649 resultados para Alvos Codificados


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Pós-graduação em Biologia Geral e Aplicada - IBB

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A protonterapia é um tipo de tratamento promissor quanto a diminuição de dose nos tecidos adjacentes ao tumor, devido às suas característica de deposição de energia ao interagir com a matéria. Para aumentar a acurácia do tratamento é necessário que as simulações sejam feitas a partir de um sistema de formação de imagem que utilize também um feixe de prótons, como a tomografia por feixe de prótons (pCT). Essa área atualmente está em desenvolvimento e se defronta com inúmeros problemas na formação de uma imagem precisa. Este trabalho tem o intuito de analisar a viabilidade de simulações computacionais para este tipo de feixe. O código computacional SRIM é um conjunto de programas que calcula o freamento e o alcance de íons ao interagir com a matéria. Esse cálculo baseia-se em ferramentas oriundas da mecânica quântica e também no método de Monte Carlo, para determinar, de modo probabilístico, trajetórias, colisões e ângulos. Foram realizadas simulações no programa SRIM para um alvo heterogêneo envolvendo água e osso cortical. Para analisar o comportamento do feixe transmitido, foram feitas alterações na posição e no tamanho da heterogeneidade. A partir dos dados obtidos pode-se obter valores médios, histogramas e gaussianas dos mesmos para cada simulação e tirar conclusões sobre a viabilidade e as dependências desse tipo de simulação

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Main occurrence of Cu-Au in Goias Magmatic Arc, the Chapada mine fits into the geological context of the Brasilia Fold Belt, specifically in the Mara Rosa Magmatic Arc. Four targets, named Hidrotermalito Norte and Sul, NW Chapada Mine Portion and Suruca, are situated in this context, which includes ortogneisses and rocks from the Mara Rosa volcanic-sedimentary sequence. All these targets have been studied due to the possibility of presenting a great potential in Cu-Au, as well as the Chapada mine. Hidrotermalitos Norte and Sul targets presents four lithological sequences, which were identified as: quartz-muscovite schist; muscovite quartzites and kyanite quartzites; quartz-biotite-amphibole schist with pyrite and epidote-amphibole-biotite gneisses with muscovite; muscovite-biotite gneisses. They are metamorphosed to amphibolites facies and retrogressive greenschist facies. Sulfetation represented mainly by pyrite. In the NW Chapada Mine Portion, three main lithological groups were identified and classified as biotite gneisses; honblende-quartz-biotite-schist; amphibolites, with the first group metamorphosed in greenschist facies (low grade), and the other two groups metamorphosed in amphibolites facies, with subsequent retrogressive metamorphism in greenschist facies. Sulfetation is represented by chalcopyrite and pyrite. Finally, also three main lithological groups were identified in the Suruca target, classified as garnet-chlorite-epidote-eiotite gneiss; biotite gneiss and chlorite-biotite gneiss with epidote and muscovite; muscovite-quartz schist, all them metamorphised in amphibolites, with retrometamorphism in greenschist facies. Sulfetation represented by pyrite and sphalerite

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Due the differences between interaction physics process with matter for protons and photons, the proton beam tomography (pCT) has some vantages to comparison with conventional tomography. Also it is confirmed that usually pCT has better dose distribution and highest contrast resolution. The pCT allow not only view the internal structure of an object without destroying it, but also directly measure of volume density of electrons. Also it is confirmed that usually pCT has better dose distribution and highest contrast resolution. At the same time, there are many scientific and technical aspects to a detailed study: the capacity and limitations of the pCT methods are not well clarified. Through computations, based on Monte Carlo Method was carried out a detailed study of the contribution of non-elastic nuclear spreading, and together was compared with an analytical model for the deflection angle and the lateral deflection of protons in the target volume. The programs used were SRIM 2006 code and MCNPX v.2.50 code

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In order to to research, the region of Perau, base metal mineralization, Grupo Votorantim Metals conducted a soil sampling on targets predetermined holding its chemical analysis. These reviews have been provided by the company for this work was to evaluate the potential use of these data pedogeochemical multi-element for refinement of the work of geological mapping. We selected six targets: Varginha, Salvador, Guararema Taquara Lisa and Coffin of Mendes, in the municipalities of Adrianople, Cerro Azul and Tunas do Paraná, located in Vale do Ribeira (PR). Both have about 10 km2 and situated in the geological context of the Fold Belt Terrane and the Massif de Joinville. The main rock types are present metasedimentary rocks of low to medium grade metamorphic, interspersed the amphibolites ortoderivados, both belonging to the Complex Perau, gneisses and migmatitic Complex. Applied to the geochemical data descriptive statistical techniques (variogram, kriging and histogram). From the correlation between the distributions of elements with the geological data, we could assess the potential of the proposed methodology.

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The study area is located in the geological context of the northern portion of the Rio Itapicuru Greenstone Belt (GBRI), located northeast of the São Francisco Craton, Bahia State. The GBRI is known for its great economic potential for gold mineralization, looking south at Fazenda Brasileiro Mine and North Mine Maria Preta, is situated in the study área. The structural pattern of the northern portion of the Greenstone, theme of this work, is of great importance to understand the mineralization present. To characterize the structural model three geologic sections (scale 1:25000) were made with NW-SE and EW directions and detailing two mineralized targets, Encantado, located northwest of the area, near the city of Nordestina, and C1W, located near Itapicuru River, west of the Maria Preta mine. Thus, field work and petrographic analysis were conducted, that allow to indicate the existence of two structural domains characterized by the existence of a main foliation, low angle dipping main foliation and another with high dip angle, both with NW, moreover, folds occur in the area Dn-1 and post-Dn folds. Dn-1 folds are observed less frequently but they occur mainly forming an oblique foliation and the Sn is present in porphyroblasts observed in petrographic analysis, whereas in relation to the folds post Dn, there are more than one type of folding in area, which differ by the orientation of their axis, a post Dn NS and EW Dn another post. Moreover, two areas of metamorphic green schist (biotite zone) and medium amphibolite, which are directly related to the structural domains found

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In the recent years, the use of proton beams in radiotherapy has been an outstanding progress (SMITH, 2006). Up to now, computed tomography (CT) is a prerequisite for treatment planning in this kind of therapy because it provides the electron density distribution required for calculation of dose and the interval of doses. However, the use of CT images for proton treatment planning ignores fundamental differences in physical interaction processes between photons and protons and is, therefore, potentially inaccurate (SADROZINSKI, 2004). Proton CT (pCT) can in principle directly measure the density distribution needed in a patient for the dose distribution (SCHULTE, et al, 2004). One important problem that should be solved is the implementation of image reconstruction algorithms. In this sense, it is necessary to know how the presence of materials with different density and composition interfere in the energy deposition by ionization and coulomb excitation, during its trajectory. The study was conducted in two stages, was used in both the program SRIM (The Stopping and Range of Ions in Matter) to perform simulations of the interaction of proton beams with pencil beam type. In the first step we used the energies in the range of 100-250 MeV (ZIEGLER, 1999). The targets were set to 50 mm in length for the beam of 100 MeV, due to its interaction with the target, and short-range, and 70 mm for 150, 200 and 250 MeV The target was composed of liquid water and a layer of 6 mm cortical bone (ICRP). It were made 9 simulations varying the position of the heterogeneity of 5 mm. In the second step the energy of 250 MeV was taken out from the simulations, due to its greater energy and less interaction. The targets were diminished to 50 mm thick to standardize the simulations. The layer of bone was divided into two equal parts and both were put in the ends of the target... (Complete abstract click electronic access below)

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A quimioterapia e uma das formas de tratamentos para o câncer, cujo processo e pela aplicação de medicamentos que alteram a síntese de DNA, interrompendo a divisão celular. No caso do câncer de pulmão, a difículdade está no fato de que as células cancerígenas criam quimiorresistência após um determinado período de tempo. Se o indivíduo desenvolver o câncer de pulmão novamente, deverá ser aplicado outro quimioterápico no paciente, e assim por diante. Nos tratamentos atuais são utilizados combinações de drogas para contornar o problema da quimiorresistência. Este trabalho utilizou a biologia de sistemas para encontrar novos alvos protéicos para auxiliar no desenvolvimento de novos quimioterápicos para o tratamento do câncer de pulmão. Foi construída uma rede baseada nos alvos protéicos já conhecidos. A rede foi expandida com o intuito de buscar quais são as proteínas que interagem com os alvos protéicos á conhecidos. Após a expansão, foram utilizadas análises de centralidades para evidenciar as proteínas mais importantes na rede, e correlacionamos com informação de expressão gênica para verificar se as proteínas mais importantes do ponto de vista topológico estão diferencialmente sub ou super expressas. A análise de centralidade junto a mostra dos dados de expressão gênica convergiu para um bom resultado, foi possível evidenciar algumas proteínas que podem ser utilizadas como novos alvos quimioterápicos

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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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Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

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The aim of this study was to evaluate the quality of spray droplet spectrum on coffee tree, by using different equipments and syrup volumes. The experiment was set up in a coffee farm, Acaiá variety, Campos Gerais city, MG, Brazil. The treatments were three syrup volumes (150, 300 and 600 L/ha). The lower volume was sprayed with the pneumatic sprayer Martignani, Whirlwind B612 Autonom-Trac mode, and the other volume rates using the conventional hydraulic sprayer to coffee tree. It was possible concludes that the spray volume can be reduced in applications on coffee tree using the pneumatic sprayer.