Mathematical Modeling of Training and Dynamics of Scientific Personnel

Qualitative and numerical analysis of mathematical model of training and dynamics of scientific personnel, which is a dynamic system of third order, describing the interaction of scientific personnel without degrees, candidates and doctors of sciences were don

On the variability of teaching mathematical methods modeling bachelors profiling «Technology and process management in the welding industry»

Actuality and characterized the main features of variable teaching methods of mathematical modeling bachelors profiling «Technology and technology management in the welding industry»Обосновывается актуальность и характеризуются основные особенности вариативного обучения методам математического моделирования бакалавров профилизации «Технологии и технологический менеджмент в сварочном производстве

Radial distribution of a single-pass amplified radiation in the active elements of CuBr lasers

The paper presents the results of study of single-pass amplified radiation distribution of copper bromide vapor laser active elements used in high-speed laser monitors. The possibility of modifying the profile of a single-pass amplified light beam by changing the copper bromide vapor concentration is demonstrated. This means of influence on the radiation profile seems to be easiest due to implementation by varying only one parameter of operation. Gaussian, ring-shaped or flat profiles can be achieved depending on the temperature of the containers with copper bromide. The diameter of the beam becomes narrower when increasing the concentration of copper bromide vapor. This feature is characteristic of the discharge tubes as small (diameter 2.5, length 5 cm) and large (diameter 5 cm, length 90 cm) active volume

Comparison of microflora isolated from peripheral blood and valvular structures of the heart in patients with infective endocarditis

Background. Infective endocarditis (IE) is defined as an infection of a native or prosthetic heart valve, endocardial surface, or permanent cardiac apparatus. Currently, the determination of microorganisms that induce a disease or are involved in the process of pathogenesis by PCR is one of the most modern and rapid tests.The aim. To determine and to compare the spectrum of infectious pathogens in homogenate samples of native heart valves and blood of patients with IE.Materials and methods. Twenty patients with confirmed IE diagnose were examined, admitted for hospitalization at the Research Institute for Complex Issues of Cardiovascular Diseases (Kemerovo, Russia) in 2019. The range of tests used in the study was aimed at detecting such microorganisms as Streptococcus pyogenes, Streptococcus agalactiae, Enterobacter spp., Klebsiella spp., Staphylococcus spp., Streptococcus spp., Bacteroides fragilis, Bacteroides vulgatus, Bacteroides thetaiotaomicron, and Bacteroides ovatus.Results. The study found that 19 samples of heart valves were characterized by the presence of microorganisms from the genus Streptococcus spp., wherein Streptococcus agalactiae was found in two patients. Staphylococcus spp. Were found in 16 samples of valve homogenate. Detection of other pathogens revealed only two cases of Enterobacter spp., Klebsiella spp. When analyzing blood samples from patients with IE, not a single infectious agent was identified. The study revealed a statistically significant difference (p < 0.001) between the incidence of Staphylococcus spp. in samples of valve homogenate and peripheral blood of patients with IE. There was also a statistically significant difference (p < 0.001) for Streptococcus spp. both in samples of valve homogenate and peripheral blood from patients with IE.Conclusion. Molecular genetic research using PCR technologies has low efficiency in detecting the pathogen in the circulating bloodstream, as well as in blood culture. However, the study of homogenized biopsy specimens of the heart valve structures removed during surgery may allow correcting antimicrobial tactics in the early postoperative period of prosthetics

Analysis of pneumococcal serotypes distribution to determine a model composition for a Russian pneumococcal conjugate vaccine

Diseases caused by Streptococcus pneumoniae, as well as antibiotic resistance of its serotypes, are the leading cause of death amongst children worldwide. To prevent pneumococcal infection, the population is immunised with conjugate vaccines containing different amounts of polysaccharides of certain serotypes. Development of a full-cycle Russian vaccine is vital because the active pharmaceutical ingredients for the vaccines registered in the Russian Federation are produced abroad, and only the final stages of production of vaccines of this group are performed in the territory of the Russian Federation. Considering the phenomenon of serotype replacement associated with the long-term widespread use of pneumococcal conjugate vaccines, it is necessary to carefully select the serotype composition for the new vaccine. The aim of this work was to analyse the serotype distribution of pneumococci in the Russian Federation and other countries in order to select optimal serotypes for the Russian vaccine for human use, taking into account vaccination schedules for each age group. This review presents an analysis of the pneumococcal serotype distribution in the Russian Federation in the pre-vaccination era, as well as after the introduction of routine vaccination. In addition, the review includes data on the serotype distribution in the Eurasian Economic Union countries. The authors described a model composition containing at least sixteen serotypes. It will increase effectiveness of immune protection of the population, providing a more complete coverage of serotypes, considering their prevalence in the Russian Federation. Based on the analysis, the serotype composition for the sixteen-valent pneumococcal conjugate vaccine is proposed for further production and preclinical and clinical trials. A new Russian pneumococcal conjugate vaccine will ensure vaccination of all population groups within the National Immunisation Schedule of the Russian Federation

Transmission of High-Power Electron Beams Through Small Apertures

Tests were performed to pass a 100 MeV, 430 kWatt c.w. electron beam from the energy-recovery linac at the Jefferson Laboratory's FEL facility through a set of small apertures in a 127 mm long aluminum block. Beam transmission losses of 3 p.p.m. through a 2 mm diameter aperture were maintained during a 7 hour continuous run.Comment: arXiv admin note: text overlap with arXiv:1305.019

Measured Radiation and Background Levels During Transmission of Megawatt Electron Beams Through Millimeter Apertures

We report measurements of photon and neutron radiation levels observed while transmitting a 0.43 MW electron beam through millimeter-sized apertures and during beam-off, but accelerating gradient RF-on, operation. These measurements were conducted at the Free-Electron Laser (FEL) facility of the Jefferson National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an energy-recovery linear accelerator. The beam was directed successively through 6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a maximum current of 4.3 mA (430 kW beam power). This study was conducted to characterize radiation levels for experiments that need to operate in this environment, such as the proposed DarkLight Experiment. We find that sustained transmission of a 430 kW continuous-wave (CW) beam through a 2 mm aperture is feasible with manageable beam-related backgrounds. We also find that during beam-off, RF-on operation, multipactoring inside the niobium cavities of the accelerator cryomodules is the primary source of ambient radiation when the machine is tuned for 130 MeV operation.Comment: 9 pages, 11 figures, submitted to Nuclear Instruments and Methods in Physics Research Section

A new endosymbiotic bacterium species associated with a nematode species of the genus Xiphinema (Nematoda, Longidoridae)

2021 virtual edition of the Conference Microscopy at the Frontiers of Science, september 29 and October 1st.Nematodes are the third largest group of metazoans; among them, the Family Longidoridae comprises two main genera of plant parasitic nematodes, Xiphinema and Longidorus, which contain several virus-vector species, e.g. the species X. index, the vector of grape fanleaf virus (GFLV), a serious pathogen of grapes. Bacterial endosymbionts of plant-parasitic nematodes represent a field of research that has become active in recent years. In this work we present a detailed characterization of the endosymbiont bacterium found in the nematode X. pachtaicum from the rhizosphere of sour orange trees (Citrus x aurantium L.) from Cordoba, Spain, and, based on morphological, phylogenetic and genomic characteristics propose a novel candidate genus and species for this uncultured bacterium (strain IAST). An intracellular bacterium, strain IAST, was observed to infect several species of the plant-parasitic nematode genus Xiphinema (X. astaregiense, X. incertum, X. madeirense, X. pachtaicum, X. parapachydermum and X. vallense). The bacterium could not be recovered on axenic medium. The localization of the bacterium (via light and fluorescence in situ hybridization microscopy) is in the X. pachtaicum females clustered around the developing oocytes, primarily found embedded inside the epithelial wall cells of the ovaries, from where they are dispersed in the intestine. Transmission electron microscopy (TEM) observations supported the presence of bacteria inside the nematode body, where they occupy ovaries and occur inside the intestinal epithelium. Ultrastructural analysis of the bacterium showed cells that appear as mostly irregular, slightly curved rods with rounded ends, 0.8–1.2 μm wide and 2.5–6.0 μm long, possessing a typical Gram-negative cell wall. The peptidoglycan layer is, however, evident only occasionally and not detectable by TEM in most cells. Another irregularly occurring shell surrounding the endosymbiont cells or the cell clusters was also revealed, probably originating from the host cell membrane. Flagella or spore-like cells do not occur and the nucleoid is diffusely distributed throughout the cell. This endosymbiont is transmitted vertically through nematode generations. These results support the proposal of IAST as a new species, although its obligate intracellular and obligate endosymbiont nature prevented isolation of a definitive type strain. Strain IAST is therefore proposed as representing ‘Candidatus Xiphinematincola pachtaicus’ gen. nov., sp. nov

Влияние миэктомии с пластикой митрального клапана на трехмерную модель клапана и обструкцию в выводном отделе левого желудочка у больных гипертрофической кардиомиопатией

Aim. To assess the effects of combined myectomy with mitral valve repair on a three-dimensional model of the mitral valve in patients with obstructive hypertrophic cardiomyopathy.Methods. 24 patients with obstructive hypertrophic cardiomyopathy and left ventricular outflow obstruction over 50 mm Hg at rest were recruited in a study. Eight patients underwent combined myectomy with mitral valve repair according to the Carpentier method. Seven patients underwent the Alfieri's edge-to-edge repair, and nine patients underwent secondary chordae resection using the Ferrazzi’s technique. Before combined myectomy and two weeks after it, all patients underwent standard transthoracic echocardiography and real-time 3D transesophageal imaging of the mitral valve, followed by quantitative 3D reconstruction of the mitral valve and calculation of the annulus, the leaflets, and the aorto-mitral angle.Results. Despite the selected mitral valve repair technique, we observed a decrease in the LVOT obstruction gradient. There were no differences in the residual obstruction gradient between the selected mitral valve repair technique. Patients with obstructive hypertrophic cardiomyopathy, who underwent combined myectomy and posterior mitral leaflet plasty valve according to the Carpentier approach, reported a correlation of a decrease in the LVOT obstruction with the non-planar angle (r = -0.83; p = 0.040), sphericity index (r = 0.83; p = 0.04) and a decrease in the velocity excursion of the annulus (r = 0.94; p = 0.005). Patients who underwent the Alfieri's edge-to-edge repair demonstrated that the residual LVOT obstruction gradient depended on the annulus height (r = 0.90; p = 0.04) and the ratio of this height to the commissural diameter of the annulus ( r = 0.90; p = 0.04). After secondary chordae resection, a decrease in the LVOT obstruction gradient correlated with the sphericity index (r = 0.77; p = 0.03), the anterolateral-posteromedial annulus diameter (r = -0.72; p = 0.04), the anterior (r = -0.78; p = 0.02) and posterior (r = -0.78; p = 0.02) leaflets, the ratio of the total leaflet length to the anteroposterior diameter of the annulus (r = -0.83; p = 0.01), the area (r = -0.76; p = 0.0з) and the mitral valve tenting height (r = -0.95; p = 0.00). Conclusion.Combined myectomy with mitral valve repair is the method of choice in the treatment of patients with obstructive hypertrophic cardiomyopathy. The comparison of three mitral valve repair techniques did not reveal any differences in the residual LVOT obstruction gradient. However, the Alfieri's edge-to-edge repair may be considered as the most physiological technique to repair dynamic LVOT obstruction.Цель. Оценить влияние миэктомии с пластикой митрального клапана (МК) на трехмерную модель клапана у больных обструктивной гипертрофической кардиомиопатией (ГКМП).Материалы и методы. Исследованы 24 пациента с ГКМП и обструкцией в выводном отделе левого желудочка (ВОЛЖ) более 50 мм рт. ст. в покое, которым выполнены миэктомия с пластикой МК по методике A. Carpentier (n = 8), O. Alfieri (по типу «край в край», n = 7) и резекцией вторичных хорд по Р. Ferrazzi (n = 9). Всем пациентам до и в течение двух недель после c-очетанной операции выполнены стандартная трансторакальная эхокардиография и чреспищеводная трехмерная визуализация МК в реальном масштабе времени с последующей трехмерной количественной реконструкцией МК и расчетом показателей фиброзного кольца (ФК), створок и аортально-митрального угла.Результаты. Независимо от метода пластики МК наблюдалось снижение градиента обструкции в ВОЛЖ. Не выявлено различий в величине резидуального градиента обструкции между применяемыми методиками пластики. У больных ГКМП после миэктомии в сочетании с пластикой задней створки МК по A. Carpentier величина снижения обструкции в ВОЛЖ коррелировала с непланарным углом (r = -0,83; p = 0,040), индексом сферичности (r = 0,83; p = 0,04) и снижением скорости движения ФК (r = 0,94; p = 0,005). У пациентов после пластики МК по типу «край в край» (O. Alfieri) резидуальный градиент обструкции в ВОЛЖ связан с высотой ФК (r = 0,90; p = 0,04) и отношением этой высоты к комиссуральному диаметру ФК МК (r = 0,90; p = 0,04). После резекции вторичных хорд величина снижения градиента обструкции в ВОЛЖ коррелировала с индексом сферичности (r = 0,77; p = 0,03), переднелатеральнозаднемедиальным диаметром ФК (r = -0,72; p = 0,04), углом передней (r = -0,78; p = 0,02) и задней (r = -0,78; p = 0,02) створок, отношением суммарной длины створок к переднезаднему диаметру ФК (r = -0,83; p = 0,01), площадью (r = -0,76; p = 0,03) и высотой (r = -0,95; p = 0,00) тентинга створок МК.Заключение. Миэктомия в сочетании с пластикой МК является предпочтительным способом лечения пациентов с ГКМП. При оценке трех методов пластики МК не выявлено различий в резидуальных градиентах обструкции в ВОЛЖ. Наиболее физиологичными технологиями коррекции динамической обструкции ВОЛЖ следует считать методики по типу «край в край»