546 research outputs found

    Enhancing the superconducting transition temperature of BaSi2 by structural tuning

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    We present a joint experimental and theoretical study of the superconducting phase of the layered binary silicide BaSi2. Compared with the layered AlB2 structure of graphite or diboride-like superconductors, in the hexagonal structure of binary silicides the sp3 arrangement of silicon atoms leads to corrugated sheets. Through a high-pressure synthesis procedure we are able to modify the buckling of these sheets, obtaining the enhancement of the superconducting transition temperature from 4 K to 8.7 K when the silicon planes flatten out. By performing ab-initio calculations based on density functional theory we explain how the electronic and phononic properties of the system are strongly affected by changes in the buckling. This mechanism is likely present in other intercalated layered superconductors, opening the way to the tuning of superconductivity through the control of internal structural parameters.Comment: Submitte

    Análisis del grado de difusión de los ODS en las memorias de sostenibilidad orientado a la estrategia de comunicación corporativa

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    [EN] The Sustainable Development Goals (SDGs) are at the heart of the management of public and private enterprises. Organizations have incorporated the SDGs into their business strategy by developing actions that they disseminate in their reports. In the last decade, academic research has paid special attention to this development, publishing a growing number of studies on the subject with the emergence of a specific line of research in the area of sustainability: sustainability reporting. In this context, this paper aims to show a methodology that serves as a tool to analyze the disclosure of SDGs in the sustainability reports. This methodology has three stages. First, a lexicographic analysis of sustainability reports has been carried out, second, a correspondence analysis, and third, outlining through “guided questions” how the information obtained can be useful to analyze SDG communication strategy. For further illustration the methodology has been applied to a company in the Spanish agri-food sector: Ebro Foods. This work has both academic and professional implications by providing a guideline for SDG dissemination analysis in sustainability reports and, on the other hand, by providing the business world with an analysis tool that serves to improve communication strategies in the field of sustainability.[ES] Los Objetivos de Desarrollo Sostenible (ODS) ocupan un lugar central en la gestión de las empresas públicas y privadas. Las organizaciones han incorporado los ODS en su estrategia de negocio desarrollando acciones que difunden en sus memorias. En la última década, la investigación académica ha prestado especial atención a esta realidad publicándose un creciente número de estudios al respecto y apareciendo una línea de investigación específica en el área de la sostenibilidad: sustainability reporting. En este contexto, este trabajo tiene como objetivo presentar una metodología que sirva como herramienta para analizar el grado de difusión de los ODS en las memorias de sostenibilidad. Dicha metodología consta de tres etapas: en primer lugar, un análisis lexicográfico de las memorias de sostenibilidad; en segundo lugar, un análisis de correspondencias y; finalmente, se muestra, en forma de preguntas-guía cómo la información obtenida puede ser de ayuda para la estrategia de comunicación de los ODS. Para ilustrar esta metodología, se ha aplicado en los informes de sostenibilidad del período 2016-2021 en una empresa del sector agroalimentario: Ebro Foods. Este trabajo tiene implicaciones tanto de tipo teórico como práctico, al aportar una pauta de análisis de la difusión de los ODS en las memorias de sostenibilidad y, por otra parte, al facilitar al mundo empresarial una herramienta de análisis que sirva para mejorar las estrategias de comunicación en el ámbito de la sostenibilidad

    Web based hybrid volumetric visualisation of urban GIS data: Integration of 4D Temperature and Wind Fields with LoD-2 CityGML models

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    City models visualisation, buildings, structures and volumetric information, is an important task in Computer Graphics and Urban Planning -- The different formats and data sources involved in the visualisation make the development of applications a big challenge -- We present a homogeneous web visualisation framework using X3DOM and MEDX3DOM for the visualisation of these urban objects -- We present an integration of different declarative data sources, enabling the utilization of advanced visualisation algorithms to render the models -- It has been tested with a city model composed of buildings from the Madrid University Campus, some volumetric datasets coming from Air Quality Models and 2D layers wind datasets -- Results show that the visualisation of all the urban models can be performed in real time on the Web -- An HTML5 web interface is presented to the users, enabling real time modifications of visualisation parameter

    Characters of the Stephanian-Permian Bronchales basin and the tourmalinization associated to calc-alkaline rhyolites (Teruel Province)

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    [Resumen] La turmalinización que afecta a riolitas calco-alcalinas presentes en la fosa transtensional de Bronchales, con edad Autuniense, destaca por el elevado contenido en B (0.87 O/o de promedio). Esta mineralización muestra un enriqueciIl\iento de HREE y un empobrecimiento en LREE debido a que el fluido mineralizante (rico en F) pudo ejercer una función acomplejante para estos elementos y, también, con carácter selectivo, para As, Sn, Sb y Bi.[Abstract] Calc-alkaline rhyolites of Bronchales transtensional basin (Autunian age) are affected by a tourmalinization process. Tourmalinized rhyolites with 0.87 O/o ofboron as average value show As, Sb, Sn and Bi increments over nontourmalinized ones, as well as important enrichments of HREE over LREE possibly because tourmalinization fluids were enriched in complexing agents (i.e .F)

    Differential gene expression profile in omental adipose tissue in women with polycystic ovary syndrome

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    10 pages, 2 figures, 5 tables.CONTEXT: The polycystic ovary syndrome (PCOS) is frequently associated with visceral obesity, suggesting that omental adipose tissue might play an important role in the pathogenesis of the syndrome. OBJECTIVE: The objective was to study the expression profiles of omental fat biopsy samples obtained from morbidly obese women with or without PCOS at the time of bariatric surgery. DESIGN: This was a case-control study. SETTINGS: We conducted the study in an academic hospital. PATIENTS: Eight PCOS patients and seven nonhyperandrogenic women submitted to bariatric surgery because of morbid obesity. INTERVENTIONS: Biopsy samples of omental fat were obtained during bariatric surgery. MAIN OUTCOME MEASURE: The main outcome measure was high-density oligonucleotide arrays. RESULTS: After statistical analysis, we identified changes in the expression patterns of 63 genes between PCOS and control samples. Gene classification was assessed through data mining of Gene Ontology annotations and cluster analysis of dysregulated genes between both groups. These methods highlighted abnormal expression of genes encoding certain components of several biological pathways related to insulin signaling and Wnt signaling, oxidative stress, inflammation, immune function, and lipid metabolism, as well as other genes previously related to PCOS or to the metabolic syndrome. CONCLUSION: The differences in the gene expression profiles in visceral adipose tissue of PCOS patients compared with nonhyperandrogenic women involve multiple genes related to several biological pathways, suggesting that the involvement of abdominal obesity in the pathogenesis of PCOS is more ample than previously thought and is not restricted to the induction of insulin resistance.This work was supported by PI020578, PI020741, PI050341, PI050551, RCMN C03/08, and RGDM 03/212 from Fondo de Investigación Sanitaria, Instituto de Salud Carlos III, and Grants 08.6/0021/2003 and GR/SAL/0137/2004 from the Consejería de Educación y Cultura, Comunidad de Madrid, Spain.Peer reviewe

    Polypharmacy Patterns: Unravelling Systematic Associations between Prescribed Medications

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    Objectives: The aim of this study was to demonstrate the existence of systematic associations in drug prescription that lead to the establishment of patterns of polypharmacy, and the clinical interpretation of the associations found in each pattern. Methods: A cross-sectional study was conducted based on information obtained from electronic medical records and the primary care pharmacy database in 2008. An exploratory factor analysis of drug dispensing information regarding 79,089 adult patients was performed to identify the patterns of polypharmacy. The analysis was stratified by age and sex. Results: Seven patterns of polypharmacy were identified, which may be classified depending on the type of disease they are intended to treat: cardiovascular, depression-anxiety, acute respiratory infection (ARI), chronic obstructive pulmonary disease (COPD), rhinitis-asthma, pain, and menopause. Some of these patterns revealed a clear clinical consistency and included drugs that are prescribed together for the same clinical indication (i.e., ARI and COPD patterns). Other patterns were more complex but also clinically consistent: in the cardiovascular pattern, drugs for the treatment of known risk factors—such as hypertension or dyslipidemia—were combined with other medications for the treatment of diabetes or established cardiovascular pathology (e.g., antiplatelet agents). Almost all of the patterns included drugs for preventing or treating potential side effects of other drugs in the same pattern. Conclusions: The present study demonstrated the existence of non-random associations in drug prescription, resulting in patterns of polypharmacy that are sound from the pharmacological and clinical viewpoints and that exist in a significant proportion of the population. This finding necessitates future longitudinal studies to confirm some of the proposed causal associations. The information discovered would further the development and/or adaptation of clinical patient guidelines to patients with multimorbidity who are taking multiple drugs

    Catalytically Active Imine-based Covalent Organic Frameworks for Detoxification of Nerve Agent Simulants in Aqueous Media

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    A series of imine-based covalent organic frameworks decorated in their cavities with di erent alkynyl, pyrrolidine, and N-methylpyrrolidine functional groups have been synthetized. These materials exhibit catalytic activity in aqueous media for the hydrolytic detoxification of nerve agents, as exemplified with nerve gas simulant diisopropylfluorophosphate (DIFP). These preliminary results suggest imine-based covalent organic frameworks (COFs) as promising materials for detoxification of highly toxic molecules.MINECO (MAT2016-77608-C3-1-P and 2-P, CTQ2017-84692-R) and EU FEDER fundin

    Expansion of different subpopulations of CD26 −/low T cells in allergic and non-allergic asthmatics

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    CD26 displays variable levels between effector (TH ≫ TH > TH > Treg) and naïve/memory (memory > naïve) CD4 T lymphocytes. Besides, IL-6/IL 6R is associated with TH -differentiation and asthma severity. Allergic/atopic asthma (AA) is dominated by TH responses, while TH immunity might either modulate the TH -dependent inflammation in AA or be an important mechanism boosting non-allergic asthma (NAA). Therefore, in this work we have compared the expression of CD26 and CD126 (IL-6Rα) in lymphocytes from different groups of donors: allergic (AA) and non-allergic (NAA) asthma, rhinitis, and healthy subjects. For this purpose, flow cytometry, haematological/biochemical, and in vitro proliferation assays were performed. Our results show a strong CD26-CD126 correlation and an over-representation of CD26 subsets with a highly-differentiated effector phenotype in AA (CD4 CD26 T cells) and NAA (CD4 CD26 γδ-T cells). In addition, we found that circulating levels of CD26 (sCD26) were reduced in both AA and NAA, while loss of CD126 expression on different leukocytes correlated with higher disease severity. Finally, selective inhibition of CD26-mRNA translation led to enhanced T cell proliferation in vitro. These findings support that CD26 down-modulation could play a role in facilitating the expansion of highly-differentiated effector T cell subsets in asthma

    Internal friction associated with ε martensite in shape memory steels produced by casting route and through additive manufacturing: Influence of thermal cycling on the martensitic transformation

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    Among the different families of shape memory alloys (SMA), the Fe-Mn-Si-Cr-Ni alloys have attracted a renewed interest because of its low cost, high corrosion resistance and high recovery strength during the shape memory effect, and the new technologies of additive manufacturing offer unforeseen possibilities for this family of SMA. In the present work, the reversible gamma - epsilon martensitic transformation (MT), responsible for the shape memory effect, is studied in two Fe-Mn-Si-Cr-Ni alloys with high (20.2 wt%) and low (15.8 wt%) Mn content, produced by the conventional route of casting and rolling, in comparison with the MT in another similar alloy, with intermediate Mn content (19.4 wt%), which was produced by gas atomization and additive manufacturing through laser metal deposition. The forward and reverse gamma - epsilon MT is studied by mechanical spectroscopy through the internal friction spectra and the dynamic modulus variation, together with a parallel microstructural characterization including in-situ observation of the gamma - epsilon MT during cooling and heating at the scanning electron microscope. The evolution of the transformed fraction of epsilon martensite, evaluated through the integral area of the internal friction peak, was followed along thermal cycling in all three alloys. Both, the internal friction and the electron microscopy studies show that the epsilon martensite amount increases very fast during the first few cycles, and then decreases with a tendency towards its stabilization for many tens of cycles. The results show that the gamma - epsilon MT is more stable on cycling in the additive manufactured sample than in the conventionally processed samples, opening new avenues for designing shape memory steels to be specifically processed through additive manufacturing.This work was supported by the ELKARTEK-CEMAP (KK-2020/00047) project from the Industry Department of the Basque Government, and the GIU-17/071 from the University of the Basque Country, UPV/EHU. This work made use of the SGIKER facilities at the UPV/EHU

    Methylation status of Wnt signaling pathway genes affects the clinical outcome of Philadelphia-positive acute lymphoblastic leukemia

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    The clinical significance of aberrant promoter methylation of the canonical Wnt pathway antagonist genes (sFRP1, sFRP2, sFRP4, sFRP5, Wif1, Dkk3, and Hdpr1) and also putative tumor-suppressor gene Wnt5a, belonging to the non-canonical Wnt signaling pathway, was investigated in a large series of 75 patients with Philadelphia chromosome-positive acute lymphoblastic leukemia by methylationspecific polymerase chain reaction. At least one methylated gene was observed in cells from 66% (49/75) of patients (methylated group). Disease-free survival and overall survival at 9 years were 51 and 40%, respectively, for the unmethylated group and 3 and 2%, respectively, for the methylated group (both P < 0.0001). Multivariate analysis demonstrated that the Wnt methylation profile was an independent prognostic factor predicting disease-free survival (P = 0.007) and overall survival (P = 0.039). Abnormal DNA methylation of promoter-associated CpG islands in the Wnt signaling pathway is very common in Philadelphia chromosome-positive acute lymphoblastic leukemia and potentially defines subgroups with distinct clinical characteristics
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