Funding for this research was provided by:
Deutsche Forschungsgemeinschaft (HE 2660/14-1, HE 2660/12-2, BE 5292/2-1, BE 5292/3-2)
Received: 29 July 2020
Accepted: 25 November 2020
First Online: 4 January 2021
Ethics approval and consent to participate
: The study was conducted in accordance with the ethical principles of the Declaration of Helsinki and approved by the Ethics Committee of the Medical Faculty of the University of Heidelberg. All participants gave written informed consent to participate in the study.
: Not applicable.
: The authors declare that they have no competing interests.