Prognostic criteria of heart rate variability at the daily monitoring

The data of comparative researches of parameters of heart rate variability on the basis of daily ECG registration with regard circadian oscillations of heart rate. Shown significant reduction in both temporary and spectral indices of daily variability of a heart rhythm in adolescents with scoliosis without significant imbalance parasympathetic and sympathetic departments of ANS. These changes indicate violations of interaction between different parts of ANS in providing functionality driving rhythm and demonstrated reduction of adaptational possibilities of the organism, which leads to a heightened risk of violations of the regulation of the heart rate in this group of adolescentsПриведены данные сравнительного исследования показателей вариабельности сердечного ритма на основе суточной регистрации ЭКГ с учетом циркадных колебаний ритма сердца. Показано достоверное снижение как временных, так и спектральных показателей суточной вариабельности сердечного ритма у подростков со сколиозом без выраженного дисбаланса парасимпатического и симпатического отделов ВНС. Данные изменения указывают на нарушения взаимодействия между различными звеньями ВНС в обеспечении функции вождения ритма и свидетельствуют о снижении адаптационных возможностей организма, что ведет к повышенному риску развития нарушений регуляции сердечного ритма в данной группе подростко

Kinetics of solid-state oxidation of iron, copper and zinc sulfide mixture

The kinetics of solid-state oxidation by air of iron, copper and zinc sulfide natural mixture, which is typical of the pyritic copper ores, is investigated. Using the high-temperature X-ray powder diffraction, thermogravimetry and differential scanning calorimetry, it was found that the process can be represented by five exothermic elementary reactions, corresponding to intensive burning of iron, copper and zinc sulfides, and two endothermic ones, associated with decomposition of copper and iron sulfates. Kinetic analysis is performed by Kissinger and Augis–Bennett methods, the model-free function mechanism was determined from y(α) master plots and iterative optimization of the kinetic parameters. The limiting steps of these reactions are nucleation and crystal growth, and the values of activation energy, pre-exponential factor and Avrami exponent are in the ranges of 140–459 kJ·mol–1, 1.41·104–3.49·1031 s–1, and 1.0–1.7, respectively. Crystallization is followed by an increase in the number of nuclei, which may be formed both at the interface and in the bulk of the ore particles, and crystal growth is one-dimensional and controlled by a chemical reaction at the phase boundary or diffusion. The results of the work can contribute to the development of theoretical ideas about the physicochemical transformations of pyritic ores and concentrates during pyrometallurgical operations

Stationary waves in a superfluid exciton gas in quantum Hall bilayers

Stationary waves in a superfluid magnetoexciton gas in nu = 1 quantum Hall bilayers are considered. The waves are induced by counter-propagating electrical currents that flow in a system with a point obstacle. It is shown that stationary waves can emerge only in imbalanced bilayers in a certain diapason of currents. It is found that the stationary wave pattern is modified qualitatively under a variation of the ratio of the interlayer distance to the magnetic length d/l. The advantages of use graphene-dielectric-graphene sandwiches for the observation of stationary waves are discussed. We determine the range of parameters (the dielectric constant of the layer that separates two graphene layers and the ratio d/l) for which the state with superfluid magnetoexcitons can be realized in such sandwiches. Typical stationary wave patterns are presented as density plotsComment: 17 pages, 8 figure

Crystal Undulator As A Novel Compact Source Of Radiation

A crystalline undulator (CU) with periodically deformed crystallographic planes is capable of deflecting charged particles with the same strength as an equivalent magnetic field of 1000 T and could provide quite a short period L in the sub-millimeter range. We present an idea for creation of a CU and report its first realization. One face of a silicon crystal was given periodic micro-scratches (grooves), with a period of 1 mm, by means of a diamond blade. The X-ray tests of the crystal deformation have shown that a sinusoidal-like shape of crystalline planes goes through the bulk of the crystal. This opens up the possibility for experiments with high-energy particles channeled in CU, a novel compact source of radiation. The first experiment on photon emission in CU has been started at LNF with 800 MeV positrons aiming to produce 50 keV undulator photons.Comment: Presented at PAC 2003 (Portland, May 12-16

Nuclear Track Emulsion in Search for the Hoyle’s State in Dissociation of Relativistic 12C Nuclei

Study of production of ensembles of alpha-particle triples associated with the Hoyle state (the second excited state 0+ 2 of the 12 C nucleus) in peripheral dissociation of relativistic 12C nuclei is started. Stacks of pellicles of nuclear track emulsion exposed to 12C of energy from hundreds MeV to few GeV per nucleon serve as the material of the study. The Hoyle state decays are reconstructed via measurements of emission angles of α-particles with accuracy that allows one to identify the unstable 8Be nucleus. A role in the Hoyle state of alpha-particle bonds corresponding to 8Be is determined

Polymorphisms in the MTHFR and MTR genes and the risk of varicose veins in ethnical Russians

© 2016 Informa UK Limited, trading as Taylor & Francis GroupObjectives: The objective of this study was to study the association of polymorphisms MTHFR C677T (rs1801133) and MTR A2756G (rs1805087) with the risk of varicose veins in ethnical Russians. Methods: We genotyped 475 patients with varicose veins, 168 individual without chronic venous disease, and the population-based group of 896 subjects. Association was studied using logistic regression analysis adopting co-dominant, additive, recessive, and dominant models of inheritance. Results: None of the polymorphisms showed a statistically significant association with the risk of varicose veins. Conclusions: Our results provide evidence that the studied polymorphisms do not contribute to genetic susceptibility to varicose veins in ethnical Russians

Polymorphisms in the MTHFR and MTR genes and the risk of varicose veins in ethnical Russians

© 2016 Informa UK Limited, trading as Taylor & Francis Group.Objectives: The objective of this study was to study the association of polymorphisms MTHFR C677T (rs1801133) and MTR A2756G (rs1805087) with the risk of varicose veins in ethnical Russians. Methods: We genotyped 475 patients with varicose veins, 168 individual without chronic venous disease, and the population-based group of 896 subjects. Association was studied using logistic regression analysis adopting co-dominant, additive, recessive, and dominant models of inheritance. Results: None of the polymorphisms showed a statistically significant association with the risk of varicose veins. Conclusions: Our results provide evidence that the studied polymorphisms do not contribute to genetic susceptibility to varicose veins in ethnical Russians