Modelagem computacional e análise do comportamento de células a combustível de membrana polimérica em regime estático e dinâmico de carga

The aim of this work is to give a feedback to the industry on the dynamic and static performance of the PEMFC (Polymer Electrolyte Membrane Fuel Cell / Proton Exchange Membrane Fuel Cell). This philosophy of study is an aid tool that models the fuel-cell to give confidence to the designer and to improve controls on a new prototype before they are assembled. In this work the most important aspects of this new device, used to generate electricity, were carefully studied and implemented in a computer in order to simulate its static and dynamic models when under the influence of a load change. The complete research involved the work to obtain design data, the operating principles for the PEMFC fuel-cell, a computer simulation was also built and finally results of the static and dynamic performance of the model are presented.Dissertação (Mestrado)O objetivo deste trabalho é fornecer informações sobre o desempenho dinâmico e estático da Célula de Combustível de Membrana Polimérica (PEMFC). Com esta filosofia de estudo, foi desenvolvida uma ferramenta auxiliar que modela a célula de combustível considerando seus parâmetros construtivos e operacionais, com a intenção de inserir um grau de certeza para o projetista, e melhorar os projetos de controle de um protótipo antes destes serem montados. Neste trabalho os aspectos mais importantes deste novo equipamento para gerar eletricidade foram cuidadosamente estudados e implementados em computador de forma a simular seus comportamentos estático e dinâmico quando sob a influência de uma variação de carga. A pesquisa completa envolveu o trabalho de obter dados sobre os princípios teóricos eletroquímicos envolvidos e os princípios de operação da célula de combustível com membrana polimérica. A partir disso, uma simulação computacional foi construída e finalmente são apresentados os resultados do desempenho estático e dinâmico do modelo

The authors' reply

Superintendência Regional do TrabalhoUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Medicina PreventivaFundacentro Centro Estadual do Rio de JaneiroUniversidade de São Paulo Faculdade de Saúde PúblicaUNIFESP, EPM, Depto. de Medicina PreventivaSciEL

Result from the partnership between RBSO and Abrasco's worker's health technical comitee

Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Medicina PreventivaFundacentro Centro Estadual do Rio de JaneiroSuperintendência Regional do Trabalho de São PauloUniversidade de São Paulo Faculdade de Saúde PúblicaUNIFESP, EPM, Depto. de Medicina PreventivaSciEL

Impact of Side Branch Predilation on Percutaneous Coronary Intervention in Complex Coronary Bifurcation Lesions

ABSTRACTBackgroundThe treatment of coronary bifurcation lesions with single stenting in the main vessel and provisional side branch stenting may be limited by the degree of anatomical/morphological complexity. Side branch predilation, a procedural step that is typically avoided, may be required to maintain side branch patency. The impact of side branch predilation on the immediate results of percutaneous coronary intervention in complex coronary bifurcation lesions was investigated.MethodsBetween May, 2008 and August, 2009, 59 patients with single coronary bifurcation lesions and significant involvement of the main and side branches were included in the study. The main exclusion criteria were the involvement of the left main coronary artery, ST-elevation acute myocardial infarction (< 72 hours) and in-stent restenosis.ResultsThe mean age of patients was 61.2±11 years, 25.4% were female, and 30.1% had diabetes mellitus. Lesions were most prevalent in the left anterior descending artery/diagonal branch (86.4%). During the procedure, 8.5% (5/59) of lesions had unsuccessful side branch predilation, and four of these bifurcations were treated with two stents. In the multivariate model, side branch stenosis at baseline was the only significant predictor of unsuccessful side branch predilation (odds ratio 1.15, 95%CI: 1.01–1.30; P=0.04), and side branch stenosis > 87.6% was identified as the most accurate cut-off value to predict failure in the receiver operating characteristic (ROC) curve.ConclusionsSide branch predilation was associated with immediate side branch failure in < 10% of cases, and the only significant predictor in the multivariate model was side branch stenosis severity (> 85%) at baseline

Impact of occlusion duration on the success rate and outcomes of percutaneous coronary intervention in chronic total occlusions

ABSTRACTBackgroundInitial studies have shown that old occlusions or those with indeterminate occlusion duration have been associated with percutaneous coronary intervention (PCI) failure and a worse prognosis. This study aimed to determine the impact of occlusion duration on the success and outcomes of contemporary PCI on chronic total occlusion (CTO).MethodsThe authors analyzed a retrospective cohort of consecutive patients submitted to PCI in CTO, who were compared according to the confirmed occlusion duration (COD) < 12 months, ≥ 12 months, or indeterminate occlusion duration (IOD).ResultsA total of 168 patients were treated, 122 (72.6%) with COD (80 < 12 months, 42 ≥ 12 months) and 46 (24.7%) with an IOD. Lesion extension was 17.0 ± 13.6mm, in 2.90 ± 0.58mm vessels, and the anterograde approach was used in 98.8% of cases. Angiographic success was attained in 79.2% of patients (80.0% vs. 73.8% vs. 82.6%; p = 0.73). The main cause of failure was the inability to cross the lesion with the guidewire (68.6%). Occlusion duration had no impact on in-hospital events (4.8% vs. 7.1% vs. 6.0%; p = 0.73), which were almost entirely explained by periprocedural myocardial infarction, or on late outcomes (18.8% vs. 7.1% vs. 15.3%; p = 0.23). At the multivariate analysis, lesion length ≥ 20mm (odds ratio - OR = 7.27; 95% confidence interval - 95% IC 1.94-29.1; p = 0.003), calcification (OR = 4.72; 95% CI 1.19-19.1; p = 0.02), and tortuosity of the occluded segment (OR = 15.98; 95% CI 2.18-144.7; p = 0.007) were predictors of failure.ConclusionsOcclusion duration was not associated with increased failure rate of the procedure or worse PCI outcomes in CTO

Laboratório de mudança: método para compreensão da crise entre universidade pública e sociedade

The purpose of this article is to analyze if a method of developmental intervention helps the professionals of the activities in interinstitutional crises to form a historical understanding of the problems faced and to create solutions for them. We present a method called Change Laboratory (CL), inspired by the Theory of Historical-Cultural Activity (THCA). It is illustrated with an empirical case of intervention where the historical genesis and the contradictions that led to the crisis in the collaborative relationship between a public university and an educational health center were identified, between 2013 and 2015. Data obtained from records made during the intervention as well as interviews and comments from the participants were used for the study. As a result, the participants analyzed their activities historically and designed the future collaboration activity aimed at a solution to the crisis, within the scope of possible academicpedagogical relations linked to the Brazilian National Health System (SUS). The analysis suggests contradictions in the objects of health care and education activities that may be at the heart of the problematic relationship among institutions that need to develop activities collaboratively. The CL as a methodology of developmental intervention integrates diagnosis, learning, the participants’ protagonism and the creation of solutions as part of the same process.O objetivo deste artigo é analisar se um método de intervenção formativa contribui para que os profissionais de atividades colaborativas formem uma compreensão histórica dos problemas enfrentados em crises interinstitucionais e criem soluções para essas situações. Apresentamos o método Laboratório de Mudança (LM), inspirado na Teoria da Atividade Histórico-Cultural (TAHC). Ele é ilustrado com um caso empírico de intervenção na qual foi identificada a gênese histórica e as contradições que levaram à crise entre uma universidade pública e um centro de saúde escola. Para o estudo foram utilizados dados obtidos a partir de registros efetuados ao longo da intervenção, entre 2013 e 2015, assim como entrevistas e comentários dos participantes. Como resultado, eles analisaram historicamente suas atividades e desenharam novos cenários de colaboração futura, visando uma solução para a crise, no âmbito de possíveis relações acadêmico-pedagógicas vinculadas ao Sistema Único de Saúde (SUS). A análise sugere a existência de contradições nos objetos das atividades de assistência à saúde e educação que podem estar no cerne da relação problemática entre outras instituições semelhantes que precisam desenvolver atividades colaborativamente. O LM, enquanto metodologia de intervenção formativa, integra diagnóstico, aprendizagem, protagonismo dos participantes e criação de soluções como parte de um mesmo processo

PRÁTICAS DE INOVAÇÃO NO SETOR PÚBLICO: uma discussão teórica

As discussões em torno da eficiência da administração pública levam à compreensão da necessidade de inovação por parte do setor público, seja para redução de custos ou para o fornecimento de serviços de melhor qualidade para o cidadão. Esta pesquisa pretende levantar uma discussão em torno do tema práticas de inovação no setor público. Mais especificamente, trata da inovação do setor público brasileiro e discute o SPED como uma política de inovação adotada pela administração tributária. A pesquisa é do tipo descritiva e faz um levantamento dos principais conceitos de inovação e da sua evolução histórica. Conclui-se que a política apresenta características de inovação em serviços que lidam com pessoas, do tipo inovação de processos, e segue uma abordagem disruptiva

Brazilian solar saltworks - ancient uses and future possibilities

Coastal solar saltworks of Brazil are exploited for sea salt, which becomes progressively concentrated by evaporation. This study aimed to review the current and new potential uses of these systems, in order to provide more dynamic for this activity. The first evaporation ponds are also used for artisanal fisheries, ensuring the livelihood of many families. All the brine rich in secondary salts (bittern) can be widely used by the chemical industry, while the Brazil shows an incipient production of "flower of salt", a salt with distinct characteristics with higher market value than sodium chloride. On the other hand, the saltponds have a high potential for management and obtaining of large populations of Artemia spp., purifying the brine through the action as biological filter. This microcrustacean occurs naturally in intermediate salinity ponds, being commonly used in aquaculture. Species of microalgae and halobacteria found in the saltworks are employed for extraction of beta-carotene and glycerol, used in an extensive list of products with high commercial value. These ecosystems represent refuge zones for many species of migratory birds, becoming imperative to promote the conservation of these hypersaline wetlands

Phenotypic effects induced by knock-down of the period clock gene in Bombyx mori.

SummaryThe lepidopteranBombyx moriis an insect of considerable scientific and economic importance. Recently, theB. moricircadian clock geneperiodhas been molecularly characterized. We have transformed aB. moristrain with a construct encoding aperioddouble-strand RNA in order to knock-downperiodgene expression. We observe that this post-transcriptional silencing produces a small but detectable disruption in the egg-hatching rhythm, as well as a reduction in egg-to-adult developmental time, without altering silk production parameters. Thus we show that both circadian and non-circadian phenotypes can be altered by changingperexpression, and, at a practical level, these results suggest thatperknock-down may provide a suitable strategy for improving the efficiency of rearing, without affecting silk productivity