Channel spaser

We show that net amplification of surface plasmons is achieved in channel in a metal plate due to nonradiative excitation by quantum dots. This makes possible lossless plasmon transmission lines in the channel as well as the amplification and generation of coherent surface plasmons. As an example, a ring channel spaser is considered

Perspectives on the Use of Transthoracic Echocardiography Results for the Prediction of Ventricular Tachyarrhythmias in Patients with Non-ischemic Cardiomyopathy

Aim. To perform a comparative analysis of indicators of transthoracic echocardiography (TE), to establish echocardiographic predictors and their predictive role in the occurrence of stable ventricular tachyarrhythmia (VT) paroxysms in patients with nonischemic chronic heart failure (HF) and cardioverter-defibrillator (ICD) implanted for primary prevention of sudden cardiac death.Material and Methods. A prospective study was carried out, which included 166 patients with nonischemic HF at the age of 54 (49; 59) years with the left ventricle ejection fraction (LV EF) ≤35% and an ICD implanted. The observation time was 24 months. The primary endpoint was the first-ever stable paroxysm of VT (lasting for ≥30 seconds), detected in the «monitor» zone of VT, or paroxysm of VT, which required ICD therapy.  A total of 34 TE indicators were evaluated. Chi-square, Fischer, Manna-Whitney, single-factor logistic regression (LR), and multi-factor LR were used for data processing and analysis and for predictive modelling. Model accuracy was estimated using 4 metrics: ROC curve area (AUC), sensitivity, specificity and diagnostic efficiency.Results. During the two-year observation, 32 patients (19.3%) had a primary endpoint. The average time of occurrence of a stable VT episode was 21.6±0.6 months (95% confidence interval [CI] 20.5-22.8 months). The value of LV end-systolic dimension was the only parameter independently associated with VT (odds ratio 2.8 per unit increase, 95% CI 1.04-7.5; p=0.042). The complex analysis of echocardiographic indicators made it possible to identify 5 factors with the greatest predictive potential, which are linearly and nonlinearly related to occurrence of VT. These included the LV end-diastolic and end-systolic volumes, LV mass, index of relative LV wall thickness, upper-lower size of the right atrium. The metrics of the best predictive model were: AUC – 0.71 0.069 with 95% CI 0.574-0.843; specificity 50%, sensitivity 90.9%; diagnostic efficiency 57.1%.Conclusion. The study made it possible to evaluate the possibilities of the results of TE in predicting the probability of VT occurrence in patients with nonischemic HF and reduced LV EF. Predictive indicators have been identified that can be used to stratify the arrhythmic risk in the exposed cohort of patients

Possibilities for predicting ventricular tachyarrhythmias in patients with heart failure with reduced ejection fraction based on surface electrocardiography. First results from a single-center prospective study

According to current clinical guidelines, the risk of life-threatening ventricular tachyarrhythmias (VTAs) in patients with heart failure (HF) is determined by left ventricular ejection fraction (LVEF). The available clinical and experimental data indicate the imperfection of this one-factor approach, which specifies the need to search for new predictors of VTAs. In this prospective study, we performed a comparative analysis of surface electrocardiographic parameters in HF patients with LVEF ≤35% without syncope or sustained ventricular arrhythmias in history, who were implanted with cardioverter defibrillator as a primary prevention of sudden cardiac death. During the two-year follow-up, the primary endpoint (new-onset persistent VTA episode, or VTA/ventricular fibrillation that required electrotherapy) was recorded in 42 patients (25,5%). The secondary endpoint (an increase in LVEF by 5% or more of the initial level against the background of cardiac resynchronization therapy) was more often recorded in the group of patients without VTAs (41 (33%) vs 4 (9,5%), p=0,005). The studied cohort of patients was characterized by a left axis deviation (72%), LV hypertrophy signs (84%), impaired intra-atrial (P wave duration of 120 (101-120) ms) and intraventricular conduction (QRS duration of 140 (110-180) ms), ventricular electrical systole prolongation (QTcor — 465 (438-504) ms). Differences between the groups divided depending on reaching the primary endpoint in terms of the Cornell product, Cornell voltage index and ICEB, as well as the detection rate of complete left bundle branch block morphology had levels of significance close to critical (p=0,09; p=0,05; p=0,1; p=0,09, respectively). The multivariate predictive model included following factors: Cornell product, Tp-Te/ QRS, P wave duration (diagnostic efficiency of the model was 60%: sensitivity, 61,1%, specificity, 59,6%; p=0,007)

Comparative analysis of left ventricular strain parameters in patients with heart failure of ischemic and non-ischemic genesis

Aim. To carry out a comparative analysis of left ventricular (LV) strain parameters, determined by the two-dimensional strain imaging in patients with heart failure (HF) with LV ejection fraction (EF) ≤35%, depending on the origin of HF.Material and methods. The study included 133 patients with NYHA class 3-4 HF with LVEF ≤35%, taking optimal therapy. Based on the HF origin, 2 following groups of patients were formed: ischemic cardiomyopathy (ICM) (n=70), nonischemic cardiomyopathy (NICM) (n=63). All patients underwent speckle-tracking echocardiography.Results. All patients included in the study showed significant alterations in longitudinal strain parameters in most myocardial segments, most pronounced in the basal and middle parts of the LV. Comparative analysis of the peak systolic longitudinal strain showed the worst characteristics in patients with ICM were found in the apical segments (p=0,008), and in patients with NICM, in the basal segments of the LV (p=0,046). The studied groups had comparable LV global longitudinal and circumferential strain (p=0,26; p=0,67; respectively).Conclusion. Groups of patients with HF of ischemic and non-ischemic origin, despite comparable LVEF values, differ in the distribution of the decrease in local longitudinal strain of LV segments. The worst strain characteristics in patients with ICM and NICM are detected in LV apical and basal segments, respectively

ORGANIZATION OF ANTI-EPIDEMIC MEASURES DURING THE ANTHRAX OUTBREAK IN THE YAMALO-NENETS AUTONOMOUS DISTRICT IN 2016

The organizational peculiarities of anti-epidemic measures during the anthrax outbreak in the Yamalo-Nenets Autonomous District in 2016 are presented. Complex of these measures provided for anthrax patients active identification and hospitalization, preventive immunization and emergency antibiotic prophylaxis of risk groups, vaccination of reindeer, utilization of fallen animals. Disinfection, deratization and desinsection measures were performed. Native residents were evacuated from infection focus and sensitization campaign among the population was carried out. Organized were sanitary inspection stations and temporary accommodation points. Due to operational implementation of anti-epidemic measures in the interagency format the anthrax focus was localized within one incubation period

ORGANIZATION OF LABORATORY RESEARCH OF CLINICAL AND ENVIRONMENTAL SAMPLES DURING THE ANTHRAX OUTBREAK IN THE YAMALO-NENETS AUTONOMOUS DISTRICT IN 2016

Presented are the order and features of organization of operative diagnostic and monitoring studies of the material during the anthrax outbreak in the Yamalo-Nenets Autonomous District in 2016. Characterized are the main directions of the laboratory base work. Represented are the results of laboratory studies of various materials (clinical samples, material from animals, samples of environmental objects) for the presence of Bacillus anthracis

Дослідження технічного стану і методів відновлення теплових мереж в Україні

Problem statement. Central heating systems in Ukraine need to be renovated and upgraded. Taking into account the constant growth of energy price, the complex modernization of the infrastructure of these systems is more than ever relevant. Most heat losses in heat supply systems occur during the heat transportation, therefore proper attention should be paid to the issue of energy conservation in existing heating networks (total heat losses reach 30…40 % on average). A significant part of the pipelines of thermal networks, built in the middle of the last century, has already completely exhausted its resource and they are in a critical condition. As a result, there are large heat losses, economic losses due to frequent emergencies, significant volumes of repairs, deteriorating quality of services for the population, accelerating the aging of the heating system, etc. These pipelines require an immediate replacement. Purpose. The purpose of this article is to study the technical state of heat networks in Ukraine and to systematize the basic methods of their restoration. Conclusions. The authors analyze the main defects that arise during the design and operation of heat conductors with mineral wool and polyurethane foam insulation, their main causes and consequences. Methods of extending the operational life of the Ukrainian heat networks, aimed at eliminating these defects, contribute to the reduction of heat losses in the transport of heat from the source to the consumer and to ensure the reliability of the heating system. Rehabilitation of the central heating systems will enable residents to get better climatic conditions in apartments, as well as significantly lower heating bills. In addition, reducing the cost of fuel and energy will lead to a reduction in CO2 emissions.Постановка проблемы. Системы центрального теплоснабжения в Украине нуждаются в реконструкции и обновлении. Учитывая постоянный рост цен на энергоносители, комплексная модернизация инфраструктуры этих систем является как никогда актуальной. Большинство теплопотерь в системах теплоснабжения происходит в процессе транспортировки теплоэнергии, поэтому должное внимание следует уделить именно вопросам энергосбережения в действующих тепловых сетях (общие потери тепловой энергии достигают в среднем 30…40 %). Значительная часть трубопроводов тепловых сетей, построенная в середине прошлого века, уже полностью исчерпала свой ресурс и находится в аварийном состоянии. В результате этого имеют место большие потери тепла, экономический ущерб из-за частых аварийных ситуаций, значительных объемов ремонтных работ, ухудшается качество услуг населению, ускоряется старение теплосетей и т. п. Трубопроводы требуют немедленной замены. Целью данной статьи является исследование технического состояния тепловых сетей в Украине и систематизация основных методов их восстановления. Выводы. Авторами проанализированы основные дефекты, возникающие при проектировании и эксплуатации теплопроводов с минераловатной и пенополиуретановой теплоизоляцией, их основные причины и последствия. Методы продления эксплуатационного ресурса тепловых сетей Украины, направленные на устранение этих дефектов, способствуют снижению теплопотерь при транспортировке теплоэнергии от источника к потребителю и обеспечению надежности работы теплосетей.Постановка проблеми. Системи центрального теплопостачання в Україні потребують реконструкції і оновлення. Враховуючи постійне зростання цін енергоносіїв, комплексна модернізація інфраструктури цих систем є як ніколи актуальною. Більшість тепловтрат в системах теплопостачання відбувається в процесі транспортування теплоенергії, тому належну увагу слід приділити саме питанням енергозбереження в діючих теплових мережах (загальні втрати теплової енергії сягають в середньому 30…40 %). Значна частина трубопроводів теплових мереж, побудована в середині минулого століття, вже повністю вичерпала свій ресурс і знаходиться в аварійному стані. В результаті цього мають місце великі втрати тепла, економічні збитки внаслідок частих аварійних ситуацій, значних обсягів ремонтних робіт, погіршується якість послуг населенню, прискорюється старіння тепломереж тощо. Ці трубопроводи потребують негайної заміни. Мета. Метою даної статті є дослідження технічного стану теплових мереж в Україні та систематизація основних методів їх відновлення. Висновки. Авторами проаналізовано основні дефекти, які виникають під час проектування та експлуатації теплопроводів з мінераловатною та пінополіуретановою теплоізоляцією, їх основні причини та наслідки. Методи подовження експлуатаційного ресурсу теплових мереж України, спрямовані на усунення цих дефектів, сприяють зниженню тепловтрат при транспортуванні теплоенергії від джерела до споживача та забезпеченню надійності роботи тепломереж. Реконструкція систем теплопостачання дасть змогу мешканцям мікрорайонів отримати кращі кліматичні умови в квартирах, а також значно менші рахунки за опалення. Крім того, зменшення витрат паливно-енергетичних ресурсів призведе до зменшення викидів СО2

Role of the cardiac extracellular matrix in the onset and progression of heart failure

Any cardiovascular disease leads to heart failure (HF) — a complex clinical syndrome, the course of which is probably specified by the influence of cardiovascular factors on cardiac extracellular matrix (ECM).The presented literature data indicate that the cardiac ECM is an important pathophysiological link in the onset and progression of HF. The morphological and electrical remodeling negatively affects the systolic and diastolic functions of the heart. Impaired myocardial blood delivery, cellular maladaptation, atrial and ventricular arrhythmias are additional mechanisms of the influence of myocardial fibrosis on HF course.Understanding this role of ECM and the development of algorithms for verifying the individual status of ECM in cardiovascular patients can provide additional data on the course of HF, help to assess the risk of adverse cardiovascular events and effectively control the ongoing pharmacological and non-drug therapy

Numerical modeling of generation and propagation of Gӧrtler vortices

Abstract: Using a recent experiment on a local generation and propagation of Gӧrtler vortices different issues of numerical modeling of the wind tunnel experiments to study the stability of subsonic flows of viscous incompressible fluid are discussed. Further development of the finite element FEATFLOW package for such modeling is outlined and substantiated.Note: Research direction:Theoretical and applied problems of mechanic