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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
RESUMO
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.
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Objective To investigate the expressions and significances of micro RNA -192 and zinc finger transcription factor 1 in endometrial carcinoma.Methods 59 cases of endometrial cancer,42 cases of uterine fibroids and 42 cases of normal endometrial tissues were selected.The expressions of miR -192 and ZEB1 in different tissues were detected by using qRT -PCR.The expressions of ZEB1 proteins in difference tissues were tested by Western blot.Results The relative expressions of miR -192 in endometrial cancer tissues were (0.69 ±0.13),which were lower than the normal endometrial tissues and uterine fibroid tissues,which were (1.03 ±0.21)and (0.98 ±0.17), the differences were statistically significant (t =10.983 and 8.572,all P <0.05).The relative expressions of ZEB1 mRNA and the expressions of ZEB proteins in endometrial cancer tissues were (0.47 ±0.08)and (1.13 ±0.24), which were higher than the normal endometrial tissues and uterine fibroid tissues,which were (0.28 ±0.05),(0.89 ± 0.17),(0.31 ±0.07)and (0.87 ±0.21 ),the differences were statistically significant (t =6.834,7.053 and 5.983,6.751,all P <0.05).The expressions of miR -192 and ZEB1 in endometrial carcinoma tissues were associated with FIGO stage and lymph node metastasis (t =1.840 and 2.465,all P <0.05).Pearson correlation analysis showed that,the relative expressions of miR -192 in endometrial carcinoma tissues were negatively correlated with the expres-sions of ZEB1 (r =-0.402,P =0.002).Conclusion The expression of miR -192 in endometrial carcinoma tissues was low.It might participate in invasion and metastasis of endometrial carcinoma through acting on ZEB1.
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Objective To investigate the value of vascular disease of lower extremity of 64 slice spiral CT angiography in patients with diabetic foot.Methods 48 patients with diabetic lower limb underwent arterial CT angi-ography,Using CT a variety of post -processing techniques and compared with the original image.Results 48 patients were successfully obtained CTA image,41 patients had peripheral artery disease,40 cases were bilateral,39 cases of unilateral or bilateral had severe stenosis or occlusion;25 cases had obvious collateral circulation.Lower extremity arterial segments CTA and DSA showed good agreement (Kappa Value =0.887).Positive predictive rate was 92.5%,the negative predictive value was 98.6%.After delayed scanning,CTA on the foot artery count develo-ping increased,checked with the DSA consistency.Conclusion 64 slice spiral CTA can accurately and comprehen-sive assessment of lower extremity arterial disease of diabetic foot.Diabetic lower limb vascular lesions can be used as the preferred method of examination.