1. Paul Scherrer Institut 5232 Villigen PSI Switzerland
2. Inst. f. Chemie- u. Bioingenieurwissenschaften ETH Zürich 8092 Zürich Switzerland
3. European Synchrotron Radiation Facility 38000 Grenoble France
4. Institute for Biomedical Engineering ETH Zürich, and University of Zürich 8093 Zürich Switzerland
5. Shell Technology Centre Amsterdam 1031HW Amsterdam The Netherlands
6. Institut Néel CNRS UPR2940 38042 Grenoble France