Частотная характеристика неусвоения ритма при фибрилляции желудочков сердца собаки

Ventricular fibrillation is the main cause of sudden cardiac death in many countries, including Russia; therefore to study ventricular fibrillation is an urgent problem. Objective: to study rhythm non-assimilation in canine ventricular fibrillation. Materials and methods. The author made a frequency analysis of electrocardiograms in 25 dogs with ventricular fibrillation, by applying the fast Fourier transform method. The frequency analysis was carried out in the frequency ranges corresponding to those of delta, theta, alpha, beta, and gamma rhythms of an electroencephalogram. Results. Ventricular fibrillation is characterized by rhythm non-assimilation with the oscillations being recorded on an electrocardiogram in the frequency ranges corresponding to those of delta, theta, alpha, beta, and gamma rhythms of an electroencephalogram. The proportion of oscillations in the frequency ranges of delta, theta, alpha, beta, and gamma rhythms is determined by cardiac functional mobility (lability). The latter is reduced by ischemia in ventricular fibrillation. Diminished cardiac lability in ventricular fibrillation reflects the stages of rhythm non-assimilation with a dominant and non-dominant frequency pattern naturally detectable by the frequency analysis of an electrocardiogram in the frequency ranges of delta, theta, alpha, beta, and gamma rhythms. The greater proportion of alpha, beta, and gamma rhythm frequencies in the non-dominant frequency pattern of rhythm non-assimilation in ventricular fibrillation is, the deeper cardiac lability fall is. Conclusion. The frequency analysis of an electrocardiogram in the frequency ranges of delta, theta, alpha, beta, and gamma rhythms allows the stages of rhythm non-assimilation to be objectively determined in the entire range — at all stages of ventricular fibrillation. The findings may be included into the algorithms of an automated electrocardiogram analysis, which permits objective determination of ventricular fibrillation stages in automated defibrillators. Key words: canine heart, ventricular fibrillation, rhythm non-assimilation.Фибрилляция желудочков является основной причиной внезапной сердечной смерти во многих странах, включая Россию, поэтому изучение фибрилляции желудочков является актуальной проблемой. Цель исследования . Изучение неусвоения ритма при фибрилляции желудочков сердца собаки. Материал и методы. Проведен частотный анализ электрокардиограммы методом быстрого преобразования Фурье при фибрилляции желудочков у 25 собак. Частотный анализ проводился в диапазонах частот, соответствующих частотным диапазонам дельта-, тета-, альфа-, бета- и гамма-ритмов электроэнцефалограммы. Результаты. Фибрилляция желудочков характеризуется неусвоением ритма с регистрацией на электрокардиограмме осцилляций в диапазонах частот, соответствующих частотным диапазонам дельта-, тета-, альфа-, бета- и гамма-ритмов электроэнцефалограммы. Удельный вес осцилляций в частотных диапазонах дельта-, тета-, альфа-, бета- и гамма-ритмов определяется функциональной подвижностью (лабильностью) сердца. Лабильность сердца снижается под влиянием ишемии при фибрилляции желудочков. Снижение лабильности сердца при фибрилляции желудочков отражают стадии неусвоения ритма с доминантной и бездоминантной частотной структурой, закономерно выявляемые при частотном анализе электрокардиограммы в частотных диапазонах дельта-, тета-, альфа-, бета- и гамма-ритмов. Чем больше удельный вес частот альфа-, бета- и гамма-ритмов в бездоминантной частотной структуре неусвоения ритма при фибрилляции желудочков, тем глубже падение лабильности сердца. Заключение. Частотный анализ электрокардиограммы в частотных диапазонах дельта-, тета-, альфа-, бета- и гамма-ритмов позволяет объективно определять стадии неусвоения ритма во всем диапазоне — на всех стадиях фибрилляции желудочков. Результаты работы можно включать в алгоритмы автоматического анализа электрокардиограммы, что позволит объективно определять стадии фибрилляции желудочков сердца в автоматических дефибрилляторах. Ключевые слова: сердце собаки, фибрилляция желудочков, неусвоение ритма

Clay nanotube-biopolymer composite scaffolds for tissue engineering

© The Royal Society of Chemistry 2016.Porous biopolymer hydrogels doped at 3-6 wt% with 50 nm diameter/0.8 μm long natural clay nanotubes were produced without any cross-linkers using the freeze-drying method. The enhancement of mechanical strength (doubled pick load), higher water uptake and thermal properties in chitosan-gelatine-agarose hydrogels doped with halloysite was demonstrated. SEM and AFM imaging has shown the even distribution of nanotubes within the scaffolds. We used enhanced dark-field microscopy to visualise the distribution of halloysite nanotubes in the implantation area. In vitro cell adhesion and proliferation on the nanocomposites occur without changes in viability and cytoskeleton formation. In vivo biocompatibility and biodegradability evaluation in rats has confirmed that the scaffolds promote the formation of novel blood vessels around the implantation sites. The scaffolds show excellent resorption within six weeks after implantation in rats. Neo-vascularization observed in newly formed connective tissue placed near the scaffold allows for the complete restoration of blood flow. These phenomena indicate that the halloysite-doped scaffolds are biocompatible as demonstrated both in vitro and in vivo. The chitosan-gelatine-agarose doped clay nanotube nanocomposite scaffolds fabricated in this work are promising candidates for tissue engineering applications

Investigation of the effect of upper electrode material on the memristor properties of strained carbon nanotubes

The reported study was funded by RFBR according to the research project No. 16-29-14023 ofi_m

INDUSTRY 4.0 DIGITAL PRODUCTION ORGANIZATION BASED ON CYBER AND PHYSICAL SYSTEMS AND ONTOLOGIES

Subject of Research. The paper proposes the work organization schemes in the Industry 4.0 instrument making production companies of “smart factory” type equipped with cyber and physical systems. Studies on the production cyber-physiphication are being carried out aimed at the development and implementation of ideas and decisions in the domestic industry, which will help to establish “smart companies” in our country capable of functioning in the conditions of digital economy and possessing new production technologies. Method.We used the work organization methods for item design manufacturing with the cyber and physical systems and ontologies implementation in the conditions of the companies of the future on the basis of the design automation general theory. Main Results. It is shown that the effect of the production companies proposed organization principles implementation in the factories of the future format can boost the Russian Federation industry transfer to the most advanced digital, intellectual production technologies, robotized systems, new materials and designing methods that corresponds to the Russian Federation State Scientific and Technical Policy in the field of instrument making and machine manufacturing. Practical Relevance. The results of this research can be applied in the development of automation design algorithms for instrument making (machine manufacturing) digital production operating in the conditions of the Russian Federation digital economy

IR Bismuth active centers in optical fibers: Combined excitation-emission spectroscopy

3D excitation-emission luminescence spectra of Bi-doped optical fibers of various compositions were measured in a wide wavelength range 450-1700 nm. Such luminescence spectra were obtained for Bi-doped pure silica and germania fibers, and for Bi-doped Al- or P-codoped silica fibers (at room and liquid nitrogen temperatures). The energy level schemes of IR bismuth active centers in pure silica and germania core fibers were derived from spectra obtained. The energy level schemes similarity of bismuth active centers in these two types of fibers was revealed.Comment: 12pages, 7 figures, 5 table

Study of the electromechanical properties of aligned carbon nanotubes coated with ZnO using atomic force microscopy

The reported study was funded by RFBR according to the research projects No. 18-32-00652 mol_a, No.18-29-11019 mk and by grant of the Southern Federal University (project No. VnGr-07/2017-26)

Additional Impact of Glucose Tolerance on Telomere Length in Persons With and Without Metabolic Syndrome in the Elderly Ukraine Population

Rationale: Association between different components of metabolic syndrome and the rate of age-related telomere shortening was reported repeatedly, although some findings are inconsistent across studies, suggesting the need for further research on the topic. In the present study, we examined relationships between different components of metabolic syndrome (MetS); glucose tolerance reflected in 2-h post-load plasma glucose (2hPG) levels and age on the leukocyte telomere length (LTL) in Ukraine population.Methods: The study was conducted on the 115 adult individuals residing in the Kyiv region (Ukraine). Among them, 79 were diagnosed with MetS according to the International Diabetes Federation definition. LTL were determined by a qPCR-based method. Multivariate logistic regression (MLR) and artificial neural networks (ANN) modeling were used for the analysis of the results. ROC-analysis was also performed to compare the predictively values of this models.Results: MetS was associated with a high (OR = 3.0 CI 1.3–6.7; p = 0.01) risk of having shorter telomeres that remained significant after adjusting for age, gender and 2hPG levels. Fasting plasma glucose (FPG) levels and other MetS components did not affect the magnitude of the relationship and did not reveal the independent influence of these factors. The level of 2hPG in turn, demonstrated a significant relationship (OR = 1.3 CI 1.0–1.6 per 1 mmol/l; p = 0.04) with LTL regardless of the presence of MetS. The non-linearity of the interactions between age, gender and 2hPG level was revealed by neural network modeling (AUC = 0.76 CI 0.68–0.84).Conclusion: Our study found that impaired glucose tolerance, but not FPG levels, affected the association between LTL and MetS, which may be also indicative for pathophysiological differences in these hyperglycemia categories. 2hPG levels can provide an opportunity for a more accurate diagnostics of MetS and for evaluating the rate of aging in patients with MetS. Further research, however, is needed to verify this assumption

Russian and American Presidents’ Implied Powers

This report is dedicated to clarify several crucial points of hidden presidential powers. The subject of that research is aimed at analysing the status of Russian and American Presidency. It demonstrates pros and cons of the implied powers. This article expresses the view to the implied powers’ legitimacy, powers that are not contained in the Constitutions’ texts, but are legitimate according to their legal nature