In the published version of Fig. 2, images at 1 h 0 kV and 10 kV overlap with image 5 kV. The corrected version of Fig. 2 shows new images for 1 h-0 kV and 10 kV. The authors regret their oversight during figure assembly and would like to sincerely apologize for this error. This unintentional error has no bearing on the article's scientific conclusion.