Funding for this research was provided by:
Received: 17 March 2020
Accepted: 17 June 2020
First Online: 29 June 2020
Ethics approval and consent to participate
: This study was approved by the ethics committee of Rhineland-Palatinate, Germany.Written informed consent was obtained from all participants. All procedures performed in this study were in accordance with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Not applicable.
: All authors declare no competing interests.