974 resultados para Info Lit 101
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The zircon mineral is widely studied in geochronology. In the case of the fission track method (FTM), the age is determined by the density of fission tracks at the zircon surface, which can be observed with an optical microscope after an appropriate chemical treatment (etching). The etching must be isotropic at the zircon grain surface to be used in the FTM, which leads those zircon grains whose etching is anisotropic to be discarded. The only reason for this discarding is the nonuniform morphology of the surface grain seen by optical microscopy, that is, no further physicochemical analysis is performed. In this work, combining micro-Raman and scanning electron microscopy (SEM) to study the etching anisotropy, it was shown that zircon grains that present at least one area at the surface where the density of fission track is uniform can be used in the FTM. The micro-Raman showed characteristic spectra of the standard zircon sample either from the areas where there are tracks or from where there are not. The only difference found was in the Raman bandwidths, which were broader for the areas with higher density of fission tracks. This suggests simply a decrease in the relative percentage of the crystalline/amorphous phases at these areas. The SEM/energy dispersive spectrometry (EDX) showed that there were no significant differences in the principal chemical composition at the areas with and without fission tracks. Copyright (c) 2008 John Wiley & Sons, Ltd.
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The acceptance of orange juice from the frozen concentrated orange juice (FCOJ) processing steps was evaluated by 101 consumers for color, overall impression, aroma, flavor and texture. The juice from the extraction, filtration, concentration, cooling and blend steps was collected at the beginning and the end of the 2009 harvest period. The juice from the extraction and filtration steps showed higher acceptance means for overall impression, aroma and flavor, while the juice from the concentration, cooling and blend steps had acceptance lower than the cutoff score. The internal preference mapping showed that color discriminated the juice from the collection periods while texture allowed discrimination between the steps of extraction and of filtration. The acceptance of the orange juice was driven by the aroma and flavor. The sensory acceptance was successfully applied to evaluate change during the process and the difference between the orange juice from different steps of the FCOJ processing.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Strongyloidiasis is a disease of emerging public health importance. A survey was conducted in Araraquara city, São Paulo state, Brazil, in order to evaluate the frequency distribution of Strongyloides stercoralis in the area. A total of 9582 single stool samples were examined by direct examination, and by the Coprotest and Rugai's methods from January 2005 to January 2007. Out of the total samples examined, 408 (4,3%) were found to be infected by S. stercoralis (143 men and 265 women). The months with the highest frequency (5,0 - 8,2%) of positive patients were February, September and December (2005); April and November (2006) and January (2007). The frequencies from the other months varied around 2,5 to 4,9%. It was concluded that strongyloidiasis is endemic in Araraquara, but in some months, which presented the highest temperatures followed by rainy periods, the frequencies are typical from hyperendemic areas.
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In this paper, synthesis, characterization and antimycobacterial properties of a new water-soluble complex identified as silver-mandelate are described. Elemental and thermal analyses are consistent with the formula [Ag(C6H5C(OH)COO)](n). The polymeric structure was determined by single X-ray diffraction and the two-dimensional structure is based on the bis(carboxylate-O,O') dimer [Ag-O, 2.237(3), 2.222(3) angstrom]. The structure is extended along both the b and c axes through two oxygen atoms of a bidentate alpha-hydroxyl-carboxylate residue [Ag-OH(hydroxyl), 2.477(3) angstrom; Ag-O(carboxylate), 2.502(3) angstrom; O-Ag-O, 63.94(9)degrees]. A strong d(10)-d(10) interaction was observed between two silver atoms. The Ag...Ag distance is 2.8307(15) angstrom. The NMR C-13 spectrum in D2O shows that coordination of the ligand to Ag(l) occurs through the carboxylate group in solution. Potentiometric titration shows that only species with a molar metaHigand ratio of 2:2 are formed in aqueous solution. The mandelate complex and the silver-glycolate, silver-malate and silver-hydrogen-tartarate complexes were tested against three types of mycobacteria, Mycobacterium avium, Mycobacterium tuberculosis and Mycobacterium kansasii, and their minimal inhibitory concentration (MIC) values were determined. The results show that the four complexes are potential candidates for antiseptic or disinfectant drugs for discharged secretions of patients affected with tuberculosis. (c) 2006 Published by Elsevier B.V.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Estudou-se o comportamento biológico e histopatológico de uma cepa genuínamente mariliense de Trypanosoma cruzi, isolada em 1997 através de xenodiagnóstico artificial. Vinte e cinco camundongos swiss foram infectados intraperitonealmente, sendo 11 utilizados para a realização da curva parasitêmica e observação da morfologia dos tripomastigotas e 14 foram sacrificados após o 17, 23, 30, 60 e 180 dias pós-infecção e coletados coração, esôfago, fígado, cólon, e músculo esquelético (fragmento da coxa direita) para análise histopatológica. Cultura em meio LIT foi realizada para análise de DNA. Os resultados mostraram predomínio de formas largas, baixa parasitemia com picos médios de 860 tripomastigotas/5mil de sangue ao redor do 20º dia de infecção. Nenhum camundongo morreu na fase aguda da infecção. Exame histopatológico mostrou poucos ninhos de amastigotas em coração, raros em músculo esquelético e cólon com discreto processo inflamatório. Comparada com a cepa Y, que foi isolada de uma paciente da mesma região, notamos diferentes características biológicas e comportamentais, porém a análise de DNA as coloca no mesmo grupo, demonstrando a proximidade dessas cepas.
Triatomíneos rupestres infectados por Trypanosomatidae, coletados em Quaraí, Rio Grande do Sul, 2003
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Foram capturados triatomíneos rupestres em seis localidades do município de Quaraí-RS, com o intuito de verificar o índice de infecção por Trypanosomatidae, bem como o animal reservatório. A captura ocorreu no ambiente silvestre, sendo coletados 453 exemplares, os quais foram identificados e separados por estádio ninfal. Coletaram-se 421 (92,9%) exemplares de Triatoma rubrovaria, 26 (5,7%) de Triatoma circummaculata e 6 (1,3%) de Panstrongylus tupynambai. Dentre as três espécies coletadas, somente Triatoma rubrovaria mostrou-se positivo para Trypanosomatidae, num total de 13 (4,2%) exemplares. Após a inoculação em camundongos e meio de cultura LIT, isolaram-se cinco cepas de Trypanosoma cruzi. Dos triatomíneos infectados com Trypanosomatidae, 4 (30,8%) tiveram a reação de precipitina não reagente para os anti-soros testados, 4 (30,8%) positivos para anti-soro de roedor, 4 (30,8%) para anti-soro de cabra e 1 (7,7%) para anti-soro de porco e humano.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The general statement that birds are recorded more often on morning than on afternoon counts is quite common and widespread among ornithologists. Although many investigators have reported temporal variations in bird detections using Point Counts in temperate regions, few researches regarding the same objectives have been conducted in Neotropical habitats or used transect counts as field method. We used transect counts to test the hypothesis that birds are evenly recorded between times of day in a predominantly open Cerrado landscape in southeastern Brazil. Although not always significantly, the number of species and individuals were consistently greater during the morning counts, which corroborates the fact that birds can be more detectable during this time of day. However, a few families as well as a small percentage of species were more likely to be recorded during either one of the two periods we analyzed. Our results suggest that morning counts should detect higher number of both species and individuals in our study area, but specific taxa show distinct patterns of detection which should be acknowledged prior to sampling.
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The absorption edge and the bandgap transition of sol-gel-dip-coating SnO2 thin films, deposited on quartz substrates, are evaluated from optical absorption data and temperature dependent photoconductivity spectra. Structural properties of these films help the interpretation of bandgap transition nature, since the obtained nanosized dimensions of crystallites are determinant on dominant growth direction and, thus, absorption energy. Electronic properties of the bulk and (110) and (101) surfaces are also presented, calculated by means of density functional theory applied to periodic calculations at B3LYP hybrid functional level. Experimentally obtained absorption edge is compared to the calculated energy band diagrams of bulk and (110) and (101) surfaces. The overall calculated electronic properties in conjunction with structural and electro-optical experimental data suggest that the nature of the bandgap transition is related to a combined effect of bulk and (101) surface, which presents direct bandgap transition.