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Acceleration of wound healing can be achieved with the use of wound dressings. Through the electrospinning technique, a polymeric scaffold composed of two layers was processed: a gelatin and polyvinylpyrrolidone layer with gentamicin, and a second layer of cellulose acetate. The conditions for the electrospinning process were standardized for voltage parameters, feed flow and the distance from the injector to the collector. Once the values of the main variables for the electrospinning were optimized, a three-hour processing time was established to allow the separation of the material from the collector. The obtained material was characterized by observations on scanning electron microscopy, Fourier transform infrared spectroscopy and thermal analysis; contact angle measurement was performed to evaluate wettability properties, and antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus were evaluated using the Kirby-Bauer test. The obtained fibers that form the bi-layer scaffold present diameters from 100 to 300 nm. The scaffold presents chemical composition, thermal stability, wettability characteristics and antibacterial activity that fulfill the proposal from this study, based on obtaining a scaffold that could be used as a drug delivery vehicle and a wound dressing material.

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Because of the high energies and long distances to the sources, astrophysical observations provide a unique opportunity to test possible signatures of Lorentz invariance violation (LIV). Superluminal LIV enables the decay of photons at high energy. The high altitude water Cherenkov (HAWC) observatory is among the most sensitive gamma-ray instruments currently operating above 10 TeV. HAWC finds evidence of 100 TeV photon emission from at least four astrophysical sources. These observations exclude, for the strongest of the limits set, the LIV energy scale to 2.2×10^{31} eV, over 1800 times the Planck energy and an improvement of 1 to 2 orders of magnitude over previous limits.

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We present the first catalog of gamma-ray sources emitting above 56 and 100 TeV with data from the High Altitude Water Cherenkov Observatory, a wide field-of-view observatory capable of detecting gamma rays up to a few hundred TeV. Nine sources are observed above 56 TeV, all of which are likely galactic in origin. Three sources continue emitting past 100 TeV, making this the highest-energy gamma-ray source catalog to date. We report the integral flux of each of these objects. We also report spectra for three highest-energy sources and discuss the possibility that they are PeVatrons.

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In the present work, we introduce an improved version of the hyperspheres path tracking method adapted for piecewise linear (PWL) circuits. This enhanced version takes advantage of the PWL characteristics from the homotopic curve, achieving faster path tracking and improving the performance of the homotopy continuation method (HCM). Faster computing time allows the study of complex circuits with higher complexity; the proposed method also decrease, significantly, the probability of having a diverging problem when using the Newton-Raphson method because it is applied just twice per linear region on the homotopic path. Equilibrium equations of the studied circuits are obtained applying the modified nodal analysis; this method allows to propose an algorithm for nonlinear circuit analysis. Besides, a starting point criteria is proposed to obtain better performance of the HCM and a technique for avoiding the reversion phenomenon is also proposed. To prove the efficiency of the path tracking method, several cases study with bipolar (BJT) and CMOS transistors are provided. Simulation results show that the proposed approach can be up to twelve times faster than the original path tracking method and also helps to avoid several reversion cases that appears when original hyperspheres path tracking scheme was employed.

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This article proposes the application of Laplace Transform-Homotopy Perturbation Method and some of its modifications in order to find analytical approximate solutions for the linear and nonlinear differential equations which arise from some variational problems. As case study we will solve four ordinary differential equations, and we will show that the proposed solutions have good accuracy, even we will obtain an exact solution. In the sequel, we will see that the square residual error for the approximate solutions, belongs to the interval [0.001918936920, 0.06334882582], which confirms the accuracy of the proposed methods, taking into account the complexity and difficulty of variational problems.

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Se relata un caso de Papiloma Escamoso de Esófago (PEE) en una paciente de 90 años. Esta patología es de carácter benigno y por lo general es un hallazgo endoscópico. Sólo existen 150 casos relatados en la literaura médica mundial. Su tratamiento consiste en resección endoscópica con asa diatérmica o un tratamiento conservador de observación más control endoscópico periódico de acuerdo al tipo de paciente.

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Se relata un caso de Papiloma Escamoso de Esófago (PEE) en una paciente de 90 años. Esta patología es de carácter benigno y por lo general es un hallazgo endoscópico. Sólo existen 150 casos relatados en la literaura médica mundial. Su tratamiento consiste en resección endoscópica con asa diatérmica o un tratamiento conservador de observación más control endoscópico periódico de acuerdo al tipo de paciente. (AU)

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The syndrome of hypercalcemia during the course of acute renal failure (usually associated with rhabdomyolysis) occurs most commonly in young men with very severe renal failure. Although fewer than 90 such patients have been reported, the prevalence of hypercalcemia in patients with rhabdomyolysis-associated renal failure averages 30%. Hypercalcemia occurs most commonly in the diuretic phase and resolves spontaneously. The mean duration of hypercalcemia is 14 days. The pathogenesis of this syndrome has not been clearly defined. In the rare instances where it has been measured, intact PTH is suppressed. In contrast, both elevated and suppressed values of plasma 1,25-dihydroxyvitamin D have been reported. The release of calcium from ectopic calcification in damaged muscle tissue provides a potential explanation for this syndrome. Therapy for the hypercalcemia should generally be conservative given its self-limited nature.

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