Spectroscopy studies of 4H-SiC

Calculations of the total dielectric functions and the optical bandgap energy (OBGE) of 4HSiC were performed by the full-potential linear muffin-tin-orbital method. The results are compared to spectroscopic ellipsometry dielectric measurements agreeing closely over in a wide range of energies. The obtained theoretical value of the (OBGE) agrees very closely with the measured ones obtained by transmission and photoacoustic spectroscopies at room temperature performed on 470 µm thick wafer and a 25 µm thick homoepitaxial layer of 4H-SiC samples grown (n-type, Siface) by hot wall CVD

Plasma lipid profiles discriminate bacterial from viral infection in febrile children

Fever is the most common reason that children present to Emergency Departments. Clinical signs and symptoms suggestive of bacterial infection ar

Estructura y diversidad del matorral desértico rosetófilo rehabilitado con rodillo aireador, Coahuila, México

ABSTRACT: We assessed the changes generated in the structure and diversity of rosetophyllous desert scrubland vegetation applying habitat rehabilitation techniques with aerator roller in the years 2004, 2008 and 2011 and an area burned naturally. In 5 treatments: control (MDRt), aerator roller applied in 2004 (RA04), 2008 (RA08), 2011 (RA11) and burned area 2011 (IN11) diversity and similarity were evaluated among sites using the Shannon and Sørensen index. t diversity tests were conducted and importance value index of species (IVI) was determined. 21 tree and shrub species belonging to 11 families were recorded, highlighting: Cactaceae, Fabaceae and Asteraceae. Shannon index showed that the treatment IN11 presented higher richness (H' = 1.903), while RA11 treatment had the lowest index (H' = 1.30). According to Sørensen index the highest similarity was between the IN11 and MDRt treatments with 0.75 and the most dissimilar was between MDRt and RA04 with 0.38. Kruskall-Wallis showed no significant difference between treatments respect to IVI (p = 0.859). The aerator roller treatment increased in short-term the species richness and substantially decreased the coverage of species of Cactaceae and increased coverage of Larrea tridentata. In contrast, fire treatment substantially reduced the coverage of Larrea tridentata and promoted the presence and coverage of species of the Fabaceae family.RESUMEN: Se evaluaron los cambios generados en la estructura y diversidad de la vegetación del matorral desértico rosetófilo aplicando técnicas de rehabilitación de hábitat con el rodillo aireador en los años 2004, 2008 y 2011 y un área incendiada naturalmente. En cinco tratamientos: testigo (MDRt), rodillo aireador aplicado en 2004 (RA04), 2008 (RA08), 2011 (RA11) y área incendiada 2011 (IN11) se evaluó la diversidad y la similitud entre sitios con los índices de Shannon y Sørensen. Se realizaron pruebas de diversidad de t y se determinó el índice de valor de importancia de las especies (IVI). Se registraron 21 especies arbóreas y arbustivas pertenecientes a 11 familias, destacando: Cactaceae, Fabaceae y Asteraceae. El índice de Shannon mostró que el tratamiento IN11 presentó una mayor riqueza (H´ = 1.903), mientras que el tratamiento RA11 presentó el menor índice (H´ = 1.30). De acuerdo con el índice de Sørensen, la mayor similitud fue entre los tratamientos IN11 y MDRt con 0.75 y los más disímiles fueron RA04 y MDRt con 0.38. La Prueba de Kruskall-Wallis mostró que no hay diferencia significativa entre los tratamientos respecto al IVI (p = 0.859). El tratamiento de rodillo aireador incrementó a corto plazo la riqueza de especies y disminuyó substancialmente la cobertura de especies de la familia Cactaceae e incrementó la cobertura de Larrea tridentata. Contrastando el tratamiento de fuego que disminuyó substancialmente la cobertura de Larrea tridentata y fomentó la presencia y cobertura de especies de la familia Fabaceae

Stoma-free survival after anastomotic leak following rectal cancer resection: worldwide cohort of 2470 patients

Background: The optimal treatment of anastomotic leak after rectal cancer resection is unclear. This worldwide cohort study aimed to provide an overview of four treatment strategies applied. Methods: Patients from 216 centres and 45 countries with anastomotic leak after rectal cancer resection between 2014 and 2018 were included. Treatment was categorized as salvage surgery, faecal diversion with passive or active (vacuum) drainage, and no primary/secondary faecal diversion. The primary outcome was 1-year stoma-free survival. In addition, passive and active drainage were compared using propensity score matching (2: 1). Results: Of 2470 evaluable patients, 388 (16.0 per cent) underwent salvage surgery, 1524 (62.0 per cent) passive drainage, 278 (11.0 per cent) active drainage, and 280 (11.0 per cent) had no faecal diversion. One-year stoma-free survival rates were 13.7, 48.3, 48.2, and 65.4 per cent respectively. Propensity score matching resulted in 556 patients with passive and 278 with active drainage. There was no statistically significant difference between these groups in 1-year stoma-free survival (OR 0.95, 95 per cent c.i. 0.66 to 1.33), with a risk difference of -1.1 (95 per cent c.i. -9.0 to 7.0) per cent. After active drainage, more patients required secondary salvage surgery (OR 2.32, 1.49 to 3.59), prolonged hospital admission (an additional 6 (95 per cent c.i. 2 to 10) days), and ICU admission (OR 1.41, 1.02 to 1.94). Mean duration of leak healing did not differ significantly (an additional 12 (-28 to 52) days). Conclusion: Primary salvage surgery or omission of faecal diversion likely correspond to the most severe and least severe leaks respectively. In patients with diverted leaks, stoma-free survival did not differ statistically between passive and active drainage, although the increased risk of secondary salvage surgery and ICU admission suggests residual confounding