Funding for this research was provided by:
Russian Foundation for Basic Research
Russian Scientific Fund (Presidential Grant)
Tomsk Polytechnic University (Competitiveness Enhancement Program grantCome)
Text and Data Mining valid from 2018-07-20
Received: 22 November 2017
Accepted: 4 July 2018
First Online: 20 July 2018
Ethics approval and consent to participate
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Written informed consent was obtained from all participants for being included in the study. Written consent for participation in the study has been signed and submitted by two independent experts. The study was approved by the ethics commission of the committee of healthcare of Saint-Petersburg, Russia.
: Not applicable
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.