Funding for this research was provided by:
Deutsche Forschungsgemeinschaft (KFO 256, BO 1487/11–1.)
Text and Data Mining valid from 2019-11-15
Received: 23 August 2019
Accepted: 23 October 2019
First Online: 15 November 2019
Ethics approval and consent to participate
: The study was conducted in accordance with the Declaration of Helsinki, and was approved by the Research Ethics Board of the University of Heidelberg. Subjects provided written informed consent prior to study participation.
: Not applicable.
: The authors declare that they have no competing interests.