国家自然科学基金资助项目、陕西省自然科学基金、陕西省卫生厅科研基金资助项目No.81370379、2016JM8061和2014D38Supported by the National Natural Science Foundation of China ,the Natural Science Foundation of Shaanxi Province ,and Research Foundation of Shaanxi Health and Family Planning Commission 81370379 ,2016JM8061 and 2014D38