2,635 research outputs found

    Recent advances in niobium-based materials for photocatalytic solar fuel production

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    The search for renewable and clean energy sources is a key aspect for sustainable development as energy consumption has continuously increased over the years concomitantly with environmental concerns caused by the use of fossil fuels. Semiconductor materials have great potential for acting as photocatalysts for solar fuel production, a potential energy source able to solve both energy and environmental concerns. Among the studied semiconductor materials, those based on niobium pentacation are still shallowly explored, although the number of publications and patents on Nb(V)-based photocatalysts has increased in the last years. A large variety of Nb(V)-based materials exhibit suitable electronic/morphological properties for light-driving reactions. Not only the extensive group of Nb2O5 polymorphs is explored, but also many types of layered niobates, mixed oxides, and Nb(V)-doped semiconductors. Therefore, the aim of this manuscript is to provide a review of the latest developments of niobium based photocatalysts for energy conversion into fuels, more specifically, CO2 reduction to hydrocarbons or H2 eVolution from water. Additionally, the main strategies for improving the photocatalytic performance of niobium-based materials are discussed

    Pattern of humoral immune response to Plasmodium falciparum blood stages in individuals presenting different clinical expressions of malaria

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    Abstract\ud \ud \ud \ud Background\ud \ud The development of protective immunity against malaria is slow and to be maintained, it requires exposure to multiple antigenic variants of malaria parasites and age-associated maturation of the immune system. Evidence that the protective immunity is associated with different classes and subclasses of antibodies reveals the importance of considering the quality of the response. In this study, we have evaluated the humoral immune response against Plasmodium falciparum blood stages of individuals naturally exposed to malaria who live in endemic areas of Brazil in order to assess the prevalence of different specific isotypes and their association with different malaria clinical expressions.\ud \ud \ud \ud Methods\ud \ud Different isotypes against P. falciparum blood stages, IgG, IgG1, IgG2, IgG3, IgG4, IgM, IgE and IgA, were determined by ELISA. The results were based on the analysis of different clinical expressions of malaria (complicated, uncomplicated and asymptomatic) and factors related to prior malaria exposure such as age and the number of previous clinical malaria attacks. The occurrence of the H131 polymorphism of the FcγIIA receptor was also investigated in part of the studied population.\ud \ud \ud \ud Results\ud \ud The highest levels of IgG, IgG1, IgG2 and IgG3 antibodies were observed in individuals with asymptomatic and uncomplicated malaria, while highest levels of IgG4, IgE and IgM antibodies were predominant among individuals with complicated malaria. Individuals reporting more than five previous clinical malaria attacks presented a predominance of IgG1, IgG2 and IgG3 antibodies, while IgM, IgA and IgE antibodies predominated among individuals reporting five or less previous clinical malaria attacks. Among individuals with uncomplicated and asymptomatic malaria, there was a predominance of high-avidity IgG, IgG1, IgG2 antibodies and low-avidity IgG3 antibodies. The H131 polymorphism was found in 44.4% of the individuals, and the highest IgG2 levels were observed among asymptomatic individuals with this allele, suggesting the protective role of IgG2 in this population.\ud \ud \ud \ud Conclusion\ud \ud Together, the results suggest a differential regulation in the anti-P. falciparum antibody pattern in different clinical expressions of malaria and showed that even in unstable transmission areas, protective immunity against malaria can be observed, when the appropriated antibodies are produced.We would like to especially thank Dr. Cristóvão Luis Pitangueira Mangueira, Flávia Cristina Kinskowski and Milca Geane de Lamos Valim at the Central Laboratory of the Clinical Hospital for participating in the determination of the total IgE and IgA levels. This work was supported by FAPESP (process number 2001/04073-5) and Laboratório de Investigações Médicas do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (LIM-48/HCFMUSP)We would like to especially thank Dr. Cristóvão Luis Pitangueira Mangueira, Flávia Cristina Kinskowski and Milca Geane de Lamos Valim at the Central Laboratory of the Clinical Hospital for participating in the determination of the total IgE and IgA levels. This work was supported by FAPESP (process number 2001/040735) and Laboratório de Investigações Médicas do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (LIM48/HCFMUSP

    UTILIZAÇÃO DE MATERIAL COLAGENOSO E GORDUROSO EXTRAÍDO DE PELES DE FRANGO NA INDÚSTRIA ALIMENTÍCIA, COSMÉTICA E DE SABÃO

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    O aumento do consumo mundial de carne de frango leva, conseqüentemente, a uma maior geração de subprodutos nesta indústria como penas, pescoços, peles que, por terem baixo valor comercial, são processados e utilizados na fabricação de produtos menos nobres. A potencialidade da utilização de material colagenoso extraído de peles de frango por processamento térmico na indústria alimentícia e cosmética, foi avaliada através da incorporação do material em leite UHT integral e em creme dermatológico, buscando agregar valor a estes produtos através das vantagens que o colágeno oferece. Do processo de extração, além do conteúdo protéico, uma fração de material gorduroso também foi obtida, a qual foi testada na produção de sabões. Três diferentes concentrações do material colagenoso de 0,5%; 1,0% e 1,5% foram adicionadas ao leite e ao creme. Os produtos obtidos foram submetidos a testes de estabilidade, no sentido de avaliar diferenças físico-químicas e organolépticas em relação aos padrões de produtos sem adição de material colagenoso. Os resultados mostraram-se satisfatórios no que tange a estabilidade dos produtos, inclusive melhorando algumas características físico-químicas

    Activation of leukocyte rolling by the cysteine-rich domain and the hyper-variable region of HF3, a snake venom hemorrhagic metalloproteinase

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    AbstractThe functionality of the disintegrin-like/cysteine-rich domains of snake venom metalloproteinases (SVMPs) has been shown to reside in the cysteine-rich region, which can interact with VWA-containing proteins. Recently, the hyper-variable region (HVR) of the cysteine-rich domain was suggested to constitute a potential protein–protein adhesive interface. Here we show that recombinant proteins of HF3, a hemorrhagic P-III SVMP, containing the cysteine-rich domain (disintegrin-like/cysteine-rich and cysteine-rich proteins) but not the disintegrin-like protein were able to significantly increase leukocyte rolling in the microcirculation. Peptides from the HVR also promoted leukocyte rolling and this activity was inhibited by anti-alphaM/beta2 antibodies. These results show, for the first time, that the cysteine-rich domain and its HVR play a role in triggering pro-inflammatory effects mediated by integrins

    Automatic diagnosis of the 12-lead ECG using a deep neural network

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    The role of automatic electrocardiogram (ECG) analysis in clinical practice is limited by the accuracy of existing models. Deep Neural Networks (DNNs) are models composed of stacked transformations that learn tasks by examples. This technology has recently achieved striking success in a variety of task and there are great expectations on how it might improve clinical practice. Here we present a DNN model trained in a dataset with more than 2 million labeled exams analyzed by the Telehealth Network of Minas Gerais and collected under the scope of the CODE (Clinical Outcomes in Digital Electrocardiology) study. The DNN outperform cardiology resident medical doctors in recognizing 6 types of abnormalities in 12-lead ECG recordings, with F1 scores above 80% and specificity over 99%. These results indicate ECG analysis based on DNNs, previously studied in a single-lead setup, generalizes well to 12-lead exams, taking the technology closer to the standard clinical practice

    Desempenho preliminar de novos genótipos de aveia e trigo na Depressão Ccentral do RS

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    More than two hundred oat and wheat advanced-lines selected in 1983 were grown in field experiments at Guaíba, RS, Brazil, in 1984. The objective was to quantify, grain yield, 100 grain weight, hectoliter weight, biological yield, heading time, and plant stature. The results were significant for all traits, indicating that selection was efficient in oats; on the other hand, only one wheat-line showed superiority to the best check-variety.Mais de 200 linhagens avançadas de aveia (Avena sativa L.) e trigo (Triticum aestivum L.), selecionadas em 1983, foram avaliadas em dois experimentos, conduzidos em Guaíba, RS, durante o ano de 1984. O objetivo foi testar rendimento de grãos, peso do hectolitro e de 100 grãos, rendimento biológico, ciclo de desenvolvimento e estatura de planta. Os resultados foram significativos para todas as variáveis, indicando que a seleção tem sido eficiente na aveia; por outro lado, em trigo, somente uma linhagem mostrou superioridade em rendimento de grãos sobre a melhor cultivar-padrão

    Aging-related predictive factors for oxygenation improvement and mortality in COVID-19 and acute respiratory distress syndrome (ARDS) patients exposed to prone position: A multicenter cohort study

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    Background: Elderly patients are more susceptible to Coronavirus Disease-2019 (COVID-19) and are more likely to develop it in severe forms, (e.g., Acute Respiratory Distress Syndrome [ARDS]). Prone positioning is a treatment strategy for severe ARDS; however, its response in the elderly population remains poorly understood. The main objective was to evaluate the predictive response and mortality of elderly patients exposed to prone positioning due to ARDS-COVID-19. Methods: This retrospective multicenter cohort study involved 223 patients aged ≥ 65 years, who received prone position sessions for severe ARDS due to COVID-19, using invasive mechanical ventilation. The PaO2/FiO2 ratio was used to assess the oxygenation response. The 20-point improvement in PaO2/FiO2 after the first prone session was considered for good response. Data were collected from electronic medical records, including demographic data, laboratory/image exams, complications, comorbidities, SAPS III and SOFA scores, use of anticoagulants and vasopressors, ventilator settings, and respiratory system mechanics. Mortality was defined as deaths that occurred until hospital discharge. Results: Most patients were male, with arterial hypertension and diabetes mellitus as the most prevalent comorbidities. The non-responders group had higher SAPS III and SOFA scores, and a higher incidence of complications. There was no difference in mortality rate. A lower SAPS III score was a predictor of oxygenation response, and the male sex was a risk predictor of mortality. Conclusion: The present study suggests the oxygenation response to prone positioning in elderly patients with severe COVID-19-ARDS correlates with the SAPS III score. Furthermore, the male sex is a risk predictor of mortality
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