Polar Molecules
Mostrando 13-24 de 176 artigos, teses e dissertações.
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13. Isoxazolinas: uma classe de materiais avançados revisitada
The synthesis and characterization of novel series of liquid crystalline materials containing N-heterocyclic isoxazoline are described. These molecules were obtained from the reaction of 1,3-dipolar cycloaddition of nitrile oxides to different compounds containing double bonds. Thermal properties were analyzed by MOLP, DSC and TGA, and optical properties by
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2010
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14. Side effects of oxysterols: cytotoxicity, oxidation, inflammation, and phospholipidosis
Oxysterols are 27-carbon atom molecules resulting from autoxidation or enzymatic oxidation of cholesterol. They are present in numerous foodstuffs and have been demonstrated to be present at increased levels in the plasma of patients with cardiovascular diseases and in atherosclerotic lesions. Thus, their role in lipid disorders is widely suspected, and they
Brazilian Journal of Medical and Biological Research. Publicado em: 2008-07
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15. Effect of triplet encapsulated atoms in [60] fullerenes: a theoretical analysis
The present investigation reports on the interaction of the C/O triplet atoms inside of the [60] fullerene (C60) species with small polar molecules (H²O, CH³OH, HF, NH³) using Density Functional Theory (DFT) calculations. The calculations show that in all the computed cases the encapuslated complexes with the molecules are more stable than without interna
Eclética Química. Publicado em: 2008
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16. Bombeamento optico de moleculas polares por laser selado de 13 ANTPOT. ( C O IND. 2 ) para geração de ondas Terahertz / Optically pumped of polar molecules for sealled-off 13 ANTPOT. ( C O IND. 2 ) laser for generation Terahertz waves
Neste trabalho realizamos três importantes etapas: 1) montar e caracterizar um laser selado de 13C02, 2) empregar o laser selado de 13C02 como fonte de bombeamento óptico para a molécula de metanol CH30H, e utilizá-lo pela primeira vez, para excitar o isótopo de metanol 13CH30H para geração de ondas na região do TeraHertz (THz) e 3) Propor "assignmen
Publicado em: 2007
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17. Effect of polysaccharide capsule of the microalgae Staurastrum iversenii var. americanum on diffusion of charged and uncharged molecules, using EPR technique
The existence of a mucilaginous envelope, sheath or capsule is usual in many desmids, but few data concerning its function are available. Previous studies of the transport function and permeation of molecules through the algae capsules were done using the algae Spondylosium panduriforme and Nephrocytium lunatum, the Electron Paramagnetic Resonance (EPR) tech
Brazilian Journal of Physics. Publicado em: 2006-03
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18. Quantificação de farmacos em estudos de biodisponibilidade relativa por espectrometria de massas com a utilização da tecnica de fotoionização / Drug quantification for relative biovailability studies by means of photoionization mass spectrometry
The development of atmospheric pressure ionization techniques has been of utmost importance to turn high performance liquid chromatography coupled to mass spectrometry into a routine solution, enabling the development of robust, high performance, high sensitivity and specific quantitative methods. In this sense, the recent development of the atmospheric pres
Publicado em: 2006
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19. Anestésicos locais: interação com membranas de eritrócitos de sangue humano, estudada por ressonância magnética nuclear de ¹H e 31P
The literature carries many theories about the mechanism of action of local anesthetics (LA). We can highlight those focusing the direct effect of LA on the sodium channel protein and the ones that consider the interaction of anesthetic molecules with the lipid membrane phase. The interaction between local anesthetics and human erythrocyte membranes has been
Química Nova. Publicado em: 2004-02
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20. Incorporação de solutos não iônicos em micelas de alquil óxido de difenila dissulfonados / Incorporation of non ionic solutes in alkyl diphenyloxide disulfonate micelles
The solubilization of non ionic molecules in detergent micelles is a property that has been extensively investigated and that is of great practical importance. Several applications in which solubilization is of relevance are detergency, remediation of contaminated soils and catalysis. In earlier work, the group of Prof. Quina has shown that linear free energ
Publicado em: 2003
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21. Elastic and rotational excitation cross sections for electron scattering by polyatomic molecules
In this work we present a theoretical study on electron scattering by both polar and nonpolar polyatomic molecules in the low-energy range. More specifically, we report calculated elastic and rotationally inelastic differential cross sections for electron scattering by CH4, H2O, and H2S in the (2.14-30)-eV range. Exact static-exchange plus model correlation-
Brazilian Journal of Physics. Publicado em: 2002-09
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22. Hidrogenofosfato de titânio lamelar: síntese, troca iônica e intercalação
The development associated with the research field involving crystalline inorganic lamellar titanium hydrogenphosphate, Ti(HPO4).H2O, synthesized as alpha or gamma forms, is directly linked to the huge number of reactions, that occur inside the free interlamellar space. Two distinguishable well-characterized features such as ion-exchange and intercalation re
Química Nova. Publicado em: 2001-12
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23. Preparação de fases estacionarias SiO2(PMOS), imobilizadas por microondas para cromatografia liquida de alta eficiencia
In the preparation of stationary phases (SP), an alternative to minimize the undesirable effects of the silanol groups consists of promoting a better covering of the surface of the silica by the sorption of a polymer onto the support, a sorbed phase being obtained. The stability of these SP is increased by the immobilization process using, as an example, mic
Publicado em: 2001
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24. Estados críticos orientacionais em cristais líquidos liotrópicos induzidos por campos magnéticos. / Orientations critical states in lyotropic liquid crystals induced by magnetic fields.
Liquid crystalline structures are found in materials made from molecules which are anisotropic in shape; such material are characterized mainly by a long range orientational order. In the nematic phase, the rodlike molecules tend to align parallel to each other. The average orientation defines a unit vector, called director n. Lyotropic liquid crystals are u
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/12/2000