Peculiarities of the formation of silicon oxide films modified with metal nanoparticles

ABSTRACT: Introduction. Silicon oxide film coatings have unique properties and are widely used in various industries, including construction. This paper presents the results on the preparation of polyalkylhydroxysiloxane liquid film in the presence of nanoscale particles of metallic bismuth. Methods and materials. Laser ablation method of metallic bismuth in aqueous medium was used to obtain bismuth nanoparticles. The surface of the target was treated with a laser beam at the workstation of an ytterbium pulsed fiber laser are discussed. The particle size and electrokinetic properties of colloidal bismuth sols were determined method by dynamic light scattering. After drying, Bi powder was added to polyalkylhydroxysiloxane liquid. Thin films cured under different heat treatment modes are applied to glass substrates by dipping. The resulting films were characterized by SEM, X-ray phase analysis, and FTIR spectroscopy. Results. In this work, the electrokinetic properties of colloidal bismuth sols are discussed. Laser ablation of a bismuth substrate leads to an increase in electrical conductivity and the appearance of a double electric layer in colloidal sols. The effect of the curing temperature on the properties of the coating is shown. It was found that the content of bismuth nanoparticles in the polyalkylhydroxysiloxane coating (3 wt.%) does not lead to the formation of crystalline phases. At the same time, the composition of the film and the mode of heat treatment affect the short-range order of molecular bonds. Increasing the content of bismuth nanoparticles in the coating of more than 10 wt.% leads to the appearance of microcrystalline phases of bismuth silicates in the system. Conclusion. The results obtained in the course of the study supplement the information about the production of bismuth nanoparticles by laser ablation and are of great importance in the practice of creating composite film

The use of immunoglobulins and monoclonal antibodies against COVID-19

Introduction. When a new disease occurs, one of the most affordable remedies is drugs containing specific antibodies to this infectious agent. The use of such drugs is aimed at reducing the amount of the pathogen in the macroorganism and the associated reduction in the severity of the symptoms of the disease or recovery. The purpose of this review is to analyze the experience of using immunoglobulins and monoclonal antibodies in the treatment of COVID-19 patients during the pandemic. Results and conclusion. The two main groups of medical protective agents that block the penetration of the SARS-CoV-2 virus into permissive cells are drugs obtained from blood plasma of convalescents (immunoglobulin) and human monoclonal antibodies. The first group of drugs in the treatment of COVID-19 includes blood plasma of convalescents, which can be successfully used for emergency prevention. The main disadvantage of using blood plasma convalescents is the difficulty of standardization due to the different content of specific antibodies in donors. Another disadvantage is the undesirable side effects in recipients that occur after plasma administration. An alternative approach to COVID-19 therapy is the use of humanized and genetically engineered human monoclonal antibodies against certain epitopes of the SARS-CoV-2 virus. For example, monoclonal antibodies against receptor-binding domain of the S-protein, which prevents the virus from entering permissive cells and interrupts the development of infection. The advantages of these drugs are their safety, high specific activity, and the possibility of standardization. However, the complexity of their production and high cost make them inaccessible for mass use in practical medicine

Problems of personnel irradiation in modern medical technologies

BACKGROUND: The widespread use of radiation sources in medical practice (cardio-endovascular surgery, endoscopy, traumatology, urology, neurosurgery, dentistry, and radioisotope diagnostics departments) leads to irradiation of the lens of the eye and the skin of the hands. The introduction of new recommendations by the IAEA to reduce the limit of the annual equivalent dose to the lens (20 mSv) has led to an inaccurate dose assessment based on the effective dose. AIM: To analyze approaches and assess equivalent doses of irradiation of the lens of the eye and skin of the hands of medical personnel during various diagnostic studies under the influence of X-rays and radiopharmaceuticals studies and to compare the results obtained with previously published data. MATERIALS AND METHODS: Thermo-luminescent dosimetry was used. Dose assessment was performed by cardio-endovascular surgery, endoscopy, isotope diagnostics, dentistry, and urology personnel. RESULTS: The estimated annual equivalent doses to the lens of the eye for doctors of cardio-endovascular surgery departments, in most cases, ranging 3590 mSv, 619 mSv for the average medical staff (in some cases, the doctor [225 mSv] and the nurse [180 mSv]) and 4.59 mSv for the staff of the department of radioisotope diagnostics. The annual calculated equivalent doses to the skin of the hands for cardio-endovascular surgery personnel were 17100 and 24220 mSv for the staff working with radiopharmaceuticals. It is shown that the use of an estimate of the average dose per operation by cardio-endovascular surgery doctors, as a rule, inevitably leads to an excess of the equivalent dose to the lens of the eye after a certain number of operations. CONCLUSION: When a certain number of operations are exceeded (100200), equivalent doses to the eyes lens in cardio-endovascular surgery doctors above 20 mSv per year can be formed. At current radiation levels, a lesion of the eyes lens was found in a cardio-endovascular surgery doctor. The results indicate the need for further dosimetric measurements and epidemiological studies, based on which recommendations for radiation protection of the eyes lens and the skin of the hands of medical personnel working in low-intensity, scattered, gamma X-ray radiation can be developed

Measurement of charged particle spectra in deep-inelastic ep scattering at HERA

Charged particle production in deep-inelastic ep scattering is measured with the H1 detector at HERA. The kinematic range of the analysis covers low photon virtualities, 5 LT Q(2) LT 100 GeV2, and small values of Bjorken-x, 10(-4) LT x LT 10(-2). The analysis is performed in the hadronic centre-of-mass system. The charged particle densities are measured as a function of pseudorapidity (n(*)) and transverse momentum (p(T)(*)) in the range 0 LT n(*) LT 5 and 0 LT p(T)(*) LT 10 GeV in bins of x and Q(2). The data are compared to predictions from different Monte Carlo generators implementing various options for hadronisation and parton evolutions

Координатное и частотно-временное обеспечение полета космического аппарата в режиме автономной навигации с использованием сигма-точечного алгоритма фильтра Калмана

There are investigated errors of a spacecraft current coordinate and velocity estimates, time-frequency scale bias of the board receiver reference oscillator. The receiver is a component of the autonomic nav- igation system using signals of global navigation systems GLONASS or GPS. Estimates are formed by the navigation calculator on the bases of pseudo range and pseudo velocity measurements taken in the regime of navigation signals delay and Doppler frequencies tracking under the condition of the receiver noise. The calculator utilizes sigma-point Kalman filter. Analysis of estimations accuracy is done by the Monte-Carlo method while spacecraft moves along a high elliptic orbitВ работе выполнено исследование среднеквадратичной погрешности оценок текущих координат и скорости космического аппарата (КА), смещения шкалы времени и частоты опорного генерато- ра бортового приемника КА, который оснащен системой автономной навигации, использующей сигналы глобальных навигационных систем ГЛОНАСС или GPS. Оценки формируются в нави- гационном вычислителе на основе обработки наблюдений псевдодальностей и псевдоскоростей, формируемых навигационным приемником в режиме слежения за временными задержками на- вигационных сигналов и их частотами Доплера при наличии шума приемника. Навигационный вычислитель реализует сигма-точечный алгоритм фильтра Калмана. Анализ точности оценок выполнен численным методом Монте-Карло при движении КА на высокоэллиптической орбит

Координатное и частотно-временное обеспечение полета космического аппарата в режиме автономной навигации с использованием сигма-точечного алгоритма фильтра Калмана

There are investigated errors of a spacecraft current coordinate and velocity estimates, time-frequency scale bias of the board receiver reference oscillator. The receiver is a component of the autonomic nav- igation system using signals of global navigation systems GLONASS or GPS. Estimates are formed by the navigation calculator on the bases of pseudo range and pseudo velocity measurements taken in the regime of navigation signals delay and Doppler frequencies tracking under the condition of the receiver noise. The calculator utilizes sigma-point Kalman filter. Analysis of estimations accuracy is done by the Monte-Carlo method while spacecraft moves along a high elliptic orbitВ работе выполнено исследование среднеквадратичной погрешности оценок текущих координат и скорости космического аппарата (КА), смещения шкалы времени и частоты опорного генерато- ра бортового приемника КА, который оснащен системой автономной навигации, использующей сигналы глобальных навигационных систем ГЛОНАСС или GPS. Оценки формируются в нави- гационном вычислителе на основе обработки наблюдений псевдодальностей и псевдоскоростей, формируемых навигационным приемником в режиме слежения за временными задержками на- вигационных сигналов и их частотами Доплера при наличии шума приемника. Навигационный вычислитель реализует сигма-точечный алгоритм фильтра Калмана. Анализ точности оценок выполнен численным методом Монте-Карло при движении КА на высокоэллиптической орбит

Outcomes of Cryoballoon Ablation in High- and Low-Volume Atrial Fibrillation Ablation Centres: A Russian Pilot Survey

Purpose. The results of cryoballoon ablation (CBA) procedure have been mainly derived from studies conducted in experienced atrial fibrillation (AF) ablation centres. Here, we report on CBA efficacy and complications resulting from real practice of this procedure at both high- and low-volume centres. Methods. Among 62 Russian centres performing AF ablation, 15 (24%) used CBA technology for pulmonary vein isolation. The centres were asked to provide a detailed description of all CBA procedures performed and complications, if encountered. Results. Thirteen sites completed interviews on all CBAs in their centres (>95% of CBAs in Russia). Six sites were high-volume AF ablation (>100 AF cases/year) centres, and 7 were low-volume AF ablation. There was no statistical difference in arrhythmia-free rates between high- and low-volume centres (64.6 versus 60.8% at 6 months). Major complications developed in 1.5% of patients and were equally distributed between high- and low-volume centres. Minor procedure-related events were encountered in 8% of patients and were more prevalent in high-volume centres. Total event and vascular access site event rates were higher in women than in men. Conclusions. CBA has an acceptable efficacy profile in real practice. In less experienced AF ablation centres, the major complication rate is equal to that in high-volume centres

Outcomes of Cryoballoon Ablation in High-and Low-Volume Atrial Fibrillation Ablation Centres: A Russian Pilot Survey

properly cited. Purpose. The results of cryoballoon ablation (CBA) procedure have been mainly derived from studies conducted in experienced atrial fibrillation (AF) ablation centres. Here, we report on CBA efficacy and complications resulting from real practice of this procedure at both high-and low-volume centres. Methods. Among 62 Russian centres performing AF ablation, 15 (24%) used CBA technology for pulmonary vein isolation. The centres were asked to provide a detailed description of all CBA procedures performed and complications, if encountered. Results. Thirteen sites completed interviews on all CBAs in their centres (>95% of CBAs in Russia). Six sites were high-volume AF ablation (>100 AF cases/year) centres, and 7 were low-volume AF ablation. There was no statistical difference in arrhythmia-free rates between high-and low-volume centres (64.6 versus 60.8% at 6 months). Major complications developed in 1.5% of patients and were equally distributed between high-and low-volume centres. Minor procedurerelated events were encountered in 8% of patients and were more prevalent in high-volume centres. Total event and vascular access site event rates were higher in women than in men. Conclusions. CBA has an acceptable efficacy profile in real practice. In less experienced AF ablation centres, the major complication rate is equal to that in high-volume centres