8,339 research outputs found

    Triethylphosphite as a network forming agent enhances in-vitro biocompatibility and corrosion protection of hybrid organic-inorganic sol-gel coatings for Ti6Al4V alloys

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    The biocompatibility and life of metallic implants can be enhanced through improving the biocompatibility and corrosion protection characteristics of the coatings used with these materials. In this study, triethylphosphite (TEP) was used to introduce phosphorus into organic-inorganic hybrid silica based sol gel coatings prepared using γ-methacryloxypropyltrimethoxysilane and tetramethylorthosilicate. Addition of TEP dramatically increased the rate of intermolecular condensation and resulted in materials showing greater cross linking. Protein (fibrinogen) uptake, osteoblast in vitro biocompatibility and corrosion resistance was enhanced in coatings containing TEP. Although higher concentrations of phosphorus supported the greatest improvement in biocompatibility, a compromise in the phosphorus concentration used would be required if corrosion resistance was most desirable parameter for optimisation. Films prepared by dip coating on Ti6Al4V alloys from these sols offer a promising alternative to wholly metallic prostheses

    Open charm meson in nuclear matter at finite temperature beyond the zero range approximation

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    The properties of open charm mesons, DD, Dˉ\bar D, DsD_s and Dˉs\bar D_s in nuclear matter at finite temperature are studied within a self-consistent coupled-channel approach. The interaction of the low lying pseudoscalar mesons with the ground state baryons in the charm sector is derived from a tt-channel vector-exchange model. The in-medium scattering amplitudes are obtained by solving the Lippmann-Schwinger equation at finite temperature including Pauli blocking effects, as well as DD, Dˉ\bar D, DsD_s and Dˉs\bar D_s self-energies taking their mutual influence into account. We find that the in-medium properties of the DD meson are affected by the DsD_s-meson self-energy through the intermediate DsYD_s Y loops coupled to DNDN states. Similarly, dressing the Dˉ\bar{D} meson in the DˉY\bar{D}Y loops has an influence over the properties of the Dˉs\bar{D}_s meson.Comment: 23 pages, 9 figures, 2 table

    Impact of low-energy nuclear excitations on neutrino-nucleus scattering at MiniBooNE and T2K kinematics

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    [Background] Meticulous modeling of neutrino-nucleus interactions is essential to achieve the unprecedented precision goals of present and future accelerator-based neutrino-oscillation experiments. [Purpose] Confront our calculations of charged-current quasielastic cross section with the measurements of MiniBooNE and T2K, and to quantitatively investigate the role of nuclear-structure effects, in particular, low-energy nuclear excitations in forward muon scattering. [Method] The model takes the mean-field (MF) approach as the starting point, and solves Hartree-Fock (HF) equations using a Skyrme (SkE2) nucleon-nucleon interaction. Long-range nuclear correlations are taken into account by means of the continuum random-phase approximation (CRPA) framework. [Results] We present our calculations on flux-folded double differential, and flux-unfolded total cross sections off 12^{12}C and compare them with MiniBooNE and (off-axis) T2K measurements. We discuss the importance of low-energy nuclear excitations for the forward bins. [Conclusions] The CRPA predictions describe the gross features of the measured cross sections. They underpredict the data (more in the neutrino than in the antineutrino case) because of the absence of processes beyond pure quasielastic scattering in our model. At very forward muon scattering, low-energy nuclear excitations (ω<\omega < 50 MeV) account for nearly 50% of the flux-folded cross section.Comment: 8 pages, 9 figures. Version published in Physical Review

    Diachronic analiysis of motor comunication in traditional games and sports of the canary island

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    Se realiza un análisis diacrónico de la comunicación motriz en tres grupos de juegos y deportes tradicionales canarios ('juegos aborígenes', 'juegos tradicionales', y 'deportes tradicionales') para deducir pautas sociales que encierran estas prácticas. Se analizan y categorizan la red de comunicación motriz y la interacción motriz siguiendo criterios de la praxiología motriz. Bajo el significado del enfrentamiento como función lúdica principal, la estructura dualista se muestra de manera hegemónica, en detrimento de otras formas de comunicación motriz. También, se desvela que la diversificación de la interacción motriz del grupo 'juegos tradicionales' no es equivalente en los otros grupos estudiados, mostrando aquel grupo significados etnomotores hetereogéneos para una misma actividad. Las prácticas motrices estudiadas dan idea de la complejidad de la construcción de la tradición lúdica canariaA diachronic analysis of motor communication in three groups of traditional Canary Island games (‘aboriginal games’, ‘traditional games’, and ‘traditional sports’) was carried out in order to detect and define their social models. Both motor communication and motor interaction were analyzed and categorized according to motor praxeology criteria. When confrontation was the main function of the game, the dual structure was dominant over other forms of motor communication. The motor interaction diversification in the ‘traditional games’ group was not comparable to the other two groups due to the various ethno-motor modes used for the same activity. The motor study allows us to form an idea of the complexity of the construct of traditional Canary game

    Nuclear effects in neutrino and antineutrino CCQE scattering at MINERvA kinematics

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    We compare the charged-current quasielastic neutrino and antineutrino observables obtained in two different nuclear models, the phenomenological SuperScaling Approximation and the Relativistic Mean Field approach, with the recent data published by the MINERvA Collaboration. Both models provide a good description of the data without the need of an ad hoc increase in the mass parameter in the axial-vector dipole form factor. Comparisons are also made with the MiniBooNE results where different conclusions are reached.Comment: 6 pages, 7 figures, Accepted for publication in Physical Review

    Ballistic resistivity in aluminum nanocontacts

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    One of the major industrial challenges is to profit from some fascinating physical features present at the nanoscale. The production of dissipationless nanoswitches (or nanocontacts) is one of such attractive applications. Nevertheless, the lack of knowledge of the real efficiency of electronic ballistic/non dissipative transport limits future innovations. For multi-valent metallic nanosystems -where several transport channels per atom are involved- the only experimental technique available for statistical transport characterization is the conductance histogram. Unfortunately its interpretation is difficult because transport and mechanical properties are intrinsically interlaced. We perform a representative series of semiclassical molecular dynamics simulations of aluminum nanocontact breakages, coupled to full quantum conductance calculations, and put in evidence a linear relationship between the conductance and the contact minimum cross-section for the geometrically favored aluminum nanocontact configurations. Valid in a broad range of conductance values, such relation allows the definition of a transport parameter for nanomaterials, that represents the novel concept of ballistic resistivity

    Membrane protein Oca3 is essential to keep structural integrity of mitochondria and endoplasmic reticulum

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    Mitochondrial function is tightly conserved through evolution since it becomes essential for the fitness of any eukaryotic cell. Defective function of this organelle represents the cellular basis of some severe diseases in humans. Thus, the characterization of genes involved in the correct mitochondrial structure and function is critical to understand and treating these diseases. In our laboratory, using the fission yeast as a model, we are characterising the function of oca3 gene, the ortholog of EMC2 gene in human. This gene is predicted to be a member of the ER membrane protein complex involved in the mitochondrion-endoplasmic reticulum membrane tethering1. We find the protein in the non-aqueous phase in cell extracts and Oca3-mCherry tagging actually decorates most cell membranes. Oca3 over-expression cause lethality2 and the gene deletion becomes cold-sensitive. In both situations aberrant mitochondria aggregations are observed and endoplasmic reticulum seems disorganised. Interestingly, addition of Tween20 restores the viability of oca3 deletion at low temperature. This result suggests that Oca3 may have a role in membrane fluidity homeostasis. In addition to this, we will analyse different gene interaction between some of the EMC complex members to clarify both, the importance of Oca3 for the complex and the importance of the complex itself for the cell
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