Objective To simulate dynamic response of cervical spine of the pilot during typical maneuver flight movements using finite element method, as well as make analysis and prediction on damage failure of the pilot neck during flight by impact injury and fatigue injury model of biological tissues.Methods A geometrically accurate finite element model of the neck was constructed, and validity of the model was verified by relevant examples. Then, the acceleration curves of centrifugal trainer under different modes were loaded for numerical simulation, and impact injury and fatigue injury of tissues were predicted by using the universal cervical injury criterion and the fatigue damage model of biological tissues.Results The maximum stress of the vertebrae and intervertebral disc caused by overload impact was 66.53 MPa and 58.63 MPa respectively during typical maneuver flight. According to the Nij injury criteria, the maximum Nij was 0.096, which was lower than the injury tolerance threshold of 1, and would not cause direct acute injury to cervical tissues. Based on fatigue damage model of biological tissues, it was found that cancellous bone suffered fatigue failure under the condition of uninterrupted repeated loading for more than 40 000 times. Considering the limited flight career of the pilot, the vertebral tissues would not be fractured due to the accumulation of fatigue damage.Conclusions To a certain extent, the results can contribute to formulating pilot training and flight plans, and also provide data support for the development of its protective equipment.

Objective Based on construction and verification of the lumbar finite element model, the simulation calculation and injury prediction on dynamic response of normal lumbar model and L5 unilateral and bilateral spondylolysis models of the pilot were carried out, so as to explore the influence of persistent flight overload on normal and spondylolysis lumbar vertebrae of the pilot. Methods The precise finite element model of lumbavertebrae was established using reverse engineering software and computer-aided engineering (CAE) technology based on CT images. The validity of the lumbar vertebrae model was verified by static and dynamic in vitro experiments. The biomechanical simulation analysis on normal and spondylolysis lumbar vertebrae of the pilotunder persistent overload was carried out, and the spinal injury was predicted and analyzed by dynamic response index (DRI) injury evaluation and prediction method. Results The maximum isthmus stress of L5 vertebra in unilateral and bilateral spondylolysis models were 105. 29 MPa and 126. 32 MPa, respectively, which were significantly higher than those in normal model. The L4-5 and L5-S1 intervertebral discs of the spondylolysis model were more prone to premature degenerative changes than those of normal model. Combined with DRI spinal injury prediction method, the probability of spinal injury in normal lumbar vertebrae, lumbar vertebrae with L5 unilateral and bilateral spondylolysis were 0. 001 4% , 2. 26% and 3. 21% , respectively, and the probability of spinal injury was significantly increased after the occurrence of spondylolysis. Conclusions The spondylolysis increases the load of lumbar isthmus under flight overload. The results provide more accurate data support for the formulation of training programs and the development of protective devices to ensure flight safety

OBJECTIVE：To establ ish the fingerprint of Sojae Semen Nigrum and content determination method of 5 kinds of isoflavones，so as to provide reference for controlling its quality better. METHODS ：HPLC method was adopted to establish the fingerprint and detect the contents of 5 kinds of isoflavones. The determination was performed on Phenomenex C 18 column with mobile phase consisted of acetonitrile- 0.12％ formic acid solution （gradient elution ）at the flow rate of 1 mL/min. The detection wavelength was set at 260 nm；the column temperature was 30 ℃ and sample size was 10 μL. Using daidzin as reference，HPLC fingerprints of 12 batches of samples were determined. The similarity of 12 batches of samples was evaluated by TCM Chromatographic Fingerprint Similarity Evaluation System （2012A） to confirm common peak. Cluster analysis and principal component analysis were performed by using SPSS 20.0 software and SIMCA 13.0 software. RESULTS ：There were 19 common peaks in HPLC fingerprints of 12 batches of samples ，the similarity of which was higher than 0.94. Totally 5 components were identified，such as daidzin ，glycitin，genistin，daidzein，genistein. Cluster analysis showed that 12 batches of Sojae Semen Nigrum were clustered into 2 categories，i.e. S 1-S3 clustered into one category ，and S 4-S12 clustered into the other category. By principal component analysis ，the contribution rates of two principle components were 53.261％ and 40.715％；accumulative contribution rate was 93.976％. The linear range of above 5 components were 5.97-191.00 µg/mL（r＝0.999 9），1.05-33.46 µg/mL（r＝0.999 9）， 8.93-285.61 µg/mL（r＝0.999 5），0.82-26.33 µg/mL（r＝0.999 9），0.93-29.64 µg/mL（r＝0.999 7），respectively. The limits of quantitation were 0.881 1，0.611 6，0.078 6，0.243 3，0.511 6 μg/mL，respectively. The limits of detection were 0.264 3，0.244 7， 0.021 4，0.124 8，0.106 7 μg/mL，respectively. RSDs of precision ，stability，reproducibility and durability tests were all lower than 5％. Recoveries were 95.15％-96.56％（RSD＝0.51％，n＝6），98.52％-103.45％（RSD＝1.88％，n＝6），95.37％-97.91％ （RSD＝0.95％，n＝6），99.75％-102.00％（RSD＝0.78％，n＝6），100.26％-103.65％（RSD＝1.21％，n＝6）. Among 12 batches of Sojae Semen Nigrum ，the contents of above 5 components were 0.178 3-0.265 9，0.021 7-0.096 2，0.288 5-0.597 2，0.014 1- 0.058 8，0.012 9-0.082 9 mg/g. CONCLUSIONS ：Established HPLC fingerprint and content determination method of 5 kinds of isoflavones can be used for quality control of Sojea Semen Nigrum. The Isoflavone components are similar ，but the contents are different among Sojae Semen Nigrum from different producing areas.