1. Department of Obstetrics and Gynecology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China
2. Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China
3. National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
4. Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, Hunan, China
5. Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
6. Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China