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991.
Luís Antônio Dantas Silva Fernanda Vieira Teixeira Raphael Caixeta Serpa Najla Locatelli Esteves Rayane Ramos dos Santos Eliana Martins Lima Marcílio Sérgio Soares da Cunha-Filho Adriano Antunes de Souza Araújo Stephânia Fleury Taveira Ricardo Neves Marreto 《Journal of Thermal Analysis and Calorimetry》2016,123(3):2337-2344
992.
Marie-Claire Giel Dr. Christopher J. Smedley Emily R. R. Mackie Taijie Guo Prof. Dr. Jiajia Dong Dr. Tatiana P. Soares da Costa Prof. Dr. John E. Moses 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(3):1197-1202
The boom in growth of 1,4-disubstituted triazole products, in particular, since the early 2000’s, can be largely attributed to the birth of click chemistry and the discovery of the CuI-catalyzed azide–alkyne cycloaddition (CuAAC). Yet the synthesis of relatively simple, albeit important, 1-substituted-1,2,3-triazoles has been surprisingly more challenging. Reported here is a straightforward and scalable click-inspired protocol for the synthesis of 1-substituted-1,2,3-triazoles from organic azides and the bench stable acetylene surrogate ethenesulfonyl fluoride (ESF). The new transformation tolerates a wide selection of substrates and proceeds smoothly under metal-free conditions to give the products in excellent yield. Under controlled acidic conditions, the 1-substituted-1,2,3-triazole products undergo a Michael addition reaction with a second equivalent of ESF to give the unprecedented 1-substituted triazolium sulfonyl fluoride salts. 相似文献
993.
Carlos M. da Fonseca 《Linear and Multilinear Algebra》2019,67(8):1713-1714
994.
A detailed chemical kinetic model has been developed for supercritical water oxidation (SCWO) of methylamine, CH3NH2, providing insight into the intermediates and final products formed in this process as well as the dominant reaction pathways. The model was adapted from previous mechanisms, with a revision of the peroxyl radical chemistry to include imine formation, which has recently been identified as the dominant gas-phase pathway in amine oxidation. The developed model can reproduce previous experimental data on methylamine consumption and major product formation to reasonable accuracy, although with deficiencies in describing the induction time. Our simulations indicate that oxidation of the •CH2NH2 radical to methanimine, CH2NH, is the major channel in methylamine SCWO, with subsequent hydrolysis of CH2NH providing the experimentally observed reaction products ammonia and formaldehyde. Integral-averaged reaction rates were used to identify major reaction pathways, and a first-order sensitivity analysis indicated that the concentration of CH3NH2 is most sensitive to OH radical kinetics. Overall, this work clarifies the importance of imine chemistry in the oxidation of nitrogen-containing compounds and indicates that they are necessary to model these compounds in SCWO processes. 相似文献
995.
Determination of fexofenadine in Hank's balanced salt solution by high‐performance liquid chromatography with ultraviolet detection: application to Caco‐2 cell permeability studies
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Marco Antônio dos. Reis Júnior Ana Cláudia Miranda de Faria Eudes da. Silva Velozo Teresa Dalla Costa Frank Pereira de Andrade Whocely Victor de Castro 《Biomedical chromatography : BMC》2015,29(4):537-544
The drug‐transporting proteins can affect the pharmacokinetics and pharmacodymanics of many drugs, resulting in an erratic and unpredictable pharmacological response. The Caco‐2 monolayer is routinely applied to investigate the carrier‐mediated transport of drugs. Therefore, the selection of a marker compound able to characterize the activity of such transporters is crucial. Fexofenadine (FEX), a P‐gp/OATP substrate, can be considered a suitable probe. However, in order to use be used as a marker compound, it is mandatory to develop an analytical method able to quantify this drug during the in vitro permeability assay. An HPLC method with ultraviolet detection was developed; the mobile phase consisted of phosphate buffer (pH 3.2) containing 10 m m of sodium octanosulphonate and acetonitrile (60:40) and the flow rate was set at 1.2 mL/min. Fexofenadine was eluted at 40°C, the retention time was about 4.6 min. The LOD and LOQ values were 1.9 and 6.2 ng/mL, respectively. Verapamil and ketoconazole, the most common P‐gp inhibitors, were eluted as distinct peaks of that corresponding to fexofenadine The method was successfully applied to quantify the amount of FEX transported across the Caco‐2 monolayer and could be an additional tool for those investigating the role of membrane transporters on drug absorption. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
996.
997.
do Nascimento Marreiro Teixeira Ana Siqueira Siqueira Teixeira Paulo Ronaldo Sousa de Oliveira Farias Emanuel Airton Ferraz e Sousa Brandon Moura Sérvulo Kátia Bonfim de Leite da Silva Durcilene Alves Eiras Carla 《Journal of Solid State Electrochemistry》2020,24(5):1143-1155
Journal of Solid State Electrochemistry - The present work proposes a new electrochemical sulfite biosensor based on babassu mesocarp nanoparticles (BMNPs) immobilized on the surface of a pyrolytic... 相似文献
998.
Srigokul Upadhyayula Vicente Nu?ez Eli M. Espinoza Jillian M. Larsen Duoduo Bao Dewen Shi Jenny T. Mac Bahman Anvari Valentine I. Vullev 《Chemical science》2015,6(4):2237-2251
Cyanine dyes are broadly used for fluorescence imaging and other photonic applications. 3,3′-Diethylthiacyanine (THIA) is a cyanine dye composed of two identical aromatic heterocyclic moieties linked with a single methine, –CH. The torsional degrees of freedom around the methine bonds provide routes for non-radiative decay, responsible for the inherently low fluorescence quantum yields. Using transient absorption spectroscopy, we determined that upon photoexcitation, the excited state relaxes along two parallel pathways producing three excited-state transients that undergo internal conversion to the ground state. The media viscosity impedes the molecular modes of ring rotation and preferentially affects one of the pathways of non-radiative decay, exerting a dominant effect on the emission properties of THIA. Concurrently, the polarity affects the energy of the transients involved in the decay pathways and further modulates the kinetics of non-radiative deactivation. 相似文献
999.
1000.