Machine learning in predicting immediate and long-term outcomes of myocardial revascularization: a systematic review

Machine learning (ML) is among the main tools of artificial intelligence and are increasingly used in population and clinical cardiology to stratify cardiovascular risk. The systematic review presents an analysis of literature on using various ML methods (artificial neural networks, random forest, stochastic gradient boosting, support vector machines, etc.) to develop predictive models determining the immediate and long-term risk of adverse events after coronary artery bypass grafting and percutaneous coronary intervention. Most of the research on this issue is focused on creation of novel forecast models with a higher predictive value. It is emphasized that the improvement of modeling technologies and the development of clinical decision support systems is one of the most promising areas of digitalizing healthcare that are in demand in everyday professional activities

The Methodology of a Locomotive Simulation Model Development within the Model-Oriented Approach

The use of mathematical modelling at the early stages of product design makes it possible to substantiate fundamental technical solutions, taking into account all possible (large number) requirements for the product by consumers and operation. At this (early) stage, it is important to use well-tested and convenient tools for designers to create virtual stands and digital twins (DC), confirming compliance, as well as forming the structure of systems and products as a whole. The article discusses a comprehensive methodology for the process of constructing a numerical model of a locomotive for analysing dynamics under various operating conditions. It is based on the top-level structural model (LBM), which is presented in the form of a block diagram and is used at all stages of product design. The required detailing of such a model depends on the actual tasks. The detailed models of the systems that have been developed within the framework of the work are presented. © 2021 Institute of Physics Publishing. All rights reserved

Algorithm for selecting predictors and prognosis of atrial fibrillation in patients with coronary artery disease after coronary artery bypass grafting

Aim. To develop an algorithm for selecting predictors and prognosis of atrial fibrillation (AF) in patients with coronary artery disease (CAD) after coronary artery bypass grafting (CABG).Material and methods. This retrospective study included 886 case histories of patients with CAD aged 35 to 81 years (median age, 63 years; 95% confidence interval [63; 64]), who underwent isolated CABG under cardiopulmonary bypass. Eighty-five patients with prior AF were excluded from the study. Two groups of persons were identified, the first of which consisted of 153 (19,1%) patients with newly recorded AF episodes, the second — 648 (80,9%) patients without cardiac arrhythmias. Preoperative clinical and functional status was assessed using 100 factors. Chi-squared, Fisher, and Mann-Whitney tests, as well as univariate logistic regression (LR) were used for data processing and analysis. Multivariate LR and artificial neural networks (ANN) were used to develop predictive models. The boundaries of significant ranges of potential predictors were determined by stepwise assessment of the odds ratio and p-value. The model accuracy was assessed using 4 metrics: area under the ROC-curve (AUC), sensitivity, specificity, and accuracy.Results. A comprehensive analysis of preoperative status of patients made it possible to identify 11 factors with the highest predictive potential, linearly and nonlinearly associated with postoperative AF (PAF). These included age (55-74 years for men and 60-78 years for women), anteroposterior and superior-inferior left atrial dimensions, transverse and longitudinal right atrial dimensions, tricuspid valve regurgitation, left ventricular end systolic dimension >49 mm, RR length of 1000-1100 ms, PQ length of 170-210 ms, QRS length of 50-80 ms, QT >420 ms for men and >440 ms for women, and heart failure with ejection fraction of 4560%. The metrics of the best predictive ANN model were as follows: AUC — 0,75, specificity — 0,73, sensitivity — 0,74, and accuracy — 0,73. These values in best model based on multivariate LR were lower (0,75; 0,7; 0,68 and 0,7, respectively).Conclusion. The developed algorithm for selecting predictors made it possible to verify significant predictive ranges and weight coefficients characterizing their influence on PAF development. The predictive model based on ANN has a higher accuracy than multivariate HR

Inter-calibration of Infrared Channels of Geostationary Meteorological Satellite Imagers

This article examines a method of inter-calibration for MSU-GS imager of the Russian Geostationary Earth Orbit (GEO) satellite Elektro-L No. 2. Since the launch (December 11, 2015), the satellite's radiation cooler has been operating in an abnormal mode, so the calibration of the IR channels of the MSU-GS imager differed from that pre-flight and, in general, could have a daily variability. To ensure the satellite's further operation in orbit, it was necessary to calibrate imager channels at a frequency that would allow to identify daily calibration course to detect and compensate its sources. In order to do this, we have developed a special method of GEO-GEO inter-calibration. The calibration of MSU-GS was performed using SEVIRI imager installed on the GEO satellite Meteosat-10. SEVIRI was chosen as a reference instrument because its spectral channels are similar to those of MSU-GS. The MSU-GS was calibrated according to the regressions calculated from the simultaneous images of the field of regard selected between the sub-satellite points. The dynamic brightness temperature range was determined by deep convective clouds in high troposphere and warm ocean surface. Using the proposed method of inter-calibration, it was possible to confirm the absence of a significant daily variation of the calibration since November 2017. The amplitude of the variation smoothly increases from ~0.2 K at high (~300 K) BTs to ~1.0 K when the brightness temperature decreased to 200 K. These estimates allow the use of the Fourier spectrometer IKFS-2 installed on the Russian Low-Earth-Orbit (LEO) satellite Meteor-M No. 2 to verify the developed GEO-GEO scheme of inter-calibration. Despite the specifics of the situation on board Elektro-L No. 2, the proposed method of GEO-GEO inter-calibration can be applied to radiometers of other neighboring satellites that differ in SSP and spatial resolution

Отработка методов моделирования зубчатых шестерен планетарного редуктора с применением объемной постановки конечноэлементного анализа в рамках пакета ANSYS

В статье проведен модальный анализ ведущего колеса (эпицикла) планетарной зубчатой передачи и рассмотрен возможный алгоритм анализа процесса зацепления в квазистатической постановке. По результатам модального анализа и после построения резонансных диаграмм получили, что наиболее опасной для эпицикла оказалась формаколебания с тремя узловыми диаметрами и менее опасной с четырьмя узловыми диаметрами при условии вращения вала двигателя в рабочем диапазоне частот. Возникновение резонансных колебаний может привести к разрушению зубчатого колеса, которое начинается от впадины между зубьями, развивается в диафрагму и приводит к поломке шестерни. В процессе статического анализа была произведена попытка проверить подход, применяемый для расчета зубчатых передач, а именно определение напряженнодеформированного состояния (НДС) во впадине зубьев ведущего зубчатого колеса авиационного двигателя при приложении рабочих нагрузок. Предложенный подход не претендует на точные количественные значения и может рассматриваться как метод, который должен впоследствии сам подвергнуться тщательному анализу с учетом практических результатов испытаний

It is grounding optimum applying kinds technical of control

Наведена коротка класифікація видів технічного контролю і їх використання. Обгрунтована доцільність використання статистичного контролю при виготовленні і постачанні сільгосптехніки. Дани варіанти рішень за результатами контролю і критерії для їх прийняття.The short classification of kinds technical control and their applying was pointed out. The expedient applying of statistic control under making and supply gricultural machinery was grounded. It was given varsions decisions on results control and criterion for their adoption

The Source of Proton in the Noyori−Ikariya Reaction

The study of the mechanism of the Noyori‒Ikariya asymmetric transfer hydrogenation of ketones spans nearly three decades of investigations. Whereas the early part of the catalytic cycle being the hydride transfer is now well-understood, the late part being the proton transfer is still ambiguous. Specifically, the source of the proton can be the N‒H functionality of the catalyst and/or the O‒H functionality of the reagent/solvent leading to two conceptually different catalytic cycles or even their combination. For three popular reagents/solvents typically used in the method, namely propan-2-ol, 5:2 HCO2H‒NEt3 and water, the source of the proton is presently either unknown, or the evidence is presented partially by only one approach ‒ experimental or computational. This work eliminates this ambiguity by means of various state-of-the-art molecular dynamics simulation methods (ab initio, quantum mechanics/molecular mechanics and path integral to include quantum tunneling effects). Here we show that the source of proton in propan-2-ol is catalyst’s N‒H functionality, whereas in more acidic water, binary 5:2 HCO2H‒NEt3 or neat formic acid the source of proton is reagent/solvent. Thus, depending on the source of reagent/solvent the catalyst’s ligand can be either chemically non-innocent or chemically innocent in the Noyori‒Ikariya reaction, which opens new opportunities for the outer-sphere homogeneous catalysts design

Analysis of the structures of individual milking machines to meet the requirements of milk production

Розглянуто основні вимоги до конструкцій індивідуальних доїльних установок згідно з міжнародними стандартами. Наведено блок схему транспортування молока від дійок вимені до збірної ємності. Вказано напрямок удосконалення технічного забезпечення покращення якості молока в умовах технологій доїння особистих селянських та фермерських господарствах. Розроблена і апробована конструкція удосконаленого устрію для індивідуальних доїльних установок. Considered set of requirements for individual construction milking according to international standards to ensure milk quality at the global level, which was based on the analysis of the standard ISO 5707:2007 and ISO 6690:2007. It is possible by using a systematic approach to consider the individual components of the milking machines and create a flowchart. On the basis of which it was found that transport milk is in the system milking machine. It was therefore examined the interaction of the components of the reduced system of individual milking machines and their impact on the quality of milk. This analysis allowed to be determined with the the least protected stage in the line of transporting, and by direction of improvement of the technical providing and improvement of quality of milk in the conditions of technologies of milking the personal peasant and farmer economies. Based on patent information retrieval have been confirmed are listed priority areas of work and design. Improvements are taken to the improvement of receipt of quality of milk at his transporting in accordance with world requirements. A maintainance of the maximally close bacterial state of milk is on an output from a cattle. Designed and tested device of improved design for individual milking machines