1,738 research outputs found

    Marine 5-thiohistidines as protective molecules from skin damage

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    Introduction Marine environment is a great source of bioactive molecules, whose biological properties and applications are often used especially to prevent skin diseases and aging caused by UVA­exposure. Ovothiols are methyl­5­thiohistidines from marine invertebrates, bacteria, and microalgae, which protect cells from environmental stressors. Recently, we have shown that, ovothiol, isolated from sea urchin eggs, exerts anti­inflammatory and antioxidant activities on human endothelial cells, and exhibits antifibrotic effect in an in vivo model of liver fibrosis.info:eu-repo/semantics/publishedVersio

    Chemical Abundances of the Damped Lya Systems at z>1.5

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    We present chemical abundance measurements for 19 damped lya systems observed with HIRES on the 10m W.M. Keck Telescope. Our principal goal is to investigate the abundance patterns of the damped systems and thereby determine the underlying physical processes which dominate their chemical evolution. We place particular emphasis on gauging the relative importance of two complementary effects often invoked to explain the damped lya abundances: (1) nucleosynthetic enrichment from Type II supernovae and (2) an ISM-like dust depletion pattern. Similar to the principal results of Lu et al. (1996), our observations lend support both for dust depletion and Type II SN enrichment. Specifically, the observed overabundance of Zn/Fe and underabundance of Ni/Fe relative to solar abundances suggest significant dust depletion within the damped lya systems. Meanwhile, the relative abundances of Al, Si, and Cr vs. Fe are consistent with both dust depletion and Type II supernova enrichment. Our measurements of Ti/Fe and the Mn/Fe measurements from Lu et al. (1996), however, cannot be explained by dust depletion and indicate an underlying Type II SN pattern. Finally, the observed values of [S/Fe] are inconsistent with the combined effects of dust depletion and the nucleosynthetic yields expected for Type II supernovae. This last result emphasizes the need for another physical process to explain the damped lya abundance patterns. We also examine the metallicity of the damped lya systems both with respect to Zn/H and Fe/H. Our results confirm previous surveys by Pettini and collaborators, i.e., [] = -1.15 +/- 0.15 dex. [abridged]Comment: 18 pages, 4 embedded figures, 20 additional figures. Accepted to the Astrophysical Journal 10/20/98. Uses Latex2e, emualteapj.sty, and onecolfloat.st

    Efeito da adubação mineral na produção de matéria seca de pimenta longa (Piper hispidinervium).

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    Temperature Fluctuations and Abundances in HII Galaxies

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    There is evidence for temperature fluctuations in Planetary Nebulae and in Galactic HII regions. If such fluctuations occur in the low-metallicity, extragalactic HII regions used to probe the primordial helium abundance, the derived 4He mass fraction, Y_P, could be systematically different from the true primordial value. For cooler, mainly high-metallicity HII regions the derived helium abundance may be nearly unchanged but the oxygen abundance could have been seriously underestimated. For hotter, mainly low-metallicity HII regions the oxygen abundance is likely accurate but the helium abundance could be underestimated. The net effect is to tilt the Y vs. Z relation, making it flatter and resulting in a higher inferred Y_P. Although this effect could be large, there are no data which allow us to estimate the size of the temperature fluctuations for the extragalactic HII regions. Therefore, we have explored this effect via Monte Carlos in which the abundances derived from a fiducial data set are modified by \Delta-T chosen from a distribution with 0 < \Delta-T < \Delta-T_max where \Delta-T_max is varied from 500K to 4000K. It is interesting that although this effect shifts the locations of the HII regions in Y vs. O/H plane, it does not introduce any significant additional dispersion.Comment: 11 pages, 9 postscript figures; submitted to the Ap

    Comparison of fungal contamination between hospitals and companies food units

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    A descriptive study was developed to compare air and surfaces fungal contamination in ten hospitals’ food units and two food units from companies. Fifty air samples of 250 litres through impaction method were collected from hospitals’ food units and 41 swab samples from surfaces were also collected, using a 10 by 10 cm square stencil. Regarding the two companies, ten air samples and eight surface samples were collected. Air and surface samples were collected in food storage facilities, kitchen, food plating and canteen. Outdoor air was also collected since this is the place regarded as a reference. Simultaneously, temperature, relative humidity and meal numbers were registered. Concerning air from hospitals’ food units, 32 fungal species were identified, being the two most commonly isolated genera Penicillium sp

    Anemia de Fanconi – Estudo retrospetivo num período 34 anos

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    Introdução: A Anemia de Fanconi (AF) é uma doença rara, com uma frequência estimada de 1 a 5 per 1.000.000 de nascimentos, podendo este valor aumentar se for considerado um grupo étnico com consanguinidade. É uma doença autossómica recessiva, que poderá ter uma transmissão ligada ao cromossoma X. Doentes com AF podem apresentar malformações congénitas, falência da medula óssea (que se carateriza por pancitopénia), hipersensibilidade a agentes clastogénicos, fragilidade cromossómica e uma maior suscetibilidade para doenças oncológicas. Devido à grande complexidade desta patologia a primeira abordagem de diagnóstico, consiste na deteção de aberrações cromossómicas (quebras, rearranjos estruturais, radiais, anéis) em células de sangue periférico em cultura com um agente clastogénico como o diepoxibutano (DEB) ou mitomicina C (MMC). Objetivo: Neste trabalho pretende-se apresentar os resultados dos estudos de instabilidade cromossómica induzida por DEB e MMC efetuados na nossa instituição. Métodos: Foi realizada a análise de uma série retrospetiva de 34 anos (1980-2014) de 243 amostras enviadas ao laboratório citogenética com suspeita de AF e de 28 amostras de familiares de doentes com AF. No total, foram analisadas 260 amostras de sangue periférico, 6 de biópsia de pele, 3 de líquido amniótico, 1 de sangue do cordão e 1 de sangue medular. As amostras foram processadas segundo o protocolo estabelecido para a análise cromossómica de doenças associadas a fraturas, incluindo cultura celular com estimulação por MMC e/ou DED, para cada produto biológico, seguida de análise microscópica com determinação da instabilidade cromossómica induzida pelo DEB, de acordo com o protocolo estabelecido pelo International Fanconi Anemia Registry (IFAR). Resultados: Nas 243 amostras analisadas, foram identificados 37 casos com AF. Nos estudos citogenéticos dos familiares com AF foram identificados mais 2 casos positivos para AF. Foram ainda observados, em 4 amostras de suspeita de AF, cariotipos anormais. Conclusão: Neste trabalho foram identificados 39 novos casos com AF, oriundos maioritariamente da região de Lisboa e Vale do Tejo e alguns casos pontuais da região autónoma dos Açores, região centro e dos países africanos de língua oficial portuguesa (PALOP). Este estudo evidência que a maioria dos casos apresentados se encontra subdiagnosticado. Estes resultados não permitem estimar uma frequência de doentes com AF em Portugal, uma vez que não engloba indivíduos de todas as regiões portuguesas, por outro lado estão incluídos dois indivíduos de origem PALOP. É necessário estabelecer um registo nacional de doentes com AF, para se poder calcular a frequência desta patologia no nosso país

    Air fungal contamination in ten hospitals’ food units from Lisbon

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    A descriptive study was developed to monitor air fungal contamination in ten food units from hospitals. Fifty air samples of 250 litres were collected through impaction method. Samples were collected in food storage facilities, kitchen, food plating, canteen and also, outside premises, since this is the place regarded as reference. Simultaneously, environmental parameters were also monitored, including temperature and relative humidity through the equipment Babouc, LSI Sistems and according to the International Standard ISO 7726
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