SINTESIS DE NANOPARTICULAS DE OXIDO DE TITANIO EN FASE RUTILO PARA EL DESARROLLO DE UN MATERIAL COMPUESTO DE ESPUMA DE POLIURETANO

Este artículo reporta un procedimiento para mejorar las capacidades mecánicas y térmicas de la espuma de poliuretano, buscando desarrollar un material compuesto que pueda ser usado como recubrimiento interior de vehículos y mejore las condiciones de seguridad y confort para sus ocupantes. Para ello, se desarrolló un método de síntesis de nanopartículas de óxido de titanio en fase de rutilo por un proceso sol-gel y posterior tratamiento térmico entre 620 y 700°C. Se encontró que la fase rutilo es obtenida a 700 °C y que las nanopartículas presentan un tamaño promedio de 24.7 nm. Estas nanopartículas fueron incorporadas en las espumas de poliuretano. Análisis de microscopía electrónica de rastreo (SEM–EDX), espectroscopia infrarroja con transformada de Fouriel (FT-IR) y ensayos mecánicos de flexión y tracción aplicados sobre la espuma compuesta, mostraron que concentraciones por debajo de 1.5 %p, cubre puntos huecos en la estructura del poliuretano, generando mejoras en las propiedades mecánicas y térmicas de este material. Palabras clave: Rutilo, nanopartículas, isocianato, poliol, poliuretano, material compuesto

ESTUDIO DE UN CATALIZADOR ÁCIDO MAGNÉTICO EN LA OBTENCIÓN DE FURFURAL A PARTIR DE LA DESHIDRATACIÓN DE XILOSA

Se  estudiaron sólidos sulfonados (Al2O3-SO3H)  y  sulfonados magnéticos (Fe3O4-Al2O3-SO3H)  en la reacción de deshidratación de xilosa a furfural. Los catalizadores se caracterizaron por distintas técnicas como fisisorción de N2 a 77K, espectroscopia infrarroja FTIR y curvas de magnetización. Estos solidos mostraron una relación lineal entre el área superficial y la capacidad ácida mostrando una mejor dispersión de los grupos -SO3H en el sólido que no presenta carácter  magnético. Sin embargo, la presencia de las partículas magnéticas Fe3O4 permite una fácil separación del medio de reacción al aplicar un campo magnético externo, con rendimientos a furfural del 67% con el catalizador  Al2O3-SO3H  y del 11% con Fe3O4-Al2O3-SO3H.Palabras clave: furfural, xilosa, ácido, magnético, sulfónic

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group