[1] Bulgarian Acad Sci, Inst Expt Morphol Pathol & Anthropol Museum, Acad Georgi Bonchev Str,Bl 25, Sofia 1113, Bulgaria
[2] BIOVET JSC, Chem Dept Res & Dev, 39 Peter Rakov St, Peshtera 4550, Bulgaria
[3] Univ Vienna, Inst Analyt Chem, 38 Waehringer Str, A-1090 Vienna, Austria
[4] Med Univ Vienna, Dept Biomed Imaging & Image Guided Therapy, Div Mol & Struct Preclin Imaging, 18-20 Waehringer Guertel, A-1090 Vienna, Austria
[5] Gen Hosp Vienna, 18-20 Waehringer Guertel, A-1090 Vienna, Austria
[6] Univ Vienna, Inst Inorgan Chem, 42 Waehringer Str, A-1090 Vienna, Austria
[7] Sofia Univ St Kliment Ohridski, Fac Med, Kozjak Str 1, Sofia 1407, Bulgaria