1. Department of Anesthesiology, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, China
2. Department of Ultrasound, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, China
3. Department of medical Genetics and cell biology of school of Basic Medical Science, Ningxia Medical University, Yinchuan, Ningxia, China