Effect of Mesenchimal Stem Cells on Apoptosis Indices in Renal Parenchyma during Experimental Stress

Background. Kidneys are extremely sensitive to various environmental factors. Stress disturbs prooxidant-antioxidant balance, causes hyperproduction of reactive oxygen species, changes activity of the nitroxidergic system components, regulating apoptosis. The use of mesenchymal stem cells can normalize functioning of damaged organs in the pathological process.Aim: to assess the effectiveness of mesenchymal stem cells in a single 24-hour immobilization according to the dynamics of apoptosis indices in renal tissue – nitric oxide (NO) and fragmented DNA.Materials and methods. The study included male nonlinear white rats aged 3 to 4 months and weighing 225 ± 25 grams. Experimental stress was modeled by the immobilization of animals in the fixation chambers within 24 hours. The efficacy of cell therapy was determined by the change in the concentration of the tested substances at 1, 3, 7, 14, 21 and 30 days of the experiment.Results. There was a sharp increase in the total amount of nitrates / nitrites and the level of DNA fragmentation in the homogenates of the renal parenchyma after the action of an acute stressor, which may indicate the induction of apoptosis. It was proved that in animals, receiving mesenchymal stem cells as a treatment, the restoration of the studied parameters in the kidney tissue was significantly accelerated in comparison with the controls values.Conclusion. Mesenchymal stem cells protect cells from self-destruction and activate reparation, which makes them promising for further study

Structural features and physico-mechanical properties of AlN-TiB2-TiSi2 amorphous-like coatings

The coating of the AlN–TiB2–TiSi2 system has been produced by the magnetron sputtering of a target. At the hightemperature (900 and 1300°C) actions the coating crystallization to form crystallites of sizes 11–25 nm has been observed. It has been defined that the amorphouslike structure is promising for the use of these coatings as diffusion barriers both as the independent elements and a contacting layer in multilayer wearresistant coatings. It has been shown that the use of the resultant composite as an effec tive protective coating for cutting tools will make it possible to increase the tools wear resistance by more than 30% at the temperature up to 1300°C in the cutting zone

Structural features and physico-mechanical properties of AlN-TiB2-TiSi2 amorphous-like coatings

The coating of the AlN–TiB2–TiSi2 system has been produced by the magnetron sputtering of a target. At the hightemperature (900 and 1300°C) actions the coating crystallization to form crystallites of sizes 11–25 nm has been observed. It has been defined that the amorphouslike structure is promising for the use of these coatings as diffusion barriers both as the independent elements and a contacting layer in multilayer wearresistant coatings. It has been shown that the use of the resultant composite as an effec tive protective coating for cutting tools will make it possible to increase the tools wear resistance by more than 30% at the temperature up to 1300°C in the cutting zone

Standing stock of Antarctic krill (Euphausia superba Dana, 1850) (Euphausiacea) in the Southwest Atlantic sector of the Southern Ocean, 2018–19

Estimates of the distribution and density of Antarctic krill (Euphausia superba Dana, 1850) were derived from a large-scale survey conducted during the austral summer in the Southwest Atlantic sector of the Southern Ocean and across the Scotia Sea in 2018–19, the ‘2018–19 Area 48 Survey’. Survey vessels were provided by Norway, the Association of Responsible Krill harvesting companies and Aker BioMarine AS, the United Kingdom, Ukraine, Republic of Korea, and China. Survey design followed the transects of the Commission for the Conservation of Antarctic Marine Living Resources synoptic survey, carried out in 2000 and from regular national surveys performed in the South Atlantic sector by the U.S., China, Republic of Korea, Norway, and the U.K. The 2018–19 Area 48 Survey represents only the second large-scale survey performed in the area and this joint effort resulted in the largest ever total transect line (19,500 km) coverage carried out as one single exercise in the Southern Ocean. We delineated and integrated acoustic backscatter arising from krill swarms to produce distribution maps of krill areal biomass density and standing stock (biomass) estimates. Krill standing stock for the Area 48 was estimated to be 62.6 megatonnes (mean density of 30 g m–2 over 2 million km2) with a sampling coefficient variation of 13%. The highest mean krill densities were found in the South Orkney Islands stratum (93.2 g m–2) and the lowest in the South Georgia Island stratum (6.4 g m–2). The krill densities across the strata compared to those found during the previous survey indicate some regional differences in distribution and biomass. It is currently not possible to assign any such differences or lack of differences between the two survey datasets to longer term trends in the environment, krill stocks or fishing pressure

Experimental Studies and Condition Monitoring of Auxiliary Processes in the Production of Al2O3 by Sol–Gel Technology

Powders and granules of heavy metal oxides produced through condition monitoring are in high demand as intermediate products for obtaining fine-grained ceramics for a wide range of applications, i.e., nuclear fuel and fuel elements for nuclear power plants. Sol–gel technology to produce nuclear fuel (UO2), as well as catalysts (ThO2) for organic synthesis in the form of granules from pressed microspheres, is a promising method to obtain powders and granules of heavy metal oxides (fine-graded ceramics). Al2O3 was selected as the model analog at the stages of obtaining a solution of heavy metal and sol, the formation and gelation of droplets, and the preparation of gel spheres and their further washing and drying, as well as recovery and firing of particles. In the study, the main parameters were substantiated, e.g., the diameter and angle of inclination of the axis for the holes in the perforated shell, the multiplicity of sol circulation before the holes, the coefficients of liquid (sol) flow rate, the oscillation frequency of the disperser, and the concentration of surfactant and acid in sol. All of these parameters affect the characteristics of the granules that are obtained by sol–gel technology. Moreover, recommendations to increase productivity and the energy efficiency of production were also given. In particular, it was found that oscillation frequency in a range of 70–80 Hz leads to a granulometric composition of the obtained granules of 2.0–2.2 mm. A hole of 0.85 mm and a frequency of 100 Hz slightly change this range to 1.2–2.0 mm, while maintaining monodispersity

Влияние ионной имплантации Au–на микроструктуру аморфно-нанокристаллического AlN-TiB2-TiSi2

Прямі вимірювання за допомогою TEM, HRTEM, XRD и SEM з мікроаналізом показали, що термічний відпал при 1300 °С на повітрі призводить до утворення нанорозмірних фаз 10÷15 нм з AlN, AlB2, Al2O3 і TiO2, а іонна імплантація негативних іонів Au- призводить до фрагментації (зменшення) розмірів нанозерен до 2-5 нм з утворенням «сфероїдів» з Au– і формуванню аморфної оксидної плівки в глибині (приповерхневому шарі) покриття.Прямые измерения с помощью TEM, HRTEM, XRD и SEM с микроанализом показали, что термический отжиг 1300 С на воздухе приводит к образованию наноразмерных фаз 1015 нм из AlN, AlB2, Al2O3 и TiO2, а ионная имплантация отрицательных ионов Au- приводит к фрагментации (уменьшению) размеров нанозерен до 2-5 нм с образованием «сфероидов» из Au– и формированию аморфной оксидной пленки в глубине (приповерхностном слое) покрытия.Direct measurements were performed using TEM, HRTEM, XRD and SEM with microanalysis. The results showed that the thermal annealing at 1300 С in air leads to the formation of nanoscale phases 1015 nm from AlN, AlB2, Al2O3 and TiO2. Moreover, the ion implantation of the negative ions Au– causes fragmentation (decrease) of the size of nanograins to 2-5 nm with the formation of Au– clusters. In addition, the ion implantation leads to the formation of an amorphous oxide film in the depth (at the undersurface layer) of the coating

Влияние ионной имплантации Au–на микроструктуру аморфно-нанокристаллического AlN-TiB2-TiSi2

Прямі вимірювання за допомогою TEM, HRTEM, XRD и SEM з мікроаналізом показали, що термічний відпал при 1300 °С на повітрі призводить до утворення нанорозмірних фаз 10÷15 нм з AlN, AlB2, Al2O3 і TiO2, а іонна імплантація негативних іонів Au- призводить до фрагментації (зменшення) розмірів нанозерен до 2-5 нм з утворенням «сфероїдів» з Au– і формуванню аморфної оксидної плівки в глибині (приповерхневому шарі) покриття.Прямые измерения с помощью TEM, HRTEM, XRD и SEM с микроанализом показали, что термический отжиг 1300 С на воздухе приводит к образованию наноразмерных фаз 1015 нм из AlN, AlB2, Al2O3 и TiO2, а ионная имплантация отрицательных ионов Au- приводит к фрагментации (уменьшению) размеров нанозерен до 2-5 нм с образованием «сфероидов» из Au– и формированию аморфной оксидной пленки в глубине (приповерхностном слое) покрытия.Direct measurements were performed using TEM, HRTEM, XRD and SEM with microanalysis. The results showed that the thermal annealing at 1300 С in air leads to the formation of nanoscale phases 1015 nm from AlN, AlB2, Al2O3 and TiO2. Moreover, the ion implantation of the negative ions Au– causes fragmentation (decrease) of the size of nanograins to 2-5 nm with the formation of Au– clusters. In addition, the ion implantation leads to the formation of an amorphous oxide film in the depth (at the undersurface layer) of the coating

High Temperature Annealing of Ion-Plasma Nanostructured Coatings Based on AlN−TiB2(TiSi2)AlN-TiB_2(TiSi_2)

The coatings investigated in this paper were deposited via the magnetron sputtering of $AlN-TiB_2-Ti-Si_2$ target in Ar atmosphere. The investigation of structural-phase composition, element composition, morphology and mechanical properties before and after annealing up to 1350°C was carried out. The concentration of elements in the coating was changed after annealing at 900°C and further annealing at 1350°C (especially after annealing at 1350°C). The hardness of as-deposited coatings was 15 GPa, but after annealing at 1350°C the value of hardness increased up to 22÷23.5 GPa. The value of the viscoplastic index was 0.07. All this provide high damping properties of the coating, and amorphous-like structure makes promising the use of these coatings as diffusion barriers in the form of independent elements, and as a contacting layer in multilayer wear resistant coatings

Catalytic performance of carbon nanotubes in H2O2 decomposition: experimental and quantum chemical study

1521Budapest, Hungary 4 Department of Physical Chemistry and Material Science, University of Szeged, H-6720 Szeged, Aradi Vértanúk tere 1., Hungary Abstract The catalytic performance of multi-walled carbon nanotubes (MWCNTs) with different surface chemistry was studied in the decomposition reaction of H2O2 at various values of pH and temperature. A comparative analysis of experimental and quantum chemical calculation results is given. It has been shown that both the lowest calculated activation energy (~18.9 kJ/mol) and the highest rate constant correspond to the N-containing CNT. The calculated chemisorption energy values correlate with the operation stability of MWCNTs. Based on the proposed quantum chemical model it was found that the catalytic activity of carbon materials in electron transfer reactions is controlled by their electron donor capability