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Relevance. Hemorrhagic fever with renal syndrome (HFRS) is leading among natural focal human diseases in Russia, the causative agents of which - orthohantaviruses - belong to the order Bunyavirales, family Hantaviridae. More than 98% of HFRS cases in Russia are caused by the Puumala virus. It is a serious zoonosis for which there is still no specific treatment. The WHO has not approved a vaccine. The aim of this study was to investigate the effect of formaldehyde, β-propiolactone, hydrogen peroxide, ultraviolet rays, gamma irradiation and thermal inactivation on the immunogenic activity of inactivated vaccine preparations against HFRS Materials and methods. To achieve this aim, experimental vaccine preparations based on the PUU-TKD/VERO strain of Puumala virus were prepared and inactivated using the methods described above. The time intervals required for complete inactivation of the virus were determined, and the effects of the inactivators on viral RNA and immunogenic activity of the vaccine preparations were evaluated in BALB/c mouse and Syrian hamster models. Results. According to our results, vaccine preparations inactivated by different chemical and physical methods, which differ significantly in the mechanism of the mechanism of interaction with the virus, show no significant differences in immunogenic activity, except for thermal inactivation. Conclusion. A certain advantage of β-propiolactone is the short virus inactivation time, its complete degradation into non-toxic compounds within a few hours, and the reduction of total protein content after sterilization filtration, which is probably due to less aggregation of virus particles and cellular proteins

Natural honey can change its physicochemical and biological properties during storage. According to State Standard 19792-2017, honey should be stored at ≤ 20°C. Some publications promote long-term storage of honey at temperatures between 0 and –20°C that preserves its physicochemical parameters, especially the content of hydroxymethylfurfural. Promising as they seem, such temperature modes may affect other physicochemical parameters of honey. The research objective was to study the effect of different temperature conditions on various honey samples and their physicochemical and biological parameters during long-term storage. The study applied standard and authentic research methods to fresh linden, buckwheat, and sunflower honey samples obtained from Rostov, Volgograd, Kursk, Voronezh, Saratov, and Krasnodar regions. They were stored in heat, cold, and moisture test chambers M-60/100-500 for 12 months. Hydroxymethylfurfural proved stable at –18°C for 12 months. After 12 months at 18°C, it showed a sharp increase of 472.5–488.1%. The activity of enzymic diastase, D-glucose-1-oxidase, and catalase occurred at all temperature modes after 1 month of storage. At 0–5°C, the changes were minimal: hydrogen peroxide (H2O2) remained stable, and its concentration decreased by ≤ 12.2% after 12 months of storage. Moisture, mass fraction of reducing sugars, and acidity remained stable in all samples. An antimicrobial test by Escherichia coli (strain 1257), Staphylococcus aureus (strain 209-P), and Bacillus cereus (strain 96) showed that the best inhibiting properties belonged to the samples of linden and buckwheat honey stored at 5 and 0°C for 12 months. The optimal temperatures for long-term honey storage were in the range between 5 and 0°C. The results obtained can be used in updated honey storage standards.

Background. Тhe development of technologies for processing organic resources, including plant residues, into organic and organomineral fertilizers and their application is relevant. Purpose. Studying the effect of hydrogen peroxide oxidation of plant residues in the presence of sulfuric acid on the composition and functional groups of organic substances. Methodology. The study of the influence of hydrogen peroxide oxidation of plant residues in the presence of sulfuric acid on the composition and functional groups of organic substances is carried out by determining the elemental composition of the organic part of the original plant material and oxidation products, determining the functional groups, graphostatic and IR spectroscopic studies of the original plant material and oxidation products. Originality. For the first time, the degree of oxidation and the kinetics of transformation of plant substances into extractive substances extracted by 1% sodium hydroxide solution were studied, the changes in the chemical composition and functional groups of the formed organic acids during the oxidation of plant residues using hydrogen peroxide in the presence of sulfuric acid were determined. Findings. The elemental composition of the original and oxidized plant residues, the extractive substances extracted by 1% sodium hydroxide solution, and the residual plant residue after extraction of the extractive substances, as well as the content of functional groups in them, have been determined. It has been shown that as a result of the oxidation of plant substances in the latter, the content of oxygen and active functional groups increases, both in the shroud itself and in its extractive substances, including extractive substances. [ABSTRACT FROM AUTHOR]

Background. At Almalyk MMC JSC, produces a stub of molybdenum industrial product, while sublimated rhenium semioxide is absorbed, perrenate ions from the technological solution are adsorbed, the sorption process is inhibited by organic contamination of the solution.. Purpose: to develop and test a method without permanganate oxidation of organic compounds in a rhenium-containing production solution. Methodology. Process solutions were monitored by elemental analysis (Agilent 7500 IСP-MS), X-ray fluorescence (Rigaku NEXCGEDXRFAnalyzer), IR spectroscopic (PYE NiCAM and IR-Fourier Nicolet iS50, ThermoScientific, 700-3600 cm-1). Originality. The possibility of using ozonation for the destruction of organic compounds in a process solution is substantiated. Findings. IR spectra of solutions, the values of their redox potentials, and data on the destruction of impurities by the ozonation method were obtained. [ABSTRACT FROM AUTHOR]

In this work, biocorrosion of D16T and AMg6 aluminum alloys under the influence of microscopic fungi was studied. It has been shown that micromycetes produce reactive oxygen species – superoxide anion-radical, hydrogen peroxide, which initiate biocorrosion of metals. The composition products of biocorrosion of D16T and AMg6 after exposure of the alloys on the lawn of a consortium of micromycetes was determined by energy-dispersive X-ray spectroscopy. An X-ray phase study of alloy biocorrosion products was carried out. Scanning electron microscopy and X-ray diffraction analysis show the formation of nanosized and submicron copper clusters. A physicochemical mechanism of biocorrosion of aluminum alloys by microscopic fungi is proposed. An assumption is made about the mechanism of operation of the «zerovalent metal – hydrogen peroxide» systems, which can trigger a cascade of reactions leading to the destructive oxidation of metals. The paper attempts to explain the role of microfungal community biofilms as the main factor in the mycological corrosion of metals.

Disinfection measures in the event of an outbreak of epidemics created by natural and artificial causes are connected with high consumption of disinfectants, especially in anthrax foci. This does not exclude the situation, when the stock of authorized disinfectants may turn out to be insufficient. So it will be necessary to use non-authorized disinfectants. The aim of this paper is to reveal among the disinfectants, registered in Russia, the most convenient to use by the NBC Protection Troops in epidemic emergencies. 770 such disinfectants have been analyzed. It is established, that the disinfectants of the group of cationic surfactants (CPAS) based on quaternary ammonium compounds, amines, polyguanidines and compositions of these active substances in various combinations have been introduced into practice of Russian medical institutions for almost two decades. The analysis of the scientific literature and the results of our own experiments show that the solutions of these disinfectants, recommended for high-level sterilization and disinfection of medical devices, do not have any sporicidal effect. Because of that, only disinfectants based on chlorine-containing and oxygen-containing active substances can be interesting for the NBC Protection Troops and may be used as non-authorized disinfectants. The solutions of such agents have a wide range of antimicrobial action and provide complete death of not only bacteria, viruses and fungi, but also spores of various bacilli, at temperatures below 0 ºС as well. The most convenient in use by the NBC Protection Troops are the products in the form of instant tablets based on sodium dichloroisocyanuric acid, as well as in the form of liquid concentrates based on hydrogen peroxide or peracetic acid. Because of that the above mentioned agents should be used by the NBC Protection Troops in cases of biological emergencies according to the regimes of standard approved disinfectants.

The growing demand for pectin in food, pharmaceutical and cosmetic industries requires the search for raw materials for its production and the development of innovative, environmentally friendly and cost-effective ways to obtain it. A secondary resource of sugar beet processing – pressed beet pulp which is formed in significant volumes at the sugar beet factories of the Russian Federation can serve as promising source pectin. At present, the growth of scientific and technological progress has led to the prospect of using such methods of controlled transformation of plant materials, in which the impact on the quality and yield of the target component is minimal, in contrast to the classical acid-ethanol method for producing pectin. Of greatest interest are biotechnological methods for extracting biologically active substances from plant materials, which provide a higher yield while maintaining their properties. However, to ensure the maximum effect, it is necessary to prepare plant materials for extraction, since biotechnological methods have a point focus, as a result of which, under suboptimal conditions, the efficiency of extracting biologically active substances will be reduced. The aim of the research is to develop a technology for the preparation of pressed beet pulp using chemical and physical impact methods for the subsequent process of biotechnological extraction of pectin. To achieve this aim, the pressed beet pulp treatment with an aqueous solution of hydrogen peroxide has been used as a chemical impact method, and grinding of pressed beet pulp and its treatment with microwave electromagnetic field (MV EMF) has been used as physical impact method. Effective technological regimes for the preparation of pressed beet pulp for pectin extraction using chemical and physical impact methods have been determined, namely, treatment of pressed beet pulp with a 20% aqueous solution at a ratio of pressed beet pulp: hydrogen peroxide solution equal to 1,0: 1,0, and constant stirring for 90 minutes, separating the pulp from the liquid phase, its subsequent grinding to a particle size of less than 2.0 mm and EMF MV treating with a heating rate to reach a temperature of 60℃, equal to 0,6℃/s. The technology has been developed for preparing pressed beet pulp for pectin extraction, providing a degree of pectin extraction of 12,78% to its initial content in pressed beet pulp, which is 10,39% higher compared to the control (without grinding and treating).

Background. The mitochondrial electron transport chain, in particular the respiratory complex I, is one of the main sources of reactive oxygen species (ROS) in living cells. Suppression of the complex I activity in human cells through chemical inhibition or mutations that disrupt the functionality of this complex leads to a significant increase in the content of ROS. The complex I mutants are also known for plants; however, it is still not clear whether the suppression of the activity of this complex leads to an increase in the level of ROS and the development of oxidative stress. Purpose. To study the level of superoxide, hydrogen peroxide and sensitivity to prooxidants in Arabidopsis ndufs4 cells with complex I inactivated by insertional mutagenesis. Materials and methods. A suspension culture of wild-type Arabidopsis cells and a line with knockout the NDUFS4 complex I subunit was used. The level of hydrogen peroxide in the cells was determined using dichlorofluorescein. The superoxide content was estimated by cell staining in the presence of nitroblue tetrazolium. Results. It has been shown that inactivation of the NADH-dehydrogenase complex in Arabidopsis cells due to the absence of one of its subunits leads to a decrease in the content of superoxide and hydrogen peroxide. It was also shown that the level of ROS in cells treated with the menadione and hydrogen peroxide increased several times in wild-type cells, but remained almost unchanged in ndufs4 cells. Conclusion. Suppression of the activity of the NADH dehydrogenase complex in plant cells, but not in animal cells, leads to a decrease in the content of both hydrogen peroxide and superoxide. Cells of ndufs4 line have an increased ability to detoxify ROS, possibly associated with the constant mobilization of antioxidant defense systems.

Background. Among household chemicals, bleaching agents stand out: for bleaching linen and auxiliary agents used in the washing process. In both cases bleaching agents are used. Purpose is to develop a technology for producing potassium peroxycarbonate from potassium car- bonate in the presence of hydrogen peroxide. Methodology. Chemical, radiographic, electron microscopic, isothermal methods of analysis. Originality. Data on the solubility of K2CO3 -H2O2-H2O at -10 and 0°C were obtained. The liquidus curve of the solubility diagram of the K2CO3 -H2O2-H2O system, at the studied temperatures, is characterized by the presence of three branches of crystallization of the initial components and a new compound of the composition - K2CO3·3H2O2. Findings. A method has been developed for the preparation of sodium and potassium peroxycar- bonates from potassium and sodium carbonates in the presence of hydrogen peroxide. Crystallization is car- ried out in a polythermal mode, and the slow cooling of the saturated solution causes the formation of a coarse-crystalline precipitate of the peroxide compound, with lamellar and cylindrical particles, up to 1-3 mm. [ABSTRACT FROM AUTHOR]

Background. An urgent problem of natural gas purification is the creation of an adsorbent on a local raw material base, of which interest is attracted by zeolites created using template additives that provide their predetermined functional properties. Purpose: to study a two-stage approach to the synthesis of nanostructured crystalline type A zeolite with the inclusion of chitosan gel crosslinked with glutaraldehyde as a template in the process, solving the problem of removing the chitosan template from the structure of the resulting zeolite.. Methodology. The use of the hydrothermal method in the sol-gel process of synthesizing nanostructured crystalline zeolite type A. The use of SEM, EMF, X-ray diffraction, nitrogen porosimetry to determine the structural characteristics, the study of CO2 adsorption-desorption on the resulting nanozeolite. Originality. Nanostructured crystalline type A zeolite was synthesized by a two-stage method. Chitosan crosslinked with glutaraldehyde was used as a template. To remove the chitosan template from the aluminosilicate, the product was treated with hydrogen peroxide. Findings. Nanostructured crystalline type A zeolite was synthesized, its physicochemical characteristics were studied, incl. no pore shrinkage, crystallinity, CO2 adsorption. [ABSTRACT FROM AUTHOR]

Background. The development of the process of soil salinization can be accompanied by both a decrease and an increase in pH; at the same time, plants experience complex stress (salt + alkaline stress, salt + acid stress). The purpose of the research is to trace the dynamics of hydrogen peroxide content, peroxidase activity and proline content in oat leaves under the influence of NaCl against the background of acidic, neutral and alkaline reactions of the root environment. Materials and methods.The oat Avena sativa L. was used as the object of study. Plants were grown on vermiculite for 6 days, then stress factors were added, which were solutions combining NaCl salinity (200 mM) and different pH levels (pH 3, pH 6.5, pH ten). The alkaline medium was created with a glycine-KOH buffer, and the acidic medium was created with acetic acid. After stress exposure for 48 hours, peroxide content was determined in plant leaves by the ferrothiocyanate method, peroxidase function – by the Boyarkin method, proline – by the Bates method. Results. When exposed to NaCl salinity against the background of a neutral reaction of the environment, the height of the plants was lower than the control variant only after 48 hours of observation; in oat leaves, variability in the content of peroxide, an increase in the activity of peroxidases, and the accumulation of proline were observed. In the NaCl variant on an alkaline medium, the height of oats did not differ from the height of plants against the background of an alkaline reaction of the medium; in some periods of observation, an increase in the activity of peroxidases and the accumulation of proline were noted in oat leaves. Salinization against the background of an acid reaction of the environment contributed to a decrease in the height of oat plants; the activity of peroxidases did not increase in the leaves, and the accumulation of proline was noted only a day after the stress exposure. Conclusions. Against the background of neutral, alkaline and acid reactions of the environment, different degrees of manifestation of salt stress were noted. Increased inhibition and weak plant responses indicate the most negative effect of salts against the background of an acidic environment.

In the course of this study, the technology of bleaching of cotton pulp for various purposes has been improved, which can be used in the production of cotton pulp by "Khlopoprom-Cellulose" LLP and other enterprises to increase the production efficiency and competitiveness of the products obtained. The proposed development makes it possible to obtain cellulose with a high degree of polymerization and whiteness, as well as to solve the problem of stabilization and high decomposition rate of hydrogen peroxide in the technological cycle. The bleached cellulose meets the requirements of GOST (State Standard) 595-79 "Cotton cellulose" and has an average degree of whiteness of 90%, which is 5-6% higher than the samples of cotton cellulose bleached without the use of a hydrogen peroxide stabilizer.

Relevance. Oxidative reactions (based on peroxidase activity, POX and polyphenol oxidase, PPO; hydrogen peroxide content) that occur in response to infection or reinfection of the off-spring of infected plants depend on the type of host-virus interaction (sensitive, tolerant, stable) and the nature of the interaction with viral infection (primary infection, reinfection of second and third generations).Results. Reinfection with tomato aspermy virus (TАV) or tobacco mosaic virus (TMV) of the off-spring of third infected tomato generation caused a significant decrease in POX activity compared to successive generations of infected plants (G2) for Craigella (Tm-22/Tm- 22) and S. pimpinellifolium genotypes or an increase for Rufina and Craigella (Tm-1/Tm-1) ones. In genotypes containing resistance genes, Rufina and Craigella, no differences were observed in PPO of TMV primary infection and control, while significant differences were found in case of TAV (susceptibility). As a result of TMV infection, the sensitive (Elvira) and tolerant (S. pimpinellifolium) genotypes showed an increase in PPO values compared to the control. At the same time, in most genotypes primarily / secondarily infected with TAV or TMV, statistically significant differences were revealed in the activity of POX or PPO, as well as the accumulation of hydrogen peroxide in plant leaves, which indicates specific protective reactions of the genotypes.

Catalytic properties of the nanocluster iron-molybdenum polyoxometalate {Mo72Fe30} in solutions during the oxidation of iodide ions by persulfate have been studied. Automated installation based on spectrophotometric method of analysis controlled by computer was used. Comparison of literary data and kinetic datа on the oxidation of iodide with persulfate showed that keplerate {Mo72Fe30} is a heterogeneous catalyst. These data allowed to assume a non-radical mechanism for persulfate decomposition on the surface of cluster molecules at the first stage of the potassium iodide oxidation reaction. The value of the effective activation energy of the process indicates the catalytic effect of {Mo72Fe30} at the intermediate stage of the decomposition of the hydrogen peroxide.

Today the environmental problem of modern society is the rapid contamination of water resources around the world for pharmaceutical products, including antibiotics. According to the University of York (UK), contamination with antibiotics had covered two-thirds of the waterways of the planet. It was established experimentally that 90 % of antibiotics are applied into the surrounding environment: soil and water. Residues of medical drugs fall into rivers via human waste and animals and through the treatment plant, including pharmaceutical companies. On the other hand, under the influence of antibiotics can significantly change the biocenosis of water bodies. And bacteria gradually become immune to the effects of antibiotics. Therefore, the Ukrainian research Institute of ecological problems in cooperation with the National scientific center Kharkiv Institute of physics and technology experimental studies aimed at inactivation of bactericidal properties of antibiotic solution during processing ozone-air mixture. The study assessed the effectiveness of inactivation of antibiotic ciprofloxacin hydrochloride by methods related to deep oxidation AOPs technologies (Advanced Oxidation Processes) on the basis of combinations of ozonation, UV irradiation, treatment with hydrogen peroxide. Shown the prospects of using ozonation and O3/UV and O3/UV/H2O2 to reduce the toxic effect of the antibiotic residues of ciprofloxacin relative to the test object E. coli in the aquatic environment. Found that ozonation of activated sludge treated with ciprofloxacin, reduces the toxic effect of the antibiotic and promotes the enzymatic activity of the biocenosis of activated sludge

The research deals with determination of low levels of hydrogen peroxide in objects of technogenic and geological origins. The aim of the work was to develop a sensitive sensor based on silver nanoparticles to detect hydrogen peroxide in water objects. Objects: artesian and rainwater collected in the city and suburbs. Methods: voltammetry, transmission microscopy. Results. The shape, size and amount of silver nanoparticles depend on the nature of the reducing agent. When using two reducing agents of borohydride and sodium citrate, the smallest spherical particles – from 0,5 to 17,5 nm, are obtained. When using sodium citrate, larger silver nanoparticles – from 10 to 55 nm, in various shapes are obtained. They are as follows: rod-shaped, prismatic, triangular with a particle size from 10 to 55 nm. AgNPs-Bg have a rod-like and prismatic shapes 5–65 nm in size, connected in chains, i. e. agglomerated. The mechanism of electrochemical processes of silver nanophase transition on the surface of graphite electrode to 0,1 M NaOH in the presence of various reducing agents is proposed. This mechanism does not depend on the nature of the reducing agent. A feature of electroreduction of silver nanophase obtained in the presence of citrate potassium is the reduction of silver ions from the complex ions [Ag(OH)2]–. The authors have proposed the mechanism of electrochemical transition processes of silver nanophase in the presence of various reducing agents. It was found that the cathode maxima at Ес=0,08 V corresponds to hydrogen peroxide reduction. Using a sensor based on the silver nanoparticles obtained in the presence of sodium citrate the dependence of the current of the maximum on hydrogen peroxide concentration was linear – in the range from 0,1–1 nM, and the detection limit was 0,087 nM. The content of hydrogen peroxide in rain and artesian water was determined. The proposed sesor modified by silver nanoparticles obtained in presence of sodium citrate is simple, rapid, and sensitive. This sensor has a wide range of concentrations for determination of hydrogen peroxide.

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Relevance of the research topic: modern bleaching systems are based on the use of hydrogen peroxide preparations or carbamide peroxide, in combination with activating factors. Hydrogen peroxide acts as a strong oxidant by the formation of free radicals, reactive oxygen molecules and hydrogen peroxide anions. Many researchers believe that the discoloration of tooth whitening is determined primarily by changes in the dentin. Others dispute the idea of color change in dentin and believe that it occurs only in enamel, masking unchanged dentin. Objective: to study histological changes in the structure of hard tooth tissues during whitening. Materials and methods: 12 intact teeth removed by orthodontic indications after in vitro bleaching procedure and 4 intact teeth not subjected to the bleaching procedure were selected. To whiten teeth, a system was used that included a gel based on 24% hydrogen peroxide (Amazing White Professional). After the bleaching procedure, histological preparations were made and the study was carried out using a microscope mVIZO-101 (OJSC LOMO, Russia). Results: the surface of the enamel after bleaching had a significant number of wedge-shaped defects, as well as a slight delamination. In the upper and middle third of the enamel, cavity changes in the form of pores in a significant amount were observed. The dentinal tubules were enlarged, the location was not traced. Conclusions: a single photochemical bleaching procedure leads to significant morphological changes in the structure of hard tissues of the teeth, which manifest themselves as wedge-shaped defects in the enamel, as well as the appearance of cavities in the enamel-dentine border and the heterogeneity of dentin with a significant number of pores.

Relevance. One of the most important factors which can influence on the growth and development of strawberries is the negative temperature in winter and especially in its snowless period. We were interested to study special aspects of the oxidative stress, accumulation of protector’s conjunctions, antioxidant and water status in autumn period of varieties strawberry garden different ecologicalgeographical origin in the conditions of the Orel region.Methods. The objects of the research were the leaves of Fragaria ananassa of different ecological and geographical origin in autumn period: Tsaritsa, Alba, Sara, Korona, Kokinskaya Rannya, Solovushka, Urozhainaya TsGL.Results. As the result was shown that in autumn period, when plants began preprocessing for winter, strawberry varieties Solovushka, Tsaritsa, Sara and Korona have been marked by increased antioxidant activity (for example, the enzymes SOD and catalase), little formation of reactive oxygen species and, in the end, low structural and functional damage to cell membranes. Also it was shown an increase in bound and a decrease in free water in the leaves of plants when the temperature decreased. At the same time, in the end of autumn, on the background of high content of free proline (19.38-29.73 mg/kg) and sucrose (2.65-6.46 mg/g), the varieties Solovushka, Tsaritsa, Sara and Korona had the highest ratio of bound/free water (4.10-8.10) in comparison with the with Urozhainaya TsGL and Alba. Thus, the varieties Solovushka, Tsaritsa, Sara and Korona are characterized by high adaptability to the winter conditions in the Orel region.

According to modern ideas, plant mitochondria regulate the expression of nuclear genes and act as signalling organelles providing the tolerance of plants to external stressors. Highly conservative membrane proteins prohibitines (Phb) responsible for membrane-peptide interactions in organelles of animals, plants and microorganisms accumulate in mitochondria and modulate the state of their membranes, participating in the regulation of mitochondrial-mediated signalling. The tuning of the content of the Phb is poorly investigated for today day. Most of biotic and abiotic stresses are associated with production of reactive oxygen species (ROS) which can play as signalling role as well as cause damage. Hydrogen peroxide is one of the forms of ROS. The goal of this research was to study the effect of different doses of hydrogen peroxide on the Phb3 and Phb4 content in Arabidopsis plants. In the leaves of Arabidopsis thaliana heat shock (HS, 42°C, 3 h) caused the increasing of the content of Phb after 24 h from the stop of the influence and the increasing of superoxide radical content immediately after HS. So the increasing of the content of Phb and ROS as a result of HS occurs simultaneously. Next we investigated the influence of oxidative stress on Phb content. It was shown at first that H2O2 decreases the content of Phb in dose-depend manner at the starting hours of the action (2 to 40 mM H2O2 during 1 to 2 h were used). At the continuation of the influence till 24 h the content of Phb returns to the control value. Herewith the suppressing effect is demonstrated by non-stress doses of H2O2 (2 to 10 mM). The stress dose of H2O2 (40 mM at 24 h) doesn’t effect on the content of Phb, but causes the increasing of the content of Hsp 17.7 and wilting of the leaves which indicates the stressed condition of the plants. The results received speak in favor that at the protein level the increasing of Phb3 and Phb4 content is not activated by ROS-mediated system even during the development of the oxidative stress.

The relevance of the research is determined by the need to solve the problem of toxic substances, including arsenic compounds, entry into water bodies, by searching for and developing effective photochemical methods for cleaning and neutralizing arsenic-containing solutions using environmentally friendly oxidants and modern mercury-free sources of UV radiation. The main aim of the research is to study the possibilities of using excilamps for neutralizing As-containing waters and to establish the regularities of photochemical activation of arsenic oxidation by hydrogen peroxide using a mercury-free source of quasi-monochromatic radiation from the KrCl excilamp. Objects: model aqueous solutions of arsenic (III) with a concentration of 2,7 μM (~0,2 mg/L), prepared on distilled water (UEP=2 μS / cm, pH 5,8) and tap water. Methods: spectrophotometric determination of arsenic (III) ions; pH control by potentiometric method, shooting of electronic absorption spectra of solutions of reacting substances; determination of absorbed emission power of the excilamp by the method of chemical actinometry with atrazine; evaluation of doses of UV radiation. Results. The authors have established the principal possibility of using the mercury-free source of quasi-monochromatic radiation of the KrCl excilamp (222 nm) for photochemical oxidation of As (III) by the oxidation system {UV/H2O2}. They studied the main regularities of photochemical oxidation of arsenic (III) using the mercury-free UV source KrCl-excilamp (222 nm) and carried out the comparative studies of the efficiency of direct photolysis and combined oxidation of arsenic (III) in aqueous solution with ultraviolet radiation of the KrCl excilamp in the presence of hydrogen peroxide. According to the efficiency of As (III) oxidation the considered oxidation systems may be arranged as {UV/H2O2}>{H2O2}>{UV}. At the combined treatment of {UV/H2O2} the significant intensification of oxidation is observed, after 10 minutes the residual arsenic concentration in the solution is below the MPC (0,01 mg/l). The paper considers as well the effect of hydrocarbonate ions, being the most characteristic anions of natural «water matrices», on the oxidation rate of As (III). The authors proposed the ion-radical mechanism of arsenic photochemical oxidation in a combined oxidation system {UV/H2O2} using the UV radiation of the KrCl excilamp.

A method is proposed for studying the evaporation process of unusable rocket propellant residues in worked-off stage under weightless conditions. Two options are considered as boundary conditions for liquid rocket propellant residues: a) liquid drop distribution in N identical drops, which surface decreases during evaporation and b) the liquid location in the lower tank bottom and the mirror presence, which area decreases during evaporation. A high-temperature stream of hydrogen peroxide decomposition products is used as a heat carrier fed to the fuel tank. The physical and mathematical model of the liquid evaporation process is based on the first thermodynamics law. Based on the analysis of the Frud and Grashof criteria, the assumption that there is no convection movement inside the drop (Rayleigh number is less than critical) for both boundary conditions variants, the heat transfer coefficient of the gas-vapor mixture produced in the tank is determined based on the regression dependence obtained in ground conditions as a function of from the Nusselt, Reynolds, Prandtl numbers. Comparisons of the gasvapor mixture parameters for the considered boundary conditions variants and the proposed physical mathematical model with the results, obtained earlier, for the boundary conditions variant of uniform fluid distribution over the inner tank wall (third boundary conditions variant) and using the boundary layer theory based on integral impulses, energy and diffusion ratios are given. The thermophysical gas-vapor mixture parameters and the gas-vapor mixture exhaust velocity for oxygen, kerosene for two boundary conditions types are given, using the example of Soyuz-2.1.v type fuel tanks. The total rocket propellant residues evaporation system design mass is less than 1,3% of the total «dry» worked-off stage design mass

With the using of a thermographic method reaction of oxidation of dibutylsulfide in a noctane 95,6 % concentrated solution of hydrogen peroxide in the mixture reactor with the propeller mixer is studied.It is established that dibutylsulfide oxidation by hydrogen peroxide in an ekvimoly-arny ratio 1:1 at a temperature of 80 °C proceeds before formation of a dibutilsulfoksid, and at a ratio 1:2 and at a temperature of 100 °C – to a dibutilsulfon.The increase in amount of hydrogen peroxide and temperature is followed by for-mation of sour products – the sulfoniyevykh and sulfonew acids.By method of a gas-liquid chromatography it is proved that during oxidation of dibutylsulfide by hydrogen peroxide his destruction doesn't happen.

Introduction: Hydrogen peroxide is well soluble, odourless and colourless liquid with syrup consistency. It has different application depending on concentration. In 3% of concentration is present in almost every home as a disinfectant product, in higher concentration (35%) is used in pharmaceutical, chemical and cosmetic industry. The aim of the study: The purpose of this systemic review was to collect and analyse causes and possibilities of treatment a patient after ingestion a caustic substance. Material and method: Standard criteria were used to review the literature data. The search of articles in the PubMed and Google Scholar database was carried out using the following keywords: hydrogen peroxide, exposure, toxicology. Description of the state of knowledge: Exposure for hydrogen peroxide is not very common and most of the times is unintentional, except suicide attempts. Because it is a caustic substance and the main route of exposure is ingestion, most of symptoms are due to damage of gastrointestinal tract. However, the consequences of exposure range from short-time illness to brain damage or even death. Summary: Patient after exposure to >30% hydrogen peroxide should receive a complex treatment. Physicians need to be alert to the symptoms of not only gastrointestinal tract but also CNS. The patient may require specialized care by many specialists.

Photooxidized psoralen solutions possess a variety of biological effects, which implementation mechanism may presumably involve hydroperoxides. Here, the hydroperoxide content in photooxidized psoralen solutions was assessed using photometric FOX assay (from Ferrous Oxidation + Xylenol Orange). FOX reagent with 10× content of Xylenol Orange, modified for quantitative analysis of up to 50 μM of hydroperoxides in aqueous phase was used in experiments. During photooxidation of 0.1 mM psoralen in phosphate buffer solution, hydroperoxide production increases with dose of UVA irradiation (~2.5 μM eq. of H2O2 for dose of 252 kJ/m2 and ~11 μM eq. of H2O2 for dose of 1512 kJ/m2) and reaches ~16.5 μM eq. of H2O2 at the highest dose investigated (3024 kJ/m2). A comparison of kinetics of psoralen photolysis and hydroperoxide generation allows us to suggest that generation of hydroperoxide results from the secondary photochemical processes involving psoralen photoproducts, presumably from photoinduced autooxidation of aldehydic photoproducts of psoralen.

With the help of thin-layer and high-performance liquid chromatography, the change in the composition of the reaction mass during the chlorination of salicylic acid was studied by three methods: molecular chlorine in acetic acid, sodium hypochlorite in an aqueous alkaline solution and oxidative chlorination with a mixture of hydrogen peroxide and hydrochloric acid in an acetic acid environment. It is shown that the most complete transformation of salicylic acid into 3,5-dichlorosalicylic acid is observed in the reaction with sodium hypochlorite, and the least complete - in the reaction of oxidative chlorination. It was found that the adverse reaction of the ipso-replacement of the carboxyl group with the formation of 2,4,6-trichlorophenol to the greatest extent occurs in chlorination of salicylic acid with gaseous chlorine in the acetic acid and with sodium hypochlorite in the aqueous alkaline medium. It is established that recrystallization technical 3,5-dichlorosalicylic acid of 50% aqueous 2-propanol to most effectively allows you to remove the admixture of 2,4,6-trichlorophenol, and to a lesser extent, admixture chlorosalicylic acids.

Aim. Evaluation of the effect of metabolites of vaginal lactobacilli on the enzymatic and bactericidal activity of muramidase. Materials and methods. We investigated how the enzymatic and bactericidal activity of muramidase changes after treatment with supernatants of lactobacilli containing surfactants, hydrogen peroxide, or a combination thereof. The enzymatic activity was measured by the rate of Micrococcus luteus lysis, bactericidal activity for test strains of Escherichia coli and Lactobacillus acidophilus by results of seeding on agar plates. Results. The hydrogen peroxide and surfactants reduced the enzymatic activity of lysozyme. Bactericidal activity of lysozyme against L. acidophilus and E. coli was decreased under the influence of surfactants. Hydrogen peroxide and its combinations with surfactants decreased bactericidal activity of lysozyme against L. acidophilus and increased for E. coli. Low concentrations of surfactants potentiated the effect of H2O2 on the antibacterial activity of lysozyme. Conclusion. It is concluded that the metabolites of the normal microflora is a implement for modification of host defense factors in order to create favorable conditions for its own existence, and prevent introduction of allochthonous species.

The authors investigate the influence of hydrogen peroxide concentration on the conductivity of the porous silicon with silver nanoparticles / crystalline silicon system. A simple resistive sensor with Ag nanoparticles was used as a catalyst in order to study processes occuring in porous silicon during hydrogen peroxide detection. Porous silicon was formed using a two-stage metal-assisted chemical etching with Ag nanoparticles. It was shown that two simultaneous processes are involved here: carrier extraction to porous silicon caused by interaction with hydrogen peroxide molecules and heating caused by hydrogen peroxide decomposition in presence of Ag nanoparticles. Dimensions of the investigated sensor structure were comparable with a drop of the solution, thus at 30‰ concentration heating could reach 10°C. As porous silicon/crystalline silicon system has a negative temperature coefficient, two above mentioned processes counteract which leads to a maximum, or saturation, on the graph of the dependence of resistivity on hydrogen peroxide concentration at 10—11‰. Sensitivity declines from 0.001—0.02 to 0.0001—0.0003%/‰. To prove these thesis resistivity-concentration dependences were adjusted taking into account calculated heating caused by hydrogen peroxide decomposition. It was shown that in this case the slope of the dependence curve remains stable up to 30‰ and sensitivity remains about 0.001—0.02%/‰.

The article is dedicated to finding out the specific features of the behavior of rare-earth metals in hydrometallurgical processing of pyrochlore-monazite-goetite ores of the Chuktukonsky ore field is shown in the work. Chuktukonsky ore field is a potential source of rare earth metals. The mentioned ores are practically unenforceable. Hydrometallurgical methods for their complex processing were suggested. Agitational and autoclave nitric acid leaching depending on such technological parameters as temperature, HNO3 concentration, process duration, S:L ratio and the use of H2O2 were studied. The possibility of transferring manganese (that is present in a significant amount in the ore) into a nitric acid solution by hydrogen peroxide was considered. Based on the results of the conducted studies, the distribution of REM in the products of the hydrometallurgical conversion of pyrochlore-monazitegoetite ore was estimated. It was found out that incomplete opening of the ore material was observed during agitational leaching: average REM recovery into the solution is 60%. The study made it possible to solve the problem of purifying nitric acid solutions from phosphorus that hinders the subsequent extraction and separation of rare earth metal ions forming strong complexes with rare earths. Removal of phosphorus from the solution was achieved by conducting the process under pressure at elevated temperatures (200-230 0C). It was found that the optimal decomposition conditions ensuring the transfer of almost 99% of the REM into the nitric acid solution are: 25% solution of HNO3, ore size - 0.071 mm; 5% by volume H2O2; t(160 0С) = 1 h; t(230 0С) = 1 h, gradual temperature increase from 160 to 230 0С; S:L = 1:8. Autoclave nitric-acid leaching allows selecting rare earth metals from the main part of iron, phosphorus and niobium.

A technological process of manufacturing glycidol designed for the production capacity of 10 thousand tons per year and consisting in the direct oxidation of allyl alcohol with an aqueous solution of hydrogen peroxide in the presence of nanostructured titanium silicate in methanol is proposed. Due to the exothermic process, the solvent is not only a homogenizer of the mixture of the initial reagents of the epoxy process - allyl alcohol and hydrogen peroxide ensuring their interaction on the surface of the solid catalyst: it also prevents overheating of the reaction mass. On the basis of the research trial of the process the optimal parameters of the process were determined: temperature 30-40 °C; pressure 0.25 MPa; the initial hydrogen peroxide : allyl alcohol ratio = 1:(3-4) mass., methanol concentration in the reaction mixture 12-13 mol/l. Hydrogen peroxide conversion is 98%, the yield of the glycidol - 94%, the selectivity is no less than 95%. The process includes three main stages: (1) raw materials preparation, (2) liquid-phase epoxidation of allyl alcohol, (3) distillation of the target product. The scheme involves recirculation of unreacted allyl alcohol and the solvent - methanol. The developed technological process provides the following indicators (per 1 t of commercial glycidol): consumption of allyl alcohol no more than 0.843 t; consumption of hydrogen peroxide no more than 0.50 t (calculated for 100% hydrogen peroxide); consumption of methanol is no more than 0.022 tons All the waste products correspond to the 3-rd or 4-th hazard class.

Background: Molecules of hydrogen peroxide (H2O2) can be formed during radiolysis process in water medium after irradiation. A hypothesis about the possible role of hydrogen peroxide in blocking of processes of nonspecific DNA recognition by proteins is proposed in [1]. As one of the most long-living products, H2O2 molecules can diffuse considerable distances in the intracellular medium and reach DNA in the cell nucleus and form complexes with macromolecule phosphate groups. To confirm this hypothesis, the quantum chemical calculations of complexes structure of hydrogen peroxide molecule with atomic groups of the DNA backbone are performed. Objectives: To determine the optimal geometries and formation energies of stable complexes of hydrogen peroxide with DNA phosphate group. To perform a comparative analysis of hydrogen peroxide and water molecules binding to phosphate group based on quantum chemical calculations. Materials and Methods: The complexes which consist of phosphate group, hydrogen peroxide, water molecules, and sodium counterion are analyzed. The optimization of complex geometry and energy calculations is performed using the methods of quantum chemistry within Gaussian 03 software: HF/6-31+G(d,p), MP2/6-31+G(d,p), B3LYP/6-31+G(d,p). Results: This research shows that the hydrogen peroxide molecule as well as water molecule can form stable complexes with phosphate group, especially with the presence of sodium counterion Na+. The results of complex formation calculations with atom-atom potential functions method are confirmed. It is shown that the presence of sodium counterion significantly influences the geometry of the hydrogen peroxide complex with the phosphate group. The performed calculations indicate the possibility of hydrogen peroxide geometry change in the processes of complex formation. Conclusions: The obtained results confirm the possibility of stable complexes forming for hydrogen peroxide and phosphate group. Prolonged situation of H2O2 molecule near the DNA backbone may block the nucleic-protein recognition processes as well as damage the macromolecule via decay into OH-radicals in close proximity to double helix.

Resume. In vitro experiments performed on human endothelial ceLL culture (HUVEC), nerve growth factor (NGF) angiotropic effects were studied. An intact ceLL culture it was shown that NGF exhibited angiogenic properties and stimulated the initial stage of angiogenesis -tubuLogenesis at a 10-9 M concentration, as evidenced by a statisticaLLy significant increase in the average totaL Length of microtubuLes compared with the control. Under conditions of oxidative stress, NGF neutraLizes the damaging effect of hydrogen peroxide in a high concentration (200 |±M) and not onLy shows an angioprotective effect, but aLso prevents the deveLopment of morphoLogicaL changes in nucLear chromatin, characteristic for apoptosis. Under these conditions NGF (10-9 M) reduces statisticaLLy significant by comparison with the controL the number of ceLLs with condensed and fragmented chromatin: 44 ± 9 and 78 ± 9 (р ≤ 0,05), respectiveLy. The obtained resuLts confirm the data about the NGF angiogenic activity and indicate that under conditions of the vesseLs endotheLiaL ceLLs damage by oxidative stress, it exhibits pronounced angioprotective and anti-apoptotic activity.

Consideration of the complexation of components in the polymerization systems becomes an important step in the study of the mechanisms of all stages of the polymerization process. An important role in this process is played by the solvent, which modifies the intermolecular interactions (IMI) between a monomer and an initiator or with both components, leading to unexpected effects that affect both the kinetics of polymerization and the properties of the final products. These effects are especially strong in systems whose components are prone to active IMI. Such systems include mixtures in which hydrogen peroxide (HP) is used as an initiator, capable of acting as an active donor and acceptor of protons in a hydrogen bond. In the preparation of oligodienes with terminal hydroxyl groups, the diene-HP-alcohol system is used. HP molecule forms a π-complex with diene's double bonds as a hydrogen donor and a hydrogen bond with a solvent, where the peroxide group of HP is solvated by alcohol. The resulting triple complex decomposes into water and two radicals - alcohol hydroxyl-containing and hydroxyl ones, which initiate the polymerization of diene. When using isopropyl alcohol, the alcohol's radical contains a tertiary hydroxyl group. Th is leads to the formation in this alcohol of an oligomer with an effective functionality of 1.5 instead of the expected 2, since the tertiary hydroxyl group is inactive in the urethane formation reaction. It is shown that in this process, the termination of macroradicals occurs by the chain transfer to HP, not by recombination of macroradicals. The new polymerization scheme in the studied system is proposed, taking into account the experimental facts presented. The scheme is confirmed by thermochemical and quantum-chemical calculations and the distribution of oligomer molecules by functionality. [ABSTRACT FROM AUTHOR]

Background. Olefin oxides are widely used as cheese and intermediates in the synthesis of organic compounds. In this regard, the study of the synthesis of oxides based on hexene-1 and its isomers is one of the main tasks in the present time. Purpose. Investigation of the process of catalytic epoxidation of hexene isomers with sodium hypochloride and hydrogen peroxide. Methodology. The effectiveness of the influence of the nature of oxidizing agents, the catalyst, and their ratio on the yield of the resulting epoxy compounds was evaluated by classical methods, and the composition and structure of the products of the epoxidation reaction were determined by IR spectroscopy. IR spectra of the initial and obtained compounds were recorded on a Perkin-Elmer Sistem-200 Fourier spectrometer in the region of 4000-400 cm-1. Originality. The possibility of carrying out the epoxidation of hexene isomers in the presence of hydrogen peroxide and acetic acid is shown. Findings. The optimal conditions for catalytic epoxidation reaction: the nature of the oxidizing agents and the ratio of the starting reagents and the length of the reaction time. [ABSTRACT FROM AUTHOR]

The luminol-hydrogen peroxide chemiluminescent system is widely used for the creation of diagnostic systems, for chemical analysis, for studying the kinetics and mechanisms of chemical reactions, for the creation of special and emergency light sources, and for monitoring living systems. However, the use of the luminol-hydrogen peroxide chemiluminescent system is limited by the fact that there are almost no ways of managing the reaction. The introduction of organized molecular systems into the luminol-hydrogen peroxide chemiluminescent system can create an additional channel for controlling chemiluminescent reactions. The luminol-hydrogen peroxide system was not previously studied in various classes of hydrocarbon and perfluorinated micellar solutions. This work was the first to study the effect of cationic, anionic and nonionic hydrocarbon surface-active substances (cetyltrimethylammonium bromide, sodium decyl sulfate, sodium dodecyl sulfate, triton X 100) and perfluorinated surface-active substances (FT-135 and FT-248) on the chemiluminescent systems luminol-hydrogen peroxide-potassium hexacyanoferrate(III) and luminol-hydrogen peroxide-copper(II) sulphate. The systems retain the ability to chemiluminescence in the presence of a surfactant. Cationic surfactants lower the intensity of chemiluminescence, and anionic surfactants increase the intensity of chemiluminescence. The introduction of a surfactant into the system allows increasing the range of dependence of the chemiluminescence intensity on the catalyst concentration. Kinetic curves of the growth and decay of chemiluminescence were measured in the systems. The rate constants of the chemiluminescence decay were measured in the framework of the first-order kinetics model.

It is known that regulation of plant tolerance to adverse environmental factors is connected with short term increase of the concentration of endogenous reactive oxygen species (ROS), which are signalling molecules for the induction of protective mechanisms. Introduction and expression of heterologous gox gene, which encodes glucose oxidase enzyme in plant genome, induce constantly higher content of hydrogen peroxide in plant tissues. It is not known how the introduction of native or modified gox gene affects the plant resistance to high-temperature stress, one of the most commonly used model for the study of stress response and thermal tolerance. In this study, we investigated biological effects of transformation and evaluated the resistance to temperature stress of potato plants with altered levels of glucose oxidase expression. Transformation of potato plants by gox gene led to the more early coming out from tuber dormancy of transformed plants and slower growth rate. Transformants containing the glucose oxidase gene were more sensitive to lethal thermal shock (50 °C, 90 min) than the transformant with the empty vector (pBI) or untransformed plants (CK). Pre-heating of plants at 37 °C significantly weakened the damaging effect of lethal thermal shock. This attenuation was more significant in the non-transformed plants.

The relevance of the research is caused by the need to develop the methods that are cheaper than hydrodesulfurization for refining vacuum gas oil. The main aim is to establish concentrating relations of oxidation of VGO sulfur-containing constituents. Object of the research is Novokuibyshevsk oil refinery vacuum gas oil. Methods: oxidation, liquid-adsorption chromatography, thin-layer chromatography, X-ray fluorescence determination of sulfur content, material analysis. Results. The authors have determined the optimal conditions for oxidative desulfurization of vacuum gas oil sulfur compounds: duration 90 min, So:Н2О2 molar ration 1:5, stirring speed 2500 rpm. The greatest efficiency of adsorption purification from oxidation products of sulfurorganic compounds is achieved at a mass ratio of «silica gel: object of study»=1:1. The influence of oxidant amount and process duration on the yield of oxidative desulfurization products and the sulfur content in them is shown. The authors determined the oxidation basic patterns of sulfur-containing compounds of oils of vacuum gas oil: increasing of oxidation duration and the molar ratio So:H2O2 does not affect the content of saturated compounds; the yields of mono- and bi-aromatic compounds, the sulfur content in them decreases linearly. With an oxidation time of 30 minutes with increasing molar ratio So:H2O2, the yield and sulfur content of tri and polyaromatic compounds increases due to the accumulation of unadsorbed oxidation products of mono- and bi-aromatic sulfur-containing compounds. The increase in the process duration leads to the development of oxidation side reactions of mono- and biaromatic hydrocarbons, the oxidation products of which are segregated in the composition of polyaromatic hydrocarbons. The oxidized sulfur-containing compounds under these conditions are segregated in the resin composition. Changing of asphaltenes content is insufficient.

The Aim of the Study: Optimization of methods for treating dental discoloration using whitening systems based on hydrogen peroxide by laboratory studying their chemical properties., Material and Methods: The effectiveness of the bleaching system was assessed by quantitatively assessing the color change of model samples of hydroxyapatite (HAP) in the CIE L*a*b* system on a Spectron-M color analyzer after exposure to coloring food media. Safety assessment was carried out on samples made from teeth removed according to indications., Results: The results of laboratory tests allow us to conclude that the Chairside Light Whitening System professional teeth whitening system fläsh. (WHITEsmile GmbH, Germany) has high whitening efficiency with a whitening degree of ~84%, which significantly exceeds the norm of GOST R 702.3.004-2021. the microhardness of the enamel of samples exposed to the whitening gel for 15 minutes changes extremely little. After exposure of the studied samples to the Chairside Light Whitening System fläsh whitening system for 45 minutes, an increase in digital microhardness indicators is observed, which indicates the dynamics of processes demineralizing the hard tooth structure., Conclusions: Chairside Light Whitening System fläsh professional teeth whitening system has high whitening efficiency with minimal impact on the teeth structure and high safety.

It was studied the epoxidation mechanism of allyl alcohol using titanosilicate zeolite (TS-1) at 40°C by means of procedures for the nomination and discrimination of mechanism hypotheses. The hypotheses was carried out using the literature data and the preliminary experiment results. Discrimination hypothetical mechanisms implemented on the basis of the univariate results of the kinetic experiment, varying concentrations of allyl alcohol, hydrogen peroxide and glycidol. The most probable mechanism involves the hydrogen peroxide and allyl alcohol adsorption at the catalyst active centers and the glycidol formation at a reversible stage in the interaction of the adsorbed molecules of the reactants. Considered hypotheses include a different sequence of interaction of the reactants with active catalyst centre. In addition, hypotheses take into account the formation of intermediate compounds as well as inactive products of the interaction of substances present in the reaction system, with the active centers on the silicalite surface. For each hypothesis, it was formulated the corresponding system of differential equations and carried out the estimation of the rate constants. The quality of the experimental data description was judged by the residual sums of squared deviations and correlation coefficients. The best results are obtained for the hypothesis involving the hydrogen peroxide and allyl alcohol adsorption at the two active catalyst centers with subsequent interaction of the resultant intermediates between them, with the formation of glycidol adsorbed on one center, free catalyst centre and molecule of water. Formation of free glycidol occurs at a reversible stage. A significant part of the active centers of the catalyst increasing the concentration of glycidol is associated with it. This is the main reason for the decrease of the reaction rate, apart from reducing the concentration of the reactants.

The work objective is to study issues of determining the hydrogen peroxide concentration. The task is to evaluate metrological aspects of the hydrogen peroxide decomposition. Alongside with a standard permanganatometric (analytical) method of determining the hydrogen peroxide concentration, a fairly new technique of the acoustic emission is considered. A new methodology of the problem solution developed by the authors is presented. The study has found that the hydrogen peroxide catalytic decomposition reaction is characterized by a strongly marked transient process at the initial stage. Further, the total number of pulses uniformly increases, and then the hydrogen peroxide concentration gradually decreases. The proposed method of monitoring the acoustic emission parameters shows high informativity and sensitivity. It is found that the spread in the experimental values obtained by the two methods is identical - 5 - 6% of the measured value.

Abstract The changes in bacterial genetic material under the action of different biocidal products have been investigated. It was confirmed by PCR and genetic engineering that biocidal product Ecocid was able to remove both chromosomal and plasmid DNA, either isolated or contained within the bacterial cells. Using a disinfectant that destroys DNA on the surfaces of meat production equipment is a promising measure to prevent horizontal transfer of unwanted genetic material, such as bacterial genes associated with the resistance to antibiotics, or genes of toxin production.

The work objective is to study the metrological aspects of the acoustic emission (AE) method as applied to the monitoring of the hydrogen peroxide decay rate. The AE changing parameter that determines the method metrological properties as a whole is selected. It is established that the process of the hydrogen peroxide decomposition causes stress waves in the local liquid volume. This leads to the formation of the acoustic signals that allow firmly control this process through the AE method. The metrological evaluation of the method implemented in two stages is analyzed. The significance of the first stage allowing for the quality relative AE-research is identified. The experiments performed have confirmed high sensitivity of the proposed method. Thus, it is possible to carry out effective relative studies of the compared processes according to the AE parameters. The acoustic emission data show that instrumental and methodological errors of the AE method in general can be significant in case of the counter conditions, and this fact can be a benchmark for future research.

Background: Proteins oxidized by the action of X-rays represent long-lived reactive species, which trigger the secondary generation of reactive oxygen species (ROS). A change in the hydrogen peroxide (H2O2) content induced by various physical impacts may be an important factor of the therapeutic effect and the adaptation of the organism to unfavorable environmental conditions. Moderate hyperthermia and a number of physiotherapeutic procedures leading to a local warming of tissues are widely used in medical practice. However, the biological mechanisms of their curative effect are poorly understood. The prolonged generation of H2O2 long-lived reactive protein species (LRPS) after heating may be one of the mechanisms of activation of protective cellular mechanisms and thus to contribute to overcoming the disease. Aim: To investigate if the serum proteins bovine serum albumin (BSA) and bovine gamma-globulin (BGG) can form LRPS under moderate hyperthermia and show that heat induces LRPS, which in turn continuously generate ROS, in particular H2O2. Materials and methods: LRPS were studied by measuring the heat-induced chemiluminescence of protein solutions using a specially elaborated highly sensitive photon-counting chemiluminometer Biotoks-7 AM. The Results: Here we studied the possibility of formation of long-lived species of the blood serum proteins BSA and BGG in air-saturated solutions under the action of heat. It is shown that heat induces the generation of long-lived protein species, which in turn generate ROS (1O2, О2-•, OH•, H2O2). The formation of the long-lived reactive species of BSA and BGG with a half-life of about 4 h induced by moderate hyperthermia was revealed using the chemiluminescence of protein solutions. It was found that long-lived reactive species of BSA and BGG cause prolonged generation of H2O2. Conclusion: Thus, we found a new fundamental property of serum proteins: by the action of moderate heating, they are able to transform into LRPS that produce H2O2 over a long period of time. Therefore, it cannot be excluded that the heat treatment during physiotherapeutic procedures in clinical practice is accompanied by local heating and the formation of LRPS. H2O2 generated by these species may participate in signaling pathways and induce adaptive response in humans.

Analysis of control and transgenic plants of potato, grade Skarb, transformed by vector constructions pBI-L-GOX (LP line) и pBI-F-GOX (F line) with native gene of glucose oxidase gox and pBI-GOX-mod (MOD line) with modified gene gox-mod has been carried out. It has been shown that transgenic potato plants with genes gox and gox-mod did not have fenotypic differences with control plants. It has been confirmed that there was an increase of level of hydrogen peroxide produced by reaction, which catalized by glucose oxidase in leaves of transgenic plants. Using antibodies against some heat shock proteins (Hsp101, Hsp70/Hsc70, Hsp60, Hsp17.6C-1, Hsp17.6C-2) we revealed an increased content of Hsp17.6C-2 in leaves of LP line and Hsp60 in leaves of LP and F in the morning. It has been shown that rise in temperature in the daytime (from 18-23°С to 35-43°С) led to intensification of all studied Hsps synthesis both in control and in transformed lines.

Influence of herbicides on the hydrogen peroxide generation in vacuolar extracts of red beet root (Beta vulgaris L.) was investigated. Belonging to different chemical classes of herbicide compounds have been used. Herbicides differ from each other in the mechanism of effects on plants. Clopyralid (aromatic acid herbicide, derivative of picolinic acid) and 2.4-D (phenoxyacetic herbicide), characterized by hormone-like effects, contributed to the formation of H2O2 in vacuolar extracts. Fluorodifen (nitrophenyl ether herbicide) and diuron (urea herbicide) also have increased contents H2O2. These compounds inhibit the electron transport, photosynthesis, and photorespiration in sensitive plants. Herbicidal effect of glyphosate (organophosphorus herbicide) is due to the inhibition of amino acid synthesis in plant cells. Glyphosate did not affect the content of H2O2 in vacuolar extracts. Herbicide dependent H2O2-generation did not occur with oxidoreductase inhibitors, potassium cyanide and sodium azide. The results suggest that the formation of ROS in the vacuoles due to activity of oxidoreductases, which could interact with herbicides.

Aim. Study regularities of effects of various types of vaginal microsymbionts on the ability of mucosal epitheliocytes of the vagina to modify biological properties of bacteria. Materials and methods. Effect of thermo-inactivated cells of Staphylococcus aureus, Escherichia coli, H2O2-producing and H2O2-nonproducing lactobacilli on the ability of primary vaginal epitheliocytes to alter growth and antagonistic activity of Staphylococcus aureus, Escherichia coli, H2O2-producing and H2O2-nonproducing lactobacilli was studied using a multicomponent module system. Results. Alterations of composition of vaginal epitheliocyte exometabolites under the effect of S. aureus and E. coli was established to result in a pronounced stimulation of antagonistic activity of H2O2-producing and an increase of the number of H2O2-nonproducing lactobacilli. Thermo-inactivated cells oflactobacilli stimulated production of metabolites by epitheliocytes, that suppress the growth and antagonistic activity of allochthonous microflora and stimulate similar parameters of lactobacilli. The strongest effects on the ability of vaginal epitheliocytes to alter biological properties of bacteria were rendered by H2O2-producing lactobacilli. Conclusion. The regularities identified allow to examine epitheliocytes and normoflora of vagina as a symbiotic system, the coordinated interaction of its components is directed on maintaining microecological stability of female reproductive tract.

Cwynar Anna, Olszewska-Słonina Dorota, Pukownik Ewelina. The effect of oxidative modifications of amino acid residues in the active center of tyrosinase on the process of graying = Wpływ oksydacyjnych modyfikacji reszt aminokwasowych w centrum aktywnym tyrozynazy na proces siwienia. Journal of Education, Health and Sport. 2015;5(9):102-108. ISSN 2391-8306. DOI10.5281/zenodo.30027 http://dx.doi.org/10.5281/zenodo.30027 http://ojs.ukw.edu.pl/index.php/johs/article/view/2015%3B5%289%29%3A102-108 https://pbn.nauka.gov.pl/works/616347 Formerly Journal of Health Sciences. ISSN 1429-9623 / 2300-665X. Archives 2011–2014http://journal.rsw.edu.pl/index.php/JHS/issue/archive Deklaracja. Specyfika i zawartość merytoryczna czasopisma nie ulega zmianie. Zgodnie z informacją MNiSW z dnia 2 czerwca 2014 r., że w roku 2014 nie będzie przeprowadzana ocena czasopism naukowych; czasopismo o zmienionym tytule otrzymuje tyle samo punktów co na wykazie czasopism naukowych z dnia 31 grudnia 2014 r. The journal has had 5 points in Ministry of Science and Higher Education of Poland parametric evaluation. Part B item 1089. (31.12.2014). © The Author (s) 2015; This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland and Radom University in Radom, Poland Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. The authors declare that there is no conflict of interests regarding the publication of this paper. Received: 25.07.2015. Revised 24.08.2015. Accepted: 24.08.2015. THE EFFECT OF OXIDATIVE MODIFICATIONS OF AMINO ACID RESIDUES IN THE ACTIVE CENTER OF TYROSINASE ON THE PROCESS OF GRAYING WPŁYW OKSYDACYJNYCH MODYFIKACJI RESZT AMINOKWASOWYCH W CENTRUM AKTYWNYM TYROZYNAZY NA PROCES SIWIENIA Anna Cwynar1, Dorota Olszewska-Słonina1, Ewelina Pukownik2 1 Katedra i Zakład Patobiochemii i Chemii Klinicznej, Collegium Medicum w Bydgoszczy 2 Katedra Pediatrii, Hematologii i Onkologii, Collegium Medicum w Bydgoszczy Summary Reactive oxygen species (ROS) are molecules that form during physiological processes of cellular metabolism. Production of ROS in the organism is strictly controlled by the system of numerous anti-oxidative mechanisms. Insufficiency of defense systems and an increase in the level of free radicals leads to disturbances of the oxidative-antioxidative balance, and consequently, to generation of oxidative stress. Many observations indicate that the process which underlies graying is oxidative stress induced by hydrogen peroxide. Milimole concentrations of hydrogen peroxide (H2O2) are accumulated within gray hairs. Its presence inhibits transformation of tyrosine to melanin through the inactivation of the enzyme tyrosinase. The cause of an increase in H2O2 level is most probably a decrease in activity of catalase (CAT) responsible for its detoxication. This is a significant step forward, since the studies have indicated that another enzyme, called pseudocatalase, may prevent generation of gray hair. Scientists are working on obtaining effective inhibitors of the process of graying that could in the future serve as medicines preventing premature graying. Finding the mechanisms responsible for this process creates possibilities for developing new objectives for pharmacological therapy. The aim of this work is to present current reports concerning the problem of graying and a potential participation of oxidative stress in the course of this process. Streszczenie Reaktywne formy tlenu (RFT) są molekułami powstającymi podczas fizjologicznych procesów metabolizmu komórkowego. Produkcja RFT w organizmie podlega ścisłej kontroli przez system licznych mechanizmów antyoksydacyjnych. Niewydolność systemów obrony oraz wzrost poziomu wolnych rodników prowadzi do zaburzeń równowagi oksydacyjno-antyoksydacyjnej, a w konsekwencji do generacji stresu oksydacyjnego. Wiele obserwacji wykazuje, że procesem leżącym u podłoża siwienia jest stres oksydacyjny indukowany przez nadtlenek wodoru. W obrębie siwych włosów gromadzone są milimolowe stężenia nadtlenku wodoru (H2O2). Jego obecność hamuje przemianę tyrozyny w melaninę poprzez inaktywację enzymu tyrozynazy. Przyczyną wzrostu poziomu H2O2 jest najprawdopodobniej spadek aktywności katalazy (CAT) odpowiedzialnej za jego detoksykację. Jest to znaczący krok naprzód, ponieważ badania wykazały, że inny enzym, zwany pseudokatalazą, może zapobiec tworzeniu się siwych włosów. Naukowcy pracują nad uzyskaniem skutecznych inhibitorów procesu siwienia, mogących w przyszłości służyć jako leki zapobiegające przedwczesnemu siwieniu. Poznanie mechanizmów odpowiedzialnych za ten proces stwarza możliwości na opracowanie nowych celów dla terapii farmakologicznej. Celem prezentowanej pracy jest przedstawienie aktualnych doniesień na temat problemu siwienia i potencjalnego udziału stresu oksydacyjnego w przebiegu tego procesu. Keywords: catalase, hydrogen peroxide, melanogenesis, oxidative stress, tyrosinase. Słowa kluczowe: katalaza, nadtlenek wodoru, melanogeneza, stres oksydacyjny, tyrozynaza.

One of the main functions of enzyme complexes that constitute electron transport (respiratory) chains of organisms is to maintain cellular redox homeostasis by oxidizing reducing equivalents, NADH and quinol. Cytochrome bd is a unique terminal oxidase of the chains of many bacteria including pathogenic species. This redox enzyme couples the oxidation of ubiquinol or menaquinol by molecular oxygen to the generation of proton motive force, a universal energy currency. The latter is used by the organism to produce ATP, another cellular energy currency, via oxidative phosphorylation. Escherichia coli contains two bd-type oxidases, bd-I and bd-II, encoded by the cydAB and appCB operons, respectively. Surprisingly, both bd enzymes make a further contribution to molecular mechanisms of maintaining the appropriate redox balance in the bacterial cell by means of elimination of reactive oxygen species, such as hydrogen peroxide. This review summarizes recent data on the redox-modulated H2O2-scavenging activities of cytochromes bd-I and bd-II from E. coli. The possibility of such antioxidant properties in cytochromes bd from other bacteria is also discussed.

Aim: to study the effect incubation in NaCI hypertonic solutions on the yield of DNA single-strand breaks (SSB) and alkali-labile sites (ALS) induced by y-radiation and hydrogen peroxide in human peripheral blood lymphocytes in vitro. Material and methods. The lymphocytes isolated from the peripheral blood of healthy women donors aged 21-26 years were used for the study. Cell irradiation at doses of 1, 2, 3 and 5 Gy was performed using the "AGAT P1" unit (Russia, y-radiation source — 60Co, a dose rate of 1 Gy/min) at 4°C. In case of hydrogen peroxide exposure (25, 50 and 100 uM) the cells were incubated for 15 minutes at 4°C. Analysis of the DNA SSB and ALS was performed using the alkaline DNA comet assay. Results. Incubation of cells in 0.35 M NaCI solution (non-histone proteins dissociation) increases the yield of DNA SSB and ALS induced by v-radiation and hydrogen peroxide at ~ 1.3 times. Increasing the NaCI concentration to 0.6 M (linker histone H1 dissociation) leading to almost double increase in the DNA damage yield (~ 1.7-1.8 times). Further increasing the NaCI concentration leading to disruption of the structure of nucleosomes (1.2 M) and almost complete chromatin deproteinization (2 M) increased the yield of DNA damage not such pronounced as expected (~ 2.2-fold at 2 M concentration). Conclusion. The results showed that incubation in NaCI hypertonic solutions significantly increases the sensitivity of lymphocytes to DNA damaging action of free radicals.