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ETHENE,POLYMERS --- CRYSTALLINE POLYMERS --- SOLID STATE NMR SPECTROSCOPY
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L’utilisation de la RMN solide du noyau 31P des molécules sondes d’oxides de trialkylphosphine (R3PO) par rotation à l’angle magique (MAS) de 15 kHz est une approche simple et sûre pour la caractérisation des sites acides de Brønsted des ponts SiOHAl dans les zéolites Y ultra-stables (USY), nécessaires à la catalyse des procédés d'hydrocraquage. Cette technique permet de différencier les sites de Brønsted de ceux de Lewis, de détecter leur localisation à l'aide des sondes de taille différentes, d'identifier leurs forces en fonction du déplacement chimique dans le spectre et de déterminer la concentration de chaque site. Les différentes zéolites USY à analyser sont obtenues par un traitement de désalumination plus ou moins sévère et le rapport Si /Al devient 6 (CBV712), 15 (CBV720) et 30 (CBV760), alors que la structure microporeuse n'est pas altérée. Avec le TMPO, le TEPO et le TBPO, on utilise trois molécules de sonde ayant des températures de fusion et d'évaporation, une basicité et surtout une taille différente. TMPO et TEPO distinguent 4 sites d'acide de Brønsted différents, alors que seulement 2 sont reconnus lors de l'analyse avec le TBPO, parce qu’il est considéré de ne pas pénétrer dans les supercages de la microstructure. Pour les zéolithes les plus fortement désaluminées, une concentration en site acide plus faible est mesurée. A l'exception du CBV712 à très faible mésoporosité, le TBPO détecte le plus de sites acides, taille, grâce à une forte basicité, malgré sa grande taille. Les forces mesurées des sites acides varient de faible à relativement forte, mais aucune différence significative entre les zéolithes n'est détectée. The use of solid state (SS) 15 kHz Magic Angle Spinning (MAS) NMR of the 31P nucleus of trialkylphosphine oxides (R3PO) probe molecules is an easy and safe approach for the characterization of the SiOHAl - bridge Brønsted acid sites of ultra-stable Y (USY) zeolites, necessary for the catalysis of hydrocracking processes. This technique is able to differentiate the Brønsted acid sites from Lewis acid sites, to detect their location using probes of a different size, to identify their strengths based on the chemical shift in the spectrum and to determine the concentration of each acid site. The different USY zeolites to be analyzed are obtained by a more or less severe dealumination treatment and the Si/Al ratio becomes 6 (CBV712), 15 (CBV720) and 30 (CBV760), whereas the microporous structure is not altered. With TMPO, TEPO and TBPO, three probe molecules with various fusion and evaporation temperature, a different basicity and especially a distinct size are used, all found out to have their advantages and disadvantages. TMPO and TEPO distinguish 4 different Brønsted acid sites, while only 2 are recognized during the analysis with TBPO, because it is considered not to enter the supercages in the microstructure. For more strongly dealuminated zeolites, a lower acid site concentration is measured and except for CBV712 with a very low mesoporosity, TBPO detects the most acid sites, despite its big size, due to a strong basicity and probing of the sites from outside the pores. Acid site strength from weak to relatively strong are measured, but no significant difference in between the zeolites is detected.
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Nuclear magnetic resonance spectroscopy. --- Fourier transform(NMR) --- NMR spectroscopy --- Solid state NMR spectroscopy --- Structural determination of organic compounds --- Quantitative chemical analysis --- Structural determination of inorganic compounds --- Equilibria in solutions --- Biopolymer NMR spectroscopy --- Kinetics(Chemical)NMR spectroscopy --- Nuclear magnetic resonance spectroscopy
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The demand for new materials with novel properties on the micro- and nano-scale continues to grow. This book provides an overview of state-of-the-art techniques for the synthesis and characterization of inorganic nanomaterials including sonochemistry, microwave dielectric heating, sonoelectrochemistry and RAPET, high-throughput experimentation in heterogeneous catalyst research, photoluminescence, and methods for surface structuring. Imaging techniques include X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, single crystal and powder X-ray diffraction, X-ray microimaging (SAXS,WAXS & GISAXS), electron microscopy, and solid state NMR. The work is essential reading for all researchers in academia and industry working in the field of nanosciences.
Chemistry, Inorganic. --- Nanostructured materials. --- Nanomaterials --- Nanometer materials --- Nanophase materials --- Nanostructure controlled materials --- Nanostructure materials --- Ultra-fine microstructure materials --- Microstructure --- Nanotechnology --- Inorganic chemistry --- Chemistry --- Inorganic compounds --- Electron microscopy. --- Materials Science. --- Nanotechnology. --- Solid-State NMR. --- X-Ray Imaging Techniques.
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solar energy conversion --- n/a --- carboxylic acid --- organic salts --- 2?:6? --- Cerium --- drug delivery --- layered materials --- coordination polymer --- copper --- solid state NMR --- metal–organic frameworks --- synthesis --- coordination polymers --- in situ characterisation --- mechanochemistry --- phosphonic acids --- amorphous --- nickel(II) oxide --- heterogeneous catalysis --- phosphonic acid --- MOF --- porosity --- phosphonate ester --- proton conduction --- X-ray and electron diffraction --- gas sorption/separation --- metal phosphonate --- electron diffraction tomography --- ionic compounds --- dye-sensitized solar cell --- 2?-terpyridine --- dye --- 2 --- rechargeable batteries --- anchor --- defects --- p-type --- crystal structure --- diphosphinate --- zinc(II) --- metal phosphonates and phosphinates --- metal-organic frameworks
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This Special Issue examines state-of-the-art in-cell NMR spectroscopy as it relates to biological systems of increasing complexity. The compendia of research and recent innovations from prominent laboratories in the field of solid state and solution in-cell NMR spectroscopy, metabolomics and technology development are presented. The work establishes in-cell NMR spectroscopy as the premier method for determining the structures and interaction capabilities of biological molecules at high resolution within the delicately intricate interior of living cells, and the means of utilizing cells as living laboratories to directly assess the effects of exogenous and endogenous stimuli on cell physiology.]
protein NMR --- time-resolved NMR --- Ribosome --- structural calculation 4 --- crystalline and amorphous starch --- in-cell NMR --- protein dynamics --- DNP --- protein modification --- Tau --- spectrum reconstruction 3 --- mRNA --- Thioredoxin --- protein structure --- protein interactions --- drug discovery --- protein structure determination 1 --- review --- enzyme activity --- MARK2 phosphorylation --- post-translational modifications --- Dihydrofolate reductase --- mammalian cells --- target engagement --- non-uniform sampling 2 --- paramagnetic effects --- protein structure-function --- cross-correlated relaxation --- structure function --- rRNA --- 2D INADEQUATE --- lipid membrane --- Thymidylate synthase --- whole cell NMR --- enzyme kinetics --- magic-angle spinning --- live cell --- solid-state NMR --- Adenylate kinase --- DNA --- in-situ NMR --- antimicrobial peptide --- NMR spectroscopy --- intrinsically disordered proteins
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In 2015, the first pharmaceutical cocrystal was approved by the FDA. Since then, the number of cocrystals on the market and in the development pipeline has been slowly but steadily growing. It is now well established that cocrystals are a versatile new approach to oral drug formulation. This Reprint Book is a collection of articles that show the utility of pharmaceutical cocrystals and various aspects of cocrystal research: • Cocrystals as a strategy to modify the physicochemical properties of a drug such as dissolution behaviour, tabletability, and melting point; • Development of new coformers; • Screening studies for multiple cocrystal forms; • Cocrystals in nano-sized drug delivery.
Research & information: general --- nitazoxanide --- cocrystals --- multicomponent crystals --- dissolution behavior --- supersaturated formulations --- crystallization inhibitors --- drug-polymer interactions --- nano co-crystals --- crystal engineering --- polydispersity index --- zeta potential --- particle size --- zidovudine --- lamivudine --- HIV/AIDS --- sonochemistry --- imidazole N-oxides --- barbituric acid --- thiobarbituric acid --- pharmaceutical cocrystals --- mechanochemistry --- solid state NMR --- X-ray Diffraction --- design of experiments --- Quality by Design --- cocrystal --- compaction --- nanoindentation --- slip plane --- tabletability --- surface topology --- interparticulate bonding area --- interparticulate bonding strength --- nefiracetam --- solid state --- solubility --- dissolution rate --- stability --- formulation --- diclofenac sodium --- L-proline --- salt cocrystal --- multicomponent crystal --- monohydrate --- tetrahydrate --- dissolution --- itraconazole --- terephthalic acid --- crystal structure --- solid-state --- thermal analysis --- wettability --- n/a
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In 2015, the first pharmaceutical cocrystal was approved by the FDA. Since then, the number of cocrystals on the market and in the development pipeline has been slowly but steadily growing. It is now well established that cocrystals are a versatile new approach to oral drug formulation. This Reprint Book is a collection of articles that show the utility of pharmaceutical cocrystals and various aspects of cocrystal research: • Cocrystals as a strategy to modify the physicochemical properties of a drug such as dissolution behaviour, tabletability, and melting point; • Development of new coformers; • Screening studies for multiple cocrystal forms; • Cocrystals in nano-sized drug delivery.
nitazoxanide --- cocrystals --- multicomponent crystals --- dissolution behavior --- supersaturated formulations --- crystallization inhibitors --- drug-polymer interactions --- nano co-crystals --- crystal engineering --- polydispersity index --- zeta potential --- particle size --- zidovudine --- lamivudine --- HIV/AIDS --- sonochemistry --- imidazole N-oxides --- barbituric acid --- thiobarbituric acid --- pharmaceutical cocrystals --- mechanochemistry --- solid state NMR --- X-ray Diffraction --- design of experiments --- Quality by Design --- cocrystal --- compaction --- nanoindentation --- slip plane --- tabletability --- surface topology --- interparticulate bonding area --- interparticulate bonding strength --- nefiracetam --- solid state --- solubility --- dissolution rate --- stability --- formulation --- diclofenac sodium --- L-proline --- salt cocrystal --- multicomponent crystal --- monohydrate --- tetrahydrate --- dissolution --- itraconazole --- terephthalic acid --- crystal structure --- solid-state --- thermal analysis --- wettability --- n/a
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In 2015, the first pharmaceutical cocrystal was approved by the FDA. Since then, the number of cocrystals on the market and in the development pipeline has been slowly but steadily growing. It is now well established that cocrystals are a versatile new approach to oral drug formulation. This Reprint Book is a collection of articles that show the utility of pharmaceutical cocrystals and various aspects of cocrystal research: • Cocrystals as a strategy to modify the physicochemical properties of a drug such as dissolution behaviour, tabletability, and melting point; • Development of new coformers; • Screening studies for multiple cocrystal forms; • Cocrystals in nano-sized drug delivery.
Research & information: general --- nitazoxanide --- cocrystals --- multicomponent crystals --- dissolution behavior --- supersaturated formulations --- crystallization inhibitors --- drug-polymer interactions --- nano co-crystals --- crystal engineering --- polydispersity index --- zeta potential --- particle size --- zidovudine --- lamivudine --- HIV/AIDS --- sonochemistry --- imidazole N-oxides --- barbituric acid --- thiobarbituric acid --- pharmaceutical cocrystals --- mechanochemistry --- solid state NMR --- X-ray Diffraction --- design of experiments --- Quality by Design --- cocrystal --- compaction --- nanoindentation --- slip plane --- tabletability --- surface topology --- interparticulate bonding area --- interparticulate bonding strength --- nefiracetam --- solid state --- solubility --- dissolution rate --- stability --- formulation --- diclofenac sodium --- L-proline --- salt cocrystal --- multicomponent crystal --- monohydrate --- tetrahydrate --- dissolution --- itraconazole --- terephthalic acid --- crystal structure --- solid-state --- thermal analysis --- wettability
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