2,265 research outputs found

    Change of surface critical current in the surface superconductivity and mixed states of superconducting Niobium

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    A systematic study of irreversible magnetization was performed in bulk Niobium after different surface treatments. Starting with smooth surfaces and abrading them, a strong increase of the critical current is observed up an apparent limiting value. An impressive change of the critical current is also observed in the surface superconductivity (SSC) state, reaching values of the same order of magnitude as in the mixed state. We explain also the observation of strong SSC for magnetic field perpendicular to larges facets in terms of nucleation of SC along bumps of a corrugated surface.Comment: Accepted for publication in Superconducing Science and Technolog

    Analysis of the multiferroicity in the hexagonal manganite YMnO3

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    We performed magnetic and ferroelectric measurements, associated with Landau theory and symmetry analysis, in order to clarify the situation of the YMnO3 system, a classical example of type I multiferroics. We found that the only magnetic group compatible with all experimental data (neutrons scattering, magnetization,polarization, dielectric constant, second harmonic generation) is the P6'3 group. In this group a small ferromagnetic component along c is induced by the Dzyaloshinskii-Moriya interaction, and observed here in SQUID magnetization measurements. We found that the ferromagnetic and antiferromagnetic components can only be switched simultaneously, while the magnetic orders are functions of the polarization square and therefore insensitive to its sign

    Análisis de los microRNA en enfermedades cardiovasculares y envejecimiento cardiaco

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    Cardiovascular diseases (CVD) are one of the main causes of death that affect worldwide. Thereare several risk factors for the development of CVD, among them, aging is important, whichimplies the anatomical and functional deterioration of the heart. CVD constitute a great burdenin advanced societies. There is a need for the development of therapies and non-invasiveprognostic and diagnostic biomarkers to effectively tackle them. microRNAs (miRNAs) are smallRNAs known to regulate main biological process. For this reason, miRNAs have been proposedas a powerful therapeutic targets or biomarkers.Here the role of miRNAs in the development of CVD and cardiac aging has been reviewed. Inaddition, the translation level of results in animal models to human has been investigated. Asresult, a complete compilation of miRNAs that contribute to CVD and cardiac aging is offered.This literature compilation points out that the great majority of the described miRNAs remainunstudied in human. Based in the high degree of miRNA sequence conservation between speciesand their target sequences, similar functions could be expected in human. Yet, otherphysiological differences in comparison with animal models could suggest the contrary. Toassess the contribution of miRNA in cardiac related pathophysiology, cardiomyocytes derivedfrom human induced pluripotent stem cells (iPSC-CMs) emerge as a model for their studyavoiding this translation difficulties.In addition, the BSICoS group has built a bioinformatic regulatory network controlled by miRNAsassociated with biological age (BIO-AGEmiRNAs) of the human myocardium. Experimentalvalidation of the interactions within this network is required. A new cost-effective validation toolhas been built using fluorescence. Last, luciferase reporter assays (DualGlo assay) are used tostudy interaction of cardiac-related genes with miR-3916. As a result, positive interaction trendshave been observed for CASQ2, ACTN2 and DSP with miR-3916. This fact highlights the potentialof miRNAs in the regulation of genes associated with human cardiac aging and CVD and theirpowerful value as therapeutic targets.<br /

    Magnetodielectric coupling in a triangular Ising lattice

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    Dielectric constant measurement under magnetic field is an efficient technique to study the coupling between charges and spins in insulating materials. For magnetic oxides, the geometric frustration is known to be a key ingredient to observe such a coupling. Measurements for the triangular Ising-like cobaltite Ca3Co2O6 have been made. Single crystals of Ca3Co2O6 are found to exhibit a magnetodielectric effect below TN=25K with a peak in the e(H) curve at the ferri to ferromagnetic transition. This relation between e and magnetization has been modelized by using two order parameters in an energy expansion derived from the Landau formalism and the fluctuation-dissipation theorem. This result emphasizes the great potential of insulating transition metal oxides for the search of magnetodielectric effect

    Coupled Negative magnetocapacitance and magnetic susceptibility in a Kagome staircase-like compound Co3V2O8

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    The dielectric constant of the Kagome staircase-like Co3V2O8 polycrystalline compound has been measured as function of temperature and magnetic field up to 14T. It is found that the application of an external magnetic field suppresses the anomaly for the dielectric constant beyond 6.1K. Furthermore, its magnetic field dependence reveals a negative magnetocapacitance which is proportional to the magnetic susceptibility, suggesting a common magnetostrictive origin for the magnetic field dependence of the two quantities. This result is very different from that obtained from the isostructural compound Ni3V2O8 that presents a peak in the dielectric constant at the incommensurate magnetic phase transition coupled to a sign change of the magnetocapacitance

    Direct correlation between strengthening mechanisms and electrical noise in strained copper wires

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    We have measured the resistance noise of copper metallic wires during a tensile stress. The time variation of the main resistance is continuous up to the wire breakdown, but its fluctuations reveal the intermittent and heterogeneous character of plastic flow. We show in particular direct correlations between strengthening mechanisms and noise spectra characteristics.Comment: accepted in Phys Rev

    Realidad simulada como herramienta de enseñanza-aprendizaje en Criminología

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    El diseño de prácticas docentes de realidad simulada constituye un avance en el proceso de enseñanza-aprendizaje en el alumnado de Criminología. Mediante este tipo de actividades, los estudiantes desarrollan las competencias académicas y profesionales adquiridas durante su formación, recreando contextos y situaciones reales en un entorno de aprendizaje. El objetivo de este trabajo es evaluar las competencias adquiridas por el alumnado de último curso del Grado en Criminología, tras la implementación de una práctica de realidad simulada basada en la recreación de un Juicio donde el alumnado deberá poner en práctica los conocimientos y técnicas de evaluación criminológica aplicados al ámbito de la Justicia Penal. Se describen los resultados de aprendizaje y la satisfacción del alumnado con la incorporación de esta experiencia piloto mediante el análisis de respuestas de un cuestionario informatizado ad hoc

    Persistent Facial Oedema and Erythema in a Woman, An Uncommon Manifestation of Chronic Cutaneous Lupus Erythematosus

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    Manifestations of chronic cutaneous lupus erythematosus are variable. Periorbital and facial swelling occurs in dermatomyositis and systemic lupus, but it has been rarely reported as a manifestation of exclusively cutaneous lupus. A 48-year-old woman presented with a 16-year history of asymptomatic, bilateral swelling and erythema of her face with marked worsening after sun exposure. No systemic symptoms were associated. A complete evaluation did not reveal other findings. Cutaneous biopsy showed features of lupus erythematosus. She was treated with photoprotection, topical tacrolimus, hydroxychloroquine and azathioprine with a partial response. Facial swelling with erythema represents quite an unusual manifestation of chronic cutaneous lupus erythematosus. Dermatomyositis, systemic lupus and Morbihan disease are the main differential diagnoses

    Desarrollo de nanotransportadores de DNA de vanguardia con capacidad cardioregenerativa utilizando el potencial terapéutico de los microRNAs

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    El infarto de miocardio, si no es mortal, conduce a un remodelado del tejido cardíaco que evoluciona hacia la insuficiencia cardíaca puesto que el corazón carece de capacidad regenerativa. Actualmente no existe una terapia regenerativa, pero se han descrito microRNAs (miR), por ejemplo, el miR-199a-3p, que la promueven a través de la estimulación la proliferación de cardiomiocitos. En este trabajo se han desarrollado y caracterizado nanoestructuras de DNA (DNS) capaces de transportar el miR-199a-3p, internalizarse de manera eficiente en la célula y liberar el miR de manera funcional utilizando la propia maquinaria de la célula. Este trabajo sienta las bases para futuros desarrollos de la terapia cardioregenerativa basada en miR
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