Accepted for Publication: December 6, 2012.
Author Contributions:Study concept and design: Jang, L. Yu, Cao, Z. Yu, and Mu. Acquisition of data: Jang, L. Yu, Z. Yu, and Mu. Analysis and interpretation of data: Jang, L. Yu, Wang, Cao, and Mu. Drafting of the manuscript: Jang and Mu. Critical revision of the manuscript for important intellectual content: Jang, L. Yu, Wang, Cao, Z. Yu, and Mu. Statistical analysis: Jang, L. Yu, and Mu. Administrative, technical, and material support: Jang, Wang, Cao, Z. Yu, and Mu. Study supervision: L. Yu, Wang, and Mu
Financial Disclosure: None reported.
Funding/Support: This study was supported by the Science and Technology Commission of Shanghai Municipality (project 08411952100).