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

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

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

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

Определение профиля флавоноидов в гипогликемическом сборе методом высокоэффективной жидкостной хроматографии

Objectives. Herbal hypoglycemic drugs complement the conventional approach to the treatment of type-2 diabetes based on the use of synthetic prescription drugs. However, their scientifically based application and standardization are limited due to inadequate and often outdated information on their chemical composition. Accordingly, we have developed a hypoglycemic collection (HGС) consisting of common bean pods (Phaseolus vulgaris L.), bilberry shoots (Vaccinium myrtillus L.), galega herb (Gallega officinalis L.), common knotgrass herb (Polygonum aviculare L.), burdock roots (Arctium lappa L.), and cinnamon rose hips (Rosa cinnamomea L.). According to a number of researchers, the antidiabetic properties of these herbs are largely due to the presence of polyphenolic compounds, especially flavonoids. The aim of this study was to determine the profile of flavonoids in the HGС and in its total dry extract (TDE).Methods. The study was performed by reverse-phase high-performance liquid chromatography with diode array and mass spectrometric detection.Results. Nine individual flavonol glycosides—derivatives of myricetin, quercetin, kaempferol and kaempferide—were identified in the HGC and the TDE. The main flavonol glycosides in the studied objects were robinin and kaempferol-3-glucuronide, the contents of which in the HGC were 2.09 and 2.22 mg/g, in the TDE 4.85 and 3.84 mg/g, respectively. The other flavonol glycosides were determined in the HGC and its TDE at significantly lower concentrations.Conclusions. The method developed in the study can be used to standardize HGCs and estimate their pharmacological activities.Цели. Гипогликемические препараты растительного происхождения успешно дополняют синтетические рецептурные лекарства, использующиеся в традиционном подходе к лечению сахарного диабета 2 типа. Однако научно обоснованное применение и стандартизация таких препаратов ограничены из-за неадекватной и часто устаревшей информации об их химическом составе. Нами был разработан гипогликемический сбор (ГГС), состоящий из створок фасоли обыкновенной (Phaseolus vulgaris L.), побегов черники обыкновенной (Vaccinium myrtillus L.), травы галеги лекарственной (Gallega officinalis L.), травы горца птичьего (спорыша) (Polygonum aviculare L.), корней лопуха большого (Arctium lappa L.), плодов шиповника коричного (Rosa cinnamomea L.). По мнению ряда исследователей, антидиабетические свойства вышеупомянутых растений во многом обусловлены присутствием в них полифенольных соединений, особенно флавоноидов. Цель данного исследования – определение профиля флавоноидов в ГГС и в суммарном сухом экстракте (ССЭ) на основе ГГС.Методы. Исследование проводили методом обращено-фазовой высокоэффективной жидкостной хроматографии с диодно-матричным и масс-спектрометрическим детектированием.Результаты. В ГГС и ССЭ было идентифицировано девять индивидуальных флавонолгликозидов – производных мирицетина, кверцетина, кемпферола и кемпферида. Основными флавонолгликозидами в исследуемых объектах были робинин и кемпферол-3-глюкуронид, содержание которых в ГГС составило 2.09 и 2.22 мг/г, в ССЭ – 4.85 и 3.84 мг/г, соответственно. Остальные флавонолгликозиды были обнаружены в ГГС и ССЭ в существенно более низких концентрациях.Выводы. Результаты работы могут быть использованы при стандартизации ГГС и оценке его фармакологической активности

Effect of antibodies to glutamate on age-related memory changes in C57Bl/6 mice

Chronic intranasal administration of antibodies to glutamate to aging C57Bl/6 mice improved passive avoidance conditioning, had no effect on horizontal and vertical locomotor activity, but slowed locomotion in the open-field test. Administration of antibodies to glutamate increased the content of dopamine and its metabolites in mouse hippocampus, but had no effect on the metabolism of neurotransmitter amino acids. In the frontal cortex, antibodies to glutamate did not affect neurotransmitter metabolism, but increased the level of both excitatory and inhibitory amino acids without changing their ratio

CELLULAR IMMUNITY PARAMETERS IN PATIENTS WITH REMITTING MULTIPLE SCLEROSIS

The aim of this work was to study some parameters of cellular immunity in patients with multiple sclerosis (MS). The study included 10 patients with relapsing-remitting MS aged 32 to 50 years. Diagnosis was clinically established and confirmed by magnetic resonance imaging. Patients did not receive immunosuppressive therapy for at least 6 months prior to study entry. The neurological status of all examined patients was assessed using the Kurtzke functional scale using the Extended Disability Scale (EDSS) and averaged 4.0±0.67 points, the mean number of exacerbations per year was 1.25±0.25. While studying such parameters of the immune status such as the number of T, B, NK-cells, the content of immunoglobulins, the phagocytic activity of monocytes and granulocytes, their production of reactive oxygen species, no significant differences were observed in patients with MS in comparison with the normal donor level. At the same time, we have noted an increase in the proliferative response of mononuclear blood cells to myelin antigen by 2.35 times. The content of CD4+CD45RO+CD62L+ and CD8+CD45RO+CD62L+ central memory T-cells, as well as CD8+CD45RO+CD62L- effector memory T-cells in the blood of MS patients significantly exceeded the control values (p < 0.05). Also, in MS patients, compared with healthy individuals, there was an increased level of naive IFNγ-positive CD4+CD45RO- and CD8+CD45ROT-cells (p < 0.01), and an increase in CD4+CD45RO+ and CD8+CD45RO+ memory T-cells producing IFNγg or IFNγg together with IL-4 in response to the activation (p < 0.01). Consistent with these data, there were significantly increased serum IFNγ and IL-17 levels and no changes in IL-4 levels. The relative level of naive CD4+CD25+FoxP3+, as well as induced CD4+CD25- FoxP3+ regulatory T-cells in MS patients did not significantly change compared to donor values. The results of assessing some parameters of the immune status in MS patients indicate a functional reshaping of the immune system towards the Th1 type of immune response. It is obvious that immunotropic treatment of MS should be aimed at inactivating auto-immune Tand B-lymphocytes, suppressing the production of proinflammatory mediators, and enhancing the activity of natural and induced regulatory T-cells

MONOCYTE SUBSETS IN HEALTHY ADULTS AND SEPSIS PATIENTS

Monocytes play a key role in the development of immune response in bacterial infection, because of their phagocytic, antigen-presenting and secretory functions. There are three subpopulations of monocytes: “classical” CD14+CD16-, “intermediate” CD14+CD16+, and “nonclassical” CD14+dimCD16+. These monocyte subtypes have different phenotypes and functions. The ratio of appropriate subpopulations varies with development of the antibacterial response. The aim of the present research was to study phenotypes of the monocyte subpopulations in the patients with sepsis, and changes in the monocyte subpopulation ratio, depending on the presence of bacteria in circulating blood of the patients, as well as to estimate contribution of the monocyte subpopulations to the cytokine production. We observed 16 patients with sepsis (10 men and 6 women; mean age, 58±14 years, SOFA 9.4±2.1; a total of 44 blood samples) examined in dynamics. The control group included healthy adults (n = 23, 12 men and 11 women; mean age, 51±13 years). Laboratory studies included bacteriological cultures, determination of absolute and relative numbers of subpopulations of classical, intermediate and non-classical monocytes and their expression of HLA-DR and CD64, determination of IL-6, TNFα, IL-1β, IL-10 concentration in blood serum. Absolute number of monocytes was increased in the sepsis patients, the ratio of classical monocytes was also increased, like as relative and absolute numbers of  intermediate cells. Meanwhile, the subpopulation of non-classical monocytes did not change significantly. The monocyte subpopulation ratio depended on the presence of bacteria in blood, i.e., a higher proportion of intermediate cells was observed in the samples positive for bacteria in blood cultures. The ratio of subpopulations was restored after elimination of bacteria from the circulation. The expression density of LPS receptor (CD14), IgG receptors (CD16 and  CD64) was found to be increased, especially in the subpopulations of intermediate and nonclassical monocytes. In all subpopulations of monocytes, expression of HLA-DR is reduced, most notably in classical monocytes, least in intermediate cells. There was a significant increase in serum levels of IL-6, IL-1β, TNFα and IL-10 cytokines. Direct correlation between the absolute number of classical monocytes and IL-6 concentration was revealed, as well as intensity of multiple organ dysfunction. Increase in absolute amount of classical monocytes and IL-6 concentration might serve as an indirect criterion for evaluation of endothelial activation, an active producer of IL-6 and myeloid cell growth factors. A direct correlation between the percentage of CD14+CD16+ cells and IL-10 concentration in blood serum indicates to an important role of intermediate monocytes in IL-10 production. IL-10 suppresses the antigen-presenting function of intermediate cells, namely, expression of HLA-DR molecules, as suggested by inverse correlation between the IL-10 concentration and HLA-DR expression density on CD14+CD16+ cells. We have also determined an inverse correlation between the degree of multi-organ dysfunction  and relative amount of HLA-DR+ monocytes. The larger was a classical monocyte subpopulation, the more noticeable was a decrease of this index. The studies in ratios of monocyte subpopulations help to understand the mechanisms of antibacterial protection in sepsis. Monitoring of classical monocyte numbers and serum concentrations of IL-6 is necessary for a comprehensive assessment of inflammatory response in sepsis. Determination of HLADR expression on monocytes allows us to evaluate the intensity of immune suppression in critically ill patients

The influence of a combined strain-heat treatment on the features of electromagnetic testing of fatigue degradation of quenched constructional steel

The possibilities of the magnetic and eddy-current methods for testing fatigue degradation during low-cycle loading of quenched steel 50 (0.51% C) that was subjected to a combined strain-heat treatment according to an optimal regime that included friction treatment with subsequent tempering at T = 350 C, were investigated. It is shown that for steel that was subjected to a combined nanostructuring treatment, the accumulation of a plastic strain under "hard" cyclic loading can be tested using the coercimetric method and values of the residual magnetic induction on the major and minor magnetic-hysteresis loops, values of the maximum and initial magnetic permeabilities, and readings of an eddy-current instrument at a low excitation frequency of the eddy-current transducer. The appearance of surface fatigue cracks can be tested via eddy-current measurements at high frequencies, when the contribution of the crack formation in the hardened layer to the eddy-current characteristics is considerable. © 2013 Pleiades Publishing, Ltd

New materials based on polylactide modified with silver and carbon ions

An integrated study of poly-L-lactide (PL) synthesis and the physicochemical properties of film surfaces, both modified by silver and carbon ion implantation and also unmodified PL surfaces, has been carried out. Surface modification was done using aMevva-5.Ru metal ion source with ion implantation doses of 1·1014, 1·1015 and 1·1016 ion/cm2. Material characterization was done using NMR, IRS, XPS and AFM. The molecular weight (MW), micro-hardness, surface resistivity, and limiting wetting angle of both un-implanted and implanted samples were measured. The results reveal that degradation of PL macromolecules occurs during ion implantation, followed by CO or CO2 removal and MW decrease. With increasing implantation dose, the glycerol wettability of the PL surface increases but the water affinity decreases (hydrophobic behavior). After silver and carbon ion implantation into the PL samples, the surface resistivity is reduced by several orders of magnitude and a tendency to micro-hardness reductionis induced

MANAJEMEN STRATEGI PELAKSANAAN KURIKULUM DALAM MEWUJUDKAN MADRASAH UNGGUL (Studi atas MA Muhammadiyah Kota Metro)

The public demand for quality or quality education is increasing. This phenomenon is at least influenced by two main factors namely; factors of globalization challenges and parents' awareness of the need for quality or quality education for their children. Another phenomenon that is not less interesting, today many schools are qualified and give more religious content became the first choice for parents, this condition is a challenge as well as opportunities for Senior High School  (MA) Muhammadiyah Metro City to rise from the shackles of dualism that is artificial and dualism management at once showcasing the various advantages that can be an attraction at the same time can invite public interest to make this institution as an option for the continuation of their children's education. This study aims to analyze management and strategy Implementation of the curriculum in realizing Senior High School (MA) Muhammadiyah Metro City Becomes a Superior School. This type of research is descriptive qualitative in which the data collection in this study was conducted by the method of observation, interview, and documentation study. Data that have been collected is then analyzed descriptively qualitative to then drawn conclusions. The results of this study will show that the management and implementation strategy of the curriculum in realizing Senior High School Muhammadiyah Metro City becomes a superior school. The results of this study recommend to management tiem in the implementation of the curriculum in realizing Senior High School Muhammadiyah Metro City Becomes a Superior School

Tricalcium Phosphate Ceramics Doped with Silver, Copper, Zinc, and Iron (III) Ions in Concentrations of Less Than 0.5 wt.% for Bone Tissue Regeneration

© 2016, Springer Science+Business Media New York.Novel materials with a variety of properties, such as biocompatibility, antibacterial activity, interconnected porosity, and functionalities combined in one, are required for regenerative medicine. Porous β-tricalcium phosphate (β-TCP) ceramics doped with Cu2+, Zn2+, Ag+, and Fe3+ ions in the concentrations of less than 0.5 wt.% were synthesized and investigated. The obtained samples were analyzed by the diversity of analytical tools. The structure, solubility, and antimicrobial properties of the porous ceramics are shown to be very sensitive to the presence and the type of the cationic substituent. It opens the way to manage structure and properties of the materials for bone tissue regeneration by co-doping of the initial matrix simultaneously with different types of substituent ions