1. Institute of Biomaterials, Department of Materials Science and Engineering; University of Erlangen-Nuremberg; 91058 Erlangen Germany
2. Institute for Technical Chemistry, Leibniz University; Hanover Germany
3. FEI Visualization Sciences Group; Wernigeroder Str. 129 D-40595 Duesseldorf Germany
4. GE Sensing & Inspection Technologies GmbH; Niels-Bohr-Straße 7 31515 Wunstorf Germany
5. Department of Biotechnology; University of Natural Resources and Life Science; Vienna Austria