Fig. 2

(A): Surviving fraction (SF) of U87 cells irradiated with 2–8 Gy and treated with xenon (Xe), memantine (Mem) or both (Xe + Mem). Error bars indicate 95% confidence interval. Significant reduction in SF was found for Xe starting at a dose of 4 Gy and for Xe + Mem starting at 2 Gy (*p < 0.05). (B): Linear-quadratic regression analysis. Error bars indicate standard error of mean. Data are given as means of at least three independent experiments and were normalised to plating efficiency. Non-normalized data are shown in the appendix (Supplementary Fig. 3)