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. 2017 Oct 12;12(10):e0186323. doi: 10.1371/journal.pone.0186323

Fig 4. Chromium and nickel concentrations in urine preoperatively and at the time of bar removal.

Fig 4

Bars show mean concentrations of chromium and nickel in urine and error bars show standard error of the mean. The difference between chromium concentrations preoperatively and at the time of bar removal was statistically significant (**p<0.001).