Delocalization of slowly damped eigenmodes on Anosov manifolds

We look at the properties of high frequency eigenmodes for the damped wave equation on a compact manifold with an Anosov geodesic flow. We study eigenmodes with spectral parameters which are asymptotically close enough to the real axis. We prove that such modes cannot be completely localized on subsets satisfying a condition of negative topological pressure. As an application, one can deduce the existence of a "strip" of logarithmic size without eigenvalues below the real axis under this dynamical assumption on the set of undamped trajectories.Comment: 28 pages; compared with version 1, minor modifications, add two reference

\epsilon-regularity for systems involving non-local, antisymmetric operators

We prove an epsilon-regularity theorem for critical and super-critical systems with a non-local antisymmetric operator on the right-hand side. These systems contain as special cases, Euler-Lagrange equations of conformally invariant variational functionals as Rivi\`ere treated them, and also Euler-Lagrange equations of fractional harmonic maps introduced by Da Lio-Rivi\`ere. In particular, the arguments presented here give new and uniform proofs of the regularity results by Rivi\`ere, Rivi\`ere-Struwe, Da-Lio-Rivi\`ere, and also the integrability results by Sharp-Topping and Sharp, not discriminating between the classical local, and the non-local situations

Transplantation of cells for cardiac repair

AbstractThe inability of adult cardiomyocytes to divide to a significant extent and regenerate the myocardium after injury leads to permanent deficits in the number of functional cells, which can contribute to the development and progression of heart failure. The transplantation of skeletal myoblasts or stem cells or cardiomyocytes derived from them into the injured myocardium is a novel and promising approach in the treatment of cardiac disease and the restoration of myocardial function. In this article, skeletal myoblasts and embryonic and bone marrow stem cells are discussed in the context of their potential therapeutic use in cardiac failure. The state of the art in both laboratory and clinic is presented. We discuss current and intrinsic limitations of cardiac cellular transplantation and suggest directions for future research

Membrane-embedded TSPO: an NMR view

Translocator Protein (18 kDa) (TSPO) is a mitochondrial transmembrane protein commonly used as a biomarker for neuroinflammation and is also a potential therapeutic target in neurodegenerative diseases. Despite intensive research efforts, the function of TSPO is still largely enigmatic. Deciphering TSPO structure in the native lipid environment is essential to gain insight into its cellular activities and to design improved diagnostic and therapeutic ligands. Here, we discuss the influence of lipid composition on the structure of mammalian TSPO embedded into lipid bilayers on the basis of solid-state NMR experiments. We further highlight that cholesterol can influence both the tertiary and quaternary TSPO structure and also influence TSPO localization in mitochondria-associated endoplasmic reticulum membranes

Corrosion behaviour of substoichiometric TiNx films produced by DC magnetron sputtering

The present work describes the corrosion behaviour of substoichiometric TiNx films obtained by dc reactive magnetron sputtering. The coatings thickness ranged from 1.7 to 4.2 µm and the nitrogen content varied between 0 and 55 at. %. According to structural characterization by XRD, the films revealed a hexagonal α-Ti phase with a strong [002] orientation for low nitrogen contents. For nitrogen contents of 20% and 30%, the ε-Ti2N phase appears with a [200] orientation and further increasing of nitrogen content showed that the δ-TiN phase was dominant. Potentiodynamic polarisation and Electrochemical Impedance Spectroscopy (EIS) techniques were used to study the corrosion properties of TiNx films when immersed in artificial sweat solutions. Results of potentiodynamic polarisation tests showed that all films have a high corrosion resistance reflected by corrosion current densities values lower than 0.7µA/cm2. Also, EIS tests corroborated the results obtained in the polarisation tests, showing that films containing low percentages of nitrogen (less than 8 %) reveal the best corrosion resistance. Further increases in nitrogen content lead to a decrease in corrosion resistance. An exception to this behaviour was found for the film, with 30 % N. This sample presents an excellent corrosion resistance which increases with the immersion time. Higher nitrogen contents (52 and 55 %) promote a relative increase in the corrosion resistance when compared with 45 and 50 at % films, but never reaching values obtained for nitrogen contents lower than 30 % at.Fundação para a Ciência e a Tecnologia - (FCT

Structural evolution in ZrNxOy thin films as a function of temperature

Single-layered zirconium oxynitride (ZrNxOy) thin films have been deposited on steel substrates, at a constant temperature of 300 °C, by radiofrequency (rf) reactive magnetron sputtering of a pure Zr target in an argon-oxygen-nitrogen atmosphere. The variation of the flow rate of the reactive gases enabled changes in the composition and structure of the films. X-ray diffraction (XRD) and glancing incidence X-ray diffraction (GIXRD) were used to study the as-deposited films and their structural changes during or after heat treatment, from 400 to 900 °C, in controlled atmosphere and in vacuum.http://www.sciencedirect.com/science/article/B6TVV-4DPYN97-6/1/3785b40b130ad12af7221c230d2968c

Optimization and thermal stability of TiAlN-Mo multilayers

In this work we focus on the optimization and thermal stability of nanocomposite TiAlN/Mo multilayers that were produced by reactive magnetron sputtering on high-speed steel substrates, with modulation periods below 5 nm. These multilayers were annealed between 600– 900 ºC for 1 h in a vacuum furnace. Preliminary X-ray diffraction results reveal that these coatings are very stable up to 900 ºC, since the multilayer chemical modulation is not severely affected. At intermediate annealing temperatures the modulation period decreases due to interdiffusion at the interface, resulting in a thicker interface between metal/nitride and hence decreasing the thickness of those layers.Portuguese FCT/MCES scientific program

Entropy of semiclassical measures for nonpositively curved surfaces

We study the asymptotic properties of eigenfunctions of the Laplacian in the case of a compact Riemannian surface of nonpositive sectional curvature. We show that the Kolmogorov-Sinai entropy of a semiclassical measure for the geodesic flow is bounded from below by half of the Ruelle upper bound. We follow the same main strategy as in the Anosov case (arXiv:0809.0230). We focus on the main differences and refer the reader to (arXiv:0809.0230) for the details of analogous lemmas.Comment: 20 pages. This note provides a detailed proof of a result announced in appendix A of a previous work (arXiv:0809.0230, version 2