737 research outputs found

    Historia de la Medicina Local y la formación cultural de los estudiantes de Ciencias Médicas

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    The need to enhance the cultural training of the students throughout the History of Local Medicine (HLM) made possible the bibliographic search, document analysis and the review of doctoral thesis. The objective of this paper is to set the foundations of the need to apply the knowledge of HLM to contribute to the cultural training of medical students in Ciego de Ávila.La necesidad de potenciar la formación cultural de los estudiantes a través de la Historia de la Medicina Local (HML) propició la revisión bibliográfica, así como el análisis de documentos y consulta de tesis doctorales. El objetivo de este artículo es reflexionar acerca de la HML como una vía para contribuir a la formación cultural de los estudiantes de las ciencias médicas en Ciego de Ávila. &nbsp

    A new approach for the fabrication of cytocompatible PLLA-magnetite nanoparticle composite scaffolds

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    Magnetic biomimetic scaffolds of poly(L-lactide) (PLLA) and nanoparticles of magnetite (nFe3O4) are prepared in a wide ratio of compositions by lyophilization for bone regeneration. The magnetic properties, cytotoxicity, and the in vitro degradation of these porous materials are closely studied. The addition of magnetite at 50 °C was found to produce an interaction reaction between the ester groups of the PLLA and the metallic cations of the magnetite, causing the formation of complexes. This fact was confirmed by the analysis of the infrared spectroscopy and the gel permeation chromatography test results. They, respectively, showed a displacement of the absorption bands of the carbonyl group (C=O) of the PLLA and a scission of the polymer chains. The iron from the magnetite acted as a catalyser of the macromolecular scission reaction, which determines the final biomedical applications of the scaffolds—it does so because the reaction shortens the degradation process without appearing to influence its toxicity. None of the samples studied in the tests presented cytotoxicity, even at 70% magnetite concentrations.This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-R (AEI/FEDER, UE) and from the Basque Government Industry Department under the ELKARTEK, HAZITEK and PIBA programs. Supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013, project POCI-01-0145-FEDER-028237 and grant SFRH/BD/111478/2015 (S.R.) is acknowledged

    Otter-Knowledge: benchmarks of multimodal knowledge graph representation learning from different sources for drug discovery

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    Recent research in representation learning utilizes large databases of proteins or molecules to acquire knowledge of drug and protein structures through unsupervised learning techniques. These pre-trained representations have proven to significantly enhance the accuracy of subsequent tasks, such as predicting the affinity between drugs and target proteins. In this study, we demonstrate that by incorporating knowledge graphs from diverse sources and modalities into the sequences or SMILES representation, we can further enrich the representation and achieve state-of-the-art results on established benchmark datasets. We provide preprocessed and integrated data obtained from 7 public sources, which encompass over 30M triples. Additionally, we make available the pre-trained models based on this data, along with the reported outcomes of their performance on three widely-used benchmark datasets for drug-target binding affinity prediction found in the Therapeutic Data Commons (TDC) benchmarks. Additionally, we make the source code for training models on benchmark datasets publicly available. Our objective in releasing these pre-trained models, accompanied by clean data for model pretraining and benchmark results, is to encourage research in knowledge-enhanced representation learning

    Sheet metal plate design: a structured approach to product optimization in the presence of technological constraints

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    Geometrical optimization of structural components is a topic of high interest for engineers involved with design activities mainly related to mass reduction. The study described in these pages focuses on the optimization of plates subjected to bending for which stiffness is obtained by a pattern of ribs. Although stiffening by means of ribs is a well-known and old technique, the design of ribs for maximum stiffness is often based on practice and experience. Classical optimization methods such as topological, topographical and parametric optimization fail to give an efficient design with a reasonable programming effort, especially when dealing with many and complex constraints. These constraints are both technical and technological. A most promising technique to obtain optimal rib patterns was to define a set of feasible rib trajectories and then to select the subset with the most efficient combinations. The result is not unique and a method to select the optimal patterns is required. In fact, the stiffening effect increases with increasing rib length, but at a greater cost. A trade-off must be found between structural performance and cost: The tools to guide this selection process is the main objective of the paper, with particular attention in evaluating the stiffening due to the presence of beads on the plate with a close link with the production system and possible technological constraints which can occur during manufacturing processes, such as minimum rib distance or the presence of discontinuities or the presence of holes or other elements on the plate. A special tool with enforced rib cross section is considered, and optimal rib deployment has to be found. Numerical examples attached show the methodology and obtainable results. \ua9 2011 Springer-Verlag London Limited

    One of the closest exoplanet pairs to the 3:2 Mean Motion Resonance: K2-19b \& c

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    The K2 mission has recently begun to discover new and diverse planetary systems. In December 2014 Campaign 1 data from the mission was released, providing high-precision photometry for ~22000 objects over an 80 day timespan. We searched these data with the aim of detecting further important new objects. Our search through two separate pipelines led to the independent discovery of K2-19b \& c, a two-planet system of Neptune sized objects (4.2 and 7.2 RR_\oplus), orbiting a K dwarf extremely close to the 3:2 mean motion resonance. The two planets each show transits, sometimes simultaneously due to their proximity to resonance and alignment of conjunctions. We obtain further ground based photometry of the larger planet with the NITES telescope, demonstrating the presence of large transit timing variations (TTVs), and use the observed TTVs to place mass constraints on the transiting objects under the hypothesis that the objects are near but not in resonance. We then statistically validate the planets through the \texttt{PASTIS} tool, independently of the TTV analysis.Comment: 18 pages, 10 figures, accepted to A&A, updated to match published versio

    Síndrome de Sjögren y ultrasonido

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    El síndrome de Sjögren es una enfermedad autoinmune crónica que afecta principalmente a las glándulas salivales y lacrimales produciendo un estado de sequedad de mucosas. Se genera un estado de proliferación linfoplasmocítico en las glándulas exócrinas que conlleva a un estado de deterioro progresivo hasta su afuncionalidad. Su prevalencia es de 0.05 a 0.7% de la población general, siendo el género femenino el más afectado. Los criterios de clasificación realizados en el 2002 por Vitali y Cols, son los que con mayor frecuencia se usan en una consulta externa de reumatología; sin embargo, la aplicación de algunos de estos criterios no siempre es posible debido a algunas limitantes, como la biopsia de glándula salival, sialografía por contraste o centellografía de glándula salival. El uso del ultrasonido de glándula salival es una alternativa válida que aporta en la evaluación del paciente sospechoso de síndrome de Sjögren, herramienta de fácil acceso, no iónica, poco tiempo, evaluación en tiempo real y dinámica. Se propone en esta revisión su uso como alternativa y/o adyuvante al resto de herramientas de evaluación descritas en la literatur

    Formation and Structures of Horizontal Submarine Fluid Conduit and Venting Systems Associated With Marine Seeps

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    Funder: Spanish Marine Science and Technology ProgramAbstract: Methane‐rich water moves through conduits beneath the seafloor whose surfaces are formed through precipitation reactions. To understand how such submarine fluid conduit and venting systems form and grow, we develop a detailed mathematical model for this reaction‐advection system and we quantify the evolution of an ensemble of similar filaments. We show that this growth can be described by a superposition of advection and dispersion. We analyze analog laboratory experiments of chemical‐garden type to study the growth of a single filament undergoing a precipitation reaction with the surrounding environment. We apply these findings to geological fluid conduit and venting systems, showing that their irregular trajectories can lead to very effective spreading within the surrounding seabed, thus enhancing contact and exchanges of chemicals between the conduit and external fluids. We discuss how this methane venting leads to the formation of marine authigenic carbonate rocks, and for confirmation, we analyze two field samples from the Gulf of Cadiz for composition and mineralogy of the precipitates. We note the implications of this work for hydrate melting and methane escape from the seabed
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