1. Dept. of Inorg, and Anal. Chem, Univ. of Szeged, Dóm sq. 7, H-6720 Szeged, Hungary
2. Inst. of Biophys, Biol. Res. Cent, Temesvári blvd. 62, H-6726 Szeged, Hungary
3. Dept. of Opt, and Quant. Electr. Univ. of Szeged, Dóm sq. 9, H-6720 Szeged, Hungary