Macroscopic Quantum Tunneling in Small Antiferromagnetic Particles: Effects of a Strong Magnetic Field

We consider an effect of a strong magnetic field on the ground state and macroscopic coherent tunneling in small antiferromagnetic particles with uniaxial and biaxial single-ion anisotropy. We find several tunneling regimes that depend on the direction of the magnetic field with respect to the anisotropy axes. For the case of a purely uniaxial symmetry and the field directed along the easy axis, an exact instanton solution with two different scales in imaginary time is constructed. For a rhombic anisotropy the effect of the field strongly depends on its orientation: with the field increasing, the tunneling rate increases or decreases for the field parallel to the easy or medium axis, respectively. The analytical results are complemented by numerical simulations.Comment: 11 pages, 6 figure

Penicilliform anthropomorphic manipulator

In the article a description of robot-equippe

Toxicological parameters of the drug based on Ornidazole and Levamisole hydrochloride

The purpose of the research is the study of pharmaco-toxicological properties of the Ornidazole- and Levamisole hydrochloride-based drug.Materials and methods. The pharmaco-toxicological properties of the Ornidazole- and Levamisole hydrochloride-based drug were studied in the premises of the Laboratory of Preclinical Studies, Faculty of Veterinary Medicine, Stavropol State Agrarian University. Acute and chronic toxicity, and irritant effect of the drug was studied under the Guidelines for Preclinical Studies of Drugs (2012). Hematological studies of laboratory animals were performed with an automatic hematological analyzer, and biochemical studies of the blood serum were done with an automatic biochemical analyzer.Results and discussion. It has been found that the Ornidazole- and Levamisole hydrochloride-based drug belongs to the Hazard Class 3 for the median lethal oral dose in accordance with GOST 12.1.007–76 as moderately hazardous substances; it does not have a pronounced subchronic toxicity or irritant effect. Multiple use of the active substance for 14 days does not cause significant changes in the clinical condition, or in hematological and biochemical profile of laboratory animals

Quantum analogue of the spin-flop transition for a spin pair

Quantum (step-like) magnetization curves are studies for a spin pair with antiferromagnetic coupling in the presence of a magnetic field parallel to the easy axis of the magnetic anisotropy. The consideration is done both analytically and numerically for a wide range of the anisotropy constants and spins up to $S \gtrsim 100$. Depending on the origin of the anisotropy (exchange or single-ion), the magnetization curve can demonstrate the jumps more than unity and the concentration of the unit jumps in a narrow range of the field. We also point the region of the problem parameters, where the behavior is quasiclassical for $S = 5$, and where system is substantially quantum in the limit $S \to \infty$.Comment: 5 pages, 5 figure

Sorption Properties of Polymeric Enterosorbent and Its Specific Modified Analogue in Simulated Cholera Toxin Solutions <I>in vitro</I>

Carried out was comparative study of the sorption properties in polymeric enterosorbent - chitosan, and its specific modified analogue obtained through absorption of anti-toxin immunoglobulins onto the soluble chitosan template. It is determined that soluble chitosan and its specific counterpart express high sorption activity in relation to cholera toxin, thus making lower its initial concentrations. Equilibrium adsorption capacity of the chitosan and its modified variant increase with the raise of initial cholera toxin concentration in the solution. Cholera toxin extraction rate was identified under static conditions. Adsorbate substance recovery rate was registered in the progression. In the course of experiments proved was modified sorbent specific sorption efficiency, occasioned by the presence of the active component in the analogue composition - namely, anti-toxic anticholeraic immunoglobulins. The data obtained are of the importance for further development of specific anticholeraic enterosorbent

Research Leadership of the “Priority 2030” Program: Success Factors

The article presents the results of comparative analysis of universities’ activities over the past five years, which won the special grant in the “Research Leadership” track of the “Priority 2030” program. The comparison is carried out between the following groups of universities: 1) all universities of the “Research Leadership” track, 2) the first, second and third groups, selected according to the results of the competition, and 3) group of Project 5-100 participants. The state strategic initiatives in the field of the higher education system over the past 15 years were considered to determine their impact on the development of the considered groups of universities; the indicators that make significant contribution to the results of educational, research, international and financial activities of universities were selected. The aggregation of indicators for university groups has been carried out using the Displaced Ideal method and the comparative analysis for 2016 – 2020. The significant indicators of scientific and research activities of analyzed groups of universities for 2018 – 2020 were considered. Based on the analysis, the most significant factors of success have been identified that ensured the victory of the considered universities in the Priority 2030 competition on the “Research Leadership” track

The First Year of the Priority 2030 Program Implementation: Positive Results and Problem Areas of Research Track Universities

The article considers the results of the main activities of universities – participants’ groups of the Priority 2030 program of the «Leadership in Research» track (hereinafter referred to as the research track) at the initial stage of its implementation. An analysis of performance indicators’ dynamics for groups of universities in the period preceding the implementation of the program (2017–2020) and the first year of its implementation (2021) was carried out. Special attention is given to the analysis of the activities of universities that are leaders in the research track. As part of the comprehensive analysis, positive results were identified, as well as some problem areas in the activities of universities. An analysis of the basic indicators shows that the researched groups of universities in a number of indicators have a relatively small difference in the achieved values, while the indicators of the special part revealed an unconditional group of leaders