342 Views | 931 Downloads
E-mail: huanglei@nju.edu.cn (LH); jbi@nju.edu.cn (JB)
Conceived and designed the experiments: CSQ LH JB.
Performed the experiments: CSQ JY ZWM.
Analyzed the data: CSQ ZWM.
Contributed reagents/materials/analysis tools: CSQ YL.
Wrote the paper: CSQ LH.
One author (JY) is employed by a commercial company, SGS-CSTC Standards Technical Services (Shanghai) Co., Ltd.
However, this study was not funded by the SGS company.
SGS company is a cooperative partner in this study.
The authors have cooperation agreement with SGS company.
This does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials.
This work was supported by the National Natural Science Foundation (41171411, 41271014 & 41201545) and the Jiangsu Natural Science Foundation (BK2012733).
© 2012 Qu et al.