Funding for this research was provided by:
Deutsche Forschungsgemeinschaft (SE 494/7-1, SA 735/18-1)
Text and Data Mining valid from 2019-04-01
Received: 24 October 2018
Accepted: 26 March 2019
First Online: 1 April 2019
Compliance with ethical standards
: All authors report to have no biomedical or financial interest or potential conflict of interest.
: The Ethics Committees of the Universities of Wuppertal and Düsseldorf approved the study. The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committees on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008.