17 research outputs found

    Modelos numéricos sencillos para el cálculo de las Regiones de Entrada Mecánica y Térmica en conductos

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    Cuando un fluido es forzado a entrar en un conducto en el cual se ve confinado, se genera una región justo al inicio conocida como “Región de Entrada”. En esta zona se produce una evolución de las propiedades del fluido desde las condiciones antes de la entrada al conducto, hasta unas condiciones estables y estacionarias. El punto en el cual las condiciones pasan a ser invariables marca el final de esta región de entrada. El objetivo fundamental de este trabajo es resolver las ecuaciones que rigen el comportamiento del fluido para poder analizar la evolución de las propiedades en la región de entrada bajo distintas condiciones. Para conseguir este objetivo, se intentarán implementar de forma eficiente diferentes métodos numéricos en un entorno MATLAB. A su vez se comprobará la validez de los resultados obtenidos comparándolos con los resultados de los diferentes autores de la bibliografía.If a fluid is forced to enter a pipe in which it is confined, a region is generated just behind the entrance known as “Entrance Region”. In this area, an evolution of the fluid properties from the status just before the entrance to a condition stable and stationary takes place. The point in which these properties become invariant determines the end of this entrance region. The main objective of this paper is to solve the equations that govern the fluid’s behavior in order to analyze the evolution of the properties in the entrance region under different conditions. To achieve that goal, we will try to use several numerical methods in a MATLAB environment. After that, the results obtained will be compared with those provided by the different authors of the bibliography in order to study their validity.Universidad de Sevilla. Grado en Ingeniería Aeroespacia

    Adipose Tissue and Inflammation

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    Adipose tissue is composed mainly by adipocytes and stromal-vascular fraction, which are composed by different cell types including macrophages. There are three types of adipose tissue: brown (BrAT), white (WAT), and beige (BeAT). BrAT is less abundant and is implicated in lipid oxidation and energy balance; BeAT has the pathway of adaptive thermogenesis, and WAT is endocrine in nature and lipid storage site and is implicated as an endocrine organ that secretes hormones and different molecules. These molecules are pro-inflammatory and anti-inflammatory factors, including the adipokines leptin, adiponectin, resistin, and visfatin, as well as cytokines and chemokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, leptin, adiponectin, and others, are involved with the development of adipose tissue inflammation and obesity. This pathological condition, together with other factors such as oxidative stress, may develop insulin resistance and the pathogenesis of type 2 diabetes mellitus (T2DM)

    Increases of Corporal Temperature as a Risk Factor of Atherosclerotic Plaque Instability

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    This work explores for the first time the effects of temperature increments on the development of high shear stresses between plaque and arterial wall due to their different dilatational properties. Data from the literature report febrile reactions prior to myocardial infarction in patients with normal coronary arteries and that coronary syndromes seem to be triggered by bacterial and viral infections, being fever the common symptom. Methods The thermo-mechanical behavior of thoracic aortas of New Zealand White rabbits with different degrees of atherosclerosis was measured by means of pressure–diameter tests at different temperatures. In addition, specific measurements of the thermal dilatation coefficient of atheroma plaques and of healthy arterial walls were performed by means of tensile tests at different temperatures. Results Results show a different thermo-mechanical behavior, the dilatation coefficient of atheroma plaque being at least twice that of the arterial wall. The calculation of temperature-induced mechanical stress at the plaque–vessel interface yielded shear stress levels enough to promote plaque rupture. Conclusions Increases of corporal temperature either local—produced by the inflammatory processes associated with atherosclerosis—or systemic—by febrile reactions—can play a role in increasing the risk of acute coronary syndromes, and they deserve a more comprehensive study

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Actualidad y prospectiva de la investigación científica en el Centro Universitario Amecameca de la Universidad Autónoma del Estado de México

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    Con responsabilidad, se organizó un programa cuya finalidad fuera publicitar con transparencia dichos avances, a través de un esfuerzo de rendición de cuentas a la comunidad inmediata, la universitaria, y a la comunidad abierta, la sociedad que la principal referencia para tal efecto. El programa se concretiza a través del presente libro, conformado con una inspiración de investigación multidisciplinaria; sin embargo, para llegar a tal fin, el reto es realizar el proceso de búsqueda y generación de conocimiento transitando hacia la colaboración de los cuerpos académicos, que puedan construir nuevos conocimientos fortalecidos por la convergencia de diferentes campos del saber. En consecuencia, la primera etapa de esta estrategia es la publicidad de los trabajos investigativos ejercidos, para hacer un balance al día, pero también proyectar el futuro de cada campo y área del conocimiento. La organización explicativa está organizada por tres bloques representativos del quehacer en la generación de conocimiento del Centro Universitario, un primer bloque centra el interés en las humanidades, educación y sustentabilidad; el segundo bloque lo integra la reflexión científica sobre la construcción democrática, derechos humanos y equidad de género; en el tercer segmento se destina a la seguridad alimentaria, salud pública y sistemas agropecuarios. La actualidad de la investigación eleva la producción lograda y lo que en el momento se encuentra en construcción y los alcances que produce para la docencia, la investigación misma, y para la sociedad en general. La prospectiva es un área que todos los capítulos desarrollan con el propósito de delinear los alcances innovadores por andar en teoría, metodología e incluso en los saberes mismo

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Economía y política en América Latina, actores y procesos en el contexto actual

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    El libro que usted tiene en sus manos recoge algunos de los grandes temas de la agenda latinoamericana actual, con especial énfasis en el campo del desarrollo económico y la promoción y consolidación de los regímenes democráticos. Se reconoce aquí que el bienestar de los países de la región va de la mano de un papel propositivo y activo de sus gobiernos, y que esta actitud proactiva atraviesa necesariamente por el aprovechamiento de acuerdos de cooperación entre tales países. Se reconoce asimismo que la eficacia de las políticas activas que debieran emprenderse en la región pueden optimizarse si se instrumentan en un entorno macroeconómico estable y sólido, caracterizado por equilibrios razonables en el plano fiscal y con baja inflación, así como en una atmósfera política y social de concordia y con una vida democrática consolidada
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