Light-driven hydrogen evolution assisted by covalent organic frameworks

Altres ajuts: RSCCovalent organic frameworks (COFs) are crystalline porous organic polymers built from covalent organic blocks that can be photochemically active when incorporating organic semiconducting units, such as triazine rings or diacetylene bridges. The bandgap, charge separation capacity, porosity, wettability, and chemical stability of COFs can be tuned by properly choosing their constitutive building blocks, by extension of conjugation, by adjustment of the size and crystallinity of the pores, and by synthetic post-functionalization. This review focuses on the recent uses of COFs as photoactive platforms for the hydrogen evolution reaction (HER), in which usually metal nanoparticles (NPs) or metallic compounds (generally Pt-based) act as co-catalysts. The most promising COF-based photocatalytic HER systems will be discussed, and special emphasis will be placed on rationalizing their structure and light-harvesting properties in relation to their catalytic activity and stability under turnover conditions. Finally, the aspects that need to be improved in the coming years will be discussed, such as the degree of dispersibility in water, the global photocatalytic efficiency, and the robustness and stability of the hybrid systems, putting emphasis on both the COF and the metal co-catalyst

The role of emotional intelligence in adolescent bullying: a systematic review

Bullying is a problem within the school context and with important consequences for the victim. The scientific literature has shown that emotional intelligence (EI) enhances the role of cohabitation within the school context. This systematic review aims to analyze the evidence of the role of EI in bullying. Results show greater levels of emotional perception in students involved in bullying and lower levels of emotional understanding and regulation compared to students not involved in these behaviors. In addition, gender differences in their levels of EI were found among students involved in bullying. The results reveal the importance of designing and implementing programs of EI in the school context as prevention and action against bullying

Surface-Functionalized Nanoparticles as Catalysts for Artificial Photosynthesis

Altres ajuts: acords transformatius de la UABAnalogously to enzymatic catalysis, where the active metal sites and their environment are controlled by protein residues, the catalytic properties of metal nanoparticles (NPs) can be tuned by carefully selecting their surface-coordinated species. In artificial photosynthesis, surface-functionalization emerged in the last decade, grounded on the development of reliable methods for tailored synthesis, advanced characterization and theoretical modeling of metal NPs, altogether with the aim of transferring to the nanoscale the mechanistic knowledge acquired from molecular complexes. Metal NPs surface-functionalization modulates the energetics of key catalytic intermediates, introduces second coordination sphere effects, influences the catalyst-electrolyte interface, and determines the metal NPs surface coverage and, accordingly, the number of accessible active sites. In photoactivated systems, metal NPs surface-functionalization may play a key role in modulating the charge transfers and recombination processes between the light absorber and the active sites and in the light absorber itself. Thus, after a presentation of the most relevant synthetic methods to produce well-defined surface-functionalized metal NPs, a critical analysis of why the above effects are the cornerstone in enhancing their catalytic performance in the key processes of artificial photosynthesis, namely the oxygen evolution reaction, the hydrogen evolution reaction, and the CO2 reduction reaction, is given

«Botellon» and alcohol and other drug use in youth

El objetivo de este trabajo es analizar la relación existente entre la participación en el botellón (reuniones de jóvenes en espacios públicos para beber, charlar, etc.), el abuso de alcohol y otras drogas y la realización de conductas vandálicas en jóvenes. Para ello se ha realizado una encuesta escolar en centros educativos de Secundaria, Bachillerato, ciclos de Formación Profesional y Universidad en la ciudad de Lugo. La muestra, de edades comprendidas entre los 12 y los 30 años, fue dividida en tres grupos en función de su consumo de alcohol y la participación en el botellón, y se analizó el nivel de abuso de drogas, los problemas asociados con esos abusos y el grado de implicación en actos vandálicos. Los resultados muestran que aquellos que participan habitualmente en el botellón presentan mayores problemas con el alcohol y otras drogas. Son también los que más actos vandálicos realizan. Esa relación se observa con mayor intensidad en los estudiantes más jóvenes. El incremento del riesgo en los adolescentes asociado a la práctica del botellón es explicado por la presión del grupo de amigos hacia el consumo y por la mayor accesibilidad al alcohol y otras drogas en estos contextosThe main aim of this paper is to analyze the relationships of involvement in the "botellon" (meetings of youth in public places to drink, chat, etc.) with alcohol/other drug abuse and vandalism in young people. A school survey was performed in centres of Compulsory Secondary School (E.S.O.), high school, professional training and University education in Lugo, NW Spain. The sample (aged 12 to 30) was split into three groups according to alcohol use and botellon involvement; drug abuse, drug-related problems and vandalism were assessed in each group. Results indicate that regular botellon attendants display more problems with alcohol and other drugs, as well as higher involvement in vandalism; this relationship is stronger among young students. The increase in adolescent risk associated with the practice of the botellon is explained by peer group pressure to use drugs and the greater accessibility of alcohol/other drugs in these contextsS

Synthesis of 0D to 3D hybrid-carbon nanomaterials carrying platinum(0) nanoparticles : towards the electrocatalytic determination of methylparabens at ultra-trace levels

A generic synthetic methodology has been applied for functionalizing four conducting carbon nanoallotropes, such as 0D carbon nanohorns (CNHs), 1D carbon nanotubes (CNTs), 2D reduced graphene oxide (rGO) and 3D graphite (GP) with platinum(0) nanoparticles (Pt-NP), and exploited towards the electrocatalytic determination of methylparaben (MeP), which has been classified as a potential endocrine-disrupting chemical. After an accurate physical, electrochemical and electroanalytical characterization, the hybrid Pt-NP@CNTs yields detection limits at nM levels, rather than the μM levels obtained with the rest of carbon homologous because of the optimum carbon/nanoparticle composition ratio. The proposed electrochemical sensing system has also been successfully validated by comparison with the standard bench-top chromatographic tool (HPLC), demonstrating its feasibility for MeP quantification in real cosmetic samples at ultra-trace levels. According to the outstanding performance of the hybrid Pt-NP@CNTs electrochemical platform, it can be regarded as a potential alternative to the conventional HPLC technique for the development of rapid, straightforward, cost-effective, reproducible and highly sensitive electrochemical sensors to be exploited in pharmacological, biomedical and environmental field

Organocatalytic vs. Ru-based electrochemical hydrogenation of nitrobenzene in competition with the hydrogen evolution reaction

The electrochemical reduction of organic contaminants allows their removal from water. In this contribution, the electrocatalytic hydrogenation of nitrobenzene is studied using both oxidized carbon fibres and ruthenium nanoparticles supported on unmodified carbon fibres as catalysts. The two systems produce azoxynitrobenzene as the main product, while aniline is only observed in minor quantities. Although PhNO2 hydrogenation is the favoured reaction, the hydrogen evolution reaction (HER) competes in both systems under catalytic conditions. H2 formation occurs in larger amounts when using the Ru nanoparticle based catalyst. While similar reaction outputs were observed for both catalytic systems, DFT calculations revealed some significant differences related to distinct interactions between the catalytic material and the organic substrates or products, which could pave the way for the design of new catalytic materials

Enhanced yield of pepper plants promoted by soil application of volatiles from cell-free fungal culture filtrates is associated with activation of the beneficial soil microbiota

Plants communicate with microorganisms by exchanging chemical signals throughout the phytosphere. Such interactions are important not only for plant productivity and fitness, but also for terrestrial ecosystem functioning. It is known that beneficial microorganisms emit diffusible substances including volatile organic compounds (VOCs) that promote growth. Consistently, soil application of cell-free culture filtrates (CF) of beneficial soil and plant-associated microorganisms enhances plant growth and yield. However, how this treatment acts in plants and whether it alters the resident soil microbiota, are largely unknown. In this work we characterized the responses of pepper (Capsicum annuum L.) plants cultured under both greenhouse and open field conditions and of soil microbiota to soil application of CFs of beneficial and phytopathogenic fungi. To evaluate the contribution of VOCs occurring in the CFs to these responses, we characterized the responses of plants and of soil microbiota to application of distillates (DE) of the fungal CFs. CFs and their respective DEs contained the same potentially biogenic VOCs, and application of these extracts enhanced root growth and fruit yield, and altered the nutritional characteristics of fruits. High-throughput amplicon sequencing of bacterial 16S and fungal ITS rRNA genes of the soil microbiota revealed that the CF and DE treatments altered the microbial community compositions, and led to strong enrichment of the populations of the same beneficial bacterial and fungal taxa. Our findings show that CFs of both beneficial and phytopathogenic fungi can be used as biostimulants, and provide evidence that VOCs occurring in the fungal CFs act as mediators of the plants’ responses to soil application of fungal CFs through stimulation of the beneficial soil microbiota.This work was supported by the Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (Spain) (grants BIO2013-49125-C2-1-P, BIO2016-78747-P, and PID2019-104685GB-100), the Government of Navarra (refs. P1044 AGROESTI, P1004 PROMEBIO, and P1046 MICROBIOME), and the project “Plants as a tool for sustainable global development” (registration number: CZ.02.1.01/0.0/0.0/16_019/0000827) within the program Research, Development and Education (OP RDE)

Plant responses to fungal volatiles involve global posttranslational thiol redox proteome changes that affect photosynthesis

Microorganisms produce volatile compounds (VCs) that promote plant growth and photosynthesis through complex mechanisms involving cytokinin (CK) and abscisic acid (ABA). We hypothesized that plants' responses to microbial VCs involve posttranslational modifications of the thiol redox proteome through action of plastidial NADPH-dependent thioredoxin reductase C (NTRC), which regulates chloroplast redox status via its functional relationship with 2-Cys peroxiredoxins. To test this hypothesis, we analysed developmental, metabolic, hormonal, genetic, and redox proteomic responses of wild-type (WT) plants and a NTRC knockout mutant (ntrc) to VCs emitted by the phytopathogen Alternaria alternata. Fungal VC-promoted growth, changes in root architecture, shifts in expression of VC-responsive CK- and ABA-regulated genes, and increases in photosynthetic capacity were substantially weaker in ntrc plants than in WT plants. As in WT plants, fungal VCs strongly promoted growth, chlorophyll accumulation, and photosynthesis in ntrc–Δ2cp plants with reduced 2-Cys peroxiredoxin expression. OxiTRAQ-based quantitative and site-specific redox proteomic analyses revealed that VCs promote global reduction of the thiol redox proteome (especially of photosynthesis-related proteins) of WT leaves but its oxidation in ntrc leaves. Our findings show that NTRC is an important mediator of plant responses to microbial VCs through mechanisms involving global thiol redox proteome changes that affect photosynthesis.Comisión Interministerial de Ciencia y Tecnología BIO2013‐ 49125‐C2‐1‐P, BIO2017‐85195‐C2‐1‐P, BIO2016‐78747‐PEuropean Regional Development CZ.02.1.01/0.0/0.0/16_019/0000827Ministry of Education, Youth and Sport of the Czech Republic LO1204Japan Society for the Promotion of Sciences 15H02486Gobierno de Navarra P1004 PROMEBIO, P1044 AGROEST

Unravelling the Mechanistic Pathway of the Hydrogen Evolution Reaction Driven by a Cobalt Catalyst

Acord transformatiu CRUE-CSICA cobalt complex bearing a κ-NP ligand is presented (1 or Co(L), where L is (1E,1'E)-1,1'-(pyridine-2,6-diyl)bis(N-(3-(diphenylphosphanyl)propyl)ethan-1-imine). Complex 1 is stable under air at oxidation state Co thanks to the π-acceptor character of the phosphine groups. Electrochemical behavior of 1 reveals a two-electron Co/Co oxidation process and an additional one-electron reduction, which leads to an enhancement in the current due to hydrogen evolution reaction (HER) at E=−1.6 V vs Fc/Fc. In the presence of 1 equiv of bis(trifluoromethane)sulfonimide, 1 forms the cobalt hydride derivative Co(L)-H (2), which has been fully characterized. Further addition of 1 equiv of CoCp* (Cp* is pentamethylcyclopentadienyl) affords the reduced Co(L)-H (2) species, which rapidly forms hydrogen and regenerates the initial Co(L) (1). The spectroscopic characterization of catalytic intermediates together with DFT calculations support an unusual bimolecular homolytic mechanism in the catalytic HER with 1