[Qin, Chunxiang] Cent S Univ, Xiangya Sch Nursing, Xiangya Hosp 3, Obstet Dept, Changsha, Hunan, Peoples R China.
[Li, Ying] Cent S Univ, Neonatol Dept, Changsha, Hunan, Peoples R China.
[Wang, Dianjun] Cent S Univ, Cardiac Surg Dept, Xiangya Hosp 3, Changsha, Hunan, Peoples R China.
[Shi, Zeya] Hunan Univ Chinese Med, Peoples Hosp Hunan Prov, Nursing Dept, Changsha, Hunan, Peoples R China.
[Yao, Rui] Hunan Univ Chinese Med, Psychol Counseling Ctr, Changsha, Hunan, Peoples R China.