1,968 research outputs found
Cluster investigation of mixed O76:H19 Shiga toxin-producing Escherichia coli and atypical enteropathogenic E. coli infection in a Spanish household
A Spanish household was identified through a Public Health follow up on a Shiga toxin-producing Escherichia coli (STEC)-positive 14-month-old girl reporting bloody diarrhoea, with the four household members experiencing either symptomatic or asymptomatic STEC and/or atypical enteropathogenic E. coli (aEPEC) shedding. In total, two different O76:H19 STEC strains and six aEPEC strains belonging to multiple serotypes were isolated and characterized in the household during a 5-month period. Prolonged asymptomatic shedding of O76:H19 STEC and O51:H49 aEPEC was detected in two family members. Although there was no conclusive evidence, consumption of vegetables fertilized with sheep manure was the suspected source of infection. This study highlights the risk of cross-infections posed by prolonged asymptomatic carriage and close household contact between family members, and illustrates the importance of molecular epidemiology in understanding disease clusters.We thank José Manuel Luquin and Gemma Poignonfor facilitating the follow-up sampling of the house-hold members and relatives. We thank DanielEibach for critically reviewing the manuscript. Wealso thank Flemming Scheutz for conventional O:Hserotyping the strains. Sergio Sánchez acknowledgesthe Juan de la Cierva programme from theMinisterio de Economía y Competitividad for hisresearch contract. This study was supported by theMadrid Regional Government (P2009/AGR-1489)
Preparation of hollow magnetite microspheres and their applications as drugs carriers
Hollow magnetite microspheres have been synthesized by a simple process through a template-free hydrothermal approach. Hollow microspheres were surface modified by coating with a silica nanolayer. Pristine and modified hollow microparticles were characterized by field-emission electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, FT-IR and Raman spectroscopy, and VSM magnetometry. The potential application of the modified hollow magnetite microspheres as a drug carrier was evaluated by using Rhodamine B and methotrexate as model drugs. The loading and release kinetics of both molecules showed a clear pH and temperature dependent profile
2. Praxis educativa en el contexto de la educación tecnológica universitaria venezolana. Una mirada ético-moral
The present qualitative research was oriented to generate emerging theoretical elements on teacher´s conceptions about the sense and moral meaning of their practice in Venezuelan University technology education. Methodologically, it corresponds to a study with a hermeneutic phenomenological design. The context of study was located in the University Institute of technology of Puerto Cabello. Key informants correspond to teachers working in national training programs form this institution. Findings revealed what has been termed "teachers’ invisibility syndrome" which emphasizes a set of symptoms that they feel and experience in the daily exercise of their educational practice from the moral perspective in addition tempo-spatial, economic, social-cultural, personal character and conditions linked to each person and the physical environment at the IUTPC.El presente estudio de enfoque cualitativo estuvo orientado a Generar elementos teóricos emergentes sobre las concepciones de los docentes sobre el sentido y significado ético-moral de su praxis en el contexto de la Educación Tecnológica Universitaria Venezolana.Metodológicamente corresponde a un estudio con un diseño fenomenológico hermenéutico. El contexto de estudio se ubicó en el Instituto Universitario de Tecnología de Puerto Cabello. Los informantes claves corresponden a sujetos pertenecientes al Personal docente que laboran en esta institución en los Programas Nacionales de Formación que allí se ofertan. Los hallazgos develados integradosconforman lo que se ha denominado ” síndrome de la invisibilidad del docente” que destaca un conjunto de síntomas que este siente y experimenta en el ejercicio cotidiano de su praxis educativa desde lo ético-moral además de condiciones de carácter personal, social y cultural, económico, tempo-espacial y ligadas a cada persona y al medio físico del IUTPC
Virtual Excursions: a new way to explore science in class
The educational platform Virtual Science Hub (ViSH) has been developed as part of the GLOBAL excursion European project. ViSH (http://vishub.org/) is a portal where teachers and scientist interact to create virtual excursions to science infrastructures. The main motivation behind the project was to connect teachers - and in consequence their students - to scientific institutions and their wide amount of infrastructures and resources they are working with. Thus the idea of a hub was born that would allow the two worlds of scientists and teachers to connect and to innovate science teaching. The core of the ViSH?s concept design is based on virtual excursions, which allow for a number of pedagogical models to be applied. According to our internal definition a virtual excursion is a tour through some digital context by teachers and pupils on a given topic that is attractive and has an educational purpose. Inquiry-based learning, project-based and problem-based learning are the most prominent approaches that a virtual excursion may serve. The domain specific resources and scientific infrastructures currently available on the ViSH are focusing on life sciences, nano-technology, biotechnology, grid and volunteer computing. The virtual excursion approach allows an easy combination of these resources into interdisciplinary teaching scenarios. In addition, social networking features support the users in collaborating and communicating in relation to these excursions and thus create a community of interest for innovative science teaching. The design and development phases were performed following a participatory design approach. An important aspect in this process was to create design partnerships amongst all actors involved, researchers, developers, infrastructure providers, teachers, social scientists, and pedagogical experts early in the project. A joint sense of ownership was created and important changes during the conceptual phase were implemented in the ViSH due to early user feedback. Technology-wise the ViSH is based on the latest web technologies in order to make it cross-platform compatible so that it works on several operative systems such as Windows, Mac or Linux and multi-device accessible, such as desktop, tablet and mobile devices. The platform has been developed in HTML5, the latest standard for web development, assuring that it can run on any modern browser. In addition to social networking features a core element on the ViSH is the virtual excursions editor. It is a web tool that allows teachers and scientists to create rich mash-ups of learning resources provided by the e-Infrastructures (i.e. remote laboratories and live webcams). These rich mash-ups can be presented in either slides or flashcards format. Taking advantage of the web architecture supported, additional powerful components have been integrated like a recommendation engine to provide personalized suggestions about educational content or interesting users and a videoconference tool to enhance real-time collaboration like MashMeTV (http://www.mashme.tv/)
Los accidentes de tráfico desde el punto de vista de los medios impresos. Guadalajara, México 2011 = The Road-Traffic Accidents from the Point of View of the Print Mass Media. Guadalajara, Mexico 2011
Resumen: Introducción. Los medios de comunicación tienen un papel importante en la Salud Pública al informar a la población. Uno de los temas que más ha cobrado interés en nuestro país son los accidentes de tráfico, por lo que nos interesa analizar el papel de los medios en este problema de salud. Objetivo. Analizar el contenido de las notas periodísticas relacionadas con siniestros viales, publicados en abril y mayo de 2011. Material y métodos. Es un estudio de análisis de contenido acumulativo que recabó notas periodísticas de tres diarios con distribución en Guadadalajara, México; las cuales fueron clasificadas de acuerdo al tipo de nota y posteriormente, para la codificación solamente se consideraron las piezas informativas, con los que se conformaron categorías. Resultados. Durante el período se captaron 196 notas periodísticas, de éstas 112 fueron reportes de evento, 78 piezas informativas, principalmente. De la codificación resultaron tres categorías principales: actores involucrados, causalidad y medidas para la disminución de accidentes. Conclusión. Los medios impresos no están siendo aprovechados para ofrecer información a la población sobre medidas preventivas y factores de riesgo, la mayor parte de la notas no exponen las causas de los accidentes de tráfico describen el evento y fincan responsabilidades. Palabras clave: accidentes de tránsito, prevención de accidentes, artículo de periódico, análisis cualitativo Abstract: Background. The media have an important role on Public Health to provide information to the population. In the country, traffic accidents are an important topic, that is the reason for analyze the print media role in the traffic accidents. Objective. Analyze the Content of News from Print Media about Road-Traffic Accidents, published between April and May, 2011. Material and Methods. It´s a Summative Content Analysis that included News Reports of three Newspapers with distribution in Guadalajara, Mexico. Those news reports were classified by the content and then, for the codification only included informative notes, which ones formed category. Results. During the period, we captured 196 news reports, of these 112 were reports on crash, 78 informational pieces, principally. From codification resulted three mainly category: stakeholders, causality and actions for reducing accidents. Conclusions. The Print Mass Media are being underestimate to provide information about prevention and risks factors, because most of news reports did not expose causes of the Road-Traffic accidents but described the road-traffic accident and they looked for responsibilities. Keywords: traffic accident, accident prevention, newspaper article, qualitative analysi
CREACIÓN DE SISTEMAS DE CONTROL QUE POSIBILITEN EL DESARROLLO Y CRECIMIENTO DE LAS MIPYMES
La economía del mundo está sustentada en un 90% por las mipymes, que a través de los años han sido la principal fuente de ingresos de las familias que las crean, sin embargo es notorio que su crecimiento y desarrollo es leve ó nulo, esto se debe principalmente a la falta de bases administrativas que las consoliden y de sistemas de control que las haga más productivas y eficientes en sus operaciones. Este artículo presenta cómo se usa el tablero de control creado con el programa Microsoft Excel, propiciando un sistema dinámico e interrelacionado. Estos indicadores permiten al empresario información oportuna para la toma de decisiones con certidumbre. De igual manera, plantea un panorama acerca del medio interno y externo en el que interactúa la empresa
Determination of aflatoxins in cacao powder and cocoa-derivatives by high-performance liquid chromatography
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High glucose concentrations induce TNF-α production through the down-regulation of CD33 in primary human monocytes
<p>Abstract</p> <p>Background</p> <p>CD33 is a membrane receptor containing a lectin domain and a cytoplasmic immunoreceptor tyrosine-based inhibitory motif (ITIM) that is able to inhibit cytokine production. CD33 is expressed by monocytes, and reduced expression of CD33 correlates with augmented production of inflammatory cytokines, such as IL-1β, TNF-α, and IL-8. However, the role of CD33 in the inflammation associated with hyperglycemia and diabetes is unknown. Therefore, we studied CD33 expression and inflammatory cytokine secretion in freshly isolated monocytes from patients with type 2 diabetes. To evaluate the effects of hyperglycemia, monocytes from healthy donors were cultured with different glucose concentrations (15-50 mmol/l D-glucose), and CD33 expression and inflammatory cytokine production were assessed. The expression of suppressor of cytokine signaling protein-3 (SOCS-3) and the generation of reactive oxygen species (ROS) were also evaluated to address the cellular mechanisms involved in the down-regulation of CD33.</p> <p>Results</p> <p>CD33 expression was significantly decreased in monocytes from patients with type 2 diabetes, and higher levels of TNF-α, IL-8 and IL-12p70 were detected in the plasma of patients compared to healthy donors. Under high glucose conditions, CD33 protein and mRNA expression was significantly decreased, whereas spontaneous TNF-α secretion and SOCS-3 mRNA expression were increased in monocytes from healthy donors. Furthermore, the down-regulation of CD33 and increase in TNF-α production were prevented when monocytes were treated with the antioxidant α-tocopherol and cultured under high glucose conditions.</p> <p>Conclusion</p> <p>Our results suggest that hyperglycemia down-regulates CD33 expression and triggers the spontaneous secretion of TNF-α by peripheral monocytes. This phenomenon involves the generation of ROS and the up-regulation of SOCS-3. These observations support the importance of blood glucose control for maintaining innate immune function and suggest the participation of CD33 in the inflammatory profile associated with type 2 diabetes.</p
Clathrin switches transforming growth factor-β role to pro-tumorigenic in liver cancer
Background & Aims: Upon ligand binding, tyrosine kinase receptors, such as epidermal growth factor receptor (EGFR), are recruited into clathrin-coated pits for internalization by endocytosis, which is relevant for signalling and/or receptor degradation. In liver cells, transforming growth factor-beta (TGF-beta) induces both pro- and anti-apoptotic signals; the latter are mediated by the EGFR pathway. Since EGFR mainly traffics via clathrin-coated vesicles, we aimed to analyse the potential role of clathrin in TGF-beta-induced signalling in liver cells and its relevance in liver cancer. Methods: Real-Time PCR and immunohistochemistry were used to analyse clathrin heavy-chain expression in human (CLTC) and mice (Cltc) liver tumours. Transient knockdown (siRNA) or overexpression of CLTC were used to analyse its role on TGF-beta and EGFR signalling in vitro. Bioinformatic analysis was used to determine the effect of CLTC and TGEB1 expression on prognosis and overall survival in patients with hepatocellular carcinoma (HCC). Results: Clathrin expression increased during liver tumorigenesis in humans and mice. CLTC knockdown cells responded to TGF-beta phosphorylating SMADs (canonical signalling) but showed impairment in the anti-apoptotic signals (EGFR transactivation). Experiments of loss or gain of function in HCC cells reveal an essential role for clathrin in inhibiting TGF-beta-induced apoptosis and upregulation of its pro-apoptotic target NOX4. Autocrine TGF-beta signalling in invasive HCC cells upregulates CLTC expression, switching its role to pro-tumorigenic. A positive correlation between TGEB1 and CLTC was found in HCC cells and patients. Patients expressing high levels of TGEB1 and CLTC had a worse prognosis and lower overall survival. Conclusions: This work describes a novel role for clathrin in liver tumorigenesis, favouring non-canonical pro-tumorigenic TGF-beta pathways. CLTC expression in human HCC samples could help select patients that would benefit from TGF-beta-targeted therapy. Lay summary: Clathrin heavy-chain expression increases during liver tumorigenesis in humans (CLTC) and mice (Mc), altering the cellular response to TGF-beta in favour of anti-apoptotic/pro-tumorigenic signals. A positive correlation between TGEB1 and CLTC was found in HCC cells and patients. Patients expressing high levels of TGEB1 and CLTC had a worse prognosis and lower overall survival. CLTC expression in HCC human samples could help select patients that would benefit from therapies targeting TGF-beta. (C) 2019 European Association for the Study of the Liver. Published by Elsevier B
Genetic variability of Trypanosoma cruzi TcI isolates from rural and urban areas of Venezuela
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