4,932 research outputs found

    Especiação redox de cromo em solo acidentalmente contaminado com solução sulfocrômica.

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    Determination of Cr(VI) and Cr(III) was studied in soil samples accidentally contaminated with sulphochromic solution. Molecular absorption spectrophotometry based on the diphenylcarbazide method was used for the determination of Cr(VI) after its alkaline extraction. The total chromium concentration was determined using ICP OES. The quantification of Cr(III) was accomplished by subtracting the Cr(VI) concentration from the total chromium concentration. Regardless of the known contamination of the soil samples by sulphochromic solution, concentrations of Cr(VI) were below the detection limit. Addition and recovery experiments for Cr(VI) in soil samples with and without organic matter indicated its influence on the reduction of Cr(VI) to Cr(III)

    Edge phonons in black phosphorus

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    Exfoliated black phosphorus has recently emerged as a new two-dimensional crystal that, due to its peculiar and anisotropic crystalline and electronic band structures, may have potentially important applications in electronics, optoelectronics and photonics. Despite the fact that the edges of layered crystals host a range of singular properties whose characterization and exploitation are of utmost importance for device development, the edges of black phosphorus remain poorly characterized. In this work, the atomic structure and the behavior of phonons near different black phosphorus edges are experimentally and theoretically studied using Raman spectroscopy and density functional theory calculations. Polarized Raman results show the appearance of new modes at the edges of the sample, and their spectra depend on the atomic structure of the edges (zigzag or armchair). Theoretical simulations confirm that the new modes are due to edge phonon states that are forbidden in the bulk, and originated from the lattice termination rearrangements.Comment: 15 pages, 4 figure

    Levantamento de espécies frutíferas em área de várzea do Município de Parintins - Amazonas.

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    Este trabalho buscou identificar as espécies frutíferas que são encontradas nos quintais florestais em áreas de várzeas e descrever a sua importância e a sua utilização pelos ribeirinhos e agricultores do município de Parintins ? AM

    Ground-state proton decay of 69Br and implications for the rp-process 68Se waiting-point

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    The first direct measurement of the proton separation energy, Sp, for the proton-unbound nucleus 69Br is reported. Of interest is the exponential dependence of the 2p-capture rate on Sp which can bypass the 68Se waiting-point in the astrophysical rp process. An analysis of the observed proton decay spectrum is given in terms of the 69Se mirror nucleus and the influence of Sp is explored within the context of a single-zone X-ray burst model.Comment: 6 pages, 6 figures, INPC 2010 conference proceeding

    Banco ativo de germoplasma de abacaxi.

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    Centro de origem; Classificação botânica; Manejo de germoplasma; Coleta e introdução/intercâmbio; Quarentena; Conservação; Caracterização; Avaliação.bitstream/CNPMF/23162/1/documento_146.pd

    A SURVEY of CHRONIC GVHD and OTHER OUTCOMES - A SNAPSHOT of BRAZILIAN ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANTATION (HCT) CENTERS

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    Univ Fed Parana, BR-80060000 Curitiba, Parana, BrazilNatl Canc Inst, Rio de Janeiro, BrazilState Univ São Paulo, São Paulo, BrazilUniv Estadual Campinas, Campina, BrazilUniv Fed Rio de Janeiro, Rio de Janeiro, BrazilAmaral Carvalho Hosp, Jau, BrazilAmaral Carvalho Hosp, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilAlbert Einstein Hosp, São Paulo, BrazilCanc Hosp Barretos, São Paulo, BrazilUniv Fed Rio Grande do Sul, Porto Alegre, RS, BrazilPernambuco Blood Bank, Recife, PE, BrazilUniv Fed Minas Gerais, Belo Horizonte, MG, BrazilUniv State Univ São Paulo, Ribeirao Preto, BrazilFred Hutchinson Canc Res Ctr, Seattle, WA 98104 USAUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

    Maturation and fertilisation of sheep oocytes cultured in serum-free medium containing silk protein sericin

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    Sericin is a water-soluble component of silk and has been used as a biomaterial due to its antibacterial and ultraviolet radiation-resistant properties. This study was designed to evaluate the effect of sericin supplementation in a maturation medium on the meiotic competence and fertilisability of sheep oocytes. Cumulus-oocyte complexes (COCs) were cultured in TCM199 supplemented with sericin at various concentrations of 0 (control), 0.1, 0.25 and 0.5%, either with or without bovine serum albumin (BSA). When the COCs were matured without BSA, the supplementation of 0.1% sericin significantly increased the rates of maturation to metaphase II and the total fertilisation of oocytes compared with the other concentrations of sericin. When the COCs were matured with BSA, the beneficial effects of 0.1% sericin supplementation on the maturation and fertilisation of oocytes were not observed. Our findings indicate that supplementation with 0.1% sericin during maturation culture may improve the nuclear maturation and fertilisability of sheep oocytes. Moreover, it may be possible to replace BSA with sericin in chemically defined media without the risk of disease transmission

    A cultura do abacaxi: práticas de cultivo.

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    O trabalho aborda a escolha e preparo do solo mais apropriados para o abacaxizeiro, bem como o conjunto de técnicas de cultivos recomendadas para exploração comercial da cultura, incluindo o controle das principais pragas e doenças, as variedades mais cultivadas e o manejo adequado das mudas. Finalmente, faz-se referências a consorciação de culturas, ao rendimento, colheita e comercialização das primeiras e segunda safras.bitstream/item/81615/1/A-cultura-do-abacaxi-Getulio-Cunha-Cicular-tecnica-1-1993.pdf5. e
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