1. Illinois EPR Research Center and Department of Veterinary Clinical Medicine, 190 MSB, 506 S. Mathews Ave., University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
2. Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk 6300090, Russia
3. Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
4. Department of Chemistry, Stanford University, Stanford, CA 94305, USA
5. Faculty of Pharmaceutical Sciences, University of British Columbia, 2146 East Mall, Vancouver, BC V6T 1Z3, Canada