Funding for this research was provided by:
Russian State assignment in the area of scientific activities (19.9777.2017/8.9)
Text and Data Mining valid from 2018-07-06
Received: 19 December 2017
Accepted: 3 July 2018
First Online: 6 July 2018
Compliance with Ethical Standards
: The authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards approved by the Local Ethics Committee of the Kazan State Medical University (6.21.06.18) and with the 1964 Helsinki declaration and its later amendments.
: Informed consent was obtained from all individual participants included in the study.