66 research outputs found

    Antibacterial and Cytotoxic Activities of Pinus tropicalis and Pinus elliottii Resins and of the Diterpene Dehydroabietic Acid Against Bacteria That Cause Dental Caries

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    Considering the impact of dental caries on public health and the wide biological potential described for species belonging to the genus Pinus, here we investigate the antibacterial activity of the P. elliottii and P. tropicalis resins and of the diterpene dehydroabietic acid (DHA) against cariogenic bacteria. For this purpose, we have determined the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the resins and of the diterpene. We have also investigated the biofilm inhibition ability (through MBIC50 determination), as well as the synergistic effect (through fractional inhibitory concentration index) and the cytotoxic potential (through XTT assay) of the P. elliottii and P. tropicalis resins. The resins gave promising MIC and MBC values, which ranged from 12.5 to 400 μg/mL; DHA provided MIC and MBC values ranging from 25 to 400 μg/mL. The MICB50 values ranged from 0.78 to 400 μg/mL for the resins. Neither additive nor synergistic effects emerged for the combinations of one of the resins with chlorhexidine. The cytotoxic activity was ≥312.5 and ≥156.3 μg/mL for the P. elliottii and P. tropicalis resins, respectively. The resins showed antibacterial activity against planktonic and sessile cariogenic bacteria. These data are relevant and encourage further research into these plants, which may contribute to the discovery of new substances that can inhibit the growth of cariogenic microorganisms and reduce the incidence of dental caries

    Observing the Evolution of the Universe

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    How did the universe evolve? The fine angular scale (l>1000) temperature and polarization anisotropies in the CMB are a Rosetta stone for understanding the evolution of the universe. Through detailed measurements one may address everything from the physics of the birth of the universe to the history of star formation and the process by which galaxies formed. One may in addition track the evolution of the dark energy and discover the net neutrino mass. We are at the dawn of a new era in which hundreds of square degrees of sky can be mapped with arcminute resolution and sensitivities measured in microKelvin. Acquiring these data requires the use of special purpose telescopes such as the Atacama Cosmology Telescope (ACT), located in Chile, and the South Pole Telescope (SPT). These new telescopes are outfitted with a new generation of custom mm-wave kilo-pixel arrays. Additional instruments are in the planning stages.Comment: Science White Paper submitted to the US Astro2010 Decadal Survey. Full list of 177 author available at http://cmbpol.uchicago.ed

    In vitro schistosomicidal effects of the essential oil of Tagetes erecta

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    The in vitro schistosomicidal effects of the essential oil obtained from Tagetes erecta L. Asteraceae, leaves (TE-EO) collected in Brazil against Schistosoma mansoni worms are reported in this paper. The oil caused a significant decrease in the motor activity at 50 µg/mL as minimal concentration after 24 h. This oil also caused death of all the parasites and the separation of coupled pairs into individual male and female at 100 µg/mL after 24 h. The viability of adult worm groups treated with the TE-EO at 100 µg/mL was similar to that of groups treated with praziquantel (positive control). In addition, the oil promoted the inhibition of eggs development at all the tested concentrations. These data indicate that the TE-EO could be considered as a promising source for the development of new schistosomicidal agents

    Geografic Information System for the planning of the apicultural activity in Padre Josimo Tavares Settlement - PA

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    Atualmente, a apicultura é aproveitada de forma econômica pelo homem na polinização das plantações, assim como na produção de própolis, geléia real, apitoxina e o mais conhecido e explorado pelo homem, o mel. A apicultura tem se consolidado como uma das atividades mais importantes do ponto de vista econômico, social e ambiental, uma vez que ao empregar mão-de-obra familiar e proporcionar geração de fluxo de renda, reduz a dependência dos produtos agrícolas de subsistência e favorece a fixação do homem no campo. Todavia, sem utilizar nenhum recurso computacional ou uma metodologia sistemática, os apicultores escolhem o local para instalar suas colméias, seja dentro dos perímetros da propriedade, ou numa região geográfica mais abrangente, como, por exemplo, um município. O Sistema de Informações Geográficas (SIG) é uma ferramenta computacional, resultado de combinação da Cartografia com a Informática, que permite efetuar análise espacial e cruzamento de informações espaciais de uma forma, antes, quase impossível de se pensar, pelo enorme esforço requerido, tempo exigido e o custo resultante. Este trabalho visa criar um SIG destinado a escolha do local que possa otimizar a produção apícola. Como conseqüência desta metodologia, surge também um melhoramento na polinização de zonas escolhidas, afetando e acelerando o processo de recuperação de áreas degradadas. As técnicas de manejo apícola desenvolvidas têm conseqüências econômicas e sociais para as populações envolvidas, como é o caso do exemplo utilizado neste trabalho, assentamento rural Padre Josimo Tavares.Today, apiculture is economically exploited by the man in the pollination of crops, as well as the production of propolis, royal jelly, bee venom and the best known and exploited by the man, the honey. Apiculture has been established as one of the most important activity in terms of economic, social and environmental, once employing family labor-intensive and providing flow generation of income, reduces dependence on agricultural livelihoods and promotes the settling of the man in the field. However, without using any computer resource or a systematic methodology, beekeepers choose where to install their hives, is within the perimeters of the property, or a wider geographical area as a city, for example. The Geographic Information System (GIS) is a computational tool result of combining Cartography with Computer Science, that allows to perform spatial analysis and crossing spatial information in a way that, before, was almost impossible to think, by the enormous effort required, time required and the resulting cost. This work aims to create a GIS for site selection that can optimize hives production. As a result of this methodology it also appears an improvement in the pollination of selected areas, affecting and accelerating the recovery of degraded areas. The developed apicultural management techniques have economic and social consequences for the involved populations, such as the example used in this study, \"Padre Josimo Tavares rural settlement

    Patient-specific CFD modelling in the thoracic aorta with PC-MRI–based boundary conditions: A least-square three-element Windkessel approach

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    The increasing use of computational fluid dynamics for simulating blood flow in clinics demands the identification of appropriate patient-specific boundary conditions for the customization of the mathematical models. These conditions should ideally be retrieved from measurements. However, finite resolution of devices as well as other practical/ethical reasons prevent the construction of complete data sets necessary to make the mathematical problems well posed. Available data need to be completed by modelling assumptions, whose impact on the final solution has to be carefully addressed. Focusing on aortic vascular districts and related pathologies, we present here a method for efficiently and robustly prescribing phase contrast MRI-based patient-specific data as boundary conditions at the domain of interest. In particular, for the outlets, the basic idea is to obtain pressure conditions from an appropriate elaboration of available flow rates on the basis of a 3D/0D dimensionally heterogeneous modelling. The key point is that the parameters are obtained by a constrained optimization procedure. The rationale is that pressure conditions have a reduced impact on the numerical solution compared with velocity conditions, yielding a simulation framework less exposed to noise and inconsistency of the data, as well as to the arbitrariness of the underlying modelling assumptions. Numerical results confirm the reliability of the approach in comparison with other patient-specific approaches adopted in the literature

    Estudo fitoquímico preliminar e bioensaio toxicológico frente a larvas de Artemia salina Leach. de extrato obtido de frutos de Solanum lycocarpum A. St.-Hill (Solanaceae)

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    The phytochemical profile of ethanolic extract of Solanum lycocarpum fruits was analyzed and preliminary toxicity tests were performed against brine shrimp larvae. The extract was subjected to preliminary phytochemical analysis to identify the main classes of secondary metabolites and tested against the larvae of A. salina to obtain the median lethal concentrations (LC50%). The phytochemical tests showed the presence of phenols, tannins, saponins, alkaloids and free steroids. The extract was fractionated with various solvents for toxicity testing against the larvae and the hydroalcoholic fraction showed considerable cytotoxicity (CL50% = 285.546 g/mL).Neste trabalho avaliou-se o perfil fitoquímico e a toxicidade preliminar frente a larvas de Artemia salina do extrato etanólico de frutos de Solanum lycocarpum. O extrato foi submetido à analise fitoquímica preliminar para identificação das principais classes de metabolitos secundários presentes e testado frente a larvas de A. salina para obtenção das concentrações letais médias (CL50%). Os testes fitoquímicos demonstraram a presença de fenóis, taninos, saponinas, alcalóides e esteróides e triterpenos livres. O extrato foi fracionado em diferentes solventes para a avaliação da toxicidade frente à A. salina, apresentando considerável citotoxicidade encontrada na fração hidroalcoólica (CL50% = 285,546 µg/mL)
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