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A seismogeological model of the junction zone of the Nepa-Botuoba anteclise and the Ygyattinskaya depression was built based on the results of a comprehensive interpretation of deep drilling and seismic data. The position and propagation of regional high-rank faults have been specified, and a model of tectonic faults of the study area has been constructed. All faults of the study area were divided into three classes: those that cut the entire sedimentary cover; developed in the lower part of the sedimentary section, fading in the Cambrian salt pack; complicating the upper post-salt complex of rocks. Criteria for identifying thinning zones were developed and were made use of to identify oil and gas perspective objects within the Talakh, Ulakhan and Kharystan productive horizons.

The paper presents the results of a study of the structure and mechanical properties of high-strength austenitic dispersionally hardened Mn–Ni–V–C steel with a yield strength of at least 700 MPa. Its composition and the hardening method were selected so that the steel meets the requirements for high strength and nonmagnetic properties. It is shown that the introduction of 1–2% Cu into Mn–Ni–V–C steel expands the region of existence of the γ-phase in the Fe–Ni–Mn phase diagram, narrows the two-phase γ+α-region and shifts it towards lower Mn contents, increasing stability of austenite to martensitic transformation during cold deformation. A numerical assessment of the influence of alloying austenite-forming elements Ni, Mn, Cu on the critical degree of cold plastic deformation, leading to the formation of deformation martensite in steel, is proposed. The temperature range of the reverse transformation of this martensite into austenite during annealing is established, depending on the nickel content in the steel. For precipitation hardened steel with a composition of 10%Mn; 10%Ni; 2%Cu; 0.3–0.4%C; ~1.4%V the regularities of dissolution upon heating for quenching and precipitation during aging of particles of the strengthening carbide phase VC were studied. It has been shown that the maximum strength is achieved after quenching from 1150°C and aging at 650°C for 15 hours. Taking into account the studies carried out on the stability of austenite, static and cyclic strength and durability, the optimal alloying range of steel with nickel, manganese and copper was substantiated, and the optimal mode of heat treatment was revealed, which provides a combination of high strength with good ductility and toughness of steel.

This article shows the possibility of using high-strength nitrogen-containing corrosion-resistant steel grade 04Kh20N6G11M2AFB for the construction of critical elements and units of marine equipment operating at low temperatures, including the Arctic. The advantages of nitrogen-containing steel over clad steel AB2 + 08Kh18N10T always used in shipbuilding and welded steel of F500W category are considered. According to the assessment of testing of homogeneous nitrogen steel sheets, the level of its physical and mechanical properties exceeds the analogous parameters of traditional AB2 + 08Kh18N10T steels in a wide temperature range, up to –90°C.

Purpose.Analysis of the immediate results of emergency glomus-sparing auto-transplantation of the internal carotid artery (ICA) in the acute period of ischemic stroke, developed on the basis of the City Alexandrovskaya Hospital, St. Petersburg.Material and methods.In this prospective, single-center study from January 2017 to August 2020. 49 patients were included in the acute period of ischemic stroke with hemodynamically significant extended atherosclerotic lesions of the ICA. All patients underwent glomus-sparing ICA autotransplantation, developed on the basis of the City Alexandrovskaya Hospital, St. Petersburg (Kazantsev A. N., Zarkua N. E., Chernykh K. P. et al. Аrteries with extended atherosclerotic lesions of the internal carotid artery. Patent application No. 202.013.4151/14 (062595), filing date 10/16/2020). Glomus-sparing ICA autotransplantation, developed on the basis of the City Alexandrovskaya Hospital, St. Petersburg, was performed as follows. On the inner edge of the external carotid artery (ECA), adjacent to the carotid sinus, 2–3 cm above the orifice, depending on the spread of atherosclerotic plaque (ASB), arteriotomy was performed with the transition to the common carotid artery (CCA) (also 2–3 see below the mouth of the NSA). The ICA was cut off at the site formed by the sections of the wall of the NSA and the CCA. Then the ICA was cut off as distally as possible in front of the hypoglossal nerve, so that the artery was completely resected. In view of the presence of an intact carotid glomus on the resected area of the ICA, which connects it to the wound, endarterectomy from the ICA was performed inside the operating field by its complete eversion. Then, open endarterectomy from ECA and CCA was performed. At the next stage, the ICA was implanted in its previous place with the creation of proximal and distal end-to-end anastomoses, so that the continuing ASB above the endarterectomy zone was fixed with a circular vascular suture.Results.There were no complications in the postoperative period. No cases of restenosis / thrombosis of the reconstruction zone were identified in all the sample according to the color duplex scanning data. On the 7th day after the operation, all patients were diagnosed with regression of neurological symptoms according to the National Institute of Health Stroke Scale: on admission, the mean score was 10.5±3.5; at the moment of the control point — 6.5±1.5; p=0.001. This reflects the effectiveness of the chosen treatment strategy. According to the data on the dynamics of systolic blood pressure, stable systolic parameters were observed in the postoperative period against the background of antihypertensive therapy taken before the operation.Conclusion.Carotid endarterectomy in the acute period of ischemic stroke is safe in the presence of mild neurological deficits (up to 25 points on the National Institute of Health Stroke Scale) and the diameter of the ischemic focus in the brain not exceeding 2.5 cm according to the computer data. tomography. Glomussparing ICA autotransplantation, developed on the basis of the Aleksandrovskaya Hospital, St. Petersburg, does not require the use of a patch and is not characterized by the risk of developing ICA thrombosis as a result of intimal detachment behind the endarterectomy zone. Preservation of the carotid glomus during reconstructive intervention on the ICA prevents the development of labile arterial hypertension and hemorrhagic transformation in the postoperative period.

The inclusive differential cross sections for the production of $$\pi^{\pm}$$ and $$k^{-}$$ mesons, protons, and antiprotons with momenta between 6 and 50 GeV/c and nuclear fragments of mass number $$1\leq A\leq 10$$ in the momentum range between 20 and 220 GeV/c were measured in carbon–lead collisions at a beam kinetic energy of 19.6 GeV per nucleon ( $$\sqrt{S_{NN}}=6.3$$ GeV). A comparison with the respective cross sections for carbon–carbon interactions is performed, and the dependence on the target mass number ( $$A$$ ) is estimated. The present analysis shows that the observed particles originate predominantly from peripheral interactions.

Aim. This study provides an analysis of the results of eversion carotid endarterectomy (CEE) with transposition of the internal carotid artery (ICA) over the hypoglossal nerve, according to A.N. Kazantsev. Materials and Methods. The given prospective open study covering the period from January 2017 to May 2020 involved 311 patients who underwent eversion CEE with transposition of ICA over the hypoglossal nerve, according to A.N. Kazantsev. Transposition was performed in the following way: after standard isolation of the carotid arteries, their compression, arteriosection, and removal of atherosclerotic plaque, ICA was extracted in the area above the hypoglossal nerve and was implanted to the same position. The condition of the patient was controlled on repeated visits to the clinic every six months. Hemodynamics in the reconstruction zone were studied using multispiral computed tomography with angiography of carotid bifurcation with 0.6 mm steps and processing the obtained results in Sim Vascular and Open Foam programs in DICON format. The follow-up period was 18.37.1 months. In case of development of restenosis, reCEE was performed with patch plasty of the reconstruction zone. For histologic examination, the restenosis area was stained by the van Gieson method. Results. In the hospital follow-up period, one case of myocardial infarction was noted that developed due to the stents thrombosis in the anterior descending artery deployed two years before. When studying the hemodynamic properties of carotid bifurcation in the postoperative period using computer modeling, in all cases, no changes or obstacles to blood flow were formed in the ICA in the area above the hypoglossal nerve. In the long-term follow-up period, two cases of lethal outcome were recorded connected with the onset of an oncological disease. In one case, due to recurrence of the pulmonary artery thromboembolism. In two cases, the cause of myocardial infarction was thrombosis/occlusion of venous anastomoses (in one patient to the circumflex artery, in the other to the right coronary artery). In four cases, repeated acute cerebrovascular accidents developed due to restenosis after CEE. In cases of significant restenosis (n=8), reCEE was performed with plasty of the reconstruction zone with a patch. The average restenosis period was 8.23.6 months. No cardiovascular complications and cases of hypoglossal nerve traumatization were identified. Intraoperatively, it was confirmed that restenosis was formed in the bifurcation zone, in front of the perimeter of the primary arteriosection. According to the results of histological examination, the main cause of all restenoses was hyperplasia of the neointima. Conclusion. The eversion CEE with the transposition of the ICA, according to A.N.Kazantsev, creates conditions for additional maneuvers in case of restenosis and implementation of reCEE. The ICAs placement over the hypoglossal nerve during primary CEE allows more confident isolation of carotid artery bifurcation from scar tissues with a zero risk of damage to the hypoglossal nerve. Such a course of the operation makes it possible to apply a clamp on the ICA and perform arteriotomy in any location without the threat of injury to the nerve structures.

Aim of study.Analysis of the results of a new method of emergency glomus-sparing carotid endarterectomy (CEE) according to A.N. Kazantsev in the acute period of ischemic stroke.Material and methods.This cohort comparative prospective open-label study from January 2017 to April 2020 included 517 patients operated on for occlusive stenotic lesions of the internal carotid arteries (ICA) in the acute period of ischemic stroke (within 24 hours after the development of ischemic stroke). Depending on the implemented revascularization strategy, all patients were divided into three groups: group 1 — 214 patients (41.4%) — glomus-sparing CEE according to A.N. Kazantsev; 2nd group — 145 (28%) — classical CEE with plasty of the reconstruction zone with a patch; 3rd group — 158 (30.6%) — eversion CEE. The observation period was 35.2±9.6 months. Glomus-saving СE according to A.N. Kazantsev was carried out as follows. Arteriotomy with transition to the common carotid artery (CCA) was performed along the inner edge of the external carotid artery (ECA) adjacent to the carotid sinus, 2–3 cm above the ostium, depending on the spread of atherosclerotic plaque, the ICA was cut off at the site formed by the sections of the wall of the ECA and CCA. Then endarterectomy from the ICA was performed using the eversion technique. The next step was open endarterectomy from ECA and CCA. Then the ICA was implanted in the same position on the saved site.Results.In the hospital follow-up period, there were no significant intergroup differences in the number of complications. However, it should be noted that in the CEE group according to A.N. Kazantsev had no adverse cardiovascular events. In the long-term follow-up period, the smallest number of cardiovascular accidents was detected after CEE according to A.N. Kazantsev. However, intergroup differences were found only in the combined endpoint and the incidence of thrombosis, which were the highest in the 2nd and 3rd groups (p = 0.01). When analyzing the survival curves, it was revealed that the greatest number of cardiovascular accidents in the group of classical and eversion CEE occurred either during the hospital observation period or during the first months after surgery, and after CEE according to A.N. Kazantsev - in a year or more. When analyzing the graph of the dynamics of systolic blood pressure (BP), it was revealed that after glomus-sparing CEE according to A.N. Kazantsev, stable numbers are maintained while receiving preoperative antihypertensive therapy and do not rise above 140 mm Hg. In turn, after classical and eversion CEE, critical hypertension persists in the first three days, which is difficult to treat. In the future, blood pressure figures are unstable and fluctuate in the range from 140 to 160 mm Hg. All cases of myocardial infarction and ischemic stroke were recorded against the background of critical numbers of systolic blood pressure, reaching 180-200 mm Hg.Conclusion.The presented glomus-sparing carotid endarterectomy according to A.N. Kazantsev meets the modern standards of carotid surgery, combined with the minimum permissible risks of developing adverse cardiovascular events, both in hospital and in the long-term follow-up. The confident effect of the developed revascularization is based on the precise removal of plaque from the common, external and internal carotid arteries, as well as maintaining the stability of hemodynamic parameters.

Aim of the study : to evaluate safety and feasibility of clinical use of an extracorporeal blood adsorber based on a hypercrosslinked styrene-divinylbenzene copolymer with immobilized lipopolysaccharide (LPS)-selective ligand designed to remove endotoxins from the bloodstream to treat patients with septic shock. Materials and methods . Nine patients (mean age 58 years, 5 men and 4 women, initial median APACHE II score 28 points, SOFA score 10 points) with confirmed Gram-negative bacterial infection and septic shock (SEPSIS-3, 2016) underwent LPS-selective hemoperfusion using an extracorporeal blood adsorber based on a hypercrosslinked styrene divinylbenzene copolymer with immobilized LPS-selective ligand for 6 hours, followed by prolonged veno-venous hemodiafiltration. Before the hemoperfusion (day 0), immediately after it, a day after its end (day 1) and once daily for the next 4 days we assessed the hemodynamic parameters, oxygenation, organ failure signs, white blood cell count, procalcitonin, C-reactive protein, clinical chemistry parameters. Results. Hemoperfusion resulted in a rapid decrease in the endotoxin activity (EAA test), more than twofold decrease in plasma level of interleukin-1 (immunoenzyme test). At the end of the procedure, the plasma lactate level decreased to normal values by day 3, pH values restored to normal within 1-2 days. The noradrenaline requirement rapidly decreased and completely resolved within 1-3 days, which corresponded to the restoration of mean blood pressure values. The values of the PaO2/FiO2 oxygenation index increased significantly after 24 hours, and the median values of 300 were maintained during all subsequent days of observation. During the first day, hemoperfudion caused a rapid decline in APACHE II and SOFA scores, while acute renal failure (estimated by urea and creatinine levels) resolved gradually by day 5. The hemoperfusion did not affect the unchanged coagulation parameters (prothrombin, fibrinogen, INR). During the first day after the procedure, we observed a short-term 1.5-fold decrease in platelet count with subsequent recovery by days 2-3 in most patients. Two patients, both differing from the rest of the patients prior to treatment in the highest values of APACHE II score (above 30), APTT (above 40) and endotoxin activity in EAA test (above 0.9), died on the 4th and 8th days of treatment. The rest of the patients survived, with clinical improvement in all parameters. Conclusion . The results of extracorporeal blood purification using Efferon LPS extracorporeal blood adsorber indicate a high therapeutic potential of the method and suggest the need for extended clinical trials to assess its clinical efficacy in ICU to reduce the high mortality in patients with septic shock.

Physicochemical characteristics of the melt of nitrogen-alloyed steel of 04Kh20N6G11M2AFB grade (nitrogen content 0.47 0.49 %) were investigated by the method of torsional vibrations of a crucible with a metal in the atmosphere providing a stable nitrogen content during the experiment (80 % nitrogen and 20 % helium). Using sensitivity of the method to aggregate state of the test substance, at a heating rate of 0.0033 0.0050 K/s, the liquidus temperatures were experimentally determined for 04Kh20N6G11M2AFB steel (1660 1666 K) and lownitrogen steel ([N] = 0.063 %) with identical content of other elements (1685 1690 K). This made it possible to recommend the value of the coefficient - 60 K/% [N] for the calculated assessment of the effect of nitrogen on liquidus temperature of complex and high-alloy steels. It is shown that the viscosity of the melt of 04Kh20N6G11M2AFB steel has a relatively high level ((11.5 ± 0.7) 10-7 m2/s) in comparison with the traditional ((8.2 ± 0.2) 10-7 m2/s) austenitic steels with a relatively small partial effect of nitrogen. A significant non-equilibrium of the melt structural state of this steel was established by high-temperature viscometry methods. Comparative analysis of polytherms and isotherms of the melt kinematic viscosity for 04Kh20N6G11M2AFB steel and its low nitrogenous ([N] = 0.063 %) analogue made it possible to conclude that the presence of nitrogen at concentrations close to saturation plays a decisive role in the level of non-equilibrium of the melt and low rate of its relaxation. It was confirmed as a result of special experiments on the saturation of low-nitrogen steel with nitrogen, during which a sharp increase in non-equilibrium of the melt structural state was recorded with achievement of nitrogen concentration in the metal of limiting values (0.45 0.50 %). The principal possibility of increasing and stabilizing the operational properties of corrosion resistant nitrogen-alloyed steels is indicated by reducing non-equilibrium of the melt structural state by eliminating the excess of nitrogen concentration limits for the considered chemical composition. © 2020 National University of Science and Technology MISIS. All rights reserved.

Aim. Analysis of hospital and long-term results of carotid endarterectomy (CEA) in different periods of acute cerebrovascular event (ACVE). Materials and Methods . The given study was retrospective and was conducted using the method of patients sampling. In the period from 2010 to 2019, 1113 patients with ACVE in history who were later conducted CEA, were selected. Depending on the time interval between the last ACVE and CAE, all the patients were divided into 4 groups: the 1 st group – in the acutest period of ACVE (1-3 days) (n=24; 2.2%); the 2 nd group – in the acute period of ACVE (up to 28 days) (n=493; 44.3%); the 3 rd group – in the early rehabilitation period of ACVE (up to 6 months) (n=481; 43.2%); the 4 th group – in the late rehabilitation period of ACVE (up to 2 years) (n=115; 10.3%). The long-term period was 34.8±12.5 months. Results . In the hospitalization period of observation the following complications were found: lethal outcome ((group 1 – 0%; group 2 – 0.4% (n=2); group 3 – 0.2% (n=1); group 4 – 0%; р=0.16)); myocardial infarction ((group 1 – 0%; group 2 – 0.4% (n=2); group 3 – 0%; group 4 – 0.9% (n=1); р=0.35)); ACVE/transient ischemic attack (TIA), ((group 1 – 4.2% (n=1); group 2 – 0.4% (n=2); group 3 – 0.2% (n=1); group 4 – 0%; р 1-2 =0.01; р 1-3 =0.009; р 1-4 =0.01)). By the end of hospitalization period the composite endpoint consisting of lethal outcome + myocardial infarction + ACVE/TIA made in group 1 – 4.2% (n=1), in group 2 – 1.2% (n=6), in group 3 – 0.4% (n=2), in group 4 – 2.6% (n=3), р=0.08. Complications of the long-term follow-up period were: lethal outcome from all causes ((group 1 – 25% (n=6); group 2 – 5.5% (n=27); group 3 – 7.3% (n=35); group 4 – 14% (n=16); р 1-2 =0.002; р 1-3 =0.008; р 2-4 =0.012)); lethal outcome from cardiovascular causes ((group 1 – 4.2% (n=1); group 2 – 3.6% (n=18); group 3 – 4.8% (n=23); group 4 – 5.2% (n=6); р=0.79)), myocardial infarction ((group 1 – 12.5% (n=3); group 2 – 3.6% (n=18); group 3 – 5.4% (n=26); group 4 – 6.1% (n=7); р=0.15)), ACVE/TIA ((group 1 – 16.6% (n=4); group 2 – 6.3% (n=31); group 3 – 6% (n=29); group 4 – 11.3% (n=13); р=0.05)); composite endpoint including lethal outcome + myocardial infarction + ACVE/TIA ((group 1 – 54.2% (n=13); group 2 – 15.4% (n=76); group 3 – 18.7% (n=90); group 4 – 31.3% (n=36); р 1-2 =0.0001; р 1-3 =0.0001; р 1-4 =0.005; р 2-4 =0.0006; р 3-4 =0.012)). Conclusion. Application of CEA demonstrated effectiveness and safety in the acute and early rehabilitation period of ACVE.

Purpose of the study. Comparison of hospital and long-term results of autoarterial reconstruction of carotid artery bifurcation and the formation of a new bifurcation with an extended atherosclerotic lesion of the internal carotid artery (ICA). Materials and methods. In the period from January 2018 to May 2020, this cohort, comparative, prospective, open-label study included 279 patients with an extended atherosclerotic lesion of the ICA operated on in the Alexandr Hospital. Depending on the implemented strategy of surgical correction, all patients were divided into two groups: group 1 (n=132) — autoarterial reconstruction of bifurcation of the carotid arteries; Group 2 (n=147) — the formation of a new bifurcation. Complications were recorded in the hospital and long-term postoperative periods. The total follow-up period was 16.4±9.3 months. The endpoints of the study were such adverse cardiovascular events as death, myocardial infarction (MI), stroke, thrombosis / restenosis of the anastomosis zone, combined endpoint (death from stroke / IM + IM + stroke). Results. The ICA clamping time in group 1 was 32.6±3.3 minutes, in group 2 – 31.7±3.5 minutes, which did not receive statistically significant differences (р=0.81). In the hospital postoperative period, adverse cardiovascular events were not recorded. In the long-term follow-up, the groups were comparable in the frequency of all complications. Identified lethal outcomes developed as a result of the formation of MI in patients with multiple lesions of the coronary arteries and a history of myocardial revascularization. The likely cause was shunt / stent thrombosis with subsequent coronary insufficiency and an increase in ischemic heart damage. The causes of stroke, recorded in each group in isolated cases, were the presence of atrial fibrillation. Patients did not comply with the recommended regimen of anticoagulant therapy, which provoked the development of cerebral catastrophe. In turn, the identified restenoses of the reconstruction zone were asymptomatic and were also observed in isolated cases in each group in the period 12 months after CEE. Conclusion. Autoarterial reconstruction of carotid bifurcation and the formation of a new bifurcation are comparable in safety and effectiveness methods of surgical treatment of an extended atherosclerotic lesion of the ICA. Operation techniques differ in the choice of an artery that is cut off from bifurcation — the external carotid artery or ICA. Further, the reconstruction progress is absolutely identical. Hospital and long-term follow-up results showed minimal indicators of the development of cardiovascular and hemodynamic changes due to the type of operation. Thus, both reconstruction techniques can be the operation of choice for an extended ICA lesion.

The invariant cross sections for forward charged-hadron production at zero angle in carbon–carbon collisions at a beam kinetic energy of 19.6 GeV per nucleon were measured at the U-70 accelerator in an experiment performed with the aid of a combined spectrometer including beam line 22 and detectors of the modified FODS setup. The beam line rigidity was varied between 7 and 70 GeV/ $$c$$ . The results are compared with the predictions of the FTFP model and a self-similar solution for nucleus–nucleus collisions.

The structure and the physicochemical properties of nitrided chromium- and manganese-based ferroalloys have been studied experimentally. Nitrogen in the alloys is shown to be mainly in the form of nitrides Mn2N, CrN, and Cr2N, the fractions of which are dependent on the nitrogen content and the methods of alloy manufacture. The liquidus temperature of the nitrided chromium-bearing ferroalloys is lower than that of analogous nitrogen-free ferroalloys, which positively influences the rate and degree of assimilation of elements by steel. The introduction of 8–16% nitrogen in the ferroalloy compositions decreases their real densities, which enables one to produce alloys with the optimal density. The apparent densities of the nitrided chromium and manganese ferroalloys are very low (3000–4200 kg/m3) due to their high porosity; as a result, they will be melted at the steel melt surface and will have a low degree of nitrogen assimilation. Higher degrees of nitrogen assimilation can be achieved as powdered alloys are injected in a gaseous nitrogen jet. The degree of transition of nitrogen to steel from the ferroalloys is 47–84%; it is mainly dependent on the holding time of a nitrided steel in liquid state, the physicochemical characteristics of nitrided ferroalloys, the composition of an alloyed metal, and the types and content of nitride-forming elements (Cr, Mn, Ti, etc.) in it. The highest degree of transition of nitrogen to steel (84%) was reached using an as-cast nitrided chromium sample with 8% N in the first minute of holding. Further holding up to 30 min of the liquid sample at 1500°C leads to a decrease in the degree of nitrogen assimilation to 52%.

Theoretical and experimental studies are conducted in the field of nitriding high strength nonmagnetic steels. Temperature-time correlation of the degree nitrogen assimilation and nitrogen content in steel 04Cr20Ni6Mn11Mo2NVNb in the case of alloying with nitrogencontaining manganese and chromium ferroalloys in air and during purging with nitrogen are determined by experiment. Gas phase nitriding of this steel is possible at 1450 °C during 30 min reaching a nitrogen content of 0.42%. A twostage process for lowcost nitriding is developed. In the first stage melts are purged with highpurity nitrogen to reach a nitrogen content of 0.25–0.30%. In the second stage powder alloying additions are injected into a stream of nitrogen with a melt temperature as low as possible.

The issues of determining the momentum of charged particles at the focusing double-arm spectrometer (FODS) are discussed. The coordinate detectors are located at the exit from the analyzing magnet, while a profilometer of the center of gravity of the beam at the target during an accelerator cycle is at its entrance. ANSIS finite-element analysis software is used to obtain a regular grid of magnetic field vector values measured by the Hall sensor in a part of the magnet. The charged-particle momentum is determined based on the algorithm of decision tables with a polynomial approximation. Tables are produced by the Monte Carlo method by reconstructing the motion of a particle with a prescribed momentum in the magnetic field. The accuracies in determining the particle momentum and the particle production angles while accounting for the contributions from multiple scattering, measurement errors, and approximation uncertainties are presented. The distribution of the reconstructed trajectories in the target and the momentum spectrum of particles are shown.

A procedure for finding the trajectories of charged particles on the FODS (focusing double-arm spectrometer) is described, which includes channel calibration (r(t)-dependence) of drift detectors for calculating the coordinates of particles and reconstruction of tracks. The organization of time measurements and construction of a least-squares functional on their basis is considered. The criteria for selecting candidates for the tracks are discussed. A procedure has been developed for obtaining geodesic corrections for drift chambers and tubes at the analysis of physical events. Accuracies of measuring the coordinates in drift chambers of 600 μm and chambers on drift tubes of 500 μm were obtained. The distribution of particle trajectories in the target is given.

The structure of the adhesion zone between the base and cladding layers in new 10KhN3MD + 04Kh20N6G11M2AFB two-layer steel obtained using different techniques, namely, application of deposit welding followed by rolling, pack rolling, and explosive welding, is studied. It is found that, irrespective of the chosen technique of preparation, the strength of adhesion of the layers is at the level of the strength of the steel of the base layer.

Aim. To analyze the results of using a novel method of glomus-saving carotid endarterectomy (CEE) sensu A. N. Kazantsev.Materials and methods. This cohort, comparative, prospective, open-label study from January 2018 to April 2020 included 475 patients who undergone one of the three glomus-saving types of CEE. Depending on the implemented revascularization strategy, all patients were divided into 3 groups: group 1 — 136 patients (28,631%) CEE sensu R. A. Vinogradov; group 2 — 125 patients (26,316%) — sensu K. A. Antsupov; group 3 — 214 patients (45,053%) — sensu A. N. Kazantsev. Glomus-saving CEE sensu A. N. Kazantsev was carried as follows. Arteriotomy was performed along the inner edge of the external carotid artery (ECA) adjacent to the carotid sinus, 2 to 3 cm above the mouth, depending on the atherosclerotic lesion, with a transition to the common carotid artery (CCA) (also 2 to 3 cm below the mouth of the ECA). The internal carotid artery (ICA) was cut off at the site formed by the wall of the ECA and CCA. Next, an endarterectomy from the ICA was performed using the eversion technique. The next step was an open endarterectomy from EСA and СCA. Next, the ICA at the saved site was implanted in the previous position.Results. No intergroup differences were observed during hospitalization. Due to intraoperative visualization of an extended lesion of the ICA, in some cases it became necessary to transform the operation: in group 1, 4,4% of cases required ICA prosthetics; in groups 2 and 3 — autologous ICA transplantation in 4,8% and 4,7% of cases, respectively. Also, 1 case of ischemic stroke was recorded in groups 1 and 2. The cause of the latter was ICA thrombosis due to intimal detachment distal to the removed plaque. All cases of ECA thrombosis in the hospital postoperative period were differentiated in group 2.In the long-term follow-up, the groups were also comparable in the complication rate. The cause of all ischemic strokes was the development of restenosis or thrombosis of the ICA/prosthesis. Among patients who underwent forced autologous transplantation of the ICA, restenosis was not recorded. It should also be noted that new ECA occlusions (n=12; 9,6%) were visualized 6 months after reconstruction only in group 2.Conclusion. CEE sensu A. N. Kazantsev is the simplest technique of glomus-saving reconstructions, which have demonstrated their safety and effectiveness.

The CALPHAD method has been employed to compose thermodynamic description of the Fe–Cr–Mn–Ni–Si–C–N system. Using an algorithm based on finding a global minimum of Gibbs energy, the calculations of system phase composition were performed in the temperature range from 1750°C to hardening and in the range of compositions corresponding to 04Kh20N6G11M2AFB steel. Calculations showed that at temperatures above liquidus line, Cr and Mn increase nitrogen solubility in the melt, while Ni and Si reduce it. With an increase in the content of Cr, Mn, Ni, and Si in steel in the studied composition range, both liquidus and solidus temperature decrease. The degree of influence on these temperatures of Cr, Mn, Ni and Si within the steel grade is different and ranges from ~3 to ~14°C. Calculations taking into account the possibility of nitrogen transfer between steel and the atmosphere of air showed that the amount of fixed nitrogen in the alloy under study varies, depending on the composition of the steel and temperature, from ~0.3 to ~0.6 wt%. As the temperature decreases from liquidus to solidus, the amount of fixed nitrogen increases, with the exception of those steel compositions when ferrite and not austenite is released from the liquid phase.

Thermodynamic modeling is performed for phase formation of nitrogen-containing steel 04Kh20N6G11M2AFB during crystallization, solidification, and cooling that shows crystallization proceeds through δ-ferrite. In this case depending on alloying element content within the limits of the grade composition δ-ferrite may exist both at temperatures corresponding to the cuidus — solidus interval, and also be retained below the solidus temperature. Ingot metal is examined comprehensively in different ingot zones in order to study structure formation throughout the ingot volume, alloying element liquation, and nonmetallic inclusion and secondary phase composition and distribution.

Relative yields of high-x F charged hadrons (π ±, К±, р, $$\overline p $$ , and d) in proton–nucleus interactions at incident-proton momenta of 25 and 50 GeV/c were measured at an angle of 0° in the momentum range between 15 and 40 GeV/c. An upper limit on the forward production of two protons in proton–nucleus interactions at 50 GeV/c was estimated. The properties of a carbon beam with an energy of 25 GeV per nucleon and fragment yields in its interaction with nuclear targets were measured within a short exposure.

The paper presents results of comparative studies of corrosion resistance and corrosion-mechanical strength for low-magnetic shipbuilding steels of alloying systems Mn–C, C–Mn–Ni, Cr–Ni, Cr–Ni–Mo, and Cr–Ni–Mn–N, produced using various hardening mechanisms. It is shown that nitrogen-containing steels developed by CRISM Prometey constitute new constructional material superior in resistance to corrosion cracking in seawater compared with low-magnetic steels used in shipbuilding nowadays.

The effect of cathodic polarization in seawater on the mechanical properties of high-strength nitrogen-containing steel 04H20N6G11M2AFB was studied.

Austenitic steel Kh20N6G11AM2BF with a nitrogen content of 0.4 wt % exhibits enhanced mechanical properties, high wear, and high resistance to stress-corrosion cracking (SCC) after quenching from rolling heating and after quenching from 1150°C and 15% cold deformation. This shows that it can be used in arctic shipbuilding as a cladding material for hull plates. Strong bonding of Kh20N6G11M2AFB austenitic steel cladding with a nitrogen content of 0.4 wt % with 10N3KhDMBF hull steel is obtained. The shear resistance is registered to be 437–520 MPa. Redistribution of the alloying elements with the formation of a martensitic layer, which is observed at the interface between the cladding layer and the base material, must be taken into account in the final heat treatment considering different processing conditions.

The structural, mechanical, and magnetic properties of metal cut out from the welded joint and from the near-weld zone of the welded joint of high-strength nitrogen-containing 04Kh20N6G11M2AFB austenitic steel have been investigated. The behavior of the magnetic parameters of materials under study subjected to various schemes of loading, such as tension, torsion, internal pressure, and combination of tension and torsion have been investigated. It has been established that the metal of the welded joint and near-weld zone of the welded joint, just as the base metal, has a stable phase composition and magnetic properties under various loading conditions. It has been concluded that 04Kh20N6G11M2AFB steel can be used in the fabrication of welded parts and elements of welded constructions that require low magnetization and high stability of magnetic characteristics under the force action.

Recrystallization of austenitic nitrogen-containing steel is studied during hot deformation in the range 800–1000°C. It is established that weakening occurs first immediately during hot plastic deformation, and second during post-deformation pauses between passes. In the first case weakening is accomplished as a result of dynamic recrystallization, and second as a result of static recrystallization. Conditions are determined for the start of dynamic recrystallization and the static recrystallization temperature is established, and also its time characteristics: incubation period τ0 and completion time τc.

Cross sections for the production of high-transverse-momentum charged hadrons in proton–nucleus interactions at the incident-proton energy of 50 GeV were measured with the aid of the FODS double-arm spectrometer. Single hadrons (charged pions and protons) emitted at a c.m. angle of about 90° and high-effective-mass pairs of hadrons flying apart at a c.m. angle of 180° were detected simultaneously. Results on the production of single hadrons are presented.

The effect of technology of introducing REM on the composition and shape of nonmetallic inclusions and physicomechanical properties of carbon and low-alloy steels for different purposes is analyzed, and criteria are provided for REM consumption in relation to sulfur and oxygen content within metal, making it possible to determine the optimum REM distribution with which there is an increase in ductility properties, impact energy, and sheet and plate anisotropy properties of the sheet are reduced. Microalloying of carbon and alloy steels and alloys with REM improves corrosion resistance, hot ductility, thermal shock resistance, and other operating properties.

Physical and physicochemical properties are considered for rare-earth elements (metals) and their reaction with oxygen, sulfur, and nonferrous metal admixtures during steel production. Introduction of REMs in optimum amounts makes it possible to modify nonmetallic inclusions both in a liquid condition and during steel crystallization, to refine cast workpiece structure due to inoculation action, and to improve physicomechanical and operating properties of a broad range of steels and alloys. Melt stirring is necessary in order to improve steel purity with respect to nonmetallic inclusions during REM introduction and subsequent steel treatment.

Analysis of the results of emergency carotid endarterectomy (CEE) in internal carotid artery (ICA) thrombosis in the acute period of acute cerebrovascular accident (ACVI) in patients with COVID-19.During the COVID-19 pandemic (April 1, 2020 - May 1, 2021), 43 patients with ICA thrombosis and a positive polymerase chain reaction (PCR) result for SARS-CoV-2 were included in this prospective study. In all cases, CEE was performed in the acutest period of ACVA. These patients were included in group 1. The comparison group was represented by 89 patients who underwent CEE in the acute period of stroke, in the period before the COVID-19 pandemic (April 1, 2019 - March 1.2020).In the hospital postoperative period, the groups were comparable in terms of the incidence of deaths (group 1: 2.3%,Emergency CEE in the acute period of stroke is an effective and safe method of cerebral revascularization in case of ICA thrombosis in conditions of COVID-19.Анализ результатов экстренной каротидной эндартерэктомии (КЭЭ) по поводу тромбоза внутренней сонной артерии (ВСА) в острейшем периоде острого нарушения мозгового кровообращения (ОНМК) у пациентов с COVID-19.За период пандемии COVID-19 (01.04.20—01.05.21) в настоящее проспективное исследование включены 43 пациента с тромбозом ВСА и положительным результатом полимеразной цепной реакции на наличие SARS-CoV-2. Во всех случаях была выполнена КЭЭ в острейшем периоде ОНМК. Данные больные вошли в 1-ю группу. Группа сравнения была представлена 89 пациентами, которым была реализована КЭЭ в острейшем периоде ОНМК, в период до пандемии COVID-19 (01.04.19—01.03.20).В госпитальном послеоперационном периоде группы были сопоставимы по частоте развития летальных исходов (1-я группа: 2,3%,Экстренная КЭЭ в острейшем периоде ОНМК является эффективным и безопасным методом реваскуляризации головного мозга при тромбозе ВСА в условиях COVID-19.

The article is concerned with solving of the practical and theoretical issues of usability characteristics assessment of systems of information protection from unauthorized access digital educational environment. A comparative analysis of innovative technologies of usability characteristics assessment used to assess the quality characteristics of software user interfaces is carried out. The considered methods can be applied to assess the functional quality of systems of information protection in terms of ease of use for users of various categories. Apart from that, the security administrator applies special requirements to the systems of information protection interface. A qualitative and quantitative assessment of usability characteristics for this category of users is required in connection with the significant influence exerted by the administrator on the information security processes and the dependence of his work efficiency on the systems of information protection usability characteristics.

Aim. Analysis of the results of hospital and medium-long-term results obtained using a new method of glomus-saving carotid endarterectomy (CEE) according to A. N. Kazantsev.Methods. This prospective study was conducted during January 2018 to April 2020 on 214 patients who were operated for occlusive stenotic lesions of the internal carotid artery (ICA) using holomus-saving CEE as per the method described by A.N. Kazantsev. The average observation duration was 17.2 ± 6.5 months.Glomus-saving CEE as per the method by A. N. Kazantsev is performed as follows. Arteriotomy is performed along the inner edge of the external carotid artery (ECA) adjacent to the carotid sinus, 2–3 cm above the mouth, depending on the distribution of atherosclerotic plaque, with a transition to the common carotid artery (also 2–3 cm below the ECA mouth). The ICA was cut off at the site formed by the wall sections of the ECA and the common carotid artery. Thereafter, an endarterectomy from the ICA was performed using the eversion technique. The next step was an open endarterectomy from the ECA and OCA. Then, the ICA at the saved site was implanted in the previous position. A 6-0 Prolene thread was used as the suture material for performing a vascular anastomosis.Results. The average ICA clamping time was 33.1 ± 3.4 min. Considering the intraoperative visualisation of an extended atherosclerotic plaque in the ICA, in some cases, there was a need to transform the operation. In 4.7% (n = 10) cases, autologous ICA transplantation was performed as per E. V. Rosseykinu. During the hospitalisation, the observation of cardiovascular complications was not recorded. When analysing the dynamics graph of systolic blood pressure, it was revealed that after glomus-saving CEE as per the method by A. N. Kazantsev, stable numbers are maintained during preoperative antihypertensive therapy and do not rise above 137.9 ± 7.5 mm Hg. In the mid-long-term follow-up, 1 (0.46 %) death was recorded, 1 (0.46%) due to myocardial infarction, 1 (0.46%) due to non-lethal ischaemic stroke, and 2 (0.9%) due to hemodynamically significant restenosis 12 mon after CEE. The combined endpoint (death + myocardial infarction + stroke) was reached in 3 (1.4%) patients. The cause of the lethal outcome was circular myocardial infarction that developed, given the patient's refusal to follow double disaggregant therapy (2 stents were previously implanted in the anterior descending and right coronary arteries). The cause of ischaemic stroke was the development of ICA restenosis (12 mon after CEE) owing to neointimal hyperplasia, as shown by histological examination after repeated surgery.Conclusion. CEE as per the method by A. N. Kazantsev is the simplest method of operation for known glomus-preserving reconstructions. The absence of complex arteriotomy, the preservation of carotid bifurcation structures, and the possibility of transformation of the intervention into autologous autologous transplantation with prolonged lesion is preferred over other methods. An additional opportunity for high-quality endarterectomy from ЕCA also creates preventive conditions in the prevention of cerebral haemodynamics. Stable blood pressure indicators in the hospital and mid-term follow-up periods demonstrate the importance of the preservation of the carotid glomus during reconstructive surgery on the carotid arteries. Thus, the presented type of CEE meets all the requirements of modern carotid surgery and can be an elective operation in the personalised treatment of patients with occlusal-stenotic lesions of the carotid arteries.Received 10 May 2020. Revised 25 May 2020. Accepted 26 May 2020.Funding: The study did not have sponsorship.Conflict of interest: Authors declare no conflict of interest.Author contributionsMethod development and testing: A.N. KazantsevConception and design: T.E. Zaitseva, A.E. Chikin, A.N. KazantsevDrafting the article: A.N. KazantsevDrawing up tables: E.Yu. KalininStatistical analysis: K.P. ChernykhLiterature review: R.Yu. Leader, G.Sh. BagdavadzeCritical revision of the article: N.E. Zarkua, K.G. KubachevFinal approval of the version to be published: A.N. Kazantsev, K.P. Chernykh, R.Yu. Leader, N.E. Zarkua, K.G. Kubachev, G.Sh. Bagdavadze, E.Yu. Kalinin, T.E. Zaitseva, A.E. Chikin, Yu.P. Linets

The article discusses the issues of information support for the safety of composite engineering structures (CES), such as railway and automobile bridges, dams, high-rise buildings, objects of operation at space centers, etc. The most effective approach to creating systems for monitoring the CES safe state is the integrated use of data from the ground and space high-precision monitoring tools for the static and dynamic displacements and deformations of the CES design elements. The information service developed by the specialists of JSC “Russian Space Systems” relates to the field of monitoring composite engineering structures, namely for operational monitoring of the complex structural elements’ and unique engineering structures’ state. The services are provided by a measuring complex, which can be included as traditional for this area precision meters of physical quantities and meters that work with the support of global navigation satellite systems. The service identifies the dangerous state of a composite engineering structure, based on an analysis of the dynamics of changes in the CES parameters and scenarios of the dangerous state of a composite engineering structure. The ultimate goals of creating such information services is to provide the data necessary for assessing the mechanical safety of engineering structures, departments and individual enterprises involved in organizing the execution of functions to support the life CES cycles.

The inclusive differential cross sections for forward production of nuclear fragments at an angle of 0 ∘ in CC collisions at beam energy 20.5 GeV/nucleon ( S N N = 6.3 GeV ) are presented. Measurements have been performed at the U-70 Accelerator Complex (Protvino) using a combined spectrometer on base of the beamline. Fragments selection was carried out by measuring of ionization in scintillation counters taking into account the data from threshold Cherenkov counters and hadron calorimeter. Fragment mass was determined through Cherenkov light emission angle measured in the spectrometer of ring imaging Cherenkov radiation. Data are given for fragments with charge 1 ≤ Z ≤ 6 , atomic number 1 ≤ A ≤ 10 and A / Z 3.4 with momenta from 20 to 210 GeV/c. The measurements are compared with Fritiof model, statistical models and theoretical parameterizations. The discovered differences between theory and experiment are discussed.

The paper considers the results of low-cycle tests for high-strength nitrogen-containing austenitic steels with different systems of alloying in order to prevent cyclic softening of these steels.

The paper depicts long-term research resulting in creation of high-nitrogen austenitic steels for shipbuilding. It shows the influence of the chemical composition and technology on the crystal lattice and steel structure, mechanical and corrosion properties, weldability, and other characteristics. The paper studies the fine structure of nitrogen austenitic steels and shows the important role of nitrogen, which impacts the strength and corrosion resistance more effectively than carbon while maintaining a high level of plastic properties and resistance to cyclic and dynamic loading. Magnetic and vibrodamping characteristics are evaluated. High-strength nitrogen austenitic steel with the yield strength of 650 MPa has been successfully adopted by the domestic industry. Its implementation for heavy duty structures is in the final stage. A prognostic evaluation for further development of nitrogen austenitic steels for various industries is given.

Amplitude and time spectra of a drift tube (DT) were investigated using cosmic radiation at different voltages applied to it and different compositions of an Ar + CO2 gas mixture. The dependence of the drift time on the CO2 concentration was studied. The mode of DT response mainly to the first cluster was selected. The working point for the high voltage applied to the tube was determined. It was shown that the spatial resolution of a DT for the FODS tracking system for cosmic events is ~0.5 mm.

We report on the studied influence of the applied normal and tangential stresses, as well as their combined effect on the structure, phase composition, and magnetic properties of three high-nitrogen steels (HNS). Two of the studied steels in the initial state had an austenitic structure and were diamagnetic. The third steel, according to the data of the X-ray diffraction and metallographic analysis, contained 7% δ-ferrite in its composition, which specifies its ferromagnetic properties. The nitrogen steels studied in this work have demonstrated the stability of the phase composition, as well as of the magnetic properties at various loading conditions, and, thus, can be used in the production of articles and elements of structures that are required to exhibit low magnetization and high stable magnetic characteristics under an applied force. Parameters that can be used as the informative ones when estimating changes that occur upon the production and exploitation of articles and elements made of HNSs with small contents of δ ferrite have been determined.