Oxidation of CO and methanol on Pd-Ni catalysts supported on different chemically-treated carbon nanofibers

In this work, palladium-nickel nanoparticles supported on carbon nanofibers were synthesized, with metal contents close to 25 wt % and Pd:Ni atomic ratios near to 1:2. These catalysts were previously studied in order to determine their activity toward the oxygen reduction reaction. Before the deposition of metals, the carbon nanofibers were chemically treated in order to generateoxygen and nitrogen groups on their surface. Transmission electron microscopy analysis (TEM) images revealed particle diameters between 3 and 4 nm, overcoming the sizes observed for thenanoparticles supported on carbon black (catalyst Pd-Ni CB 1:2). From the CO oxidation at different temperatures, the activation energy Eact for this reaction was determined. These values indicated a high tolerance of the catalysts toward the CO poisoning, especially in the case of the catalystssupported on the non-chemically treated carbon nanofibers. On the other hand, apparent activation energy Eap for the methanol oxidation was also determined finding—as a rate determining step—the COads diffusion to the OHads for the catalysts supported on carbon nanofibers. The results here presented showed that the surface functional groups only play a role in the obtaining of lower particlesizes, which is an important factor in the obtaining of low CO oxidation activation energies

Long-term immune response accompanies clinical outcomes in severe asthmatics treated with anti-IL-5/IL-5R biologics

This work was supported by ISCIII - Instituto de Salud Carlos III, FIS (Fondo de Investigación Sanitaria - Spanish Health Research Fund) grants PI21/00896 and FI19/00067; Ciber de Enfermedades Respiratorias (CIBERES); SEAIC grants 22A07; BASEAS STUDY (Basophils in EosinophilicAsthma) Study Code ESR-20-20764 AstraZeneca International; Comunidad de Madrid grant PEJ2021-AI_BMD-22320 and FEDER funds (Fondo Europeo de Desarrollo Regiona

Nanoestructuras de carbono nitrogenadas para pilas de combustible de electrolito polimérico.

El reto de la descarbonización de la economía se ha encontrado con un hándicap añadido, como es la pandemia COVID-19, que va a condicionar una agenda ya de por sí comprometida y de difícil gestión para gobiernos, instituciones, empresas e incluso ciudadanos. En cambio, la gestión de esta crisis económica derivada de la alarma sanitaria podría utilizarse como palanca y motor del cambio para introducir con mayor diligencia la tan necesaria transición hacia el empleo de energías limpias y sostenibles en sustitución de los combustibles fósiles en los sectores de transporte y de generación de electricidad. Dentro de este escenario, el hidrógeno es un vector energético limpio y versátil, por lo que su aplicación en pilas de combustible supone una apuesta segura en la industria automovilística, ya que garantiza el objetivo de cero emisiones y presenta mejores prestaciones en términos de autonomía y tiempos de carga. En este contexto, el trabajo principal de esta Tesis Doctoral se ha basado en el estudio de catalizadores para su utilización en pilas de combustible, con el objetivo de reducir la cantidad de metal noble necesaria y, por tanto, la reducción de sus costes, manteniendo un alto rendimiento. Concretamente, la investigación se ha centrado en la modificación con grupos nitrogenados de materiales carbonosos que se utilizan como soporte, para mejorar sus características y analizar cómo influyen en el comportamiento de los catalizadores, buscando así reducir o incluso eliminar la cantidad de metal noble requerida.Para ello, se han sintetizado y caracterizado materiales de carbono de diferente naturaleza como son las nanofibras de carbono, los xerogeles de carbono y los materiales mesoporosos ordenados, y se han comparado con un negro de carbono comercial, Vulcan XC 72R. Se han aplicado diferentes técnicas de modificación con nitrógeno para cada uno de estos materiales, observándose que con aquellas en las que los grupos nitrogenados se introducían durante la síntesis de dichos materiales, se obtenían materiales carbonosos dopados con mayor cantidad de grupos nitrogenados que con los tratamientos de modificación después de la obtención del material. Asimismo, se ha realizado la caracterización fisicoquímica de los materiales carbonosos dopados con nitrógeno y se han estudiado electroquímicamente como catalizadores sin metal para analizar la influencia de los grupos nitrogenados en la reacción de reducción de oxígeno en medio básico. La mejor actividad se ha obtenido para los materiales mesoporosos ordenados dopados con N, que han sido, a su vez, los de mayor contenido en N. Finalmente, los materiales carbonosos con nitrógeno se han utilizado como soporte de catalizadores de Pt y de PtRu para su investigación en las reacciones de reducción de oxígeno y de oxidación de metanol, respectivamente. En este caso, el estudio ha comprendido tanto medio básico como medio ácido. De este modo, se ha analizado la influencia del dopado en la síntesis de dichos catalizadores, en la interacción del soporte-metal, así como en su actividad electroquímica en función del medio de reacción. En cuanto a los catalizadores de Pt, los catalizadores que presentan mayor actividad son los soportados sobre los materiales mesoporosos ordenados dopados con nitrógeno, debido a que los grupos nitrogenados han creado defectos que mejoran la interacción del electrolito con el catalizador. En cambio, en los catalizadores de PtRu, los que han presentado la actividad más elevada son los soportados sobre nanofibras de carbono y Vulcan XC 72R porque son los que se envenenan más lentamente por la formación de especies intermedias de reacción.<br /

Serum micrornas as tool to predict early response to benralizumab in severe eosinophilic asthma

Severe eosinophilic asthma poses a serious health and economic problem, so new therapy approaches have been developed to control it, including biological drugs such as benralizumab, which is a monoclonal antibody that binds to IL-5 receptor alpha subunit and depletes peripheral blood eosinophils rapidly. Biomarkers that predict the response to this drug are needed so that microRNAs (miRNAs) can be useful tools. This study was performed with fifteen severe eosinophilic asthmatic patients treated with benralizumab, and serum miRNAs were evaluated before and after treatment by semi-quantitative PCR (qPCR). Patients showed a clinical improvement after benralizumab administration. Additionally, deregulation of miR-1246, miR-5100 and miR-338-3p was observed in severe asthmatic patients after eight weeks of therapy, and a correlation was found between miR-1246 and eosinophil counts, including a number of exacerbations per year in these severe asthmatics. In silico pathway analysis revealed that these three miRNAs are regulators of the MAPK signaling pathway, regulating target genes implicated in asthma such as NFKB2, NFATC3, DUSP1, DUSP2, DUSP5 and DUSP16. In this study, we observed an altered expression of miR-1246, miR-5100 and miR-338-3p after eight weeks of benralizumab administration, which could be used as early response markers.This manuscript was funded by Fondo de Investigación Sanitaria–FIS and FEDER (Fondo Europeo de Desarrollo Regional) [PI15/00803, PI18/00044, and FI16/00036], CIBER de Enfermedades Respiratorias (CIBERES), Merck Health Foundation funds, and Ministerio de Ciencia, Innovación y Universidades (RTC-2017-6501-1

Clustering COVID-19 ARDS patients through the first days of ICU admission. An analysis of the CIBERESUCICOVID Cohort

Background Acute respiratory distress syndrome (ARDS) can be classified into sub-phenotypes according to different inflammatory/clinical status. Prognostic enrichment was achieved by grouping patients into hypoinflammatory or hyperinflammatory sub-phenotypes, even though the time of analysis may change the classification according to treatment response or disease evolution. We aimed to evaluate when patients can be clustered in more than 1 group, and how they may change the clustering of patients using data of baseline or day 3, and the prognosis of patients according to their evolution by changing or not the cluster.Methods Multicenter, observational prospective, and retrospective study of patients admitted due to ARDS related to COVID-19 infection in Spain. Patients were grouped according to a clustering mixed-type data algorithm (k-prototypes) using continuous and categorical readily available variables at baseline and day 3.Results Of 6205 patients, 3743 (60%) were included in the study. According to silhouette analysis, patients were grouped in two clusters. At baseline, 1402 (37%) patients were included in cluster 1 and 2341(63%) in cluster 2. On day 3, 1557(42%) patients were included in cluster 1 and 2086 (57%) in cluster 2. The patients included in cluster 2 were older and more frequently hypertensive and had a higher prevalence of shock, organ dysfunction, inflammatory biomarkers, and worst respiratory indexes at both time points. The 90-day mortality was higher in cluster 2 at both clustering processes (43.8% [n = 1025] versus 27.3% [n = 383] at baseline, and 49% [n = 1023] versus 20.6% [n = 321] on day 3). Four hundred and fifty-eight (33%) patients clustered in the first group were clustered in the second group on day 3. In contrast, 638 (27%) patients clustered in the second group were clustered in the first group on day 3.Conclusions During the first days, patients can be clustered into two groups and the process of clustering patients may change as they continue to evolve. This means that despite a vast majority of patients remaining in the same cluster, a minority reaching 33% of patients analyzed may be re-categorized into different clusters based on their progress. Such changes can significantly impact their prognosis

Enteric methane mitigation strategies for ruminant livestock systems in the Latin America and Caribbean region: a meta-analysis.

Latin America and Caribbean (LAC) is a developing region characterized for its importance for global food security, producing 23 and 11% of the global beef and milk production, respectively. The region?s ruminant livestock sector however, is under scrutiny on environmental grounds due to its large contribution to enteric methane (CH4) emissions and influence on global climate change. Thus, the identification of effective CH4 mitigation strategies which do not compromise animal performance is urgently needed, especially in context of the Sustainable Development Goals (SDG) defined in the Paris Agreement of the United Nations. Therefore, the objectives of the current study were to: 1) collate a database of individual sheep, beef and dairy cattle records from enteric CH4 emission studies conducted in the LAC region, and 2) perform a meta-analysis to identify feasible enteric CH4 mitigation strategies, which do not compromise animal performance. After outlier?s removal, 2745 animal records (65% of the original data) from 103 studies were retained (from 2011 to 2021) in the LAC database. Potential mitigation strategies were classified into three main categories (i.e., animal breeding, dietary, and rumen manipulation) and up to three subcategories, totaling 34 evaluated strategies. A random effects model weighted by inverse variance was used (Comprehensive Meta-Analysis V3.3.070). Six strategies decreased at least one enteric CH4 metric and simultaneously increased milk yield (MY; dairy cattle) or average daily gain (ADG; beef cattle and sheep). The breed composition F1 Holstein × Gyr decreased CH4 emission per MY (CH4IMilk) while increasing MY by 99%. Adequate strategies of grazing management under continuous and rotational stocking decreased CH4 emission per ADG (CH4IGain) by 22 and 35%, while increasing ADG by 22 and 71%, respectively. Increased dietary protein concentration, and increased concentrate level through cottonseed meal inclusion, decreased CH4IMilk and CH4IGain by 10 and 20% and increased MY and ADG by 12 and 31%, respectively. Lastly, increased feeding level decreased CH4IGain by 37%, while increasing ADG by 171%. The identified effective mitigation strategies can be adopted by livestock producers according to their specific needs and aid LAC countries in achieving SDG as defined in the Paris Agreement

Oxidation of CO and Methanol on Pd-Ni Catalysts Supported on Different Chemically-Treated Carbon Nanofibers

In this work, palladium-nickel nanoparticles supported on carbon nanofibers were synthesized, with metal contents close to 25 wt % and Pd:Ni atomic ratios near to 1:2. These catalysts were previously studied in order to determine their activity toward the oxygen reduction reaction. Before the deposition of metals, the carbon nanofibers were chemically treated in order to generateoxygen and nitrogen groups on their surface. Transmission electron microscopy analysis (TEM) images revealed particle diameters between 3 and 4 nm, overcoming the sizes observed for thenanoparticles supported on carbon black (catalyst Pd-Ni CB 1:2). From the CO oxidation at different temperatures, the activation energy Eact for this reaction was determined. These values indicated a high tolerance of the catalysts toward the CO poisoning, especially in the case of the catalystssupported on the non-chemically treated carbon nanofibers. On the other hand, apparent activation energy Eap for the methanol oxidation was also determined finding—as a rate determining step—the COads diffusion to the OHads for the catalysts supported on carbon nanofibers. The results here presented showed that the surface functional groups only play a role in the obtaining of lower particlesizes, which is an important factor in the obtaining of low CO oxidation activation energies