The immune system of athletes of different sports

Purpose : the comparative study of the immunity features of elite athletes of different sports. Material : study involved athletes of the highest mastery level of cyclic and acyclic sports (n = 147, age 18-23 years). Athletes were divided into groups by kinds of sport. Skiers (n = 54), swimmers (n = 23), wrestlers (n = 49), boxers (n = 21). Results : It was determined that athletes of acyclic sports (wrestlers and boxers) had a significant double increase in the level of secretory immunoglobulin IgA. In parallel, the level of immunoglobulins IgG is reduced. The highest indicators of lysosomal activity were recorded in skiers. Boxers, wrestlers, and swimmers had a decrease in the lysosomal activity level. The maximum phagocytic number is determined in wrestlers, and the minimum - in boxers. Conclusions : Comparative study of the immunity features of elite athletes in various sports suggests that there is a strain on the immune status. This condition is especially expressed in acyclic sports athletes (wrestling, boxing). This is due to the loads in the preparation process. The data received allow to confirm the significance of immune protection indicators in monitoring the athletes functional status

Photodynamic Processes in Fluoride Crystals Doped with Ce

Integrated studies of photoelectric phenomena and their associated photodynamic processes in LiCaAlF6, LiLuF4, LiYF4, LiY0,5Lu0,5F4, SrAlF5 crystals doped with Ce3+ ions have been carried out using the combination of the methods of optical and dielectric spectroscopy. The numerical values of the basic parameters of photodynamic processes and their spectral dependence in 240 – 310 nm spectral range are evaluated. It has been shown that the most probable process, which leads to the photoionization of Ce3+ ions in LiYxLu1-xF4:Ce3+ (x=0; 0,5; 1) and LiCaAlF6:Ce3+ crystals, is excited-state absorption to the states of mixed configurations of Ce3+ ions localized near/in the conduction band of crystal

Photodynamic Processes in Fluoride Crystals Doped with Ce3+

Integrated studies of photoelectric phenomena and their associated photodynamic processes in LiCaAlF6, LiLuF4, LiYF4, LiY0,5Lu0,5F4, SrAlF5 crystals doped with Ce3+ ions have been carried out using the combination of the methods of optical and dielectric spectroscopy. The numerical values of the basic parameters of photodynamic processes and their spectral dependence in 240 – 310 nm spectral range are evaluated. It has been shown that the most probable process, which leads to the photoionization of Ce3+ ions in LiYxLu1-xF4:Ce3+ (x=0; 0,5; 1) and LiCaAlF6:Ce3+ crystals, is excited-state absorption to the states of mixed configurations of Ce3+ ions localized near/in the conduction band of crystal

LiY0.3Lu0.7F4: Ce3+,Pr3+ Mixed Crystal as a Perspective Up-Conversionally Pumped UV Active Medium

Investigation results of effective population of states of 5d-configuration of Ce3+ ions by energy transfer from Pr3+ ions in LiY0.3Lu0.7F4 (LYLF) crystals are discussed. The real concentrations of Pr3+ and Ce3+ ions in LYLF crystals are determined. Such parameters as excited 4f-5d state photoionization cross-section of Pr3+ ions, ground state cross-section of Ce3+ ions at 266 nm wavelengths and energy transfer coefficients of energy transfer from Pr3+ to Ce3+ ions were estimated. The results of pump-probe experiments on 5d-4f transitions of Ce3+ ions in LYLF crystals are presented. The optimal parameters for getting maximal gain on 5d-4f transitions of Ce3+ ions were determined by mathematical modeling

Spatial anomalies in spectral-kinetic properties of Pr³⁺ - Doped LiY<inf>1-x</inf>Lu<inf>x</inf>F<inf>4</inf> mixed crystals

© 2020 We present the spectral-kinetic including excited state absorption spatial-dependent features of Pr3+ - doped LiY1-xLuxF4 mixed crystals grown by Bridgeman technique

LiY

Investigation results of effective population of states of 5d-configuration of Ce3+ ions by energy transfer from Pr3+ ions in LiY0.3Lu0.7F4 (LYLF) crystals are discussed. The real concentrations of Pr3+ and Ce3+ ions in LYLF crystals are determined. Such parameters as excited 4f-5d state photoionization cross-section of Pr3+ ions, ground state cross-section of Ce3+ ions at 266 nm wavelengths and energy transfer coefficients of energy transfer from Pr3+ to Ce3+ ions were estimated. The results of pump-probe experiments on 5d-4f transitions of Ce3+ ions in LYLF crystals are presented. The optimal parameters for getting maximal gain on 5d-4f transitions of Ce3+ ions were determined by mathematical modeling

Electromagnetically induced transparency in a mono-isotopic ¹⁶⁷Er:⁷LiYF<inf>4</inf>crystal below 1 Kelvin: Microwave photonics approach

© 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement. Electromagnetically induced transparency allows for the controllable change of absorption properties, which can be exploited in a number of applications including optical quantum memory. In this paper, we present a study of the electromagnetically induced transparency in a 167Er:7LiYF4 crystal at low magnetic fields and ultra-low temperatures. The experimental measurement scheme employs an optical vector network analysis that provides high precision measurement of amplitude, phase and group delay and paves the way towards full on-chip integration of optical quantum memory setups. We found that sub-Kelvin temperatures are the necessary requirement for observing electromagnetically induced transparency in this crystal at low fields. A good agreement between theory and experiment is achieved by taking into account the phonon bottleneck effect

OVNA-measured coherence in erbium doped Y<inf>2</inf>SiO<inf>5</inf> and LiYF<inf>4</inf> crystals at sub-Kelvin temperatures

© 2020 Author(s). The optical vector network analysis technique is a handful technique in analysis of optical networks. We here discuss application of the optical vector network analysis for the coherence studies in atomic ensembles

Spectral and magnetic properties of impurity Tm3+ ions in YF3

Stark structure of 3H6, 3H5, 3H4, 3F4, 3F3, 3F2 and 1G4 multiplets of impurity non-Kramers Tm3+ ions in the orthorhombic YF3 crystal has been determined from luminescence studies. High frequency electron paramagnetic resonance (EPR) spectra (~ 207 GHz) of Tm3+ ions have been measured at temperature 4.2 K in external magnetic field applied perpendicular to the b-axis of YF3:Tm3+ single crystal. The results of measurements are interpreted in the frameworks of the crystal field theory. The set of crystal field parameters related to the crystallographic system of coordinates of the YF3 lattice has been obtained and used to reproduce satisfactory the crystal field energies and the EPR spectra

Spectral-Kinetic Properties and Energy Transfer in Nanoparticles of Y<inf>0.5–x</inf>Ce<inf>0.5</inf>Tb<inf> x</inf>F<inf>3</inf> Solid Solution

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Crystalline nanoparticles of Y0.5–xCe0.5TbxF3, doped with various concentrations (x = 0, 0.005, 0.01, 0.05, 0.1, 0.15, and 0.2) of Tb3+ ions were synthesized by co-precipitation. The crystal structure and chemical composition of nanoparticles were studied using transmission electron microscopy, scanning electron microscopy, and X-ray diffractometry. The obtained nanoparticles of solid solutions had an elliptical shape with a size of 10–15 nm along the long axis and good crystallinity with the structure of a CeF3 crystal. The spectral-kinetic properties of the obtained nanoparticles, and the effect of the concentration of Tb3+ activator ions on the energy transfer from Ce3+ to Tb3+ ions were investigated. Energy transfer from Ce3+ to Tb3+ ions in nanocrystals of the Y0.5–xCe0.5TbxF3 solid solutions occurs mainly through the dipole–dipole interaction. The results of evaluating the efficiency of energy transfer from Ce3+ to Tb3+ ions show its increase with increasing concentration of Tb3+ ions