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151.
Dr. Youness Touati-Jallabe Dr. Thibault Tintillier Dr. Elodie Mauchauffée Dr. Jean-Luc Boucher Jérémy Leroy Booma Ramassamy Dr. Abdallah Hamzé Dr. Karima Mezghenna Amine Bouzekrini Claudia Verna Jean Martinez Dr. Anne-Dominique Lajoix Dr. Jean-François Hernandez 《ChemMedChem》2020,15(6):517-531
More than 160 arginine analogues modified on the C-terminus via either an amide bond or a heterocyclic moiety (1,2,4-oxadiazole, 1,3,4-oxadiazole and 1,2,4-triazole) were prepared as potential inhibitors of NO synthases (NOS). A methodology involving formation of a thiocitrulline intermediate linked through its side-chain on a solid support followed by modification of its carboxylate group was developed. Finally, the side-chain thiourea group was either let unchanged, S-alkylated (Me, Et) or guanidinylated (Me, Et) to yield respectively after TFA treatment the corresponding thiocitrulline, S-Me/Et-isothiocitrulline and N-Me/Et-arginine substrate analogues. They all were tested against three recombinant NOS isoforms. Several compounds containing a S-Et- or a S-Me-Itc moiety and mainly belonging to both the dipeptide-like and 1,2,4-oxadiazole series were shown to inhibit nNOS and iNOS with IC50 in the 1–50 μM range. Spectral studies confirmed that these new compounds interacted at the heme active site. The more active compounds were found to inhibit intra-cellular iNOS expressed in RAW264.7 and INS-1 cells with similar efficiency than the reference compounds L-NIL and SEIT. 相似文献
152.
Gimerson Weigert Subtil Jean César Marinozi Vicentini Daiane Marques de Oliveira Lidiane Vizioli de Castro-Hoshino Patricia Hissae Yassue-Cordeiro Renata Corrêa Vicentino Mara Heloisa Neves Olsen Scaliante 《加拿大化工杂志》2023,101(3):1345-1357
The photocatalyst composition affects the chemical–physical properties and directly impacts photocatalytic activity, both in the hydrogen production and degradation of organic contaminants. In this work, the influence of zeolitic structures NaA, NaY, and ZSM-5 combined with a 10% active phase, TiO2 catalyst doped with 1% copper, and cobalt cocatalysts was tested to mineralize the reactive blue dye (CI250) and to produce hydrogen by photocatalysis under ultraviolet radiation. The band gap energy was affected mainly by the cocatalyst, while the Brunauer-Emmett-Teller method (BET) area was affected by the zeolite structure as well as the X-ray diffraction (XRD). The most active catalyst was the Cu@TiO2/NaY, which promoted a hydrogen production rate of 240 μmolH2gcat−1 using 10% ethanol (v/v) aqueous solution as a sacrificial agent and mineralization of 53% of the organic dye, followed by the catalysts impregnated on ZSM-5 zeolites, which had discolouration up to 50% and hydrogen evolution of 92.6 and 109.7 μmolH2gcat−1 for the catalyst doped with Cu and Co, respectively. 相似文献
153.
Oxygenation reactions (hydroxylation, epoxidation, N- or S-oxide formation, etc.) catalyzed by cytochrome P450 enzymes and related biomimetic models involve an electrophilic oxidative species as the active species, namely a high-valent metal-oxo intermediate. Among the different methods to study the oxygenation reactions mediated by high-valent metal-oxo porphyrin complexes, the recent discovery of oxo-hydroxo tautomerism provides a useful tool to investigate the mechanism of O-atom transfer reactions in aqueous media. 相似文献
154.
Frédéric Destaillats Jean B. Jean-Denis Joseph Arul Robert L. Wolff Paul Angers 《Journal of the American Oil Chemists' Society》2002,79(11):1091-1094
GC analysis was performed to determine regiospecific distribution and FA composition in seed oils of the Aceraceae species,
Acer saccharum and A. saccharinum. The oil content in the seeds was low at 5.0% in A. saccharum and 5.8% in A. saccharinum, and the main FA were linoleic (30.8 and 29.4%), oleic (21.3 and 27.6%), palmitic (10.1 and 10.5%), and cis-vaccenic (9.4 and 7.9%) acids, respectively. In addition, both oils contained long-chain monoenes of the n−9 and n−7 groups,
including 11-eicosenoic, 13-docosenoic, 15-tetracosenoic, 13-eicosenoic, and 15-docosenoic acids, whereas γ-linolenic acid
accounted for 0.8% of total FA in A. saccharum, and 0.5% in A. saccharinum. Regiospecific analysis, performed using the methodology of dibutyroyl derivatives of MAG, indicated that linoleic, oleic,
and linolenic acids were mainly esterified at the internal position of TAG in both seed oils, whereas long-chain monoenes
of the n−7 group were almost exclusively esterified on the external positions. 相似文献
155.
A novel approach to monodispersed porous polymer beads allowing accurate control over a broad range of pore size distribution has been developed. It involves the use of monodispersed template particles which are used as polymeric porogens in the suspension polymerization of monomers such as styrene and divinylbenzene. The size uniformity of the template particles is retained by the final porous beads. The porous properties of the final beads are determined in large part by the characteristics of the porogenic mixture such as its composition, the molecular weight of the polymeric porogen, as well as the relative amount of monomers, polymeric and low molecular weight porogens used. 相似文献
156.
Alessandro Martucci Mirko Pasquale Massimo Guglielmi Mike Post Jean Claude Pivin 《Journal of the American Ceramic Society》2003,86(9):1638-1640
Sol–gel derived silica (SiO2 ) films doped with nickel oxide (NiO) nanocrystals were fabricated. A bifunctional ligand was used, bearing amine groups capable of coordinating the nickel ions and hydrolysable siloxane groups for anchoring the metal complex moiety to the silicate matrix. Nickel oxide nanocrystals precipitated at 500°C while the film was still porous. The nanocomposite films showed a reversible change in the optical transmittance in the VIS-NIR range when exposed to carbon monoxide gas. The effects of residual porosity, testing temperature, and carbon monoxide gas concentration on optical transmittance were studied. 相似文献
157.
Jianding Chen Christian Carrot Yvan Chalamet Jean‐Charles Majeste Mohamed Taha 《应用聚合物科学杂志》2003,88(5):1376-1383
Poly(n‐butyl methacrylate) (PBMA) composites with calcium carbonate (CaCO3) were prepared by in situ radical copolymerization of butyl methacrylate (BMA) and methacrylic acid (MA) with precipitated calcium carbonate. To compare the different rheological behaviors of the monomer mixtures with CaCO3 and the composites, the steady and dynamic viscosities of BMA/MA/CaCO3 and poly(BMA/MA/CaCO3) were measured by means of steady and oscillatory shear flows. The viscosity of the mixture BMA/MA/CaCO3 was found to increase evidently with the increasing of CaCO3%. The influence of MA% on viscosity of BMA/MA/CaCO3 was slight. During the in situ polymerization, the viscosity of the reacting system was measured to be enhanced by a factor of about 104 from the monomer/CaCO3 mixture to composites. The dependency of zero‐shear viscosity on molar mass of PBMA was also investigated. The relation between the zero‐shear viscosity and molar mass is η0 = 10?15 Mw3.5. The evolution of the viscosity with the temperature for both PBMA and its composites was obtained and time–temperature superposition was used to build master curves for the dynamic moduli. The flow activation energies were found to be 115.0, 148.6, and 178.7 kJ/mol for PBMA, composite PBMA/CaCO3 (90/10), and PBMA/MA/CaCO3 (89/1/10), respectively. The viscosity of the composites containing less than 10% CaCO3 was lower than that of pure PBMA with the same molar mass. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1376–1383, 2003 相似文献
158.
The telomerization of dimethylaminoethyl methacrylate (DMAEMA) with mercaptoethanol initiated by 2,2′-azobisisobutyronitrile was first investigated at 70 °C and the influence of the type of solvent was studied. The results showed that well-defined telomers of DMAEMA could not be synthetized via telomerization of DMAEMA in water or water/acetonitrile mixture since the telomerization reaction is in competition with the nucleophilic addition of thiol onto the monomer. Transfer constants for mercaptoethanol in benzene and acetonitrile were determined by Mayo's and O'Brien's methods. The transfer constant obtained in acetonitrile (0,6) was higher than that obtained in benzene. This difference can be explained by the fact that the thiol was consumed by two reactions: nucleophilic addition and telomerization. The influence of solvents on the polymerization kinetics was enlightened. These results were applied to the synthesis of macromonomers of DMAEMA with isocyanatoethyl methacrylate (IEM). These macromonomers were copolymerized with styrene. 相似文献
159.
Interfacial reaction kinetics between Ag and ceramic-filled glass (CFG) substrate, containing borosilicate glass, high-silica glass, and alumina, has been investigated at 850°–925°C in different atmospheres. No chemical reaction at the interface of Ag/CFG is found when firing takes place in N2 or N2 + 1% H2 . Fired in air, however, an interfacial reaction zone is formed at the interface of Ag/CFG with Ag+ ion diffusing from silver and Al3+ ion dissolving from CFG, and both ions are always coupled together in the reaction zone. Microstructural and chemical analyses show that the reaction zone consists of two distinct layers; one is homogeneous, and the other, heterogeneous. The homogeneous layer, which is adjacent to Ag, is uniform in microstructure with a composition rich in Ag+ and Al3+ . The heterogeneous layer is not uniform in microstructure with Si-rich and Ag–Al-rich phases. The reaction zone moves toward CFG with time, forming a heterogeneous layer first and then converting into a homogenous layer when diffusion of Ag+ ion into the CFG becomes significant. The growth kinetics for the homogeneous layer follows a linear rate equation, whereas the heterogeneous layer, a parabolic rate equation. Activation analyses suggest that the formation of the homogeneous layer is controlled by the combination of breakage and formation of M–O bonds, but the heterogeneous layer, by the diffusion of Ag+ ion in the BSG. 相似文献
160.
Valorization of waste thermoset material as a filler in thermoplastic: Mechanical properties of phenolic molding compound waste‐filled PP composites 下载免费PDF全文
Fabien Bernardeau Didier Perrin Anne‐Sophie Caro Jean‐Charles Benezet Patrick Ienny 《应用聚合物科学杂志》2018,135(12)
As most thermoset material, phenolic molding compound (PMC) wastes are an environmental problem. Very few recycling solutions have been proposed so far for this type of material. A mechanical recycling method to valorize these materials is proposed in this work. It relies on the use of phenolic waste as filler in thermoplastic. Such phenolic filler can increase mechanical properties (tensile, flexural) of the matrix, and be used in substitution of traditional particulate fillers such as calcium carbonate or talc. In this study, several morphological parameters influencing the final mechanical properties of a PMC‐filled polypropylene (PP) micro‐composite are studied, such as filler loading rate, particles size distribution of the filler, and interfacial adhesion between the filler and the matrix. Some structural parameters are also studied and linked with mechanical properties, such as dispersion of the filler and crystallinity of the matrix. Finally, the properties of PMC‐filled PP are compared with CaCO3‐ and talc‐filled PP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45849. 相似文献