Affiliation: | 1. Department of Histology and Embryology, Hebei Medical University, Shijiazhuang 050017, China;2. College of Life Science, Hebei Normal University, Shijiazhuang 050016, China;3. The No.3 Hospital of Shijiazhuang, 050037 Hebei Province, China;4. Department of Histology and Embryology, Medical Faculty, Hebei Union University, 063000 Hebei Province, China;5. Medical Faculty, Hebei University, 071000 Hebei Province, China |