Funding for this research was provided by:
Bundesministerium für Bildung und Forschung (13GW0388A)
Text and Data Mining valid from 2019-08-05
Received: 17 January 2019
Accepted: 25 July 2019
First Online: 5 August 2019
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.