In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: From day 0 to day 3 , the mean peak increase in creatinine was 0 . 13 mg per deciliter in the iodixanol group and 0 . 55 mg per deciliter in the iohexol group ( P = 0 . 001 ; the increase with iodixanol minus the increase with iohexol , - 0 . 42 mg per deciliter [ 95 percent confidence interval , - 0 . 73 to - 0 . 22 ] ) .
### Output Text:
From day 0 to day 3 , the mean peak increase in <span class="chemical">creatinine</span> was 0 . 13 mg per deciliter in the <span class="chemical">iodixanol</span> group and 0 . 55 mg per deciliter in the <span class="chemical">iohexol</span> group ( P = 0 . 001 ; the increase with <span class="chemical">iodixanol</span> minus the increase with <span class="chemical">iohexol</span> , - 0 . 42 mg per deciliter [ 95 percent confidence interval , - 0 . 73 to - 0 . 22 ] ) . 