Conselho Nacional de Desenvolvimento Científico e Tecnológico / Phenolic compounds are secondary metabolites, widely distributed in the plant kingdom, which present antiinflamatory, antibacterial, antiviral, antialergical and antitumoral activities, in addition to antioxidant activities. Even in low concentrations compared to the oxidant substrate, the antioxidant compounds can delay or inhibit free radical oxidation rates. Thus, this study aimed to quantitatively determine and classify the compounds as natural antioxidants isolated and its contribution to the antiradical activity from the chromatographic analysis (HPLC-DAD) and a systematic study of the antiradical activity of antioxidant compounds isolated (patterns reference) and natural (herbal extracts) using in vitro and ex vivo.bem. Furthermore, the antioxidant species bioactivity was assessed from cells of the cortex and permeation cell biomembranes, artificial lipid. Among the antioxidant compounds studied, quercetrin presented protection action against free radicals on cell-based studies (cortex cells), high in vitro and cell-based antiradical actions, and also biomembrane permeations. These responses, when added, can confer to quercitrin higher relevance as a antioxidant at physiological levels when compared to others poliphenols. This work presents a systematic study on antiradical activities of isolated antioxidant compounds (from reference standards) and natural antioxidant compounds (medicinal plant extracts), by using in vitro and ex vivo methods. / Os compostos fenólicos constituem-se por um grupo de metabólitos secundários, amplamente distribuídos no reino vegetal, que apresentam propriedades antinflamatórias, antibacterianas, antivirais, antialérgicas e antitumorais, além de possuírem propriedades antioxidantes. Mesmo presentes em baixas concentrações em relação ao substrato oxidante, os antioxidantes podem atrasar ou inibir as taxas de oxidação dos radicais livres. Desta forma, este estudo teve como objetivo classificar e determinar quantitativamente os compostos antioxidantes isolados e naturais quanto a sua contribuição na atividade antirradicalar a partir da análise cromatográfica (HPLC-DAD) e de um estudo sistemático da atividade antirradicalar de compostos antioxidantes isolados (padrões de referência) e naturais (extratos de plantas medicinais) usando métodos in vitro e ex vivo.bem. Além disso, a bioatividade das espécies antioxidantes foi avaliada a partir de células de córtex e da permeação por biomembranas celulares artificiais lipídicas. Dentre os antioxidantes estudados, a quercitrina apresentou ação protetora contra radicais livres em nível celular (células de córtex), alta ação antirradicalar in vitro e em nível celular (ex vivo), além de permear biomembranas. Essas respostas, quando somadas, podem credenciar a quercitrina com um dos antioxidantes da classe dos polifenóis de maior relevância em nível fisiológico.

This study shows basic and advanced methods of information systems benefit quantification and applies selected methods to a real life problem. The practical part has been used to justify an information systems investment of already implemented and future systems. This work also appeals to a need of theoretical background and practical creativity when quantifying social properties of information systems. It is unacceptable to tolerate laical stance against social concepts of information systems and their quantification.

Les gisements de type roll-front du Kazakhstan représentent près de 13% des réserves mondiales en uranium en 2015. Les minéraux argileux, présents à chaque étape du cycle minier, ont récemment suscité l’intérêt des exploitants. L’étude de la distribution et des proportions de ces minéraux dans les sédiments à l’échelle d’un gisement permettraient d’améliorer à la fois l’exploration, l’exploitation et la réhabilitation de ce type de gisement.Différentes méthodes ont été développées pour identifier et quantifier les minéraux d’intérêt à partir de la spectrométrie infrarouge (IR), une technique instrumentale rapide, adaptée à une utilisation sur le terrain. Ces méthodes ont été calibrées à l’aide d’une large base de données de spectres IR et la préparation de sables artificiels.Il est possible d’obtenir, à partir d’une seule mesure spectrale, la teneur en argiles des sables et particulièrement celle en smectite afin d’identifier les zones les plus riches et adapter l’extraction de l’uranium. L’ensemble de ces méthodes permettent de réaliser des cartographies de la répartition des minéraux argileux à l’échelle du gisement pour comprendre sa géométrie et sa mise en place.La migration des corps minéralisés à l’échelle régionale a été mise en évidence par spectrométrie de résonance paramagnétique, avec l’étude des défauts structuraux engendrés par la proximité des minéraux argileux avec les minéraux uranifères. / Uranium roll-front type sandstone-hosted deposits from Kazakhstan account for about 13% of the worldwide uranium reserve in 2015. Clay minerals occur at every step of the mining cycle and recently begun to be considered by mining companies.The proportions and distribution of these clay minerals in the sediments at the roll-front deposit scale could improve the exploration, exploitation and rehabilitation of such uranium deposits.Several methods were developed to identify and quantify minerals using a portable near-infrared spectrometer, a convenient and fast analytical tool for use in the field. These methods were calibrated with the help of a wide spectral database and the conception of artificial sands.The clay mineral content, and more importantly, the smectite content can be obtained from a single spectral measurement. It enables the detection of smectite-rich areas to optimise the uranium extraction process where they occur. Combination of the methods provide a mapping tool for clay minerals at the ore deposit scale, yielding information about its actual geometry and formation.Uranium ore bodies migration was observed at the ore deposit scale with the use of the electron paramagnetic resonance spectroscopy. Crystalline radiation induced defects in clay minerals that were in close contact with uranium showed records of the past migration.