933 research outputs found
Atención y procesamiento emocional en personas con trastorno bipolar
Las personas con trastorno bipolar se caracterizan por una desregulación emocional que afecta a cómo atienden a la información que les rodea. Investigaciones recientes han encontrado sesgos atencionales en las personas con trastorno bipolar, tanto cuando su estado de ánimo es bajo (mayor atención a palabras negativas y rostros tristes) como cuando su estado de ánimo es elevado (mayor atención a palabras positivas y caras alegres). Es importante destacar que, en personas con depresión, estos sesgos pueden entrenarse de manera que disminuye la sintomatología afectiva. Esta opción podría contemplarse como una nueva alternativa de intervención en el trastorno bipolar
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
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
Abnormal magnetic behaviour of powder metallurgy austenitic stainless steels sintered in nitrogen
The magnetic response of AISI 304L and AISI 316L obtained through powder metallurgy and sintered in nitrogen were studied. AISI 304L sintered in nitrogen showed a ferromagnetic behaviour in as-sintered state while AISI 316L was paramagnetic. After solution annealing both were paramagnetic. Magnetic behaviour was analysed by using a vibrating sample magnetometer, a magnetic ferritscope and magnetic etching. A microstructural characterization was performed by means of optical metallography, X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive analysis of X-rays (EDS). Some samples when needed were submitted to aged heat treatments at 675 and 875 °C for 90 min, 4, 6, 8 or 48 h. The main microstructural feature found was the presence of a lamellar constituent formed by nitride precipitates and an interlamellar matrix of austenite and/or ferrite. The abnormal magnetic response was explained based on this.Dirección General de Programas y Transferencia de Conocimiento, Ministerio de Ciencia e Innovación, España, MAT2008-0278
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
Attentional biases toward emotional images in the different episodes of bipolar disorder: An eye-tracking study.
Attentional biases toward emotional information may represent vulnerability and maintenance factors in bipolar disorder (BD). The present experimental study examined the processing of emotional information in BD patients using the eyetracking technology. Bipolar patients in their different states (euthymia, mania, depression) simultaneously viewed four pictures with different emotional valence (happy, neutral, sad, threatening for 20 s while their eye movements were monitored. A group of healthy individuals served as the control. The data revealed the following: (i) a decrease in attention to happy images in BD patients in their depressive episodes compared to healthy individuals, and (ii) an increase in attention to threatening images in BD patients (regardless of their episode) relative to the healthy controls. These biases appeared in the late stages of information processing and were sustained over the 20 s interval. Thus, the present findings reveal that attentional biases toward emotional information can be a key feature of BD, in that:(i) an anhedonic lack of sensitivity to positive stimuli during the bipolar depressive episode may be considered a maintaining factor of this clinical state, and (ii) the trait-bias toward threat, even in asymptomatic patients, may reflect a marker of vulnerability in BD
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
Effect of vanadium carbide on dry sliding wear behavior of powder metallurgy AISI M2 high speed steel processed by concentrated solar energy
Mixtures of AISI M2 high speed steel and vanadium carbide (3, 6 or 10 wt.%) were prepared by powder metallurgy and sintered by concentrated solar energy (CSE). Two different powerful solar furnaces were employed to sinter the parts and the results were compared with those obtained by conventional powder metallurgy using a tubular electric furnace. CSE allowed significant reduction of processing times and high heating rates. The wear resistance of compacts was studied by using rotating pin-on-disk and linearly reciprocating ball-on-flat methods. Wear mechanisms were investigated by means of scanning electron microscopy (SEM) observations and chemical inspections of the microstructures of the samples. Better wear properties than those obtained by conventional powder metallurgy were achieved. The refinement of the microstructure and the formation of carbonitrides were the reasons for this.JCCM in the Spanish National Programme (Project PPIC10-0052-5968
Effect of ageing heat treatments on the microstructure and intergranular corrosion of powder metallurgy duplex stainless steels
The influence of ageing heat treatments (675 and 875 °C for 1.5 to 48 h) on the microstructure and intergranular corrosion resistance of sintered in nitrogen duplex stainless steels was investigated. The materials were obtained by sintering mixtures of austenitic AISI 316L and ferritic AISI 430L powders. Corrosion behaviour was evaluated by using electrochemical techniques. The beneficial effect of nitrogen on corrosion behaviour of solution annealed samples was established. During ageing, secondary phases were precipitated and the intergranular and transgranular corrosion resistance significantly decreased though repassivation was observed in specimens aged at 875 °C for times up to 8 h.Ministerio de Ciencia e Innovación, Dirección General de Programas y Transferencia de Conocimiento, Proyectos I+D, MAT2008-0278
Characterization of porous nickel-free austenitic stainless steel prepared by mechanical alloying
Nickel-free austenitic powder metallurgy stainless steels were prepared and characterized. The main issue was to obtain potential biocompatible materials. Mechanical alloying in a nitrogen atmosphere was used to obtain these powders. The main factor to be controlled was the milling time. Powder metallurgy was the technique to obtain massive samples from alloyed powders. Two sintering processes were applied by controlling the sinter-cooling rate (furnace and water-cooling). The sintering atmosphere applied was nitrogen because of its gammagenic effect. Samples made of powders milled for 48 h, sintered in nitrogen and water-cooled showed a clean austenitic microstructure, which is a suitable microstructure for biological applications. A complete microstructural characterization, including optical metallography, image analysis, Scanning Electron Microscopy with X-ray microanalysis, X-Ray diffraction and Vickers hardness and microhardness, was carried out. The electrochemical behaviour in a simulated body fluid, phosphate buffered saline, was also studied. The biocorrosion behaviour was evaluated in terms of anodic polarization measurements.2020-07-102020-07-1
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