Lecture Course “Modern Physics”

In the paper, the structure of the lecture course “Modern Physics” is described in detail. The course is based on a logical presentation of modern ideas about quantum-, atomic-, nuclear-, and molecular physics as well as astrophysics. A special attention is paid to a relatively new interdisciplinary research field, namely the physics of open systems, and to the study of clusters as one of the most promising scientific areas. Separate chapters of the textbook are devoted to nonlinear optics, quantum information, structure and dynamics of molecules. The fundamental laws and concepts of modern physics, their relationship and origin are comprehensively discussed. It is underlined that this lecture course is intended, first of all, for students of technical universities, postgraduate students of relevant specialties, as well as professors of vocation-related subjects. The inclusion of new sections of physics in the curricula of universities is rationalized, in particular, by the fact that physics is closely related to engineering. Due to this fact, the important role that physics plays in society becomes especially evident. The paper may also be of interest to those who are fond of physics and its state-of-the art

Aspects of actoprotective activity of certain natural compounds with different chemical structure

Objective: the purpose of the present research was the complex assessment of the influence of natural compounds on high-speed characteristics, working capacity, endurance of laboratory mice during physical activities. Materials and methods: actoprotective activity of natural compounds was estimated by the method of shuttle swimming in laboratory mice, anti-hypoxic activity of natural compounds was evaluated on two models: histotoxic and circulatory model. Results: administration of the ATACL compound increased the high-speed and power characteristics and endurance of laboratory animals and also positively affected both histotoxic and circulatory hypoxia. Conclusions: study results showed that compounds under the ATACL code had the most profound actoprotective and anti-hypoxic effects in comparison with other studied compounds. At the same time the pharmacological effect of the use of this compound was comparable to that of the use of reference drugs at all stages of the experiment

Thiol peroxidase deficiency leads to increased mutational load and decreased fitness in saccharomyces cerevisiae

Thiol peroxidases are critical enzymes in the redox control of cellular processes that function by reducing low levels of hydroperoxides and regulating redox signaling. These proteins were also shown to regulate genome stability, but how their dysfunction affects the actual mutations in the genome is not known. Saccharomyces cerevisiae has eight thiol peroxidases of glutathione peroxidase and peroxiredoxin families, and the mutant lacking all these genes (Δ8) is viable. In this study, we employed two independent Δ8 isolates to analyze the genome-wide mutation spectrum that results from deficiency in these enzymes. Deletion of these genes was accompanied by a dramatic increase in point mutations, many of which clustered in close proximity and scattered throughout the genome, suggesting strong mutational bias. We further subjected multiple lines of wild-type and Δ8 cells to long-term mutation accumulation, followed by genome sequencing and phenotypic characterization. Δ8 lines showed a significant increase in nonrecurrent point mutations and indels. The original Δ8 cells exhibited reduced growth rate and decreased life span, which were further reduced in all Δ8 mutation accumulation lines. Although the mutation spectrum of the two independent isolates was different, similar patterns of gene expression were observed, suggesting the direct contribution of thiol peroxidases to the observed phenotypes. Expression of a single thiol peroxidase could partially restore the growth phenotype of Δ8 cells. This study shows how deficiency in nonessential, yet critical and conserved oxidoreductase function, leads to increased mutational load and decreased fitness.National Institutes of Health (GM065204

Influence of ATACL compounds on some biochemical indicators in conditions of exhausting exercise in animals

Objective: to study the effect of the ATACL (4-hydroxy-3,5-di-tert-butylcinnamicacid) compound on some biochemical parameters under conditions of exhausting exercise in animals. Materials and methods: the study was conducted to study the effect of a cinnamic acid derivative on certain biochemical parameters under conditions of exhausting exercise in animals. The experiment was performed on 40 outbred male mice weighing 22-24 grams. Animals were subject to daily exhausting exercise for 5 days in the treadmill running test. The test compound ATACL was administered intragastrically at a dose of 100 mg/kg for 30 minutes before the exercise. At the end of the experiment, the animals were decapitated and blood was taken to assess lactic, pyruvic acid, the lactate/pyruvate coefficient and myoglobin as the marker of muscle damage. Results: It was found that upon exercise, 4-hydroxy-3,5-di-tert-butylcinnamic acid neutralizes the acidic pH. 10.7 times (p<0.05) increase in the concentration of pyruvate in the blood was observed compared to the negative control group, and a decrease in the lactate / pyruvate coefficient by 28.6 times (p<0.05). At the same time, the level of myoglobin in the group receiving ATACL was 2.1 times lower compared to the negative control group (p<0.05). No significant differences were observed in terms of lactate, pyruvate, and myoglobin concentration in the group treated with ATACL, in comparison with the group of animals treated with Metaprot. Conclusions: the data obtained allow us to recommend this compound as a corrector of biochemical shifts that are possible during physical exertion

N-terminal acetylation promotes synaptonemal complex assembly in C. elegans

N-terminal acetylation of the first two amino acids on proteins is a prevalent cotranslational modification. Despite its abundance, the biological processes associated with this modification are not well understood. Here, we mapped the pattern of protein N-terminal acetylation in Caenorhabditis elegans, uncovering a conserved set of rules for this protein modification and identifying substrates for the N-terminal acetyltransferase B (NatB) complex. We observed an enrichment for global protein N-terminal acetylation and also specifically for NatB substrates in the nucleus, supporting the importance of this modification for regulating biological functions within this cellular compartment. Peptide profiling analysis provides evidence of cross-talk between N-terminal acetylation and internal modifications in a NAT substrate-specific manner. In vivo studies indicate that N-terminal acetylation is critical for meiosis, as it regulates the assembly of the synaptonemal complex (SC), a proteinaceous structure ubiquitously present during meiosis from yeast to humans. Specifically, N-terminal acetylation of NatB substrate SYP-1, an SC structural component, is critical for SC assembly. These findings provide novel insights into the biological functions of N-terminal acetylation and its essential role during meiosis

Elastic turbulence in curvilinear flows of polymer solutions

Following our first report (A. Groisman and V. Steinberg, \sl Nature $\bf 405$, 53 (2000)) we present an extended account of experimental observations of elasticity induced turbulence in three different systems: a swirling flow between two plates, a Couette-Taylor (CT) flow between two cylinders, and a flow in a curvilinear channel (Dean flow). All three set-ups had high ratio of width of the region available for flow to radius of curvature of the streamlines. The experiments were carried out with dilute solutions of high molecular weight polyacrylamide in concentrated sugar syrups. High polymer relaxation time and solution viscosity ensured prevalence of non-linear elastic effects over inertial non-linearity, and development of purely elastic instabilities at low Reynolds number (Re) in all three flows. Above the elastic instability threshold, flows in all three systems exhibit features of developed turbulence. Those include: (i)randomly fluctuating fluid motion excited in a broad range of spatial and temporal scales; (ii) significant increase in the rates of momentum and mass transfer (compared to those expected for a steady flow with a smooth velocity profile). Phenomenology, driving mechanisms, and parameter dependence of the elastic turbulence are compared with those of the conventional high Re hydrodynamic turbulence in Newtonian fluids.Comment: 23 pages, 26 figure

Involvement of human beta-defensin-2 in regulation of malignant potential of cultured human melanoma cells

Background and Aim: Human beta-defensin-2 (hBD-2) is an antimicrobial cationic peptide capable to control human carcinoma cell growth via cell cycle regulation. The present study was aimed on determination of hBD-2 influence on the growth patterns and malignant potential of cultured human melanoma cells. Methods: The study was performed on cultured human melanoma cells of mel Z and mel Is lines treated with recombinant hBD-2 (rec-hBD-2); cell viability, proliferation, cell cycle distribution, and anchorage-independent growth were analyzed using MTT test, direct cell counting, flow cytometry, and colony forming assay respectively. Expression and/or phosphorylation levels of proteins involved in cell cycle control were evaluated by Western blotting. Results: The treatment of mel Z and mel Is cells with rec-hBD-2 in a concentration range of 100–1000 nM resulted in a concentration-dependent suppression of cell proliferation, viability, and colony forming activity. It has been shown that rec-hBD-2 exerts its growth suppression effects via significant downregulation of B-Raf expression, activation of pRB and upregulation of p21WAF1 expression, downregulation of cyclin D1 and cyclin E resulting in cell cycle arrest at G1/S checkpoint. Conclusion: According to obtained results, hBD-2 exerts its growth suppression effect toward human melanoma cells via downregulation of B-Raf, cyclin D1 and cyclin E expression, upregulation of p21WAF1 expression and activation of pRB. Key Words: human beta-defensin-2, melanoma, proliferation, viability, cell cycle, B-Raf, anchorage-independent growth

Different morphological structures of breast tumors demonstrate individual drug resistance gene expression profiles

AIM

Aberrant expression of selenium-containing glutathione peroxidases in clear cell renal cell carcinomas

Aim: To find putative diagnostic markers for clear cell renal cell carcinomas (ccRCC). Material and methods: Quantitative polymerase chain reaction (Q-PCR), bisulfite treatment, methylation-specific PCR, analysis on cBioPortal for Cancer Genomics. Results: We have found that expression of GPX 1, GPX3, and GPX4 genes was decreased in ccRCC. We have shown that the number of alanine (GCG) repeats at the amino terminus of the GPX1 protein is variable. It was reported earlier that an allele that possess 5 alanine repeats is associated with the increased cancer risk. According to the obtained data, the allele with the 5 alanine repeats was also present in a group of healthy donors. Moreover, the frequency of alleles with repeats was similar among ccRCC patients and healthy individuals. We found that decreased expression of GPXs genes was not associated with promoter methylation. To provide other explanation, an analysis on the gene copy number was performed. We have found the heterozygous deletions for GPX1 gene, amplification for GPX3 gene, and no change in gene copy number for GPX4. Conclusions: Our data support the hypothesis that GPX1, GPX3, and GPX4 genes may play a role in ccRCC cancerogenesis and therefore they might be considered as putative diagnostic markers for ccRCC. Key Words: clear cell renal cell carcinomas, selenium-containing GPXs, genetic and epigenetic regulation