56 research outputs found

    ELON LAGES LIMA E O SEU PRIMEIRO LIVRO: TOPOLOGIA DOS ESPAÇOS MÉTRICOS

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    O Brasil vem conquistando cada vez mais espaço na Matemática mundial. Tal reconhecimento se deu graças à grande quantidade de matemáticos de sucesso que o nosso país tem revelado ao longo das décadas. Entre todos eles, destaca-se Elon Lages Lima (1929-2017), que se consolidou como um dos maiores matemáticos brasileiros. O trabalho a seguir trata-se de um estudo sobre a vida e a carreira de Elon, discutindo também sua atuação como escritor, com foco no livro Topologia dos Espaços Métricos, que ao longo do tempo foi transformado no livro Espaços Métricos e rendeu ao autor o Prêmio Jabuti, outorgado pela Câmara Brasileira do Livro. O objetivo desta pesquisa é apresentar um levantamento da carreira de Elon Lages Lima e suas principais contribuições para a Matemática, como professor, pesquisador e escritor. Além disso, compreender o livro Topologia dos Espaços Métricos, de sua autoria, por meio de uma breve discussão sobre a metodologia usada pra explanar o assunto. A pesquisa é do tipo descritiva, por meio de um levantamento bibliográfico e documental. Após a análise do livro, é notável o cuidado do autor em usar uma linguagem mais acessível para explanar os conteúdos, sem abrir mão do rigor necessário para um bom aproveitamento do estudo. Sua metodologia mostra ainda o desejo de despertar o interesse e a curiosidade no leitor, usando táticas para fazê-lo participar das demonstrações e demais operações contidas nos capítulos. Constata-se, com esse estudo, a grande importância de Elon para a Matemática brasileira e que sua atuação na área rendeu enormes avanços para o ensino e a pesquisa em Matemática. Dessa forma, espera-se incentivar o aprofundamento de pesquisas sobre a carreira e as obras de Elon Lages Lima e contribuir para a disseminação dos ensinamentos desse matemático para aqueles interessados no assunto

    Zika Brazilian Cohorts (ZBC) Consortium: Protocol for an Individual Participant Data Meta-Analysis of Congenital Zika Syndrome after Maternal Exposure during Pregnancy.

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    Despite great advances in our knowledge of the consequences of Zika virus to human health, many questions remain unanswered, and results are often inconsistent. The small sample size of individual studies has limited inference about the spectrum of congenital Zika manifestations and the prognosis of affected children. The Brazilian Zika Cohorts Consortium addresses these limitations by bringing together and harmonizing epidemiological data from a series of prospective cohort studies of pregnant women with rash and of children with microcephaly and/or other manifestations of congenital Zika. The objective is to estimate the absolute risk of congenital Zika manifestations and to characterize the full spectrum and natural history of the manifestations of congenital Zika in children with and without microcephaly. This protocol describes the assembly of the Consortium and protocol for the Individual Participant Data Meta-analyses (IPD Meta-analyses). The findings will address knowledge gaps and inform public policies related to Zika virus. The large harmonized dataset and joint analyses will facilitate more precise estimates of the absolute risk of congenital Zika manifestations among Zika virus-infected pregnancies and more complete descriptions of its full spectrum, including rare manifestations. It will enable sensitivity analyses using different definitions of exposure and outcomes, and the investigation of the sources of heterogeneity between studies and regions

    Polymorphisms in the MBL2 gene are associated with the plasma levels of MBL and the cytokines IL-6 and TNF-α in severe COVID-19

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    IntroductionMannose-binding lectin (MBL) promotes opsonization, favoring phagocytosis and activation of the complement system in response to different microorganisms, and may influence the synthesis of inflammatory cytokines. This study investigated the association of MBL2 gene polymorphisms with the plasma levels of MBL and inflammatory cytokines in COVID-19.MethodsBlood samples from 385 individuals (208 with acute COVID-19 and 117 post-COVID-19) were subjected to real-time PCR genotyping. Plasma measurements of MBL and cytokines were performed by enzyme-linked immunosorbent assay and flow cytometry, respectively.ResultsThe frequencies of the polymorphic MBL2 genotype (OO) and allele (O) were higher in patients with severe COVID-19 (p< 0.05). The polymorphic genotypes (AO and OO) were associated with lower MBL levels (p< 0.05). IL-6 and TNF-α were higher in patients with low MBL and severe COVID-19 (p< 0.05). No association of polymorphisms, MBL levels, or cytokine levels with long COVID was observed.DiscussionThe results suggest that, besides MBL2 polymorphisms promoting a reduction in MBL levels and therefore in its function, they may also contribute to the development of a more intense inflammatory process responsible for the severity of COVID-19

    2 nd Brazilian Consensus on Chagas Disease, 2015

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    Abstract Chagas disease is a neglected chronic condition with a high burden of morbidity and mortality. It has considerable psychological, social, and economic impacts. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on the articulation and strategic contribution of renowned Brazilian experts with knowledge and experience on various aspects of the disease. It is the result of a close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. It is hoped that this document will strengthen the development of integrated actions against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research

    Continuous and Intermittent Drying of Rough Rice: Effects on Process Effective Time and Effective Mass Diffusivity

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    The choice of the drying process plays a key role in reducing the costs of electricity consumption in the food industry. Thus, this study aimed to evaluate continuous and intermittent drying of rough rice, using empirical and diffusion models to describe the drying kinetics, considering only effective time of operation to compare and evaluate these processes. Experiments were carried out during the month of April 2018, in Campina Grande, Paraiba Brazil, and were conducted with continuous and intermittent drying of rough rice grains (about 20 g, each experiment) using a fixed-bed dryer with constant power, at temperatures of 50 and 70 °C. For the intermittent experiments, the intermittency ratio was α = 2/3 and the drying periods were 10 and 20 min, with intermittency periods of 20 and 40 min, respectively. Comparison between continuous and intermittent drying kinetics indicated reduction in the effective time of all intermittent drying experiments, reaching up to 32.2%, hence promoting energy saving. It was also found that a one-dimensional diffusion model with boundary condition of the first kind properly described all rough rice drying processes and that the effective mass diffusivity is higher in intermittent drying, compared to continuous drying at the same temperature

    Levels of Tannins and Flavonoids in Medicinal Plants: Evaluating Bioprospecting Strategies

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    There are several species of plants used by traditional communities in the Brazilian semiarid. An approach used in the search for natural substances that possess therapeutic value is ethnobotany or ethnopharmacology. Active substances that have phenolic groups in their structure have great pharmacological potential. To establish a quantitative relationship between the species popularly considered to be antimicrobial, antidiabetic, and antidiarrheal, the contents of tannins and flavonoids were determined. The plant selection was based on an ethnobotanical survey conducted in a community located in the municipality of Altinho, northeastern Brazil. For determination of tannin content was utilized the technique of radial diffusion, and for flavonoids, an assay based on the complexation of aluminum chloride. The group of plants with antimicrobial indications showed a higher content of tannins compared to the control groups. The results evidence suggests a possible relationship between these compounds and the observed activity

    Atividade farmacológica da monocrotalina isolada de plantas do gênero Crotalaria

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    Crotalaria retusa é uma planta encontrada no Nordeste brasileiro, pertence ao gênero Crotalaria e à família Leguminosae, e possuem mais de seissentas espécies no mundo e mais de quarenta no Brasil. As variedades tóxicas mais conhecidas são C. spectabilis, C. crispata, C. retusa, C. dura e C. globifera. Plantas do gênero Crotalaria são de interesse porque são usadas na medicina popular. Esses gêneros são ricos em alcaloides pirrolizidínicos (AP), que são as principais toxinas e apresentam efeitos pneumotóxicos, nefrotóxicos, cardiotóxicos, fetotóxicos, carcinogênicos, inflamação, hemorragia e fibrose. A monocrotalina é o principal alcaloide pirrolizidínico encontrado nessas plantas e é ativamente oxidada in vivo pelo citocromo P450 no fígado, formando intermediários altamente reativos tipo pirrólicos que são responsáveis pela ligação cruzada do DNA-DNA e DNA-proteína. O presente trabalho teve como objetivo fazer um levantamento bibliográfico via internet, utilizando bancos de dados, programas de pesquisa científica e pesquisa em livros relacionados, acerca da atividade farmacológica e do mecanismo de ação da monocrotalina extraída de plantas do gênero Crotalaria, ressaltando desde os aspectos botânicos da planta, estrutura química dos alcaloides pirrolizidínicos, exemplos experimentais de toxicidade e provável mecanismo de ação
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