Funding for this research was provided by:
Deutsche Forschungsgemeinschaft (DFG HU 411/18-1)
Text and Data Mining valid from 2018-08-14
Received: 30 May 2018
Revised: 24 July 2018
Accepted: 6 August 2018
First Online: 14 August 2018
Compliance with ethical standards
: None of the authors has a potential conflict of interest.
: The study design was approved by the local Ethics Committee.