5,654 research outputs found

    Two-Dimensional Modeling of Thermoelectric Cells

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    The present paper is aimed at putting forward a two-dimensional model for thermoelectric cells. The energy conservation equation was formulated in order to account for the Fourier, the Thomson and the Joule effects on the temperature distribution. The electric field was also solved to come out with the current and voltage distributions. The governing equations were discretized by means of the finite-volume method, whereas the TDMA algorithm was adopted for solving the sets of linear equations. An explicit iterative solution scheme was employed to address the temperature influence on the Seebeck coefficient. The model results were compared with experimental data, when a satisfactory agreement was achieved for both cooling capacity and COP, with errors within a ?10% band. In addition, the model was employed to assess the effects of the thermoelectric properties and the couple geometry on the thermodynamic performance of the thermoelectric cell

    Latex insole with sensor system for investigation of plantar pressure distribution in autistic individuals

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    Autism is a behavior syndrome in which developing process of the affected children is changed. One of the biggest challenges to identify the person with Autistic Disorder lays on the wide range of autism spectrum. As autism affects the abilities of each child differently, like the corporal posture and gestures, it is assumed that the way of moving has as a differentiated result of pressure and energy applied in plant foot. Foot alterations produce differences in plantar pressure during walking and present a modified mechanical etiology due to the cinematic and dynamic alterations. Before the exposed, the aim of this study is to analyze the gait of the person with Autism Spectrum Disorder. For this purpose, it is necessary to, i) make a custom insole derived from latex (biomaterial) integrated with electronic sensors; II) detect differences of pressures applied during gait between individuals with and without ASD. Preliminary results point to a slight difference between both groups of children

    SHORT-TERM SOCIAL ISOLATION DOES NOT REDUCE ELEVATED PLUS-MAZE EXPLORATION IN EARLY PROTEIN MALNOURISHED RATS

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    An increased number of visits and time spent in the open arms of the elevated plus-maze by malnourished rats has been used as indicative of lower anxiety or impulsiveness. In order to study how this behavior profile responds to an anxiogenic procedure (short-term social isolation), control (16% protein) and malnourished (6% protein) rats were socially isolated prior to the test in the maze. Litters (dam plus 6 male 2 female pups) were fed the diets from birth to 49 days of age. From 50 days on, all rats were fed a lab chow diet. Social isolation consists in removing the rats from the group and placing in individual cages for 2h before the test. During the test each rat was individually placed on the center of the maze and allowed to explore for 5 min. The results showed higher open arms exploration and lower attempts to enter open arms by the malnourished rats than by the controls. Social isolation decreased open arm exploration and increased time spent on the central platform in control animals, but had no effect on the malnourished rats. The results reinforce the lower anxiety or higher impulsiveness of malnourished rats, as well as the anxiogenic effect of social isolation in control rats. However, the malnourished rats were unresponsive to the anxiogenic effects of social isolation, indicating that protein deficiency early in life not only induces lower anxiety or higher impulsiveness in the maze, but also changes the behavior of these animals in response to another environmentally-induced procedure of anxiety (social isolation). Keywords: Early protein malnutrition, Social isolation, Anxiety, Impulsiveness, Stress, Rats.

    High Avidity dsDNA Autoantibodies in Brazilian Women with Systemic Lupus Erythematosus: Correlation with Active Disease and Renal Dysfunction

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    We investigated in Brazilian women with SLE the prevalence and levels of high avidity (HA) dsDNA antibodies and tested their correlation with lupus activity and biomarkers of renal disease. We also compared these correlations to those observed with total dsDNA antibodies and antibodies against nucleosome (ANuA). Autoantibodies were detected by ELISA, while C3 and C4 levels were determined by nephelometry. Urine protein/creatinine ratio was determined, and lupus activity was measured by SLEDAI-2K. The prevalence of total and HA dsDNA antibodies was similar to but lower than that verified for ANuA. The levels of the three types of antibodies were correlated, but the correlation was more significant between HA dsDNA antibodies and ANuA. High avidity dsDNA antibodies correlated positively with ESR and SLEDAI and inversely with C3 and C4. Similar correlations were observed for ANuA levels, whereas total dsDNA antibodies only correlated with SLEDAI and C3. The levels of HA dsDNA antibodies were higher in patients with proteinuria, but their levels of total dsDNA antibodies and ANuA were unaltered. High avidity dsDNA antibodies can be found in high prevalence in Brazilian women with SLE and are important biomarkers of active disease and kidney dysfunction

    Herpetofauna of an urban environmental protection area in an Amazon forest remnant of Amapá state, northern Brazil

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    The herpetofauna of Amazonia biome is one of the richest in the world. However, there is a lack of information on its richness and distribution. Here we provide a list of the herpetofauna from the Environmental Protection Area of Lagoa dos Índios, state of Amapá, Brazil, in the northern Amazon Forest. Sampling effort was conducted by active search in three distinct transects from January to May 2018 (rainy season) and August to December 2019 (drought season). We recorded 46 species composing the local herpetofauna, being 18 amphibians and 28 reptiles. Scinax ruber, Gonatodes humeralis and Helicops angulatus were the most abundant species. Regarding the conservation status, two species are categorized as Date Data deficient, (Lysapsus bolivianus and Eunectes deschauenseei), and one as Vulnerable (Podocnemis unifilis) in the Red List of the International Union for Conservation of Nature. Podocnemis unifilis is also considered Near Threatened in the Brazilian Red List of Endangered Species. Our results suggest that local biodiversity is still underestimated and, if expanded, could increase the species richness in the area. This study represents preliminary trends and raise further questions concerning the herpetofauna assemblage of Eastern Brazilian Amazonia.El bioma de la herpetofauna de la Amazonia es uno de los más ricos del mundo. Sin embargo, falta información sobre su riqueza y distribución. Aquí proporcionamos una lista de la herpetofauna del Área de Protección Ambiental de Lagoa dos Índios, estado de Amapá, Brasil, en el norte de la Selva Amazónica. El esfuerzo de muestreo se realizó mediante búsqueda activa en tres transectos distintos de enero a mayo de 2018 (temporada de lluvias) y de agosto a diciembre de 2019 (temporada de sequía). Registramos 46 especies que componen la herpetofauna local, siendo 18 anfibios y 28 reptiles. Scinax ruber, Gonatodes humeralis y Helicops angulatus fueron las especies más abundantes. En cuanto al estado de conservación, dos especies están categorizadas como Datos deficientes en fecha, (Lysapsus bolivianus y Eunectes deschauenseei), y una como Vulnerable (Podocnemis unifilis) en la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza. Podocnemis unifilis también se considera Casi Amenazada en la Lista Roja Brasileña de Especies Amenazadas. Nuestros resultados sugieren que la biodiversidad local todavía se subestima y, si se amplía, podría aumentar la riqueza de especies en el área. Este estudio representa tendencias preliminares y plantea más preguntas sobre el conjunto de herpetofauna de la Amazonia brasileña oriental.Asociación Herpetológica Argentin

    Rhinovirus C and Respiratory Exacerbations in Children with Cystic Fibrosis

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    To investigate a possible role for human rhinovirus C in respiratory exacerbations of children with cystic fibrosis, we conducted microbiologic testing on respiratory specimens from 103 such patients in São Paulo, Brazil, during 2006–2007. A significant association was found between the presence of human rhinovirus C and respiratory exacerbations

    The Effect of Aluminium Surface Treatments on the Bonding Properties of Silica-Modified Epoxy Adhesive Joints: A Statistical Approach

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    A full factorial design is carried out to investigate the effects of different surface treatments, the inclusion of silica microparticles and the use of wash primer on the apparent shear strength and adherent strength of single-lap aluminium joints. Scanning electron microscopy, surface energy and roughness measurements are performed to characterise the aluminium surface. The results show that the use of wash primer decreases the apparent shear strength of the joints significantly. The cohesive failure of the primer is the main cause of the reduction in strength. On the other hand, the inclusion of 10 wt.% of silica microparticles in the adhesive layers increases the shear strength by 26%. Surfaces treated with NaOH for one minute, without using a wash primer, result in the most resistant joint. In contrast to the apparent shear strength, adherent strength is most effective when only degreasing is considered
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