[1] Guangdong Med Univ, Dept Respirat, Affiliated Hosp 2, Zhanjiang, Guangdong, Peoples R China
[2] Guangdong Med Univ, Inst Nephrol, Affiliated Hosp, Zhanjiang, Guangdong, Peoples R China
[3] Guangzhou Med Univ, Natl Clin Res Ctr Resp Dis, China State Key Lab Resp Dis, Affiliated Hosp 1, Guangzhou, Guangdong, Peoples R China
[4] Guangdong Med Univ, Sch Clin Med 1, Zhanjiang, Guangdong, Peoples R China