Funding for this research was provided by:
Deutsche Forschungsgemeinschaft (WE 4682/4-1)
Received: 22 May 2018
Accepted: 22 August 2018
First Online: 26 September 2018
Ethics approval and consent to participate
: Ethics approval was obtained from Ethics Committee of the Faculty of Medicine, Ludwig-Maximilians-University Munich (Nr 773-15). All participants provided written consent.
: Not applicable
: The authors declare that they have no competing interests.
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