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

«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

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

Soil application of volatile compounds emitted by Alternaria alternata enhance yield of pepper plants cultured under greenhouse conditions

Póster presentado en el 2nd World Congress on the use of Biostimulants in Agriculture, celebrado en Florencia del 16 al 19 de noviembre de 2015.Peer Reviewe

Arabidopsis responds to Alternaria alternata volatiles by triggering plastid phosphoglucose isomerase-independent mechanisms

Sánchez-López, Ángela María et al.Volatile compounds (VCs) emitted by phylogenetically diverse microorganisms (including plant pathogens and microbes that do not normally interact mutualistically with plants) promote photosynthesis, growth, and the accumulation of high levels of starch in leaves through cytokinin (CK)-regulated processes. In Arabidopsis (Arabidopsis thaliana) plants not exposed to VCs, plastidic phosphoglucose isomerase (pPGI) acts as an important determinant of photosynthesis and growth, likely as a consequence of its involvement in the synthesis of plastidic CKs in roots. Moreover, this enzyme plays an important role in connecting the Calvin-Benson cycle with the starch biosynthetic pathway in leaves. To elucidate the mechanisms involved in the responses of plants to microbial VCs and to investigate the extent of pPGI involvement, we characterized pPGI-null pgi1-2 Arabidopsis plants cultured in the presence or absence of VCs emitted by Alternaria alternata. We found that volatile emissions from this fungal phytopathogen promote growth, photosynthesis, and the accumulation of plastidic CKs in pgi1-2 leaves. Notably, the mesophyll cells of pgi1-2 leaves accumulated exceptionally high levels of starch following VC exposure. Proteomic analyses revealed that VCs promote global changes in the expression of proteins involved in photosynthesis, starch metabolism, and growth that can account for the observed responses in pgi1-2 plants. The overall data show that Arabidopsis plants can respond to VCs emitted by phytopathogenic microorganisms by triggering pPGI-independent mechanisms.This work was supported by the Comisión Interministerial de Ciencia y Tecnología and Fondo Europeo de Desarrollo Regional, Spain (grant nos. BIO2010–18239 and BIO2013–49125–C2–1–P), by the Government of Navarra (grant no. IIM010491.RI1), by the I-Link0939 project from the Ministerio de Economía y Competitividad, by the Ministry of Education, Youth, and Sports of the Czech Republic (grant no. LO1204 from the National Program of Sustainability), by Palacky University institutional support, by predoctoral fellowships from the Spanish Ministry of Science and Innovation (to A.M.S.-L. and P.G.-G.), and by postdoctoral fellowships from the Public University of Navarra (to M.B. and G.A.).Peer Reviewe

Volatile compounds emitted by the plant pathogen Alternaria alternata promote photosynthesis, growth and accumulation of high levels of starch in Arabidopsis through pPGI dependent and independent cytokinin biosynthetic processes

Póster presentado en el XXI Reunión de la Sociedad Española de Fisiología Vegetal y el XIV Congreso Hispano-Luso Fisiología Vegetal, celebrado en Toledo del 14 al 17 de junio de 2015.Peer Reviewe

Soil application of volatile compounds emitted by the plant pathogen Alternaria alternata enhance yield of pepper plants cultured under greenhouse conditions

Póster presentado en la International Conference "Plant Biotechnology: Green for Good III", celebrada en Olomouc (República Checa) del 15 al 18 de junio de 2015.Peer Reviewe