An improved descriptor of cluster stability: application to small carbon clusters

Producción CientíficaThe mass spectra of gas-phase clusters in cluster beams have a rich structure where the relative heights of the peaks compared to peaks corresponding to clusters of neighbor sizes reveal the stability of the clusters as a function of the size N. In an analysis of the published mass spectrum of carbon clusters cations C + N with N ≤16 we have employed the most common descriptor of cluster stability, which is based on comparing the total energy of the cluster of size N with the averaged energies of clusters with sizes N+1 and N-1. Those energies have been obtained from density functional calculations. The comparison between the stability function and the mass spectrum leaves some experimental features unexplained; in particular, the correlation with the detailed variation of the height of the mass peaks as a function of size N is not satisfactory. We then propose a novel stability descriptor which improves matters substantially, in particular the correlation with the detailed variation of the height of the mass peaks. The new stability index is based on comparing the atom-evaporation energy of the cluster of size N with the averaged atom-evaporation energies of clusters with sizes N+1 and N-1. The substantial improvement achieved is attributed to the fact that evaporation energies are quantities directly connected with the processes controllig the cluster abundances in the beam.Ministerio de Economía, Industria y Competitividad ( Grants MAT2017-85089-C2-1-R / RYC-2015-17730)Junta de Castilla y Leon (Grant VA021G18)Universidad de Valladolid (Grupo de Física de Nanoestructuras), y Unión Europea a través de ERC-Synergy Program (Grant ERC-2013-SYG610256 NANOCOSMOS

Hydrogen quenches the size effects in carbon clusters

Producción CientíficaA characteristic fingerprint of atomic clusters is that their properties can vary in a non-smooth way with the cluster size N. This is illustrated herein by studying the cluster size dependence of several properties of neutral CN and cationic C+N carbon clusters: C–C bond lengths, cluster structure, intrinsic cluster stability, ionization energy, and spatial distribution of the reactivity index for charge exchange with electrophiles. Nonetheless, clusters can lose the size dependence of their properties by interaction with other chemical species, which is rationalized in this study by analyzing carbon clusters fully saturated with hydrogen to form linear alkanes, CNH2N+2. In all cases, the lowest energy structures are zigzagging linear chains, the variations of C–C bond lengths and Image ID:c9cp01114e-t1.gif angles with alkane size are very minor and smooth, the stability function shows practically no structure as a function of the alkane size, the ionization energies just decrease smoothly with alkane size, and the spatial distribution of the reactivity index is analogous and highly delocalized in all the alkanes. In summary, the interaction of carbon clusters with hydrogen to form alkanes quenches all the size-dependent features that the carbon clusters originally owned. The arrival at the quenching of the size effects follows an involved path. In each CNHn family with fixed N, the values of the properties of the molecules like the ionization potential, the electron affinity, and others show sizable oscillations as the number of hydrogen atoms grows from the pure carbon cluster to the alkane.Ministerio de Economía, Industria y Competitividad ( grants MAT2017-85089-C2-1-R / RYC-2015-17730)Comunidad de Madrid (FotoArt-CM Project P2018/NMT-4367)Junta de Castilla y León (Grant VA021G18)Universidad de Valladolid (GIR Grupo de Física de Nanoestructuras),y Unión Europea mediante el programa ERC-Synergy (Grant ERC-2013-SYG-610256 Nanocosmos

Cardiac electrical defects in progeroid mice and Hutchinson-Gilford progeria syndrome patients with nuclear lamina alterations

Hutchinson–Gilford progeria syndrome (HGPS) is a rare genetic disease caused by defective prelamin A processing, leading to nuclear lamina alterations, severe cardiovascular pathology, and premature death. Prelamin A alterations also occur in physiological aging. It remains unknown how defective prelamin A processing affects the cardiac rhythm. We show age-dependent cardiac repolarization abnormalities in HGPS patients that are also present in the Zmpste24-/- mouse model of HGPS. Challenge of Zmpste24-/- mice with the ß-adrenergic agonist isoproterenol did not trigger ventricular arrhythmia but caused bradycardia-related premature ventricular complexes and slow-rate polymorphic ventricular rhythms during recovery. Patch-clamping in Zmpste24-/- cardiomyocytes revealed prolonged calcium-transient duration and reduced sarcoplasmic reticulum calcium loading and release, consistent with the absence of isoproterenol-induced ventricular arrhythmia. Zmpste24-/- progeroid mice also developed severe fibrosis-unrelated bradycardia and PQ interval and QRS complex prolongation. These conduction defects were accompanied by overt mislocalization of the gap junction protein connexin43 (Cx43). Remarkably, Cx43 mislocalization was also evident in autopsied left ventricle tissue from HGPS patients, suggesting intercellular connectivity alterations at late stages of the disease. The similarities between HGPS patients and progeroid mice reported here strongly suggest that defective cardiac repolarization and cardiomyocyte connectivity are important abnormalities in the HGPS pathogenesis that increase the risk of arrhythmia and premature death.Peer ReviewedPostprint (published version

Hydrogen Chemical Configuration and Thermal Stability in Tungsten Disulfide Nanoparticles Exposed to Hydrogen Plasma

Producción CientíficaThe chemical configuration and interaction mechanism of hydrogen adsorbed in inorganic nanoparticles of WS2 are investigated. Our recent approaches of using hydrogen activated by either microwave or radiofrequency plasma dramatically increased the efficiency of its adsorption on the nanoparticle surface. In the current work we put an emphasis on elucidation of the chemical configuration of the adsorbed hydrogen. This configuration is of primary importance as it affects its adsorption stability and possibility of release. To get insight on the chemical configuration, we combined the experimental analysis methods with theoretical modeling based on the density functional theory (DFT). Micro-Raman spectroscopy was used as a primary tool to elucidate chemical bonding of hydrogen and to distinguish between chemi- and physisorption. Hydrogen adsorbed in molecular form (H2) was clearly identified in all plasma-hydrogenated WS2 nanoparticles samples. It was shown that the adsorbed hydrogen is generally stable under high vacuum conditions at room temperature, which implies its stability at the ambient atmosphere. A DFT model was developed to simulate the adsorption of hydrogen in the WS2 nanoparticles. This model considers various adsorption sites and identifies the preferential locations of the adsorbed hydrogen in several WS2 structures, demonstrating good concordance between theory and experiment and providing tools for optimizing hydrogen exposure conditions and the type of substrate materials.2018-08-08Ministerio de Economía, Industria y Competitividad (Project MAT2014- 54378-R)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Ref. VA050U14

Major inconsistencies of inferred population genetic structure estimated in a large set of domestic horse breeds using microsatellites

STRUCTURE remains the most applied software aimed at recovering the true, but unknown, population structure from microsatellite or other genetic markers. About 30% of structure-based studies could not be reproduced (Molecular Ecology, 21, 2012, 4925). Here we use a large set of data from 2,323 horses from 93 domestic breeds plus the Przewalski horse, typed at 15 microsatellites, to evaluate how program settings impact the estimation of the optimal number of population clusters Kopt that best describe the observed data. Domestic horses are suited as a test case as there is extensive background knowledge on the history of many breeds and extensive phylogenetic analyses. Different methods based on different genetic assumptions and statistical procedures (dapc, flock, PCoA, and structure with different run scenarios) all revealed general, broad-scale breed relationships that largely reflect known breed histories but diverged how they characterized small-scale patterns. structure failed to consistently identify Kopt using the most widespread approach, the ΔK method, despite very large numbers of MCMC iterations (3,000,000) and replicates (100). The interpretation of breed structure over increasing numbers of K, without assuming a Kopt, was consistent with known breed histories. The over-reliance on Kopt should be replaced by a qualitative description of clustering over increasing K, which is scientifically more honest and has the advantage of being much faster and less computer intensive as lower numbers of MCMC iterations and repetitions suffice for stable results. Very large data sets are highly challenging for cluster analyses, especially when populations with complex genetic histories are investigated.info:eu-repo/semantics/publishedVersio

Evaluación de la implementación del programa de Preparación para el Nacimiento en Cataluña: características de las matronas y fidelidad al programa

Objetivo: conocer las características de las matronas y su grado de fidelidad a la metodología, contenidos, actividades y evaluación del programa de Preparación para el Nacimiento (PN) del Departament de Salut de la Generalitat de Catalunya, para la evaluación de su implementación. Método: estudio observacional, descrip-tivo y transversal en 38 unidades de atención a la salud sexual y reproductiva de Cataluña, en el que participaron 334 matronas que dinamizaban grupos de PN. La información se recogió a través de un cuestionario ad hoc y permitió obtener información respecto a variables sociodemográficas, experiencia profesional, formación, conocimiento y utilización del programa, así como variables rela-cionadas con la fidelidad al mismo. Resultados: se envió el cuestionario a 451 matronas y lo respondieron 334 (74,1%). El programa lo conocía el 97,6% de las matronas (n= 325), y el 81,4% (n= 272) lo está utilizando. El 49,4% de las matronas realiza el número de sesiones recomendadas y el 85,3% procura una participación activa de las gestantes, aunque el 51,5% utiliza sesiones expositivas. El 64,1% no puede ajustarse al tiempo establecido para cada sesión, y tan sólo un 11,4% evalúa el programa. Conclusiones: Las matronas que utilizan el programa y tienen más años de experiencia mantienen una mayor fidelidad a los contenidos y metodología. La formación previa a la implantación del programa es clave para su conocimiento y utilización, pero requiere mantenerse en el tiempo. Se ha producido una adaptación al programa y las matronas no lo evalúan sistemáticamente, por lo que debe haber una implicación institucional para su ejecución

Association between serum copper levels and risk of cardiovascular disease: A nested case-control study in the PREDIMED trial

Background and aim: Certain trace elements have been associated with increased cardiovascular risk. The aim of this study was to evaluate the association between serum copper (S-Cu) levels and the risk of a first event of cardiovascular disease (CVD) in a population of older adults with high cardiovascular risk. Methods and results: We conducted a case-control study nested within the PREDIMED trial. During a median follow-up of 4.8 years, a total of 207 incident cases diagnosed with CVD were matched for sex, age, and intervention group with 436 controls. Personal interviews, reviews of medical records, and validated questionnaires were used to assess known CVD risk factors. Biological serum samples were collected annually. Inductively coupled plasma mass spectrometry analysis was used to determine S-Cu levels. Adjusted odds ratios were calculated using multivariate conditional logistic regression models. All participants had S-Cu levels within the reference values, 750 μg/L to 1450 μg/L. Among men, but not among women, the mean S-Cu concentration was higher in cases 1014.1 μg/L than in controls 959.3 μg/L; (p = 0.004). In men, the multivariable-adjusted odds ratio for CVD was 2.36 (95% CI 1.07-5.20 for the comparison of the highest vs. the lowest quartile; p for trend = 0.02), in women, it was 0.43 (95% CI 0.11-1.70; p for trend = 0.165). Conclusion: In older Spanish men with high cardiovascular risk, a significant association was observed between high S-Cu levels, but still within the reference values, and an increased risk of a first event of CVD. Our findings suggest a sex difference in CVD risk and S-Cu levels. To confirm this relationship and to analyze the differences observed between men and women, further studies are needed

Estrategias docentes para la activacion del clima/ambiente en el aula

Los cambios producidos en los últimos años, con los nuevos planes de estudio, han configurado nuevas titulaciones y con ello, vienen asociados nuevos horarios de trabajo en las diferentes asignaturas. Ahora la mayoría de las titulaciones tienen turnos de mañana o de tarde en rangos que comprenden desde las 8.00 de la mañana hasta las 21:30 y donde independientemente de la hora, se le exige al alumno/a una atención activa y una participación que se les mide con bastante constancia, afectando en su rendimiento final. El objetivo de este proyecto es realizar un estudio sobre asignaturas que tiene horarios en franjas horarias de la primera hora de la mañana y/o última de la tarde, ver cómo afecta su motivación y participación en las diferentes actividades docentes, e introducir técnicas alternativas transversales (investigación de acción) que puedan influenciar en su ciclo circadiano para mejorar sus rendimientos

Remdesivir in Very Old Patients (≥80 Years) Hospitalized with COVID-19: Real World Data from the SEMI-COVID-19 Registry

Background: Large cohort studies of patients with COVID-19 treated with remdesivir have reported improved clinical outcomes, but data on older patients are scarce. Objective: This work aims to assess the potential benefit of remdesivir in unvaccinated very old patients hospitalized with COVID-19; (2) Methods: This is a retrospective analysis of patients >= 80 years hospitalized in Spain between 15 July and 31 December 2020 (SEMI-COVID-19 Registry). Differences in 30-day all-cause mortality were adjusted using a multivariable regression analysis. (3) Results: Of the 4331 patients admitted, 1312 (30.3%) were >= 80 years. Very old patients treated with remdesivir (n: 140, 10.7%) had a lower mortality rate than those not treated with remdesivir (OR (95% CI): 0.45 (0.29-0.69)). After multivariable adjustment by age, sex, and variables associated with lower mortality (place of COVID-19 acquisition; degree of dependence; comorbidities; dementia; duration of symptoms; admission qSOFA; chest X-ray; D-dimer; and treatment with corticosteroids, tocilizumab, beta-lactams, macrolides, and high-flow nasal canula oxygen), the use of remdesivir remained associated with a lower 30-day all-cause mortality rate (adjusted OR (95% CI): 0.40 (0.22-0.61) (p < 0.001)). (4) Conclusions: Remdesivir may reduce mortality in very old patients hospitalized with COVID-19

Serum Selenium and Incident Cardiovascular Disease in the PREvención con DIeta MEDiterránea (PREDIMED) Trial: Nested Case-Control Study

Background: Selenium is an essential trace mineral with potential interest for cardiovascular disease (CVD) prevention owing to its antioxidant properties. Epidemiological data on selenium status and CVD remain inconsistent. The objective of this study was to ascertain whether low serum selenium (SSe) concentrations are related to an increased risk of a first CVD event in a population at high cardiovascular risk. Methods: We undertook a case-control study nested within the PREvencion con DIeta MEDiterranea (PREDIMED) trial. A total of 207 participants diagnosed with CVD (myocardial infarction, stroke, or cardiovascular death) during the follow-up period (2003-2010) were matched by sex, age, and intervention group to 436 controls by incidence density sampling. Median time between serum sample collection and subsequent CVD event occurrence was 0.94 years. SSe levels were determined using inductively coupled plasma mass spectrometry analysis. Covariates were assessed through validated questionnaires, in-person interviews, and medical record reviews. Conditional logistic regression was used to calculate multivariable-adjusted odds ratios (ORs). Results: Among women, the mean SSe concentration was lower in cases than in controls (98.5 mu g/L vs. 103.8 mu g/L; p = 0.016). In controls, SSe levels were directly associated with percentage of total energy intake from proteins and fish intake (p for linear trend < 0.001 and 0.049, respectively), whereas SSe concentrations were inversely associated with age, body mass index, and percentage of total energy intake from carbohydrates (p for linear trend < 0.001, 0.008 and 0.016 respectively). In the total group, we observed an inverse dose-response gradient between SSe levels and risk of CVD in the fully-adjusted model (highest vs. lowest quartile: OR = 0.47, 95% CI: 0.27-0.81; ptrend = 0.003). Conclusions: Among elderly individuals at high cardiovascular risk, high SSe concentrations within population reference values are associated with lower first CVD incidence