Yields
Mostrando 25-36 de 4322 artigos, teses e dissertações.
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25. Efficient Synthesis and Antimicrobial Activities of Long Alkyl Chain Trifluoromethyl-1H-pyrazol-1-(thio)carboxamides and Trifluoromethyl-1H-pyrazol-1-yl-thiazoles
The synthesis of 3-alkyl-5-trifluoromethyl-1H- pyrazole-1-carboxamides, 3-alkyl-5-trifluoromethyl-1H-pyrazole-1-thiocarboxamides, and 2-(3-alkyl-5-trifluoromethyl-1H-pyrazol-1-yl)-thiazoles derivatives are reported. [3 + 2] cyclocondensations for a series of long alkyl chain 1,1,1-trifluoro-4-methoxyalk-3-en-2-ones and semicarbazide or thiosemicarbazide were
J. Braz. Chem. Soc.. Publicado em: 2021-04
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26. MACROALGAE Fucus vesiculosus OIL: BIODIESEL PRODUCTION USING ALKALINE TRANSESTERIFICATION
This work studied the obtaining of methyl biodiesel and ethyl biodiesel using alkaline transesterification from macroalgae Fucus vesiculosos oil (FVO). FVO has 86.59% of its composition in unsaturated fatty acids, with a greater quantity of linoleic acid and oleic acid, a chemical composition near the soybean oil, the most used raw material for the productio
Quím. Nova. Publicado em: 2021-04
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27. Characterization of Otto Chips by Particle Swarm Optimization
Abstract Recently a surface plasmon resonance (SPR) optical sensor, based on the Otto configuration — the Otto chip — has been developed. One essential step in the quality control of the fabrication process is characterization of the active region of several devices in a batch. Characterization is done by measuring the angular spectrum of the optical re
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-03
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28. Synthesis of 1,2,3-Triazole Benzophenone Derivatives and Evaluation of in vitro Sun Protection, Antioxidant Properties, and Antiproliferative Activity on HT-144 Melanoma Cells
Benzophenones display several biological activities, including antioxidant, anticancer, and photoprotective. Furthermore, antioxidants can minimize both ultraviolet absorption and tumor development. In the present investigation, a series of twenty-six 1,2,3-triazole-benzophenone derivatives were synthesized and had their antioxidant, anticancer, and photopro
J. Braz. Chem. Soc.. Publicado em: 2021-03
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29. Synthesis of Antioxidant Additive from Safflower Seed Oil
Several published studies have evaluated the problems associated with the utilization of biodiesel obtained from safflower (Carthamus tinctorius L.) oil due to the low oxidative stability, caused by the high content of unsaturated fatty acids. Thus, this study aimed at the extraction of safflower seed oil and its use as an unsaturation source to obtain a syn
J. Braz. Chem. Soc.. Publicado em: 2021-01
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30. INSIGHT INTO THE CONFORMATIONAL SPACE OF N-BENZYL-N-(FURAN-2-YLMETHYL)ACETAMIDE BY NMR SPECTROSCOPY AND DFT CALCULATIONS
In this study, the conformational behavior of N-benzyl-N-(furan-2-ylmethyl) acetamide in chloroform was addressed by using a combined experimental/theoretical strategy using NMR spectroscopy and quantum chemical calculations. The 1H and 13C one-dimensional NMR spectra, as well as the two-dimensional HSQC-DEPT and HMBC-DEPT NMR spectra, evinced the presence o
Quím. Nova. Publicado em: 2021-01
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31. Evidências internacionais sobre a previsibilidade dos retornos e do crescimento de dividendos utilizando o dividend yield
RESUMO Este artigo examina a previsibilidade dos retornos e do crescimento de dividendos utilizando dividend yields em sete mercados desenvolvidos: EUA, Reino Unido, Japão, França, Alemanha, Itália e Espanha. No total, esses países representam cerca de 85% do índice Morgan Stanley Capital International (MSCI) World Index. O uso de séries temporais long
Rev. contab. finanç.. Publicado em: 2020-12
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32. Bergenin of Peltophorum dubium (Fabaceae) Roots and Its Bioactive Semi-Synthetic Derivatives
This work describes the isolation of pure bergenin from Peltophorum dubium roots with good yields and its further derivatization through Williamson synthesis. The alkyl derivatives of the bergenin were identified by nuclear magnetic resonance and mass spectrometry data analysis. Among them, three derivatives were reported for the first time herein, 8,10-dihe
J. Braz. Chem. Soc.. Publicado em: 2020-12
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33. Synthesis, in silico Study and Antimicrobial Activity of New Piperine Derivatives Containing Substituted δ-Esters
A series of fifteen new piperine-derived diesters was synthesized through the substitution reaction between the salt of piperic acid, obtained through piperine basic hydrolysis, with the δ-chloro-esters, obtained through the cleavage of tetrahydrofuran (THF) with acyl chlorides in the presence of ZnCl2. The final compounds were obtained with yields ranging
J. Braz. Chem. Soc.. Publicado em: 2020-12
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34. Antifungal potential of essential oils from two varieties of Citrus sinensis (lima orange and bahia navel orange) in postharvest control of Rhizopus stolonifer (Ehrenb.: Fr.) Vuill.
Abstract Brazil, the world’s largest citros producer, yields around 19 million tons per year and exports most part of its production as orange juice. Essential oils (EOs) extracted from leaves, fruit and flowers of many species of the genus Citrus have been widely used as the result of their promising bioactivities. The fungus Rhizopus stolonifer (Ehrenb.)
Food Sci. Technol. Publicado em: 2020-12
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35. Improvements in Methyl-Bambus[6]uril Synthesis Yield
Bambus[n]uril synthesis may be challenging, and it is frequently achieved with low purity and low yields. We have studied the effect of different anions on the synthesis of bambus[6]uril, especially in terms of yield, exploring template effects driven by anions in the reaction medium. The influence of the anions is evident on such syntheses and ClO4− parti
J. Braz. Chem. Soc.. Publicado em: 2020-11
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36. Where’s the Spin? A DFT Study of Mixed-Valence Cyanide-Bridged Ruthenium Polypyridines
This article discusses the use of density functional theory (DFT) calculations in classifying and characterizing bimetallic ruthenium mixed-valence systems in terms of their electronic localization/delocalization degree. A standard B3LYP/LanL2DZ methodology including integral equation formalism-polarizable continuum model (IEF-PCM) solvent model is evaluated
J. Braz. Chem. Soc.. Publicado em: 2020-11