Growth peculiarities and non-linear properties of profiled doped strontium-barium niobate crystals

The nominally pure and doped with Ce, Cr, Co strontium-barium niobate crystals of SBN:61 were grown by modified Stepanov technique. The specific features of the technique were studied and growth conditions for obtaining the high homogeneous SBN crystals in bulk-profiled configuration were optimized. The photorefractive and non-linear properties of SBN pure and doped with Ce, Cr and Co were investigated. It was shown that SBN:Ce crystal is an excellent medium for high efficiency holographic information recording. SBN:Cr and SBN:Co crystals are promising photorefractive materials with short response time. The as-grown SBN crystals were also used to demonstrate the diffuse noncollinear second harmonic generation emitted by a random domain SBN structure and Stimulated Raman Scattering and two-photon absorption associated with cubic nonlinear susceptibility of the materials

Temperature Effect on the Stability of the Polarized State Created by Local Electric Fields in Strontium Barium Niobate Single Crystals

The stability of ferroelectric domain patterns at the nanoscale has been a topic of much interest for many years. We investigated the relaxation of the polarized state created by application of a local electric field using a conductive tip of a scanning probe microscope for the model uniaxial relaxor system SrxBa1−xNb2O6 (SBN) in its pure and Ce-doped form. The temporal relaxation of the induced PFM contrast was measured at various temperatures. The average value of the induced contrast decreases during heating for all investigated crystals. Below the freezing temperature the induced state remains stable after an initial relaxation. Above the freezing temperature the induced state is unstable and gradually decays with time. The stability of the induced state is strongly affected by the measuring conditions, so continuous scanning results in a faster decay of the poled domain. The obtained effects are attributed to a decrease of the induced polarization and backswitching of the polarized area under the action of the depolarization field

Annealing-Induced Structural Behavior of Mn Dopant Ions in Calcium Orthovanadate Ca3(VO4)2Single Crystals

The crystal and local structures of Czochralski-grown calcium orthovanadate (Ca3(VO4)2) single crystals doped with over-stoichiometric 0.05 wt % Mn2O3 (CVO:0.05Mn) and annealed under different conditions are studied by single-crystal conventional and synchrotron X-ray diffraction, X-ray absorption spectroscopy, and electron paramagnetic resonance for the first time. Bottom (annealing in air) and top (annealing in air and in vacuum) parts of the CVO:0.05Mn crystal differ in the manganese content (higher in the bottom part), formal charge (Mn4+ and Mn(3+)+, respectively), and color (orange bottom part; light orange and yellow top parts annealed in air and vacuum, respectively). Manganese ions are located in one (Ca3, distorted two-capped trigonal prism) of five crystallographic Ca sites and have octahedral coordination, which is consistent with crystal-chemical properties of transition-metal ions. The presence of vacancies in one of three V sites is revealed. Formal charge 5+ for vanadium ions is confirmed by X-ray photoelectron spectroscopy. Different colors of CVO:Mn crystals and different formal charges of manganese are explained depending on the growth and post-growth treatment conditions. © 2022 American Chemical Society

Hypolipidemic effect and leskol tolerance in hypertensive patients with hypercholesterolemia: Results of multicenter trial

Hypertensive patients with hyperlipidemia are at high risk to develop coronary heart disease (CHD). Chemotherapeutic correction of hyperlipidemia seems most reliable modality to prevent CHD. Hypolipidemic effect and tolerance of leskol (fluvastatin) in dietotherapy-resistant hypercholesterolemia were studied in 74 patients with essential hypertension treated with hypotensive drugs. The patients were included in a multicenter trial. A 12-week course reduced total cholesterol level under 6.2 mmol/l in 59% of the patients, under 5.2 mmol/l in 29% of them. LDLP cholesterol lowered to 3.5% in 34% of the patients. Mean apo B diminished by 23%. There was a 27% decrease in the proportion of atherogenic fraction apo B to antiatherogenic fraction of transport proteins apo A-I. Leskol is well tolerated and effective against hypercholesterolemia, it is safe in relation to side effects and blood biochemistry

HYPOLIPIDEMIC EFFECT AND LESKOL TOLERANCE IN HYPERTENSIVE PATIENTS WITH HYPERCHOLESTEROLEMIA - RESULTS OF MULTICENTER TRIAL

Hypertensive patients with hyperlipidemia are at high risk to develop coronary heart disease (CHD). Chemotherapeutic correction of hyperlipidemia seems most reliable modality to prevent CHD. Hypolipidemic effect and tolerance of leskol (fluvastatin) in dietotherapy-resistant hypercholesterolemia were studied in 74 patients with essential hypertension treated with hypotensive drugs. The patients were included in a multicenter trial. A 12-week course reduced total cholesterol level under 6.2 mmol/l in 59% of the patients, under 5.2 mmol/l in 29% of them. LDLP cholesterol lowered to 3.5% in 34% of the patients. Mean apo B diminished by 23%. There was a 27% decrease in the proportion of atherogenic fraction apo B to antiatherogenic fraction to transport proteins apo A-I. Leskol is well tolerated and effective against hypercholesterolemia, it is safe in relation to side effects and blood biochemistry

HYPOLIPIDEMIC EFFECT AND LESKOL TOLERANCE IN HYPERTENSIVE PATIENTS WITH HYPERCHOLESTEROLEMIA - RESULTS OF MULTICENTER TRIAL

Hypertensive patients with hyperlipidemia are at high risk to develop coronary heart disease (CHD). Chemotherapeutic correction of hyperlipidemia seems most reliable modality to prevent CHD. Hypolipidemic effect and tolerance of leskol (fluvastatin) in dietotherapy-resistant hypercholesterolemia were studied in 74 patients with essential hypertension treated with hypotensive drugs. The patients were included in a multicenter trial. A 12-week course reduced total cholesterol level under 6.2 mmol/l in 59% of the patients, under 5.2 mmol/l in 29% of them. LDLP cholesterol lowered to 3.5% in 34% of the patients. Mean apo B diminished by 23%. There was a 27% decrease in the proportion of atherogenic fraction apo B to antiatherogenic fraction to transport proteins apo A-I. Leskol is well tolerated and effective against hypercholesterolemia, it is safe in relation to side effects and blood biochemistry