Text and Data Mining valid from 2018-11-02
Received: 9 August 2018
Accepted: 22 October 2018
First Online: 2 November 2018
Conflict of interest
: O.J. Ott, M. Schmidt, S. Semrau, V. Strnad, K.E. Matzel, I. Schneider, D. Raptis, W. Uter, R. Grützmann, and R. Fietkau declare that they have no competing interests. None of the authors has had relationship with an entity that has a financial interest in the subject matter discussed in this manuscript.