Schirmer, M
Trentin, L
Queudeville, M
Seyfried, F
Demir, S
Tausch, E
Stilgenbauer, S
Eckhoff, S M
Meyer, L H
Debatin, K-M
Article History
Received: 22 July 2015
Revised: 24 November 2015
Accepted: 26 November 2015
First Online: 14 January 2016
Competing interests
: The authors declare no conflict of interest.