1. CERM, and Department of Chemistry
“U. Schiff”, University of Florence, Sesto Fiorentino, Italy
2. Technische Universitaet Muenchen, Dept. Chemie, Lichtenbergstrasse 4, D85747
Garching, Germany
3. Department
of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106,
United States