Received: 2 July 2018
Accepted: 5 October 2018
First Online: 19 October 2018
Ethics approval and consent to participate
: The study protocol for the current study was conducted according to the principles of the Declaration of Helsinki and was approved by the local Ethics Committee of the Medical Faculty of the University of Giessen (AZ 79/14). All participants provided informed written consent.
: Not applicable
: All authors declare that they have no competing interests.
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