Применение импульсного тока для растворения жаропрочного сплава ЖС32-ВИ

Objectives. To identify the regularities of electrochemical processing of the heat-resistant GS32-VI alloy in a sulfuric acid electrolyte with a concentration of 100 g/dm3 under the action of a pulsed current in a pulsed mode.Methods. Using the electrochemical technological complex EHK-1012 (developed by IP Tetran) and a non-compensatory method of measuring potential, polarization and depolarization curves with a change in pulse duration and a pause between them were recorded. The current pulses had an amplitude ranging from 0 to 3.5 A (when recording the polarization and depolarization curves), pulse durations ranging from 200 to 1200 ms, and a pause (delay) between pulses ranging from 50 to 500 ms. There were no reverse current pulses.Results. The parameters of the current program that provide the maximum values of the alloy dissolution rate and current output were determined: with a current pulse amplitude of 2 A, a current pulse duration of 500 ms, and a pause duration between pulses of 250 ms, the maximum dissolution rate of the alloy is 0.048 g/h·cm2, while the current output for nickel is 61.6% with an anode area of 10 cm2. The basic technological scheme for processing the heat-resistant GS32-VI alloy, which includes anodic alloy dissolution in a pulsed mode, is proposed.Conclusions. Electrochemical dissolution of GS32-VI alloy under pulsed current action results in an optimal dissolution rate ratio of the alloy components, ensuring the production of a cathode precipitate with a total nickel and cobalt content of 97.5%.Цели. Выявить закономерности электрохимической переработки жаропрочного сплава ЖС32-ВИ, проводимой в импульсном режиме в сернокислом электролите с концентрацией 100 г/дм3 под действием импульсного тока.Методы. Снятие поляризационных и деполяризационных кривых с изменением длительности импульса и паузы между ними проводили с помощью электрохимического технологического комплекса ЭХК-1012 (разработан ООО ИП «Тетран»), использующего некомпенсационный способ измерения потенциала. Амплитуда импульсов тока находилась в диапазоне значений от 0 до 3.5 А (при снятии поляризационных и деполяризационных кривых), длительности импульсов изменялись от 200 до 1200 мс, пауза (задержка) между импульсами – от 50 до 500 мс, импульсы реверсивного тока отсутствовали.Результаты. Определены параметры токовой программы, обеспечивающие максимальные значения скорости растворения сплава и выхода по току. При амплитуде импульса тока 2 А, длительности импульса тока 500 мс и продолжительности паузы между импульсами 250 мс максимальная скорость растворения сплава 0.048 г/ч·см2, при этом выход по току для никеля равен 61.6% при площади анода 10 см2. Предложена принципиальная технологическая схема переработки жаропрочного сплава ЖС32-ВИ, включающая анодное растворение сплава в импульсном режиме.Выводы. Электрохимическое растворение сплава ЖС32-ВИ под действием импульсного тока способствует оптимальному соотношению скоростей растворения составляющих сплава, что обеспечивает получение катодного осадка с суммарным содержанием никеля и кобальта 97.5%

Shortterm and long-term results of bimammary bypass surgery in patients with multivessel coronary disease and type 2 diabetes mellitus after propensity score matching

Background. Among patients who have undergone coronary artery bypass surgery (CABG), the proportion of people with diabetes mellitus (DM) is about 40 %. To date, the problem of choosing the optimal method of surgical myocardial revascularization, which can provide the best result in this cohort, remains completely unresolved. The aim of the study. To assess the in-hospital and long-term results of bimammary and traditional bypass surgery in patients with type 2 diabetes mellitus. Methods. From September 2018 to December 2021, 176 CABG surgeries were performed in patients with coronary heart disease (CHD) and type 2 diabetes at the Federal Center for Cardiovascular Surgery (Krasnoyarsk). Group 1 (n = 45) included patients who underwent myocardial revascularization using two mammary arteries; group 2 (n = 131) included patients who underwent myocardial revascularization using traditional technique. After propensity score matching, 45 patients were selected into each group, comparable by basic preoperative characteristics. Results. In group  1, cardiopulmonary bypass surgeries were performed in 23 (51.1 %) patients (group 1CPB), off-pump surgeries – in 22 (58.2 %) (group 1OP); in group  2, all patients underwent cardiopulmonary bypass surgeries. Hospital mortality was recorded in group 2 in 1 (2.2 %) case. Deep sternal infection developed in 1 (4.5 %) patient in group 1OP. Long-term survival in group 2 was 85.3 %, in group 1CPB – 83.3 % (p = 0.689), in group 1OP – 84.2 % (p = 0.739). 84.2 % of patients in group 2 and 100 % in groups 1CPB and 1OP had no cardiovascular events (p = 0.144 and p = 0.145, respectively). Conclusion. Bimammary bypass surgery in patients with type 2 diabetes is a safe and effective method of surgical treatment of coronary artery disease in both shortand long-term period and may be the operation of choice in patients with multivessel disease. There were no differences in patient survival up to 45 months; bimammary revascularization was associated with 100 % absence of cardiac mortality

Cardiac tumors: analysis of surgical treatment

Aim. To analyze the preoperative status, intraoperative tumor characteristics and further clinical manifestations in patients after surgery for a cardiac tumor.Material and methods. The study included 54 patients who were operated on for a heart tumor from 2014 to 2020. We assessed clinical performance, diagnostic investigations before and after (during hospitalization) surgery, tumor size and histological characteristics.Results. Among patients operated on for cardiac tumors, women predominated (74%). Among comorbidities, hypertension (79,3%), chronic kidney disease (48,3%), and obesity (25,9%) were most common. There were following clinical manifestations before surgery: shortness of breath — 47 (81%) patients, palpitations and heart rhythm disturbance — 26 (44,8%), chest pain — 25 (43,1%), chest discomfort — 28 (49,1%), edema — 6 patients (10,3%). The predominant tumor localization was the left atrial fossa ovalis area (50%). According to histological analysis, myxoma prevailed — 38 cases (86,4%). After surgery, atrial fibrillation prevalence decreased from 8 patients before surgery to 6 after surgery (p=0,034), while left atrial size decreased by 0,6 mm (95% confidence interval, 4,39-6,2 mm) (p<0,001).Conclusion. According to presented analysis over a 6-year period, cardiac neoplasms are more common in women (74,1%), while the mean age of patients is 59,7 years. Among comorbidities, hypertension prevails — 79,3%. Histological examination revealed a predominance of myxoma (86,4%). Predominant tumor location was the left atrial fossa ovalis area (50%). Surgical treatment of neoplasms was effective. So, prevalence of atrial fibrillation decreased by 25%, while left atrial size decreased by 0,6 mm. Postoperative complications and in-hospital deaths were not registered

МУЛЬТИСПИРАЛЬНАЯ КОМПЬЮТЕРНАЯ ТОМОГРАФИЯ В ДИАГНОСТИКЕ ПАТОЛОГИИ ДУГИ АОРТЫ И АНОМАЛИЙ БРАХИОЦЕФАЛЬНЫХ АРТЕРИЙ У ДЕТЕЙ ПЕРВОГО ГОДА ЖИЗНИ

Aortic malformations often cause critical states in the neonatal period. MSCT method allows you to get a detailed understanding of the anatomy of vice and identify concomitant bronchopulmonary disease. This paper presents a comparative analysis of 27 patients of the first year of life with the pathology of the aortic arch, which were performed echocardiography and MSCT. After analysis of both research methods in 4 patients revealed a discrepancy echocardiography and MSCT data which led to a change in surgical approach. Just according to SITC 2 patients revealed tracheal stenosis, in one case, isolated, in another due to compression of the vascular ring. MSCT is a highly informative method for diagnosing pathology of the aortic arch and associated bronchopulmonary disease in children in the first year of life.Пороки развития аорты зачастую являются причиной критических состояний в неонатальном периоде. Метод МСКТ позволяет получить детальное представление об анатомии порока и выявить сопутствующую бронхолегочную патологию. В работе представлен сравнительный анализ данных 27 пациентов первого года жизни с патологией дуги аорты, которым была выполнена ЭхоКГ и МСКТ. После анализа обоих методов исследования у 4 пациентов выявлено несоответствие данных ЭхоКГ и МСКТ, что привело к изменению хирургической тактики. Также по данным МСТК, у 2 пациентов выявлен стеноз трахеи, в одном случае - изолированный, в другом - за счет сдавления сосудистым кольцом. МСКТ является высокоинформативным методом диагностики патологии дуги аорты и сопутствующей бронхолегочной патологии у детей первого года жизни

Modern concepts of the nation-state through the prism of archetypal methodology

The paper dwells on the nation-state’s future in the information age. The futuristic tour of the nation-state’s future leaves a wide field for reflection and research. It is time to create a qualitatively new postmodern concept of the nation as opposed to the traditional industrial-modern one, which will help the modern man not only to moderately distance himself from the globalization foundations of world life but also to create a kind of axio-resistant for the nation-state. The object of research is the entire sphere of national consciousness through the prism of the research of modern Western theoreticians of the nation in spectral analysis. The research subject is the sociological concept of the nation (D. Schnapper) and the political and legal concept of triad nationalism (R. Brubaker). The main idea is to find out the specifics of the theoretical load of the supramodern Western concepts of nation and nationalism, to analyze and compare the concepts of modern theorists of the nation with modern ones, to create a new strategic theory of the development of the nation-state in the information age, to prove the impossibility of the nation-state in changing conditions of the globalized 21st century. The author determines the cognitive value and intellectual load of the theoretical decline and praxeological aspects of modern scientific versions of the nation and nationalism and the heuristic potential that can give impetus to constructing a new theory of strategic development of the nation-state in the 21st century. The methodological orientations of the problem of the position of the national state in the era of global society are clarified in comparison with theoreticians of the concepts of global world life – M. McLuhan, N. Postman, M. Castells, and, based on this, the aspects of changing the functional load of the concept of the national state at the current stage are determined. Expressed mobility of nationology is determined

Adaptor protein Ruk/CIN85 modulates resistance to doxorubicin of murine 4T1 breast cancer cells

The acquisition of chemoresistance in the course of tumor progression includes activation of membrane ABC transporters, detoxification enzymes, cell cycle deceleration and activation of specific signaling pathways such as Akt/mTOR, MAPK, NF-κB. Adaptor proteins play an essential role in the assembly of supramolecular signaling complexes, maintaining and directing the intracellular signaling. One of such proteins, called Ruk/CIN85, is strongly associated with malignant transformation and metastasis. In present study we investigated the Ruk/CIN85 effect of up/down-regulation on the transforming potential and doxorubicin resistance of highly aggressive mouse breast adenocarcinoma 4T1 cells. It was demonstrated that 4T1 cells overexpressing Ruk/CIN85 possessed increased resistance to doxorubicin (in the range of concentrations 0.1–10.0 µM) while knockdown cells were the most sensitive. Also, high levels of Ruk/CIN85 in 4T1 cells positively correlated with their ability to form colonies in semi-solid agar. Ruk/CIN85-overexpressing cells formed four times more colonies in comparison with Ruk/CIN85 nockdown cells, the growth of which revealed higher resistance to doxorubicin action

Electrochemical dissolution of nickel-rheniumcontaining alloys

This work is devoted to the study of electrochemical dissolution of nickel-rhenium (10% wt.) alloy and nickel-rhenium (20% wt.) alloy. The study was carried out under pulsed current in acidic electrolytes (sulfuric, nitric and hydrochloric acids). It was established that the highest dissolution rate of alloys was achieved at the current pulse amplitude of 1.0-1.5 A, current pulse duration of 500 ms, pause between pulses 50 ms. It is difficult to know exactly which areas meet the electrochemical reaction, but at the expense of depolarization the polarization curve is divided into several sections, each of which correspond to electrochemical reactions. It was shown that both the galvanostatic and potentiostatic modes occur in the selective dissolution of nickel and rhenium. Moreover, the rate of dissolution of nickel and rhenium depends on the acidic electrolyte (sulfuric acid, nitric acid, hydrochloric acid), the ratio of the concentrations of components in the solution, and the content of nickel and rhenium on the surface of the alloy in the nickel-rhenium (10% wt.) and nickel-rhenium (20% wt.) alloys. It was revealed that the highest dissolution rate for the nickel-rhenium (10% wt.) alloy (10.76 g/A·h) is achieved by dissolving in nitric acid, which is less than the dissolution rate of the nickelrhenium (20% wt.) alloy (12.08 g/A·h) in nitric acid. In contrast, in sulfuric and hydrochloric acids the dissolution rate of nickel-rhenium (20% wt.) alloy is much higher compared to the nickel-rhenium (10% wt.) alloy