bluuebunny/crossref_metadata_2025 huggingface dataset:
A method and a model framework for planning R&D changes in manufacturing enterprises
Authors:   Saint Petersburg University, Stoianova Olga V. , Moskaleva Valeriia D. ,   Saint Petersburg University
Published: March 2021

This paper presents a method and a model framework for R&D changes planning in manufacturing enterprises, implementing digital transformation projects. The relevance of development of such method is evident because of growing number of factors, influencing the decision-making process and simultaneously the complexity of such influence estimation increases. Classical changes planning methods in such cases do not ensure required level of estimation objectivity and credibility. The objects of research are industrial enterprises, actively engaged in research, design and engineering. The subject of research are methods and models for R&D process changes planning in context of digital transformation endeavors, being implemented in the companies. The research objective is to develop a R&D process planning method, enabling to account for corporate changes, related to digital transformation processes. The proposed method is based on the analysis of the discrepancies between the actual enterprise architecture and the target one and search for possible solution to rectify these discrepancies. For quantitative estimation of the changes, an integral indicator "stakeholder satisfaction level" is proposed. This indicator is calculated using a set of models (a model framework), those preparation and application sequence is defined by the considered method. The paper describes the concept of the method, the problems, being solved within each stage, tools used and final outcomes. The example of planning R&D changes in manufacturing enterprise illustrates the method in work and provides for better understanding of the concepts, presented in the paper.
Virtualization technologies and information system security
Authors:   Synergy University, Puzynya Tatyana A. , Lokhtina Irina V. ,   Synergy University, Vlasova Ekaterina A. ,   Synergy University
Published: March 2021

The relevance of the study is dictated by the introduction of digitalization in all spheres of human life, and timely protection of information and personal data of citizens in the first place. The objective of the study was the need to transform the methods and approaches of information protection during its transmission, creation and storage. Methodological arsenal of the study is presented by scientific methods of cognition of the studied phenomenon content, the structuring of its components and the system of generalization, and analysis of the causal relationship between the visualization functionality and information security of management decisions. The author analyzed the main virtualization technologies for digital business transformation and concluded that there is the need to improve the legal framework in this area. The significance of this article lies in the fact that the use of the virtualization method will increase the level of business security with minimal losses. Current GOST R 56938-2016 "Information protection when using virtualization technologies" does not fully reflect the issues of information protection in terms of its visualization, which leads to the need to improve the legal framework when using virtualization technologies for data protection. It is essential to pay special attention to cloud storage, collaboration and communication services, remote project management programs, cybersecurity solutions, and CRM systems. This is particularly relevant today during the emergence of virtual workplaces and transferring employees to remote work from home.
Matters of economic ecosystem classification
Authors:   Saint Petersburg State University, Chernova Galina V. , Kalayda Svetlana A. ,   Saint Petersburg State University, Khalin Vladimir G. ,   Saint Petersburg State University, Yurkov Alexander V. ,   Saint Petersburg State University
Published: March 2021

Economic convergence and digitalization are the most important trends of the modern community development. It is their interaction that creates new opportunities for the improvement of competitive capability and performance in the framework of joint business conducted by representatives of the wide variety of segments and sectors of economy. In response to digitalization, an ecosystem becomes the main institutional and organizational form of business in the framework of inter-sectoral economic convergence. The purpose of this article is to define more exactly the concept of an ecosystem as a form of doing joint business in the environment of inter-sectoral economic convergence and digitalization, and to build a classification of ecosystems. The following hypothesis is put forward in the study: an ecosystem as an institutional and organizational form of doing joint business is the result of the concurrent impact of inter-sectoral economic convergence and digitalization thereon, and the "connection of the base product provided to customer by the inter-sectoral economic convergence initiator prior to creating an ecosystem with digital and/or information technology" may be a criterion for classification of economic ecosystems. The novelty of the approach is as follows. The consideration of an ecosystem as a form of doing joint business simultaneously influenced by economic inter- sectoral convergence and digitalization has made it possible to define more exactly the concept of an ecosystem, identify an ecosystem parameter to be applied for classification of ecosystems and the main characteristic thereof the values of which may be used to classify economic ecosystems.
Data Mining technologies in managing the assortment of trading companies
Authors:   Russian University of Transport (MIIT), Loginova Lyudmila N. , Shash Alexander M. ,   Russian University of Transport (MIIT)
Published: March 2021

In the conditions of fierce competition, satisfaction of all customer needs provides a trading enterprise with a sustainable competitive advantage. With the traditional structure of the assortment, there is a decrease in both the potential and real level of profit, the loss of competitive positions in promising markets, and, therefore, there is a decrease in the stability of the enterprise. The development of an analysis system to determine the specifics of the product range, optimize the range, and adapt it to the conditions of the Russian market is undoubtedly an urgent task. This article provides an overview of trade and IT companies that use data mining technologies. The survey showed that many companies are using data mining technology to improve customer service, turnover and sales in stores. In this regard, the management of Familia decided to develop its own software that will combine the analysis of turnover and sales in the company's stores in order to increase sales and improve the placement of goods in stores so that the client buys the necessary things, increasing the company's profit. The paper shows the possibility of combining several data mining methods in one system; shows the results of the analysis system and shows the effectiveness of the developed analysis system at Familia. The uniqueness of the developed software is the combination of data mining algorithms into one software product. The developed analysis system, based on the joint work of two data mining algorithms K-means and Apriori, allows you to manage the range of trade enterprises, reducing company losses.
Net worth and Mental Health Problems
Authors: Lee J , Allen J
Published: March 2021

Assets and debts and other accumulated wealth should be considered to understand one’s mental health because they influence quality of life over time. Researchers acknowledge limitations of previous studies regarding mental health, which did not consider net worth [1]. Previous studies have mainly addressed Socioeconomic Status (SES) as an indicator influencing mental health [2,3], rather than considering net worth. As a result, the importance of net worth (Wealth and debt) has been growing, and these factors should be included to deeply understand mental health [1].
ADIPOSE TISSUE AS THE MOST IMPORTANT ELEMENT DETERMINING THE QUALITY OF PORK
Authors:   Volga Region Research Institute of Manufacture and Processing of Meat-and-Milk Production, GORLOV I.F. ,   Volgograd State Technical University, SLOZHENKINA M.I. ,   Volga Region Research Institute of Manufacture and Processing of Meat-and-Milk Production,   Volgograd State Technical University, BARANIKOV V.A. ,   Volga Region Research Institute of Manufacture and Processing of Meat-and-Milk Production,   Don State Agrarian University, MOSOLOV A.A. ,   Volga Region Research Institute of Manufacture and Processing of Meat-and-Milk Production, CHERNYAK A.A. ,   Volga Region Research Institute of Manufacture and Processing of Meat-and-Milk Production, FROLOVA M.V. ,   Volga Region Research Institute of Manufacture and Processing of Meat-and-Milk Production
Published: March 2021

The article presents the materials of research conducted on fattening growing young pigs of large white breed, in the diet of which synthetic amino acids were used. As a result of experiments, the high efficiency of their use was confirmed. The positive effect of the use of synthetic amino acids on the formation of more optimal indicators of the chemical composition of fat is proved. Experiments have shown that the most effective productive effect of feed was shown in group IV animals that received a basic diet balanced in amino acids due to the introduction of synthetic lysine and feed methionine.
The catalytic activity of copper nanoparticles on aminomodified silica support in the flow azide-alkyne cycloaddition reaction using macrocyclic substrates
Authors:   Kazan Federal University, Nurmukhametova Albina T. , Belov Roman N. ,   Kazan Federal University, Burilov Vladimir A. ,   Kazan Federal University, Antipin Igor S. ,   Kazan Federal University
Published: March 2021

Using the chemical reduction method, a copper-containing catalyst on an amino-modified silica was obtained. The structure and composition of the catalyst were characterized by low-temperature nitrogen adsorption and inductively coupled plasma mass spectrometry. It was found that the modification of silica with amino groups and copper nanoparticles leads to a significant change in textural characteristics: nanoparticles and the modifier fill the pores in the size range of 5-10 nm. Obtained catalyst showed good activity in the flow cycloaddition of azides and alkynes of various nature. The comparative activity of azides and alkynes was analyzed. It has been established that among the azides studied (benzyl azide, p-nitrobenzylazide, p-methoxybenzylazide, 2-azidoethylacetate and 1-azidodecane), alkyl and aryl azides with electron-withdrawing groups were most active due to an increase in the electrophilicity of the terminal nitrogen atom of the azide group. Among the studied acetylenes (phenylacetylene, hexin-1, trimethylsilylacetylene and propargyl alcohol), propargyl alcohol was the most and trimethylsilylacetylene was the less active. Increased activity of propargyl alcohol may be due to a donor hydroxyl group capable of coordinating with copper; reduced activity of trimethylsilylacetylene can be resulted from steric hindrances. p-tert-Butyl and p-H-calix[4]arens were also used in the reaction. Full conversion of macrocycles was achieved after 3 consecutive reaction cycles. The resulting triazoles were isolated and characterized by a complex of physical methods. Thus, It has been demonstrated that carrying out the reaction in a flow by maintaining stable and fully reproducible reaction parameters makes it possible to quickly evaluate the relative reactivity of molecules.
Kinetics and mechanism of acyl transfer reactions. Part 15. Quantumchemicalsimulation of mechanisms of reactions of N-ethylaniline sulfonation
Authors:   Ivanovo State University, Kochetova Ludmila B. , Kustova Tatiana P. ,   Ivanovo State University
Published: March 2021

The RHF/6-31G(d) quantum chemical simulation of the mechanism of the interaction of the secondary fatty aromatic amine N-ethylaniline with benzenesulfonyl chloride under conditions of non-specific water solvation, using the continuum model of the solvent, as well as of sulfonylation reactions of N-ethylaniline solvation complexes containing one water molecule, modeled specific solvation of N-ethylaniline with water, and one molecule of water and one of dioxane, which simulate the solvation of the amine with aqueous dioxane. Three-dimensional potential energy surface of these processes is calculated. It is shown that in the case of a reaction proceeding under conditions of non-specific solvation of reagents, the route with axial attack of the N-ethylaniline molecule to the sulfonyl reaction center is realized, in the two other cases the reactions proceed along a single route, starting as an axial attack of the nucleophile, which goes further with decreasing of the attack angle as reagent molecules approach each other. It was established that all the simulated reactions proceed in accordance with bimolecular coordinated mechanism of nucleophilic substitution SN2, which implies the formation of a single transition state in the reaction path. It was found that geometrical configuration of the reaction center in the transition state of N-ethylaniline reaction with benzenesulfonyl chloride under non-specific solvation by water is close to trigonal-bipyramidal, which is determined by the axial direction of the nucleophilic attack, in the two other cases it is medium between the trigonal-bipyramidal and tetragonal-pyramidal, which is associated with the change in the angle of N-ethylaniline attack as the reactant molecules approach each other. In a reaction involving N-ethylaniline monohydrate, a water molecule forms a 6-membered cyclic structure with reagent molecules in the transition state, in which the transfer of a proton from N-ethylaniline amino group to a hydrogen chloride molecule occurs via a relay mechanism involving the water molecule. The activation energy values of the studied processes were calculated; it is shown that both specific and universal solvation significantly lower the energy barrier of the reaction compared to the reaction occurring in gas phase, which is consistent with the data obtained earlier for related processes.
The investigation influence of high carbon technical filler on the properties of the plantar rubber
Authors:   Chuvash State University  of I.N. Ulyanov, Usmarin Nikolay F. , Vasilyev Andrey N. ,   Chuvash State University  of I.N. Ulyanov, Tsareva Lyudmila Yu. ,   Chuvash State University  of I.N. Ulyanov, Kirillova Tatiana A. ,   Chuvash State University  of I.N. Ulyanov, Koltsov Nikolay I. ,   Chuvash State University  of I.N. Ulyanov
Published: March 2021

The article investigates the influence of the high-carbon technical filler of the RP-CARBON series of three brands RP-C 100, RP-C 150 and RP-C 200, differing in the size of microparticles, on the properties of the rubber mixture which used for the manufacture of rubber shoe soles. The investigation influence of replacement of technical carbon grades TU N 330 and TU P 803 on high-carbon technical filler in the plantar rubber compound based on the combination of SKI-3 and SKMS-30ARKM-15 caoutchoucs has been investigated. The rubber mixture contained caoutchoucs, vulcanizing agent sulfur, vulcanization accelerators thiazole 2 MBS and guanid F, vulcanization activators zinc oxide and stearic acid, antioxidant naphtham-2; plasticizers rosin and industrial oil I-8A; chalk fillers and carbon blacks of grades TU N 330 and TU P 803. The plasto-elastic, rheometric properties of the rubber mixture and the physicomechanical properties of vulcanizates, as well as the change of these properties after thermal aging of vulcanizates in air were studied. It was established that with replacement of technical carbon grades TU N 330 and TU P 803 with high-carbon technical filler, the plantar rubber mixture has satisfactory technological, physicomechanical and operational properties. Rubber mixture containing 11 weith parts high-carbon technical filler brand RP-C 100 instead of carbon black TU P 803, characterized by improved technological properties during calendering and can be recommended for the manufacture of sole rubber based on non-polar rubbers.
Zinc and copper content in soil and plant during different vegetation periods
Authors:   Orenburg State Pedagogical University, Shiryaeva Olga Yu.
Published: March 2021

Important biogenic elements of plants are zinc and copper, which come into them from the soil in the form of cations. Plants selectively absorb the elements they need in accordance with physiological and biochemical needs, as well as the characteristics of their vegetation. Copper and zinc are part of the enzymes that are necessary for the normal course of many biochemical reactions. Lack or excess of any chemical element causes a violation of the normal course of biochemical and physiological processes in plants. The paper presents the results of the study of zinc and copper content in the soil, as well as in the above-ground and underground organs of the studied plant object. Quantitative determination of zinc and copper was carried out on an atomic absorption spectrometer. As an object of study, a flower plant of the Gentian family (lat. Gentianáceae), genus Eustoma (lat. Eustoma), grade Aube Pink Picotee. Vegetation experiments were carried out on the basis of LLC "Greenhouse "Iceberg". According to the data, the content of zinc and copper in the organs of the studied plant decreases in a number of root – aboveground part – flower. In different periods of vegetation there is a different accumulation of copper and zinc in the aboveground and underground organs. The root of this plant performs a barrier function, blocking the flow of copper into the plant from the soil at 27 weeks of development. In this case, the zinc content in the root of the plant during this period increases significantly, but this figure in the above-ground part of the plant varies slightly. According to the calculated average value of the biological absorption coefficient, it can be seen that the accumulation of zinc in the plant occurs to a greater extent than the accumulation of copper.
Study of the biological activity of 2-methyl-5-nitrobenzoxazole and its dinitroderivatives
Authors:   Tula State Lev Tolstoy Pedagogical University, Mukhtorov Loik G. , Peshkova Alisa M. ,   Tula State Lev Tolstoy Pedagogical University, Nikishina Maria B. ,   Tula State Lev Tolstoy Pedagogical University, Ivanova Evgenia V. ,   Tula State Lev Tolstoy Pedagogical University, Atroshchenko Yury M. ,   Tula State Lev Tolstoy Pedagogical University, Shakhkeldyan Irina V. ,   Tula State Lev Tolstoy Pedagogical University
Published: March 2021

Growing crops is one of the priority state programs. For agriculture, this is due to the difficulties associated with unstable climatic conditions, low levels of anthropogenic pollution of the environment. Therefore, to increase the yield and improve the quality of crops, substances with regulatory properties are used. It is extremely difficult to obtain yields on an industrial scale, without using growth regulators that promote growth, enhance the immune system of plants and increase their resistance to stress. This study is part of a great work on the study of the biological activity of various classes of compounds. The effect of the tested substances on the growth rate and development of agricultural plants, their chemical composition is analyzed. In addition, the fungicidal activity of these compounds is determined. Thus, the task is to solve the problem of obtaining and preserving the crop yield of crop production. For the study of biological activity were selected compounds: 2-methyl-5-nitrobenzoxazole, 2-methyl-5,7-dinitrobenzoxazole, 2-phenyl-5,7-dinitrobenzoxazole. The analytes were tested for biological activity against wheat seeds and plants. The effect of substances on the universe and the seed germination energy, plant growth rate, and cell and carotene synthesis were studied. In addition, it was determined the effect of processing compounds in a given mass of wheat plants. Experienced seeds and wheat plants were treated with solutions of 2-methyl-5-nitrobenzoxazole, 2-methyl-5,7-dinitrobenzoxazole, 2-phenyl-5,7-dinitrobenzoxazole, the control plants were watered with water. The research results show that 2-methyl-5,7-dinitrobenzoxazole has the greatest influence on the growth rate and synthesis of substances in the mass of wheat plants. This leads to an increase in the number of all kinds of seeds by 42.2%, biometric growth rates by 17.15%, root mass by 30.8%, carotene content by 74.45%, compared to control plants.
Thermodynamic simulation of oxidation process of the Moss-Mo3Si hypoeutectic alloy, doped with scandium or neodymium
Authors:   Institute of Metallurgy of Ural Branch of Russian Academy of Sciences, Larionov Alexey V. , Udoeva Ludmila Y. ,   Institute of Metallurgy of Ural Branch of Russian Academy of Sciences, Chumarev Vladimir M. ,   Institute of Metallurgy, Ural Branch of the Russian Academy of Sciences
Published: March 2021

In order to study the effect of yttrium additives on the oxidation of molybdenum silicide alloys, thermodynamic modeling of the interaction in Mo-Mo3Si-Sc5Si3 и Mo-Mo3Si-NdSi systems with dry and moist air was performed in the temperature range 25-2000 °C. The calculations were performed using the HSC Chemistry 6.12 software, into the database of which the calculated missing thermochemical characteristics silicates, molybdates of scandium and neodymium were entered. Based on the obtained dependences of the composition of phases on temperature and charge of the oxidant (air or vapor-air mixture), the sequence of phase formation was determined and the compositions of oxidation products were estimated. It is shown that, under equilibrium conditions, the oxidation process with dry and moist air proceeds almost equally, since the interaction of the components of the alloy with oxygen is thermodynamically preferable than with water vapor. According to the obtained thermodynamic models, the oxidation process of the Mo-5Si-3(Sc, Nd) (wt.%) alloys involves a sequence of the following chemical transformations: at the beginning Mo and Sc (Nd) silicides oxidize forming Sc2O3 ( Nd2O3), SiO2 and elemental Mo, then molybdenum is oxidized to MoO2 and Sc2O3 or Nd2O3 interacts with SiO2 with the formation of appropriate silicates Sc2Si2O7 или Nd2Si2O7. As a result of the complete oxidation of the alloy, MoO3 and Sc2(MoO4)3 or Nd2Mo4O15 are added to the condensed product, and molybdenum oxide (MoO3)n vapor appears in the gas phase. In addition, the formation of Nd2Mo2O7 and Nd2 (MoO4)3 is possible. During the oxidation of the Mo-5Si-3Nd alloy at T> 1700 oC, Nd(OH)3 can be formed in the condensed reaction products. According to the results of complete thermodynamic analysis, the formation of silicates and molybdates of scandium and neodymium can promote to the formation of a protective film on the surface of the alloys, which limits the diffusion of oxygen in them, and as a result, the oxidation resistance of alloys should increase.
Prediction of physico-chemical properties for polycyclic aromatic hydrocarbons based on electronic characteristics of molecules
Authors:   Ufa State Petroleum Technological University, Dolomatov Mikhail Yu. , Paymurzina Natalia H. ,   Institute of Physics and Technology of Bashkir State University, Kovaleva Ella A. ,   Institute of Physics and Technology of Bashkir State University
Published: March 2021

QSPR models have been developed to predict of polycyclic aromatic hydrocarbons (PAHs) based on quantum chemical and integral spectroscopic descriptors. The first ionization potentials calculated from the energies of the highest occupied molecular orbital (HOMO), relative autocorrelation empirical parameters and the total number of electrons of non-ionized molecules were used as quantum chemical descriptors. Ionization potentials, electron affinities, boiling points, molecular masses, saturation vapor pressure of PAHs were studied as physical-chemical properties. Ionization potentials and electron affinities (IPs and EAs) are calculated by the use of density functional theory (DFT). Relative empirical autocorrelation parameters µ were calculated from the spectra of PAH molecules experimentally obtained and taken from the databases. The predictive power of resulting model is demonstrated by testing it on unseen data that were not used during model generation. Coefficients of determination for all dependencies considered in this paper are not less than 0.95. To assess the reliability for coefficients of determination, their mean errors were calculated. In this paper, we compared theoretical (experimental) and model-calculated values. Relative errors were estimated: for the electron donating ability of PAHs is 1.11% (for IP) and 0.86% (for EA); at about 3.1% for boiling points; not more than 0.51% for molar mass, for saturated vapor pressure, the error is more significant, which is apparently due to the difficulties of determining this value. The obtained models make it possible to estimate physical and chemical properties with sufficient accuracy for practical applications. The research results can be practically used in petrochemistry, carbon chemistry, organic chemistry, for prediction of physical and chemical properties PAH molecules.
Synthesis, structure and reactivity of oxalyl di(4-methylimidazole)
Authors:   Samara National Research University, Purygin Pyotr P. , Shargalo Alina V. ,   Samara National Research University, Milyutin Konstantin V. ,   Samara National Research University, Zarubin Yury P. ,   Samara National Research University, Grigoryeva Olga B. ,   Togliatti State University
Published: March 2021

The article describes a two-step method for the synthesis of oxalyl di(4-methylimidazole) from 4(5)-methylimidazole through 1-trimethyl-4-methylimidazole followed by interaction with oxalyl chloride; the yield of the final product is 89%. The kinetics of hydrolysis, alcoholysis, and aminolysis of oxalyl di(4-methylimidazole) in acetonitrile – water (9 : 1), acetonitrile – methanol (9 : 1), acetonitrile – diethylamine (9 : 1) at 25 °C was studied. To study the thermodynamic features of the reactions to obtain this compound in the Spartan’14 1.1.4 program, a number of thermodynamic characteristics were determined that determine the spontaneous and exothermic nature of the process. The data obtained make it possible to select the optimal conditions for the synthesis of oxalyl di(4-methylimidazole) and to draw a conclusion about its low stability in media containing nucleophiles. Possible conformers were found for the oxalyl di(4-methylimidazole) molecule in the Molecular Operating Environment 2014.0901 program, for which nucleophilic susceptibility surfaces were calculated in the SCIGRESS Modeling 3.1.4 program. It was shown that the most reactive conformers in which carbonyl groups are minimally screened by fragments of 4-methylimidazole. The structure of oxalyl di(4-methylimidazole) was confirmed by IR and 1H NMR spectroscopy. Characteristic absorption bands were found in the IR spectra, confirming the presence of the corresponding functional groups in the structure of the compound, and proton signals with characteristic chemical shifts for the corresponding functional groups were detected in 1H NMR spectra. In the PASS Professional 2007 program, the most probable types of biological activity of the test compound were predicted. The most significant types of biological activity are in relation to urological diseases, antiseborrheic effect, stimulator of renal function, stimulator of leukopoiesis.
New methylphenylsiloxane resin based on alkoxysilanes
Authors:   State research center Joint stock company “State scientific-research Institute of chemistry and technology  of Organoelement compounds”, Kontorov Andrey M.
Published: March 2021

Currently interested in the reaction for producing oligosilsesquioxanes based on acidolysis alkoxysilanes. In this regard, the author was given the following tasks: development of optimal synthesis conditions; preparation of new methylphenylsiloxane resins with different properties. In this paper, the properties of new methylphenylsiloxane resins (MPR) with various radicals in silicon were studied. New IFSS were obtained by a new universal technology-acidolysis of a mixture of methyltriethoxysilane (MTEOS) and phenyltriethoxysilane (PTEOS) with various radicals, which are environmentally friendly raw materials. The obtained MPR were characterized by NMR spectroscopy on 1H and 29Si nuclei. Spectra were recorded at room temperature in deuteroacetone using Bruker AM-360 Fourier spectrometer. 29Si NMR spectra were measured using the pulse program "Inverse Gated Heteronuclear Decoupling". The content of residual functional groups (Si-OH, Si-OEt) in IFSS was determined by functional analysis methods. Determination of ethoxy groups and hydroxy groups was carried out by iodometric and aluminohydride method, respectively. Thermogravimetric analysis was performed on the device Derivatograph-H (firm Mom). TGA studies were carried out in the argon atmosphere and in the air at a heating rate of 10 ºC/min. Measurements of kinematic viscosity of 20 % and 50% by weight. toluene solutions of MPR were carried out at 20 °C on the viscometer HPV-2. The reaction acidolysis of methyltriethoxysilane and oligophenylenes is a convenient and versatile method for the synthesis of new heat-resistant resins methylphenylsiloxanes. In the course of the study, it was found that the resins obtained on the basis of organoalkoxysilanes are characterized by higher thermal and thermo-oxidative stability.
Insulin-mimetic macromolecular poly-N-vinylpyrrolidone-based vanadium metallocomplexes. Part 1. Synthesis of macromolecular vanadium metallocomplex and its acute oral toxicity evaluation
Authors:   Saint Petersburg State Chemical Pharmaceutical University, Ivanov Alexey G. , Prikhodko Veronika A. ,   Saint Petersburg State Chemical Pharmaceutical University, Mukhina Veronika A. ,   Saint Petersburg State Chemical Pharmaceutical University, Kirillova Nadezhda V. ,   Saint Petersburg State Chemical Pharmaceutical University, Anisimova Natalia A. ,   Saint Petersburg State Chemical Pharmaceutical University
Published: March 2021

Diabetes mellitus (DM) is a severe chronic disease affecting virtually all kinds of metabolic processes in the human body. As incidence and prevalence of DM are increasing worldwide, WHO estimates the number of people living with diabetes to be as high as half a billion and still rising. Long-term health complications of DM, such as diabetic nephropathy, retinopathy, neuropathy, and cardiovascular pathology, although preven-table in most cases, are known to be severe, potentially life-threatening and often irreversible, which makes the search for new effective antidiabetic drugs a research priority and one of the most pressing issues in health care today. To date, the insulin-mimetic properties of vanadium compounds have been the subject of quite a significant number of studies. In vivo experiments have shown that vanadium, acting in an insulin-like fashion, takes part in the regulation of glucose and lipid metabolism. In particular, vanadium stimulates glucose uptake and metabolism in insulin target tissues, increases the intensity of glycogen and lipid biosynthesis, and inhibits that of gluconeogenesis, glycogenolysis, and lipolysis. Organic vanadium complexes are known to be less toxic than its inorganic salts, which are characterized by a number of potentially serious adverse effects, mainly but not exclusively on the central nervous system and the kidneys; in addition to lower toxicity, organic vanadium compounds have been found to have higher bioavailability when to compared to those of inorganic nature. Such observations clearly hold promise for the development of an entirely novel therapeutic class of antidiabetic drugs. The aims of this study are to obtain new polymeric vanadyl(VO2+) derivatives based on poly-N-vinylpyrrolidone (PVP) that would exert hypoglycemic effect in vivo, and to explore the possibilities of using such compounds or formulations derived thereof for type 2 DM prophylaxis and/or treatment. This work gives a method of obtaining and isolation of an oxovanadium(IV)-polymer metallocomplex, and describes the structural features of said compound, confirmed experimentally. The results of the acute oral toxicity study revealed that the newly synthesized compound is of low toxicity, having a median lethal dose (LD50) that is at a level well above those typical of inorganic vanadium salts.
Method of synthesis of O-methyl-N-alkylcarbamate from amines and dialkylcarbonate
Authors:   Mendeleev University of Chemical Technology of Russia, Dashkin Ratmir R. , Vorobieva Tatiana Yu. ,   Mendeleev University of Chemical Technology of Russia, Seferyan Mary A. ,   Mendeleev University of Chemical Technology of Russia, Danilova Daria V. ,   Mendeleev University of Chemical Technology of Russia, Mantrov Sergey N. ,   Mendeleev University of Chemical Technology of Russia
Published: March 2021

A carbamates (urethanes) are an organic compounds with the general formula R'R''NCOOR are esters of carbamic acid and its derivatives. Due to their biological activity, carbamates are common as pesticides, insecticides, herbicides, and are used as drugs. Polyurethanes are widely used in industry. The main method of synthesis is the interaction of isocyanates with the corresponding alcohols or phenols, it is also possible to use urea, isocyanic acid or other methods, including the use of in-situ formed isocyanate. In the literature, N-alkyl-O-methylcarbamate is synthesized by reacting amines with dimethylcarbonates with various catalysts. In view of the economic feasibility and difficulty of isolating the target product the overwhelming number of the described methods are hardly applicable for scaling and industrial synthesis. A study was conducted to develop a method of synthesis of O-methyl-N-alkylcarbamate, which will be able to scale and be introduced into production. The most promising synthesis methods described in the literature have been tested, and a new method for producing various carbamates has been developed. The model amines for the experiment were selected industrially important – n-butylamine and cyclohexylamine. The structure of the product was confirmed by 1H NMR spectra. A number of the described methods had a way out in practice several times below the literature data presented, and some target products could not be received. The best way to react with n-butylamine is to use water as a catalyst. The yield obtained according to this procedure for O-methyl-N-cyclohexylcarbamate was 53%, for O-methyl-N-n-butylcarbamate – 68%, so the method was expanded to obtain several O-methyl-N-alkylcarbamate.
Synthesis of morpholinium salts based on chloroacylated derivatives of dihydroquercetin
Authors:   Moscow Pedagogical State University, Pozdeev Anton O. , Koroteev Alexander M. ,   Moscow Pedagogical State University, Pimankina Sofia N. ,   Moscow Pedagogical State University, Koroteev Mikhail P. ,   Moscow Pedagogical State University, Ofitserov Evgeny N. ,   Russian University of Chemical Technology D.I. Mendeleev
Published: March 2021

The flavonoid dihydroquercetin and its esterified derivatives possess various biological activities and are widely used as dietary supplements and in pharmacology. A significant disadvantage of this flavonoid is its low solubility in water at ordinary temperatures of up to 0.03%, which negatively affects its biological activity. Nature overcomes this problem by glycosylation, sulfation, and phosphorylation. In chemistry and pharmacology to overcome this problem, there are several synthetic approaches. For dihydroquercetin (DHQ) is the inclusion of DHQ in the cyclodextrin matrix or the formation of a complex of DHQ with basic natural amino acids. In this paper, a method is proposed for obtaining water-soluble morpholinium salts based on chloroacylated derivatives of DHQ. The acylation reaction was carried out in dioxane, pyridine was used as an acceptor of choric hydrogen. The target compounds were obtained with a yield of 68-79%. As a result, chlorinated derivatives based on DHQ and its acyl and benzyl derivatives were synthesized. These derivatives in the interaction with morpholine form its salts, which, as it turned out, have a high water solubility. Pentamorpholine salt of DHQ had the highest solubility in water, up to 6.5% at room temperature, which is 200 times more soluble than the original DHQ. The proposed synthetic approach to increase the water solubility of acyl derivatives of DHQ can be extended using other nitrogenous bases and other haloacyl derivatives of DHQ.
Influence of chemical composition of the dental paste on the buffering systems in the mouth and the environmental indicator
Authors:   Federal State Budgetary Educational Institution of Higher Education ", Gromova Svetlana N. ,   Kirov State Medical University",   of the Ministry of Healthcare  of the Russian Federation, Kuklina Svetlana A. ,   Federal State Budgetary Educational Institution of Higher Education "Kirov State Medical University" of the Ministry of Healthcare  of the Russian Federation, Elikov Anton V. ,   Federal State Budgetary Educational Institution of Higher Education "Kirov State Medical University" of the Ministry of Healthcare  of the Russian Federation, Smetanina Olga A. ,   Federal State Budgetary Educational Institution of Higher Education "Kirov State Medical University" of the Ministry of Healthcare  of the Russian Federation, Petrov Sergey B. ,   Federal State Budgetary Educational Institution of Higher Education "Kirov State Medical University" of the Ministry of Healthcare  of the Russian Federation
Published: March 2021

In this paper we consider buffering properties of saliva, which are regulated by a colloidal system. It includes Ca2+ and НPO42- ions, which affect on qualitative characteristics of saliva. The constancy of the pH determines neutralizing and mineralizing capabilities of saliva. The aim of this work was to define influence of toothpaste composition on the pH, salivary buffer systems, and the acid-base balance in the oral cavity. The acid-base disruption results in disbalance in demineralization-remineralization processes. Students of the Dentistry Department of Kirov State Medical University of the Ministry of Health of Russia took part in this research. They were divided into three groups. Each group had been using different products for 28 days. We selected 3 toothpastes of the same manufacturer. These toothpastes contain same ingredients, which by their chemical properties are not able to affect on the pH of the oral fluid and salivary buffer systems accordingly. However, there were distinctive components such as dicalcium phosphate dihydrate, hydroxyapatite, tetrapotassium pyrophosphate, calcium lactate, which increase НРО42- and Ca2+. This fact has a positive effect on maintaining fixity of the phosphate buffer system in the oral cavity. It therefore helps to normalize the pH to a neutral level. The acid-base equilibrium is supported by buffering properties of saliva. It knows that saliva is regulated by the colloidal system including Ca2+ and НPO42- ions. These ions are part of the phosphate buffer system, which affect on qualitative characteristics of saliva. Based on the above, there is dependence between the row of toothpaste ingredients and protein level, hydrogen phosphate ions, calcium ions, and pH values.
On un-harmonic vibrations of diatomic molecule and atomic dimer
Authors:   Novosibirsk State University, Umirzakov Ikhtier H. , Mayer Edward N. ,   Novosibirsk State University
Published: March 2021

According to modern concepts, the interaction potential as a function of the interatomic distance has a single minimum, has no other extremum points, and does not have inflection points, where its derivative is zero. Usually, to take into account harmonic vibrations and the effect of anharmonic effects on these vibrations, the interaction potential is expanded in the Taylor series and a quadratic term is taken into account, which takes into account harmonic vibrations, and third and fourth order corrections for deviations of the interatomic distance from its equilibrium value, taking into account anharmonic effects. These three members of the Taylor series constitute an approximate interaction potential. To take into account the anharmonic effects in the partition function of the diatomic molecule in the Boltzmann factor, an exponential factor is selected that takes into account the anharmonic part of the above approximate potential, and this factor is expanded in the Taylor series, the integration limits are changed to plus and minus infinity, the integration is carried out and the first few members of the power series are left on return temperature. Obviously, the approximate potential, like the initial potential, should not have other extremum points, except for a single minimum, and inflection points, where its derivative is equal to zero. In this paper, it is shown that: if the coefficient in front of the fourth-order term in the approximate potential is negative, then the approximate potential has two false maxima; if it is zero, then there is one false maximum; if it is positive, then the potential can have one false minimum and one false maximum or one inflection point where the derivative of the potential is equal to zero. The conditions imposed on the interaction potential are found when the anharmonic effects in the vibrations of a diatomic molecule can be approximately taken into account by corrections of the third and fourth orders to the quadratic harmonic potential. It is shown that this approximation can be used in the case of the interaction of atoms of a diatomic molecule by means of the Mie-Grüneisen and Lennard-Jones potential.
Azo compounds based on 2-(4'-aminophenyl)-4-quinoline carboxylic acid: synthesis and properties
Authors:   A.N. Kosygin Russian State University (Technology. Design. Art), Mavlonov Mirzoolim H. , Kuznetsov Dmitry N. ,   A.N. Kosygin Russian State University (Technology. Design. Art), Kobrakov Konstantin I. ,   A.N. Kosygin Russian State University (Technology. Design. Art)
Published: March 2021

Synthesis and studies of the properties of dyes for coloring textile materials from fibers of various chemical structures, which contain, in addition to chromophore, also pharmacophore groups in the molecule, which impart biocidal properties to both the dyes themselves and the materials dyed by them, are interesting both theoretically and from an applied point of view. The article presents data on the synthesis of a series of previously undescribed azo compounds based on 2-(4'-aminophenyl)-4-quinolinecarboxylic acid and aromatic hydroxy- and aminocompounds of the naphthalene series. Five naphthylazo derivatives of 2-(4'-aminophenyl)-4-quinolinecarboxylic acid were synthesized in high yields. The structures of the synthesized azo compounds were confirmed by mass-spectrometry and UV-spectroscopy. In the electronic absorption spectra, the absorption maximum of the synthesized azo compounds lies in the range of 480-550 nm, in contrast to the initial diazo and azo components, the absorption maxima of which lie in the near UV region of the spectrum. Dyeing techniques have been developed that provide optimal indicators for the process of coloration of polypeptide fibers (wool and nylon) with synthesized dyes. The colors of the samples have bright, and deep colors of orange-red-violet scales. The obtained painted samples were examined for color fastness to wet processing according to GOST 9733.4-83, sweat GOST 9733.6-83 and light exposure GOST 11279.2-83. It has been shown that the synthesized azo compounds can be used for coloring woolen and polyamide fibers and provide satisfactory performance properties of dyes, which is consistent with generally accepted ideas about acid dyes. Samples of dyed polyamide fabric showed satisfactory color fastness to light (1-3 points), the best result was shown by wool samples dyed with the studied dyes.
Possibility of using the brabender plastometer to study the peroxide crosslinking of polyethylene. Part 2. Use of the mixture 1,3- and 1,4-bis(tret-butylperoxyisopropyl)benzene for crosslinking polyethylene
Authors:   Vladimir State University Named after Alexander Grigorievich  and Nikolay Grigorievich Stoletovs, Timakov Evgeny A. , Panov Yury T. ,   Vladimir State University Named after Alexander Grigorievich  and Nikolay Grigorievich Stoletovs
Published: March 2021

The paper shows the possibility of using the mixture 1,3- and 1,4-bis(tert-butylperoxyisopropyl)-benzene as a cross-linking agent in the production of polyethylene foam. Most often, cross-linked polyethylene foam, which has high performance properties, is obtained by pressing, using azoicarbonamide as a foaming agent and dicumyl peroxide as a cross-linking agent. Dicumyl peroxide has a significant drawback: high toxicity of decomposition products. Using the soxlet extratctor, the optimal degree of crosslinking (57-62%) required to obtain foam with optimal performance properties was determined. Using the brabender plastograph, which allows you to study, in a wide range of values, the crosslinking kinetics. It was found that the degree of crosslinking 57-62% corresponds to the torque in the range of 1700-2500 g∙m. a comparative characteristic of two crosslinking agents is given: traditional (dicumyl peroxide) and the studied peroxide. It was found that the crosslinking rate in the presence of the mixture 1,3- and 1,4-bis(tert-butylperoxyisopropyl)-benzene is significantly lower, but the final degree of crosslinking is at the same level as when using dicumyl peroxide. The dependence of the maximum torque on temperature is studied. There are restrictions on the Use of the brabender plastometer for studying the crosslinking kinetics. When the degree of crosslinking is more than 70%, the composition goes into a non-melting state, and the device's performance drops sharply. For practical use of the mixture 1,3- and 1,4-bis(tert-butylperoxyisopropyl)-benzene, the degree of crosslinking in the presence of the foaming agent azodicarbonamide was studied. It is shown that the introduction of a gas-forming agent (azodicarbonamide) into the composition significantly reduces the degree of crosslinking of polyethylene foam only in the case of the mixture 1,3- and 1,4-bis(tert-butylperoxyisopropyl)benzene. The optimal concentration of new crosslinking peroxides, allowing to foam, density 80-100 kg/m3, not inferior to original compositions by main technical-economic indicators have been determined.