- Correspondence to Professor Dr Peizeng Yang, The First Affiliated Hospital of Chongqing Medical University, Youyi Road 1, Chongqing 400016, P. R. China;
- Received June 23, 2015
- Revised October 26, 2015
- Accepted November 1, 2015
- First published December 1, 2015.
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- Data supplement 1 - Online supplement
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