346 research outputs found

    Upward unsteady-state solidification of silute Al–Nb alloys : microstructure characterization, microhardness, dynamic modulus of elasticity, damping, and XRD analyses

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    Aluminium alloys form many important structural components, and the addition of alloying elements contributes to the improvement of properties and characteristics. The objective of this work is to study the influence of thermal variables on the microstructure, present phases, microhardness, dynamic modulus of elasticity, and damping frequency in unidirectional solidification experiments, which were performed in situ during the manufacturing of Al–0.8 Nb and Al–1.2 Nb (wt.%) alloys. Experimental laws for the primary ( 1) and secondary ( 2) dendritic spacings for each alloy were given as a function of thermal variables. For Al–0.8%wt Nb, 1 = 600.1(˙T)1.85 and 2 = 186.1(VL)3.62; and for Al–1.2%wt Nb, 1 = 133.6(˙T)1.85 and 2 = 55.6(VL)3.62. Moreover, experimental growth laws that correlate the dendritic spacings are proposed. An increase in dendritic spacing influences the solidification kinetics observed, indicating that metal/mold interface distance or an increase in Nb content lowers the liquidus isotherm velocity (VL) and the cooling rate (˙T). There is also a small increase in the microhardness, dynamic modulus of elasticity, and damping frequency in relation to the composition of the alloy and the microstructure

    Systemic Inflammation Changes the Site of RAGE Expression from Endothelial Cells to Neurons in Different Brain Areas

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    The receptor for advanced glycation endproducts (RAGE) is a transmembrane, immunoglobulin-like receptor that interacts with a broad repertoire of extracellular ligands. RAGE belongs to a family of cell adhesion molecules and is considered a key receptor in the inflammation axis and a potential contributor to the neurodegeneration. The present study aimed to investigate the content and cell localization of RAGE in the brain of Wistar rats subjected to systemic inflammation induced by a single dose of lipopolysaccharide (LPS, 5 mg/kg, i.p.). Fifteen days after LPS administration, the content of RAGE was analyzed in the prefrontal cortex (PFC), hippocampus (HIPP), cerebellum (CB), and substantia nigra (SN) were investigated. RAGE levels increased in all structures, except HIPP; however, immunohistochemistry analysis demonstrated that the cell site of RAGE expression changed from blood vessel-like structures to neuronal cells in all brain areas. Besides, the highest level of RAGE expression was found in SN. Immunofluorescence analysis in SN confirmed that RAGE expression was mainly co-localized in endothelial cells (RAGE/PECAM-1 co-staining) in untreated animals, while LPS-treated animals had RAGE expression predominantly in dopaminergic neurons (RAGE/TH co-staining). Decreased TH levels, as well as increased pro-inflammatory markers (TNF-α, IL-1β, Iba-1, GFAP, and phosphorylated ERK1/2) in SN, occurred concomitantly to RAGE stimulation in the same site. These results suggest a role for RAGE in the establishment of a neuroinflammation-neurodegeneration axis that develops as a long-term response to systemic inflammation by LPS

    Terapêutica cirúrgica na síndrome de Fournier: relato de caso

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    Síndrome de Fournier ou Gangrena de Fournier é uma fasceíte necrotizante que acomete região perineal, perianal e genital, ocasionada por uma infecção polimicrobiana sinergística de bactérias aeróbicas e anaeróbicas, com predomínio em homens em média aos 50 anos. A enfermidade é caracterizada por uma endarteríte obliterante causando trombose vascular subcutânea e necrose de tecidos. Microrganismos distintos aparecem como patógenos nas culturas dos pacientes com essa enfermidade. O quadro clínico pode se manifestar com dor, eritema e edema, cianose e crepitação em bolsa escrotal e períneo associada ou não a febre e calafrios. Diagnóstico e intervenção precoce, com antibioticoterapia de largo espectro e drenagem ampla, permitiu melhores resultados nestes doentes. A mortalidade permanece elevada quando o diagnóstico é tardio e o tratamento operatório retardado. O objetivo do artigo é relatar um caso de Síndrome de Fournier em um paciente de 52 anos e discutir a melhor abordagem cirúrgica e seus impactos no sucesso terapêutico nesta enfermidade.Fournier syndrome or Fournier’s gangrene is a necrotizing fasciitis that affects the perineal, perianal and genital region, caused by a polymicrobial infection of aerobic and anaerobic synergistic bacteria predominantly in men, on average at age 50. The disease is characterized by obliterative endarteritis causing subcutaneous vascular thrombosis and tissue necrosis. Different microorganisms appear as patogens in cultures of patients with this disease. The clinical picture may manifest as pain, redness and swelling, cianosis and crepitus in the scrotum and perineum with or without fever and chills. Early diagnosis and intervention with broad spectrum antibiotics and ample drainage contributed to a better outcome for these patients. Mortality remains high when diagnosis is late and the surgical procedure postponed. The aim of this paper is to report a case of Fournier syndrome in a 52 year old patient, discuss the best surgical approach and its impact on therapeutic success in this disease

    Evaluation of the aging management system for the Triga research nuclear reactor in Brazil / Avaliação do sistema de gerenciamento do envelhecimento do reator nuclear de pesquisa Triga no Brasil

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    As most research reactors have over 40 years of operational experience, maintenance, modernization and renovation are increasingly important for safety and operational life extension. This is due to the monitoring and development of techniques to control and mitigate the negative effects of operating conditions on structures, systems and components. Aging management is a strategy of engineering, operation, maintenance and other actions to control, within acceptable limits, the aging degradation of the facility. The first criticality of the IPR-R1 Triga research reactor (Training, Research, Isotopes, Atomics) occurred in 1960 with a maximum thermal power of 30 kW. Therefore, this reactor has been operating for more than 60 years. One of the issues that comes from the long time of the operation is the management of aging. This includes functions and issues related to operation, inspections, design changes, testing, and others. The IPR-R1 reactor is a North American project. So, the requirements of United State Nuclear Regulatory Commission (U.S.NRC) are applicable. This article discusses the International Atomic Energy Agency (IAEA), and U.S.NRC requirements to implement an aging management system for the CDTN IPR-R1 Triga Reactor

    BRCA-1 depletion impairs pro-inflammatory polarization and activation of RAW 264.7 macrophages in a NF-κB-dependent mechanism

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    BRCA-1 is a nuclear protein involved in DNA repair, transcriptional regulation, and cell cycle control. Its involvement in other cellular processes has been described. Here, we aimed to investigate the role of BRCA-1 in macrophages M(LPS), M(IL-4), and tumor cell-induced differentiation. We used siRNAs to knockdown BRCA-1 in RAW 264.7 macrophages exposed to LPS, IL-4, and C6 glioma cells conditioned medium (CMC6), and evaluated macrophage differentiation markers and functional phagocytic activity as well as DNA damage and cell survival in the presence and absence of BRCA-1. LPS and CMC6, but not by IL-4, increased DNA damage in macrophages, and this effect was more pronounced in BRCA-1-depleted cells, including M(IL-4). BRCA-1 depletion impaired expression of pro-inflammatory cytokines, TNF-α and IL-6, and reduced the phagocytic activity of macrophages in response to LPS. In CMC6-induced differentiation, BRCA-1 knockdown inhibited TNF-α and IL-6 expression which was accompanied by upregulation of the anti-inflammatory markers IL-10 and TGF-β and reduced phagocytosis. In contrast, M(IL-4) phenotype was not affected by BRCA-1 status. Molecular docking predicted that the conserved BRCA-1 domain BRCT can interact with the p65 subunit of NF-κB. Immunofluorescence assays showed that BRCA-1 and p65 co-localize in the nucleus of LPS-treated macrophages and reporter gene assay showed that depletion of BRCA-1 decreased LPS and CMC6-induced NF-κB transactivation. IL-4 had no effect upon NF-κB. Taken together, our findings suggest a role of BRCA-1 in macrophage differentiation and phagocytosis induced by LPS and tumor cells secretoma, but not IL-4, in a mechanism associated with inhibition of NF-κB

    Oral administration of carvacrol/β-cyclodextrin complex protects against 6-hydroxydopamine-induced dopaminergic denervation

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    Carvacrol (CARV) presents valuable biological properties such as anti-inflammatory and antioxidant activities. However, pharmacological uses of CARV are largely limited due to disadvantages related to solubility, bioavailability, preparation and storage processes. The complexation of monoterpenes with β-cyclodextrin (β-CD) increases their stability, solubility and oral bioavailability. Here, the protective effect of oral treatment with CARV/β-CD complex (25 μg/kg/day) against dopaminergic (DA) denervation induced by unilateral intranigral injection of 6-hydroxydopamine (6-OHDA - 10 μg per rat) was analyzed, in order to evaluate a putative application in the development of neuroprotective therapies for Parkinson's disease (PD). Pretreatment with CARV/β-CD for 15 days prevented the loss of DA neurons induced by 6-OHDA in adult Wistar rats. This effect may occur through CARV anti-inflammatory and antioxidant properties, as the pretreatment with CARV/β-CD inhibited the release of IL-1β and TNF-α; besides, CARV prevented the increase of mitochondrial superoxide production induced by 6-OHDA in cultured SH-SY5Y cells. Importantly, hepatotoxicity or alterations in blood cell profile were not observed with oral administration of CARV/β-CD. Therefore, this study showed a potential pharmacological application of CARV/β-CD in PD using a non-invasive route of drug delivery, i.e., oral administration

    La integración de las TIC en la formación docente: retos y oportunidades para la profesionalización y actualización de los educadores

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    This review article titled "The Integration of ICT in Teacher Training: Challenges and Opportunities for Professionalization and Upgrading of Educators" aims to analyze and discuss the importance of Information and Communication Technologies (ICT) in the process of teacher training and updating. A systematic literature review was conducted, using rigorous selection criteria and covering studies published in Spanish in relevant databases such as Scopus in the last five years. The methodology employed includes the analysis of thematic categories, such as teacher digital competence, initial and ongoing teacher training, the use of mobile devices, and the development of ICT training models. Additionally, training proposals and strategies for evaluating teacher digital competence are discussed. The main findings reveal that ICT training is essential for teachers to adapt to the challenges and demands of the 21st century, and that teacher digital competence is a crucial skill for success in pedagogical practice. There is also evidence of the need for a more robust and structured initial and ongoing training, promoting the use of ICT as learning and teaching tools. Finally, the importance of developing and applying appropriate assessment instruments to measure teacher digital competence and ensure its improvement over time is highlighted.El presente artículo de revisión titulado "La integración de las TIC en la formación docente: retos y oportunidades para la profesionalización y actualización de los educadores" tiene como objetivo analizar y discutir la importancia de las Tecnologías de la Información y la Comunicación (TIC) en el proceso de formación y actualización del profesorado. Para ello, se llevó a cabo una revisión sistemática de la literatura, utilizando criterios de selección rigurosos y abarcando estudios publicados en español en bases de datos relevantes como Scopus en los últimos cinco años. La metodología empleada incluye el análisis de categorías temáticas, como la competencia digital docente, la formación inicial y continua del profesorado, el uso de dispositivos móviles y el desarrollo de modelos de formación en TIC. Además, se discuten propuestas formativas y estrategias de evaluación de la competencia digital docente. Los principales hallazgos revelan que la formación en TIC es fundamental para que los docentes se adapten a los desafíos y exigencias del siglo XXI, y que la competencia digital docente es una habilidad crucial para el éxito en la práctica pedagógica. También se evidencia la necesidad de una formación inicial y continua más sólida y estructurada, que promueva el uso de las TIC como herramientas de aprendizaje y enseñanza. Finalmente, se destaca la importancia de desarrollar y aplicar instrumentos de evaluación adecuados para medir la competencia digital docente y garantizar su mejora en el tiempo

    Differential brain and spinal cord cytokine and BDNF levels in experimental autoimmune encephalomyelitis are modulated by prior and regular exercise

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    The interactions between a prior program of regular exercise and the development of experimental autoimmune encephalomyelitis (EAE)-mediated responses were evaluated. in the exercised EAE mice, although there was no effect on infiltrated cells, the cytokine and derived neurotrophic factor (BDNF) levels were altered, and the clinical score was attenuated. Although, the cytokine levels were decreased in the brain and increased in the spinal cord, BDNF was elevated in both compartments with a tendency of lesser demyelization volume in the spinal cord of the exercised EAE group compared with the unexercised. (C) 2013 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)NIHUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Fisiol & Biofis, Nucleo Neurociencias, BR-31270901 Belo Horizonte, MG, BrazilMinist Educ Brazil, CAPES Fdn, Programa Pos Grad Ciencias Biol Fisiol Farmacol, BR-70040020 Brasilia, DF, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Patol, BR-31270901 Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, Dept Biofis, BR-04023062 São Paulo, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Bioquim & Imunol, Lab Venenos & Toxinas Anim, BR-31270901 Belo Horizonte, MG, BrazilUniv Miami, Miller Sch Med, Miami Project Cure Paralysis, Miami, FL 33136 USALa Trobe Univ, Dept Biochem, Bundoora, Vic 3086, AustraliaUniversidade Federal de São Paulo, Dept Biofis, BR-04023062 São Paulo, BrazilCAPES: BEX 0020/12-5NIH: NS051709NIH: NS065479FAPEMIG: CBB-APQ-01459-10FAPEMIG: PPM-00200-12Web of Scienc

    The effects of retinol oral supplementation in 6-hydroxydopamine dopaminergic denervation model in Wistar rats

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    Vitamin A (retinol) is involved in signaling pathways regulating gene expression and was postulated to be a major antioxidant and anti-inflammatory compound of the diet. Parkinson's disease (PD) is a progressive neurodegenerative disorder, characterized by loss of nigral dopaminergic neurons, involving oxidative stress and pro-inflammatory activation. The aim of the present study was to evaluate the neuroprotective effects of retinol oral supplementation against 6-hydroxydopamine (6-OHDA, 12 μg per rat) nigrostriatal dopaminergic denervation in Wistar rats. Animals supplemented with retinol (retinyl palmitate, 3000 IU/kg/day) during 28 days exhibited increased retinol content in liver, although circulating retinol levels (serum) were unaltered. Retinol supplementation did not protect against the loss of dopaminergic neurons (assessed through tyrosine hydroxylase immunofluorescence and Western blot). Retinol supplementation prevented the effect of 6-OHDA on Iba-1 levels but had no effect on 6-OHDA-induced GFAP increase. Moreover, GFAP levels were increased by retinol supplementation alone. Rats pre-treated with retinol did not present oxidative damage or thiol redox modifications in liver, and the circulating levels of TNF-α, IL-1β, IL-6 and IL-10 were unaltered by retinol supplementation, demonstrating that the protocol used here did not cause systemic toxicity to animals. Our results indicate that oral retinol supplementation is not able to protect against 6-OHDA-induced dopaminergic denervation, and it may actually stimulate astrocyte reactivity without altering parameters of systemic toxicity

    Impacto dos traços de perfeccionismo na percepção de coesão de grupo de jogadores de futsal

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    El objetivo de este estudio transversal fue investigar la relación entre los rasgos de perfeccionismo y la percepción de cohesión grupal en deportistas de fútbol sala. Participaron 301 deportistas de la Liga Nacional de Fútsal 2013 con una edad media de 25,48 ± 4,90 años. Los instrumentos fueron: Escala de Perfeccionismo Multidimensional para el Deporte-2 y Cuestionario de Ambiente Grupal. Para el análisis se realizó con las pruebas de Kolmogorov-Smirnov, MANOVA, Correlación de Pearson y Regresión Múltiple (p <0,05). Los resultados mostraron que los rasgos del perfeccionismo adaptativo predijeron positivamente la cohesión social para los atletas no clasificados. Mientras tanto, el perfeccionista se preocupa por los rasgos de perfeccionismo poco adaptativo que pueden predecir negativamente la cohesión social y de tareas, con la excepción de la "presión parental percibida", que presentó una predicción positiva en todos los grupos de atletas para la cohesión social y de tareas. Los deportistas no clasificados tenían una mayor percepción de cohesión para la tarea, mientras que los reservas tenían una mayor percepción de los aspectos sociales. Así, podemos concluir que existe una relación positiva entre el perfeccionismo adaptativo y la percepción de cohesión social en deportistas no clasificados, además de una relación negativa entre las dimensiones del perfeccionismo pobremente adaptativo y la cohesión grupal.This cross-sectional study was to investigate the relationship between the traits of perfectionism and the perception of group cohesion in futsal athletes. 301 athletes from the 2013 National Futsal League participated with an average age of 25.48 ± 4.90 years. The instruments were: Multidimensional Perfectionism Scale for Sport-2 and the Group Environment Questionnaire. For analysis, it was conducted using the Kolmogorov-Smirnov, MANOVA, Pearson correlation and Multiple Regression tests (p<0,05). The results showed that the traits of adaptive perfectionism positively predicted social cohesion for unclassified athletes. Meanwhile, the perfectionist concerns traits of poorly adaptive perfectionism can negatively predict social and task cohesion, with the exception of “perceived parental pressure” which showed a positive prediction in all groups of athletes for social and task cohesion. Unclassified athletes had a higher perception of cohesion for the task, while reserves had a higher perception of social aspects. Thus, we can conclude that there is a positive relationship between adaptive perfectionism and the perception of social cohesion in unclassified athletes, in addition to a negative relationship between the dimensions of poorly adaptive perfectionism and group cohesion.O objetivo desse estudo transversal foi investigar a relação entre os traços de perfeccionismo e a percepção de coesão de grupo em atletas de futsal. Participaram 301 atletas da Liga Nacional de Futsal 2013 com média de idade de 25,48±4,90 anos. Os instrumentos foram: Escala Multidimensional de Perfeccionismo para o Esporte-2 e o Questionário de Ambiente de Grupo. Para análise foi conduzida por meio dos testes de Kolmogorov-Smirnov, MANOVA, Correlação de Pearson e Regressão Múltipla (p<0,05). Os resultados evidenciaram que os traços de perfeccionismo adaptativo se associaram positivamente com a coesão social dos atletas das equipes não classificadas para a fase final da competição. Os traços de perfeccionismo mal adaptativo se associaram negativamente com a coesão social e para tarefa, com exceção da “pressão parental percebida” que apresentou uma predição positiva em todos os grupos de atletas na coesão social e para tarefa. Os atletas não classificados apresentaram maior escore de coesão para tarefa, e os reservas apresentaram maior coesão social. Concluiu-se que existe uma relação positiva entre o perfeccionismo adaptativo e a percepção de coesão social em atletas não classificados, além de uma relação negativa entre as dimensões de perfeccionismo mal adaptativo e a coesão de grupo
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