Unadjusted and adjusted hierarchical regression model-pH effect vs die-off rate, n = 30.

Confidence Interval in parentheses; Note: p value for all the parameters was less than 0.01.
A: Model Main effect, B: Adjusting for metal, C: Adjusting for incubation period (Time), D: Adjusting for metal and time, E: Adjusting for metal, time and metal*pH interaction, F: Adjusting for metal, time and time* pH interaction, G: adjusting for metal, time, metal*pH interaction and and time* pH interaction.
Note: Each model includes the coefficient and their confidence interval in bracket.

括号内为置信区间（Confidence Interval）；注：所有参数的p值均小于0.01。
A：模型主效应；B：校正金属因素；C：校正培养周期（Time）；D：同时校正金属与时间因素；E：校正金属、时间以及金属与pH的交互作用；F：校正金属、时间以及时间与pH的交互作用；G：校正金属、时间、金属与pH的交互作用以及时间与pH的交互作用。
注：每个模型均给出了系数及其括号内的置信区间。