Article History
Received: 7 November 2019
Accepted: 4 May 2020
First Online: 16 May 2020
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: The investigations were approved by the ethics committee of the Medical Faculty, Heidelberg University (Nr. S-366/2015). Written informed consent was obtained from all participants in accordance with the 1964 Declaration of Helsinki and its later amendments after the procedures of the study had been fully explained.