157 research outputs found

    Influence of overload on low-frequency instability of working process in the combustion chamber of the solid propellant rocket engine

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    In the paper the real oscillatory process is reproduced by statement of direct numerical experiment and the mechanism of occurrence and refill of low-frequency acoustic instability in the combustion chamber of the solid propellant rocket engine with the account of flight overload is investigated for the first time. The direct numerical modeling of low-frequency acoustic instability is carried out by means of Davydov’s method (method of large particles), which is well-suited for the solutions of many problems of mechanics of the continuous media. The results of numerical modeling are presented here. The hydrodynamic highly nonlinear nature of low-frequency fluctuations connected to structure and character of current in the combustion chamber of the rocket engine on firm fuel are proved to be tru

    Influence of overload on low-frequency instability of working process in the combustion chamber of the solid propellant rocket engine

    Get PDF
    In the paper the real oscillatory process is reproduced by statement of direct numerical experiment and the mechanism of occurrence and refill of low-frequency acoustic instability in the combustion chamber of the solid propellant rocket engine with the account of flight overload is investigated for the first time. The direct numerical modeling of low-frequency acoustic instability is carried out by means of Davydov’s method (method of large particles), which is well-suited for the solutions of many problems of mechanics of the continuous media. The results of numerical modeling are presented here. The hydrodynamic highly nonlinear nature of low-frequency fluctuations connected to structure and character of current in the combustion chamber of the rocket engine on firm fuel are proved to be tru

    Influence of overload on low-frequency instability of working process in the combustion chamber of the solid propellant rocket engine

    Get PDF
    In the paper the real oscillatory process is reproduced by statement of direct numerical experiment and the mechanism of occurrence and refill of low-frequency acoustic instability in the combustion chamber of the solid propellant rocket engine with the account of flight overload is investigated for the first time. The direct numerical modeling of low-frequency acoustic instability is carried out by means of Davydov’s method (method of large particles), which is well-suited for the solutions of many problems of mechanics of the continuous media. The results of numerical modeling are presented here. The hydrodynamic highly nonlinear nature of low-frequency fluctuations connected to structure and character of current in the combustion chamber of the rocket engine on firm fuel are proved to be tru

    DEVELOPMENT OF FUNCTIONAL BEVERAGES FROM PLANTRAW MATERIALS — REPLACEMENTS FOR DAIRY PRODUCTS

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    Nowadays, there is a growing consumer interest in food products, made from vegeta-ble raw materials. The article is devoted to an actual topic related to the choice of plant mate-rials, based on its nutritional and biological value, in order to create functional beverages. The analysis of the world market of vegetable analogues of milk was implemented. Based on the literature, the following raw materials were analyzed: cashew nuts, cannabis fruits, sesame and poppy seeds, almond kernels, buckwheat seeds and oats, soybeans. The data on nutritional value, vitamin-mineral and amino acid composition, as well as the composition of fatty acids of the specified raw materials was presented. The conclusion is made about the perspective of its use for the manufacture of drinks, alternative cow’s milk. The article reflects the results of research work on the creation of a functional drink based on sesame seeds, provides information about the nutritional value and biochemical composition of the drink, made on the basis of this raw material. Sesame milk when used regularly can help prevent diseases of the car-diovascular system, the gastrointestinal tract, the musculoskeletal system.Nowadays, there is a growing consumer interest in food products, made from vegeta-ble raw materials. The article is devoted to an actual topic related to the choice of plant mate-rials, based on its nutritional and biological value, in order to create functional beverages. The analysis of the world market of vegetable analogues of milk was implemented. Based on the literature, the following raw materials were analyzed: cashew nuts, cannabis fruits, sesame and poppy seeds, almond kernels, buckwheat seeds and oats, soybeans. The data on nutritional value, vitamin-mineral and amino acid composition, as well as the composition of fatty acids of the specified raw materials was presented. The conclusion is made about the perspective of its use for the manufacture of drinks, alternative cow’s milk. The article reflects the results of research work on the creation of a functional drink based on sesame seeds, provides information about the nutritional value and biochemical composition of the drink, made on the basis of this raw material. Sesame milk when used regularly can help prevent diseases of the car-diovascular system, the gastrointestinal tract, the musculoskeletal system

    A case of successful comprehensive treatment of necrotizing enterocolitis in a newborn child

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    Necrotizing enterocolitis is an inflammatory disease caused by infection and hypoxic–ischemic damage of the intestinal mucosa, which leads to generalization with the development of a systemic inflammatory response. The pathogenetic mechanisms leading to intestinal wall damage are ischemia and pain. Therefore, the use of central neuraxial blocks, which provide the analgesic effect and preganglionic blockade of the sympathetic nervous system, is pathogenetically justified. The aim of the work is to acquaint practitioners with the case of successful comprehensive treatment using neuraxial blocks in a newborn with necrotizing enterocolitis. Materials and methods. The child was treated at the Department of Anesthesiology and Intensive Care for Newborns of Zaporizhzhia City Pediatric Hospital No. 5. He underwent clinical and biochemical blood tests, microbiological, radiological and ultrasound examinations using hospital equipment. Results. A child was operated due to suspected intestinal perforation and pneumoperitoneum. It was found that throughout the small and large intestines had multiple hemorrhages and air bubbles in the subserosa, but no perforation sites were found. Subsequently, the child underwent conservative treatment with antibacterial therapy according to the de-escalation principle, antifungal therapy, intravenous immunoglobulins, total parenteral nutrition. In addition to this standard treatment, the child underwent caudal-epidural blocks twice a day for a week in the postoperative period for effective analgesia, improvement of microcirculation and splanchnic blood flow. Conclusions. Surgical intervention performed on a newborn child with the second stage of necrotizing enterocolitis (intestinal pneumatosis), when its perforation could not be excluded, did not significantly affect the course of the disease, so the positive outcome can be considered the result of successful comprehensive intensive care. In our opinion, the decisive factor that influenced the positive treatment outcomes (prevention of perforation and peritonitis) was the effect of neuraxial caudal epidural blocks, which contributed to the improvement of microcirculation in the splanchnic area, elimination of intestinal ischemia and effective anesthesia

    Observation of attraction between dark solitons

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    We demonstrate a dramatic change in the interaction forces between dark solitons in nonlocal nonlinear media. We present what we believe is the first experimental evidence of attraction of dark solitons. Our results indicate that attraction should be observable in other nonlocal systems, such as Bose-Einstein condensates with repulsive long-range interparticle interaction

    Errors in determining coordinates in the digital holography of particles

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    Based on the approach applied to diffraction-limited optical systems, the study evaluates the measurement errors of transverse and longitudinal coordinates of particle images reconstructed from digital holograms. The paper shows the experimental results of testing the above estimates

    О вкладе уральской науки в практическое здравоохранение

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    Данная статья посвящена истории становления и развития медицинской науки Свердловской области, выдающимся деятелям отечественной медицины, основателям Свердловского государственного медицинского института, а так же о сформировавшихся в вузе медицинских научных школах, которые приобрели широкую известность в мире науки. Особую честь стоит отдать работающим в настоящее время в профессорско-преподавательском составе университета Заслуженным деятелям науки РФ, чья научная и трудовая деятельность охвачена периодом становления медицинского вуза от института до университета

    The role of the KIBRA and APOE genes in developing spatial abilities in humans

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    In the contemporary high-tech society, spatial abilities predict individual life and professional success, especially in the STEM (Science, Technology, Engineering, and Mathematics) disciplines. According to neurobiological hypotheses, individual differences in cognitive abilities may be attributed to the functioning of genes involved in the regulation of neurogenesis and synaptic plasticity. In addition, genome-wide association studies identified rs17070145 located in the KIBRA gene, which was associated with individual differences in episodic memory. Considering a significant role of genetic and environmental components in cognitive functioning, the present study aimed to estimate the main effect of NGF (rs6330), NRXN1 (rs1045881, rs4971648), KIBRA (rs17070145), NRG1 (rs6994992), BDNF (rs6265), GRIN2B (rs3764030), APOE (rs7412, rs429358), and SNAP25 (rs363050) gene polymorphisms and to assess the effect of gene-environment interactions on individual differences in spatial ability in individuals without cognitive decline aged 18–25 years (N = 1011, 80 % women). Spatial abilities were measured using a battery of cognitive tests including the assessment of “3D shape rotation” (mental rotation). Multiple regression analysis, which was carried out in the total sample controlling for sex, ethnicity and the presence of the “risk” APOE ε4 allele, demonstrated the association of the rs17070145 Т-allele in the KIBRA gene with enhanced spatial ability (β = 1.32; pFDR = 0.037) compared to carriers of the rs17070145 CC-genotype. The analysis of gene-environment interactions revealed that nicotine smoking (β = 3.74; p = 0.010) and urban/rural residency in childhood (β = –6.94; p = 0.0002) modulated the association of KIBRA rs17070145 and АРОЕ (rs7412, rs429358) gene variants with individual differences in mental rotation, respectively. The data obtained confirm the effect of the KIBRA rs17070145 Т-allele on improved cognitive functioning and for the first time evidence the association of the mentioned genetic variant with spatial abilities in humans. A “protective” effect of the APOE ε2 allele on enhanced cognitive functioning is observed only under certain conditions related to childhood rearing

    Impact of graft-versus-host disease prophylaxis on immune reconstitution in patients after allogeneic hematopoietic stem cell transplantation

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    The graft-versus-host disease (GVHD) is among the most common complications after hematopoietic stem cell transplantation (allo-HSCT). The main tools for GVHD prevention remain calcineurin inhibitors (cyclosporin A, tacrolimus), methotrexate, mycophenolate mofetil. Upon implementation of reduced-intensity conditioning regimens, antithymocyte globulin was widely introduced. However, negative effects upon reconstitution of T-cell immunity have been noted, thus increasing risk of severe infectious complications and disease relapse. With extended practice of HSCT from alternative (partially matched or haploidentical) donors, cyclophosphamide was increasingly used. Our aim was to study reconstitution of immune cell subpopulations in the patients undergoing bone marrow transplantation (BMT), when using different GVHD prophylaxis regimens, including the schedules with post-transplant CP usage. The study concerned 44 cases classified into 2 groups. The first one included patients with standard immunosuppressive therapy, antithymocyte therapy, cyclosporine A, methotrexate, mycophenolate mofetil. The second group included the patients who received CP as immunosuppressive drug combined with other treatments (cyclosporine A, methotrexate, mycophenolate mofetil). At specified control terms, (D+14, +30, +60, +90) the blood leukocyte subpopulations were assayed by means of multicolor flow cytometry. Absolute counts of CD4+ cells in HSCT recipients treated with CP post-BMT proved to be sufficiently lower at D+14 and +30, than in those treated with classical immunosuppressive therapy. However, at later terms, (D+60, +90), these differences were not observed. Moreover, in CP-treated bone marrow recipients, absolute numbers of CD8+ cells was significantly higher, compared to the patients who received conventional GVHD prophylaxis. Reconstitution of the studied lymphocyte populations in hematopoietic cell recipients did not depend on the GVHD prophylaxis regimen. Usage of CP combined with bone marrow as a source of stem cells, brings about sufficient decrease of some cell populations (CD4+; CD8+; NK cells) at early terms post-transplant. Administration of CP combined with hematopoietic stem cells as the source of hematopoietic graft seems to be more reasonable
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