Object To develop a mathematical model on the relationship between the temperature used in the course of extraction of medicinal herbs and the concentration of active component obtained Methods Based on the kinetic model on medicinal herb extraction process reported in our previous article *, diffusion coefficient and concentration gradient varying with temperature were further studied Results The process which tanshinone was extracted from Salvia miltiorrhiza Bge at different temperatures showed that the model could well match the experimental data Conclusion The relation between the temperature and the concentration of active component could be described by this model

Objective To summarize the effect of transurethral vaporization of the prostate (TUVP) in combination with transurethral resection of the prostate (TURP) for the treatment of benign prostatic hyperplasia (BPH). Methods A combined use of TUVP and TURP was carried out for treating 122 cases of BPH. There were 8 cases of Rous stage Ⅰ disease, 58 cases of stage Ⅱ, 32 cases of stage Ⅲ, and 24 cases of Ⅳ. Results The length of duration of the operation was 20~140 min (mean, 68 min). The intraoperative blood loss was 40~200 ml (mean, 80 ml). A blood transfusion of 200 ml was required in 2 cases after the operation. No transurethral resection syndrome (TURS) occurred. The mean postoperative catheterization time was 6 days. All 122 patients had been followed for 4~19 months (mean, 10 months). The international prostate symptom score (IPSS) decreased from 30.2?2.3 pre-)operation to 10.8?2.5 post-operation (t=10.84,P=0.000); the residual urine (RU) decreased from 252.6?65.3 ml pre-operation to 35.6?10.4 ml post-operation (t=23.52,P=0.000); the maximum urinary flow rate (Qmax) increased from 8.5?2.8 ml/s to 20.6?3.8 ml/s (t=6.67,P=0.000). Postoperatively, transient urinary incontinence was observed in 2 cases, and anterior urethral stricture occurred in 2 cases. Conclusions Combined use of transurethral electrovaporization and resection of the prostate for the treatment of BPH gives satisfactory effects.