145 research outputs found

    Glassy Carbon Electrode Modified with Layering of Carbon Black/Poly(Allylamine Hydrochloride) Composite for Multianalyte Determination

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    © 2020 Wiley-VCH GmbH An electrochemical sensor using glassy carbon electrode modified with carbon black within a poly(allylamine hydrochloride) film is proposed in this work. The novel sensor was characterized by scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry using the redox probe Fe(CN)63−/4−. The sensor was applied for the simultaneous determination of dopamine (DA), paracetamol (PAR), amlodipine (AML), and rosuvastatin (RSV). The quantification of all four analytes was carried out by linear sweep voltammetry and presented a linear concentration range for all analytes from 1.0 to 90 μmol L−1, with limit of detection of 0.55, 1.3, 5.7, and 3.0 μmol L−1 for DA, PAR, AML, and RSV, respectively. This sensor was successfully applied in the simultaneous determination of these analytes in environmental, pharmaceutical, and biological samples

    Application of botryosphaeran as a carbon black adherent on a glassy carbon electrode for the electrochemical determination of cyclobenzaprine

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    The present work describes the performance of a new voltammetric sensor based on the modification of glassy carbon electrodes (GCE) with carbon black (CB) and botryosphaeran (BOT) (CB-BOT/GCE) for the electroanalytical determination of cyclobenzaprine. BOT is a fungal exocellular (1→3)(1→6)-β-ᴅ-glucan, which was used to improve the adherence of CB onto the surface of GCE. The electrochemical characterisation was performed by electrochemical impedance spectroscopy which showed an improvement in the transfer of electrons on the surface of the sensor developed in relation to the unmodified (bare) GCE. The voltammetric behaviour of cyclobenzaprine was studied using bare GCE, BOT/GCE, CB/GCE, and CB-BOT/GCE. All electrodes presented an oxidation peak (+ 1.0 V) for cyclobenzaprine, while the cyclobenzaprine peak intensity on CB-BOT/GCE was found to be 480% higher than the bare GCE. Through employing square-wave voltammetry, the analytical curve was found to be linear over the concentration range of 2.0 to 20.6 μmol L−1 (in 0.1 mol L−1 NaCl solution) with a detection limit (based on 3-sigma) of 0.63 μmol L−1. The developed electrochemical sensor exhibited excellent sensitivity and selectivity and was successfully applied for the voltammetric determination of cyclobenzaprine in pharmaceutical, biological, and environmental samples for the first time using the CB-BOT/GCE electrochemical sensing platform

    Time course and specificity of sensory-motor alpha modulation during the observation of hand motor acts and gestures: a high density EEG study

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    The main aim of the present study was to explore, by means of high-density EEG, the intensity and the temporal pattern of event-related sensory-motor alpha desynchronization (ERD) during the observation of different types of hand motor acts and gestures. In particular, we aimed to investigate whether the sensory-motor ERD would show a specific modulation during the observation of hand behaviors differing for goal-relatedness (hand grasping of an object and meaningless hand movements) and social relevance (communicative hand gestures and grasping within a social context). Time course analysis of alpha suppression showed that all types of hand behaviors were effective in triggering sensory-motor alpha ERD, but to a different degree depending on the category of observed hand motor acts and gestures. Meaningless gestures and hand grasping were the most effective stimuli, resulting in the strongest ERD. The observation of social hand behaviors such as social grasping and communicative gestures, triggered a more dynamic time course of ERD compared to that driven by the observation of simple grasping and meaningless gestures. These findings indicate that the observation of hand motor acts and gestures evoke the activation of a motor resonance mechanism that differs on the basis of the goal-relatedness and the social relevance of the observed hand behavior

    Molecular phylogeny and timing of diversification in Alpine Rhithrogena (Ephemeroptera: Heptageniidae).

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    BACKGROUND: Larvae of the Holarctic mayfly genus Rhithrogena Eaton, 1881 (Ephemeroptera, Heptageniidae) are a diverse and abundant member of stream and river communities and are routinely used as bio-indicators of water quality. Rhithrogena is well diversified in the European Alps, with a number of locally endemic species, and several cryptic species have been recently detected. While several informal species groups are morphologically well defined, a lack of reliable characters for species identification considerably hampers their study. Their relationships, origin, timing of speciation and mechanisms promoting their diversification in the Alps are unknown. RESULTS: Here we present a species-level phylogeny of Rhithrogena in Europe using two mitochondrial and three nuclear gene regions. To improve sampling in a genus with many cryptic species, individuals were selected for analysis according to a recent DNA-based taxonomy rather than traditional nomenclature. A coalescent-based species tree and a reconstruction based on a supermatrix approach supported five of the species groups as monophyletic. A molecular clock, mapped on the most resolved phylogeny and calibrated using published mitochondrial evolution rates for insects, suggested an origin of Alpine Rhithrogena in the Oligocene/Miocene boundary. A diversification analysis that included simulation of missing species indicated a constant speciation rate over time, rather than any pronounced periods of rapid speciation. Ancestral state reconstructions provided evidence for downstream diversification in at least two species groups. CONCLUSIONS: Our species-level analyses of five gene regions provide clearer definitions of species groups within European Rhithrogena. A constant speciation rate over time suggests that the paleoclimatic fluctuations, including the Pleistocene glaciations, did not significantly influence the tempo of diversification of Alpine species. A downstream diversification trend in the hybrida and alpestris species groups supports a previously proposed headwater origin hypothesis for aquatic insects

    Ursolic Acid Increases Skeletal Muscle and Brown Fat and Decreases Diet-Induced Obesity, Glucose Intolerance and Fatty Liver Disease

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    Skeletal muscle Akt activity stimulates muscle growth and imparts resistance to obesity, glucose intolerance and fatty liver disease. We recently found that ursolic acid increases skeletal muscle Akt activity and stimulates muscle growth in non-obese mice. Here, we tested the hypothesis that ursolic acid might increase skeletal muscle Akt activity in a mouse model of diet-induced obesity. We studied mice that consumed a high fat diet lacking or containing ursolic acid. In skeletal muscle, ursolic acid increased Akt activity, as well as downstream mRNAs that promote glucose utilization (hexokinase-II), blood vessel recruitment (Vegfa) and autocrine/paracrine IGF-I signaling (Igf1). As a result, ursolic acid increased skeletal muscle mass, fast and slow muscle fiber size, grip strength and exercise capacity. Interestingly, ursolic acid also increased brown fat, a tissue that shares developmental origins with skeletal muscle. Consistent with increased skeletal muscle and brown fat, ursolic acid increased energy expenditure, leading to reduced obesity, improved glucose tolerance and decreased hepatic steatosis. These data support a model in which ursolic acid reduces obesity, glucose intolerance and fatty liver disease by increasing skeletal muscle and brown fat, and suggest ursolic acid as a potential therapeutic approach for obesity and obesity-related illness

    Genome-Wide Association Analysis of Oxidative Stress Resistance in Drosophila melanogaster

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    Background: Aerobic organisms are susceptible to damage by reactive oxygen species. Oxidative stress resistance is a quantitative trait with population variation attributable to the interplay between genetic and environmental factors. Drosophila melanogaster provides an ideal system to study the genetics of variation for resistance to oxidative stress. Methods and Findings: We used 167 wild-derived inbred lines of the Drosophila Genetic Reference Panel for a genomewide association study of acute oxidative stress resistance to two oxidizing agents, paraquat and menadione sodium bisulfite. We found significant genetic variation for both stressors. Single nucleotide polymorphisms (SNPs) associated with variation in oxidative stress resistance were often sex-specific and agent-dependent, with a small subset common for both sexes or treatments. Associated SNPs had moderately large effects, with an inverse relationship between effect size and allele frequency. Linear models with up to 12 SNPs explained 67–79 % and 56–66 % of the phenotypic variance for resistance to paraquat and menadione sodium bisulfite, respectively. Many genes implicated were novel with no known role in oxidative stress resistance. Bioinformatics analyses revealed a cellular network comprising DNA metabolism and neuronal development, consistent with targets of oxidative stress-inducing agents. We confirmed associations of seven candidate genes associated with natural variation in oxidative stress resistance through mutational analysis. Conclusions: We identified novel candidate genes associated with variation in resistance to oxidative stress that hav

    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

    Measurement of the branching fraction for the decay BK(892)+B \to K^{\ast}(892)\ell^+\ell^- at Belle II

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    We report a measurement of the branching fraction of BK(892)+B \to K^{\ast}(892)\ell^+\ell^- decays, where +=μ+μ\ell^+\ell^- = \mu^+\mu^- or e+ee^+e^-, using electron-positron collisions recorded at an energy at or near the Υ(4S)\Upsilon(4S) mass and corresponding to an integrated luminosity of 189189 fb1^{-1}. The data was collected during 2019--2021 by the Belle II experiment at the SuperKEKB e+ee^{+}e^{-} asymmetric-energy collider. We reconstruct K(892)K^{\ast}(892) candidates in the K+πK^+\pi^-, KS0π+K_{S}^{0}\pi^+, and K+π0K^+\pi^0 final states. The signal yields with statistical uncertainties are 22±622\pm 6, 18±618 \pm 6, and 38±938 \pm 9 for the decays BK(892)μ+μB \to K^{\ast}(892)\mu^+\mu^-, BK(892)e+eB \to K^{\ast}(892)e^+e^-, and BK(892)+B \to K^{\ast}(892)\ell^+\ell^-, respectively. We measure the branching fractions of these decays for the entire range of the dilepton mass, excluding the very low mass region to suppress the BK(892)γ(e+e)B \to K^{\ast}(892)\gamma(\to e^+e^-) background and regions compatible with decays of charmonium resonances, to be \begin{equation} {\cal B}(B \to K^{\ast}(892)\mu^+\mu^-) = (1.19 \pm 0.31 ^{+0.08}_{-0.07}) \times 10^{-6}, {\cal B}(B \to K^{\ast}(892)e^+e^-) = (1.42 \pm 0.48 \pm 0.09)\times 10^{-6}, {\cal B}(B \to K^{\ast}(892)\ell^+\ell^-) = (1.25 \pm 0.30 ^{+0.08}_{-0.07}) \times 10^{-6}, \end{equation} where the first and second uncertainties are statistical and systematic, respectively. These results, limited by sample size, are the first measurements of BK(892)+B \to K^{\ast}(892)\ell^+\ell^- branching fractions from the Belle II experiment

    JPN Guidelines for the management of acute pancreatitis: epidemiology, etiology, natural history, and outcome predictors in acute pancreatitis

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    Acute pancreatitis is a common disease with an annual incidence of between 5 and 80 people per 100 000 of the population. The two major etiological factors responsible for acute pancreatitis are alcohol and cholelithiasis (gallstones). The proportion of patients with pancreatitis caused by alcohol or gallstones varies markedly in different countries and regions. The incidence of acute alcoholic pancreatitis is considered to be associated with high alcohol consumption. Although the incidence of alcoholic pancreatitis is much higher in men than in women, there is no difference in sexes in the risk involved after adjusting for alcohol intake. Other risk factors include endoscopic retrograde cholangiopancreatography, surgery, therapeutic drugs, HIV infection, hyperlipidemia, and biliary tract anomalies. Idiopathic acute pancreatitis is defined as acute pancreatitis in which the etiological factor cannot be specified. However, several studies have suggested that this entity includes cases caused by other specific disorders such as microlithiasis. Acute pancreatitis is a potentially fatal disease with an overall mortality of 2.1%–7.8%. The outcome of acute pancreatitis is determined by two factors that reflect the severity of the illness: organ failure and pancreatic necrosis. About half of the deaths in patients with acute pancreatitis occur within the first 1–2 weeks and are mainly attributable to multiple organ dysfunction syndrome (MODS). Depending on patient selection, necrotizing pancreatitis develops in approximately 10%–20% of patients and the mortality is high, ranging from 14% to 25% of these patients. Infected pancreatic necrosis develops in 30%–40% of patients with necrotizing pancreatitis and the incidence of MODS in such patients is high. The recurrence rate of acute pancreatitis is relatively high: almost half the patients with acute alcoholic pancreatitis experience a recurrence. When the gallstones are not treated, the risk of recurrence in gallstone pancreatitis ranges from 32% to 61%. After recovering from acute pancreatitis, about one-third to one-half of acute pancreatitis patients develop functional disorders, such as diabetes mellitus and fatty stool; the incidence of chronic pancreatitis after acute pancreatitis ranges from 3% to 13%. Nevertheless, many reports have shown that most patients who recover from acute pancreatitis regain good general health and return to their usual daily routine. Some authors have emphasized that endocrine function disorders are a common complication after severe acute pancreatitis has been treated by pancreatic resection
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