bluuebunny/crossref_metadata_2025 huggingface dataset:
Prospects for international cooperation in the Arctic in the implementation of energy projects
Authors: Spiridonov Andrei
Published: April 2023

The article discusses the prospects of international cooperation in the field of energy, taking into account modern geopolitical trends. Under the conditions of sanctions pressure, Russian companies cannot conduct their activities in the European energy market. In these circumstances, one of the priority strategic tasks for Russia is the development of new export directions for the purpose of energy supplies. As part of the implementation of this task in 2022, Russia was able to significantly increase the volume of Arctic oil supplies to China and India, as well as conclude several long-term contracts for the supply of oil and gas. The development of these areas will not only offset the negative effect of sanctions from Western countries, but also become a driver for the implementation of major infrastructure projects.
Criminal procedural legal personality: the concept, legal nature, and the process of formation
Authors:   Togliatti State University, Zaburdaeva K. A.
Published: April 2023

Despite the existence of a sufficient number of scientific papers on the issues of legal personality, it is prematurely to consider this term developed and understandable, first of all, due to the lack of a scientifically based theoretical concept of legal personality. Based on the analysis of the doctrinal and legal definition of legal personality, the author shows the identified contradictions in the generally accepted understanding of this category, the essence of which is the lack of consistency with the established legal terms – a legal subject, legal status, legal capability, and legal capacity to act. Resolving the identified contradictions, the author comes to the conclusion about the exclusively branch-specific meaning of legal personality, justifying the illogicality of using the term “general legal personality”, and within the theoretical and legal analysis of criminal procedural legal personality, shows the existing relations and dependences between legal personality and legal categories that are close in content – a legal subject and a subject of legal relations, legal status, legal capability, and legal capacity to act. Using a systematic approach in the study of criminal procedural legal personality, the author step by step reveals the process of formation of legal personality, limiting the sphere of its application to law enforcement. Based on the results of the study, the author substantiates the necessity of distinguishing between the concepts of procedural legal personality, a legal subject, legal status, and a subject of legal relations, proposes the author’s definitions of these terms. An understanding of procedural legal personality as a legal property of a specified court procedure participant arising as a result of acquiring the status of a legal subject is formulated. In understanding a criminal procedure subject, the author substantiates two aspects: regulatory and law enforcement. In the regulatory aspect, a legal subject is a generalized, abstract person vested with procedural legal capability and legal capacity to act; in the law enforcement sphere, a legal subject acts as a specified person with procedural legal personality.
Methodological toolkit for evaluating an investment project using the FCFF and FCFE models
Authors:   Togliatti State University, Polteva T. V.
Published: April 2023

Maintaining the competitiveness of enterprises is impossible without the implementation of investment projects. The current global situation, which requires enterprises to use modern solutions aimed at the Russian economy development in the face of sanctions dictates the necessity to develop investment activity. The study substantiates the need to develop methodological tools for evaluating an investment project. Based on the analysis of scientific literature and the systematization of the best practices, the author developed the most complete methodological toolkit for evaluating investment projects according to the FCFF and FCFE models, which allows increasing the assessment objectivity to make the most informed management decisions both on the part of an investment project initiator and on the part of an investor. The following key aspects formed the basis of the developed methodological toolkit for evaluating investment projects: checking a project for feasibility; reasonable choice of the discount rate taking into account a chosen model (FCFF or FCFE); taking into account the specifics of building a cash flow depending on the chosen model (FCFF or FCFE); the exclusion of “double counting”; correct accounting for inflation when forecasting cash flows; the compliance with the relevance principle when forecasting cash flows; taking into account risk and uncertainty when forecasting cash flows; the assessment of the investment project effectiveness; the analysis and assessment of risks from the perspective of various stakeholders (an initiator, an owner, a creditor, the state). The application of the proposed methodological toolkit will make it possible to take into account key aspects when forecasting cash flows, when choosing a discount rate, and when conducting an assessment, and thus will allow project initiators and owners to increase the investment portfolio efficiency due to the most objective assessment of projects.
A methodology for organizing management control as a means of ensuring tax security of an enterprise
Authors:   Togliatti State University, Malyarovskaya A. Yu.
Published: April 2023

In the modern conditions of the development of digitalization, an increase in the volume of the information used and the speed of decision-making, there comes an understanding that the effective control of various business processes can be ensured as promptly and efficiently as possible only through intra-production administration. Management control is designed to provide this function. At the same time, the implementation of control measures in relation to the accomplished facts of economic life is not enough to make effective management decisions. Therefore, it is necessary to carry out both the retrospective and prospective control. This problem determined the aim of this study, which is the development of such methodology for organizing management control, which will ensure the tax security of an economic entity through the application of preliminary and subsequent control procedures. This goal is achieved by clarifying the control environment elements available in the scientific literature and developing a list of relevant procedures for the management control of tax liabilities. The result of this study is the developed methodology for organizing management control, through which an acceptable level of tax security of enterprises is ensured. Within the framework of the study, the author paid special attention to the managerial control procedures, which allow realizing its prospective nature – tax analysis and tax passport completion. Within tax analysis, the author proposes separating the strategic and subsequent analysis. To assess the state of the tax system of an economic entity, a number of coefficients corresponding to the areas of tax analysis were developed and proposed for use in practice. Besides, the author proposed to form a tax passport of an enterprise and determined its structure. The organization of managerial control according to the proposed methodology contributes to the consistency of intra-production tax administration with the requirements of state tax control and ensures the stable tax security of an economic entity and the necessary information component for making management decisions related to tax liabilities.
Strain rate sensitivity of mechanical properties of the ZK60 alloy with the high degree of corrosion damage
Authors:   Togliatti State University, Merson E. D. , Poluyanov V. A. ,   Togliatti State University, Myagkikh P. N. ,   Togliatti State University, Merson D. L. ,   Togliatti State University
Published: April 2023

According to the stable opinion, hydrogen absorbed by magnesium alloys during corrosion can cause their stress corrosion cracking. One of the characteristic markers indicating the involvement of diffusible hydrogen into the fracture mechanism of metals is the negative strain rate dependence of the embrittlement degree. Recent studies show that the loss of ductility of the ZK60 alloy specimens subjected to a short-term (1.5 h) pre-exposure in a corrosive medium actually decreases with the increasing strain rate. However, after the removal of corrosion products from the surface of specimens, the strain rate dependence of the ductility loss becomes positive, which indicates the absence of hydrogen in the bulk of a metal. At a short-term exposure in a corrosive environment, the deep penetration of hydrogen into a metal could be limited due to the insufficient time for hydrogen diffusion. The paper studies the mechanical behavior of the ZK60 alloy subjected to a longer (12 h) pre-exposure in a corrosive medium followed by tensile testing in air at various strain rates. The authors consider the effect of strain rate, long-term pre-exposure in a corrosive medium, and subsequent removal of corrosion products on the strength, ductility, stages of work hardening, and localized deformation, as well as on the state of the side and fracture surfaces of specimens. The study identified that the ductility loss of specimens pre-exposed in a corrosive medium for 12 h decreases with the increasing strain rate, regardless of whether the corrosion products have been removed from their surface or not. It is shown that in this case, the negative strain rate dependence of the ductility loss is associated not with hydrogen dissolved in the bulk of a metal but with the presence of severe corrosion damage of the specimens’ surface. The authors proposed an explanation for the effect of corrosion damage on the mechanical properties and their strain rate sensitivity.
Fatigue strength of 30ХГСА–40ХМФА welded joints produced by rotary friction welding
Authors:   ZBO Drill Industries, Inc., Priymak E. Yu. ,   Orenburg State University, Kuzmina E. A. ,   ZBO Drill Industries, Inc., Gladkovskii S. V. ,   Gorkunov Institute of Engineering Science of the UB RAS, Vichuzhanin D. I. ,   Institute of Engineering Science of Ural Branch of the Russian Academy of Sciences, Veselova V. E. ,   Institute of Engineering Science of Ural Branch of the Russian Academy of Sciences
Published: April 2023

Rotary friction welding (RFW) is used in the production of drill pipes for solid mineral prospecting. The need for the creation of the lightened drill strings for high-speed diamond drilling of ultradeep wells dictates the necessity of a greater focus on the study of a weld zone and setting the RFW technological parameters. This paper presents the results of experimental studies of a welded joint of a drill pipe of the H standard size according to ISO 10097, made of the 30ХГСА (pipe body) and 40ХМФА (tool joint) steels under the cyclic loads. The authors evaluated the influence of the force applied to the workpieces in the process of friction of the contacting surfaces (force during heating), and postweld tempering at a temperature of 550 °С on the cyclic life of welded joints, under the conditions of alternate tension-compression at the cycle amplitude stress of ±420 MPa. The study determined that with an increase in the force during heating, the microstructure changes occur in the zone of thermomechanical influence, contributing to an increase in the fatigue strength of welded joints. The authors identified the negative effect of postweld tempering on the fatigue strength of welded joints, which is expressed in the decrease in the number of cycles before failure by 15–40 %, depending on the magnitude of the force during heating. The optimal RFW mode of the specified combination of steels is determined, which provides the largest number of cycles before failure: the force during heating (at friction) Fh=120 kN, forging force Ffor=160 kN, rotational frequency during heating n=800 Rpm, and upset during heating l=8 mm. A series of fatigue tests have been carried out at various values of the cycle amplitude stress of the welded joint produced at the optimal mode and the 30ХГСА steel base metal; limited endurance curves have been plotted. It is shown that the differences in the limited endurance curves of the pipe body material (30ХГСА steel) and the welded joint are insignificant. The obtained results are supplemented by the microhardness measurement data and fractographs of fractured samples, revealing the mechanism of crack propagation under the cyclic loads.
The study of the influence of micro-arc oxidation modes on the morphology and parameters of an oxide coating on the D16AT aluminum alloy
Authors:   Komsomolsk-na-Amure State University, Bao Fengyuan , Bashkov O. V. ,   Komsomolsk-na-Amure State University, Zhang Dan ,   Heilongjiang University of Science and Technology, Lyu Lan ,   Komsomolsk-na-Amure State University,   Heilongjiang University of Science and Technology, Bashkova T. I. ,   Komsomolsk-na-Amure State University
Published: April 2023

An effective way to protect valve metals and their alloys is the micro-arc oxidation method (MAO), which is currently used in various industries. However, to achieve the desired characteristics and properties of oxide coatings, a large number of experiments are required to determine an optimal oxidation mode, which makes the MAO method labor-intensive and resource-consuming. One of the ways to solve this problem is the search for an informative parameter or several parameters, the use of which during the oxidation process monitoring allows identifying a relationship between the MAO modes and the specified characteristics of oxide coatings. This paper studies the influence of the specified technological MAO modes (current density, oxidation time, amplitude of acoustic emission (AE) signals recorded during MAO) on the morphology and parameters of oxide coatings (thickness δ and surface roughness Ra) deposited on the D16AT aluminum alloy clad with pure aluminum. Multivariate planning of an experiment and the performed regression analysis allowed establishing a relationship between two oxidation factors (current density and oxidation time) and the parameters of the produced coatings. The authors proposed an additional factor, which is determined in the monitoring mode during the oxidation process as the time from the moment when the maximum or minimum of the acoustic emission (AE) amplitude recorded in the MAO process is reached until the end of the oxidation process. The study established that the introduction of an additional factor allows increasing significantly the reliability of the dependence between the coating parameters obtained experimentally and by the computational method based on the regression analysis. The authors note that when performing MAO, with the additional use of the MAO process monitoring by recording the AE amplitude, it is possible to achieve a high reliability between the calculated and actual values of the parameters of oxide coatings.
DETERMINATION OF THE OPTIMAL PHYSICAL AND MATHEMATICAL MODEL AND WEIGHT FUNCTIONS FOR CALCULATING THE TOPOLOGY OF COUNTERPINE CONVERTERS OF SURFACE ACOUSTIC WAVES
Authors: Lepikh Ya. I.
Published: April 2023

The article is devoted to the analysis of existing physical and mathematical models describing the operation of Rayleigh’s counter-pin converters of surface acoustic waves (SAW), which are widely used in acoustoelectronics in the creation of microelectronic devices of various functional purposes. The weighting functions are also analyzed, with the help of which the topology of the counter-in converters is adjusted in order to reduce the influence of Gibbs pulsations.
The advantages and disadvantages of each of the physical and mathematical models, as well as weighting functions from the point of view of achieving the specified requirements for the characteristics of devices on the characteristic curve, are also considered.
DEVELOPMENT OF CONDUCTOMETRIC ARGININE-SENSITIVE BIOSENSOR BASED ON ARGININE DEIMINASE
Authors: Berketa K. O. , Saiapina O. Y. , Fayura L. R. , Sibirny A. A. , Dzyadevych S. V. , Soldatkin O. O.
Published: April 2023

An arginine-sensitive conductometric biosensor was developed. Two pairs of gold interdigitated electrodes deposited on the ceramic substrate were used as a conductometric transducer. Arginine deiminase was used to create a bioselective membrane. The enzyme was immobilized on the sensitive surface of one pair of electrodes of the conductometric transducer by covalent crosslinking with glutaraldehyde; a reference membrane based on bovine serum albumin was deposited on the second pair of electrodes.
The optimal conditions of enzyme immobilization (enzyme concentration, duration and method of immobilization) were determined. The influence of solution parameters (ionic strength, buffer capacity, pH and protein concentration) on the operation of the developed biosensor was studied as well as stability of its functioning and storage. The iosensor  selectivity and main analytical characteristics detection limit, linear and dynamic ranges of the iosensor operation etc.) were investigated. The proposed biosensor was shown to be promising for the quantitative determination of arginine content in real samples.
«Split» of the Peopleʼs Movement of Ukraine in 1999 (retrospective analysis)
Authors: Ovsiienko Stanislav
Published: April 2023

Among all national political parties there are the «right-wing» parties, which have always stood for the protection of state interests stand out. Among these parties, the People’s Movement, which was the hegemon of the national-democratic camp during the 1990s, occupies a special place. The «split» of the NRU in 1999 was a resonance event, because the crisis embrace the largest state-owned party, the situation in which depended on the future path of the country’s development.
O. Melnikova, A. Rusnachenko, S. Hrytsai, l. Rozhkova, G. Honcharuk addressed the problem of the NRU «split» in 1999 in their researches. Therefore, the goal of the article is an attempt to rethink such a phenomenon as the NRU «split» in 1999, which was the subject of the dissertation study, its causes, the course of events against the background of nationwide processes, consequences, coverage in the press, based on the challenges of the Ukrainian present time.
Biased media were inclined to accuse political rivals of the centrality of internal party processes in the NRU.
The «split» in the NRU in 1999 is a natural crisis process that had a subjective and objective nature. The crisis in the NRU and the «split» as its consequence arose as a result of the activities of the party (political and business) leadership. The situation in the NRU and in the entire party environment was an objective process that was caused by the method of creation and development of the party movement in Ukraine.
The analysis of the course of events in the NRU since the 1998 elections gives grounds to assert that the «split» was not a surprise.
The problem of the «split» in the NRU took place against the background of the problem of the participation of movement activists in the elections and the problem of the unity of the National Democrats and the nomination of a single candidate. The reasons for the Movement’s defeat in the presidential elections were both purely party factors and formal factors of campaigning.
The end of 1999 was the final stage in the «split» of the NRU, on the basis of which two parties were formed. As a result of the «split», the influence of the Movement on processes in the country weakened both at the higher and local levels; a tangible blow was inflicted on the entire national-democratic camp.
The «red threat» to the existence of independent Ukraine was the factor that forced the majority of national democratic parties to vote for l. Kuchma, as the «lesser evil».
An analysis of a number of periodicals from the end of 1999 to 2001 showed that crisis processes continued in the NRU and UNR.
The oligarchic system formed in the times of Leonid Kuchma and Russian threats were the challenges that at the beginning of the 21st century forced the Movements and other right-centered forces, despite the party egoism, to unite around new leaders, political projects and together with the nationally conscious part of society to fight for civil rights and freedoms, for the territorial integrity and independence of Ukraine.
Metabolomic approach to investigate Dactylis glomerata L. from the VIR collection
Authors: Malysheva N. Yu. , Shelenga T. V. , Solovyeva A. E. , Nagiev T. B. , Kovaleva N. V. , Malyshev L. L.
Published: April 2023

The perennial grass cocksfoot (Dactylis glomerata L.) is a valuable early highly nutritious crop used as green fodder in agricultural production. The species is widespread across the Eurasian continent; it is characterized by plasticity and high ecological and geographical variability. The article considers the metabolic profiles of 15 accessions of the cocksfoot from the collection of the N.I. Vavilov Institute of Plant Genetic Resources (VIR). The material is represented by varieties and wild forms of various origin: the European part of the Russian Federation, Norway and Finland. The study was carried out using gas-liquid chromatography coupled with mass spectrometry. The study and comparison of groups of metabolites of cocksfoot accessions of various ecological and geographical origin was carried out. Statistical processing included the calculation of the main parameters of variability, factor analysis of the correlation system (Qand R-technique), cluster analysis by Ward’s method and discriminant analysis. The variability of the quantitative and qualitative composition of the substances identified was revealed. Based on statistical processing of the results obtained, five groups of cocksfoot accessions were identified, differing in the profile of metabolites. One of the groups with a similar composition of metabolites consisted of accessions from one ecological and geographical region; another, of accessions of different origin. Significant differences were noted in the metabolomic profiles of a late-maturing wild cocksfoot accession from the Republic of Karelia at the booting stage from earlyand mid-maturing accessions at the heading stage; it contained the largest number of free amino acids and the smallest number of identified primary and secondary metabolites. Wild-growing accession k-44020 from Norway surpassed other wild-growing accessions in the content of free amino acids, sugars and phosphates at the heading stage. Wildgrowing accessions differed from breeding varieties with a high content of proline and threonine, indicators of high resistance to lack of moisture and high air temperature.
Alkaloid content variability in the seeds of narrow-leafed lupine accessions from the VIR collection under the conditions of the Russian Northwest
Authors: Vishnyakova M. A. , Salikova A. V. , Shelenga T. V. , Egorova G. P. , Novikova L. Yu.
Published: April 2023

Alkaloid content was assessed in the seeds of 59 narrow-leafed lupine (Lupinus angustifolius L.) accessions from the VIR collection in the environments of Leningrad Province. The selected set included accessions of different statuses (wild forms, landraces, and advanced cultivars) and different years of introduction to the collection. Alkaloids were analyzed using gas-liquid chromatography coupled with mass spectrometry. Concentrations of main alkaloids: lupanine, 13-hydroxylupanine, sparteine, angustifoline and isolupanine, and their total content were measured. The total alkaloid content variability identified in the seeds of the studied set of accessions was 0.0015 to 2.017 %. In most cases, the value of the character corresponded to the accession’s status: modern improved cultivars, with the exception of green manure ones, entered the group with the range of 0.0015–0.052 %, while landraces and wild forms showed values from 0.057 to 2.17 %. It is meaningful that the second group mainly included accessions that came to the collection before the 1950s, i. e., before the times when low-alkaloid cultivars were intensively developed. Strong variability of the character across the years was observed in the accessions grown under the same soil and climate conditions in both years. In 2019, the average content of alkaloids in the sampled set was 1.9 times higher than in 2020. An analysis of weather conditions suggested that the decrease in alkaloid content occurred due to a significant increase in total rainfall in 2020. Searching for links between the content of alkaloids and the type of pod (spontaneously non-dehiscent, or cultivated, spontaneously dehiscent, or wild, and intermediate) showed a tendency towards higher (approximately twofold in both years of research) total alkaloid content in the accessions with the wild pod type and the nearest intermediate one compared to those with the pod non-dehiscent without threshing. The correlation between the average total alkaloid content and seed color, reduced to three categories (dark, or wild, light, or cultivated, and intermediate), was significantly stronger in the group with dark seeds (5.2 times in 2019, and 3.7 times in 2020). There were no significant differences in the percentage of individual alkaloids within the total amount either between the years of research or among the groups with different pod types or the groups with different seed coat colors.
DNA marker identification of downy mildew resistance locus Rpv10 in grapevine genotypes
Authors: Ilnitskaya E. T. , Makarkina M. V. , Toкmakov S. V. , Naumova L. G.
Published: April 2023

One of the most common and harmful diseases of grapevine is downy mildew, caused by Plasmopara viticola. Cultivars of Vitis vinifera, the basis of high-quality viticulture, are mainly not resistant to downy mildew. Varieties with natural resistance to downy mildew belong to the vine species of North America and Asia (V. aestivalis, V. berlandieri, V. cinerea, V. labrusca, V. amurensis, etc.), as well as Muscadinia rotundifolia. The breeding of resistant cultivars is based on interspecific crossing. Currently, molecular genetic methods are increasingly used in pre-selection work and directly in breeding. One of the major loci of downy mildew resistance, Rpv10, was first identified in the variety Solaris and was originally inherited from wild V. amurensis. DNA markers that allow detecting Rpv10 in grapevine genotypes are known. We used PCR analysis to search for donors of resistance locus among 30 grape cultivars that, according to their pedigrees, could carry Rpv10. The work was performed using an automatic genetic analyzer, which allows obtaining high-precision data. Rpv10 locus allele, which determines resistance to the downy mildew pathogen, has been detected in 10 genotypes. Fingerprinting of grape cultivars with detected Rpv10 was performed at 6 reference SSR loci. DNA marker analysis revealed the presence of a resistance allele in the cultivar Korinka russkaya, which, according to publicly available data, is the offspring of the cultivar Zarya Severa and cannot carry Rpv10. Using the microsatellite loci polymorphism analysis and the data from VIVC database, it was found that Korinka russkaya is the progeny of the cultivar Severnyi, which is the donor of the resistance locus Rpv10. The pedigree of the grapevine cultivar Korinka russkaya was also clarified.
Stability analysis for seed yield of chickpea (Cicer arietinum L.) genotypes by experimental and biological approaches
Authors: Karimizadeh R. , Pezeshkpour P. , Mirzaee A. , Barzali M. , Sharifi P. , Safari Motlagh M. R.
Published: April 2023

A range of environmental factors restricts the production of chickpea; therefore, introducing compatible cultivars to a range of environments is an important goal in breeding programs. This research aims to find high-yielding and stable chickpea genotypes to rainfed condition. Fourteen advanced chickpea genotypes with two control cultivars were cultivated in a randomized complete block design in four regions of Iran during 2017–2020 growing seasons. The first two principal components of AMMI explained 84.6 and 10.0 % of genotype by environment interactions, respectively. Superior genotypes based on simultaneous selection index of ASV (ssiASV), ssiZA, ssiDi and ssiWAAS were G14, G5, G9 and G10; those based on ssiEV and ssiSIPC were G14, G5, G10 and G15 and those based on ssiMASD were G14, G5, G10 and G15. The AMMI1 biplot identified G5, G12, G10 and G9 as stable and high-yielding genotypes. Genotypes G6, G5, G10, G15, G14, G9 and G3 were the most stable genotypes in the AMMI2 biplot. Based on the harmonic mean and relative performance of genotypic values, G11, G14, G9 and G13 were the top four superior genotypes. Factorial regression indicated that rainfall is very important at the beginning and end of the growing seasons. Genotype G14, in many environments and all analytical and experimental approaches, has good performance and stability. Partial least squares regression identified genotype G5 as a suitable genotype for moisture and temperature stresses conditions. Therefore, G14 and G5 could be candidates for introduction of new cultivars.
The mitochondrial genome of Dendrobaena tellermanica Perel, 1966 (Annelida: Lumbricidae) and its phylogenetic position
Authors: Shekhovtsov S. V. , Vasiliev G. V. , Latif R. , Poluboyarova T. V. , Peltek S. E. , Rapoport I. B.
Published: April 2023

Earthworms are an important ecological group that has a significant impact on soil fauna as well as plant communities. Despite their importance, genetic diversity and phylogeny of earthworms are still insufficiently studied. Most studies on earthworm genetic diversity are currently based on a few mitochondrial and nuclear genes. Mitochondrial genomes are becoming a promising target for phylogeny reconstruction in earthworms. However, most studies on earthworm mitochondrial genomes were made on West European and East Asian species, with much less sampling from other regions. In this study, we performed sequencing, assembly, and analysis of the mitochondrial genome of Dendrobaena tellermanica Perel, 1966 from the Northern Caucasus. This species was earlier included into D. schmidti (Michaelsen, 1907), a polytypic species with many subspecies. The genome was assembled as a single contig 15,298 bp long which contained a typical gene set: 13 protein-coding genes (three subunits of cytochrome c oxidase, seven subunits of NADH dehydrogenase, two subunits of ATP synthetase, and cytochrome b), 12S and 16S ribosomal RNA genes, and 22 tRNA genes. All genes were located on one DNA strand. The assembled part of the control region, located between the tRNA-Arg and tRNA-His genes, was 727 bp long. The control region contained multiple hairpins, as well as tandem repeats of the AACGCTT monomer. Phylogenetic analysis based on the complete mitochondrial genomes indicated that the genus Dendrobaena occupied the basal position within Lumbricidae. D. tellermanica was a rather distant relative of the cosmopolitan D. octaedra, suggesting high genetic diversity in this genus. D. schmidti turned out to be paraphyletic with respect to D. tellermanica. Since D. schmidti is known to contain very high genetic diversity, these results may indicate that it may be split into several species.
Genetic profile of domestic cat (Felis catus L.) population of Aoshima Island (Japan)
Authors: Kholin S. K.
Published: April 2023

The paper analyzes the genetic profile of the domestic cat population of the Aoshima Island. The population has been established in the middle of the last century, after a small group of animals was imported for rodent control. Based on three photographs, the genotypes of the cats in three overlapping groups (75, 56, and 70 individuals) were determined. The mutant allele frequencies of the sex-linked O (Orange) locus and the three autosomal loci a, W, and l (Agouti, White, and Long hair) responsible for coat color and length were estimated. The population lacks the mutant alleles d (Dilution locus), W and wg (White), tab (Tabby), TiA (Ticked) present in other populations of Japan. This is an almost monomorphic population with prevailing red and tortoiseshell individuals. Most cats have interrupted stripes (genotype Ti+Ti+TaM-). The island’s population differs from the other populations of the Japanese islands in the frequencies of two mutant alleles, O and a. The frequency of the O allele (q(O) = 0.580) is one of the highest in the region, while the frequency of the a allele (q(a) = 0.276) is two times lower than in the other populations. In both cases, the differences in frequencies between the neighbouring populations are significant (p < 0.0001). An independent study of the same population revealed a similar genetic structure. However, it detected the presence of the d allele, the frequency of the a allele was higher (0.534 versus 0.276, p < 0.020). The genetic profile, frequencies of mutant alleles in the population, and history of its origin indicate a significant influence of the founder effect on the genetic structure of the island’s domestic cat population.
Assessment of adherence to therapy in comorbid patients
Authors: Khidirova L. D. , Yakhontov D. A. , Madonov P. G.
Published: April 2023

Objective. To evaluate adherence to therapy in patients with hypertension (HTN) and atrial fibrillation (AF) in combination with extracardiac comorbid pathology. Design and methods. In an observational cohort study, 884 patients aged 45–65 years with AF (paroxysmal and persistent form) and HTN were observed, in combination with extracardiac comorbid diseases: diabetes mellitus (DM), n = 123; abdominal obesity (AO), n = 171; chronic obstructive pulmonary disease (COPD), n = 137, hypothyroidism, n = 156; thyrotoxicosis, n = 112. The comparison group consisted of 185 patients with AF and HTN, without concomitant extracardiac pathology. Clinical, anthropometric parameters, the Morischi–Green adherence test were evaluated in the work. To assess the social aspects of low adherence, special questionnaires were developed. All statistical calculations were performed using the Rstudio program. Results. Among patients with AF and HTN, 66 % had concomitant extracardiac comorbid pathology, 20 % of them with DM; COPD was detected in 22 % of patients, and AO was observed in 44 % of patients, 6 % patients had thyroid disease. 15,2 % patients were insufficiently adherent (ADH), 37,2 % were not adherent to therapy (NADH), and only 47,8 % respondents were adherent to therapy. The duration of HTN was not a significant motivation for adherence, because the NADH group had a significantly longer duration of arterial hypertension compared with the ADH group (12.3 vs 10.5 years; p < 0.03); patients with the permanent form of AF were more than ADH (p = 0,001), and the adherence did not differ between groups depending on extracardiac diseases. The blockers of the renin-angiotensin-aldosterone system showed the greatest use — up to 66 %, while adherent patients were more likely to take single-pill combination (SPC) of perindopril (SPC indapamide/perindopril and SPC amlodipine/indapamide/perindopril) (p = 0,003; p = 0,01). Based on the analysis, it was found that the presence of a family, higher education, income level, motivation and trust in doctors are significant factors that increase adherence to treatment. Conclusions. The problem of non-commitment has been and remains one of the most complex and difficult to solve. The main reason for low adherence among patients with AF with concomitant extracardiac diseases was polypharmacy, and it is associated with the use of a large number of drugs and a complex treatment regimen. Thus, the limitation of the use of fixed combinations is one of the main reasons for the lack of adherence and needs to be addressed soon.
Sleep reactivity to stress and insomnia: sleep measures and molecular markers
Authors: Gordeev A. D. , Bochkarev M. V. , Korostovtseva L. S. , Zabroda E. N. , Amelina V. V. , Osipenko S. I. , Sviryaev Yu. V. , Alekhin A. N.
Published: April 2023

Objective. To identify objective measures of sleep and molecular markers of sleep reactivity to stress to determine its role for insomnia prevention and management. Design and methods. The sample included 42 subjects with sleep disturbances and 23 subjects without sleep-related complaints (control group) aged 18 to 72 years. Altogether there are 19 men and 55 women. Nine participants were excluded from the study. Sleep reactivity to stress was assessed using the Ford Insomnia Response to Stress Test (FIRST) questionnaire. The Integrative Anxiety Test was used to screen for anxiety. Sleep indices were assessed by polysomnography (PSG). Blood plasma samples were collected in the morning after PSG to determine brain-derived neurotrophic factor (BDNF), and 24-hour urine was collected one week after PSG to assess metanephrine levels. Results. There were 64 % healthy subjects with low sleep reactivity to stress and low anxiety and 79 % subjects showed insomnia among persons with high sleep reactivity and anxiety. Significant differences in PSG measures were found in groups with low and high sleep reactivity: the efficiency of sleep and the percentage of the second stage of NREM sleep were higher in group with low reactivity, also sleep latency and wake time after sleep onset were lower in group with high reactivity. In addition, serum BDNF level was significantly higher in group with low reactivity, and it correlates positively with daily urinary metanephrine excretion and the absolute duration of stage N3 and negatively with sleep latency. Conclusions. Subjects with high reactivity to stress have lower sleep quality and depth that corresponds to other studies. The level of BDNF is a possible marker of sleep reactivity to stress and it can indicate the potential adaptation to stress.
The problem of hyperuricemia in the hypertensive population of the Nizhny Novgorod region
Authors: Borovkova N. Yu. , Kurashin V. K. , Tokareva A. S. , Krisanova K. I. , Savitskaya N. N. , Pershina N. K. , Makarova E. V. , Nekrasov A. A. , Doyutova M. V. , Zelyaeva N. V. , Mazhara R. A.
Published: April 2023

Objective. To assess the prevalence of hypertension (HTN) in the population of the Nizhny Novgorod region and its relationship with hyperuricemia (HU) and other cardiovascular risk factors. Design and methods. We examined 2501 people aged 35–74 in the population of the Nizhny Novgorod region, selected by the stratified multi-stage random sample. All respondents underwent a laboratory study of the following parameters: total cholesterol, low-density lipoproteins (LDL), high-density lipoproteins, triglycerides (TG), fasting glucose, creatinine, uric acid, highly sensitive C-reactive protein (Hs-CRP) and fibrinogen. We also calculated body mass index (BMI), visceral obesity index with Amato formula and glomerular filtration rate with CKD-EPI formula. Binary logistic regression method was used to construct a predictive model for the risk of HTN. Statistical analysis was performed with IBM SPSS Statistics 26 software (USA). Results. HU was identified in 29,3 % of respondents with HTN. The mean uric acid level in this group was 345,1 [285,6; 410,55] µmol/l and significantly differed from the same indicator in residents without HTN — 297,5 [249,9; 351,1] µmol/L (p < 0,001). In the multiple logistic regression model, the most significant factors associated with HTN were age over 53 years (odds ratio (OR) 2,954, 95 % confidence interval (CI) 2,456-3,554 p < 0,001), abdominal obesity (OR 2,112, 95 % CI 1,663-2,730, p < 0,001) and HU (OR 1,709, 95 % CI 1,341–2,177, p < 0,001). A lesser contribution was made by such factors as the respondents’ BMI over 25 kg/m2 (OR 1,634, 95 % CI 1,262–2,117, p < 0,001), elevated TG level (OR 1,567, 95 % CI 1,289–1,906, p < 0,001), male gender (OR 1,553, 95 % CI 1,281–1,883, p < 0,001), elevated Hs-CRP (OR 1,498, 95 % CI 1,242–1,806, p < 0,001), elevated LDL (OR 1,277, 95 % CI 1,038–1,570, p = 0,020). Conclusions. The results of the study indicate the widespread prevalence of HU in residents of the Nizhny Novgorod region with HTN: almost every third (29,3 %) had this disorder. In a multiple logistic regression model, HU was found to be highly correlated with HTN (OR 1,709, 95 % CI 1,341–2,177, p < 0,001), along with traditional cardiovascular risk factors such as male gender, age, overweight and obesity, lipid metabolism disorders. The high frequency of HU, its independent correlation with HTN, and the prospects for urate-lowering therapy in the prevention of cardiovascular diseases determine the need for further research.
Estimation of metabolic burden within the concept of vascular ageing in hypertension (a study of the able-bodied population of a large industrial center)
Authors: Malinova L. I. , Dolotovskaya P. V. , Furman N. V. , Tolstov S. N. , Klochkov V. A. , Denisova T. P.
Published: April 2023

The objective of the study was to assess the metabolic burden within the concept of vascular ageing in hypertension (HTN) based on the results the able-bodied population study of a large industrial center. Design and methods. A continuous non-randomized cross-sectional study was performed, it included the employees of two medium-sized industrial and commercial enterprises (n = 547). All subjects underwent a formalized medical questionnaire aimed at identifying cardiovascular risk factors, symptoms and signs of cardiovascular pathology, measuring blood pressure (BP), serum levels of total cholesterol, high-density lipoproteins cholesterol, low-density lipoproteins cholesterol, triglycerides, glucose, creatinine and uric acid. Values for 10-year risk of fatal cardiovascular events, total cardiovascular risk, vascular age, and metabolic burden were calculated. Results. In the formed sample, the metabolic burden varied from 0.00 (0.00; 28.57) % in patients with low BP (without antihypertensive medication) to 42,86 (42,86; 57,14) % in patients with the 3rd degree HTN. Positive relationships were found between the magnitude of the metabolic burden, the level of systolic BP (R = 0,432; p < 0,01), diastolic BP (R = 0,360; p < 0,01), 10-year risk of fatal cardiovascular events (R = 0,777; p < 0,01) and total cardiovascular risk (R = 0,781; p < 0,01). Patients with HTN who achieved target BP differed from those with similar BP levels by higher metabolic burden values (p < 0,05). Conclusions. HTN is associated with an increase in metabolic burden, regardless of BP level achieved during treatment. Metabolic burden assessment may be useful in identifying potentially unfavorable HTN phenotypes.
The possibilities of the new START indicator in the assessment of vascular stiffness in healthy individuals
Authors: Sumin А. N. , Shcheglova A. V. , Bakholdin I. B.
Published: April 2023

Objective. To study the possibility of using the new arterial stiffness index START in healthy individuals of different ages. Design and methods. The study included data from healthy individuals without any medical history (n = 190), 121 men and 69 women aged 25–64 years. Arterial stiffness was assessed for all subjects on the VaSera VS-1000 device (Fukuda Denshi, Japan). As an additional parameter, the new domestic stiffness index START was analyzed retrospectively. Results. The average age of the participants was 37,0 ± 8,1 years, 63,7 % men. The median of the CAVI index was 6,6 on the right, 6,7 on the left. The median of the START index was 5,02 on the right, 5,3 on the left. A strong correlation between CAVI and START indicators was found (r = 0,829, p < 0,001). The relationship of age with the CAVI and START indices was established (CAVI r = 0,469, p < 0,001, START r = 0,49, p < 0,001). The dependence of vascular wall stiffness indicators on smoking experience (CAVI r = 0,458, p < 0,001, START r = 0,466, p < 0,001), glomerular filtration rate (GFR) (CAVI r = –0,265, p < 0,001, START r = –0,282, p < 0,001) was found. The gender features of the dependence of vascular wall stiffness on the level of high-density lipoproteins (HDL) (in women, CAVI r = 0,241, p = 0,048; START r = 0,358, p = 0,003) and body mass index (BMI) (in women, CAVI r = 0,411, p = 0,027, START r = 0,374, p = 0,046). Conclusions. When examining healthy individuals, a high correlation of the new START index with the CAVI index was shown both in the whole sample and in men and women separately. The START index had a statistically significant correlation with age, smoking experience and GFR among all surveyed, as well as with HDL and BMI in women.
Diagnosis of pheochromocytoma and paraganglioma. Focus on chromogranin A
Authors: Kravchuk E. N. , Tsoy U. A. , Kruk A. S. , Vasilyeva E. Yu. , Grineva E. N.
Published: April 2023

Objective. To analyze the results of a laboratory examination for chromogranin A in the blood performed in the laboratory at Almazov National Medical Research Centre in patients with confirmed diagnosis of pheochromocytoma/paraganglioma (PPGL) and in patients with unconfirmed neuroendocrine tumor based on the results of a comprehensive examination and to determine the possibilities of this method in the diagnosis of PPGL. Design and methods. A single-center retrospective cohort study was conducted. Electronic medical histories of patients with valid chromogranin A blood test in the period from 2015 to 2021 were studied. The patients included in the study were divided into 2 groups. Group 1 (study group) included 51 patients with a confirmed diagnosis of PPGL, and Group 2 (control group) included 120 patients, who were examined for suspected neuroendocrine tumor, but the diagnosis was not confirmed. The threshold value of chromogranin A was determined using ROC-analysis, the presence of PPGL was selected as a dependent variable. Results. The median of chromogranin A in the study group was 495,93 µg/l (0–100). According to the ROC-analysis, the optimal point of separation of the chromogranin A value for the diagnosis of PPGL with a test sensitivity of 82,4 %, specificity of 94,2 % (area under curve AUC — 0,939, standard error — 0,024, 95 % confidence interval — 0,892–0,986, p < 0,001) was 97,2 µg/l. After dividing patients with PPGL into 3 subgroups, depending on the size of the adrenal gland formation and the prevalence of the lesion according to computer tomography (less than 5 cm — subgroup 1, 5 cm or more — subgroup 2, multiple lesion — subgroup 3), the sensitivity of the threshold value of chromogranin A 97 µg/l in subgroup 1 was 70 %, in subgroup 2 — 95 % and in subgroup 3 — 82 %. Conclusions. Performing a blood test for chromogranin A can be used as an effective marker of PPGL, complementing the standard methods of laboratory diagnostics. This indicator may be an additional factor in the diagnosis of PPGL, especially in the presence of large formations, but the absence of an increase in chromogranin A should not be used to exclude the diagnosis.