Reaction cross-section predictions for nucleon induced reactions

A microscopic calculation of the optical potential for nucleon-nucleus scattering has been performed by explicitly coupling the elastic channel to all the particle-hole (p-h) excitation states in the target and to all relevant pickup channels. These p-h states may be regarded as doorway states through which the flux flows to more complicated configurations, and to long-lived compound nucleus resonances. We calculated the reaction cross sections for the nucleon induced reactions on the targets $^{40,48}$Ca, $^{58}$Ni, $^{90}$Zr and $^{144}$Sm using the QRPA description of target excitations, coupling to all inelastic open channels, and coupling to all transfer channels corresponding to the formation of a deuteron. The results of such calculations were compared to predictions of a well-established optical potential and with experimental data, reaching very good agreement. The inclusion of couplings to pickup channels were an important contribution to the absorption. For the first time, calculations of excitations account for all of the observed reaction cross-sections, at least for incident energies above 10 MeV.Comment: 6 pages, 6 figures. Submitted to INPC 2010 Conference Proceeding

Recurrent Upper Gastro-Intestinal Bleed Caused by a Pseudo-Aneurysm of the Gastro-Duodenal Artery

Os autores apresentam o caso clínico de um homem de 39 anos de idade com antecedentes de pancreatite crónica, que apresenta um quadro de hemorragia digestiva alta recorrente, com repercussão hemodinâmica, endoscopias altas sucessivas sem alterações, e cujos exames imagiológicos revelam presença de mal-formação vascular do tronco celíaco. Na sequência de mais um episódio de hemorragia digestiva alta com franca repercussão hemodinâmica, é internado no Serviço de Medicina,realizando arteriografia selectiva que mostrou a presença de pseudo-aneurisma da artéria gastroduodenal. Após a embolização, verificou-se uma progressiva e mantida melhoria da sua situação clínica. Descrevem os autores um quadro de hemorragia digestiva alta recorrente por malformação arterial associada à pancreatite crónica

Docência coletiva: saberes e fazeres na Educação a Distância.

Este trabalho se organizou a partir de uma pesquisa qualitativa com uma abordagem sóciohistórica que se fundamenta, principalmente, na teoria da construção social do conhecimento de Vygotsky, na dialogicidade e autonomia de Freire e na formação de professores, como prática reflexiva de Nóvoa e Alarcão. Trata-se de um estudo de caso referente ao curso de Pós-graduação em Informática na Educação (PIE) ofertado pelo Instituto Federal do Espírito Santo (Ifes). Busca analisar a docência coletiva na modalidade a distância, com base nas percepções dos professores conteudistas e/ou formadores a partir da sua prática na EaD. Os dados foram coletados mediante aplicação de questionário, observação da atuação dos professores, entrevistas individuais, documentos do curso e reflexões a partir dos registros nas salas virtuais. Os dados foram analisados a partir de três categorias: Docência Coletiva na EaD; EaD e o Uso de Tecnologias na Educação; Planejamento e Características do Processo de Ensino- aprendizagem na EaD. Os resultados apontam que o fato do docente coletivo ser constituído por vários professores com percepções diferentes sobre processo de ensinoaprendizagem pode ser considerado positivo, pois o processo pode ser compartilhado e enriquecido a partir dos vários olhares, embora, provoque desafios de natureza interativa. Quanto ao planejamento realizado na PIE os resultados apontam que tem sido possível vivenciar momentos interdisciplinares entre as disciplinas, principalmente as concomitantes, possibilitando aos alunos a percepção da interligação de saberes e a diminuição de redundâncias entre os conteúdos. O estudo aponta para a necessidade de pensar a formação de professores para a EaD enquanto prática reflexiva que perpasse a busca de conhecimentos tecnológicos e pedagógicos

Hemangiopericytoma

A propósito de um caso clínico de hemangiopericitoma com localização no membro inferior esquerdo, os autores fazem uma breve revisão desta entidade patológica. Destacam-se as suas principais características clínicas e salienta-se o contributo da arteriografia, no diagnóstico, e tratamento coadjuvante da cirurgia

Disfagia e Disartria. Forma Invulgar de Apresentação da Miastenia Gravis

Myasthenia Gravis is an autoimmune disorder that generally presents with ocular symptoms, specially diplopia and ptosis. Dysphagia may be a manifestation of the generalised type of the disease, but rarely is its presenting feature. The authors describe a case of Myasthenia Gravis in an old patient complaining of dysphagia and dysarthria. Because Myasthenia Gravis is a potentially serious but treatable disease, we emphasize the need to consider it in the differential diagnosis of dysphagia, namely in the elderly. In fact, the disorder is probably underdiagnosed in this population group, because clinicians tend to accept other more frequent diagnosis to explain these symptoms

On the equivalence of the Ashkin-Teller and the four-state Potts-glass models of neural networks

We show that for a particular choice of the coupling parameters the Ashkin-Teller spin-glass neural network model with the Hebb learning rule and one condensed pattern yields the same thermodynamic properties as the four-state anisotropic Potts-glass neural network model. This equivalence is not seen at the level of the Hamiltonians.Comment: 3 pages, revtex, additional arguments presente

Optimization of a fructooligosaccharides purification method using activated charcoal

Fructooligosaccharides (FOS) have gained large commercial interest due to its beneficial properties in the human health as prebiotics. FOS are produced industrially by fermentative processes. However, the result of such fermentations is a complex mixture containing salts and approximately 50% (w/w) of low molecular weight sugars that have to be eliminated. Among other techniques that have been studied, the adsorption onto activated carbon is still the most suitable one since activated carbon is cheap, has a large surface area and pore volume conducting to a good sorption capacity. Furthermore, this sorbent can be regenerated during desorption with ethanol. Based on the above discussion, in this work the adsorption and desorption characteristics of FOS on activated carbon, using a gradient of ethanol, were optimized. Initially, the activated carbon was loaded with fermentative broth. To remove the non adsorbed sugars, a washing step with pure water was included. Afterwards, the retained sugars were recovered by elution with a gradient of ethanol increased sequentially with specific volumes from 1 to 50% (v/v). Fractions collected at different time points were evaporated and subsequently freeze‐dried. This process was found to be very efficient in the demineralization of broth, and it was possible to recover 80% of the initial FOS loaded on the column with 89% of purity. Some of the fractions were found to contain 97% of pure FOS in total sugars. In summary, purification of FOS using an activated charcoal column is a very efficient process yielding high levels of purity from a fermentative broth

Encerramento Percutâneo de um Volumoso Pseudoaneurisma da Aorta Ascendente

Pseudoaneurysm of the ascending aorta is a rare complication, usually after thoracic surgery or trauma. Since surgical repair is associated with very high morbidity and mortality, percutaneous closure has been described as an alternative. In this regard, we present a case in which a symptomatic large pseudoaneurysm of the ascending aorta was treated percutaneously due to the high surgical risk. Despite the technical difficulties, this procedure had a good final result followed by clinical success.info:eu-repo/semantics/publishedVersio