Wang, Ziqian
Liu, Pan
Ito, Yoshikazu
Ning, Shoucong
Tan, Yongwen
Fujita, Takeshi
Hirata, Akihiko
Chen, Mingwei
Article History
Received: 15 December 2015
Accepted: 27 January 2016
First Online: 22 February 2016
Competing interests
: The authors declare no competing financial interests.