Relativistic theory of inverse beta-decay of polarized neutron in strong magnetic field

The relativistic theory of the inverse beta-decay of polarized neutron, $\nu _{e} + n \to p + e ^{-}$, in strong magnetic field is developed. For the proton wave function we use the exact solution of the Dirac equation in the magnetic filed that enables us to account exactly for effects of the proton momentum quantization in the magnetic field and also for the proton recoil motion. The effect of nucleons anomalous magnetic moments in strong magnetic fields is also discussed. We examine the cross section for different energies and directions of propagation of the initial neutrino accounting for neutrons polarization. It is shown that in the super-strong magnetic field the totally polarized neutron matter is transparent for neutrinos propagating antiparallel to the direction of polarization. The developed relativistic approach can be used for calculations of cross sections of the other URCA processes in strong magnetic fields.Comment: 41 pages in LaTex including 11 figures in PostScript, discussion on nucleons AMM interaction with magnetic field is adde

Cardiovascular status and echocardiographic changes in survivors of COVID-19 pneumonia three months after hospital discharge

Coronavirus disease 2019 (COVID-19) affects the function of all organs and systems. Today, studying the effect of COVID-19 on cardiovascular system, including on echocardiographic characteristics, is relevant.Aim. To study the prevalence of symptoms, cardiovascular disease and changes in echocardiographic data in persons after documented COVID-19 pneumonia 3 months after discharge from the hospital.Material and methods. The study included 106 patients after documented COVID-19 pneumonia. The patients underwent a comprehensive examination during hospitalization and 3 months±2 weeks after discharge from the hospital. The mean age of participants was 47±16 years (19-84 years); 49% of subjects were women.Results. Three months after hospital discharge, the symptoms persisted in 86% of examined patients. There were significant echocardiographic changes as follows: a decrease in LV end-diastolic, end-systolic and stroke volume (113,8±26,8 ml vs 93,5±29,4 ml; 37,7±13,0 ml vs 31,3±14,2 ml; 77,2±17,8 ml vs 62,2±18,7 ml, respectively, p<0,001 for all). The right ventricular anteroposterior dimension and the pulmonary trunk diameter decreased over time (26,0 [24,0-29,3] mm vs 25,0 [23,0-27,0] mm, p=0,004; 21,7±3,6 mm vs 18,7±2,5 mm, p<0,001), the same as the pulmonary artery systolic pressure, estimated by tricuspid regurgitation gradient (28,0 [25,0-32,25] mm Hg vs 21,5 [17,0-25,0] mm Hg). The right atrial volume (42,0 [37,0-50,0] m><0,001), the same as the pulmonary artery systolic pressure, estimated by tricuspid regurgitation gradient (28,0 [25,0-32,25] mm Hg vs 21,5 [17,0-25,0] mm Hg). The right atrial volume (42,0 [37,0-50,0] ml vs 31,0 [22,0-36,5] ml, p<0,001) a><0,001) and maximum width (36,1±4,6 mm vs 34,5±6,5 mm, p=0,023) decreased, while the right atrial maximum length increased (46,7±6,8 mm vs 48,6±7,1 mm, p=0,021).Conclusion. In survivors of COVID-19 pneumonia three months after hospital discharge, complaints persisted in 86% of cases. Cardiovascular diseases were detected in 52% of participants, including hypertension in 48,1% and coronary artery disease in 15,1%. Compared with in-hospital data, the echocardiographic characteristics improved, which was expressed mainly in a decrease in right heart load

Echocardiographic characteristics of COVID-19 pneumonia survivors three months after hospital discharge

Coronavirus disease 2019 (COVID-19) is an infectious disease that affects almost all organs and systems. The main target is the respiratory system, but cardiovascular involvement is also common. Today, it is relevant to study the effect of complicated COVID-19 course on the patient’s cardiovascular system after hospital discharge — in particular, echocardiographic parameters.Aim. To study the echocardiographic parameters of patients with COVID-19 pneumonia 3 months after discharge from the hospital.Material and methods. The study included 106 patients with documented COVID-19 pneumonia. Patients underwent a comprehensive examination during hospitalization and 3 months ± 2 weeks after hospital discharge. The mean age of participants was 47±16 years (from 19 to 84 years), while 49% were women.Results. Three months after discharge, the average body mass index of the subjects was 28,2±5,7 kg/m2. Obesity was noted in 37,1%, cardiovascular diseases — in 52%. According to echocardiography, the prevalence of right ventricular (RV) dilatation was 2,9%, a decrease in tricuspid annular plane systolic excursion (TAPSE) — 9,5%, grade ≥2 tricuspid regurgitation — 1,9%, pulmonary hypertension (pulmonary artery systolic pressure >36 mm Hg) — 3,8%. The mean value of RV global longitudinal myocardial strain (GLMS RV) and global longitudinal myocardial strain (GLES RV) was 19,6±4,5 and 20,6±4,6, respectively. We found moderate correlations between GLMS RV and blood flow time through the left ventricular outflow tract (OT) (r=-0,436), through the mitral valve (r=-0,390; both p<0,0001) and through the RVOT (r=-0,348; р=0,004), with cardiac index (CI) (r=0,316; p=0,009), as well as between GLES RV and blood flow time through the LVOT (r=-0,411; p<0,0001) and RVOT (r=-0,300; p=0,005), and with CI (r=0,302; p=0,004). At the same time, the correlation of GLES RV with RV fractional area change (FAC) was weak (r=-0,283; p=0,007), while there was no correlation with the TAPSE. In addition, correlation of GLMS RV with these parameters were not defined.Conclusion. Three months after COVID-19 pneumonia, RV strain parameters were shown to have stronger relationships with time characteristics of flows in LVOT and RVOT, as well as with CI, than with such generally accepted characteristics of RV function as FAC and TAPSE

Комбинированное лечение больных раком прямой кишки с использованием программы полирадиомодификации в сочетании с короткими курсами неоадъювантной лучевой терапии

Objective: to improve the outcomes of combination treatment of patients with rectal cancer using polyradiomodification and short courses of neoadjuvant radiotheragy.Materials and methods. A total of 905patients were included into this retrospective study based on the data retrieved from a prospective database. Of them, 241 patients underwent combination treatment with polyradiomodification (CT + PRM); 271 patients underwent combination treatment with preoperative radiotherapy alone (CT); 393patients underwent surgical treatment only (ST). Combination treatment with polyradiomodification included a course of radiotherapy with a total dose of 25 Gy delivered in 5 fractions (5 Gy each), rectal administration of biopolymer composition containing metronidazole at a dose of 10 g/m2 (5-h exposure in the rectum on days 3 and 5), and chemotherapy with capecitabine at a dose of 2 g/m2 on days 1—14 followed by surgery within the next 4—6 weeks. We analyzed the incidence of postoperative complications, 5-year relapse-free survival, and frequency of relapses.Results. The incidence of grade IIIB postoperative complications was significantly lower in patients who underwent combination treatment with polyradiomodification than in those who had surgery only (p = 0.0023) and those who had combination therapy without polyradiomodification (p = 0.0003). The 5-year relapse-free survival rate was 80.5 % in the group of CT + PRM compared to 64.9 % in the group of CT (p = 0.00315) and 60.1 % in the group of ST (p = 0.000001). The frequency of relapses was 0.4 %, 8.5 % (p = 0.00001), and 13.7 % (p = 0.00001) in the groups CT + PRM, CT, and ST respectively. There were no significant differences in the incidence of distant metastasis between the groups.Conclusions. The developed variant of combination treatment with polyradiomodification did not increase the number of complications and ensured better relapse-free survival due to improved locoregional control.Цель исследования — улучшить результаты комбинированного метода лечения больных раком прямой кишки с использованием программы полирадиомодификации в сочетании с короткими курсами неоадъювантной лучевой терапии.Материалы и методы. В ретроспективное исследование, основанное на данных проспективно заполняемой базы данных, включено 905 больных, из которых у 241 проведено комбинированное лечение с применением программы полирадиомодификации, у 271 пациента ранее проведено комбинированное лечение с использованием только предоперационной лучевой терапии в монорежиме, и у 393 — только хирургическое лечение. Комбинированное лечение с применением программы полирадиомодификации включало проведение курса лучевой терапии в разовой очаговой дозе 5 Гр в течение 5 дней до суммарной очаговой дозы 25 Гр, внутриректальной сверхвысокочастотной гипертермии в дни 3 и 5, введение биополимерной композиции, содержащей метронидазол в дозе 10 г/м2, с экспозицией ее в прямой кишке в течение 5 ч в дни 3 и 5, а также проведение химиотерапии капецитабином в дозе 2 г/м2 в дни 1—14 с последующим оперативным вмешательством в сроки от 4 до 6 нед. Анализировали частоту послеоперационных осложнений, 5-летнюю безрецидивную выживаемость, частоту рецидивов.Результаты. Частота послеоперационных осложнений IIIB степени тяжести в группе комбинированного лечения с применением программы полирадиомодификации была ниже по сравнению с группой хирургического лечения (р = 0,0023) и группой комбинированного лечения без применения программы полирадиомодификации (р = 0,0003). Пятилетняя безрецидивная выживаемость в группе комбинированного лечения с применением программы полирадиомодификации составила 80,5 % по сравнению с 64,9 % в группе комбинированного лечения без использования полирадиомодификации (р = 0,00315) и 60,1 % в группе хирургического лечения (р = 0,000001). Частота рецидивов составила 0,4 %, 8,5 % (р = 0,00001) и 13,7 % (р = 0,00001) соответственно. Частота отдаленного метастазирования достоверно не различалась между группами.Выводы. Созданный вариант комбинированного лечения с применением программы полирадиомодификации не приводит к увеличению общего количества осложнений и в рамках проведенного ретроспективного исследования обеспечивает более высокие показатели безрецидивной выживаемости за счет усиления локорегионарного контроля

Mechanisms of Aerosol Sedimentation by Acoustic Field

Acoustic radiation sources are successfully applied to cleaning rooms from dust of fairly large particle sizes (ten micrometers and larger). The sedimentation of fine aerosols (particle diameter of 1–10 microns) is a more complicated challenge. The paper is devoted to the substantiation of the acoustic sedimentation method for such aerosols. On the basis of the mathematical model analysis for aerosol sedimentation by the acoustic field the mechanisms of this process have been determined and include the particle coagulation acceleration and radiation pressure effect. The experimental results of the acoustic sedimentation of a model aerosol (NaCl) are shown. The calculation results according to the mathematical model for coagulation and sedimentation, on the basis of the Smolukhovsky’s equation taking into account various mechanisms of aerosol sedimentation by sound depending on the particle sizes and sound intensity, are given. The necessity to use intensive sources of high-frequency sound has been confirmed, suggesting that these sources must be located above dust clouds

Clinical, laboratory and instrumental characteristics of children with sydenham’s chorea

Sydenham's chorea (SC) is a major clinical criterion in acute rheumatic fever (RF). SC is a late neurological manifestation of acute rheumatic fever which occurs 1 to 6 months after pharyngeal infection with group A betahemolytic streptococci. SC is characterized by clinical symptoms: involuntary hyperkinetic movements, muscular hypotonia, hyperreflexia, gait disturbance, emotional lability. Objective: The aim of the study was to identify frequency, clinical manifestations and the treatment of SC. The study included 56 children 4-17 years old, who were hospitalized in the Morozovskaya children’s clinical city hospital in 2001-2015 with RF. Clinical history, laboratory and instrumental methods (electrocardiography, transthoracic echocardiogram, cranial computed tomography scan and/or magnetic resonance imaging, electroencephalography, electroneuromyography). The study revealed frequent errors (66%) in RF diagnosis before hospitalization. Besides chorea, the clinical manifestations of RF were: carditis (89,3%), arthritis (46,4%), erythema marginatum (10,7%), subcutaneous nodule (1,8%). The peculiarity of our study washighfrequency of chorea (42,9%). Isolated chorea wasseen in 12,5%, mixed chorea - in 30,4% of SC. The clinical manifestations of chorea were typical. The nervous system lesion most often occured in children with a neurological history (p < 0,05). The clinical or laboratory evidence of streptococcal infection were seldom found (p = 0,02) in patients withchorea (45,8%) compared with patients without chorea symptoms (69%). RF issue requires attention from the medical community. SC, especially isolated chorea (29%), is the most challenging manifestation of RF for the differential diagnosis.Chronic rheumatic heart disease can be developed even in patients with isolated chorea (12,5%). In the treatment of SC in addition antibiotics and drugs which affect domamine and GABA metabolism, glucocorticoids (Prednisolone) are needed

Combination treatment of rectal cancer using polyradiomodification and short courses of neoadjuvant radiotherapy

Objective: to improve the outcomes of combination treatment of patients with rectal cancer using polyradiomodification and short courses of neoadjuvant radiotheragy.Materials and methods. A total of 905patients were included into this retrospective study based on the data retrieved from a prospective database. Of them, 241 patients underwent combination treatment with polyradiomodification (CT + PRM); 271 patients underwent combination treatment with preoperative radiotherapy alone (CT); 393patients underwent surgical treatment only (ST). Combination treatment with polyradiomodification included a course of radiotherapy with a total dose of 25 Gy delivered in 5 fractions (5 Gy each), rectal administration of biopolymer composition containing metronidazole at a dose of 10 g/m2 (5-h exposure in the rectum on days 3 and 5), and chemotherapy with capecitabine at a dose of 2 g/m2 on days 1—14 followed by surgery within the next 4—6 weeks. We analyzed the incidence of postoperative complications, 5-year relapse-free survival, and frequency of relapses.Results. The incidence of grade IIIB postoperative complications was significantly lower in patients who underwent combination treatment with polyradiomodification than in those who had surgery only (p = 0.0023) and those who had combination therapy without polyradiomodification (p = 0.0003). The 5-year relapse-free survival rate was 80.5 % in the group of CT + PRM compared to 64.9 % in the group of CT (p = 0.00315) and 60.1 % in the group of ST (p = 0.000001). The frequency of relapses was 0.4 %, 8.5 % (p = 0.00001), and 13.7 % (p = 0.00001) in the groups CT + PRM, CT, and ST respectively. There were no significant differences in the incidence of distant metastasis between the groups.Conclusions. The developed variant of combination treatment with polyradiomodification did not increase the number of complications and ensured better relapse-free survival due to improved locoregional control

The metrological provision for development and application of TPTS platforms

В докладе представлены основные положения метрологического обеспечения средств программно-технических ТПТС как средств измерений, применяемых в сфере государственного регулирования обеспечения единства измерений. Поскольку средства ТПТС входят в состав измерительных каналов атомных электростанций, в докладе показаны основные проблемы метрологического обеспечения измерительных каналов, применяемых в области использования атомной энергии, и изложены подходы к их решению. The paper presents main theses of the metrological provision for the TPTS platforms as measurement instruments in the state system for ensuring the uniformity in the measurements field. Since the TPTS platforms’ components are a constituent part of measuring channels at nuclear power plants, the paper shows main problems of the metrological provision for the measuring channels in the nuclear energy field and outlines approaches to the solutions for these problems