Objective To summarize the experience of modified mini-cholecystectomy. Methods A total of 128 patients underwent mini-cholecystectomy by using a modified Bookwalter retractor, a self-made deep-site tying tool and an L-shape electrotome from September 1998 to June 2003. Results That the length of incision ≤ 6 cm was regarded as a surgical success. Out of the 128 patients, the surgical success was achieved in 110 patients (85 9%). Conclusions In mini-cholecystectomy, the use of the modified Bookwalter retractor greatly improves the visualization of operation field, and the use of the self-made tying tool facilitates deep-site manual knot tying.

Gas chromatography with mass spectrum detector ( GC-MSD) coupled with purge-and-trap system was set up to analyze the concentration of isoprene in natural waters. The best experimental conditions were established, including purge gas flow rate ( 50 mL/min ) , purge time ( 15 min ) , the optimum capillary column ( Rt-Alumina BOND/KCl) and the appropriate condition of temperature programming. When analyzing isoprene in natural waters, the precision was <4% (n=6), the detection limit was 0. 5 pmol/L and the recovery was 91%-102%. The preservative experiment showed that there was no obvious variation in sample concentrations of isoprene within 60 days. The concentrations of isoprene measured with the method ranged from 60 . 8 to 278 . 7 pmol/L in the Jiaozhou Bay and its adjacent river estuaries and from 44 . 7 to 77 . 2 pmol/L in Yellow River estuary, which was in good accord with those results reported in literatures in other coastal waters. In conclusion, the analytical method could meet the requirements of the analysis of concentration of isoprene in natural waters.