Error bar plots for the peak areas of four potential biomarkers with representative changing trends. The normalized peak area is shown on the vertical coordinate, and the time points of sample collection on the horizontal coordinate. Error bars represent the means and 95% confidence interval (CI) of the normalized peak areas. Low-calcium group (LCG) rats are indicated by green boxes and normal-calcium group (NCG) rats by black boxes.
Wang et al. BMC Medicine 2013 11:86 doi:10.1186/1741-7015-11-86