3,320 research outputs found

    Measured data of Drosophila melanogaster (Diptera Drosophilidae) development and learning and memory behaviour after copper exposition

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    This article presents the statistical analysis data from Drosophila melanogaster development (from larvae to adult) and learning and memory retention behavior of a Pavlovian conditioning in male and female flies exposed to copper. While the full data sets are available In the article: Copper decrease associative learning and memory in D. melanogaster, this data-in-brief article includes the detailed statistical analysis performed. Data demonstrates Statistica Software analysis between the subject part of the analysis: 2 treatments x 2 sexes x 2 ages and within subject part of the analysis: 2 treatments x 2 sex x 2 ages x 4 times, repeated measures

    Graphene-Based Materials Immobilized within Chitosan: Applications as Adsorbents for the Removal of Aquatic Pollutants

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    Graphene and its derivatives, especially graphene oxide (GO), are attracting considerable interest in the fabrication of new adsorbents that have the potential to remove various pollutants that have escaped into the aquatic environment. Herein, the development of GO/chitosan (GO/CS) composites as adsorbent materials is described and reviewed. This combination is interesting as the addition of graphene to chitosan enhances its mechanical properties, while the chitosan hydrogel serves as an immobilization matrix for graphene. Following a brief description of both graphene and chitosan as independent adsorbent materials, the emerging GO/CS composites are introduced. The additional materials that have been added to the GO/CS composites, including magnetic iron oxides, chelating agents, cyclodextrins, additional adsorbents and polymeric blends, are then described and discussed. The performance of these materials in the removal of heavy metal ions, dyes and other organic molecules are discussed followed by the introduction of strategies employed in the regeneration of the GO/CS adsorbents. It is clear that, while some challenges exist, including cost, regeneration and selectivity in the adsorption process, the GO/CS composites are emerging as promising adsorbent materials

    “Não quero perder meu Português”: Uma conversa sobre a experiência do Português como língua de herança / “I don’t want to lose my Portuguese”: A conversation about the experience of Portuguese as heritage language

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    O que caracteriza a experiência do Português como língua de herança? Este texto apresenta uma entrevista que realizei com a Profa. Me. Daniele Ferreira, logo após a conclusão de sua pesquisa de Mestrado sobre manutenção do português como língua de herança. Aqui, são realçadas questões centrais de pressupostos teóricos concernentes ao tema, bem como sua própria experiência como mãe-professora-pesquisadora e sua trajetória na alfabetização de crianças longe da terra natal.

    Boosting spatial resolution by incorporating periodic boundary conditions into single-distance hard-x-ray phase retrieval

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    A simple coherent-imaging method due to Paganin et al. is widely employed for phase-amplitude reconstruction of samples using a single paraxial x-ray propagation-based phase-contrast image. The method assumes that the sample-to-detector distance is sufficiently small for the associated Fresnel number to be large compared to unity. The algorithm is particularly effective when employed in a tomographic setting, using a single propagation-based phase-contrast image for each projection. Here we develop a simple extension of the method, which improves the reconstructed contrast of very fine sample features. This provides first-principles motivation for boosting fine spatial detail associated with high Fourier frequencies, relative to the original method, and was inspired by several recent works employing empirically-obtained Fourier filters to a similar end

    Cyclodextrins as Supramolecular Recognition Systems: Applications in the Fabrication of Electrochemical Sensors

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    Supramolecular chemistry, although focused mainly on noncovalent intermolecular and intramolecular interactions, which are considerably weaker than covalent interactions, can be employed to fabricate sensors with a remarkable affinity for a target analyte. In this review the development of cyclodextrin-based electrochemical sensors is described and discussed. Following a short introduction to the general properties of cyclodextrins and their ability to form inclusion complexes, the cyclodextrin-based sensors are introduced. This includes the combination of cyclodextrins with reduced graphene oxide, carbon nanotubes, conducting polymers, enzymes and aptamers, and electropolymerized cyclodextrin films. The applications of these materials as chiral recognition agents and biosensors and in the electrochemical detection of environmental contaminants, biomolecules and amino acids, drugs and flavonoids are reviewed and compared. Based on the papers reviewed, it is clear that cyclodextrins are promising molecular recognition agents in the creation of electrochemical sensors, chiral sensors, and biosensors. Moreover, they have been combined with a host of materials to enhance the detection of the target analytes. Nevertheless, challenges remain, including the development of more robust methods for the integration of cyclodextrins into the sensing unit

    The association between cardiovascular risk factors and major cardiovascular diseases decreases with increasing frailty levels in geriatric outpatients

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    BACKGROUND: Frailty marks a process of increasing dysregulation of physiological systems which increases the risk of adverse health outcomes. This study examines the hypothesis that the association between multiple cardiovascular risk factors (CVRF) and cardiovascular diseases (CVD) becomes stronger with increasing frailty severity. METHODS: Cross-sectional analysis of 339 older adults (55.2% women; aged 75.2 ± 9.1 years) from an outpatient geriatric clinic from a middle-income country. The frailty index (FI) was calculated as the proportion of 30 possible health deficits. We assessed hypertension, diabetes, obesity, dyslipidemia, sedentarism and smoking as CVRF (determinants) and myocardial infarction, stroke, heart failure as CVD. Poisson regression models adjusted for age, sex, and education was applied to estimate the association between frailty as well as CVRF (independent variables) with CVD (dependent variable). RESULTS: Of the 339 patients, 18,3% were frail (FI ≥ 0.25) and 32.7% had at least one CVD. Both frailty and CVRF were significantly associated with CVD (PR = 1.03, 95% CI 1.01 to 1.05; p = 0.001, and PR = 1.46, 95% 1.24 to 1.71; p < 0.001, respectively) adjusted for covariates. The strength of the association between CVRF and CVD decreased with increasing frailty levels, as indicated by a significant interaction term of frailty and CVRF (p < 0.001). CONCLUSION: Frailty and CVRF are both associated with CVD, but the impact of CVRF decreases in the presence of frailty. When confirmed in longitudinal studies, randomized controlled trials or causal inference methods like Mendelian randomization should be applied to assess whether a shift from traditional CVRF to frailty would improve cardiovascular outcome in the oldest old

    Serologic Survey of Hantavirus Infection, Brazilian Amazon

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    Federal University of Maranhão. São Luís, MA, Brazil.Federal University of Maranhão. São Luís, MA, Brazil.Federal University of Maranhão. São Luís, MA, Brazil.Federal University of Maranhão. São Luís, MA, Brazil.Federal University of Maranhão. São Luís, MA, Brazil.Federal University of Maranhão. São Luís, MA, Brazil.State Department of Health. São Luís, MA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil

    Recent Developments in Chitosan-Based Adsorbents for the Removal of Pollutants from Aqueous Environments

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    The quality of water is continuously under threat as increasing concentrations of pollutants escape into the aquatic environment. However, these issues can be alleviated by adsorbing pollutants onto adsorbents. Chitosan and its composites are attracting considerable interest as environmentally acceptable adsorbents and have the potential to remove many of these contaminants. In this review the development of chitosan-based adsorbents is described and discussed. Following a short introduction to the extraction of chitin from seafood wastes, followed by its conversion to chitosan, the properties of chitosan are described. Then, the emerging chitosan/carbon-based materials, including magnetic chitosan and chitosan combined with graphene oxide, carbon nanotubes, biochar, and activated carbon and also chitosan-silica composites are introduced. The applications of these materials in the removal of various heavy metal ions, including Cr(VI), Pb(II), Cd(II), Cu(II), and different cationic and anionic dyes, phenol and other organic molecules, such as antibiotics, are reviewed, compared and discussed. Adsorption isotherms and adsorption kinetics are then highlighted and followed by details on the mechanisms of adsorption and the role of the chitosan and the carbon or silica supports. Based on the reviewed papers, it is clear, that while some challenges remain, chitosan-based materials are emerging as promising adsorbents

    Implementation of management actions at an association of recyclable materials.

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    O artigo apresenta as a??es e os resultados de um projeto de extens?o intitulado ?Implementa??o de A??es Gestion?rias em uma Associa??o de Catadores de Materiais Recicl?veis?. Promoveram-se capacita??es e interven??es f?sicas na associa??o, as quais contribu?ram para o seu desenvolvimento e perpetua??o. A associa??o, que ? a ?nica fonte de renda dos catadores, foi fundada em 2006 pela Prefeitura de Ouro Preto-MG para retir?-los das condi??es prec?rias de trabalho no lix?o do munic?pio. A metodologia utilizada foi de car?ter qualitativo, com observa??o direta, entrevistas semiestruturadas e princ?pios da andragogia, a qual proporcionou maior intera??o entre pesquisadores e catadores, facilitando a troca de saberes e a apropria??o das t?cnicas utilizadas. Como resultado, t?m-se melhorias na divulga??o, na periodicidade e nas rotas da coleta seletiva; na organiza??o do trabalho, nos aspectos ergon?micos, no aumento do volume coletado e na gera??o de renda

    Catheter-associated urinary infections and consequences of using coated versus non-coated urethral catheters-outcomes of a systematic review and meta-analysis of randomized trials

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    Coated urethral catheters were introduced in clinical practice to reduce the risk of catheter-acquired urinary tract infection (CAUTI). We aimed to systematically review the incidence of CAUTI and adverse effects in randomized clinical trials of patients requiring indwelling bladder catheterization by comparing coated vs. non-coated catheters. This review was performed according to the 2020 PRISMA framework. The incidence of CAUTI and catheter-related adverse events was evaluated using the Cochran-Mantel-Haenszel method with a random-effects model and reported as the risk ratio (RR), 95% CI, and p-values. Significance was set at p 14 days) (RR 0.82 95% CI 0.68-0.99, p = 0.04). There was no difference between the two groups in the incidence of the need for catheter exchange or the incidence of lower urinary tract symptoms after catheter removal. The benefit of coated catheters in reducing CAUTI risk among patients requiring long-term catheterization should be balanced against the increased direct costs to health care systems when compared to non-coated catheters
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