Hydrogel Nanocomposites with Silver Nanoparticles

Copolymer hydrogels based on acrylic monomers (primarily acrylamide and acrylonitrile) are synthesized and their physicochemical properties are investigated. Methods of incorporation of nanoparticles of gold and silver into hydrogel pores and methods of their stabilization using reagents of different nature are developed. Our studies showed pronounced bactericidal properties of the nanocomposites regarding gram-positive and gram-negative bacteria and, at the same time, their biocompatibility to stem cells

Detection of decametre-wavelength pulsed radio emission of 40 known pulsars

International audienceThe study of pulsars at the lowest radio frequencies observable from the ground (10-30 MHz) is complicated by strong interstellar (dispersion, scattering) and ionospheric (scintillation, refraction) propagation effects, as well as intense Galactic background noise and interference. However, it permits us to measure interstellar plasma parameters (the effects of which increase by a power of two to >4 times the wavelength), the spectrum and the pulse profile at low frequencies more accurately. Up to now, only ˜10 pulsars have been successfully detected at these frequencies. The recent upgrade of the receivers at the Ukrainian T-shaped Radio telescope, second modification (UTR-2) has increased its sensitivity and motivated a new search for pulsed radio emissions. In this work we carried out a survey of known pulsars with declination above -10°, period >0.1 s and dispersion measure (DM) < 30 pc cm-3, i.e. a sample of 74 sources. Our goal was either to detect pulsars not recorded before in the decametre range or to identify factors that prevent their detection. As a result, we have detected the radio emission of 40 pulsars, i.e. 55 per cent of the observed sample. For 30 of them, this was a first detection at these frequencies. Parameters of their average profiles have been calculated, including the intrinsic widening of the pulse (not due to interstellar scattering) with decreasing frequency. Furthermore, two pulsars beyond the selected DM (B0138+59 with DM ≈ 35 pc cm-3 and B0525+21 with DM ≈51 pc cm-3) were also detected. Our results indicate that there is still room to detect new transient and pulsed sources with low-frequency observations

INCREASING OPERATION EFFECTIVITY OF METAL PRODUCTS LOADING POINTS BY THE RATIONAL USE OF BRIDGE CRANES

Purpose. Taking into account research and improvement of transport and storage processes for loading railway cars with bridge cranes the purpose of the study is the analysis of actual crane operation zones, development of simulation models of their functioning and determination of the most effective load technology. The real object of the study — the finished goods warehouse of a metallurgical enterprise — is formalized as a linear load point. Methodology. To analyse various options for the crane operation zones of the investigated object, the simulation modelling method was used. It was taken into account that each bridge crane can load railway cars, which are located in different zones of the loading track. Situations when the cranes are on the same crane ways during cargo operations and the service area of cars partially coincides were considered. Under such conditions, cranes can interfere with each other; it makes it difficult to carry out the transport-technological process of loading. Findings. A simulation model in which the service elements, which are the individual cargo packages, move along certain routes has been developed. Freight traffic volumes are set according to certain laws of random value distribution, taking into account the stochastic nature of real transport processes. A model of the linear loading point of railway cars with bridge cranes has been developed. It allows us to analyse the performance indicators of various options for assigning service areas to loading facilities. The analysis of such indicators as an average transporting time of service elements, a time percentage of cranes work and idle, time for separate movement operations of freight traffic volume is performed. Based on the developed model, a procedure has been developed to determine the most effective strategy for managing the loading point operation. The methodology, which has been tested on the example of a finished product warehouse of a metallurgical enterprise, and allows reducing the total costs in the process of rolled metal products loading has been developed. Originality. Theoretical research and improvement of the operation models of the metallurgical enterprise`s transport and storage complex due to the rational assignment of vehicle loading areas to the cranes. Practical value. The results obtained make it possible to increase the efficiency of the transport and storage complex by reducing the time spent by railway cars in the system with the rational use of loading resources

ПОШИРЕНІСТЬ ЛАЙМ-БОРЕЛІОЗУ СЕРЕД ХВОРИХ НА ТУБЕРКУЛЬОЗ

The aim of the study was to identify the prevalence of Lyme borreliosis among patients with tuberculosis.Patients and Methods. Under supervision there were 99 patients with tuberculosis (TB) treated at the Ternopil Regional TB Dispensary during 2015–2017. The patients responded to the question of a unified international questionnaire regarding the the history of tick bites and Lyme borreliosis and were examined by ELISA for the presence of antibodies to B. burgdorferi sensu lato.Results. Antibodies of at least one IgM and / or IgG class to B. burgdorferi sensu lato (B. burgdorferi sensu stricto, B. afzelii and B. garinii) were detected in 25.2 % of the examined patients with TB. Surveyed patients who indicated tick-borne bites, sero-confirmation of borreliosis was obtained in 9 out of 53 (17.0%), among 46 patients with tuberculosis who did not mind mite bites – 16 (34.7 %) (p&lt;0.05). Patients with tuberculosis with concomitant LB significantly more often noted delayed healing of cavities of dacay in (36.0±9.6) % of cases in 2 months of treatment compared with (14.9±4.1) % of patients without it and cardiogram disorders (sinus bradycardia, conduction retardation and repolarization abnormalities) (p&lt;0.05).Conclusions. The prevalence of Lyme borreliosis in patients with tuberculosis is 25.2 %. Concomitant Lyme borreliosis negatively affects the course of tuberculosis, which manifests itself in the slowed healing of cavities of decay and ECG disorders in this category of patients (p&lt;0.05).Мета дослідження – виявити поширеність Лайм-бореліозу у хворих на туберкульоз та його вплив на перебіг основного захворювання.Пацієнти і методи. Спостерігали 99 пацієнтів з туберкульозом (ТБ), які лікувались стаціонарно протягом 2015-2017 рр. у Тернопільському обласному протитуберкульозному диспансері. Хворі дали відповіді на питання уніфікованої міжнародної анкети-опитувальника щодо наявності в анамнезі укусів кліща та бореліозу та обстежені методом ІФА на наявність антитіл  до B. burgdorferi sensu lato.Результати. Антитіла хоча б одного класу IgM і/чи IgG до B. burgdorferi sensu lato виявлено у 25,2 % обстежених хворих на туберкульоз. З числа обстежених пацієнтів, які вказували на укуси кліщів, серологічне підтвердження бореліозу отримано у 9 із 53 (17,0 %), серед 46 хворих на туберкульоз, які не пам’ятали про укуси кліща, – у 16 (34,7 %) (p&lt;0,05). У хворих на туберкульоз із супутнім ЛБ суттєво частіше відзначено сповільнене загоєння порожнин розпаду через 2 місяці ОКХТ - у (36,0±9,6) % випадків порівняно з (14,9±4,1) % хворих без нього та зміни ЕКГ (синусова брадикардія, сповільнення провідності та розлади реполяризації) (p&lt;0,05). Висновки. Поширеність Лайм-бореліозу у хворих на туберкульоз становить 25,2 %. Супутній Лайм-бореліоз негативно впливає на перебіг туберкульозу, що проявляється у сповільненому загоєнні порожнин розпаду та змінами ЕКГ у даної категорії пацієнтів (p&lt;0,05)

ПЕРФОРАЦІЯ ТОНКОЇ КИШКИ У ВІЛ-ІНФІКОВАНОЇ ХВОРОЇ З ПОЗАЛЕГЕНЕВИМ ТУБЕРКУЛЬОЗОМ

SUMMARY. Perforation of the small intestine in HIV-infected disease with extrapulmonary tuberculosis was describe as clinical case. Pay attention of the difficult clinical course of disease and diagnostic terms. According to the authors, available in Ukraine regulations aimed mainly at protecting the personal rights of HIV-positive people and do not protect other members of society.Key words: small intestine, perforation, HIV, tuberculosis.Наведено клінічний випадок перфорації тонкої кишки у ВІЛ-інфікованої хворої з позалегеневим туберкульозом. Звертається увага на різноманітність клінічного перебігу і складність в діагностичному плані. На думку авторів, наявні в Україні нормативно-правові акти направлені в основному на захист особистих прав ВІЛ-інфікованих осіб і не захищають інших членів суспільства.Ключові слова: тонка кишка, перфорація, ВІЛ-інфекція, туберкульоз.

Characteristics of marine strain Streptomyces sp. with antimicrobial and cytotoxic activity

The Black Sea is a unique water basin consisting of a thin superficial oxygenic layer with moderate salinity, and a deep anoxic water mass. The microbiota of the Black Sea remains relatively understudied, which makes it interesting first of all from the most practical point of view of the search for producers of new biologically active compounds. A strain of actinobacteria Streptomyces sp. ONU 561 was isolated from the surface of mussel shells collected in the coastal zone of Odesa. It demonstrated a wide range of antagonistic activity, inhibiting the growth of a set of opportunistic pathogens, including representatives of Staphylococcus aureus, Escherichia coli, Proteus vulgaris, and Klebsiella pneumoniae. In addition, bacteria of this strain were able to inhibit the growth of all tested strains of mycelial fungi, including representatives of Aspergillus niger, A. flavus and Fusarium oxysporum species, and Candida albicans yeast. A significant cytotoxic effect was revealed in the cell cultures of human malignant cells – human rhabdomyosarcoma (RD) and human laryngeal adenocarcinoma (Hep-2). Analysis of the exometabolome of the strain did not explain these effects.The strain was comprehensively characterized, including physiological, biochemical, and morphological traits. The complete genome of the strain was sequenced using Illumina HiSeq 4000 (2x150) and ONT and annotated using NCBI PGAP. Its genome has a size of 8 359 197 bp. GC content – 71.59%. Using antiSMASH 7.0, 35&nbsp;biosynthetic clusters were revealed. The indices of digital DNA-DNA hybridization and orthoANI for all of the type strains with Streptomyces sp. ONU 561 are much lower than threshold values for the species separation. The obtained results, including a comparative analysis of the genome, indicate the possible affiliation of the strain Streptomyces sp. ONU 561 to a new species and the potential ability of these actinobacteria to synthesize previously unknown antibiotic compounds

Digital receivers for low-frequency radio telescopes UTR-2, URAN, GURT

This paper describes digital radio astronomical receivers used for decameter and meter wavelength observations. This paper describes digital radio astronomical receivers used for decameter and meter wavelength observations. Since 1998, digital receivers performing on-the-fly dynamic spectrum calculations or waveform data recording without data loss have been used at the UTR-2 radio telescope, the URAN VLBI system, and the GURT new generation radio telescope. Here we detail these receivers developed for operation in the strong interference environment that prevails in the decameter wavelength range. Data collected with these receivers allowed us to discover numerous radio astronomical objects and phenomena at low frequencies, a summary of which is also presented.Comment: 24 pages, 15 figure

Problems of measuring country's financial security

The aim is to define the key issues ensuring financial security of a country. The studies propose a technique to calculate a country's quality management index for a financial as a weighted average of the country's overall compliance with key international standards, rules and principles in the sector. The study uses statistical information from the Consultative Group to Assist the Poor, the World Bank Database and the Organization for Economic Co-operation and Development, to study financial security of the population in 142 countries with different levels of economic development. 47 variables, grouped into 10 aggregates, were included in the study: Disclosure of information upon opening a deposit account, Disclosure of information upon opening a credit account, Disclosure of general information, Periodic disclosure upon opening deposit accounts, Periodic disclosure Monitoring, Enforcing, Fair treatment, Recourses, Standards for complaints resolution. Analysis of the results show that the levels of financial security in the studied countries have a wide variation from the minimum to the maximum values. We see that among the countries with high levels of economic development, the leaders are Italy, Canada and Puerto Rico. Transition economies include Venezuela, Argentina and Mexico; among developing countries, we can mention Armenia, Azerbaijan and Uzbekistan

High temporal resolution delayed analysis of clinical microdialysate streams

We thank the Wellcome Trust DOH (HICF-0510-080), the EPSRC (EP/H009744/1) (cycling experiments), and the Imperial Confidence in Concept scheme, Ovarian Cancer Action UK (ovarian tissue measurements), the National Science Foundation (CHE-1608757), and the NIH (R01 MH104386) for fundin

Развитие электрохимических методов измерения скорости коррозии металлов научной школы профессора Л.И. Антропова

Розглянуто розвиток наукових основ електрохімічних методів визначення швидкості корозії металів, робота над якими започаткована під керівництвом видатного електрохіміка Л.І. Антропова та продовжується послідовниками його школи. Опрацьовано аспекти точності визначення швидкості корозії методом поляризаційного опору (Rp). Показано, що використання двохелектродної схеми істотно знижує похибку вимірювань Rp. Уточнені співвідношення для коефіцієнта пропорційності між Rp і швидкістю корозії з урахуванням структури подвійного електрохімічного шару та впливу специфічної адсорбції іонів, які перевірено експериментально. Виведено аналітичну залежність для визначення швидкості корозії за наявності великих поляризаційних ємностей. Розглянуто метод нелінійної подвійної поляризації для визначення кінетичних параметрів корозії за аналітичною формулою в системі з дифузійним або пасиваційним контролем, який не потребує застосування емпіричних коефіцієнтів. Описано новий неруйнівний метод на основі поляризаційного опору з використанням неполяризованих електродів. Показано приклади практичного застосування цього методу в дослідженнях корозійної стійкості зварного з’єднання. За дослідженнями характеру зміни поляризаційного опору в часі в сульфатній кислоті за наявності амінокислот і похідних гуанідину виведено кількісні співвідношення, які визначають зростання фазових плівок на поверхні металів залежно від часу експозиції та концентрації інгібітору.The development of scientific bases of electrochemical methods for the determination of the corrosion rate, which were originated under the guidance of outstanding electrochemists L.I. Antropov and continued by his followers’ school, was investigated. Accuracy aspects of the corrosion rate determination by polarization resistance (Rp) method were discussed. It was shown that application of the two-electrode cell significantly decreases Rp determination error. The relations for the proportionality constant between R p and corrosion rate accounting the electrochemical double layer structure and the influence of specific ion adsorption were improved and experimentally tested. Analytical dependence for corrosion rate determination in the presence of large polarization capacities was derived. A method of non-linear double polarization for the kinetic parameters of corrosion determination was discussed using analytical equation in systems with diffusion or passivation control without application of empirical coefficients. New non-destructive methods based on polarization resistance with application of non-polarizable electrodes were described. The examples of the practical application of this method in corrosion research of welded connection were shown. Quantitative relations for films growth on the metal surface at different exposure time and acid concentration were derived from time dependences of polarization resistance in sulfuric acid in the presence of aminoacids and guanidine derivatives.Рассмотрено развитие научных основ электрохимических методов определения скорости коррозии, работа над которыми была начата под руководством выдающегося электрохимика Л.И. Антропова и продолжается последователями его школы. Рассмотрены аспекты точности определения скорости коррозии методом поляризационного сопротивления (Rp). Показано, что использование двухэлектродной схемы существенно снижает погрешность измерений Rp. Уточнены соотношения для коэффициента пропорциональности между Rp и скоростью коррозии с учетом структуры двойного электрического слоя и влияния специфической адсорбции ионов, которые проверены экспериментально. Выведена аналитическая зависимость для определения скорости коррозии при наличии больших поляризационных емкостей. Представлен метод нелинейной двойной поляризации для определения кинетических параметров коррозии в системе с диффузионным или пассивационным контролем по аналитической формуле, который не требует использования эмпирических коэффициентов. Описан новый неразрушающий метод на основе поляризационного сопротивления с использованием неполяризуемых электродов. Показаны примеры практического применения этого метода в исследованиях коррозионной стойкости сварного шва. По результатам исследований характера изменения поляризационного сопротивления во времени в серной кислоте в присутствии аминокислот и производных гуанидина выведены количественные соотношения, которые определяют рост фазовых пленок на поверхности металла в зависимости от времени экспозиции и концентрации ингибитора