Optical vector network analysis of ultra-narrow transitions in 166^{166}Er3+^{3+}:7^7LiYF4_4

We present optical vector network analysis (OVNA) of an isotopically purified $^{166}$Er$^{3+}$:$^7$LiYF$_4$ crystal. The OVNA method is based on generation and detection of modulated optical sideband by using a radio-frequency vector network analyzer. This technique is widely used in the field of microwave photonics for the characterization of optical responses of optical devices such as filters and high-Q resonators. However, dense solid-state atomic ensembles induce a large phase shift on one of the optical sidebands which results in the appearance of extra features on the measured transmission response. We present a simple theoretical model which accurately describes the observed spectra and helps to reconstruct the absorption profile of a solid-state atomic ensemble as well as corresponding change of the refractive index in the vicinity of atomic resonances.Comment: 4 pages, 5 figure

Phase Mapping for Cardiac Unipolar Electrograms with Neural Network Instead of Phase Transformation

A phase mapping is an approach to processing signals of electrograms that are recorded from the surface of cardiac tissue. The main concept of the phase mapping is an application of the phase transformation with the aim to obtain signals with useful properties. In our study, we propose to use a simple sawtooth signal instead of a phase of a signal for processing of electrogram data and building of the phase maps. We denote transformation that can provide this signal as a phase-like transformation (PLT). PLT defined via a convolutional neural network that is trained on a dataset from computer models of cardiac tissue electrophysiology. The proposed approaches were validated on data from the detailed personalized model of the human torso electrophysiology. This paper includes visualization of the phase map based on PLT and shows the applicability of the proposed approaches in the analysis of the complex non-stationary periodic activity of the excitable cardiac tissue. © 2020 IEEE.The reported study was funded by RFBR, according to the research project No. 18-31-00401. Development of the mathematical models is supported by IIF UrB RAS theme №AAAA-A19-119070190064-4, RF Government Act №211 of March 16, 2013, the Program of the Presidium RAS

Improving the algorithm for selecting welding mode parameters under the impact of boundary conditions of the workpiece

This article discusses the application of a mathematical model of heat transfer during welding to create an algorithm for choosing the welding mode parameters during programming of automatic welding systems. The results of the industrial implementation of a robotic welding system equipped with a developed algorithm for choosing a welding mode are presented. © 2020 Published under licence by IOP Publishing Ltd

Application of double electrode welding as the way to increase welding productivity of fillet welds of bridge structures

One of the ways to solve the task to increase productivity and obtain an enlarged leg in one pass is the use of two-electrode submerged arc welding (welding with a split electrode). When testing this welding method with respect to welding bridge metal structures, it was found that the quality of the welded joints and the productivity of the process substantially depend on the positioning of the electrodes relative to the groove. However, for the effective implementation of this method, a comprehensive study of its functionality for welding of bridge metal structures is necessary to conduct. An effective tool in solving such problems is physical and mathematical modeling, which allows without running a large number of experiments to study the features of the formation of fillet welds. To carry out this analysis, we used the previously developed physical and mathematical model of weld formation in single-arc submerged arc welding, added a description of the spatial position of the split electrode relative to the joint and defined the distribution of the heat flux and pressure of the double arc. It was found that the location of the electrodes with the lagging arc on the web provides better weld formation. © Published under licence by IOP Publishing Ltd

STOCHASTIC DYNAMICS OF Rab5/Rab7 PROTEINS IN ENDOSOMES INFLUENCED BY MULTIPLICATIVE NOISE

The influence of multiplicative noise on the dynamics of active Rab5 and Rab7 proteins on the surface of endosomes has been studied. The distribution of pH (Rab5, Rab7) values in endosomes and the proportion of endosomes with pH lesser than the critical value have been obtained

ELECTROMECHANICAL MODEL OF THE LEFT VENTRICLE OF THE HUMAN HEART

We developed a mathematical model of the left ventricle electromechanical function of the human heart. We examine one full cycle of the left ventricle contraction with various parameters of the speed of the wave of excitation and spin of the myocardial fibers in the ventricle wall

Metabolic disorders associated with early menopause in the female population of Eastern Siberia: results of a cross-sectional study

Background. Menopause is an independent predictor of the development of metabolic syndrome, in the pathogenesis of which insulin resistance plays a leading role. Early menopause occurs in 5 % of women and, according to several studies, is associated with an increased risk of cardiovascular disease (CVD), which is one of the leading causes of death. The features of the course of metabolic syndrome in women with early menopause have not been sufficiently studied.The aim: to establish the prevalence of early menopause and its metabolic complications in the female population of Eastern Siberia.Materials and methods. The study population included 2695  women aged 18 to 80 years, who underwent the annual medical examination. The period of the study was March 2016 – December 2019. Among the surveyed women of 41–45  years old, a group of patients with early menopause (n = 18) and controls (n = 25) were identified. The diagnosis was made according to the STRAW criteria. The study used clinical, instrumental and laboratory research methods, including the assessment of hormonal and biochemical parameters, as well as the assessment of questionnaire data and statistical analysis.Results. The examined women with early menopause have an increase in BMI, waist volume, arterial hypertension, and an increase in the level of triglycerides and gonadotropic hormones. These changes potentially underlie the relationship between menopause and cardio-metabolic disease.Conclusion. These findings indicate the need to monitor the hormonal and metabolic parameters in this category of women to ensure timely prevention and correction of long-term complications associated with early menopause

Hafnia-yttria-alumina-silica based optical fibers with diminished mid-IR (> 2 mu m) loss

Fabrication details and basic characteristics of a set of novel multimode hafniayttria- alumina-silicate (HYAS) core-glass based fibers, one of which is co-doped with bismuth (Bi), for the mid-IR (> 2 mu m) spectral range are reported. It is demonstrated that fibers of this type possess low fundamental loss in the spectral range beyond 2 mu m, lowered by fewer times as compared to conventional silica-based ones, even at moderate (units of mol.%) co-doping with hafnium. This makes them attractive for versatile mid-IR applications. Furthermore, HYAS core-glass fiber co-doped with Bi is revealed to have all the signs of `active' (fluorescing) Bi-related centers, thus being suitable for lasing/amplifying in the nearIR spectral range. (C) 2017 Optical Society of Americ

АНАЛИЗ ОСЛОЖНЕНИЙ ВНУТРИТКАНЕВОЙ ЛУЧЕВОЙ ТЕРАПИИ С ИСПОЛЬЗОВАНИЕМ ПОСТОЯННЫХ ИСТОЧНИКОВ У БОЛЬНЫХ РАКОМ ПРЕДСТАТЕЛЬНОЙ ЖЕЛЕЗЫ

Brachytherapy is a standard treatment for localized advanced prostate cancer (PC). Complications due to interstitial radiotherapy using permanent sources were analyzed in 149 patients. The incidence of early grade 3 radiation urethritis was 7.4 % and that of rectitis was 3.4%. Late radiation urethritis and rectitis were recorded in 3.4 and 0.7 %, respectively. Sexual function 12 months later was preserved in 86.6 % of the patients. Studies established no statistically significant factors that influenced the frequency of complications. The patients with a prostate volume of > 50 cm3, a preoperative international prostate symptom score of > 15, a urine flow rate of < 15 ml/min, and urethral andrectal radiation doses of > 210 and > 180 Gy, respectively, tended to have more common radiation reactions. Thus, brachytherapy is a reasonably safe treatment for PC.Брахитерапия — стандартный метод лечения локализованного рака предстательной железы (РПЖ). Нами проведен анализ осложнений внутритканевой лучевой терапии с использованием постоянных источников у 149 пациентов. Частота ранних лучевых уретритов III степени составила 7,4 %, ректитов — 3,4 %. Поздние лучевые уретриты зафиксированы в 3,4 % случаев, ректиты — в 0,7 %. Половая функция через 12 мес сохранена у 86,6 % пациентов. По результатам исследования статистически значимых факторов, влияющих на частоту осложнений, не установлено. Выявлена тенденция к более частым лучевым реакциям у пациентов с объемом предстательной железы > 50 см3, предоперационной оценкой IPSS (International prostate symptoms score) > 15, скоростью мочеиспускания < 15 мл/мин, дозой облучения уретры > 210 Гр и прямой кишки > 180 Гр. Таким образом, брахитерапия представляется достаточно безопасным методом лечения РПЖ

The experience in the development and validation of method for testosterone measurement in blood serum of premenopausal women using HPLC-MS/MS

Testosterone assessment is essential for detecting biochemical hyperandrogenism, one of the important diagnostic criteria of polycystic ovary syndrome (PCOS) both in clinical practice and in epidemiological studies. Currently, tandem liquid chromatography-mass spectrometry (LC-MS/MS) is the most preferred technique to measure testosterone level in women. Its validation is important to reproducibility of androgen tests results for clinical practice and for epidemiological studies of the prevalence PCOS.The aim of the study. To develop and validate a method for determining total testosterone in blood serum using highly efficient LC-MS/MS to assess androgenemia in the epidemiological study of the prevalence of PCOS and its phenotypes in Eastern Siberia (ESPEP STUDY).Materials and methods. We determined a total testosterone level in serum blood using triple quadrupole mass spectrometer LCMS-8060 (Shimadzu, Japan). The protocol of technique was developed using self-prepared purified human testosteronefree serum with a known concentration of analyzed compound. We used the serum samples of women of reproductive age to test the developed method.Results. Optimum chromatographic conditions were obtained with a Kromasil 100-2.5-C18 column (2.1 mm × 100 mm; AkzoNobel, Netherlands), and an isocratic elution mode using a mobile phase consisting of acetonitrile and 0.1 % aqueous solution of formic acid. The total flow rate was 0.35 ml/min. The lower limit of quantification was 5 ng/dl with an average accuracy of 100.2 %. During the approbation of the method in a test population sample of 1138 premenopausal women (mean age – 34.3 ± 6.3 years), the median testosterone concentration was 26.9 ng/dl.Conclusion. It was found that the proposed method for determining testosterone in blood serum has acceptable linearity and reproducibility and meets the requirements for bioanalytical methods under the regulatory documentation. This method can be used for clinical practice and epidemiological study of the prevalence of PCOS