Text and Data Mining valid from 2018-03-29
Received: 26 December 2017
Accepted: 28 March 2018
First Online: 29 March 2018
Compliance with ethical standards
: All authors declare no conflict of interest and no financial relationship to disclose.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.