Aim: To investigate risk factors which impact on common carotid artery intima media thickness (IMT).Methods: A total of 86 obese children and adolescents and 22 healthy children and adolescents with normal weight were enrolled. Moreover, 23 of 86 obese children and adolescents were diagnosed with metabolic syndrome (MetS). The clinical, biochemical data and the IMT of the common carotid artery were measured in all subjects.Results: Obese and obese with MetS subjects demonstrated a significantly (p < 0.01) thicker intima media (0.69mm, 0.66mm) as compared to the control group (0.38mm), but there was no significant difference of IMT between obese and MetS group. IMT was correlated to body weight, body mass index, waist circumference, waist to hip ratio, systolic blood pressure, diastolic blood pressure, fasting insulin, homoeostasis model assessment-insulin resistance, triglyceride, high-density lipoprotein- cholesterol, low-density lipoprotein-cholesterol, alanine aminotransferase, aspartate aminotransferase and fatty liver. Waist circumference, waist to hip ratio, triglyceride and homoeostasis model assessment-insulin resistance were independent determinants of mean IMT level.Conclusion: Obesity especially abdominal obesity, high TG and insulin resistance may be the main risk predictors of increased IMT.

The Stress Distribution in the Connection of the Spherical Shell and the Opening Nozzle Is Very Complex. Sharp-Angled Transition and Round Transition Are Used Respectively in the Connection in the Light of the Spherical Shell with the Small Opening and the Large One. the Influence of the Two Connecting Forms on Stress Distribution Is Analyzed by Establishing Finite Element Model and Solving it. the Result Shows there Is Obvious Stress Concentration in the Connection. Round Transition Can Reduce the Maximum Stress in Comparison with Sharp-Angled Transition in both Cases of the Small Opening and the Large Opening, Mainly Reducing the Bending Stress and the Peak Stress, but Not the Membrane Stress. the Effect of Round Transition on Reducing Stress Was Not Significant. so Sharp-Angled Transition Should Be Adopted in the Connection when a Finite Element Model Is Built for Simplification in the Future.

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To study the stress condition at the junction of the spherical shell with opening nozzle, using the finite element analysis, a finite element model is built in view of the same spherical shell joining a flatting nozzle and inside-stretching nozzles with different inner lengths differently. The maximum stress and stress distribution are got. All kinds of stresses are obtained by the total stress which is carried on linear processing. The result shows the inside-stretching nozzle can reduce the maximum stress in comparison with the flatting nozzle, mainly reducing the local membrane stress, but not the peak stress. The maximum stress falls with increasing the inner length of the nozzle to some extent, and beyond the extent, the maximum stress tends to reach a stable value basically without changing the inner length. The stress variation can effectively provide a reference for improving the strength of the spherical shell.