Text and Data Mining valid from 2018-04-18
Received: 10 January 2018
Accepted: 12 April 2018
First Online: 18 April 2018
Ethics approval and consent to participate
: This study was approved by the local Institutional Review Board (Ethics Committee of the Ruhr-Universität Bochum, Germany; registration number 15–5280). All participants agreed to participate in the study. A written informed consent was obtained from all participants.
: The authors declare that they have no competing interests.
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