Doping effect on the evolution of the pairing symmetry in n-type superconductor near antiferromagnetic phase boundary

We present the investigation results of the in-plane \{rho}(T) resistivity tensor at the temperature range 0.4-40 K in magnetic fields up to 90kOe (H||c, J||ab) for electron-doped Nd{2-x}Ce{x}CuO{4+{\delta}} with different degree of disorder near antiferromagnetic - superconducting phase boundary. We have experimentally found that for optimally doped compound both the upper critical field slope and the critical temperature decrease with increasing of the disorder parameter (d-wave pairing) while in the case of the underdoped system the critical temperature remains constant and (dHc2/dT)|Tc increases with increasing of the disorder (s-wave pairing). These features suggest a possible implementation of the complex mixture state as the (s+id)-pairing.Comment: 9 pages, 2 figure

The estimation of coherence length for electron-doped superconductor Nd2−x_{2-x}Cex_xCuO4+δ_{4+\delta}

Results of low-temperature upper critical field measurements for Nd$_{2-x}$Ce$_x$CuO$_{4+\delta}$ single crystals with various $x$ and nonstoichiometric disorder ($\delta$) are presented. The coherence length of pair correlation $\xi$ and the product $k_F$$\xi$, where $k_F$ is the Fermi wave vector, are estimated. It is shown that for investigated single crystals parameter $k_F$$\xi$ $\cong$ 100 and thus phenomenologically NdCeCuO - system is in a range of Cooper-pair-based (BCS) superconductivity.Comment: 8 pages, 3 figures, 2 table

The role of stress in acute cardiovascular disease (review of literature)

Cardiovascular diseases are the leading cause of death worldwide. Acute and chronic stress that triggers a complex cascade of neurohumoraldisturbances, has an important role in the development of acute cardiovascular disease. Stress increases the risk of atherosclerosis and cardiovascular diseases due to increased levels of inflammatory cytokines on the background of persistent negative emotions. Stress is not only one of the most important reasons for the development of ischemic damage to the myocardium or brain tissue, but hypoxia, which is the main pathogenetic factor in ischemic brain tissue, especially of the structures of the limbic-reticular complex governing system homeostasis, run a stress indicator processes in the body that aggravate the course and outcome of acute cardiovascular disease. Knowledge of neurohumoral disturbances underlying these pathological processes that will enable it to adequately and woermann to make their correction in order to achieve the most favorable outcomes in acute cardiovascular disease.Сердечно-сосудистые заболевания являются основной причиной смерти во всем мире. Острый и хронический стресс, запускающий сложный каскад нейрогуморальных нарушений, имеет важную роль в развитии острой сердечно-сосудистой патологии. Стресс повышает риск развития атеросклероза и кардиоваскулярных заболеваний вследствие повышения уровня противовоспалительных цитокинов на фоне персистирующих негативных змоций. Стресс - зто не только одна из важнейших причин развития ишемического повреждения миокарда или мозговой ткани, но и сама гипоксия, являющаяся основным патогенетическим фактором развития ишемии мозговой ткани, а особенно структур лимбико-ретикулярного комплекса, определяющих систему гомеостаза организма, запускают стресс-индикаторные процессы в организме, усугубляющие течение и исход острой сердечно-сосудистой патологии. Знание нейрогуморальных нарушений, лежащих в основе зтих патологических процессов, позволят адекватно и своеременно осуществлять их коррекцию с целью достижения наиболее благоприятных исходов при острой сердечно-сосудистой патологии

Suppression of 2D superconductivity by the magnetic field: quantum corrections vs superconductor-insulator transition

Magnetotransport of superconducting Nd_{2-x}Ce_xCuO_{4+y} (NdCeCuO) films is studied in the temperature interval 0.3-30 K. The microscopic theory of the quantum corrections to conductivity, both in the Cooper and in the diffusion channels, qualitatively describes the main features of the experiment including the negative magnetoresistance in the high field limit. Comparison with the model of the field-induced superconductor-insulator transition (SIT) is included and a crossover between these two theoretical approaches is discussed.Comment: 5 pages, 4 figures. Submitted to JETP Letter

Resistivity tensor correlations in the mixed state of electron-doped superconductor Nd2-xCexCuO4+δ

The magnetic-field dependencies of the longitudinal and Hall resistance of the electron-doped compounds Nd2-xCexCuO4+δ in underdoped region with x = 0.14 and with varying degrees of disorder (δ) were investigated. It was established experimentally that the correlation between the longitudinal electrical resistivity and the Hall resistivity can be analyzed on the basis of scaling relationships: ρxy(B) ∼ [ρxx(B)]β. For the totality of the investigated single-crystal films of Nd2-xCexCuO4+δ/SrTiO3 the values of β from 0.8 to 1.55 is found. The observed feature in the electron-doped two-dimensional systems can be associated both with a displaying of anisotropic s - wave or d - wave pairing symmetry and with a pinning due to an essential degree of disorder in the samples under study. © 2016 Published by Elsevier B.V

The study of the structure of anxiety in athletes

Objective: to study the structure of disorders caused by anxiety in athletes. Materials and methods: the objects of the first task of the research were different terminological definitions and classifications of anxiety disorders. Comparative analysis of the definitions and concepts used in psychology, physiology, sports medicine, theory and methodology of physical education has been carried out. The second task was to determine the leading factors characterizing the psychological status of athletes, and to give them the descriptive characteristics. A factor analysis was conducted on the results of testing 79 athletes of combat sports (34 men, 45 women) using the M Luscher color test and the integrative anxiety test by AP Bizyuk, LI Wasserman, BV Iovlev. Results: Luscher's test scores (total deviation from the autogenous rate, mental performance, vegetative coefficient) explained only 14.5% of the total variance. Simultaneously, the indicator of situational anxiety from Luscher's test was not included in any factor. The informativeness of more detailed integrative anxiety test was significantly higher: its indicators were included in 3 factors, explaining totally 49.5% of the total variance, as well as in the general factor, which explains 33% of the total variance. Conclusions: the emotional component (emotions which cause situational anxiety) contributes largely to the total anxiety level, some smaller contribution accounts for the social components (fear of condemnation, dependence on the opinions of others), finally, the personal anxiety contributes to it even less