1. Leibniz- IFW Dresden; Dresden P.O. Box 270116, Dresden D-01171 Germany
2. TU Dresden; Institute of Materials Science; Dresden D-01062 Germany
3. TU Dresden; Institute of Physiological Chemistry, Carl Gustav Carus Faculty of Medicine; Fiedlerstrasse 42 Dresden D-01307 Germany
4. Justus-Liebig-Universitä Gießen; Department of Veterinary-Anatomy; -Histology and -Embryology; Justus-Liebig-University; Frankfurter Str. 98 Gießen D-35392 Germany