal and electrochemical stability for fuel cell applications. The composites formed between bitriazole and poly(ethylene oxides) give proton conductivities that can be described by the Vogel\u2212Tamman\u2212Fulcher (VTF) equation. These characteristics suggest coupling between polymer segmental motion and ion transport. The bitriazole N-H proton is shown to be the source of conductivity, and bitriazole and poly(ethylene oxides) function synergistically through specific intermolecular interactions and polymer-induced segmental motion to create a pathway for proton transport via structural diffusion.", "doi": "10.1021/cm901772q", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2009-10-13", "series_number": "19", "volume": "21", "issue": "19", "pages": "4645-2652" }, { "id": "authors:thhx1-wea78", "collection": "authors", "collection_id": "thhx1-wea78", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091102-140636691", "type": "article", "title": "Development of universal antidotes to control aptamer activity", "author": [ { "family_name": "Oney", "given_name": "Sabah", "clpid": "Oney-S" }, { "family_name": "Lam", "given_name": "Ruby T. S.", "clpid": "Lam-R-T-S" }, { "family_name": "Bompiani", "given_name": "Kristin M.", "clpid": "Bompiani-K-M" }, { "family_name": "Blake", "given_name": "Charlene M.", "clpid": "Blake-C-M" }, { "family_name": "Quick", "given_name": "George", "clpid": "Quick-G" }, { "family_name": "Heidel", "given_name": "Jeremy D.", "clpid": "Heidel-J-D" }, { "family_name": "Liu", "given_name": "Joanna Yi-Ching", "clpid": "Liu-J-Y-C" }, { "family_name": "Mack", "given_name": "Brendan C.", "clpid": "Mack-B-C" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Leong", "given_name": "Kam W.", "clpid": "Leong-K-W" }, { "family_name": "Sullenger", "given_name": "Bruce A.", "clpid": "Sullenger-B-A" } ], "abstract": "With an ever increasing number of people taking numerous medications, the need to safely administer drugs and limit unintended side effects has never been greater. Antidote control remains the most direct means to counteract acute side effects of drugs, but, unfortunately, it has been challenging and cost prohibitive to generate antidotes for most therapeutic agents. Here we describe the development of a set of antidote molecules that are capable of counteracting the effects of an entire class of therapeutic agents based upon aptamers. These universal antidotes exploit the fact that, when systemically administered, aptamers are the only free extracellular oligonucleotides found in circulation. We show that protein- and polymer-based molecules that capture oligonucleotides can reverse the activity of several aptamers in vitro and counteract aptamer activity in vivo. The availability of universal antidotes to control the activity of any aptamer suggests that aptamers may be a particularly safe class of therapeutics.", "doi": "10.1038/nm.1990", "issn": "1078-8956", "publisher": "Nature Publishing Group", "publication": "Nature Medicine", "publication_date": "2009-10", "series_number": "10", "volume": "15", "issue": "10", "pages": "1224-1229" }, { "id": "authors:44xh9-zd805", "collection": "authors", "collection_id": "44xh9-zd805", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090825-134717535", "type": "article", "title": "Pharmacokinetics and tumor dynamics of the nanoparticle IT-101 from PET imaging and tumor histological measurements", "author": [ { "family_name": "Schluep", "given_name": "Thomas", "clpid": "Schluep-T" }, { "family_name": "Hwang", "given_name": "Jungyeon", "clpid": "Hwang-Jungyeon" }, { "family_name": "Hildebrandt", "given_name": "Isabel J.", "clpid": "Hildebrandt-I-J" }, { "family_name": "Czernin", "given_name": "Johannes", "clpid": "Czernin-J" }, { "family_name": "Choi", "given_name": "Chung Hang J.", "clpid": "Choi-Chung-Hang-J" }, { "family_name": "Alabi", "given_name": "Christopher A.", "orcid": "0000-0003-2654-018X", "clpid": "Alabi-C-A" }, { "family_name": "Mack", "given_name": "Brendan C.", "clpid": "Mack-B-C" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "IT-101, a cyclodextrin polymer-based nanoparticle containing camptothecin, is in clinical development for the treatment of cancer. Multiorgan pharmacokinetics and accumulation in tumor tissue of IT-101 is investigated by using PET. IT-101 is modified through the attachment of a 1,4,7,10-tetraazacyclododecane-1,4,7-Tris-acetic acid ligand to bind ^(64)Cu^(2+). This modification does not affect the particle size and minimally affects the surface charge of the resulting nanoparticles. PET data from ^(64)Cu-labeled IT-101 are used to quantify the in vivo biodistribution in mice bearing Neuro2A s.c. tumors. The ^(64)Cu-labeled IT-101 displays a biphasic plasma elimination. Approximately 8% of the injected dose is rapidly cleared as a low-molecular-weight fraction through the kidneys. The remaining material circulates in plasma with a terminal half-life of 13.3 h. Steadily increasing concentrations, up to 11% injected dose per cm^3, are observed in the tumor over 24 h, higher than any other tissue at that time. A 3-compartment model is used to determine vascular permeability and nanoparticle retention in tumors, and is able to accurately represent the experimental data. The calculated tumor vascular permeability indicates that the majority of nanoparticles stay intact in circulation and do not disassemble into individual polymer strands. A key assumption to modeling the tumor dynamics is that there is a \"sink\" for the nanoparticles within the tumor. Histological measurements using confocal microscopy show that IT-101 localizes within tumor cells and provides the sink in the tumor for the nanoparticles.", "doi": "10.1073/pnas.0905487106", "pmcid": "PMC2703672", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2009-07-07", "series_number": "27", "volume": "106", "issue": "27", "pages": "11394-11399" }, { "id": "authors:ayeyg-s8032", "collection": "authors", "collection_id": "ayeyg-s8032", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090904-125622074", "type": "article", "title": "Dielectric constant measurement of zeolite powders by time-domain reflectometry", "author": [ { "family_name": "Sun", "given_name": "Minwei", "clpid": "Sun-Minwei" }, { "family_name": "Maichen", "given_name": "Wolfgang", "clpid": "Maichen-W" }, { "family_name": "Pophale", "given_name": "Ramdas", "clpid": "Pophale-R" }, { "family_name": "Liu", "given_name": "Yan", "orcid": "0000-0002-5837-4908", "clpid": "Liu-Yan" }, { "family_name": "Cai", "given_name": "Rui", "clpid": "Cai-Rui" }, { "family_name": "Lew", "given_name": "Christopher M.", "clpid": "Lew-C-M" }, { "family_name": "Hunt", "given_name": "Heather", "clpid": "Hunt-H" }, { "family_name": "Deem", "given_name": "Michael W.", "clpid": "Deem-M-W" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Yan", "given_name": "Yushan", "clpid": "Yan-Yushan" } ], "abstract": "Low-dielectric-constant (low-k) insulator materials are desired for future integrated circuits (IC) to lower both the crosstalk between wires and power consumption. Previous work in our group has demonstrated that pure silica zeolites (PSZs) are the best candidates for ultra low-k materials. Although there are many different types of zeolite framework structures, only a few (e.g., MFI and MEL) have been investigated because measurement of the dielectric constant requires the preparation of a high quality thin film. The development of a simple measurement method for powdered zeolite samples is essential to accelerate the screening process for zeolites. In this paper, time-domain reflectometry (TDR) coupled with the use of a transmission line is introduced for the first time for measuring low-k powdered materials. The technique can quickly measure the dielectric constants of powdered samples over a large frequency range using less than 0.5 g of sample with high reliability and accuracy. Successful measurements on quartz and high-k materials (e.g., HfO_2) indicate that this method can be applied to powdered samples in general.", "doi": "10.1016/j.micromeso.2009.03.013", "issn": "1387-1811", "publisher": "Elsevier", "publication": "Microporous and Mesoporous Materials", "publication_date": "2009-07-01", "series_number": "1-3", "volume": "123", "issue": "1-3", "pages": "10-14" }, { "id": "authors:m8jg5-szh60", "collection": "authors", "collection_id": "m8jg5-szh60", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090903-095514247", "type": "article", "title": "Preclinical Results of Camptothecin-Polymer Conjugate (IT-101) in Multiple Human Lymphoma Xenograft Models", "author": [ { "family_name": "Numbenjapon", "given_name": "Tontanai", "clpid": "Numbenjapon-T" }, { "family_name": "Wang", "given_name": "Jianyi", "clpid": "Wang-Jianyi" }, { "family_name": "Colcher", "given_name": "David", "clpid": "Colcher-D" }, { "family_name": "Schluep", "given_name": "Thomas", "clpid": "Schluep-T" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Duringer", "given_name": "Julienne", "clpid": "Duringer-J" }, { "family_name": "Kretzner", "given_name": "Leo", "clpid": "Kretzner-L" }, { "family_name": "Yen", "given_name": "Yun", "clpid": "Yen-Y" }, { "family_name": "Forman", "given_name": "Stephen J.", "clpid": "Forman-S-J" }, { "family_name": "Raubitschek", "given_name": "Andrew", "clpid": "Raubitschek-A" } ], "abstract": "Purpose: Camptothecin (CPT) has potent broad-spectrum antitumor activity by inhibiting type I DNA topoisomerase (DNA topo I). It has not been used clinically because it is water-insoluble and highly toxic. As a result, irinotecan (CPT-11), a water-soluble analogue of CPT, has been developed and used as salvage chemotherapy in patients with relapsed/refractory lymphoma, but with only modest activity. Recently, we have developed a cyclodextrin-based polymer conjugate of 20-(S)-CPT (IT-101). In this study, we evaluated the preclinical antilymphoma efficacy of IT-101 as compared with CPT-11.\n\nExperimental Design: We determined an in vitro cytotoxicity of IT-101, CPT-11, and their metabolites against multiple human lymphoma cell lines. In human lymphoma xenografts, the pharmacokinetics, inhibitions of tumor DNA topo I catalytic activity, and antilymphoma activities of these compounds were evaluated.\n\nResults: IT-101 and CPT had very high in vitro cytotoxicity against all lymphoma cell lines tested. As compared with CPT-11 and SN-38, IT-101 and CPT had longer release kinetics and significantly inhibit higher tumor DNA topo I catalytic activities. Furthermore, IT-101 showed significantly prolonged the survival of animals bearing s.c. and disseminated human xenografts when compared with CPT-11 at its maximum tolerated dose in mice.\n\nConclusions: The promising present results provide the basis for a phase I clinical trial in patients with relapsed/refractory lymphoma.", "doi": "10.1158/1078-0432.CCR-08-2619", "issn": "1078-0432", "publisher": "American Association for Cancer Research", "publication": "Clinical Cancer Research", "publication_date": "2009-07-01", "series_number": "13", "volume": "15", "issue": "13", "pages": "4365-4373" }, { "id": "authors:xs74y-j9q07", "collection": "authors", "collection_id": "xs74y-j9q07", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090804-104718881", "type": "article", "title": "The rise and realization of molecular chemical engineering", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Modern chemical engineering involves the integration of physical and chemical phenomena over length scales ranging from the atomic/molecular to the macroscopic. The ability to delve into the molecular world and to learn how to engineer it has opened broad sectors of new technology. How has chemical engineering reached this point? How is chemical engineering taking advantage of this position? How will chemical engineering move forward based on its ability to engineer at the molecular/atomic length scale? In this article, I will provide my biased answers to these questions. Since I will provide my perspective on these issues, I begin by outlining my career in chemical engineering so that my responses can be placed in the context of that portion of chemical engineering history.", "doi": "10.1002/aic.11940", "issn": "0001-1541", "publisher": "Wiley", "publication": "AIChE Journal", "publication_date": "2009-07", "series_number": "7", "volume": "55", "issue": "7", "pages": "1636-1640" }, { "id": "authors:42f4g-6bp81", "collection": "authors", "collection_id": "42f4g-6bp81", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090901-142619577", "type": "article", "title": "Conductivity of Mono- and Divalent Cations in the Microporous Zincosilicate VPI-9", "author": [ { "family_name": "McKeen", "given_name": "John C.", "clpid": "McKeen-J-C" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Impedance spectroscopy is used to investigate the long-range ionic conductivity of the microporous, zincosilicate VPI-9 (Si/Zn = 4.0) (International Zeolite Association framework type VNI) containing the alkali cations Li^+, Na^+, K^+, Rb^+, and Cs^+, and the alkaline earth cations Mg^(2+), Ca^(2+), and Sr^(2+). Monovalent cation-exchanged samples Li- and Na-VPI-9 lose X-ray crystallinity upon vacuum dehydration at 450 \u00b0C, whereas K-, Rb-, and Cs-VPI-9 remain crystalline and exhibit conductivities of 1.7 \u00d7 10^(\u22124), 3.5 \u00d7 10^(\u22124), and 4.9 \u00d7 10^(\u22124) S/cm, respectively, at 450 \u00b0C and activation energies of 0.72, 0.64, and 0.69 eV, respectively, in the temperature range 150\u2212450 \u00b0C. Divalent cation-exchanged sample Mg-VPI-9 also loses X-ray crystallinity, but Ca- and Sr-VPI-9 remain crystalline and exhibit conductivities of 2.3 \u00d7 10^(\u22126) S/cm and 7.7 \u00d7 10^(\u22127) S/cm, respectively, at 450 \u00b0C, and activation energies of 0.88 and 0.91 eV, respectively, over the temperature range 150\u2212450 \u00b0C. When compared to aluminosilicate zeolite X (Si/Al = 1.25) exchanged with the same cations, all crystalline M-VPI-9 materials have greater conductivities than M-X, with the exception of K-X (1.6 \u00d7 10^(\u22123) S/cm at 450 \u00b0C), with the greatest differences arising between the divalent exchanged materials. Dense, crystalline zincosilicate samples with the compositions K_2ZnSi_xO_(2(x+1)) (x = 2\u22125), Rb_2ZnSi_5O_(12), and Cs_2ZnSi_5O_(12) are also prepared and characterized for comparison with the microporous materials and exhibit much lower conductivities than their microporous counterparts at the same composition.", "doi": "10.1021/jp902235z", "issn": "1932-7447", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry C", "publication_date": "2009-06-04", "series_number": "22", "volume": "113", "issue": "22", "pages": "9870-9877" }, { "id": "authors:emt2s-h6z22", "collection": "authors", "collection_id": "emt2s-h6z22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090820-150240761", "type": "article", "title": "The First Targeted Delivery of siRNA in Humans via a Self-Assembling, Cyclodextrin Polymer-Based Nanoparticle: From Concept to Clinic", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Experimental therapeutics developed to exploit RNA interference (RNAi) are now in clinical studies. Here, the translation from concept to clinic for the first experimental therapeutic to provide targeted delivery of synthetic, small interfering RNA (siRNA) in humans is described. This targeted, nanoparticle formulation of siRNA, denoted as CALAA-01, consists of a cyclodextrin-containing polymer (CDP), a polythethylene glycol (PEG) steric stabilization agent, and human transferrin (Tf) as a targeting ligand for binding to transferrin receptors (TfR) that are typically upregulated on cancer cells. The four component formulation is self-assembled into nanoparticles in the pharmacy and administered intravenously (iv) to patients. The designed features of this experimental therapeutic are described, and their functions illustrated", "doi": "10.1021/mp900015y", "issn": "1543-8384", "publisher": "American Chemical Society", "publication": "Molecular Pharmaceutics", "publication_date": "2009-03", "series_number": "3", "volume": "6", "issue": "3", "pages": "659-668" }, { "id": "authors:7qk36-93f40", "collection": "authors", "collection_id": "7qk36-93f40", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181114-082848785", "type": "article", "title": "Nanomedicine Targets Cancer", "author": [ { "family_name": "Heath", "given_name": "James R.", "orcid": "0000-0001-5356-4385", "clpid": "Heath-J-R" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Hood", "given_name": "Leroy", "orcid": "0000-0001-7158-3678", "clpid": "Hood-L-E" } ], "abstract": "Viewing each human body as a system of interacting molecular networks and targeting disruptions in the system with nanoscale technologies can transform how disease is understood, attacked and possibly prevented.", "doi": "10.1038/scientificamerican0209-44", "pmcid": "PMC3700418", "issn": "0036-8733", "publisher": "Scientific American", "publication": "Scientific American", "publication_date": "2009-02", "series_number": "2", "volume": "300", "issue": "2", "pages": "44-51" }, { "id": "authors:f0xd3-dxm13", "collection": "authors", "collection_id": "f0xd3-dxm13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:KIMjpcc09", "type": "article", "title": "Sodium Diffusion through Aluminum-Doped Zeolite BEA System: Effect of Water Solvation", "author": [ { "family_name": "Kim", "given_name": "Hyungjun", "orcid": "0000-0001-8261-9381", "clpid": "Kim-Hyungjun" }, { "family_name": "Deng", "given_name": "Wei-Qiao", "clpid": "Deng-Wei-Qiao" }, { "family_name": "Goddard", "given_name": "William A., III", "orcid": "0000-0003-0097-5716", "clpid": "Goddard-W-A-III" }, { "family_name": "Jang", "given_name": "Seung Soon", "orcid": "0000-0002-1920-421X", "clpid": "Jang-Seung-Soon" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Yan", "given_name": "Yushan", "clpid": "Yan-Yushan-S" } ], "abstract": "To investigate the effect of hydration on the diffusion of sodium ions through the aluminum-doped zeolite BEA system (Si/Al = 30), we used the grand canonical Monte Carlo (GCMC) method to predict the water absorption into aluminosilicate zeolite structure under various conditions of vapor pressure and temperature, followed by molecular dynamics (MD) simulations to investigate how the sodium diffusion depends on the concentration of water molecules. The predicted absorption isotherm shows first-order-like transition, which is commonly observed in hydrophobic porous systems. The MD trajectories indicate that the sodium ions diffuse through zeolite porous structures via hopping mechanism, as previously discussed for similar solid electrolyte systems. These results show that above 15 wt % hydration (good solvation regime) the formation of the solvation cage dramatically increases sodium diffusion by reducing the hopping energy barrier by 25% from the value of 3.8 kcal/mol observed in the poor solvation regime.", "doi": "10.1021/jp804873s", "issn": "1932-7447", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry C", "publication_date": "2009-01-22", "series_number": "3", "volume": "113", "issue": "3", "pages": "819-826" }, { "id": "authors:3g1wb-a8395", "collection": "authors", "collection_id": "3g1wb-a8395", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:LEWafm08", "type": "article", "title": "Pure-Silica-Zeolite MFI and MEL Low-Dielectric-Constant Films with Fluoro-Organic Functionalization", "author": [ { "family_name": "Lew", "given_name": "Christopher M.", "clpid": "Lew-C-M" }, { "family_name": "Li", "given_name": "Zijian", "clpid": "Li-Zijian" }, { "family_name": "Li", "given_name": "Shuang", "clpid": "Li-Shuang" }, { "family_name": "Hwang", "given_name": "Son-Jong", "orcid": "0000-0002-3210-466X", "clpid": "Hwang-Son-Jong" }, { "family_name": "Liu", "given_name": "Yan", "orcid": "0000-0002-5837-4908", "clpid": "Liu-Yan" }, { "family_name": "Medina", "given_name": "Dora I.", "clpid": "Medina-D-I" }, { "family_name": "Sun", "given_name": "Minwei", "clpid": "Sun-Minwei" }, { "family_name": "Wang", "given_name": "Junlan", "clpid": "Wang-Junlan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Yan", "given_name": "Yushan", "clpid": "Yan-Yushan" } ], "abstract": "The synthesis of organic-functionalized pure-silica-zeolites (PSZs) with MFI- and MEL-type structures for low-k applications prepared through a direct-synthesis method by adding a fluorinated silane to the synthesis solution is reported. The added fluorine functionality increases the hydrophobicity of the zeolites, which are characterized by scanning electron microscopy, X-ray diffraction, 29Si and 19F solid-state NMR spectroscopy, nitrogen adsorption, and thermogravimetric analysis. The functionalized zeolite powders have low water content and calcined spin-on films prepared from the functionalized nanoparticle suspensions exhibit higher water contact angles and lower k values (2.1 and 1.8 for the functionalized MFI- and MEL-type zeolites, respectively) than PSZ films. The use of a direct-synthesis method to decrease the moisture adsorption in the films eliminates the extra post-spin-on silylation steps that are traditionally used to render the zeolite films hydrophobic.", "doi": "10.1002/adfm.200800390", "issn": "1616-301X", "publisher": "Wiley", "publication": "Advanced Functional Materials", "publication_date": "2008-11-10", "series_number": "21", "volume": "18", "issue": "21", "pages": "3454-3460" }, { "id": "authors:fe7nc-y3q25", "collection": "authors", "collection_id": "fe7nc-y3q25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:MARjacs08", "type": "article", "title": "Nanoscale Organization of Thiol and Arylsulfonic Acid on Silica Leads to a Highly Active and Selective Bifunctional, Heterogeneous Catalyst", "author": [ { "family_name": "Margelefsky", "given_name": "Eric L.", "clpid": "Margelefsky-E-L" }, { "family_name": "Bendj\u00e9riou", "given_name": "Anissa", "clpid": "Bendj\u00e9riou-A" }, { "family_name": "Zeidan", "given_name": "Ryan K.", "clpid": "Zeidan-R-K" }, { "family_name": "Dufaud", "given_name": "V\u00e9ronique", "clpid": "Dufaud-V" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Ordered mesoporous silicas functionalized with alkylsulfonic acid and thiol group pairs have been shown to catalyze the synthesis of bisphenols from the condensation of phenol and various ketones, with activity and selectivity highly dependent on the distance between the acid and thiol. Here, a new route to thiol/sulfonic acid paired catalysts is reported. A bis-silane precursor molecule containing both a disulfide and a sulfonate ester bond is grafted onto the surface of ordered mesoporous silica, SBA-15, followed by simultaneous disulfide reduction and sulfonate ester hydrolysis. The resulting catalyst, containing organized pairs of arylsulfonic acid and thiol groups, is significantly more active than the alkylsulfonic acid/thiol paired catalyst in the synthesis of bisphenol A and Z, and this increase in activity does not lead to a loss of regioselectivity. The paired catalyst has activity similar to that of a randomly bifunctionalized arylsulfonic acid/thiol catalyst in the bisphenol A reaction but exhibits greater activity and selectivity than the randomly bifunctionalized catalyst in the bisphenol Z reaction.", "doi": "10.1021/ja804082m", "issn": "0002-7863", "publisher": "American Chemical Society", "publication": "Journal of the American Chemical Society", "publication_date": "2008-10-08", "series_number": "40", "volume": "130", "issue": "40", "pages": "13442-13449" }, { "id": "authors:eef1d-j6b12", "collection": "authors", "collection_id": "eef1d-j6b12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:DAVnatrdd08", "type": "article", "title": "Nanoparticle therapeutics: an emerging treatment modality\n for cancer", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Chen", "given_name": "Zhou (Georgia)", "clpid": "Chen-Zhou-Georgia" }, { "family_name": "Shin", "given_name": "Dong M.", "clpid": "Shin-Dong-M" } ], "abstract": "Nanoparticles \u2014 particles in the size range 1\u2013100 nm \u2014 are emerging as a class of therapeutics for cancer. Early clinical results suggest that nanoparticle therapeutics can\nshow enhanced efficacy, while simultaneously reducing side effects, owing to properties such as more targeted localization in tumours and active cellular uptake. Here, we\nhighlight the features of nanoparticle therapeutics that distinguish them from previous anticancer therapies, and describe how these features provide the potential for\ntherapeutic effects that are not achievable with other modalities. While large numbers of preclinical studies have been published, the emphasis here is placed on preclinical and clinical studies that are likely to affect clinical investigations and their implications for advancing the treatment of patients with cancer.", "doi": "10.1038/nrd2614", "issn": "1474-1776", "publisher": "Nature Publishing Group", "publication": "Nature Reviews. Drug Discovery", "publication_date": "2008-09", "series_number": "9", "volume": "7", "issue": "9", "pages": "771-782" }, { "id": "authors:dqcsx-7bf16", "collection": "authors", "collection_id": "dqcsx-7bf16", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090428-083740090", "type": "article", "title": "Proton conductivity of acid-functionalized zeolite beta, MCM-41, and MCM-48 : effect of acid strength", "author": [ { "family_name": "McKeen", "given_name": "John C.", "clpid": "McKeen-J-C" }, { "family_name": "Yan", "given_name": "Yushan S.", "clpid": "Yan-Yushan-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Direct methanol fuel cells (DMFCs) and hydrogen proton exchange membrane fuel cells (PEMFCs) are two types of fuel cells where commercial products have been developed, but have yet to find widespread deployment. Although these devices are compact, easily refuelable, and operate at comparatively low temperatures, problems such as catalyst poisoning, methanol crossover, and water management exist and are current topics of research. One important component of both the DMFC and PEMFC is a protonically conducting but electronically insulating membrane placed between the anode and cathode. To minimize internal ohmic losses, the membrane must possess a high proton conductivity, and is commonly formed from Nafion or other perfluorosulfonic acid polymers. When fully hydrated, these polymers exhibit proton conductivites on the order of 1 \u00d7 10^(-1) to 1 \u00d7 10^(\u22122) S/cm. For hydrogen PEMFC without active humidification, proton conductivity decreases rapidly with increasing temperaure. For DMFC, membrane swelling allows methanol diffusion directly from anode to cathode decreasing cell efficiency.", "doi": "10.1021/cm801418r", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2008-08-26", "series_number": "16", "volume": "20", "issue": "16", "pages": "5122-5124" }, { "id": "authors:btsmx-9v140", "collection": "authors", "collection_id": "btsmx-9v140", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-100739154", "type": "article", "title": "Proton Conductivity in Sulfonic Acid-Functionalized Zeolite Beta: Effect of Hydroxyl Group", "author": [ { "family_name": "McKeen", "given_name": "John C.", "clpid": "McKeen-J-C" }, { "family_name": "Yan", "given_name": "Yushan S.", "clpid": "Yan-Yushan-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Sulfonic acid groups are more important than framework aluminum for fast proton transport in zeolite beta, but the presence of dangling hydroxyls is also advantageous for high proton conductivity.", "doi": "10.1021/cm800762x", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2008-06-24", "series_number": "12", "volume": "20", "issue": "12", "pages": "3791-3793" }, { "id": "authors:a2gcr-2jf85", "collection": "authors", "collection_id": "a2gcr-2jf85", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:MARcsr08", "type": "article", "title": "Cooperative catalysis by silica-supported organic functional groups", "author": [ { "family_name": "Margelefsky", "given_name": "Eric L.", "clpid": "Margelefsky-E-L" }, { "family_name": "Zeidan", "given_name": "Ryan K.", "clpid": "Zeidan-R-K" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Hybrid inorganic\u2013organic materials comprising organic functional groups tethered from silica surfaces are versatile, heterogeneous catalysts. Recent advances have led to the preparation of silica materials containing multiple, different functional groups that can show cooperative catalysis; that is, these functional groups can act together to provide catalytic activity and selectivity superior to what can be obtained from either monofunctional materials or homogeneous catalysts. This tutorial review discusses cooperative catalysis of silica-based catalytic materials, focusing on the cooperative action of acid\u2013base, acid\u2013thiol, amine\u2013urea, and imidazole\u2013alcohol\u2013carboxylate groups. Particular attention is given to the effect of the spatial arrangement of these organic groups and recent developments in the spatial organization of multiple groups on the silica surface.", "doi": "10.1039/b710334b", "issn": "0306-0012", "publisher": "Royal Society of Chemistry", "publication": "Chemical Society Reviews", "publication_date": "2008-06", "series_number": "6", "volume": "37", "issue": "6", "pages": "1118-1126" }, { "id": "authors:51azc-65s48", "collection": "authors", "collection_id": "51azc-65s48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170104-135213212", "type": "article", "title": "A dose-finding pharmacokinetic study of IT-101, the first de novo designed nanoparticle therapeutic, in refractory solid tumors", "author": [ { "family_name": "Oliver", "given_name": "J. C.", "clpid": "Oliver-J-C" }, { "family_name": "Yen", "given_name": "Y.", "orcid": "0000-0003-0815-412X", "clpid": "Yen-Yun" }, { "family_name": "Synold", "given_name": "T. W.", "clpid": "Synold-T-W" }, { "family_name": "Schluep", "given_name": "T.", "clpid": "Schluep-T" }, { "family_name": "Davis", "given_name": "M.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Background: IT-101 is the first de novo designed experimental nanoparticle therapeutic for cancer and is comprised of a cyclodextrin-based polymer conjugate of camptothecin (CPT) that self-assembles into nanoparticles with diameter of ca. 40 nm and near neutral surface charge. The nanoparticle properties have been designed to accomplish extended circulation, tumor penetration, and slow intracellular drug release to enhance the mechanism of action of the CPT. Methods: Patients with refractory solid tumors received IT-101 by 90 minute IV infusions on days 1, 8, and 15 of a 28 day cycle over a dose range of 6 mg/m^2/wk to 18 mg/m^2/wk. Dose escalation was conducted with a Simon's design. Dose limiting toxicity (DLT) was determined over the first cycle. Progressive disease (PD) was defined by RECIST (CT) results. Pharmacokinetics of free and total CPT in blood and urine were collected over after the 1st dose. Patients completing 6 cycles with stable disease (SD) or better were eligible to receive compassionate IT-101 at the same dose level every other week (QOW). Results: Twelve patients [6 (6 mg/m^2), 3 (12 mg/m^2), and 3 (18 mg/m^2)] were enrolled. 4 of 12 (33%) had PD by CT. 8 of 12 (66%) did not have PD. (6-SD and 2 clinical deterioration (CD). Hematologic toxicity was the DLT. The MTD was < 30 mg/m^2/mo. In patients receiving > 2 cycles, SD was observed at cumulative doses of 18 mg/m^2/mo to 27 mg/m^2/mo. Three patients (pancreatic, renal cell, NSCLC) completed 6 cycles and received treatment QOW with a PFS of \u226518, 14, and 11 months, respectively. Over 7 days, the mean plasma total CPT and free CPT t_(\u00bd \u03b2) were 39 \u00b1 1.1 and 51 \u00b1 1.5 hrs, respectively. The AUC of free and total CPT were linear with 9.9 \u00b1 4.0 % of the CPT dose free. Urinary excretion averaged 16 \u00b1 9.1% of the total CPT dose in the first 48 hrs. Conclusions: These data appear to demonstrate that IT-101 is safe, tolerable, and is associated with acceptable toxicity at the MTD. SD was maintained in patients treated beyond 6 cycles QOW at doses of 6 to 9 mg/m^2/wk. In addition, twice monthly regimens maintained SD with minimal drug-related toxicity. A QOW schedule (allowing for 99% elimination of CPT) is warranted in future clinical trial.", "doi": "10.1200/jco.2008.26.90150.14538", "issn": "1527-7755", "publisher": "American Society of Clinical Oncology", "publication": "Journal of Clinical Oncology", "publication_date": "2008-05-20", "series_number": "15", "volume": "26", "issue": "15", "pages": "Art. No. 14538" }, { "id": "authors:eekcr-vyk41", "collection": "authors", "collection_id": "eekcr-vyk41", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:HEAarm08", "type": "article", "title": "Nanotechnology and cancer", "author": [ { "family_name": "Heath", "given_name": "James R.", "orcid": "0000-0001-5356-4385", "clpid": "Heath-J-R" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The biological picture of cancer is rapidly advancing from models built from phenomenological descriptions to network models derived from systems biology, which can capture the evolving pathophysiology of the disease at the molecular level. The translation of this (still academic) picture into a clinically relevant framework can be enabling for the war on cancer, but it is a scientific and technological challenge. In this review, we discuss emerging in vitro diagnostic technologies and therapeutic approaches that are being developed to handle this challenge. Our discussion of in vitro diagnostics is guided by the theme of making large numbers of measurements accurately, sensitively, and at very low cost. We discuss diagnostic approaches based on microfluidics and nanotechnology. We then review the current state of the art of nanoparticle-based therapeutics that have reached the clinic. The goal of the presentation is to identify nanotherapeutic strategies that are designed to increase efficacy while simultaneously minimizing the toxic side effects commonly associated with cancer chemotherapies.", "doi": "10.1146/annurev.med.59.061506.185523", "pmcid": "PMC3706454", "issn": "0066-4219", "publisher": "Annual Reviews", "publication": "Annual Review of Medicine", "publication_date": "2008-02", "volume": "59", "pages": "251-265" }, { "id": "authors:ev6va-04b82", "collection": "authors", "collection_id": "ev6va-04b82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170426-160051235", "type": "article", "title": "Organized Surface Functional Groups: Cooperative Catalysis via Thiol/Sulfonic Acid Pairing", "author": [ { "family_name": "Margelefsky", "given_name": "Eric L.", "clpid": "Margelefsky-E-L" }, { "family_name": "Zeidan", "given_name": "Ryan K.", "clpid": "Zeidan-R-K" }, { "family_name": "Dufaud", "given_name": "V\u00e9ronique", "clpid": "Dufaud-V" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The synthesis and characterization of heterogeneous catalysts containing surfaces functionalized with discrete pairs of sulfonic acid and thiol groups are reported. A catalyst having acid and thiol groups separated by three carbon atoms is ca. 3 times more active than a material containing randomly distributed acid and thiol groups in the condensation of acetone and phenol to bisphenol A and 14 times more active in the condensation of cyclohexanone and phenol to bisphenol Z. Increasing the acid/thiol distance in the paired materials decreases both the activity and selectivity. This work clearly reveals the importance of nanoscale organization of two disparate functional groups on the surface of heterogeneous catalysts.", "doi": "10.1021/ja074761e", "issn": "0002-7863", "publisher": "American Chemical Society", "publication": "Journal of the American Chemical Society", "publication_date": "2007-11-07", "series_number": "44", "volume": "129", "issue": "44", "pages": "13691-13697" }, { "id": "authors:jt3np-4ka33", "collection": "authors", "collection_id": "jt3np-4ka33", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BARpnas07", "type": "article", "title": "Impact of tumor-specific targeting on the biodistribution and efficacy of siRNA nanoparticles measured by multimodality in vivo imaging", "author": [ { "family_name": "Bartlett", "given_name": "Derek W.", "clpid": "Bartlett-D-W" }, { "family_name": "Su", "given_name": "Helen", "clpid": "Su-Helen" }, { "family_name": "Hildebrandt", "given_name": "Isabel J.", "clpid": "Hildebrandt-I-J" }, { "family_name": "Weber", "given_name": "Wolfgang A.", "clpid": "Weber-W-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Targeted delivery represents a promising approach for the development of safer and more effective therapeutics for oncology applications. Although macromolecules accumulate nonspecifically in tumors through the enhanced permeability and retention (EPR) effect, previous studies using nanoparticles to deliver chemotherapeutics or siRNA demonstrated that attachment of cell-specific targeting ligands to the surface of nanoparticles leads to enhanced potency relative to nontargeted formulations. Here, we use positron emission tomography (PET) and bioluminescent imaging to quantify the in vivo biodistribution and function of nanoparticles formed with cyclodextrin-containing polycations and siRNA. Conjugation of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid to the 5' end of the siRNA molecules allows labeling with 64Cu for PET imaging. Bioluminescent imaging of mice bearing luciferase-expressing Neuro2A s.c. tumors before and after PET imaging enables correlation of functional efficacy with biodistribution data. Although both nontargeted and transferrin-targeted siRNA nanoparticles exhibit similar biodistribution and tumor localization by PET, transferrin-targeted siRNA nanoparticles reduce tumor luciferase activity by {approx}50% relative to nontargeted siRNA nanoparticles 1 d after injection. Compartmental modeling is used to show that the primary advantage of targeted nanoparticles is associated with processes involved in cellular uptake in tumor cells rather than overall tumor localization. Optimization of internalization may therefore be key for the development of effective nanoparticle-based targeted therapeutics.", "doi": "10.1073/pnas.0707461104", "pmcid": "PMC1978218", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2007-09-25", "series_number": "39", "volume": "104", "issue": "39", "pages": "15549-15554" }, { "id": "authors:mbsqf-vrf88", "collection": "authors", "collection_id": "mbsqf-vrf88", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-100737862", "type": "article", "title": "TPA+-Mediated Conversion of Silicon Wafer into Preferentially-Oriented MFI Zeolite Film under Steaming", "author": [ { "family_name": "Chaikittisilp", "given_name": "Watcharop", "clpid": "Chaikittisilp-W" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Okubo", "given_name": "Tatsuya", "clpid": "Okubo-Tatsuya" } ], "abstract": "TPA^+-mediated conversion of silicon wafers into preferentially oriented siliceous MFI zeolite films is achieved by steam-assisted crystallization. Indeed, silicon wafers as the substrate are oxidized by TPAOH(aq) and therefore supplied as Si source for simultaneous crystallization of zeolite film.", "doi": "10.1021/cm071475t", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2007-08-21", "series_number": "17", "volume": "19", "issue": "17", "pages": "4120-4122" }, { "id": "authors:m6efs-q0t46", "collection": "authors", "collection_id": "m6efs-q0t46", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:HEIpnas07", "type": "article", "title": "Administration in non-human primates of escalating intravenous doses of targeted nanoparticles containing ribonucleotide reductase subunit M2 siRNA", "author": [ { "family_name": "Heidel", "given_name": "Jeremy D.", "clpid": "Heidel-J-D" }, { "family_name": "Yu", "given_name": "Zhongping", "clpid": "Yu-Zhongping" }, { "family_name": "Liu", "given_name": "Joanna Yi-Ching", "clpid": "Liu-Joanna-Yi-Ching" }, { "family_name": "Rele", "given_name": "Shyam M.", "clpid": "Rele-S-M" }, { "family_name": "Liang", "given_name": "Yongchao", "clpid": "Liang-Yongchao" }, { "family_name": "Zeidan", "given_name": "Ryan K.", "clpid": "Zeidan-R-K" }, { "family_name": "Kornburust", "given_name": "Douglas J.", "clpid": "Kornbrust-D-J" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The results of administering escalating, i.v. doses of targeted nanoparticles containing a siRNA targeting the M2 subunit of ribonucleotide reductase to non-human primates are reported. The nanoparticles consist of a synthetic delivery system that uses a linear, cyclodextrin-containing polycation, transferrin (Tf) protein targeting ligand, and siRNA. When administered to cynomolgus monkeys at doses of 3 and 9 mg siRNA/kg, the nanoparticles are well tolerated. At 27 mg siRNA/kg, elevated levels of blood urea nitrogen and creatinine are observed that are indicative of kidney toxicity. Mild elevations in alanine amino transferase and aspartate transaminase at this dose level indicate that the liver is also affected to some extent. Analysis of complement factors does not reveal any changes that are clearly attributable to dosing with the nanoparticle formulation. Detection of increased IL-6 levels in all animals at 27 mg siRNA/kg and increased IFN-{gamma} in one animal indicate that this high dose level produces a mild immune response. Overall, no clinical signs of toxicity clearly attributable to treatment are observed. The multiple administrations spanning a period of 17\u201318 days enable assessment of antibody formation against the human Tf component of the formulation. Low titers of anti-Tf antibodies are detected, but this response is not associated with any manifestations of a hypersensitivity reaction upon readministration of the targeted nanoparticle. Taken together, the data presented show that multiple, systemic doses of targeted nanoparticles containing nonchemically modified siRNA can safely be administered to non-human primates.", "doi": "10.1073/pnas.0701458104", "pmcid": "PMC1829492", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2007-04-03", "series_number": "14", "volume": "104", "issue": "14", "pages": "5715-5721" }, { "id": "authors:kk202-mk011", "collection": "authors", "collection_id": "kk202-mk011", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170131-080032126", "type": "article", "title": "Physicochemical and Biological Characterization of Targeted, Nucleic Acid-Containing Nanoparticles", "author": [ { "family_name": "Bartlett", "given_name": "Derek W.", "clpid": "Bartlett-D-W" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Nucleic acid-based therapeutics have the potential to provide potent and highly specific treatments for a variety of human ailments. However, systemic delivery continues to be a significant hurdle to success. Multifunctional nanoparticles are being investigated as systemic, nonviral delivery systems, and here, we describe the physicochemical and biological characterization of cyclodextrin-containing polycations (CDP) and their nanoparticles formed with nucleic acids including plasmid DNA (pDNA) and small interfering RNA (siRNA). These polycation/nucleic acid complexes can be tuned by formulation conditions to yield particles with sizes ranging from 60 to 150 nm, \u03b6 potentials from 10 to 30 mV, and molecular weights from \u223c7 \u00d7 10^7 to 1 \u00d7 10^9 g mol^(-1) as determined by light scattering techniques. Inclusion complexes formed between adamantane (AD)-containing molecules and the \u03b2-cyclodextrin molecules enable the modular attachment of poly(ethylene glycol) (AD\u2212PEG) conjugates for steric stabilization and targeting ligands (AD\u2212PEG\u2212transferrin) for cell-specific targeting. A 70 nm particle can contain \u223c10\u2009000 CDP polymer chains, \u223c2000 siRNA molecules, \u223c4000 AD\u2212PEG_(5000) molecules, and \u223c100 AD\u2212PEG_(5000)\u2212Tf molecules; this represents a significant payload of siRNA and a large ratio of siRNA to targeting ligand (20:1). The particles protect the nucleic acid payload from nuclease degradation, do not aggregate at physiological salt concentrations, and cause minimal erythrocyte aggregation and complement fixation at the concentrations typically used for in vivo application. Uptake of the nucleic acid-containing particles by HeLa cells is measured by flow cytometry and visualized by confocal microscopy. Competitive uptake experiments show that the transferrin-targeted particles display enhanced affinity for the transferrin receptor through avidity effects (multiligand binding). Functional efficacy of the delivered pDNA and siRNA is demonstrated through luciferase reporter protein expression and knockdown, respectively. The analysis of the CDP delivery vehicle provides insights that can be applied to the design of targeted nucleic acid delivery vehicles in general.", "doi": "10.1021/bc0603539", "pmcid": "PMC2517011", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2007-03", "series_number": "2", "volume": "18", "issue": "2", "pages": "456-468" }, { "id": "authors:3xhz7-vzw96", "collection": "authors", "collection_id": "3xhz7-vzw96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-141753934", "type": "article", "title": "Proton-Conducting Solid Electrolyte via Ozonolysis of Cationic Ammonium Organoalkoxysilane Surfactant-Templated MCM-41", "author": [ { "family_name": "Alabi", "given_name": "Christopher A.", "orcid": "0000-0003-2654-018X", "clpid": "Alabi-C-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A functional polymerizable surfactant has been synthesized and used as a template to prepare MCM-41. Ozonolysis of the olefin functional group in the composite material generates a nonporous proton-conducting solid acid that has a conductivity of ca. 6 mS cm^(-1) at 95 \u00b0C and an activation energy of 14.2 kJ/mol.", "doi": "10.1021/cm061722d", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2006-11-28", "series_number": "24", "volume": "18", "issue": "24", "pages": "5634-5636" }, { "id": "authors:sc902-jpe65", "collection": "authors", "collection_id": "sc902-jpe65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110714-113854842", "type": "article", "title": "Imidazole groups on a linear, cyclodextrin-containing polycation produce enhanced gene delivery via multiple processes", "author": [ { "family_name": "Mishra", "given_name": "Swaroop", "orcid": "0000-0002-2665-5385", "clpid": "Mishra-S" }, { "family_name": "Heidel", "given_name": "Jeremy D.", "clpid": "Heidel-J-D" }, { "family_name": "Webster", "given_name": "Paul", "clpid": "Webster-P" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The linear, cyclodextrin-containing polycation (CDP) is one of many non-viral gene delivery vectors that show improved transfection efficiency when modified to have pH-buffering capacity. The buffering activity is presumed to confer enhanced ability to escape the endocytic pathway. Here, the differences in delivery behavior between CDP and its pH-buffering, imidazole-containing variant (CDPim) are investigated in order to elucidate the mechanism(s) by which these related materials exhibit differences in gene delivery. In cell-free assays that include dye exclusion and heparan sulfate displacement, CDP appears to have weaker binding strength with nucleic acids than CDPim. Numerous analyses involving transfected cells, however, indicate that CDPim more readily releases nucleic acids in the intracellular setting. Together, these data suggest that differences in transfection efficiency between CDP and CDPim result from factors beyond buffering activity and endosomal escape.", "doi": "10.1016/j.jconrel.2006.06.018", "issn": "0168-3659", "publisher": "Elsevier", "publication": "Journal of Controlled Release", "publication_date": "2006-11-28", "series_number": "2", "volume": "116", "issue": "2", "pages": "179-191" }, { "id": "authors:zarch-y9j49", "collection": "authors", "collection_id": "zarch-y9j49", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170125-093852720", "type": "article", "title": "A Solvent-Free Method for Isotopically or Radioactively Labeling Cyclodextrins and Cyclodextrin-Containing Polymers", "author": [ { "family_name": "Zeidan", "given_name": "Ryan K.", "clpid": "Zeidan-R-K" }, { "family_name": "Kalovidouris", "given_name": "Stacey A.", "clpid": "Kalovidouris-S-A" }, { "family_name": "Schluep", "given_name": "Thomas", "clpid": "Schluep-T" }, { "family_name": "Fazio", "given_name": "Robert", "clpid": "Fazio-R" }, { "family_name": "Andresini", "given_name": "Robert", "clpid": "Andresini-R" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A method for installing a distinguishable label onto cyclodextrins or cyclodextrin-containing polymers is reported. Cyclodextrins (CD) and cyclodextrin-containing polymers are exposed to labeled (^2H or ^(14)C) ethylene oxide (EO) vapor and the alcohol groups on the CD ring open the EO to give ether-linked labeled methylenes and a terminal alcohol. This method provides for the incorporation of an easily tracked and quantified label without the use of solvents or purification steps. The method can be generalized for use with materials that contain nucleophiles other than alcohols, e.g., amines.", "doi": "10.1021/bc060211e", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2006-11-15", "series_number": "6", "volume": "17", "issue": "6", "pages": "1624-1626" }, { "id": "authors:tfwve-3cq45", "collection": "authors", "collection_id": "tfwve-3cq45", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170517-070821385", "type": "article", "title": "Structure\u2212Function Correlation of Chloroquine and Analogues as Transgene Expression Enhancers in Nonviral Gene Delivery", "author": [ { "family_name": "Cheng", "given_name": "Jianjun", "clpid": "Cheng-Jianjun" }, { "family_name": "Zeidan", "given_name": "Ryan", "clpid": "Zeidan-R-K" }, { "family_name": "Mishra", "given_name": "Swaroop", "orcid": "0000-0002-2665-5385", "clpid": "Mishra-S" }, { "family_name": "Liu", "given_name": "Aijie", "clpid": "Liu-Aijie" }, { "family_name": "Pun", "given_name": "Suzie H.", "orcid": "0000-0003-1443-4996", "clpid": "Pun-Suzie-Hwang" }, { "family_name": "Kulkarni", "given_name": "Rajan P.", "clpid": "Kulkarni-Rajan-P" }, { "family_name": "Jensen", "given_name": "Gregory S.", "clpid": "Jensen-G-S" }, { "family_name": "Bellocq", "given_name": "Nathalie C.", "clpid": "Bellocq-N-C" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "To understand how chloroquine (CQ) enhances transgene expression in polycation-based, nonviral gene delivery systems, a number of CQ analogues with variations in the aliphatic amino side chain or in the aromatic ring are synthesized and investigated. Our studies indicate that the aliphatic amino moiety of CQ is essential to provide increased gene expression. Further, the enhancements are more dramatically affected by changes to the aromatic ring and are positively correlated to the strength of intercalation between DNA and the CQ analogues. Quinacrine (QC), a CQ analogue with a fused acridinyl structure that can strongly intercalate DNA, enhances transfection similarly to CQ at a concentration 10 times lower, while N^4-(4-pyridinyl)-N^1,N^1-diethyl-1,4-pentanediamine (CP), a CQ analogue that has a weakly intercalating pyridinyl ring, shows no effect on gene expression. Subtle change on the 7-substituent of the chloroquine aromatic structure can also greatly affect the ability of the CQ analogues to enhance transgene expression. Transfection in the presence of N^4-(7-trifluoromethyl-4-quinolinyl)-N^1,N^1-diethyl-1,4-pentanediamin e (CQ7a) shows expression efficiency 10 times higher than in the presence of CQ at same concentration, while transfection in the presence of N^4-(4-quinolinyl)-N^1,N^1-diethyl-1,4-pentanediamine (CQ7b) does not reveal any enhancing effects on expression. Through a number of comparative studies with CQ and its analogues, we conclude that there are at least three mechanistic features of CQ that lead to the enhancement in gene expression:\u2009 (i) pH buffering in endocytic vesicles, (ii) displacement of polycations from the nucleic acids in polyplexes, and (iii) alteration of the biophysical properties of the released nucleic acid.", "doi": "10.1021/jm060736sD", "issn": "0022-2623", "publisher": "American Chemical Society", "publication": "Journal of Medicinal Chemistry", "publication_date": "2006-11-02", "series_number": "22", "volume": "49", "issue": "22", "pages": "6522-6531" }, { "id": "authors:h47tw-1et56", "collection": "authors", "collection_id": "h47tw-1et56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170605-133517758", "type": "article", "title": "Structure-Directing Agent Location and Non-Centrosymmetric Structure of Fluoride-Containing Zeolite SSZ-55", "author": [ { "family_name": "Burton", "given_name": "Allen", "clpid": "Burton-A-W" }, { "family_name": "Darton", "given_name": "Richard J.", "clpid": "Darton-R-J" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Hwang", "given_name": "Song-Jong", "clpid": "Hwang-Song-Jong" }, { "family_name": "Morris", "given_name": "Russell E.", "clpid": "Morris-R-E" }, { "family_name": "Ogino", "given_name": "Isao", "clpid": "Ogino-Isao" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" } ], "abstract": "Single crystals of pure silica zeolite SSZ-55 were prepared using the fluoride route. Single-crystal X-ray diffraction at a synchrotron source revealed the framework structure of the material, but the unit cell (orthorhombic a = 12.905(2) \u00c5, b = 21.344(4) \u00c5, c = 5.1279(10)) is too small to accommodate ordered arrays of the organic structure-directing agent. Molecular modeling was used to simulate the docking of the structure-directing agent in the channels of the material, and this revealed a strong space-filling interaction with a number of possible orientations of the organic cation. The overall non-centrosymmetric structure of the solid (spacegroup C222_1) was confirmed using second harmonic generation experiments.", "doi": "10.1021/jp054950o", "issn": "1520-6106", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry B", "publication_date": "2006-03-23", "series_number": "11", "volume": "110", "issue": "11", "pages": "5273-5278" }, { "id": "authors:ck338-d6110", "collection": "authors", "collection_id": "ck338-d6110", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BARnar06", "type": "article", "title": "Insights into the kinetics of siRNA-mediated gene silencing from live-cell and live-animal bioluminescent imaging", "author": [ { "family_name": "Bartlett", "given_name": "Derek W.", "clpid": "Bartlett-D-W" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Small interfering RNA (siRNA) molecules are potent effectors of post-transcriptional gene silencing. Using noninvasive bioluminescent imaging and a mathematical model of siRNA delivery and function, the effects of target-specific and treatment-specific parameters on siRNA-mediated gene silencing are monitored in cells stably expressing the firefly luciferase protein. In vitro, luciferase protein levels recover to pre-treatment values within <1 week in rapidly dividing cell lines, but take longer than 3 weeks to return to steady-state levels in nondividing fibroblasts. Similar results are observed in vivo, with knockdown lasting ~10 days in subcutaneous tumors in A/J mice and 3\u20134 weeks in the nondividing hepatocytes of BALB/c mice. These data indicate that dilution due to cell division, and not intracellular siRNA half-life, governs the duration of gene silencing under these conditions. To demonstrate the practical use of the model in treatment design, model calculations are used to predict the dosing schedule required to maintain persistent silencing of target proteins with different half-lives in rapidly dividing or nondividing cells. The approach of bioluminescent imaging combined with mathematical modeling provides useful insights into siRNA function and may help expedite the translation of siRNA into clinically relevant therapeutics for disease treatment and management.", "doi": "10.1093/nar/gkj439", "issn": "0305-1048", "publisher": "Nucleic Acids Research", "publication": "Nucleic Acids Research", "publication_date": "2006-01-01", "series_number": "1", "volume": "34", "issue": "1", "pages": "322-333" }, { "id": "authors:aaamj-6zh88", "collection": "authors", "collection_id": "aaamj-6zh88", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170125-093852468", "type": "article", "title": "A Nanoparticle-Based Model Delivery System To Guide the Rational Design of Gene Delivery to the Liver. 1. Synthesis and Characterization", "author": [ { "family_name": "Popielarski", "given_name": "Stephen R.", "clpid": "Popielarski-S-R" }, { "family_name": "Pun", "given_name": "Suzie H.", "orcid": "0000-0003-1443-4996", "clpid": "Pun-Suzie-Hwang" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Nonviral gene delivery systems are amenable to forming colloidal particles with a wide range of physicochemical properties that include size, surface charge, and density and type of ligand presented. However, it is not known how to best design these particles without having a set of physicochemical design constraints that have been optimized for the intended gene delivery application. Here, a nanoparticle-based model delivery system is developed that can mimic the surface properties of nonviral gene delivery particles, and this model system is used to define design constraints that should be applied to next generation gene delivery particles. As a test case, a well-defined nanoparticle-based system is developed to guide the rational design of gene delivery to hepatocytes in the liver. The synthetic scheme utilizes monodisperse polystyrene particles and provides for variation of mean particle size and particle size distribution through variation in reaction conditions. The nanoparticles are PEGylated to provide stability in serum and also incorporate targeting ligands, e.g., galactose, at tunable densities. Four nanoparticles are synthesized from uniformly sized polystyrene beads specifically for the purpose of identifying design constraints to guide next generation gene delivery to the liver. These four nanoparticles are Gal-50 and Gal-140, that are galactosylated 50 and 140 nm nanoparticles, and MeO-50 and MeO-140, that are methoxy-terminated 50 and 140 nm nanoparticles. All four particles have the same surface charge, and Gal-50 and Gal-140 have the same surface galactose density. The availability of galactose ligands to receptor binding is demonstrated here by agglutination with RCA_(120).", "doi": "10.1021/bc050113d", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2005-09-01", "series_number": "5", "volume": "16", "issue": "5", "pages": "1063-1070" }, { "id": "authors:bkjkj-6hz16", "collection": "authors", "collection_id": "bkjkj-6hz16", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170131-080127280", "type": "article", "title": "A Nanoparticle-Based Model Delivery System To Guide the Rational Design of Gene Delivery to the Liver. 2. In Vitro and In Vivo Uptake Results", "author": [ { "family_name": "Popielarski", "given_name": "Stephen R.", "clpid": "Popielarski-S-R" }, { "family_name": "Hu-Lieskovan", "given_name": "Siwen", "clpid": "Hu-Lieskovan-S" }, { "family_name": "French", "given_name": "Samuel W.", "clpid": "French-S-W" }, { "family_name": "Triche", "given_name": "Timothy J.", "clpid": "Triche-T-J" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "In Part 1 of our work (1), four nanoparticles were synthesized specifically for the purpose of identifying design constraints to guide next generation gene delivery to the liver. The four nanoparticles are Gal-50 and Gal-140 (galactosylated 50 and 140 nm nanoparticles) and MeO-50 and MeO-140 (methoxy-terminated 50 and 140 nm nanoparticles). All four particles have the same surface charge, and Gal-50 and Gal-140 have the same surface galactose density (ca. 25\u221230 pmol/cm^2). Here, the hepatocyte uptake in vitro and hepatic distribution in vivo of these four nanoparticles is investigated. With freshly isolated hepatocytes, Gal-50 nanoparticles are taken up to a greater extent than are MeO-50, and both 50 nm beads are taken up to a much greater extent than either of the 140 nm nanoparticles. In mice, about 90% of the in vivo dose of Gal-140 nanoparticles is found within the liver 20 min after tail-vein injection. TEM and immunohistochemistry images confirm that Gal-140 nanoparticles are primarily internalized by Kupffer cells, though isolated examples of a few Gal-140 in hepatocytes are also observed. Gal-50 nanoparticles are overwhelmingly found in vesicles throughout the cytoplasm of hepatocytes, with only isolated examples of Kupffer cell uptake 20 min after tail vein injections in mice. Despite similar surface charge and ligand density, 50 nm nanoparticles are primarily found in hepatocytes while 140 nm nanoparticles are primarily observed in Kupffer cells. These results clearly show that slightly anionic, galactose-PEGylated nanoparticles with 25\u221230 pmol/cm^2 galactose should be about 50 nm in diameter to preferentially target hepatocytes while they should be about 140 nm in diameter to selectively target Kupffer cells.", "doi": "10.1021/bc0501146", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2005-09", "series_number": "5", "volume": "16", "issue": "5", "pages": "1071-1080" }, { "id": "authors:3s816-6fh75", "collection": "authors", "collection_id": "3s816-6fh75", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:ROSnar05", "type": "article", "title": "Functional polarity is introduced by Dicer processing of short substrate RNAs", "author": [ { "family_name": "Rose", "given_name": "Scott D.", "clpid": "Rose-S-D" }, { "family_name": "Kim", "given_name": "Dong-Ho", "clpid": "Kim-Hong-Ho" }, { "family_name": "Amarzguioui", "given_name": "Mohammed", "clpid": "Amarzguioui-M" }, { "family_name": "Heidel", "given_name": "Jeremy D.", "clpid": "Heidel-J-D" }, { "family_name": "Collingwood", "given_name": "Michael A.", "clpid": "Collingwood-M-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Rossi", "given_name": "John J.", "clpid": "Rossi-J-J" }, { "family_name": "Behlke", "given_name": "Mark A.", "clpid": "Behlke-M-A" } ], "abstract": "Synthetic RNA duplexes that are substrates for Dicer are potent triggers of RNA interference (RNAi). Blunt 27mer duplexes can be up to 100-fold more potent than traditional 21mer duplexes (1). Not all 27mer duplexes show increased potency. Evaluation of the products of in vitro dicing reactions using electrospray ionization mass spectrometry reveals that a variety of products can be produced by Dicer cleavage. Use of asymmetric duplexes having a single 2-base 3'-overhang restricts the heterogeneity that results from dicing. Inclusion of DNA residues at the ends of blunt duplexes also limits heterogeneity. Combination of asymmetric 2-base 3'-overhang with 3'-DNA residues on the blunt end result in a duplex form which directs dicing to predictably yield a single primary cleavage product. It is therefore possible to design a 27mer duplex which is processed by Dicer to yield a specific, desired 21mer species. Using this strategy, two different 27mers can be designed that result in the same 21mer after dicing, one where the 3'-overhang resides on the antisense (AS) strand and dicing proceeds to the 'right' ('R') and one where the 3'-overhang resides on the sense (S) strand and dicing proceeds to the 'left' ('L'). Interestingly, the 'R' version of the asymmetric 27mer is generally more potent in reducing target gene levels than the 'L' version 27mer. Strand targeting experiments show asymmetric strand utilization between the two different 27mer forms, with the 'R' form favoring S strand and the 'L' form favoring AS strand silencing. Thus, Dicer processing confers functional polarity within the RNAi pathway.", "doi": "10.1093/nar/gki732", "pmcid": "PMC1180746", "issn": "0305-1048", "publisher": "Oxford University Press", "publication": "Nucleic Acids Research", "publication_date": "2005-08", "series_number": "13", "volume": "33", "issue": "13", "pages": "4140-4156" }, { "id": "authors:28vnm-zgq11", "collection": "authors", "collection_id": "28vnm-zgq11", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160226-114842424", "type": "article", "title": "Single Cell Kinetics of Intracellular, Nonviral, Nucleic Acid Delivery Vehicle Acidification and Trafficking", "author": [ { "family_name": "Kulkarni", "given_name": "Rajan P.", "clpid": "Kulkarni-R-P" }, { "family_name": "Mishra", "given_name": "Swaroop", "orcid": "0000-0002-2665-5385", "clpid": "Mishra-S" }, { "family_name": "Fraser", "given_name": "Scott E.", "orcid": "0000-0002-5377-0223", "clpid": "Fraser-S-E" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Mechanistic understanding of the intracellular trafficking of nonviral nucleic acid delivery vehicles remains elusive. A live, single cell-based assay is described here that is used to investigate and quantitate the spatiotemporal, intracellular pH microenvironment of polymeric-based nucleic acid delivery vehicles. Polycations such as polyethylenimine (PEI), poly-L-lysine (PLL), \u03b2-cyclodextrin-containing polymers lacking or possessing imidazole termini (CDP or CDP-imid), and cyclodextrin-grafted PEI (CD-PEI) are used to deliver an oligonucleotide containing a single fluorophore with two emission lines that can be employed to measure the pH. Delivery vehicles were also sterically stabilized by addition of poly(ethylene glycol) (PEG) and investigated. The intracellular trafficking data obtained via this new methodology show that vectors such as PEI and CDP-imid can buffer the endocytic vesicles while PLL and CDP do not. Additionally, the PEGylated vectors reveal the same buffering capacity as their unstabilized variants. Here, the live cell, spatiotemporal mapping of these behaviors is demonstrated and, when combined with cell uptake and luciferase expression data, shows that there is not a correlation between buffering capacity and gene expression.", "doi": "10.1021/bc050081u", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2005-07", "series_number": "4", "volume": "16", "issue": "4", "pages": "986-994" }, { "id": "authors:y3s62-grt41", "collection": "authors", "collection_id": "y3s62-grt41", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141121-093134521", "type": "article", "title": "Quantitating intracellular transport of polyplexes by spatio-temporal image correlation spectroscopy", "author": [ { "family_name": "Kulkarni", "given_name": "Rajan P.", "clpid": "Kulkarni-R-P" }, { "family_name": "Wu", "given_name": "David D.", "clpid": "Wu-David-D" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Fraser", "given_name": "Scott E.", "orcid": "0000-0002-5377-0223", "clpid": "Fraser-S-E" } ], "abstract": "Quantitatively understanding how nonviral gene delivery vectors (polyplexes) are transported inside cells is essential before they can be optimized for gene therapy and medical applications. In this study, we used spatio-temporal image correlation spectroscopy (ICS) to follow polymer-nucleic acid particles (polyplexes) of various sizes and analyze their diffusive-like and flow behaviors intracellularly to elucidate the mechanisms responsible for their transport. ICS is a quantitative imaging technique that allows the assessment of particle motion in complex systems, although it has not been widely used to date. We find that the internalized polyplexes are able to use microtubule motors for intracellular trafficking and exhibit different transport behaviors for short (<10 s) versus long (\u224860 s) correlation times. This motion can be explained by a memory effect of the microtubule motors. These results reveal that, although microtubule motor biases may be present for short periods of time, resulting in a net directional velocity, the overall long-term motion of the polyplexes is best described as a random walk-like process. These studies suggest that spatio-temporal ICS is a powerful technique for assessing the nature of intracellular motion and provides a quantitative tool to compare the transport of different objects within a living cell.", "doi": "10.1073/pnas.0501950102", "pmcid": "PMC1140437", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2005-05-24", "series_number": "21", "volume": "102", "issue": "21", "pages": "7523-7528" }, { "id": "authors:3k4rs-2zt51", "collection": "authors", "collection_id": "3k4rs-2zt51", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170605-071527798", "type": "article", "title": "Zeolite Synthesis Using Degradable Structure-Directing Agents and Pore-Filling Agents", "author": [ { "family_name": "Lee", "given_name": "Hyunjoo", "clpid": "Lee-Hyunjoo" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolites and molecular sieves are synthesized using organic structure-directing agents (SDAs) that have the potential to be degraded into fragments within the pore space so that they can be readily extracted at mild conditions. The zeolites and molecular sieves, VPI-8, ZSM-12, and ZSM-5, are synthesized using the ketal-containing SDA, 8,8-dimethyl-1,4-dioxa-8-azoniaspiro[4,5]decane (SDA-1). As expected, solids with unidimensional pore systems (VPI-8, ZSM-12) are much more difficult to process by this methodology than solids containing multidimensional pore systems (ZSM-5). Pore-filling agents (PFAs) such as isobutylamine and cyclopentylamine are used together with the ketal-containing SDA-1 to prepare ZSM-5. Extraction of the PFA is shown to be feasible, and its removal provides space for components to enter the zeolite micropores where they react with and cleave SDA-1. Removal of the cleavage fragments from SDA-1 gives ZSM-5 that has the appropriate pore volume, framework aluminum (measured by ^(27)Al NMR), and catalytic behavior. Reasons for desiring this new type of zeolite synthesis method are enumerated.", "doi": "10.1021/jp048908p", "issn": "1520-6106", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry B", "publication_date": "2005-02-17", "series_number": "6", "volume": "109", "issue": "6", "pages": "2187-2191" }, { "id": "authors:qrwev-r9729", "collection": "authors", "collection_id": "qrwev-r9729", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150408-151729591", "type": "article", "title": "Cyclodextrin-based pharmaceutics: Past, present and future", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Brewster", "given_name": "Marcus E.", "clpid": "Brewster-M-E" } ], "abstract": "Cyclodextrins are cyclic oligomers of glucose that can form water-soluble inclusion complexes with small molecules and portions of large compounds. These biocompatible, cyclic oligosaccharides do not elicit immune responses and have low toxicities in animals and humans. Cyclodextrins are used in pharmaceutical applications for numerous purposes, including improving the bioavailability of drugs. Current cyclodextrin-based therapeutics are described and possible future applications discussed. Cyclodextrin-containing polymers are reviewed and their use in drug delivery presented. Of specific interest is the use of cyclodextrin-containing polymers to provide unique capabilities for the delivery of nucleic acids.", "doi": "10.1038/nrd1576", "issn": "1474-1776", "publisher": "Nature Publishing Group", "publication": "Nature Reviews Drug Discovery", "publication_date": "2004-12", "series_number": "12", "volume": "3", "issue": "12", "pages": "1023-1035" }, { "id": "authors:gfx6m-arc13", "collection": "authors", "collection_id": "gfx6m-arc13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150513-095404544", "type": "article", "title": "Lack of interferon response in animals to naked siRNAs", "author": [ { "family_name": "Heidel", "given_name": "Jeremy D.", "clpid": "Heidel-J-D" }, { "family_name": "Hu", "given_name": "Siwen", "clpid": "Hu-Siwen" }, { "family_name": "Liu", "given_name": "Xian Fang", "clpid": "Liu-Xian-Fang" }, { "family_name": "Triche", "given_name": "Timothy J.", "clpid": "Triche-T-J" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "RNA interference (RNAi) is rapidly becoming the method of choice for the elucidation of gene function and the identification of drug targets. As with other oligonucleotide-based strategies, RNAi is envisioned to ultimately be useful as a human therapeutic. Unlike previous nucleic acid therapeutics, small interfering RNAs have the potential to elicit immune responses via interactions with Toll-like receptor 3 and trigger interferon responses like long, double-stranded RNA and its analogs, such as poly(I:C). Recently, the safety of siRNAs has been questioned because they have been shown to trigger an interferon response in cultured cells. We show here that it is possible to administer naked, synthetic siRNAs to mice and downregulate an endogenous or exogenous target without inducing an interferon response.", "doi": "10.1038/nbt1038", "issn": "1087-0156", "publisher": "Nature Publishing Group", "publication": "Nature Biotechnology", "publication_date": "2004-12", "series_number": "12", "volume": "22", "issue": "12", "pages": "1579-1582" }, { "id": "authors:7stmh-t9670", "collection": "authors", "collection_id": "7stmh-t9670", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170125-115431256", "type": "article", "title": "Synthetic Biocompatible Cyclodextrin-Based Constructs for Local Gene Delivery to Improve Cutaneous Wound Healing", "author": [ { "family_name": "Bellocq", "given_name": "Nathalie C.", "clpid": "Bellocq-N-C" }, { "family_name": "Kang", "given_name": "David W.", "clpid": "Kang-David-W" }, { "family_name": "Wang", "given_name": "Xuehui", "clpid": "Wang-Xuehui" }, { "family_name": "Jensen", "given_name": "Gregory S.", "clpid": "Jensen-G-S" }, { "family_name": "Pun", "given_name": "Suzie H.", "orcid": "0000-0003-1443-4996", "clpid": "Pun-Suzie-Hwang" }, { "family_name": "Schluep", "given_name": "Thomas", "clpid": "Schluep-T" }, { "family_name": "Zepeda", "given_name": "Monica L.", "clpid": "Zepeda-M-L" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The localized, sustained delivery of growth factors for wound healing therapy is actively being explored by gene transfer to the wound site. Biocompatible matrices such as bovine collagen have demonstrated usefulness in sustaining gene therapy vectors that express growth factors in local sites for tissue repair. Here, new synthetic biocompatible materials are prepared and shown to deliver a protein to cultured cells via the use of an adenoviral delivery vector. The synthetic construct consists of a linear, \u03b2-cyclodextrin-containing polymer and an adamantane-based cross-linking polymer. When the two polymers are combined, they create an extended network by the formation of inclusion complexes between the cyclodextrins and adamantanes. The properties of the network are altered by controlling the polymer molecular weights and the number of adamantanes on the cross-linking polymer, and these modifications and others such as replacement of the \u03b2-cyclodextrin (host) and adamantane (guest) with other cyclodextrins (hosts such as \u03b1, \u03b3, and substituted members) and inclusion complex forming molecules (guests) provide the ability to rationally design network characteristics. Fibroblasts exposed to these synthetic constructs show proliferation rates and migration patterns similar to those obtained with collagen. Gene delivery (green fluorescent protein) to fibroblasts via the inclusion of adenoviral vectors in the synthetic construct is equivalent to levels observed with collagen. These in vitro results suggest that the synthetic constructs are suitable for in vivo tissue repair applications.", "doi": "10.1021/bc0498119", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2004-11", "series_number": "6", "volume": "15", "issue": "6", "pages": "1201-1211" }, { "id": "authors:vd11m-0ed66", "collection": "authors", "collection_id": "vd11m-0ed66", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170315-160226263", "type": "article", "title": "SSZ-33: A Promising Material for Use as a Hydrocarbon Trap", "author": [ { "family_name": "Elangovan", "given_name": "S. P.", "clpid": "Elangovan-S-P" }, { "family_name": "Ogura", "given_name": "Masaru", "clpid": "Ogura-Masaru" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Okubo", "given_name": "Tatsuya", "clpid": "Okubo-Tatsuya" } ], "abstract": "SSZ-33 is tested for possible application as a hydrocarbon trap by investigating the temperature-programmed desorption behavior of toluene (used as a probe molecule) and the results are compared to those obtained with zeolites \u03b2, Y, mordenite, and ZSM-5. SSZ-33 shows higher adsorption capacity than the other zeolites at the conditions used here, and as well as better hydrothermal stability than zeolite \u03b2, and is therefore identified as a promising candidate for use as a hydrocarbon trap in cold-start emission control.", "doi": "10.1021/jp047394r", "issn": "1520-6106", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry B", "publication_date": "2004-09-02", "series_number": "35", "volume": "108", "issue": "35", "pages": "13059-13061" }, { "id": "authors:19bbf-mwk44", "collection": "authors", "collection_id": "19bbf-mwk44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141112-154850334", "type": "article", "title": "Biomineralization [Book Review]", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The contributors offer specialists and nonspecialists alike a comprehensive introduction to the processes of biological mineralization and to the effects of these processes on Earth history.", "doi": "10.1126/science.1099773", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "2004-07-23", "series_number": "5683", "volume": "305", "issue": "5683", "pages": "480" }, { "id": "authors:ae3as-1p963", "collection": "authors", "collection_id": "ae3as-1p963", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170125-093852180", "type": "article", "title": "Cyclodextrin-Modified Polyethylenimine Polymers for Gene Delivery", "author": [ { "family_name": "Pun", "given_name": "Suzie H.", "orcid": "0000-0003-1443-4996", "clpid": "Pun-Suzie-Hwang" }, { "family_name": "Bellocq", "given_name": "Nathalie C.", "clpid": "Bellocq-N-C" }, { "family_name": "Liu", "given_name": "Aijie", "clpid": "Liu-Aijie" }, { "family_name": "Jensen", "given_name": "Greg", "clpid": "Jensen-G-S" }, { "family_name": "Machemer", "given_name": "Todd", "clpid": "Machemer-T" }, { "family_name": "Quijano", "given_name": "Erlinda", "clpid": "Quijano-E" }, { "family_name": "Schluep", "given_name": "Thomas", "clpid": "Schluep-T" }, { "family_name": "Wen", "given_name": "Shufen", "clpid": "Wen-Shufen" }, { "family_name": "Engler", "given_name": "Heidrun", "clpid": "Engler-H" }, { "family_name": "Heidel", "given_name": "Jeremy", "clpid": "Heidel-J-D" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Linear and branched poly(ethylenimines), lPEI and bPEI, respectively, grafted with \u03b2-cyclodextrin are prepared to give CD\u2212lPEI and CD\u2212bPEI, respectively, and are investigated as in vitro and in vivo nonviral gene delivery agents. The in vitro toxicity and transfection efficiency are sensitive to the level of cyclodextrin grafting. The cyclodextrin-containing polycations, when combined with adamantane\u2212poly(ethylene glycol) (AD\u2212PEG) conjugates, form particles that are stable at physiological salt concentrations. PEGylated CD\u2212lPEI-based particles give in vitro gene expression equal to or greater than lPEI as measured by the percentage of EGFP expressing cells. Tail vein injections into mice of 120 \u03bcg of plasmid DNA formulated with CD\u2212lPEI and AD\u2212PEG do not reveal observable toxicities, and both nucleic acid accumulation and expression are observed in liver.", "doi": "10.1021/bc049891g", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2004-07", "series_number": "4", "volume": "15", "issue": "4", "pages": "831-840" }, { "id": "authors:8h9eg-2z895", "collection": "authors", "collection_id": "8h9eg-2z895", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170421-102633668", "type": "article", "title": "Dehydrogenation of Propane over Platinum Containing CIT-6", "author": [ { "family_name": "Andy", "given_name": "P.", "clpid": "Andy-P" }, { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The catalytic dehydrogenation of propane is carried out on platinum-impregnated CIT-6 catalysts. Prior to loading platinum, numerous postsynthesis treatments of the as-made CIT-6 are investigated, e.g., calcination, structure directing agent (SDA) extraction, ion exchange, etc., to observe the effects of catalyst preparation on the dehydrogenation of propane. The catalytic behavior depends strongly on the method of postsynthesis treatment. When the as-made CIT-6 is contacted with NH_4NO_3 to remove the SDA prior to platinum loading, an active, selective, and stable catalyst is obtained. ^(29)Si NMR studies show that, after this postsynthesis treatment, some of the zinc remains within the CIT-6 framework. Contacting as-made CIT-6 with Zn(NO_3)_2 to remove the SDA prior to platinum loading gives a solid with a higher level of extraframework zinc. This additional amount of extraframework zinc does not lead to a more stable catalyst. When as-made CIT-6 is contacted with acetic acid at 60 \u00b0C, the SDA and also the zinc are extracted to give pure-silica CIT-6. Platinum loading into this material gives a catalyst that deactivates very rapidly. Thus, framework zinc appears to be essential for the creation of a stable platinum-impregnated CIT-6 catalyst for propane dehydrogenation.", "doi": "10.1021/ie030357m", "issn": "0888-5885", "publisher": "American Chemical Society", "publication": "Industrial & Engineering Chemistry Research", "publication_date": "2004-06-09", "series_number": "12", "volume": "43", "issue": "12", "pages": "2922-2928" }, { "id": "authors:nj2gd-0r332", "collection": "authors", "collection_id": "nj2gd-0r332", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170728-145956263", "type": "article", "title": "Antitumor Activity of \u03b2-Cyclodextrin Polymer\u2212Camptothecin Conjugates", "author": [ { "family_name": "Cheng", "given_name": "Jianjun", "clpid": "Cheng-Jianjun" }, { "family_name": "Khin", "given_name": "Kay T.", "clpid": "Khin-K-T" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Antitumor activity of linear, \u03b2-cyclodextrin polymer (CDP)\u2212camptothecin (CPT) conjugates (HGGG6, LGGG10, HG6, and HGGG10) is investigated in nude mice bearing human LS174T colon carcinoma tumors. These conjugates differ in polymer molecular mass [97 kDa (H) or 35 kDa (L)], CDP\u2212CPT linker structure [glycine (G) or triglycine (GGG)], and CPT loading [ca. 6 wt % (6) or 10 wt % (10)]. Maximum tolerable doses (MTDs) of the three conjugates, LGGG10, HG6, and HGGG10, are determined to be 36, 9, and 9 mg of CPT/kg, respectively, while the MTD of the CDP alone exceeds 240 mg/kg (highest value investigated). The three CDP\u2212CPT conjugates with high polymer molecular masses (HGGG6, HG6, and HGGG10) demonstrate antitumor activity at their MTDs superior to that of CPT at the same amount and to that of irinotecan at its optimal dose. They also show tumor growth inhibition that is superior to that of the conjugate containing the low-molecular mass polymer (LGGG10) at the same dose of CPT. No significant effects of CPT weight loading or linker structure on tumor growth delay are observed. However, conjugates containing G appear to be less toxic than these with GGG. These antitumor studies demonstrate that the CDP-based conjugates of CPT exhibit tumor growth inhibition superior to that of CPT or irinotecan at the conditions employed in this study. The striking observation is that a short course of treatment with the polymer conjugates gives long-term control of tumor growth that does not occur with either CPT or irinotecan. Intracellular CDPs are demonstrated by analyzing cells that were cultured in the presence of rhodamine-labeled CDP (HRhod) containing medium using both confocal microscopy and flow cytometry. The long-term therapeutic efficacy of CDP\u2212CPT conjugates observed in mice may in part be due to the sustained release of CPT from these conjugates in the acidic, intracellular compartments since these conjugates are shown to have significantly slower release rates at acidic pH than at physiological pH.", "doi": "10.1021/mp049966y", "issn": "1543-8384", "publisher": "American Chemical Society", "publication": "Molecular Pharmaceutics", "publication_date": "2004-05", "series_number": "3", "volume": "1", "issue": "3", "pages": "183-193" }, { "id": "authors:tdg38-0r458", "collection": "authors", "collection_id": "tdg38-0r458", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190828-102316945", "type": "article", "title": "Reflections on Routes to Enantioselective Solid Catalysts", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The intellectual and practical challenges of preparing enantioselective solids are discussed and two routes to the possible assembly of chiral inorganic structures highlighted. These synthesis methods are the imprinting of amorphous structures and the crystallization of chiral, crystalline, and microporous materials. For both types of solids, there is the potential to create chirality within the structure that may allow for long-term, robust use in catalytic reactions without significant loss of enantioselectivity.", "doi": "10.1023/b:toca.0000003093.74240.23", "issn": "1022-5528", "publisher": "Springer", "publication": "Topics in Catalysis", "publication_date": "2003-11", "series_number": "1-4", "volume": "25", "issue": "1-4", "pages": "3-7" }, { "id": "authors:7ma4x-xpd38", "collection": "authors", "collection_id": "7ma4x-xpd38", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150326-134801555", "type": "article", "title": "A combustion-free methodology for synthesizing zeolites and zeolite-like materials", "author": [ { "family_name": "Lee", "given_name": "Hyunjoo", "clpid": "Lee-Hyunjoo" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolites are mainly used for the adsorption and separation of ions and small molecules, and as heterogeneous catalysts. More recently, these materials are receiving attention in other applications, such as medical diagnosis and as components in electronic devices. Modern synthetic methodologies for preparing zeolites and zeolite-like materials typically involve the use of organic molecules that direct the assembly pathway and ultimately fill the pore space. Removal of these enclathrated species normally requires high temperature combustion that destroys this high cost component, and the associated energy release in combination with the formed water can be extremely detrimental to the inorganic structure. Here we report a synthetic methodology that avoids these difficulties by creating organic structure-directing agents (SDAs) that can be disassembled within the zeolite pore space to allow removal of their fragments for possible use again by reassembly. The methodology is shown for the synthesis of zeolite ZSM-5 using a SDA that contains a cyclic ketal group that is removed from the SDA while it is inside the zeolite without destruction of the inorganic framework. This approach should be applicable to the synthesis of a wide variety of inorganic and organometallic structures.", "doi": "10.1038/nature01980", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2003-09-25", "series_number": "6956", "volume": "425", "issue": "6956", "pages": "385-388" }, { "id": "authors:0jt1j-6rs52", "collection": "authors", "collection_id": "0jt1j-6rs52", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170125-084653099", "type": "article", "title": "Synthesis of Linear, \u03b2-Cyclodextrin-Based Polymers and Their Camptothecin Conjugates", "author": [ { "family_name": "Cheng", "given_name": "Jianjun", "clpid": "Cheng-Jianjun" }, { "family_name": "Khin", "given_name": "Kay T.", "clpid": "Khin-K-T" }, { "family_name": "Jensen", "given_name": "Gregory S.", "clpid": "Jensen-G-S" }, { "family_name": "Liu", "given_name": "Aijie", "clpid": "Liu-Aijie" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "6^A,6^D-Bis-(2-amino-2-carboxylethylthio)-6^A,6^D-dideoxy-\u03b2-cyclodextrin 1, a diamino acid derivative of \u03b2-cyclodextrin, is synthesized and condensed with difunctionalized PEG comonomers to give linear, high molecular weight (M_w over 50 kDa) \u03b2-cyclodextrin-based polymers (2\u22124) with pendant functionality (carboxylate). 2\u22124 are all highly soluble in aqueous solutions (over 200 mg/mL). 20-O-trifluoroglycinylcamptothecin, 5a, and 20-O-trifluoroglycinylglycinylglycinylcamptothecin, 5b, are synthesized and conjugated to 2 to give polymer\u2212camptothecin (CPT) prodrugs. The solubility of CPT is increased by more than three orders of magnitude when it is conjugated to 2. The rates of CPT release from the conjugates HGGG6 (high molecular weight polymer (M_w 97 kDa), glyglygly linker and 6 wt % CPT loading) and HG6 (high MW polymer (M_w 97 kDa), gly linker and 6 wt % CPT loading) in either mouse or human plasma are dramatically accelerated over the rates of pure hydrolysis at pH = 7.4, indicating the presence of enzymatic cleavage as a rate-determining step at this pH in the release of the CPT. The pH of aqueous solution has a large effect on hydrolysis rate of CPT from HGGG6 and HG6; the lower the pH, the slower the rate in the range at 4.1 \u2264 pH \u2264 13.1. The IC50's of polymer 2e, CPT, and the CPT conjugates HG6 and HGGG6 are found to be cell-line dependent with LS174T, HT29, A2780, and PC3 cells using in vitro MTT assays. The parent polymer 2e has very low toxicity to all cultured cells tested.", "doi": "10.1021/bc0340924", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2003-09", "series_number": "5", "volume": "14", "issue": "5", "pages": "1007-1017" }, { "id": "authors:zfepg-b2154", "collection": "authors", "collection_id": "zfepg-b2154", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170419-115603178", "type": "article", "title": "Design of Heterogeneous Catalysts via Multiple Active Site Positioning in Organic\u2212Inorganic Hybrid Materials", "author": [ { "family_name": "Dufaud", "given_name": "V\u00e9ronique", "clpid": "Dufaud-V" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Catalytic materials bearing multiple sulfonic acid functional groups and positioned at varying distances from one another on the surface of mesoporous solids are prepared to explore the effects that the spatial arrangement of active sites have on catalytic activity and selectivity. A series of organosiloxane precursors containing either disulfide or sulfonate ester functionalities (synthons of the eventual sulfonic acid groups) are synthesized. From these molecular precursors, a variety of organic\u2212inorganic hybrid, mesostructured SBA-15 silica materials are prepared using a postsynthetic grafting procedure that leads to disulfide and sulfonate ester modified silicas:\u2009 [Si]CH_2CH_2CH_2SS-pyridyl, 2\u00b7SBA, [Si]CH_2CH_2CH_2SSCH_2CH_2CH_2[Si], 3\u00b7SBA, [Si]CH_2CH_2(C_6H_4)(SO_2)OCH_2CH_3, 4\u00b7SBA, and [Si]CH_2CH_2(C_6H_4)(SO_2)OC_6H_4O(SO_2)(C_6H_4)CH_2CH_2[Si], 6\u00b7SBA ([Si] = (\u22eeSiO)_x(RO)_(3-x)Si, where x = 1, 2). By subsequent chemical derivatization of the grafted species, thiol and sulfonic acid modified silicas are obtained. The materials are characterized by a variety of spectroscopic (^(13)C and ^(29)Si CP MAS NMR, X-ray diffraction) and quantitative (TGA/DTA, elemental analysis, acid capacity titration) techniques. In all cases, the organic fragment of the precursor molecule is grafted onto the solid without measurable decomposition, and the precursors are, in general, attached to the surface of the mesoporous oxide by multiple siloxane bridges. The disulfide species 2\u00b7SBA and 3\u00b7SBA are reduced to the corresponding thiols 7\u00b7SBA and 8\u00b7SBA, respectively, and 4\u00b7SBA and 6\u00b7SBA are transformed to the aryl sulfonic acids 11\u00b7SBA and 12\u00b7SBA, respectively. 7\u00b7SBA and 8\u00b7SBA differ only in terms of the level of control of the spatial arrangement of the thiol groups. Both 7\u00b7SBA and 8\u00b7SBA are further modified by oxidation with hydrogen peroxide to produce the alkyl sulfonic acid modified materials 9\u00b7SBA and 10\u00b7SBA, respectively. The performances of the sulfonic acid containing SBA-15 silica materials (with the exception of 12\u00b7SBA) are tested as catalysts for the condensation reaction of phenol and acetone to bisphenol A. The alkyl sulfonic acid modified material 10\u00b7SBA derived from the cleavage and oxidation of the dipropyl disulfide modified material 3\u00b7SBA is more active than not only its monosite analogue 9\u00b7SBA, but also the presumably stronger acid aryl sulfonic acid material 11\u00b7SBA. It appears that a cooperative effect between two proximal functional groups may be operating in this reaction.", "doi": "10.1021/ja034594s", "issn": "0002-7863", "publisher": "American Chemical Society", "publication": "Journal of the American Chemical Society", "publication_date": "2003-08-06", "series_number": "31", "volume": "125", "issue": "31", "pages": "9403-9413" }, { "id": "authors:45pep-77d25", "collection": "authors", "collection_id": "45pep-77d25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170125-084654389", "type": "article", "title": "Structural Effects of Carbohydrate-Containing Polycations on Gene Delivery. 3. Cyclodextrin Type and Functionalization", "author": [ { "family_name": "Popielarski", "given_name": "Stephen R.", "clpid": "Popielarski-S-R" }, { "family_name": "Mishra", "given_name": "Swaroop", "orcid": "0000-0002-2665-5385", "clpid": "Mishra-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Linear cationic \u03b2-cyclodextrin (\u03b2-CD)-based polymers can form polyplexes with plasmid DNA and transfect cultured cells. The effectiveness of the gene delivery and the cellular toxicity has been related to structural features in these polycations. Previous \u03b2-CD polycations were prepared from the cocondensation of 6^A,6^D-dideoxy-6^A,6^D-diamino-\u03b2-CD monomers with other difunctionalized monomers such as dimethyl suberimidate (DMS). Here, the type of CD and its functionalization are varied by synthesizing numerous 3^A,3^B-dideoxy-3^A,3^B-diamino-\u03b2- and \u03b3-CD monomers. Both alkyl- and alkoxydiamines are prepared in order to vary the nature of the spacing between the CD and the primary amines in the monomers. These diamino-CD-monomers are polymerized with DMS to yield amidine-based polycations. The nature of the spacer between the CD-ring and the primary amines of each monomer is found to influence both molecular weight and polydispersity of the polycations. When these polycations are used to form polyplexes with plasmid DNA, longer alkyl regions between the CD and the charge centers in the polycation backbone increase transfection efficiency and toxicity in BHK-21 cells, while increasing hydrophilicity of the spacer (alkoxy versus alkyl) provides for lower toxicity. Further, \u03b3-CD-based polycations are shown to be less toxic than otherwise identical \u03b2-CD-based polycations.", "doi": "10.1021/bc034010b", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2003-05", "series_number": "3", "volume": "14", "issue": "3", "pages": "672-678" }, { "id": "authors:hzeag-44h88", "collection": "authors", "collection_id": "hzeag-44h88", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141112-144159690", "type": "article", "title": "Distinguishing the (Almost) Indistinguishable", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolite and zeolite-like materials--crystalline solids containing a large number of uniformly sized pores with diameters of <2 nm--can discriminate between molecules that can enter the pore space and those that cannot on the basis of their size and shape. In his Perspective, Davis highlights the report by Lai et al., who have synthesized the first zeolite membrane that can separate para-xylene molecules from the only slightly larger ortho-xylene molecules, with high permeance of the para-xylene. The membrane was prepared using a clever integration of a number of synthetic steps and consists of a thin layer of zeolite ZSM-5 that is oriented to allow molecular transport through straight pores running perpendicular to the membrane surface.", "doi": "10.1126/science.1083470", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "2003-04-18", "series_number": "5618", "volume": "300", "issue": "5618", "pages": "438-439" }, { "id": "authors:ssw9e-mrs90", "collection": "authors", "collection_id": "ssw9e-mrs90", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170125-084653632", "type": "article", "title": "Structural Effects of Carbohydrate-Containing Polycations on Gene Delivery. 1. Carbohydrate Size and Its Distance from Charge Centers", "author": [ { "family_name": "Reineke", "given_name": "Theresa M.", "clpid": "Reineke-T-M" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Cationic polymers have the ability to bind plasmid DNA (pDNA) through electrostatic interactions and condense it into particles that can be readily endocytosed by cultured cells. The effects that polycation structure has on toxicity and gene delivery efficiency are investigated here by synthesizing a series of amidine-based polycations that contain the carbohydrates d-trehalose and \u03b2-cyclodextrin (CD) within the polycation backbone. The carbohydrate size (trehalose vs CD) and its distance from the charge centers affect the gene delivery behavior in BHK-21 cells. It is found that as the charge center is further removed from the carbohydrate unit, the toxicity is increased. Also, as the size of the carbohydrate moiety is enlarged from trehalose to \u03b2-cyclodextrin, the toxicity is reduced. The absence of a carbohydrate in the polycation produces high toxicity. All carbohydrate polycations transfect BHK-21 cells to approximately the same level of gene expression.", "doi": "10.1021/bc025592k", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2003-01", "series_number": "1", "volume": "14", "issue": "1", "pages": "247-254" }, { "id": "authors:fnmt8-cbe18", "collection": "authors", "collection_id": "fnmt8-cbe18", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170125-084654113", "type": "article", "title": "Structural Effects of Carbohydrate-Containing Polycations on Gene Delivery. 2. Charge Center Type", "author": [ { "family_name": "Reineke", "given_name": "Theresa M.", "clpid": "Reineke-T-M" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Recent polycation structure\u2212gene delivery studies reveal that subtle changes in the molecular structure of polycations have substantial influences on DNA-binding and condensation and on in vitro toxicity and gene delivery efficiency. In Part 1 of this structure\u2212property study using carbohydrate-containing polycations (1), it is demonstrated that as the amidine charge center is removed further from the carbohydrate unit within the polycation structure, the toxicity increases. Inclusion of larger carbohydrate species within the polycation backbone also reduces the toxicity. Here, the effect that polycation charge center type has on toxicity and gene delivery efficiency is investigated. A series of quaternary ammonium polycations containing N,N,N',N'-tetramethyl-1,6-hexanediamine, d-trehalose, and \u03b2-cyclodextrin are synthesized in order to elucidate the effects of charge center type (by comparison to the data given in Part 1) on gene delivery. In all cases, it is found that the quaternary ammonium analogues exhibit lower gene expression values and similar toxicities to their amidine analogues. Additionally, transfection experiments conducted in the presence of chloroquine reveal increased gene expression from quaternary ammonium containing polycations and not from their amidine analogues.", "doi": "10.1021/bc025593c", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2003-01", "series_number": "1", "volume": "14", "issue": "1", "pages": "255-261" }, { "id": "authors:arr0q-97509", "collection": "authors", "collection_id": "arr0q-97509", "cite_using_url": "https://resolver.caltech.edu/CaltechBOOK:2003.001", "type": "book", "title": "Fundamentals of chemical reaction engineering", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Davis", "given_name": "Robert J.", "clpid": "Davis-R-J" } ], "abstract": "This book is an introduction to the quantitative treatment of chemical reaction engineering. The level of the presentation is what we consider appropriate for a one-semester course. The text provides a balanced approach to the understanding of: (1) both homogeneous and heterogeneous reacting systems and (2) both chemical reaction engineering and chemical reactor engineering. We have emulated the teachings of Prof. Michel Boudart in numerous sections of this text. For example, much of Chapters 1 and 4 are modeled after his superb text that is now out of print (Kinetics a/Chemical Processes), but they have been expanded and updated. Each chapter contains numerous worked problems and vignettes. We use the vignettes to provide the reader with discussions on real, commercial processes and/or uses of the molecules and/or analyses described in the text. Thus, the vignettes relate the material presented to what happens in the world around us so that the reader gains appreciation for how chemical reaction engineering and its principles affect everyday life. Many problems in this text require numerical solution. The reader should seek appropriate software for proper solution of these problems. Since this software is abundant and continually improving, the reader should be able to easily find the necessary software. This exercise is useful for students since they will need to do this upon leaving their academic institutions. Completion of the entire text will give the reader a good introduction to the fundamentals of chemical reaction engineering and provide a basis for extensions into other nontraditional uses of these analyses, for example, behavior of biological systems, processing of electronic materials, and prediction of global atmospheric phenomena. We believe that the emphasis on chemical reaction engineering as opposed to chemical reactor engineering is the appropriate context for training future chemical engineers who will confront issues in diverse sectors of employment. \n\nWe gratefully acknowledge Prof. Michel Boudart who encouraged us to write this text and who has provided intellectual guidance to both of us. MED also thanks Martha Hepworth for her efforts in converting a pile of handwritten notes into a final product. In addition, Stacey Siporin, John Murphy, and Kyle Bishop are acknowledged for their excellent assistance in compiling the solutions manual. The cover artwork was provided courtesy of Professor Ahmed Zewail's group at Caltech, and we gratefully thank them for their contribution. We acknowledge with appreciation the people who reviewed our project, especially A. Brad Anton of Cornell University, who provided extensive comments on content and accuracy. Finally, we thank and apologize to the many students who suffered through the early drafts as course notes. We dedicate this book to our wives and to our parents for their constant support.", "isbn": "007245007X", "publisher": "McGraw-Hill Higher Education", "place_of_publication": "New York, NY", "publication_date": "2003" }, { "id": "authors:n7pz2-xs927", "collection": "authors", "collection_id": "n7pz2-xs927", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:WUDcc03", "type": "article", "title": "Shape-selective oxidation of primary alcohols using perruthenate-containing zeolites", "author": [ { "family_name": "Wu", "given_name": "Daniel L.", "clpid": "Wu-D-L" }, { "family_name": "Wight", "given_name": "Andrea P.", "clpid": "Wight-A-P" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Potassium perruthenate (KRuO4), a known, effective oxidant for the conversion of primary and secondary alcohols into carbonyl compounds is impregnated into zeolite X and shown to be a shape-selective oxidant using benzyl alcohol (reacted) and pyrenemethanol (not reacted).", "doi": "10.1039/b212866g", "issn": "1359-7345", "publisher": "Chemical Communications", "publication": "Chemical Communications", "publication_date": "2003", "series_number": "6", "volume": "2003", "issue": "6", "pages": "758-759" }, { "id": "authors:wg23v-8bb21", "collection": "authors", "collection_id": "wg23v-8bb21", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191015-143301005", "type": "article", "title": "The Effects of Structure on Gene Delivery with Linear \u03b2- and \u03b3-Cyclodextrin-Containing Polycations", "author": [ { "family_name": "Popielarski", "given_name": "Stephen R.", "clpid": "Popielarski-S-R" }, { "family_name": "Mishra", "given_name": "Swaroop", "orcid": "0000-0002-2665-5385", "clpid": "Mishra-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Cyclodextrin (CD)-containing polycations are prepared bycopolymerization of3^A3^B-dideoxy-3^A,3^B-diamino-\u03b2- and \u03b3-CDs with dimethyl suberimidate\u00b72HCl to yieldpolyamidine products. Both alkyl- and alkoxy-diamines are used to vary the spacing between the CDand the amidine charge centers. It is found that the transfection efficiency andtoxicity of such polycations is dramatically affected by the structure of the spacer separatingthe CD ring from the charge centers and less so by the type of CD used.", "doi": "10.1023/a:1023084322759", "issn": "0923-0750", "publisher": "Springer Nature", "publication": "Journal of Inclusion Phenomena and Macrocyclic Chemistry", "publication_date": "2002-12", "series_number": "1/4", "volume": "44", "issue": "1/4", "pages": "453-457" }, { "id": "authors:ya83p-tr196", "collection": "authors", "collection_id": "ya83p-tr196", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170206-065923323", "type": "article", "title": "Design and Preparation of Organic\u2212Inorganic Hybrid Catalysts", "author": [ { "family_name": "Wight", "given_name": "A. P.", "clpid": "Wight-A-P" }, { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Solid catalysts provide numerous opportunities for\nrecovering and recycling catalysts from reaction\nenvironments. These features can lead to improved\nprocessing steps, better process economics, and environmentally\nfriendly industrial manufacturing.\nThus, the motivating factors for creating recoverable\ncatalysts are large.", "doi": "10.1021/cr010334m", "issn": "0009-2665", "publisher": "American Chemical Society", "publication": "Chemical Reviews", "publication_date": "2002-10", "series_number": "10", "volume": "102", "issue": "10", "pages": "3589-3614" }, { "id": "authors:04vcz-gd004", "collection": "authors", "collection_id": "04vcz-gd004", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150327-125413406", "type": "article", "title": "Ordered porous materials for emerging applications", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "\"Space\u2014the final frontier.\" This preamble to a well-known television series captures the challenge encountered not only in space travel adventures, but also in the field of porous materials, which aims to control the size, shape and uniformity of the porous space and the atoms and molecules that define it. The past decade has seen significant advances in the ability to fabricate new porous solids with ordered structures from a wide range of different materials. This has resulted in materials with unusual properties and broadened their application range beyond the traditional use as catalysts and adsorbents. In fact, porous materials now seem set to contribute to developments in areas ranging from microelectronics to medical diagnosis.", "doi": "10.1038/nature00785", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2002-06-20", "series_number": "6891", "volume": "417", "issue": "6891", "pages": "813-821" }, { "id": "authors:qn5aq-nrb48", "collection": "authors", "collection_id": "qn5aq-nrb48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170407-070957668", "type": "article", "title": "Organocations in Zeolite Synthesis: Fused Bicyclo [l.m.0] Cations and the Discovery of Zeolite SSZ-48", "author": [ { "family_name": "Lee", "given_name": "Greg S.", "clpid": "Lee-Greg-S" }, { "family_name": "Nakagawa", "given_name": "Yumi", "clpid": "Nakagawa-Yumi" }, { "family_name": "Hwang", "given_name": "Son-Jong", "orcid": "0000-0002-3210-466X", "clpid": "Hwang-Son-Jong" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Wagner", "given_name": "Paul", "clpid": "Wagner-P" }, { "family_name": "Beck", "given_name": "Larry", "clpid": "Beck-L" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" } ], "abstract": "A set of zeolite synthesis experiments is described where lattice substitution is varied in the context of the structure of particular structure-directing organocations (at times referred to as templates). In this particular series, the organocations are constructed as members of a fused bicyclo organonitrogen class of compounds, described as having ring construction [l.m.n], where n = 0. We show that these compounds can best be achieved from starting cyclic ketones that are converted to imines via a Beckman rearrangement reaction. A particular approach to the Beckmann reaction works best in our hands. In some instances isomeric organocations are made and separated. Often their use in zeolite synthesis led to different products. There is a high correlation for the space-filling details of the guest organocations and the type of crystalline host lattice developed in the synthesis. In one instance involving isomers of a decahydroquinoline derivative, a new zeolite, SSZ-48, is discovered and contains only one of the isomers. Characterization of the isomers and their use in the zeolites is followed by 13C MAS NMR analyses. Some details of the new zeolite are given and it is shown that a reasonable symmetry operation predicting a 14-ring zeolite could be generated under similar conditions to SSZ-48 (a 12-ring zeolite).", "doi": "10.1021/ja011513o", "issn": "0002-7863", "publisher": "American Chemical Society", "publication": "Journal of the American Chemical Society", "publication_date": "2002-06-19", "series_number": "24", "volume": "124", "issue": "24", "pages": "7024-7034" }, { "id": "authors:w8gta-4pw76", "collection": "authors", "collection_id": "w8gta-4pw76", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170125-093852983", "type": "article", "title": "Development of a Nonviral Gene Delivery Vehicle for Systemic Application", "author": [ { "family_name": "Pun", "given_name": "Suzie Hwang", "orcid": "0000-0003-1443-4996", "clpid": "Pun-Suzie-Hwang" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Polycation vehicles used for in vitro gene delivery require alteration for successful application in vivo. Modification of polycations by direct grafting of additional components, e.g., poly(ethylene glycol) (PEG), either before or after DNA complexation, tend to interfere with polymer/DNA binding interactions; this is a particular problem for short polycations such as linear, \u03b2-cyclodextrin-containing polycations (\u03b2CDPs). Here, a new method of \u03b2CDP polyplex (polycation/DNA composite structures) modification is presented that exploits the ability to form inclusion complexes between cyclodextrins and adamantane. Surface-PEGylated \u03b2CDP polyplexes are formed by self-assembly of the polyplexes with adamantane\u2212PEG conjugates. While unmodified polyplexes rapidly aggregate and precipitate in salt solutions, the PEGylated \u03b2CDP polyplexes are stable at conditions of physiological salt concentration. Addition of targeting ligands to the adamantane\u2212PEG conjugates allows for receptor-mediated delivery; galactosylated \u03b2CDP-based particles reveal selective targeting to hepatocytes via the asialoglycoprotein receptor. Galactosylated particles transfect hepatoma cells with 10-fold higher efficiency than glucosylated particles (control), but show no preferential transfection in a cell line lacking the asialoglycoprotein receptor. Thus, surface modification of \u03b2CDP-based polyplexes through the use of cyclodextrin/adamantane host/guest interactions endows the particles with properties appropriate for systemic application.", "doi": "10.1021/bc0155768", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2002-05", "series_number": "3", "volume": "13", "issue": "3", "pages": "630-639" }, { "id": "authors:909g0-aqc80", "collection": "authors", "collection_id": "909g0-aqc80", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170518-083547580", "type": "article", "title": "Thermodynamics of Pure-Silica Molecular Sieve Synthesis", "author": [ { "family_name": "Piccione", "given_name": "Patrick M.", "clpid": "Piccione-P-M" }, { "family_name": "Yang", "given_name": "Sanyuan", "clpid": "Yang-Sanyuan" }, { "family_name": "Navrotsky", "given_name": "Alexandra", "orcid": "0000-0002-3260-0364", "clpid": "Navrotsky-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The thermodynamics of pure-silica molecular sieves (denoted by their structural codes ^*BEA, MFI, MTW, and STF) are investigated by solution calorimetry at 323.15 K using 25% aqueous HF as solvent. The enthalpies of solution are determined for both calcined (silica frameworks) and organic structure-directing agent (SDA) occluded samples (SDAs:\u2009 tetraethylammonium (TEA), tetrapropylammonium (TPA), trimethylenebis(N-methyl,N-benzylpiperidinium) (BISPIP), and 2,6-dimethyl-1-aza-spiro[5.4]decane (SPIRO)). These measurements provide data that enable the determination of the following interaction enthalpies between the molecular sieve frameworks and SDAs at 323.15 K:\u2009^*BEA/TEA, \u22123.1 \u00b1 1.4 kJ/mol SiO_2 (\u221232 \u00b1 15 kJ/mol SDA); ^*BEA/BISPIP, \u22125.9 \u00b1 0.7 kJ/mol SiO_2 (\u2212181 \u00b1 21 kJ/mol SDA); MFI/TEA, \u22121.1 \u00b1 1.4 kJ/mol SiO_2 (\u221227 \u00b1 33 kJ/mol SDA); MFI/TPA, \u22123.2 \u00b1 1.4 kJ/mol SiO_2 (\u221281 \u00b1 34 kJ/mol SDA); MTW/BISPIP, \u22121.6 \u00b1 1.3 kJ/mol SiO_2 (\u2212124 \u00b1 97 kJ/mol SDA); and STF/SPIRO, \u22124.9 \u00b1 0.9 kJ/mol SiO_2 (\u221283 \u00b1 16 kJ/mol SDA). Interaction entropies are estimated, and when used in combination with the measured interaction enthalpies, provide the following Gibbs free energies of interaction between the SDAs and the molecular sieve frameworks:\u2009^*BEA/TEA, \u22125.4 \u00b1 1.5 kJ/mol SiO_2; MFI/TEA, \u22122.0 \u00b1 1.4 kJ/mol SiO_2; and MFI/TPA, \u22124.9 \u00b1 1.4 kJ/mol SiO2. The energetics of the synthesis of molecular sieves (considering all components present in the synthesis mixture) are examined and reveal small differences between various molecular sieve/SDA combinations. Assuming complete transformation of the starting amorphous silica into a molecular sieve, the Gibbs free energy changes for the crystallization are ^*BEA/TEA, \u22128.5 \u00b1 2.9 kJ/mol SiO_2; MFI/TEA, \u22124.9 \u00b1 2.8 kJ/mol SiO_2; and MFI/TPA, \u22128.1 \u00b1 2.8 kJ/mol SiO_2. No single factor (enthalpy, entropy, etc.) dominates the overall Gibbs free energies, and these small energetic differences suggest that kinetic factors are of major importance in molecular sieve preparation.", "doi": "10.1021/jp014427j", "issn": "1520-6106", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry B", "publication_date": "2002-04-11", "series_number": "14", "volume": "106", "issue": "14", "pages": "3629-3638" }, { "id": "authors:bbmek-fx193", "collection": "authors", "collection_id": "bbmek-fx193", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170822-154809325", "type": "article", "title": "Non-viral gene delivery systems", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Non-viral gene delivery systems have the potential to create viable pharmaceuticals from nucleic acids. These DNA delivery systems contain lipids and/or cationic polymers. In order for these systems to be developed into commercial products, several barriers must be overcome. These include obstacles in manufacturing, formulation and stability. In vivo, problems of extracellular non-specific interactions and intracellular trafficking to the nucleus are also encountered. Recent progress has been made in overcoming these issues.", "doi": "10.1016/S0958-1669(02)00294-X", "issn": "0958-1669", "publisher": "Elsevier", "publication": "Current Opinion in Biotechnology", "publication_date": "2002-04-01", "series_number": "2", "volume": "13", "issue": "2", "pages": "128-131" }, { "id": "authors:z17mc-xfc28", "collection": "authors", "collection_id": "z17mc-xfc28", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170518-071319729", "type": "article", "title": "Entropy of Pure-Silica Molecular Sieves", "author": [ { "family_name": "Piccione", "given_name": "Patrick M.", "clpid": "Piccione-P-M" }, { "family_name": "Woodfield", "given_name": "Brian F.", "clpid": "Woodfield-B-F" }, { "family_name": "Boerio-Goates", "given_name": "Juliana", "clpid": "Boerio-Goates-J" }, { "family_name": "Navrotsky", "given_name": "Alexandra", "orcid": "0000-0002-3260-0364", "clpid": "Navrotsky-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The entropies of a series of pure-silica molecular sieves (structural codes ^*BEA, FAU, MFI, and MTT) are obtained by calorimetric measurements of low-temperature heat capacity. The third-law entropies at 298.15 K are (on the basis of 1 mol of SiO_2):\u2009 ^*BEA, 44.91 \u00b1 0.11 J\u00b7K^(-1)\u00b7mol^(-1); FAU, 44.73 \u00b1 0.11 J\u00b7K^(-1)\u00b7mol^(-1); MFI, 45.05 \u00b1 0.11 J\u00b7K^(-1)\u00b7mol^(-1); MTT, 45.69 \u00b1 0.11 J\u00b7K^(-1)\u00b7mol^(-1); while the corresponding entropies of transition from quartz at 298.15 K are ^*BEA, 3.4 J\u00b7K^(-1)\u00b7mol^(-1); FAU, 3.2 J\u00b7K^(-1)\u00b7mol^(-1); MFI, 3.6 J\u00b7K^(-1)\u00b7mol^(-1); MTT, 4.2 J\u00b7K^(-1)\u00b7mol^(-1). The entropies span a very narrow range at 3.2\u22124.2 J\u00b7K^(-1)\u00b7mol^(-1) above quartz, despite a factor of 2 difference in molar volume. This confirms that there are no significant entropy barriers to transformations between SiO_2 polymorphs. Finally, the Gibbs free energy of transformation with respect to quartz is calculated for eight SiO_2 phases and all are found to be within twice the available thermal energy of each other at 298.15 K.", "doi": "10.1021/jp010491p", "issn": "1520-6106", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry B", "publication_date": "2001-06-28", "series_number": "25", "volume": "105", "issue": "25", "pages": "6025-6030" }, { "id": "authors:1rexn-aja20", "collection": "authors", "collection_id": "1rexn-aja20", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170125-084653375", "type": "article", "title": "Effects of Structure of \u03b2-Cyclodextrin-Containing Polymers on Gene Delivery", "author": [ { "family_name": "Hwang", "given_name": "Suzie J.", "orcid": "0000-0003-1443-4996", "clpid": "Pun-Suzie-Hwang" }, { "family_name": "Bellocq", "given_name": "Nathalie C.", "clpid": "Bellocq-N-C" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Linear cationic \u03b2-cyclodextrin-based polymers (\u03b2CDPs) are capable of forming polyplexes with nucleic acids and transfecting cultured cells. The \u03b2CDPs are synthesized by the condensation of a diamino-cyclodextrin monomer A with a diimidate comonomer B. In this paper, the effects of polymer structure on polyplex formation, in vitro transfection efficiency and toxicity are elucidated. By comparison of the \u03b2CDPs to polyamidines lacking cyclodextrins, the inclusion of a cyclodextrin moiety in the comonomer A units reduces the IC50s of the polymer by up to 3 orders of magnitude. The spacing between the cationic amidine groups is also important. Different polymers with 4, 5, 6, 7, 8, and 10 methylene units (\u03b2CDP4, 5, 6, 7, 8, and 10) in the comonomer B molecule are synthesized. Transfection efficiency is dependent on comonomer B length with up to 20-fold difference between polymers. Optimum transfection is achieved with the \u03b2CDP6 polymer. In vitro toxicity varied by 1 order of magnitude and the lowest toxicity is observed with \u03b2CDP8. The LD40 of the \u03b2CDP6 to mice is 200 mg/kg, making this polymer a promising agent for in vivo gene delivery applications.", "doi": "10.1021/bc0001084", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "2001-03", "series_number": "2", "volume": "12", "issue": "2", "pages": "280-290" }, { "id": "authors:6q5qy-nf524", "collection": "authors", "collection_id": "6q5qy-nf524", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160913-103841039", "type": "article", "title": "Characterization of Ti-Beta zeolites and their reactivity for the photocatalytic reduction of CO_2 with H_2O", "author": [ { "family_name": "Ikeue", "given_name": "Keita", "clpid": "Ikeue-K" }, { "family_name": "Yamashita", "given_name": "Hiromi", "clpid": "Yamashita-H" }, { "family_name": "Takewaki", "given_name": "Takahiko", "clpid": "Takewaki-T" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Anpo", "given_name": "Masakazu", "clpid": "Anpo-M" } ], "abstract": "A characterization of Ti-Beta zeolites synthesized under various conditions as well as an investigation of their photocatalytic properties for the reduction of CO_2 with H_2O at 323 K to produce CH_4 and CH_3OH were carried out. In situ XAFS spectra measurements indicated that a highly dispersed tetrahedral titanium oxide species was present in the zeolite framework and an increase in the coordination number of the titanium oxide species by the addition of H_2O and CO_2 molecules could be detected. The Ti-Beta zeolite having a hydrophilic property (Ti-Beta(OH)) exhibited a more dramatic increase in the coordination number than the Ti-Beta(F) zeolite which had a hydrophobic property. These results suggest that CO_2 and H_2O molecules can be adsorbed efficiently onto the highly dispersed tetrahedrally coordinated titanium oxide species. UV irradiation of these Ti-Beta zeolite catalysts in the presence of H_2O and CO_2 led to the formation of CH_4 and CH_3OH. Ti-Beta(OH) exhibited a higher reactivity than Ti-Beta(F), while the selectivity for the formation of CH_3OH on Ti-Beta(F) was higher than that for Ti-Beta(OH). These results indicated that the reactivity and selectivity of the zeolite catalyst can be determined by the hydrophilic and hydrophobic properties of the zeolites.", "doi": "10.1107/S0909049500014394", "issn": "0909-0495", "publisher": "Blackwell", "publication": "Journal of Synchrotron Radiation", "publication_date": "2001-03", "series_number": "2", "volume": "8", "issue": "2", "pages": "602-604" }, { "id": "authors:52bwy-7gf84", "collection": "authors", "collection_id": "52bwy-7gf84", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-101506437", "type": "article", "title": "Synthesis of Hydrophobic Molecular Sieves by Hydrothermal Treatment with Acetic Acid", "author": [ { "family_name": "Jones", "given_name": "Christopher W.", "clpid": "Jones-Christopher-W" }, { "family_name": "Hwang", "given_name": "Son-Jong", "orcid": "0000-0002-3210-466X", "clpid": "Hwang-Son-Jong" }, { "family_name": "Okubo", "given_name": "Tatsuya", "clpid": "Okubo-Tatsuya" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A series of calcined borosilicate molecular sieves are treated hydrothermally with aqueous acetic acid and subsequently characterized in detail. The acid treatments are shown to expel boron from the molecular sieves, and the defects created by the boron removal are subsequently healed with silicon dissolved from other parts of the crystal. By use of this procedure, highly crystalline, hydrophobic all-silica CIT-1 and SSZ-33 (CON topology) molecular sieves are synthesized for the first time. ^(29)Si Bloch decay (BD) and cross-polarization magic-angle spinning (CPMAS) NMR spectra indicate that the materials have few internal defects and allow for structural characterization of CON materials by 29Si MAS NMR. Seven unique tetrahedral silicon species are identified in the spectra in agreement with the published crystal structure. The effects of treatment conditions such as acid type, solution pH, and temperature are studied in detail. Conditions near the isoelectric point of silica (pH = 0\u22122) are found to be efficient for the production of a variety of hydrophobic materials with few structural defects including molecular sieves of the *BEA, CON, and MWW topologies. Detailed control studies using SSZ-33 show that the nearly defect-free materials contain triangular mesopores that are clearly distinguishable in field-emission electron microscopy images. The silica that previously inhabited the mesopores is a likely source for the species required to heal the defects created by boron expulsion. In addition to healing the vacancies previously inhabited by boron with dissolved silicon, an additional aluminum or gallium source can be added to the acetic acid solution and the ions are incorporated into the framework. Many of the defects that are not filled with the Al^(3+) or Ga^(3+) species are filled with silicon during the treatment to produce a more hydrophobic metallosilicate than the one containing internal silanol defects.", "doi": "10.1021/cm0007961", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "2001-03", "series_number": "3", "volume": "13", "issue": "3", "pages": "1041-1050" }, { "id": "authors:0mb2n-rkm09", "collection": "authors", "collection_id": "0mb2n-rkm09", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170816-153452128", "type": "article", "title": "Alkylation of 2-methoxynaphthalene with propylene oxide using titanium and zirconium containing molecular sieves", "author": [ { "family_name": "Brait", "given_name": "Axel", "clpid": "Brait-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Titanium and zirconium containing molecular sieves are active catalysts for the alkylation of 2-methoxynaphthalene (2-MN) with propylene oxide (PO). Temperatures above 423 K are necessary in order to promote the alkylation reaction. A major competing reaction that deactivates the catalyst is the oligomerization of PO that provides for deposition of these oligomers on the catalyst surface. A high 2-MN to PO ratio as well as the addition of PO in a semi-batch mode of operation help minimize the oligomerization reaction. The main reaction products are an O-alkylated product (I) and four C-alkylated products: 1-(2-methoxy-1-naphthyl)-2-propanol (II), 2-(2-methoxy-1-naphthyl)propanol (III), 1-(6-methoxy-2-naphthyl)-2-propanol (IV) and 2-(6-methoxy-2-naphthyl)propanol (V). The conversion of the limiting compound (PO) can be as high as 50% with selectivities towards the desired product V ranging from 12 to 20%. The ratio of 2,6- to 1,2-product is 1.6 for Ti-BEA, while Zr-BEA shows a value of 3.0. The shape-selective effect of the molecular sieve catalysts can be enhanced by passivation or poisoning of the outer surface of the catalyst by treatment with tetraethylorthosilicate (TEOS), tris[2-(diphenylphosphino)ethyl]-phosphine (TETRAPHOS-II), ethylenediaminetetraacetic acid (EDTA) or hydrogen peroxide (H_2O_2). For these cases, the 2,6- to 1,2-products ratios can reach values of up to 4. No leaching of Ti or Zr from the molecular sieve materials is observed.", "doi": "10.1016/S0926-860X(00)00510-X", "issn": "0926-860X", "publisher": "Elsevier", "publication": "Applied Catalysis A: General", "publication_date": "2000-11-06", "series_number": "1", "volume": "204", "issue": "1", "pages": "117-127" }, { "id": "authors:b1m5c-67n12", "collection": "authors", "collection_id": "b1m5c-67n12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170517-070821051", "type": "article", "title": "Thermochemistry of Pure-Silica Zeolites", "author": [ { "family_name": "Piccione", "given_name": "Patrick M.", "clpid": "Piccione-P-M" }, { "family_name": "Laberty", "given_name": "Christel", "clpid": "Laberty-C" }, { "family_name": "Yang", "given_name": "Sanyuan", "clpid": "Yang-Sanyuan" }, { "family_name": "Camblor", "given_name": "Miguel A.", "orcid": "0000-0001-9591-3432", "clpid": "Camblor-M-A" }, { "family_name": "Navrotsky", "given_name": "Alexandra", "orcid": "0000-0002-3260-0364", "clpid": "Navrotsky-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A series of pure-silica molecular sieves (structural codes AST, BEA, CFI, CHA, IFR, ISV, ITE, MEL, MFI, MWW, and STT) is investigated by high-temperature drop solution calorimetry using lead borate solvent at 974 K. The enthalpies of transition from quartz at 298 K (in kJ/mol) are AST, 10.9 \u00b1 1.2; BEA, 9.3 \u00b1 0.8; CFI, 8.8 \u00b1 0.8; CHA, 11.4 \u00b1 1.5; IFR, 10.0 \u00b1 1.2; ISV, 14.4 \u00b1 1.1; ITE, 10.1 \u00b1 1.2; MEL, 8.2 \u00b1 1.3; MFI, 6.8 \u00b1 0.8; MWW, 10.4 \u00b1 1.5; and STT, 9.2 \u00b1 1.2. The range of energies observed is quite narrow at only 6.8\u221214.4 kJ/mol above that of quartz, and these data are consistent with and extend the earlier findings of Petrovic et al. The enthalpy variations are correlated with the following structural parameters:\u2009 framework density, nonbonded distance between Si atoms, and framework loop configurations. A strong linear correlation between enthalpy and framework density is observed, implying that it is the overall packing quality that determines the relative enthalpies of zeolite frameworks. The presence of internal silanol groups is shown to result in a slight (\u22642.4 kJ/mol) destabilization of the calcined molecular sieves by comparing calorimetric data for MFI and BEA samples synthesized in hydroxide (containing internal silanol groups) and fluoride (low internal silanol group density) media.", "doi": "10.1021/jp002148a", "issn": "1520-6106", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry B", "publication_date": "2000-11-02", "series_number": "43", "volume": "104", "issue": "43", "pages": "10001-10011" }, { "id": "authors:mr6kk-beb17", "collection": "authors", "collection_id": "mr6kk-beb17", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170419-111654124", "type": "article", "title": "Si-MFI Crystallization Using a \"Dimer\" and \"Trimer\" of TPA Studied with Small-Angle X-ray Scattering", "author": [ { "family_name": "de Moor", "given_name": "Peter-Paul E. A.", "clpid": "de-Moor-P-P-E-A" }, { "family_name": "Beelen", "given_name": "Theo P. M.", "clpid": "Beelen-T-P-M" }, { "family_name": "van Santen", "given_name": "Rutger A.", "clpid": "van-Santen-R-A" }, { "family_name": "Beck", "given_name": "Larry W.", "clpid": "Beck-L-W" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The formation and consumption of precursors and the crystallization of Si-MFI using bis(tripropylammonium) hexamethylene dihydroxide (\"dimer\" of tetrapropylammonium cation, TPA) and bis(tripropylammonium-N-N'-hexamethylene)-N'\u2009',N'\u2009'-dipropylammonium trihydroxide (\"trimer\" of TPA) as structure-directing agents have been investigated in situ using simultaneous, time-resolved, SAXS and WAXS and using USAXS. The formation of 2.8-nm-sized primary units is observed upon dissolution of the silica source, which is in agreement with results from earlier studies on systems with the TPA cation as a structure-directing agent. Aggregation of these nanometer-scale primary units to 10\u221215-nm-sized particles is found to be an essential step in nucleation of the zeolite. Crystal growth occurs via the addition of the primary units to the growing crystal. Although the size of the primary units for MFI is independent of the structure-directing agent used, the organic species does have a pronounced influence on the crystal growth step and, therefore, on the crystal growth rate, size, and morphology. The results presented here confirm a common mechanism proposed for organic-mediated crystallization of high-silica zeolites.", "doi": "10.1021/jp0006476", "issn": "1520-6106", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry B", "publication_date": "2000-08-17", "series_number": "32", "volume": "104", "issue": "32", "pages": "7600-7611" }, { "id": "authors:hfjqz-k1375", "collection": "authors", "collection_id": "hfjqz-k1375", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170408-133955288", "type": "article", "title": "Adsorption studies with gmelinite zeolites containing mono-, di- and tri-valent cations", "author": [ { "family_name": "Chiyoda", "given_name": "Osamu", "clpid": "Chiyoda-Osamu" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Synthetic gmelinite zeolites are prepared via (i) hydrothermal conversion of strontium-containing zeolite Y and (ii) the use of a DABCO (1,4-diazabicyclo [2,2,2] octane) polymer structure-directing agent. The synthetic materials are compared to a sample of natural gmelinite. The adsorption capacities of the three gmelinites after ion exchange with Na^+, Sr^(2+) and La^(3+) for adsorbates such as water, methanol, ethanol, propanol, nitrogen, n-hexane and cyclohexane are presented. It is shown on each type of gmelinite and independent of the degree of faulting, the adsorption capacities of nitrogen, propanol, n-hexane and cyclohexane increase when monovalent cations are replaced by multivalent cations. However, adsorbates such as water, methanol and ethanol do not show significant variations in adsorption capacity with exchangeable ion valency.", "doi": "10.1016/S1387-1811(99)00287-5", "issn": "1387-1811", "publisher": "Elsevier", "publication": "Microporous and Mesoporous Materials", "publication_date": "2000-08", "series_number": "2-3", "volume": "38", "issue": "2-3", "pages": "143-149" }, { "id": "authors:x9g3x-1q954", "collection": "authors", "collection_id": "x9g3x-1q954", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170509-133036637", "type": "article", "title": "Guest/Host Relationships in the Synthesis of the Novel Cage-Based Zeolites SSZ-35, SSZ-36, and SSZ-39", "author": [ { "family_name": "Wagner", "given_name": "Paul", "clpid": "Wagner-P" }, { "family_name": "Nakagawa", "given_name": "Yumi", "clpid": "Nakagawa-Yumi" }, { "family_name": "Lee", "given_name": "Greg S.", "clpid": "Lee-Greg-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Elomari", "given_name": "Saleh", "clpid": "Elomari-S" }, { "family_name": "Medrud", "given_name": "Ronald C.", "clpid": "Medrud-R-C" }, { "family_name": "Zones", "given_name": "S. I.", "clpid": "Zones-S-I" } ], "abstract": "Here, we report the synthesis and structure of three high-silica molecular sieves, SSZ-35, SSZ-36, and SSZ-39, that are prepared from a library of 37 different cyclic and polycyclic quaternized amine molecules that are used as structure-directing agents (SDAs). The size and shape of the quaternized amine molecules are purposely designed in order to obtain novel zeolite structures, and the synthesis of these molecules is presented. The selectivity for the three molecular sieve phases is found to depend on both the SDA and the degree of heteroatom lattice substitution of Al^(3+) or B^(3+) in the silicate framework. Molecular modeling is utilized to probe the effects of the nonbonded SDA/zeolite-framework interaction energy on the selectivity for the observed molecular sieve phase. The Rietveld refinement of the powder X-ray data confirms the structure of the SSZ-39 zeolite to be isomorphous with the aluminophosphate molecular sieve, SAPO-18 (AEI). The structure of SSZ-36 is found to possess a range of fault probabilities between the two-dimensional channel system, end-member polymorphs, ITQ-3 and RUB-13 (International Zeolite Association Codes ITE and RTH, respectively). The SSZ-35 structure is reported to contain a one-dimensional pore system possessing stacked cages circumscribed by alternating rings of 10 and 18 tetrahedral atoms (10- and 18-membered rings).", "doi": "10.1021/ja990722u", "issn": "0002-7863", "publisher": "American Chemical Society", "publication": "Journal of the American Chemical Society", "publication_date": "2000-01-19", "series_number": "2", "volume": "122", "issue": "2", "pages": "263-273" }, { "id": "authors:cqtaw-w4h69", "collection": "authors", "collection_id": "cqtaw-w4h69", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171107-083706407", "type": "article", "title": "New Class of Polymers for the Delivery of Macromolecular Therapeutics", "author": [ { "family_name": "Gonzalez", "given_name": "Hector", "clpid": "Gonzalez-H" }, { "family_name": "Hwang", "given_name": "Sue Jean", "clpid": "Hwang-Sue-Jean" }, { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Cationic polymers show promise for the in vitro and in vivo delivery of macromolecular therapeutics. Known cationic polymers, e.g., poly(L)lysine (PLL) and polyethylenimine (PEI), have been employed in native and modified forms for the delivery of plasmid DNA (pDNA) and reveal varying levels of toxicity. Here, we report the preparation of a new class of cationic polymers that are specifically designed to deliver macromolecular therapeutics. Linear, cationic, \u03b2-cyclodextrin (\u03b2-CD)-containing polymers (CD-polymers) are synthesized by copolymerizing difunctionalized \u03b2-CD monomers (AA) with other difunctionalized comonomers (BB) such that an AABBAABB product is formed. The \u03b2-CD polymers are able to bind \u223c5 kbp pDNA above polymer to DNA (+/\u2212) charge ratios of 1.5, compact the bound pDNA into particles of approximately 100\u2212150 nm in size at charge ratios above 5+/\u2212, and transfect cultured cells at charge ratios above 10+/\u2212. In vitro transfections with the new \u03b2-CD-polymers are comparable to the best results obtained in our hands with PEI and Lipofectamine. Some cell line-dependent toxicities are observed for serum-free transfections; however, no toxicity is revealed at charge ratios as high as 70+/\u2212 in transfections conducted in 10% serum. Single IV and IP doses as high as 200 mg/kg in mice showed no mortalities.", "doi": "10.1021/bc990072j", "issn": "1043-1802", "publisher": "American Chemical Society", "publication": "Bioconjugate Chemistry", "publication_date": "1999-11", "series_number": "6", "volume": "10", "issue": "6", "pages": "1068-1074" }, { "id": "authors:a0dap-ncn98", "collection": "authors", "collection_id": "a0dap-ncn98", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170829-085311667", "type": "article", "title": "Organic-functionalized molecular sieves (OFMSs): I. Synthesis and characterization of OFMSs with polar functional groups", "author": [ { "family_name": "Tsuji", "given_name": "Katsuyuki", "clpid": "Tsuji-Katsuyuki" }, { "family_name": "Jones", "given_name": "Christopher W.", "clpid": "Jones-Christopher-W" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Organic-functionalized molecular sieves that contain polar functional groups are synthesized and characterized. Small, uniform-sized crystals with the BEA topology are obtained when tetraethylammonium fluoride is used as a structure-directing agent and added at the initiation of tetraethylorthosilicate/organosilane hydrolysis. An aminopropyl-functionalized material with the BEA topology is prepared and characterized by X-ray diffraction, solid-state NMR spectroscopy, Raman spectroscopy and diffuse reflectance ultraviolet\u2013visible spectroscopy. The results indicate that the aminopropyl groups are located within the intracrystalline void space and that they can be reacted with aldehydes to form occluded imines.", "doi": "10.1016/S1387-1811(99)00003-7", "issn": "1387-1811", "publisher": "Elsevier", "publication": "Microporous and Mesoporous Materials", "publication_date": "1999-07", "series_number": "3", "volume": "29", "issue": "3", "pages": "339-349" }, { "id": "authors:sf7mn-d9s22", "collection": "authors", "collection_id": "sf7mn-d9s22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180508-141400977", "type": "article", "title": "SSZ-35 and SSZ-44: Two Related Zeolites Containing Pores Circumscribed by Ten- and Eighteen-Membered Rings", "author": [ { "family_name": "Wagner", "given_name": "Paul", "clpid": "Wagner-P" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Medrud", "given_name": "Ronald C.", "clpid": "Medrud-R-C" } ], "abstract": "Unusual one\u2010dimensional pores circumscribed by 10\u2010 and 18\u2010membered rings are a feature of the structures of two high\u2010silica molecular sieves, SSZ\u201044 and SSZ\u201035. Structure solution and Rietveld refinement from synchrotron powder X\u2010ray data reveal that the two materials are the pure end\u2010member polymorphs of a new fault series and contain similar layerlike units (see picture). The SSZ\u201044 structure is formed by an AB stacking of the layers, whereas the SSZ\u201035 structure is formed through an ABC stacking of the layer units.", "doi": "10.1002/(SICI)1521-3773(19990503)38:9<1269::AID-ANIE1269>3.0.CO;2-3", "issn": "1433-7851", "publisher": "Wiley", "publication": "Angewandte Chemie International Edition", "publication_date": "1999-05-03", "series_number": "9", "volume": "38", "issue": "9", "pages": "1269-1272" }, { "id": "authors:rmw9v-p4694", "collection": "authors", "collection_id": "rmw9v-p4694", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171129-153606749", "type": "article", "title": "SAXS and USAXS Investigation on Nanometer-Scaled Precursors in Organic-Mediated Zeolite Crystallization from Gelating Systems", "author": [ { "family_name": "de Moor", "given_name": "Peter-Paul E. A.", "clpid": "de-Moor-P-P-E-A" }, { "family_name": "Beelen", "given_name": "Theo P. M.", "clpid": "Beelen-T-P-M" }, { "family_name": "van Santen", "given_name": "Rutger A.", "clpid": "van-Santen-R-A" }, { "family_name": "Tsuji", "given_name": "Katsuyuki", "clpid": "Tsuji-Katsuyuki" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The formation of precursor particles in the crystallization of zeolites from gelating systems has been studied using X-ray scattering at small angles. The crystallization of Si\u2212MFI using trimethylene-bis(N-hexyl, N-methyl-piperidinium) as the structure-directing agent shows the formation of two categories of precursors:\u2009 gel particles and nanometer-scaled primary units. The size of the primary units for the crystallization of Si\u2212MFI is found to be 2.8 nm both for gelating and nongelating systems using different structure-directing agents. Zeolites Si\u2212BEA and Si\u2212MTW have been prepared using the same organic (trimethylene-bis(N-benzyl, N-methyl-piperidinium)) at different concentrations. Primary units with a size of 2.6 nm are found to be present in the synthesis of Si\u2212BEA, while their size is 1.5 nm in the synthesis mixture directing to Si\u2212MTW. Our data suggest that the nanometer-scaled primary units are specific for the zeolite topology formed.", "doi": "10.1021/cm9807079", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1999-01", "series_number": "1", "volume": "11", "issue": "1", "pages": "36-43" }, { "id": "authors:bwpv0-k2176", "collection": "authors", "collection_id": "bwpv0-k2176", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171121-081127036", "type": "article", "title": "Synthesis, Characterization, and Structure Solution of CIT-5, a New, High-Silica, Extra-Large-Pore Molecular Sieve", "author": [ { "family_name": "Yoshikawa", "given_name": "Masahito", "clpid": "Yoshikawa-Masahito" }, { "family_name": "Wagner", "given_name": "Paul", "clpid": "Wagner-P" }, { "family_name": "Lovallo", "given_name": "Mark", "clpid": "Lovallo-M" }, { "family_name": "Tsuji", "given_name": "Katsuyuki", "clpid": "Tsuji-Katsuyuki" }, { "family_name": "Takewaki", "given_name": "Takahiko", "clpid": "Takewaki-Takahiko" }, { "family_name": "Chen", "given_name": "Cong-Yan", "clpid": "Chen-Cong-Yan" }, { "family_name": "Beck", "given_name": "Larry W.", "clpid": "Beck-L-W" }, { "family_name": "Jones", "given_name": "Chris", "clpid": "Jones-Christopher-W" }, { "family_name": "Tsapatsis", "given_name": "Michael", "orcid": "0000-0001-5610-3525", "clpid": "Tsapatsis-M" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The synthesis, structure solution, and characterization of the high-silica molecular sieve CIT-5 (California Institute of Technology Number 5) is described. CIT-5 is synthesized at hydrothermal conditions in the presence of N(16)-methylsparteinium and preferrably lithium cations. The structural solution of CIT-5 shows that it contains one-dimensional pores circumscribed by 14 tetrahedral atoms (14 MR). Rietveld refinement of the synchrotron X-ray powder data gives a symmetry and space group assignment for the structure of Pmn2_1 (no. 31) with refined unit cell parameters of a = 13.6738(8) \u00c5, b = 5.0216(3) \u00c5, and c = 25.4883(7) \u00c5 (V = 1750.1 \u00c5^3). Electron diffraction and transmission electron microscopy confirm the space group and the topology of the structure viewed along the [010] direction. Solid-state ^(29)Si NMR spectroscopy results are consistent with the space group assignment. The thermal/hydrothermal stability of CIT-5 compares well to that of other large- and extra-large-pore, high-silica molecular sieves. The acid form of CIT-5 is able to perform hydrocarbon reactions such as cracking and alkylation and shows behaviors that are different from other zeolites.", "doi": "10.1021/jp982169t", "issn": "1520-6106", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry B", "publication_date": "1998-09-10", "series_number": "37", "volume": "102", "issue": "37", "pages": "7139-7147" }, { "id": "authors:yg8xy-eq442", "collection": "authors", "collection_id": "yg8xy-eq442", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120119-114023342", "type": "article", "title": "CIT-5: a high-silica zeolite with 14-ring pores", "author": [ { "family_name": "Wagner", "given_name": "Paul", "clpid": "Wagner-P" }, { "family_name": "Yoshikawa", "given_name": "Masahito", "clpid": "Yoshikawa-Masahito" }, { "family_name": "Lovallo", "given_name": "Mark", "clpid": "Lovallo-M" }, { "family_name": "Tsuji", "given_name": "Katsuyuki", "clpid": "Tsuji-Katsuyuki" }, { "family_name": "Taspatsis", "given_name": "Michael", "clpid": "Taspatsis-M" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The synthesis and structure of a new zeolite, CIT-5 (California Institute of Technology Number Five), is described, which possesses one-dimensional pores comprised of 14 T-atoms (tetrahedrally coordinated silicon or aluminium atoms).", "doi": "10.1039/A704774F", "issn": "1359-7345", "publisher": "Royal Society of Chemistry", "publication": "Chemical Communications", "publication_date": "1997-11-21", "series_number": "22", "volume": "1997", "issue": "22", "pages": "2179-2180" }, { "id": "authors:y186k-56h33", "collection": "authors", "collection_id": "y186k-56h33", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170811-092543833", "type": "article", "title": "CIT-4: The first synthetic analogue of brewsterite", "author": [ { "family_name": "Khodabandeh", "given_name": "Shervin", "clpid": "Khodabandeh-S" }, { "family_name": "Lee", "given_name": "Gary", "clpid": "Lee-Gary" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The first synthetic analogue of the rare natural zeolite brewsterite has been synthesized and named CIT-4. CIT-4 crystallizes with a composition SrO:Al_2O_3:5.8-6 SiO_2:4.5 H_2O and is prepared via hydrothermal alteration of zeolite P1 by strontium-containing solutions and in the presence of seed crystals of brewsterite.", "doi": "10.1016/S0927-6513(97)00036-9", "issn": "0927-6513", "publisher": "Elsevier", "publication": "Microporous Materials", "publication_date": "1997-08", "series_number": "1-2", "volume": "11", "issue": "1-2", "pages": "87-95" }, { "id": "authors:s1atx-9g346", "collection": "authors", "collection_id": "s1atx-9g346", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170811-091545178", "type": "article", "title": "Further investigations on the synthesis of pure-silica molecular sieves via the use of organic structure-directing agents", "author": [ { "family_name": "Tsuji", "given_name": "K.", "clpid": "Tsuji-Katsuyuki" }, { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Several organic structure-directing agents (SDAs) that are variations of a 4,4\u2032-trimethylenebis(N-methyl, N-R_1-piperidinium) moiety were synthesized and used for the synthesis of pure-silica molecular sieves. Pure-silica MTW, MFI, BEA and the MCM-41-type mesoporous materials could be prepared by changing only the R_1 group. When R_1 was pentyl or hexyl, MFI was crystallized, suggesting that each SDA molecule spans two channel intersections. For R_1 groups smaller than pentyl, MTW was formed. Pure-silica BEA could easily be prepared when R_1 was benzyl or cyclohexylmethyl. Numerous variations of the organics used to crystallize BEA were explored and the features necessary to structure direct the formation of BEA elucidated. When R_1 was either octyl or nonyl, the MCM-41-type mesoporous materials were formed, indicating that these organics can act as surfactants. The results presented provide further evidence that organic molecules can serve as structure-directing agents for the synthesis of pure-silica molecular sieves.", "doi": "10.1016/S0927-6513(97)00024-2", "issn": "0927-6513", "publisher": "Elsevier", "publication": "Microporous Materials", "publication_date": "1997-08", "series_number": "1-2", "volume": "11", "issue": "1-2", "pages": "53-64" }, { "id": "authors:s4v0x-bzh65", "collection": "authors", "collection_id": "s4v0x-bzh65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170920-102018890", "type": "article", "title": "A Model for the Structure of the Large-Pore Zeolite SSZ-31", "author": [ { "family_name": "Lobo", "given_name": "Raul F.", "clpid": "Lobo-R-F" }, { "family_name": "Tsapatsis", "given_name": "Michael", "orcid": "0000-0001-5610-3525", "clpid": "Tsapatsis-M" }, { "family_name": "Freyhardt", "given_name": "Clemens C.", "clpid": "Freyhardt-C-C" }, { "family_name": "Chan", "given_name": "Ignatius", "clpid": "Chan-Ignatius" }, { "family_name": "Chen", "given_name": "Cong-Yan", "clpid": "Chen-Cong-Yan" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A model for the structure of the zeolite SSZ-31 is presented. The model is obtained by combining information from adsorption capacity measurements, transmission electron microscopy, and high-resolution X-ray diffraction. SSZ-31 is a one-dimensional large-pore zeolite with a framework density of 18.7 tetrahedral(T)-atoms per nm^(-3) and a bulk density of 1.87 g cm^(-3). The pore apertures are elliptical with major and minor axes of approximately 8.6 \u00c5 \u00d7 5.7 \u00c5. SSZ-31 is an extreme example of a complex and highly faulted zeolite. The structure can be described as an intergrowth of four different but structurally related polymorphs.", "doi": "10.1021/ja963925g", "issn": "0002-7863", "publisher": "American Chemical Society", "publication": "Journal of the American Chemical Society", "publication_date": "1997-04-23", "series_number": "16", "volume": "119", "issue": "16", "pages": "3732-3744" }, { "id": "authors:c7173-cp346", "collection": "authors", "collection_id": "c7173-cp346", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230726-189190000.1", "type": "article", "title": "Cracking Behavior of Zeolites with Connected 12- and 10-Member Ring Channels: The Influence of Pore Structure on Product Distribution", "author": [ { "family_name": "Corma", "given_name": "A.", "clpid": "Corma-A" }, { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Forn\u00e9s", "given_name": "V.", "clpid": "Forn\u00e9s-V" }, { "family_name": "Gonz\u00e1lez-Alfaro", "given_name": "V.", "clpid": "Gonz\u00e1lez-Alfaro-V" }, { "family_name": "Lobo", "given_name": "R.", "clpid": "Lobo-Raul-F" }, { "family_name": "Orchill\u00e9s", "given_name": "A. V.", "clpid": "Orchill\u00e9s-A-V" } ], "abstract": "n-Heptane has been cracked on a CIT-1 zeolite which has connected 12- and 10-member ring (MR) channels, and its behavior was compared with that of MCM-22 with nonconnected 12- and 10-MR channels, and SSZ-24 and BETA with unidirectional and tridirectional 12-MR channels, respectively. The kinetic rate constant is highest for CIT-1, and the decay constant is lowest. From the selectivity point of view, its behavior can be better represented by a system with large cavities (the intersections between the 12- and 10-MR) connected by windows. This gives a behavior typical of that of large pore zeolites. CIT-1 produces a remarkably high selectivity toi-C4, and specially to isobutane. This zeolite shows promise as an additive in FCC operations.", "doi": "10.1006/jcat.1997.1584", "issn": "0021-9517", "publisher": "Elsevier", "publication": "Journal of Catalysis", "publication_date": "1997-04-15", "series_number": "2", "volume": "167", "issue": "2", "pages": "438-446" }, { "id": "authors:gp5n7-bg883", "collection": "authors", "collection_id": "gp5n7-bg883", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151007-090424989", "type": "article", "title": "Use of diffusion barriers in the preparation of supported zeolite ZSM-5 membranes", "author": [ { "family_name": "Yan", "given_name": "Yushan", "clpid": "Yan-Yushan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Gavalas", "given_name": "George R.", "orcid": "0000-0003-1468-6835", "clpid": "Gavalas-G-R" } ], "abstract": "Zeolite ZSM-5 membranes were prepared by in situ crystallization on porous \u03b1-Al_2O_3 disks that contained a diffusion barrier to limit excessive penetration of siliceous species into the alumina pores. The barrier was introduced into the alumina pores by impregnating the porous disk with a 1:1 molar mixture of furfuryl alcohol (FA) and tetraethylorthosilicate (TEOS), polymerizing the mixture retained in the disk, and carbonizing the resulting polymer at 600\u00b0C in N_2. Following carbonization, a partial carbon burn-off was carried out by catalyzed oxidation in 2% O_2\ue5f8N_2 at 600\u00b0C to generate a carbon-free region near the surface of the support. After zeolite crystallization, the remaining carbon and the organic structure directing agent were removed by calcination in air, at 500\u00b0C. It was found that pure carbon does not support zeolite growth while the solid obtained from a mixture of FA and TEOS does, due to the presence of dispersed silica. Membranes synthesized using barriers have n-butane flux and n-butane/isobutane selectivity 2.7 \u00d7 10^(\u22123) mol m^(\u22122) s^(\u22121) and 45, respectively, at 185\u00b0C, which are, respectively, ca. 1.6 and 4 times as large as those of membranes prepared without the use of barriers. Electron probe microanalysis (EPMA) and X-ray diffraction (XRD) revealed that the internal layer of the barrier-pretreated membrane has smaller thickness and higher crystallinity accounting for the increased flux and selectivity.", "doi": "10.1016/S0376-7388(96)00263-3", "issn": "0376-7388", "publisher": "Elsevier", "publication": "Journal of Membrane Science", "publication_date": "1997-04-02", "series_number": "1", "volume": "126", "issue": "1", "pages": "53-65" }, { "id": "authors:c0z4y-e0f12", "collection": "authors", "collection_id": "c0z4y-e0f12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170811-080044022", "type": "article", "title": "Synthesis of CIT-3: a calcium aluminosilicate with the heulandite topology", "author": [ { "family_name": "Khodabandeh", "given_name": "Shervin", "clpid": "Khodabandeh-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The synthesis of CIT-3, a calcium aluminosilicate zeolite of composition CaO:Al_2O_3:7 7.2SiO_2:6H_2O possessing the HEU topology is accomplished by hydrothermal transformation of a specifically prepared zeolite P1 using calcium-containing solutions and HEU seeds. In the absence of seeds, a synthetic epistilbite phase is obtained. Details of the synthetic methodology necessary for the preparation of CIT-3 are enumerated.", "doi": "10.1016/S0927-6513(96)00098-3", "issn": "0927-6513", "publisher": "Elsevier", "publication": "Microporous Materials", "publication_date": "1997-04", "series_number": "3-4", "volume": "9", "issue": "3-4", "pages": "149-160" }, { "id": "authors:7p7ea-e1a64", "collection": "authors", "collection_id": "7p7ea-e1a64", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170811-090914415", "type": "article", "title": "Alteration of perlite to calcium zeolites", "author": [ { "family_name": "Khodabandeh", "given_name": "Shervin", "clpid": "Khodabandeh-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Hydrothermal synthesis of calcium zeolites by alteration of perlite (a rhyolitic glass) is presented. Synthetic versions of the zeolites gismondine, epistilbite and heulandite are synthesized from perlite using calcium-containing solutions, and the effects of the solution phase, pH and temperature on the distribution of the zeolitic products obtained are discussed. Transient formation of a gismondine-type zeolite during transformation of perlite to heulandite suggests a novel synthesis route for the crystallization of heulandite-type zeolites from synthetic zeolite P1.", "doi": "10.1016/S0927-6513(96)00100-9", "issn": "0927-6513", "publisher": "Elsevier", "publication": "Microporous Materials", "publication_date": "1997-04", "series_number": "3-4", "volume": "9", "issue": "3-4", "pages": "161-172" }, { "id": "authors:enz5d-5wk89", "collection": "authors", "collection_id": "enz5d-5wk89", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151007-090425546", "type": "article", "title": "Preparation of highly selective zeolite ZSM-5 membranes by a post-synthetic coking treatment", "author": [ { "family_name": "Yan", "given_name": "Yushan", "clpid": "Yan-Yushan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Gavalas", "given_name": "George R.", "orcid": "0000-0003-1468-6835", "clpid": "Gavalas-G-R" } ], "abstract": "Zeolite ZSM-5 membranes with high n-butane:isobutane selectivities, e.g., 322 at 185\u00b0C, are obtained by a selective deposition of coke into non-zeolitic pores. The zeolite membranes are prepared by in situ crystallization on either bare porous \u03b1-Al_2O_3 support disks or disks that are pretreated to include a diffusion barrier. The post-synthetic coking treatment is accomplished by impregnating these membranes with liquid 1,3,5-triisopropylbenzene (TIPB) for 24 h at room temperature and then calcining them in air at 500\u00b0C for 2 h. Calcination at 500\u00b0C for up to 30 h does not destroy the high n-butane:isobutane selectivity. Thermogravimetric analysis (TGA) experiments on two model pore systems ZSM-5 (5.5 \u00c5) and Vycor glass (40\u201350 \u00c5) suggest that micro-defects are selectively eliminated by the TIPB coking treatment while the intracrystalline pore space of the ZSM-5 is not affected. The elimination of non-zeolitic pores results in a large increase of n-butane:isobutane pure gas flux ratio (45 vs. 320 at 185\u00b0C) accompanied by a fourfold reduction of the n-butane flux. The permeation experiments reveal that the n-butane flux increases nonlinearly with the partial pressure in the feed while the n-butane:isobutane pure gas flux ratio remains relatively unchanged.", "doi": "10.1016/S0376-7388(96)00206-2", "issn": "0376-7388", "publisher": "Elsevier", "publication": "Journal of Membrane Science", "publication_date": "1997-01-08", "series_number": "1", "volume": "123", "issue": "1", "pages": "95-103" }, { "id": "authors:sschj-hzz56", "collection": "authors", "collection_id": "sschj-hzz56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151007-090425260", "type": "article", "title": "Permeation studies on oriented single-crystal ferrierite membranes", "author": [ { "family_name": "Lewis", "given_name": "John E., Jr.", "clpid": "Lewis-J-E-Jr" }, { "family_name": "Gavalas", "given_name": "George R.", "orcid": "0000-0003-1468-6835", "clpid": "Gavalas-G-R" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Large, high-quality, single crystals of pure-silica ferrierite are synthesized, and the structure is described. Selected individual crystals (approximately 600 \u03bcm X 500 \u03bcm X 20 \u03bcm) are mounted in a membrane configuration so that only the 10-membered-ring channels (5.4 \u00c5 X 5.4 \u00c5 X 4.2 \u00c5) or the 8-membered-ring channels (4.6 \u00c5 X 3.7 \u00c5 X 3.0 \u00c5) are accessible for gas-molecule permeation. The first examples of transport exclusively through 8- or 10-membered-ring channel systems are reported and obtained through crystal orientation in the membrane. A series. of adsorption experiments are conducted to help select suitable probe molecules and evaluate the role of adsorption in the permeation process for single-crystal membranes. Methane, n-butane, isobutane and nitrogen probe molecules are used to study intracrystalline sorption and transport effects for different crystal orientations, pressures and temperatures. Both pure-gas selectivities and mixed-gas separation factors are reported. A mixed-gas separation factor of n-butane/isobutane = 116 for the 10-membered-ring orientation of the crystal at 383 K and a transmembrane pressure difference of 1.01 X 10^5 Pa are found using this technique. In addition, molecular sieving is observed for the 8-membered-ring orientation of the crystal since methane, but not butane, transport is observed for this crystal orientation.", "doi": "10.1002/aic.690430111", "issn": "0001-1541", "publisher": "Wiley", "publication": "AIChE Journal", "publication_date": "1997-01", "series_number": "1", "volume": "43", "issue": "1", "pages": "83-90" }, { "id": "authors:ppxhf-t3d23", "collection": "authors", "collection_id": "ppxhf-t3d23", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170811-085616449", "type": "article", "title": "Reactions of meta-xylene on zeolites with intersecting medium and large pores I. Basic studies", "author": [ { "family_name": "Adair", "given_name": "Brian", "clpid": "Adair-B" }, { "family_name": "Chen", "given_name": "Cong-Yan", "clpid": "Chen-Cong-Yan" }, { "family_name": "Wan", "given_name": "Kam-To", "clpid": "Wan-Kam-To" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The reactions of m-xylene are conducted over all known zeolites with intersecting medium and large pores (MCM-22, NU-87, CIT-1, SSZ-33, SSZ-26) and the results compared to those from large (SSZ-24, ZSM-12, zeolite beta, zeolite L) and medium (ZSM-5, EU-1) pore zeolites. Each of the materials MCM-22, NU-87 and CIT-1/SSZ-33/SSZ-26 reveals a unique reaction behavior in terms of the p-xyleneo-xylene and isomerization/disproportionation ratios, the distribution of formed trimethylbenzenes and the rate of deactivation. The reaction activities and selectivities of MCM-22 and CIT-1/SSZ-33/SSZ-26 are somewhat like medium and large pore zeolites, respectively, as is expected from their crystal structures. NU-87 displays a lower p-xyleneo-xylene ratio and a higher turnover frequency than predicted from the crystal structure.", "doi": "10.48550/arXiv.S0927-6513(96)00050-8", "issn": "0927-6513", "publisher": "Elsevier", "publication": "Microporous Materials", "publication_date": "1996-11", "series_number": "5", "volume": "7", "issue": "5", "pages": "261-270" }, { "id": "authors:2yadw-rmr24", "collection": "authors", "collection_id": "2yadw-rmr24", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150617-090854648", "type": "article", "title": "Design for sieving", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "ZEOLITES and zeolite-like molecular sieves are fascinating materials from both an intellectual and a practical standpoint. Their elegant crystal structures have voids\nwith precise and uniform sizes, in the range of about 0.4-1.5 nn, which can be used for molecular sieving (that is, to discriminate between molecules of similar size). Zeolites are used as shape-selective catalysis they can encourage reactions that favour one particular product over another even when the difference in size between the\ntwo species is as little as 0.03 nm, as is the case for p-xylene and o-xylene. Further, zeolites are environmentally benign solids. So their use as catalysts continues to burgeon.", "doi": "10.1038/382583a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1996-08-15", "series_number": "6592", "volume": "382", "issue": "6592", "pages": "583-584" }, { "id": "authors:r7spx-phx17", "collection": "authors", "collection_id": "r7spx-phx17", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180313-125953220", "type": "article", "title": "Rational Catalyst Design via Imprinted Nanostructured Materials", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Katz", "given_name": "Alexander", "orcid": "0000-0003-3487-7049", "clpid": "Katz-A" }, { "family_name": "Ahmad", "given_name": "Wayez R.", "clpid": "Ahmad-W-R" } ], "abstract": "Progress on the use of imprinting (templating) for the synthesis of nanostructured catalysts is reviewed. In the context of providing a foundation for synthetic mimics, the basic principles of enzyme catalysis are enumerated. With these paradigms in mind, catalytic antibodies, imprinted polymers, imprinted amorphous metal oxides, and zeolites are discussed with respect to their preparation procedures and catalytic properties. These synthetic catalysts are contrasted to one another in order to highlight the advantages and disadvantages of each system. Suggestions for future work on preparing enzyme-mimicking materials by imprinting are provided.", "doi": "10.1021/cm960019u", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1996-08-14", "series_number": "8", "volume": "8", "issue": "8", "pages": "1820-1839" }, { "id": "authors:jqqfe-g2a08", "collection": "authors", "collection_id": "jqqfe-g2a08", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180319-152747571", "type": "article", "title": "Synthesis of Pure Alumina Mesoporous Materials", "author": [ { "family_name": "Vaudry", "given_name": "Fr\u00e9d\u00e9ric", "clpid": "Vaudry-F" }, { "family_name": "Khodabandeh", "given_name": "Shervin", "clpid": "Khodabandeh-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Alumina mesophases have been synthesized by reacting aluminum alkoxides and carboxylic acids with controlled amounts of water in low-molecular-weight alcoholic solvents. Calcination of these materials yields aluminas that are thermally stable to 1073 K and contain randomly ordered pores. Specific surface areas as high as 710 m2/g and narrow pore size distributions centered at 20 \u00c5 that do not contain \"zeolitic\" micropores are exhibited by the calcined solids.", "doi": "10.1021/cm9600337", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1996-07-11", "series_number": "7", "volume": "8", "issue": "7", "pages": "1451-1464" }, { "id": "authors:grsx6-jva36", "collection": "authors", "collection_id": "grsx6-jva36", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150520-103048442", "type": "article", "title": "A high-silica zeolite with a 14-tetrahedral-atom pore opening", "author": [ { "family_name": "Freyhardt", "given_name": "C. C.", "clpid": "Freyhardt-C-C" }, { "family_name": "Tsapatsis", "given_name": "M.", "orcid": "0000-0001-5610-3525", "clpid": "Tsapatsis-M" }, { "family_name": "Lobo", "given_name": "R. F.", "clpid": "Lobo-R-F" }, { "family_name": "Balkus", "given_name": "K. J., Jr.", "clpid": "Balkus-K-J-Jr" }, { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolites (microporous aluminosilicates) and related molecular sieves have found wide application as catalysts, sorbents and ion-exchange materials. New zeolites with large pores are much in demand, and have been sought for several decades. All known zeolites, both natural and synthetic, contain pores comprised of 12 or fewer tetrahedrally coordinated silicon or aluminium atoms (T-atoms), but several microporous aluminophosphates with wider pores are now known. The practical value of these large-pore phosphate-based materials is limited, however, by their poor thermal and hydrothermal stability. Here we report the synthesis of a high-silica zeolite with pores comprised of 14 T-atoms. Preliminary data indicate that this thermally stable large-pore material exhibits the kind of strong acidity that makes other zeolites useful catalysts.", "doi": "10.1038/381295a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1996-05-23", "series_number": "6580", "volume": "381", "issue": "6580", "pages": "295-298" }, { "id": "authors:p1qq0-d1y97", "collection": "authors", "collection_id": "p1qq0-d1y97", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120201-084645249", "type": "article", "title": "Synthesis of a heulandite-type zeolite by hydrothermal conversion of zeolite P1", "author": [ { "family_name": "Khodabandeh", "given_name": "Shervin", "clpid": "Khodabandeh-S" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A synthetic analogue of the zeolite heulandite is synthesized by hydrothermal treatment of zeolite P1 with solutions containing CaCl_2 and NaOH.", "doi": "10.1039/cc9960001205", "issn": "1359-7345", "publisher": "Royal Society of Chemistry", "publication": "Chemical Communications", "publication_date": "1996-05-21", "series_number": "10", "volume": "1996", "issue": "10", "pages": "1205-1206" }, { "id": "authors:c8q1c-9ef48", "collection": "authors", "collection_id": "c8q1c-9ef48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-151218497", "type": "article", "title": "Location of Pyridine Guest Molecules in an Electroneutral {^3_\u221e}[SiO_(4/2)] Host Framework: Single-Crystal Structures of the As-Synthesized and Calcined Forms of High-Silica Ferrierite", "author": [ { "family_name": "Lewis", "given_name": "John E., Jr.", "clpid": "Lewis-J-E-Jr" }, { "family_name": "Freyhardt", "given_name": "Clemens C.", "clpid": "Freyhardt-C-C" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Single crystals (up to 580 \u00d7 480 \u00d7 20 \u03bcm) of highly silicious ferrierite (Si-FER, 1), suitable for single-crystal X-ray investigations, are synthesized under organothermal conditions. The structures of the as-synthesized (1a) and the calcined (1b) Si-FER are determined at room temperature. Both structures are refined in the orthorhombic space group Pnnm (No. 58, standard setting) with a = 743.0(1) pm, b = 1409.2(2) pm, c = 1882.0(2) pm, V = 1970.5(4) \u00d7 10^6 pm^3, Z = 1, R = 0.041 (1a) and a = 741.8(1) pm, b = 1407.0(2) pm, c = 1871.3(2) pm, V = 1953.1(4) \u00d7 10^6 pm^3, Z = 1, R = 0.037 (1b). The structure solution when combined with chemical analysis and ^1H and ^(13)C MAS NMR gives a unit cell content of [Si_(36)O_(72)]{py_(4-x) ap_x} (x = 0\u22121, py = pyridine, ap = 1-amino-n-propane) and [Si_(36)O_(72)] for 1a and 1b, respectively. The structure of 1a shows only weak host\u2212guest interactions between the {^3_\u221e}[SiO_(4/2)] framework and the occluded, orientationally disordered pyridine molecules by means of relatively long organic-to-framework distances, d(C_(py)\u00b7\u00b7\u00b7O) \u2265 354(2) pm. ^(29)Si MAS NMR spectra from the organic-containing Si-FER 1a and the organic-free form 1b are in good agreement with the crystallographic results in that they conform to the well-known linear relationship between the cosine expression of the T\u2212O\u2212T angles and the chemical shift of the respective tetrahedral sites (T-sites). A new modification of this relationship is presented here and offers an improved linear correlation between the X-ray and NMR data for 1a and 1b, as well as for other high-silica microporous materials. Application of this new correlation to denser SiO_2 compounds is discussed.", "doi": "10.1021/jp9530055", "issn": "0022-3654", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry", "publication_date": "1996-03-21", "series_number": "12", "volume": "100", "issue": "12", "pages": "5039-5049" }, { "id": "authors:mk2wf-kpk59", "collection": "authors", "collection_id": "mk2wf-kpk59", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:CAMcc96", "type": "article", "title": "Unexpected contraction of a zeolite framework upon isomorphous substitution of Si by Al", "author": [ { "family_name": "Camblor", "given_name": "Miguel A.", "orcid": "0000-0001-9591-3432", "clpid": "Camblor-M-A" }, { "family_name": "Hong", "given_name": "Suk Bong", "clpid": "Hong-Suk-Bong" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Isomorphous substitution of Si by Al in the framework of sodalites synthesized in ethylene glycol causes an unexpected contraction of the zeolite framework.", "doi": "10.1039/CC9960000425", "issn": "1359-7345", "publisher": "Royal Society of Chemistry", "publication": "ChemComm", "publication_date": "1996-02-07", "series_number": "3", "volume": "1996", "issue": "3", "pages": "425-426" }, { "id": "authors:qrh1p-n4e96", "collection": "authors", "collection_id": "qrh1p-n4e96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180507-141345550", "type": "article", "title": "Thermochemical Study of the Relative Stability of Dense and Microporous Aluminophosphate Frameworks", "author": [ { "family_name": "Hu", "given_name": "Yatao", "clpid": "Hu-Yatao" }, { "family_name": "Navrotsky", "given_name": "Alexandra", "orcid": "0000-0002-3260-0364", "clpid": "Navrotsky-A" }, { "family_name": "Chen", "given_name": "Cong-Yan", "clpid": "Chen-Cong-Yan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "To understand why AlPO_4 exhibits the structural diversity observed, the relative stability of a series of dense and microporous AlPO_4 frameworks, e.g., berlinite, tridymite, cristobalite, AlPO_4-5, -8, -11, -42, and VPI-5, has been examined by the combination of DSC and high-temperature calorimetric experiments with molten lead borate (2PbO*B_2O_3) solvent at 979 K. The enthalpies of formation at 298 K, relative to berlinite (quartz structure), are the following (in kJ/mol): tridymite, 5.1 (1.4); cristobalite, 6.1 (1.2); AlPO_4-5, 14.0 (2.2); AlPO_4-8,113 (1.4); AlPO_4-11,12.4 (1.2); AlPO_4-42, 15.6 (1.9); and VPI-5, 16.7 (2.3). All microporous AlPO_4 frameworks are only 11-17 kJ/mol less stable in enthalpy than berlinite. The calcined and then fully rehydrated microporous AlPO_4's, AlPO_4\u2022nH_2O, show a linear correlation between the degree of hydration (n) and their molar volume. The enthalpy of interaction of adsorbed water with the framework ranges from -11 to -30 kJ/mol of AlPO_4, or -10 to -13 kJ normalized per mole of water. Taking the enthalpy of interaction into account, many of these microporous frameworks are energetically comparable to or more stable than berlinite in an aqueous environment. This may imply that there is little or no energy barrier to the formation of microporous AlPO_4 frameworks and explain the structural diversity observed for AlPO_4. These results are compared to those of a previous study on microporous high-silica zeolites.", "doi": "10.1021/cm00058a010", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1995-10", "series_number": "10", "volume": "7", "issue": "10", "pages": "1816-1823" }, { "id": "authors:3d49a-6j783", "collection": "authors", "collection_id": "3d49a-6j783", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180124-111649565", "type": "article", "title": "Characterization of Zeolite L Nanoclusters", "author": [ { "family_name": "Tsapatsis", "given_name": "Michael", "orcid": "0000-0001-5610-3525", "clpid": "Tsapatsis-M" }, { "family_name": "Lovallo", "given_name": "Mark", "clpid": "Lovallo-M" }, { "family_name": "Okubo", "given_name": "Tatsuya", "clpid": "Okubo-Tatsuya" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Sadakata", "given_name": "Masayoshi", "clpid": "Sadakata-Masayoshi" } ], "abstract": "Zeolite L (structure code LTL) crystals are synthesized starting from homogeneous potassium aluminosilicate solutions. Particle size and shape of the formed zeolite L are examined by high-resolution transmission electron microscopy, field emission-scanning electron microscopy, X-ray diffraction, and dynamic light scattering. The synthesis conditions reported lead to nanoclusters of aligned zeolite crystalline domains of dimensions ~40 nm\nin the channel direction and ~15 nm in the direction perpendicular to the zeolite channels. The nanoclusters have sizes of ~60 nm. Electron microscopy of the nanoclusters reveals the presence of inhomogeneities (intercrystalline porosity) on length scales ranging from 2\nto 60 nm. The N_2 and cyclohexane adsorption capacities and the thermal stability of the crystals synthesized are correlated with their microstructure. The preparation of colloidal suspensions of the zeolite L nanoclusters in water is described along with their use in seeded growth and film formation.", "doi": "10.1021/cm00057a025", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1995-09-01", "series_number": "9", "volume": "7", "issue": "9", "pages": "1734-1741" }, { "id": "authors:f8ygg-yfb44", "collection": "authors", "collection_id": "f8ygg-yfb44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180525-132415610", "type": "article", "title": "SiO^-\u2022\u2022\u2022HOSi Hydrogen Bonds in As-Synthesized High-Silica Zeolites", "author": [ { "family_name": "Koller", "given_name": "Hubert", "clpid": "Koller-H" }, { "family_name": "Lobo", "given_name": "Raul F.", "clpid": "Lobo-R-F" }, { "family_name": "Burkett", "given_name": "Sandra L.", "clpid": "Burkett-S-L" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The high-silica zeolites NON, DDR, MTW, AFI, and MFI synthesized with organic quaternary ammonium cations show in the as-synthesized form a line at 10.2 \u00b1 0.2 ppm in the ^1H MAS NMR spectra that does not originate from the organic structure directing agents (SDA's). This signal is assigned to SiO^-\u2022\u2022\u2022HOSi hydrogen bonds between defect sites with an O\u2022\u2022\u2022O distance of 2.7 \u00c5. The presence of Q^3 sites is confirmed by ^(29)Si MAS NMR. The intensity of the line at 10.2 ppm in the ^1H MAS NMR spectra decreases when the positive charge of the quaternary ammonium cations is balanced by negative framework charge by the incorporation of aluminum or boron into the zeolite structure or when the amount of defects is reduced by using fluoride ions as mineralizing agents in the synthesis. Diffuse reflectance IR spectroscopy of high-silica MFI reveals a broad band centered at 3200 cm^(-1) for the O-H stretching vibration of the SiO^-\u2022\u2022\u2022HOSi hydrogen bonds and the O\u2022\u2022\u2022O distance compares well to that obtained from ^1H MAS NMR data. Heating the sample induces protonation of the siloxy groups of the hydrogen bonds due to the decomposition of the organic tetrapropylammonium cations followed by the disappearance of the SiO^-\u2022\u2022\u2022HOSi hydrogen bonds. For MFI prepared with deuterated tetrapropylammonium cations, it is found that approximately one to two hydrogen-bonded protons in these defect sites exist per quaternary ammonium cation. Other ^1H NMR lines are found at 6.5 and 4.5-5.5 ppm and are assigned to silanol groups forming weaker hydrogen bonds and water molecules associated with alkali-metal cations, respectively. A model of the defect sites in as-synthesized high-silica zeolites is proposed.", "doi": "10.1021/j100033a036", "issn": "0022-3654", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry", "publication_date": "1995-08-17", "series_number": "33", "volume": "99", "issue": "33", "pages": "12588-12596" }, { "id": "authors:t4e07-ans27", "collection": "authors", "collection_id": "t4e07-ans27", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:HELarms95", "type": "article", "title": "Synthesis of porous silicates", "author": [ { "family_name": "Helmkamp", "given_name": "M. M.", "clpid": "Helmkamp-M-M" }, { "family_name": "Davis\u00ad", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The issues of importance and future concern in the synthesis of porous silicates and porous materials that contain a large fraction of silica, e.g. zeolites and other crystalline molecular sieves, are reviewed. The thermodynamics of zeolite synthesis are discussed, including a detailed thermodynamic analysis of the synthesis of pure-silica ZSM-5. The kinetics of porous silicate synthesis are reviewed, with particular emphasis on the control of porous structure formation through the use of organic structure-directing agents. Ordered mesoporous materials are discussed in the context of distinguishing their features from zeolites in order to describe further the unique properties of each class of material. Finally, several unresolved issues in the understanding of the synthesis process are outlined, the resolutions of which would aid in the synthesis of porous silicates by design.", "doi": "10.1146/annurev.ms.25.080195.001113", "issn": "0084-6600", "publisher": "Annual Review of Materials Science", "publication": "Annual Review of Materials Science", "publication_date": "1995-08-01", "volume": "25", "pages": "161-192" }, { "id": "authors:71n8x-y9n65", "collection": "authors", "collection_id": "71n8x-y9n65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180507-141345833", "type": "article", "title": "Mechanism of Structure Direction in the Synthesis of Pure-Silica Zeolites. 2. Hydrophobic Hydration and Structural Specificity", "author": [ { "family_name": "Burkett", "given_name": "Sandra L.", "clpid": "Burkett-S-L" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Several syntheses of zeolites that employ organic structure-directing agents are investigated via ^1H-^(29)Si CP MAS NMR spectroscopy. Inorganic-organic interactions in the tetrapropylammonium- and 1,6-hexanediamine-mediated syntheses of pure-silica ZSM-5 (Si-ZSM-5) are compared; these results are contrasted to those from the 1,6-hexanediamine-mediated synthesis of pure-silica ZSM-48 (Si-ZSM-48), in which the diamine serves as a pore-filling agent. Synthesis gels containing tetramethylammonium, tetraethylammonium, tetrabutylammonium, tetrapentylammonium, and tetraethanolammonium in lieu of tetrapropylammonium are evaluated by ^1H-^(29)Si CP MAS NMR to examine the significance of hydrophobic hydration behavior in structure direction. Finally, the effects of sodium, the silica source, and the substitution of D_2O for H_2O on the kinetics of nucleation and crystallization are discussed in terms of their mechanistic implications. A modified mechanism of structure direction in zeolite synthesis is proposed for which the formation of inorganic-organic composite structures is initiated by overlap of the hydrophobic hydration spheres of the inorganic and organic components, with subsequent release of ordered water to establish favorable intermolecular van der Waals interactions.", "doi": "10.1021/10.1021/cm00056a009", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1995-08", "series_number": "8", "volume": "7", "issue": "8", "pages": "1453-1463" }, { "id": "authors:tdf3r-5v412", "collection": "authors", "collection_id": "tdf3r-5v412", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180525-130634948", "type": "article", "title": "Quenching of Tris(2,2'-bipyridine)ruthenium(II) Luminescence by Cobalt(III) Polypyridyl Complexes in Different Sites in and on Clays", "author": [ { "family_name": "Awaluddin", "given_name": "Amir", "clpid": "Awaluddin-A" }, { "family_name": "DeGuzman", "given_name": "Roberto N.", "clpid": "DeGuzman-R-N" }, { "family_name": "Kumar", "given_name": "Challa V.", "clpid": "Kumar-C-V" }, { "family_name": "Suib", "given_name": "Steven L.", "clpid": "Suib-S-L" }, { "family_name": "Burkett", "given_name": "Sandra L.", "clpid": "Burkett-S-L" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The effect of quenching of tris(2,2'-bipyridine)ruthenium(II) [Ru(bpy)_3^(2+)] luminescence by Co(phen)_3^(3+) in various locations in and on bentolite-H clay has been investigated. Ru(bpy)_3^(2+) incorporated into the interlayer region of bentolite-H by ion exchange exhibited spectral properties that were distinct from the Ru(bpy)_3^(2+) incorporated by incipient wetness methods. For example, the samples showed different diffraction, luminescence emission, and lifetime decays. The method of preparation, the nature of counterion (chloride or cyanide), and the presence of a quencher [Co(phen)_3^(3+) influence the emission properties. For example, incipient wetness methods allow deposition on outer surfaces (OUT) of the clay whereas ion-exchange leads to deposition primarily in the interlayer spacing (IN) based on spectroscopic and diffraction data. The luminescence intensities and lifetimes decrease in the order Ru(0UT) > Ru(IN) > Ru(OUT)/Co(IN) > Ru(IN)/Co(0UT) > Ru(OUT)/Co(OUT) \u2243 Ru(IN)/Co(IN). Different methods of preparation and treatment result in location of Ru(bpy)_3^(2+) at different internal or external sites in the clay which give different luminescence and lifetime properties. By controlling the locations of Ru(II) and Co(III) (inside or outside), the quenching rates could be modulated. The location of the Ru(II) complex seems to control both the photophysical properties and the efficiency and rate of quenching by Co(III). The Ru(IN) and Co(IN) sample is very similar to the Ru(OUT) and Co(OUT) sample. These two samples are considerably different from the Ru(IN)/Co(OUT) sample and the Ru(OUT)/Co(IN) sample.", "doi": "10.1021/j100024a034", "issn": "0022-3654", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry", "publication_date": "1995-06-15", "series_number": "24", "volume": "99", "issue": "24", "pages": "9886-9892" }, { "id": "authors:f5kd4-f4678", "collection": "authors", "collection_id": "f5kd4-f4678", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151007-090427013", "type": "article", "title": "Preparation of Zeolite ZSM-5 Membranes by In-Situ Crystallization on Porous \u03b1-Al_2O_3", "author": [ { "family_name": "Yan", "given_name": "Yushan", "clpid": "Yan-Yushan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Gavalas", "given_name": "George R.", "orcid": "0000-0003-1468-6835", "clpid": "Gavalas-G-R" } ], "abstract": "Zeolite ZSM-5 membranes were grown on porous \u03b1-Al_2O_3 disks by in-situ hydrothermal synthesis at 175 \"C. The zeolite layers were formed on the bottom face of disks placed horizontally near the air-liquid interface of clear synthesis solutions. Extensive experimentation was carried out to find compositions that gave continuous polycrystalline films. The films grown with the optimized composition were about 10 \u00b5m thick and consisted of well-intergrown crystals of about 2 \u00b5m size. Pure gas permeation measurements of the most successful preparation yielded hydrogen:isobutane and n-butane:isobutane ratios of 151 and 18 at room temperature and 54 and 31 at 185 \u00b0C, respectively.", "doi": "10.1021/ie00044a018", "issn": "0888-5885", "publisher": "American Chemical Society", "publication": "Industrial & Engineering Chemistry Research", "publication_date": "1995-05", "series_number": "5", "volume": "34", "issue": "5", "pages": "1652-1661" }, { "id": "authors:akc2c-75e97", "collection": "authors", "collection_id": "akc2c-75e97", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180507-141346115", "type": "article", "title": "Mechanisms of Structure Direction in the Synthesis of Pure-Silica Zeolites. 1. Synthesis of TPA/Si-ZSM-5", "author": [ { "family_name": "Burkett", "given_name": "Sandra L.", "clpid": "Burkett-S-L" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The role of tetrapropylammonium (TPA) as a structure-directing agent in the sodium-free synthesis of pure-silica ZSM-5 (Si-ZSM-5) is investigated by solid-state ^1H-^(29)Si CP MAS NMR. It has previously been proposed that the mechanism of structure direction in a sodium-containing system involves preorganization of silicate species around the TPA ions with subsequent assembly of these inorganic-organic composite structures to yield crystalline Si-ZSM-5 with occluded TPA molecules.l ^1H-^(29)Si CP MAS NMR results indicate that short-range intermolecular interactions, i.e., on the order of van der Waals contact distances, are established during heating of the zeolite synthesis gel prior to the development of long-range order indicative of the ZSM-5 structure. These interactions are independent of the presence of sodium in the gel or the silica source used. An attempt to isolate the composite species by trimethylsilylation of the synthesis mixture was partially successful. These results provide additional evidence for the existence of preorganized, inorganic-organic composite structures during the synthesis of Si-ZSM-5. A modified mechanism of structure direction and crystal growth of Si-ZSM-5 is proposed.", "doi": "10.1021/cm00053a017", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1995-05", "series_number": "5", "volume": "7", "issue": "5", "pages": "920-928" }, { "id": "authors:ynp5g-cs518", "collection": "authors", "collection_id": "ynp5g-cs518", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120215-105850717", "type": "article", "title": "Zeolite ZSM-5 membranes grown on porous \u03b1-Al_2O_3", "author": [ { "family_name": "Yan", "given_name": "Yushan", "clpid": "Yan-Yushan" }, { "family_name": "Tsapatsis", "given_name": "Michael", "orcid": "0000-0001-5610-3525", "clpid": "Tsapatsis-M" }, { "family_name": "Gavalas", "given_name": "George R.", "orcid": "0000-0003-1468-6835", "clpid": "Gavalas-G-R" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "ZSM-5 membranes with good permeation selectivity for n-butane\u2013isobutane are grown hydrothermally from a clear solution on horizontally-held porous \u03b1-Al_2O_3 disks.", "doi": "10.1039/c39950000227", "issn": "0022-4936", "publisher": "Royal Society of Chemistry", "publication": "Journal of the Chemical Society. Chemical Communications", "publication_date": "1995-01-21", "series_number": "2", "volume": "1995", "issue": "2", "pages": "227-228" }, { "id": "authors:jbq9q-gh477", "collection": "authors", "collection_id": "jbq9q-gh477", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170710-100105789", "type": "article", "title": "Catalytic Activity of Titanium Silicates Synthesized in the Presence of Alkali-Metal and Alkaline-Earth Ions", "author": [ { "family_name": "Khouw", "given_name": "Charles B.", "clpid": "Khuow-C-B" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Titanium containing aluminum-free ZSM-5 (TS-1) synthesized in the presence and absence of alkali metal and alkaline earth ions are investigated as catalysts for the selective oxidation of alkanes and alkenes using aqueous H_2O_2 as oxidant at temperatures below 100\u00b0C. Sodium-exchanged TS-1 is not active for alkane oxidations. Similarly, no catalytic activity is observed for TS-1 synthesized in the presence of high concentrations of alkali metal ions (Si/Na <20). For both cases, the catalytic activity can be restored by washing the solid with acid solution prior to catalytic evaluation. Similar results are obtained for TS-1 synthesized in the presence of other alkali metal ions, e.g., Li, K. However, the presence of alkaline earth ions, e.g., Mg, in the synthesis gel does not have a significant effect on the catalytic activity of TS-1. Based on the catalytic data and the physicochemical properties of the samples, a plausible explanation for the above results is described. The acid treatment may be useful in overcoming the problems of synthesizing TS-1 from reagents that contain alkali metal ions, e.g., TPAOH solutions. More importantly, this treatment opens the possibility of synthesizing other titanium-containing silicate structures that require the presence of alkali metal ions in the synthesis gel for their formation.", "doi": "10.1006/jcat.1995.1010", "issn": "0021-9517", "publisher": "Elsevier", "publication": "Journal of Catalysis", "publication_date": "1995-01", "series_number": "1", "volume": "151", "issue": "1", "pages": "77-86" }, { "id": "authors:cwwdg-bt547", "collection": "authors", "collection_id": "cwwdg-bt547", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180524-160947996", "type": "article", "title": "Catalysis for Environmentally Benign Processing", "author": [ { "family_name": "Dartt", "given_name": "Christopher B.", "clpid": "Dartt-C-B" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "A short overview of the types of catalytic processes that have shown progress in creating clean technology and are likely through continued material improvements to lead to new environmentally benign processing is presented. Chemistries involving solid acid/base catalysis, clean oxidation catalysis, catalysis in water, and asymmetric catalysis are discussed. Suggested reactions and catalytic materials for future clean processing are enumerated and unifying concepts for implementing catalysis for environmentally benign technologies are outlined.", "doi": "10.1021/ie00036a001", "issn": "0888-5885", "publisher": "American Chemical Society", "publication": "Industrial & Engineering Chemistry Research", "publication_date": "1994-12", "series_number": "12", "volume": "33", "issue": "12", "pages": "2887-2899" }, { "id": "authors:2hjm3-q8v24", "collection": "authors", "collection_id": "2hjm3-q8v24", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180507-141346360", "type": "article", "title": "Chemistry of Sol-Gel Synthesis of Aluminum Oxides with In Situ Water Formation: Control of the Morphology and Texture", "author": [ { "family_name": "Rezgui", "given_name": "Saloua", "clpid": "Rezgui-S" }, { "family_name": "Gates", "given_name": "Bruce C.", "orcid": "0000-0003-0274-4882", "clpid": "Gates-B-C" }, { "family_name": "Burkett", "given_name": "Sandra L.", "clpid": "Burkett-S-L" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Sol-gel synthesis of aluminum oxide from mixtures containing Al(O-s-Bu)_3, acetic acid, and sec-butyl alcohol, whereby water was produced in situ, was characterized by infrared, ^1H NMR, ^(13)C NMR, and ^(13)C and ^(27)Al magic angle spinning NMR spectroscopies. The molar ratio (R) of acetic acid to Al(O-s-Bu)_3 strongly influenced the nature of the product. When R was < 2, the product was an opaque gelatinous precipitate, and when R was \u2265 2, transparent gels were formed. Acetic acid played crucial roles in both the hydrolysis and condensation reactions that constitute the essential chemistry of the sol-gel synthesis. Acetic acid influenced the rate of hydrolysis by (1) reacting rapidly with Al(O-s-Bu)_3 to give Al(O-s-Bu_2-OCOCH_3), which is much less reactive than Al(O-S-BU)_3 in hydrolysis, (2) catalyzing condensation reactions, and (3) catalyzing the dehydration of sec-butyl alcohol to give water. Acetic acid is involved in all the reactions of the sol-gel synthesis and thus provides a delicate control of the chemistry. The ratio R also influenced the morphology of the products formed as a result of drying at temperatures in the range 50-300 \u00b0C; these products were characterized by infrared spectroscopy, scanning electron microscopy, and surface area/pore volume measurements. Upon heating, the gelatinous precipitate was transformed into a dense material with a low surface area and low pore volume. Prior to drying, this material contained principally oligomeric species with few OH ligands and little unreacted acetic acid, thus favoring intermolecular condensation reactions and collapse of the structure during drying. In contrast, gels produced at values of R \u2265 2 gave materials with higher surface areas and higher pore volumes. Prior to drying, these materials contained principally polymeric species incorporating acetate and OH ligands located close to each other, thus favoring intramolecular condensation reactions during drying. Removal of unreacted acetic acid from the gel led to high-surface-area and high-pore-volume materials.", "doi": "10.1021/cm00048a029", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1994-12", "series_number": "12", "volume": "6", "issue": "12", "pages": "2390-2397" }, { "id": "authors:x6xqd-wj576", "collection": "authors", "collection_id": "x6xqd-wj576", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180514-155013871", "type": "article", "title": "Physicochemical Characterization of Zeolites SSZ-26 and SSZ-33", "author": [ { "family_name": "Lobo", "given_name": "Raul F.", "clpid": "Lobo-R-F" }, { "family_name": "Pan", "given_name": "Ming", "clpid": "Pan-Ming" }, { "family_name": "Chan", "given_name": "Ignatius", "clpid": "Chan-Ignatius" }, { "family_name": "Medrud", "given_name": "Ronald C.", "clpid": "Medrud-R-C" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Crozier", "given_name": "Peter A.", "clpid": "Crozier-P-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Detailed characterization of zeolites SSZ-26 and SSZ-33 is presented and includes data from adsorption experiments, X-ray powder diffraction (XRD), electron diffraction (ED), and high-resolution electron microscopy (HREM). Simulated XRD patterns and HREM images of the proposed structures agree very well with all the experimental data. These zeolites are the first synthetic high-silica molecular sieves to contain a three-dimensional pore system comprised of intersecting 10- and 12-ring pores. The structures of\nSSZ-26 and SSZ-33 are compared to the structures of known zeolites, and the relationships between the geometry of the structure-directing agents used in the synthesis of SSZ-26 and the geometry of the pores are analyzed using energy minimization calculations. Several hypothetical zeolite structures are derived based on the proposed models for SSZ-26 and SSZ-33. SSZ-26 and SSZ-33 are the first examples of molecular sieves whose multidimensional pore systems have been formed by the purposeful design of their structure-directing agents.", "doi": "10.1021/j100097a033", "issn": "0022-3654", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry", "publication_date": "1994-11-17", "series_number": "46", "volume": "98", "issue": "46", "pages": "12040-12052" }, { "id": "authors:w5tns-d4v54", "collection": "authors", "collection_id": "w5tns-d4v54", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180322-131514034", "type": "article", "title": "Synthesis and Characterization of Zincosilicates with the SOD Topology", "author": [ { "family_name": "Camblor", "given_name": "Miguel A.", "orcid": "0000-0001-9591-3432", "clpid": "Camblor-M-A" }, { "family_name": "Lobo", "given_name": "Raul F.", "clpid": "Lobo-R-F" }, { "family_name": "Koller", "given_name": "Hubert", "clpid": "Koller-H" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The incorporation of Zn^(2+) into tetrahedral framework positions of zeolites with the sodalite topology (SOD) is obtained by direct synthesis. The zincosilicates are characterized by thermal analyses, a Rietveld refinement of powder X-ray diffraction (XRD) data, and infrared\n(IR) and ^1H, ^(23)Na, ^(13)C, and ^(29)Si MAS NMR spectroscopies. A zinc substitution level as high\nas Si/Zn = 6-7 is achieved and constitutes by far the largest extent of isomorphous substitution by a doubly charged heteroatom in the framework of a zeolite. Two types of \u03b2-cage occupancies (TMA^+ and Na^+) are observed.", "doi": "10.1021/cm00047a046", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1994-11", "series_number": "11", "volume": "6", "issue": "11", "pages": "2193-2199" }, { "id": "authors:fd9rm-4vz70", "collection": "authors", "collection_id": "fd9rm-4vz70", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170710-090722816", "type": "article", "title": "Studies on the Catalytic-Oxidation of Alkanes and Alkenes by Titanium Silicates", "author": [ { "family_name": "Khouw", "given_name": "C. B.", "clpid": "Khuow-c-B" }, { "family_name": "Dartt", "given_name": "C. B.", "clpid": "Dartt-C-B" }, { "family_name": "Labinger", "given_name": "J. A.", "orcid": "0000-0002-1942-9232", "clpid": "Labinger-J-A" }, { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Titanium containing, aluminum-free ZSM-5 (TS-1) and amorphous TiO_2-SiO_2 coprecipitate are investigated as catalysts for the selective oxidation of alkanes and alkenes using a variety of oxidants at temperatures below 100\u00b0C. Comparisons between the activities of TS-1 and the TiO2-SiO2 coprecipitate for alkane oxidation and alkene epoxidation using nonaqueous H_2O_2 indicate that the absence of water is crucial for the catalytic activity of silica-supported titanium. Due to the hydrophobicity of TS-1, the concentration of water surrounding the titanium is maintained at a low value, and thus TS-1 can be used as an oxidation catalyst with aqueous H_2O_2 as oxidant. Alkyl hydroperoxides are active as oxidants for alkene epoxidation on the TiO_2-SiO_2 coprecipitate but not for alkane oxidation reactions on both TS-1 and the TiO_2-SiO_2 coprecipitate. A plausible explanation for the above results is provided. The presence of stereoscrambling without any \"radical clock\" rearrangement during alkane oxidation on TS-1 indicates that the radicals formed may have a very short life-time, or their movements are restricted such that no rearrangement can occur. A proposal for the mechanism of alkane oxidation on TS-1 is given and compared to a mechanism suggested for alkene epoxidation on TS-1 and the TiO_2-SiO_2 coprecipitate.", "doi": "10.1006/jcat.1994.1285", "issn": "0021-9517", "publisher": "Elsevier", "publication": "Journal of Catalysis", "publication_date": "1994-09", "series_number": "1", "volume": "149", "issue": "1", "pages": "195-205" }, { "id": "authors:rgxxp-exd02", "collection": "authors", "collection_id": "rgxxp-exd02", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150514-094516560", "type": "article", "title": "Design and synthesis of a heterogeneous asymmetric catalyst", "author": [ { "family_name": "Wan", "given_name": "Kam T.", "clpid": "Wan-K-T" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The need for enantiomerically pure pharmaceuticals and insecticides drives the search for new catalysts that can perform asymmetric reactions with high enantiomeric selectivity. Many chiral transformations are accomplished using homogeneous catalysts. Recently we reported a heterogeneous catalyst for asymmetric hydrogenation reactions, in which an organometallic catalytic complex is held in a film of water on a porous hydrophilic support, while the reactants and products remain within a hydrophobic organic phase. Such systems provide a large interfacial area between the catalytic phase and the solvent, and should facilitate the separation of product from catalyst. Our previous system gave selectivities of only about 70% enantiomeric excess, however, whereas values of at least 95% are needed for practical utility. Here we describe a modified process in which an enantiomeric excess of 96% is obtained for the asymmetric reduction of 2-(6\u2032-methoxy-2\u2032-naphthyl)acrylic acid to the commercially important anti-inflammatory agent naproxen. We use ethylene glycol as the hydrophilic liquid phase containing the chiral catalyst, which effectively prevents the leaching of the complex into the organic phase. Our results show that these supported-phase asymmetric catalytic systems have the potential to become commercially viable.", "doi": "10.1038/370449a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1994-08-11", "series_number": "6489", "volume": "370", "issue": "6489", "pages": "449-450" }, { "id": "authors:jb892-4a220", "collection": "authors", "collection_id": "jb892-4a220", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180405-153019952", "type": "book_section", "title": "Zeolite Synthesis: Can It Be Designed?", "book_title": "Interfacial Design and Chemical Sensing", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The possibility of designing zeolites by their controlled synthesis is discussed. The feasibility of creating pore architectures through the design of organic structure-directing agents is described for high-silica zeolites. The first example of such a design is presented. A strategy for building pure-silica zeolites from molecular precursors is outlined. It is concluded that the total design of zeolite structures through their designed synthesis is not currently obtainable but information providing \"pieces to this puzzle\" are quickly being assembled.", "doi": "10.1021/bk-1994-0561.ch003", "isbn": "9780841229310", "publisher": "American Chemical Society", "place_of_publication": "Washington, DC", "publication_date": "1994-07-16", "pages": "27-37" }, { "id": "authors:gjnzy-p7646", "collection": "authors", "collection_id": "gjnzy-p7646", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180529-155836771", "type": "article", "title": "Mechanism of Structure Direction in the Synthesis of Si-ZSM-5: An Investigation by Intermolecular ^1H-^(29)Si CP MAS NMR", "author": [ { "family_name": "Burkett", "given_name": "Sandra L.", "clpid": "Burkett-S-L" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The role of tetrapropylammonium (TPA) ions as a structure-directing agent in the synthesis of pure-silica ZSM-5 (Si-ZSM-5) is investigated by solid-state NMR. It has previously been proposed that the mechanism of structure direction involves preorganization of silicate species around the TPA ions with subsequent assembly of these inorganic-organic composite structures to yield crystalline Si-ZSM-5 with occluded TPA molecules. However, such structures have not been directly observed. Here, ^1H-^(29)Si CP MAS NMR is performed between the protons of TPA and the silicon atoms of the zeolite framework precursors in a deuterated synthesis medium to probe the relationship between the organic and inorganic components. The ^1H-^(29)Si CP MAS NMR results indicate that short-range intermolecular interactions, i.e., on the order of van der Waals interactions (\u22483.3 \u00c5 for H to Si), are established during the heating of the zeolite synthesis gel prior to the development of long-range order indicative of the ZSM-5 structure. ^1H-^(13)C CP MAS NMR spectra suggest that the TPA molecules within the composite inorganic-organic structures adopt a conformation similar to that which they have in the zeolite product. These results thus provide the first direct evidence for the existence of preorganized inorganic-organic composite structures during the synthesis of Si-ZSM-5. They also demonstrate the types of noncovalent intermolecular interactions that are relevant to the existence of an organic structure-directing effect. A modified mechanism of structure direction and crystal growth of Si-ZSM-5 is proposed.", "doi": "10.1021/j100068a027", "issn": "0022-3654", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry", "publication_date": "1994-04-28", "series_number": "17", "volume": "98", "issue": "17", "pages": "4647-4653" }, { "id": "authors:fb4q4-xfv95", "collection": "authors", "collection_id": "fb4q4-xfv95", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141210-085915197", "type": "article", "title": "SSZ-26 and SSZ-33: Two Molecular Sieves with Intersecting 10- and 12-Ring Pores", "author": [ { "family_name": "Lobo", "given_name": "Raul F.", "clpid": "Lobo-R-F" }, { "family_name": "Pan", "given_name": "Ming", "clpid": "Pan-M" }, { "family_name": "Chan", "given_name": "Ignatius", "clpid": "Chan-I" }, { "family_name": "Li", "given_name": "Hong-Xin", "clpid": "Li-H-X" }, { "family_name": "Medrud", "given_name": "Ronald C.", "clpid": "Medrud-R-C" }, { "family_name": "Zones", "given_name": "Stacey I.", "clpid": "Zones-S-I" }, { "family_name": "Crozier", "given_name": "Peter A.", "clpid": "Crozier-P-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The framework structures of two closely related molecular sieves, SSZ-26 and SSZ-33, are described. These materials possess a previously missing but desired structural feature in a group of industrially significant zeolites. They contain a three-dimensional pore system that provides access to the crystal interior through both 10- and 12-rings. This property is a consequence of the organic structure\u2014directing agents used in the synthesis of these materials. These materials are examples of the purposeful design of a micropore architecture. Both SSZ-26 and SSZ-33 contain the 4=4\u20131 building unit that had been previously found only in natural zeolites.", "doi": "10.1126/science.262.5139.1543", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "1993-12-03", "series_number": "5139", "volume": "262", "issue": "5139", "pages": "1543-1546" }, { "id": "authors:t6qyh-smq77", "collection": "authors", "collection_id": "t6qyh-smq77", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180507-141347382", "type": "article", "title": "Metalorganic chemical vapor deposition of copper from copper(II) dimethylaminoethoxide", "author": [ { "family_name": "Young", "given_name": "V. L.", "clpid": "Young-V-L" }, { "family_name": "Cox", "given_name": "D. F.", "clpid": "Cox-D-F" }, { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Copper metal films were grown on single-crystal strontium titanate (100) by the thermal decomposition of copper dimethylamino ethoxide in inert atmosphere at temperatures between 150 and 270 \u00b0C. Films grown at 200 \u00b0C are copper metal, free from contaminants, while higher temperatures result in significant carbon and oxygen incorporation. Deposition products were identified by Fourier transform infrared spectroscopic analysis of the reactor gas phase in situ and by mass spectroscopic analysis of the reactor exit gas during deposition. At 200 \u00b0C, deposition occurs by interdependent \u03b2-hydride elimination and reductive elimination reactions which produce (dimethylamino)ethanal, (dimethylamino)ethanol, and copper metal. \u03b2-Hydride and reductive elimination reactions are also dominant at 250 \"C; however, the competition of ligand fragmentation reactions with the whole-ligand eliminating reactions leads to carbon and oxygen contamination of the copper metal film.", "doi": "10.1021/cm00036a006", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1993-12", "series_number": "12", "volume": "5", "issue": "12", "pages": "1701-1709" }, { "id": "authors:d09mg-2aw08", "collection": "authors", "collection_id": "d09mg-2aw08", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180507-141347118", "type": "article", "title": "Thermochemical study of the stability of frameworks in high silica zeolites", "author": [ { "family_name": "Petrovic", "given_name": "Ivan", "clpid": "Petrovic-I" }, { "family_name": "Navrotsky", "given_name": "Alexandra", "orcid": "0000-0002-3260-0364", "clpid": "Navrotsky-A" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Zones", "given_name": "Stacy I.", "clpid": "Zones-S-I" } ], "abstract": "The series of high-silica zeolites ZSM-5,ZSM-11,ZSM-12, SSZ-24, cubic and hexagonal faujasite has been studied to understand the relation between crystal structure and stability in open silicate frameworks. High-temperature solution calorimetry using lead borate (2PbO_2\u2022B_2O_3) solvent at 977 K measured enthalpies of solution and transposed temperature drop calorimetry obtained heat contents at 977 K. Data have been compared with those for quartz and other \"dense\", crystalline polymorphs of silica. The enthalpies of formation at 298 K are as follows: ZSM-12, -(902.0 \u00b1 1.3); ZSM-5, -(902.5 \u00b1 1.3); ZSM-11, (902.5 \u00b1 1.4); SSZ-24, -(903.5 \u00b1 1.3); hexagonal faujasite, -(900.2 \u00b1 1.3); and cubic faujasite, -(897.1 \u00b1 1.2) kJ/mol. The value for quartz is -(910.70 \u00b1 1.00) kJ/mol. All zeolitic silicas are only 7-14 kJ/mol less stable in enthalpy than quartz. This implies an entropic or kinetic rather than a large stabilizing energetic role of the template in zeolite synthesis. The small variations in energy among these structures cannot be directly related either to the degree of \"openness\" (framework density or molar volume) or to the mean Si-O-Si angle. Rather, the overall distribution of bond angles seems to dictate the energy of these structures, with Si-O-Si angles below 140\u00b0 being the major destabilizing factor. On the other hand, heat contents, (H_(977)-H_(298), including those for \"dense\" crystalline polymorphs, show a linear dependence on the framework density or molar volume.", "doi": "10.1021/cm00036a019", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1993-12", "series_number": "12", "volume": "5", "issue": "12", "pages": "1805-1813" }, { "id": "authors:mt0wj-7w650", "collection": "authors", "collection_id": "mt0wj-7w650", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150609-131841804", "type": "article", "title": "Organizing for better synthesis", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "To sieve out one molecular species from another, reach for a zeolite; or now that they are available, choose a microporous inorganic oxide tailor-made for the job by\ntaking a miniature 'plaster cast' of assemblies of organic molecules. On page 430 of this issue, Archibald and Mann show how this method can be stretched to produce\nmicrotubules or stacks of lamellar crystals.", "doi": "10.1038/364391a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1993-07-29", "series_number": "6436", "volume": "364", "issue": "6436", "pages": "391-393" }, { "id": "authors:fqp3s-qwe78", "collection": "authors", "collection_id": "fqp3s-qwe78", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180405-131939192", "type": "book_section", "title": "Shape-Selective Catalysis with Zeolites and Molecular Sieves", "book_title": "Selectivity in Catalysis", "author": [ { "family_name": "Khouw", "given_name": "Charles B.", "clpid": "Khuow-C-B" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The types of shape selective catalysis that occur in zeolites and molecular sieves are reviewed. Specifically, primary and secondary acid catalyzed shape selectivity and encapsulated metal ion and zero valent metal particle catalyzed shape selectivity are discussed. Future trends in shape selective catalysis, such as the use of large pore zeolites and electro- and photo-chemically driven reactions, are outlined. Finally, the possibility of using zeolites as chiral shape selective catalysts is discussed.", "doi": "10.1021/bk-1993-0517.ch014", "isbn": "9780841225190", "publisher": "American Chemical Society", "place_of_publication": "Washington, DC", "publication_date": "1993-05-05", "pages": "206-221" }, { "id": "authors:bn62n-d6d93", "collection": "authors", "collection_id": "bn62n-d6d93", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180405-131939450", "type": "book_section", "title": "Reactions of meta-Diisopropylbenzene on Acid Molecular Sieves", "book_title": "Selectivity in Catalysis", "author": [ { "family_name": "Kim", "given_name": "Man-Hoe", "clpid": "Kim-Man-Hoe" }, { "family_name": "Chen", "given_name": "Cong-Yan", "clpid": "Chen-Cong-Yan" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Meta-diisopropylbenzene is reacted with propylene over the acid form of the molecular sieves SAPO-5, mordenite, offretite, beta, hexagonal and cubic faujasite (EMT and FAU), L, SAPO-37, and an amorphous silica-alumina at temperatures around 463 K in a flow-type fixed-bed reactor. A small amount of cracking is observed. However, the main reactions of meta-diisopropylbenzene are isomerization and alkylation. It is proposed that this alkylation can be used as a new test reaction to characterize the effective size of the voids in larger pore (12 T-atom rings or above) molecular sieves by measuring the weight ratio of 1,3,5- to 1,2,4-triisopropylbenzene formed. In most cases, this ratio increases with the increasing effective void size of the molecular sieves in the order: SAPO-5 < mordenite < offretite < beta < EMT = FAU < L < SAPO-37 < amorphous silica-alumina.", "doi": "10.1021/bk-1993-0517.ch015", "isbn": "9780841225190", "publisher": "American Chemical Society", "place_of_publication": "Washington, DC", "publication_date": "1993-05-05", "pages": "222-232" }, { "id": "authors:4dmdg-0s688", "collection": "authors", "collection_id": "4dmdg-0s688", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180405-140055751", "type": "book_section", "title": "Selective Oxidation of Alkanes, Alkenes, and Phenol with Aqueous H_2O_2 on Titanium Silicate Molecular Sieves", "book_title": "Catalytic Selective Oxidation", "author": [ { "family_name": "Khouw", "given_name": "C. B.", "clpid": "Khuow-c-B" }, { "family_name": "Li", "given_name": "H. X.", "clpid": "Li-H-X" }, { "family_name": "Dartt", "given_name": "C. B.", "clpid": "Dartt-C-B" }, { "family_name": "Davis", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Titanium containing pure-silica ZSM-5 (TS-1) materials are synthesized using different methods. The activity of the titanium containing catalysts for the oxidation of alkanes, alkenes and phenol at temperatures below 100 \u00b0C using aqueous H_2O_2 as oxidant is reported. The relationships between the physicochemical and catalytic properties of these titanium silicates are discussed. The effects of added aluminum and sodium on the catalytic activity of TS-1 are described. The addition of sodium during the synthesis of TS-1 is detrimental to the catalytic activity while sodium incorporation into preformed TS-1 is not. The framework substitution of aluminum for silicon appears to decrease the amount of framework titanium.", "doi": "10.1021/bk-1993-0523.ch020", "isbn": "9780841226371", "publisher": "American Chemical Society", "place_of_publication": "Washington, DC", "publication_date": "1993-05-05", "pages": "273-280" }, { "id": "authors:09hqj-pqc73", "collection": "authors", "collection_id": "09hqj-pqc73", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180405-140055514", "type": "book_section", "title": "Preface", "book_title": "Selectivity in Catalysis", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Suib", "given_name": "Steven L.", "clpid": "Suib-S-L" } ], "abstract": "[no abstract]", "doi": "10.1021/bk-1993-0517.pr001", "isbn": "9780841225190", "publisher": "American Chemical Society", "place_of_publication": "Washington, DC", "publication_date": "1993-05-05", "pages": "xi" }, { "id": "authors:sv91s-h7284", "collection": "authors", "collection_id": "sv91s-h7284", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:LIHjcsft93a", "type": "article", "title": "Further studies on aluminophosphate molecular sieves. Part 1.\u2014AlPO4-H2: a hydrated aluminophosphate molecular sieve", "author": [ { "family_name": "Li", "given_name": "Hong-Xin", "clpid": "Li-H-X" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Pure, highly crystalline AlPO4-H2 is synthesized from an aluminophosphate gel containing dipentylamine and characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, thermogravimetry and solid-state nuclear magnetic resonance spectroscopy. The AlPO4-H2 structure has orthorhombic symmetry with cell parameters of a= 16.184(5)\u00c5, b= 9.914(3)\u00c5, and c= 8.134(4)\u00c5. It is constructed exclusively from hydrated triple crankshaft chains that also build the 18-membered ring VPl-5. AlPO4-H2 is a microporous, hydrated aluminophosphate with highly elliptical 10-ring channels (2.9 \u00c5 by 7.6 \u00c5). One third of the framework Al atoms are octahedrally coordinated to two water molecules and four framework oxygens. Since AlPO4-H2 and VPl-5 share the same structural building unit, some of their physicochemical properties are similar. The existence of AlPO4-H2 and VPl-5 suggests that other molecular sieves with the same type of building unit can be synthesized.", "doi": "10.1039/FT9938900951", "issn": "0956-5000", "publisher": "Royal Society of Chemistry", "publication": "Journal of the Chemical Society. Faraday Transactions", "publication_date": "1993-03-21", "series_number": "6", "volume": "89", "issue": "6", "pages": "951-965" }, { "id": "authors:4bh37-zqc61", "collection": "authors", "collection_id": "4bh37-zqc61", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:LIHjcsft93b", "type": "article", "title": "Further studies on aluminophosphate molecular sieves. Part 2.\u2014VPI-5 and related aluminophosphate materials", "author": [ { "family_name": "Li", "given_name": "Hong-Xin", "clpid": "Li-H-X" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "VPI-5 and AlPO4-H2 are constructed from the same type of chain building unit which contains octahedral Al atoms (coordinated with four framework oxygens and two water molecules). The bonded water molecules are believed to stabilize the chain building unit and play an important role in the crystallization of these materials. This chain building unit limits the possibilities of incorporating silicon into the VPI-5 framework and synthesizing aluminosilicate or pure-silica versions of the VPI-5 structure. VPI-5 and AlPO4-H2 can irreversibly transform to AlPO4-8 and AlPO4-tridymite, respectively, via similar bond rearrangements. Several new aluminophosphates with X-ray powder diffraction reflections similar to some of those for VPI-5 are synthesized and their physicochemical properties do not match those for VPI-5. Strong evidence is provided to suggest that previous claims that VPI-5 and AlPO4-H1 are the same phase are unwarranted.", "doi": "10.1039/FT9938900957", "issn": "0956-5000", "publisher": "Royal Society of Chemistry", "publication": "Journal of the Chemical Society. Faraday Transactions", "publication_date": "1993-03-21", "series_number": "6", "volume": "89", "issue": "6", "pages": "957-964" }, { "id": "authors:8mz51-c1m21", "collection": "authors", "collection_id": "8mz51-c1m21", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180315-073126373", "type": "article", "title": "New Vistas in Zeolite and Molecular Sieve Catalysis", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolites and zeolite-like molecular sieves are able to\nrecognize, discriminate, and organize molecules with\nprecisions that can be less than 1 \u00c5. Because these structures (Figure 1) contain uniformly sized pores in the range of 4-13 \u00c5, they have been exploited by the petrochemical industries to perform many large-scale,\nshape-selective hydrocarbon reactions. Further information\non the materials listed in Figure 1 is provided in Table I. The pore sizes listed are the crystallographic free diameters from each structure. Additionally, the dimensionality of the pore systems is provided. (A simple way to think about the dimensionality of the pore system is to place an organic molecule into the void space and observe in how many different directions it can move. For example, an n-hexane molecule can move in one direction in the channels of VPI-5 whereas it can travel in all three directions in NaX.) For more details on the structures of zeolites and molecular sieves, see ref 3.", "doi": "10.1021/ar00027a006", "issn": "0001-4842", "publisher": "American Chemical Society", "publication": "Accounts of Chemical Research", "publication_date": "1993-03-01", "series_number": "3", "volume": "26", "issue": "3", "pages": "111-115" }, { "id": "authors:58bfz-qfm80", "collection": "authors", "collection_id": "58bfz-qfm80", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180801-081310389", "type": "article", "title": "Location and molecular motion of hexamethylbenzene in zeolite NaY", "author": [ { "family_name": "Hong", "given_name": "Suk Bong", "clpid": "Hong-Suk-Bong" }, { "family_name": "Cho", "given_name": "Herman M.", "clpid": "Cho-Herman-M" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Hexamethylbenzene (HMB) adsorbed into the supercages of zeolite Na-Y is characterized by thermogravimetric\nanalyses, proton NMR, ^(13)C NMR, proton multiple-quantum NMR, and UV, reflectance and emission spectroscopies. Room temperature, proton multiple-quantum NMR results reveal that the intracrystalline distribution of HMB is primarily pairwise at bulk concentrations of 0.5, 1.0, and 2.0 molecules per supercage. Results from emission spectroscopy suggest that the HMB pairs are uniformly dispersed among the intracrystalline supercages of Na-Y.", "doi": "10.1021/j100110a026", "issn": "0022-3654", "publisher": "American Chemical Society", "publication": "Journal of Physical Chemistry", "publication_date": "1993-02-25", "series_number": "8", "volume": "97", "issue": "8", "pages": "1629-1633" }, { "id": "authors:9ypwd-4t916", "collection": "authors", "collection_id": "9ypwd-4t916", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:LIHjcscc93", "type": "article", "title": "Aluminophosphate molecular sieves comprised of hydrated triple crankshaft chains", "author": [ { "family_name": "Li", "given_name": "Hong-Xin", "clpid": "Li-H-X" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Higgins", "given_name": "John B.", "clpid": "Higgins-J-B" }, { "family_name": "Dessau", "given_name": "Ralph M.", "clpid": "Dessau-R-M" } ], "abstract": "We report the first synthesis of pure aluminophosphate hydrate H2 (AlPO4-H2) and its structure; AlPO4-H2 is constructed exclusively from a hydrated chain building unit that also builds the 18-ring VPI-5 structure and has one-dimensional channels circumscribed by highly elliptical rings consisting often oxygen atoms, implications from the existence of this building unit for the synthesis of novel aluminophosphate molecular sieves and for the synthesis of aluminosilicate and silicate analogues of AlPO4-H2 and VPI-5 are discussed.", "doi": "10.1039/C39930000403", "issn": "0022-4936", "publisher": "Royal Society of Chemistry", "publication": "Journal of the Chemical Society. Chemical Communications", "publication_date": "1993-02-21", "series_number": "4", "volume": "1993", "issue": "4", "pages": "403-405" }, { "id": "authors:4b5tt-yhk57", "collection": "authors", "collection_id": "4b5tt-yhk57", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120308-070629885", "type": "article", "title": "Asymmetric Hydrogenation in Water by a Rhodium Complex of Sulfonated 2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl (binap)", "author": [ { "family_name": "Wan", "given_name": "Kam-to", "clpid": "Wan-K-T" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The synthesis of sulfonated 2,2\u2032-bis(diphenylphosphino)-1,1\u2032-binaphthyl (binap) is reported; a rhodium complex of this ligand is the first to perform asymmetric hydrogenation in neat water with optical yields as high as those obtained in nonaqueous solvent.", "doi": "10.1039/c39930001262", "issn": "0022-4936", "publisher": "Royal Society of Chemistry", "publication": "Journal of the Chemical Society. Chemical Communications", "publication_date": "1993", "series_number": "16", "issue": "16", "pages": "1262-1264" }, { "id": "authors:wt57m-w7s66", "collection": "authors", "collection_id": "wt57m-w7s66", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:GOEjcscc92", "type": "article", "title": "A possible role of alkali metal ions in the synthesis of pure-silica molecular sieves", "author": [ { "family_name": "Goepper", "given_name": "Michelle", "clpid": "Goepper-M" }, { "family_name": "Li", "given_name": "Hong-Xin", "clpid": "Li-H-X" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Pure-silica ZSM-12 is synthesized in the presence and absence of alkali metal ions; addition of alkali metal ions at constant hydroxide ion concentration increases the crystallization rate of ZSM-12, and it is suggested that alkali metal ions participate in both the nucleation and crystal growth processes.", "doi": "10.1039/C39920001665", "issn": "0022-4936", "publisher": "Royal Society of Chemistry", "publication": "Journal of the Chemical Society. Chemical Communications", "publication_date": "1992-11-15", "series_number": "22", "volume": "1992", "issue": "22", "pages": "1665-1666" }, { "id": "authors:zejze-9xr92", "collection": "authors", "collection_id": "zejze-9xr92", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:LOBjcsft92", "type": "article", "title": "Zeolite phi: a physical mixture of chabazite and offretite", "author": [ { "family_name": "Lobo", "given_name": "Raul F.", "clpid": "Lobo-R-F" }, { "family_name": "Annen", "given_name": "Michael J.", "clpid": "Annen-M-J" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Zeolite Phi is synthesized by two methods reported previously. Results from X-ray powder diffraction and scanning electron microscopy suggest that the materials are physical mixtures of chabazite and offretite; one sample has a small amount of phillipsite. The X-ray powder diffraction data from these samples, and those reported previously, are indexed and their unit-cell parameters compare well to those obtained from a physical mixture of chabazite and offretite. These samples show multiple particle morphologies that are indicative of physical mixtures. Zeolite Phi is concluded to be a physical mixture of chabazite and offretite and we suggest that the use of the name zeolite Phi be discontinued.", "doi": "10.1039/FT9928802791", "issn": "0956-5000", "publisher": "Royal Society of Chemistry", "publication": "Journal of the Chemical Society. Faraday Transactions", "publication_date": "1992-09-21", "series_number": "18", "volume": "88", "issue": "18", "pages": "2791-2795" }, { "id": "authors:79qt2-yjj43", "collection": "authors", "collection_id": "79qt2-yjj43", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171129-144859972", "type": "article", "title": "Zeolite and molecular sieve synthesis", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Lobo", "given_name": "Raul F.", "clpid": "Lobo-R-F" } ], "abstract": "Zeolite and molecular sieve syntheses are reviewed. The synthesis of aluminum-rich zeolites, high-silica\nzeolites, and phosphate-based molecular sieves are evaluated. Unresolved mechanistic issues are outlined\nand areas for exploration suggested. The ability to plan zeolite and molecular sieve syntheses is discussed\nand a strategy for synthesizing a chiral zeolite is used to demonstrate the current limitations in \"designing\"\nnew molecular sieves.", "doi": "10.1021/cm00022a005", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1992-07-01", "series_number": "4", "volume": "4", "issue": "4", "pages": "756-768" }, { "id": "authors:p1zhm-z7d26", "collection": "authors", "collection_id": "p1zhm-z7d26", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190930-110457353", "type": "article", "title": "Large and Extralarge Pore Molecular Sieves", "author": [ { "family_name": "Davies", "given_name": "M. E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "[no abstract]", "doi": "10.1002/chin.199221031", "issn": "0931-7597", "publisher": "Wiley", "publication": "ChemInform", "publication_date": "1992-05-26", "series_number": "21", "volume": "23", "issue": "21" }, { "id": "authors:cw2t7-8q542", "collection": "authors", "collection_id": "cw2t7-8q542", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120328-150159413", "type": "article", "title": "Synthesis of titanium-containing ZSM-48", "author": [ { "family_name": "Serrano", "given_name": "David P.", "clpid": "Serrano-D-P" }, { "family_name": "Li", "given_name": "Hong-Xin", "clpid": "Li-H-X" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Titanium-containing ZSM-48 is synthesized with silicon to titanium ratios of 26 or larger; changes in unit cell volume and IR data show that titanium is incorporated into framework positions.", "doi": "10.1039/c39920000745", "issn": "0022-4936", "publisher": "Royal Society of Chemistry", "publication": "Journal of the Chemical Society. Chemical Communications", "publication_date": "1992-05-15", "series_number": "10", "volume": "1992", "issue": "10", "pages": "745-747" }, { "id": "authors:346zf-xj259", "collection": "authors", "collection_id": "346zf-xj259", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180724-152025542", "type": "article", "title": "Dynamics of water molecules in VPI-5 and AlPO_4-5 studied by deuterium NMR spectroscopy", "author": [ { "family_name": "Goldfarb", "given_name": "Daniella", "orcid": "0000-0001-5714-7159", "clpid": "Goldfarb-Daniella" }, { "family_name": "Li", "given_name": "Hong Xin", "clpid": "Li-Hong-Xin" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The dynamic properties of water and ammonia within the channels of VPI-5 and AlPO_4-5 were studied by ^2H NMR spectroscopy over a wide range of temperatures. The results were correlated with the corresponding ^(27)Al MAS NMR spectra. In both materials two distinct types of water molecules were detected, bound molecules and physisorbed molecules undergoing isotropic reorientation within the channels. The bound molecules were assigned to molecules coordinated to framework Al undergoing some local motion. In AlPO_4-5 the line shape changes were reproduced by using a dynamic model of a two-site exchange where one site corresponds to the bound water and the second to the free water molecules. The relative populations of the two sites were found to be temperature dependent. In VPI-5 the water exhibits a higher degree of order and the two-site jump between free and bound molecules is associated with an additional 3-fold-site jump, resulting in a 6-site system. In this case the relative populations are temperature independent within the temperature range of 0-60 \u00b0C. Three types of ND_3 molecules were distinguished in VPI-5 adsorbed with ammonia: physisorbed molecules, bound molecules undergoing a rotation about the N-A1 axis, and rigid molecules. No exchange takes place between these three states within the NMR time scale.", "doi": "10.1021/ja00036a018", "issn": "0002-7863", "publisher": "American Chemical Society", "publication": "Journal of the American Chemical Society", "publication_date": "1992-05-01", "series_number": "10", "volume": "114", "issue": "10", "pages": "3690-3697" }, { "id": "authors:26092-f4y07", "collection": "authors", "collection_id": "26092-f4y07", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170809-102950569", "type": "article", "title": "Zeolites and molecular sieves: not just ordinary catalysts", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "The materials properties and applications of zeolites and molecular sieves are reviewed. Emphasis is placed upon the relation between the physicochemical properties and the macroscopic function of zeolites and molecular sieves. Uses in fields other than adsorption and catalysis are outlined, and future areas of interest are discussed.", "doi": "10.1021/ie00056a001", "issn": "0888-5885", "publisher": "American Chemical Society", "publication": "Industrial & Engineering Chemistry Research", "publication_date": "1991-08-01", "series_number": "8", "volume": "30", "issue": "8", "pages": "1675-1683" }, { "id": "authors:1awt9-4vf19", "collection": "authors", "collection_id": "1awt9-4vf19", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150513-153602609", "type": "article", "title": "Grand openings for cloverite", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "MICROPOROUS crystalline solids comprise a class of materials whose main uses are as adsorbents, catalysts and ion exchangers. Zeolites, the best known of these, are built from tetrahedral units of SiO_4 and AlO_4 which connect to form crystalline structures with cavities and/or channels large enough to accommodate (or host) guest molecules. The degree of structural specificity achievable with molecular sieves is highly advantageous in the synthesis of materials with precise functions, such as optically active materials.", "doi": "10.1038/352281a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1991-07-25", "series_number": "6333", "volume": "352", "issue": "6333", "pages": "281-282" }, { "id": "authors:g2hpr-2cq79", "collection": "authors", "collection_id": "g2hpr-2cq79", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171120-145140683", "type": "article", "title": "Systematic synthesis of zeolites that contain cubic and hexagonal stackings of faujasite sheets", "author": [ { "family_name": "Arhancet", "given_name": "Juan P.", "clpid": "Arhancet-J-P" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "Synthetic cubic faujasite (FAU) has been known for several decades, and it is one of the most studied and commercially important zeolites. Recently, the hexagonal polytype of faujasite has been synthesized by Delprato et al. We have subsequently confirmed the synthesis procedures\nused to crystallize this new zeolite and have compared\nsome of its physicochemical properties to those of\nFAU. Also, we have shown that the hexagonal polytype\nof faujasite (for our purposes denoted as hex) can be\ndealuminated by contact with SiCl_4 vapor in a manner\nsimilar to that used for the dealumination of FAU. The\nexistence of the cubic and hexagonal polytypes of faujasite\nleads one to speculate on whether zeolites can be synthesized as intergrowths between these two end members\nat any ratio of two polytype contents. ZSM-20 is an intergrowth of cubic and hexagonal stackings of faujasite\nsheets, and ZSM-2, ZSM-3, and ZSM-19 may also be intergrowths.\nThe purpose of our work is to explore the possibility of\nsynthesizing zeolites that are comprised of intergrowths\nof cubic and hexagonal stackings of faujasite sheets and\nvary in the ratio of cubic/hexagonal content. From Delprato\net al., pure hex and FAU can be synthesized from the reaction mixture R\u00b72.4Na_2O\u00b7Al_O_3\u00b710SiO_2\u00b7140H_2O,\nwhere R is 1,4,7,10,13,16-hexaoxacyclooctadecane (18-\ncrown-6) and 1,4,7,10,13-pentaoxacyclopentadecane (15-\ncrown-5), respectively. Thus, in this work we use the reaction mixture (1 - x)R_1\u00b7xR_2\u00b72.4Na_2O\u00b7Al_2O_3\u00b710SiO_2\u2022\n140H_2O, where R_1 = 18-crown-6, R_2 = 15-crown-5, and x\nis varied as 0 \u2264 x \u2264 1.", "doi": "10.1021/cm00016a001", "issn": "0897-4756", "publisher": "American Chemical Society", "publication": "Chemistry of Materials", "publication_date": "1991-07-01", "series_number": "4", "volume": "3", "issue": "4", "pages": "567-569" }, { "id": "authors:16s7d-zvh67", "collection": "authors", "collection_id": "16s7d-zvh67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120418-134612747", "type": "article", "title": "VPI-7: The First Zincosilicate Molecular Sieve Containing Three-membered T-Atom Rings", "author": [ { "family_name": "Annen", "given_name": "Michael J.", "clpid": "Annen-M-J" }, { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" }, { "family_name": "Higgins", "given_name": "John B.", "clpid": "Higgins-J-B" }, { "family_name": "Schlenker", "given_name": "John L.", "clpid": "Schlenker-J-L" } ], "abstract": "VPI-7: the first microporous zincosilicate to contain 3-membered rings (3MR) is reported.", "doi": "10.1039/C39910001175", "issn": "0022-4936", "publisher": "Royal Society of Chemistry", "publication": "Journal of the Chemical Society. Chemical Communications", "publication_date": "1991-05", "series_number": "17", "volume": "1991", "issue": "17", "pages": "1175-1176" }, { "id": "authors:fh2yq-wj732", "collection": "authors", "collection_id": "fh2yq-wj732", "cite_using_url": "https://resolver.caltech.edu/CaltechBook:1984.001", "type": "book", "title": "Numerical methods and modeling for chemical engineers", "author": [ { "family_name": "Davis", "given_name": "Mark E.", "orcid": "0000-0001-8294-1477", "clpid": "Davis-M-E" } ], "abstract": "This book is an introduction to the quantitative treatment of differential equations that arise from modeling physical phenomena in the area of chemical engineering. It evolved from a set of notes developed for courses taught at Virginia Polytechnic Institute and State University. \n\nAn engineer working on a mathematical project is typically not interested in sophisticated theoretical treatments, but rather in the solution of a model and the physical insight that the solution can give. A recent and important tool in regard to this objective is mathematical software-preprogrammed, reliable computer subroutines for solving mathematical problems. Since numerical methods are not infallible, a \"black-box\" approach of using these subroutines can be dangerous. To utilize software effectively, one must be aware of its capabilities and especially its limitations. This implies that the user must have at least an intuitive understanding of how the software is designed and implemented. Thus, although the subjects covered in this book are the same as in other texts, the treatment is different in that it emphasizes the methods implemented in commercial software. The aim is to provide an understanding of how the subroutines work in order to help the engineer gain maximum benefit from them. \n\nThis book outlines numerical techniques for differential equations that either illustrate a computational property of interest or are the underlying methods of a computer software package. The intent is to provide the reader with sufficient background to effectively utilize mathematical software. The reader is assumed to have a basic knowledge of mathematics, and results that require extensive mathematical literacy are stated with proper references. Those who desire to delve deeper into a particular subject can then follow the leads given in the references and bibliographies. \n\nEach chapter is provided with examples that further elaborate on the text. Problems at the end of each chapter are aimed at mimicking industrial mathematics projects and, when possible, are extensions of the examples in the text. These problems have been grouped into two classes: \n\nClass 1: Problems that illustrate direct numerical application of the formulas in the text. \n\nClass 2: Problems that should be solved with software of the type described in the text (designated by an asterisk after the problem number). \n\nThe level of this book is introductory, although the latest techniques are presented. The book can serve as a text for a senior or first-year graduate level course. At Virginia Polytechnic Institute and State University I have successfully used this material for a two-quarter sequence of first-year graduate courses. In the first quarter ordinary differential equations, Chapter 1 to 3, are covered. The second quarter examines partial differential equations using Chapters 4 and 5. \n\nI gratefully acknowledge the following individuals who have either directly or indirectly contributed to this book: Kenneth Denison, Julio Diaz, Peter Mercure, Kathleen Richter, Peter Rony, Layne Watson, and John Yamanis. I am especially indebted to Graeme Fairweather who read the manuscript and provided many helpful suggestions for its improvement. I also thank the Department of Chemical Engineering at Virginia Polytechnic Institute and State University for its support, and I apologize to the many graduate students who suffered through the early drafts as course texts. Last, and most of all, my sincerest thanks go to Jan Chance for typing the manuscript in her usual flawless form. \n\nI dedicate this book to my wife, who uncomplainingly gave up a portion of her life for its completion. \n\nMark E. Davis", "isbn": "0-471-88761-7", "publisher": "John Wiley & Sons", "place_of_publication": "New York, NY", "publication_date": "1984" } ]