Text and Data Mining valid from 2020-02-12
Received: 2 September 2019
Accepted: 27 January 2020
First Online: 12 February 2020
Ethics approval and consent to participate
: This study was approved by the local ethics committee of the University Medical Center in Ulm. Written informed consent was obtained from all participants.
: All participants gave written informed consent for publication.
: The authors declare that they have no competing interests