Comparison of expenditure of using experimental models of carcinogenesis

Despite significant advances in the diagnosis and treatment of oncopathology, the main epidemic indicators have a negative trend.Based on the above, a very relevant topic is the development of experimental models of carcinogenesis. The importance of scientific work in this area is increasing because in experimental conditions it is better to test new methods, diagnostics and treatment. Thus, it becomes possible to study the peculiarities of the pathogenesis of any tumor at different stages.The purpose of the work – to study and demonstrate the strengths and weaknesses of the main experimental models of carcinogenesis for further selection of the most appropriate.Results The main directions of carcinogenesis modeling are presented in the article. Initially, the problem was justified. The next step is described in chronological order of using the models.Of course, the achievements of clinical and experimental oncology played an important role in the emergence of models. Thus, the first model was the effect of physical and chemical carcinogens on a laboratory animal. The latest achievement of experimental oncology is the use of stem cells in combination with genetic engineering.No less important is the fact of comparing experimental models. We present the strengths and weaknesses of all these models.Conclusions1. To date, there are a large number of experimental models of carcinogenesis.2. When planning a study, you need to calculate all the goals to be achieved and select the appropriate model.3. The most effective and common model for ascites ovarian tumor is the transplantation of atypical cells to laboratory animals

Ab Initio Calculations of the Walls Shear Strength of Carbon Nanotubes

The dependence of the energy of interwall interaction in double-walled carbon nanotubes (DWNT) on the relative position of walls has been calculated using the density functional method. This dependence is used to evaluate forces that are necessary for the relative telescopic motion of walls and to calculate the shear strength of DWNT for the relative sliding of walls along the nanotube axis and for their relative rotation about this axis. The possibility of experimental verification of the obtained results is discussed.Comment: 4 pages, 1 figur

Enhanced superhyperfine structure of the EPR spectra of a U3+ ion introduced into the Van Vleck paramagnet LiTmF4

The observation of the superhyperfine structure (SHFS) in EPR spectra due to enhanced nuclear magnetism is reported. The X-band spectrum of a U 3+ ion introduced into the Van Vleck paramagnet LiTmF4 is measured in the temperature range of 5-20 K and compared with the spectra of LiLuF4:U3+ and LiYF4:U3+ single crystals. The spectra reveal well-resolved and strikingly different SHFS. The SHFS of Li(Lu, Y)F4:U3+ is due to the fluorine ions forming the nearest surroundings of the U3+ ion. The main contribution to the SHFS of the U3+ spectrum in LiTmF4 comes from the Tm3+ ions with a highly enhanced nuclear gyromagnetic tensor. © 2008 Pleiades Publishing, Ltd

Superhyperfine structure of the EPR spectra of Nd3+ and U3+ ions in LiRF4 (R = Y, Lu, Tm) double fluorides

The superhyperfine structure of the EPR spectra of impurity Nd3+ and U3+ ions in LiYF4, LiLuF4, and LiTmF4 double-fluoride single crystals has been observed and discussed. In LiYF4: Nd (g{pipe} = 1. 987, g⊥ = 2. 554) and LiTmF4: Nd, the superhyperfine structure is observed at the orientation of the external magnetic field B in parallel to the c axis of the crystals and consists of nine components with a splitting of ~15. 4 MHz. In LiYF4: U (g{pipe} = 1. 149, g⊥ = 2. 508) and LiLuF4: U, the superhyperfine structure is observed at both B {pipe} c and B ⊥ c and consists of nine and eleven components, respectively, with a splitting of ~21. 5MHz. It should be noted that the resolution of the superhyperfine structure of the EPR spectrum of LiLuF4: U3+ becomes significantly higher with a deviation from the orientation B ⊥ c. © 2011 Pleiades Publishing, Ltd

書評 八田達夫著 『消費税はやはりいらない』

The superhyperfine structure of the EPR spectra of impurity Nd3+ and U3+ ions in LiYF4, LiLuF4, and LiTmF4 double-fluoride single crystals has been observed and discussed. In LiYF4: Nd (g{pipe} = 1. 987, g⊥ = 2. 554) and LiTmF4: Nd, the superhyperfine structure is observed at the orientation of the external magnetic field B in parallel to the c axis of the crystals and consists of nine components with a splitting of ~15. 4 MHz. In LiYF4: U (g{pipe} = 1. 149, g⊥ = 2. 508) and LiLuF4: U, the superhyperfine structure is observed at both B {pipe} c and B ⊥ c and consists of nine and eleven components, respectively, with a splitting of ~21. 5MHz. It should be noted that the resolution of the superhyperfine structure of the EPR spectrum of LiLuF4: U3+ becomes significantly higher with a deviation from the orientation B ⊥ c. © 2011 Pleiades Publishing, Ltd

The prevention of diseases of the musculoskeletal system in children of primary classes

The article presents the results of the study of the factors determining the formation of the musculoskeletal system of primary school students and the probability of their scoliotic disorders, presents the results of a survey of 64 parents and 32 teachers of primary school students from schools of Sverdlovsk region, the city of Rezh.В статье представлены результаты изучения факторов, определяющих формирование опорно-двигательного аппарата учеников начальных классов и вероятность развития у них нарушений осанки; представлены результаты анкетирования 64 родителей и 32 учителей учеников начальных классов школ Свердловской области, города Реж

Superhyperfine structure of EPR spectra in LiLuF 4:U 3+ and LiYF 4:Yb 3+ single crystals

Electron paramagnetic resonance (EPR) spectra of doped paramagnetic crystals LiLuF 4:U 3+ and LiYF 4:Yb 3+ have been investigated at a frequency of about 9.42 GHz in the temperature range of 10-20 K. The U 3+ ion spectrum is characterized by g-factors g ∥ = 1.228 and g ⊥ = 2.516, and contains the hyperfine structure due to the 235U isotope with nuclear spin I = 7/2 and natural abundance of 0.71%. The observed hyperfine interaction constants are A ∥ = 81 G and A ⊥ = 83.8 G. Moreover, the spectrum reveals the well-resolved superhyperfine structure (SHFS) due to two groups of four fluorine ions forming the nearest surrounding of the U 3+ ion. This SHFS contains up to nine components with the spacing between components being about 12.7 G. The SHFS is observed also in the EPR spectrum of the LiYF 4:Yb 3+ crystal; up to 17 components with spacing of about 3.7 G may be traced. Some parameters of the effective Hamiltonian of the SHF interaction are estimated, the contribution of covalent bonding of f-electrons with ligands into these parameters is discussed. © 2008 Springer-Verlag

Superhyperfine structure of the EPR spectra of Ce3+ ions in LiRF4 (R = Y, Lu, Tm) double fluorides

The EPR spectra of Ce3+ impurity ions in LiYF4, LiLuF4, and LiTmF4 double-fluoride single crystals have been investigated at a frequency of ~9.3 GHz in the temperature range 5-25 K. The effective g factors of the ground Kramers doublet of the cerium ions in three crystals are close to each other (g{norm of matrix} = 2.737, g⊥ = 1.475 for LiYF4:Ce3+). A superhyperfine structure of the EPR spectrum of Ce3+ ions in the LiTmF4 Van Vleck paramagnet has been observed in the external magnetic field B oriented along the crystallographic axis c (B {norm of matrix} c). The superhyperfine structure of the EPR soectra of the Ce3+ ions in the LiYF4 and LiLuF4 diamagnetic matrices is resolved for B ⊥ c. Possible factors responsible for this pronounced difference in the properties of the systems studied have been discussed. © 2010 Pleiades Publishing, Ltd

Sequencing of a fragment of the leptin gene in adolescents with different weight status

Background. Obesity is a significant social problem among the population of the world. The leptin gene (LEP) is currently considered as a potential candidate gene influencing metabolic disorders associated with predisposition to overweight and obesity. Leptin plays an important role in body weight homeostasis by influencing food intake and energy expenditure and maintaining constant energy stores. A defect in the leptin gene may be one of the causes of obesity and, as a result, of various obesity-associated pathologies. The aim of the study. To search for single-nucleotide polymorphisms (SNP) of the leptin gene in adolescents with different weight status. Methods. The study involved 20  adolescents aged 11–17  years with normal body weight and  overweight/obesity. Research methods: assessment of clinical status with  anthropometry; Sanger sequencing of the leptin gene fragment localized in the  intron of this gene – (5’-AGCCTTGTTTTCATCATCTGGA, 3’-TGGGAGGAATCGCTCTCAGA). We also carried out bioinformatic processing of sequencing results. Results. As a result of the study, the optimal conditions for amplification of the 891 bps leptin gene region were selected for the above mentioned primer pair of the LEP gene (s16_L891, s16_R891). Based on the results of sequencing, 45 single nucleotide substitutions of the LEP gene were identified, including 23 single nucleotide substitutions which were not previously registered in GenBank. In the group of adolescents with overweight and obesity, 14 unregistered single nucleotide substitutions of the LEP gene and 13 registered SNPs were identified in the GenBank database. In the group of adolescents with normal body weight, these SNPs were not found

Borealization of the Arctic Ocean in Response to Anomalous Advection From Sub-Arctic Seas

An important yet still not well documented aspect of recent changes in the Arctic Ocean is associated with the advection of anomalous sub-Arctic Atlantic- and Pacific-origin waters and biota into the polar basins, a process which we refer to as borealization. Using a 37-year archive of observations (1981-2017) we demonstrate dramatically contrasting regional responses to atlantification (that part of borealization related to progression of anomalies from the Atlantic sector of sub-Arctic seas into the Arctic Ocean) and pacification (the counterpart of atlantification associated with influx of anomalous Pacific waters). Particularly, we show strong salinification of the upper Eurasian Basin since 2000, with attendant reductions in stratification, and potentially altered nutrient fluxes and primary production. These changes are closely related to upstream conditions. In contrast, pacification is strongly manifested in the Amerasian Basin by the anomalous influx of Pacific waters, creating conditions favorable for increased heat and freshwater content in the Beaufort Gyre halocline and expansion of Pacific species into the Arctic interior. Here, changes in the upper (overlying) layers are driven by local Arctic atmospheric processes resulting in stronger wind/ice/ocean coupling, increased convergence within the Beaufort Gyre, a thickening of the fresh surface layer, and a deepening of the nutricline and deep chlorophyll maximum. Thus, a divergent (Eurasian Basin) gyre responds altogether differently than does a convergent (Amerasian Basin) gyre to climate forcing. Available geochemical data indicate a general decrease in nutrient concentrations Arctic-wide, except in the northern portions of the Makarov and Amundsen Basins and northern Chukchi Sea and Canada Basin. Thus, changes in the circulation pathways of specific water masses, as well as the utilization of nutrients in upstream regions, may control the availability of nutrients in the Arctic Ocean. Model-based evaluation of the trajectory of the Arctic climate system into the future suggests that Arctic borealization will continue under scenarios of global warming. Results from this synthesis further our understanding of the Arctic Ocean\u27s complex and sometimes non-intuitive Arctic response to climate forcing by identifying new feedbacks in the atmosphere-ice-ocean system in which borealization plays a key role