69 research outputs found

    A Relativistic Separable Potential to Describe Pairing in Nuclear Matter

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    Using the Dirac-Hartree-Fock-Bogoliubov approximation to study nuclear pairing, we have found the short-range correlations of the Dirac 1^1S0_0 pairing fields to be essentially identical to those of the two-nucleon virtual state at all values of the baryon density. We make use of this fact to develop a relativistic separable potential that correctly describes the pairing fields.Comment: 17 pages, 4 eps-figure

    Effect of methylprednisolone on perivascular pulmonary edema, inflammatory infiltrate, VEGF and TGF-beta immunoexpression in the remaining lungs of rats after left pneumonectomy

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    Pneumonectomy is associated with high rates of morbimortality, with postpneumonectomy pulmonary edema being one of the leading causes. An intrinsic inflammatory process following the operation has been considered in its physiopathology. The use of corticosteroids is related to prevention of this edema, but no experimental data are available to support this hypothesis. We evaluated the effect of methylprednisolone on the remaining lungs of rats submitted to left pneumonectomy concerning edema and inflammatory markers. Forty male Wistar rats weighing 300 g underwent left pneumonectomy and were randomized to receive corticosteroids or not. Methylprednisolone at a dose of 10 mg/kg was given before the surgery. After recovery, the animals were sacrificed at 48 and 72 h, when the pO2/FiO2 ratio was determined. Right lung perivascular edema was measured by the index between perivascular and vascular area and neutrophil density by manual count. Tissue expression of vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-β) were evaluated by immunohistochemistry light microscopy. There was perivascular edema formation after 72 h in both groups (P = 0.0031). No difference was observed between operated animals that received corticosteroids and those that did not concerning the pO2/FiO2 ratio, neutrophil density or TGF-β expression. The tissue expression of VEGF was elevated in the animals that received methylprednisolone both 48 and 72 h after surgery (P = 0.0243). Methylprednisolone was unable to enhance gas exchange and avoid an inflammatory infiltrate and TGF-β expression also showed that the inflammatory process was not correlated with pulmonary edema formation. However, the overexpression of VEGF in this group showed that methylprednisolone is related to this elevation

    Relativistic Hartree-Bogoliubov Approach for Nuclear Matter with Non-Linear Coupling Terms

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    We investigate the pairing property of nuclear matter with Relativistic Hartree-Bogoliubov(RHB) approach. Recently, the RHB approach has been widely applied to nuclear matter and finite nuclei. We have extended the RHB approach to be able to include non-linear coupling terms of mesons. In this paper we apply it to nuclear matter and observe the effect of non-linear terms on pairing gaps.Comment: 13 pages, 5 figure

    Perfil de ácidos grasos y comportamiento reológico de aceite y grasa de semillas de achiote (Bixa orellana), y de cacao blanco (Theobroma grandiflorum) y sus mezclas

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    Annatto seed oil (ASO) and cupuassu seed fat (CSF) were combined at the ratios: 30:70, 50:50, and 70:30 (% w/w). Their fatty acid profile, nutritional quality, FTIR (Fourier Transform Infrared) spectra, and rheological behavior were evaluated. ASO increased the content of polyunsaturated fatty acids in the blends; whereas CSF conferred higher contents of monounsaturated fatty acids. The blends exhibited low atherogenicity and thrombogenicity indices, suggesting nutritional advantages. The Newtonian fluid behavior and FTIR results suggested that mixing ASO and CSF at different proportions did not affect the functional groups. ASO showed an activation energy value which indicated that this fat viscosity was more sensitive to temperature changes. The Newtonian model proved to be suitable to describe the behavior of samples, according to statistical fit parameters R2, χ2, and RSS. The resulting blends presented improved physicochemical properties and nutritional attributes, indicating their feasibility for the development of new products.Se combinaron aceite de semilla de achiote (ASO) y grasa de semilla de cacao blanco (CSF) en las proporciones: 30:70, 50:50 y 70:30 (% p/p), respectivamente. Se evaluó su perfil de ácidos grasos, calidad nutricional, espectros FTIR (Fourier Transform Infrared) y comportamiento reológico. ASO incrementó el contenido de ácidos grasos poliinsaturados en las mezclas, mientras que CSF confirió mayores contenidos de ácidos grasos monoinsaturados. Las mezclas exhibieron bajos índices de aterogenicidad y trombogenicidad, lo que sugiere ventajas nutricionales. El comportamiento del fluido newtoniano y los resultados de FTIR sugirieron que mezclar ASO y CSF en diferentes proporciones no afectó a los grupos funcionales. ASO mostró un valor de energía de activación que indicó que la viscosidad de esta grasa era más sensible a los cambios de temperatura. El modelo newtoniano demostró ser adecuado para describir el comportamiento de las muestras, según los parámetros de ajuste estadístico R2, χ2 y RSS. Las mezclas resultantes presentaron propiedades fisicoquímicas y atributos nutricionales mejorados, lo que indica su viabilidad para el desarrollo de nuevos productos
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