Objective To study the stress resistance of Rhodiola under freezing injury stress. Methods With R.kirilowii, R.crenulata, R.Algida and R.fastigiata as the experimental materials, the effects of freezing injury stress on emerging time, duration of seedling emergence, emergence rate, surviving rate, the activity of SOD and POD were observed by field test and experimental detection. Results Before seeding, the effect of freezing injury stress on R.kirilowii was the largest, and that on R.fastigiata was the least. When injury stress happened during seedling stage, surviving rate, increase of SOD and POD activities of R.kirilowii was the least, indicating the freezing injury was severe. R.fastigiata was the best in those indexes. The stress resistance of Rhodiola was as follows:R.fastigiata > R.crenulata > R.Algida > R.kirilowii. Conclusion R. fastigiata and R.crenulata are good choice in introduction and cultivation of Rhodiola in Gannan area of Gansu province, and R.fastigiata is the best.

Objective To evaluate the osteogenesis of alveolar bone graft (ABG) in patients with alveolar cleft by cone beam CT (CBCT).Methods ABG surgery was performed in 20 patients with unilateral complete alveolar cleft.The patients were followed up for 3 and 6 months after surgery and the osteogenesis of the bone graft was evaluated by CBCT.The bone density and the height of labial and palatal bone graft area were analyzed.Results There was no significant difference in the bone density between 3 months [(403.79 ± 64.70) HU] and 6 months[(411.45 ±42.62) HU] (P =0.329).However,there was significant difference in bone height in the labial and palatal side between 3 months and 6 months (labial P =0.020,palatal P =0.008).Conclusions The osteogenesis was the best 3 months after bone graft.The following treatment can start in this stage.