1,280 research outputs found

    Multiclasificadores basados en aprendizaje automåtico como herramienta para la evaluación del perl neurotóxico de líquidos iónicos

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    Los líquidos iónicos poseen un perfil fisicoquímico único, el cual los provee de un amplio rango de aplicaciones. Su variabilidad estructural casi ilimitada permite su diseùo para tareas específicas. Sin embargo, su sustentabilidad, específicamente su seguridad desde el punto de vista toxicológico, ha sido frecuentemente cuestionada. Este último aspecto limita significativamente el cumplimiento de las regulaciones establecidas por la Unión Europea para el registro, evaluación, autorización y restricción de compuestosquímicos (REACH), así como su aplicación final. Debido a que la mayoría de los líquidos iónicos no han sido sintetizados, se hace evidente la importancia del desarrollo de herramientas quimioinformåticas que, de forma eciente, permitan evaluar el potencial toxicológico de estos compuestos. En este sentido, el uso combinado de múltiples clasificadores ha demostrado superar las limitaciones de desempeùo asociadas al uso de clasificadores individuales. En el presente trabajo fueron evaluadas varias estrategias alternativas de multiclasificadores basados en tÊcnicas de aprendizaje automåtico supervisado, como herramientas para la evaluación del perfil neurotóxico de líquidos iónicos basado en la inhibición de la enzima acetilcolinesterasa, como indicador de neurotoxicidad. Se obtuvieron dos multiclasicadores con una alta capacidad predictiva sobre un conjunto de validación externa (no utilizado en el proceso de aprendizaje de los modelos). De acuerdo a los resultados obtenidos el 96% de un conjunto de nuevos líquidos iónicos podrå ser correctamente clasicado con la utilizaciónde estos multiclasicadores, los cuales constituyen herramientas de toma de decisión útiles en el campo del diseùo y desarrollo de nuevos líquidos iónicos sustentables

    Psychological factors related to time to help-seeking for cancer symptoms: A meta-analysis across cancer sites.

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    The time patients wait before seeking help for cancer symptoms is among the most important factors contributing to diagnostic delays in cancer. We reviewed the association between time to help-seeking and three psychological factors: symptom knowledge, symptom interpretation, and beliefs about cancer (Prospero review protocol CRD42018088944). Forty-seven studies published between 1990 and 2019 met the inclusion criteria, providing data on 44,961 participants from 22 countries concerning seven cancer sites. A series of random-effects meta-analyses and meta-regressions were conducted. Better symptom knowledge was related to lower odds of a long help-seeking interval in both studies with healthy populations (OR = .73, 95% CI [.63, .84], k = 19) and with patients (OR = .40, 95% CI [.23, .69], k = 12), and so was interpreting experienced symptoms as cancer-related (OR = .52, 95% CI [.36, .75], k = 13 studies with patients). More positive beliefs about cancer (i.e., that cancer is treatable) were associated with lower odds of a long help-seeking interval in both studies with healthy populations (OR = .70, 95% CI [.52, .92], k = 11) and with patients (OR = .51, 95% CI [.32, .82], k = 7). Symptom knowledge, interpretation, and beliefs about cancer are likely to be universal predictors of help-seeking. Theoretical models of patient help-seeking and interventions aiming to reduce delays should incorporate these factors

    Prosthetic valve endocarditis caused by Staphylococcus capitis: report of 4 cases

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    Although Staphylococcus capitis is considered to be a rare causative organism for prosthetic valve endocarditis, we report 4 such cases that were encountered at our hospital over the past 2 years. Case 1 was a 79-year-old woman who underwent aortic valve replacement with a bioprosthetic valve and presented with fever 24 days later. Transesophageal echocardiography revealed an annular abscess in the aorto-mitral continuity and mild perivalvular regurgitation. We performed emergency surgery 5 days after the diagnosis of prosthetic valve endocarditis was made. Case 2 was a 79-year-old woman presenting with fever 40 days after aortic valve replacement with a bioprosthesis. Transesophageal echocardiography showed vegetation on the valve, and she underwent urgent surgery 2 days after prosthetic valve endocarditis was diagnosed. In case 3, a 76-year-old man presented with fever 53 days after aortic valve replacement with a bioprosthesis. Vegetation on the prosthetic leaflet could be seen by transesophageal echocardiography. He underwent emergency surgery 2 days after the diagnosis of prosthetic valve endocarditis was made. Case 4 was a 68-year-old woman who collapsed at her home 106 days after aortic and mitral valve replacement with bioprosthetic valves. Percutaneous cardiopulmonary support was started immediately after massive mitral regurgitation due to prosthetic valve detachment was revealed by transesophageal echocardiography. She was transferred to our hospital by helicopter and received surgery immediately on arrival. In all cases, we re-implanted another bioprosthesis after removal of the infected valve and annular debridement. All patients recovered without severe complications after 2 months of antibiotic treatment, and none experienced re-infection during 163 to 630 days of observation. Since the time interval between diagnosis of prosthetic valve endocarditis and valve re-replacement ranged from 0 to 5 days, early surgical removal of the infected prosthesis and an appropriate course of antibiotics were attributed to good clinical outcomes in our cases

    Componente hiperplĂĄsico del crecimiento compensatorio renal temprano

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    La remoción de un riùón estimula inmediatamente el crecimiento y la función del otro; no obstante hay diferentes mecanismos que inician este crecimiento compensatorio renal (CCR), dependiendo en parte, de la edad y del sexo. Por ejemplo, en animales adultos la nefrectomía induce un crecimiento, principalmente, de tipo hipertrófico. Sin embargo, en trabajos previos nosotros observamos que en ratones adultos de ambos sexos, a las 26 horas de la nefrectomía (Nx), hay un aumento en la actividad mitótica (AM) de las cÊlulas de los túbulos contorneados de la corteza y rectos de la mÊdula externa del riùón contra-lateral. Con el fin de estudiar el componente hiperplåsico en etapas mås tempranas del CCR, en el presente trabajo analizamos la síntesis de ADN en las mismas poblaciones celulares, en ambos sexos, a las 10 horas post-nefrectomía.Facultad de Ciencias MÊdica

    Componente hiperplĂĄsico del crecimiento compensatorio renal temprano

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    La remoción de un riùón estimula inmediatamente el crecimiento y la función del otro; no obstante hay diferentes mecanismos que inician este crecimiento compensatorio renal (CCR), dependiendo en parte, de la edad y del sexo. Por ejemplo, en animales adultos la nefrectomía induce un crecimiento, principalmente, de tipo hipertrófico. Sin embargo, en trabajos previos nosotros observamos que en ratones adultos de ambos sexos, a las 26 horas de la nefrectomía (Nx), hay un aumento en la actividad mitótica (AM) de las cÊlulas de los túbulos contorneados de la corteza y rectos de la mÊdula externa del riùón contra-lateral. Con el fin de estudiar el componente hiperplåsico en etapas mås tempranas del CCR, en el presente trabajo analizamos la síntesis de ADN en las mismas poblaciones celulares, en ambos sexos, a las 10 horas post-nefrectomía.Facultad de Ciencias MÊdica

    Comparison of body mass index (BMI) with the CUN-BAE body adiposity estimator in the prediction of hypertension and type 2 diabetes

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    Background Obesity is a world-wide epidemic whose prevalence is underestimated by BMI measurements, but CUN-BAE (Clínica Universidad de Navarra - Body Adiposity Estimator) estimates the percentage of body fat (BF) while incorporating information on sex and age, thus giving a better match. Our aim is to compare the BMI and CUN-BAE in determining the population attributable fraction (AFp) for obesity as a cause of chronic diseases. Methods We calculated the Pearson correlation coefficient between BMI and CUN-BAE, the Kappa index and the internal validity of the BMI. The risks of arterial hypertension (AHT) and diabetes mellitus (DM) and the AFp for obesity were assessed using both the BMI and CUN-BAE. Results 3888 white subjects were investigated. The overall correlation between BMI and CUN-BAE was R2 = 0.48, which improved when sex and age were taken into account (R2 > 0.90). The Kappa coefficient for diagnosis of obesity was low (28.7 %). The AFp was 50 % higher for DM and double for AHT when CUN-BAE was used. Conclusions The overall correlation between BMI and CUN-BAE was not good. The AFp of obesity for AHT and DM may be underestimated if assessed using the BMI, as may the prevalence of obesity when estimated from the percentage of BF

    Small-scale solar magnetic fields

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    As we resolve ever smaller structures in the solar atmosphere, it has become clear that magnetism is an important component of those small structures. Small-scale magnetism holds the key to many poorly understood facets of solar magnetism on all scales, such as the existence of a local dynamo, chromospheric heating, and flux emergence, to name a few. Here, we review our knowledge of small-scale photospheric fields, with particular emphasis on quiet-sun field, and discuss the implications of several results obtained recently using new instruments, as well as future prospects in this field of research.Comment: 43 pages, 18 figure

    Comparing correction methods of RCM outputs for improving crop impact projections in the Iberian Peninsula for 21st century

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    Assessment of climate change impacts on crops in regions of complex orography such as the Iberian Peninsula (IP) requires climate model output which is able to describe accurately the observed climate. The high resolution of output provided by Regional Climate Models (RCMs) is expected to be a suitable tool to describe regional and local climatic features, although their simulation results may still present biases. For these reasons, we compared several post-processing methods to correct or reduce the biases of RCM simulations from the ENSEMBLES project for the IP. The bias-corrected datasets were also evaluated in terms of their applicability and consequences in improving the results of a crop model to simulate maize growth and development at two IP locations, using this crop as a reference for summer cropping systems in the region. The use of bias-corrected climate runs improved crop phenology and yield simulation overall and reduced the inter-model variability and thus the uncertainty. The number of observational stations underlying each reference observational dataset used to correct the bias affected the correction performance. Although no single technique showed to be the best one, some methods proved to be more adequate for small initial biases, while others were useful when initial biases were so large as to prevent data application for impact studies. An initial evaluation of the climate data, the bias correction/reduction method and the consequences for impact assessment would be needed to design the most robust, reduced uncertainty ensemble for a specific combination of location, crop, and crop management

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE
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