Active Forms Of Oxygen Research Articles

EFFECT OF LOW-TEMPERATURE ARGON PLASMA ON THE VIABILITY AND PROLIFERATION OF FIBROBLASTS IN VITRO

Background: Controlled generation of active forms of oxygen and nitrogen stimulates wound healing processes. One of the sources of controlled generation of active forms of oxygen and nitrogen is low-temperature argon plasma. Low-temperature plasma activates various forms of cellular activity. However, the subtle mechanisms of such stimulation remain unclear. Thus, there is a need for a detailed study of the biological effect of low-temperature argon plasma on human cells.Objective: to evaluate the effect of low-temperature argon plasma on the structure and proliferative activity of human fibroblasts in vitro.Materials and methods. Human fibroblast culture (line M-21, passage 25, Chumakov Institute of Poliomyelitis and Viral Encephalitis) was used in the work. After exposure to low-temperature argon plasma, the cells were cultured for 3 days in DMEM/F12 medium supplemented with 10% Gibco bovine embryo serum, then morphofunctional analysis of the cells was performed using vital staining. After 3 days, the cells were passaged (reseeded in other Petri dishes with a 1:2 dilution), then the cells were cultured for 3 days, and a repeated morphofunctional analysis was performed. All work with cell cultures was carried out in accordance with the international GMP standard.Results. Stimulation of the proliferative activity of fibroblasts was noted in the second passage after treatment with low-temperature argon plasma from a distance of 10 cm for 30 and 45 seconds and 15 cm for 45 seconds.The use of a collagen bandage screen significantly increases cell survival when exposed to plasma from a distance of 10 cm for 15 seconds. With screening, the decrease in the integrity of cell membranes after plasma exposure is less pronounced than with exposure without screening. When reseeding, cells treated in the presence of a collagen screen exhibit high proliferative activity and restore membrane integrity.

Roles of Ce0.8Zr0.2O2 Catalysts in Boosting the Efficient Combustion of Waste Plastics

AbstractBecause of superior oxygen storage and release capability, Ce‐based catalysts were widely used in the oxidation reaction, while seldomly mentioned in waste plastics combustion. Herein, Ce0.8Zr0.2O2 catalysts were prepared by the complexed hydrothermal method (CeZr(C)), oxalic acid gel method (CeZr(O)), and hydrothermal method (CeZr(N)); and then, used in PE (polyethylene) combustion. Compared with PE noncatalytic combustion that exhibited an initial combustion temperature of 269 °C, CeZr(C) slightly reduced the initial combustion temperature to 263 °C, while CeZr(N) and CeZr(O) significantly reduced the initial combustion temperature to 245 and 251 °C, respectively. It was deduced that the activity of CeZr(N) and CeZr(O) in PE catalytic combustion was significantly higher than that of CeZr(C). Based on the systematic characterization, two reaction mechanisms were proposed to explain the excellent performance of CeZr(O) and CeZr(N) in PE combustion: (1) Because of the abundant surface area and O2 adsorption, CeZr(O) enhanced the activation of molecular oxygen and the formation of active oxygen, which was easier to attack C─C/C─H bond and initiate PE combustion than molecular oxygen. (2) Because of the strong acidity, CeZr(N) enhanced the activation of C─C/C─H bond in polymer molecules, which benefited the attack of molecular oxygen, and reduced the reaction temperature.

КЛИНИКО-ЛАБОРАТОРНОЕ ОБОСНОВАНИЕ МЕСТНОГО ПРИМЕНЕНИЯ АНТИОКСИДАНТОВ ПРИ ЛЕЧЕНИИ ХРОНИЧЕСКОГО ГЕНЕРАЛИЗОВАННОГО ПАРОДОНТИТА

Introduction. In periodontitis, there is a disruption of the balance between the rate of formation of active forms of oxygen and their inactivation in the tissue. This fact dictates the need to use antioxidants to treat periodontal diseases. Objective: clinical and laboratory justification for the local use of antioxidant drugs in the treatment of chronic generalized periodontitis. Materials and methods. A study was conducted of the clinical and laboratory effectiveness of local application of 5% tocopherol acetate solution, 5% Mexidol solution and Kudesan Forte solution in 99 patients with CGP. The effectiveness of antioxidant use was assessed by the OHI-S, PBI, PMA, CPINT, PI indices, based on the OHIP-14 questionnaire and the general psychological well-being index. The level of lipid peroxidation products was determined spectrophotometrically with the registration of lipid peroxides in the heptane phase of the lipid extract. The state of antioxidant defense was assessed by the content of α-tocopherol and ceruloplasmin. Results. All the drugs, tocopherol acetate, Mexidol and Kudesan Forte, caused a reliable decrease in the value of periodontal indices, a decrease in the OHIP-14 index. In addition, Kudesan Forte improved the IOPB and increased vital energy much more effectively. When studying the laboratory parameters of oral fluid, Mexidol had unidirectional reliable differences from tocopherol acetate in reducing heptane-soluble DC and isopropanol-soluble KD and ST. Kudesan forte was superior in its effectiveness to both tocopherol acetate and Mexidol. At the same time, Kudesan Forte more effectively increased the level of ceruloplasmin and α-tocopherol in mixed saliva. Conclusions. The results of the study confirm that local use of tocopherol acetate, Mexidol and Kudesan Forte significantly improves periodontal status and laboratory parameters in the treatment of chronic periodontal disease. These drugs should be included in the complex therapy of periodontitis of not only mild and moderate, but also severe degrees. For this purpose, it is preferable to use Mexidol and Kudesan Forte.

Mitochondrial dysfunction in patients with respiratory diseases

The aim of this scientific literature review was to find new solutions to urgent problems of treating respiratory diseases and reducing the associated temporary loss of ability to work and disability. The article presents the results of the analysis of 62 scientific papers published over 23 years (2001 – 2023) on mitochondrial dysfunction (MD), new methods of its diagnosis, and ways of its correction in respiratory diseases. Disorder of the energy function of mitochondria has been identified as an urgent scientific problem of respiratory medicine. It is noted that new methods of pathogenetic therapy for common and currently difficult-to-treat diseases are being developed to solve this problem. The key section of the review is devoted to the results of studies of mitochondrial dysfunction in patients with asthma, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and pulmonary hypertension.Conclusion. The article assesses MD diagnostic methods that are potentially applicable in real clinical practice. The results of studying the electric potential of the inner mitochondrial membrane, accumulation of active forms of oxygen, production of adenosine triphosphate in blood cells, alveocytes and epithelium of the respiratory tract, as well as bronchial smooth muscle cells, endothelium and vascular smooth muscle cells in the pulmonary artery system, determination of mitochondrial DNA in biological environments are compared. Proposed methods for the correction of MD syndrome in the clinical picture of respiratory diseases are briefly covered.

REASON OF PITTING CORROSION OF MARTENSITIC STEELIN SEA WATER

Abstract. The assumption that corrosion of products from X17 martensitic stainless steel in seawater occurs due to incomplete oxidation of chromium atoms in cells on the surface of the products is made in the presented work. Incomplete oxidation of chromium atoms occurs in the cells of X17 steel. This is due to the fact that oxygen molecules at temperatures up to 350 °C not having enough energy for chemical interaction with trivalent chromium atoms entering the cubic body-centeredcells of martensitic stainless steel. There is a significant decrease in the corrosion rate after placing X17 stainless steel products in 5% iodine solution in ethanol after pre-treatment of the product surface with active forms of oxygen. The treatment was carried out during 12 hours with chemically active forms of oxygen (ozone and singlet oxygen) at a temperature of 350 °С. Most of the chromium atoms on the surface of X17 steel samples were completely oxidized as a result of 12 hours exposure to highly active forms of oxygen. The density of the oxide passivation layer on the surface of the products increased significantly as a result of the formation of new bonds CHROMIUM -OXYGEN -CHROMIUM. This resulted in increased corrosion resistance. The rate of interaction with an alcohol solution containing halogen ions was reduced by 71% for the samples with the oxide passivation layer compared to samples of untreated X17 steel.

Effect of Donor Nb(V) Doping on the Surface Reactivity, Electrical, Optical and Photocatalytic Properties of Nanocrystalline TiO2.

In this work, we primarily aimed to study the Nb(V) doping effect on the surface activity and optical and electrical properties of nanocrystalline TiO2 obtained through flame-spray pyrolysis. Materials were characterized using X-ray diffraction, Raman spectroscopy and IR, UV and visible spectroscopy. The mechanism of surface reaction with acetone was studied using in situ DRIFTs. It was found that the TiO2-Nb-4 material demonstrated a higher conversion of acetone at a temperature of 300 °C than pure TiO2, which was due to the presence of more active forms of chemisorbed oxygen, as well as higher Lewis acidity of the surface. Conduction activation energies (Eact) were calculated for thin films based on TiO2-Nb materials. The results of the MB photobleaching experiment showed a non-monotonic change in the photocatalytic properties of materials with an increase in Nb(V) content, which was caused by a combination of factors, such as specific surface area, phase composition, concentration of charge carriers as well as their recombination due to lattice point defects.

Morphophysiological features of the generative offspring of Aesculus hippocastanum L. from various ecologically unfavorable areas of an industrial city

The results of the influence of various ecological conditions of an industrial city (environmentally favorable zone, zones of motor vehicle emissions and metallurgical production, damage by the chestnut miner Cameraria ohridella Deschka & Dimič) on the functional state of the generative offspring of Aesculus hippocastanum L. were given. The average degree of the mass variability of the horse chestnut seeds was revealed, the level of which depended on the type of pollution. Higher values of the variation coefficient were established in seeds from monitoring sites ecologically unfavorable for plant growth. A decrease in the mass of ripe seeds of horse chestnut exposed to the effects of vehicle emissions, metallurgical production, and the severe attack of the chestnut moth C. ohridella was shown compared to samples from an ecologically favorable zone. It was found that the moisture loss in seeds from the ecologically favorable zone was on average 25.0 %, while from the main road zone – 15.2 %. A decrease in the content of storage proteins by an average of 14.5 % in the zones of anthropogenic pollution was observed. The largest values of this characteristics were shown by most trees from the ecologically favorable zone. In the seeds of A. hippocastanum plants, an increase in the activity of both benzidine peroxidase and catalase was established mainly under the effects of aerotechnogenic pollution. The level of enzyme activity depended on the type of phytotoxic emissions. A decrease in the activity of benzidine peroxidase was registered due to the effects of motor vehicle emissions, and an increase due to the effects of metallurgical production. A significant increase in catalase activity was found in the seeds of A. hippocastanum trees from two monitoring sites and, especially, under the influence of vehicle emissions, which can be explained by a compensatory reaction in response to reduced peroxidase activity. An individual reaction of the studied protein system (storage proteins, antioxidant enzymes) of the seeds of some trees was observed, regardless of the stress level of technogenic load and the type of pollutants. At each monitoring site, trees whose seeds had both increased and significantly decreased enzyme activity were identified. In the Botanical Garden and in the park near the metallurgical enterprise, the seeds of only one of three trees showed high activity of both peroxidase and catalase. Considering the physiological functions of the studied enzymes in the seeds and the reaction of the plant organism to biotic and abiotic stresses, the increase in the activation of catalase and peroxidase indicated their participation in antioxidant protection against active forms of oxygen to ensure a reduction in the intensity of damage processes in the generative offspring of A. hippocastanum L. The variability of the level of enzyme activity in horse chestnut seeds means adaptation to environmental conditions and, in general, reveals the adaptive ability of generative offspring to germinate due to the high antioxidant potential to counteract the development of oxidative stress under the influence of adverse environmental factors. It was concluded that the chronic influence of adverse factors of the urban environment causes the formation of individual seeds with increased antioxidant protection characteristics, which can be used as planting material when creating sustainable plantations in an industrial city.

Glutathione: synthesis, mechanism of action, antioxidant and detoxifying role

Annotation. Under the conditions of entry of toxic substances into the body and activation of redox processes, compounds of natural origin with antioxidant properties are widely used to correct metabolic disorders. The purpose of the work is to conduct an analysis and systematization of basic and modern scientific sources of literature on the role of the glutathione system in the development of pathologies. For the scientific review, data from the scientometric databases PubMed, ScienceDirect, Web of Science, Google Scholar, etc. were used, and the analysis of scientific textbooks and monographs was carried out. Among water-soluble antioxidants, low- and high-molecular compounds containing SH-groups are popular in medicine, mono-, di- and tricarboxylic acids and other anions. Glutathione, a thiol-containing tripeptide, is the main endogenous non-enzymatic antioxidant that exerts cytoprotective and detoxifying properties. Various epithelial cells – enterocytes, endotheliocytes, alveolar cells of the lungs, epithelium of the proximal renal tubules, absorb and use glutathione most intensively, in particular, taken orally, so the idea of using glutathione in diseases of organs that actively participate in detoxification processes: kidneys, liver, lungs, as well as under the conditions of systemic diseases accompanied by endothelial dysfunction and oxidative stress – diabetes, atherosclerosis, nephropathy. Under physiological conditions, the body maintains a dynamic balance between the content of oxidants, which stimulate the processes of free radical oxidation of biomolecules, and the activity of antioxidant systems. But under the conditions of damage to any link of the living system, increased formation of reactive oxygen species (ROS) and inhibition of antioxidant systems contributes to the activation of free radical oxidation processes, the intensity of which depends on the concentration of oxygen in the tissues and on the enzymatic and non-enzymatic systems of antioxidant protection, which prevents the destruction of cells by active forms of oxygen.

INFLUENCE OF HEAVY METALS ON THE BASIC PHYSIOLOGICAL PROCESSES OF CEREAL AND CEREAL PEGUM CULTURES

At the end of the 20th century, the constant growth of the population and the rapid development of production brought the situation with the state of the environment in many countries and regions of the world to the brink of an ecological crisis. One of the main factors in the degradation of the natural environment is its pollution by various pollutants, among which one of the main places is occupied by heavy metals. Given the above, it becomes clear the relevance of research on the impact of heavy metals on plants. Currently, they are actively held in many countries of the world. The article is aimed at studying the influence of heavy metals on the main physiological processes that occur in plants. The results of studies on the influence of heavy metals on the main physiological processes of grain and leguminous crops are presented. Based on the results of the analysis, it was proven that accumulating in large quantities in plants, heavy metals cause a negative impact on growth, development and other physiological processes. It was established that in the presence of large concentrations of these elements in cereal plants, a decrease in the height of the stem, a decrease in the number of internodes, a decrease in the accumulation of raw and dry biomass, as well as a decrease in the size of inflorescences are observed. The main reasons for the decrease in above-ground biomass productivity in plants are the negative impact of heavy metals on the growth and development of plants and the intensity of photosynthesis. Individual types of plant groups show different ability to accumulate heavy metals. The results of our own research established that in the presence of high concentrations of heavy metals, a decrease in the linear dimensions of leaves was observed in almost all types of plants with which research was conducted. All of the above testifies to various aspects of the effect of heavy metals on metabolic processes and the viability of plants. They affect various functional groups of biologically important substances of the body, displace essential metals from metal-containing complexes, and also generate active forms of oxygen, which often leads to the occurrence of an oxidative explosion in cells and even the death of plants.

Hypoxia-inducible factors: details create a picture. Part I. HIF-1

The review presents a comparative analysis of scientific data on the structural and functional characteristics of subunits (HIF-1α and HIF-1β) of hypoxia-inducible transcription factor-1 (HIF-1). Differences between the main regulatory HIF-1α subunit and the constitutively expressed HIF-1β subunit, sensitivity to endo- and exogenous regulators of their stability, and intracellular content depending on the cell's oxygen supply state (normoxia and hypoxia conditions) are described. In normoxia, the intracellular content of HIF-1α is determined by oxygen-dependent and oxygen-independent mechanisms. Oxygen-dependent enzymatic degradation of HIF-1α occurs by PHD-dependent hydroxylation, VHL-dependent ubiquitination, and FIH-1-dependent hydroxylation. Oxygen-independent pathways of HIF-1α pool regulation include: 1) HIF-1α gene transcription (Notch and/or NF-KB-dependent, STAT3 and Sp1 cytokine-dependent), 2) mRNA translation (cap-dependent or IRES-dependent, as well as cytokine-dependent activation of the PI-3K/AKT pathway activation under the effect of growth factors and vasoactive hormones), 3) protein-protein interactions, 4) various mechanisms of post-translational modification. Changes in Krebs cycle enzyme activity and active oxygen forms confer HIF-1α stability through PHD activity inhibition and reduction of ubiquitin-proteasome degradation. PHD-independent post-translational stabilizers of HIF-1α are: cytosolic reductase NQO1, sirtuin-2, prostaglandin E2, activated protein kinase C1 receptor competing with heat shock protein 90, human Hdm2 (a natural inhibitor of p53), glycogen synthase kinase 3β, and negative modifiers are enzymes - methyltransferase SET7/9, lysine-specific demethylase-1, sex-like kinase 3, β-arrestin-2, casein kinase-1. Under hypoxic conditions, non-hydroxylated HIF-1α subunits migrate to the nucleus where they heterodimerize with HIF-1β, HIF-1α/β heterodimers bind the main 5'-(A/G)CGTG-3' consensus sequence within the hypoxia-reaction element (HRE) of the target genes, and recruit co-activators (p300, histone modifying enzymes, histone readers, chromatin remodeling proteins, and mediator proteins for target genes transcription enhancement with the aid of RNA polymerase II), resulting in the formation of HIF-1, acting as a transcription factor for the target genes providing metabolic reprogramming from oxidative phosphorylation to anaerobic glycolysis (genes encoding glucose transporters (GLUT1 and GLUT3), genes for glycolytic enzymes hexokinase 1 and 2 (HK1 and HK2), phosphoglycerate kinase 1), as well as genes for erythropoietin, vascular endothelial growth factor and its receptors FLT1 and FLK1, endothelin 1 and angiopoietin 1, resulting in adaptation to hypoxia.

Види клітинної загибелі, що реалізуються через вплив активних форм кисню і пошкодження ДНК

The purpose of the review was to find and analyze the literature on such types of cell death, which are realized due to DNA damage, namely, mitotic catastrophe; anoikis; pyroptosis; parthanatos and due to the influence of active forms of oxygen, namely mitoptosis; lysosome-dependent cell death; necrosis associated with increased mitochondrial permeability; necroptosis; netosis; ferroptosis. Apoptosis and autophagy, which are realized both due to the influence of reactive oxygen species and DNA damage, are considered separately.Cell death plays an important role in development, tissue homeostasis, inflammation, immunity, and many pathophysiological conditions. On the one hand, it becomes an etiological determinant in diseases associated with the irreversible loss of postmitotic tissues (for example, myocardial infarction, neurodegeneration). On the other hand, defects in the signaling cascades that trigger cell death are associated with pathologies characterized by uncontrolled expansion or accumulation of cells (eg, some autoimmune diseases, cancer). Therefore, cell death can be defined as a promising therapeutic target.

Study of the Protective Properties of 2-Ethyl-6-Methyl-3-Hydroxypyridine Malate in the Model of In vitro-Induced Oxidative Stress in Myoblast Cell Culture

Background: A cellular model of oxidative stress induced by hydrogen peroxide in the primary culture of myoblasts was obtained by in vitro experiments, and the possibility of exogenous regulation of the cytotoxic effect using 2-ethyl-6-methyl-3-hydroxypyridine malate (ethoxidol) was studied. Moreover, the influence of oxidative stress and the effect of ethoxidol on the intracellular expression of such an important biomarker as myostatin was investigated. Methods: Hydrogen peroxide was used to induce oxidative stress. The effect of hydrogen peroxide on the rate of myoblast proliferation was studied by measuring the reduction level of (3-(4,5- dimethylthiazole-2-yl))-2,5-diphenyltetrazolium bromide. To measure the expression of myostatin, a real-time polymerase chain reaction (PCR-RV) method was used. Results: During the work, it was clearly demonstrated that hydrogen peroxide has a significant cytostatic effect on myoblasts in vitro, inhibiting their proliferation. Ethoxidol in physiological concentration did not show toxic effects and did not inhibit cell proliferation. This antioxidant revealed a statistically significant protective effect on the cytostatic effect of hydrogen peroxide on myoblasts. In addition, this compound inhibited the expression of myostatin mRNA caused by exposure to hydrogen peroxide as a negative regulator of growth and differentiation of muscle tissue that occurs in response to exposure to reactive oxygen species. Conclusion: Hydrogen peroxide is one of the highly active forms of oxygen and has a significant cytostatic effect on myoblasts in vitro, suppressing their proliferation. 2-ethyl-6-methyl-3- hydroxypyridine malate neutralizes the toxic effect of peroxide, thereby indirectly having a positive effect on the rate of myoblast proliferation in vitro.

RESTRICTED PROTEOLIS AND OXIDIZING MODIFICATION OF PROTEINS IN HEPATOCYATES OF PATIENTS WITH DIABETES AND TUBERCULOSIS

Objective: The objective of the work is to investigate the oxidative modification of proteins and limited proteolysis in hepatocytes in patients with diabetes and pulmonary tuberculosis. Design and method: A prospective pathomorphological study of 60 cases of death of patients who died of various causes, in which in the final clinical and pathologoanatomical diagnosis as the main disease appeared pulmonary tuberculosis. Depending on clinical forms and variants of tuberculosis, the main group was divided into three subgroups. Results: An important role in the pathogenesis of the formation of both diabetes mellitus and tuberculosis play an impairment of immune homeostasis, especially in patients with expressive symptoms of exacerbation of the disease and prolonged relapse. Oxidative stress leads to an increase in the production of active forms of oxygen and as a consequence - oxidation modification of proteins (OMB): their aggregation and fragmentation, which is accompanied by irreversible changes in the physical, chemical and biological properties of the protein molecule. Taking into account the different functional activity of hepatocytes of different zones of the acinus (according to Rappoport) according to their own research, the R / B coefficient (specific coloration on acid and main proteins for Michel Calvo) and average values of relative units of optical density of a specific color on the free amino group of proteins for A. Yasuma and T. Ichikava were determined separately in the hepatocytes of the first, second and third zones and established the linear nature of the increase in the intensity of the oxidative modification of proteins and limited proteolysis from the 1st to the 3rd zone (from peripartal to centrolobular branches of acinus) in patients with resistant forms of tuberculosis. Conclusions: Diabetes mellitus in patients with lung tuberculosis leads to increased processes of free radical oxidation of proteins with characteristic effects - increased proteolysis and oxidation of amino groups of proteins – in hepatocytes of the liver.

Activation of molecular oxygen over binuclear iron centers in Al-rich *BEA zeolite

Here, we present the unique redox properties of distant binuclear iron centers in Al-rich *BEA zeolite in O2 splitting and CH4 oxidation. Al-rich *BEA was obtained via a template-free synthesis procedure guaranteeing low-defected structure and a high fraction of Al-pairs enabling stabilization of binuclear iron centers. By employment of a multispectroscopic in-situ approach (Mössbauer and X-ray absorption) the formation of active oxygen over binuclear iron centers in Al-rich *BEA was confirmed and subsequent CH4 oxidation was studied. Spontaneous release of the reaction products to the gas stream, representing a significant advantage of the studied system, was proved by the results of in-situ FTIR and mass spectrometry. This is the first experimental proof of the formation of fully-functioned binuclear iron centers (able to split O2, stabilize active oxygen forms, and subsequently oxidize CH4) in zeolite of *BEA topology.

Effects of impure ions in precursors on the formation of active oxygen in MnO2 for promoting VOCs oxidation

Impure ions in the precursor can cause the structural transition of prepared MnO2 catalysts and influence their activity in toluene catalytic oxidation. Here, the effects of K+ and SO42- on the catalytic activity of MnO2 are examined. Removing absorbed SO42- by repeating water washing facilitates the exposure of active sites on the surface of MnO2. The temperature for toluene conversion reaches 90% (T90) of catalysts decreases from 247 ºC to 238 ºC. While the loss of K+ during the water washing leads to the inferior performance of MnO2. Re-impregnating of K+ can stimulate the generation of active oxygen species on the surface of catalysts (K/MnO2), which showed elevated catalytic activity in toluene conversion (T90, 229 ºC). In addition, K/MnO2 performs good stability for toluene combustion in long-term operation. Density Function Theory calculations reveal that the formation energy of oxygen vacancy and the adsorption energy of toluene on the surface of catalyst decrease from 6.996 eV and − 0.079 to 5.482 eV and − 0.468 eV as the introduction of K+, respectively. Our results provide a complete understanding of the effects of impurity ions on the performance of manganese oxide for catalytic oxidation of toluene.

To the question of application of new physical and chemical geotechnologies in the development of uranium ore deposits

Background. Underground uranium leaching is a promising geotechnological process due to its potential to provide for a radical increase in the technical and economic efficiency, as well as environmental safety, of uranium deposit development. In this article, we discuss the main results in this direction obtained by specialists of the Russian State University for Geological Prospecting.Aim. To study the processes of uranium leaching by activated solutions, which undergo electrophotochemical treatment prior to contacting with the ore.Materials and methods. Activation preparation of leaching solutions enables the synthesis of active hydrated forms of oxygen and hydrogen with collectivized protons and hydroxyl ions clustered by water molecules. Following the stage of pre-oxidation with an active carbonate solution, a model downhole leaching with chloride-hypochlorite, soda, and sulfuric acid solutions was carried out. Testing percolation leaching of uranium from the ores of the Uchkuduk and Sugraly deposits by activated solutions was conducted at laboratory installations designed by the the Russian State University for Geological Prospecting jointly with the Institute of Mining of Far-East Branch of the Russian Academy of Sciences and Zabaikalsky State University. As a result, the potential of a significant increase in uranium extraction was noted.Results. When leaching with sodium carbonate and ammonium carbonate solutions, the uranium extraction from ore samples from the Sugraly deposit comprised 52% and 59%, respectively. At the same time, the use of an activated solution of sodium percarbonate, which combines the functions of an oxidizing agent and a complexing agent, resulted in an 87–88% uranium extraction into productive solutions during 21 days without preliminary pre-oxidation.Conclusion. The results obtained confirm the prospects of using mine (block) and downhole uranium leaching with activated solutions.

Antioxidant system of the body of young Ukrainian beef cattle under the action of microelements

Active forms of oxygen are formed in the course of the organism's vital activity in biochemical reactions. These forms, when the pro/antioxidant balance is disturbed, trigger a cascade of lipid peroxidation, which can be the cause of the development of various pathological conditions. To prevent the negative influence of lipid peroxidation products in the body, a powerful antioxidant system is activated. This system consists of an enzymatic and a non-enzymatic link. An important aspect of the normal functioning of this system is the provision of the body with important trace elements. A number of minerals are included in the active center of antioxidant enzymes or have an effect on the reactions of non-enzymatic antioxidants. Research was conducted on fattening bulls of the Ukrainian meat breed. During the monitoring of microelements in feed, it was found that the vast majority of farm feed was deficient in copper, selenium and manganese and for this reason the animals consumed an insufficient amount of these minerals. These data were confirmed by the low content of these trace elements in blood serum. The addition of inorganic salts of microelements to the basic diet led to an increase in the concentration of copper, manganese and selenium in the blood serum by 20.5%, 37.3% and 23.9%. The study of the content of lipid peroxidation products showed that during the 30 days of the experiment, the level of lipid hydroperoxide increased by 25.5%, diene conjugates by 22.8%, and malonic dialdehyde by 22.0%. This indicates that against the background of increased age-related metabolism in the body of young animals, the oxidation-reduction reactions that are a predictor of the start of peroxidation processes increase. It was also noted that with a deficiency of certain trace elements, the activity of both the enzymatic and non-enzymatic links of the antioxidant system was reduced. Thus, in 30 days, the level of catalase, superoxide dismutase, and glutathione peroxidase decreased by 9.4%, 15.3%, and 13.0%, respectively. During this time, the content of tocopherol and ceruloplasmin decreased by 16.8% and 9.8%. Additives also had a positive effect on the activity of the antioxidant system by increasing its components. Additives of trace elements had different effects on the activity of antioxidant enzymes. The greatest effect on the level of catalase and superoxide dismutase was observed when copper salts were added, when the increase of these enzymes was noted by 1.11 and 1.23 times, respectively. Accordingly, the level of glutathione peroxidase was the highest in animals that received additional selenium – 1.21 times. The addition of copper also had the greatest biological effect on the important non-enzymatic component of antioxidant protection – ceruloplasmin. Its level increased by 1.24 times under the action of copper sulfate. The level of tocopherol was higher under the action of manganese, when its concentration was 1.11 times higher than the control. Against this background, there was a decrease in the products of lipid peroxidation: lipid hydroperoxides – 1.19 times under the action of selenium; diene conjugates – by 1.22 times and malonіс dialdehyde – by 1.11 times under the influence of copper and manganese compounds, respectively.

Role of myeloperoxidase in atrial fibrillation and ischemic heart disease

Atrial fibrillation and ischemic heart disease are the key problems in cardiology. Despite of numerous clinical trials and researches underlying molecular biology remains uncertain. Atrial fibrillation and ischemic heart disease are often combined. During ischemic heart disease progression myocardial tissue structure are changing which lead to structural and electrophysiological remodeling and promote atrial fibrillation. It has been shown a crucial role of oxidative stress and chronic systemic inflammation in ischemic heart disease and atrial fibrillation. Myeloperoxidase (MPO) is one of marker of oxidative stress and inflammation that located in azurophilic granules of neutrophils and monocytes. There are a numerous articles showed a relation between MPO level and cardiovascular disease. MPO is a peroxidase enzyme that is important part of immune system. During disease MPO could facilitate chronic inflammation and local tissue damage through active oxygen forms. MPO releases after lysosome conjunction with phagosome. Oxygen reductase activity of MPO lead synthesis of hypochlorous acid that play role not only in organism protection from infection agents but in matrix transformation and fibrosis. It has been shown MPO can destabilize atherosclerotic plaque and modifies low- and high-density lipoproteins that promote atherosclerosis and ischemic heart diseaseу progression. This review summarizes current data about role of MPO in atrial fibrillation and ischemic heart disease pathogenesis.

Potentialities of photoactivated disinfection in dentistry

Infection control is an essential part of dental practice. Oral antiseptics should be highly effective against the most common oral pathogens without causing microbial resistance, biocompatible with the human tissues with no interaction with fillings materials. Photoactivated disinfection (PAD) is based on activation of photosensitizers - specific substances releasing active oxygen forms after absorption of the light. The active oxygen forms destroy bacterial cell structures without affecting human cells. The overwhelming majority of Russian and international researchers have reported high effectiveness of PAD in periodontics, implantology and endodontics, whereas the use of PAD in caries treatment and prevention is not so fully understood yet. Earlier studies have demonstrated high sensitivity of cariogenic bacteria to PAD, suggesting it as an additional minimally invasive caries therapy improving treatment effectiveness. PAD spares dental tissues without reduction in the effectiveness of disinfection. It is particularly important in treatment of deep carious lesions and disinfection of thin dentine layer near the pulp. Effectiveness of PAD in caries treatment has been demonstrated for both permanent and deciduous dentition. PAD doesn't affect bond strength to fillings, improves plasticity of dental pulp and dental hard tissues mineralization in children. Effective control of a wide range of bacteria without causing resistance makes PAD a prospective method of treatment and prevention of caries.

Relationship between the level of reactive oxygen species in native rooster spermatozoa and the quality indicators of fresh and frozen-thawed sperm

Purpose:to study the influence of the level of active forms of oxygen in native spermatozoa of roosters on the qualitative indicators of freshly exposed and deconed individual ejaculators (mobility, damage to the cell membranes of sperm) and determining the permissible level of AFC generation to improve the cryoponement protocol.Materials and methods.The object of the study was the roosters of the Rodi-Aland Red (n = 20) breed at the age of 44 weeks of life. All males were kept in individual cells with the “Genetic Collection of Rare and Disappearing Course breeds” of VNIIGRZH systems adopted by the BRK for feeding, posting and light regime. Sperm was received in penicillin bottles with a volume of 10 ml, using the abdominal massage method. They measured the volume of each individual ejaculate, assessed the mobility of sperm, concentration. Cryoconservational was carried out in granules. Thawing of granules was carried out at T 60 ° C in a slit tie. The damage to the plasma membranes of sperm in the native and deconed seed was evaluated using the Suppitial Bluma coloring method. Spermatozoa with damaged membranes was painted red, intact cells remained white (colorless). Each drug estimates at least 200 cells. To determine the levels of AFC generation in spermatozoa of roosters, a method based on luminol-proroxidate hemilyuminescence was used, which was measured on a chemilyuminometer Lum-1200. The time of each measurement was 3 hours, based on the hemiluminiscence of the active form of oxygen (given the growth of the indicator, peak and decline). Cell concentration (7x106 classes/ml) was selected experimentally for measurements, according to the results of a series of preliminary experiments.Results.As a result of the study, data based on the method of luminol-proroxidate chemilyuminescence for the permissible level of AFC in native sperm of roosters were first obtained. The range of active forms of oxygen (from 75 to 249 volts*sec) has been established, in which cells do not receive significant damage to membrane structures during cryoponservation. In case of exceeding the threshold of 250 volts*S, the number of cells with damaged membranes increases sharply from 17.19% to 62.87%. The data obtained allow the assessment and selection of roosters on the quality of their sperm for the purposes of cryoponservation and the formation of cryobans of reproductive cells.