Spectroscopic evidence for strong correlations between local superconducting gap and local Altshuler-Aronov density-of-states suppression in ultrathin NbN films

Disorder has different profound effects on superconducting thin films. For a large variety of materials, increasing disorder reduces electronic screening which enhances electron-electron repulsion. These fermionic effects lead to a mechanism described by Finkelstein: when disorder combined to electron-electron interactions increases, there is a global decrease of the superconducting energy gap $\Delta$ and of the critical temperature $T_c$, the ratio $\Delta$/$k_BT_c$ remaining roughly constant. In addition, in most films an emergent granularity develops with increasing disorder and results in the formation of inhomogeneous superconducting puddles. These gap inhomogeneities are usually accompanied by the development of bosonic features: a pseudogap develops above the critical temperature $T_c$ and the energy gap $\Delta$ starts decoupling from $T_c$. Thus the mechanism(s) driving the appearance of these gap inhomogeneities could result from a complicated interplay between fermionic and bosonic effects. By studying the local electronic properties of a NbN film with scanning tunneling spectroscopy (STS) we show that the inhomogeneous spatial distribution of $\Delta$ is locally strongly correlated to a large depletion in the local density of states (LDOS) around the Fermi level, associated to the Altshuler-Aronov effect induced by strong electronic interactions. By modelling quantitatively the measured LDOS suppression, we show that the latter can be interpreted as local variations of the film resistivity. This local change in resistivity leads to a local variation of $\Delta$ through a local Finkelstein mechanism. Our analysis furnishes a purely fermionic scenario explaining quantitatively the emergent superconducting inhomogeneities, while the precise origin of the latter remained unclear up to now.Comment: 11 pages, 4 figure

Double Fe-impurity charge state in the topological insulator Bi2_2Se3_3

The influence of individual impurities of Fe on the electronic properties of topological insulator Bi$_2$Se$_3$ is studied by Scanning Tunneling Microscopy. The microscope tip is used in order to remotely charge/discharge Fe impurities. The charging process is shown to depend on the impurity location in the crystallographic unit cell, on the presence of other Fe impurities in the close vicinity, as well as on the overall doping level of the crystal. We present a qualitative explanation of the observed phenomena in terms of tip-induced local band bending. Our observations evidence that the specific impurity neighborhood and the position of the Fermi energy with respect to the Dirac point and bulk bands have both to be taken into account when considering the electron scattering on the disorder in topological insulators.Comment: 10 pages, accepted for publication in Applied Physics Letters, minor bugs were correcte

Fourier transform spectroscopy and coupled-channel deperturbation treatment of the A1Sigma+ ~ b3Pi complex of KCs molecule

The laser induced fluorescence (LIF) spectra A1Sigma ~ b3Pi --> X1Sigma+ of KCs dimer were recorded in near infrared region by Fourier Transform Spectrometer with a resolution of 0.03 cm-1. Overall more than 200 LIF spectra were rotationally assigned to 39K133Cs and 41K133Cs isotopomers yielding with the uncertainty of 0.003-0.01 cm-1 more than 3400 rovibronic term values of the strongly mixed singlet A1Sigma+ and triplet b3Pi states. Experimental data massive starts from the lowest vibrational level v_A=0 of the singlet and nonuniformly cover the energy range from 10040 to 13250 cm-1 with rotational quantum numbers J from 7 to 225. Besides of the dominating regular A1Sigma+ ~ b3P Omega=0 interactions the weak and local heterogenous A1S+ ~ b3P Omega=1 perturbations have been discovered and analyzed. Coupled-channel deperturbation analysis of the experimental 39K133Cs e-parity termvalues of the A1S+ ~ b3P complex was accomplished in the framework of the phenomenological 4 x 4 Hamiltonian accounting implicitly for regular interactions with the remote states manifold. The resulting diabatic potential energy curves of the interacting states and relevant spin-orbit coupling matrix elements defined analytically by Expanded Morse Oscillators model reproduce 95% of experimental data field of the 39K133Cs isotopomer with a standard deviation of 0.004 cm-1 which is consistent with the uncertainty of the experiment. Reliability of the derived parameters was additionally confirmed by a good agreement between the predicted and experimental termvalues of 41K133Cs isotopomer. Calculated intensity distributions in the A ~ b --> X LIF progressions are also consistent with their experimental counterparts.Comment: 17 pages, 14 figure

Fast front-end L0 trigger electronics for ALICE FMD-MCP tests and performance

We present design details and new measurements of the performance of fast electronics for the Forward Multiplicity Detector for ALICE. These detectors based on sector type Microchannel Plates (MCP) forming several disks gave the very first trigger decision in the experiment (L0). Fast passive summators integrated with the detectors are used for linear summation of up to eight isochronous signal channels from MCP pads belonging to one sector. Two types of microelectronics design thin film summators were produced. We present test results for these summators, working in the frequency range up to 1 Ghz. New low noise preamplifiers have been built to work with these summators. The new design shows a good performance with the usable frequency range extended up to 1 Ghz. An upgrade of the functional scheme for the L0 ALICE pre-trigger design is also presented.Abstract:List of figures Figure 1: ALICE L0 Trigger Front-End Electronics Functional Scheme. Figure 2: UHF design for a fast passive summator based on directional couplers. Figure 3: Photo of an industrially produced passive summator based on circular bridges. Figure 4: Oscillogram of the fast 4 signals separated by different delays shown at the fast output of the passive summator. Figure 5: The same as in Figure 4, but with the delays removed. Figure 6: Fast preamplifier layout. Figure 7: Gain versus Frequency Response for fast preamplifier. Figure 8: Transition response of the preamplifier for a 100 psec rise time step function. Figure 9: The shape of the MCP signal measured after the summator and fast preamplifier. </A

Fast Pre-Trigger Electronics of T0/Centrality MCP-Based Start Detector for ALICE

This work describes an alternative to the current ALICE baseline solution for a TO detector, still under development. The proposed system consists of two MCP-based T0/Centrality Start Detectors (backward-forward isochronous disks) equipped with programmable, TTC synchronized front-end electronic cards (FEECs) which would be positioned along the LHC colliding beam line on both sides of the ALICE interaction region. The purpose of this arrangement, providing both precise timing and fast multiplicity selection, is to give a pre-trigger signal at the earliest possible time after a central event. This pre-trigger can be produced within 25 ns. It can be delivered within 100 ns directly to the Transition Radiation Detector and would be the earliest L0 input coming to the ALICE Central Trigger Processor. A noise-free passive multichannel summator of 2ns signals is used to provide a determination of the collision time with a potential accuracy better than 10 ps in the case of Pb-Pb collisions, the limit coming from the electronics. Results from in-beam tests confirm the functionality of the main elements. Further development plans are presented

Component separation methods for the Planck mission

The Planck satellite will map the full sky at nine frequencies from 30 to 857 GHz. The CMB intensity and polarization that are its prime targets are contaminated by foreground emission. The goal of this paper is to compare proposed methods for separating CMB from foregrounds based on their different spectral and spatial characteristics, and to separate the foregrounds into components of different physical origin. A component separation challenge has been organized, based on a set of realistically complex simulations of sky emission. Several methods including those based on internal template subtraction, maximum entropy method, parametric method, spatial and harmonic cross correlation methods, and independent component analysis have been tested. Different methods proved to be effective in cleaning the CMB maps from foreground contamination, in reconstructing maps of diffuse Galactic emissions, and in detecting point sources and thermal Sunyaev-Zeldovich signals. The power spectrum of the residuals is, on the largest scales, four orders of magnitude lower than that of the input Galaxy power spectrum at the foreground minimum. The CMB power spectrum was accurately recovered up to the sixth acoustic peak. The point source detection limit reaches 100 mJy, and about 2300 clusters are detected via the thermal SZ effect on two thirds of the sky. We have found that no single method performs best for all scientific objectives. We foresee that the final component separation pipeline for Planck will involve a combination of methods and iterations between processing steps targeted at different objectives such as diffuse component separation, spectral estimation and compact source extraction.Comment: Matches version accepted by A&A. A version with high resolution figures is available at http://people.sissa.it/~leach/compsepcomp.pd

Two years of experience in hospital surveillance for the severe influenza like illnesses in St. Petersburg: etiology, clinical characterization of diseases, antigenic and genetic properties of isolated influenza viruses

In this paper, we analyze the etiology of the diseases occurring during two consecutive influenza epidemic seasons in St. Petersburg, Russian Federation. The analysis is based on the results of the PCR diagnostics of the clinical samples collected from patients hospitalized in three St. Petersburg hospitals with influenza like illnesses (ILI). It was shown that the influenza virus A(H1N1)pdm09 was the dominant causative agent during the 2012-2013 epidemic season while, in the 2013-2014 season, A(H3N2) virus was predominant among adults and children. The influenza B virus activity was high in the 2012-2013 season and low in the 2013-2014 season. During both seasons, the main causative agent for the hospitalization of young children was respiratory syncytial virus (RSV), followed by rhinovirus and influenza virus. The rate of involvement of parainfluenza, adenovirus, metapneumovirus and coronavirus was low and was negligible for bocavirus. Children 0-2 and 3-6 years old formed the group of patients that was affected by acute respiratory infection agents the most. Children younger than 3 months old were the major group of the intensive care unit (ICUs) patients and only 27.5% of them were adults. RSV and rhinovirus were the leading cause of ILI among the children admitted to ICU. Among the adult patients admitted to the ICU, only influenza A(H1N1)pdm09, A(H3N2) and B viruses were detected during both influenza seasons.According to the results of the antigenic and genetic analysis, most influenza A(H1N1)pdm09 and A(H3N2) viruses circulating in St. Petersburg matched the vaccine strains recommended by the WHO for vaccine composition in the 2012-2013 and 2013-2014 seasons.In this paper, we analyze the etiology of the diseases occurring during two consecutive influenza epidemic seasons in St. Petersburg, Russian Federation. The analysis is based on the results of the PCR diagnostics of the clinical samples collected from patients hospitalized in three St. Petersburg hospitals with influenza like illnesses (ILI). It was shown that the influenza virus A(H1N1)pdm09 was the dominant causative agent during the 2012-2013 epidemic season while, in the 2013-2014 season, A(H3N2) virus was predominant among adults and children. The influenza B virus activity was high in the 2012-2013 season and low in the 2013-2014 season. During both seasons, the main causative agent for the hospitalization of young children was respiratory syncytial virus (RSV), followed by rhinovirus and influenza virus. The rate of involvement of parainfluenza, adenovirus, metapneumovirus and coronavirus was low and was negligible for bocavirus. Children 0-2 and 3-6 years old formed the group of patients that was affected by acute respiratory infection agents the most. Children younger than 3 months old were the major group of the intensive care unit (ICUs) patients and only 27.5% of them were adults. RSV and rhinovirus were the leading cause of ILI among the children admitted to ICU. Among the adult patients admitted to the ICU, only influenza A(H1N1)pdm09, A(H3N2) and B viruses were detected during both influenza seasons. According to the results of the antigenic and genetic analysis, most influenza A(H1N1)pdm09 and A(H3N2) viruses circulating in St. Petersburg matched the vaccine strains recommended by the WHO for vaccine composition in the 2012-2013 and 2013-2014 seasons

Ozone therapy with obliterating atherosclerosis of lower limb arteries

Our studies show that ozone therapy is an effective method for correcting hypercoagulability and tissue hypoxia. The use of infusion of ozone therapy in most cases leads to a significant decrease in the size of venous ulcers, or their complete epithelialization, but also leads to a reduction of early postoperative thrombosis when OAANK11 В -111 Art.Наши исследования показывают, что озонотерапия является эффективным методом коррекции гиперкоагуляции и тканевой гипоксии. Применение инфузионной озонотерапии в большинстве случаев приводит к значительному уменьшению размеров трофических язв, или к их полной зпителизации, а также ведёт к уменьшению ранних послеоперационных тромбозов при ОААНК11 Б -111 ст

Time course of changes in the development of gait disorders in multiple sclerosis

Objective: to estimate the time course of changes in foot biomechanical function as multiple sclerosis (MS) progresses in patients with different degrees of disability compared to a control group. Patients and methods. To estimate the time course of changes in gait disorders in MS, changes in foot biomechanical function were explored in 30 patients with relapsing-remitting MS. Their neurological status was evaluated using the expanded disability status scale (EDSS); pedographic examination was made applying a plantar pressure distribution system; all the patients were examined twice. During the first examination, the patients were divided into two groups: 1) minimal neurological disorders (EDSS scores of &lt; 3.0) and 2) moderate ones (EDSS scores of ≥3.0). Results and discussion. The patients with a mild neurological deficit showed increases in foot load and its lateralization by elevating pressure on the heads of the fourth and fifth metatarsal bones, as evidenced by a significant rise in mean pressure, maximum force, and force-time integral. These changes occurred in the absence of the patients’ complaints of changes in movements. Pedographic examination revealed the changes indicating an enlarged anterior transverse arch and the lower role of the hallux in body weight transfer in the patients with a moderate neurological deficit despite the fact that there were no further visible negative changes in a motor process or progression in neurological deficit. The pedographic examination makes it possible to estimate the degree of gait disorders caused by pyramidal and/or cerebellar lesions and to identify a leading role of this or that functional system in their genesis. Pyramidal dysfunction has impact on the pressurization of the heads of the second and third metatarsal bones. Computed pedography can identify clinically subtle movement changes and estimate the time course of changes in movement disorders in MS patients, including those to evaluate the efficiency of therapy and rehabilitation measures