1. Faculty of Physics, Babes-Bolyai University, 3400 Cluj-Napoca, Romania
2. Physics Department, University of Osnabrück, 49069 Osnabrück, Germany
3. Faculty of Pharmacy, University of Medicine and Pharmacy, 3400 Cluj-Napoca, Romania
4. National Institute for Research and Development of Isotopic and Molecular Technologies, 3400 Cluj-Napoca, Romania