1. Department of Pediatrics, Beijing Luhe Hospital, Capital Medical University, Beijing 100000, China
2. Department of Medical Function, Mudanjiang Medical University, Mudanjiang 157011, China
3. Department of Library, Mudanjiang Medical University, Mudanjiang 157011, China
4. Stem Cell Institute, Mudanjiang Medical University, Mudanjiang 157011, China
5. Department of Histology and Embryology, Mudanjiang Medical University, Mudanjiang 157011, China