Topological phases induced by charge fluctuations in Majorana wires

One of the problems concerning topological phases in solid-state systems which still remains urgent is an issue of many-body effects. In this study we address it within perturbative theory framework by considering topological phase transitions related to charge correlations in the extended Kitaev chain model that belongs to the BDI symmetry class. Obtained corrections to a zero-frequency quasiparticle Green's function allow to separate the mean-field and fluctuation contributions to a total winding number. As a result, the phase transitions caused solely by the latter are unveiled. We thoroughly analyze the mechanism of such transitions in terms of fluctuation-induced nodal points and spectrum renormalization. Additionally, features of other quasiparticle properties such as effective mass and damping are discussed in the context of topological phase transitions.Comment: 20 pages, 15 figure

Feasibility of study magnetic proximity effects in bilayer "superconductor/ferromagnet" using waveguide-enhanced Polarized Neutron Reflectometry

A resonant enhancement of the neutron standing waves is proposed to use in order to increase the magnetic neutron scattering from a "superconductor/ferromagnet"(S/F) bilayer. The model calculations show that usage of this effect allows to increase the magnetic scattering intensity by factor of hundreds. Aspects related to the growth procedure (order of deposition, roughness of the layers etc) as well as experimental conditions (resolution, polarization of the neutron beam, background etc) are also discussed. Collected experimental data for the S/F heterostructure Cu(32nm)/V(40nm)/Fe(1nm)/MgO confirmed the presence of a resonant 60-fold amplification of the magnetic scattering.Comment: The manuscript of the article submitted to Crysstalography Reports. 23 pages, 5 figure

Contamination due to memory effects in filtered vacuum arc plasma deposition systems

Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting

Recovering rearranged cancer chromosomes from karyotype graphs

BACKGROUND: Many cancer genomes are extensively rearranged with highly aberrant chromosomal karyotypes. Structural and copy number variations in cancer genomes can be determined via abnormal mapping of sequenced reads to the reference genome. Recently it became possible to reconcile both of these types of large-scale variations into a karyotype graph representation of the rearranged cancer genomes. Such a representation, however, does not directly describe the linear and/or circular structure of the underlying rearranged cancer chromosomes, thus limiting possible analysis of cancer genomes somatic evolutionary process as well as functional genomic changes brought by the large-scale genome rearrangements. RESULTS: Here we address the aforementioned limitation by introducing a novel methodological framework for recovering rearranged cancer chromosomes from karyotype graphs. For a cancer karyotype graph we formulate an Eulerian Decomposition Problem (EDP) of finding a collection of linear and/or circular rearranged cancer chromosomes that are determined by the graph. We derive and prove computational complexities for several variations of the EDP. We then demonstrate that Eulerian decomposition of the cancer karyotype graphs is not always unique and present the Consistent Contig Covering Problem (CCCP) of recovering unambiguous cancer contigs from the cancer karyotype graph, and describe a novel algorithm CCR capable of solving CCCP in polynomial time. We apply CCR on a prostate cancer dataset and demonstrate that it is capable of consistently recovering large cancer contigs even when underlying cancer genomes are highly rearranged. CONCLUSIONS: CCR can recover rearranged cancer contigs from karyotype graphs thereby addressing existing limitation in inferring chromosomal structures of rearranged cancer genomes and advancing our understanding of both patient/cancer-specific as well as the overall genetic instability in cancer

A hydrodynamic model for asymmetric explosions of rapidly rotating collapsing supernovae with a toroidal atmosphere

We numerically solved the two-dimensional axisymmetric hydrodynamic problem of the explosion of a low-mass neutron star in a circular orbit. In the initial conditions, we assumed a nonuniform density distribution in the space surrounding the collapsed iron core in the form of a stationary toroidal atmosphere that was previously predicted analytically and computed numerically. The configuration of the exploded neutron star itself was modeled by a torus with a circular cross section whose central line almost coincided with its circular orbit. Using an equation of state for the stellar matter and the toroidal atmosphere in which the nuclear statistical equilibrium conditions were satisfied, we performed a series of numerical calculations that showed the propagation of a strong divergent shock wave with a total energy of 0.2x10^51 erg at initial explosion energy release of 1.0x10^51 erg. In our calculations, we rigorously took into account the gravitational interaction, including the attraction from a higher-mass (1.9M_solar) neutron star located at the coordinate origin, in accordance with the rotational explosion mechanism for collapsing supernovae.W e compared in detail our results with previous similar results of asymmetric supernova explosion simulations and concluded that we found a lower limit for the total explosion energy.Comment: 13 pages, 5 figures, 2 table

Research on Geometrical Errors of Geokhod Prototype Shell Based on Coordinate Control Data

The article contains results of a research on geometric accuracy of a geokhod prototype shell. The article outlines the general structural features of geokhod bodies, and the main principles of manufacturing in test production. An overview of approaches to modeling of shell error occurrence is given. The researches were conducted on the basis of data obtained by coordinate control over the stabilizing section shell. The data were studied by statistical methods and analyzed in terms of their compliance with previously proposed mathematical models of formation of geokhod shell inaccuracies. It is shown that available mathematical models can not completely explain the origin of all the errors. The authors attribute unexplained geokhod shell errors as deformations caused by welding

Surface structure of Quark stars with magnetic fields

We investigate the impact of magnetic fields on the electron distribution in the electrosphere of quark stars. For moderately strong magnetic fields $B\sim 10^{13}$G, quantization effects are generally weak due to the large number density of electrons at surface, but can nevertheless affect the spectral features of quark stars. We outline the main observational characteristics of quark stars as determined by their surface emission, and briefly discuss their formation in explosive events termed Quark-Novae, which may be connected to the $r$-process.Comment: 9 pages, 3 figures. Contribution to the proceedings of the IXth Workshop on High Energy Physics Phenomenology (WHEPP-9), Bhubaneswar, India, 3-14 Jan. 200

Remote clinical quality management of endovascular care

Aim. To assess the effectiveness of remote clinical quality management of endovascular care.Methods. The system of clinical quality management of medical care in myocardial infarction (MI) including the quality of remote control of endovascular care was developed and introduced into the health care system of the Moscow Region as a part of the comprehensive study in 2008–2020. The number of people under the study was 8375. The ground for assessing the effectiveness of remote clinical management in 2019–2020 was the health care system of megapolis. Based on the analysis of 2966 endovascular procedures protocols, the treatment tactics effectiveness of intraoperative decisions was studied after an emergency coronary angiography (ECA) had been performed by interventional cardiologists. The system of remote clinical quality management of endovascular care included a complex of audiovisual communications, computer system processes, mentoring and the algorithm for making an intraoperative decision. The effectiveness of remote clinical quality management of endovascular care was investigated on the number of percutaneous coronary interventions (PCI) in MI, mortality of patients with MI in the Regional vascular center in 2019–2020. The T-criteria was used to assess the reliability. The material statistical processing was carried out in the Statistica 6.0 package calculating adequate statistical indicators and their reliability at p≤0.005.Results. Ratio PCI/ECA in 2019, January-March 2020 counted up to 48.95%. In AprilDecember 2020 it increased up to 71.6% (p<0.001). The frequency of performing PCI increased by 1.46 times (p<0.001). Hospital mortality from MI decreased during the following period 2019, April-December 2020 from 9.7% to 8.2% (p = 0.005).Conclusion. Remote clinical management based on telemedicine and mentoring process technologies contributes to improving the quality of endovascular care in MI.Aim. To assess the effectiveness of remote clinical quality management of endovascular care.Methods. The system of clinical quality management of medical care in myocardial infarction (MI) including the quality of remote control of endovascular care was developed and introduced into the health care system of the Moscow Region as a part of the comprehensive study in 2008–2020. The number of people under the study was 8375. The ground for assessing the effectiveness of remote clinical management in 2019–2020 was the health care system of megapolis. Based on the analysis of 2966 endovascular procedures protocols, the treatment tactics effectiveness of intraoperative decisions was studied after an emergency coronary angiography (ECA) had been performed by interventional cardiologists. The system of remote clinical quality management of endovascular care included a complex of audiovisual communications, computer system processes, mentoring and the algorithm for making an intraoperative decision. The effectiveness of remote clinical quality management of endovascular care was investigated on the number of percutaneous coronary interventions (PCI) in MI, mortality of patients with MI in the Regional vascular center in 2019–2020. The T-criteria was used to assess the reliability. The material statistical processing was carried out in the Statistica 6.0 package calculating adequate statistical indicators and their reliability at p≤0.005.Results. Ratio PCI/ECA in 2019, January-March 2020 counted up to 48.95%. In AprilDecember 2020 it increased up to 71.6% (p<0.001). The frequency of performing PCI increased by 1.46 times (p<0.001). Hospital mortality from MI decreased during the following period 2019, April-December 2020 from 9.7% to 8.2% (p = 0.005).Conclusion. Remote clinical management based on telemedicine and mentoring process technologies contributes to improving the quality of endovascular care in MI

СИСТЕМНОСТЬ В МАРКЕТИНГЕ ПАССАЖИРСКИХ ПЕРЕВОЗОК

The authors consider system approach and system analysis as a methodological basis necessary to assess complex economical processes in the market of transportation services. This basis helps the authors to analyze passenger traffic system and to substantiate the core system role of market studies. They suggest their own definitions and understanding of interdependent character of internal and external factors which have direct influence on passenger traffic. They argue that the system approach and the consecutive search for market information to conduct a system analysis have direct repercussions for transport practices and cite the negative example of acquisition of foreign rolling stock which was not adapted to local conditions.Рассматриваемые в статье системный поход и системный  анализ квалифицируются в качестве необходимой методологической  основы для оценки сложных экономических процессов на рынке транспортних услуг. Под этим углом зрения авторы строят проекции на систему пассажирских перевозок и обосновывают системную роль маркетинговых исследований, предлагая свои определения в соответствующий научный аппарат и свое понимание взаимообусловленности и взаимовлияющего характера факторов внешней и внутренней среды изучаемого объекта.

NMR investigation of the molecular mobility and structure of polysulphone-polybutadiene and polysulphone-polyethylene oxide block copolymers

Molecular mobility in polyblock regular alternating block copolymers has been investigated by pulsed NMR in the temperature range 173-463°K. It was found that phase microsegregation in polysulphone-polybutadiene block copolymers is only very slightly dependent on their composition. This is due to the incompatibility of the oligobutadiene and oligosulphone components. The glass temperatures and molecular mobilities of flexible and rigid blocks in these copolymers coincide with corresponding parameters of the initial oligomers. However, at elevated temperatures there is a marked reduction in mobility of the oligobutadiene block compared with that of the initial oligomer. Owing to partial compatibility of the oligoethylene oxide and oligosulphone components in polysulphone-polyethylene oxide block copolymers the glass temperatures, phase micro-segregation and mobility of flexible and rigid blocks are largely dependent on the copolymer composition. © 1982