28 research outputs found

    Interacting circular nanomagnets

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    Regular 2D rectangular lattices of permalloy nanoparticles (40 nm in diameter) were prepared by the method of the electron lithography. The magnetization curves were studied by Hall magnetometry with the compensation technique for different external field orientations at 4.2K and 77K. The shape of hysteresis curves indicates that there is magnetostatic interaction between the particles. The main peculiarity is the existence of remanent magnetization perpendicular to easy plain. By numerical simulation it is shown, that the character of the magnetization reversal is a result of the interplay of the interparticle interaction and the magnetization distribution within the particles (vortex or uniform).Comment: 16 pages, 8 figure

    Thrombocyte aggregation activity in the conditions of intensive light deprivation

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    The aim of the research was to study the effect of photoperiodism disturbances on platelet aggregation activity. Material and methods. The experiment was conducted in two stages in 5 groups of male rats: the control group and four experimental groups. At the first stage, the animals were exposed to 24 h/day continuous light (24L:0D) for 10 and 21 days. In the second stage, animals after 10 and 21 days of round-the-clock lighting were returned to natural lighting for a period of 21 days to study the reversibility of changes. Animals were withdrawn from the experiment by intramuscular injection based on body weight of drugs for anesthesia (telazol, xylanite). Blood sampling was performed by puncture of the right heart. The functional activity of platelets was determined no later than 3 hours after the collection of blood. Results and discussion. The results of the experiment indicate a direct effect of light desynchronosis on the increase in platelet aggregation ability, while it was noted that the degree of increase in aggregation activity and reversibility of changes directly depend on the duration of round-the-clock lighting. So, a 10-day stay of animals in conditions of abnormal lighting leads to an increase in aggregation indices, which remain at a high level even when animals return to normal conditions. In animals that were under round-the-clock illumination for 21 days, a more pronounced increase in platelet aggregation values relative to animals on day 10 was noted. In this regard, it can be argued that circadian rhythm disturbances provoke the development of microvasculature disorders

    EXAMINATION AND TESTING OF EXPERIMENTAL-PRODUCTION SERIES OF POLYVALENT BRUCELLOSIS SERUM

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    At present no commercial polyvalent brucellosis serum is produced in Russia. We developed a technology of polyvalent brucellosis high-effective and specific serum production without adsorption. Experimental-production series are obeyed the technical specification project

    CYTOKINE PROFILE IN VISCERAL OBESITY AND ADVERSE CARDIOVASCULAR PROGNOSIS OF MYOCARDIAL INFARCTION

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    Presence of myocardial infarction in patients with obesity can lead to an uncontrolled increase in proinflammatory cytokines and unfavorable course of the pathological process. Objective: to study the relationship of key inflammatory factors and the development of complications at different terms after myocardial infarction in patients with visceral obesity. The study involved 94 men with myocardial infarction. Visceral obesity was diagnosed by multi-slice computed tomography (LightspeedVCT 64 ,General Electric,USA). On the 1st and 12th day of hospitalization, we determined serum concentrations of interleukins (TNFα, IL-1β, IL-6, IL-8 IL-10 and IL-12), and C-reactive protein. Adverse cardiovascular events were documented during the next year. The most informative indicators were identified by a stepwise logistic regression analysis. In patients with myocardial infarction an imbalance of cytokine profile revealed, i.e., an increase in proinflammatory markers (TNFα, IL-1β, IL-6, IL-8, IL-12, CRP), along with decrease in IL-10, being more pronounced in cases of visceral obesity. Among the studied markers, closest relationship was observed between visceral obesity and serum concentrations of IL-6 and CRP. Over the year, adverse cardiovascular events proved to be more frequent in patients with visceral obesity. Post-infarction complication risk was associated with higher concentrations of IL-6, IL-12 and IL-10 deficiency. Hence, development of adverse cardiovascular events within a year after myocardial infarction is more typical to the patients with visceral obesity, and is accompanied by activation of proinflammatory cytokines and IL-10 deficiency

    МЕХАНИЧЕСКАЯ ФУНКЦИЯ ЛЕВОГО ПРЕДСЕРДИЯ И ЕЕ НАРУШЕНИЯ ПОСЛЕ АНТРАЛЬНОЙ ИЗОЛЯЦИИ ЛЕГОЧНЫХ ВЕН

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    The article presents new insights into the left atrial mechanical function, its main components and remodeling mechanisms after pulmonary vein antrum isolation. Left atrium is a cardiac chamber that transports blood. Being a complex «organ» both in anatomical and functional terms, it responds to hemodynamic derangements, the impact of humoral and vegetative factors. Structural, mechanical and electrical remodeling of the left atrium play a key role in the arrhythmogenesis of atrial fibrillation, as well as in the mechanism of arrhythmia maintenance. Left atrial mechanical dysfunction following catheter ablation of atrial fibrillation significantly affects intracardiac hemodynamics, worsens patients' well-being, and increases the risk of thromboembolic complications both in the immediate and long-term postoperative period.В статье изложены современные представления о механической функции левого предсердия (ЛП), ее компонентах и механизмах ремоделирования после процедуры антральной изоляции легочных вен. ЛП – это сердечная камера, которая выполняет не только транспортную функцию, но, являясь «органом» сложным как в анатомическом, так и в функциональном плане, активно реагирует на изменение гемодинамических условий, влияние гуморальных и вегетативных факторов. Структурное, механическое и электрическое ремоделирование ЛП играют большую роль в аритмогенезе фибрилляции предсердий, а также в механизме поддержания аритмии. Механическая дисфункция ЛП, развивающаяся после катетерной аблации фибрилляции предсердий, оказывает существенное влияние на внутрисердечную гемодинамику, ухудшает самочувствие пациентов, а также увеличивает риск тромбоэмболических осложнений как в ближайшем, так и в отдаленном послеоперационном периодах

    International longitudinal registry of patients with atrial fibrillation and treated with rivaroxaban: RIVaroxaban Evaluation in Real life setting (RIVER)

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    Background Real-world data on non-vitamin K oral anticoagulants (NOACs) are essential in determining whether evidence from randomised controlled clinical trials translate into meaningful clinical benefits for patients in everyday practice. RIVER (RIVaroxaban Evaluation in Real life setting) is an ongoing international, prospective registry of patients with newly diagnosed non-valvular atrial fibrillation (NVAF) and at least one investigator-determined risk factor for stroke who received rivaroxaban as an initial treatment for the prevention of thromboembolic stroke. The aim of this paper is to describe the design of the RIVER registry and baseline characteristics of patients with newly diagnosed NVAF who received rivaroxaban as an initial treatment. Methods and results Between January 2014 and June 2017, RIVER investigators recruited 5072 patients at 309 centres in 17 countries. The aim was to enroll consecutive patients at sites where rivaroxaban was already routinely prescribed for stroke prevention. Each patient is being followed up prospectively for a minimum of 2-years. The registry will capture data on the rate and nature of all thromboembolic events (stroke / systemic embolism), bleeding complications, all-cause mortality and other major cardiovascular events as they occur. Data quality is assured through a combination of remote electronic monitoring and onsite monitoring (including source data verification in 10% of cases). Patients were mostly enrolled by cardiologists (n = 3776, 74.6%), by internal medicine specialists 14.2% (n = 718) and by primary care/general practice physicians 8.2% (n = 417). The mean (SD) age of the population was 69.5 (11.0) years, 44.3% were women. Mean (SD) CHADS2 score was 1.9 (1.2) and CHA2DS2-VASc scores was 3.2 (1.6). Almost all patients (98.5%) were prescribed with once daily dose of rivaroxaban, most commonly 20 mg (76.5%) and 15 mg (20.0%) as their initial treatment; 17.9% of patients received concomitant antiplatelet therapy. Most patients enrolled in RIVER met the recommended threshold for AC therapy (86.6% for 2012 ESC Guidelines, and 79.8% of patients according to 2016 ESC Guidelines). Conclusions The RIVER prospective registry will expand our knowledge of how rivaroxaban is prescribed in everyday practice and whether evidence from clinical trials can be translated to the broader cross-section of patients in the real world
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