Funding for this research was provided by:
Bundesministerium für Bildung und Forschung (031B0195)
Text and Data Mining valid from 2019-03-15
Received: 21 September 2018
Accepted: 11 March 2019
First Online: 15 March 2019
Compliance with ethical standards
: All authors declare that they have no conflict of interest.
: The experiments reported in this study comply with the current laws of Germany.