国家自然科学基金81270554;国家高技术研究发展计划863计划,2012AA021001;天津市卫生局科技基金2011KY12,12KG101National Natural Science Foundation of China81270554;National High Technology Research and Development Projects 863 Program of China2012AA021001;Science Foundation of Tianjin Health Bureau2011KY12,12KG101