1,124 research outputs found

    Graphene oxide and a GO/ZnO nanocomposite as catalysts for epoxy ring-opening of epoxidized soybean fatty acids methyl esters

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    In this work, the grapheme oxide (GO) and GO/ZnO nanocomposite were successfully obtained from the oxidation of graphite and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). In the GO/ZnO nanocomposite, the GO sheets were coated with aggregated ZnO nanoneedles with ca. 20 nm of diameter. The obtained materials were used as heterogeneous catalysts for acetylation of Soybean Fatty Acids Methyl Esters (FAME), promoting the epoxy ring-opening using acetic anhydride. The epoxy ring was almost completely opened in the presence of GO or GO/ZnO nanocomposites, with conversion rates up to 99% and selectivity of ca. 90%, and partially opened using only ZnO. The GO/Zn and GO catalysts were reused three times with conversion rates of ca. 85 and 74%, respectively

    Mouse transcriptome reveals potential signatures of protection and pathogenesis in human tuberculosis

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    Although mouse infection models have been extensively used to study the host response to Mycobacterium tuberculosis, their validity in revealing determinants of human tuberculosis (TB) resistance and disease progression has been heavily debated. Here, we show that the modular transcriptional signature in the blood of susceptible mice infected with a clinical isolate of M. tuberculosis resembles that of active human TB disease, with dominance of a type I interferon response and neutrophil activation and recruitment, together with a loss in B lymphocyte, natural killer and T cell effector responses. In addition, resistant but not susceptible strains of mice show increased lung B cell, natural killer and T cell effector responses in the lung upon infection. Notably, the blood signature of active disease shared by mice and humans is also evident in latent TB progressors before diagnosis, suggesting that these responses both predict and contribute to the pathogenesis of progressive M. tuberculosis infection

    Abnormal NK cell lymphocytosis detected after splenectomy: association with repeated infections, relapsing neutropenia, and persistent polyclonal B-cell proliferation

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    Abnormal NK cell lymphocytosis detected after splenectomy: association with repeated infections, relapsing neutropenia, and persistent polyclonal B-cell proliferation. Granjo E, Lima M, Fraga M, Santos F, Magalhães C, Queirós ML, Moreira I, Rocha S, Silva AS, Rebelo I, Quintanilha A, Ribeiro ML, Candeias J, Orfão A. Department of Hematology, Hospital S. João, Porto, Portugal. [email protected] Abstract We report the case of a boy with hereditary spherocytosis who presented with mild microcytic hypochromic anemia and recurrent leg ulcers that had been present since childhood. Chronic natural killer (NK) cell and B-cell lymphocytosis was detected 1 year after therapeutic splenectomy during investigation of recurrent episodes of neutropenia and persistent lymphocytosis. NK cells proved to be abnormal at immunophenotyping studies, and B-cells were polyclonal and displayed a normal immunophenotype. Genotypic analysis of T-cell receptor (TCR)-beta and TCR-gamma genes showed a germ-line pattern. The clinical course of this patient was characterized by multiple pulmonary infections and amygdalitis. We discuss the potential roles of persistent immune stimulation due to chronic hemolysis and severe leg ulcers and of splenectomy in the origin of NK cell lymphocytosis and the relationship between NK cells and recurrent infections, relapsing neutropenia, and polyclonal B-cell response

    Tomo 1: Prácticas, saberes y conocimientos

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    El libro de Investigación Diferentes Geografías de la Infancia: Experiencias y vivencias investigativas en Latinoamérica tiene como objetivo poder visibilizar los trabajos y avances investigativos dados en el área de la Geografía de la Infancia. Es una colección de cuatro Tomos, para el TOMO No. 1 Prácticas, Saberes, Conocimientos, se presentan las investigaciones desarrolladas con diferentes comunidades tanto indígenas como afrodescendientes en tres países: Brasil, Colombia y México. El Tomo está dividido en cuatro partes: 1) Territorio Convivido donde se muestra el trabajo desarrollado por un Grupo de Investigación Brasilero durante sus 12 años de existencia y evidencia los avances teóricos – metodológicos que marcan la ruta a seguir en la Investigación con niños y niñas en diferentes Geografías; para las partes 2, 3 y 4 se da cuenta de las investigaciones desarrolladas en los países ya mencionados: Colombia, Brasil y México. Los hallazgos más importantes están dados por la re-elaboración y el reconocimiento que hacen los niños y niñas a su territorio, espacio y lugar claramente diferenciados por la vivencia que tienen en relación con esos contextos en los que se encuentran inseridos, los datos son recabados a través de diferentes artefactos culturales entre ellos mapas vivenciales, cartografías sociales, dibujos y diferentes producciones de autoría infantil. Como contribución y conclusión al Campo de la Geografía de la Infancia se tiene el reconocimiento de los niños y niñas como sujetos sociales, culturales e históricos que se sustentan a través de la autoría de cada una de las producciones y por el protagonismo infantil que cobran en cada una de las investigaciones. Además, que, trae a discusión metodologías diferenciadas que dan cuenta de una Cultura Infantil que comienza a ser reconocida por nosotros los adultos.La Fundación Universitaria del Área Andina, en concordancia con su misión institucional, “Contribuir al desarrollo sostenible con calidad y pertinencia mediante la apropiación, aplicación y transferencia de conocimiento y la formación integral y permanente de personas, desde un enfoque humanista, y de pensamiento crítico y reflexivo”, establece un plan estratégico de desarrollo en el que se tienen en cuenta los Objetivos de Desarrollo Sostenible 2030 y el pensamiento fundacional mediante el imperativo de “Formación de calidad, innovadora y creadora de valor en la geografía nacional e internacional, fortaleciendo y propendiendo por la integración de la Comunidad Andina”. En consecuencia, el programa de Licenciatura en Pedagogía Infantil adscrito a la Facultad de Educación, tiene por objeto de conocimiento la reflexión en torno a la formación de maestros y, por tanto, propuso en el año 2014 una serie de estrategias académicas relacionadas con la producción de conocimiento para la formulación de proyectos de investigación en cooperación internacional e interinstitucional. Como resultado del trabajo de los últimos tres años de investigación, se obtiene la presente colección de libros denominada Diferentes Geografías de la Infancia: Experiencias y vivencias investigativas en Latinoamérica. Los doctores Mathusalam Pantevis Suárez, Jader Janer Lopes Moreira y Patricia Medina Melgarejo aportaron su experiencia y conocimiento para la compilación de capítulos que aportan al objetivo de la alianza en cuatro tomos: el primero “Prácticas, saberes y conocimientos”; el segundo, “Territorios usados por los niños y reelaborados”; el tercero, “Infancias y contemporaneidades”, y el cuarto, “Actores de la educación: del ser al quehacer docente”. Los diferentes capítulos exponen resultados de investigaciones que fortalecen la producción de conocimiento y la apropiación social de los grupos de investigación de Kompetenz de la Fundación Universitaria del Área Andina, GRUPEGI de la Universidade Federal de Juiz de Fora y Tendencias Actuales en Educación y Pedagogía (TAEPE) de la Universidad San Buenaventura, Bogotá

    Pathways of Superoxide (O2-) decay in the Eastern Tropical North Atlantic

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    Superoxide (O2-: IUPAC name dioxide (•1−)) is an important transient reactive oxygen species (ROS) in the ocean formed as an intermediate in the redox transformation of oxygen (O2) into hydrogen peroxide (H2O2) and vice versa. This highly reactive and very short-lived radical anion can be produced both via photochemical and biological processes in the ocean. In this paper we examine the decomposition rate of O2- throughout the water column, using new data collected in the Eastern Tropical North Atlantic (ETNA) Ocean. For this approach we applied a semi factorial experimental design, to identify and quantify the pathways of the major identified sinks in the ocean. In this work we occupied 6 stations, 2 on the West African continental shelf and 4 open ocean stations, including the CVOO time series site adjacent to Cape Verde. Our results indicate that in the surface ocean, impacted by Saharan aerosols and sediment resuspension, the main decay pathways for superoxide is via reactions with Mn(II) and organic matter

    Developmental consequences of perinatal cannabis exposure: behavioral and neuroendocrine effects in adult rodents

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    Cannabis is the most commonly used illicit drug among pregnant women. Since the endocannabinoid system plays a crucial role in brain development, maternal exposure to cannabis derivatives might result in long-lasting neurobehavioral abnormalities in the exposed offspring. It is difficult to detect these effects, and their underlying neurobiological mechanisms, in clinical cohorts, because of their intrinsic methodological and interpretative issues. The present paper reviews relevant rodent studies examining the long-term behavioral consequences of exposure to cannabinoid compounds during pregnancy and/or lactation. Maternal exposure to even low doses of cannabinoid compounds results in atypical locomotor activity, cognitive impairments, altered emotional behavior, and enhanced sensitivity to drugs of abuse in the adult rodent offspring. Some of the observed behavioral abnormalities might be related to alterations in stress hormone levels induced by maternal cannabis exposure. There is increasing evidence from animal studies showing that cannabinoid drugs are neuroteratogens which induce enduring neurobehavioral abnormalities in the exposed offspring. Several preclinical findings reviewed in this paper are in line with clinical studies reporting hyperactivity, cognitive impairments and altered emotionality in humans exposed in utero to cannabis. Conversely, genetic, environmental and social factors could also influence the neurobiological effects of early cannabis exposure in humans

    Factors influencing terrestriality in primates of the Americas and Madagascar

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    Among mammals, the order Primates is exceptional in having a high taxonomic richness in which the taxa are arboreal, semiterrestrial, or terrestrial. Although habitual terrestriality is pervasive among the apes and African and Asian monkeys (catarrhines), it is largely absent among monkeys of the Americas (platyrrhines), as well as galagos, lemurs, and lorises (strepsirrhines), which are mostly arboreal. Numerous ecological drivers and species-specific factors are suggested to set the conditions for an evolutionary shift from arboreality to terrestriality, and current environmental conditions may provide analogous scenarios to those transitional periods. Therefore, we investigated predominantly arboreal, diurnal primate genera from the Americas and Madagascar that lack fully terrestrial taxa, to determine whether ecological drivers (habitat canopy cover, predation risk, maximum temperature, precipitation, primate species richness, human population density, and distance to roads) or species-specific traits (bodymass, group size, and degree of frugivory) associate with increased terrestriality. We collated 150,961 observation hours across 2,227 months from 47 species at 20 sites in Madagascar and 48 sites in the Americas. Multiple factors were associated with ground use in these otherwise arboreal species, including increased temperature, a decrease in canopy cover, a dietary shift away from frugivory, and larger group size. These factors mostly explain intraspecific differences in terrestriality. As humanity modifies habitats and causes climate change, our results suggest that species already inhabiting hot, sparsely canopied sites, and exhibiting more generalized diets, are more likely to shift toward greater ground use

    Risk Factors Associated with Adverse Fetal Outcomes in Pregnancies Affected by Coronavirus Disease 2019 (COVID-19): A Secondary Analysis of the WAPM study on COVID-19

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    To evaluate the strength of association between maternal and pregnancy characteristics and the risk of adverse perinatal outcomes in pregnancies with laboratory confirmed COVID-19. Secondary analysis of a multinational, cohort study on all consecutive pregnant women with laboratory-confirmed COVID-19 from February 1, 2020 to April 30, 2020 from 73 centers from 22 different countries. A confirmed case of COVID-19 was defined as a positive result on real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of nasal and pharyngeal swab specimens. The primary outcome was a composite adverse fetal outcome, defined as the presence of either abortion (pregnancy loss before 22 weeks of gestations), stillbirth (intrauterine fetal death after 22 weeks of gestation), neonatal death (death of a live-born infant within the first 28 days of life), and perinatal death (either stillbirth or neonatal death). Logistic regression analysis was performed to evaluate parameters independently associated with the primary outcome. Logistic regression was reported as odds ratio (OR) with 95% confidence interval (CI). Mean gestational age at diagnosis was 30.6\ub19.5 weeks, with 8.0% of women being diagnosed in the first, 22.2% in the second and 69.8% in the third trimester of pregnancy. There were six miscarriage (2.3%), six intrauterine device (IUD) (2.3) and 5 (2.0%) neonatal deaths, with an overall rate of perinatal death of 4.2% (11/265), thus resulting into 17 cases experiencing and 226 not experiencing composite adverse fetal outcome. Neither stillbirths nor neonatal deaths had congenital anomalies found at antenatal or postnatal evaluation. Furthermore, none of the cases experiencing IUD had signs of impending demise at arterial or venous Doppler. Neonatal deaths were all considered as prematurity-related adverse events. Of the 250 live-born neonates, one (0.4%) was found positive at RT-PCR pharyngeal swabs performed after delivery. The mother was tested positive during the third trimester of pregnancy. The newborn was asymptomatic and had negative RT-PCR test after 14 days of life. At logistic regression analysis, gestational age at diagnosis (OR: 0.85, 95% CI 0.8-0.9 per week increase; p<0.001), birthweight (OR: 1.17, 95% CI 1.09-1.12.7 per 100 g decrease; p=0.012) and maternal ventilatory support, including either need for oxygen or CPAP (OR: 4.12, 95% CI 2.3-7.9; p=0.001) were independently associated with composite adverse fetal outcome. Early gestational age at infection, maternal ventilatory supports and low birthweight are the main determinants of adverse perinatal outcomes in fetuses with maternal COVID-19 infection. Conversely, the risk of vertical transmission seems negligible

    Variability in the analysis of a single neuroimaging dataset by many teams

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    Data analysis workflows in many scientific domains have become increasingly complex and flexible. To assess the impact of this flexibility on functional magnetic resonance imaging (fMRI) results, the same dataset was independently analyzed by 70 teams, testing nine ex-ante hypotheses. The flexibility of analytic approaches is exemplified by the fact that no two teams chose identical workflows to analyze the data. This flexibility resulted in sizeable variation in hypothesis test results, even for teams whose statistical maps were highly correlated at intermediate stages of their analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Importantly, meta-analytic approaches that aggregated information across teams yielded significant consensus in activated regions across teams. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset. Our findings show that analytic flexibility can have substantial effects on scientific conclusions, and demonstrate factors related to variability in fMRI. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for multiple analyses of the same data. Potential approaches to mitigate issues related to analytical variability are discussed

    Variability in the analysis of a single neuroimaging dataset by many teams

    Get PDF
    Data analysis workflows in many scientific domains have become increasingly complex and flexible. To assess the impact of this flexibility on functional magnetic resonance imaging (fMRI) results, the same dataset was independently analyzed by 70 teams, testing nine ex-ante hypotheses. The flexibility of analytic approaches is exemplified by the fact that no two teams chose identical workflows to analyze the data. This flexibility resulted in sizeable variation in hypothesis test results, even for teams whose statistical maps were highly correlated at intermediate stages of their analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Importantly, meta-analytic approaches that aggregated information across teams yielded significant consensus in activated regions across teams. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset. Our findings show that analytic flexibility can have substantial effects on scientific conclusions, and demonstrate factors related to variability in fMRI. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for multiple analyses of the same data. Potential approaches to mitigate issues related to analytical variability are discussed
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