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Regulating retail fuel prices, which are getting particularly volatile, is an urgent issue amid the shock period that the global energy industry is facing today. Price volatility, however, is a factor in coordinating consumers’ and fuel producers’ plans. Economic theory fails to explain why in some countries, during a shock period, governments tend to regulate retail prices, while in others they develop market pricing mechanisms in the fuel market. The article reveals the influence of Douglass North’s social orders on the tendency of governments to establish a price regulation mechanism in the retail fuel market. New institutional economics constitutes the theoretical framework of the study. Among the research methods are case analysis, comparative crosscountry analysis, and statistical analysis. The empirical evidence comes from regulatory legal acts, US and Russian state statistics on fuel prices for 2019–2023, and materials from the GlobalPetrolPrices project. The research results revealed differences in uncertainty assessments by the governments of countries with different social orders: for regulators in open access social orders, industry shock is the reason of finding a new way to adapt to market conditions; for regulators in limited access social orders, it is the risk of destabilization of the social order. Our findings help to outline the institutional rationale behind the implementation of industry-specific policies.

Background. The need to create antenna-waveguide paths for multi-band reflector antennas of satellite communication systems requires the use of various methods for selecting the structure, determining and optimizing the parameters of antenna-waveguide paths. Aim. Development of a mathematical model of antenna-waveguide paths of multi-band reflector antennas, built on the basis of the «polarization separation – frequency separation» method with the implementation of the auto-tracking function. Methods. A mathematical model of antenna-waveguide paths of multi-band reflector antennas, built on the basis of the «polarization separation – frequency separation» method, allows us to determine the main characteristics of antenna-waveguide paths and incoming devices with an auto-tracking function. Results. The main elements of the mathematical model of multi-band antenna-waveguide paths built on the basis of the «polarization separation – frequency separation» method are determined. Conclusion. A mathematical model has been proposed that makes it possible to reduce the requirements for the computing tools used when developing antenna-waveguide paths in terms of RAM capacity and performance. The ability to analyze and determine the characteristics of antenna-waveguide paths using a mathematical model has been implemented. The stages of determining the parameters of antenna-waveguide paths are presented, based on the developed mathematical model of the corresponding design option, as well as theoretical and experimental data confirming the correctness of the model of antenna-waveguide paths.

Abstract The lowest energy states in transition metal dichalcogenide (TMD) monolayers follow valley selection rules, which have attracted vast interest due to the possibility of encoding and processing of quantum information. However, these quantum states are strongly affected by temperature-dependent intervalley scattering leading to complete valley depolarization, which hampers practical applications at room temperature. Therefore, for achieving clear and robust valley polarization in TMD monolayers one needs to suppress parasitic depolarization processes, which is the central challenge in the growing field of valleytronics. Here, in electron-doping experiments on TMD monolayers, we show that strong doping levels beyond 1013 cm−2 can induce 61% and 37% valley contrast at room temperature in tungsten diselenide and molybdenum diselenide monolayers, respectively. Our findings demonstrate that charged excitons in TMD monolayers hold the potential for the development of efficient valleytronic devices functional at 300 K.

Relevance. The phenomenon of law as a special civilized, intellectual and value-substantive social authority attracts the attention of scientists to conceptualize its current state, development trends and problems of formation. It is relevant to establish the functional role of certain social groups in the formation of law and the mechanisms (algorithms) for its effective, fair and correct application in social reality. Various social structures and groups are involved in the development, acceptance, adaptation to social reality and assessment of applicability in life. A special social subject in the triumph of law and justice, as well as the development of its norms, is the intelligentsia, which, being a specific domestic phenomenon, at different stages of the historical development of the state and society acted as a catalyst for both the abolition of outdated norms and the rapid development of law, taking into account the needs of broad social groups. Materials and methods. The purpose of the research in the article is a comprehensive knowledge of law and the intelligentsia in their functional relationship and relationships of codependency in the minds of the subjects. The subject of the study is to understand the commonality of the social functions of law and the intelligentsia, based on the role of the domestic intelligentsia in the formation of law. To solve research problems, the authors use systemic, activity-based and formal legal approaches as a methodology, which involve the use of component, structural, functional, historical and other types of analysis, synthesis of its results, analogy, comparison, generalization, deduction and abstraction. Results and conclusions. The main results of the study include: conceptualization of the commonality of social functions of law and the intelligentsia, as well as the conclusion that in the development of the “fabric of law” and “social life of law” an active functional role is played by the intelligentsia and intelligence, which is one of the characteristics of the identity of the domestic legal system.

Background. The subterahertz and terahertz frequency ranges are very promising for development of high speed wireless communications systems because of possibility to get the bandwidth about some tens of GHz, which provides the high channel capacity. However fast signal attenuation at its propagation in atmosphere complicate the operation of communications systems in these ranges. Aim. Use of fixed narrow-beam antennas with high antenna power gain allows to provide the direct surface communications distance to some kilometers. The communications distance limitation can be partially removed decreasing the frequency down to 200 GHz and narrowing the channel bandwidth down to some GHz. Methods.The model of transmitter-receiver system (200-220 GHz) based of modern semiconductor devices is described in the manuscript. Results. The possibility of digital signals transmission with speed up to 1 Gbit/s at the distance of 1 km is experimentally shown. Conclusion. According to calculations the output power of transmitter about some hundreds mW is enough for data transmission at the distance up to 1.5 km with antenna power gain of no less than 50 dB.

Abstract Sb is a three-dimensional Peierls insulator. The Peierls instability gives rise to doubling of the translational period along the [111] direction and alternating van der Waals and covalent bonding between (111) atomic planes. At the (111) surface of Sb, the Peierls condition is violated, which in theory can give rise to properties differing from the bulk. The atomic and electronic structure of the (111) surface of Sb have been simulated by density functional theory calculations. We have considered the two possible (111) surfaces, containing van der Waals dangling bonds or containing covalent dangling bonds. In the models, the surfaces are infinite and the structure is defect free. Structural optimization of the model containing covalent dangling bonds results in strong deformation, which is well described by a topological soliton within the Su–Schrieffer–Heeger model centered about 25 Å below the surface. The electronic states associated with the soliton see an increase in the density of states (DOS) at the Fermi level by around an order of magnitude at the soliton center. Scanning tunneling microscopy and spectroscopy (STM/STS) measurements reveal two distinct surface regions, indicating that there are different surface regions cleaving van der Waals and covalent bonds. The DFT is in good agreement with the STM/STS experiments.

This paper explores the potential for using practice-based assessments in higher education in preparing humanities and social sciences specialists. The authors tested a set of innovative methodologies for practice-based summative assessment of the progress made in learning certain disciplines by students majoring in Law, International Law, and History and Archaeology at Sumy State University (Ukraine). To assess the effectiveness of practice-based assessments, the authors employed anonymous surveying, tested students' level of mastery of key theoretical concepts, and carried out a comparative analysis of the performance of students who took part in practice-based assessments and those who took exams in a traditional way. The conducted pedagogical experiment indicates the advisability of employing practice-based assessments as part of teaching humanities and social sciences disciplines. It revealed a significant increase in the level of preparation of students on subjects summative assessment around which was based on practical assignments. Having students train their practical skills can help them assimilate theoretical knowledge better and for a longer time and become more confident in their preparedness for their future profession. Practice-based assessments can also serve as a yardstick for gauging the effectiveness of instructors' teaching methods and stimulate the quest for new ways of teaching and learning that can help meet the needs of the labor market and the interests of students pursuing a higher education as much as possible.

This paper continues the authors' analysis of the policy pursued by the government of the Ukrainian State in the area of public education in 1918. The primary focus in the work's second part is on the government's policy on preschool, primary, and secondary education. The key sources employed in the work are materials from the period's periodical press, memoirs by contemporaries of the events, and published statutory enactments of the government of the Ukrainian State regulating policy on primary and secondary education. It is in the year 1918 that the primary, secondary, and higher education systems in the Ukrainian State were formalized legally. The government was deeply aware of the decisive role of the public education system in the development and strengthening of Ukrainian statehood. The authors drew the conclusion that primary and secondary schools in the region enjoyed a high level of autonomy in terms of organization of the educational process at the time. The exception was that government policy actively facilitated the Ukrainization of the educational process -- by way of introduction of instruction in the Ukrainian language and disciplines related to Ukrainian studies. This was a positive influence amid the formation of a young Ukrainian state. Despite a challenging military/political and economic situation, the government did manage to provide most of the region's educational facilities with all appropriate course materials. The government worked closely with local authorities and the public, which had a positive effect on the development of the systems of primary, secondary, and preschool education locally. [For Part 1, see EJ1284289.]

As the bureaucratic apparatus burgeoned in the Russian Empire, an urgent need arose to provide it with professional personnel. The government made a series of attempts to address the issue since the early 19th century. One effort comprised the organization of clerical workforce schools. The institutions were expected to staff various levels of numerous government bodies with properly trained clerks. In the paper, the authors adopted a comprehensive approach to highlight activities of schools for potential clerks. In particular, our study focused on the staff, financing policies in the educational institutions, functions performed by the management in the schools and supervisory bodies and learning process organization. With a variety of research works and sources reviewed, the authors can conclude that, in the environment of the ever growing functional and structural complexity of the bureaucratic apparatus in the Russian Empire, schools for future clerks considerably drove the development of professional qualities required in employees of the state bureaucracy. It was these educational institutions that to a large extend helped set up a flow of junior professional clerks to government agencies and authorities.

Relevance. Soil pollution with oil has a significant impact on soil fertility and productivity when growing crops. During soil remediation, insufficient attention is paid to soil phytotoxicity assessment in terms of the intensity of the initial growth and development of plants. The results of the study of ordinary chernozem phytotoxicity evaluation on the example of winter barley (Hordeum vulgare L.) after remediation with biochar and a bacterial preparation, containing strains of Bacillus & Paenibacillus, are presented. Aim. To evaluate ordinary chernozem integral phytotoxicity after remediation with biochar and a bacterial preparation, containing strains of Bacillus and Paenibacillus. Objects. Ordinary heavy loamy chernozem, under model conditions, which 5% of the soil mass are oil-contaminated. For soil remediation from oil pollution, biochar and a bacterial preparation with Bacillus & Paenibacillus strains were applied in various combinations: independent application of ameliorants, joint application, inoculation of bacterial preparation with Bacillus & Paenibacillus on biochar. The period of soil incubation with biochar and of bacterial preparation with Bacillus & Paenibacillus has a duration of 30 days. Methods. The residual oil content was determined by the method of extraction with carbon tetrachloride with detection on an infrared analyzer. Soil phytotoxicity after remediation was assessed by indicators of the intensity of initial growth and development of winter barley (Hordeum vulgare L.): germination, germination rate, germination energy, germination friendliness, shoot length, root length, shoot phytomass, root phytomass. As a result of determining these indicators, a complex integral indicator of soil phytotoxicity (IIPht) was calculated. Results. The combined use of biochar with of bacterial preparation with Bacillus & Paenibacillus in oil-contaminated soil leads to the most effective reduction in oil content than when self-introduced and inoculated with of bacterial preparation with Bacillus & Paenibacillus on biochar at the recommended and 100-fold dose, the efficiency is 33 and 58%, respectively. Based on the analysis of phytotoxicity, the highest sensitivity of indicators of barley initial growth intensity was established: germination, friendliness and germination rate. With the independent application of biochar and of bacterial preparation with Bacillus & Paenibacillus, the most informative indicators are shoot phytomass, germination and germination rate; with the combined application of biochar and of bacterial preparation with Bacillus & Paenibacillus, germination energy, shoot length and shoot phytomass; with inoculation of of bacterial preparation with Bacillus & Paenibacillus on a biochar, root length, phytomass of shoots and roots. The study of the phytotoxicity of oil-contaminated Haplic Chernozem after remediation made it possible to establish the ecological efficiency and expediency of using only biochar and biochar inoculated with of bacterial preparation with Bacillus & Paenibacillus.

Background. The article is devoted to the development of an ambulatory personal telemonitoring ECG systems (APTECG systems). The relationship of increasing the reliability of decisions made in APTECG systems with quality control of recorded ECGs is shown. The expediency of including the quality control module of registered ECGs in the APTECG systems is proved. Materials and methods. A block diagram of the APTECG system with a quality control module of registered ECGs in its composition has been developed. Its functions and connections with other modules are defined. The quality control module of registered ECGs is implemented as a neural network binary classifier based on 2D CNN. To represent the ECGs as an image, a wavelet transform was used. A database of images has been created for training and testing neural networks. Results and conclusions. Four deep learning neural networks have been developed in the Python programming language, according to the test results of which the VGGNet19 network showed the best result with an accuracy of 0.97, a logarithmic loss of 0.1 and an F-measure of 0.97. The developed block diagram of the APTECG system and the quality control module of the registered ones will increase the reliability of the diagnostic decisions made.

The research of the structure of the phenomenon of self-realization among specialists in the digital sphere in the context of information and computer activities is presented. The authors analyzed the hierarchy and components of self-realization among IT workers with different sets of individual psychological characteristics, which, through clustering, were divided into three subtypes: (1) introverted-confident; (2) extroverted-active; and (3) extroverted-prosocial. The study involved 154 people, including 42 women and 112 men aged 22-44 (mean age = 32.09 ± 5.71); all of them were employees of leading Russian IT companies in Moscow. Following psychodiagnostic techniques were applied: Individual-Typological Questionnaire (ITQ) by L.N. Sobchik, Eysenck Personality Inventory (EPI) - introversion - extroversion scale, Strategic Approach to Coping Scale (SACS) questionnaire by S. Hobfoll, and Multidimensional Personality Self-Realization Inventory (MPSI) by S.I. Kudinov. The results showed that the structure of self-realization had its own specific features depending on the personality type of the IT employees. For the respondents of cluster I (introverted-confident personality type), the main variables of the self-realization process were optimism, internality and constructiveness, which led to success and a positive assessment of the self-realization process. For the respondents with extroverted-active characteristics in the hierarchy of personal self-realization, the key components of self-realization were social and corporate attitudes, egocentric motivation, internality, conservatism, and destructiveness. The respondents with extroverted-prosocial traits had pronounced subjective personal attitudes, internality, creativity, destructiveness, and social barriers, with predominant limiting factors of self-realization. The results of the study can be considered in the context of psychological support for the IT specialists based on their individual psychological traits.

The article classifies rural territorial entities using the systems approach, which is based on identifying their key subsystems—natural, social, and economic. The study aims to develop and implement a procedure for creating a multi-aspect assessment range of rural development levels relying on the combined use of multivariate statistical analysis and the computational and expert comparison of objective and subjective structured information. The grouping of rural territorial entities carried out on this basis is intended to identify a pattern representing their targeted development, taking into account both the existing social and economic situation in the territory and its perception by the population. Methodological approaches to classify territorial rural units according to their level of rural development usually lack a systemic perspective and a subjective dimension to include the rural inhabitant perspectives. Using only expert opinions does not allow it to be reflected adequately enough. The comparison between the objective and subjective assessments of the natural, social, and economic conditions of rural territorial entities serves as the basis for identifying three groups of development patterns. Results were obtained through the combined application methods—cluster analysis and multidimensional scaling. The first one was used for an objective ranking of municipal districts in the region using official statistical data, while the second method was used for structuring the rural survey results. The main study result is the procedure for the multi-aspect grouping of rural areas, which enables the objective and subjective assessment of their key subsystems—economic, social, and natural—to be integrated into a single assessment tool. Its application helps establish a range of general patterns representing rural development. The study results can be used in the creation and updating of object- and subject-differentiated programs for the development of rural territorial entities.

Complex transition metal oxides are distinguished for a close interrelation between their type of crystal structure and electrical and magnetic properties, thus determining their practical importance. Bismuth ferrite based solid solutions contain simultaneously both dipole electric and magnetic ordering thus expanding their potential applications as external impact sensors. The sensitivity of these compositions to external fields is largely dependent on their structural state. 0.65BiFeO3–0.35Ba1-xSrxTiO3 solid solutions (0 ≤ x ≤ 1) the compositions of which are close to the rhombohedral/cubic morphotropic phase boundary have metastable structures and are therefore promising functional materials. The crystal structure and morphology of 0.65BiFeO3–0.35Ba1-xSrxTiO3 solid solutions has been studied using X-ray diffraction, scanning electron microscopy, Raman spectroscopy and energy dispersive X-ray spectroscopy. The chemical substitution of barium ions for strontium ones has been found to reduce the magnitude of rhombohedral distortions and decrease the unit cell parameters for all the substituted compounds. Solid solutions with x ≥ 0,25 have single-phase structure and cubic unit cells, their grain size decreasing with an increase in the concentration of the substituting ions. The results of structural studies obtained using Raman spectroscopy suggest the presence of rhombohedral distortions in the structures of all the compositions studied. The results of structural studies have allowed identifying the sequence of changes in the phase state and lattice parameter of the compounds in the vicinity of the rhombohedral/cubic morphotropic phase boundary. The concentration ranges in which the compounds have single-phase and two-phase structures have been found. The concentration stability range of the polar rhombohedral phase has been corrected on the basis of the structural data obtained using local and microscopic methods.

Inflammatory myofibroblastic tumors (IMTs) are extremely rare neoplasms, accounting for 0.04–0.7% of all tumors. Data on their clinical presentation, pathogenesis, and biological behavior are scarce. They can occur at any age, involving equally males and females. IMTs have been described as benign neoplasms with intermediate malignant potential, as local recurrence and distant metastasis may occur. IMTs are characterized by a solid growth type, and a multifocal type is uncommon. Definitive surgery is the treatment of choice. We describe a clinical case of a malignant IMT with multi-organ metastasis 6 years after definitive surgery on the primary tumor. There is no standard of care in such a clinical situation, especially given the absence of mutations in the primary and metastatic tumors.

This study investigates a unique and complex eye phenotype characterized by minimal iris defects, foveal hypoplasia, optic nerve coloboma, and severe posterior segment damage. Through genetic analysis and bioinformatic tools, a specific nonsynonymous substitution, p.(Asn114Ser), within the PAX6 gene’s paired domain is identified. Although this substitution is not in direct contact with DNA, its predicted stabilizing effect on the protein structure challenges the traditional understanding of PAX6 mutations, suggesting a gain-of-function mechanism. Contrary to classical loss-of-function effects, this gain-of-function hypothesis aligns with research demonstrating PAX6’s dosage sensitivity. Gain-of-function mutations, though less common, can lead to diverse phenotypes distinct from aniridia. Our findings emphasize PAX6’s multifaceted influence on ocular phenotypes and the importance of genetic variations. We contribute a new perspective on PAX6 mutations by suggesting a potential gain-of-function mechanism and showcasing the complexities of ocular development. This study sheds light on the intricate interplay of the genetic alterations and regulatory mechanisms underlying complex eye phenotypes. Further research, validation, and collaboration are crucial to unravel the nuanced interactions shaping ocular health and development.

In this article, using the example of a multi-channel exponential queueing system with reordering of requests, we study the problem of computer construction of the state space and coefficient matrix of a system of equilibrium equations. As a result, general principles for solving problems of this type are formulated.

Experiments on comparative assessment of effectiveness of bioagents to control the most significant fungal diseases were carried out on crops of potato breeding line in the Zernograd district, Rostov region. Biofungicide Metabakterin, WP based on Methylobacterium extorquens NVD VKM B-2879D + Validamycin Streptomyces hygroscopicus subsp. limoneus VKPM AC-1966 + Bacillus subtilis VKPM B-2918 IPM 215 and biofungicide Vitaplan based on Bacillus subtilis , strain VKM-B-2604D + Bacillus subtilis , strain VKM-B-2605D were studied in the research. The results showed that Metabakterin, WP at the rate of 80 g/ha was the most effective for control of early blight, late blight, fusarium dry rot and rhizoctonia canker on potatoes, while protection period of the biofungicide against these fungal diseases ranged from 19 to 27 days. It was noted that application rate of 80 g/ha of Metabakterin, WP provided the maximum increase in potato yield.

Introduction. Although domestic pigs and wild boars are the main reservoir of zoonotic hepatitis E virus (HEV) genotypes in temperate countries, the presence of antibodies to HEV (anti-HEV) in the indigenous population of circumpolar territories, i.e. outside the habitat of wild and domestic pigs, indicates the presence of an alternative reservoir of the virus. Reindeer (Rangifer tarandus) may be a potential reservoir for HEV in the polar regions. The purpose of the study was to determine the prevalence of anti-HEV among domestic reindeer in the Republic of Sakha (Yakutia). Materials and methods. Sera from 497 domestic reindeer from the Oymyakon (n = 425) and Ust-Yansky districts (n = 72) of the Republic of Sakha (Yakutia) were tested for anti-HEV. A commercial ELISA kit DS-ELISA-ANTI-HEV-G (Diagnostic Systems-Stolitsa LLC, Russia) was used for detection of anti-HEV IgG, but a rabbit polyclonal antibody against deer IgG labeled with horseradish peroxidase (KPL, USA) at a dilution of 1 : 100 in phosphate-buffered saline were used instead of the human specific conjugate from the kit. Results. The average detection rate of anti-HEV in reindeer sera was 15.5% (95% CI: 12.6–19.0%). The detection rate of anti-HEV significantly increased with age, from 3.5% (95% CI: 1.1–9.0%) in calves aged 3–6 months to 25.0% (95% CI: 1.6 –36.5%) in deer aged 2–4 years (p 0.0001). From this age group, anti-HEV detection rates reached a plateau, not differing significantly between older age groups (p 0.05). The average anti-HEV detection rate among reindeer 2 years of age and older was 19.0% (95% CI: 15.3–23.4%). There were no statistically significant differences in the frequency of anti-HEV detection between female and male reindeer, both among adult animals and among calves. Conclusion. The observed anti-HEV detection rates among domestic reindeer in the Republic of Sakha (Yakutia) indicate that infection caused by HEV or an antigenically similar virus is common in these animals. The dynamics of antibody accumulation in the reindeer population indicates that infection apparently occurs during the first two years of life.

Introduction. The amino acid composition of compound feed is of great importance in feeding all kinds of animals. The lack of one or another amino acid limits the assimilation of other amino acids, resulting in excessive compound feed consumption, deterioration of the metabolism in the bodies of animals and increasing of their susceptibility to diseases. The use of grain heaps of wheat in the early ripening stages as feed raw materials is a promising direction for the development of the fodder base that will provide a balanced amino acid composition of compound feed with a lower content of expensive fish meal, which is the main source of protein in compound feeds. Aim of the Article. The article is aimed at determining the optimal ripening stage of spiked cereals, at which a high content of protein and proteinogenic amino acids is observed. The proposed technology and technological tools for early harvesting of spiked cereals will reduce agrotechnical terms of harvesting, reducing losses from shatter losses, and get grain of enhanced nutritive value. Materials and Methods. To study the amino acid composition, 4 samples of a winter wheat grain heap were taken: the winter wheat varieties Admiral and Luchezar, the perennial winter wheat (trititrigia) variety Pamyati Lyubimovoy and the gray wheatgrass variety Sova. Harvesting the wheat of these varieties was carried out by a combing-threshing unit in 5 phenological stages (growth stages are presented on the BBCH scale): 77 – late milk ripeness, 83 – early phase of wax ripeness, 87 – gold wax ripeness, 89 – full ripeness, 92 – overripeness. Results. The results of analyzing amino acid composition of 4 samples of wheat grain heap showed a high content of almost all the amino acids studied in the phase of gold wax ripeness, except of aspartic acid and asparagine, glutamic acid and glutamine, and tryptophan. Discussion and Conclusion. Grain heap of waxy ripeness wheat is a promising grain raw material for the production of compound feeds, which will reduce the amount of expensive components, such as fishmeal.

Introduction Over the last decades numerous new materials and techniques for bone tissue engineering have been developed. The use of bioresorbable polymeric scaffolds is one of the most promising techniques for surgical management of bone defects. However, the lack of bioactive properties of biodegradable polymers restricts the area of their application for bone tissue engineering. The aim of study was to apply solvent/non-solvent treatment to coat the surface of 3D-printed bioresorbable poly(ε-caprolactone) scaffolds with bioactive hydroxyapatite particles and report on the physicochemical properties of the resulting materials. Material and Methods In the present study, biomimetic poly(ε-caprolactone) scaffolds were 3D-printed via fused deposition modeling technology and their surface was treated with the solvent/non-solvent method for coating with bioactive particles of hydroxyapatite. Results It has been found that treatment in the mixture of toluene and ethanol is suitable for the coating of poly(ε‑caprolactone) scaffolds with hydroxyapatite. The scaffolds maintain porous structure after treatment while hydroxyapatite particles form homogeneous coating. The amount of hydroxyapatite on the treated scaffolds was 5.7 ± 0.8 wt. %. Discussion The proposed method ensures a homogeneous coating of outer and inner surfaces of the poly(ε-caprolactone) scaffolds with hydroxyapatite without a significant impact on the structure of a scaffold. Fourier-transform infrared spectroscopy confirmed that the solvent/non-solvent treatment has no effect on the chemical structure of PCL scaffolds. Conclusion Coating of biomimetic 3D-printed PCL scaffolds with bioactive hydroxyapatite by the solvent/non-solvent treatment has been successfully carried out. Upon coating, scaffolds retained their shape and interconnected porous structure and adsorbed hydroxyapatite particles that were uniformly distributed on the surface of the scaffold.

indications for the use of PLLA/HA composite implants in clinical practice. The present study was aimed to measure the kinetics of calcium and phosphate release from PLLA and its dependence on polymer structure crystallinity. Material and methods Four types of biodegradable materials were studied in vitro. Samples of type 1 and type 3 made of crystalline PLLA after annealing contained 25 % and 50 % of HA mass fraction, respectively. Samples of type 2 and type 4 made of amorphous PLLA (without annealing) contained 25 % and 50 % of HA mass fraction, respectively. In every group, 6 samples were tested. The samples were incubated in an aqueous medium at 37 °C for 52 weeks. The rate of PLLA degradation was assessed by the accumulation of lactate monomer in the hydrolysate. The concentrations of calcium ions and phosphate ions were determined for assessment the HA hydrolysis rate. The degree of crystallinity of the polymer matrix was evaluated by scanning calorimetry. Results The hydrolysis of PLLA and HA in the samples was not simultaneous. The PLLA was hydrolyzed first followed by HA hydrolysis. By the moment of complete hydrolysis of PLLA, there was only 15 % of hydrolyzed HA. The release of calcium ions occurred from the sixth week of incubation for all tested samples, that of phosphate ions from the third week. The total amount of the released calcium ions and phosphate ions decreased in the line: material 3 > material 4 > material 1 > material 2. Calcium ions in the hydrolysates were detected up to 42 weeks of incubation, phosphate ions up to the 52nd week. Conclusion Higher crystallinity of PLLA achieved by annealing results in increased rate of hydrolysis of HA from PLLA matrix. Biological activity of PLLA/HA implants can be determined by degree of polymer crystallinity and saturation with HA.

Colorectal cancer (CRC) is one of the most common oncological diseases. On average, in 20–25% of cases after radical surgical treatment of CRC, the progression of the disease in the form of metachronous metastases in the liver and lungs, as the most common localization of CRC metastases, is noted in patients. With the advent of new drug treatment strategies for CRC, there is an increase in overall survival, as a result of which CRC metastases in the adrenal glands have become more common than previously thought, and the number of published reports of cases of CRC metastasis in the adrenal glands has increased. In this article, we report a rare clinical observation of metachronous solitary metastasis of CRC to the left adrenal gland 4 years after radical surgical treatment of the primary tumor: the patient underwent radical left-sided adrenalectomy. The period of observation of the patient without signs of progression and relapse of the disease is 6 months (at the time of publication).

Abstract Background Higher positive end-expiratory pressure (PEEP) during laparoscopic surgery may increase oxygenation and respiratory compliance. This meta-analysis aimed to compare the impact of different intraoperative PEEP strategies on arterial oxygenation, compliance, and hemodynamics during laparoscopic surgery in non-obese patients. Methods We searched RCTs in PubMed, Cochrane Library, Web of Science, and Google Scholar from January 2012 to April 2022 comparing the different intraoperative PEEP (Low PEEP (LPEEP): 0–4 mbar; Moderate PEEP (MPEEP): 5–8 mbar; high PEEP (HPEEP): >8 mbar; individualized PEEP - iPEEP) on arterial oxygenation, respiratory compliance (Cdyn), mean arterial pressure (MAP), and heart rate (HR). We calculated mean differences (MD) with 95% confidence intervals (CI), and predictive intervals (PI) using random-effects models. The Cochrane Bias Risk Assessment Tool was applied. Results 21 RCTs (n = 1554) met the inclusion criteria. HPEEP vs. LPEEP increased PaO2 (+ 29.38 [16.20; 42.56] mmHg, p

B-cell receptors can interact with antigen epitopes on various objects: macromolecules, microorganisms or on the surface of other cells, e.g., follicular dendritic cells. Accordingly, B cells, on the one hand, have the ability to evaluate the location of pathogen surface epitopes, and, on the other hand, they must adapt their receptor apparatus to different epitope locations and antigen-bearing surface properties. Indeed, B-cell receptors and antibodies better bind objects with regular and dense epitope arrangement characteristic of many pathogens. As a result, such epitope arrangement can be recognized as a pathogen-associated geometric pattern, but the conditions for such recognition depend on the isotype of membrane immunoglobulin and the degree of B cell maturity. Young B cells express membrane IgM, which is involved in B cell development and the selection of their repertoire. Receptors with IgM do not impose strict requirements on epitope location and can activate B cells even upon binding a monovalent antigen. Receptors with membrane IgD are expressed later and predominate on naive B cells before entering the immune response. These receptors are optimized for two-point antigen binding and strictly require this type of interaction to induce an activation signal. Before contact with antigen, B-cell receptors are grouped in discrete membrane zones — nanoclusters, due to close interactions with the actin cytoskeleton. Contact with the antigen leads to the detachment of receptors from the cytoskeleton, rise in their mobility and the combining nanoclusters into microclusters — large clusters enriched with signaling molecules. The most dynamic changes are observed upon contact with an antigen fixed on the membrane of adjacent cell. In this case, free actin moves to the periphery of the intercellular contact zone, where it forms the cytoskeleton of the processes carrying receptor clusters. The processes spread across the surface of the partner cell and then contract, moving the antigen-binding microclusters to the center of the contact zone. Finally, the microclusters combine into a central cluster of the immune synapse, the intensity of the activation signal drops, and the cell prepares for endocytosis of antigens grouped at the local site. Thus, the structure of B-cell receptors can contribute to the response of the B-lymphocyte to antigens with a characteristic spatial location, while the dynamic interaction between B-cell receptor apparatus and the cytoskeleton allows optimizing the binding of antigens presented on various carriers. Knowledge on spatial aspects of antigen recognition may be useful for the construction of vaccines based on virus-like particles or antigens on other artificial carriers.

Deviation of the first toe to the outside, interconnected with the deviation of the first metatarsal bone to the inside, occurs in 46% of patients of the older age group and is called valgus deformity of the first toe. The negative impact of this pathology on the quality of life of patients is the reason for seeking medical help, the gold standard of which is surgical correction, and the basic surgical technique is osteotomy (sawing the bone and fixing its fragments with implants) of the first metatarsal. At the same time, an ideal osteotomy should provide initial stability in the early postoperative period. However, a large number of ways to perform osteotomy, as well as the advantages and disadvantages of each of the surgical techniques, do not allow to consider one of them as the most successful. In this regard, the aim of the work was to develop and validate a biomechanical model of osteotomy of the first metatarsal bone to analyze its stability and reliability depending on the type of osteotomy, the degree of displacement of bone fragments, as well as the number of fastening screws. In this study, biomechanical modeling of the most commonly used variants of osteotomy of the first metatarsal bone of the foot in the surgical treatment of its valgus deformity was carried out. For this purpose, 10 models of osteotomies of a separate first metatarsal bone were created, which were then subjected to static loading to analyze their stress-strain state and assess their success. Successful (stable and reliable) treatment options were identified, as well as unsuccessful ones. Two of the ten options considered were unsuccessful – scarf type osteotomies with displacement of bone fragments by 2/3 of its diameter and fixed with a single screw. It was revealed that osteotomies of the chevron type showed higher stability in comparison with scarf osteotomies. As a result, we note that in this study, numerical experiments were conducted for the first time to compare the stability and strength of the most commonly used variants of osteotomies based on a single bone model. A biomechanical model of scarf osteotomy of the first metatarsal bone has been developed and validated on the basis of mechanical experiments.

Abstract Stem cell-based therapeutic approaches for neurological disorders are widely studied. Paracrine factors secreted by stem cells in vitro and delivered intranasally might allow bypassing the disadvantages associated with a surgical cell delivery procedure with likely immune rejection of a transplant. In this study, we investigated the therapeutic effect of the extracellular vesicles secreted by glial progenitor cells (GPC-EV) derived from human induced pluripotent stem cell in a traumatic brain injury model. Intranasal administration of GPC-EV to Wistar rats for 6 days improved sensorimotor functions assessed over a 14-day observation period. Beside, deep sequencing of microRNA transcriptome of GPC-EV was estimate, and was revealed 203 microRNA species that might be implicated in prevention of various brain pathologies. Modulation of microRNA pools might contribute to the observed decrease in the number of astrocytes that inhibit neurorecovery processes while enhancing neuroplasticity by decreasing phosphorylated Tau forms, preventing inflammation and apoptosis associated with secondary damage to brain tissue. The course of GPC-EV administration was promoted the increasing protein levels of NF-κB in studied areas of the rat brain, indicating NF-κB dependent mechanisms as a plausible route of neuroprotection within the damaged area. This investigation showed that GPC-EV may be representing a therapeutic approach in traumatic brain injury, though its translation into the clinic would require an additional research and development.

This empirical study links emotional burnout with self-attitude. The contemporary pedagogical environment subjects school teachers to emotional burnout and professional deformation. On the one hand, the state and society have extremely high professional requirements for teachers, who strive to improve their psychological, pedagogical, didactic, methodological, and digital competencies. On the other hand, the social and financial insecurity forces school teachers to increase their workload at the expense of their physical and psycho-emotional recovery. The authors hypothesized that a particular self-attitude can trigger the burnout syndrome in teachers. They relied on the subject-activity approach to the emotional burnout syndrome to survey 237 secondary school teachers (169 women, 68 men; 32–40 y.o.). Their self-attitudes were identified by the personal differential method, W. Stephenson’s Self-Image Test, and V. V. Stolin and S. R. Panteleev’s Self-Attitude Test. The level of emotional burnout was measured using V. V. Boyko’s Diagnostics of Emotional Burnout. An expert assessment served as an additional method to identify the performance indicators. The empirical research revealed that the teachers with an adequately positive self-attitude demonstrated fewer symptoms of emotional burnout, which stayed at an initial stage. They managed to maintain high standards of working capacity and professional motivation, as well as effective vertical and horizontal social communication. The teachers with a less positive self-attitude experienced severe symptoms of burnout and professional deformation, which affected their professional activities. They were confrontational and complained about low motivation, poor performance, procrastination, etc. The data obtained may help to improve psychological support programs and psychological counseling in schools.

Abstract Channelling single-photon emission in multiple well-defined directions and simultaneously controlling its polarization characteristics is highly desirable for numerous quantum technology applications. We show that this can be achieved by using quantum emitters (QEs) nonradiatively coupled to surface plasmon polaritons (SPPs), which are scattered into outgoing free-propagating waves by appropriately designed metasurfaces. The QE-coupled metasurface design is based on the scattering holography approach with radially diverging SPPs as reference waves. Using holographic metasurfaces fabricated around nanodiamonds with single Ge vacancy centres, we experimentally demonstrate on-chip integrated efficient generation of two well-collimated single-photon beams propagating along different 15° off-normal directions with orthogonal linear polarizations.

Myotonic dystrophy type 1 (DM1) is a multisystem disorder with progressive myopathy and myotonia. The clinical study was conducted in the Republic of North Ossetia-Alania (RNOA), and in it 39 individuals from 17 unrelated families were identified with DM1. Clinical presentations varied, including muscle weakness, fatigue, intellectual disability, hypersomnia, ophthalmological abnormalities, and alopecia. Using clinical and genotyping data, we confirmed the diagnosis and enabled the study of CTG-repeat anticipation and DM1 prevalence in the Ossetian and Ingush populations. CTG expansion correlated with age of onset, with clinical severity, and with offspring showing more severe symptoms than parents. In many families, the youngest child had a more severe DM1 phenotype than older siblings. The prevalence was 14.17 per 100,000 in Ossetians and 18.74 per 100,000 in Ingush people, aligning with global data. Segregation analysis showed a higher frequency of maternal transmission. The study highlights the clinical and genetic heterogeneity of DM1 and its dependence on repeat expansion and paternal and maternal age.

A new vibration-based mechanism of optical frequency/wavelength sweeping in fiber lasers induced by optical path length modulation of a laser cavity section is proposed. The mechanism is implemented for an erbium-doped fiber ring laser with a saturable absorber. Without the vibrations, the laser generates a single longitudinal mode (SLM) radiation. We show experimentally for the first time that mechanical vibrations of the laser cavity section can lead to mode dynamics in both frequency and time domains. The possibility of obtaining various mode dynamics, such as vibration-induced sweeping in a wavelength range of up to 2.2 nm or SLM generation with periodic mode hopping between two fixed longitudinal modes depending on the pump wavelength, is experimentally shown. In this vibration-based approach, the interval between changes in the laser cavity modes has good stability, because it directly relates to the vibration period.

This research is aimed at analyzing existing plugging compositions and developing a new plugging composition based on phenol-formaldehyde resin. This paper presents the results of studies of a hardening composition based on phenol-formaldehyde resin for repair and insulation work in wells. The plugging composition consists of two parts: Component “A” (resin and additives) and Component “B” (hardener). A resol-type water-soluble phenol-formaldehyde resin was selected for testing. The resin was additionally modified with special additives to improve performance properties. A mixture of acids was chosen as a hardener. Concentrations of resin and hardener were selected to ensure optimal loss of fluidity of the composition for different temperatures. The main physicochemical properties of the plugging composition were determined. The elastic-strength characteristics of the developed composition after curing at various temperatures (Poisson’s ratio, Young’s modulus, and compressive strength) were assessed. It has been experimentally proven that samples based on phenol-formaldehyde resin do not collapse completely under load but undergo longitudinal and transverse deformations. As the amount of hardener in the system increases, the compressive strength decreases. The presence of the elastic-strength properties of cementing compositions based on synthetic resins distinguishes them favorably from hardening compositions based on cement and microcement.

Mathematical equations that describe all physical processes are valid only under certain assumptions. One of them is the minimum scales used for the given description. In fact, this prohibits the use of derivatives in the mathematical models of the physical processes. This article represents a derivative-free approach for the mathematical modelling. The proposed approach for CFD and numerical heat transfer is based on the conservation and phenomenological laws, and physical constraints on the minimum problem-dependent spatial and temporal scales (for example, on the average free path of molecules and the average time of their collisions for gases). This leads to the derivative-free governing equations (the discontinuum approximation) that are very convenient for numerical simulation. The theoretical analysis of governing equations describing the fundamental conservation laws in the continuum and discontinuum approximations is given. The article demonstrates the derivative-free approach based on the correctly defined macroparameters (pressure, temperature, density, etc.) for the mathematical description of physical and chemical processes. This eliminates the finite-difference, finite-volume, finite-element or other approximations of the governing equations from the computational algorithms.

This paper is focused on a specific component of the bureaucratic apparatus in the Russian Empire -- educational functionaries. More specifically, the work explores the social background of educational functionaries in the Ukrainian lands in the first half of the 19th century. The authors composed data samples on Taurida, Volhynian, and Poltava Governorates covering the years 1830 and 1850. Use was made of a body of little-known archival documentation from the State Archive of Kharkov Oblast and the Central State Archive of Ukraine in Kiev. The authors explored the regional characteristics of the way educational institutions in rightbank, leftbank, and southern Ukrainian governorates were staffed with functionaries. The work attempted to determine how the areas' numbers of members of the various social groups in pedagogical service correlate with each other. It was found that, despite the low popularity of pedagogical service among the nobility, there were quite many members of this estate serving in the public education sector. However, due to a major need for teacher functionaries the government had to express a favorable attitude toward the hiring of members of other social groups willing to serve in educational institutions across the Russian Empire. This explains the significant number of members of the lower estates employed in the sector as well.

This paper offers an insight into some of the key practices associated with the operation of the institution of honorary supervisors in the system of public education of the Russian Empire in the first half of the 19th century. Only a member of the noble estate could be an honorary supervisor. These functionaries were an important part of the empire's public education system. They oversaw the work of uyezd (district) schools and provided them with financial assistance. Honorary supervisors were not salaried but could be awarded a high title and receive a major state award for their efforts, which could significantly raise their social status. Honorary supervisors had a wide purview over the operation of the schools they oversaw. They took part in resolving facilities issues and attended examinations and monthly teacher meetings. These functionaries could also petition senior management for the remuneration or punishment of particular school functionaries. Conversely, honorary supervisors with a negligent attitude toward their duties could legitimately face dismissal by the university administration.