Affiliation: | (1) Department of Embryology and Histology, Second Military Medical University, Xiangyin Road 800, 200433 Shanghai, Peoples Republic of China;(2) National Stem Cell Center, Beijing University, Xueyuan Road 38, 100083 Beijing, Peoples Republic of China;(3) Department of Gynecology and Obstetrics, Changhai Hospital, Second Military Medical University, Beijing, Peoples Republic of China;(4) Department of Microbiology; Department of Embryology and Histology, Second Military Medical University, Beijing, Peoples Republic of China |