The key reference to work of Mortier and Patriarche had been inadvertently omitted from this article . The statement below in the original INTRODUCTION section is not very accurate and appropriate:
"Unfortunately, ever since the first report on oxyfluoride GCs, there have been much research on the properties of nano-particles in GCs but no publication has been reported about how to obtain free nano-particles in aqueous solution from the GC-host and how to apply it to the fields mentioned above, especially in biological field."
The authors amend it as follows:
Mortier and Patriarche  showed that PbF2 nanoparticles could be produced by dissolving the amorphous GeO2-PbO phase of GCs with HF. Unfortunately, the corrosion between GeO2-PbO and HF can hardly be complete so that the nanoparticle had an amorphous phase as a shell in their experiment. Therefore, no publication has been reported about how to obtain free and pure crystalline nano-particles in aqueous solution from the GC-host and how to apply it to the fields mentioned above.
Yu Hua, Hu Nan, Wang Ya-Nan, Wang Zi-Lan, Gan Zong-Song, Zhao Li-Juan: The Fabrication of Nano-Particles in Aqueous Solution From Oxyfluoride Glass Ceramics by Thermal Induction and Corrosion Treatment.
Optical Materials 2006, 28:1401. Publisher Full Text