[1] Chinese Peoples Liberat Army Gen Hosp, Med Sch Chinese PLA, Med Ctr 2, Beijing, Peoples R China
[2] Chinese Peoples Liberat Army Gen Hosp, Med Sch Chinese PLA, Natl Clin Res Ctr Geriatr Dis, Beijing, Peoples R China
[3] Xi An Jiao Tong Univ, Affiliated Hosp 1, Dept Obstet & Gynecol, Xian, Shaanxi, Peoples R China
[4] Chinese Peoples Liberat Army Gen Hosp, Med Ctr 2, Dept Emergency, Beijing, Peoples R China
[5] Chinese Peoples Liberat Army Gen Hosp, Natl Clin Res Ctr Geriatr Dis, Beijing, Peoples R China
[6] Chinese Peoples Liberat Army Gen Hosp, Med Ctr 3, Med Sch Chinese PLA, Beijing, Peoples R China