Electrocatalytic oxidation of ascorbic acid on mesostructured SiO2-conducting polymer composites

The conducting self-doping copolymer poly(aniline-co-ABA) preserves its redox activity at pH values as high as 7. This observation was the starting point to synthesize an organic inorganic hybrid composite able to electrochemically oxidize ascorbic acid molecules at that pH. The inorganic part of the catalytic element was an ordered mesoporous electrodeposit of SiO2, which has been used as the template for the electrochemical insertion of the self-doping copolymer. The oxidation of ascorbate ions at a fixed potential on this composite was studied by means of the kinetic model proposed by Bartlett and Wallace (2001). It was observed that the effective kinetic constant K-ME increased significantly but, simultaneously, k'(ME) remained almost constant when the composite was employed as the electrocatalytic substrate. These results were interpreted in the light of two combinations of kinetic constants, which strongly suggested that the increase in K-ME should be ascribed to the improvement in electronic conductivity of the copolymer induced by the highly ordered silica template. (C) 2015 Elsevier Ltd. All rights reserved.Financial support from the Spanish Ministerio de Economia y Competitividad and FEDER funds (MAT2013-42007-P), from the Generalitat Valenciana (PROMETE02013/038) and from the Fundacion Ramon Areces is gratefully acknowledged.Rivero, O.; Huerta, F.; Montilla, F.; Sanchis, C.; Morallón, E. (2015). Electrocatalytic oxidation of ascorbic acid on mesostructured SiO2-conducting polymer composites. European Polymer Journal. 69:201-207. https://doi.org/10.1016/j.eurpolymj.2015.06.004S2012076

Dise?o y construcci?n del puente Chacaneque en San Gab?n, Puno

La presente tesis desarrolla el proyecto llamado ?Dise?o y construcci?n del puente Chacaneque en San Gaban, Puno?, siguiendo una gu?a de buenas pr?cticas se desarrolla y destaca la importancia de planes de gesti?n que deben tener los proyectos. El proyecto se desarrolla debido a que en el sur de pa?s se est?n ejecutando grandes proyectos como la construcci?n de centrales hidroel?ctricas, para ello el cliente GEPSA necesita de la construcci?n de un pase vehicular de carga extraordinaria, eligiendo as? a la empresa Agobirich para el desarrollo de este proyecto. Agobirich desea tomar este proyecto y ser un buen referente para llegar a ser la empresa que construya tambi?n las centrales hidroel?ctricas. La particularidad de este proyecto se debe a que se desarrolla en el departamento de Puno y el cliente tiene acuerdos que se deben respetar con los lugare?os. Asimismo es una zona con alto ?ndice de conflictos sociales y con una geograf?a accidentada, debiendo preveerse medidas preventivas y correctivas en caso de incidentes. As? como tambi?n establecer contactos necesarios. Por la cantidad de actores que participan del proyecto, ?stos deben ser gestionados con planes de acci?n espec?ficos por el impacto que puede causar en los otros planes de gesti?n

Amazonian Amphibian Diversity Is Primarily Derived from Late Miocene Andean Lineages

The Neotropics contains half of remaining rainforests and Earth's largest reservoir of amphibian biodiversity. However, determinants of Neotropical biodiversity (i.e., vicariance, dispersals, extinctions, and radiations) earlier than the Quaternary are largely unstudied. Using a novel method of ancestral area reconstruction and relaxed Bayesian clock analyses, we reconstructed the biogeography of the poison frog clade (Dendrobatidae). We rejected an Amazonian center-of-origin in favor of a complex connectivity model expanding over the Neotropics. We inferred 14 dispersals into and 18 out of Amazonia to adjacent regions; the Andes were the major source of dispersals into Amazonia. We found three episodes of lineage dispersal with two interleaved periods of vicariant events between South and Central America. During the late Miocene, Amazonian, and Central American-Chocoan lineages significantly increased their diversity compared to the Andean and Guianan-Venezuelan-Brazilian Shield counterparts. Significant percentage of dendrobatid diversity in Amazonia and Chocó resulted from repeated immigrations, with radiations at <10.0 million years ago (MYA), rather than in situ diversification. In contrast, the Andes, Venezuelan Highlands, and Guiana Shield have undergone extended in situ diversification at near constant rate since the Oligocene. The effects of Miocene paleogeographic events on Neotropical diversification dynamics provided the framework under which Quaternary patterns of endemism evolved

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

Técnicas grupales de reflexión para fomentar la formación de valores en los Adolescentes de 14 a 16 años, en el Programa Preventivo Club de Menores “Amigos del Policía” Acequia Alta distrito de Cayma Arequipa - 2018

TesisEl objetivo de la presente investigación es demostrar la eficacia de las técnicas grupales de reflexión para rescatar y fomentar la formación de valores en los adolescentes participantes en el programa preventivo Club de Menores “Amigos del Policía” Acequia Alta distrito de Cayma Arequipa-2018. El método de investigación es el cuantitativo, la técnica es la encuesta y el instrumento es el cuestionario tipo escala Likert. La muestra fue no probabilística con un total de 26 encuestados .Para la evaluación se ha utilizado la prueba de contraste de hipótesis “t” de Student, para determinar si luego de aplicado el tratamiento al grupo de estudio existe diferencia en los resultados. Finalmente al evaluar la eficacia de las técnicas grupales de reflexión en adolescentes participantes en el programa preventivo Club de Menores “Amigos del Policía” Acequia Alta distrito de Cayma, se ha determinado que su aplicación es eficaz, por cuanto favoreció la formación de valores corroborado con el estadístico t de Studen

Podocnemis venezuelensis, a new fossil pelomedusid (Testudines, Pleurodira) from the Pliocene of Venezuela and a review of the history of Podocnemis in South America

Volume: 376Start Page: 1End Page: 2

Design of an electrical installation for a rest center

Este proyecto consiste en una instalación eléctrica de un centro de reposo ubicado en la ciudad de Cartagena, desarrollado principalmente para un usuario que no cuenta con un diseño eléctrico en su instalación, por lo tanto, desde el punto de diseño básico de ingeniería, se dará una solución siguiendo las pautas dadas por la NTC 2050 y el RETIE (Reglamento técnico de instalaciones eléctricas) y el estudio bajo normas internacionales como IEEE 80 2000, IEC 60479-2,IEC 60947-1, IEC 60664-2, entre otras. Debido a esto, se revisan las posibles alternativas que se pueden encontrar al momento de realizar un diseño en una instalación, que serán: el tipo de subestación a instalar, que tipo de protección es conveniente, como realizar la acometida y si es necesario realizar un modelo inteligente o semi inteligente. Cada una de estas soluciones serán seleccionados bajo criterios tipo costo, eficiencia, durabilidad, área disponible, sensibilidad, control y seguridad, dependiendo de que alternativa se trate bajo la selección de una matriz de decisión. Por otro lado, se realiza un estudio de análisis de riesgo bajo el software IEC RISK ASSESSMENT CALCULATOR ante fallas externas (Descargas atmosféricas directas e indirectas), ya una vez bajo los resultados obtenidos se realiza el presupuesto, dejando por fuera obras civiles, dando un resultado total de $238.763.345 millones con IVA sobre la utilidad para el año 2020.This project consists of an electrical installation of a rest center located in the city of Cartagena, developed mainly for a user who does not have an electrical design in their installation, therefore, from the point of basic engineering design, it will be a solution following the guidelines given by the NTC 2050 and the RETIE (technical regulation of electrical installations) and the study under international standards such as IEEE 80 2000, IEC 60479-2, IEC 60947-1, IEC 60664-2, among others. Due to this, the possible alternatives that can be found when making a design in an installation are reviewed, which will be: the type of substation to be installed, what type of protection is appropriate, how to make the connection and if it is necessary to carry out a smart or semi-smart model. Each of these solutions will be selected under criteria such as cost, efficiency, durability, available area, sensitivity, control and safety, depending on which alternative is treated under the selection of a decision matrix. On the other hand, a risk analysis study is carried out under the IEC RISK ASSESSMENT CALCULATOR software in the event of external failures (direct and indirect atmospheric discharges), and once the results are obtained, the budget is made, leaving out civil works, giving a total result of$ 238,763,345 million with IVA on utility for the year 2020