Strain-Hardening Stages and Structure Evolution in Pure Niobium and Vanadium upon High Pressure Torsion

High pressure torsion (HPT) is one of the ways to form nanostructured materials with high strength properties. However, HPT hardening mechanisms vary from material to material and are poorly understood for some BCC metals, particularly niobium and vanadium. This work aims to identify strain hardening stages for Nb and V metals during HPT. Two approaches have been used to identify the deformation stages during high pressure torsion. The approaches are based on the application of a "piecewise" model, taking into account the different deformation mechanisms that determine the type of the forming structure, and on the analysis of the hardness vs. true strain dependence according to the $H$$-$${e}^{0.5}$ law. We compared the identified stages with the results of the electron microscopic study of the structure. Both models describe well the structural changes observed microscopically in HPT-deformed niobium. However, we have shown that only the piecewise model gives an adequate description of the stages of structure development in vanadium. We have provided an explanation for the observed difference in the behavior of niobium and vanadium upon HPT.Comment: 21 pages, 9 figures, 1 tabl

An assessment of attitudes towards plastics and bioplastics in Europe

Over the last 50 years, conventional fossil-based plastics have become an integral part of our everyday lives. Apart from their low production costs, this is due to a number of their unique properties, including durability, strength, lightness, electrical and thermal insulation, resistance to chemicals and corrosion. The production of plastics has increased from 1.5 million metric tons in 1950 to 359 million metric tons in 2018. Of this total, 61.8 million metric tons were produced in Europe. There are various problems associated with plastic use and disposal that pose a serious threat to both the physical environment and human health. Since public behaviour plays a key role when it comes to the use of plastic, this paper reports on a study that focused on an assessment of attitudes towards plastics and bioplastics in Europe. The results showed that packaging is the most frequent modality of plastic used among participants. In addition, majority of participants are aware that plastic waste can affect environment and human health and therefore segregate and properly dispose plastics. Also, even though most respondents were aware of the environmental problems related to plastic use and showed a positive inclination towards using bioplastic materials, their limited availability and lack of relevant information about bioplastics pose a problem for wider use. Departing from the assumption that the public attitude is a determining factor in the consumption of plastics as a whole and bioplastics in particular, this paper also sheds some light on the current situation, identifying some trends and information gaps which should be addressed in order to encourage a more rational use of plastics in Europe

Live Birth of a Healthy Child in a Couple with Identical mtDNA Carrying a Pathogenic c.471_477delTTTAAAAinsG Variant in the MOCS2 Gene.

Molybdenum cofactor deficiency type B (MOCODB; #252160) is an autosomal recessive metabolic disorder that has only been described in 37 affected patients. In this report, we describe the presence of an in-frame homozygous variant (c.471_477delTTTAAAAinsG) in the MOCS2 gene in an affected child, diagnosed with Ohtahara syndrome according to the clinical manifestations. The analysis of the three-dimensional structure of the protein and the amino acid substitutions suggested the pathogenicity of this mutation. To prevent transmitting this mutation to the next generation, we used preimplantation genetic testing for the monogenic disorders (PGT-M) protocol to select MOCS2 gene mutant-free embryos for transfer in an in vitro fertilization (IVF) program. As a result, a healthy child was born. Interestingly, both parents of the proband shared an identical mitochondrial (mt) DNA control region, assuming their close relationship and thus suggesting that both copies of the nuclear rare variant c.471_477delTTTAAAAinsG may have been transmitted from the same female ancestor. Our estimation of the a priori probability of meeting individuals with the same mtDNA haplotype confirms the assumption of a possible distant maternal relationship among the proband's direct relatives

Comparative analysis of the legal status of testamentary foundations in Russia and foreign countries

Legal rules on a testamentary foundation are a novelty for Russian legislation. Since there were no analogues of this legal institution in Russia before, many law enforcement problems arise. Russian testamentary foundations have largely adopted the provisions on the foundations of the continental legal system. For a better understanding of the legal nature of this subject of law and solving law enforcement problems, it is necessary to analyze the legal status of testamentary foundations in the states where they have existed for a long time, and take into account the positive foreign experienc

Трофічні зв’язки личинок Aedes vexans (Diptera: Culicidae) заплавних дібров р. Дніпро

Ae. vexans larvae are attributed to pseudobenthos. During feeding they are able both to filtrate and to scratch a periphyton from the substratum. As to larvae of Ae. vexans in flood oakwoods of the Dnipro River the detritus makes up two third, but algae – one third of the ration.Личинки Ae. vexans відносяться до планктобентосу. вони під час живлення можуть як безвибірково фільтрувати, так і зішкрібати перифітон із субстрату. Для личинок Ae. vexans заплавних дібров р. Дніпро, впродовж усього періоду їх розвитку, детрит складає дві третини, а водорості –близько третини раціону. Личинки Ae. vexans відносяться до планктобентосу. Вони під час живлення можуть як безвибірково фільтрувати, так і зішкрібати перифітон із субстрату. Для личинок Ae. vexans заплавних дібров р. Дніпро, впродовж усього періоду їх розвитку, детрит складає дві третини, а водорості – близько третини раціону

Monte Carlo simulations of segregation in Pt-Re catalyst nanoparticles

We have investigated the segregation of Pt atoms to the surfaces of Pt-Re nanoparticles using the Monte Carlo method and Modified Embedded Atom Method potentials that we have developed for Pt-Re alloys. The Pt75Re25 nanoparticles (containing from 586 to 4033 atoms) are assumed to have disordered fcc configurations and cubo-octahedral shapes (terminated by {l_brace}111{r_brace} and {l_brace}100{r_brace} facets), while the Pt50Re50 and Pt25Re75 nanoparticles (containing from 587 to 4061 atoms) are assumed to have disordered hcp configurations and truncated hexagonal bipyramidal shapes (terminated by {l_brace}0001{r_brace} and {l_brace}101 {bar 1}{r_brace} facets). We predict that due to the segregation process the equilibrium Pt-Re nanoparticles would achieve a core-shell structure, with a Pt-enriched shell surrounding a Pt-deficient core. For fcc cubo-octahedral Pt75Re25 nanoparticles, the shells consist of almost 100 at. percent of Pt atoms. Even in the shells of hcp truncated hexagonal bipyramidal Pt50Re50 nanoparticles, the concentrations of Pt atoms exceed 85 at. percent (35 at. percent higher than the overall concentration of Pt atoms in these nanoparticles). Most prominently, all Pt atoms will segregate to the surfaces in the hcp truncated hexagonal bipyramidal Pt25Re75 nanoparticles containing less than 1000 atoms. We also find that the Pt atoms segregate preferentially to the vertex sites, less to edge sites, and least to facet sites on the shell of Pt-Re nanoparticles

Comparative analysis of pain levels, preoperative anxiety, depression and laboratory parameters during uterine surgery

Purpose of the study was to determine the factors influencing the development of uncontrolled pain syndrome in patients who underwent uterine surgery.Цель исследования – установить факторы, влияющие на развитие неконтролируемого болевого синдрома у пациенток, перенесших операции на матке

STUDYING THE POSSIBLE MUTAGENIC PROPERTIES OF NEW MEDICINE ON THE BASIS OF COMPLEX LITHIUM CITRATE, ALUMINUM OXIDE AND POLYMETHILSILOXANE

Aim of the study was to investigate the possible mutagenic properties of a new drug based on a lithium-containing substance – a complex of lithium citrate, polymethylsiloxane and aluminum oxide. Material and methods. Methods for testing mutagenicity using chromosomal aberrations in the bone marrow cells of CBA mice and somatic recombination in Drosophila melanogaster were used. Results. It was shown that a single intragastric administration of drug at a dose of 5000 mg/kg and a fivefold course of administration at a dose of 400 mg/kg to CBA mice did not increase the level of cytogenetic disorders in bone marrow cells. The study of the lithium complex drug in a somatic mosaicism test revealed that the preparation at a dose of 2000 mg/kg does not increase the frequency of mutations in Drosophila melanogaster. Conclusion. A single intragastric administration of the studied drug at a dose of 5000 mg/kg and its course administration (400 mg/kg × 5) do not increase the level of cytogenetic disorders in the bone marrow cells of CBA mice. In the somatic recombination (mosaicism) test system on D. melanogaster, no increase in the appearance of mutant setae and spots on the body and head was observed when using yellow and singed markers. The results of the study indicate that the studied drug does not have mutagenic properties