For a one-dimensional wave equation, we consider a mixed problem in a curvilinear half-strip. The initial conditions have a first-kind discontinuity at one point. The mixed problem models the problem of a longitudinal impact on a finite elastic rod with a movable boundary. We construct the solution using the method of characteristics in an explicit analytical form. For the problem in question, we prove the uniqueness of the solution and establish the conditions under which its classical solution exists.

The present study investigated the ability of recombinant human lactoferrin (rhLF), isolated in pure form from the milk of transgenic goats, to nonspecific interactions and specific complex formation with natural DNA and synthetic DNA fragments. Intact rhLF was utilized, containing a europium ion in the metal-binding center possessing long-lived fluorescence. In a microplate system, rhLF-Eu³⁺ interacted with adsorption-immobilized total double-stranded DNA from the calf thymus with Ka = 1.7  10⁶ M^–1. In the same heterophase system, singleand double-stranded (ds-) oligonucleotides with specific (L) or nonspecific (S) sequences were bound in solution to rhLF–Eu³⁺ and competitively inhibited the interaction of the labeled protein with DNA on the solid phase. The inhibitory effect was contingent upon the specificity, structure, and length of the nucleotide sequence, exhibiting a decrease in the following sequence: ds-L₂₅ > ds-S₅₀ > ds-S₂₁₅ > ds-S₁₈₀ > ds-S₁₁₅ > L₂₅ > S₅₀. In an alternative system, specific (ds-L₂₅) and nonspecific (ds-S₅₀) oligonucleotides, biotinylated through a long mobile linker, were immobilized onto the solid phase coated with biotin-binding protein streptavidin. The affinity of rhLF for these ligands was characterized by Ka of 6.4  10⁷ and 7.1  10⁶ M^–1, respectively. The binding to the nonspecific nucleotide sequence was also much more sensitive to the ionic strength of the solution and the concentration of an inert protein. The ability of rhLF to interact with DNA would confirm the identity of natural and recombinant proteins and encourage the use of rhLF as a biologically active food supplement and pharmaceutical substance.

The process of obtaining potassium sulfate with a basic substance content of at least 95 % is realized under normal conditions. In order to achieve a high content of potassium sulfate in the product, an excess of potassium chloride relative to ammonium sulfate at a weight ratio of at least 1.6 is required. During the dissolution of potassium chloride in a solution of ammonium sulfate, the main factor of obtaining concentrated potassium sulphate is to get the purest possible nuclei of potassium sulfate crystals. The excess of potassium chloride resulting from the synthesis process is utilized by the production of NPKS-fertilizers in liquid and granulated forms.

Genetic polymorphisms of surfactant proteins SP-B and SP-C may contribute to the development of respiratory disorders among preterm newborns. The aim of this study was to analyze the contribution of intergenic and intragenic combinations of SFTPB and SFTPC genotypes to the pathogenesis of respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD) in preterm infants. A total of 567 newborns were genotyped for the polymorphic loci rs2077079 and rs1130866 of the SFTPB gene as well as rs4715, rs1124, and rs2070687 of the SFTPC gene using real-time PCR with TaqMan probes and Sanger sequencing. In preterm girls, the risk of RDS was significantly higher in those carrying the genotype combinations –18CCSFTPB/413CASFTPC and –18CCSFTPB/436-8CGSFTPC (p = 0.044 and p = 0.03, respectively). The 1580СТSFTPB/ 557ААSFTPC combination was associated with severe RDS regardless of sex (p = 0.019). Among girls, RDS severity was linked to –18CASFTPB/557CCSFTPC and 1580CT/–18CA SFTPB combinations ( p = 0.018 and p = 0.033, respectively), while in boys, the 1580TTSFTPB/413CCSFTPC combination was associated with more severe disease (p = 0.03). In preterm infants with a gestational age of 28–34 weeks, the risk of BPD was associated with the 1580СТSFTPB/413ССSFTPC genotype combination ( p = 0.031). Thus, specific intergenic and intragenic combinations of SFTPB and SFTPC gene polymorphisms are significantly associated with the risk and severity of RDS and BPD in preterm newborns.

Due to the mandatory immunosuppression and concomitant diseases, heart transplant recipients are at an increased risk of an adverse outcome from COVID-19 infection. The efficacy and safety of using vaccines to prevent COVID-19 infection in patients with heart transplants, including the development of undesirable inflammatory and autoimmune reactions, has not been sufficiently studied. This paper presents the characteristics of humoral immunity and the analysis of autoantibody production in heart transplant recipients after vaccination against a coronavirus infection. The main group consisted of patients (n = 40) who underwent orthotopic heart transplantation in the period from 2009 to 2021 at the National Research and Practical Center “Cardiology” and received two doses of the Vero Cell vaccine (China) or got a three-step booster Gam-COVID-Vac (Sputnik V, Russian Federation). It has been shown that 63 % of vaccinated individuals with no previous COVID-19 history and 85 % of patients with a history of COVID-19 infection developed humoral post-vaccination immunity. The humoral response in patients who had seroconversion prior to vaccination exhibited elevated levels of virusspecific IgG antibodies to the SARS-CoV-2 virus S protein during the post-vaccination period, with a statistically significant increase observed by 9–12 months after booster vaccination. Vaccination against the coronavirus infection does not result in an increase of serum autoantibodies (RF IgG and IgA, anti-SSR, cardiolipin IgG, β2-glycoprotein IgG, ANA, ANCA-Pro, anti-SLA/LP, anti-GD-IgA) in heart transplant recipients. At the same time, vaccinated heart transplant recipients with a history of coronavirus infection showed an increase in the level of antibodies to IFN-α for a period of 9–12 months after the main vaccination. This evidence, when associated with HLA alleles, must be taken into account for identifying patients who may be at risk of developing severe diseases.

Mesenchymal stem cells (MSCs) are multifunctional adult stem cells that can be derived from various tissues, such as adult adipose tissue, peripheral blood, bone marrow, neonatal placenta, and umbilical cord tissue. MSCs have the capacity for self-renewal and multidirectional differentiation. Despite the absence of differences in the expression of the main surface markers, MSCs obtained from tissues of the placenta-umbilical cord complex, adipose tissue and bone marrow differ significantly in their molecular profile. Cellular heterogeneity is ubiquitous across MSC cultures from different species and tissues. During the course of the study, the expression level of cell surface markers that characterize the heterogeneity of MSCs obtained from various sources was assessed. MSCs from all tissues express typical MSC markers on their surface, including CD13, CD73, CD105 and CD90, in the absence of expression of hematopoietic markers (CD14, CD34 and CD45), costimulatory molecules CD86, membrane protein CD154, adhesion molecules CD15, and markers of embryonic stem cells (TRA-1-81 and TRA-1-60R). However, they differed in the expression of stemness markers (October 4, Nanog), coinhibitory molecules (CD273, CD274, and CD200), cell adhesion molecules CD146, surface antigen SSEA-4, and transcription factor GATA4. The results on the molecular profile of MSCs as a heterogeneous cell population allow for the scientific substantiation of the choice of tissue source for the creation of biomedical cell products with specified therapeutic properties.

The results of the analysis of differences in climate norms in different months of the year during the modern climate warming period (1990–2023) and the preceding period (1956–1989) in the high latitudes of the Northern and Southern hemispheres (60–90°N and 60–90°S) are presented. A comparative analysis of changes in temperature gradient was conducted for near-equatorial (0–10°N and 0–10°S) and polar (65–90°N and 65–90°S) latitudes of the Northern and Southern hemispheres. The decrease in the gradient value was most significant in transitional seasons of the year and especially in autumn. In the Southern hemisphere, the largest decrease in temperature gradient occurred in winter and spring (June–October). The possible causes of climate warming in the high latitudes of the Northern and Southern hemispheres are considered.

The results of XRD structural studies of the evolution of the phase composition and structure of high-temperature metal-ceramic composites obtained in situ by mechanochemical synthesis in reaction mixtures (Ti–C)–хМe (Me = Ti, Ni, Mo; х = 50–70 wt. %) have been given. When processing the initial powders in a planetary ball mill with an energy intensity of 7.0 W/g, mechanically stimulated reactions are realized with the formation of metal-ceramic composites within 8–20 min. In all of the considered compositions, except for Me = 70 wt. % Ti, a liquid-phase combustion mechanism is realized with the formation of a metal-matrix amorphous-crystalline structure of supersaturated solid solutions, which are dispersion-hardened by titanium carbides. In the (Ti–C)–70 wt. % Ti mixture, solid-phase interaction is realized with the formation of a supersaturated solid solution αTi(C) with its subsequent decomposition with the precipitation of TiC0.47. The initiation stage duration tign for Me = Ti is approximately 2–4 min. The formation of a low-temperature Ni–Ti eutectic in the (Ti–C)–50Ni composition helps to reduce the duration of the reaction ignition tign to 1 minute and to increase the synthesis rate of TiC0.78–0.83 inclusions. Increasing the concentration to 70 wt. % Ni leads to an increase in tign to 4 min. A decrease in the adiabatic temperature promotes the formation of carbon-depleted carbide TiC0.64–0.78. The use of refractory molybdenum as a matrix metal increases tign and is in the range of approximately 4–8 minutes. In compositions (Ti–C)–xMe (Me = Ti, Ni), the mechanosynthesized TiC content reaches approximately 40 ± 3 wt. % at x = 50 % and approximately 27 ± 1 wt. % at x = 70 %. In compositions (Ti–C)–xMo with x = 50 and 60 wt. %, a NaCl-type (Mo, Ti)C carbide forms in quantity of 69 wt. %. The obtained results demonstrate the promising prospects for mechanochemical in situ synthesis of dispersion-strengthened composites based on refractory metals for materials with enhanced heat resistance and high-temperature stability.

DNA testing of Landrace pigs was carried out for the genes RYR1, ESR, PRLR, MUC4, ECR F18/FUT1, H-FABP (allele systems H and D) and 15 DNA microsatellites. The frequency of occurrence of the preferred genotype for the RYR1NN gene was 100 %. The desired genotypes PRLRАА, H-FABPHH and H-FABPdd were identified in pigs with a frequency of 10.0–73.3 %, 33.3–84.0 % and 33.3–40.0 %, respectively. No animals were identified as being resistant to colibacillosis (ECRАА genotype). The majority of Landrace pigs at breeding farms were resistant to E. coli F4 and had the preferred genotype MUC4CC – 70.9 %. When analyzing population genetic parameters using microsatellite DNA data, 110 alleles were identified in animals. The number of alleles for the loci ranged from 3 to 10. The highest level of allelic diversity was identified in animals bred at SE “ZhodinoAgroPlemElita” – 5.40 alleles per locus. The accuracy of assignment of the studied animals to “their” respective population exceeds 98 %. A high degree of genetic similarity was identified among the Landrace breed animals of the studied populations. The coefficients of genetic similarity ranged from 0.795 to 0.874.