Funding for this research was provided by:
No external funding (none)
Text and Data Mining valid from 2019-04-23
Received: 12 September 2018
Accepted: 12 April 2019
First Online: 23 April 2019
Ethics approval and consent to participate
: The study protocol was approved by the ethics committee of the Medical Faculty of the Technical University of Munich (reference number 450/15 s). All participants gave written consent to participate in the study.
: Not applicable.
: The authors declare that they have no competing interests.
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