Structure and phase composition of the superalloy on the basis of Ni-Al-Cr alloyed by Re and La

Qualitative and quantitative studies of the structure, phase composition, morphology of phase of the high-rhenium alloys additionally doped with La were carried out by TEM and SEM methods. The alloy was obtained by directional solidification method. It was shown that introduction of Re and La to an alloy leads to formation of new phases: [beta] and [chi] , which bring serious irregularities in the structure of quasicuboids of [gamma]'-phase

Perspectives of growth of economic security by clustering of small innovation enterprises

The authors analyze the notion, sense, criteria, and indicators of evaluation of economic security and perform the evaluation of economic security of modern economic systems with the help of the offered methodology, which leads to the conclusion that one of the most successful countries are characterized by low level of economic security; therefore, there is a necessity for the search for perspectives of the increase of economic security. As a tool for increasing economic security, clustering is offered. The authors performed the structural analysis of formation of modern clusters and allowed allocating the problems of clustering which can be solved by clustering of small innovational enterprises. It is necessary that small innovational enterprises participate in the development of the program; their joint projects should at least concern, or, even better, solve their common problems (which will increase the competitiveness of cluster, as small innovational enterprises are connected by chains of value added with the same large companies); small innovational enterprises should participate – within the limits of their competencies – in the formation of the program of cluster development; there should be no artificial disunion between clusters of large enterprises and clusters of small innovational enterprises (which requires creation of common list of clusters). As a result of the research, the authors come to the conclusion that cluster is a form of increasing competitiveness within one country and in the global market, which stipulates the growth of national economic security. The highest efficiency of cluster is achieved by clustering small innovational enterprises, which stipulates the optimal level of competition in a cluster and leads to creation of innovations – which is a moving force of development of modern economy and the basis for economic security.peer-reviewe

Problems and perspectives of formation of agricultural clusters for increasing food security of developing countries

The authors of the article develop the proprietary methodology of integral approach to formation of the projects and programs of socio-economic development, which allows differentiating the sub-system of previously viewed indicators as to the level of users’ demands. The sense of cluster approach to increasing the competitiveness of agro-industrial complex is analyzed, and the problems and perspectives for formation of agricultural clusters for the growth of food security of developing countries are determined. As a result of the research, the authors came to the conclusion that agricultural clusters are a perspective course of increasing food security of developing countries, as they improve competitiveness of domestic agricultural producers and increase food independence and food self-sufficiency of economic systems. However, implementation of internal cluster cooperation requires reconsidering the existing notions of management, related to the level of methods and control, protection of intellectual property, education, and integration. The created system of relations should allow economic agents to keep balance between self-organizing and manageable behavior, combining innovational diversity and freedom of actions with the necessary level of integration. Intercompany cooperation in this regard should be similar to cooperation of ecosystem elements.peer-reviewe

Microstructural Features in Multicore Cu–Nb Composites

none5siThe study is devoted to heavily drawn multicore Cu–18Nb composites of cylindrical and rectangular shapes. The composites were fabricated by the melt-and-deform method, namely, 600 in situ rods of Cu–18%Nb alloy were assembled in a copper shell and cold-drawn to a diameter of 15.4 mm (e = 10.2) and then rolled into a rectangular shape the size of 3 × 5.8 mm (e = 12.5). The specimens were analyzed from the viewpoints of their microstructure, microhardness, and thermal stability. The methods of SEM, TEM, X-ray analysis, and microhardness measurements were applied. It is demonstrated that, at higher strain, the fiber texture ⟨110⟩Nb∥ ⟨111⟩Cu∥ DD (drawing direction), characteristic of this material, becomes sharper. The distortions of niobium lattice can be observed, namely, the {110} Nb interplanar distance is broadened in longitudinal direction of specimens and compacted in transverse sections. The copper matrix lattice is distorted as well, though its distortions are much less pronounced due to its recrystallization. Evolution of microstructure under annealing consists mainly in the coagulation of ribbon-like Nb filaments and in the vanishing of lattice distortions. The structural changes in Nb filaments start at 300–400 °C, then develop actively at 600 °C and cause considerable decrease of strength at 700–800 °C.openElena N. Popova, Irina L. Deryagina,Evgeniya G. Valova-Zaharevskaya, Ruello Maria Letizia, Vladimir V. PopovElena N., Popova; Irina L., Deryagina; Evgeniya G., Valova-Zaharevskaya; Ruello, Maria Letizia; Vladimir V., Popo

The structure of heat-resisting alloy modified by thermal treatment and alloyed by rhenium and lanthanum

The paper presents the scanning and transmission electron microscope investigations of the structure, phase composition, and morphology of heat-resisting alloy modified by thermal treatment and additionally alloyed by rhenium and lanthanum. Rhenium alloy is obtained by the directional crystallization technique. The structural investigations are carried out for three alloy states, i.e. 1) original (after the directional crystallization); 2) 1150°С annealing during 1 h and 1100°С annealing during 480 h; 3) 1150°С annealing during 1 h and 1100°С annealing during 1430 h. It is shown that fcc-based [gamma]- and [gamma]'-phases are primary in all states of the alloy. [gamma]'-phase has L12 structure, while [gamma]-phase is a disordered phase. Rhenium and lanthanum are phase-forming elements. Investigations show that high-temperature annealing modifies the structural and phase conditions of the heat-resisting alloy

Metabolic Remodeling during Long-Lasting Cultivation of the Endomyces magnusii Yeast on Oxidative and Fermentative Substrates

In this study, we evaluated the metabolic profile of the aerobic microorganism of Endomyces magnusii with a complete respiration chain and well-developed mitochondria system during long-lasting cultivation. The yeast was grown in batches using glycerol and glucose as the sole carbon source for a week. The profile included the cellular biological and chemical parameters, which determined the redox status of the yeast cells. We studied the activities of the antioxidant systems (catalases and superoxide dismutases), glutathione system enzymes (glutathione peroxidase and reductase), aconitase, as well as the main enzymes maintaining NADPH levels in the cells (glucose-6-phosphate dehydrogenase and NADP+-isocitrate dehydrogenase) during aging of Endomyces magnusii on two kinds of substrates. We also investigated the dynamics of change in oxidized and reduced glutathione, conjugated dienes, and reactive oxidative species in the cells at different growth stages, including the deep stationary stages. Our results revealed a similar trend in the changes in the activity of all the enzymes tested, which increased 2–4-fold upon aging. The yeast cytosol had a very high reduced glutathione content, 22 times than that of Saccharomyces cerevisiae, and remained unchanged during growth, whereas there was a 7.5-fold increase in the reduced glutathione-to-oxidized glutathione ratio. The much higher level of reactive oxidative species was observed in the cells in the late and deep stationary phases, especially in the cells using glycerol. Cell aging of the culture grown on glycerol, which promotes active oxidative phosphorylation in the mitochondria, facilitated the functioning of powerful antioxidant systems (catalases, superoxide dismutases, and glutathione system enzymes) induced by reactive oxidative species. Moreover, it stimulated NADPH synthesis, regulating the cytosolic reduced glutathione level, which in turn determines the redox potential of the yeast cell during the early aging process

Metabolic Remodeling during Long-Lasting Cultivation of the Endomyces magnusii Yeast on Oxidative and Fermentative Substrates

In this study, we evaluated the metabolic profile of the aerobic microorganism of Endomyces magnusii with a complete respiration chain and well-developed mitochondria system during long-lasting cultivation. The yeast was grown in batches using glycerol and glucose as the sole carbon source for a week. The profile included the cellular biological and chemical parameters, which determined the redox status of the yeast cells. We studied the activities of the antioxidant systems (catalases and superoxide dismutases), glutathione system enzymes (glutathione peroxidase and reductase), aconitase, as well as the main enzymes maintaining NADPH levels in the cells (glucose-6-phosphate dehydrogenase and NADP+-isocitrate dehydrogenase) during aging of Endomyces magnusii on two kinds of substrates. We also investigated the dynamics of change in oxidized and reduced glutathione, conjugated dienes, and reactive oxidative species in the cells at different growth stages, including the deep stationary stages. Our results revealed a similar trend in the changes in the activity of all the enzymes tested, which increased 2–4-fold upon aging. The yeast cytosol had a very high reduced glutathione content, 22 times than that of Saccharomyces cerevisiae, and remained unchanged during growth, whereas there was a 7.5-fold increase in the reduced glutathione-to-oxidized glutathione ratio. The much higher level of reactive oxidative species was observed in the cells in the late and deep stationary phases, especially in the cells using glycerol. Cell aging of the culture grown on glycerol, which promotes active oxidative phosphorylation in the mitochondria, facilitated the functioning of powerful antioxidant systems (catalases, superoxide dismutases, and glutathione system enzymes) induced by reactive oxidative species. Moreover, it stimulated NADPH synthesis, regulating the cytosolic reduced glutathione level, which in turn determines the redox potential of the yeast cell during the early aging process

Ferroptosis-associated lesion as a potential target for cardiovascular disease: A review

Cell death is an important feature of the development of multicellular organisms, a critical factor in the occurrence of cardiovascular diseases. Understanding the mechanisms that control cell death is crucial to determine its role in the development of the pathological process. However, the most well-known types of cell death cannot fully explain the pathophysiology of heart disease. Understanding how cardiomyocytes die and why their regeneration is limited is an important area of research. Ferroptosis is an iron-dependent cell death that differs from apoptosis, necrosis, autophagy, and other forms of cell death in terms of morphology, metabolism, and protein expression. Ferroptotic cell death is characterized by the accumulation of reactive oxygen species resulting from lipid peroxidation and subsequent oxidative stress, which can be prevented by iron chelates (eg, deferoxamine) and small lipophilic antioxidants (eg, ferrostatin, liproхstatin). In recent years, many studies have been carried out on ferroptosis in the context of the development of atherosclerosis, myocardial infarction, heart failure, and other diseases. In addition to cardiovascular diseases, the review also presents data on the role of ferroptosis in the development of other socially significant diseases, such as COVID-19, chronic obstructive pulmonary disease. With the study of ferroptosis, it turned out that ferroptosis participates in the development of bacterial infection associated with the persistence in the host body of Pseudomonas aeruginosa. The review summarizes the recent advances in the study of ferroptosis, characterizing this type of cell death as a novel therapeutic target

Peculiarities of structure and phase composition of V-Ti-Cr alloy obtained by sintering technique

Abstract Alloy of the V-Ti-Cr system is a promising material exploited under high radiation and in corrosion environment. We sintered V-4.9Ti-4.8Cr alloy from particles with original average size of 30, 280 and 200 μm, respectively for vanadium, titanium and chromium powders, by pressing of the powder mixture and its further sintering. The studies were undertaken using the methods of X-ray structural analysis, scanning electron microscopy with an energy dispersive analyzer and transmission electron microscopy. It was established that the structure of the alloy represented matrix grains (BCC solid solution), along the boundaries and at junctions of which the groups of oxycarbonitride particles of V, Ti, Cr (C,N,O) type of the variable elemental composition were arranged. The particles possessed a plate-like (0.4 x 2.0 μm) and rounded (0.5 μm) shape. The solid solution of the alloy was heterogeneous by concentration. This was evidenced by the complications of the diffraction patterns obtained from the corresponding sections of the structure. These were cords of main reflexes, satellites and emergence of a moire banded contrast in separate sections of the sample. Inside the matrix grains, there were nanoparticles (15 μm) of carbide V55Cr25C20, being a source of elastic internal local stresses