Hongbo Zheng | PubMed Health

PubMed2004

Parametric study of pellets for elemental analysis with laser-induced breakdown spectroscopy.

The effect of various parameters on the accuracy of the laser-induced breakdown spectroscopy (LIBS) data taken from pellet samples has been investigated. The dependence of the standard deviation of the LIBS data on the amount and nature of the binder used, pressure used to press the powder into a pellet, and the position of the focal spot on the pellet has been investigated. Pellets made from industrially important materials such as silica, alumina, and lime with polyvinyl alcohol, sucrose, and starch as binders have been studied. The results thus obtained are tested by preparation of the calibration curves for Si, Fe, and B in the pellets made from the powder glass batch used as a surrogate for the batch employed for the vitrification of radioactive waste.

Journal Article↗

PubMed2003

[Basic study of dopamine transporter imaging with 131I-beta-CIT].

beta-CIT was labeled with 131I by the peracetic acid method. Cat model of Parkinsonism was set up with MPTP. Each of normal and PD model cats was given an injection of 74 MBq/0.5 ml 131I-beta-CIT into the femur vein. Then the blood samples were obtained at 4 h and 20 h, the radioactivity was counted with calibrator. The biodistribution data of 131I-beta-CIT in cat body was calculated (ID%/g). The cats were subjected to imaging at 0.5 h, 1 h, 2 h, 4 h, 20 h after the administration of radiopharmaceutical. The radioactivity in striatum and cerebellum was measured and striatal specific binding ratios were calculated. The Results showed that the radio chemical purity of 131I-beta-CIT was 97.62% +/- 0.31%. The 131I-beta-CIT remained stable for at least 4 h after incubation with water and serum respectively. Following intravenous administration in cats, 131I-beta-CIT showed high accumulation in striatum. The study of imaging in cats showed that striatal specific uptake of 131I-beta-CIT at 20 h after injection was 4.83 +/- 0.82 in normal cats and 2.92 +/- 0.66 in PD cats. There was a significant reduction of striatal tracer uptake in PD cats, compared to the controls. The results of biodistribution study was in agreement with the results of imaging study. These results suggest that beta-CIT is an ideal agent for dopamine transporter imaging and can be used for the diagnosis of Parkinson's disease.

Animals↗