国家自然科学基金重点项目81430007;国家卫生计生委公益性行业科研专项201302015;上海市卫生和计划生育委员会新技术研究项目2013SY058;the State Key Program of National Natural Science Foundation of China81430007;the National Health and Family Planning Commission,China201302015;the New Technology Research Project,Shanghai Municipal Commission of Health and Family Planning2013SY058