41 research outputs found

    Dados como centro de anclaje topológico en una muestra superconductora

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    Solving the Ginzburg-Landau equations, we analyzed the vortex matter in a superconducting square with a Dimer structure of circular pinning centers generated by a pulsed heat source in the presence of an applied magnetic field. We numerically solved the Ginzburg-Landau equations in order to describe the effect of the temperature of the circular defects on the Abrikosov state of the sample. The pulsed laser produced a variation of the temperature in each defect. It is shown that an anomalous vortex-anti-vortex state (A-aV) appears spontaneously at higher magnetic fields. This could be due to the breaking of the symmetry of the sample by the inclusion of the thermal defects.Resolviendo las ecuaciones de Ginzburg-Landau, analizamos el estado de vórtice en un cuadrado superconductor con centros de anclaje circulares en forma de una estructura de Dados, generados por una fuente de calor pulsada y en presencia de un campo magnético aplicado. Resolvimos numéricamente las ecuaciones Ginzburg-Landau para describir el efecto de la temperatura de los defectos sobre el estado Abrikosov de la muestra. El láser pulsado produce una variación de la temperatura en cada defecto. Se muestra que un estado anómalo vórtice-anti-vórtice (A-aV), aparece espontáneamente hacia campos magnéticos altos. Esto podría deberse a la ruptura de la simetría de la muestra por la inclusión de los defectos térmicos

    Analytical development of Ginzburg-Landau equations for superconducting thin film in presence of currents

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    An analytical analysis to obtain the time dependent Ginzburg- Landau equations in presence of a current J and magnetic field H in a mesoscopic superconducting thin film is shown. The transport current is applied in a little contact in the boundary of the sample. This contacts are included through to the deGennes extrapolation parameter b in the boundary conditions. Finally, we show a useful tool that can be used to found the evolution of ψ(A,t) in this formalism. We found the dependence of the magnetization M(H) and magnetic susceptibility χ m (H) with b for such sample.Un análisis analítico para obtener las ecuaciones Ginzburg-Landau dependientes del tiempo en presencia de una corriente J y de campo magnético H, en una película delgada superconductora mesoscópica, es mostrado. La corriente de transporte es aplicada en un pequeño contacto ubicado en la frontera de la muestra. Estos contactos son incluídos a través del parámetro de extrapolación de deGennes b en las condiciones de contorno. Finalmente, mostramos una útil herramienta que puede ser usada para encontrar la evolución de ψ(A,t) en dicho formalismo. Encontramos la dependencia de la magnetización M(H) y de la susceptibilidad magnética χ m (H) con b para dicha muestra

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    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

    Análisis técnico-económico de la producción de flores frescas y plantas ornamentales en el mercado chileno

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    Tesis (Ingeniero de Ejecución Industrial)Determinar para el negocio de la producción de flores frescas y plantas ornamentales bajo invernadero su grado de atractividad, mediante un análisis técnico-productivo, un estudio de mercado y una evaluación técnico-económica de un proyecto en el ámbito nacional
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