Prognostic Value Of Kidney Function Parameters In Patients With Chronic Heart Failure And Left Ventricular Reduced Ejection Fraction

Chronic heart failure (CHF) is a complex clinical syndrome characterized by progressive course, unsatisfactory quality of life, poor prognosis and high incidence of concomitant renal dysfunction (RD).The aim of our work was to study the prognostic value of a number of renal function indicators in patients with CHF and a reduced left ventricular ejection fraction (LVEF).Materials and methods. 134 patients with stable CHF and reduced (<40 %) LVEF, II-IVNYHA class were examined. Patients were divided into two groups according to the level of GFR: the first group of GFR<60 ml/min./1.73 m², the second – GFR≥60 ml/min./1.73 m². The average follow-up period was 13.4 months, the maximum was 27.5 months.Results. In 53 patients RD was detected (glomerular filtration rate was ˂60 ml/min/1.73 m²), which was 39.5 %. Patients of both groups did not differ in their main hemodynamic parameters, left ventricular ejection fraction, and pharmacotherapy structure, but were older in age and heavier clinically. After the analysis of survival curves of patients depending on GFR, a group of patients with RD had a significantly worse survival prognosis compared to a group without RD. After adjusting the groups by age and NYHA class, the indicated difference was maintained. The subjects were divided according to median levels: blood urea nitrogen, blood urea nitrogen / creatinine ratio, microalbuminuria, albumin / creatinine ratio in urine.The long-term survival of the formed groups was analyzed. The level of blood urea nitrogen did not significantly influence the prognosis of patients with CHF and reduced LVEF. At the same time, when the groups were divided, depending on the median value of the blood urea nitrogen / creatinine ratio, there was a significantly higher risk of fatal outcome in the group with lower indices. The level of MAU did not significantly affect the survival of patients. In addition, a comparison of the survival of patients with higher and lower values of the albumin / creatinine ratio in the urine revealed a significantly higher risk of death in patients with higher values.Conclusions:1. The presence of RD (GFR˂60 ml/min/1.73 m²) is observed in 39.5 % of patients with CHF and reduced LVEF and is associated with their worst long-term survival.2. The BUN and MAU do not have sufficient predictive information about the forecast of long-term survival of the above category of patients.3. At the same time, the values of the BUN/ Сreatinine ratio ˂24.5 and the ACR ˃12.7 indicate patients with CHF who have a higher long-term risk of death

Исследование модели удаленной аутентификации при передаче данных через сеть LTE

Проблематика. Мережі LTE підтримують широкий спектр програм та послуг. Ці системи високоякісних мобільних послуг мають підвищену швидкість передачі і часто використовуються для віддаленої біометричної автентифікації, але вплив шуму і завмирання в бездротових каналах на якість і стабільність біометричної автентифікації ще не проаналізовано. Мета досліджень. Метою роботи є вивчення моделі фізичного рівня мережі LTE, що передає біометричні шаблони для автентифікації. Методика реалізації. Було проведено комп'ютерне моделювання системи біометричної автентифікації для підготовки біометричного шаблону і Matlab моделі каналу бездротового зв'язку за технологією LTE для аналізу впливу шуму і завмирання на канал. Результати досліджень. У статті представлені результати оцінки системи автентифікації при впливі завад в каналах зв'язку, оцінено вплив використання технології MIMO на залежність кількості бітових помилок. Отримані результати показують, що для підвищення якості віддалених систем біометричної автентифікації доцільно використовувати додаткові методи завадозахищеності та використання адаптивних налаштувань на стороні передавача. Висновки. Змодельована система віддаленої біометричної автентифікації з передачею даних по мережі LTE. Проаналізовано вплив AWGS і доплеровских зсувів в каналах бездротового зв'язку. Для стійкості до завад реалізовані різні коди корекції помилок.Background. LTE networks support a wide range of applications and services. These networks provide high-quality mobile services and have increased transmission rates and often used for remote biometric authentication, but the influence of noise and fading in wireless channels on quality and stability of biometric authentication is not analyzed yet. Objective. The aim of the paper is to study the model of the physical layer of the LTE network, which transmits biometric templates for authentication. Methods. We use computer simulation of biometric authentication system for preparing biometric template and Matlab models of wireless communication channel using the LTE technology for analysis of influence of noise and fading on channel. Results. The paper presents the results of the evaluation of the authentication system under the influence of interference in communication channels. The impact of the use of MIMO technology on the dependence of the number of bit errors is evaluated. The obtained results show that in order to improve the quality of remote biometric authentication systems, it is advisable to use additional means of noise immunity and the use of adaptive settings on the transmitter side. Conclusions. The system of remote biometric authentication with data transmission via LTE network was modeled. Influence of AWGS and Doppler shifts in wireless communication channels was analyzed. For noise resistance different error correction codes are implemented.Проблематика. Сети LTE поддерживают широкий спектр приложений и услуг. Эти сети предоставляют высококачественные мобильные услуги и имеют повышенную скорость передачи и часто используются для удаленной биометрической аутентификации, но влияние шума и замирания в беспроводных каналах на качество и стабильность биометрической аутентификации еще не проанализировано. Цель исследований. Целью работы является изучение модели физического уровня сети LTE, передающей биометрические шаблоны для аутентификации. Методика реализации. Было проведено компьютерное моделирование системы биометрической аутентификации для подготовки биометрического шаблона и Matlab модели канала беспроводной связи по технологии LTE для анализа влияния шума и замирания на канал. Результаты исследований. В статье представлены результаты оценки системы аутентификации при воздействии помех в каналах связи, оценено влияние использования технологии MIMO на зависимость количества битовых ошибок. Полученные результаты показывают, что для повышения качества удаленных систем биометрической аутентификации целесообразно использовать дополнительные средства помехозащищенности и использование адаптивных настроек на стороне передатчика. Выводы. Смоделирована система удаленной биометрической аутентификации с передачей данных по сети LTE. Проанализировано влияние AWGS и доплеровских сдвигов в каналах беспроводной связи. Для устойчивости к помехам реализованы различные коды коррекции ошибок

Oil Wells Hydrate Formation Regularities

The paper considers the process of hydrate-paraffin deposits formation in oil wells. Due to the research with the author's specially designed laboratory equipment – an experimental installation containing a technological unit and an information-measuring system, the most favorable pressure-temperature conditions of hydrate formation in a wide range of pressure (0.1–120 MPa) and temperature (from –20 to +80 °C) were determined. The experimental results made it possible to determine the conditions required for hydrate deposits and iron (Fe) oxides in the range of temperature from –15 to +60 °C and pressure from 0 to 60 MPa. These results are confirmed by thermodynamic calculations of the oil-gas-hydrate phase equilibria in the annulus of the well. Data processing was performed using the methods of correlation, dispersion and regression analysis, which allowed comparing the processes of hydrates and iron (Fe) oxides formation in the annulus of oil wells. The results of the study can be used to prevent and eliminate hydrate-paraffin plugs in the downhole equipment of oil wells, and also to determine the operation mode of the well for long-term operation of the downhole equipment without complications, accidents and stops for repair works, which reduces downtime

Studying the Kinetics of Extraction Treatment of Rice Husk When Obtaining Silicon Carbide

Silicon carbide is characterized by a wide range of beneficial electrophysical, anti-corrosion, and strength properties. A promising raw material for the synthesis of silicon carbide is the waste of rice production, which includes compounds of silicon and carbon-containing organic substances. The cheapness and availability of such raw materials necessitate the development of technologies to obtain silicon carbide from it. An important direction in silicon carbide synthesis technology is to obtain a high purity product. To remove impurities from rice husks, it is necessary to carry out its pre-extraction treatment. It has been established that the extraction treatment of rice husks with acid solution makes it possible to clean the raw materials from metal compounds and the excess amount of carbon-containing components. To remove impurities of metal compounds and the excess amount of carbon-containing compounds from rice husks, it has been proposed to perform the extraction with an aqueous solution of the mixture of 10 % sulfur and 15 % acetic acids. We have derived the time dependences of the degree of extraction of cellulose from rice husks. Two temporal sections of the process have been identified. It is shown that the extraction of cellulose from rice husks obeys a pseudo first-order reaction. We have calculated the constants of speed and activation energy in the course of extraction for the two time sections of the process. The activation energy of extraction over a first period is 10.75 kJ/mol; over a second period, the activation energy value is 26.10 kJ/mol. It has been established that an increase in the extraction temperature from 20 to 100 °C leads to a two-fold improvement in the process efficiency. It is shown that silicon carbide, synthesized from rice husk after its extraction treatment, is a pure crystalline material whose particles' size is from 1 to 20 micrometer

A rare CACNA1H variant associated with amyotrophic lateral sclerosis causes complete loss of Cav3.2 T-type channel activity

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the progressive loss of cortical, brain stem and spinal motor neurons that leads to muscle weakness and death. A previous study implicated CACNA1H encoding for Cav3.2 calcium channels as a susceptibility gene in ALS. In the present study, two heterozygous CACNA1H variants were identified by whole genome sequencing in a small cohort of ALS patients. These variants were functionally characterized using patch clamp electrophysiology, biochemistry assays, and molecular modeling. A previously unreported c.454GTAC > G variant produced an inframe deletion of a highly conserved isoleucine residue in Cav3.2 (p.ΔI153) and caused a complete loss-of-function of the channel, with an additional dominant-negative effect on the wild-type channel when expressed in trans. In contrast, the c.3629C > T variant caused a missense substitution of a proline with a leucine (p.P1210L) and produced a comparatively mild alteration of Cav3.2 channel activity. The newly identified ΔI153 variant is the first to be reported to cause a complete loss of Cav3.2 channel function. These findings add to the notion that loss-of-function of Cav3.2 channels associated with rare CACNA1H variants may be risk factors in the complex etiology of ALS.Medicine, Faculty ofNon UBCBiochemistry and Molecular Biology, Department ofReviewedFacult