Preparo, sinterização e caracterização de eletrólitos sólidos baseados em Céria-Zircônia

Featuring fluorite structure and easy doping with rare earths, responsible for maintaining the stability and formation of oxygen vacancies, cerium-based solid electrolytes are the main focus in research for intermediate temperature fuel cells (700 ° C). The research pursue the multiple doping of cerium oxide (Ce0,8Gd0,18Sm0,02O1,9)  with zirconia oxide (Zr0,9Y0,1O2) in concentration of 10,20, 30 and 40%. Preparation of the doped oxide was done using the chemical synthesis of the Pechini method. The refined powder obtained by the technique was milled in a high energy mill, shaped in a cold uniaxial pressing, and sintered in two different sintering curves: The first, with only one step at 1500°C, and the second in two stages, with plateau at 1650°C followed by cooling and plateau of 1500°C. The physical and chemical properties of the samples were evaluated through TGA, XRD, density and surface evaluation through SEM. The evaluation of the resistive characteristics of the samples was evaluated through the Impedance Spectroscopy, evaluated in the range of 310°C to 385°C. The result provided the evaluation of the conductivity and activation energy of the samples through the Arrhenius graph. It was observed that the samples with higher percentage of cerium oxide, as well as sintered samples in the sintering ramp in 2 stages, showed lower activation energy and higher conductivity.Apresentando estrutura fluorita e fácil dopagem com terras raras, responsáveis por manter a estabilidade e formação de vacâncias de oxigênio, os eletrólitos sólidos baseados em cério são o principal foco em pesquisa para células a combustível de temperatura intermediária (700°C). Esta pesquisa busca fazer a múltipla dopagem do óxido de cério (Ce0,8Gd0,18Sm0,02O1,9), com óxido de zircônia ( Zr0,9Y0,1O2), em concentração de 10,20, 30 e 40%. A preparo do óxido dopado se deu utilizando a síntese química do método Pechini. O pó refinado obtido graças a técnica foi moído em moinho de alta energia, conformado em prensagem uniaxial a frio, e sinterizado em duas diferentes curvas de sinterização: A primeira, com apenas um patamar em 1500°C, e a segunda em duas etapas, com patamar em 1650°C seguido de resfriamento e patamar de 1500°C. As propriedades físicas e químicas das amostras foram avaliadas através do TGA, DRX, densidade e avaliação da superfície através do MEV. A avaliação das características resistivas das amostras foi avaliada através da Espectroscopia de Impedância, na faixa de 310°C a 385°C. O resultado proporcionou a avaliação da condutividade e da energia de ativação das amostras através do gráfico de Arrhenius. Foi observado que as amostras com maior porcentagem de óxido de cério, assim como as amostras sinterizadas na rampa de sinterização em 2 etapas, apresentaram menor energia de ativação e maior condutividade

Aspectos da comercialização do caranguejo-uçá (Ucides cordatus): estudo preliminar realizado no município de Parnaíba-PI.

Neste trabalho apresentamos um estudo preliminar da comercialização do caranguejo-uçá, Ucides cordatus, no município de Parnaíba-PI (2°54'50"S e 41°46'02"), visando determinar o perfil dos vendedores e caracterizar os espécimes capturados

Neuroanatomy and cadaver dissection in Italy: History, medicolegal issues, and neurosurgical perspectives.

Despite the significant Italian tradition of important anatomical studies, an outdated law historically influenced by the Catholic church restricts the use of cadavers for teaching and scientific purposes. The object of the present paper was to trace the historical evolution of the Italian anatomical tradition, particularly neuroanatomical studies, in relation to the juridical regulations on the use of cadavers today. Special attention was paid to the opportunities offered to neurosurgery by using cadavers and to the scientific and social issues in neurosurgical training in the twenty-first century. Considering the new Common European Constitution, the authors advocate a political solution from the European community to improve the quality of training in the disciplines with a social impact such as neurosurgery

Calcium binding promotes prion protein fragment 90–231 conformational change toward a membrane destabilizing and cytotoxic structure

Microglia-mediated inflammation in the central nervous system is a hallmark of the pathogenesis of several neurodegenerative diseases including Alzheimer's disease. Microglial cells activation follows the deposition of amyloid beta fibrils and it is generally considered a triggering factor in the early steps of the onset of Alzheimer's disease. Although the initial engagement of microglia seems to play a neuroprotective role, many lines of evidence indicate that a persistent activation with the production of pro-inflammatory molecules contributes to dismantle neuronal activity and to induce neuronal loss occurring in neurodegenerative diseases. To date, limited proteomic data are available on activated microglial cells in response to extracellular amyloidogenic peptides. In this study, murine microglial cells have been employed to investigate the effects of amyloid beta peptides in triggering microglial activation. The response was monitored at the proteome level through a two-dimensional gel electrophoresis based approach. Results show only a limited number of differentially expressed proteins, among these a more acidic species of the cytosolic actin, and the 14-3-3 protein, found significantly up-regulated in A-activated cells. 14-3-3 belongs to a regulatory protein family involved in important cellular processes, including those leading to neurodegenerative diseases, and thus its increased expression suggests a role of this protein in tuning microglia activation

Mild cognitive impairment is associated with poor physical function but not bone structure or density in late adulthood:Findings from the Hertfordshire Cohort Study

Mini Abstract This study investigated the association between mild cognitive impairment (MCI) and physical function and bone health in older adults. MCI was associated with poor physical performance but not bone mineral density or bone microarchitecture. Abstract Purpose: Cross-sectional study to investigate the association between mild cognitive impairment (MCI) and physical performance, and bone health, in a community-dwelling cohort of older adults. Methods: Cognitive function of 222 men and 221 women (mean age 75.5 and 75.8 years in men and women, respectively) was assessed by the Strawbridge questionnaire and Mini Mental State Exam (MMSE). Participants underwent dual-energy x-ray absorptiometry (DXA), peripheral-quantitative computed tomography (pQCT) and high-resolution peripheral-quantitative computed tomography (HR-pQCT) scans to assess their bone density, strength and microarchitecture. Their physical function was assessed and a physical performance (PP) score was recorded. Results: 11.8% of women and 8.1% of men in the study were cognitive impaired on the MMSE (score<24). 24% of women were deemed cognitively impaired on the Strawbridge questionnaire, compared to 22.3% of men. Cognitive impairment on the Strawbridge questionnaire was associated with poorer physical performance score in men but not women in the unadjusted analysis. MMSE <24 was strongly associated with the risk of low physical performance in men (OR 12.9, 95% CI 1.67, 99.8, p=0.01) Higher MMSE score was associated with better physical performance in both sexes. Poorer cognitive function, whether assessed by the Strawbridge questionnaire, or by MMSE score, was not associated with bone density, shape or microarchitecture, in either sex. Conclusion: MCI in older adults was associated with poor physical performance, but not bone density, shape or microarchitecture

Eugenia punicifolia leaf extract has a hypotensive effect and inhibits angiotensin-converting enzyme activity in both in vitro and in vivo models.

Chronic high blood pressure has for many years been considered a public health problem. Eugenia punicifolia is a plant used to treat diabetes by the local population, however its hypotensive effect has never been investigated