Hydrogen Bonds
Mostrando 13-24 de 668 artigos, teses e dissertações.
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13. Influence of Crystallization and Ageing Time on the Reproducibility of Mesoporous Molecular Sieve SBA-15
ABSTRACT The study aimed to assess how the crystallization and ageing times in SBA-15 synthesis influence the reproducibility and particle size of mesoporous molecular sieves. X-ray diffraction showed that higher crystallization times provide greater reproducibility of mesoporous silica, due to the fact that there is no significant variation in the width and
Matéria (Rio J.). Publicado em: 10/06/2019
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14. Facial Selectivity between Carbohydrates and Aromatic Amino Acids Explained by a Combination of NCI, NBO and EDA Techniques with NMR Spectroscopy
The influence of electrostatic and dispersion components of intermolecular interactions on the recognition of carbohydrates by aromatic protein residues is important for many biological processes. Interactions between glucose and galactose and aromatic moieties of tryptophan, phenylalanine and histidine were investigated through 1H nuclear magnetic resonance
J. Braz. Chem. Soc.. Publicado em: 08/04/2019
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15. The structural modification of cassava starch using a saline water pretreatment
Abstract The cassava has been modified successfully by using the saline water, which was abundantly available on the planet. The biomass was submerged in saline waters that salt concentrations were altered at 0, 3.5 percent (seawater) and 10 percent (w/w) and were kept 5 days. After recovery by washing steps, the treated solids were characterized by using X
Food Sci. Technol. Publicado em: 05/04/2018
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16. BaltDC: purification, characterization and infrared spectroscopy of an antiplatelet DC protein isolated from Bothrops alternatus snake venom
Abstract Background: Snake venoms are a complex mixture of proteins, organic and inorganic compounds. Some of these proteins, enzymatic or non-enzymatic ones, are able to interact with platelet receptors, causing hemostatic disorders. The possible therapeutic potential of toxins with antiplatelet properties may arouse interest in the pharmacological areas.
J. Venom. Anim. Toxins incl. Trop. Dis. Publicado em: 08/02/2018
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17. An Examination of the Prediction of Hydrate Formation Conditions in the Presence of Thermodynamic Inhibitors
Abstract Gas hydrates are crystalline compounds, solid structures where water traps small guest molecules, typically light gases, in cages formed by hydrogen bonds. They are notorious for causing problems in oil and gas production, transportation and processing. Gas hydrates may form at pressures and temperatures commonly found in natural gas and oil product
Braz. J. Chem. Eng.. Publicado em: 2018-01
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18. Estudio teorico de las interacciones de dos modelos de ácidos húmicos con los cationes Al3+, Ca2+, Mg2+, Zn2+, K+ y NH4+ a un nivel de calculo DFT y un modelo de solvatación PCM
In this paper, two models of humic acids, the Temple-Northeastern-Birmingham (TNB) and Kolla models, were studied. Also, the complexation reaction of the structures formed by the interaction of the TNB and Kolla models with Al3+, Ca2+, Mg2+, Zn2+, K+ and NH4+ cations, common in agricultural soils, was studied. These calculations were made for the complexes,
Quím. Nova. Publicado em: 2017-04
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19. Electrical Conductivity in the KDP, ADP, and K1-x(NH4)xH2PO4 Crystals
Impedance Spectroscopy was performed to examine the electrical conductivity on KH2PO4 KDP, (NH4)H2PO4 ADP and K1-x(NH4)xH2PO4 (x = 0.076, 0.118, 0.357, 0.857, 0.942) crystals with increasing temperature. They were grown by solvent evaporation method. Zview simulation software was used to theoretically fit electrical conductivity results as a function of freq
Mat. Res.. Publicado em: 23/02/2017
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20. Development of Molecularly Imprinted Polymers for Solid Phase Extraction of Parabens in Plasma Samples and Analysis by UHPLC-MS/MS
Two molecularly imprinted polymers (MIPs) were synthesized, by sol-gel and radical polymerization procedures. These MIPs were evaluated as selective stationary phases for miniaturized solid phase extraction (MISPE) to determine parabens in plasma samples by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Selective cavitie
J. Braz. Chem. Soc.. Publicado em: 2017-02
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21. Crystal Structures of 1-Aryl-1H- and 2-Aryl-2H-1,2,3-triazolyl Hydrazones. Conformational Consequences of Different Classical Hydrogen Bonds
The crystal structures of (Z)-1-phenyl-4-[((2-phenylhydrazono)methyl)]-1H-1,2,3-triazole, (Z)-4-[(2-(2,4-dimethylphenyl)hydrazono)methyl]-2-phenyl-2H-1,2,3-triazole, (E)-4-[(2-(2,4-dinitrophenyl)hydrazono)methyl]-2-phenyl-2H-1,2,3-triazole, and (E)-N'-((2-phenyl-2H-1,2,3-triazol-4-yl)methylene)isonicotinohydrazide dihydrate are reported. The formations of (Z
J. Braz. Chem. Soc.. Publicado em: 2016-12
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22. O PARADIGMA DA ESTRUTURA DO DOADOR DE PRÓTON NA FORMAÇÃO DE LIGAÇÕES DE HIDROGÊNIO: COMPLEXO C2H2···6(HF)
The DFT, QTAIM, NBO and ChelpG methods were used in a theoretical study of structural parameters, vibration stretch modes and absorption intensities, electronic properties, molecular orbital analyses and molecular topography of the heptamer C2H2···6(HF) complex. One of the great aims concerns to the studying of the proton donor structure, which is conside
Quím. Nova. Publicado em: 2016-11
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23. Characteristics and thermodynamics of the interaction of 6-shogaol with human serum albumin as studied by isothermal titration calorimetry
ABSTRACT The interaction between 6-shogaol, a pharmacologically active ginger constituent, and human serum albumin (HSA), the main in vivo drug transporter, was investigated using isothermal titration calorimetry (ITC). The value of the binding constant, Ka (5.02 ± 1.37 × 104 M−1) obtained for the 6-shogaol-HSA system suggested intermediate affinity. Ana
Braz. J. Pharm. Sci.. Publicado em: 2016-09
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24. Retrogradation of heat-gelatinized rice grain in sealed packaging: investigation of moisture relocation
Abstract The aggregation of water molecules inside heat-gelatinized rice grain due to retrogradation of the grain was investigated by textural change and scanning electron microscopy (SEM) analysis of cooked grains after storage at 11 °C in a sealed package. Relaxation tests using a disc-type tip showed an increase in hardness (strength) of the cooked grain
Food Sci. Technol. Publicado em: 21/07/2016