Complete classification of stationary flows with constant total pressure of ideal incompressible infinitely conducting fluid

The exhaustive classification of stationary incompressible flows with constant total pressure of ideal infinitely electrically conducting fluid is given. By introduction of curvilinear coordinates based on streamlines and magnetic lines of the flow the system of magnetohydrodynamics (MHD) equations is reduced to a nonlinear vector wave equation extended by the incompressibility condition in a form of a generalized Cauchy integral. For flows with constant total pressure the wave equation is explicitly integrated, whereas the incompressibility condition is reduced to a scalar equation for functions, depending on different sets of variables. The central difficulty of the investigation is the separation of variables in the scalar equation, and integration of the resulting overdetermined systems of nonlinear partially differential equations. The canonical representatives of all possible types of solutions together with equivalence transformations, that extend the canonical set to the whole amount of solutions are represented

Waves in the regions with mobile permeable boundaries. Control problems

Крутиков, В. С. Волны в областях с подвижными проницаемыми границами. Вопросы управления : моногр. / В. С. Крутиков. – Николаев : НУК, 2015. – 392 с.Около трех столетий, с момента создания волнового уравнения, перед математической физикой стоят проблемы решения нелинейных задач, описываемых уравнениями в частных производных, сложнейшая из которых – проблема подвижных границ. Предложен и разработан нетрадиционный, авторский, подход решения проблем подвижных проницаемых границ – это методы обратных задач с учетом взаимодействия нелинейных аргументов. Метод позволил сделать качественный шаг вперед, перейти от познания волновых процессов к более сложному и важному процессу управления волновыми явлениями. Определены функции управления волновыми процессами в областях с подвижными проницаемыми, подвижными излучающими границамиFor about three centuries, from the moment of creation of wave equation, mathematical physics has been facing the problems of solution of nonlinear problems described by equations in partial derivatives. The most complex of them is the problem of mobile boundaries. An alternative author's approach to mobile permeable problems solution was proposed and developed. The method allowed making a qualitative step forward, turning from the learning of wave processes to more complex and important process of wave processes control. The functions of wave processes control in the regions with mobile permeable boundaries, mobile radiating boundaries were defined

Single-turn Coils for Magnetic Pulse Welding of High-strength Steel Parts

Magnetic pulse welding provides high quality joining of fuel pin cladding for fast nuclear reactors. The tool coil there operates under the most stressful conditions: 40 T magnetic fields with tens of microseconds duration. This requires minimal coil inductance and affects the capabilities and lifetime of the coils. Two approaches are being practiced to enhance the coil durability: material research and construction optimization. The first approach considers the use of high strength steels or composite materials for the coil working area. The present work is aimed to realize the second approach – the use of multi position coils in order to maximize the number of parts welded in one coil. Experiments and finite element modeling were carried out for two designs of two- and four-position single-turn coils, which were made to process several workpieces in one current pulse. The main parameters measured and calculated were the magnetic field between the coil and the workpiece, and the ratio of its amplitude to the discharge current, Bm/Im. The currents flowing through the coils were about 700 kA, which correspond to the magnetic fields of 40–45 T. The FEM modeling revealed a 17–19% drop of the magnetic induction near the insulated slit, which, however, did not prevent the helium-tight joining of the tubes to the end plugs

COMPARATIVE EFFICACY OF BLOCKADE OF THE RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM WITH COMBINATIONS OF ALISKIREN AND AMLODIPINE, RAMIPRIL AND AMLODIPINE IN PATIENTS WITH ESSENTIAL HYPERTENSION

Hypertension is one of the most common disease of the cardiovascular system. Important components of a rational antihypertensive therapy are drugs that block the RAAS. The aim of the study was to conduct a comparative evaluation of the effectiveness of blockade of the renin-angiotensin-aldosterone system with drug combinations – aliskiren and amlodipine and combination of ramipril and amlodipine in patients with hypertension and increased body weight. 50 patients with hypertension of stage II, II degree, high and very high risk were involved in the study. Patients were randomized into two groups depending on the received treatment. The first group (25 patients) consisted of patients treated with combined therapy including ramipril and amlodipine, the second group (25 patients) consisted of patients receiving a combination of aliskiren and amlodipine. The control group (25 people) included apparently healthy people. By the 12th week of the study the daily average systolic blood pressure in the first group was 146 (145; 150) mm Hg and 131 (130; 137) mm Hg in the second group, respectively, the daily average diastolic blood pressure was equal to 94 (91; 96) mm Hg in the first group and 81 (80; 82) mm Hg in the second group . By the 12th week of treatment plasma renin levels in the first group was equal to 73 (50; 78) and 15 (14; 27) in the second group, respectively, the level of angiotensin-I in the first group was 6 (4; 7) and 1,4 (1,1; 1,9) in the second group, aldosterone levels in the first group was equal to 134 (132; 145) and 130 (123; 132) in the second group, respectively. It is found that combination of aliskiren and amlodipine have the advantage over the combination of ramipril and amlodipine in achieving of purposeful level of systolic and diastolic blood pressure in patients with hypertension and overweight. The purposeful level of blood pressure reached to 56,6% of patients in group I and 80% of patients in group II to 12th week of the study. Receiving both combinations equally reduces plasma aldosterone levels at the same time receiving a combination of aliskiren and amlodipine accompanied by a decrease in plasma rennin level of 69% and angiotensin-I of 67%, while the combination of ramipril and amlodipine increases of these hormones on 68% and 65% respectively. Thus, using combination of ramipril and amlodipine more effective in patients with low rennin hypertension , patients with normal and high rennin hypertension necessary combination of aliskiren and amlodipine

EARLYDIAGNOSIS OFINTRARENAL BLOOD FLOW DISORDERSIN PATIENTS WITH ESSENTIAL ARTERIAL HYPERTENSION

Summary. Among the causes of end-stage renal failure essential arterial (EAH) hypertension has a leading place. One of thepathogenic mechanisms of hypertensive nephropathy is a violation of intrarenal blood flow. The purpose of this study was to conduct an early diagnosis of intrarenal blood flow disorders using Doppler examination and comparison of these data with the standard criteria of nephropathy in EAH. Materials and methods. 80patients with stage II EAH were examined. Results. In patients with grade II and III EAH noted depletion of intrarenal blood flow, characterized by low Vmax and Vmin, while there was an increase IR characterizing renal vascular resistance. Hyper phase in hypertensive nephropathy was characterized by a relative increase in hemodynamic indices at the level of the trunk of the renal artery and segmental artery with a reduction in the small arteries to the level in healthy people. Hypofiltration phase was characterized by a significant reduction of velocity indexes that accompanied by a decreasing of vascular resistance (theirpseudonormalization). In assessing renal hemodynamics in patients with EAH and microalbuminuria showed a decreasening of Vmin and increasening of IR. A inverse correlation between the level of night BP decreasing and IR segmental artery (r = - 0,61, p<0,05). Conclusions: 1. In patients with essential hypertension grade IIand IIImarked depletion of intrarenal blood flow characterized by a decrease in peak systolic and minimum diastolic velocity. At the same time there is increasing resistance indices characterizing renal vascular resistance. 2. Early stage of fypertensive nephropathy criteria before the development of microalbuminuria, hyperfiltration can be the increase in the indices at the level of resistance of main and segmental arteries according to Doppler examination of renal vessels. 3. In patients with essential hypertension and microalbuminuria there is a decrease in diastolic velocity and resistive index increase, indicating an increase in intrarenal vascular resistance and may also be a diagnostic criterion of nephropathy. 4. The inverse correlation between the level of nighttime decrease in blood pressure and segmental artery resistance index indicate the negative impact of the lack of night reduction in blood pressure to renal function in hypertension

КОРРЕКЦИЯ ИММУНОЛОГИЧЕСКИХ НАРУШЕНИЙ У БЕРЕМЕННЫХ С ХРОНИЧЕСКИМ ПИЕЛОНЕФРИТОМ

Дослідження проведено з метою оцінки ефективності пребіотика лактулози як імунокорегуючого засобу при загостренні хронічного пієлонефриту у вагітних із функціональними запорами. Матеріал та методи дослідження. Проведено обстеження та лікування 37 вагітних жінок із загостренням хронічного пієлонефриту, які страждають функціональними закрепами. Тривалість спостереження склала 28 діб. У всіх вагітних вивчали показники антиендотоксинового імунітету, фагоцитарну активність клітин крові та рівень цитокінів. Результати дослідження. Виявлено, що у пацієнток, які отримували лактулозу в комплексному лікуванні пієлонефриту, нормалізуються такі показники антиендотоксінових імунітету як Ig класів А, M і G до ліпополісахариду кишкової палички та рівень експресії ліпополісахаридзв’язуючих рецепторів гранулоцитами і моноцитами периферичної крові, а також підвищується фагоцитарна активність гранулоцитів периферичної крові, як фактор неспецифічного захисту, при достовірно якнайшвидшому зниженні активності запальних реакцій. Висновки. Використання пребіотика лактулози у комплексному лікуванні загострення хронічного пієлонефриту у вагітних з функціональними закрепами веде до нормалізації вказаних показників антиендотоксинового імунітету, а також до підвищення фагоцитарної активності гранулоцитів периферичної крові

Magnetic Pulse Welding of the “Tube – Plug” Pair of STS410 Steel

The research was focused on the magnetic pulse welding (MPW) of 12.5% Cr steel STS410. The experiments were performed in the tube-plug geometry (both details were made of the same steel). Magnetic pulse unit consisted of pulsed current generator (PCG) loaded to a single-turn coil. Magnetic field amplitude of 40 T was generated in the coil during experiments. The amplitude of pulsed current reached 750 kA. The effects of energy storage capacity, charging voltage, and end plug shape were studied. The welded samples were investigated by optical microscopy. The optimal velocities of impact and contact front motion were evaluated as 300 m/s and 3-3.5 km/s, respectively. The paper includes the leakage test results as well. To date, the joints with a helium leak rate of 10-9 mbar·l·s-1 have been produced

Spectral studies of the dithiacrown ether derivative in the presence of metal cations and modeling their possible complexes

© ISUCT Publishing. The preparation of compositions comprising multifunctional compound is one of the key directions for design of chemosensoring materials that are important for the determination of particular ions in solutions. These compounds are characterized by ionophoric and photosensitive parts with reliable optical response and ion-selectivity. Their structures suggest the possibility of the complex formation with particular metal cations. The main goals of this study are as following: a) to investigate the absorption spectra of the novel derivative of the dithiacrown ethers (DTCE), synthesized in the laboratory of Professor S.P. Gromov (Photochemistry Center RAS), both: in salt solutions and in monolayers; b) to study the DTCE interaction with various metal cations, including mercury, as well as to carry out quantum-chemical calculations of their possible complexes. Spectral characteristics were examined in the DTCE acetonitrile solutions and their changes in the presence of some cations were found. The pronounced changes were obtained in the case of Hg2+ which are expressed as a hypsochromic shift on 22 nm. Absorption spectra of aqueous solutions of DTCE and perchlorates of alkali, alkaline earth, and heavy metals (lithium, sodium, potassium, cesium, magnesium, calcium, strontium, barium, copper, zinc, lead, cadmium, and mercury) at various concentrations were obtained. When the DTCE concentration equals to 10–5 M, the absorption intensity is low, and DTCE absorption maximum shifts in the presence of all the salts are rather small. The greatest shift (by 6 nm) of the DTCE absorption maximum to shorter wavelengths was observed for the mercury(II) perchlorate only. In order to select the DTCE concentration for further research the spectral dependence of the optical density vs. DTCE concentration was obtained (10 M was the most appropriate value of the DTCE concentration). Based on these results the DTCE extinction coefficient in aqueous solutions was determined (ε = 9329 M–1cm–1). Assuming the formation of the DTCE-cation complexes as 1:1, the metal perchlorates with lack and excess of the cations in the aqueous solutions were chosen. The absorption spectra had minor differences at DTCE concentration of 10–4 M and metal perchlorates concentration of 10–5 M (lack of the metal cations). Maximum hypsochromic shift by 4 nm was observed in the presence of mercury(II) perchlorate. It appeared that the lack of concentration of the metal salt does not allow the formation of complexes between the crown ether ring and a cation. The absorption intensity in the presence of most of salts was slightly reduced up to 85–95 % from baseline. The absorption spectra showed significant shifts of the absorption maxima to shorter wavelengths by 29 nm only in the presence of mercury(II) perchlorate at high concentrations (10–3 M). This fact proves a DTCE selectivity for mercury(II) cation. Moreover, the value of the shift depends on the salt concentration. An additional confirmation of these results was obtained in the study of the absorption spectra of the DTCE monolayers transferred from bidistilled water and aqueous solutions of Hg(ClO4)2 at constant surface pressure (about 10 mN/m). In all cases, the broad absorption maxima in the region of 350–450 nm were found. The main feature was that the maximum absorption for DTCE monolayer transferred to 10–5 M solution of Hg(ClO4)2 was 0.00575 a.u. at 406 nm. This is by 209% higher than those for the DTCE monolayer transferred from the water. Thus, the shift of the absorption maximum of DTCE monolayer in the presence of mercury salt was 23 nm to shorter wavelengths. This is further evidence of complex formation between DTCE (in monolayer) and mercury(II) cations from the aqueous subphase. For visualization and confirmation of the possibility of complex formation between DTCE and mercury(II) cation the quantum-chemical calculations of their structural models were carried out. The total energy of the optimized structure of the complex between DTCE cation and mercury(II) (with 2 perchlorate counter-anions) is set to E0 = –565.1231 a.u. It can be compared with the energies of individual species: the DTCE cation (E0 = –250.5477 a.u.) and Hg(ClO4)2 (E0 = –314.4877 a.u.). Thus, the change in energy (ΔE) upon complex formation is about –0.0877 a.u. (–230 kJ/mol). High energy of complex formation and high covalency of the Hg–S bonds explain the significant blue shift of the maximum in the absorption spectra of the solutions of DTCE with Hg(ClO4)2

Extraspinal articular tuberculosis: An 11-year retrospective study of demographic features and clinical outcomes in East London

OBJECTIVES: To describe demographic features, clinical outcomes and diagnostic delay amongst patients with extra-spinal articular tuberculosis (TB) in a low-incidence setting. METHODS: Cases of TB treated at our institution between 2004 and 2014 were identified via the London TB register (LTBR). Demographic features of extra-spinal articular TB cases were compared to controls with TB at all other sites. For articular cases (excluding individuals <16 years or with spinal TB without peripheral joint involvement) clinical data were retrospectively collected. RESULTS: 6,146 TB patients were identified over the study period; 146 (2.4%) cases had extra-spinal articular infection. There was no difference in median age between extra-spinal articular TB cases and controls with TB at other sites (31 vs 32 years, p = 0.57). Articular cases were more likely to be male (70.6% vs 59.5%, p = 0.007), Bangladeshi (28.7% vs 18.0%) or Pakistani (24.0% vs 16.1%) and were less likely to be Black-African (9.5% vs 19.8%) (p < 0.001). 93 cases were included in the case series; 85 (88.5%) were migrants and 83 (89.2%) were South Asian. Knee and elbow joints were affected in 22 (23.7%) and 18 (19.4%) cases respectively. The median durations of pre-healthcare and healthcare associated delay were 16 and 6 weeks respectively. Where mycobacterial culture was performed, 57/75 (76%) were positive for Mycobacterium tuberculosis. 86 (92.5%) cases received standard quadruple therapy for a median of 6 months (IQR 6–9). Recurrence of TB infection occurred in 4 (4.3%) cases and there were no TB related deaths. Seven (7.6%) cases required surgical intervention. CONCLUSIONS: Extra-spinal articular TB more commonly affected men and people of South Asian ethnicity. Significant diagnostic delays were identified, including avoidable healthcare-associated delays

OXIDATIVE STRESS IN THE PATIENTS WITH CKD V STAGE AND ANEMIA WHO RECEIVE REPLACEMENT HEMODIALYSIS THARAPY

The article presents research data of oxidative stress role in the pathogenesis of anemia in patients with CKD V stage, who receive hemodialysis replacement therapy. Background. Oxidative stress is a part of the pathogenesis of many complications in patients with CKD stage V on replacement therapy with hemodialysis. Anemia syndrome is the most frequent complication of this patient`s population. Aim. The aim of this study was to study indicators of oxidative stress in patients with            CKD stage V and anemia on replacement therapy with hemodialysis. Materials and methods. We studied laboratory parameters in 42 hemodialysis patients with CKD V stage. Biochemical methods are used for investigation of lipid peroxidation processes: studied diene conjugates (DC), malondialdehyde (MDA), total lipids and catalase, lipid’s structure of erythrocytes membranes and their osmotic resistance. Results. We found that in dialysis patients anemic syndrome was associated with high activity of oxidative stress. Also increased destruction of red blood cells depends from high activity of oxidative stress. In the blood of the patients concentration of DC was 1,12±0,26 opt.den.units/ mg of lipids (p<0,01), and MDA level 0,35±0,05 opt.den.units/ mg of lipids (p<0,01). Levels of catalase, decreased to 0,029±0,0019 mm/l*sec (p<0,001). Also osmotic resistance of erythrocytes significantly decreased. MDA has inverse correlation relationship with hemoglobin in the blood, with a correlation coefficient r=-0,36. Investigation of erythrocyte membrane lipid structure of patients by TLC showed a significant decrease of phospholipids and monoglycerides of higher fatty acids, and the increase of cholesterol fractions. Conclusions. In patients with chronic kidney disease on dialysis replacement therapy anemic syndrome is associated with high activity of oxidative stress, as there is an inverse relationship between the level of hemoglobin and the content of MDA in blood. As a consequence of oxidative stress changes the lipid composition of erythrocyte membranes of the patient, because some fraction of lipids are substrates for oxidative processes. Impairment of lipid membranes of red blood cells of hemodialysis patients is one of the probably causes of anemia