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This review summarizes the available information on the epidemiology and prognosis of patients with left bundle branch block (LBBB), morphological alterations of the myocardium both resulting in and ensuing LBBB, cardiac biomechanics in LBBB, and possibilities of its correction.

Aim.We aimed to assess safety and effectiveness of class III antiarrhythmic drug Refralon for conversion of atrial fibrillation (AFib) and flutter (AFl) in post-registration trial and to compare data of primary center (National medical research center in cardiology) with data of other hospitals.Material and Methods. We performed retrospective cohort study in 727 patients (451 enrolled in primary center and 276 enrolled in other hospitals) admitted between June 24, 2014 and June 24, 2019. Refralon was administered for conversion of AFib and AFl in intense care units in escalating doses (10-30 micrograms/kg) intravenously.Results.Conversion of AFib and AFl into sinus rhythm was achieved in 53,6% after administration of 10 mcg/kg dose, in 73% after administration of 20 mcg/kg dose and in 91,6% after administration of Refralon in dose up to 30 mcg/kg. No mortality and no major adverse cardiac events registered in our study. Asystole >3.0 sec observed in 5% (35 of 727) of patients): in 5% (24 of 451) of patients enrolled in primary center and in 4% (11 of 276) of patients enrolled in other hospitals; 95% confidence interval (CI) [-0.09; 0.113]. Asystole> 5.0 s observed in 1.7% of patients who further required non-urgent implantation of a permanent pacemaker due to manifestations of sinus node dysfunction. Cardiac conduction disturbances (exclusively sinus bradycardia) were registered in 7% (53 of 727) patients: in 8% (37 of 451) of patients enrolled in primary center and in 6% (17 of 276) of patients enrolled in other hospitals; 95% CI: [-0.1; 0.15]. Only 0.14% of patients had symptomatic sinus bradycardia that resolved after atropine injection. Ventricular arrhythmias (exclusively Torsade de pointes tachycardia in excessive QT interval prolongation) were registered in 1.7% (12 of 727) patients: in 2% (9 of 451) of patients in primary center and in 1% (3 of 276) of patients of other hospitals; 95% CI: [-0.06; 0.08]. QTc interval prolongation to values >500 ms documented in 19% (138 of 727) of patients: in 21% (95 of 451) of patients in primary center and in 16% (43 of 276) of patients in other hospitals; 95% CI: [-0.13; 0.24].Conclusion:In post-registration multicenter trial Refralon demonstrated good safety profile in conversion of AFib and AFl. Potential risk of TdP tachycardia mandates precautions with the use of the drug. In other hospitals Refralon did not demonstrate lower safety than in primary medical center.

We present two cases of successful pharmacological cardioversion using antiarrhythmic drug refralon in patients with persistent atrial fibrillation after pulmonary vein cryoablation and ineffective electrical cardioversion. These clinical cases represent the first experience of successful use of refralon in patients who underwent cryoablation.

Aim.We aimed to assess safety and effectiveness of class III antiarrhythmic drug Refralon for conversion of atrial fibrillation (AFib) and flutter (AFl) in post-registration trial and to compare data of primary center (National medical research center in cardiology) with data of other hospitals.Material and Methods. We performed retrospective cohort study in 727 patients (451 enrolled in primary center and 276 enrolled in other hospitals) admitted between June 24, 2014 and June 24, 2019. Refralon was administered for conversion of AFib and AFl in intense care units in escalating doses (10-30 mcg/kg) intravenously. Primary endpoints: restoration of sinus rhythm (SR) within 24 hours after the start of infusion of the study drug in a total dose of up to 30 pg / kg; registration of SR on an electrocardiogram (ECG) 24 hours after the start of the study drug infusion. Secondary endpoints: restoration of SR after infusion of the study drug at a dose of 10 pg / kg; restoration of SR after infusion of the studied drug in a total dose of up to 20 pg / kg; no recurrence of AFib/AFl after restoration of AFl within 24 hours of observation after the start of the study drug infusion.Results.Conversion to SR was achieved in 53,6% (391 of 727) after administration of 10 mcg/kg dose, in 73% (531 of 727) after administration of 20 mcg/kg dose and in 91,6% (666 of 727) after administration in dose up to 30 mcg/kg. SR was restored in 89% (402 of 451) of patients in primary center, and in 96% (264 of 276) of patients in other hospitals; 95% confidence interval (CI): (-0,1;-0,03). SR preserved 24 hours after conversion in 98% (650 of 666) successfully converted patients. In primary center SR preserved in 97% (390 of 402) successfully converted patients. In other hospitals - in 98,5% (260 of 264) successfully converted patients. 95 CI: (-0,09;0,06).Conclusion:In post-registration multicenter trial Refralon demonstrated high effectiveness in conversion of AFib and AFl to SR. In other hospitals Refralon did not demonstrate lower effectiveness than in primary medical center.

An integral computer model/program AusEvol Pro was developed to describe the evolution of steel microstructure during thermomechanical processing (hot rolling, forging), as well as subsequent heat treatment (normalization, tempering), and to evaluate the final mechanical properties (yield stress, tensile stress, elongation), hardness and impact toughness. The program implements a set of physically based models that allow quantitative description of all significant processes of steel structure formation with account of the effects of chemical composition both during thermomechanical processing and heat treatment. Calculations of the final mechanical properties are carried out using the developed models that take into account all physically meaningful contributions. The models created are verified both on the extensive database of our own experimental studies and on reliable data from literature for steels of various chemical compositions.

Introduction Atrial fibrillation (AF) is one of the most common forms of arrhythmia. Niferidil is a new russian class III antiarrhythmic drug that has shown high efficiency in restoration of sinus rhythm (SR) in persistent AF (87%) in clinical trials that is non-inferior to direct current cardioversion. Currently, a three-stage scheme of drug administration is used (10 μg/kg – 10 μg/kg – 10 μg/kg). In a number of patients, SR restored before the end of injection of the first dose of the drug, which suggests the effectiveness of an even lower dose (5 μg/kg) of the drug, which has not been studied in clinical trials. Objective To evaluate the effectiveness and safety of the modified protocol of niferidil administration in patients with paroxysmal and persistent AF. Materials and methods This study included 100 patients with paroxysmal (n=20) and persistent AF (n=80), 53 of them were men, mean age 63±12 years. After exclusion of contraindications, all patients received niferidil according to the following scheme. The initial dose of niferidil was 5 μg/kg of body weight, if AF did not terminate after 15 minutes (min.), niferidil was additionally administered at a dose of 5 μg/kg (total dose of 10 μg/kg). If SR was not restored patients received subsequent injections of niferidil 10 μg/kg, each after 15 min. (maximal total dose of 30 μg/kg). Injections were discontinued in case of SR restoration, QTc >500 ms or proarrhythmia. All patients underwent continuous ECG monitoring within 24 hours to assess effectiveness and safety of niferidil. Results SR was restored in 94 out of 100 patients (cumulative effectiveness of niferidil in doses up to 30 μg/kg was 94%). 37% of patients restored SR after a dose of 5 μg/kg. All 20 patients with paroxysmal AF restored SR within 24 hours. Niferidil restored SR in 74 of 80 patients with persistent AF (92,5%). 26 (32,5%) of them restored SR after administration of 5 μg/kg dose, 62% – after 10 μg/kg dose and 92,5% – after 30 μg/kg dose. In none of the cases was there any development of life-threatening ventricular arrhythmias. Prolongation of the QTc >500 ms was recorded in 16 patients (16%). In all patients, prolongation of the QTc interval to the maximum values was noted within the first 6 hours from the start of drug administration. Bradyarrhythmias after SR recovery were reported in 11 patients (11%). In all cases sinus bradycardia was asymptomatic and resolved within a few minutes without any therapeutic intervention. Conclusions The modified protocol of cardioversion allows SR to be restored in a significant number of AF patients lower doses of niferidil. The drug is highly effective in the treatment of paroxysmal AF, while in many patients, SR recovery occurs after injection of lowest (5 μg/kg and 10 μg/kg) doses of the drug. Despite the prolongation of the QTc interval >500 ms in a number of patients, in none of the cases the development of Torsades de pointes observed. Funding Acknowledgement Type of funding sources: None.

This article analyzes the known techniques of calculating the energy intensity of continuous hot rolling of broad steel strips. The analysis is used to propose new rolling modes to ensure better energy efficiency by considering the influence of the partial cold work of the strip’s material on the energy consumption. The proposed modes were tested and adopted in the continuous finishing train of rolling mill 2000.

The study results show the normal growth of recrystallized ferrite grains under the isothermal annealing of cold-rolled sheets made of five automotive steels (DX54D, HX260YD, CR210B2, 08ps, HX300LAD) obtained using a Gleeble 3800 experimental system. Based on the obtained data, a mathematical model of this process has been developed. The simulation results obtained for the kinetics of ferrite grain growth in a practically important annealing temperature range agree well with the experimental data.

Aim. To evaluate standard 12-lead ECG indices for the differential diagnosis of wide QRS tachycardias with right bundle branch block (RBBB) pattern. Materials and methods. Study analyses the 244 ECG indices in 111 patients (79 males and 32 females, age 53±17 years) with RBBB tachycardias, who underwent electrophysiological studies. First step includes retrospective analysis of QRS characteristics in 20 patients with ventricular tachycardias (VT), 24 pts with aberrant supraventricular tachycardias (SVT+RBBB) and 14 pts with antidromic SVTs (WPW). ROC- and multifactorial analyses were performed to develop diagnostic ECG algorithms. The prognostic accuracy of the algorithms was subsequently evaluated on a prospective group of patients with RBBB tachycardias (n=53). Results and discussion. ECG criteria of RBBB VTs were: 1) the presence Q-wave in lead II, 2) the duration interval R(peak)-S(end) >100 ms in lead V5. ECG criteria for antidromic SVTs with RBBB were: 1) the duration of the R wave in lead I ≥80 ms, 2) the absence of split (M-sharp) R-waves in lead V2, 3) the absence notch in ascending S wave in lead aVL. The accuracy of the algorhythm for diagnostic of VTs with RBBB was 83% (sensitivity 100%, specificity 73%). The accuracy of the algorhythm for diagnostic of antidromic SVTs with RBBB was 91% (sensitivity 85%, specificity 96%). Conclusion. The proposed algorithms are based on new ECG criteria for the differential diagnosis of wide QRS complexes tachycardias with RBBB pattern, unlike the previous algorithms.

Aim. To compare safety of new class III antiarrhythmic drug Refralon with direct current cardioversion (DCC) in patients with persistent atrial fibrillation (AF). Material and methods. 60 patients with persistent AF were randomized to groups of DCC (n=30) and pharmacologic conversion (PCV; n=30). There were no significant differences in age, sex, AF duration, concomitant cardiovascular diseases, CHA2DS2-VASc score and echocardiographic parameters between the groups compared. Initial assessment excluded contraindications to restore sinus rhythm (SR). In DCC group two attempts using biphasic synchronized shocks of 150 J and 170 J were performed. In PCV group patients received up to three subsequent intravenous injections of Refralon 10 μg/kg (maximal dose 30 μg/kg). Results. There were no mortality, stroke, transient ischemic attack, ventricular arrhythmia, asystole longer than 3,0 sec (primary safety criteria) in both groups. Prolongation of QT interval longer than 500 ms observed in 1 of 30 patients (3,3%) in DCC group and in 7 of 30 patients (23,3%) in PCV group. 2 patients (one patient in each group; 3,3%) developed asymptomatic bradycardia after conversion to SR that resolved spontaneously within 30 minutes. 95% confidence interval (95%CI) for secondary safety criteria is [0,02-0,38] for QT prolongation and [-0,04-0,04] for bradycardia. Conclusion. Safety of PCV is noninferior to DCC in patients with persistent AF in terms of primary safety criteria and bradyarrhythmias. More frequent QT interval prolongation to values >500 ms observed in PCV group points to necessity of precautions with use of the drug.

Aim To identify risk factors for recurrence of atrial fibrillation (AF) following cryoballoon ablation (CBA).Material and methods This prospective study included patients with paroxysmal AF who had undergone CBA (141 patients, median age 60 years, 3% men). The evaluation prior to CBA included clinical instrumental parameters (electrocardiography (ECG), 24-h ECG monitoring, echocardiography, contrast-enhanced cardiac multispiral computed tomography). Also, possible intraoperative indexes that could affect the CBA effectivity, were evaluated. The postoperative follow-up duration was 12 months. Effectivity was assessed during in-person visits at 3, 6, and 12 months, when questioning of patients and 24-h ECG monitoring were performed. CBA was considered ineffective if the patient had recurrences of any atrial tachyarrhythmia longer than 30 sec after the end of the 3-month “blind” period.Results During the 12-month follow-up, recurrences of atrial tachyarrhythmia were observed in 46 (32.6 %) patients. Patients with ineffective CBA more frequently had AF during the first 3 months (71.7 % vs. 11.6 %; рvs. 20.0 %; р=0.008), and stroke/recurrent ischemic attacks (15.2 % vs. 5.2 %; р=0.047). Multifactorial regression analysis showed that the factors of AF recurrence included common PV collector (relative risk (RR) 2.35; 95 % confidence interval (CI) 1.29–4.25; р=0.005), multiple ineffective AADs (RR 1.42; 95 % CI 1.08–1.86; р=0.011), and early AF recurrence (RR 7.57; 95 % CI 3.84–14.90; рConclusion Common PV collector and multiple ineffective AADs are risk factors of ineffective CBA. Early recurrences during the first 3 postoperative months are a significant risk factor of long-term AF recurrences.

Alterations of heart rhythm are a common clinical event. They can be caused by almost any kind of heart disorder. Atrial fibrillation (AF) is the most common type of abnormal heart rhythm. Prevalence of AF in the general population is 1-2%, and given that AF incidence rate continues to increase it can be predicted that the number of patients will be doubled within the next 50 years. This review provides the most recent diagnostic and treatment methods, including both unique domestic antiarrhythmic drugs and non - drug methods for AF treatment which were developed and implemented in clinical practice at NMRC of Cardiology of the Ministry of Health of the Russian Federation.Нарушения ритма сердца - широко распространенное клиническое явление. Их возникновение может быть обусловлено практически любым видом сердечной патологии. Фибрилляция предсердий (ФП) является наиболее распространенной формой нарушений ритма сердца. Распространенность ФП в общей популяции составляет 1-2%, и продолжающийся рост заболеваемости позволяет прогнозировать удвоение количества больных в течение ближайших 50 лет. В данном обзоре представлены новейшие диагностические методики и методы лечения, включающие как уникальные отечественные антиаритмические препараты, так и немедикаментозные методы лечения ФП, разработанные и внедренные в клиническую практику в НМИЦ кардиологии Минздрава России.

Based on the results of an experimental investigation of cold-rolled automobile body sheet steels of various strength classes, we developed a mathematical model to predict the recrystallized ferrite grain size as a function of the ferrite grain size after hot rolling and the strain during cold rolling. The model can reproduce the experimental data at a good accuracy.

Kinetic recrystallization curves are obtained during isothermal annealing of cold-rolled automobile body sheet steels of five grades. The most correct technique of processing EBSD maps is chosen by comparing the degrees of recrystallization estimated by various techniques of processing EBSD maps with the softening determined by hardness measurements.

A model is proposed for predicting the Lankford coefficient of steel sheet produced for the auto industry at PAO Severstal. The set of empirical model parameters is determined using an experimental database on the mean Lankford coefficient (for 138 strips of 13 steels differing greatly in composition) and additional databases on calculated steel microstructure parameters after hot rolling, and after heat treatment of cold-rolled strips. The mean error in calculations of the Lankford coefficient using the model is 7.1%. It is found that the Lankford coefficient is determined not only by the carbon content in the solid solution before cold rolling but also by the amount of carbon deposited at the ferrite grain boundaries in the form of tertiary cementite. The additional free carbon appearing in the solution when the tertiary cementite particles dissolve on heating of the cold-rolled sheet significantly affects the recrystallization and the texture formation.

The softening kinetics associated with recovery and recrystallization is investigated, along with the kinetics of phase transformation (austenitization) on heating cold-rolled autompotive steel sheet. The kinetics of softening in isothermal holding is studied using the Gleeble 3800 system for 12 steels, and the phase transformation in continuous heating at constantrate is studied for 6 steels of different strength class, with different chemical composition. Considerable slowing of the steel’s recovery and recrystallization is observed with increase in the Mn and Ti content in the ferrite solid solution. The grain size of the recrystallized ferrite hardly depends on the annealing temperature. The results may be used in developing a quantitative integral model to describe the complex microstructural evolution of cold-rolled steel sheet on annealing in industrial production.

An integral computer model STAN 2000 designed for of-line simulation and control of hot rolling on mill 2000 of SEVERSTAL was developed. The capabilities of the model include the following features: ‒ calculations of power parameters for all stands of mill 2000 for a given rolling schedule; ‒ strip temperature calculations depending on selected rolling and accelerated cooling regimes; ‒ follow-up of steel microstructure evolution at all stages of strip production and prediction of ultimate mechanical properties (yield stress, ultimate tensile stress, relative elongation and toughness); ‒ optimization of rolling regimes for existing steel grades and developing them for a new one. The STAN 2000 program is written in С++ programming language and can work on all modern Microsoft Windows family operating systems. The program has a well-designed and user-friendly interface facilitating its practical use. The integral model was calibrated using an extensive data base on rolling regimes and forces, measured temperatures and final mechanical properties for a number of steel grades rolled on mill 2000 of SEVERSTAL with chemical compositions covering the following range of alloying elements content (mass.%): С(≤0.65); Mn(≤2.0); Si(≤1.0); Cr(≤0.9); Ni(≤0.6); Cu(≤0.5); Mo(≤0.4); Nb(≤0.05); V(≤0.065); Ti(≤0.06); B(≤0.003). The examples of STAN 2000 program use in practice of industrial hot strip production on mill 2000 of SEVERSTAL are presented and discussed.

An integral computer model/program STAN 2000 for simulation of steels hot rolling on mill 2000 of SEVERSTAL was developed. The capacity of the model includes, for example, the following features:‒ control of power parameters and prediction of hot strip temperature for a given rolling and accelerated cooling regimes;‒ follow-up of the evolution of steel microstructure at all stages of strip production and prediction of ultimate mechanical properties (yield stress, ultimate tensile stress and relative elongation);‒ optimization of rolling regimes for existing steel grades and developing them for a new ones.The STAN 2000 program is written in С++ programming language and can work on all modern Microsoft Windows family operating systems. The program has a well-designed and user-friendly interface facilitating its practical use.The integral model was calibrated using an extensive data base on rolling regimes and forces, measured temperatures and final mechanical properties for a number of steel grades rolled on mill 2000 of SEVERSTAL with chemical compositions covering the following ranges of alloying elements content (mass.%): С(≤0.65); Mn(≤2.0); Si(≤1.0); Cr(≤0.9); Ni(≤0.6); Cu(≤0.5); Mo(≤0.4); Nb(≤0.05); V(≤0.065); Ti(≤0.06); B(≤0.003).Some results of calculations performed with STAN 2000 program for temperatures, rolling forces and mechanical properties are presented and compared with experimental data. Some examples of the program utilization in hot strip production on mill 2000 of SEVERSTAL are presented and discussed.

We present in this article 2 cases of successful pharmacological restoration of sinus rhythm by a new class III antiarrhythmic drug refralon in patients with obesity and persistent atrial fibrillation. In both cases, the effective use of refralon was preceded by repeated ineffective attempts of electrical cardioversion. In the article we discuss the role of obesity as the factor leading to a substantial increase of transthoracic electrical resistance, and thus significantly reducing the probability of sinus rhythm restoration by means of electrical cardioversion. The clinical examples described in this article clearly show that the use of refralon may represent a unique clinical alternative to electrical cardioversion for sinus rhythm restoration in patients with persistent atrial fibrillation, and in some cases where the success of electrical cardioversion is obviously questionable, like in patients with severe obesity, the use of refralon seems preferable.

To evaluate the efficacy and safety of refralon (niferidil), a new class III antiarrhythmic agent whose activity is related to the block of delayed rectifying potassium current and to the prolongation of atrial and ventricular action potential and refractory periods, when it is used as an agent for pharmacological cardioversion for atrial fibrillation (AF) and atrial flutter (AFL).The efficacy of the drug as 3 intravenous boluses of 10 μg/kg was evaluated in 134 patients (90 men; 57.8 ± 11 years) with a mean AF duration of 3 (1.5; 6) months. Its effect was controlled by 24-hour Holter ECG monitoring. The criterion for its antiarrhythmic effect was 24-hour sinus rhythm (SR) recovery.Niferidil restored SR in 47.7% of the patients with AF after administration of bolus 1, in 62% after bolus 2, and in 84.6% after bolus 3. SR was restored in all 100% patients with AFL. With the AF duration of less than 3 months, the efficacy of niferidil was 91.8%. There was nonsustained polymorphic ventricular tachycardia (VT) (torsade de pointes) in 1 (0.7%) patient and nonsustained monomorphic VT was stated in 5 (3.7%) patients. CONCLUSIONPharmacological cardioversion with niferidil for persistent AF and VT may be regarded as a possible alternative to electrical cardioversion.Цель исследования. Оценка эффективности и безопасности рефралона (ниферидила) - нового антиаритмического препарата III класса, действие которого связано с блокадой калиевых токов задержанного выпрямления, удлинением потенциала действия и рефрактерных периодов в предсердиях и желудочках, при его применении в качестве средства для медикаментозной кардиоверсии при фибрилляции предсердий (ФП) и трепетании предсердий (ТП). Материалы и методы. Эффективность препарата в виде 3 болюсов по 10 мкг/кг внутривенно оценена у 134 больных (57,8±11 лет, 90 мужчин) при средней длительности ФП 3 (1,5; 6) мес. Действие препарата контролировалось при 24-часовом холтеровском мониторировании электрокардиограммы. Критерием антиаритмического эффекта было восстановление синусового ритма (СР) в течение 24 ч. Результаты. Ниферидил восстановил СР у 47,7% больных с ФП после введения 1-го болюса, у 62% - после введения 2-го и у 84,6% - после введения 3-го болюса. СР восстановлен у всех 100% больных с ТП. При длительности ФП менее 3 мес эффективность ниферидила составила 91,8%. Неустойчивая полиморфная желудочковая тахикардия (ЖТ) типа torsades de pointes отмечена в 1 (0,7%) случае. Неустойчивая мономорфная желудочковая тахикардия (ЖТ) констатирована у 5 (3,7%) больных. Заключение. Медикаментозная кардиоверсия персистирующей ФП и ТП с использованием ниферидила может рассматриваться как возможная альтернатива электрической кардиоверсии.

OBJECTIVE To assess and compare the safety and efficacy of allapinine and quinidine bisulphate in the treatment of patients with persistent atrial fibrillation after cardioversion. Design--Prospective, randomised, open study. Patients--73 consecutive patients (men only, mean age 44 ± 11 years) with persisnent atrial fibrillation and flutter. Interventions--37 patients were randomised to allapinine (ALP) (1.5 mg/kg/d), 36 to quinidine bisulphate (QUIN) (15 mg/kg/d) with subsequent successful pharmacological or electrical cardioversion. Main outcome measures--Recurrence of atrial fibrillation or side effects. RESULTS In the ALP group 15 of the 37 patients developed atrial fibrillation up to 12 month of follow-up, while in the QUIN group 20 patients developed atrial fibrillation and 5 experienced significant side effects. Relative risk (RR) (ALP vs QUIN) 0.58 (95% CI 0.37-0.91, p < 0.02). The number needed to treat (NNT) was (-3.48) (14.2-1.97 harm). When 5 patients with significant side effects were excluded from the analysis RR was 0.62 (95% CI 0.39-1.0, p = 0.052) and NNT--(-4.1) (122.7-2.1 harm) but power of the study was too low--67%. CONCLUSION Allapinine is as effective as quinidine bisulphate in the long term treatment of patients with persistent atrial fibrillation after successful cardioversion but causes significantly less side effects.

We aimed to compare safety and effectiveness of new class III antiarrhythmic drug Refralon with direct current cardioversion (DCC) in patients with persistent atrial fibrillation (AFib). 60 patients with persistent AFib were randomized to groups of DCC (n=30) and pharmacological conversion (PCV; n=

An integral mathematical physically based model is developed for prediction of the microstructure and mechanical properties of steels processed in accordance with a given hot deformation and accelerated cooling regimes. The model predicts austenite microstructure evolution under hot deformation, as well as its transformation during subsequent cooling with account of formation of ferrite, pearlite, bainite and martensite. Structure-property relationships are developed using an extensive experimental database chemical composition - microstructure - mechanical properties obtained for 10 steel grades. Austenite transformation depending on grain size, cooling rate and preliminary plastic deformation was investigated with the help of Gleeble 3800 system to obtain a set of practically important morphologically different microstructures for each steel grade. A quantitative analysis of the microstructures was performed using optical and scanning electron microscopy (EBSD-method). Investigation of the mechanical properties of steels with wide spectrum of obtained microstructures was carried out on the double-samples processed using Gleeble 3800. The predicted microstructure parameters for investigated steels obtained using the developed model, as well as their mechanical properties, are in good agreement with the experimental data.

A mathematical physically based model of the decomposition of undercooled austenite (γ-phase) with the formation of ferrite (α-phase) and pearlite has been developed. The model differs from the currently existing analogs by a new approach to the inclusion of the effect of complex alloying of steels on the nucleation rate of ferrite grains and on the mobility of the α/γ-phase boundary. In the model, the effect of alloying of steels with substitutional elements on the diffusion coefficient of carbon in the bulk of austenite is taken into account. The results of the modeling of the kinetics of austenite decomposition and the calculation of the final ferrite grain size are in good quantitative agreement with the experimental data obtained for a set of steels with a wide range of chemical compositions.

Mathematical models are proposed for calculating the onset temperature of ferrite transformation and the ferrite grain size as a function of the cooling conditions and the initial austenite grain size. The models are calibrated on the basis of experimental data for steels with ferrite-pearlite microstructure. The models are integrated in HSMM software, with considerable gain in computational power when considering the mechanical properties of steel rolled on the 2000 mill at OAO Severstal’.

An experimental study (physical modeling) of the processes of austenite microstructure evolution occurring under hot rolling was performed for line-pipe steels with different chemical composition. All investigations were conducted with the help of the Gleeble 3800 system. Empirical quantitative models of austenite grain growth, static and dynamic recrystallization, as well as a flow stress model were developed. The effect of complex alloying by such elements as C; Mn; Si; Ni; Mo; Nb; Ti; and V on grain growth and recrystallization is accounted for under the condition that all elements are in a solid solution. The set of the models empirical parameters is determined utilizing corresponding experimental data available from literature. Modeling results for static recrystallization and flow stress in the investigated steels are compared with experimental data.

Results of modification of the HSMM model (Hot Strip Mill Model) for enhancing precision of the mechanical properties prediction for hot-rolled steels after rolling on the mill 2000 of OAO Severstal are presented.

The experimental data on the self-diffusion coefficient of austenite with different chemical compositions obtained by the radioactive isotope method have been analyzed quantitatively. The self-diffusion activation energy in pure γ-iron is shown to be ∼312 kJ/mol. Alloying of austenite with such elements as Mn, Mo, Nb, Ti, and Si (to a lower degree) increases the self-diffusion activation energy, and alloying with C, V, or Cr (for the element content ≥3 at %) decreases it. The empirical formula is derived for calculation of the self-diffusion activation energy in austenite solid solutions with complex composition.

The influence of deformation-induced ferrite transformation on the microstructure of microalloyed pipe steel is investigated by means of a Gleeble 3800 test system. The results show that such dynamic transformation permits considerable reduction in ferrite grain size and improves the mechanical properties of the steel.

The effect of the thermomechanical treatment parameters on the structure and properties of a high-strength nitrogen-bearing austenitic Cr-Ni-Mn steel is studied using a Gleeble 3800 plastometer. An increase in the interdeformation pause time during multipass deformation of the steel is shown to decrease the temperature of formation of carbonitride hardening phases in its structure. A shift in the temperature range of deformation toward low temperatures is found to increase the strength properties of the steel, and its plasticity decreases.

This article reviews experimental and clinical studies of a novel antiarrhythmic agent niferidile. Niferidile, a class III antiarrhythmic agent, blocks potassium outward currents, prolongs repolarization and refractory periods predominantly in atria than in ventricles. Intravenous Niferidile was efficient for interruption of AV-nodal and orthodromic re-entrant tachycardias with rates of 75% to 80%. Niferidile had a conversion rate of up to 87.3% in persistent atrial fibrillation and up to 100% in persistent atrial flutter. Proarrhythmic action of niferidil administration manifested as nonsustained torsade de pointes and monomorphic ventricular tachycardia in 1.2 and 3.7% of cases, respectively. Niferidile can be used for pharmacological cardioversion of persistent atrial fibrillation and flutter as an alternative to electrical cardioversion.