4,658 research outputs found

    Salmonella typhimurium and Escherichia coli dissimilarity: closely related bacteria with distinct metabolic profiles

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    Live attenuated strains of Salmonella typhimurium have been extensively investigated as vaccines for a number of infectious diseases. However, there is still little information available concerning aspects of their metabolism. S. typhimurium and Escherichia coli show a high degree of similarity in terms of their genome contents and metabolic networks. However, this work presents experimental evidence showing that significant differences exist in their abilities to direct carbon fluxes to biomass and energy production. It is important to study the metabolism of Salmonella in order to elucidate the formation of acetate and other metabolites involved in optimizing the production of biomass, essential for the development of recombinant vaccines. The metabolism of Salmonella under aerobic conditions was assessed using continuous cultures performed at dilution rates ranging from 0.1 to 0.67 h1, with glucose as main substrate. Acetate assimilation and glucose metabolism under anaerobic conditions were also investigated using batch cultures. Chemostat cultivations showed deviation of carbon towards acetate formation, starting at dilution rates above 0.1 h1. This differed from previous findings for E. coli, where acetate accumulation was only detected at dilution rates exceeding 0.4 h1, and was due to the lower rate of acetate assimilation by S. typhimurium under aerobic conditions. Under anaerobic conditions, both microorganisms mainly produced ethanol, acetate, and formate. A genome-scale metabolic model, reconstructed for Salmonella based on an E. coli model, provided a poor description of the mixed fermentation pattern observed during Salmonella cultures, reinforcing the different patterns of carbon utilization exhibited by these closely related bacteria. This article is protected by copyright. All rights reserved.Special thanks to Amadeus Azevedo for the HPLC analyses and technical assistance. The authors acknowledge the national funding received from CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico, Brazil), the international cooperation project CAPES-FCT (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior/Brazil-Fundacao para a Ciencia e a Tecnologia/Portugal-Process 315/11), CAPES (Atracao de Jovens Talentos-Process 064922/2014-01) and to Fundacao para a Ciencia e Tecnologia the strategic funding of UID/BIO/04469/2013 unit

    Estimating the time-dependent performance of nanocatalysts in fuel cells based on a cost-normalization approach

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    CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESResearchers have developed new catalysts for fuel cells (FC), whose performances are compared after applying different normalization procedures. However, there is not a standard procedure. The current produced from CO electrooxidation was compared for Pt4271119801988CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES454516/2014-2SEM INFORMAÇÃOThe authors acknowledge financial assistance from CNPq (grant No. 454516/2014-2), FUNDECT (grant No. 026/2015), CAPES and FINE

    Circulating miRNAs are associated with the systemic extent of atherosclerosis : novel observations for miR-27b and miR-146

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    Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).The mechanisms that regulate the systemic extent of atherosclerosis are not fully understood. We investigated whether the expression of circulating miRNAs is associated with the extent of stable atherosclerosis to a single territory or multiple territories (polyvascular) and with the severity of atherosclerosis in each territory. Ninety-four participants were prospectively recruited and divided into five age- and sex-matched groups: presenting no atherosclerosis, isolated coronary atherosclerosis, coronary and lower extremity atherosclerosis, coronary and carotid atherosclerosis, and atherosclerosis of the coronary, lower extremity, and carotid territories. The expression of six circulating miRNAs with distinct biological roles was assessed. The expression of miR-27b and miR-146 differed across groups (p < 0.05), showing a decrease in the presence of atherosclerosis, particularly in the three territories. miR-27b and miR-146 expression decreased in association with a higher severity of coronary, lower extremity, and carotid atherosclerosis. Polyvascular atherosclerosis involving the three territories was independently associated with a decreased miR-27b and miR-146 expression. Both miRNAs presented an area under the curve of ≥0.75 for predicting polyvascular atherosclerosis involving the three territories. To conclude, miR-27b and miR-146 were associated with the presence of severe polyvascular atherosclerosis and with the atherosclerosis severity in each territory. Both are potential biomarkers of severe systemic atherosclerosis.info:eu-repo/semantics/publishedVersio

    Association between mir-146a and tumor necrosis factor alpha (Tnf-α) in stable coronary artery disease

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    Background and Objectives: Tumor necrosis factor alpha (TNF-α) is proatherogenic and associated with the risk of acute ischemic events, although the mechanisms that regulate TNF-α expression in stable coronary artery disease (SCAD) are not fully understood. We investigated whether metabolic, inflammatory, and epigenetic (microRNA (miRNA)) markers are associated with TNF-α expression in SCAD. Materials and Methods: Patients with SCAD were prospectively recruited and their metabolic and inflammatory profiles were assessed. TNF-α levels were assessed using an enzyme-linked immunosorbent assay. The relative expression of six circulating miRNAs associated with the regulation of inflammation and/or atherosclerosis was determined. Results: Of the 24 included patients with the mean age of 65 (9) years, 88% were male, and 54% were diabetic. The TNF-α levels were (median (interquartile range)) 1.0 (0.7–1.1) pg/mL. The percentage of glycosylated hemoglobin (r = 0.418, p = 0.042), serum triglyceride levels (r = 0.429, p = 0.037), and C-reactive protein levels (r = 0.407, p = 0.048) were positively correlated with TNF-α levels. Of the candidate miRNAs, miR-146a expression levels were negatively correlated with TNF-α levels (as indicated by r = 0.500, p = 0.035 for correlation between delta cycle threshold (∆Ct) miR-146a and TNF-α levels). In multivariate analysis, serum triglyceride levels and miR-146a expression levels were independently associated with TNF-α levels. miR-146 expression levels were not associated with metabolic or other inflammatory parameters and were negatively correlated with the number of coronary vessels with obstructive disease (as indicated by r = 0.556, p = 0.017 for correlation between ∆Ct miR-146a and number of diseased vessels). Conclusions: miR-146a expression levels were negatively correlated with TNF-α levels in patients with SCAD, irrespective of other metabolic or inflammatory markers, and with the severity of coronary artery disease. The results add to the knowledge on the role of miR-146a in TNF-α-based inflammation in SCAD and support future research on the potential therapeutic use of miR-146a in such a clinical scenario.publishersversionpublishe

    Cigarette smoking, miR-27b downregulation, and peripheral artery disease : insights into the mechanisms of smoking toxicity

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    Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Cigarette smoking is a risk factor for the development of peripheral artery disease (PAD), although the proatherosclerotic mediators of cigarette smoking are not entirely known. We explored whether circulating microRNAs (miRNAs) are dysregulated in cigarette smokers and associated with the presence of PAD. Ninety-four participants were recruited, including 58 individuals without and 36 with PAD, 51 never smokers, 28 prior smokers, and 15 active smokers. The relative expression of six circulating miRNAs with distinct biological roles (miR-21, miR-27b, miR-29a, miR-126, miR-146, and miR-218) was assessed. Cigarette smoking was associated with the presence of PAD in multivariate analysis. Active smokers, but not prior smokers, presented miR-27b downregulation and higher leukocyte, neutrophil, and lymphocyte counts; miR-27b expression levels were independently associated with active smoking. Considering the metabolic and/or inflammatory abnormalities induced by cigarette smoking, miR-27b was independently associated with the presence of PAD and downregulated in patients with more extensive PAD. In conclusion, the atheroprotective miR-27b was downregulated in active smokers, but not in prior smokers, and miR-27b expression was independently associated with the presence of PAD. These unreported data suggest that the proatherogenic properties of cigarette smoking are mediated by a downregulation of miR-27b, which may be attenuated by smoking cessation.info:eu-repo/semantics/publishedVersio

    Enterotype May Drive the Dietary-Associated Cardiometabolic Risk Factors

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    Analyses of typical bacterial clusters in humans named enterotypes may facilitate understanding the host differences in the cardiometabolic profile. It stills unknown whether the three previously described enterotypes were present in populations living below the equator. We examined how the identification of enterotypes could be useful to explain the dietary associations with cardiometabolic risk factors in Brazilian subjects. In this cross-sectional study, a convenience sample of 268 adults (54.2% women) reported their dietary habits and had clinical and biological samples collected. In this study, we analyzed biochemical data and metagenomics of fecal microbiota (16SrRNA sequencing, V4 region). Continuous variables were compared using ANOVA, and categorical variables using chi-square test. Vsearch clustered the operational taxonomic units, and Silva Database provided the taxonomic signatures. Spearman coefficient was used to verify the correlation between bacteria abundances within each enterotype. One hundred subjects were classified as omnivore, 102 lacto-ovo-vegetarians, and 66 strict vegetarians. We found the same structure as the three previously described enterotypes: 111 participants were assigned to Bacteroides, 55 to Prevotella, and 102 to Ruminococcaceae enterotype. The Prevotella cluster contained higher amount of strict vegetarians individuals than the other enterotypes (40.0 vs. 20.7 and 20.6, p = 0.04). Subjects in this enterotype had a similar anthropometric profile but a lower mean LDL-c concentration than the Bacteroides enterotype (96 +/- 23 vs. 109 +/- 32 mg/dL, p = 0.04). We observed significant correlations between bacterial abundances and cardiometabolic risk factors, but coefficients differed depending on the enterotype. In Prevotella enterotype, Eubacterium ventriosum (r BMI = -0.33, p = 0.03, and r HDL-c = 0.33, p = 0.04), Akkermansia (r 2h glucose = -0.35, p = 0.02), Roseburia (r BMI = -0.36, p = 0.02 and r waist = -0.36, p = 0.02), and Faecalibacterium (r insulin = -0.35, p = 0.02) abundances were associated to better cardiometabolic profile. The three enterotypes previously described are present in Brazilians, supporting that those bacterial clusters are not population-specific. Diet-independent lower LDL-c levels in subjects from Prevotella than in other enterotypes suggest that a protective bacterial cluster in the former should be driving this association. Enterotypes seem to be useful to understand the impact of daily diet exposure on cardiometabolic risk factors. Prospective studies are needed to confirm their utility for predicting phenotypes in humans.FAPESPUniv Sao Paulo, Sch Publ Hlth, Dept Epidemiol, Sao Paulo, BrazilFundacao Oswaldo Cruz, Rene Rachou Res Ctr, Belo Horizonte, MG, BrazilUniv Fed Sao Paulo, Dept Prevent Med, Sao Paulo, BrazilUniv Sao Paulo, Sch Med, Heart Inst Incor, Lab Genet & Mol Cardiol, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Prevent Med, Sao Paulo, BrazilFAPESP: 2012/12626-9FAPESP: 2012/03880-9Web of Scienc

    Avaliação da cultura de segurança do paciente na Amazônia Ocidental

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    Introdução: A cultura de segurança do paciente é fator contribuinte para a manutenção do bem-estar do usuário no sistema de saúde, pois por meio dela obtém-se uma sistematização organizada e de qualidade do cuidado ao paciente, prevenindo possíveis intercorrências que possam trazer danos. Objetivo: Analisar a Cultura de Segurança do Paciente (CSP) na perspectiva dos profissionais de saúde no Hospital de Referência do Alto Rio Juruá, na Amazônia Ocidental Brasileira. Método: Trata-se de um estudo transversal desenvolvido em um hospital público de médio porte em um município da Amazônia Ocidental. O questionário Hospital Survey on Patient Safety Culture, da Agency for Healthcare Research and Quality foi aplicado em 280 profissionais, no período dezembro de 2016 a fevereiro de 2017. Foi realizada a análise descritiva dos dados e a consistência interna do instrumento. Resultados: Os resultados apontam as melhores avaliações nas dimensões de Trabalho em equipe nos âmbitos das unidades (60%) e Aprendizado organizacional (60%). Os aspectos com os piores resultados foram as dimensões de Respostas não punitivas aos erros (18%) e Frequência de eventos relatados (32%). A análise de confiabilidade interna (Alpha de Cronbach) das dimensões variou entre 0,35 a 0,90. Conclusão: A cultura do medo parece predominar nesse hospital, contudo o estudo demonstrou que há possibilidades de melhoria em todas as dimensões da CSP. Os valores do Alpha de Cronbach apresentaram semelhança com os resultados obtidos pelo processo de validação.Introduction: The safety culture of the patient is a contributing factor for the maintenance of the user’s well-being in the health system because, through it, an organized systematization and quality of patient care are obtained, preventing possible intercurrences that can cause damages. Objective: To analyze the Patient Safety Culture (PSC) from the perspective of health professionals at the Reference Hospital of the Upper Juruá River, in the Brazilian Western Amazon. Methods: This is a cross-sectional study developed in a medium-sized public hospital in a municipality in Western Amazonia. The Survey for Patient Safety Culture survey of the Agency for Healthcare Research and Quality was applied to 280 professionals from December 2016 to February 2017. Descriptive analysis of the data and the internal consistency of the instrument were performed. Results: The results indicate the best evaluations in the dimensions of Teamwork in the scopes of the units (60%) and Organizational learning (60%). The aspects with the worst results were the dimensions of non-punitive responses to errors (18%) and frequency of events reported (32%). The internal reliability (Cronbach’s Alpha) analysis of the dimensions ranged from 0.35 to 0.90. Conclusion: The "culture of fear" seems to predominate in this hospital, however, the study showed that there is scope for improvement in all dimensions of CSP. The values of Cronbach’s Alpha presented similarity to the results obtained by the validation process

    Understanding the Influence of the Biomass-Derived Alcohols on the Activity and Stability of Pt Nanoparticles Supported on Graphene Nanoribbons

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    We produced Pt/GNRs by a one-step synthesis procedure and evaluated their electroactivity and stability towards glycerol electrooxidation reaction (GEOR) for the first time. We compared the electrocatalytic performance of GEOR with methanol and ethanol electrooxidation on Pt/GNRs at identical experimental conditions. The activities and stabilities for the electrooxidation of these biomass-derived alcohols on Pt/GNRs were compared to commercial Pt/C. The synthesis of the Pt/GNRs was confirmed by transmission electron microscopy, x-ray diffractometry, ultraviolet spectrophotometry, and Raman spectroscopy. We found that the activities of Pt/GNRs for these reactions are comparable to Pt/C, with improvement in terms of current density for methanol electrooxidation. Comparing potentiostatic measurements, we found that glycerol produces lower pseudo-stationary current densities than ethanol and methanol on both catalysts, with greatest values found for methanol electrooxidation on Pt/C. Otherwise, the GNRs remarkably enhance the stability of the catalyst for all the reactions, by increasing the stability of the current density during successive potential cycles, and by preventing the loss of electrochemically active surface area by avoiding carbon corrosion and Pt detachment. Moreover, we showed that the stability of the NPs depends on the biomass-derived alcohol used. The solution containing methanol reveals itself the most aggressive electrochemical environment to the catalyst, impacting in the decrease of surface area, while glycerol is less aggressive. Hence, the different products formed at the interface electrode/solution might lead to a different electrochemical environment, which plays an important role on the stability of the catalysts.The authors acknowledge financial assistance from CNPq (grant no. 454516/2014-2), FUNDECT (grant no. 026/2015), FAPESP (grant no. 2016/01365-0), CAPES, FINEP, and FAPESP.Peer reviewe

    Facing Erosion Identification in Railway Lines Using Pixel-wise Deep-based Approaches

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    Soil erosion is considered one of the most expensive natural hazards with a high impact on several infrastructure assets. Among them, railway lines are one of the most likely constructions for the appearance of erosion and, consequently, one of the most troublesome due to the maintenance costs, risks of derailments, and so on. Therefore, it is fundamental to identify and monitor erosion in railway lines to prevent major consequences. Currently, erosion identification is manually performed by humans using huge image sets, a time-consuming and slow task. Hence, automatic machine learning methods appear as an appealing alternative. A crucial step for automatic erosion identification is to create a good feature representation. Towards such objective, deep learning can learn data-driven features and classifiers. In this paper, we propose a novel deep learning-based framework capable of performing erosion identification in railway lines. Six techniques were evaluated and the best one, Dynamic Dilated ConvNet, was integrated into this framework that was then encapsulated into a new ArcGIS plugin to facilitate its use by non-programmer users. To analyze such techniques, we also propose a new dataset, composed of almost 2,000 high-resolution images

    Desafios e possibilidades da Educação Ambiental nas escolas públicas: o caso da cidade de São Paulo

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    From a critical perspective of environmental education, the objective of this work was to analyze, through a diagnostic questionnaire, the challenges and possibilities related to environmental education in municipal schools of São Paulo. The data were analyzed quantitatively and qualitatively, considering contributions from content analysis. The results showed a clear awareness of socio-environmental problems in the system and that, despite the challenges, most schools develop or have developed environmental education projects.Desde una perspectiva crítica de la educación ambiental, el objetivo de este trabajo fue analizar, a través de un cuestionario de diagnóstico, los desafíos y posibilidades relacionados con la educación ambiental en las escuelas municipales de San Pablo. Los datos fueron analizados cuantitativa y cualitativamente, considerando las aportaciones del análisis de contenido. Los resultados mostraron una clara conciencia en la red de los problemas socioambientales y que, a pesar de los desafíos, la mayoría de las escuelas desarrollan o han desarrollado proyectos de educación ambiental.Partindo de uma perspectiva crítica de educação ambiental, o objetivo deste trabalho foi analisar, por meio de questionário diagnóstico, desafios e possibilidades relacionados à educação ambiental das escolas municipais de São Paulo. Os dados foram analisados de forma quantitativa e qualitativa, considerando contribuições da análise de conteúdo. Os resultados mostraram uma consciência clara na rede dos problemas socioambientais e que, apesar dos desafios, a maioria das escolas desenvolve ou já desenvolveu projetos de EA
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