OBJECTIVE:To optimize the extraction technology of asiaticosides from Centella asiatica. METHODS:Using to-tal amounts of asiaticoside and hydroxy asiaticoside as investigation indexes,single factor and orthogonal test were used to investi-gate the enzyme amount,enzymolysis time,enzymolysis temperature,ethanol volume fraction,liquid material ratio and ultrasonic extraction time and optimize the extraction technology of asiaticosides from C. asiatica by ultrasonic-enzyme method,and verifica-tion test was conducted. RESULTS:Optimal extraction technology was as follow as cellulose dosage of 12 mg/g,10-fold liquid ma-terial ratio added into 60% ethanol,enzyme hydrolysis for 60 min at 60 ℃,ultrasonic assisted extraction for 50 min. Average ex-traction rate of total asiaticosides was 1.92%(RSD=1.83%,n=3)in verification test. CONCLUSIONS:Ultrasonic-enzyme meth-od is stable and feasible for the extraction technology of asiaticosides from C. asiatica.

Objective:To characterize the severe sports injuries related to alpine skiing during the 2022 Beijing Winter Olympics and Paralympics so as to provide information for the prevention and treatment of sports injuries in the Yanqing National Alpine Skiing Center tracks.Methods:The medical data were collected of all the alpine skiing athletes and related staff who had sought medical treatment in Peking University Third Hospital Yanqing Hospital during January 20, 2022 to March 26, 2022. Descriptive statistical analyses were conducted for body part, type, occurrence place, and severity of the injuries.Results:There were 49 patients who had suffered severe injuries related to alpine skiing events during this Olympic Games, with 68 injuries by body parts and 72 injuries by types. The most common injury part was the knee (25.0%, 17/68), followed by the head (14.7%, 10/68), and the shoulder (8.8%, 6/68). The most common types of injury were contusion (including hematoma and abrasion, 30.6%, 22/72), followed by sprain (including dislocation, subluxation, and ligament injury, 22.2%, 16/72), and fracture (20.8%, 15/72). The most common occurrence place in the tracks for athletes was the "Haituo Bowl" area (41.7%, 10/24). In terms of severity, the injuries led to an absence from training or competition in 48 athletes [98.0% (48/49)], of whom 33 were severely injured [67.3% (33/49)].Conclusions:The most vulnerable part for severe sports injuries in the alpine skiing events of the 2022 Beijing Winter Olympics and Paralympics was the knee, mostly with ligament injuries, which is consistent with the findings of previous events. The high proportion of severe injuries indicated the difficulty of this track. The place where injuries mostly occurred was the "Haituo Bowl" area of the racing track, also the most challenging part of this track, indicating a necessity of more medical resources in this area.