Khmelnytskyi National University

According to international anatomical nomenclature, sphincter structures across various organs and systems are uniformly designated by the term M. sphincter (A04.0.00.028), with the English equivalent “sphincter muscle” and the Ukrainian equivalent «miaz-zamykach». However, these structures do not exhibit a consistent circular arrangement of striated or smooth muscle fibres encircling the luminal junction between segments of the urinary or digestive tracts. The aim of the study was to elucidate the microscopic structural patterns and to systematise the morpho-functional characteristics of the closing apparatuses in the urinary and digestive systems during the prenatal period of human ontogenesis. Material and methods of the study. The study was conducted on 25 prefetuses (parieto-coccygeal length 12.0–80.0 mm) and 20 fetuses (parieto-coccygeal length 81.0–375.0 mm) using a combination of morphological techniques: vascular injection, preparation and analysis of serial histological sections, and three-dimensional computer reconstruction. The Biomedical Ethics Committee of Bukovinian State Medical University (Minutes No. 2, dated 16 October 2025) confirmed compliance with ethical and legal standards. The study forms part of the scheduled research project of the Department of Histology, Cytology and Embryology, Bukovinian State Medical University, entitled “Structural and functional features of tissues and organs in ontogenesis, patterns of variant, constitutional, sex-age, and comparative morphology of humans” (state registration No. 0121U110121; implementation period January 2021 – December 2025). Results. The closing apparatuses of the digestive and urinary systems in human fetuses demonstrate considerable structural diversity. Nevertheless, all share three principal components: muscular, vascular, and modification of mucosal surface relief. The relative prominence of each component varies according to the functional demands and topographic relationships of the specific closing segment. Given this evidence, replacement of the Ukrainian term «miaz-zamykach» with «sfinkter» is recommended to eliminate terminological ambiguity and enable more precise and comprehensive description of human closing structures. Conclusions. 1. Closing structures regulating the passage of contents between hollow organs of the urinary and digestive systems are characterised by three fundamental components: a muscular layer, a vascular network, and alterations in the relief of the mucosal lining. 2. The muscular component, manifesting as a sphincter muscle with circularly oriented bundles, is present in the orbicularis oculi muscle, external anal sphincter, and external urethral sphincter, where it integrates closely with adjacent musculature. The internal urethral sphincter and pyloric sphincter consist of localised thickenings and direct extensions of the circular muscle coat of the respective tubular organ. 3. At the junction of the common bile duct with the duodenum, and the ureter with the bladder, the closing mechanism is achieved through penetration of the intestinal or bladder muscular wall by the tubular structure, combined with submucosal vascular engorgement and modification of mucosal surface relief. 4. The neck of the gallbladder at its transition to the cystic duct, and the renal pelvis at its transition to the ureter, exhibit distinctive luminal configuration and structure due to mucosal protrusions that function as both active and passive resistive mechanisms, regulating fluid flow velocity via submucosal vascular filling.

This paper presents an experimental and analytical study of the variation of the total acid number (TAN) in engine oils under operational contamination. The research is aimed at assessing the correlation between the acidity growth of lubricants and their wear behavior in the four-ball test configuration. Theoretical modeling and experimental testing were performed to identify the parameters of a wear law that incorporates contact pressure, oil viscosity, hardness, and TAN as key variables. The obtained results confirm that the acid number increases significantly during oil operation: from 0.9 to 2.9 mg KOH/g—which leads to an intensified wear rate of the contact surfaces. The proposed model quantitatively describes the relationship between the acidity level and wear intensity and enables prediction of oil performance based on its physicochemical degradation. The developed approach allows for improved evaluation of the residual life of lubricants and optimization of maintenance intervals for internal combustion engines.

Purpose. The scientific novelty of this study lies in the identification and structured interpretation of thematic clusters that characterize the contemporary research landscape of rehabilitation in martial arts. To conduct an analytical review of publications devoted to the problem of rehabilitation in martial arts using the VOSviewer software tool in the PubMed database. Material & Methods. To create the study sample as of December 31, 2025, a bibliometric analysis of data from the PubMed database was performed. The search was conducted using the key phrase “rehabilitation in martial arts”. Publications from 2001 to 2025 were analyzed. VOSviewer version 1.6.19 was used, applying keyword analysis and direct citation analysis with the construction of bibliometric maps, cluster density visualization, and citation weights. Results. Using VOSviewer 1.6.19, a total of 1111 publications were identified. All publications were written in English. A substantial increase in the number of publications was observed in each five-year period, which can be explained by the growing interest in and popularization of research on rehabilitation in martial arts. Overall, 4713 researchers from 2943 organizations studied rehabilitation issues across various martial arts disciplines. The publication activity of 1049 authors with a link strength greater than zero was analyzed. These authors were grouped into 41 clusters, characterized by 5333 links with a total link strength of 6836. The most productive authors were Tsang W. (25 publications), Wayne P. (23), Li F. (21), Tao J. (19), Chen L. (17), Huang J. (15), Yen G. (14), Franchini E. (13), and Wang C. (13). For network visualization, 371 elements (keywords) were selected and grouped into 9 clusters. The network included 14701 links with a total strength of 67,750. The most prominent research topics were centered around the keywords “humans”, “male”, “martial arts”, “adult”, “female”, “aged”, “tai ji”, “exercise”, “treatment outcome” and “quality of life”. Overlay visualization demonstrated a clear evolution of scientific research: from general assessment of functional status and risk prevention (early stage), through the implementation of specialized rehabilitation methods (transitional stage), to individualized physical rehabilitation programs with an emphasis on motor activity control and exercise tolerance (modern stage). Conclusions. Using the VOSviewer software, a bibliometric analysis of publications indexed in the PubMed database was conducted, revealing a steady increase in scientific interest in rehabilitation in martial arts, as evidenced by a significant growth in the number of publications over the analyzed period. A high level of international scientific cooperation was identified, reflected in the wide range of authors, institutions, and interdisciplinary links. The analysis of bibliometric maps made it possible to identify nine key thematic clusters encompassing sports, clinical, psychosocial, and preventive aspects of rehabilitation. The leading research directions focus on recovery from sports injuries, improvement of the functional state of the musculoskeletal system, quality of life, and mental health. Overlay visualization confirmed the evolution of scientific approaches – from basic functional and clinical studies to contemporary individualized physical rehabilitation programs with load control. The obtained results confirm the need for further research aimed at integrating rehabilitation measures directly into the structure of the training process, as well as at developing scientifically grounded models of long-term athletic recovery.

The processes to plan transport deliveries in logistics systems involving hierarchical models have been investigated in this paper. The task to optimally plan freight delivery for transport and distribution logistics enterprises is associated with problems arising from fluctuations in demand, geographically distributed orders, as well as limited and heterogeneous resources. The results of this study include the construction of a hierarchical model that allows for multi-level transportation planning, clustering of previously unclassified orders, and adjusting the choice of vehicles based on current conditions. Such adaptive choice of vehicles flexibly takes into account logistical constraints. The findings indicate a reduction in transportation costs by 11.7% (p < 0.05). At the same time, it was found that under conditions of small samples, the stability of cluster solutions is limited and, therefore, additional verification and extended validation are required for their practical implementation. The novelty of the proposed model is in the application of hierarchical decomposition of the multi-index transportation planning problem with the allocation of the global stage of cluster formation and the local stage of route planning. An approach to order clustering based on a limited sample of the closest applications in time and distance and an algorithm for adaptive selection of vehicles taking into account cost, carrying capacity and urgency of execution have been proposed. The model built makes it possible to reduce the computational complexity of the problem compared to classical routing models while maintaining the interpretability of solutions at each stage due to transparent clustering rules. The scope of practical use of the results covers transport and logistics companies, delivery services, urban distribution systems, and retail logistics.

This study investigates ecological succession within quarry-stockpile complexes across the mining landscapes. Post-extraction use of quarries is often limited due to high restoration costs, technical challenges, and perceived impracticality. However, such sites can become valuable ecological assets, showcasing region-specific zonal flora. Focusing on primary succession, the research highlight shows edaphic conditions of disturbed substrates influence vegetation dynamics and broader landscape transformation. Conducted from 2019 to 2022, the study employed an integrated methodological approach, including route field surveys, aerial photography, observation, comparison, experimentation, statistical analysis, synthesis, and logical modeling to assess the plant community development. Field studies were conducted during the growing season from March to October. We determined the features of the plant cover and dominant plants in the structure of the sand quarry – stockpile complex and developed schemes of succession stages. Zoning based on the normalized difference vegetation index (NDVI) revealed a moderate expansion of highly productive phytocenoses (from 25.5% in 2019 to 27.2% in 2022) alongside a decline in the overall productive vegetation cover from 89.1% to 74.7%. Concurrently, open substrate and sparse vegetation areas expanded from 11.3% to 25.2%. The average similarity coefficient of species composition between study sites increased over time, indicating structural shifts in the plant communities. Notably, the coefficient rose from 0.54 to 0.63 on the hilly loamy-sandy surfaces, and from 0.55 to 0.81 on the rugose overburden ledges. Disturbances caused by the extraction of minerals contributed to the formation of man-made accumulative relief with a predominance of segetal-ruderal species. The findings suggest that, in the absence of active renaturalization, vegetation succession and species differentiation are largely governed by anthropogenic factors and localized ecotopic conditions. This emphasizes the ecological potential of post-mining landscapes and the importance of monitoring for informed conservation and restoration strategies.

The paper examines the formation of adolescents’ emotional stability in the contemporary educational environment through the prism of pedagogical support. It emphasizes that emotional stability is a key determinant of effective socialization, psychological well-being, and adaptation of students to changing life circumstances, particularly in the context of social crises and the Russian-Ukrainian war. The study focuses on the role of teachers in creating a safe educational environment that fosters the development of adolescents’ self-regulation skills, emotional awareness, and the ability to build constructive relationships with others. The main areas of pedagogical support are identified, including the implementation of art therapy methods, cognitive-behavioral techniques, body-oriented practices, and the engagement of adolescents in social and creative projects. It has been established that these approaches enable adolescents not only to process complex emotional states but also to maintain a sense of inner balance, self-confidence, empathy, and social responsibility. Particular attention is given to the impact of the Russian-Ukrainian war as a psychotraumatic factor that demands increased flexibility, tolerance, empathy, and readiness for psychological support within the educational environment. Under such circumstances, pedagogical support becomes not only a means of education but also an essential mechanism for stabilizing adolescents’ emotional state, promoting their personal growth, resilience, and positive self-esteem.

Dual education has gained relevance as a strategy to strengthen links between higher education institutions and the productive sector, particularly in professional fields requiring intensive practical training. This study aims to describe the preparedness of higher education institutions for implementing the dual education model by identifying institutional, regulatory, and operational factors influencing its adoption. A mixed descriptive and comparative approach was applied, combining regulatory analysis, statistical data review, and a survey administered to academic and administrative staff from selected institutions in Ukraine, Poland, and Germany. The survey explored perceptions of benefits, barriers, institutional capacity, and implementation conditions. Quantitative data were examined using descriptive and inferential statistics, while qualitative inputs supported contextual interpretation. The findings reveal cross national differences in regulatory frameworks, institutional coordination, and perceived preparedness, alongside shared challenges such as limited institutional experience, organizational complexity, and resource constraints. Respondents also emphasized benefits related to employability, practical skills development, and stronger university industry collaboration. Rather than measuring readiness levels through indices or scales, the study provides a diagnostic overview of current conditions. The results offer evidence based insights that can inform institutional planning, policy development, and future research on technological and organizational readiness within dual education systems worldwide today broadly.

This study proposes a spatial model of the development process and its projection onto a plane in the form of a development diagram. This diagram is then used to interpret the process of human history. The study also considers the threats posed by the rapid growth of computing power, coupled with the degradation of human intellectual capacity. Finally, the only possible way out of the impending impasse of self-destruction is proposed. In conclusion, it is argued that the universe is a superposition of developmental processes formed by a basic microprocess, the core of which is time.

The article examines specific features of the use of marketing tools and their impact on the economic security of enterprises. It has been determined that an effective pricing policy can not fully compensate for the impact of such negative factors as force majeure circumstances, deficit of resource, a fall in solvent demand, and negative institutional influence. At the same time, a reliable assessment of the levels of these factors, combined with flexible regulation of pricing policy, can determine the strategic directions for ensuring the economic security of the enterprise in terms of four key indicators: Profitability increase, ensuring competitiveness, increasing market share, and forming a positive reputational capital. A model for assessing the impact of negative factors and pricing policy on the economic security of the enterprise has been developed using fuzzy Sugeno inference. To model the impact on the key indicators of economic security, four rules of the fuzzy knowledge base have been suggested, which allows adjusting the marketing strategy in accordance with the current state of the external environment. The model has been tested at light industry enterprises. The obtained results were used to form an optimal set of marketing tools aimed at increasing the market share and forming a positive reputational capital for the enterprise. To determine the proportional distribution of marketing tools, a method of dynamic planning based on the ratio of values of economic security indicators has been developed.

Against the backdrop of a protracted military conflict, the mental health of servicemen who sustained numerous injuries during combat missions had become increasingly relevant. This study addressed the psychological states of combatants in the context of their professional functioning during war and their subsequent adaptation to civilian life. The purpose of the research was to analyze key factors that supported the mental health of military personnel. The methodology involved analysis and synthesis, systematization, comparison, generalization, and abstraction. The study identified major difficulties faced by combatants in adapting to normal social roles following prolonged combat exposure. It examined manifestations of destructive mental states, including anxiety, apathy, depression, stress, frustration, and post-traumatic stress disorder. The research analyzed the characteristics and symptoms of these conditions and explored ways to alleviate or overcome them through active social support, religious practices, and the mobilization of personal psychological resources. Particular attention was given to the psychological state of combatants after returning from active duty and the importance of timely mental health interventions. The factors influencing the psychological well-being of soldiers are examined through the prism of interaction between society and culture. The findings emphasized the need for effective rehabilitation programs, greater public awareness, and targeted psychological support to facilitate the reintegration and long-term well-being of former servicemen.