Funding for this research was provided by:
Bundesministerium für Bildung und Forschung (03VP0085)
Text and Data Mining valid from 2018-10-06
Received: 10 January 2018
Accepted: 28 September 2018
First Online: 6 October 2018
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: Informed consent was obtained from all individual participants included in the study.