Hydration of clinker phases in alkaline conditions

This research is focused on the individual behaviour of calcium silicates (C3S and C2S) and tricalcium aluminate (C3A) when hydrated with water, but in the presence of 4 wt% Na2SO4. Two- and 28‑day mechanical strength of pastes were determined and the reaction products were identified by means of XRD, SEM/EDX and 29Si and 27 Al MAS NMR. Analysis of C3A revealed that hydration was favoured in the presence of Na2SO4. This salt governed hydration kinetics while providing the alkalinity required to induce the joint precipitation of carbonated and calcium sulfoaluminate hydrate reaction product, both observed to contribute to the mechanical strength of the resulting material. In both silicates (C3S and C2S), the findings showed that the presence of Na2SO4 stimulated mechanical strength development. The synergy among all chemical reactions taking place during the hydration of these calcium silicates favoured a substantial rise in the alkalinity of the pastes formed. In addition, the anion SO42- induced the precipitation of cementitious gels with a high percentage of Q2 units, which leads to a significant increase in the mechanical strength of the materials at 28 day

A protocol for resuscitation of severe burn patients guided by transpulmonary thermodilution and lactate levels: A 3-year prospective cohort study

Introduction: The use of urinary output and vital signs to guide initial burn resuscitation may lead to suboptimal resuscitation. Invasive hemodynamic monitoring may result in over-resuscitation. This study aimed to evaluate the results of a goal-directed burn resuscitation protocol that used standard measures of mean arterial pressure (MAP) and urine output, plus transpulmonary thermodilution (TPTD) and lactate levels to adjust fluid therapy to achieve a minimum level of preload to allow for sufficient vital organ perfusion. Methods: We conducted a three-year prospective cohort study of 132 consecutive critically burned patients. These patients underwent resuscitation guided by MAP (>65 mmHg), urinary output (0.5 to 1 ml/kg), TPTD and lactate levels. Fluid therapy was adjusted to achieve a cardiac index (CI) >2.5 L/minute/m2 and an intrathoracic blood volume index (ITBVI) >600 ml/m2, and to optimize lactate levels. Statistical analysis was performed using mixed models. We also used Pearson or Spearman methods and the Mann-Whitney U-test. Results: A total of 98 men and 34 women (mean age, 48 ± 18 years) was studied. The mean total body surface area (TBSA) burned was 35% ± 22%. During the early resuscitation phase, lactate levels were elevated (2.58 ± 2.05 mmol/L) and TPTD showed initial hypovolemia by the CI (2.68 ± 1.06 L/minute/m2) and the ITBVI (709 ± 254 mL/ m2). At 24 to 32 hours, the CI and lactic levels were normalized, although the ITBVI remained below the normal range (744 ± 276 ml/m2). The mean fluid rate required to achieve protocol targets in the first 8 hours was 4.05 ml/ kg/TBSA burned, which slightly increased in the next 16 hours. Patients with a urine output greater than or less than 0.5 ml/kg/hour did not show differences in heart rate, mean arterial pressure, CI, ITBVI or lactate levels. Conclusions: Initial hypovolemia may be detected by TPTD monitoring during the early resuscitation phase. This hypovolemia might not be reflected by blood pressure and hourly urine output. An adequate CI and tissue perfusion can be achieved with below-normal levels of preload. Early resuscitation guided by lactate levels and below-normal preload volume targets appears safe and avoids unnecessary fluid input

Responsabilidad social universitaria ante la inclusión educativa y social: generando una cultura de diversidad

Se presenta una memoria final del PIMCD nº 36 del cuso 2014-2015 en el que se ha desarrollado una herramienta online con bibliografía, documentación, enlaces de interés, materiales de aplicación en el aula y trabajos de los estudiantes para atender a diversidades funcionales, culturales, sexo-genéricas e invisibles en el sistema educativa

Metodología aplicada en el estudio del desarrollo del lenguaje en niños con detección temprana de la hipoacusia neonatal

Producción CientíficaDado que el potencial discapacitante que causa la deficiencia auditiva neonatal disminuye con una detección e intervención tempranas, hemos elaborado un proyecto de investigación, con el que nos proponemos conocer el grado de desarrollo del lenguaje de los niños y niñas que procedentes del cribado auditivo universal, han sido diagnosticados/as por nosotros de hipoacusia prelingual en estos últimos 15 años y analizar las variables determinantes y las que son modificables. El objeto de esta comunicación consistirá en presentar la metodología que vamos a utilizar. Método: Partimos de los datos almacenados en nuestro Servicio de ORL, que comprende a 282 niños con hipoacusia. Hemos tenido la oportunidad de crear un grupo de investigación en el que coincidimos especialistas de la audición infantil y del lenguaje, por lo que contamos con medios suficientes para el estudio. Resultados: Describimos los elementos que configuran este proyecto, en relación al equipo de trabajo y a su desarrollo. Tras aplicar unos criterios de exclusión/inclusión, hemos seleccionado a un grupo de 45 niños entre 3 y 15 años, definiendo sus características auditivas. Mediante pruebas específicas, adaptadas a la edad, estudiaremos los diferentes aspectos del lenguaje; y a través Rev. ORL, 20xx, x x de una entrevista estructurada realizada a los padres, intentaremos determinar las variables que influyen en el proceso re-habilitador. Finalmente, los datos serán analizados estadísticamente. Discusión: La variabilidad y la escasa prevalencia de la hipoacusia infantil, dificultan la realización de estudios con población suficiente para obtener resultados estadísticamente significativos. Sin embargo, creemos que el grupo de niños seleccionado y la metodología utilizada nos permitirán conocer mejor las variables influyentes en el desarrollo del lenguaje. Conclusiones: El programa de cribado auditivo universal ha permitido una intervención más precoz, lo que debería mejorar los niveles de lenguaje de los niños detectados/as con hipoacusia. Aunque el desarrollo normalizado de la comunicación depende de otros factores difíciles de determinar, a través del protocolo presentado pretendemos equiparar estos resultados, validando el proceso de cribado/diagnóstico e intervención de nuestro medio.Universidad de Valladoli

Linear and crosslinked polyimide aerogels: synthesis and characterization

Linear and crosslinked polyimide aerogels have been synthesized by means of a simple and eco-friendly process. Water-soluble poly(amic acid), PAA, solution was produced and thermal imidization was employed. Furthermore, freeze drying was used. In the present work, the influence of the solid content of the PAA solution and the crosslinking addition on the properties of the resulted aerogels were evaluated. An increase in solid content resulted in denser structures. Thermogravimetric analysis demonstrated thermal stability of polyimide aerogels up to 550 °C. Moreover, the crosslinking addition resulted in mechanical properties improvements. In addition, the obtained polyimide aerogels retained an oil amount of 14 times higher than its dry weight. Besides, polyimide aerogels showed very good values of sound absorption coefficient (maximum value of 0.91) and low thermal conductivities (0.038–0.045 W/m K). Summarizing, PI aerogels presented very good thermal and acoustic insulation properties, excellent thermal stability and good oil sorption capability.Se han sintetizado aerogeles de poliimida lineales y reticulados mediante un proceso sencillo y ecológico. Se produjo una solución de poli(ácido ámico), PAA, soluble en agua y se empleó la imidización térmica. Además, se utilizó liofilización. En el presente trabajo se evaluó la influencia del contenido de sólidos de la solución de PAA y la adición de entrecruzamiento sobre las propiedades de los aerogeles resultantes. Un aumento en el contenido de sólidos resultó en estructuras más densas. El análisis termogravimétrico demostró la estabilidad térmica de los aerogeles de poliimida hasta 550 ºC Además, la adición de reticulación dio como resultado mejoras en las propiedades mecánicas. Además, los aerogeles de poliimida obtenidos retuvieron una cantidad de aceite 14 veces superior a su peso seco. Además, los aerogeles de poliimida mostraron muy buenos valores de coeficiente de absorción acústica (valor máximo de 0,91) y bajas conductividades térmicas (0,038–0,045 W/m · K). En resumen, los aerogeles de PI presentaron muy buenas propiedades de aislamiento térmico y acústico, excelente estabilidad térmica y buena capacidad de sorción de aceite

Todo lo que siempre quiso saber sobre la evaluación, pero no se atrevió a preguntar: a propósito de una encuesta

La evaluación es un proceso sistemático, continuo e integral destinado a determinar hasta qué punto han sido alcanzados los objetivos educativos. En ella se aúnan dos actividades fundamentales: medir y emitir juicios de valor a partir, de los datos. Sin embargo, a pesar de la claridad de estos conceptos la forma de evaluar a los alumnos todavía sigue plagada de importantes contradicciones entre los profesores, lo que manifiesta unas conductas didácticas alejadas de lo que debiera ser una pedagogía basada en la evidencia. El objetivo de este trabajo es evidenciar las citadas discrepancias, entre los agentes del proceso de enseñanza aprendizaje (alumnos y profesores), a la hora de elaborar, realizar y calificar las pruebas de evaluación (“exámenes”) de los alumnos de varias disciplinas relacionadas con la Biomedicina. La metodología empleada ha consistido en aplicar a los estudiantes un sencillo cuestionario con preguntas de elección múltiple. A partir de los resultados, se pretende reflexionar sobre conjunto de criterios sólidos que permitan realizar las evaluaciones de los alumnos con mayor validez, fiabilidad, objetividad y pertinencia, como recomienda la OMS en su Guía Pedagógica para el Personal de Salud

The anti-aging factor Klotho protects against acquired long QT syndrome induced by uremia and promoted by fibroblast growth factor 23

[Background]: Chronic kidney disease (CKD) is associated with increased propensity for arrhythmias. In this context, ventricular repolarization alterations have been shown to predispose to fatal arrhythmias and sudden cardiac death. Between mineral bone disturbances in CKD patients, increased fibroblast growth factor (FGF) 23 and decreased Klotho are emerging as important effectors of cardiovascular disease. However, the relationship between imbalanced FGF23-Klotho axis and the development of cardiac arrhythmias in CKD remains unknown. [Methods]: We carried out a translational approach to study the relationship between the FGF23–Klotho signaling axis and acquired long QT syndrome in CKD-associated uremia. FGF23 levels and cardiac repolarization dynamics were analyzed in patients with dialysis-dependent CKD and in uremic mouse models of 5/6 nephrectomy (Nfx) and Klotho deficiency (hypomorphism), which show very high systemic FGF23 levels. [Results]: Patients in the top quartile of FGF23 levels had a higher occurrence of very long QT intervals (> 490 ms) than peers in the lowest quartile. Experimentally, FGF23 induced QT prolongation in healthy mice. Similarly, alterations in cardiac repolarization and QT prolongation were observed in Nfx mice and in Klotho hypomorphic mice. QT prolongation in Nfx mice was explained by a significant decrease in the fast transient outward potassium (K+) current (Itof), caused by the downregulation of K+ channel 4.2 subunit (Kv4.2) expression. Kv4.2 expression was also significantly reduced in ventricular cardiomyocytes exposed to FGF23. Enhancing Klotho availability prevented both long QT prolongation and reduced Itof current. Likewise, administration of recombinant Klotho blocked the downregulation of Kv4.2 expression in Nfx mice and in FGF23-exposed cardiomyocytes. [Conclusion]: The FGF23–Klotho axis emerges as a new therapeutic target to prevent acquired long QT syndrome in uremia by minimizing the predisposition to potentially fatal ventricular arrhythmias and sudden cardiac death in patients with CKD.This work was supported by projects from the Instituto de Salud Carlos III, Ministry of Economy, Industry and Competitiveness (PI17/01093, PI17/01193, PI20/00763, CP15/00129, F18/00261, CPII20/00022, SAF2017-84777-R, PID2020-113238RB-I00), from the Sociedad Española de Cardiología (SEC), and from the Fundación Renal Íñigo Alvarez de Toledo (FRIAT), co-funded by the European Regional Development Fund (Fondos FEDER)

Heterozygous and Homozygous Variants in SORL1 Gene in Alzheimer's Disease Patients: Clinical, Neuroimaging and Neuropathological Findings

In the last few years, the SORL1 gene has been strongly implicated in the development of Alzheimer’s disease (AD). We performed whole-exome sequencing on 37 patients with early-onset dementia or family history suggestive of autosomal dominant dementia. Data analysis was based on a custom panel that included 46 genes related to AD and dementia. SORL1 variants were present in a high proportion of patients with candidate variants (15%, 3/20). We expand the clinical manifestations associated with the SORL1 gene by reporting detailed clinical and neuroimaging findings of six unrelated patients with AD and SORL1 mutations. We also present for the first time a patient with the homozygous truncating variant c.364C>T (p.R122*) in SORL1, who also had severe cerebral amyloid angiopathy. Furthermore, we report neuropathological findings and immunochemistry assays from one patient with the splicing variant c.4519+5G>A in the SORL1 gene, in which AD was confirmed by neuropathological examination. Our results highlight the heterogeneity of clinical presentation and familial dementia background of SORL1-associated AD and suggest that SORL1 might be contributing to AD development as a risk factor gene rather than as a major autosomal dominant gene.This work was supported by the Instituto de Salud Carlos III (PI17/01067) and AGAUR from the Autonomous Catalan Government (2017SGR1134). Dr. Víctor Antonio Blanco-Palmero is supported by the Instituto de Salud Carlos III (ISCIII, Spanish Biomedical Research Institute) through a “Río Hortega” contract (CM18/0095). Dr. Sara Llamas-Velasco is supported by the Instituto de Salud Carlos III (ISCIII; Spanish Biomedical Research Institute) through a “Juan Rodés” contract (JR 18/00046).S