Objective To evaluate the effieaey of test bolus technique with multi-slice spiral CT (MSCT) for determining the optimal scan delay time in CT Hepatic artery (HA)-portal vein (PV) angiography and multi-phase scanning.Methods MSCT liver angiography and multi-phase scanning were performed in 187 patients divided randomly into two groups.In group A (n =59),the scan delay time was set according to the subjective experiences of operators; in group B (n=128),the scan delay time was determined by test bolus technique.Abdominal aorta and superior mesenteric,vein were selected as target blood vessels,and 50 HU was set as enhancement threshold value.20 ml contrast agent was injected intravenously and time-density curve of target blood vessels were obtained,then HA-PV scanning delay time were calculated respectively.The quality of CTA images obtained by using these 2 methods were compared and statistically analysed using Chi-square criterion.Resuits For hepatic artery phase,the images of group A are:excellent in 34(58%),good in 17(29%),and poor in 8 (13%),while those of group B are excellent in 128( 100%),good in 0(0%),and poor in 0(0%).For portal vein phase,the images of group Aare:excellent in 23(39%),good in 27(46%),and poor in 9(15%),while those of group B are excellent in 96 (75%),good in 28 (22%),and poor in 4 (3%) respectively.There was statistically significant difference between the ratios of image quality in group A and group B (X2=14.97,9.18,P < 0.05).Conclusion Accurate scan delay time was best determined by using test bolus technique,which can improve the image quality of liver angingraphy and multi-phase scanning.

OBJECTIVE The N-methyl-D-aspartate(NMDA)receptor has been shown to be strongly associ-ated with rapid antidepressant effects.GW043 is a com-pound with a novel structure that we designed and syn-thesized to act on the NMDA receptor(NMDAR).METH-ODS In this study,we first confirmed the target of GW043 using a receptor binding assay.We observed the effect of GW043 on NMDAR currents in vivo and in vitro assays using a membrane clamp technique with a view to characterizing the function of GW043.We investi-gated the antidepressant effect of GW043 in rodent behavioral models such as FST,TST and CUMS.Fur-thermore,we explored the mechanism of GW043 onset using Western blotting,BrdU staining,Golgi staining and electrophysiological techniques.RESULTS GW043 interacts with high affinity only at the NMDAR.Electro-physiological studies have indicated that GW043 is a par-tial agonist of NMDAR.Meanwhile,behavioral experi-ments were conducted to confirm the antidepressant effect of GW043 in rodents.The mechanism study found that GW043 regulate synaptic plasticity through LTP and BDNF/mTOR pathways and increase the number of new-born neurons to cause antidepressant effects.GW043,a partial agonist of NMDAR,reversed depression-like behav-ior in rats by modulating synaptic plasticity,suggesting an antidepressant effect.CONCLUSION The results suggest that GW043 is a partial agonist of NMDA recep-tors and has significant antidepressant effects.