Polarity
Mostrando 13-24 de 1472 artigos, teses e dissertações.
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13. Chemical characterization, antioxidant and anti-HIV activities of a Brazilian propolis from Ceará state
ABSTRACT Propolis (bee glue) a product of Apis mellifera L. is a resinous mixture containing chiefly beeswax and resin harvested by bees from plant leaves, buds and exudates. Extracts of a propolis sample from Salitre, a municipality of Ceará state (northeast Brazil) were obtained with solvents of increasing polarity (hexane, chloroform, ethyl acetate and m
Rev. bras. farmacogn.. Publicado em: 26/08/2019
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14. Humic Substances and Chemical Properties of an Acrisol Amended with Vermicomposted Vegetal and Animal Residues
ABSTRACT Vermicomposted vegetal and animal residues are rich in nutrients and humic substances and thus can be applied to the soil as a source of functionalized organic matter (OM) and as an alternative to chemical fertilizers. In Southern Brazil, many animal and vegetal residues are easily accessible. Therefore, this study aimed to evaluate alterations in s
Rev. Bras. Ciênc. Solo. Publicado em: 16/05/2019
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15. Brown Stink Bug Mortality by Seed Extracts of Tephrosia Vogelii Containing Deguelin and Tephrosin
ABSTRACT Extracts of the seeds of Tephrosia vogelii Hook. f. were studied in relation to its chemical composition and toxicity to the brown stink bug Euschistus heros (F.). The extracts were obtained in ethyl acetate and ethanol in the sequence according to the polar nature of the solvents. Extracts were sprayed in concentration of 1.0, 2.5, 5.0, 7.5 and 10%
Braz. arch. biol. technol.. Publicado em: 29/11/2018
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16. Influence of clay surfactants polarity on the crystallization and rheological behavior of nanocomposites of PDLLA
The effect of clay hydrophobicity on the cold crystallization and rheological properties of nanocomposites of poly(D,L-lactic acid) (PDLLA) was investigated. Crystallization was evaluated by DSC for isothermal and non-isothermal conditions. The clay modified with a hydrophilic surfactant acts as a nucleating agent, while the clay modified with a hydrophobic
Mat. Res.. Publicado em: 11/10/2018
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17. Study on the Mixed-Mode HPLC Separation of Shuang-Huang-Lian and Xue-Bi-Jing Injections Based on an Ionic Liquid Column
Both Shuang-Huang-Lian and Xue-Bi-Jing injections are clinically proven efficient and low cost medicines. However, the studies of their chromatographic separation are limited. In this study, a column based on ionic liquid stationary phase was applied for the first time for the analysis of these two injections. For Shuang-Huang-Lian injection, U-shaped plots
J. Braz. Chem. Soc.. Publicado em: 2018-07
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18. Multiple Spectroscopic and Theoretical Approaches to Study the Interaction between HSA and the Antiparasitic Drugs: Benznidazole, Metronidazole, Nifurtimox and Megazol
The interaction between four antiparasitic drugs (benznidazole (BZL), metronidazole (MTZ), nifurtimox (NFX) and megazol (MZ)) with human serum albumin (HSA), the main vehicle of biodistribution of xenobiotics, hydrophobic, small and endogenous molecules in the bloodstream, was evaluated by multiple spectroscopic techniques and theoretical calculations. In al
J. Braz. Chem. Soc.. Publicado em: 2018-07
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19. Determination of the effective anticandidal concentration of denture cleanser tablets on some denture base resins
Abstract Objective Although the effectiveness of chemical cleansing against Candida albicans biofilm has been shown, the effective concentration of denture cleanser tablets has not been studied. The aim of this study was to assess the effect of three denture materials against Candida albicans biofilm and to determine effective concentrations of denture clea
J. Appl. Oral Sci.. Publicado em: 18/01/2018
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20. Mass transfer and kinetic modelling of supercritical CO 2 extraction of fresh tea leaves (Camellia sinensis L.)
Abstract Supercritical carbon dioxide extraction was employed to extract solids from fresh tea leaves (Camellia sinensis L.) at various pressures(15 to 35 MPa) and temperatures (313 to 333K) with addition of ethanol as a polarity modifier. The diffusion model and Langmuir model fit well to experimental data and the correlation coefficients were greater than
Braz. J. Chem. Eng.. Publicado em: 2017-07
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21. Synthesis, Characterization and Dielectric Properties of New 5-(4-Hydroxyphenyl)- 10,15,20-tri-4-[2-(3-pentadecylphenoxy)ethoxy]phenyl porphyrin and Their Ni, Co and Cu Complexes
New asymmetric cardanol-based porphyrins, free-base and coordinated with Ni, Co and Cu, were synthesized and completely characterized as A3B type. Such porphyrins were obtained aiming improved solubility in polar solvents due insertion of an -OH phenolic group. Their thermal and dielectric properties were also evaluated. Changes in the synthetic route reduce
J. Braz. Chem. Soc.. Publicado em: 2017-06
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22. HS-SPME optimization and extraction of volatile compounds from soursop (Annona muricata L.) pulp with emphasis on their characteristic impact compounds
Abstract Aroma and taste are decisive factors in the selection of any food. The aim of this study was to extract the volatile compounds present in soursop (Annona muricata L.) pulp by Solid-phase microextraction (SPME) technique using 3 different fibers (DVB/CAR/ PDMS, CAR/PDMS and PDMS/DVB). An experimental design was set up to evaluate the best extraction
Food Sci. Technol. Publicado em: 29/05/2017
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23. Efficiency of Single Site Phase Transfer Catalyst in Free Radical Polymerization of Butyl Methacrylate - A Kinetic Study
ABSTRACT The effectiveness of single site phase transfer catalyst- 2- benzoylethyldecyldimethylammonium bromide has been studied with the help of kinetics of free radical polymerization of butyl methacrylate. The radical polymerization was catalysed with single site phase transfer catalyst, initiated by water soluble potassium peroxydisulphate initiator in e
Braz. arch. biol. technol.. Publicado em: 23/01/2017
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24. SYNERGIC EXTRACTION OF PANTOTHENIC ACID WITH TWO DIFFERENT EXTRACTANTS
Abstract The influences of extractants concentrations and solvent polarity on the efficiency of pantothenic acid separation by synergic extraction with tri-n-octylamine (TOA) and di(2-ethylhexyl) phosphoric acid (D2EHPA) mixture have been analyzed. The results indicated the formation of an interfacial compound which includes one molecule of pantothenic acid
Braz. J. Chem. Eng.. Publicado em: 2016-12