1. Department of Pharmacy, Dongying City People's Hospital, Dongying, Shandong 257091, P.R. China
2. Department of Spinal Surgery, Dongying City People's Hospital, Dongying, Shandong 257091, P.R. China
3. Intravenous Drug Distribution Center, Dongying City People's Hospital, Dongying, Shandong 257091, P.R. China