2,289 research outputs found
Anisotropy and percolation threshold in a multifractal support
Recently a multifractal object, , was proposed to study percolation
properties in a multifractal support. The area and the number of neighbors of
the blocks of show a non-trivial behavior. The value of the
probability of occupation at the percolation threshold, , is a function
of , a parameter of which is related to its anisotropy. We
investigate the relation between and the average number of neighbors of
the blocks as well as the anisotropy of
Intususcepción intestinal con alteración hepatobiliar grave en un perro
Las hepatopatías caninas caninas son frecuentes y secundarias a multitud de alteraciones, pero son raras las asociadas a obstrucciones extrahepáticas con compromiso sanguíneo y/o biliar del hígado. Estas obstrucciones suelen obedecer a lesiones espacio-ocupantes por alteración en órgnaos adyacentes. No se ha descrito la intususcepción intestinal como potencialmente responsable de hepatopatías secundarias a obstrucción extrahepática en el perro. Por otro lado, en perros adultos las intususcepciones intestinales son poco frecuentes y suelen ocurrir secundarias a cirugía o tumores abdominales. Presentamos un caso poco frecuente de intususcepción intestinal idiopática en un Shar-Pei adulto que comprometió el riego sanguíneo hepático y obstruyó las vías biliares, desencadenando una colangiohepatopatía. El perro presentó simultáneamente signos clínicos de ambas alteraciones por lo que, aunque el diagnóstico laboratorial nos confirmó la colangiohepatopatía, fue necesario realizar una exploración exhaustiva y exámenes radiológicos y ecográficos para llegar al diagnóstico definitivo.
Experimental validation of an optical and thermal model of a Linear Fresnel Collector
2nd European Conference on Polygeneration – 30th March 1st April, 2011– Tarragona, SpainThis paper describes the design and validation of a mathematical model for a solar Fresnel collector. The function of the model is to simulate the optical and thermal dynamics of a Fresnel system for heating water. The model is validated using real data gathered from a cooling plant with double effect absorption chiller located in the School of Engineering University of Seville, Spain (Experimental cooling plant is also described in the paper). Comparison of calculated and plant measured data shows that the error is lower than 3% in the optical model and within 7% in the thermal model.
The model uses a new approach to include a solar tracking mirror mechanism in one axis. This tracking has been designed to maximise the reception of available solar radiation by the absorption pipe. The thermal model used is based around classical models for solar receivers and it is validated with real operating data gathered from a supervisor system.
The Fresnel model has been designed with sufficient flexibility to consider different geometries and thermal parameters, and may be used to simulate the performance of a proposed Fresnel collector system at any location
Genetic and Molecular Factors in Drug-Induced Liver Injury: A Review
The diagnosis of drug-induced liver injury (DILI) is challenging and based on complex diagnostic criteria. DILI falls into two main categories i) intrinsic 'dose-dependent' Type A reactions ii) 'idiosyncratic' or Type B reactions (which are usually not predictable). Idiosyncratic reactions can be immunoallergic (hypersensitivity), or metabolic, although overlap between categories can occur. The aim of this review is to summarise the general view of underlying mechanisms in DILI and to highlight individual risk factors for developing hepatotoxicity. Polymorphisms of bioactivation/ toxification pathways through CYP450 enzymes (Phase I), detoxification reactions (Phase II) and excretion/transport (Phase III) are explored together with immunological factors that might determine DILI. The importance of establishing a multidisciplinary and multi-centric network to promote the understanding and research in hepatotoxicity is underlined. Challenges such as genetic analyses for association studies and whole genome studies, pharmacogenetic testing and future approaches to study DILI are considered. Knowledge regarding these operational mechanisms could provide further insight for the prospective identification of susceptible patients at risk of developing drug-induced hepatotoxicity.
Introducción a la citología digestiva en pequeños animales
La citología es un método de diagnóstico atractivo para el veterinario clínico por ser técnicamente simple, rápido y económico. La endoscopia ha permitido que la citología digestiva sea además mínimamente invasiva. Los resultados de la citología dependen de una buena obtención y preparación de las muestras así como de nuestra capacidad para identificar los diferentes tipos celulares presentes. En este artículo se exponen de forma fácil y práctica los fundamentos necesarios para una aproximación eficaz a la citología diagnóstica digestiva: equipos endoscópicos más aconsejables, selección, obtención y número de biopsias, y las bases para la identificación de las células presentes en las muestras del tracto digestivo en perro y gato.Cytology is an easy, fast cost-effective diagnostic method very atíractive to practitioners. Also, the advent of endoscopy has made gastrointestinal tract cytology a non invasive method. However, results of the cytologic analysis depend on a proper obtention and preparation of the samples and on our skill to identify the different cell types observed. In this article the essentials for an effective approach to diagnostic gastrointestinal tract cytology are presented: endoscopy equipment, selection, obtention and number of biopsy samples and the basis for the identification of cells present in the digestive tract of dogs and cats
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