Scientific Reports 6: Article number: 26065; published online: 17 May 2016; updated: 10 June 2016.

The original HTML version of this Article contained typographical errors in the spelling of the author Lv-yun Zhu which was incorrectly given as Ling-yun Zhu.

In addition, Lv-yun Zhu was incorrectly listed as a corresponding author, rather than Ling-yun Zhu.

These errors have now been corrected.