1. Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
2. Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland
3. Ophthalmology, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 8, FI-00290 Helsinki, Finland
4. The European Synchrotron Radiation Facility - ESRF, 71 Avenue des Martyrs, CS 40220, Grenoble Cedex 9 38043, France
5. Synchrotron SOLEIL, L’Orme des Merisiers, Départementale 128, 91190 Saint-Aubin, France