67 research outputs found

    Solos.

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    Amostragem; Critérios para a divisão da área de amostragem; Numero de amostras simples ou subamostras; Profundidade de coleta de subamostras; Composição da amostra; Material para a amostragem; época, freqüência e algumas recomendações gerais para amostragem; Acondicionamento e identificação da amostra; Registro e preparo da amostra; Secagem; Moagem, peneiragem e armazenagem

    Tecidos vegetais.

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    Amostragem; Procedimento para coleta de amostras de folhas no campo; Coleta da amostra; Identificacao da amostra; Moagem; Armazenagem; Integridade da amostra; Problemas de contaminacao; Arquivo de amostra

    Água.

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    Quando, onde e como amostrar; Acondicionamento de amostras: tipos e procedimentos de limpeza; Preservação das amostras

    Purification and Crystal Growth of the Bismuth (III) Iodide-influence of Trace Impurities on the Crystal Quality

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    This work describes the experimental procedure of purification and preparation of BiI3 crystals by Repeated Vertical Bridgman technique, aiming a future application of this semiconductor crystal as a room temperature radiation detector. The BiI3 powder used as raw material was purified three times and, at each purification, the crystal was evaluated by systematic measurements of the reduction of the impurities, crystalline structure, stoichiometry and surface morphology. The reduction of the trace metal impurities in the BiI3, at each purification, was analyzed by Instrumental Neutron Activation Analysis (INAA), in order to evaluate the efficiency of the purification technique established in this work. It was demonstrated that the Repeated Bridgman technique is effective to reduce the concentration of many impurities in BiI3, such as Ag, As, Br, Cr, K, Mo, Na and Sb. The crystalline structure of the BiI3 crystal purified twice and three times was similar to BiI3 pattern. However, for BiI3 powder and purified once, an intensity contribution of the BiOI was observed in the diffractograms. Improvement in the stoichiometric ratio was observed at each purification step, as well as the crystal surface morphology

    Common Promoter Elements in Odorant and Vomeronasal Receptor Genes

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    In mammals, odorants and pheromones are detected by hundreds of odorant receptors (ORs) and vomeronasal receptors (V1Rs and V2Rs) expressed by sensory neurons that are respectively located in the main olfactory epithelium and in the vomeronasal organ. Even though these two olfactory systems are functionally and anatomically separate, their sensory neurons show a common mechanism of receptor gene regulation: each neuron expresses a single receptor gene from a single allele. The mechanisms underlying OR and VR gene expression remain unclear. Here we investigated if OR and V1R genes share common sequences in their promoter regions

    Targeting cancer cell death with a bcl-x S adenovirus

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    Transformation is a complex cellular process that requires several genetic abnormalities. In many cases, one of these abnormalities is an inhibition of PCD, which provides a selective advantage for tumor cells. This has been recently shown in an in vivo model, where overexpression of Bcl-x L is a crucial step in the progression from hyperplasia to neoplasia and is accompanied by a significant decrease in tumor apoptosis [56].Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46936/1/281_2004_Article_BF00787225.pd
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