Ebel, A. [P:(DE-HGF)0] ; Memmesheimer, M. [P:(DE-HGF)0] ; Wurzler, S. [P:(DE-HGF)0] ; Dorn, H.-P. [P:(DE-Juel1)16317] ; Friese, E. [P:(DE-HGF)0] ; Jakobs, H. J. [P:(DE-HGF)0]