KTM TOKAMAK OPERATION SCENARIOS SOFTWARE INFRASTRUCTURE

One of the largest problems for tokamak devices such as Kazakhstan Tokamak for Material Testing (KTM) is the operation scenarios' development and execution. Operation scenarios may be varied often, so a convenient hardware and software solution is required for scenario management and execution. Dozens of diagnostic and control subsystems with numerous configuration settings may be used in an experiment, so it is required to automate the subsystem configuration process to coordinate changes of the related settings and to prevent errors. Most of the diagnostic and control subsystems software at KTM was unified using an extra software layer, describing the hardware abstraction interface. The experiment sequence was described using a command language.The whole infrastructure was brought together by a universal communication protocol supporting various media, including Ethernet and serial links. The operation sequence execution infrastructure was used at KTM to carry out plasma experiments

Goldstone Mode Relaxation in a Quantum Hall Ferromagnet due to Hyperfine Interaction with Nuclei

Spin relaxation in quantum Hall ferromagnet regimes is studied. As the initial non-equilibrium state, a coherent deviation of the spin system from the ${\vec B}$ direction is considered and the breakdown of this Goldstone-mode state due to hyperfine coupling to nuclei is analyzed. The relaxation occurring non-exponentially with time is studied in terms of annihilation processes in the "Goldstone condensate" formed by "zero spin excitons". The relaxation rate is calculated analytically even if the initial deviation is not small. This relaxation channel competes with the relaxation mechanisms due to spin-orbit coupling, and at strong magnetic fields it becomes dominating.Comment: 8 page

Vaccine interchangeability: problems and prospects

Vaccines by different manufacturers are available for most of the vaccine-preventable infections covered by the National Immunisation Schedule of the Russian Federation. Determination of the possibility of replacing a vaccine in the case of routine or emergency vaccination still remains a challenging issue. The aim of the study was to substantiate the problem of vaccine interchangeability, outline specific challenges and ways of solving them, analyse criteria underlying evaluation of vaccine interchangeability in Russia, and international experience in this area. The procedure for determining the interchangeability of biological products, including vaccines, was established in the Decree of the Government of the Russian Federation of 5 September 2020, No. 1360 “On the procedure for determination of interchangeability of medicinal products for human use”. The paper analyses the applicability of the official criteria for interchangeability of biological products, including vaccines. It outlines the main problems of performing evaluation of vaccine interchangeability in accordance with the established criteria. It is concluded that the vaccine interchangeability criteria need to be clarified in order to allow for assessment of comparability of active substances, and comparison of efficacy, safety, and immunogenicity of vaccines, taking into account vaccination schedules for different age groups. The possibility of evaluating interchangeability based on the results of post-authorisation studies also needs clarification. It is also necessary to align patient information leaflets for interchangeable vaccines

Localized states in 2D semiconductors doped with magnetic impurities in quantizing magnetic field

A theory of magnetic impurities in a 2D electron gas quantized by a strong magnetic field is formulated in terms of Friedel-Anderson theory of resonance impurity scattering. It is shown that this scattering results in an appearance of bound Landau states with zero angular moment between the Landau subbands. The resonance scattering is spin selective, and it results in a strong spin polarization of Landau states, as well as in a noticeable magnetic field dependence of the $g$ factor and the crystal field splitting of the impurity $d$ levels.Comment: 12 pages, 4 figures Submitted to Physical Review B This version is edited and updated in accordance with recent experimental dat

Topological solitons in highly anisotropic two dimensional ferromagnets

e study the solitons, stabilized by spin precession in a classical two--dimensional lattice model of Heisenberg ferromagnets with non-small easy--axis anisotropy. The properties of such solitons are treated both analytically using the continuous model including higher then second powers of magnetization gradients, and numerically for a discrete set of the spins on a square lattice. The dependence of the soliton energy $E$ on the number of spin deviations (bound magnons) $N$ is calculated. We have shown that the topological solitons are stable if the number $N$ exceeds some critical value $N_{\rm{cr}}$. For $N < N_{\rm{cr}}$ and the intermediate values of anisotropy constant $K_{\mathrm{eff}} <0.35J$ ($J$ is an exchange constant), the soliton properties are similar to those for continuous model; for example, soliton energy is increasing and the precession frequency $\omega (N)$ is decreasing monotonously with $N$ growth. For high enough anisotropy $K_{\mathrm{eff}} > 0.6 J$ we found some fundamentally new soliton features absent for continuous models incorporating even the higher powers of magnetization gradients. For high anisotropy, the dependence of soliton energy E(N) on the number of bound magnons become non-monotonic, with the minima at some "magic" numbers of bound magnons. Soliton frequency $\omega (N)$ have quite irregular behavior with step-like jumps and negative values of $\omega$ for some regions of $N$. Near these regions, stable static soliton states, stabilized by the lattice effects, exist.Comment: 17 page

Intrinsic electric polarization in spin-orbit coupled semiconductor heterostructures

We present Maxwell equations with source terms for the electromagnetic field interacting with a moving electron in a spin-orbit coupled semiconductor heterostructure. We start with the eight--band ${\bm k}{\bm p}$ model and derive the electric and magnetic polarization vectors using the Gordon--like decomposition method. Next, we present the ${\bm k}{\bm p}$ effective Lagrangian for the nonparabolic conduction band electrons interacting with electromagnetic field in semiconductor heterostructures with abrupt interfaces. This Lagrangian gives rise to the Maxwell equations with source terms and boundary conditions at heterointerfaces as well as equations for the electron envelope wave function in the external electromagnetic field together with appropriate boundary conditions. As an example, we consider spin--orbit effects caused by the structure inversion asymmetry for the conduction electron states. We compute the intrinsic contribution to the electric polarization of the steady state electron gas in asymmetric quantum well in equilibrium and in the spin Hall regime. We argue that this contribution, as well as the intrinsic spin Hall current, are not cancelled by the elastic scattering processes.Comment: 12 pages, 3 figure

Review of global use of licensed vaccines and development of new vaccines for the prevention of pneumococcal infection

Streptococcus pneumoniae infection is the most common cause of high morbidity and mortality among children under 5 years of age, immunocompromised people, and the elderly. Despite significant success, the approved pneumococcal conjugate and polysaccharide vaccines are of limited efficacy, providing protection against a small fraction of the known pneumococcal serotypes. The rapid spread of multidrug-resistant strains exacerbates the global challenge of treating infection caused by S. pneumoniae. At the same time, the emerging new strains dictate the need to include new serotypes into vaccines. In view of this, further improvement of vaccines for the prevention of pneumococcal infections is an urgent task. The aim of this study was to review advances in the development of polysaccharide, conjugate, whole-cell pneumococcal vaccines, as well as vaccines based on protein antigens and vaccines with an antigen delivery system. Genomics and proteomics data have helped to improve approaches to the creation of polysaccharide and protein-based vaccines, as well as whole-cell vaccines with the potential for population prophylactic coverage against various pneumococcal serotypes that are not included in the licensed pneumococcal vaccines. The method of antigen delivery to the cell is of great importance in the development of vaccines. The most promising strategy for improving pneumococcal vaccines is the creation of vaccines based on bacterium-like or synthetic particles carrying several antigens, including pneumococcal surface proteins. In conclusion, it should be noted that top-priority vaccines are those that provide a wide range of protection against circulating pneumococcal serotypes and, in addition to eliciting a systemic immune response, also induce local immunity

Electronic structure of nuclear-spin-polarization-induced quantum dots

We study a system in which electrons in a two-dimensional electron gas are confined by a nonhomogeneous nuclear spin polarization. The system consists of a heterostructure that has non-zero nuclei spins. We show that in this system electrons can be confined into a dot region through a local nuclear spin polarization. The nuclear-spin-polarization-induced quantum dot has interesting properties indicating that electron energy levels are time-dependent because of the nuclear spin relaxation and diffusion processes. Electron confining potential is a solution of diffusion equation with relaxation. Experimental investigations of the time-dependence of electron energy levels will result in more information about nuclear spin interactions in solids

ДНК- и РНК-вакцины: современное состояние, требования к качеству и особенности проведения доклинических исследований

This review focuses on DNA and RNA vaccines whose potential use was first considered at the end of the 20th century. However, not a single bacterial plasmid-based or mRNA vaccine has been used since that time in public healthcare for the prevention of infectious diseases. Nevertheless, vaccines containing recombinant nucleic acids as the active ingredient still attract interest due to the possibility of rapid development, low-cost production, safety of the technology and the potential to activate cellular and humoral immunity. Recent technological advances have largely overcome the problems of low immunogenicity, instability, and difficulties with the delivery of DNA and RNA vaccines in humans. The aim of this review was to present the main strategies of development of DNA and RNA vaccines designed to prevent infectious diseases, and to summarise requirements for the quality control and preclinical studies. The article examines the general principles of creation of plasmid vectors encoding protective antigens. It describes new technologies used in the creation of DNA vaccines with plasmids encoding an attenuated virus genome (iDNA and PPLAV), and RNA vaccines based on mRNA and self-amplifying RNAs. The article presents current regulatory requirements for the choice of quality parameters to be tested and the general principles of preclinical studies of DNA and RNA vaccines.Обзор посвящен ДНК- и РНК-вакцинам, возможность использования которых была показана еще в конце XX века. При этом до сих пор ни одна вакцина, основанная на использовании бактериальных плазмид и мРНК, не нашла применения в практике здравоохранения для профилактики инфекционных заболеваний. Но, несмотря на это, интерес к вакцинам, действующим веществом которых являются рекомбинантные нуклеиновые кислоты, сохраняется из-за возможности их быстрой разработки, малозатратного производства, безопасности технологии и возможности активации клеточного и гуморального иммунитета. Последние технологические достижения в значительной степени преодолели проблемы низкой иммуногенности, нестабильности и трудности доставки при применении ДНК- и РНК-вакцин у человека. Цель работы — изложение основных стратегий создания ДНК- и РНК-вакцин, предназначенных для профилактики инфекционных заболеваний, обобщение требований к оценке их качества и проведению доклинических исследований. Представлены общие принципы создания плазмидных векторов, кодирующих протективные антигены. Описаны новые технологии создания ДНК-вакцин, плазмиды которых кодируют геном аттенуированного вируса (iDNA и PPLAV). Приведены стратегии создания РНК-вакцин на основе мРНК и самоамплифицирующихся РНК. Представлены современные регуляторные требования к выбору необходимых показателей качества и общим принципам проведения доклинических исследований ДНК- и РНК-вакцин