There is an error in affiliation 2 for authors Xin-chang Zhang, Wen-tao Xu, Wen-zhen Hou, Ying-ying Cheng, and Guang-xia Ni. Affiliation 2 should be: The NO.2 Clinical Medical College, Nanjing University of Chinese Medicine, Nanjing 210023, P.R. China.