80 research outputs found

    Organización de Centros Educativos en la Sociedad del Conocimiento [Reseña]

    Get PDF
    Recensión de Cantón, I. y Pino, M. (coords.) (2014). Organización de Centros Educativos en la Sociedad del Conocimiento. Madrid: Alianza, 316 pp

    Reaction pathways in the solid state synthesis of multiferroic BiFeO 3

    Get PDF
    The obtaining of multiferroicBiFeO3 as a pure single-phase product is particularly complex since the formation of secondary phases seems to be unavoidable. The process by which these secondary impurities are formed is studied by analyzing the diffusion and solidstate reactivity of the Bi2O3–Fe2O3 system. Experimental evidence is reported which indicates that the progressive diffusion of Bi3+ ions into the Fe2O3 particles governs the solidstatesynthesis of the perovskite BiFeO3 phase. However a competition is established between the diffusion process which tends to complete the formation of BiFeO3, and the crystallization of stable Bi2Fe4O9 mullite crystals, which tend to block that formation reaction

    Influencia de la segregación de Ti4+ en la respuesta multiferroica de materiales basados en BiFeO3

    Get PDF
    Los materiales multiferroicos han cobrado un interés creciente en los últimos años dada la potencialidad de sus aplicaciones prácticas. Los materiales basados en BiFeO3 pueden considerarse los más estudiados hasta la fecha dentro de los pocos multiferroicos conocidos. No obstante, sus propiedades aún no son adecuadas para su empleo en dispositivos pues suelen presentar una elevada conductividad eléctrica y/o una respuesta antiferromagnética. La modificación de estos materiales mediante dopado con Ti4+ puede disminuir las pérdidas dieléctricas y proporcionar un comportamiento ferromagnético. Sin embargo, los cambios producidos en la estructura, microestructura y propiedades de los materiales de BiFeO3 como consecuencia del dopado con Titanio no están claros. En este trabajo se presenta una caracterización detallada de cerámicas de composición nominal BiFe0.95Ti0.05O3 con una elevada resistencia y una respuesta magnética extraordinaria. Los resultados evidencian la formación de una nanoestructura relacionada con la segregación del dopante en borde de grano que es la responsable de los cambios producidos en las propiedades magnetoeléctricas de estos materiales

    Experimental phase function and degree of linear polarization curve of olivine and spinel and the origin of the Barbarian polarization behaviour

    Get PDF
    We explore experimentally possible explanations of the polarization curves of the sunlight reflected by the Barbarian asteroids. Their peculiar polarization curves are characterized by a large-inversion angle, around 30 degrees, which could be related to the presence of FeO-bearing spinel embedded in Calcium-Aluminum inclusions. In order to test this hypothesis, we have measured the phase function and degree of linear polarization of six samples of Mg-rich olivine and spinel. For each material, we have analysed the light scattering properties of a millimeter-sized grain and of two powdered samples with size distributions in the micrometer size range. The three spinel samples show a well-defined negative polarization branch with an inversion phase angle located around 24 degrees-30 degrees. In contrast, in the case of the olivine samples, the inversion angle is highly dependent on particle size and tends to decrease for larger sizes. We identify the macroscopic geometries as a possible explanation for the evident differences in the polarization curves between olivine and spinel millimeter samples. Although the polarization behaviour in near backscattering of the Barbara asteroid is similar to that of our spinel mm-sized sample in random orientation, this similarity could result in part from crystal retro-reflection rather than composition. This is part of an ongoing experimental project devoted to test separately several components of CV3-like meteorites, representative of the Barbarians composition, to disentangle their contributions to the polarization behaviour of these objects.Peer reviewe

    Predictive model to identify multiple failure to biological therapy in patients with rheumatoid arthritis

    Full text link
    Despite advances in the treatment of rheumatoid arthritis (RA) and the wide range of therapies available, there is a percentage of patients whose treatment presents a challenge for clinicians due to lack of response to multiple biologic and target-specific disease-modifying antirheumatic drugs (b/tsDMARDs).To develop and validate an algorithm to predict multiple failure to biological therapy in patients with RA.Observational retrospective study involving subjects from a cohort of patients with RA receiving b/tsDMARDs.Based on the number of prior failures to b/tsDMARDs, patients were classified as either multi-refractory (MR) or non-refractory (NR). Patient characteristics were considered in the statistical analysis to design the predictive model, selecting those variables with a predictive capability. A decision algorithm known as 'classification and regression tree' (CART) was developed to create a prediction model of multi-drug resistance. Performance of the prediction algorithm was evaluated in an external independent cohort using area under the curve (AUC).A total of 136 patients were included: 51 MR and 85 NR. The CART model was able to predict multiple failures to b/tsDMARDs using disease activity score-28 (DAS-28) values at 6 months after the start time of the initial b/tsDMARD, as well as DAS-28 improvement in the first 6 months and baseline DAS-28. The CART model showed a capability to correctly classify 94.1% NR and 87.5% MR patients with a sensitivity = 0.88, a specificity = 0.94, and an AUC = 0.89 (95% CI: 0.74-1.00). In the external validation cohort, 35 MR and 47 NR patients were included. The AUC value for the CART model in this cohort was 0.82 (95% CI: 0.73-0.9).Our model correctly classified NR and MR patients based on simple measurements available in routine clinical practice, which provides the possibility to characterize and individualize patient treatments during early stages.© The Author(s), 2022

    Improved classification of rheumatoid arthritis with a score including anti‑acetylated ornithine antibodies

    Get PDF
    The presence of rheumatoid factor (RF) or anti-cyclic citrullinated peptide (anti-CCP) autoantibodies contributes to the current rheumatoid arthritis (RA) classification criteria. These criteria involve stratification on antibody levels, which limits reproducibility, and underperform in the RA patients without RF and anti-CCP. Here, we have explored if two anti-acetylated peptide antibodies (AAPA), anti-acetylated lysine (AcLys) and anti-acetylated ornithine (AcOrn), could improve the performance of the current criteria. The analysis was done in 1062 prospectively-followed early arthritis (EA) patients. The anti-AcOrn were more informative than the anti-AcLys, the conventional RA antibodies and the anti-carbamylated protein antibodies. The anti-AcOrn produced a classification that did not require antibody levels and showed improved specificity (77.6% vs. 72.6%, p = 0.003) and accuracy (79.0% vs. 75.8%, p = 0.002) over the current criteria. These improvements were obtained with a scoring system that values concordance between anti-AcOrn, RF and anti-CCP. No significant gain was obtained in sensitivity (80.2% vs. 78.8%, p = 0.25) or in improving the classification of the RA patients lacking RF and anti-CCP, although the anti-AcOrn ranked first among the analysed new antibodies. Therefore, the anti-AcOrn antibodies could contribute to the improvement of RA classification criteria by exploiting antibody concordance.This work was supported by the Instituto de Salud Carlos III (Spain) through grants [RD16/0012/0014 and PI17/01606 to AG; RD16/0012/0012 to AB; PI14/00442 and RD16/0012/0011 to IG-A]. These grants are partially financed by the European Regional Development Fund of the EU (FEDER). LRM was supported by Xunta de Galicia (Spain) through a Gain pre-doctoral fellowship. CR was supported by Ministerio de Educacion Cultura y Deporte (Spain) through a FPU pre-doctoral fellowship [FPU15/03434]

    Efficacy, Safety and Cost-Effectiveness of Methotrexate, Adalimumab or Their Combination in Non-infectious Non-anterior Uveitis: A Protocol for a Multicentre, Randomised, Parallel Three Arms, Active-Controlled, Phase III Open Label With Blinded Outcome Assessment Study

    Get PDF
    [Abstract] Introduction: Non-infectious uveitis include a heterogeneous group of sight-threatening and incapacitating conditions. Their correct management sometimes requires the use of immunosuppressive drugs (ISDs), prescribed in monotherapy or in combination. Several observational studies showed that the use of ISDs in combination could be more effective than and as safe as their use in monotherapy. However, a direct comparison between these two treatment strategies has not been carried out yet. Methods and analysis: The Combination THerapy with mEthotrexate and adalImumAb for uveitis (CoTHEIA) study is a phase III, multicentre, prospective, randomised, single-blinded with masked outcome assessment, parallel three arms with 1:1:1 allocation, active-controlled, superiority study design, comparing the efficacy, safety and cost-effectiveness of methotrexate, adalimumab or their combination in non-infectious non-anterior uveitis. We aim to recruit 192 subjects. The duration of the treatment and follow-up will last up to 52 weeks, plus 70 days follow-up with no treatment. The complete and maintained resolution of the ocular inflammation will be assessed by masked evaluators (primary outcome). In addition to other secondary measurements of efficacy (quality of life, visual acuity and costs) and safety, we will identify subjects’ subgroups with different treatment responses by developing prediction models based on machine learning techniques using genetic and proteomic biomarkers. Ethics and dissemination: The protocol, annexes and informed consent forms were approved by the Reference Clinical Research Ethic Committee at the Hospital Clínico San Carlos (Madrid, Spain) and the Spanish Agency for Medicines and Health Products. We will elaborate a dissemination plan including production of materials adapted to several formats to communicate the clinical trial progress and findings to a broad group of stakeholders. The promoter will be the only access to the participant-level data, although it can be shared within the legal situation. Trial registration number: 2020-000130-18; NCT04798755.This work was supported by the Instituto de Salud Carlos III, grant number [ICI19/00020]. Sponsor: Fundación para la Investigacion Biomédica del Hospital Clínico San Carlos. Executive Committee: Administrative and executive arm of the clinical trial, providing overall oversight for the study and making decisions on day-to-day operational issues (Study Coordinator (Luis Rodriguez-Rodriguez), a representative from the Spanish Clinical Trial Network (Amanda López Picado), and 5 Site Directors (these seats will be rotatory, with changes every 6 months months)); Data Coordinating and Analysis Committee: Supervising data collection,management and quality control, designing the statistical analysis plan, performing unmasked data analysis and preparing interim and final reports for the Data Security Monitoring Board and the Executy Committee (Study Coordinator (Luis Rodriguez-Rodriguez), a representative from the Spanish Clinical Trial Network (Amanda López Picado) and Ester Carreño); Biobank and Biomarker Identification Committee (Maintaining an up-to-date manual of operations for blood extraction, processing and storage, and monitoring procedures adherence, supervising biological sample collection, sample shipment coordination, coordinating the phamacogenetic and proteomic analysis (Study Coordinator (Luis Rodriguez-Rodriguez), a representative from the Instituto de Salud Carlos III Biobank Platform (Elena Molino), a representative the Instituto de Investigación Biomédica de A Coruña, a representative from, the Data Coordinating and Analysis Committee); Data Security Monitoring Committee (PierGiogio Neri, Andrew Dick, Loreto Carmona

    Potential relation of cardiovascular risk factors to disease activity in patients with axial spondyloarthritis

    Get PDF
    Background: Axial spondyloarthritis (axSpA) patients are known to have a higher prevalence of several comorbidities, including, among others, an increased risk of atherosclerosis, hypertension, dyslipidemia, and diabetes. The purpose of the present study was to determine whether the sum of traditional cardiovascular (CV) risk factors is related to disease characteristics, such as disease activity, in patients with axSpA. Methods: A cross-sectional study that encompassed 804 patients with axSpA was conducted. Patients were assessed for the presence of five traditional CV risk factors (diabetes mellitus, dyslipidemia, hypertension, obesity, and smoking status), and disease activity measurements. A multivariable regression analysis was performed to evaluate whether the number of classic CV risk factors was independently associated with specific features of the disease, to include disease activity. Results: A multivariable analysis showed that Ankylosing Spondylitis Disease Activity Score-C reactive protein (ASDAS-CRP) activity score was significantly higher in patients with 1 [beta coefficient 0.3 (95% confidence interval (CI) 0.1-0.5), p = 0.001] and ?2 [beta coefficient 0.5 (95% CI 0.3-0.7), p = 0.000] CV risk factors compared with those without CV risk factors. Similarly, patients with 1 [OR 2.00 (95%CI 0.99-4.02), p = 0.053] and ?2 [OR 3.39 (95%CI 1.82-6.31), p = 0.000] CV risk factors had a higher odds ratio for the presence of high disease activity compared with the zero CV category. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) activity score was significantly associated with the number of CV risk factors, being higher in patients with more CV risk factors. These relationships showed a CV risk factor-dependent effect being beta coefficients and ORs higher for the effect of ?2 over 1 CV risk factor. Conclusion: Among patients with axSpA, as the number of traditional CV risk factors increased, disease activity similarly increases in an independent manner.Funding: The authors disclosed receipt of the following financial support for the research, authorship, and/ or publication of this article: This research was funded by a grant to MAG-G from the Instituto de Salud Carlos III (ISCIII) (Fondo de Investigación Sanitaria grants PI06/0024, PI09/00748, PI12/00060, PI15/00525, PI18/00043) and the ISCIII RETICS programs (RD12/0009 and RD16/0012)

    Challenges of neural interfaces for stroke motor rehabilitation

    Get PDF
    More than 85% of stroke survivors suffer from different degrees of disability for the rest of their lives. They will require support that can vary from occasional to full time assistance. These conditions are also associated to an enormous economic impact for their families and health care systems. Current rehabilitation treatments have limited efficacy and their long-term effect is controversial. Here we review different challenges related to the design and development of neural interfaces for rehabilitative purposes. We analyze current bibliographic evidence of the effect of neuro-feedback in functional motor rehabilitation of stroke patients. We highlight the potential of these systems to reconnect brain and muscles. We also describe all aspects that should be taken into account to restore motor control. Our aim with this work is to help researchers designing interfaces that demonstrate and validate neuromodulation strategies to enforce a contingent and functional neural linkage between the central and the peripheral nervous system. We thus give clues to design systems that can improve or/and re-activate neuroplastic mechanisms and open a new recovery window for stroke patients
    corecore