According to the quantumchemical calculations of N-phenylmaleimide (PMI) using the LCAO MO method in Hückel π-electron approximation, a maximum deficit of π-electrons is observed on carbonyl carbon atoms; subsequently, a nucleophilic attack of “pyridinic” nitrogen atoms on carbonyl carbon is likely to occur.Moreover, an alternative attack on olefinic atoms with the opening of a multiple bond is possible.Since the nitrogen atoms N1 and N3 are equivalent in nucleophilic reactions of 1H-benzotriazole (BT) and taking the spectroscopic data on the BT adduct into account, it is impossible to conclude that all three nitrogen atoms are involved. For these purposes, it is advisable to use benzotriazoles with substitution in position 5 (or 6), where the nitrogen atoms N1 and N3 are not equivalent in these reactions.The reaction products were analysed using the¹³С NMR-spectroscopy method. The obtained data testify to the preferential occurrence of the nucleophilic attack of benzotriazoles on the multiple maleimide bond during their interaction in the melt at elevated temperatures, as well as on the participation of all three nitrogen atoms of the 1H-benzotriazolyl fragment in the nucleophilic attachment of benzotriazoles to the multiple PMI bond.

Organic polymers with N, S-functional groups are widely used as effective materials for the adsorption of transition metal ions. The adsorption of noble metals by copolymer of divinyl sulphide with 4-vinylpyridine has been studied in solutions of mineral acids. The copolymer under study has displayed high values of static sorption capacities, amounting to 1200, 340, 1040, 520 mg/g in Au (III), Ag (I), Pt (IV) and Pd (II), respectively. A comparative study of the Langmuir, Freundlich and Dubinin-Radushkevich adsorption models has been carried out to describe the experimental adsorption isotherms of noble metal ions on the surface of the copolymer under investigation. Constants and parameters of the considered adsorption models have been identified. Analysis of the values of the coefficients of determination R² indicates that the adsorption of noble metal ions from sulphuric acid solutions and Ag from nitric acid solutions is most adequately described within the Langmuir model. The obtained results demonstrate that the adsorption of noble metal ions occurs on an energetically heterogeneous surface and represents a monomolecular process.

Novel silver-containing nanocomposites based on 1-vinyl-1,2,4-triazole and vinyl acetate copolymer have been synthesised. The reduction of silver ions to the zero-valent state was carried out by a chemical method using the metal precursor AgNO₃ and the reducing agent NaBH₄. The copolymer obtained is established to exhibit a high stabilising ability by coordinating silver nanoparticles with the predominant participation of triazole and a partial participation of macromolecular acetate fragments. The physicochemical, optical and structural properties of the nanocomposites were analysed by IR and UV spectroscopy, transmission electron microscopy, X-ray diffraction and atomic absorption analysis. The obtained polymeric nanocomposites with silver nanoparticles sized 2-28 nm are characterised by a good water solubility, plasmon resonance absorption with a maximum of 420 nm and corresponding reflections on X-ray diffraction patterns. In addition, the nanocomposites exhibit antimicrobial activity against test microorganisms.

The reaction of reductive amination of vinyl acetate and acrolein copolymers by the cyclic polypeptide polymyxin B1 was investigated. The synthesis was carried out using copolymers with a molecular weight from 40 000 to 120 000 containing acrolein and vinyl alcohol units in amounts of up to 5-7 wt.% and 12 wt.%, respectively. The degree of peptide addition to the polymers is established to increase proportionally with a decrease in the molecular weight of the copolymers from 120 000 to 40 000 and an increase in the proportion of hydroxyl groups from 1 to 12 wt.%. The maximum degree of attachment was 7 wt.%. The (co)polymer-peptide conjugates are readily soluble in volatile organic solvents. During the solvent evaporation, thin transparent films are formed from their diluted alcohol or acetone solutions, firmly adhering to the surface of the glasses. A study of the biological properties (complexation) of a covalently bound peptide has shown the immobilisation of the conjugates on the glass surface without the effect on its interaction with bacterial lipopolysaccharides. The degree of extraction of lipopolysaccharides from biological fluid amounted to 80-90%. The modified polymers may be of interest as secondary reagents for a selective isolation and concentration of lipopolysaccharides from biological or technological media with a view of their subsequent study.

In this work, we synthesized a series of N-(2,2,2-trichloroethyl) amides with the general formula of RCONHCH (R´) CCl₃ (where R = CH₃, CH₂Cl; R´ = C₆H₅, C₆H₄CH₃, C₆H₄OCH₃, C₆H₄OH) and investigated their acid/base properties in dimethyl sulfoxide (DMSO). For the first time, the curves and constants for the NH-acidity of the acetamides have been drawn using titration data. Under the potentiometric titration of the acetamides, curves with a pronounced jump in the potential of the indicator electrode were obtained in all the studied cases. The NH-acidity of the acetamides under study is shown to depend on the polar effects of substituents. The possibility of quantitative potentiometric analysis of individual acetamides, as well as double and ternary mixtures under their joint presence with sulfonamides in DMSO, was established. The metrological characteristics of the results obtained during a potentiometric determination of the constants under consideration were evaluated. These characteristics are demonstrated to possess a fairly high laboratory precision, with the coefficient of variation ranging from 0,04% to 0,52%. The obtained results were verified using the “introduced-found” method.

The purpose of this work was to assess the possibility of applying the method of phospholipid fatty acid analysis in the composition of lipids of cell membranes of soil microorganisms for monitoring the state of the soil in the process of recovery. The experimental part consisted in a determination of phospholipid fatty acids (FFA), including extraction of phospholipids with organic solvents, extraction of the lipid fraction using polar silicate columns, preparation of methyl esters of fatty acids by alkaline methanolysis and analysis of the content of FFA with gas chromatography. The identification of microorganisms was carried out on the basis of an evaluation of the experimental results obtained, which are represented by a combination of chromatogram peaks. The impact of stress factors on microorganisms is determined by the presence of cis-trans-isomerism or cycles of three carbon atoms at the ends of phospholipid fatty acid radicals. In order to verify the objectivity of the results obtained using the proposed method for analysing microorganisms, this work also used the traditional method of controlling soil microorganisms based on the activity of their enzymes - glucosidases, proteases, arylsulphatases and phosphatases. The data obtained indicate the presence of viable soil microorganisms; however, their number does not match the control samples, indicating a failure of the recovery process. The identification results demonstrate the dominance of Gram-negative (Gr^-) bacteria in the control samples in comparison with the samples in conditions of natural recovery. At the same time, in the process of natural restoration, a greater quantity of fungi was found in the soil. According to the data obtained, the largest amounts of cis - isomers and the value of cyclisation of phospholipid fatty acids are characteristic of microorganisms in the control samples, which may be due to the depletion of the substrate when using the soil for agricultural purposes. The experimental data obtained in the course of this work allow us to propose the procedure as an independent method for conducting biological monitoring of ecosystems when analysing phospholipid fatty acids in the composition of cell membrane lipids.

He study is dedicated to solving the problem of microRNA extraction from human blood for further use of the microRNA profile in the diagnosis of various diseases. The aim of the work is to choose an effective, accelerated method for the isolation of microRNA from human blood plasma, sufficient in quantity for diagnosing in clinical practice. Comparison of three methods for obtaining microRNA was carried out: 1) using a silicon oxide-based QIAamp RNA Blood Mini Kit column, 2) phenol-chloroform extraction using TRIzol LS Reagent and 3) phenol-chloroform extraction using TRIzol Reagent. It was established that for the most complete isolation of total human RNA from human blood plasma in order to obtain microRNA, TRIzol LS Reagent can be efficiently used. Because its use allows obtaining microRNA in less time - 30-40 min, and in an amount sufficient for clinical analysis (total RNA - up to 0,116 ng/μl, and microRNA - 350,3 picograms/μl), and also with the least amount of concomitant messenger RNA and long non-coding RNA. Using TRIzol LS Reagent allows you to increase the output of miRNA by 2,7 times compared with the use of TRIzol Reagent.

The kinetics of the species composition of immobilised sludge under brush filtering is studied. The experiment was conducted using a multistage method of calculating a calibrated drop. The situation of a long-term stop and emptying of a bioreactor containing brush filtering with immobilised sludge at a humidity level of 92% was simulated. The application of a bioreactor with sludge adapted to wastewater allows a required degree of purification to be achieved faster than when imported non-adapted sludge is used. The experiment was carried out using a physical model of such a bioreactor, representing a transverse vertical section of an industrial aerotank-bioreactor. According to the obtained results, immobilised sludge exposed to atmospheric air and fixed on a synthetic filtering loses moisture; however, the viability of the biocoenosis of the wet part of the filters lasts for more than ten days. The kinetic dependence of the species composition of the biocoenosis of immobilised sludge on its functional state has been obtained. It is shown that a bioreactor should be started no later than ~8 days after its loading, while transferring the immobilised sludge to a free-floating form by means of its air-mechanical or water-to-air regeneration.

In this research, we investigated changes in the concentration of hydrogen peroxide in the potato plants and their cell cultures (Solanum tuberosum L.) of two varieties - Lugovskoy and Lukyanovsky - under the action of the necrotrophic bacterial phytopathogen Pectobacterium carotovorum ssp. сarotovorum (Pcc) and its exometabolites (filtrate devoid of bacterial cells and thermally inactivated bacterial suspension). A biphasic accumulation of hydrogen peroxide is shown to occur in the cell cultures of the potato varieties under investigation infected with Pcc It is established that a thermally inactivated Pcc culture affects both the cell cultures and plant roots of the plants under study by causing a significant change in the generation of hydrogen peroxide in comparison with a filtrate devoid of bacterial cells. When infected with pathogens and their exometabolites, the intensity and dynamics of changes in hydrogen peroxide in the potato plants is significantly higher compared to a suspension cell culture. The intensity and dynamics of changes in the generation of hydrogen peroxide indicate the development of a systemic induced resistance in the studied potato varieties to Pcc bacteria and their exometabolites.

The chemical composition of basidiomycetes in the technogenic conditions is a crucial issue. The aim of the article is to study accumulation of heavy metals in edible fungi and soils of Transbaikalia. The X-ray fluorescence analysis was used to study the content of microelements. The study revealed low and medium levels of pollution in mushrooms growing in the Chita suburbs. The content of manganese, lead and zinc slightly exceeds the MPC level. According to the accumulation coefficient value, zinc was the microelement which more often migrates from the soil to the fungal fruit, especially to the Agaricus bisporus fruit; other chemical elements had a lower accumulation coefficient value than the soil. It was revealed that iron, manganese and zinc were accumulated more intensively than other biogenic chemical elements with various biophilicity and toxicity degrees. The comparison of these data with the ones obtained in the area of Asian Russia revealed a high bioconcentration similarity between central Yakutia and Transbaikalia. It might be due to the most unfavorable geochemical and natural-climatic factors.

In previous studies, the authors of this article demonstrated the metabolism of white phosphorus by fungal cultures. However, the toxic properties of substances are characterised by a different nature. Therefore, research into genotoxicity as a possible source of mutations appears to be of a great interest. In the present work, the genotoxicity of white phosphorus was evaluated using the Ames test, which showed its absence. However, despite all the advantages of this method, the sole Ames test cannot be considered to be a reliable assessment of genotoxicity. For this purpose, a number of tests are frequently used, including the SOS-lux test for DNA damaging activity. In the present work, the SOS-lux test did demonstrate the genotoxicity of white phosphorus. Although the value of DNA-damaging activity for this substance was low, this result was obtained for the first time: all available literature sources had thus far reported no genotoxic properties of white phosphorus. Since the genetic apparatus in prokaryotes is distinct from that in eukaryotes (including humans), the results of studies on Salmonella cannot be directly extrapolated to humans. In addition to gene mutations studied by the Ames and SOS-lux tests and characterised by a common nature in all living organisms, there are genomic rearrangements that should be studied on eukaryotes. For this purpose, the Allium test applied in onion roots (Allium cepa L.) is suitable. In the present study, a negative effect of white phosphorus on the cell cycle of eukaryotes was studied for the first time by the Allium test. Even at very low concentrations of about 0,01%, white phosphorus is established to increase the number of chromosomal aberrations by an order of magnitude.

He present work was aimed at investigating the composition and content of phenolic compounds contained in polymorphic plants Polygonum aviculare L. (Polygonaceae) of geographically distant populations using the method of high-performance liquid chromatography (HPLC). Research materials included leaf samples collected during the flowering period across the regions of Novosibirsk, Irkutsk and Murmansk, as well as the Republics of Khakassia, Buryatia and Altai. Waterbath extraction was performed in 70% ethanol for the purpose of extracting phenolic compounds (flavonoids and phenolic acids). The composition of the phenol complex was analysed by an Agilent 1200 liquid chromatograph equipped with a diode matrix detector. The plants under investigation are found to contain the following phenolic compounds: flavonol glycosides, such as juglanin, hyperoside, avikularin, quercitrin, aglycones quercetin, kaempferol and myrsetin; C-glycosides of flavones - orientin and vitexin; ferulic and other acids. The first group consisting of 8 samples predominantly featured juglanin (3,6 mg/g) and hyperoside (3,0 mg/g), while 4 samples in the second group mostly contained avcularin (4,9 mg/g). The major component in plants from two distance populations was flavonol glycoside quercitrin (2,2 mg/g). Ferulic acid (1.6 mg/g) was found only in plants comprising the first group. Therefore, phenolic compounds contained in Polygonum aviculare are shown to be characterized by a high biochemical variability in terms of composition and content. At the same time, no correlation has been found between the qualitative composition of phenolic compounds in the plants under study and their habitats.

This research is aimed at investigating the effects of aeration on the cell growth of the Brettanomyces bruxellensis yeast and its production of acetic acid and ethanol. Experiments were carried out in a glucose medium and with an air supply of 0-300 dm³/h. It is established that the growth of the biomass is stimulated by a moderate aeration, with the optimal value of the airflow rate being 60 dm³/h. When this value is exceeded, the concentration of the cellular biomass decreases. The yield of ethanol and acetic acid is shown to be dependent on the level of aeration: the greater the volume of air supplied to the fermenter, the higher the yield of acetic acid, and the lower the yield of ethanol. Under a high intensity of aeration, a significant decrease in the ethanol yield is observed. An aeration intensity of above 180 dm³/h results in a decline in the glucose consumption by yeast cells and an increase in the acetic acid concentration in the culture medium (6,0 g/dm³). The ethanol + acetic acid ratio produced per mole of utilized glucose was analysed according to the mass balance of the reaction. The ethanol + acetic acid ratio is shown to remain unchanged under the given conditions. This allows the stoichiometric equation of the fermentation reaction to be clarified for the calculation of the optimal value of oxygen supply and the yield of main products.

In this research, we set out to search for methods that can be used in biotechnological processing of sulphide carbonaceous refractory gold-containing ores with a view of subsequent gold extraction. The mesophilic strain of the Acidithiobacillus ferrooxidans bacterium, which exhibits sustained activity over prolonged periods (12 months), has been isolated and adapted. The activity of this strain is shown to vary from 1,4 to 2,8 g/l of oxidised iron per hour. In the process of heap bacterial oxidation, a significant decrease in the refractoriness of sulphide ores is observed. Under the conditions of ore crushing to a particle size of 2 mm, the oxidation degree of arsenopyrite and pyrite is determined to reach the values of 89-93% and 50-56%, respectively. Thus, ores containing 0,9-1,5 g/t of gold appear to be appropriate for processing, since the gold recovery reaches 65-75% after heap bioleaching (HB). The obtained results are confirmed by semi-industrial tests. The proposed technology of heap bacterial oxidation permits the preparation of sulphide refractory gold-containing ores for subsequent gold extraction based on the bacterial leaching technology (BL), which leads to a significant increase in the extraction of gold. Under this process, sulphide minerals are transformed into natural oxidised forms with a minimal anthropogenic impact on the environment.

Data on the elemental composition of plant materials is important for establishing their therapeutic value in medical practice and ensuring the safety of drugs produced therefrom. This article presents the results of a study aimed at determining the elemental composition of the above-ground organs of Vaccinium vitis-idaea L. (lingberry) collected across the Slyudyansky district of the Irkutsk Oblast. Growing under favourable environmental conditions, this species is characterised by a high bioproductivity. The method of X-ray fluorescence analysis (XRF) was used to estimate the content of the following elements in leaf samples: Na, Mg, Al, Si, P, S, Cl, K, Ca, Fe, Cr, Mn, Ni, Ti, Cu, Zn, Ba, Rb, Sr and Pb. According to the obtained data, the plant under study features such essential elements as calcium, potassium, magnesium and phosphorus, as well as such microelements as manganese and barium. The content of potentially toxic metals (Ti, Cr, Ni, Cu, Zn, Sr, Ba and Pb) does not exceed the threshold levels established for land plants. A high content of vital elements and the absence of toxic effects make Vaccinium vitis-idaea L. a promising medicinal material for the prevention and treatment of microelementoses. Due to their broad-spectrum therapeutic properties, lingberry leaves are widely used in traditional medicine.

For the first time, the complete set of quality indicators and sorption properties was studied in pectins extracted from the seed coats of peas, using standard and modified methods. It is established that organoleptic and physico-chemical indicators of pectins from pea seed coats meet the requirements of GOST 29186-91; moreover, safety and microbiological indicators conform to both GOST 29186-91 and SanPiN 2.3.2.1078-01. According to the main analytical characteristics, pectins from pea seed coats are highly esterified and meet the requirements for industrial pectins. The sorption properties of the studied pectins are the most pronounced when exposed to lead, cadmium and copper ions, and to a lesser extent, zinc ions. The obtained data allows us to recommend pectins from pea seed coats as structure-forming agents and sorbents of heavy metal ions in the production of functional foods.

Simulation of technological processes involving the combustion of liquid energy products with an attempt to accurately describe their hydrodynamics is known to greatly complicate the model. In this article, we discuss the problem of effective use of organic energy products. A mathematical model describing the combustion process of liquid fuel is presented. The modelling is carried out using a number of justified simplifying assumptions, which permit the original model to be reduced to simpler dependencies between the parameters of the process. The constructed model includes a stationary model of the combustion process and that of liquid fuel burning in a furnace. Key factors affecting the character of the process are investigated. A formula for calculating the oxygen concentration at the reaction surface is obtained. The combustion rate under consideration was assumed to be determined not only by the oxygen concentration in the diffusion layer, but also by the total surface of unreacted particles, calculated taking into account the density of the particle distribution. The material balance of oxygen is drawn, which includes two equations, i.e. for the diffusion and dense parts. The results of the calculations are presented in the form of diagrams. An engineering computational model has been developed for calculating the energy characteristics of the combustion of liquid hydrocarbon fuel in an industrial furnace. The resulting combustion model can be used for predicting the extent and consequences of emergency situations.

This paper presents the results of a study undertaken to investigate the thermal oxidative stability of the Mobil 10W-40SC/CC mineral engine oil at temperatures of 170, 180 and 190 °С. The research technique involved the use of the following controls and tests: a device for oil thermostatting; a photometer for a direct photometry of oxidised oils; electronic scales for determining the mass of the oil evaporated during thermostatting. According to the obtained results, graphical dependences of the optical density D, evaporability G and coefficient of thermo-oxidative destruction P_TOD on the experimental time and temperature were built. A method for calculating the coefficients of thermal-oxidative degradation at the temperature of 190 °С using the data obtained at temperatures of 170 and 180 °С has been validated. A comparative analysis of experimental and calculated data was carried out, with the relative error being calculated. It is established that the application of the proposed analytical model not only reduces the research complexity involved with determination of thermo-oxidative stability coefficients, but also allows directions for improving measurement and testing tools to be specified.

The experimental study of supercritical extraction of the organic substance (OS) from various genetic types of oil shale in a wide range of state parameters was carried out. The dependences of the liquid yield on the temperature at pressure values varying from 3 to 20 MPa were identified. It was found that pressure has a significant effect on the overall degree of organic substance conversion and the liquid yield. With an increase in reactor pressure, the dissolving capacity and the solvent penetration depth increase which contributes to full extraction of soluble components of the organic substance from the porous structure. The results of the study of extraction of the organic substance from oil shale showed that with an increase in pressure the degree of organic substance conversion and the total liquid yield increase by 49-73% and 1,9-3,9 times respectively. The article concludes that variation in thermodynamic parameters of the supercritical fluid extraction process can be used to increase the degree of OS conversion and the liquid yield.