1. Institute for X-Ray Physics, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
2. European Synchrotron Radiation Facility, 38000 Grenoble, France
3. Department of Analytical Chemistry, Ghent University, B-9000 Ghent, Belgium
4. German Cancer Research Centre, 69121 Heidelberg, Germany
5. Institute of Neuropathology, University Hospital Erlangen, 91054 Erlangen, Germany