Akgün, Doruk
Müller, Michael
Perka, Carsten
Winkler, Tobias
Article History
Received: 24 October 2018
Accepted: 6 March 2019
First Online: 13 March 2019
Ethics approval and consent to participate
: The study protocol was reviewed and approved by the ethics committee Charite Universitätsmedizin (EA4/040/14). No consent to participate was needed.
: Not applicable
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.