**Figure 2.** **Characteristics of lipidomics in positive ion model.** (**A**) Score scatter plot of OPLS-DA model for group C vs M in POS model. The X axis t [1] P denotes the predicted principal component score of the first principal component, the Y axis t [1] O denotes the orthogonal principal component scores. The two groups of samples are very distinct in this model. C, control group. M, model group. POS, positive ion model. (**B**) Score scatter plot of OPLS-DA model for group M vs R in POS. M, model group. R, Rb1 group. POS, positive ion model (**C**) Permutation test of OPLS-DA model for group Control vs Model in POS. The X axis represents the replacement retention, the Y axis represents the value of R^{2}Y or Q^{2}, the green dot represents the value of R^{2}Y and the blue square represents the value of Q of the replacement test. The dotted lines represent the regression lines of R Y and Q, respectively. The original model can well explain the difference between the two groups of samples. (**D**) Permutation test of OPLS-DA model for group Rb1 vs Model in POS. (**E**) Pathway analysis for group Control vs Model in POS. The bubble size indicates the influencing factor in the topological analysis; the bubble color represents the P value of enrichment analysis. (**F**) Pathway analysis for group Rb1 ve Model in POS.