Characterization of thermoplastic starch/poly(lactic acid) blends obtained by extrusion and thermopressing

Blends of poly(lactic acid) (PLA)/thermoplastic starch (TPS) were prepared by extrusion and thermopressing, with proportions of 0.1, 0.2 and 0.3 g of PLA per g TPS. Thermoplastic starch was obtained from the extrusion of 0.30 g or 0.25 g of glycerol per g of starch. The mechanical properties and water vapor permeability were tested and water sorption isotherms were obtained. The morphological characteristics of the samples were observed through scanning electron microscopy (SEM) and the thermal properties of the pure polymers and the blends by differential scanning calorimetry (DSC). The SEM and DSC results indicated the immiscibility of the TPS/PLA blends and the presence of two phases. For blends with 20% and 30% of PLA increases in the tensile strength and modulus were observed. The lowest water vapor permeability was observed for the blend with 30% of PLA, which is related to the lowest diffusion coefficient value observed for this sample

Controle de plantas daninhas na cultura do milho utilizando leucena (Leucaena leucocephala (Lam.) de wit).

Avaliou-se o efeito da parte aérea da leucena, em condiçoes de casa de vegetação e campo, sobre o desenvolvimento de plantas daninhas, fitotoxicidade para o milho e acréscimo de nitrogênio para a cultura. Em casa de vegetação (vasos) foram avaliadas 25 t ha-1 da parte aérea da leucena incorporada e colocada em cobertura. Após a distribuição da leucena nos vasos, seguiu-se o plantio do milho, 5, 10, 20 e 40 dias. Em condições de campo, foram avaliados 20, 30 e 40 t ha-1 de matéria verde em cobertura e incorporada. A leucena, em casa de vegetação, inibiu o desenvolvimento das plantas daninhas, não apresentando fitotoxicidade para o milho. Em condições de campo, 40 t ha-1 de leucena em cobertura controlaram o desenvolvimento das plantas daninhas sem prejudicar o rendimento de grãos de milho

Generalized Hermite-Gauss decomposition of the two-photon state produced by spontaneous parametric down-conversion

We provide a general decomposition of the two-photon state produced by spontaneous parametric down-conversion in Hermite-Gaussian modes, in the case that the pump beam is described by a Hermite-Gaussian beam of any order. We show that the spatial correlations depend explicitly on the order of the pump beam, as well as other experimental parameters. We use the decomposition to demonstrate a few interesting cases. Our results are applicable to the engineering of two-photon spatial entanglement, in particular for non-Gaussian states.Comment: 14 page draft, 5 figure

HIF-1 alpha-independent hypoxia-induced rapid PTK6 stabilization is associated with increased motility and invasion

© 2014 Landes Bioscience. PTK6/Brk is a non-receptor tyrosine kinase overexpressed in cancer. Here we demonstrate that cytosolic PTK6 is rapidly and robustly induced in response to hypoxic conditions in a HIF-1-independent manner. Furthermore, a proportion of hypoxic PTK6 subsequently re-localized to the cell membrane. We observed that the rapid stabilization of PTK6 is associated with a decrease in PTK6 ubiquitylation and we have identified c-Cbl as a putative PTK6 E3 ligase in normoxia. The consequences of hypoxia-induced PTK6 stabilization and subcellular re-localization to the plasma membrane include increased cell motility and invasion, suggesting PTK6 targeting as a therapeutic approach to reduce hypoxia-regulated metastatic potential. This could have particular significance for breast cancer patients with triple negative disease