1,359 research outputs found

    Sustained reentry in a 3d regionally ischemic human heart. A simulation study

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    In this work, we have studied the vulnerable window and propagation patterns in a human heart during acute ischemia. A 3-D biventricular model of a human heart with realistic heterogeneity and fiber orientations has been considered. The ischemic region was located in the anterior left ventricular wall mimicking the occlusion of the circumflex artery. The electrical activity of the tissue was modeled with the monodomain model along with a modified version of the ten Tusscher 2006 ionic model. The model predicts the generation of sustained re-entrant activity in the form of a rotor around the ischemic zone. Patterns in the form of figure-of-eight were also observed within the vulnerable window. The re-entrant activity originates in the endocardial surface and propagates transmurally towards the epicardium

    Vulnerability to Reentry in a 3D Regionally Ischemic Ventricular Slab Preparation, a Simulation Study

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    Ventricular tachycardia and ventricular fibrillation are known to be two types of cardiac arrhythmias that usually take place during acute ischemia and frequently lead to sudden death. In this work, we have studied the different patterns of activation displayed in a virtual ventricular slab preparation after premature stimulation during acute ischemia. Furthermore, we also have analyzed the vulnerable window (VW) under such conditions. Influence of the tissue structure and morphology of the ischemic zone have also been considered. For a centered ischemic zone, eight shaped reentry was originated at the mid plane of the slab and the VW was found to be almost the same as for the 2D simulations. Eight shaped reentry were formed in the epicardial surface as the morphology of the ischemic zone changed (the centre of the ischemic zone was moved toward the epicardial surface). These changes also caused a reduction in the VW of a 24% as compared with the centered ischemic zone

    Clavo Gamma 3 (Stryker) para el tratamiento de fracturas trocantéreas: nuestra experiencia durante el año 2005

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    Objetivos: estudiar los resultados del sistema de enclavado Gamma 3 en el tratamiento de las fracturas trocantéreas durante el año 2005. Material y Métodos: 73 pacientes con fractura trocantérea mayores de 60 años tratados mediante enclavado céfalo-medular Gamma 3 durante el año 2005 con un seguimiento de 8 a18 meses. Edad media 80 años, 40% de los pacientes deambulantes de forma independiente previo a la fractura, 50% ASA III y IV. Resultados: tiempo quirúrgico 90 minutos, 54% de pacientes transfundidos con una media de 0,89 concentrados por paciente sin diferencias estadisticamente significativas entre aquellos en lo que se colocó y tapón y los que no; 63% de los pacientes deambulan si ayuda en el pstoperatorio. Conclusiones: el sistema Gamma 3 proporciona resultados fiables y reproducible en cualquier variedad de fractura trocanterea y nos parece un sistema eficaz y válido para el tratamiento de este tipo de fracturas.Objectives: to study the results of Gamma 3 for the treatment of trochanteric fractures. Material and Methods: 73 patients older than 60 years old with trochanteric fracture tre- ated using Gamma 3 nailing during year 2005. Follow-up 8-18 months. Mean age 80 years old, 40% preoperative walking without help, 50% ASA III and IV. Results: surgical time 90 minutes, 54% of the patients need blood transfusion with 0,89 concentrates per patients mean. No difference was found in blood transfusion with the use of end cup. 63% walking wit- hout help of with cane postoperatively. Conclusions: Gamma 3 nail is a valid system for the treatment of all types of tro- chanteric fractures

    Color characterization of coatings with diffraction pigments

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    Coatings with diffraction pigments present high iridescence, which needs to be characterized in order to describe their appearance. The spectral bidirectional reflectance distribution functions (BRDFs) of six coatings with SpectraFlair diffraction pigments were measured using the robot-arm-based goniospectrophotometer GEFE, designed and developed at CSIC. Principal component analysis has been applied to study the coatings of BRDF data. From data evaluation and based on theoretical considerations, we propose a relevant geometric factor to study the spectral reflectance and color gamut variation of coatings with diffraction pigments. At fixed values of this geometric factor, the spectral BRDF component due to diffraction is almost constant. Commercially available portable goniospectrophotometers, extensively used in several industries (automotive and others), should be provided with more aspecular measurement angles to characterize the complex reflectance of goniochromatic coatings based on diffraction pigments, but they would not require either more than one irradiation angle or additional out-of-plane geometries.European Metrology Research Programme (EMRP) (EMRP IND52); Comunidad de Madrid (SINFOTON-CM: S2013/MIT-2790); Ministerio de Economía y Competitividad (MINECO) (DIP2015-65814)

    Oestrid myiasis in European Mouflon from Spain

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    From February 1992 to March 1997, 245 European mouflon (Ovis orientalis musimon) from Sierras de Cazorla, Segura y Las Villas Natural Park (southern Spain) were surveyed for oestrid larvae in order to estimate prevalence and mean intensity of parasitism by Oestrus ovis. Over 46 percent of the animals surveyed were infected, with a mean intensity of 9.6 larvae/host parasitized. No significant differences in prevalence rates between host sexes were observed, but older mouflons were infected with more larvae than younger ones.Peer Reviewe

    Método para la obtención de cultivares de tomate con frutos partenocárpicos (sin semillas) y mayor calidad organoléptica

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    Método para la obtención de cultivares de tomate con frutos partenocárpicos (sin semillas) y mayor calidad organoléptica. El método se basa en la transferencia y expresión del gen LFY de Arabidopsis thaliana en plantas transgénicas de tomate. Los frutos de las plantas transgénicas con el gen LFY mantienen el mismo tamaño y peso que los del cultivar original, pero carecen de semillas, tienen más carne, menos pulpa y una forma ligeramente apuntillada. El análisis de calidad refleja un incremento del 60% en el contenido en sólidos solubles (la media alcanza 6,12 ºBrix) y del 60% en ácidos valorables (la media llega al 0,72%), lo que indica una mejora de la calidad organoléptica de los frutos en comparación con los del cultivar original no transgénico. Además, los frutos de las plantas transgénicas tienen otros atributos que indican una mayor calidad, tales como un mayor contenido en azúcares (sobre todo glucosa y fructosa) y licopeno, una sustancia que tiene propiedades antioxidantes.Peer reviewedUniversidad Politécnica de Valencia, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Consejo Superior de Investigaciones Científicas (España), Universidad de AlmeríaB2 Patente con examen previ

    On the assertion that PCT violation implies Lorentz non-invariance

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    Out of conviction or expediency, some current research programs take for granted that "PCT violation implies violation of Lorentz invariance". We point out that this claim is still on somewhat shaky ground. In fact, for many years there has been no strengthening of the evidence in this direction. However, using causal perturbation theory, we prove here that when starting with a local PCT-invariant interaction, PCT symmetry can be maintained in the process of renormalization.Comment: 13 page

    Working together: a review on safe human-robot collaboration in industrial environments

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    After many years of rigid conventional procedures of production, industrial manufacturing is going through a process of change toward flexible and intelligent manufacturing, the so-called Industry 4.0. In this paper, human-robot collaboration has an important role in smart factories since it contributes to the achievement of higher productivity and greater efficiency. However, this evolution means breaking with the established safety procedures as the separation of workspaces between robot and human is removed. These changes are reflected in safety standards related to industrial robotics since the last decade, and have led to the development of a wide field of research focusing on the prevention of human-robot impacts and/or the minimization of related risks or their consequences. This paper presents a review of the main safety systems that have been proposed and applied in industrial robotic environments that contribute to the achievement of safe collaborative human-robot work. Additionally, a review is provided of the current regulations along with new concepts that have been introduced in them. The discussion presented in this paper includes multidisciplinary approaches, such as techniques for estimation and the evaluation of injuries in human-robot collisions, mechanical and software devices designed to minimize the consequences of human-robot impact, impact detection systems, and strategies to prevent collisions or minimize their consequences when they occur

    Realización de vídeo de enseñanza online y presencial para prácticas por internet y presenciales de la radiografía de muñeca como método para valorar el desarrollo óseo

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    Se ha realizado un video en el que el alumno visualiza los diferentes estadios de desarrollo que tienen lugar en la osificación de la muñeca y puede aprender cómo utilizar la radiografía de muñeca para determinar el momento de desarrollo del paciente

    Reentrada en figura de ocho en epicardio ventricular sujeto a isquemia regional: estudio de simulación

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    Estudiamos mapas isocronales y electrogramas de simulaciones bidimensionales de taquicardia ventricular en un modelo virtual de epicardio sujeto a isquemia regional. Reentradas en figura de ocho fueron obtenidas, sus respectivos potenciales analizados, al igual que el comportamiento de las corrientes involucradas en heterogeneidad fisiológica y bioquímica. El circuito reentrante consiste de un arco funcional de bloqueo de conducción alrededor del cual el frente de activación avanza de manera circular con una lenta e irregular velocidad
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