Phase equilibria and thermodynamic properties of oxide systems on the basis of rare earth, alkaline earth and 3d-transition (Mn, Fe, Co) metals. A short overview of

Review is dedicated studies of phase equilibria in the systems based on rare earth elements and 3d transition metals. It’s highlighted several structural families of these compounds and is shown that many were found interesting properties for practical application, such as high conductivity up to the superconducting state, magnetic properties, catalytic activity of the processes of afterburning of exhaust gases, the high mobility in the oxygen sublattice and more

Evaluation of selected lactic acid bacteria as starter cultures for gluten-free sourdough bread production

Received: January 30th, 2021 ; Accepted: April 8th, 2021 ; Published: May 19th, 2021 ; Correspondence: [email protected] is one of the most promising technologies for gluten-free bread. The selection of appropriate starter cultures for the production of gluten-free sourdoughs is of a great importance, since not all microorganisms can adapt equally to the same raw material. The aim was to create a new starter microbial composition for gluten-free sourdough preparation, allowing improving the quality and the microbiological safety of gluten-free bread. Screening was conducted on 8 strains of lactic acid bacteria (LAB) and 5 strains of yeast previously isolated from spontaneously fermenting rice and buckwheat sourdoughs. The strain S. cerevisiae Y205 had the highest fermentative activity and alcohols content. The lactic acid bacteria L. brevis E139 and L. plantarum Е138 were also experimentally selected for new gluten-free sourdoughs on the basis of acidity and volatile acids production and antagonistic activity. Two types of microbial composition were created and its influence on sourdough biotechnological indicators was studied. Sourdough with L. plantarum Е138 had in 1.2 times lower titratable acidity, in 3.4 times lower volatile acids content compared to sourdough with L. brevis E139. Alcohol content was the same in both sourdoughs similarly to yeast cells amount. Sourdough dough proofing time increased in 1.2–1.3 times compared to the control. Sourdough did not affect the specific volume, porosity and compressibility of gluten-free bread, but its sensory characteristics were improved. Bread made with sourdoughs had more pronounced taste and flavor, brighter crust color and better texture compared bread without sourdough. The microbiological safety of sourdough gluten-free bread was also increased, especially when L. brevis E139 was used

Ensuring resilience and agility of complex organizational-technical systems

Modern organizational and technical systems have been developing in an environment that is marked by capriciousness, uncertainty, risk, variability, and evolution (CURVE factors). As organizational-technical systems grow bigger, their internal complexity increases, too, both structurally and dynamically. The article substantiates the appropriateness of employing the principles of systems engineering for managing such systems. The authors analyzed various theoretical concepts of and practice-based approaches to the development of systems engineering in the context of ensuring the resilience and agility of complex organizational-technical systems. Using the case of power engineering and hi-tech industries, the authors show that for organizations that operate critical infrastructure facilities it is essential to make sure that the system stays functional in adverse conditions and is able to recover quickly after a failure. It is demonstrated that for addressing the above task it is critical to use instruments that nurture interdisciplinary competences in individual professionals and in teams that manage the development of complex systems and implement major innovation projects. As part of the study, the authors also look at the possibility of using the principles of resilient systems design and the fundamental principles for agile systems engineering when managing critical infrastructure facilities. © 2018 WIT Press.ACKNOWLEDGEMENTS The work was supported by Act 211 of the Government of the Russian Federation, contract No. 02.A03.21.0006

Phase equilibria, crystal structure and oxygen nonstoichiometry of the complex oxides in Sm – (Sr, Ba) – (Co, Fe) – O systems

Received: 18.01.2018. Accepted: 14.02.2018. Published: 10.05.2018.Present paper contains available information on the phase equilibria in the Sm – (Sr, Ba) – (Co, Fe) – O systems, including the synthesis routes used, crystal structure, which is often depended on oxygen nonstoichiometry, the data on thermodynamic stability of complex oxides, the obtained results on the homogeneity ranges of solid solutions, formed in the systems, and graphical presentation of phase relations in a form of phase diagrams

Phase equilibria, crystal structure and oxygen content of intermediate phases in the Y-Ba-Co-O system

The phase equilibria in the Y-Ba-Co-O system were systematically studied at 1373 K in air. The intermediate phases formed in the Y-Ba-Co-O system at 1373 K in air were: YBaCo2O5+δ, YBaCo4O 7 and BaCo1-yYyO3-δ (0.09≤y≤0.42). It was shown that YBaCo2O5+δ possesses tetragonal structure with the 3ap×3a p×2ap superstructure (sp. gr. P4/mmm). High-temperature X-ray diffraction analysis of the YBaCo2O 5+δ in the temperature range from 298 K up to 1073 K under Po2=0.21 atm has not shown any phase transformations. The value of oxygen content for the YBaCo2O5+δ at room temperature was estimated as 5.40 and at 1323 K it was equal to 5.04. Thermal expansion of sample shows a linear characteristics and the average thermal expansion coefficient (TEC) is about 13.8×10-6, K-1 in the temperature range 298-1273 K. The homogeneity range and crystal structure of the BaCo1-yYyO3-δ (0.09≤y≤0.42) solid solutions were determined by X-ray diffraction of quenched samples. All BaCo1-yYyO3-δ solid solutions were found to have cubic structure (sp. gr. Pm3m). The unit cell parameters were refined using Rietveld full-profile analysis. Oxygen nonstoichiometry of BaCo 1-yYyO3-δ solid solutions with 0.1≤y≤0.4 was measured by means of thermogravimetric technique within the temperature range 298-1373 K in air. Thermal expansion of BaCo 1-yYyO3-δ (y=0.0; 0.1; 0.2; 0.3) samples was studied within the temperature range 298-1200 K in air. The projection of isothermal-isobaric phase diagram for the Y-Ba-Co-O system to the compositional triangle of metallic components was presented. © 2013 Elsevier Inc

Biological, cytomorphological and karyological heterogeneity of transformed cell lines derived from domestic pig (Sus scrofa L.) organs

The main advantage of transformed cell lines as compared to primary ones is that they allow generation of the stable material suitable for long-term research and practical use. Therefore, development of new continuous cell cultures from various animal tissues is of great practical importance. Results of examination of transformed cell lines derived from organs of domestic pigs (Sus scrofa L.) for their biological, cytomorphological and karyological features are described in the paper. The said cell cultures are confirmed to be susceptible to various animal viruses. Also, a procedure for preparation of new diploid cell culture from porcine spleen (SSs – Splеen Sus scrofa) is described. Based on the obtained data analysis it was concluded that the epithelial cells derived from trypsinized porcine spleens could be successfully immortalized. All transformed cell lines of porcine origin have similar morphology with predominated epithelium-like forms. Some of them – SPEV, А4 С2 , RSK – tend to adopt a spherical shape in suspension. Such cell lines as PSGK-30 and PPES cell lines form partial multilayer or they are characterized by significant monolayer compaction with pseudosyncytium formation. Only pseudodiploid cell culture (SPEV cell culture) tends to grow in suspension, it also grows in rotating culture flasks. Karyological transformations in different cell cultures stabilized at certain level. Spontaneous increase in chromosome numbers in the main population of transformed cell lines towards triploidy resulted in stabilization of culture properties and increase in proliferation. PSGK-30 cell culture has the highest modal class – 64 chromosomes. Near-diploid cultures (А4 С2 , RSK) demonstrate stable growth properties and are similar to SPEV cell culture in adopting spherical cell forms in medium, monolayer character and cell morphology. PK-15 cell culture having a distinct karyotype under different cultivation conditions while retaining other culture properties is found to be the most adaptive. A new transformed diploid SSs cell culture is developed by long-term incubation, subcultivation (more than 80 passages) and selection at the FGBI “ARRIAH” laboratory; it can remain diploid or may spontaneously become heteroploid-immortalized during further passaging. The cell hyperploidy is very likely to enhance telomerase activity, which in turn stabilizes immortalization and results in proliferative activity increase The cell viability has been maintained so far by regular reseedings (split ratio – 1:2–1:3) performed 1–2 times a week

Preparation, crystal structure and properties of HoBaCo 2-xFexO5+δ

A series of samples of overall composition HoBaCo2-xFe xO5+δ with 0.0 ≤ x ≤ 0.8 were prepared by glycerin nitrate technique in air and in pure oxygen. Irrespective of atmosphere used the homogeneity range of single phase iron substituted holmium barium cobaltate was proved to exist within the range 0.0 ≤ x ≤ 0.4. All samples prepared in air and samples within the compositional range 0.2 ≤ x ≤ 0.4 obtained in oxygen possess tetragonal ap × ap × 2ap (sp. gr. 4/mmm) structure. HoBaCo2O 5+δ and HoBaCo1.9Fe0.1O 5+δ synthesized in oxygen crystallized in orthorhombic a p × 2ap × 2ap (sp. gr. mmm) structure. The structural parameters were refined by the Rietveld analysis. It was shown that parameter a remains practically constant while parameter c gradually increases with the increase of iron content. The changes of oxygen content in HoBaCo2-xFexO5+δ (x = 0, 0.2, 0.4) were measured by TGA within the temperature range 25-1100 °C in air. The absolute value of oxygen content was determined by the reduction of the samples in hydrogen flow. The influence of oxygen and iron content on the crystal structure has been discussed. The chemical stability of HoBaCo 2-xFexO5+δ in contact with the solid electrolyte materials Ce0.8Sm0.2O2 and Zr 0.85Y0.15O2 was examined. © 2013 Elsevier Ltd

LONG-LIVED BONE MARROW PLASMA CELLS DURING IMMUNE RESPONSE TO ALPHA (1→3) DEXTRAN

Production kinetics and some functional properties of long-lived marrow plasma cells were studied in mice immunized with T-independent type 2 antigens. Alpha (1→3) dextran was used as an antigen for immunization. The mice were immunized by dextran, and the numbers of IgM antibody producing cells were determined by ELISPOT method. The cell phenotype was determined by cytofluorimetric technique. In the area of normal bone marrow lymphocytes ~4% of T and ~85% of B cells were detected. About 35% of the cells expressed a plasmocyte marker (CD138); 3% were CD138+IgM+, and about 6% of the lymphocytes were double-positive for CD138+IgA+. Among spleen lymphocytes, 50% of T and 47% of B cells were detected. About 1.5% lymphocytes were CD138+, and 0.5% were positive for CD138 and IgM. Time kinetics of antibody-producing cells in bone marrow and spleen was different. In spleen populations, the peak amounts of antibody-secreting cells have been shown on the day 4; the process abated by the day 28. Vice versa, the numbers of the antibody-producing cells in bone marrow started to increase on the day 4. The process reached its maximum on day 14, and after 28th day became stationary. The in vitro experiments have shown that supplementation of bone marrow cells from immune mice with dextran did not influence their functional activity. It was previously shown for cells responding to T-dependent antigens only. A specific marker for the long-lived plasma cells is still unknown. However, these cells possess a common CD138 marker specific for all plasma cells. A method for isolation of bone marrow CD138+ cells was developed. The CD138+ cells were of 87-97% purity, being enriched in long-lived bone marrow cells, and produced monospecific antibodies

Peculiarities of the antioxidant status of adolescents with arterial hypertension

One of the most topical problems in the field of healthcare is to solve the issues of an early diagnosis, timely prevention and effective treatment of cardiovascular diseases, which include arterial hypertension (the AH]. Prevalence of EAH in the pediatric population in Russia amounts to 20 %. Despite the fact that the mechanisms of the disease were studied in detail, metabolic changes that led to its early deve^ment in teenagers were still not entirely clear. In the Clinic of FSBSI Scientific Center for Family Health Problems and Human Reproduction (Irkutsk], clinical and functional examination of 48 male adolescents aged 14-17 years, of which 25 patients with stable arterial hypertension and 23 adolescents without somatic pathology with normal blood pressure, was conducted. Antioxidant status was studied in blood plasma and hemolysate. A comparative analysis of the following indicators was conducted: total antioxidant activity, superoxide dismutase activity, level of retinol and α-tocopherol, glutathione system parameters. Patients with stable arterial hypertension were recorded with level of overall antioxidant activity in blood 29 % higher than the benchmark, decreased superoxide dismutase activity by 11 % and content of а-tocopherol by 44 %. Retinol concentration in teenagers with hypertension was two times higher than the content of this indicator in the control group (р = 0.00]. Decrease in the antioxidant levels was found in adolescents with arterial hypertension that can be the cause of the oxidative stress development

A Study of the Crystal Structure of SmCaCo1−xFexO4−δ and Sm0.9Ca1.1Fe1−yCoyO4−δ Solid Solutions

Complex oxides with general compositions SmCaCo1−xFexO4−δ and Sm0.9Ca1.1Fe1−yCoyCO4−δ are synthesized using the glycerol-nitrate technique at 1100 °C in air. By powder X-ray diffraction it is determined that SmCaCo1−xFexO4−δ solid solutions exist in a composition range 0 ≤ x ≤ 0.3 and Sm0.9Ca1.1Fe1−yCoyO4−δ solid solutions exist in a composition range 0 ≤ y ≤ 0.7. The samples with high concentrations of cobalt ions are found to crystallize in the tetragonal unit cell (space group I4/mmm), whereas the solid solutions enriched with iron ions have the orthorhombic structure (space group Bmab). For all single phase samples the unit cell parameters and volume and the structural parameters (atomic coordinates and bond lengths) are calculated by the full-profile Rietveld method. © 2019, Pleiades Publishing, Ltd