Objective To investigate the efficiency of intraclot microbubbles (MB) combined with urokinase (UK) mediated ultrasound (US) thrombolysis.Metho ds Fifty clots prepared by bovine whole blood were equally divided into 5 groups and were treated in a circulation system with collateral circulation tube.The clots were treated by US,MB and UK in group 1,by US and MBingroup 2,by US and UK in group 3 and by UK in group 4.The group5 was the control group without any treatment.The thrombolysis rate of each group was measured and compared.Residual clots were histologically observed with hematoxylin-eosin staining and immunofluorescence.Results The thrombolysis rate of group 1 ([73.64±14.16]％) was significantly higher than group 2 ([47.97± 11.66]％),group 3 ([57.33±8.65]％),group 4 ([50.85±9.63]％),and group 5 ([29.76±18.06] ％,all P＜0.05).Histological examination of the clots in group 1 showed multiple thrombolysis foci with clots collapse,and the degradation of fibrin network was further confirmed by immunofluorescence.Conclusion The intraclot MB mediated US thrombolysis combined with UK can enhance the rate of thrombolysis in vitro experiment.

【Objective】 To optimize the bottom and top(B&T) method for nucleated cell separation in cord blood in order to reduce the disturbance and improve the nucleated cell yield. 【Methods】 A new device comprised of two plastic plates and connection units was developed. B&T Cord blood bag was put between the plates, which were then centrifuged and put into the serum expresser together to go through serum and red blood cells separation simultaneously. After centrifugation parameter adjustment, the new Plates-B&T method was compared with traditional method in parallel. 【Results】 New Plates-B&T method could avoid buffy coat movement and disturbance. Compared to conventional PRP method, Plates-B&T method reduced centrifugation and separation time from(29.12±2.79)min to(14.91±2.12)min(P<0.05). Using new method, the recovery rate of total nucleated cell(TNC) was (89.04±5.19)%, the removal rate of red blood cell(RBC) was(55.56±22.57) %, and hematocrit(HCT) in buffy coat was(0.48±0.09)L/L. RBC removal was enhanced significantly, especially for cord blood samples with medium-low volume. 【Conclusion】 Based on B&T method, we established a new device and method, which increased the efficiency and quality of cord blood nucleated cell separation.