Li, Ting
Wang, Lei
Wang, Huijie
Zhang, Shujuan
Atikan·Kawuli,
Zhang, Xiaowei
Luo, Zhiguo
Wang, Chunmeng
Article History
Received: 2 July 2016
Accepted: 2 September 2016
First Online: 8 September 2016
Compliance with ethical standards
:
: The authors declare that they have no competing interests.
: None.
: For this type of study formal consent is not required.