Видання зареєстровані авторами шляхом самоархівування
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Item The associason of vitamin d receptor gene (VDR) polymorphisms with high blood pressure in stroke patients of Ukrainian population(Aluna Publishing, 2020) Obukhova, Olha Anatoliivna; Обухова, Ольга Анатоліївна; Ataman, Oleksandr Vasylovych; Атаман, Олександр Васильович; Zavadska, Maryna Mykolaivna; Завадська, Марина Миколаївна; Piven, Svitlana Mykolaivna; Півень, Світлана Миколаївна; Levchenko, Zoia Mykhailivna; Левченко, Зоя МихайлівнаVenous blood of 170 patients with atherothrombotic ischemic stroke (AIS) and 124 healthy individuals (control group) was used for genotyping. Four polymorphisms (FokI, BsmI, ApaI, TaqI) of gene VDR were examined with PCR-RFLP methodology. Statistical analysis was performed by using SPSS-17.0 program. The correlation of genotypes of polymorphic variants of FokI, BsmI, ApaI and TaqI of the VDR gene with the development of ischemic atherothrombotic stroke in individuals with normal and high blood pressure was detected. Statistical analysis of the obtained data revealed that among carriers of genotypes F/F, b/b, a/a, a/A, and T/T patients with AI have statistically significantly higher incidence of hypertension than patients in the control group. It was found that persons with genotypes F/F, b/b, a/a, a/A, and T/T showed a statistically significant relationship between hypertension and the development of IAS. The application of logistic regression has made it possible to establish that the risk of IAS in people with normal blood pressure and genotype F/f is 3.2 times higher than in normotensive homozygotes for the F-allele.Item Vortex-Type Granulation Machines: Technological Basis of Calculation and Implementation Roadmap(Sciendo, 2022) Артюхов, Артем Євгенович; Артюхов, Артем Евгеньевич; Artiukhov, Artem Yevhenovych; Krmela, J.; Krmelova, V.; Ospanov, D.This work is devoted to describing the technological foundations and the main stages of calculating granulation machines with active hydrodynamic modes. The optimisation criterion is substantiated when choosing the design of the granulation machine. The work uses methods of analysis and synthesis, search for cause-and-effect relationships, theoretical and computer modelling, and experimental studies. The nodes of the vortex granulator directly influence the formation of a vortex fluidised bed, and the directional movement of granules of various sizes are determined. A technique for carrying out a computer simulation of the hydrodynamic operating conditions of a granulation machine in various operating modes with an assessment of the qualityof granulated products (e.g., the production of porous ammonium nitrate) is proposed. The results of a computer simulation of the process of formation of a vortex fluid-ised bed are presented. A variant of the solution for developing an automation scheme for a vortex-type granulation machine is shown. A roadmap for introducing granulation technology in vortex-type granulation machines is described with details of the main stages. The prospects for improving the design of a vortex-type granulation machine and optimising the operation of a granulation plant to produce porous ammonium nitrate are outlined.Item Electric-Spark Alloying of Metal Surfaces with Graphite(G. V. Kurdyumov Institute for Metal Physics of the N.A.S. of Ukraine, 2022) Tarelnyk, V. B.; Гапонова, Оксана Петрівна; Гапонова, Оксана Петровна; Haponova, Oksana Petrivna; Konoplianchenko, Ye.V.The article reviews and analyses the current scientific research in the field of surface treatment of metal surfaces with concentrated energy fluxes (CEF) — the electric-spark (in the literature, known also as electrospark) alloying (ESA), which makes it possible to obtain surface structures with unique physical, mechanical and tribological properties at the nanoscale. The ESA method with a graphite electrode (electrospark carburizing — EC) is based on the process of diffusion (saturation of the surface layer of a part with carbon), and it is not accompanied by an increase in the size of the part. In this article, the influence of the EC parameters on the quality of the carburized layer is investigated. The microstructural analysis shows that the three characteristic zones could be distinguished in the structure: the carburized (‘white’) layer, the finely dispersed transition zone with fine grain, and the base metal zone. The analysis of the results of the durometric studies of the coatings is carried out. To achieve the required parameters of dimensional accuracy and roughness of the working surface of the part after the EC process, it is necessary to use the method of non-abrasive ultrasonic finishing (NAUF). In addition, because of applying the NAUF method, the surface roughness is decreased, the tensile stresses are changed to the compressive ones, and the fatigue strength is increased too. In addition, to reduce the roughness of the treated surface, it is proposed to apply the EC technology in stages, reducing the energy of the spark discharge at each subsequent stage. In order to increase the quality of the carburized layer obtained by the EC process, it is proposed to use a graphite powder, which is applied to the treated surface before alloying. The comparative analysis shows that, after the traditional EC process at Wp = 4.6 J, the surface roughness of steel 20 is Ra = 8.3–9.0 μm, and after the proposed technology, Ra = 3.2–4.8 μm. In this case, the continuity of the alloyed layer increases up to 100%; there increases the depth of the diffusion zone of carbon up to 80 μm as well as the microhardness of the ‘white’ layer and its thickness, which increase up to 9932 MPa and up to 230 μm, respectively. The local micro-x-ray spectral analysis of the obtained coatings shows that, at the EC process carried out in a traditional way, the applying Wp = 0.9, 2.6, 4.6 J provides the formation of the surface layers with high-carbon content depths of 70, 100, 120 μm, respectively, and with the use of a graphite powder, they are of 80, 120, 170 μm. While deepening, the amount of carbon is decreasing from 0.72–0.86% to the carbon content in the base metal — 0.17–0.24%. In the near-surface layer formed with the use of the new technology, the pores are filled with free graphite, which could be used as a solid lubricant to improve the operating characteristics of the friction-pairs parts processed thereby.Item Diagnostic and genetic markers associated with pulmonary tuberculosis in HIV-infected individuals(Nicolaus Copernicus University in Torun, 2021) Чемич, Микола Дмитрович; Чемич, Николай Дмитриевич; Chemych, Mykola Dmytrovych; Янчук, Світлана Миколаївна; Янчук, Светлана Николаевна; Yanchuk, Svitlana Mykolaivna; Жук, Катерина Ігорівна; Жук, Екатерина Игоревна; Zhuk, Kateryna IhorivnaВажливим аспектом спостереження, подальшого своєчасного і ефективного лікування ко-інфекції ВІЛ-туберкульоз є вчасно та правильно проведена діагностика, що базується на всебічному клінічному, лабораторному та інструментальному дослідженнях. Багато факторів відіграють роль у виникненні туберкульозу у ВІЛ-інфікованих осіб, проте ключовими та достатньо важливими елементами є дослідження генетичних маркерів та біомаркерів запалення. Здійснена низка досліджень запальних маркерів, але актуальними і недостатньо вивченими, при ко-інфекції, залишаються IL-6, INF-γ, MIG, CRP, IL-18. Комплексне дослідження, яких матиме важливе значення при скринінгу ко-інфекції ВІЛ-туберкульоз. Визначення у ВІЛ-інфікованих осіб та хворих на СНІД наявності (SNP) rs4331426, розташованої у ділянці хромосоми 18q11.2, дозволить вирішити питання схильності до розвитку туберкульозу на ранніх етапах ВІЛ-інфекції та сприятиме виробленню подальшої тактики лікування та ведення пацієнтів.Item Fluoride ion conductivity of solid solutions KxPb0.86-xSn1.14F4-x(Serbian Chemical Society, 2021) Pohorenko, Y.; Пшеничний, Роман Миколайович; Пшеничный, Роман Николаевич; Pshenychnyi, Roman Mykolaiovych; Pavlenko, T.; Omelchuk, A.; Trachevskyi, V.The electrical conductivity of solid solutions with tetragonal syngony formed in 0.86(xKF–(1–x)PbF₂)–1.14SnF₂ systems has been studied by ¹⁹F-NMR and impedance spectroscopy. It was found that the Pb₀.₈₆Sn₁.₁₄F₄ phase is characterized by better values of fluoride-ion conductivity than the β-PbSnF₄ compound. It was found that the substitution of Pb²⁺ by K⁺ up to х = 0.07 in the structure of Pb₀.₈₆Sn₁.₁₄F₄ contributes to increase in electrical conductivity by an order of magnitude relative to the original Pb₀.₈₆Sn₁.₁₄F₄. The sample of composition K₀.₀3Pb₀.₈₃Sn1.14F₃.₉₇ has the highest electrical conductivity (σ₆₀₀ = = 0.38 S cm-1, σ₃₃₀ = 0.01 S cm-1). The fluoride anions in the synthesized samples of KxPb₀.₈₆-xSn1.14F4-x solid solutions occupy three structurally nonequivalent positions. It is shown that with increasing temperature, there is a redistribution of fluorine anions between positions in the anion lattice, which results in an increase in the concentration of highly mobile fluoride ions, which determine the electrical conductivity of the samples.Item The Impact of the Sharing Economy as an Ecosystem on the Tourism Sector(Center for International Scientific Research of VŠO and VŠPP, 2021) Navickas, V.; Petroke, I.; Baciuliene, V.; Васильєва, Тетяна Анатоліївна; Васильева, Татьяна Анатольевна; Vasylieva, Tetiana AnatoliivnaThe authors of the article investigated the sharing economy elements as an ecosystem and analyzed the advantages and disadvantages of the sharing economy in the tourism sector. Exploring the elements of the sharing economy's ecosystem can help identify the challenges of globalization and lead to exploiting the sharing economy's potential more efficiently in the tourism sector. The study of the impact of the sharing economy as an ecosystem on the tourism sector is also made relevant by the lack of research examining the advantages and disadvantages of sharing economy models. To determine the impact of the sharing economy on the tourism sector, the authors analyzed the scientific literature. An empirical study of business models based on the sharing economy in the tourism sector was carried out. Moreover, the advantages and disadvantages were identified of the sharing economy in the tourism sector. The authors' analysis has shown that, despite conflicting views on the impact and importance of the sharing economy in the tourism sector, many experts are optimistic about sharing economy-based models in this sector. Research by the authors of the article shows that sharing economy-based businesses are superior to traditional business models. The sharing economy-based models are preeminent because of more affordable prices for tourists, better satisfaction of individual needs, opportunities to become part of the community, a more comprehensive range of services, better access to tourism services. A better quality of services also highlights the advantages of economy-based businesses. Although the study was conducted in the Lithuanian tourism sector, we can assume that the study data can be unified and applied to analyze similar markets in other countries.Item Shape of a sliding capillary contact due to the hysteresis of contact angle: theory and experiment(University of Niš, Serbia, 2021) Popov, V.L.; Ляшенко, Яків Олександрович; Ляшенко, Яков Александрович; Liashenko, Yakiv Oleksandrovych; Starcevic, J.We consider a classical problem of a capillary neck between a parabolic body and a plane with a small amount of liquid in between. In the state of thermodynamic equilibrium, the contact area between the bodies and the liquid layer has a circular shape. However, if the bodies are forced to slowly move in the tangential direction, the shape will change due to the hysteresis of the contact angle. We discuss the form of the contact area under two limiting assumptions about the friction law in the boundary line. We also present a detailed experimental study of the shape of sliding capillary contact in dependence on the roughness of the contacting surfaces.Item Histoultramicroscopic Investigation of the Rats’ Thymus (Experimental Data)(Duzce University Medical School, 2021) Приходько, Ольга Олексіївна; Prykhodko, Olha Oleksiivna; Дмитрук, Сергій Миколайович; Дмитрук, Сергей Николаевич; Dmytruk, Serhii Mykolaiovych; Avilova, O.; Kubikova, E.; Бумейстер, Валентина Іванівна; Бумейстер, Валентина Ивановна; Bumeister, Valentyna Ivanivna; Ярмоленкo, Ольга Сергіївна; Ярмоленко, Ольга Сергеевна; Yarmolenkо, Olha Serhiivna; Гордієнко, Олена Володимирівна; Гордиенко, Елена Владимировна; Hordiienko, Olena VolodymyrivnaThe research paper presents the characteristic of cytoarchitectonics of the thymus of intact white mature male laboratory rats. Topicality of the study is due to the need to clarify the data on the contribution of each type of thymus cells in the formation of its structure. The aim of the research was to determine the specifics of localization and ultramicroscopic structure of thymus cells in male mature Wistar laboratory rats. Material and Methods: The study was conducted using histological and ultramicroscopic methods on 10 mature male laboratory rats, weighing 130-150 g. Semi-thin (0.5-1 μm) and ultrathin (0.05-0.2 μm) sections were made on a microtome UMTP-4 (Ukraine), which were stained with 1% methylene blue solution with the addition of 1% sodium tetraborate solution. Histological analysis and photographic recording were performed using Olympus light microscope (Japan) and DSM 510 camcorder with magnification in 1000 times. Results: With a detailed study of the semi-thin and ultrathin sections in the thymus lobules the specifics of localization and ultramicroscopic structure of thymus cells were clearly identified. The features of localization and ultramicroscopic structure of epithelial, mesenchymal, vascular and hematopoietic thymus cells were determined from the point of view of their functional loads and interactions. Conclusion: The described structural peculiarities of the components of the thymus and their relative location in different zones reflect significant organ polymorphism, which must be taken into account in order to achieve the required level of objectivity in the result evaluation of simulated biomedical experiments.