A linear control system with an almost periodic matrix of coefficients and control in the form of the feedback linear in phase variables is considered. It is assumed that the feedback coefficient is almost periodic and its frequency module, i. e. the smallest additive group of real numbers, including all the Fourier exponents of this coefficient, is contained in the frequency module of the coefficient matrix. The system under consideration is studied in the case of a triangular average value of the matrix of coefficients. For the described class of systems, the control problem of the asynchronous spectrum with a target set of frequencies is solved. This task is to construct such a control from an admissible set that the system closed by this control has almost periodic solutions, a set of the Fourier exponents of which contains a predetermined subset, and the intersection of the solution frequency modules and the coefficient matrix is trivial. The necessary and sufficient conditions for the solvability of this problem are obtained.

The fast multilevel algorithm to cluster color images (MACC – Multilevel Algorithm for Color Clustering) is presented. Currently, several well-known algorithms of image clustering, including the k‑means algorithm (which is one of the most commonly used in data mining) and its fuzzy versions, watershed, region growing ones, as well as a number of new more complex neural network and other algorithms are actively used for image processing. However, they cannot be applied for clustering large color images in real time. Fast clustering is required, for example, to process frames of video streams shot by various video cameras or when working with large image databases. The developed algorithm MACC allows the clustering of large images, for example, FullHD size, on a personal computer with an average deviation from the original color values of about five units in less than 20 milliseconds, while a parallel version of the classical k‑means algorithm performs the clustering of the same images with an average error of more than 12 units for a time exceeding 2 seconds. The proposed algorithm of multilevel color clustering of images is quite simple to implement. It has been extensively tested on a large number of color images.

The principles of formation of the complex vacancy defects (V-clusters), their ensembles and patterns of formation of superlattices of the V-clusters are determined. The inclusion of the drift component of the elementary defects into the field of elastic stresses of the V-cluster in the analysis allowed describing its genesis and development adequately. The mechanisms of motion of the V-clusters in the material are described in detail, considering their interaction with each other. The authors have developed the original physical and mathematical formalism within which it has become possible to describe the order-disorder phase transition when an ensemble of clusters chaotically distributed in the irradiated solid transforms into an ordered coherent superlattice. The critical point of the phase transition and the parameters of the defect lattice itself are determined. They are confirmed by the experimental results. The ordering process in this system is understood as the motion of the undamped wave of order parameter through the material, while other configuration states of the V-cluster ensemble constitute rapidly damping fluctuations. The article also shows the mechanism of linking the symmetry of the V-cluster superlattice to the symmetry of the initial crystal.

The transient absorption spectra dynamics for hybrid associates of colloidal CdS quantum dots, passivated by thioglycolic acid (CdS/TGA QDs), and methylene blue cationic dye molecules (MB+) were studied by femtosecond spectroscopy. It was established that one of the main channels of relaxation of the CdS/TGA QDs excitation energy in hybrid associates based on CdS/TGA QDs and MB+ is a fast energy transfer to the reduced forms of MB+ (MBOH•, MB•) that are formed still at the synthesis stage of samples. This channel strongly competes with the resonant energy transfer from the centers of radiative recombination in quantum dots to MB+. Therefore, for hybrid associates based on QDs/TGA and methylene blue, there is no any noticeable signal of the transient absorption corresponding to the triplet state of MB+ dye, which is then known to be actively involved in charge transfer.

In this work, soluble and solid phase immunoreagents, including recombinant human lactoferrin (rhLF), a complex of rhLF with europium ions, rabbit antiserum to rhLF, anti-rhLF immunoglobulin purified by antigen-affinity chromatography and the conjugates of this immunoglobulin with an Eu3+ chelate or horseradish peroxidase have been obtained by a combination of biochemical and synthetic methods using rhLF as an initial compound. Biospecific interactions of the reagents in four immunochemical systems were assessed by measuring the enzyme activity or time-resolved fluorescence. The study resulted in the development of fast and precise immunoassays for biologically active rhLF in transgenic goat milk and in protein fractions obtained in the course of pure rhLF manufacture, as well as in pharmaceutical preparations and food additives.

Biospecific sorbents for the removal of IgG and subclasses from biological fluids based on oligopeptides, containing aromatic amino acid residues, were created. The selectivity properties of specific sorbents for IgM, IgE, and plasma proteins were evaluated. It was found that the created sorbents exhibit the low activity to the total plasma protein, albumin, IgM, IgE and are highly specific for IgG.

Kinetics of phosphatidylcholine (PC) hydrolysis under the action of pancreatic phospholipase A2 IB, (EC 3.1.1.4, PLA2) in the presence of a lipophilic derivative of the antiviral drug Virazole 1-(3-((tert-butyldimethylsilyl)oxy)-4-hydroxy-5- (((4-methoxyphenyl)diphenylmethoxy)methyl)tetrahydrofuran-2-yl)-1H-1,2,4-triazole-3-carboxamide (Virazole2ЗГ) was studied. The both steps of phospholipolysis were quantitatively characterized: the binding of the enzyme to the lipid-water interface (Ks) and directly the catalytic act (Km) with the determination of the maximum reaction rate (Vmax). It was found that Virazole2ЗГ at a concentration of 0.5 μmol/ml does not affect the Ks value; on the contrary, the Michaelis constant, Km, increases by a factor of 1.8 along with the constancy of the parameter Vmax. Based on the constancy of the Ks values, it seems to be assumed that there is no inhibition of the disintegration of the enzyme-micelle complex in the presence of the effector under the studied reaction conditions. The kinetic parameters of the reaction (the increase in Km and the constancy of Vmax in the presence of Virazole2ЗГ) testify in favor of a moderate competitive inhibition of pancreatic PLA2, Ki = 65 mM, which indicates the possibility of searching for the biological activity of the anti-pancreatitis action in the series of pro-drugs of nucleoside nature.

The organic anion balance is critical for metabolic, bioenergetic, and electrochemical processes in plant cells, controlling the quality and quantity of yield and plant stress resistance. Nevertheless, the redistribution and membrane transport of these substances in plant tissues have not been investigated in detail. The mechanism of passive anion efflux from a plant cell through the ion channels has not been established so far. Here, using the patch-clamp technique, we have characterized the ion channel-mediated conductances of ascorbate, malate, gluconate, citrate, fumarate, and pronionate in the root cells of Arabidopsis thaliana, Triticum aestivum, and Helianthus annuus. These conductances showed high permeability to ascorbate, malate, and citrate, as well as low permeability to fumarate, propionate, and gluconate. Anion channel conductances of root cells showed rapid activation kinetics and low potential dependence. They were also inhibited by 9-anthracenecarboxylic acid, suggesting that they belong to the ALMT family of anion channels found only in higher plants. Aequorin chemilu minometry was used to test the effect of organic anions on the Ca2+ signaling in root cells. Among four organic anions tested, only ascorbate induced a significant increase in the cytosolic Ca2+ activity at physiological levels (1 and 10 mM). This effect may underlie the previously unknown functions of exogenous ascorbate related to short- and long-distance signaling in higher plants.

Seedlings of yellow lupine treated with Colletotrichum lupini isolate were studied by the method of SRAP-analysis with the purpose to assess the differential expression of genes. As a result, the PCR fragment corresponding to tolerant seedlings was found. The genetic determinants found are likely involved in the control of the resistance (tolerance) of lupine plants to anthracnose.

In the article, the symptoms of coronavirus infection COVID-19, its effect on the cognitive functions and physical performance of students of a higher education institution of medical profile are described, the measures to prevent the spread of this infection are considered, as well as the measures for a subsequent recovery of students, who have undergone this disease and have entered the educational process, are proposed.

The pattern of lumican expression in corneal explants of patients with chronic dystrophic cornea diseases and the changes in its expression after 1 % sodium hyaluronate expression are established. The prospective study included 37 patients with chronic dystrophic diseases of the cornea: keratopathies in the outcome of keratitis (20 cases) and endothelial-epithelial dystrophy (17 cases). The patients were divided into 2 groups. The first group in the preoperative period received the injections of 1 % low molecular weight sodium hyaluronate, the second group did not receive additional treatment. All patients included in the study underwent penetrating keratoplasty. The immunohistochemical study of corneal explants was performed using primary monoclonal antibodies to lumican with subsequent morphometric evaluation of the preparations. The proportion of pixels with high and moderate intensity and the index of expression intensity in immunopositive regions were calculated. In the group of patients with aggressive keratitis, the intensity of lumican expression both in the epithelium and in the corneal stroma was statistically significantly higher than in the control group and decreased with the use of 1 % low molecular weight sodium hyaluronate. After the leukoma formation, the expression of lumican both in the epithelium and in the corneal stroma was comparable to that in the control group with higher parameters of epithelial expression after sodium hyaluronate administration. In the groups of endothelial-epithelial dystrophy, an increase in the intensity of expression was noted after sodium hyaluronate injections. The noted increase in the epithelial expression of lumican against the background of pronounced alteration is accompanied by its gradual decrease as the regeneration is completed. An important factor is its normal content in the corneal stroma, since both a sharp increase and low expression parameters are accompanied by a decrease in corneal transparency.

Radon transported from the atmosphere to the earth’s surface is shown to have a significant role in the formation of its concentration levels in the lowest atmospheric layers. The amount of radon escaping from the atmosphere with sporadically occurred rainfalls is quantitatively comparable with the amounts emitted from the soil into the atmosphere. A stable dependence has been established between the radon concentration levels in the surface atmosphere and the air humidity

This article contains the microparticle accelerator scheme, the methods, and the results of practical study of magnetic field induction and electromagnetic radiation formed during explosion product ionization and energy accumulation during explosive charge detonation, as well as the influence of some process parameters on its change. The purpose of this work is to study the influence of accelerator energy parameters and silicon carbide microparticle sizes on the change in magnetic field induction during their acceleration. The influence of technological parameters on the electrodynamic properties of the ionization process of a complex chemical system, which is condensed EXPLOSIVES, was studied by the developed method based on the Hall effect with the use of the developed semiconductor Hall sensors and a special measuring complex. The average magnetic field induction value is 48 MT. The influence of the energy parameters of the accelerator (explosive charge mass), as well as of the size of microparticles introduced into the explosion products (PV) on the electrodynamic properties of the processes of ionization and acceleration of microparticles was determined by measuring and calculating magnetic field induction. Practical results were obtained and confirmed the particle size influence on the plasma state. With an increase in the particle size from 20 to 100 microns, the induction value increases to 50 MT and decreases sharply with a change in the size from 150 to 300 microns. The obtained dependences are the technological characteristics of the process of processing materials by high-speed flows of microparticles with the use of explosion energy, which can be adjusted to make the process manageable.

The methods of molecular genetic analysis are widely used to assess the genetic structure and to study the dynamics of population-genetic processes in populations of domestic animals. I n particular, these are the highly polymorphic genetic markers – the microsatellites that are the most common molecular markers in genetic and genomic research. The aim of the research was to develop the genealogical structure of the Belarusian black-and-white breed based on the microsatellite analysis of the lines bred at a gene pool enterprise. The research was carried out with the animals bred at the JSC “SGC “Zarechye”. For the microsatellite analysis of boars of the Belarusian black-and-white breed, the DNA testing was carried out at 9 STR-loci (SО155, SО355, SО386, SО005, SW72, SW951, SО101, SW240, and SW857). In all studied lines, the largest number of effective alleles was at the SО005 locus – 4.00–5.14. The lines of animals with heterozygosity can be used in various breeding schemes, both in purebred breeding (in pedigree pig breeding) and in crossing (in industrial pig breeding). Polymorphism determines the degree of genetic variation in populations. The locus is classified as polymorphic when the frequency of the most common allele of this locus does not exceed 95% (р ≤ 95). The revealed polymorphism of loci in the lines Maket, Tik, and Veseliy indicates the presence of genetic variability in them, which allows using them in breeding and breed-forming processes. Based on the studies made, the genealogical structure of the Belarusian black-and-white breed, consisting of one subcluster and two branches, has been developed, which makes it possible to assess the state and degree of relation of structural units (lines), and reflects the prospect of their further use.

The organomineral compost compositions, which provide increased biometric indicators of seedlings of forest plants, are described. Compost is obtained on the basis of the secondary resources of forest and agricultural production. The compost readiness indicator, depending on the composition and composting time, is proposed. The influence of the polymer structure-forming agent of the soil on the compost quality is shown. The influence of compost composition variations on the morphometric parameters of seedlings is studied. The recommended ratios of ingredients in organomineral compost for growing planting material in forest nurseries are given.