One-Step Preparation of Large Area Films of Oriented MoS2 Nanoparticles on Multilayer Graphene and Its Electrocatalytic Activity for Hydrogen Evolution

[EN] MoS2 is a promising material to replace Pt-based catalysts for the hydrogen evolution reaction (HER), due to its excellent stability and high activity. In this work, MoS2 nanoparticles supported on graphitic carbon (about 20 nm) with a preferential 002 facet orientation have been prepared by pyrolysis of alginic acid films on quartz containing adsorbed (NH4)(2)MoS4 at 900 degrees C under Ar atmosphere. Although some variation of the electrocatalytic activity has been observed from batch to batch, the MoS2 sample exhibited activity for HER (a potential onset between 0.2 and 0.3 V vs. SCE), depending on the concentrations of (NH4)(2)MoS4 precursor used in the preparation process. The loading and particle size of MoS2, which correlate with the amount of exposed active sites in the sample, are the main factors influencing the electrocatalytic activity.Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa and CTQ2015-69513-CO2-R1) and Generalidad Valenciana (Prometeo 2013/014) is gratefully acknowledged. Jinbao He thanks the Chinese Scholarship Council for supporting his PhD studies.He, J.; Fernández-Blanco, AC.; Primo Arnau, AM.; García Gómez, H. (2018). One-Step Preparation of Large Area Films of Oriented MoS2 Nanoparticles on Multilayer Graphene and Its Electrocatalytic Activity for Hydrogen Evolution. Materials. 11(1):1-11. https://doi.org/10.3390/ma11010168S111111Chhowalla, M., Shin, H. S., Eda, G., Li, L.-J., Loh, K. P., & Zhang, H. (2013). The chemistry of two-dimensional layered transition metal dichalcogenide nanosheets. Nature Chemistry, 5(4), 263-275. doi:10.1038/nchem.1589Lukowski, M. A., Daniel, A. S., Meng, F., Forticaux, A., Li, L., & Jin, S. (2013). Enhanced Hydrogen Evolution Catalysis from Chemically Exfoliated Metallic MoS2 Nanosheets. Journal of the American Chemical Society, 135(28), 10274-10277. doi:10.1021/ja404523sVoiry, D., Yamaguchi, H., Li, J., Silva, R., Alves, D. C. B., Fujita, T., … Chhowalla, M. (2013). Enhanced catalytic activity in strained chemically exfoliated WS2 nanosheets for hydrogen evolution. Nature Materials, 12(9), 850-855. doi:10.1038/nmat3700Li, Y., Wang, H., Xie, L., Liang, Y., Hong, G., & Dai, H. (2011). MoS2Nanoparticles Grown on Graphene: An Advanced Catalyst for the Hydrogen Evolution Reaction. Journal of the American Chemical Society, 133(19), 7296-7299. doi:10.1021/ja201269bLatorre-Sánchez, M., Esteve-Adell, I., Primo, A., & García, H. (2015). Innovative preparation of MoS2–graphene heterostructures based on alginate containing (NH4)2MoS4 and their photocatalytic activity for H2 generation. Carbon, 81, 587-596. doi:10.1016/j.carbon.2014.09.093Primo, A., Sánchez, E., Delgado, J. M., & García, H. (2014). High-yield production of N-doped graphitic platelets by aqueous exfoliation of pyrolyzed chitosan. Carbon, 68, 777-783. doi:10.1016/j.carbon.2013.11.068Mateo, D., Esteve-Adell, I., Albero, J., Royo, J. F. S., Primo, A., & Garcia, H. (2016). 111 oriented gold nanoplatelets on multilayer graphene as visible light photocatalyst for overall water splitting. Nature Communications, 7(1). doi:10.1038/ncomms11819Primo, A., Esteve-Adell, I., Blandez, J. F., Dhakshinamoorthy, A., Álvaro, M., Candu, N., … García, H. (2015). High catalytic activity of oriented 2.0.0 copper(I) oxide grown on graphene film. Nature Communications, 6(1). doi:10.1038/ncomms9561Primo, A., Esteve-Adell, I., Coman, S. N., Candu, N., Parvulescu, V. I., & Garcia, H. (2015). 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. Angewandte Chemie International Edition, 55(2), 607-612. doi:10.1002/anie.201508908Primo, A., Atienzar, P., Sanchez, E., Delgado, J. M., & García, H. (2012). From biomass wastes to large-area, high-quality, N-doped graphene: catalyst-free carbonization of chitosan coatings on arbitrary substrates. Chemical Communications, 48(74), 9254. doi:10.1039/c2cc34978gPedraza, F., Cruz-Reyes, J., Acosta, D., Yanez, M. J., Avalos-Borja, M., & Fuentes, S. (1993). Journal of Physics: Condensed Matter, 5(33A), A219-A220. doi:10.1088/0953-8984/5/33a/069Li, H., Zhang, Q., Yap, C. C. R., Tay, B. K., Edwin, T. H. T., Olivier, A., & Baillargeat, D. (2012). From Bulk to Monolayer MoS2: Evolution of Raman Scattering. Advanced Functional Materials, 22(7), 1385-1390. doi:10.1002/adfm.201102111Yan, Y., Ge, X., Liu, Z., Wang, J.-Y., Lee, J.-M., & Wang, X. (2013). Facile synthesis of low crystalline MoS2 nanosheet-coated CNTs for enhanced hydrogen evolution reaction. Nanoscale, 5(17), 7768. doi:10.1039/c3nr02994hLi, H., Tsai, C., Koh, A. L., Cai, L., Contryman, A. W., Fragapane, A. H., … Zheng, X. (2015). Activating and optimizing MoS2 basal planes for hydrogen evolution through the formation of strained sulphur vacancies. Nature Materials, 15(1), 48-53. doi:10.1038/nmat4465Tsai, C., Chan, K., Nørskov, J. K., & Abild-Pedersen, F. (2015). Theoretical insights into the hydrogen evolution activity of layered transition metal dichalcogenides. Surface Science, 640, 133-140. doi:10.1016/j.susc.2015.01.01

Polymeric foams as the matrix of voltammetric sensors for the detection of catechol, hydroquinone, and their mixtures

Producción CientíficaPorous electrodes based on polymethylmethacrylate and graphite foams (PMMA_G_F) have been developed and characterized. Such devices have been successfully used as voltammetric sensors to analyze catechol, hydroquinone, and their mixtures. The presence of pores induces important changes in the oxidation/reduction mechanism of catechol and hydroquinone with respect to the sensing properties observed in nonfoamed PMMA_graphite electrodes (PMMA_G). The electropolymerization processes of catechol or hydroquinone at the electrode surface observed using PMMA_G do not occur at the surface of the foamed PMM_G_F. In addition, the limits of detection observed in foamed electrodes are one order of magnitude lower than the observed in the nonfoamed electrodes. Moreover, foamed electrodes can be used to detect simultaneously both isomers and a remarkable increase in the electrocatalytic properties shown by the foamed samples, produces a decrease in the oxidation potential peak of catechol in presence of hydroquinone, from +0.7 V to +0.3 V. Peak currents increased linearly with concentration of catechol in presence of hydroquinone over the range of 0.37·10−3 M to 1.69·10−3 M with a limit of detection (LOD) of 0.27 mM. These effects demonstrate the advantages obtained by increasing the active surface by means of porous structures.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-67482-R)Junta de Castilla y Leon - Fondo Europeo de Desarrollo Regional (project VA-011U16

Comorbilidad entre trastornos de conducta y depresión mayor en la adolescencia: prevalencia, teorías explicativas y estatus nosológico

This theoretical study examines the main findings and researches regarding the comorbidity between conduct disorder and major depression in adolescence. On the one hand, it is argued that high prevalence of comorbidity imply common risk factors (biological, cognitive- emotional and socio-cultural) and a causal relationship between these mental illness, usually conduct disorder preceding major depression. On the other hand, independent nosological status of this comorbidity» is advocated on the basis of several external criteria (e.g. response to treatment, course into adulthood and psychopathological profile), which distinguish this mixed clinical entity from conduct disorder and major depression, especially the latter category. These findings are discussed concerning the classification of «depressive conduct disorder» within current diagnosis reference manuals

Eco-trench: a novel trench solution based on reusing excavated material and a finishing layer of expansive concrete

Installing utility pipelines generates a significant amount of trench arisings, which are usually transported to landfills instead of being reused as backfill material. This practice generates CO2 emissions and wastes raw materials. This paper presents a more sustainable solution, an eco-trench, which is based on re-using trench arisings as backfill and adding a top layer of expansive concrete to improve the eco-trench’s structural performance. The technical feasibility of the eco-trench was evaluated through a finite element model, which identified the degree of expansion in concrete required to avoid failure or subside the stresses caused by traffic. The potential expansion of concrete was measured under confined conditions in the laboratory by means of a novel test developed for this purpose. The results showed that adding calcium oxide generates the required internal stress. The results were then confirmed in a pilot experience.Peer ReviewedPostprint (published version

Monitoring the phenolic ripening of red grapes using a multisensor system based on metal-oxide nanoparticles

Producción CientíficaThe maturity of grapes is usually monitored by means of the sugar concentration. However, the assessment of other parameters such as the phenolic content is also important because the phenolic maturity has an important impact on the organoleptic characteristics of wines. In this work, voltammetric sensors able to detect phenols in red grapes have been developed. They are based on metal oxide nanoparticles (CeO2, NiO, and TiO2,) whose excellent electrocatalytic properties toward phenols allows obtaining sensors with detection limits in the range of 10−8 M and coefficients of variation lower than 7%. An electronic tongue constructed using a combination of the nanoparticle-based sensors is capable to monitor the phenolic maturity of red grapes from véraison to maturity. Principal Component Analysis (PCA) can be successfully used to discriminate samples according to the ripeness. Regression models performed using Partial Least Squares (PLS-1) have established good correlations between voltammetric data obtained with the electrochemical sensors and the Total Polyphenolic Index, the Brix degree and the Total Acidity, with correlation coefficients close to 1 and low number of latent variables. An advantage of this system is that the electronic tongue can be used for the simultaneous assessment of these three parameters which are the main factors used to monitor the maturity of grapes. Thus the electronic tongue based on metal oxide nanoparticles can be a valuable tool to monitor ripeness. These results demonstrate the exciting possible applications of metal oxide nanoparticles in the field of electronic tongues.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-67482- R)Junta de Castilla y Leon - Fondo Europeo de Desarrollo Regional (project VA011U16)Junta de Castilla y León (grant BOCYL-D-24112015-9

The fishing and seafood sector in the time of COVID-19: Considerations for local and global opportunities and responses

This paper provides an overview of the impact of the COVID-19 pandemic on the fishing sector over the world, including several economic, social, environmental, and health challenges that the fisheries have had to face during the early days of the health crisis and some of them still continue today. These problems, in short, are translated into a decrease in seafood demand, loss of jobs, changes in food consumption habits, economic losses or increased vulnerability of the industry. As consequence, governments have been forced to implement regulations and measures in support of this sector. However, a positive aspect of the pandemic also stands out; the opportunity to transform the food system to be greener, more inclusive, and resilient against future shocks.This work was supported by the EAPA_576/2018 NEPTUNUS project. The authors would like to acknowledge the financial support of Interreg Atlantic Are

Evaluation of angiogenesis with the expression of VEGF and CD34 in human non-small cell lung cancer

Angiogenesis is an essential process in the progression of malignant tumors and the most potent angiogenic factor is the vascular endothelial growth factor (VEGF). On the other hand, the CD34 is an endothelial antigen that has been used to highlight the microvasculature vessel density (MVD) as a direct marker of the degree of neoangiogenesis. In the present study we report the VEGF expression and its relationship with MVD, measured by CD34, in two lineages of non-small cell lung cancer (NSCL): low differentiated adenocarcinomas and epidermoid carcinomas, in order to consider the possibility of using the correlation between both antibodies as a prognostic factor. Tumor sections were stained by immunohistochemistry for CD34 and VEGF. The results showed that the mean value of VEGF for adenocarcinoma was significantly higher than the one for epidermoid carcinoma (p < 0.001). However, the mean of MVD did not show significant differences between both types of tumors. The conventional factors taken into consideration (age over 60, sex, and presence of lymph nodes) was not significantly related to the angiogenic factors examined. In conclusion, we could affirm that CD34 is a better prognostic marker of neoangiogenesis in NSCLC, because both types of tumors have the same clinical prognosis, and so we expected the same behaviour from both markers.Facultad de Ciencias Médica

Evaluation of angiogenesis with the expression of VEGF and CD34 in human non-small cell lung cancer

Angiogenesis is an essential process in the progression of malignant tumors and the most potent angiogenic factor is the vascular endothelial growth factor (VEGF). On the other hand, the CD34 is an endothelial antigen that has been used to highlight the microvasculature vessel density (MVD) as a direct marker of the degree of neoangiogenesis. In the present study we report the VEGF expression and its relationship with MVD, measured by CD34, in two lineages of non-small cell lung cancer (NSCL): low differentiated adenocarcinomas and epidermoid carcinomas, in order to consider the possibility of using the correlation between both antibodies as a prognostic factor. Tumor sections were stained by immunohistochemistry for CD34 and VEGF. The results showed that the mean value of VEGF for adenocarcinoma was significantly higher than the one for epidermoid carcinoma (p < 0.001). However, the mean of MVD did not show significant differences between both types of tumors. The conventional factors taken into consideration (age over 60, sex, and presence of lymph nodes) was not significantly related to the angiogenic factors examined. In conclusion, we could affirm that CD34 is a better prognostic marker of neoangiogenesis in NSCLC, because both types of tumors have the same clinical prognosis, and so we expected the same behaviour from both markers.Facultad de Ciencias Médica

From the sea to the table: the environmental impact assessment of fishing, processing, and end-of-life of albacore in Cantabria

Cantabria, a small coastal region of Northern Spain, is one of the biggest producers of gourmet tuna cans in Europe. The fish capture in the Cantabrian Sea and the subsequent transformation in a local processing plant give distinction to this product, which is widely marketed in cans of 105 g of net weight. This work evaluates for the first time the environmental profile of the whole supply chain of this product, from fishing, processing, and waste valorization to inter-stage transport and packaging management in the end-of-life. To this end, the life cycle assessment methodology was applied considering primary data from the stakeholders involved in the supply chain and analyzing the seven most studied categories in this sector. Results revealed that fishing and processing accounted for the majority of the environmental impacts, while valorization and end-of-life treatments only avoid less than 10% of the burdens. The most important findings are focused on the high dependence on fuel use, identified as a hotspot in most stages although low compared to other fisheries, and on the intensive use of resources, especially sunflower oil, which contributes more than 70% of the impact on the global warming potential of the processing. This current framework forces the enhancement of the efficiency of a sector that attempts to engage the challenge of societal sustainability, by identifying the critical points and guiding policy makers on the path to sustainable development.This work was supported by the EAPA_576/2018NEPTUNUS project. The authors would like to acknowledge the financial support of Interreg Atlantic Area. The authors are grateful for the funding of the Spanish Ministry of Science and Innovation through the KAIROS-BIOCIR project (PID2019-104925RB) (AEO/FEDER, UE). Ana Fernández thanks the Ministry of Economy and Competitiveness of Spanish Government for their financial support via the research fellowship RE2020-094029. We also want to thank the fishermen and those responsible for the processing plant for the provision of the data