96 research outputs found

    AgSn[Bi1−xSbx]Se3: Synthesis, Structural Characterization, and Electrical Behavior

    Get PDF
    Herein, we report the synthesis, characterization, and electrical properties of lead-free AgSnm[Bi1−xSbx]Se2+m (m = 1, 2) selenides. Powder X-ray diffraction patterns and Rietveld refinement data revealed that these selenides consisted of phases related to NaCl-type crystal structure. The microstructures and morphologies of the selenides were investigated by backscattered scanning electron microscopy, energy-dispersive X-ray spectroscopy, and high-resolution transmission electron microscopy. The studied AgSnm[Bi1−xSbx]Se2+m systems exhibited typical p-type semiconductor behavior with a carrier concentration of approximately ~+1020 cm−3. The electrical conductivity of AgSnm[Bi1−xSbx]Se2+m decreased from ~3.0 to ~10−3 S·cm−1 at room temperature (RT) with an increase in m from 1 to 2, and the Seebeck coefficient increased almost linearly with increasing temperature. Furthermore, the Seebeck coefficient of AgSn[Bi1−xSbx]Se3 increased from ~+36 to +50 μV·K−1 with increasing Sb content (x) at RT, while its average value determined for AgSn2[Bi1−xSbx]Se4 was approximately ~+4.5 μV·K−1.Depto. de Química InorgánicaFac. de Ciencias QuímicasTRUEpu

    Assessing the Electrochemical Performance of Different Nanostructured CeO2 Samples as Anodes for Lithium-Ion Batteries

    Get PDF
    In this work, six samples of CeO2 are successfully prepared by diverse synthesis routes leading to different microstructures regarding both morphology and particle size. The structural and microstructural characteristics presented by the samples and their influence on the electrochemical response of the prepared anodes are analyzed. In particular, the Ce-CMK3 sample, synthesized from a mesoporous carbon obtained through a CMK3 silica template, displays an enhanced electrochemical response. Thus, capacity values of ~220 mA h g−1 are obtained at a current rate of 0.155 A g−1 after 50 cycles and an excellent cyclability at intermediate current densities. On the other hand, it is observed that the capacity values are satisfactorily recovered at 0.31 A g−1, displaying ~100 mA h g−1 after 550 cycles and efficiencies close to 100%. The electrochemical performance is interpreted considering the microstructural peculiarities of this anode, which are deeply analyzed.Depto. de Química InorgánicaFac. de Ciencias QuímicasTRUEMINECOpu

    Influence of MnO2-Birnessite Microstructure on the Electrochemical Performance of Aqueous Zinc Ion Batteries

    Get PDF
    KxMnO2 materials with birnessite-type structure are synthetized by two different methods which make it possible to obtain manganese oxides with different degrees of crystallinity. The XPS results indicate that the sample obtained at high temperature (KMn8) exhibits a lower oxidation state for manganese ions as well as a denser morphology. Both characteristics could explain the lower capacity value obtained for this electrode. In contrast, the sample obtained at low temperature (KMn4) or by hydrothermal method presents a manganese oxidation state close to 4 and a more porous morphology. Indeed, in this case higher capacity values are obtained. At current density of 30 mA g−1, the KMn8, KMn4, and HKMn samples display a capacity retention of 88, 82, and 68%, respectively. The higher capacity loss obtained for the HKMn compound could be explained considering that the incorporation of Zn2+ in the structure gives rise to the stabilization of a ZnMn2O4 spinel-type phase. This compound is obtained in the discharge process but remains in the charge stage. Thus, when this spinel-type phase is obtained the capacity loss increases. Moreover, the stabilization of this phase is more favorable at low current rates where 100% of retention for all samples, before 50 cycles, was observed

    Type 2 Diabetes-Related Variants Influence the Risk of Developing Prostate Cancer: A Population-Based Case-Control Study and Meta-Analysis

    Get PDF
    This study was supported by grants from the FIBAO foundation (Granada, Spain) and from the Instituto de Salud Carlos III (PI12/02688, PI17/02256 and PI20/01845; Madrid, Spain).In this study, we have evaluated whether 57 genome-wide association studies (GWAS)-identified common variants for type 2 diabetes (T2D) influence the risk of developing prostate cancer (PCa) in a population of 304 Caucasian PCa patients and 686 controls. The association of selected single nucleotide polymorphisms (SNPs) with the risk of PCa was validated through meta-analysis of our data with those from the UKBiobank and FinnGen cohorts, but also previously published genetic studies. We also evaluated whether T2D SNPs associated with PCa risk could influence host immune responses by analysing their correlation with absolute numbers of 91 blood-derived cell populations and circulating levels of 103 immunological proteins and 7 steroid hormones. We also investigated the correlation of the most interesting SNPs with cytokine levels after in vitro stimulation of whole blood, peripheral mononuclear cells (PBMCs), and monocyte-derived macrophages with LPS, PHA, Pam3Cys, and Staphylococcus Aureus. The meta-analysis of our data with those from six large cohorts confirmed that each copy of the FTOrs9939609A, HNF1B(rs7501939T), HNF1B(rs75721T), HNF1B(rs4430796G), and JAZF1(rs10486567A) alleles significantly decreased risk of developing PCa (p = 3.70 x 10(-5), p = 9.39 x 10(-54), p = 5.04 x 10(-54), p = 1.19 x 10(-71), and p = 1.66 x 10(-18), respectively). Although it was not statistically significant after correction for multiple testing, we also found that the NOTCH2(rs10923931T) and RBMS1(rs7593730) SNPs associated with the risk of developing PCa (p = 8.49 x 10(-4) and 0.004). Interestingly, we found that the protective effect attributed to the HFN1B locus could be mediated by the SULT1A1 protein (p = 0.00030), an arylsulfotransferase that catalyzes the sulfate conjugation of many hormones, neurotransmitters, drugs, and xenobiotic compounds. In addition to these results, eQTL analysis revealed that the HNF1B(rs7501939), HNF1B(rs757210), HNF1B(rs4430796), NOTCH2(rs10923931), and RBMS1(rs7593730) SNPs influence the risk of PCa through the modulation of mRNA levels of their respective genes in whole blood and/or liver. These results confirm that functional TD2-related variants influence the risk of developing PCa, but also highlight the need of additional experiments to validate our functional results in a tumoral tissue context.FIBAO foundation (Granada, Spain)Instituto de Salud Carlos III PI12/02688 PI17/02256 PI20/0184

    Zr supported on non-acidic sepiolite for the efficient one-pot transformation of furfural into γ-valerolactone

    Get PDF
    10 figures y 4 tables.-- Supplementary information available.The growing demand of energy needs the search for alternative energy sources different to fossil fuels. The use of biomass as energy source is one of the most studied, because there are high value products that can be produced from biomass. One of these products is γ-valerolactone, that can be obtained from furfural, which is a biomass derived product. To transform furfural into γ-valerolactone is necessary a bifunctional catalyst and a hydrogen source. In this work, γ-valerolactone was obtained from furfural using 2-propanol as solvent and as hydrogen donor on Zr supported on sepiolite catalysts. It was demonstrated that sepiolite, which is a cheap material, can be used to develop efficient catalysts to produce high yields to γ-valerolactone from furfural in one-pot. The catalysts that presented the highest yield to γ-valerolactone were the ones with intermediate Zr-content (9–17 wt% ZrO2). The highest TOFs have been obtained by those catalysts with Zr-loading up to 9 wt% ZrO2, in which the ZrO2 nanoparticles are well dispersed on the support and no formation of large clusters of ZrO2 has been observed. Lewis and Brønsted acid sites are essential in the catalysts to produce the reactions to transform furfural into γ-valerolactone in one-pot, although in the present work, low concentration of Brønsted acid sites were observed in the catalysts. A possible positive role of basic sites to promote some intermediate steps has been also proposed. The catalytic results obtained are in the order of catalysts with Zr supported on zeolitic supports.A.G. thanks MINECO for the pre-doctoral grant (PRE2018-085211). This work was funded by the MAT2017-84118-C2-1-R, MAT2017-84118-C2-2-R, MCIN/AEI/10.13039/501100011033/projects and FEDER Una manera de hacer Europa. Authors thank the electron microscopy CAI center of UCM. Authors also thank the Generalitat Valenciana for CIAICO/2021/094.Peer reviewe

    Material docente con un enfoque práctico dirigido a la caracterización de compuestos inorgánicos

    Get PDF
    Se han elaborado una coleccón de ejercicios utilizando las técnicas de caracterizacion de materiales inorgánicos Además se incluyen un tutorial en el que se dirige al estudiante como es la manera de identificar las bandas caracteristicas de los compuestos, y tambien hay conocimientos generales de EDS. Los ejercicios propuestos tambien se presentan resueltos paso a paso para que se puedan seguir de manera sencilla su desarrollo

    Type 2 Diabetes-Related Variants Influence the Risk of Developing Prostate Cancer:A Population-Based Case-Control Study and Meta-Analysis

    Get PDF
    In this study, we have evaluated whether 57 genome-wide association studies (GWAS)-identified common variants for type 2 diabetes (T2D) influence the risk of developing prostate cancer (PCa) in a population of 304 Caucasian PCa patients and 686 controls. The association of selected single nucleotide polymorphisms (SNPs) with the risk of PCa was validated through meta-analysis of our data with those from the UKBiobank and FinnGen cohorts, but also previously published genetic studies. We also evaluated whether T2D SNPs associated with PCa risk could influence host immune responses by analysing their correlation with absolute numbers of 91 blood-derived cell populations and circulating levels of 103 immunological proteins and 7 steroid hormones. We also investigated the correlation of the most interesting SNPs with cytokine levels after in vitro stimulation of whole blood, peripheral mononuclear cells (PBMCs), and monocyte-derived macrophages with LPS, PHA, Pam3Cys, and Staphylococcus Aureus. The meta-analysis of our data with those from six large cohorts confirmed that each copy of the FTOrs9939609A, HNF1Brs7501939T, HNF1Brs757210T, HNF1Brs4430796G, and JAZF1rs10486567A alleles significantly decreased risk of developing PCa (p = 3.70 × 10−5, p = 9.39 × 10−54, p = 5.04 × 10−54, p = 1.19 × 10−71, and p = 1.66 × 10−18, respectively). Although it was not statistically significant after correction for multiple testing, we also found that the NOTCH2rs10923931T and RBMS1rs7593730 SNPs associated with the risk of developing PCa (p = 8.49 × 10−4 and 0.004). Interestingly, we found that the protective effect attributed to the HFN1B locus could be mediated by the SULT1A1 protein (p = 0.00030), an arylsulfotransferase that catalyzes the sulfate conjugation of many hormones, neurotransmitters, drugs, and xenobiotic com-pounds. In addition to these results, eQTL analysis revealed that the HNF1Brs7501939, HNF1Brs757210, HNF1Brs4430796, NOTCH2rs10923931, and RBMS1rs7593730 SNPs influence the risk of PCa through the modulation of mRNA levels of their respective genes in whole blood and/or liver. These results confirm that functional TD2-related variants influence the risk of developing PCa, but also highlight the need of additional experiments to validate our functional results in a tumoral tissue context

    Optimización de Campus Virtual. Ampliación y ordenación del archivo/repositorio en red bajo el parámetro “estrategias artísticas"

    Get PDF
    Proyecto dedicado a ampliar e introducir un orden en la herramienta realizada en el Proyecto de Innovación y Mejora de la Calidad Docente, PIMCD nº 216, realizado durante el curso 2017-2018, y cuyo título fue: “Optimización de Campus Virtual: archivo/repositorio en red de referencias artísticas desde 1900 hasta la actualidad”. La ordenación se ha realizado mediante el parámetro "estrategias artísticas"
    corecore