Surface structured platinum electrodes for the electrochemical reduction of carbon dioxide in imidazolium based ionic liquids

The direct CO2 electrochemical reduction on model platinum single crystal electrodes Pt(hkl) is studied in [C2mim+][NTf2−], a suitable room temperature ionic liquid (RTIL) medium due to its moderate viscosity, high CO2 solubility and conductivity. Single crystal electrodes represent the most convenient type of surface structured electrodes for studying the impact of RTIL ion adsorption on relevant electrocatalytic reactions, such as surface sensitive electrochemical CO2 reduction. We propose here based on cyclic voltammetry and in situ electrolysis measurements, for the first time, the formation of a stable adduct [C2mimH–CO2−] by a radical–radical coupling after the simultaneous reduction of CO2 and [C2mim+]. It means between the CO2 radical anion and the radical formed from the reduction of the cation [C2mim+] before forming the corresponding electrogenerated carbene. This is confirmed by the voltammetric study of a model imidazolium-2-carboxylate compound formed following the carbene pathway. The formation of that stable adduct [C2mimH–CO2−] blocks CO2 reduction after a single electron transfer and inhibits CO2 and imidazolium dimerization reactions. However, the electrochemical reduction of CO2 under those conditions provokes the electrochemical cathodic degradation of the imidazolium based RTIL. This important limitation in CO2 recycling by direct electrochemical reduction is overcome by adding a strong acid, [H+][NTf2−], into solution. Then, protons become preferentially adsorbed on the electrode surface by displacing the imidazolium cations and inhibiting their electrochemical reduction. This fact allows the surface sensitive electro-synthesis of HCOOH from CO2 reduction in [C2mim+][NTf2−], with Pt(110) being the most active electrode studied.This work has been partially financed by Generalitat Valenciana through Ayudas para la realización de proyectos de I+D para grupos de investigación emergentes (GV/2014/096) and by the MICINN (project CTQ2013-48280-C3-3-R)

Electrocatalytic studies on imidazolium based ionic liquids: defining experimental conditions

The number of publications devoted to studying electrochemical reactions in room temperature ionic liquids (RTILs) is constantly growing, but very few of them have been devoted to defining proper experimental conditions to obtain reproducible electrochemical results. In this work, we demonstrate that the combination of a proper RTIL purification treatment and a filtered Ar gas stream allow us to obtain featureless voltammograms in [C4mim][BF4], [C4mim][NTf2], and [C4m2im][NTf2], which otherwise present signals associated with different types of impurities such as water and some minor electroactive impurities acquired during the RTIL synthesis process. Moreover, we demonstrate that bubbling Ar, or another inert gas, through the electrolyte in order to purge O2 dissolved in RTILs is one of the major sources of water and O2 impurities incorporated in RTILs within the electrochemical cell. To overcome this source of water uptake, we have incorporated a gas stream purification filter before the gas reaches the RTIL in the electrochemical cell. To illustrate the effect of these impurities in relevant electrocatalytic studies, we study the electrocatalytic reduction of CO2 on Pt nanoparticles and the key role of an appropiate filter when the CO2 gas stream is bubbled within imidazolium based RTILs. Our cyclic voltammetric studies point out that CO2 electroreduction on Pt nanoparticles only presents activity in [C4mim][NTf2] and [C4m2im][NTf2], thus suggesting that the C-2 position on the imidazolium ring is not the key position in CO2 electrochemical reduction. In contrast, the same Pt nanoparticles are inactive towards CO2 electroreduction in [C4mim][BF4], which is a more hydrophilic RTIL.The authors acknowledge financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) (projects CTQ2013-48280-C3-3-R and CTQ2016-76231-C2-2-R) (AEI/FEDER, UE) and from the CNRS (projet Défi Instrumentation aux limites 2015). J. S.-G. acknowledges financial support from VITC (Vicerrectorado de Investigación y Transferencia de Conocimiento) of the University of Alicante (UATALENTO16-02). C. M. S.-S. acknowledges financial support from the University of Alicante, visiting researcher grant INV16-15

Uniqueness of static decompositions

We classify static manifolds which admit more than one static decomposition whenever a condition on the curvature is fullfilled. For this, we take a standard static vector field and analyze its associated one parameter family of projections onto the base. We show that the base itself is a static manifold and the warping function satisfies severe restrictions, leading us to our classification results. Moreover, we show that certain condition on the lightlike sectional curvature ensures the uniqueness of static decomposition for Lorentzian manifolds.Comment: 14 page

Assessment of DNA Damage by Comet Assay in Buccal Epithelial Cells: Problems, Achievement, Perspectives

DNA damage risk assessment in comet assay by the use of buccal mucosa cells has great advantages in comparison with other cell type sample due to more safely, easier, cheaper, and non-invasive method for in vivo studies. According to the OECD Guidelines, the in vivo mammalian alkaline comet assay is well-established and validated method for measuring DNA strand breaks in single eukaryotic cells. Considering exposure to xenobiotics and endogenous damage inductors, buccal mucosa cells are the first to be in direct contact after exposure and this makes them an ideal biomatrices in evaluation of the level of individual genotoxicity to several compounds already mentioned. Their clinical diagnostic applicability confers a potential use in patients across time. However, the number of publications referring to the human buccal comet assay is low in the last two decades. This low growing interest may be explained by several factors, including its relative technical problems. Different procedures have been used in collecting and processing the samples. In order to have widespread acceptance and credibility in human population studies, the comet assay in buccal cells requires standardization of the protocol, of parameters analyzed, and a better knowledge of critical features affecting the assay outcomes, including the definition of the values of spontaneous DNA damage. There is a need for further collaborative work as in the HUMN (micronucleus assay on lymphocytes) and HUMNxL (micronucleus assay on buccal cells) collaborative projects. The creation of a network of laboratories will allow more focused validation studies, including the design of a classic, historic, prospective cohort study in order to explore the link between measures of genetic instability in the buccal mucosa and the risk of cancer and other chronic-degenerative diseases. One such network connection will start in 2016 as a COST project under the name “hCOMET—The comet assay as a human biomonitoring tool” launched by Prof. Andrew Collins

Agronomic biofortification with selenium improves the yield and nutraceutical quality in tomato under soilless conditions

Selenium (Se) is an essential element for humans. Its consumption comes from food of animal or vegetal origin; whose content varies widely depending on its availability in soil or anthropogenic sources. Biofortification improves food nutritional quality, and its consumption has a positive influence in human health. Thus, the objective of this research was to assess agricultural biofortification with Se in tomato fruit and its effects on yield, nutraceutical quality, and antioxidant capacity.  Five Se doses (0, 2, 4, 6, and 8 mg L-1) in the form of sodium selenite (Na2SeO3) were added in a nutritional solution in a hydroponic system.  The results obtained indicated that agricultural biofortification with Se applied in the nutritional solution improved yield, nutraceutical quality, and Se concentration in tomato fruit. The optimum Se dose that maximized yield and nutraceutical quality, as well as the recommended consumption concentration in tomato fruit in this study was 2 mg L-1 (Na2SeO4) because higher doses decreased yield and bioactive compound biosynthesis. Incorporating Se in the nutritional solution is an alternative to increase phytochemical compound biosynthesis in tomato fruit and yield with the possibility of improving public health with its consumption

Spanish ATLAS tier-2: Facing up to LHC Run 2

The goal of this work is to describe the way of addressing the main challenges of Run 2 by the Spanish ATLAS Tier-2. The considerable increase of energy and luminosity for the upcoming Run 2 with respect to Run 1 has led to a revision of the ATLAS computing model as well as some of the main ATLAS computing tools. In this paper, the adaptation to these changes will be described. The Spanish ATLAS Tier-2 is a R&D project which consists of a distributed infrastructure composed of three sites and its members are involved in ATLAS computing progress, namely the work in different tasks and the development of new tools (e.g. Event Index)This work has been supported by MINECO, Spain (Proj. Ref. FPA2010-21919-C03-01,02,03 & FPA2013-47424-C3,01,02,03), which include FEDER funds from the European Unio

Estudio y caracterización de algunas 5-E-aldoximino-4-glucosilaminopirimidinas

La reacción de 1,6-dihidro-5-formil-4-β-D-(2 ', 3 ' 4 ', 6 '-tetra-O-acetil)-glucopiranosilamino-1-metil-2-metoxi-6-oxopirimidina con exceso de ClH.H2NOH permite aislar 5-E-aldoximino derivado como único producto. La estructura del mismo ha sido establecida en base a pruebas químicas y espectroscópicas.The reaction between 1,6-dihydro-S-formil-4- β -D-(tetra-O-acetyl}glucopyranosylamino-l-methyl-2-methoxy-6-oxo-pyrimidine and an excess of ClH.H2 NOH yields S-E-aldoximine derivative as the only producto On the basis of its chemical behaviour and espectroscopic data we propose its structure

Estudio y caracterización de algunas 5-E-aldoximino-4-glucosilaminopirimidinas

The reaction between 1,6-dihydro-5-formil-4-β-D-(tetra-O-acetyl)glucopyranosylamino-1-methyl-2-methoxy-6-oxo-pyrimidine and an excess of ClH.H2NOH yields 5-E-aldoximine derivative as the only product. On the basis of its chemical behaviour and espectroscopic data we propose its structure.La reacción de 1,6-dihidro-5-formil-4-β-D-(2 ', 3 ' 4 ', 6 '-tetra-O-acetil)-glucopiranosilamino-1-metil-2-metoxi-6-oxopirimidina con exceso de ClH.H2NOH permite aislar 5-E-aldoximino derivado como único producto. La estructura del mismo ha sido establecida en base a pruebas químicas y espectroscópicas

Estudio piloto de metilfenidato y entrenamiento a padres en el tratamiento de niños con trastorno por déficit de atención hiperactividad [A pilot study of methylphenidate and parent training in the treatment of children with attention-deficit hiperactivity disorder]

Objetivo. Este estudio comunica la eficacia de un programa de entrenamiento a padres y un ensayo clínico con medicación estimulante (metilfenidato), en la disminución de síntomas de trastorno por déficit de atención-hiperactividad (TDAH) en una muestra de niños venezolanos.Pacientes y métodos. 24 niños, con edades entre 6 y 10 años, con diagnóstico de TDAH, identificados en unas jornadas de cribado de TDAH, se asignaron aleatoriamente a los dos grupos de tratamiento: entrenamiento a padres y medicación estimulante (metilfenidato).Resultados. Ambos grupos mostraron reducción de síntomas al finalizar la fase de intervención terapéutica en diferentes grados. Estas diferencias fueron estadísticamente significativas para las valoraciones de los padres en ambos grupos, en los síntomas de falta de atención, hiperactividad e impulsividad. Las valoraciones de los profesores mostraron disminución de síntomas significativos en el grupo de medicación para las medidas de hiperactividad e impulsividad, pero no para las de falta de atención, mientras que para el grupo de entrenamiento a padres sólo hubo diferencias significativas en el índice de TDAH. No hubo diferencia en cuanto a la efectividad de ambas intervenciones.Conclusiones. Al comparar ambos programas de tratamiento, se observa que tanto el entrenamiento a padres como la medicación psicoestimulante son tratamientos efectivos para la disminución de los síntomas del TDAH. A pesar de que no existen diferencias entre la efectividad de ambas intervenciones, se observa una tendencia a que la medicación sea más efectiva. - OBJECTIVE. This study gives information about a parent training program and a clinical trial with a stimulant drug (methylphenidate) to reduce the symptoms of attention deficit hiperactivity disorder (ADHD) in a group of children in Venezuela.PATIENTS AND METHODS. 24 children, aged between 6 and 10 years and diagnosed as having ADHD, identified in ADHD screening days, were randomly assigned to two groups of treatment: parent training and a stimulant drug (methylphenidate).RESULTS. Both groups showed an improvement in their symptoms, to different degrees, after treatment. The differences were statistically significant, as evaluated by their parents, regarding the symptoms of inattention, hyperactivity and impulsivity. The teachers observed a significant improvement for the medication group with respect to the symptoms of hyperactivity and impulsivity, but no change in the inattention, whilst in the parent training group there was only significant difference in the ADHD index. There was no difference in the effectiveness of the two types of treatment.CONCLUSIONS. When the two programs of treatment were compared it was observed that both parent training and psychostimulant medication were effective in reducing the symptoms of ADHD. Although there was no difference in the effectiveness of the two programs, there was a tendency for medication to be more effectiv

Congreso online: nueva herramienta para fomentar el aprendizaje

Los congresos científicos son una herramienta valiosa en el aprendizaje para estudiantes de tercer ciclo. Sin embargo, no son aprovechados al máximo con esta finalidad, puesto que las intervenciones por parte de los estudiantes, en cuanto a plantear cuestiones se refiere, son prácticamente nulas. Con el objetivo de fomentar la participación de los estudiantes de tercer ciclo en los congresos científicos, se presenta una propuesta de congreso online para estudiantes de doctorado en el programa interuniversitario `Electroquímica. Ciencia y Tecnología`, empleando la herramienta Moodle. Este congreso consiste en dar a conocer, de forma visible y con formato de pósters, comunicaciones científicas de los estudiantes, quienes deben hacer preguntas acerca de las mismas y responder a las realizadas sobre su contribución. Además, y siempre con la finalidad de fomentar la participación en forma de preguntas y discusiones científicas, se otorgarán premios tales como al estudiante más participativo y al mejor póster, para lo que se evaluará la defensa del póster por parte del estudiante