Ru- and Ir-complex decorated periodic mesoporous organosilicas as sensitizers for artificial photosynthesis

A versatile and facile strategy based on an inverse electron demand Diels–Alder reaction between 5-norbornen-2-yltriethoxysilane and a tetrazine derivative has been established for the synthesis of a new triethoxysilane precursor containing dipyridylpyridazine units. Such a precursor has been incorporated into the mesostructure of an ethylene-bridged periodic mesoporous organosilica (PMO) material through a one-pot synthesis via a co-condensation method. Upon attachment of Ru- and Ir-complexes to the pendant N-chelating heterocyclic ligands, the resulting decorated PMOs have acted as photosensitizers in artificial photosynthetic systems. The deposition of Pt on these PMOs has allowed us to obtain efficient photocatalytic materials for the hydrogen evolution reaction as a result of electron transfer from the light harvesting Ru- and Ir-complexes to the supported Pt nanoparticles through methyl viologen as an electron relay. They have exhibited total turnover number values of 573 and 846, respectively, under visible light irradiation. The role played by each component and the stability of the photocatalytic systems have been discussed. The present approach paves the way to the synthesis of different materials with coordination sites capable of forming surface complexes to be applied as sensitizers and catalysts

The Inverse Scattering Method, Lie-Backlund Transformations and Solitons for Low-energy Effective Field Equations of 5D String Theory

In the framework of the 5D low-energy effective field theory of the heterotic string with no vector fields excited, we combine two non-linear methods in order to construct a solitonic field configuration. We first apply the inverse scattering method on a trivial vacuum solution and obtain an stationary axisymmetric two-soliton configuration consisting of a massless gravitational field coupled to a non-trivial chargeless dilaton and to an axion field endowed with charge. The implementation of this method was done following a scheme previously proposed by Yurova. We also show that within this scheme, is not possible to get massive gravitational solitons at all. We then apply a non-linear Lie-Backlund matrix transformation of Ehlers type on this massless solution and get a massive rotating axisymmetric gravitational soliton coupled to axion and dilaton fields endowed with charges. We study as well some physical properties of the constructed massless and massive solitons and discuss on the effect of the generalized solution generating technique on the seed solution and its further generalizations.Comment: 17 pages in latex, changed title, improved text, added reference

FeN4 active sites generated on dipyridylpyridazine functionalized reduced graphene oxide for high-performance air electrode in a Zn-air battery

The growing global electricity demand requires the development of cost-effective energy conversion and storage systems, integrating inexpensive, eco-friendly, and high-efficiency catalysts. Oxygen reduction reaction (ORR) is considered crucial process to achieve high-power-density fuel cells and Zn-air batteries (ZABs). The latter have attracted the attention of scientific community due to its high theoretical energy density, reliable safety and low-cost. However, several limitations must be overcome, designing ORR catalysts thought versatile and economical synthetic routes. In this sense, the non-noble iron–nitrogen-carbon materials (Fesingle bondNsingle bondC) have been reported as the most potential candidates for attaining superior activity toward ORR in substitution of the high-priced commercial Pt-C catalysts. Herein, Diels-Alder surface adducts based on dipyridylpyridazine units have been created along 2D surface of reduced graphene oxide (rGO) nanosheets for the controlled generation of FeN4 active sites at the edges through successive solvent-free mechanochemical reactions and an additional thermal treatment. The optimized catalyst provided high content of pyridinic-N, graphitic-N and Fe2+ species, contributing to the excellent activity delivered as electrocatalyst for ORR processes. In addition, a flooded ZAB assembled with this material as cathodic/air electrode exhibited excellent specific capacities of 4.94 and 2.77 A·h·g−1 at -1 and -5 mA, respectively, improving the catalytic performance obtained for the 10 wt% Pt-C benchmark electrocatalyst

Cultural effects on neurodevelopmental testing in children from six European countries: An analysis of NUTRIMENTHE Global Database

Cultural background is an important variable influencing neuropsychological performance. Multinational projects usually involve gathering data from participants from different countries and/or different cultures. Little is known about the influence of culture on neuropsychological testing results in children and especially in European children. The objectives of this study were to compare neuropsychological performance of children from six European countries (Belgium, Germany, Italy, The Netherlands, Poland and Spain) using a comprehensive neuropsychological battery and to apply a statistical procedure to reduce the influence of country/cultural differences in neuropsychological performance. As expected, the results demonstrated differences in neuropsychological performance among children of the six countries involved. Cultural differences remained after adjusting for other confounders related to neuropsychological execution, such as sex, type of delivery, maternal age, gestational age and maternal educational level. Differences between countries disappeared and influence of culture was considerably reduced when standardised scores by country and sex were used. These results highlight the need for developing specific procedures to compare neuropsychological performance among children from different cultures to be used in multicentre studies

Development of a mobile application for the virtualization of science laboratories

Desde la inclusión de España en la Declaración de Bolonia, cuyo objetivo es reformar el sistema universitario a través del Espacio Europeo de Educación Superior (EEES), el alumno adquiere un papel de liderazgo en el proceso de enseñanza-aprendizaje. Con el fin de promover la autonomía entre los estudiantes en el proceso de capacitación, el uso de las Tecnologías de la Información y la Comunicación (TIC) es cada vez más común. Entre ellos, el e-learning con aplicaciones móviles tiene un gran potencial para fortalecer el proceso de aprendizaje, dado su uso popular entre los estudiantes universitarios. Esto se debe principalmente a que estas herramientas tienen una variedad de ventajas sobre los métodos tradicionales, como conferencias magistrales, entre los que cabe citar, entre otras, el que permiten la comunicación profesor-estudiante más allá de los espacios tradicionales, rompiendo las barreras o límites de espacio y tiempo, que favorecen la autonomía (autoaprendizaje) del estudiante o que permiten la presentación de la información en una gran variedad de formas y lenguajes. Además, son fácilmente conectables a las redes sociales, lo que hace que el proceso de aprendizaje sea más atractivo, más accesible y más cooperativo. Con el propósito de aumentar la motivación de los estudiantes, en este trabajo, se diseñó y desarrolló una aplicación móvil, en la que se han virtualizado tres laboratorios pertenecientes a la Facultad de Ciencias (Biología y Química) y la Escuela Politécnica Superior (Física de Ingeniería Mecánica) de la Universidad de Córdoba. En cada uno de los tres laboratorios, los estudiantes pueden acceder a información multimedia correspondiente a diversos materiales, equipos, videos, enlaces, laboratorios virtuales, así como una explicación de algunas sesiones prácticas. Para el desarrollo de diferentes escenarios, se han utilizado imágenes panorámicas de 360º, que se han realizado utilizando técnicas HDR (High Dynamic Range). La plataforma elegida para el desarrollo fue Android, debido al uso mayoritario de este sistema operativo en dispositivos móviles entre los estudiantes. Conviene destacar que este tipo de e-learning facilita a los estudiantes el acceso a materiales relacionados con las materias prácticas en estudio que son muy importantes en la enseñanza de las ciencias. Además, se familiarizan más con los términos técnicos de una manera interactiva, más entretenida y eficiente, mejorando el grado de motivación y la participación del estudiante en los temas en estudio. Esto conduce a una mayor asimilación de conocimientos y habilidades. Para verificar esto, para cada laboratorio, dividimos a los estudiantes en un grupo sin acceso a la aplicación (grupo de control) y otro (grupo de prueba) con acceso. Llevamos a cabo una serie de cuestionarios con los grupos de prueba usando la plataforma basada en juegos "Kahoot!" y Google Forms. Los cuestionarios intentaron aclarar el grado de aceptación de la herramienta, el impacto en el aprendizaje de los temas en estudio y la identificación de posibles áreas de mejora. En general, los estudiantes del grupo de prueba encontraron la herramienta muy interesante y les ayudó a mejorar sus puntuaciones en comparación con el grupo de control. No se aprecia una distinción clara entre los estudiantes de diferentes materias. Entre los aspectos a mejorar, se encuentra el contenido relativamente limitado de esta primera versión. Además, la evaluación se realizó con un único grupo control y un grupo de prueba en cada materia, lo que limita su potencial para extraer conclusiones definitivas. En el futuro, se realizarán más cargas y pruebas de contenido en diferentes cursos para evaluar los beneficios del aprendizaje de ciencias mediante esta aplicación.Since the inclusion of Spain in the Bologna Declaration, whose objective is to reform the university system through the European Higher Education Area (EHEA), the student acquires a leading role in the teaching-learning process. In order to promote autonomy among the students in the training process, the use of Information and Communication Technologies (ICT) is increasingly common. Among them, e-learning using mobile apps has a great potential to strengthen the learning process given its popular use among university students. This is mostly because these tools have assorted advantages over traditional methods, e.g. magisterial lectures, such as ubiquitous access, possibility to update and increase content, self-learning, etc. Moreover, they are easily linkable to social media, thus making the learning process more attractive, more easily accessible and more cooperative. For the purpose of increasing student motivation, in this work, a mobile application has been designed and developed, in which three laboratories, belonging to the faculties of Sciences (Biology and Chemistry) and Engineering, have been virtualized. In each of the three laboratories, the students can access to some multimedia information corresponding to various materials and equipment, videos, links, virtual laboratories as well as an explanation of some practical sessions. For the different scenarios development, 360º panoramic pictures have been used, which have been made using HDR (High Dynamic Range) techniques. The platform chosen for the development was Android, due to the majority use of this operating system on mobile devices among the students. It is good to notice that this type of e-learning facilitates students the accessibility to materials related to the practical subjects under study which are very important in science teaching. Furthermore, they become more familiar with technical terms in an interactive, more entertaining and efficient manner, improving the motivation degree and the student's involvement in the subjects under study. This leads to a greater assimilation of knowledge and skills. To verify this, for each laboratory, we divided the students in a group without access to the app (control group) and another one (testing group) with access. We conducted a series of questionnaires with the testing groups using the game-based platform “Kahoot!” and Google Forms. The questionnaires intended to enlighten the degree of acceptance of the tool, the impact on learning of the subjects under study and the identification of potential areas of improvement. Generally, the testing group students found the tool very interesting and helped them improving their scores compared to the control group. No clear distinction between students of different subjects was appreciated. A limited content in this first version was major drawback. Moreover, this evaluation has been conducted only with one control and one testing group of each subject, thus limiting its potential to extract definite conclusions. Further content upload and testing on different courses will be done in the future to evaluate the benefits of science learning using this app

Oral Anticoagulation and Risk of Symptomatic Hemorrhagic Transformation in Stroke Patients Treated With Mechanical Thrombectomy: Data From the Nordictus Registry

Introduction: We aimed to evaluate if prior oral anticoagulation (OAC) and its type determines a greater risk of symptomatic hemorrhagic transformation in patients with acute ischemic stroke (AIS) subjected to mechanical thrombectomy. Materials and Methods: Consecutive patients with AIS included in the prospective reperfusion registry NORDICTUS, a network of tertiary stroke centers in Northern Spain, from January 2017 to December 2019 were included. Prior use of oral anticoagulants, baseline variables, and international normalized ratio (INR) on admission were recorded. Symptomatic intracranial hemorrhage (sICH) was the primary outcome measure. Secondary outcome was the relation between INR and sICH, and we evaluated mortality and functional outcome at 3 months by modified Rankin scale. We compared patients with and without previous OAC and also considered the type of oral anticoagulants. Results: About 1.455 AIS patients were included, of whom 274 (19%) were on OAC, 193 (70%) on vitamin K antagonists (VKA), and 81 (30%) on direct oral anticoagulants (DOACs). Anticoagulated patients were older and had more comorbidities. Eighty-one (5.6%) developed sICH, which was more frequent in the VKA group, but not in DOAC group. OAC with VKA emerged as a predictor of sICH in a multivariate regression model (OR, 1.89 [95% CI, 1.01–3.51], p = 0.04) and was not related to INR level on admission. Prior VKA use was not associated with worse outcome in the multivariate regression model nor with mortality at 3 months. Conclusions: OAC with VKA, but not with DOACs, was an independent predictor of sICH after mechanical thrombectomy. This excess risk was associated neither with INR value by the time thrombectomy was performed, nor with a worse functional outcome or mortality at 3 months

Structural and elastic properties of defect chalcopyrite HgGa2S4 under high pressure

In this work, we focus on the study of the structural and elastic properties of mercury digallium sulfide (HgGa2S4) at high pressures. This compound belongs to the family of AB(2)X(4) ordered-vacancy compounds and exhibits a tetragonal defect chalcopyrite structure. X-ray diffraction measurements at room temperature have been performed under compression up to 15.1 GPa in a diamond anvil cell. Our measurements have been complemented and compared with ab initio total energy calculations. The axial compressibility and the equation of state of the low-pressure phase of HgGa2S4 have been experimentally and theoretically determined and compared to other related ordered-vacancy compounds. The pressure dependence of the theoretical cation-anion and vacancy-anion distances and compressibilities in HgGa2S4 are reported and discussed in comparison to other related ordered-vacancy compounds. Finally, the pressure dependence of the theoretical elastic constants and elastic moduli of HgGa2S4 has been studied. Our calculations indicate that the low-pressure phase of HgGa2S4 becomes mechanically unstable above 13.8 GPa. (C) 2013 Elsevier B. V. All rights reserved.This study was supported by the Spanish government MEC under Grants No: MAT2010-21270-C04-01/03/04 and CTQ2009-14596-C02-01, by the Comunidad de Madrid and European Social Fund (S2009/PPQ-1551 4161893), by MALTA Consolider Ingenio 2010 Project (CSD2007-00045), by Generalitat Valenciana (GVA-ACOMP-2013-1012), and by the Vicerrectorado de Investigacion y Desarrollo of the Universidad Politecnica de Valencia (UPV2011-0914 PAID-05-11 and UPV2011-0966 PAID-06-11). E.P-G., A. M., and P.R-H. acknowledge computing time provided by Red Espa ola de Supercomputacion (RES) and MALTA-Cluster. J.A.S. acknowledges Juan de la Cierva fellowship program for financial support.Gomis Hilario, O.; Santamaría-Pérez, D.; Vilaplana Cerda, RI.; Luna Molina, R.; Sans, JA.; Manjón Herrera, FJ.; Errandonea, D.... (2014). Structural and elastic properties of defect chalcopyrite HgGa2S4 under high pressure. Journal of Alloys and Compounds. 583:70-78. https://doi.org/10.1016/j.jallcom.2013.08.123S707858

Isotemporal substitution of inactive time with physical activity and time in bed: cross-sectional associations with cardiometabolic health in the PREDIMEDPlus study

Background: This study explored the association between inactive time and measures of adiposity, clinical parameters, obesity, type 2 diabetes and metabolic syndrome components. It further examined the impact of reallocating inactive time to time in bed, light physical activity (LPA) or moderate-to-vigorous physical activity (MVPA) on cardio-metabolic risk factors, including measures of adiposity and body composition, biochemical parameters and blood pressure in older adults. Methods: This is a cross-sectional analysis of baseline data from 2189 Caucasian men and women (age 55-75 years, BMI 27-40 Kg/m2) from the PREDIMED-Plus study (http://www.predimedplus.com/). All participants had ≥3 components of the metabolic syndrome. Inactive time, physical activity and time in bed were objectively determined using triaxial accelerometers GENEActiv during 7 days (ActivInsights Ltd., Kimbolton, United Kingdom). Multiple adjusted linear and logistic regression models were used. Isotemporal substitution regression modelling was performed to assess the relationship of replacing the amount of time spent in one activity for another, on each outcome, including measures of adiposity and body composition, biochemical parameters and blood pressure in older adults. Results: Inactive time was associated with indicators of obesity and the metabolic syndrome. Reallocating 30 min per day of inactive time to 30 min per day of time in bed was associated with lower BMI, waist circumference and glycated hemoglobin (HbA1c) (all p-values < 0.05). Reallocating 30 min per day of inactive time with 30 min per day of LPA or MVPA was associated with lower BMI, waist circumference, total fat, visceral adipose tissue, HbA1c, glucose, triglycerides, and higher body muscle mass and HDL cholesterol (all p-values < 0.05). Conclusions: Inactive time was associated with a poor cardio-metabolic profile. Isotemporal substitution of inactive time with MVPA and LPA or time in bed could have beneficial impact on cardio-metabolic health

Long daytime napping is associated with increased adiposity and type 2 diabetes in an elderly population with metabolic syndrome

Research examining associations between objectively-measured napping time and type 2 diabetes (T2D) is lacking. This study aimed to evaluate daytime napping in relation to T2D and adiposity measures in elderly individuals from the Mediterranean region. A cross-sectional analysis of baseline data from 2190 elderly participants with overweight/obesity and metabolic syndrome, in the PREDIMED-Plus trial, was carried out. Accelerometer-derived napping was measured. Prevalence ratios (PR) and 95% confidence intervals (CI) for T2D were obtained using multivariable-adjusted Cox regression with constant time. Linear regression models were fitted to examine associations of napping with body mass index (BMI) and waist circumference (WC). Participants napping ≥90 min had a higher prevalence of T2D (PR 1.37 (1.06, 1.78)) compared with those napping 5 to <30 min per day. Significant positive associations with BMI and WC were found in those participants napping ≥30 min as compared to those napping 5 to <30 min per day. The findings of this study suggest that longer daytime napping is associated with higher T2D prevalence and greater adiposity measures in an elderly Spanish population at high cardiovascular risk