616 research outputs found

    Caracterización del plasmidoma presente en la comunidad bacteriana de un biofiltro construido en base turba-suelo para la decontaminación de pesticidas

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    Los objetivos del presente trabajo han sido delineados para avanzar en el conocimiento de base de los plásmidos presentes en aislamientos recuperados de un biofiltro enriquecido con pesticidas, para conocer la relación de los mismos con los presentes en otras bacterias y otros ambientes, y para obtener nueva evidencia molecular que ayude a comprender de modo más acabado el peso de la transferencia horizontal de plásmidos en la dinámica de transferencia de ADN y en la adaptación/tolerancia de las bacterias presentes en dicho ambiente. Asimismo esperamos contribuir en el desarrollo de herramientas que permitan avanzar en la captura de plásmidos y estudio. Objetivo general Caracterización molecular y funcional de plásmidos aislados de un biofiltro utilizado para la decontaminación de pesticidas. Objetivos específicos En el marco del objetivo general expuesto, en la presente Tesis Doctoral se establecen los siguientes objetivos específicos: - Obtención de una colección de bacterias portadoras de plásmidos de alto peso molecular. Caracterización de dichos aislamientos. - Purificación y secuenciamiento del conjunto de plásmidos de la colección bacteriana. Análisis bioinformático del contenido plasmídico. - Búsqueda, identificación, clonado, expresión y caracterización de actividades con potencial interés industrial. - Diseño, construcción y validación de una nueva herramienta para la captura de plásmidos de muestras ambientales y cultivos puros.Facultad de Ciencias Exacta

    Estrous cycle influences the expression of neuronal nitric oxide synthase in the hypothalamus and limbic system of female mice

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    <p>Abstract</p> <p>Background</p> <p>Nitric oxide plays an important role in the regulation of male and female sexual behavior in rodents, and the expression of the nitric oxide synthase (NOS) is influenced by testosterone in the male rat, and by estrogens in the female. We have here quantitatively investigated the distribution of nNOS immunoreactive (ir) neurons in the limbic hypothalamic region of intact female mice sacrificed during different phases of estrous cycle.</p> <p>Results</p> <p>Changes were observed in the medial preoptic area (MPA) (significantly higher number in estrus) and in the arcuate nucleus (Arc) (significantly higher number in proestrus). In the ventrolateral part of the ventromedial nucleus (VMHvl) and in the bed nucleus of the stria terminalis (BST) no significant changes have been observed. In addition, by comparing males and females, we observed a stable sex dimorphism (males have a higher number of nNOS-ir cells in comparison to almost all the different phases of the estrous cycle) in the VMHvl and in the BST (when considering only the less intensely stained elements). In the MPA and in the Arc sex differences were detected only comparing some phases of the cycle.</p> <p>Conclusion</p> <p>These data demonstrate that, in mice, the expression of nNOS in some hypothalamic regions involved in the control of reproduction and characterized by a large number of estrogen receptors is under the control of gonadal hormones and may vary according to the rapid variations of hormonal levels that take place during the estrous cycle.</p

    A Novel T6 Rapid Heat Treatment for AlSi10Mg Alloy Produced by Laser-Based Powder Bed Fusion: Comparison with T5 and Conventional T6 Heat Treatments

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    AlSi10Mg is the most widely studied Al alloy used to produce components by laser-basedpowder bed fusion (LPBF), also known as selective laser melting. Several papers have alreadyinvestigated the effects of conventional heat treatment on the microstructure and mechanicalbehavior of the LPBF AlSi10Mg alloy, overlooking, however, the particular microstructureinduced by rapid solidification. This paper reports on the effects of a T5 heat treatment and anovel T6 heat treatment on microstructure and mechanical behavior of the LPBF AlSi10Mgalloy, consisting of rapid solution (10 minutes at 510°C) followed by artificial aging (6 hours at160°C). The short solution soaking time reduced the typical porosity growth occurring at thehigh temperature and led to a homogeneous distribution of fine globular Si particles in the Almatrix. In addition, it limited the diffusion processes, increasing the amount of Mg and Si insolid solution available for precipitation hardening and avoiding the microstructuralcoarsening. As a result, the strength-ductility balance was improved by increasing both yieldstrength and elongation to failure, respectively of about 14 and 7 pct compared with the bestsolution among those reported in the literature for conventional T6 heat treatment of LPBFAlSi10Mg alloy

    Influence of Microstructure on Fracture Mechanisms of the Heat-Treated AlSi10Mg Alloy Produced by Laser-Based Powder Bed Fusion

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    Few systematic studies on the correlation between alloy microstructure and mechanical failure of the AlSi10Mg alloy produced by laser-based powder bed fusion (L-PBF) are available in the literature. This work investigates the fracture mechanisms of the L-PBF AlSi10Mg alloy in as-built (AB) condition and after three different heat treatments (T5 (4 h at 160 degrees C), standard T6 (T6B) (1 h at 540 degrees C followed by 4 h at 160 degrees C), and rapid T6 (T6R) (10 min at 510 degrees C followed by 6 h at 160 degrees C)). In-situ tensile tests were conducted with scanning electron microscopy combined with electron backscattering diffraction. In all samples the crack nucleation was at defects. In AB and T5, the interconnected Si network fostered damage at low strain due to the formation of voids and the fragmentation of the Si phase. T6 heat treatment (T6B and T6R) formed a discrete globular Si morphology with less stress concentration, which delayed the void nucleation and growth in the Al matrix. The analysis empirically confirmed the higher ductility of the T6 microstructure than that of the AB and T5, highlighting the positive effects on the mechanical performance of the more homogeneous distribution of finer Si particles in T6R

    VitalApp: Aplicativo para acompanhamento de treinos, avaliações e nutricional da Academia Vital Pró

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    As academias nos ultimos anos tem dado um grande passo e inserindo em novas recnologias em seus espaços. Neste resumo é apresentado o VitalApp, um webapp que oferece aos profissionais e alunos uma ferramenta para o gerenciamento de treinos, avaliações físicas e nutricionais e dados dos alunos. Dentre suas principais funcionalidades a ferramente disponibiliza o treino cadastrado pelos professores, suas avaliaçõoes físicas bem como o histórico das mesmas. Também conta com a área Nutrição, onde o aluno que faça acompanhamento nutricional, pode consultar sua dieta cadastrada por um nutricionista. Para o desenvolvimento foram utilizadas ferramentas com suporte ao desenvolvimento webapp nas linguagens de programação JavaScript, CSS, PHP e HTML. Levando em conta que as telas e estilos da aplicação foram muito importantes no desenvolvimento de software, foi utilizado para a aplicação webapp o framework Metronic, que agilizou o desenvolvimento do front-end. O VitalApp foi desenvolvido para ser executado em navegadores de internet, e em diversas plataformas móveis, como tablets e smartphones. O webapp é separado pelos módulos de cliente, que roda no dispositivo móvel e o módulo servidor, onde as informaçõese dados são armazenados. Testes e avaliações informais foram realizados com os proprietários da academia, onde foi comprovado que a ferramenta é de facil uso, com uma interface amigavel e um bom desempenh

    Inverse association of circulating SIRT1 and adiposity. A study on underweight, normal weight, and obese patients

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    Context: Sirtuins (SIRTs) are NAD+-dependent deacetylases, cellular sensors to detect energy availability, and modulate metabolic processes. SIRT1, the most studied family member, influences a number of tissues including adipose tissue. Expression and activity of SIRT1 reduce with weight gain and increase in conditions of starvation. Objective: To focus on SIRT1 plasma concentrations in different conditions of adiposity and to correlate SIRT1 with fat content and distribution, energy homeostasis and inflammation in under-weight, normal-weight, and obese individuals. Materials and Methods: 21 patients with anorexia nervosa, 26 normal-weight and 75 patients with obesity were evaluated. Body fat composition by dual-energy X-ray absorptiometry, ultrasound liver adiposity, echocardiographic epicardial fat thickness (EFT), inflammatory (ESR, CRP, and fibrinogen), and metabolic (FPG, insulin, LDL- and HDL-cholesterol, triglycerides) parameters, calculated basal metabolic rate (BMR) and plasma SIRT1 (ELISA) were measured. Results: SIRT1 was significantly higher in anorexic patients compared to normal-weight and obese patients (3.27 ± 2.98, 2.27 ± 1.13, and 1.36 ± 1.31 ng/ml, respectively). Linear regression models for each predictor variable adjusted for age and sex showed that SIRT1 concentration was inversely and significantly correlated with EFT, fat mass %, liver fat content, BMR, weight, BMI, WC, LDL-cholesterol, insulin, ESR. Stepwise multiple regression analysis revealed that age and EFT were the best independent correlates of SIRT1 (β = -0.026 ± 0.011, p = 0.025, and β = -0.516 ± 0.083, p < 0.001, respectively). Conclusions: Plasma SIRT1 shows a continuous pattern that inversely follows the whole spectrum of adiposity. SIRT1 significantly associates with EFT, a strong index of visceral fat phenotype, better than other indexes of adiposity studied here

    The San Carlo Colossus: An Insight into the Mild Galvanic Coupling between Wrought Iron and Copper

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    : The San Carlo Colossus, known as San Carlone, is a monument constituted by an internal stone pillar support to which a wrought iron structure is attached. Embossed copper sheets are fixed to the iron structure to give the final shape to the monument. After more than 300 years of outdoor exposure, this statue represents an opportunity for an in-depth investigation of long-term galvanic coupling between wrought iron and copper. Most iron elements of the San Carlone appeared in good conservation conditions with scarce evidence of galvanic corrosion. In some cases, the same iron bars presented some portions in good conservation conditions and other nearby portions with active corrosion. The aim of the present study was to investigate the possible factors correlated with such mild galvanic corrosion of wrought iron elements despite the widespread direct contact with copper for more than 300 years. Optical and electronic microscopy and compositional analyses were carried out on representative samples. Furthermore, polarisation resistance measurements were performed both on-site and in a laboratory. The results revealed that the iron bulk composition showed a ferritic microstructure with coarse grains. On the other hand, the surface corrosion products were mainly composed of goethite and lepidocrocite. Electrochemical analyses showed good corrosion resistance of both the bulk and surface of the wrought iron, and galvanic corrosion is not occurring probably due to the iron's relatively noble corrosion potential. The few areas where iron corrosion was observed are apparently related to environmental factors, such as the presence of thick deposits and to the presence of hygroscopic deposits that create localized microclimatic conditions on the surface of the monument
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