1: Spectrochim Acta A Mol Biomol Spectrosc. 2005 Oct;61(13-14):3131-8. Epub 2005
Jan 11. 

Multi-frequency electron paramagnetic resonance study of irradiated human finger
phalanxes.

Zdravkova M, Vanhaelewyn G, Callens F, Gallez B, Debuyst R.

Ghent University, Department of Solid State Sciences, Krijgslaan 281-S1, B-9000
Gent, Belgium.

Electron paramagnetic resonance (EPR) is often used in dosimetry using
biological samples such as teeth and bones. It is generally assumed that the
radicals, formed after irradiation, are similar in both tissues as the mineral
part of bone and tooth is carbonated hydroxyapatite. However, there is a lack of
experimental evidence to support this assumption. The aim of the present study
was to contribute to that field by studying powder and block samples of human
finger phalanxes that were irradiated and analyzed by multi-frequency EPR. The
results obtained from bones are different from the ones obtained in enamel by
several respects: the ordering of the apatite crystallites is much smaller in
bone, complicating the assignment of the observed CO(2)(-) radicals to a
specific location, and one type of CO(3)(3-) radical was only found in enamel.
Moreover, a major difference was found in the non-CO(2)(-) and non-CO(3)(3-)
signals. The elucidation of the nature of these native signals (in bone and
tooth enamel) still represents a big challenge.

PMID: 16165064 [PubMed - in process]