Cancer epidemics and the cancer prevention and control strategies in the United States: a review study / 中华预防医学杂志

In the past two decades,the United States made an impressed progress in the prevention and control of cancer that the overall morbidity and mortality of cancer had shown a downward trend, while China had seen an opposite trend. Cancer, one of the major public health concerns in China, has imposed an enormous burden onthe society and individuals. Therefore,in order to scientifically formulate cancer prevention and control policies, it is essential to make a comprehensive understanding of the practical experience in the field of cancer prevention and control from the United States. This article reviews the relevant literature on cancer trends as well as the prevention and control strategies in the United States,depictsthe cancer epidemic situation in the United States in the past 30 years, and summarizes the influencing factors, strategies and intervention experiences that lead to the improvement of cancer epidemic. It highlights the policy support, surveillance and intervention adopted by the United States for the cancer prevention and control. This article is expected to provide some implications and reference for the cancer prevention and control in China.

Experimental study on an in vitro vascular tensile stress loading device / 医用生物力学

Objective To develop an in vitro vascular tensile stress loading device and study the distributions of tensile stress and tensile strain on the elastic basement membrane (silicone sheet). Method The in vitro vascular tensile stress loading device which simulated the human hemodynamic environment was developed based on the elastic basement membrane deformation loading technology. The images of grid points before and after the stretch of the silicon sheet were recorded by camera and transformed into the digital images. The characteristics for the location of the grid points were calculated by using Matlab software, so as to obtain the strain distribution on the silicon sheet. Experiments were conducted on the silicon sheet by using the universal material testing machine, so as to calculate the mechanical parameters of the silicon sheet. The finite element model was established according to the mechanical parameters, and the distribution of tensile stress and tensile strain on the silicon sheet was simulated and calculated. The experimental results and simulative results were then compared. Results The finite element results were basically in accordance with the experimental results. The maximum value of tensile stress and tensile strain appeared on the loading point, while the stress and strain in intermediate area were comparatively homogeneous. 60% of the intermediate area in the silicone sheet could be regarded as homogeneous strain fields Conclusions The research finding can provide experimental techniques for the dynamic culture of vascular endothelial cells and the research on cell mechanics in the future.