Graphene superlattice with periodically modulated Dirac gap

Graphene-based superlattice (SL) formed by a periodic gap modulation is studied theoretically using a Dirac-type Hamiltonian. Analyzing the dispersion relation we have found that new Dirac points arise in the electronic spectrum under certain conditions. As a result, the gap between conduction and valence minibands disappears. The expressions for the position of these Dirac points in ${\bf k}$-space and threshold value of the potential for their emergence were obtained. At some parameters of the system, we have revealed interface states which form the top of the valence miniband.Comment: 5 pages, 4 figures, accepted to Physical Review

Optimization of Agriculture Land Use Development Basing on Natural-resource Potential (On the Example of the Stavropol Territory)

Natural resources potential of the territory and natural-historical mechanism of its development are pacing factors in agriculture differentiation and AIC-development. Key branches in the Stavropol Territory are crop production, sheep breeding and meat and milk cattle breeding. To meet the market demands “equating” differentiation of agricultural enterprises is implemented. Thus, in Stavropol Territory crop lands have been increased for crops required in the market that disbalanced the crop rotation, disturbed agro technologies and resulted in reduction in yields and grain quality. In the Territory 70 % of tillage is in risky agriculture. About 65 % of crop production (wheat, barley and others) are in draughty areas where out of 141 years (1861–2002) 41 % draughty, which determine high natural-climatic dependence of grain economy [1]. Annual and areal variability of grain production is also determined by topsoil heterogeneity and variety of relief. At present production of the basic market crop – winter wheat, which takes 75 % of acreage for cereals and leguminous crops, the productivity of the cultivated crop is 22.4–39.5 centner/hectare. It results in top soil changes such as compaction, fertilizer impoverishment and organic matter content (organic matter deficit is 400–700 kg/ha). Intensification of agrarian production results in quicker erosion processes, soil properties decline and lower fertility. The total area of eroded lands in the Territory is 1792000 ha [2]. That is why it is important to develop a new model of the economic use of Stavropol Territory. The main methods of study are analysis of the current status and organization of the agricultural zones of the Territory. The data were preceded with the software Statistica

Association of polymorphism rs10841855 in the glycogen synthase 2 gene with hypercholesterolemia and type 2 diabetes mellitus

The aim of the study: To investigate the association of polymorphism rs10841855 (G>T) GYS2 with the risk of T2D in residents of Central Russiaassessmen

Surfaces roughness effects on the transmission of Gaussian beams by anisotropic parallel plates

Influence of the plate surfaces roughness in precise ellipsometry experiments is studied. The realistic case of a Gaussian laser beam crossing a uniaxial platelet is considered. Expression for the transmittance is determined using the first order perturbation theory. In this frame, it is shown that interference takes place between the specular transmitted beam and the scattered field. This effect is due to the angular distribution of the Gaussian beam and is of first order in the roughness over wavelength ratio. As an application, a numerical simulation of the effects of quartz roughness surfaces at normal incidence is provided. The interference term is found to be strongly connected to the random nature of the surface roughness.Comment: 18 pages, Journal of Physics D: Applied Physics, volume 36, issue 21, pages 2697 - 270

Scanning Electron Microscopy Study of Drilling Cuttings in Tomsk Oblast Sites

The research is focused on determining mineralogical composition of drilling cuttings by scanning electron microscope as well as imaging the sample surface of high resolution that allows studying the structural characteristics of the site. In addition, a number of other techniques permit obtaining information on chemical composition of sample in near-surface layers. The study in drilling cuttings by means of scanning microscopy has revealed the presence of titanium, iron, zirconium oxides, iron sulphide, barium sulphate. The former is a mineral that concentrates rare-earth elements, presumably monocyte, as well as uranium silicate, etc. The results obtained confirm the data of previous X-ray structural analysis, i.e. the study samples consist of alumosilicate matrix. Apart from silicon and aluminium oxides, the matrix includes such elements as Na, K, Mg. Such a composition corresponds to rock-forming minerals: quartz, albite, microcline, clinochlore, muscovite, anorthoclase

СИНТЕЗ И СВОЙСТВА БИОАКТИВНЫХ ОРГАНОМИНЕРАЛЬНЫХ КОМПОЗИТОВ ДЛЯ ЗАЩИТЫ КЕРАМИЧЕСКИХ ФИЛЬТРУЮЩИХ МАТЕРИАЛОВ

The method of obtaining hybrid organic biocidal structures through the interaction of the guanidine base with alumophosphates and copper hydroxy carbonate has been described. It is established that the reaction products consist of tripolyphosphates and pyrophosphates of aluminum forming ionic bonds with polyhexamethylene guanidine ions and copper (II). It is shown that when applied to the surface of a ceramic filter element at a temperature of 170 °C, a biocidal composite is fixed on them, on average, amounting to 50.0 wt. % of a product that provides the protection of filters from biofouling.Описан метод получения «гибридных» органоминеральных биоцидных структур путем взаимодействия основания полигексаметиленгуанидина с алюмофосфатами и гидрокарбонатом меди. Установлено, что продукты реакции состоят из триполифосфатов и пирофосфатов алюминия, образующих ионные связи с полигексаметиленгуанидином и ионами меди (II). Показано, что при нанесении на поверхности керамических фильтроэлементов при температуре 170 °С биоцидного композита на них закрепляется в среднем 50,0 масс. % продукта, обеспечивающего защиту фильтров от биообрастания

The Role of Phosphatidylethanolamine-N-methyltransferase (PEMT) Gene rs12449964 Polymorphism in the Development of Acute Pancreatitis and its Complications

Background. Acute pancreatitis is considered to be an important issue in modern medicine. The phosphatidylethanolamine-N-methyltransferase enzyme plays a significant role in the regulation of lipid metabolism by catalyzing the process of methylation of phosphatidylethanolamine to phosphatidylcholine. These lipids are key components of mitochondrial and cell membranes, providing their fluid and plastic properties and participating in the transport of fats, fatty acids and cholesterol. Along with its function in the synthesis of phosphatidylcholine, the methylation of phosphatidylethanolamine promotes the turnover of S-adenosylmethionine for the synthesis of cysteine and glutathione through transulphurisation. PEMT is a gene encoding the phosphatidylethanolamine-N-methyltransferase enzyme.Aim. To determine the role of PEMT C/T rs12449964 polymorphism in the risk of developing acute pancreatitis and its complications among Russian residents in Central Russia.Materials and methods. Whole blood samples were collected from 502 unrelated patients with acute non-biliary pancreatitis (97 women and 405 men) of Russian nationality who had been admitted to the surgical departments of the city of Kursk from 2015 to 2018, as well as from 513 unrelated individuals of Russian nationality without gastrointestinal diseases (101 women and 412 men). The average age of patients and healthy individuals was 48.9 ± 13.1 and 47.89 ± 12.1 years, respectively. Genomic DNA was isolated by a standard phenol-chloroform extraction method. Genotyping of rs12449964 polymorphism was performed using real-time PCR by allelic discrimination using a CFX96 Bio-Rad Laboratories amplifier (USA) with TaqMan probes and commercial TaqMan SNP Genotyping Assays reagents purchased from Applied Biosystems (USA).Results. The study has shown that the frequency of the C allele and the C/C PEMT C/T rs12449964 genotype was higher in the group of patients with acute pancreatitis, while the C/T genotype was predominant in the control group. C/T — T/T genotypes demonstrated a protective effect on the development of infected pancreatic necrosis, purulent necrotic peripancreatitis and severe acute pancreatitis.Conclusions. The disruption of phosphatidylethanolamine methylation processes increases the sensitivity of cells to oxidative stress, which can lead to the development of acute pancreatitis

Optimization of Agriculture Land Use Development Basing on Natural-resource Potential (on the Example of the Stavropol Territory)

Natural resources potential of the territory and natural-historical mechanism of its development are pacing factors in agriculture differentiation and AIC-development. Key branches in the Stavropol Territory are crop production, sheep breeding and meat and milk cattle breeding. To meet the market demands “equating” differentiation of agricultural enterprises is implemented. Thus, in Stavropol Territory crop lands have been increased for crops required in the market that disbalanced the crop rotation, disturbed agro technologies and resulted in reduction in yields and grain quality. In the Territory 70 % of tillage is in risky agriculture. About 65 % of crop production (wheat, barley and others) are in draughty areas where out of 141 years (1861–2002) 41 % draughty, which determine high natural-climatic dependence of grain economy [1]. Annual and areal variability of grain production is also determined by topsoil heterogeneity and variety of relief. At present production of the basic market crop – winter wheat, which takes 75 % of acreage for cereals and leguminous crops, the productivity of the cultivated crop is 22.4–39.5 centner/hectare. It results in top soil changes such as compaction, fertilizer impoverishment and organic matter content (organic matter deficit is 400–700 kg/ha). Intensification of agrarian production results in quicker erosion processes, soil properties decline and lower fertility. The total area of eroded lands in the Territory is 1792000 ha [2]. That is why it is important to develop a new model of the economic use of Stavropol Territory. The main methods of study are analysis of the current status and organization of the agricultural zones of the Territory. The data were preceded with the software Statistica

The Role of Phosphatidylethanolamine-N-methyltransferase (PEMT) Gene rs12449964 Polymorphism in the Development of Acute Pancreatitis and its Complications

Background. Acute pancreatitis is considered to be an important issue in modern medicine. The phosphatidylethanolamine-N-methyltransferase enzyme plays a significant role in the regulation of lipid metabolism by catalyzing the process of methylation of phosphatidylethanolamine to phosphatidylcholine. These lipids are key components of mitochondrial and cell membranes, providing their fluid and plastic properties and participating in the transport of fats, fatty acids and cholesterol. Along with its function in the synthesis of phosphatidylcholine, the methylation of phosphatidylethanolamine promotes the turnover of S-adenosylmethionine for the synthesis of cysteine and glutathione through transulphurisation. PEMT is a gene encoding the phosphatidylethanolamine-N-methyltransferase enzyme.Aim. To determine the role of PEMT C/T rs12449964 polymorphism in the risk of developing acute pancreatitis and its complications among Russian residents in Central Russia.Materials and methods. Whole blood samples were collected from 502 unrelated patients with acute non-biliary pancreatitis (97 women and 405 men) of Russian nationality who had been admitted to the surgical departments of the city of Kursk from 2015 to 2018, as well as from 513 unrelated individuals of Russian nationality without gastrointestinal diseases (101 women and 412 men). The average age of patients and healthy individuals was 48.9 ± 13.1 and 47.89 ± 12.1 years, respectively. Genomic DNA was isolated by a standard phenol-chloroform extraction method. Genotyping of rs12449964 polymorphism was performed using real-time PCR by allelic discrimination using a CFX96 Bio-Rad Laboratories amplifier (USA) with TaqMan probes and commercial TaqMan SNP Genotyping Assays reagents purchased from Applied Biosystems (USA).Results. The study has shown that the frequency of the C allele and the C/C PEMT C/T rs12449964 genotype was higher in the group of patients with acute pancreatitis, while the C/T genotype was predominant in the control group. C/T — T/T genotypes demonstrated a protective effect on the development of infected pancreatic necrosis, purulent necrotic peripancreatitis and severe acute pancreatitis.Conclusions. The disruption of phosphatidylethanolamine methylation processes increases the sensitivity of cells to oxidative stress, which can lead to the development of acute pancreatitis