1. Central Institute of Biomedical Engineering, Department of Biomaterials, ENSOMA-Laboratory, University of Ulm, 89081 Ulm, Germany
2. School of Dentistry, Department of Diagnostic and Therapeutic, Federal University of Bahia, Salvador, BA 40110-150, Brazil
3. Semmelweis University of Medicine, Department of Radiology and Oncotherapy, 1082 Budapest, Hungary
4. NASA-Marshall Space Flight Center, Huntsville, Alabama 35812