Free Radicals Chemistry
Mostrando 1-12 de 16 artigos, teses e dissertações.
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1. RPE aplicada à caracterização de radicais livres orgânicos em diesel marítimo
A técnica de Ressonância Paramagnética Eletrônica (RPE) em banda-X (9 GHz) e em banda- W (94 GHz) foi utilizada no estudo de diesel marítimo (bunker). Foram realizadas medidas no intervalo de temperaturas de 170 a 400 K. O espectro em banda-X, à temperatura ambiente, apresentou um sinal isotrópico com típico desdobramento hiperfino de prótons com pa
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/04/2009
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2. Mecanistic Studies of Reactions involving Tellurium Compounds and Synthetic Application of Chalcogenide Compounds / Estudo de mecanismos de reações envolvendo compostos de telúrio e aplicações sintéticas de compostos calcogenados
The first experimental evidence for the formation of an organic tellurium-centered radical (RTe center dot, R = Ph or nBu groups) during the hydrotelluration of alkenes and alkynes is provided. The radicals were detected by electronic paramagnetic ressonance (EPR), using DBNBS (3,5-dibromo-4-nitrosobenzene-sulfonate) as the spin trap. The radical adducts (DB
Publicado em: 2009
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3. Polimerização via radical livre fotoiniciada de sistemas multicomponentes para utilização em dispositivos oftalmicos : aspectos opticos e mecanicos / Free radical polymerization photoinitiated of multicomponent systems for us e in ophthalmic devices : optical and mechanical aspects
The current market calls for materials presenting good optical properties which satisfy consumers and users in general and that can be easily handled and processed. Generally, a polymer must present good optical properties, impact resistance and hardness - all compatible in their use as ophthalmic lenses. For quite a long period of time, ophthalmic lenses ma
Publicado em: 2009
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4. AVALIAÇÃO TOXICOLÓGICA DE ORGANOCALCOGÊNIOS EM ERITRÓCITOS HUMANOS / TOXICOLOGICAL EVALUATION OF ORGANOCHALCOGENS IN HUMAN ERYTHROCYTES
The interest in organochalcogen chemistry, biochemistry and pharmacology has increased in the last two decades mainly due to the fact that a variety of organochalcogen compounds possess biological activity and due the use of these compounds in industrial applications. However, literature data showed that these compounds present pro-oxidant properties, causin
Publicado em: 2009
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5. Interações de peroxirredoxinas citossólicas da levedura Saccharomyces cerevisiae com peróxidos. Estudos cinéticos e funcionais / Saccharomyces cerevisiae cytosolic peroxiredoxin interactions with peroxides. Kinetics and functional studies
Peroxiredoxins constitute a family of cysteine-based peroxidases that are able to reduce hydrogen peroxide, organic peroxides and peroxinitrite to water, alcohol and nitrite, respectively, through the use of reducing equivalents provided by thioredoxin, thioredoxin reductase and NADPH. Peroxiredoxins are abundant enzymes (correspond to approximately 0.7% of
Publicado em: 2009
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6. Contribuição ao estudo químico e biológico de Pouteria gardnerii (Mart. &Miq.) Baehni (Sapotaceae)
The present dissertation describes the chemical study and the biological activities of leaves of Pouteria gardnerii (Mart. &Miq.) Baehni, Sapotaceae, usually found at biome Cerrado around Distrito Federal and popularly called frutinha-de-veado, cabritão, sapotinha, leiteiro-da-folha-miúda, aguai-guacú or marmelinho. From the hexane crude extract were isol
Publicado em: 2007
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7. Produto lácteo contendo fitoquímicos bioativos de extratos de especiarias
Compostos antioxidantes naturais, adicionados em alimentos, podem ter um impacto fisiológico sobre a saúde humana, principalmente porque podem reduzir o risco de doenças ou promover um retardamento dos danos provocados pelo efeito de radicais livres, como as doenças cardiovasculares, câncer intestinal, infecções intestinais, entre outras. Rosemarinus
Publicado em: 2007
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8. CH and C2 radicals characterization in natural gas turbulent diffusion flames
This paper reports the construction of an axisymmetric nonpremixed piloted jet burner, with well-defined initial and boundary conditions, known as the Delft burner, to assess turbulence-chemistry interaction in non-premixed turbulent flames. Detailed experimental information is described, involving hot-wire anemometry, thin-wire thermocouples and chemilumine
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2005-06
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9. QUANTIFICATION OF REDUCED GLUTATHIONE IN HUMAN ERYTHROCYTES BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY-UV: VALIDATION AND APLICATION / QUANTIFICAÇÃO DA GLUTATIONA REDUZIDA EM ERITRÓCITOS HUMANOS POR CROMATOGRAFIA LÍQUIDA DE ALTA EFICIÊNCIA-UV: VALIDAÇÃO E APLICAÇÃO
Oxidative stress may be initiated by a decline in the antioxidant defence system or by an overproduction of free radicals leading to an imbalance between oxidants and antioxidants. The most significant alteration in the antioxidant defence is a decrease in reduced glutathione (GSH) concentration. GSH depletion is linked to a number of disease states; includi
Publicado em: 2005
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10. Caracterização de radicais livres em biocombustíveis, petróleo e derivados por ressonância paramagnética eletrônica (RPE)
Neste trabalho, caracterizaram-se amostras de petróleo, óleo lubrificante, óleo de xisto e bioóleos por Ressonância Paramagnética Eletrônica. O petróleo apresentou g=2,0029 e largura de linha ÄHpp=5-7 Gauss. Estes valores concordam com a elevada aromaticidade deste óleo e sua forma de linha com tendência Lorentziana, indica homogeneidade de espéc
Publicado em: 2005
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11. Influencia da radiação ionizante em compositos odontologicos, ionomero de vidro e ceramica
The influence of the ionizing radiation from diagnosis radiographic exams or radiotherapy treatment in dental materials as resin composite, glass ionomer and ceramic dental is not wide known. Trying a better understanding about the ionizing radiation influence in the chemical behavior, in molecular scale, of the esthetics restoration materials used in the de
Publicado em: 2005
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12. On the interactions between atmospheric radicals and cloud droplets: A molecular picture of the interface
How gas-phase materials become incorporated with cloud droplets has been an intriguing subject for decades, and considerable work has been done to understand the interactions between closed-shell molecules and liquid water. The interactions between open-shell radical species and liquid-phase cloud droplets, however, are not well understood. To probe thes
National Academy of Sciences.