Article History
Received: 26 February 2018
Accepted: 31 July 2018
First Online: 9 August 2018
Ethics approval and consent to participate
: The study followed the 1964 Declaration of Helsinki on medical protocol and ethics. Ethical approval was maintained from the local ethical committee (ethics committee of Rhineland-Palatinate, no.837.067.09 (6572)).
: This manuscript contains no individual personal data.
: The authors declare that they have no competing interests.
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