Mejoras operativas en la valoración genética del ganado caprino lechero de raza murciano-granadina

Se compararon diferentes modelos para la evaluación de cabras lecheras para su uso en un programa de mejora genética establecido entre la Asociación de Ganaderos de Caprino de Raza Murciano-Granadina de la Comunidad Valenciana y el Centro de Investigación y Tecnología Animal del Instituto Valenciano de Investigaciones Agrarias. Se compararon en primer lugar dos modelos mixtos con diferente estructura de covarianzas. También se realizaron comparaciones entre modelos que incluyeron otros efectos sistemáticos: edad de la hembra en el momento del parto y días desde el parto hasta el primer control de la lactación. Se consideraron los caracteres estandarizados producción de leche y porcentajes de grasa y proteína. Las comparaciones se realizaron considerando criterios estadísticos de información. Los resultados indican que el modelo de repetibilidad es el más adecuado al tener en cuenta las covarianzas entre medidas de una cabra. La inclusión del efecto edad de la hembra al parto sólo fue ventajosa para el carácter producción de leche. La consideración del efecto tiempo desde el parto al primer control lechero fue positiva para los caracteres de producción de leche y de porcentaje de proteína. Ninguno de los efectos incluidos mejoró el modelo actualmente utilizado para porcentaje de grasa

Carbon Dioxide Utilisation -The Formate Route

UIDB/50006/2020 CEEC-Individual 2017 Program Contract.The relentless rise of atmospheric CO2 is causing large and unpredictable impacts on the Earth climate, due to the CO2 significant greenhouse effect, besides being responsible for the ocean acidification, with consequent huge impacts in our daily lives and in all forms of life. To stop spiral of destruction, we must actively reduce the CO2 emissions and develop new and more efficient “CO2 sinks”. We should be focused on the opportunities provided by exploiting this novel and huge carbon feedstock to produce de novo fuels and added-value compounds. The conversion of CO2 into formate offers key advantages for carbon recycling, and formate dehydrogenase (FDH) enzymes are at the centre of intense research, due to the “green” advantages the bioconversion can offer, namely substrate and product selectivity and specificity, in reactions run at ambient temperature and pressure and neutral pH. In this chapter, we describe the remarkable recent progress towards efficient and selective FDH-catalysed CO2 reduction to formate. We focus on the enzymes, discussing their structure and mechanism of action. Selected promising studies and successful proof of concepts of FDH-dependent CO2 reduction to formate and beyond are discussed, to highlight the power of FDHs and the challenges this CO2 bioconversion still faces.publishersversionpublishe

111 oriented gold nanoplatelets on multilayer graphene as visible light photocatalyst for overall water splitting

[EN] Development of renewable fuels from solar light appears as one of the main current challenges in energy science. A plethora of photocatalysts have been investigated to obtain hydrogen and oxygen from water and solar light in the last decades. However, the photon-to-hydrogen molecule conversion is still far from allowing real implementation of solar fuels. Here we show that 111 facet-oriented gold nanoplatelets on multilayer graphene films deposited on quartz is a highly active photocatalyst for simulated sunlight overall water splitting into hydrogen and oxygen in the absence of sacrificial electron donors, achieving hydrogen production rate of 1.2 molH2 per gcomposite per h. This photocatalytic activity arises from the gold preferential orientation and the strong gold–graphene interaction occurring in the composite system.Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa and CTQ2012-32315) and Generalitat Valenciana (Prometeo 2013-019) is gratefully acknowledged. D.M. and I.E.-A. thank to Spanish Ministry of Science for PhD scholarships.Mateo Mateo, D.; Esteve Adell, I.; Albero Sancho, J.; Sánchez Royo, JF.; Primo Arnau, AM.; García Gómez, H. (2016). 111 oriented gold nanoplatelets on multilayer graphene as visible light photocatalyst for overall water splitting. Nature Communications. 2016(7):1-8. https://doi.org/10.1038/ncomms11819S1820167Lv, X. J., Zhou, S., Huang, X., Wang, C. & Fu, W. F. Photocatalytic overall water splitting promoted by SnOx-NiGa2O4 photocatalysts. Appl. Cat. B: Environ. 182, 220–228 (2016).Xu, J., Wang, L. & Cao, X. Polymer supported graphene-CdS composite catalyst with enhanced photocatalytic hydrogen production from water splitting under visible light. Chem. Eng. J. 283, 816–825 (2016).Tanigawa, S. & Irie, H. Visible-light-sensitive two-step overall water-splitting based on band structure control of titanium dioxide. Appl. Cat. B: Environ. 180, 1–5 (2016).Maeda, K. et al. GaN:ZnO solid solution as a photocatalyst for visible-light-driven overall water splitting. J. Am. Chem. Soc. 127, 8286–8287 (2005).Maeda, K. et al. Photocatalyst releasing hydrogen from water. Nature 440, 295 (2006).Kato, H. & Kudo, A. Visible-light-response and photocatalytic activities of TiO2 and SrTiO3 photocatalysts codoped with antimony and chromium. J. Phys. Chem. B 106, 5029–5034 (2002).Xiang, Q., Cheng, B. & Yu, J. Graphene-based photocatalysts for solar-fuel generation. Angew. Chem. Int. Ed. 54, 11350–11366 (2015).Navalon, S., Dhakshinamoorthy, A., Alvaro, M. & Garcia, H. Carbocatalysis by graphene-based materials. Chem. Rev. 114, 6179–6212 (2014).Yu, J., Jin, J., Cheng, B. & Jaroniec, M. A noble metal-free reduced graphene oxide-cds nanorod composite for the enhanced visible-light photocatalytic reduction of CO2 to solar fuel. J. Mat. Chem. A 2, 3407–3416 (2014).Meng, F., Cushing, S. K., Li, J., Hao, S. & Wu, N. Enhancement of solar hydrogen generation by synergistic interaction of La2Ti2O7 photocatalyst with plasmonic gold nanoparticles and reduced graphene oxide nanosheets. ACS Catal. 5, 1949–1955 (2015).Shown, I. et al. Highly efficient visible light photocatalytic reduction of co2 to hydrocarbon fuels by cu-nanoparticle decorated graphene oxide. Nano Lett. 14, 6097–6103 (2014).Shang, L. et al. Graphene-supported ultrafine metal nanoparticles encapsulated by mesoporous silica: robust catalysts for oxidation and reduction reactions. Angew. Chem. Int. Ed. 53, 250–254 (2014).Latorre-Sánchez, M., Primo, A. & García, H. P-doped graphene obtained by pyrolysis of modified alginate as a photocatalyst for hydrogen generation from water-methanol mixtures. Angew. Chem. Int. Ed. 52, 11813–11816 (2013).Lavorato, C., Primo, A., Molinari, R. & Garcia, H. N-doped graphene derived from biomass as a visible-light photocatalyst for hydrogen generation from water/methanol mixtures. Chem. - A Eur. J. 20, 187–194 (2014).Shams, S. S., Zhang, L. S., Hu, R., Zhang, R. & Zhu, J. Synthesis of graphene from biomass: a green chemistry approach. Mater. Lett. 161, 476–479 (2015).Meng, F. et al. Biomass-derived high-performance tungsten-based electrocatalysts on graphene for hydrogen evolution. J. Mater. Chem. A 3, 18572–18577 (2015).Vilatela, J. J. & Eder, D. Nanocarbon composites and hybrids in sustainability: a review. ChemSusChem 5, 456–478 (2012).Rani, P. & Jindal, V. K. Designing band gap of graphene by B and N dopant atoms. RSC Adv. 3, 802–812 (2013).Zheng, Y. et al. Hydrogen evolution by a metal-free electrocatalyst. Nat. Commun. 5, 3783 (2014).Wang, X. et al. A metal-free polymeric photocatalyst for hydrogen production from water under visible light. Nat. Mater. 8, 76–80 (2009).Huang, H., Yang, S., Vajtai, R., Wang, X. & Ajayan, P. M. Pt-decorated 3D architectures built from graphene and graphitic carbon nitride nanosheets as efficient methanol oxidation catalysts. Adv. Mater. 26, 5160–5165 (2014).Shiraishi, Y. et al. Platinum nanoparticles strongly associated with graphitic carbon nitride as efficient co-catalysts for photocatalytic hydrogen evolution under visible light. Chem. Commun. 50, 15255–15258 (2014).G. Baldoví, H. et al. Visible-light photoresponse of gold nanoparticles supported on TiO2: A combined photocatalytic, photoelectrochemical, and transient spectroscopy study. ChemPhysChem 16, 335–341 (2015).Serra, M., Albero, J. & Garcia, H. Photocatalytic Activity of Au/TiO2 photocatalysts for H-2 evolution: role of the Au nanoparticles as a function of the irradiation wavelength. ChemPhysChem 16, 1842–1845 (2015).Gomes Silva, C., Juárez, R., Marino, T., Molinari, R. & García, H. Influence of excitation wavelength (UV or visible light) on the photocatalytic activity of titania containing gold nanoparticles for the generation of hydrogen or oxygen from water. J. Am. Chem. Soc. 133, 595–602 (2011).El Kadib, A. Chitosan as a sustainable organocatalyst: a concise overview. ChemSusChem 8, 217–244 (2015).Primo, A., Atienzar, P., Sanchez, E., Delgado, J. M. & García, H. From biomass wastes to large-area, high-quality, N-doped graphene: catalyst-free carbonization of chitosan coatings on arbitrary substrates. Chem. Commun. 48, 9254–9256 (2012).Primo, A. & Quignard, F. Chitosan as efficient porous support for dispersion of highly active gold nanoparticles: design of hybrid catalyst for carbon-carbon bond formation. Chem. Commun. 46, 5593–5595 (2010).Primo, A. et al. One-step pyrolysis preparation of 1.1.1 oriented gold nanoplatelets supported on graphene and six orders of magnitude enhancement of the resulting catalytic activity. Angew. Chem. Int. Ed. 54, 1–7 (2015).Lalov, I. G., Guerginov, I. I., Krysteva, M. A. & Fartsov, K. Treatment of waste water from distilleries with chitosan. Water Res. 34, 1503–1506 (2000).No, H. K. & Meyers, S. P. Application of Chitosan for Treatment of Wastewaters in Reviews of Environmental Contamination and Toxicology: Continuation of Residue Reviews eds George W. W. 1–27Springer (2000).Liu, C. et al. Hydrothermal synthesis of N-doped TiO2 nanowires and N-doped graphene heterostructures with enhanced photocatalytic properties. J. Alloys Compd. 656, 24–32 (2016).Radnik, J., Mohr, C. & Claus, P. On the origin of binding energy shifts of core levels of supported gold nanoparticles and dependence of pretreatment and materials synthesis. Phys. Chem. Chem. Phys. 5, 172–177 (2003).Primo, A. et al. High catalytic activity of oriented 2.0.0 copper(I) oxide grown on graphene film. Nat. Commun. 6, 8561 (2015).Abbasi, M. et al. Application of transmitted Kikuchi diffraction in studying nano-oxide and ultrafine metallic grains. ACS Nano 9, 10991–11002 (2015).Trimby, P. T. Orientation mapping of nanostructured materials using transmission kikuchi diffraction in the scanning electron microscope. Ultramicroscopy 120, 16–24 (2012).Johnson, C. J., Dujardin, E., Davis, S. A., Murphy, C. J. & Mann, S. Growth and form of gold nanorods prepared by seed-mediated, surfactant-directed synthesis. J. Mater. Chem. 12, 1765–1770 (2002).Ikeda, S. et al. Mechano-catalysis—a novel method for overall water splitting. Phys. Chem. Chem. Phys. 1, 4485–4491 (1999).Khalid, N. R., Ahmed, E., Hong, Z., Sana, L. & Ahmed, M. Enhanced photocatalytic activity of graphene-TiO2 composite under visible light irradiation. Curr. Appl. Phys. 13, 659–663 (2013).Singh, G. P., Shrestha, K. M., Nepal, A., Klabunde, K. J. & Sorensen, C. M. Graphene supported plasmonic photocatalyst for hydrogen evolution in photocatalytic water splitting. Nanotechnology 25, 265701 (2014).Wang, M., Han, J., Xiong, H. & Guo, R. Yolk@shell nanoarchitecture of Au@r-GO/TiO2 hybrids as powerful visible light photocatalysts. Langmuir 31, 6220–6228 (2015).Luo, Z. et al. Modulating the electronic structures of graphene by controllable hydrogenation. Appl. Phys. Lett. 97, 233111 (2010).Sridhara Rao, D. V., Muraleedharan, K. & Humphreys, C. J. in Microscope Science, Technology, Applications and Education 3, 1232–1244Formatec (2010)

Influence of Hydrogen Annealing on the photocatalytic activity of diamond supported gold catalysts

Fenton-treated diamond nanoparticles have been submitted to hydrogen reduction at 500 °C with the purpose of modifying the nature of the functional groups present on the diamond surface. The nature of the functional groups on the diamond samples was characterized by a combination of spectroscopic and analytical techniques. In particular, Fouriertransformed infrared spectroscopy, temperature-programmed desorption, and X-ray photoelectron spectroscopy (XPS) show the decrease in the population of carboxylic acids, esters, and anhydrides after hydrogen treatment. XPS also shows a decrease on the oxygen content after the hydrogen treatment of the diamond nanoparticles and lower electronegativity of the carbons as assessed by the lower binding energy values. Although Fentontreated diamond colloids in water changes the zeta potential from positive to negative values as a function of the pH, hydrogen annealing and the disappearance of the carboxyl groups determines that the zeta potential of the resulting sample remains positive in the complete pH range. Deposition of gold nanoparticles was carried out by the polyol method consisting on the reduction of HAuCl4 by hot ethylene glycol in the presence of the support. TEM analysis shows a variation of the average gold nanoparticle size that decreases after hydrogen reduction of carboxylic groups and becomes smaller for low gold loadings. The catalytic activity of the diamond supported gold nanoparticles as a function of the surface annealing treatment and gold loading was evaluated for the natural sunlight-assisted peroxidation of phenol by H2O2. It was observed that the most efficient sample was the one having lower gold nanoparticle size that was obtained for diamond samples reduced by hydrogen at 500 °C after the Fenton treatment and having low gold loading (0.05 wt %). Turnover frequencies above 2400 and 940 h−1 were obtained for phenol degradation and H2O2 decomposition, respectively.Financial support by the Spanish Ministry of Economy and Competitiveness (MINECO, Severo Ochoa program and CTQ 2012-32315), Universidad Politecnica de Valencia (PAID-06-11, no 2095) and Generalitat Valenciana (Prometeo 2013/014 and GV/2013/040).Navalón Oltra, S.; Sempere Aracil, D.; Alvaro Rodríguez, MM.; García Gómez, H. (2013). Influence of Hydrogen Annealing on the photocatalytic activity of diamond supported gold catalysts. ACS Applied Materials and Interfaces. 5(15):7160-7169. https://doi.org/10.1021/am401489nS7160716951

Active sites on graphene-based materials as metal-free catalysts

Graphenes and related materials have attracted growing interest as metal-free catalysts. The present review is focused on describing the active sites that have been proposed to be responsible for the catalytic activity observed for such systems. It will be shown that diverse defects and chemical functionalities on the graphene layers can catalyze reactions, including oxygenated functional groups, carbon vacancies and holes, edge effects, and the presence of dopant elements. Besides discrete active sites, the catalytic activity arising from the collective properties of graphenes as materials by adsorbing substrates and reagents and activating them by charge transfer is also commented. The review has an introductory general section summarizing the general methodologies that have been used to support the proposed structure of the active sites, including theoretical calculations, comparison of the catalytic activity of graphene samples with different compositions, the use of organic molecules as models of the active centers, and selective masking of functional groups. The review is concluded with our view on future developments in the field

Challenges and opportunities for N-hydroxyphthalimide supported over heterogeneous solids for aerobic oxidations

Organocatalysis, in combination with, or as an alternative to the use of metals, is attracting increasing interest as a sustainable route to promote selective transformations. In this context, Nhydroxyphthalimide (NHPI) has found ample application as an effective organocatalyst capable to promote the aerobic oxidation of a wide range of organic substrates, including saturated and unsaturated hydrocarbons, alcohols, amines and sulphides among others. However, most of these transformations required the use of NHPI dissolved in solution, with consequent limits in the scale-up of the process. Leaving aside the reviews of NHPI as organocatalyst in homogeneous phase, the present review describes the strategies reported to support or anchor NHPI on a wide range of insoluble solids, thus converting this homogeneous organocatalyst into a heterogeneous system, with the consequent advantages related to the ease of separation and recovery of the catalyst from the reaction medium, its recyclability and the possibility to develop continuous flow reactions. After a brief introductory section, a detailed description of the catalytic mechanism is here presented, also providing a comparison between NHPI and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical, and by highlighting the main challenges associated to NHPI heterogenization. The critical description of the heterogeneous solutions is organized according to the nature of the support, focusing on metal–organic frameworks (MOFs), organic polymers, carbon-based materials, and inorganic supports, while the growing use of NHPI-containing photocatalysts is presented separately. In the final section, we outline the main achievements on the use of NHPI heterogeneous catalysis and provide our views for future developments in the area