181 research outputs found

    Formation of a National Assessment of the Probability of Investing in Fraudulent ICOs

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    The study covers such concepts as ICO and IPO, their characteristics, similarities and differences. A national estimate of the probability of investing in fraudulent ICOs has been formed. Also, the work is about comparing the likelihood of investing in fraudulent IPOs and ICO.     Keywords: cryptocurrency, block technology, ICO, IP

    Correction of postkeratoplastic astigmatism by intrastromal corneal segments implantation using a femtosecond laser

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    Background. After penetrating keratoplasty, mild to high induced corneal astigmatism was observed in each case. The existing choice of correction of postkeratoplastic astigmatism is aimed at fi nding an individual approach in order to compensate for it and not weaken the biomechanical properties of the corneal graft.The aim: to analyze the clinical, functional, and morphological results of postkeratoplastic astigmatism correction by implantation of intrastromal corneal segments using a femtosecond laser.Methods. 22 patients were examined before and 1 year after surgery. The operation was performed under local anesthesia: stage I – an intrastromal tunnel was formed using a femtosecond laser “Femto Visum” 1 MHz (Optosystems, Russia); stage II – the intrastromal corneal segments were implanted. The results were assessed using standard and special research methods using optical coherence tomography Visante OCT (Zeiss, Germany), keratotopography (Tomey-5, Japan), optical corneal analyzer ORA (Reichert, USA), laser tindalemetry FC-2000 (Kowa, Japan) and confocal microscope Confoscan-4 (Nidek, Japan).Results. Before the operation, uncorrected visual acuity averaged 0.09 ± 0.05, after a year – 0.50 ± 0.16; best corrected visual acuity – 0.30 ± 0.12 and 0.60 ± 0.05 respectively; cylindrical component of refraction – –10.29 ± 3.12 and –2.20 ± 0.64 D respectively; mean keratometry value – 43.59 ± 2.14 and 38.56 ± 1.75 D respectively; corneal hysteresis – 7.92 ± 1.22 and 8.95 ± 1.05 mm Hg respectively; corneal resistance factor – 7.01 ± 1.81 and 8.44 ± 1.44 mm Hg respectively; protein fl ux in the moisture of the anterior chamber – 2.97 ± 0.28 and 3.04 ± 0.24 f/ms respectively; endothelial cell density – 1521 ± 327 and 1475 ± 419 cells/mm2 respectively.Conclusion. Intrastromal corneal segments implantation into a corneal graft using a femtosecond laser has efficiency and safety method in correcting postkeratoplastic astigmatism

    АВТОМАТИЧЕСКОЕ УПРАВЛЕНИЕ ГРУППОЙ НАСОСНЫХ АГРЕГАТОВ С ЦЕЛЬЮ СНИЖЕНИЯ ЗАТРАТ ЭЛЕКТРОЭНЕРГИИ

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    Booster pumping plants, equipped with a group of pump units operating in parallel, are typical objects of the city water supply system. Improving its power efficiency is a very urgent topical objective, because its power consumption is a significant part in the structure of power consumption of water utilities. The aim of the present study is to identify opportunities of improving the power efficiency of pumping stations due to the automatic control of the pump group. The paper presents results of the study of the instantaneous efficiency changes of booster pumping stations under the conditions of variable water consumption. The basic reasons of the reducing pumping plant efficiency are reported in the article. Among them, there is a sharp decline in the effectiveness of the regulated pump units, when they functioning for the hydraulic network with a significant static component of the pressure. The main factors affecting the duration of the adjustable pumping unit in inefficient area are determined. The method of controlling a group of pumping units, taking into account the instantaneous efficiency of each of them was suggested. The approbation of this method at the local booster pumping stations was fulfilled. The effects of disabling the controlled pump unit which is in the ineffective area, on the overall efficiency of the pumping station and on alteration of its output pressure immediately after the pump is switched off are studied. It was shown that the timely shutdown of an inefficiently controlled pump unit can reduce the power consumption of the pumping plant by 8–10 % as compared to the traditional control methods. The range of variation of the instantaneous efficiency of the pumping station can serve as a criterion of correct selection of pumping equipment as well it can be the rationale of the necessity for its replacement.Повысительные насосные станции, оснащенные группой насосных агрегатов, работающих параллельно, являются типовыми объектами системы водоснабжения городов. Повышение их энергоэффективности – актуальная задача, поскольку энергопотребление станций составляет существенную долю в структуре энергопотребления водоканала. Цель исследования – определение возможностей повышения энергоэффективности насосных станций за счет автоматического управления режимами работы группой насосных агрегатов. В статье приведены результаты исследования изменения мгновенной эффективности повысительных насосных станций в условиях переменного водопотребления. Выявлены основные причины снижения эффективности работы насосных станций. Среди них – резкое снижение эффективности регулируемых насосных агрегатов при работе на гидравлическую сеть со значительной статической составляющей напора. Определены основные факторы, влияющие на длительность нахождения регулируемого насосного агрегата в неэффективной зоне. Предложен метод управления группой насосных агрегатов с учетом мгновенной эффективности каждого из них. Проведена апробация данного метода на локальных повысительных насосных станциях. Изучено влияние отключения регулируемого насосного агрегата, находящегося в неэффективной зоне, на общую эффективность работы насосной станции и на изменение ее выходного давления непосредственно после момента отключения насоса. Исследование показало, что своевременное отключение неэффективного регулируемого насосного агрегата может снизить энергопотребление насосной станции на 8–10 % по сравнению с управлением по традиционным методам. Диапазон изменения мгновенной эффективности насосной станции может служить критерием оценки правильности подбора насосного оборудования, а также быть обоснованием для его замены

    Efficacy and safety of ultra-low dose inhaled melphalan in the treatment of hospitalized patients with COVID-19

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    Background. One of the most important components of COVID-19 therapy is the suppression of the hyperergic immune response. There is an urgent need of creating the optimal tactics of efficient and safe anti-inflammatory therapy. A new method of treatment of COVID-19 with inhalation of ultra-low (non-cytotoxic) doses of the alkylating drug melphalan is proposed, based on previous experimental, preclinical, and clinical data on its use in severe bronchial asthma.The aim. To evaluate the efficacy and safety of inhalation of ultra-low doses of melphalan in hospitalized patients with COVID-19-associated lung damage.Materials and methods. A prospective, open, controlled, blind for the central expert study was conducted. Sixty adult patients were included, 30 patients were consecutively admitted to the hospital and received nebulized inhalations of 0.1 mg of melphalan for 7 days. Thirty patients of the control group were selected by an independent expert retrospectively using the computer algorithm for selecting «close» patients based on the «case-control» principle. The primary endpoints were the dynamics on the WHO Clinical Improvement Scale and the dynamics of dyspnea according to the modified Borg scale, secondary – assessment of adverse events, dynamics of indicators of clinical, biochemical blood tests, lungs computed tomography data from the beginning of inhalations in the melphalan group and from the corresponding day in the control group.Results. Inhalations of melphalan led to a significant improvement in the clinical condition of patients according to the WHO scale, decrease in the intensity of dyspnea on day 7 of treatment and by the time of discharge, a significant anti-inflammatory effect. Adverse events and dynamics of laboratory parameters did not differ from the control group.Conclusion. The method of treatment of COVID-19 by inhalation of ultra-low doses of the alkylating drug melphalan is safe and leads to a significant clinical improvement of hospitalized patients with COVID-19-associated lung damage
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