7 research outputs found

    A História da Alimentação: balizas historiográficas

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    Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

    Personalized 3D-printed anthropomorphic phantoms for dosimetry in charged particle fields

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    Anthropomorphic phantoms used for radiation dose measurements are designed to mimic human tissue in shape, size, and tissue composition. Reference phantoms are widely available and are sufficiently similar to many, but not all, human subjects. 3D printing has the potential to overcome some of these shortcomings by enabling rapid fabrication of personalized phantoms for individual human subjects based on radiographic imaging data. Objective. The objective of this study was to test the efficacy of personalized 3D printed phantoms for charged particle therapy. To accomplish this, we measured dose distributions from 6 to 20 MeV electron beams, incident on printed and molded slices of phantoms. Approach. Specifically, we determined the radiological properties of 3D printed phantoms, including beam penetration range. Additionally, we designed and printed a personalized head phantom to compare results obtained with a commercial, reference head phantom for quality assurance of therapeutic electron beam dose calculations. Main Results. For regions of soft tissue, gamma index analyses revealed a 3D printed slice was able to adequately model the same electron beam penetration ranges as the molded reference slice. The printed, personalized phantom provided superior dosimetric accuracy compared to the molded reference phantom for electron beam dose calculations at all electron beam energies. However, current limitations in the ability to print high-density structures, such as bone, limited pass rates of 60% or better at 16 and 20 MeV electron beam energies. Significance. This study showed that creating personalized phantoms using 3D printing techniques is a feasible way to substantially improve the accuracy of dose measurements of therapeutic electron beams, but further improvements in printing techniques are necessary in order to increase the printable density in phantoms
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