Adsorptive Voltammetry of 4-chlordehydromethyltestosterone

The article presents the results of the study of the electrochemical behavior of the anabolic steroid 4-chlordehydromethyltestosterone. The studies detected operating conditions for the voltammetric determination of anabolic glassy carbon electrode. The influence of such factors as pH, supporting electrolyte, the electrolysis and adsorption component on the analytical signal of the analyte was studied. The algorithm of sample preparation is presented and conditions for the quantitative determination of the active ingredient of the drug “Turinabol” by voltammetry is proposed. The evaluation of the proposed method accuracy was conducted

Asymptomatic Lone Atrial Fibrillation in Pregnant Women

We examined 43 pregnant women with paroxysms of asymptomatic lone atrial fibrillation. It was revealed that the increasing of the gestational age leads to increase of number of single, paired and group supraventricular extrasystoles; single and paired ventricular extrasystoles; number and duration of paroxysms of atrial fibrillation. However, the number of extrasystoles and paroxysms of arrhythmia decreased to baseline values after delivery. Thus, it was proved that pregnancy contributes to the increase of paroxysms of lone atrial fibrillation due to the increased influence of modulating components on the triggering extrasystoles. The importance of the method of 24-hour ECG monitoring in the detection of arrhythmia in pregnant women is emphasized. Keywords: lone atrial fibrillation, extrasystole, pregnancy

Nephelometric Method for Determination of Growth Parameters of Chlorella Culture

Nephelometric method for the determination of growth parameters of chlorella culture using a photoelectric colorimeter was described. Use of photoelectric colorimeter for cell counting in suspension requires periodic calibration of meter readings using chlorella standard culture (with a certain cell concentration). Chlorella vulgaris IPPAS С-66, IPPAS С-111 and IPPAS С-2019 strains served as object of research. Density of initial in vitro suspensions (after inoculation) was 0.9 mln cells/ml. Cultivation was carried out during 12 days on a Hoagland medium with a pH of 7 (temperature of 35∘C, illumination of 10 klx). Sample selection for analysis and measurement was carried out daily, three times per day. Based on the obtained data, readings of photoelectric colorimeter KFK-3.01 were calibrated via direct count of chlorella cells quantity in Goryaev’s chamber. Use of calibration curve made it possible to reduce significantly time and error in determination of cell number in suspension cultures. The proposed technique allows counting chlorella cells in the growth and development dynamics with sufficient accuracy, high sensitivity, reproducibility and speed. It can be used for comparative determination of the growth parameters of strains in vitro, standardization of suspension cultures, semi-quantitative determination of chlorella biomass in order to predict the yield of desired product

Neurotrophins in the pathogenesis of pulmonary hypertension and right ventricular dysfunction

Pulmonary hypertension (PH) is a pathophysiological and hemodynamic condition that complicates the course of various diseases and negatively affects morbidity and mortality. The search for the new pathophysiological mechanisms for PH development and progression, the markers for predicting the PH course, and the possible targets for therapy remains relevant. This review is devoted to the role of neurotrophin (NT) system in PH pathogenesis, the possible use of NT and their receptors as a laboratory marker of its severity, and also as a potential target for influencing the pulmonary artery remodeling in PH. In addition, the participation of NTs in neoangiogenesis and restoration of nervous and muscle tissues was described

The Impact of Generator Market Power on the Electricity Hedge Market

The incentive of an electricity generating firm with market power to influence the market price depends strongly on the volume the firm has pre-sold in the forward, or hedge, markets. However, the choice of hedge level may be a strategic decision in itself. In the normal case where participants in the hedge market cannot observe the hedge position of dominant generators, we show that the optimal choice of hedging for a dominant generator facing a linear demand curve is an all-or-nothing decision and there is no equilibrium level of hedging in pure strategies. This outcome may explain an observed lack of hedge market liquidity in wholesale electricity markets where individual generators have substantial market power. We perform the analysis for the monopoly and oligopoly cases and extend it for realistic cost functions and various degrees of competitiveness in the market. These results contribute to the extensive body of research on the price formation and strategic behavior in electricity forward and spot markets, as well as providing implications for transparency initiatives in market design

Influence of Infrastructure on Population Distribution and Socio-Economic Development of Russian Regions

Высокий уровень дивергенции в демографическом и социально-экономическом развитии является значимым барьером обеспечения устойчивого роста российской экономики. Данная статья посвящена анализу влияния уровня развития инфраструктуры на особенности размещения населения и регионального развития России. Основной исследовательской задачей являлось изучение теоретических и практических вопросов, связанных с выявлением особенностей развития инфраструктуры как фактора расселения и формирования численности населения регионов страны с учетом их миграционной привлекательности. Базовым методом исследования является поиск корреляции между уровнем инфраструктурного развития региона и особенностями размещения населения, характеризующимися его плотностью и миграционным приростом. Корреляция указанных показателей размещения населения рассчитывалась с индексами развития транспортной, энергетической, социальной, коммунальной и телекоммуникационной инфраструктуры. Для этих же индексов развития инфраструктуры была рассчитана корреляция с валовым региональным продуктом. В результате корреляционный анализ показал, что существует слабая прямая зависимость между плотностью населения региона, величиной его миграционного прироста и всеми индексами развития инфраструктуры, кроме социального. Наиболее сильная прямая зависимость наблюдается между плотностью населения регионов и индексом развития транспортной инфраструктуры. Хорошая транспортная доступность облегчает доступ населения к другим видам инфраструктуры, повышая уровень связанности территорий и их демографический потенциал. Значимость развития инфраструктуры проявляется в экономических показателях развития регионов не менее ярко, чем в социальных. Это показывает корреляция между валовым региональным продуктом и уровнем развития транспортной, телекоммуникационной и энергетической инфраструктуры. Таким образом, статистический анализ подтвердил наличие взаимосвязи между показателями инфраструктурного развития и расселением населения, хотя и не так явно, что доказывает наличие комплекса факторов, среди которых инфраструктурный не является первичным. Тем не менее, именно снятие инфраструктурных ограничений и повышение качества и доступности основных видов инфраструктуры будет способствовать преодолению как демографического, так и экономического сжатия пространства России.High divergence of demographic and socio-economic development significantly hinders the sustainable growth of the Russian economy. This article analyses the influence of infrastructure on population distribution and development of Russian regions. The study focuses on theoretical and practical issues related to identifying the features of infrastructure development as a factor of settlement and formation of population, considering the migration attractiveness of Russian regions. The research aimed to reveal a correlation between the regional infrastructure development and population distribution characterised by its density and net migration. To this end, we calculated the correlation between these indicators of population distribution and development indices of transport, energy, social, communal and telecommunications infrastructure. Additionally, the correlation between gross regional product and the same infrastructure development indices was estimated. The correlation analysis revealed the presence of a weak positive relationship between the regional population density, net migration, and all infrastructure development indices, except for social one. The strongest positive relationship is observed between the regional population density and the transport infrastructure development index. Good transport accessibility gives people easier access to other types of infrastructure and consequently increases the spatial connectivity and demographic potential of certain areas. Infrastructure development greatly influences not only social indicators of regional development but also economic ones, as shown by the correlation between gross regional product and development indices of transport, telecommunications and energy infrastructure. Thus, according to the conducted statistical analysis, the existing but weak relationship between infrastructure development indices and population distribution confirms the presence of a set of factors, where infrastructure is not the main one. Nevertheless, the removal of infrastructure constraints and an increase in the infrastructure quality and availability will help overcome both the demographic and economic contraction of Russia

ЭЛЕКТРОХИМИЧЕСКИЕ СЕНСОРЫ, МОДИФИЦИРОВАННЫЕ ЗОЛОТОМ И СОЛЯМИ АРЕНДИАЗОНИЯ ДЛЯ ОПРЕДЕЛЕНИЯ МЕДИ И РТУТИ В ВОЛОСАХ ЧЕЛОВЕКА

Current article presents the results of using a solid carbon-containing electrochemical sensor modified with arenediazonium salts (ME-ADT-COOH) for the joint determination of copper and mercury in human hair. The sensitivity of the determination of copper and mercury ions using a graphite electrode modified with gold and arenediazonium salts with a substituent carboxy group is higher compared to the other carbon-containing modified electrodes. The influence of the concentration of arenediazonium tosylates with various substituents on the obtained analytical signal was studied. The conditions for the manufacturing the new carbon-containing modified electrochemical sensor have been developed. The effective surface area of the modified electrode was calculated, which was estimated using a cyclic voltammogram against the background of 0.1 M KCl with the addition of potassium hexacyanoferrate (С=5*10-4mol/l) salts and calculated using the Randles-Ševčík equation for the reversible electrode process. A linear range of determined concentrations in the voltametric determination of microelements on the arendiazonium-modified gold-graphite electrode was established - from 0.1 to 12 µg/g. The error of the determination did not exceed 25 %. The correctness of the results of the determination of copper and mercury in real objects by the “introduced-found” method, which correlates well with the known values, has been verified.Keywords: voltammetry, modifier, arenediazonium tosylates, gold-graphite electrode, copper, mercury, hairDOI: http://dx.doi.org/10.15826/analitika.2022.26.2.004G.B. Slepchenko, M.S. Ostapenko, Yu.A. Akeneev, E.S. MoiseevaNational Research Tomsk Polytechnic University,Lenina Avenue, 30, Tomsk, 634050, Russian FederationПредставлены результаты использования твердого углеродсодержащего электрохимического сенсора, модифицированного солями арендиазония (МЭ-ADT-СООН), для совместного определения меди и ртути в волосах человека. Чувствительность определения ионов меди и ртути с использованием графитового электрода, модифицированного золотом и арендиазониевыми солями с заместителем карбокси-группой, выше по сравнению с другими углеродсодержащими модифицированными электродами. Изучено влияние концентрации тозилатов арендиазония с различными заместителями на получаемый аналитический сигнал. Разработаны условия изготовления нового углеродсодержащего модифицированного электрохимического сенсора. Произведен расчет эффективной площади поверхности модифицированного электрода, которая оценивалась с помощью циклической вольтамперограммы на фоне 0.1 M KCl с добавкой солей гексацианоферрата калия (С = 5·10-4 моль/л) и рассчитывалась с использованием уравнения Рэндлса-Шевчика для обратимого электродного процесса. Установлен линейный диапазон определяемых концентраций при вольтамперометрическом определении микроэлементов на модифицированном арендиазонием золото-графитовом электроде – от 0.1 до  12 мкг/г. Погрешность их определения не превышала 25 %. Проверена корректность результатов определения меди и ртути в реальных объектах методом «введено-найдено», хорошо коррелирующего с известными значениями.Ключевые слова: вольтамперометрия, модификатор, арендиазоний тозилат, органо-модифицированный электрод, медь, ртуть, волосыDOI: http://dx.doi.org/10.15826/analitika.2022.26.2.00

Dynamics of endothelial function indexes in patients with post-Covid syndrome using a combination drug of ethylmethylhydroxyperidine succinate/vitamin B6

Aim: to evaluate endothelial function in patients after COVID-19 before and after treatment with combination drug of ethylmethylhydroxyperidine succinate (EMHPS)/vitamin B

THE SIGNIFICANCE OF OSTEOPONTINE AND MATRIX METALLOPROTEASE-9 IN THORACAL AORTA ANEURYSM DEVELOPMENT

Aim. To evaluate the significance of osteopontine and MMP-9 in the development of thoracal aorta aneurysm in patients with tricuspid (TAV) and bicuspid (BAV) aorta valve. Material and methods. Totally 94 patients included with the dilation of thoracal aorta for more than 40 mm, and 50 patients without aorta pathology, that were the comparison group. All patients underwent echocardiographic study by Vivid 7 (GE, USA) device by standard protocol. The osteopontine concentration and MMP-9 were measured in blood serum with manual plate immune-enzyme assay. Results. The concentration of MMP-9 in blood serum of the patients with aorta pathology and TAV did not differ significantly with the value in comparison group. Otherwise, in IHD the concentration of MMP-9 was significantly higher than in patients without aorta pathology (164,9±76,6 ng/ml and 106,8±82,7 ng/ml, respectively, p<0,01) and closely correlated with the Valsalva sinuses diameters (r=0,302, р=0,007). Comparative analysis of the osteopontine serum concentration did not show differences in the subgroups studied.Conclusion. The positive correlation revealed of the aorta diameter and concentration of MMP-9 in blood serum of the patients with BAV confirms not only the differences in the pathogenesis of thoracal aorta aneurysm in TAV and BAV, but makes it possible to think on the usage of MMP-9 as biomarker of thoracal aorta dilatation

Effectiveness of immunosuppressive therapy for lymphocytic myocarditis according: data from actual clinical practice

Aim. To compare the effectiveness of standard heart failure therapy with and without combined immunosuppressive therapy in patients with documented lymphocytic myocarditis (LM) based on data from actual clinical practice.Material and methods. This observational study included 70 patients with documented LM, 40% (n=28) of whom received immunosuppressive therapy. All patients underwent standard echocardiographic and laboratory investigations, endomyocardial biopsy with histological, immunohistochemical and molecular genetic analysis. Contrast-enhanced cardiac magnetic resonance imaging was performed in 74% of patients. All patients received standard therapy for heart failure at baseline.Results. The groups did not differ in demographic and echocardiographic characteristics. The appointment of immunosuppressive therapy was accompanied by an increase in ejection fraction by 12,2% compared to 6,4% (p=0,02). There were no significant differences in combined endpoints (survival and the need for heart transplantation) depending on therapy regimen (log-rank p=0,97).Conclusion. The prognosis of patients with chronic LM depends on the process activity, the severity of impaired hemodynamics and ventricular arrhythmias, as well as on the presence of persistent viral infection. Compliance with patient selection algorithm before prescribing immunosuppressive therapy is associated with the improvement in myocardial global contractility