ABSTRACT
ObjectiveTo develop a finite element computational model of the torso for the numerical simulation of mechanical responses of human torso to non-penetrating ballistic impact. MethodsBased on the CT data of a Chinese adult man, the finite element model of human torso was created by using the medical image processing software Mimics and the finite element pre-processing software HyperMesh. The pressure and acceleration response of the human torso outfitted with soft body armor to the ballistic impact from 9 mm ammunition at a velocity of 360 m/s was calculated numerically by the explicit finite element code LS-DYNA. ResultsThe finite element model of human torso including thoracic skeletal structure, organs, mediastinum and muscle/skin was established. The pressure response of heart, lung, liver and stomach, as well as the acceleration response of sternum were obtained by numerical calculation. It was found that the peak pressure and its time phase were dependent on the distance between the impact point and the measured point wherever in various organs or different position of an organ. Conclusions The finite element computational model of human torso outfitted with soft body armor is available for the simulation of human response to non-penetrating ballistic impact, and the simulated response can be used as evidence for the investigation on mechanism and protection of behind armor blunt frauma.
ABSTRACT
<p><b>OBJECTIVE</b>To seek an effective drug for treatment of human hyperplastic scar through studying the effects of curcumin on fibroblast growth and collagen synthesis.</p><p><b>METHODS</b>Fibroblasts derived from scar tissue and from normal epidermal tissue were isolated and cultured separately with tissue-block method, their morphology were observed under invert phase contrast microscope, their growth curve was drawn respectively to determine the speed of growth. Then, fibroblasts from scar were stimulated with curcumin in different concentrations (0, 12.5, 25, 50 and 100 micromol/L) for detecting the inhibitory effect of curcumin on growth of fibroblasts using MTT methods and that on activity of procollagen alpha-1 gene transcription in fibroblast was detected by RT-PCR.</p><p><b>RESULTS</b>The cell growth curve showed that double-multiplying time was 5 days in fibroblasts from scar and 4 days in those from normal dermis, showing significant difference between them (P < 0.05). MTT showed that curcumin in 12.5 micromol/L showed a cell proliferation enhancing trend, and its absorbance value was significantly higher than that in the normal group, but the effect turned to inhibition when concentration increased to over 25-100 micromol/L, and became significant inhibition at concentration of 50 and 100 micromol/L. Besides, curcumin also showed markedly inhibition on collagen type I synthesis in fibroblasts (P < 0.01).</p><p><b>CONCLUSION</b>High concentration curcumin can inhibit effectively the fibroblast proliferation and collagen I synthesis in hyperplastic scar, therefore, may has therapeutic effect on the disease in human being.</p>