Anisotropic creep and damage in structural elements under cyclic loading

A method is described to calculate creep and damage in structural elements under cyclic loading. Materials exhibiting anisotropic creep-damage behavior are considered. The results of calculating the deformation and fracture of structural elements at a plane stress state are presented

LACK OF INNOVATION PROBLEM IN TEACHING ACTIVITIES

This article examines the attitude of teachers towards innovations in education, as well as the teacher's readiness to participate in the innovative educational process. The teacher's ability to determine the prospects for his professional development in the light of innovative processes in education is crucial in the formation of a modern education system

The predictive value of various indicators of sperm for male fertility

Introduction. DNA fragmentation of sperm is one of the possible causes of reduced fertility potential of men. However, a significant correlation between conventional semen parameters and sperm DNA fragmentation was not found. This fact determines the relevance of the study of the influence of various parameters of sperm on male fertility.Materials and methods. The study included 60 men, aged 26–36 years (median – 30 years) with idiopathic infertility and the level of DNA fragmentation of sperm is higher than 15 %. These men were treated with hyperbaric oxygen therapy, after 3 months in vitro fertilization performed partners of these men. DNA fragmentation of sperm cells was determined by TUNEL (upper limit of normal – 15 %). The level of reactive oxygen species (ROS) of the ejaculate were determined by chemiluminescence (upper limit of normal – 0.64 mV/s).Results. The frequency of pregnancy in vitro fertilization was following: 62.8 and 64.7 % (p > 0.05) for the total number sperm of spermatozoa < 38 × 106 /ejaculate and ≥ 39 × 106 /ejaculate, respectively; 63.3 and 63.6 % (p > 0.05) for mobility (a + b) of spermatozoa < 40 and ≥ 40 %, respectively; 58.3 and 64.6 % (p > 0.05) for normal forms of spermatozoa < 4 and ≥ 4 %, respectively; 67.3 and 20.0 % (p < 0.05) for the level of DNA fragmentation of sperm ≤ 15 and > 15 %, respectively; 64.9 and 33.3 % (p < 0.05) for the level of ROS in semen ≤ 0.64 and > 0.64 mV/s, respectively.Conclusion. The probability of pregnancy after in vitro fertilization significantly depends on the levels of sperm DNA fragmentation in the sperm and level of ROS in semen

Modified Oligonucleotides: New Structures, New Properties, and New Spheres of Application

Abstract: Nucleic acids have made a long and arduous journey “from the bench to the bedside.” At present, it can be assumed that drugs based on modified oligonucleotides will find a worthy application in personalized medicine of the future