Capital Med Univ, Beijing Tiantan Hosp, Dept Neurol, Beijing, Peoples R China; Duke Clin Res Inst, Durham, NC USA; Fudan Univ, Sch Life Sci, Shanghai, Peoples R China; Capital Med Univ, Tiantan Clin Trial, Dept Neurol, Beijing, Peoples R China; Capital Med Univ, Beijing Tiantan Hosp, Res Ctr Stroke, Beijing, Peoples R China; Capital Med Univ, Beijing Tiantan Hosp, Neurointens Care Unit, Dept Neurol, Beijing, Peoples R China