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: In patients with diabetes , SCr increases > or = 0 . 5 mg / dL were 5 . 1 % ( 4 of 78 patients ) with iopamidol and 13 . 0 % ( 12 of 92 patients ) with iodixanol ( P = 0 . 11 ) , whereas SCr increases > or = 25 % were 10 . 3 % and 15 . 2 % , respectively ( P = 0 . 37 ) .
### Output Text:
In patients with diabetes , SCr increases > or = 0 . 5 mg / dL were 5 . 1 % ( 4 of 78 patients ) with <span class="chemical">iopamidol</span> and 13 . 0 % ( 12 of 92 patients ) with <span class="chemical">iodixanol</span> ( P = 0 . 11 ) , whereas SCr increases > or = 25 % were 10 . 3 % and 15 . 2 % , respectively ( P = 0 . 37 ) . 