981 resultados para Statique-99


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In vivo determination of the incorporated activity of Tc-99(m)-MDP (methylene diphosphonate) in bone tissue by means of a scintillation camera requires calibration of the device. This can be carried out by using an anthropomorphic physical phantom. In this work, a new human tibia and fibula phantom is presented to estimate incorporated activity to bone tissue. A tibia and a fibula, taken from a real skeleton, were used to develop the phantom. Images were acquired of the legs of 65 volunteers at different times of incorporation (minimum of 120 and maximum of 2500 min after injection) and count rates of such a region were obtained by means of a computer program. The calibration factor obtained was then used to assess the activity in the two bents. The final result is 0.4995 kBq per cpm for technetium. The proposed method can be used both for radiation protection purposes and for metabolism studies.

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The sun mushroom is the popular name for the Agaricus blazei Murill fungus, a mushroom native to south-eastern Brazil, which has been frequently used in popular medicine mainly in the form of tea to treat various ailments (stress, diabetes, etc.). In the present study, the genotoxic and/or anti-genotoxic effects ofA. blazei on mammalian cells in culture was assessed by checking the increase or reduction of micronucleus (MN) frequency and comets. The sun mushroom (lineage 99/26) was used as aqueous extracts prepared (2.5%) at three different temperatures (60, 25 and 4°C). The in vitro micronucleus (MN) test in binucleated cells and comet assay were used in V79 cells cultivated in HAM-F10+DMEM medium (1:1), supplemented with 10% of fetal bovine serum. The experiments were divided into four treatment types: 1. Negative control; 2. Positive control with MMS; 3. Treatments with the three forms of extracts (60, 25 and 4°C); and 4. Treatments with the extracts in different associations (simultaneous, pre-treatment, post-treatment and simultaneous after pre-incubation for 1 h) with MMS. None of the A. blazei extracts show genotoxic activity. In the comet assay no protecting effect was found. The results obtained in the MN test showed that the three forms of extracts used had protective activity, suggesting that the compound or active ingredients of A. blazei are always present in these extracts. The greater protective efficiency of the simultaneous treatment and simultaneous treatment with pre-incubation mixture with MMS suggests that the extracts have an antimutagenic action of the desmutagenic type. © 2002 Elsevier Science Ltd. All rights reserved.

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Includes bibliography

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La edición número 99 de la revista Notas de Población destaca por la variedad de temas que se presentan en los seis artículos incluidos. En ellos se abordan cuestiones de relevancia para la investigación sociodemográfica en América Latina y el Caribe, que van desde las tendencias familiares y la edad en la primera unión y el primer hijo, hasta la migración de retorno, pasando por la información sobre las personas con discapacidad, los asentamientos precarios y las percepciones ambientales en áreas metropolitanas, entre otros.

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O texto da Lei 9.795/99, que institui a educação ambiental e estabelece a Política Nacional de Educação Ambiental é uma resposta do Estado brasileiro aos anseios das comunidades tradicionais, que dependem diretamente dos recursos naturais, tais como indígenas, ribeirinhos e quilombolas. Este trabalho teve como objetivo central a identificação nessa Lei de interesses outros, que não só permeiam o texto como são mesmo predominantes. Para tanto, foi necessário analisar o texto da Lei como o ambiente propício para o conflito de interesses, aqui identificados como ideológicos e como esses interesses se manifestam na forma discursiva. A Lei foi estudada na particularidade de cada artigo a fim de detectar, em cada um, as escolhas linguísticas, a situação concreta de enunciação configurada e o discurso ideológico predominante. Houve preferência por formas nominais, aquelas com maior carga semântico-conceitual, inclusive em formas derivadas de processos verbais. Houve muita variedade na configuração da situação enunciativa, com predomínio do caráter imperativo, como em determinações e atribuições. No plano ideológico, propriamente dito, predominou o discurso conservador, vinculado ideologicamente aos interesses da classe dominante. Outro discurso bastante sentido no texto foi o reformista, próprio dos grupos mediadores dos conflitos entre dominantes e dominados. Uma vez que a Lei atende pouco ou nada aos interesses daqueles mais a aguardavam, conclui-se que a classe dominante consegue absorver as demandas sociais, mas transformando-as para seu próprio benefício. E visto que, por seus interesses serem postos na forma de lei, adquirem caráter universal e, como tal, é imposto para todos, como se fossem de todos, embora representem, de fato, apenas os interesses de alguns.

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This paper proposes some reflections from activities developped in the context of a research supported by FAPESP called “As políticas de educação profissional e tecnológica no Brasil pós LDB 9394/96”. Our purpose is to analyze the federal legislation of professional and technological education, by enphasizing its impacts in technical schools of São Paulo (Brazil).

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The nature of the dark matter in the Universe is one of the greatest mysteries in modern astronomy. The neutralino is a nonbaryonic dark matter candidate in minimal supersymmetric extensions to the standard model of particle physics. If the dark matter halo of our galaxy is made up of neutralinos some would become gravitationally trapped inside massive bodies like the Earth. Their pair-wise annihilation produces neutrinos that can be detected by neutrino experiments looking in the direction of the centre of the Earth. The AMANDA neutrino telescope, currently the largest in the world, consists of an array of light detectors buried deep in the Antarctic glacier at the geographical South Pole. The extremely transparent ice acts as a Cherenkov medium for muons passing the array and using the timing information of detected photons it is possible to reconstruct the muon direction. A search has been performed for nearly vertically upgoing neutrino induced muons with AMANDA-B10 data taken over the three year period 1997-99. No excess above the atmospheric neutrino background expectation was found. Upper limits at the 90 % confidence level has been set on the annihilation rate of neutralinos at the centre of the Earth and on the muon flux induced by neutrinos created by the annihilation products.

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