Funding for this research was provided by:
Deutsche Forschungsgemeinschaft (NI 1591/1-1, IN-1150438)
Received: 28 November 2018
Accepted: 5 February 2019
First Online: 3 March 2019
Ethics approval and consent to participate
: Ethics approval for this study was granted by the Medical Ethics Committee II of the medical faculty Mannheim at Heidelberg University (protocol no. 2013-654 N-MA). All participants provided written, informed consent prior to participation.
: Not applicable.
: The authors declare that they have no competing interests.
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