Protective Cr Coatings with ZrO2/Cr Multilayers for Zirconium Fuel Claddings

This article described the protective properties of Cr coatings with a barrier layer composed of ZrO2/Cr multilayers deposited onto E110 zirconium alloy. The coatings with a ZrO2/Cr multilayer thickness of 100, 250, and 750 nm and single-layer (1.5 µm) ZrO2 barrier were obtained by multi-cathode magnetron sputtering in Ar + O2 atmosphere. Then, cracking resistance and oxidation behavior were studied under conditions of thermal cycling (1000 °C) in air and high-temperature oxidation at 1200-1400 °C in a water steam. The role of the ZrO2/Cr multilayers and multilayer thickness on cracking resistance of the experimental coatings and oxidation resistance of the coated E110 alloy was discussed. It was shown that the coatings with more quantity of the ZrO2/Cr multilayers have higher cracking resistance, but such types of samples have a large amount of coating spallation under thermal cycling. The high-temperature steam oxidation (1200-1400 °C) demonstrated that interfaces of the ZrO2/Cr multilayers can act as a source of cavities formed by the Kirkendall mechanism that results in accelerating Cr-Zr interdiffusion for Cr-coated E110 alloy

Correlation of the zinc level in the spermoplasm with the fertility characteristics of human ejaculate

Background: Zinc is essential for the normal functioning of the male reproductive system. The data on the diagnostic value of the zinc level in the human spermoplasm and its relationship with the main parameters of the sperm fertility are contradictory. Aim: study of the correlations between the zinc level in the spermoplasm and the spermogram characteristics. Methods: The sperm of men of the reproductive age (n=486, average age 33.073.03 years) was studied. In addition to the standard spermogram, MAR tests (IgA, IgG and IgM) were performed in the sperm samples, the degree of fragmentation of the sperm DNA, the sperm interaction with hyaluronic acid, the acrosine activity, and the neutral alpha-glucosidase activity were assessed, the citric acid, fructose and glycodelin levels were determined, and the level of reactive oxygen species was studied. The zinc level determination in the spermoplasm was carried out by a standard spectrophotometric method with 5-Br-PAPS chromogen. The Pearson's formula was used for the correlation analysis. The study was conducted from 2018 to May 2022, once. Results: A significant negative correlation of the zinc level in the spermoplasm with the age of men was revealed (r=-0.16; p 0.001). The level of zinc in the spermoplasm weakly negatively correlated with the dilution time and with the viscosity of the sperm. The positive correlation was found with the number of spermatozoa (r=0.13; p 0.01) and their mobility (r=0.38; p 0.00001). The level of zinc in the spermoplasm negatively correlated with the degree of the sperm DNA fragmentation and with the amount of reactive oxygen species, and positively correlated with the results of the test for binding to hyaluronic acid. Conclusions: The level of zinc in the spermoplasm significantly correlates with a number of physiological and biochemical characteristics of the sperm. The data obtained allow us to recommend determination of the zinc level in the sperm plasma to not only assess the functional activity of the prostate gland, but also to diagnose the fertility of the ejaculate, as well as to optimize the therapy with zinc-containing drugs and improve the control over the effectiveness of the treatment