861 research outputs found

    Synaptic transmission as a cooperative phenomenon in confined systems

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    In this review paper, the theory of synaptic transmission (ST) was developed and discussed. We used the hypothesis of isomorphism between: (a) the cooperative behavior of mediators --- acetylcholine molecules (ACh) and cholinoreceptors in a synaptic cleft with binding into mediator-receptor (AChR) complexes, (b) the critical phenomena in confined binary liquid mixtures. The systems of two (or three) nonlinear differential equations were proposed to find the change of concentrations of ACh, AChR complexes, and ferment acetylcholinesterase. The main findings of our study: the linear size of the activation zone was evaluated; the process of postsynaptic membrane activation was described as a cooperative process; different approximations of ACh synchronous release were examined; stationary states and types of singular points were studied for the proposed models of ST; the nonlinear kinetic model with three order parameters demonstrated a strange-attractor behavior.Comment: 12 pages, 1 figur

    Modeling of the Labour Force Redistribution in Investment Projects with Account of their Delay

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    The mathematical model of the labour force redistribution in investment projects is presented in the article. The redistribution mode of funds, labour force in particular, according to the equal risk approach applied to the loss of some assets due to delay in all the investment projects is provided in the model. The sample of the developed model for three investment projects with the specified labour force volumes and their defined unit costs at the particular moment is given

    Constructive solution of highly effective photoenergy module: development and experimental testing

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    Based on experimental study and computermodeling of working temperature influence on the efficiency of Chinese production silicon solar cells identified temperature dependence of efficiency shows the feasibility of using Chinese production Si-SC in the construction of photovoltaic thermal system, which together with the heat pump is part of a combined system for hot water supply, heating and air conditioning. Based on a detailed analysis of the working temperature influence on the efficiency of photovoltaic processes that determine the solar cells work, it has been developed the optimal construction and technological solution of hybrid solar generated module, the main feature ofwhich is the heat exchange block, designed to reduce the solar cells working temperature. The experimental testing of hybrid modules samples equipped with developed cooling system, high-voltage part of power take-off system demonstrates their reliability and high efficiency which allow to achieve the such module efficiency up to 18.5 %.На основе экспериментального исследования в комплексе с компьютерным моделированием влияния рабочей температуры на эффективность кремниевых солнечных элементов китайского производства выявлена температурная зависимость их эффективности. Температурная зависимость показывает целесообразность использования солнечных элементов китайского производства в составе фотоэлектрической тепловой системы, которая вместе с тепловым насосом является частью комбинированной системы горячего водоснабжения, отопления и кондиционирования воздуха. На основе детального анализа влияния рабочей температуры на эффективность фотоэлектрических процессов, определяющих работу солнечных элементов, было разработано оптимальное конструктивно-технологическое решение гибридного солнечного генерирующего модуля, основной особенностью которого является теплообменный блок, предназначен для снижения рабочей температуры солнечных элементов. Экспериментальные испытания образцов таких модулей, оснащенных разработанной системой охлаждения и высоковольтной системой отбора мощности, демонстрируют их надежность и высокую эффективность, позволяющие достичь КПД гибридного модуля до 18,5 %

    О возможности дистанционной диагностики дыхательной системы человека методом аускультации

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    Development of technical base, software, accumulated information on the diagnosis of the respiratory system provided the prerequisites for creating remote diagnostics of the human respiratory system through auscultation. The known methods do not solve the problem of determining auscultation points at patent´s housing without a diagnostic specialist. The purpose of this study is to develop a method for remote diagnostics of the respiratory system which provides ability to determine the points of auscultation without presence of a diagnostic specialist. The definition of auscultation points is provided using a computer program that allows to calculate the points´ coordinates based on the coordinates of points that determine the anatomical structure of the patient's torso. The patient or his assistant places the recording device at the auscultation points combining their images on the display with the image of the location of the recording device. The signal recorded at the auscultation point is remotely transmitted to a specialist for direct analysis and/or computer processing. The diagnostic module consists of two main units. The first unit contains a stethoscope, microphone, and amplifier connected to a mobile phone or other similar device containing an accelerometer. The patient or his assistant at the housing uses the unit. The second unit is a mobile phone with a mechanical marker or a computer with the ability to access the network in conjunction with the necessary software and is used remotely by a diagnostic specialist. The layout of the unit for recording and transmitting breath sounds was made. To avoid discrepancies in the diagnostic results the technical characteristics of the module elements must be normalized. Unified software is required for the module to function. The organizational tasks that need to be solved for the implementation of diagnostics are formulated. Use of the method of remote diagnostics of the respiratory system, providing the ability to determine points of auscultation without the direct presence of a diagnostic specialist and the module will allow increasing efficiency of treatment of pulmonary diseases reduce infection risks and economic costs

    Intuition in business: Empirical base

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    In this article, the authors propose economic projection of the views of Daniel Kahneman on intuition. The authors believe intuition to act as an operative category in entrepreneurship. The results of given statistical experiment prove viability of the phenomenon of intuition when making investment decisions. Two independent mechanisms for investment decisions are being defined - the «rational» and the «intuitive» ones. The research leads to conclusion that entrepreneurs’ intuitive decisions possess a relatively high level of efficiency. © 2016 Fomin et al

    Improving the system of healthcare institution management in conditions of pandemic threats

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    The article is devoted to analysing activities of the infectious disease unit of a medical institution in one of Ukrainian regions. The unit is designed for intensive care of patients. The study main goal is to develop a strategy for further development of this unit to improve quality of its services and patient satisfaction. During the research, the initial conditions for the in-patient medical care provision were discussed. A comprehensive analysis of activities and structural problems within the infectious unit was carried out. Based on the study results, a strategic plan for further development was generated to enhance the unit efficiency and quality of its provided medical services. During analysing the infectious unit work, it was found that the in-patient care provision meets the worldwide infectious care norms. In the conditions of reforming the Ukrainian medical industry, many issues remain unresolved (in particular, restructuring and improvement of the healthcare system as a whole and that of the infectious disease unit). The latter plays an important role in creating a high-quality national program for medical service provision by healthcare institutions. Therefore, we succeed in improving resilience in the face of public health threats and risks. The analysis showed current positive trends in understanding the importance of this structural unit activities within the healthcare system. Besides, new ways of its modernisation are found. The authors substantiate this area development requires the national quality control indicators, the marketing policy improvement as well as the strengthened organisational and methodological role of the infectious disease service in healthcare institutions. Specific recommendations were formulated regarding ways to develop the infectious disease unit. They will help raise service satisfaction among patients of medical institutions. The obtained results are of practical importance and can be used in managing healthcare institutions at the national and regional levels

    Dynamics of СО2 evolution bу plants at low pressure

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    Dynamics of СО2 evolut:ion at low pressure was studied in barley, maize, реа, wheat and pine seedlings using the gas exchange system with laser photoacoust:ic spectrometer. The СО2 evolut:ion from plant surfaces to environment increased with decreasing air pressure. Simultaneously the changes in act:ivities of phosphoenolpyruvat

    FEATURES OF IMMUNOCOMPETENT CELLS IN THE PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA AT PRIMARY DIAGNOSIS

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    Some basic parameters of immune profile have been investigated in 140 patients with chronic lymphocytic leukemia (CLL). There was shown that the cohort of CLL patients is heterogeneous for their immune profile as early as at primary diagnosis stage, showing sufficient differences in the numbers of immunocompetent cells in peripheral blood. In most cases, the interpretation of appropriate quantitative characteristics is quite difficult, if based on the conventional criteria. The numbers of activated T-lymphocytes and NK-cells were proven to be the most informative parameters of cellular immunity in this cohort. Progression of leukemic events shows a close association with only a single parameter under study, i.e., CD4+/CD8+ cell ratio
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