3,402 research outputs found

    Seroprevalence of Toxoplasmosis in Blood Donors: An Investigation from the Endemicity. Non-systematic Review

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    Toxoplasma gondii is an intracellular protozoan that causes toxoplasmosis, the most common parasitic disease in the world, which infects humans and animals. It is transmitted through cat feces through the process of excretion and ingestion of oocysts. Humans become infected by eating improperly washed vegetables, raw or undercooked meat, contaminated water, the soil or area where the cat defecates, or by transfusing infected blood. The study aims to identify, through scientific evidence, the seroprevalence of T. gondii in blood donors, considering its global endemicity. A non-systematic documentary review was used for searching articles worldwide on the topic of T. gondii seroprevalence in blood donors, in different databases such as SciELO, Google Academics, etc. A total of 27 articles that had the required information; grouping the seroprevalence results by region, obtained positive IgG and IgG + IgM. Calculating the prevalence, it was identified in Asia at 7.8%, America 32.8%, Africa 40.7%, Oceania 34%, and Europe 38.1%. In conclusion, it is convenient to carry out this type of study in each country to verify the prevalence and, in addition, to determine the incidence of infection in blood donors to calculate the risk of transmission. Keywords: Toxoplasma, seroepidemiologic studies, antibodies, immunoglobulin G, immunoglobulin M, blood donors. Resumen Introducción: Toxoplasma gondii en un protozoo intracelular causante de la toxoplasmosis, la enfermedad parasitaria más frecuente del mundo la cual infecta a humanos y animales, se trasmite por medio de las heces de los gatos mediante el proceso de excreción e ingestión de los ooquistes. Los humanos se infectan al ingerir vegetales mal lavados, carne cruda o poco cocida, agua contaminada, el suelo o área donde defeca el gato, o al transfundir sangre infectada. Objetivo: identificar mediante evidencias científicas la seroprevalencia de T. gondii en donantes de sangre, considerando su endemicidad global. Metodología: se empleó una revisión no sistemática, documental realizando la búsqueda de artículos a nivel mundial del tema seroprevalencia de T. gondii en donantes de sangre, en diferentes bases como SciELO, Google Academics, etc. Resultados: un total de 27 artículos que contaron con la información requerida; agrupando los resultados de seroprevalencia por región, anticuerpos positivos IgG e IgG + IgM. Calculando la prevalencia se identificó, en Asia 7,8%; América 32,8%; África 40,7%; Oceanía 34% y Europa 38,1%. Conclusión: es conveniente realizar este tipo de estudio en cada país para comprobar la prevalencia y, además, determinar la incidencia de la infección en donantes de sangre para calcular el riesgo de transmisión. Palabras Clave: Toxoplasma, estudios seroepidemiológicos, anticuerpos, inmunoglobulina G, inmunoglobulina M, donantes de sangre

    The costs of preventing and treating chagas disease in Colombia

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    Background: The objective of this study is to report the costs of Chagas disease in Colombia, in terms of vector disease control programmes and the costs of providing care to chronic Chagas disease patients with cardiomyopathy. Methods: Data were collected from Colombia in 2004. A retrospective review of costs for vector control programmes carried out in rural areas included 3,084 houses surveyed for infestation with triatomine bugs and 3,305 houses sprayed with insecticide. A total of 63 patient records from 3 different hospitals were selected for a retrospective review of resource use. Consensus methodology with local experts was used to estimate care seeking behaviour and to complement observed data on utilisation. Findings: The mean cost per house per entomological survey was 4.4(inUS4.4 (in US of 2004), whereas the mean cost of spraying a house with insecticide was 27.Themaincostdriverofsprayingwasthepriceoftheinsecticide,whichvariedgreatly.TreatmentofachronicChagasdiseasepatientcostsbetween27. The main cost driver of spraying was the price of the insecticide, which varied greatly. Treatment of a chronic Chagas disease patient costs between 46.4 and 7,981peryearinColombia,dependingonseverityandthelevelofcareused.Combiningcostandutilisationestimatestheexpectedcostoftreatmentperpatientyearis7,981 per year in Colombia, depending on severity and the level of care used. Combining cost and utilisation estimates the expected cost of treatment per patient-year is 1,028, whereas lifetime costs averaged $11,619 per patient. Chronic Chagas disease patients have limited access to healthcare, with an estimated 22% of patients never seeking care. Conclusion: Chagas disease is a preventable condition that affects mostly poor populations living in rural areas. The mean costs of surveying houses for infestation and spraying infested houses were low in comparison to other studies and in line with treatment costs. Care seeking behaviour and the type of insurance affiliation seem to play a role in the facilities and type of care that patients use, thus raising concerns about equitable access to care. Preventing Chagas disease in Colombia would be cost-effective and could contribute to prevent inequalities in health and healthcare.Wellcome Trus

    Estudio del efecto solvatocrómico en derivados fenólicos naturales

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    Se describen las características espectrofluorimétricas de dos derivados de quercetina aislados de las hojas deFlaveria bidentis, un derivado de 6-prenilpinocembrina, aislado de las raíces de Dalea elegans y un compuesto deestructura antraquinónica aislado de las hojas de Heterophyllaea pustulata. Todos ellos presentan espectros deabsorción con máximos en la región UV-visible acordes con los grupos cromóforos presentes en su estructura. Loscuatro compuestos estudiados presentan fluorescencia nativa. La posición de los máximos de emisión de fluorescenciase modifica en función del disolvente. Los desplazamientos producidos están relacionados con el diferente gradode solvatación de las moléculas en estado excitado según la polaridad del disolvente. La adición de ácidos mineralesprovoca desplazamientos en los máximos de fluorescencia concordantes con los ya descritos para compuestos deestructura similar. Estas modificaciones espectrales tienen un gran interés analítico desde el punto de vista de laidentificación y caracterización de productos naturales de estructura fenólica

    Seminar Users in the Arabic Twitter Sphere

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    We introduce the notion of "seminar users", who are social media users engaged in propaganda in support of a political entity. We develop a framework that can identify such users with 84.4% precision and 76.1% recall. While our dataset is from the Arab region, omitting language-specific features has only a minor impact on classification performance, and thus, our approach could work for detecting seminar users in other parts of the world and in other languages. We further explored a controversial political topic to observe the prevalence and potential potency of such users. In our case study, we found that 25% of the users engaged in the topic are in fact seminar users and their tweets make nearly a third of the on-topic tweets. Moreover, they are often successful in affecting mainstream discourse with coordinated hashtag campaigns.Comment: to appear in SocInfo 201

    Screening of conditions controlling spectrophotometric sequential injection analysis

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    <p>Abstract</p> <p>Background</p> <p>Despite its potential benefits over univariate, chemometrics is rarely utilized for optimizing sequential injection analysis (SIA) methods. Specifically, in previous vis-spectrophotometric SIA methods, chemometrically optimized conditions were confined within flow rate and reagent concentrations while other conditions were ignored.</p> <p>Results</p> <p>The current manuscript reports, for the first time, a comprehensive screening of conditions controlling vis-spectrophotometric SIA. A new diclofenac assay method was adopted. The method was based on oxidizing diclofenac by permanganate (a major reagent) with sulfuric acid (a minor reagent). The reaction produced a spectrophotometrically detectable diclofenac form. The 2<sup>6 </sup>full-factorial design was utilized to study the effect of volumes of reagents and sample, in addition to flow rate and concentrations of reagents. The main effects and all interaction order effects on method performance, i.e. namely sensitivity, rapidity and reagent consumption, were determined. The method was validated and applied to pharmaceutical formulations (tablets, injection and gel).</p> <p>Conclusions</p> <p>Despite 64 experiments those conducted in the current study were cumbersome, the results obtained would reduce effort and time when developing similar SIA methods in the future. It is recommended to critically optimize effective and interacting conditions using other such optimization tools as fractional-factorial design, response surface and simplex, rather than full-factorial design that used at an initial optimization stage. In vis-spectrophotometric SIA methods those involve developing reactions with two reagents (major and minor), conditions affecting method performance are in the following order: sample volume > flow rate ≈ major reagent concentration >> major reagent volume ≈ minor reagent concentration >> minor reagent volume.</p

    Transient peak-strain matching partially recovers the age-impaired mechanoadaptive cortical bone response

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    Mechanoadaptation maintains bone mass and architecture; its failure underlies age-related decline in bone strength. It is unclear whether this is due to failure of osteocytes to sense strain, osteoblasts to form bone or insufficient mechanical stimulus. Mechanoadaptation can be restored to aged bone by surgical neurectomy, suggesting that changes in loading history can rescue mechanoadaptation. We use non-biased, whole-bone tibial analyses, along with characterisation of surface strains and ensuing mechanoadaptive responses in mice at a range of ages, to explore whether sufficient load magnitude can activate mechanoadaptation in aged bone. We find that younger mice adapt when imposed strains are lower than in mature and aged bone. Intriguingly, imposition of short-term, high magnitude loading effectively primes cortical but not trabecular bone of aged mice to respond. This response was regionally-matched to highest strains measured by digital image correlation and to osteocytic mechanoactivation. These data indicate that aged bone’s loading response can be partially recovered, non-invasively by transient, focal high strain regions. Our results indicate that old murine bone does respond to load when the loading is of sufficient magnitude, and bones’ age-related adaptation failure may be due to insufficient mechanical stimulus to trigger mechanoadaptation

    Variations of training load, monotony, and strain and dose-response relationships with maximal aerobic speed, maximal oxygen uptake, and isokinetic strength in professional soccer players

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    This study aimed to identify variations in weekly training load, training monotony, and training strain across a 10-week period (during both, pre- and in-season phases); and to analyze the dose-response relationships between training markers and maximal aerobic speed (MAS), maximal oxygen uptake, and isokinetic strength. Twenty-seven professional soccer players (24.9±3.5 years old) were monitored across the 10-week period using global positioning system units. Players were also tested for maximal aerobic speed, maximal oxygen uptake, and isokinetic strength before and after 10 weeks of training. Large positive correlations were found between sum of training load and extension peak torque in the right lower limb (r = 0.57, 90%CI[0.15;0.82]) and the ratio agonist/antagonist in the right lower limb (r = 0.51, [0.06;0.78]). It was observed that loading measures fluctuated across the period of the study and that the load was meaningfully associated with changes in the fitness status of players. However, those magnitudes of correlations were small-to-large, suggesting that variations in fitness level cannot be exclusively explained by the accumulated load and loading profile
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