Obtención de cemento eco-eficiente a base de ceniza procedente de caldera de lecho fluidizado

El objetivo principal de este trabajo ha sido la valorización de una ceniza procedente de un combustor de lecho fluidizado de biomasa forestal (CCBF) para su posible empleo como adición puzolánica con el fin de obtener un material base cemento más ecoeficiente. Esta ceniza es un residuo procedente de un combustor que es alimentado fundamentalmente por restos de corteza de eucalipto para la fabricación de pasta de papel, originando toneladas de dichas cenizas. La ceniza CCBF tiene importantes contenidos en SiO2, CaO, Al2O3 y K2O, como componentes mayoritarios. Estos óxidos la hacen atractiva para el campo de los materiales de construcción. Para su valorización se somete a la ceniza a un tratamiento hidrotermal (TH) durante un periodo de 4h a dos temperaturas (150 y 200ºC) en contacto con dos medios, agua desmineralizada y una disolución de NaOH 1M, en ambos casos se ha empleado una relación líquido/sólido de 10. Los cambios que se producen en la fase sólida resultante del TH se analizan mediante diferentes técnicas de caracterización Después del TH, se identifica, como fase predominante, la fase tipo tobermorita, precursora del gel C-S-H. La obtención de dicha fase, se optimiza durante el TH a 200ºC, temperatura en la que desapareen prácticamente la fase cuarzo y disminuye la de calcita, lo que favorece la formación de las fases tobermorita por incorporación de iones calcio y silicio, a su estructura. Previa a la incorporación de la ceniza a la matriz de cemento es necesario determinar su activididad puzolánica. Por ello, se ha estudiado la actividad puzolánica de la ceniza CCBF y de la ceniza CCBF activada hidrotermalmente (200ºC/4h). Para determinar esta activiad se ha empleado en ambos casos el método de la disolución saturada de cal, desarrollado en el Instituto Ciencias de la Construcción “Eduardo Torroja”. En ambas cenizas, CCBF y CCBF-200º/4h, se alcanzan valores de cal fijada a los 28 días, de 52,1 y 98,2% respectivamente. Debido a la alta actividad puzolánica que presentan, se procedió a una sustitución parcial de cemento Portland por ambas cenizas, en porcentajes del 0, 10 y 20% del cemento por ceniza, según la EN 196-3. Para evaluar el efecto de las mismas, se fabricaron probetas de 1x1x6cm, las cuales se sometieron a pruebas de resistencia mecánica a compresión a diferentes edades de hidratación (2, 7 y 28 días). Se pudo observar como con la adición de ambos tipos de ceniza mejoraba hasta un 30% la resistencia mecánica a los 28 días en relación a la referencia (0%), obteniendo mayores resistencias en ambos casos (CCBF y CCBF-200ºC-4h) con el 10% de sustitució

Boosting the visible-light photoactivity of Bi2WO6 using acidic carbon additives

We have explored the role of the physicohemical properties of carbon materials as additives to bismuth tungstate on its structure, optical properties, and photocatalytic activity for the degradation of rhodamine B under visible light. For this purpose, C/Bi2WO6 hybrid composites were prepared following two different routes: (i) physical mixture of the catalyst components, and (ii) one-pot hydrothermal synthesis of the semiconductor in the presence of the carbon additive. Three carbons with different properties were selected as additives: biomass-derived activated carbon, carbon nanotubes and carbon spheres obtained from polysaccharides. Data has shown the outstanding role of the acidic/basic nature of the carbon additive, and of the synthetic method on the photocatalytic performance of the resulting composites. For a given additive, the degradation rate of RhB is greatly improved for the catalysts prepared through a one-step hydrothermal synthesis, where there is low shielding effect of the carbon matrix. Carbon additives of acidic nature boost the surface acidity of the hybrid photocatalyst, thereby enhancing the photodegradation of RhB under visible light via a coupled mechanism (photosensitization, semiconductor photocatalysis and carbon-photon mediated reactions).The authors thank the financial support of MINECO (grants CTM2011/23378 and CTQ2011/26617) and PCTI Asturias (Fondos Feder 2007-2013, grant PC10-002). RJC thanks PCTI Asturias for her Severo Ochoa fellowshipPeer reviewe

Stability of class II malocclusion treatment with the austro repositioner followed by fixed appliances in brachyfacial patients

One of the goals of functional-appliance devices is to modify the vertical growth pattern, solving several kinds of malocclusion. This study aimed to evaluate Class II malocclusion treatment’s stability with Austro Repositioner, followed by fixed appliances, and assess its capacity to modify vertical dimensions in brachyfacial patients. A test group of 30 patients (16 boys and 14 girls, mean 11.9 years old) with Class II malocclusion due to mandibular retrognathism and brachyfacial pattern treated with Austro Repositioner and fixed appliance were compared to a matched untreated Class II control group of 30 patients (17 boys and 13 girls, mean age 11.7 years old). Lateral cephalograms were taken at T1 (initial records), T2 (end of treatment), and T3 (one year after treatment). Statistical comparisons were performed with a paired-sample t-test and two-sample t-tests. Significant improvements in the skeletal Class II relationship were observed in the treated group. The ANB angle decreased (4.75°), the SNB angle increased (3.92°), and the total mandibular length (Co-Pg) increased (8.18 mm) (p < 0.001). Vertical dimensions were also significantly modified, the FMA angle increased (3.94°), LAFH-distance increased (3.15 mm), and overbite decreased (3.35 mm). These changes remained stable one year after treatment. The Austro Repositioner was adequate for treating the skeletal Class II malocclusion resulting from the mandible retrusion in brachyfacial patients

The 4q25 variant rs13143308T links risk of atrial fibrillation to defective calcium homoeostasis

Aims: Single nucleotide polymorphisms on chromosome 4q25 have been associated with risk of atrial fibrillation (AF) but the exiguous knowledge of the mechanistic links between these risk variants and underlying electrophysiological alterations hampers their clinical utility. Here, we tested the hypothesis that 4q25 risk variants cause alterations in the intracellular calcium homoeostasis that predispose to spontaneous electrical activity. Methods and results: Western blotting, confocal calcium imaging, and patch-clamp techniques were used to identify mechanisms linking the 4q25 risk variants rs2200733T and rs13143308T to defects in the calcium homoeostasis in human atrial myocytes. Our findings revealed that the rs13143308T variant was more frequent in patients with AF and that myocytes from carriers of this variant had a significantly higher density of calcium sparks (14.1¿±¿4.5 vs. 3.1¿±¿1.3 events/min, P¿=¿0.02), frequency of transient inward currents (ITI) (1.33¿±¿0.24 vs. 0.26¿±¿0.09 events/min, P¿<¿0.001) and incidence of spontaneous membrane depolarizations (1.22¿±¿0.26 vs. 0.56¿±¿0.17 events/min, P¿=¿0.001) than myocytes from patients with the normal rs13143308G variant. These alterations were linked to higher sarcoplasmic reticulum calcium loading (10.2¿±¿1.4 vs. 7.3¿±¿0.5¿amol/pF, P¿=¿0.01), SERCA2 expression (1.37¿±¿0.13 fold, P¿=¿0.03), and RyR2 phosphorylation at ser2808 (0.67¿±¿0.08 vs. 0.47¿±¿0.03, P¿=¿0.01) but not at ser2814 (0.28¿±¿0.14 vs. 0.31¿±¿0.14, P¿=¿0.61) in patients carrying the rs13143308T risk variant. Furthermore, the presence of a risk variant or AF independently increased the ITI frequency and the increase in the ITI frequency observed in carriers of the risk variants was exacerbated in those with AF. By contrast, the presence of a risk variant did not affect the amplitude or properties of the L-type calcium current in patients with or without AF. Conclusions: Here, we identify the 4q25 variant rs13143308T as a genetic risk marker for AF, specifically associated with excessive calcium release and spontaneous electrical activity linked to increased SERCA2 expression and RyR2 phosphorylation.Peer ReviewedPostprint (author's final draft

GAP WORK project report: training for youth practitioners on tackling gender-related violence

This project sought to challenge gender-related violence against (and by) children and young people by developing training for practitioners who have everyday contact with general populations of children and young people (‘youth practitioners’). Through improved knowledge and understanding practitioners can better identify and challenge sexist, sexualising, homophobic or controlling language and behaviour, and know when and how to refer children and young people to the most appropriate support services. This summary outlines the Project and our initial findings about the success of the four training programmes developed and piloted.Co-funded by the DAPHNE III programme of the EU

Characterization of IHF Binding to DNA Four-Way Junctions and Forks

The objective of the study is to characterise the mechanical properties of Ti-15Zr binary alloy dental implants and to describe their biomechanical behaviour as well as their osseointegration capacity compared with the conventional Ti-6Al-4V (TAV) alloy implants. The mechanical properties of Ti-15Zr binary alloy were characterised using Roxoli

Treatment with implants in patients with diabetes. A 7-year comparative study

Introducción. La implantología oral puede constituir una modalidad terapéutica en el tratamiento prostodóncico de los pacientes con compromiso médico. El estudio muestra la evaluación del tratamiento con implantes en pacientes con diabetes comparados con pacientes sin diabetes. Métodos. 48 pacientes edéntulos totales (24 pacientes diabéticos y 24 no diabéticos) fueron tratados con 96 implan- tes con superficie arenada y grabada Galimplant ® en la mandíbula para su rehabilitación prostodóncica con sobre- dentaduras mandibulares. 2 implantes fueron insertados en cada paciente. Los implantes fueron cargados funcional- mente tras un periodo de tiempo de 6 semanas con retenedores de fricción. Los hallazgos clínicos (implantológicos y prostodóncicos) se han seguido durante 7 años. Resultados. Los resultados indican una supervivencia de los implantes del 95,8%. Durante el periodo de seguimeinto clínico se perdieron 4 implantes (dos implantes en cada grupo). La pérdida de hueso marginal media fué de 0,7 mm en ambos grupos. El 100% de los pacientes fueron tratados mediante una sobredentadura implantorretenida con anclajes de fricción. En 14 pacientes se realizaron cambios en los componentes plásticos de los ataches. El seguimiento clínico medio fue de 82,5 meses (60-102 meses). Conclusiones. Los resultados del presente estudio indican que el tratamiento con implantes dentales en pacientes diabéticos es una terapéutica exitosa sin diferencias entre los pacientes diabéticos y no diabéticos. PALABRAS CLAVE: Implantes dentales, pacientes geriátricos, diabetes mellitus, sobredentaduras, oseo- integración, implantología oral.Introduction. Implant dentistry can to constitute a therapeutic modality in the prosthodontic treatment of medically compromised patients. This study reports the evaluation of treatment with implants in patients with diabetes compared with patients without diabetes. Methods. 48 edentulous patients (24 diabetic patients and 24 non-diabetic patients) were treated with 96 Galimplant ® sand-blasted and acid-etched surface implants for prosthodontic rehabilitation with mandibular overdentures. Two implants were inserted in each patient. Implants were loaded after a healing free-loading period between 6 weeks with locator attaches. Clinical findings (implant and prosthodontics) were followed during at 7 years. Results. Clinical results indicate a survival rate of implants of 95.8% in both groups. Four implant was lost during the follow-up period (two implants in each group). Media marginal bone loss was 0.7 mm in both groups. 100% of patients were treated with overdentures retained with 2 implants with locator attaches. Changes in plastic components of attaches were reported in 14 patients. The media follow-up was of 82.5 months (60-102 months). Conclusions. Clinical results of this study indicate that treatment with dental implants in diabetic patients is a successful implant treatment without differences with nondiabetic patients