Text and Data Mining valid from 2018-10-03
Accepted: 24 September 2018
First Online: 3 October 2018
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: The study was approved by the Ethics Committee of the University of Leipzig. All procedures were in accordance with the ethical standards of the national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all participants.