Text and Data Mining valid from 2018-03-27
Received: 23 June 2017
Accepted: 7 March 2018
First Online: 27 March 2018
Ethics approval and consent to participate
: Ethical approval for this study [Ethical Committee N° 837.519.11 (8061)] was provided on 3rd January 2012 by the Regional Ethics Committee of Rhineland-Palatinate, Mainz, Germany. All participants gave informed consent.
: Not applicable.
: The authors declare that they have no competing interests.
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