28 resultados para partitions

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Citrus aurantium L. is commonly used as an alternative treatment for insomnia, anxiety and epilepsy. Essential oil from peel (EOP) and hydroethanolic (70% w/v) extract (HE) from leaves were obtained. Hexanic (HF), dichloromethanic (DF) and final aqueous (AF) fractions were obtained from HE by successive partitions. Swiss male mice (35-45 g) were treated orally with 0.5 or 1.0 g/kg of these preparations 30 min before the experiments for the evaluation of the sedative/hypnotic activity (sleeping time induced by sodium pentobarbital-SPB: 40 mg/kg, i.p.), anxiolytic activity (elevated plus maze-EPM) and anticonvulsant activity (induced by pentylenetetrazole-PTZ: 85 mg/kg, se or by maximal electroshock-MES: 50 mA, 0.11s, corneal). The results showed that EOP (0.5 g/kg) increased the latency period of tonic seizures in both convulsing experimental models. This effect was not dose-dependent. Treatment with 1.0 g/kg increased the sleeping time induced by barbiturates and the time spent in the open arms of the EPM. Specific tests indicated that the preparation, in both doses used, did not promote deficits in general activity or motor coordination. HF and DF fractions (1.0 g/kg) did not interfere in the epileptic seizures, but were able to enhance the sleeping time induced by barbiturates. The results obtained with EOP in the anxiety model, and with EOP, HF and DF in the sedation model, are in accord with the ethnopharmacological use of Citrus aurantium L., which could be useful in primary medical care, after toxicological investigation.

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The partitioning of Green Fluorescent Protein (GFP) in poly(ethylene glycol)/Na-poly(acrylate) aqueous two-phase systems (PEG/NaPA-ATPS) has been investigated. The aqueous two-phase systems are formed by mixing the polymers with a salt and a protein solution. The protein partitioning in the two-phase system was investigated at 25 degrees C. The concentration of the GFP was measured by fluorimetry. It was found that the partitioning of GFP depends on the salt type, pH and concentration of PEG. The data indicates that GFP partitions more strongly to the PEG phase in presence of Na2SO4 relative to NaCl. Furthermore, the GFP partitions more to the PEG phase at higher pH. The partition to the PEG phase is strongly favoured in systems with larger tie-line lengths (i.e. systems with higher polymer concentrations). The molecular weight of PEG is important since the partition coefficient (K) of GFP gradually decreases with increasing PEG size, from K ca. 300-400 for PEG 400 to K equal to 1.19 for PEG 8000. A separation process was developed where GFP was separated from a homogenate in two extraction steps: the GFP is first partitioned to the PEG phase in a PEG 3000/NaPA 8000 system containing 3 wt% Na2SO4, where the K value of GFP was 8. The GFP is then re-extracted to a salt phase formed by mixing the previous top-phase with a Na2SO4 solution. The K-value of GFP in this back-extraction was 0.22. The total recovery based on the start material was 74%. (c) 2008 Elsevier B.V. All rights reserved.

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The partition of hemoglobin, lysozyme and glucose-6-phospate dehydrogenase (G6PDH) in a novel inexpensive aqueous two-phase system (ATPS) composed by poly(ethylene glycol) (PEG) and sodium polyacrylate (NaPA) has been studied. The effect of NaCl and Na2SO4, pH and PEG molecular size on the partitioning has been studied. At high pH (above 9), hemoglobin partitions strongly to the PEG-phase. Although some precipitation of hemoglobin occurs, high recovery values are obtained particularly for lysozyme and G6PDH. The partitioning forces are dominated by the hydrophobic and electrochemical (salt) effects, since the positively charged lysozyme and negatively charged G6PDH partitions to the non-charged PEG and the strongly negatively charged polyacrylate enriched phase, respectively. (c) 2007 Elsevier B.V. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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A análise de crescimento de plantas pode ser considerada um bom indicativo para a avaliação das bases fisiológicas de produção e da influência exercida por variáveis ambientais, genéticas e agronômicas. Avaliou-se o crescimento da figueira 'Roxo de Valinhos', submetida a irrigação e cobertura morta (bagacilho de cana-de-açúcar triturado), em Botucatu (SP). O experimento utilizou blocos casualizados, em esquema fatorial 2x2 (cobertura morta x irrigação), com 4 repetições, sendo cada repetição constituída por 3 plantas, com caracterização dos seguintes tratamentos: T1 - sem irrigação e sem cobertura morta; T2 - sem irrigação e com cobertura morta; T3 - com irrigação e sem cobertura morta; T4 - com irrigação e cobertura morta. Foram realizadas análises destrutivas e não destrutivas, aos 7, 55, 76, 97, 114, 135, 156, 176, 198, 219, 240, 254 e 275 dias após o transplantio, com base nos seguintes parâmetros: diâmetro do ramo e do caule, comprimento do ramo, número de folhas, número de entrenós e número de frutos. Foram particionados os diferentes órgãos da planta, para obtenção da massa seca e fresca das partições isoladas. As medições da área foliar (cm²) foram realizadas com aparelho integrador fotoelétrico. O manejo da irrigação foi realizado com o auxílio da técnica de tensiometria, mantendo o potencial matricial do solo próximo a -30 kPa. O uso de cobertura morta e irrigação favoreceu o desenvolvimento das plantas (diâmetro do caule de 36,60 mm e comprimento do ramo de 1,28 m), e as taxas de crescimento, crescimento relativo e assimilatória líquida da cultura foram de 7 g m-2 dia-1, 0,015 g g-1 dia-1 e 17 g m-2 dia-1, respectivamente. As taxas indicaram que a cobertura morta ofereceu condições hídricas satisfatórias ao rápido estabelecimento das mudas.

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No presente trabalho, mostram-se equações de estimativa da irradiação solar global (R G), por meio do modelo de Angstrom, com partições sazonal e mensal para a região de Cascavel - PR. Os dados experimentais foram cedidos pelo IAPAR, coletados na sua estação meteorológica localizada na COODETEC/Cascavel - PR, no período de 1983 a 1998. Dos 16 anos de dados, 12 anos foram utilizados para cálculo dos coeficientes (a e b) e quatro anos para a validação das equações. Os coeficientes de determinação encontrados foram superiores a 80% para as duas partições. O mínimo da R G é superestimado e o máximo é subestimado quando comparados com o mínimo e o máximo para dados reais, sendo esses encontrados no solstício de inverno e equinócio de primavera, respectivamente. A variação sazonal e mensal do coeficiente a foi menor (0,16 a 0,19 e 0,14 a 0,21) e do coeficiente b maior (0,34 a 0,43 e 0,32 a 0,44). As maiores variações dos erros médios diários ocorreram no equinócio de primavera (-19,45% a 27,28%) e as menores no equinócio de outono (-11,32% a 10,61%). O ajuste mais eficaz das equações foi encontrado para a partição mensal.

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This paper introduces the concept of special subsets when applied to generator matrices based on lattices and cosets as presented by Calder-bank and Sloane. By using the special subsets we propose a non exhaustive code search for optimum codes. Although non exhaustive, the search always results in optimum codes for given (k1, V, Λ/Λ′). Tables with binary and ternary optimum codes to partitions of lattices with 8, 9 e 16 cosets, were obtained.

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We present a non-linear symplectic map that describes the alterations of the magnetic field lines inside the tokamak plasma due to the presence of a robust torus (RT) at the plasma edge. This RT prevents the magnetic field lines from reaching the tokamak wall and reduces, in its vicinity, the islands and invariant curve destruction due to resonant perturbations. The map describes the equilibrium magnetic field lines perturbed by resonances created by ergodic magnetic limiters (EMLs). We present the results obtained for twist and non-twist mappings derived for monotonic and non-monotonic plasma current density radial profiles, respectively. Our results indicate that the RT implementation would decrease the field line transport at the tokamak plasma edge. © 2010 Elsevier B.V. All rights reserved.

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This work presents an application of a Boundary Element Method (BEM) formulation for anisotropic body analysis using isotropic fundamental solution. The anisotropy is considered by expressing a residual elastic tensor as the difference of the anisotropic and isotropic elastic tensors. Internal variables and cell discretization of the domain are considered. Masonry is a composite material consisting of bricks (masonry units), mortar and the bond between them and it is necessary to take account of anisotropy in this type of structure. The paper presents the formulation, the elastic tensor of the anisotropic medium properties and the algebraic procedure. Two examples are shown to validate the formulation and good agreement was obtained when comparing analytical and numerical results. Two further examples in which masonry walls were simulated, are used to demonstrate that the presented formulation shows close agreement between BE numerical results and different Finite Element (FE) models. © 2012 Elsevier Ltd.

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The crude ethanolic extract from aerial parts of Pothomorphe umbellata L. (Piperaceae) and fractions obtained by partitions sequentially among water-methanol, methylene chloride, and ethyl acetate, as well as the major constituent, 4-nerolidylcatechol, were, respectively, evaluated and evidenced for antioxidant and cytotoxic effects through fluorometric microplate and microculture tetrazolium assays in HL-60 cells. The crude ethanolic extract demonstrated the preeminent antioxidant activity (IC50 = 1.2 μg/mL) against exogenous cytoplasmic reactive oxygen species, followed by the water-methanolic (IC50 = 4.5 μg/mL), methylene chloride (IC 50 = 5.9 g/mL), ethyl acetate (IC50 = 8.0 g/mL), 4-nerolidylcatechol (IC50 = 8.6 g/mL), and the sterol fractions (IC50 > 12.5 μg/mL). Vitamin C, the positive control used in this assay, presented IC50 value equivalent to 1.7 μg/mL. 4-Nerolidylcatechol (IC50 = 0.4 μg/mL) and methylene chloride fraction (IC50 = 2.3 μg/mL) presented considerable cytotoxicity probably because of the presence of an o-quinone, an auto-oxidation by product of the catechol. Polar compounds, present in the ethanol extract, appear to increase the solubility and stability of the major active constituent, acting synergistically with 4-nerolidylcatechol, improving its pharmacokinetic parameters and increasing significantly its antioxidant activity which, in turn, suggests that the aqueous-ethanolic extract, used in folklore medicine, is safe and effective. © 2013 Andrey P. Lopes et al.

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In this paper, we present a measure of quantum correlation for a multipartite system, defined as the sum of the correlations for all possible partitions. Our measure can be defined for quantum discord (QD), geometric quantum discord or even for entanglement of formation (EOF). For tripartite pure states, we show that the multipartite measures for the QD and the EOF are equivalent, which allows direct comparison of the distribution and the robustness of these correlations in open quantum systems. We study dissipative dynamics for two distinct families of entanglement: a W state and a GHZ state. We show that, for the W state, the QD is more robust than the entanglement, while for the GHZ state, this is not true. It turns out that the initial genuine multipartite entanglement present in the GHZ state makes the EOF more robust than the QD. © IOP Publishing and Deutsche Physikalische Gesellschaft.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)