The design features of the body of the portable electrocardiograph "ECG-EXPRESS"

The sequence of the industrial product shaping is specified, the main modeling characteristics of the configuration and some of its parts are designated subject to the electrocardiograph design and the technologies used for the production of its body

Comparative characterisation of forest litter on sod-podzolic soils of Forest Experimental Dacha in RSAU–MAA named after K.A. Timiryazev

Forest litter under linden and pine forests was studied at the Forest Experimental Dacha of the RSAU–MAA named after K.A. Timiryazev. Despite significant differences in physical and chemical parameters between the litter formed under the conditions of different forest communities, the properties of sod-podzolic soils formed under both vegetation types are quite similar. The litter under linden forest has higher ash content, it is less acidic and contains almost 2 times more exchangeable bases, the content of hydrogen and nitrogen is higher by 0.82 wt% and 0.66 wt%, respectively. The litter of linden and pine forests, according to the atomic ratios H : C, C : N and the degree of oxidation, are equal to 1.82, 30.3, -0.92 and 1.64, 45.7, -0.71, respectively; the litter of linden forests differs from litter of pine forests in the higher content of aliphatic, nitrogen-rich, reduced organic compounds. In the litter of linden forests concentration coefficients of phosphorus and magnesium 1.2 times higher; of carbon, potassium and aluminium – 1.3 times higher; of calcium – 1.4 times higher; of nitrogen – 1.8 times higher, and of silicon – 3 times higher, than in the litter of pine trees. However, the concentration factor of manganese in the pine forest litter is 1.9 times higher compared to the litter of linden. According to the results of UV spectroscopy, water-soluble organic matter of pine forest litter, unlike water-soluble organic matter of linden forest litter, is more enriched by components of aromatic origin. This is evidenced by higher values of SUVA254 and lower values of coefficients E2/E3 and E4/E6

Comparative characteristics of the properties of Halpic Chernozem of the Kursk Region of different land use

Analytical data show that prolonged extensive agricultural use of typical Chernozem of Kursk region (Haplic Chernozem) results in adverse changes in some soil properties. This primarily concerns the humus content and the structural state of the Chernozem. Under the influence of continuous winter wheat growing (for 54 years) the losses of humus made up 24% of its content in virgin soil. The permanent corn growing (for 54 years) led to humus 32% losses, and under the influence of the bare fallow (for 54 years) – 48%. As a result of mineralization of humus, which is one of the main aggregative agents, water resistance of Chernozem structure has deteriorated. The number of water-resistant aggregates in variants with continuous winter wheat and continuous corn decreased in comparison with virgin soil (by 30% and 39% respectively). In terms of water resistance, the structure of Chernozem was transformed in agrocenoses from “extremely high” to “good”. Under the influence of the bare fallow the content of water-resistant units decreased by 75%, and the structure became “non-water resistant”. At the same time, the average diameter of waterproof aggregates decreased 2.8, 3.6 and 4.8 times in variants with continuous winter wheat, corn and permanent bare fallow, respectively, whereas the content of the water peptized clay increased 2.8–4.7-fold, and pH of medium increased by 0.16–0.57. At the same time, the content of soil exchangeable calcium reduced (more than 1.1-fold), as well as hydrolytic acidity (1.1–1.7-fold), the content of organic forms of phosphorus (1.1–1.4-fold) and the ratio of organic forms of phosphorus to mineral ones also decreased 2.1–4.1-fold. When the bare fallow is transferred to the abandoned land, the properties of Chernozem vary with different intensity. The most significant changes occurred with water-resistant aggregates. Their content has increased by 53% over 20 years, and the structure has transformed from “non-water resistant” to “good”, while the content water peptized clay has decreased 2.1 times. During the 20-year period, the content of exchangeable calcium and hydrolytic acidity increased by 1.9 and 1.03 mg-eq/100 g of soil. The content of humus has increased by 0.78%, i. e. humus content restoration occurred with a speed of only 0.04% per year. It is necessary to consider this factor when regulating the humus status of the plowed and eroded soils. In general, the impact of continuous bare fallow on the properties of Chernozem was so profound that 20 years after its transfer to the category of abandoned lands, the properties of Chernozem, in most cases, have been restored only to the level typical of variants with crop cultivation

Machine-learning Driven Synthesis of TiZrNbHfTaC5 High-Entropy Carbide

Synthesis of high-entropy carbides (HEC) requires high temperatures that can be provided by electric arc plasma method. However, the formation temperature of a single-phase sample remains unknown. Moreover, under some temperatures multi-phase structures can emerge. In this work we developed an approach for a controllable synthesis of HEC TiZrNbHfTaC5 based on theoretical and experimental techniques. We used canonical Monte Carlo (CMC) simulations with the machine learning interatomic potentials to determine the temperature conditions for the formation of single-phase and multi-phase samples. In full agreement with the theory, the single-phase sample, produced with electric arc discharge, was observed at 2000 K. Below 1200 K the sample decomposed into (Ti-Nb-Ta)C and a mixture of (Zr-Hf-Ta)C, (Zr-Nb-Hf)C, (Zr-Nb)C, and (Zr-Ta)C. Our results demonstrate the conditions for the formation of HEC and we anticipate that our approach can pave the way towards targeted synthesis of multicomponent materials.Comment: 16 pages, 8 figure

The risk factors for development of an acute biliary pancreatitis and its signs in obstruction of extrahepaic bilairy ducts

Objective. A search for factors, promoting development of an acute biliary pancreatitis, and peculiarities of its signs in patients, suffering obstruction of extrahepatic biliary ducts. Materials and methods. Retrospective analysis of treatment in 283 patients, suffering obstruction of extrahepaic biliary ducts, was conducted, together with various indices analysis in patients, suffering an acute biliary pancreatitis and without acute biliary pancreatitis. Results. An acute biliary pancreatitis was diagnosed in 30 (10.6%) patients. Trustworthy differences (p < 0.05) were revealed, concerning pronounced pain syndrome, hyperthermia, leukocytosis, young neutrophils, general bilirubin, amylase in the blood, the gallbladder volume, choledocholithiasis, the fixed calculus and stenosis of duodenal papilla magna, cholangitis. Big calculi of hepaticocholedochus did not associated with development of an acute biliary pancreatitis, and a sludge in common biliary duct and stenosis of duodenal papilla magna were characteristic for an acute biliary pancreatitis (p < 0.001). Conclusion. Sludge of common biliary duct, stenosis and fixed calculus of duodenal papilla magna, bilirubinemia 70 mcmol/l and higher constitute the risk factors for development of an acute biliary pancreatitis, and the pronounced abdominal pain syndrome, hyperthermia, hyperamylasemia, leucocytosis, increase of the young neutrophils content up to 7% and higher, the volume of  a gallbladder 50 cm3 and more - served as the signs of an acute biliary pancreatitis in obstruction of extrahepatic biliary ducts. In obstruction of extrahepatic biliary ducts with an acute biliary pancreatitis, comparing with obstruction of extrahepatic biliary ducts without an acute biliary pancreatitis, cholangitis is revealed trustworthily: 16.7 and 5.1% accordingly (p < 0.05)

Факторы риска развития и проявления острого холангита у больных с доброкачественной обструкцией внепеченочных желчных путей

Цель. Определение факторов, способствующих развитию острого холангита (ОХ) или являющихся его признаками при доброкачественной обструкции внепеченочных желчных путей (ДОВЖП). Материалы и методы. Ретроспективно проанализированы 144 наблюдения ДОВЖП, ОХ отмечен в 17 наблюдениях. Проведено сравнение встречаемости различных факторов и признаков у больных с ОХ и без ОХ. Результаты. Различия выявлены (p 0,05) между следующими показателями: пол, возраст, индекс массы тела, наличие абдоминального болевого синдрома, холецистэктомия в анамнезе, объем ЖП, причина обструкции, расширение гепатикохоледоха, эндоскопическая папиллосфинктеротомия в анамнезе, наличие околососочкового дивертикула и острого билиарного панкреатита. Выводы. Факторы риска развития ОХ: уровень общего билирубина 70 мкмоль/л и выше, утолщение стенки ЖП до 4 мм и более, отключенный ЖП, фиксированный камень БСДПК, размер БСДПК 15 мм и более. Проявления ОХ: гипертермия, наличие триады Шарко, лейкоцитоз 9 × 109 в 1 л и выше, увеличение содержания палочкоядерных нейтрофилов до 7% и выше, гиперамилаземия

Recent ecological change in ancient lakes

Ancient lakes are among the best archivists of past environmental change, having experienced more than one full glacial cycle, a wide range of climatic conditions, tectonic events, and long association with human settlements. These lakes not only record long histories of environmental variation and human activity in their sediments, but also harbor very high levels of biodiversity and endemism. Yet, ancient lakes are faced with a familiar suite of anthropogenic threats, which may degrade the unusual properties that make them especially valuable to science and society. In all ancient lakes for which data exist, significant warming of surface waters has occurred, with a broad range of consequences. Eutrophication threatens both native species assemblages and regional economies reliant on clean surface water, fisheries, and tourism. Where sewage contributes nutrients and heavy metals, one can anticipate the occurrence of less understood emerging contaminants, such as pharmaceuticals, personal care products, and microplastics that negatively affect lake biota and water quality. Human populations continue to increase in most of the ancient lakes’ watersheds, which will exacerbate these concerns. Further, human alterations of hydrology, including those produced through climate change, have altered lake levels. Co‐occurring with these impacts have been intentional and unintentional species introductions, altering biodiversity. Given that the distinctive character of each ancient lake is strongly linked to age, there may be few options to remediate losses of species or other ecosystem damage associated with modern ecological change, heightening the imperative for understanding these systems

New national and regional bryophyte records, 59

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