- Received June 13, 2014, and in revised form February 25, 2015.
- Accepted for publication March 23, 2015.
- Reprints: Jin Su, Department of Respiratory Diseases, Nanfang Hospital, Southern Medical University, #1838, Northern Guangzhou Ave., Guangzhou, Guangdong, People’s Republic of China. E-mail: ; or Shao-Xi Cai, Department of Respiratory Diseases, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. E-mail: .
- This work was supported by the grants from the Guangdong province Medical research Foundation (A2011364), Nation Science Foundation (China) (81071847), and Guangdong Province Science Foundation (S2011010003881) and Guangdong Province Science Program (2012B031800394).
- The authors declare no conflict of interest.
- G.-H.H. and X.-L.Z. contributed equally to this work.
- First published December 15, 2015.
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