objective: To observe the variations of stress magnitude in the cervical vertebra exerted by vertical traction force from various angles and different points. Methods: The cervical vertebra model was produced by using elastic material of light (polycarbonate) and silica rubber(1:1). By calculating the arithmetical progression of interference fringe. The author judged the stress magnitude in the posterior edge of the C4-7 vertebral bodies when different kinds of pulling force acted on. Result: The interference pattern was seen clearly on the screen while the force acted on the model. When the pulling force acted on C1 or C2, the force was acting at an angle of 150the maximum of the stress presented in C4-5 and when the force acted at an angle of 25° the maximum stress presented in C5-6 and C6-7. Conclusion: The stress distributed upon the posterior edge of the vertebral joints is closely related to the points that the force aced on and the direction of the force． Appropriate points and direction of the pull should be selected according to the change of the lesion joints when manual manipulation is used for the treatment of cervical vertebral disease.

Objective:To investigate the correlation between the clinical features and endoscopic ultrasound-guided portal pressure gradient (EUS-PPG) in patients with cirrhosis.Methods:A total of 148 patients with cirrhosis and portal hypertension who underwent EUS-PPG measurement at the Third Xiangya Hospital of Central South University from March 15, 2022 to June 20, 2023 were selected. The clinical data of patients collected before EUS-PPG measurement were analyzed. Variations in the EUS-PPG across different clinical data subgroups were analyzed. Multivariate linear regression analysis was used to explore the independent factors influencing EUS-PPG.Results:The EUS-PPG was significantly elevated in patients exhibiting red signs (16.62±5.33 mmHg VS 13.44±5.34 mmHg, t=3.616, P<0.001), gastroesophageal varices (15.78±5.30 mmHg VS 9.70±4.77 mmHg, t=4.247, P<0.001), hepatic encephalopathy (20.83±7.52 mmHg VS 14.92±5.35 mmHg, t=2.606, P=0.010), thrombocytopenia (15.66±5.39 mmHg VS 13.29±5.83 mmHg, t=2.136, P=0.034), hypoproteinemia (16.13±5.86 mmHg VS 14.12±5.03 mmHg, t=2.230, P=0.027), and an increased international normalized ratio (16.25±6.00 mmHg VS 14.40±5.11 mmHg, t=2.022, P=0.045). Conversely, the EUS-PPG was significantly reduced in patients with a history of splenectomy and devascularization (13.17±5.88 mmHg VS 15.73±5.34 mmHg, t=-2.379, P=0.019). The EUS-PPG in patients with varying degrees of ascites (no VS slight VS moderate or severe: 13.40±5.48 mmHg VS 15.90±5.49 mmHg VS 16.69±5.17 mmHg, F=5.188, P=0.007) and different Child-Pugh classifications (A VS B VS C: 14.07±5.05 mmHg VS 15.69±5.74 mmHg VS 17.64±5.99 mmHg, F=3.066, P=0.049) increased gradually. Multivariable linear regression analysis showed that red signs ( β=2.44, t=2.732, P=0.007), gastroesophageal varices ( β=4.45, t=2.990, P=0.003), ascites ( β=1.75, t=2.368, P=0.019), and hepatic encephalopathy ( β=5.82, t=2.644, P=0.009) were independent factors for the elevated EUS-PPG. Conclusion:There is a significant correlation between EUS-PPG and the clinical features related to the severity of cirrhotic portal hypertension, which indicates the feasibility of EUS-PPG in evaluating cirrhotic portal hypertension.