3,787 research outputs found

    Modelo de indicadores de calidad de las universidades

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    Quién lee ahora a Ortega y Gasset? NO se lee ya su Misión de la Universidad, a pesar de que todavía sorprende por su modernidad. Se publica casi al mismo tiempo que La rebelión de las masas, quizás su libro más leído en el mundo. ORTEGA intuye que la universidad tiene tres funciones: docencia, investigación y compromiso. La universidad se dedica a preservar y avanzar el conocimiento. La docencia es su misión principal. Pero además tiene que ser «ciencia» en el sentido de realizar investigación, de inquirir sobre los problemas científicos

    Tet2 Rescues Age-Related Regenerative Decline and Enhances Cognitive Function in the Adult Mouse Brain.

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    Restoring adult stem cell function provides an exciting approach for rejuvenating the aging brain. However, molecular mechanisms mediating neurogenic rejuvenation remain elusive. Here we report that the enzyme ten eleven translocation methylcytosine dioxygenase 2 (Tet2), which catalyzes the production of 5-hydroxymethylcytosine (5hmC), rescues age-related decline in adult neurogenesis and enhances cognition in mice. We detected a decrease in Tet2 expression and 5hmC levels in the aged hippocampus associated with adult neurogenesis. Mimicking an aged condition in young adults by abrogating Tet2 expression within the hippocampal neurogenic niche, or adult neural stem cells, decreased neurogenesis and impaired learning and memory. In a heterochronic parabiosis rejuvenation model, hippocampal Tet2 expression was restored. Overexpressing Tet2 in the hippocampal neurogenic niche of mature adults increased 5hmC associated with neurogenic processes, offset the precipitous age-related decline in neurogenesis, and enhanced learning and memory. Our data identify Tet2 as a key molecular mediator of neurogenic rejuvenation

    Discrete modeling of human body using preprocessing and segmentation techniques of medical images

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    Los tejidos humanos son estructuras anatómicas que se caracterizan por tener una morfología compleja y solapada entre sí, razones por las cuales la generación de modelos geométricos precisos no resulta una tarea fácil. En la actualidad, esta tarea se ha beneficiado por el desarrollo de técnicas de diagnóstico por imágenes médicas, las cuales permiten visualizar el cuerpo humano en una forma confiable y no invasiva, generando cortes transversales que representan una sección de los tejidos bajo evaluación. En este trabajo, se propone el uso de un conjunto de técnicas numéricas de procesamiento digital de imágenes implementadas en una herramienta de software para la obtención de modelos geométricos a través de cinco etapas: (1) lectura y reconstrucción tridimensional (3D) inicial de los cortes originales de imágenes de tomografía computacional y resonancia magnética; (2) corrección de la baja calidad de las imágenes utilizando algoritmos de preprocesamiento para suavizar el ruido y realzar los bordes de los tejidos; (3) segmentación híbrida para obtener la geometría 3D de los tejidos de interés; (4) posprocesamiento para corregir errores de segmentación, y (5) exportación de los volúmenes en formatos legibles por otras herramientas de visualización médica y de Diseño Asistido por Computador (CAD) para verificar su utilidad para la generación de modelos discretos a través del análisis con los métodos numéricos. Las técnicas utilizadas fueron validadas calculando descriptores estadísticos en los modelos generados y los modelos proporcionados por otros medios como base de datos libres disponibles en sitios web. Los resultados demostraron que las técnicas implementadas generan modelos precisos y útiles para el análisis numérico, de manera versátil y en corto tiempo de procesamiento.The generation of anatomical models is one the most important concern to biomedical researchers as well as to medical doctors, due to needed to understand the human tissues. Is know that the soft tissues like heart, brain, prostate and hard tissues like jaw, bones, skull, etc are structures of complex morphologies, so, the anatomical models generation is not an easy and trivial task. Currently, this task has benefited of advances of imaging diagnostic, which permit obtain cross and longitudinal sections of human body. In this research, we describe a method to obtain 3D discrete models of human body given by a dataset of medical images. Five main modules were implemented in prototype software: (1) Reading and 3D reconstruction of Computerized Axial Tomography and Magnetic Resonance Images. (2) Preprocessing techniques for improve the low medical images quality by using enhancement algorithms to reduce image noise and to increase structures contrast. (3) Combined segmentation techniques for tissue identification, which were applied through a multi-stage approach. (4) Post processing techniques to improve segmented volumes and (5) Exportation task of volumes to readable formats by Computer Aided Design (CAD) tools to be later analyzed by numerical methods. The performance of our method is shown on several medical examples and the techniques were validated using statistical descriptors to compare our models with models from free databases. Results showed that the implemented techniques generate precise and useful models for numerical analysis and medical survey, planning and surgery in a short processing time.Peer Reviewe

    Discovery of spirooxadiazoline oxindoles with dual-stage antimalarial activity

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    © 2022 Published by Elsevier Masson SAS.Malaria remains a prevalent infectious disease in developing countries. The first-line therapeutic options are based on combinations of fast-acting artemisinin derivatives and longer-acting synthetic drugs. However, the emergence of resistance to these first-line treatments represents a serious risk, and the discovery of new effective drugs is urgently required. For this reason, new antimalarial chemotypes with new mechanisms of action, and ideally with activity against multiple parasite stages, are needed. We report a new scaffold with dual-stage (blood and liver) antiplasmodial activity. Twenty-six spirooxadiazoline oxindoles were synthesized and screened against the erythrocytic stage of the human malaria parasite P. falciparum. The most active compounds were also tested against the liver-stage of the murine parasite P. berghei. Seven compounds emerged as dual-stage antimalarials, with IC50 values in the low micromolar range. Due to structural similarity with cipargamin, which is thought to inhibit blood-stage P. falciparum growth via inhibition of the Na + efflux pump PfATP4, we tested one of the most active compounds for anti-PfATP4 activity. Our results suggest that this target is not the primary target of spirooxadiazoline oxindoles and further studies are ongoing to identify the main mechanism of action of this scaffold.This work was supported by FCT (Fundação para a Ciência e a Tecnologia, I.P.) through iMed.ULisboa (UID/DTP/04138/2019), project PTDC/QUI-QOR/29664/2017, and PhD fellowship SFRH/BD/137544/2018 (E. Lopes). The NMR spectrometers are part of the National NMR Network (PTNMR) and are partially supported by Infrastructure Project Nº 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC). Financial support from FCT and Portugal 2020 to the Portuguese Mass Spectrometry Network (Rede Nacional de Espectrometria de Massa – RNEM; LISBOA-01-0145-FEDER-402-022125) is also acknowledged.info:eu-repo/semantics/publishedVersio

    The Diboson Excess: Experimental Situation and Classification of Explanations; A Les Houches Pre-Proceeding

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    We examine the `diboson' excess at ∼2\sim 2 TeV seen by the LHC experiments in various channels. We provide a comparison of the excess significances as a function of the mass of the tentative resonance and give the signal cross sections needed to explain the excesses. We also present a survey of available theoretical explanations of the resonance, classified in three main approaches. Beyond that, we discuss methods to verify the anomaly, determining the major properties of the various surpluses and exploring how different models can be discriminated. Finally, we give a tabular summary of the numerous explanations, presenting their main phenomenological features.Comment: 37 pages, 9 Figures, 1 Tabl

    A Fermented Food Product Containing Lactic Acid Bacteria Protects ZDF Rats from the Development of Type 2 Diabetes

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    Type 2 diabetes (T2D) is a complex metabolic disease, which involves a maintained hyperglycemia due to the development of an insulin resistance process. Among multiple risk factors, host intestinal microbiota has received increasing attention in T2D etiology and progression. In the present study, we have explored the effect of long-term supplementation with a non-dairy fermented food product (FFP) in Zucker Diabetic and Fatty (ZDF) rats T2D model. The supplementation with FFP induced an improvement in glucose homeostasis according to the results obtained from fasting blood glucose levels, glucose tolerance test, and pancreatic function. Importantly, a significantly reduced intestinal glucose absorption was found in the FFP-treated rats. Supplemented animals also showed a greater survival suggesting a better health status as a result of the FFP intake. Some dissimilarities have been observed in the gut microbiota population between control and FFP-treated rats, and interestingly a tendency for better cardiometabolic markers values was appreciated in this group. However, no significant differences were observed in body weight, body composition, or food intake between groups. These findings suggest that FFP induced gut microbiota modifications in ZDF rats that improved glucose metabolism and protected from T2D development
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