Método para la determinación de la densidad de una muestra de granos enteros de alubia por procesamiento digital de imágenes

En este trabajo se presenta una metodología alternativa para la determinación de la densidad de una muestra de granos enteros de alubia (Phaselous vulgaris L) basada en procesamiento digital de imágenes, caracterizada por su sencillez y fácil implementación. Requiere de las medidas de la masa y del volumen de la muestra, las que son realizadas con una balanza y con un modelo tridimensional del grano respectivamente. En este modelo tridimensional se asume que el volumen de cada grano es proporcional a su largo y al cuadrado de su ancho. Estos dos últimos valores son determinados a partir del empleo de técnicas de procesamiento digital de imágenes aplicadas a la imagen de muestras de granos enteros obtenidas con un escáner de escritorio. La constante de proporcionalidad se determina experimentalmente por comparación con el volumen de la muestra obtenido posteriormente por el método de desplazamiento de tolueno. Se prepararon diez muestras para determinar y analizar el comportamiento de la constante de proporcionalidad y cinco para validación del modelo propuesto. La densidad obtenida con esta metodología para las muestras de validación se contrastó con la obtenida con el método de desplazamiento de tolueno siendo la diferencia relativa porcentual inferior al 5%

Body mass index and complications following major gastrointestinal surgery: A prospective, international cohort study and meta-analysis

Aim Previous studies reported conflicting evidence on the effects of obesity on outcomes after gastrointestinal surgery. The aims of this study were to explore the relationship of obesity with major postoperative complications in an international cohort and to present a metaanalysis of all available prospective data. Methods This prospective, multicentre study included adults undergoing both elective and emergency gastrointestinal resection, reversal of stoma or formation of stoma. The primary end-point was 30-day major complications (Clavien–Dindo Grades III–V). A systematic search was undertaken for studies assessing the relationship between obesity and major complications after gastrointestinal surgery. Individual patient meta-analysis was used to analyse pooled results. Results This study included 2519 patients across 127 centres, of whom 560 (22.2%) were obese. Unadjusted major complication rates were lower in obese vs normal weight patients (13.0% vs 16.2%, respectively), but this did not reach statistical significance (P = 0.863) on multivariate analysis for patients having surgery for either malignant or benign conditions. Individual patient meta-analysis demonstrated that obese patients undergoing surgery formalignancy were at increased risk of major complications (OR 2.10, 95% CI 1.49–2.96, P < 0.001), whereas obese patients undergoing surgery for benign indications were at decreased risk (OR 0.59, 95% CI 0.46–0.75, P < 0.001) compared to normal weight patients. Conclusions In our international data, obesity was not found to be associated with major complications following gastrointestinal surgery. Meta-analysis of available prospective data made a novel finding of obesity being associated with different outcomes depending on whether patients were undergoing surgery for benign or malignant disease