Text and Data Mining valid from 2018-03-26
Received: 20 November 2017
Accepted: 18 March 2018
First Online: 26 March 2018
Compliance with Ethical Standards
: The authors declare that there are no conflicts of interests.
: The authors declare that 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.
: The authors declare that informed consent was obtained from all individual participants included in the study.