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: When examined individually , mean IF , MIC , total dose , mean daily dose , and ln ( mean Cmax / MIC ) correlated significantly ( P less than . 05 ) with cure .
### Output Text:
When examined individually , mean IF , MIC , total dose , mean daily dose , and ln ( mean Cmax / MIC ) correlated significantly ( P less than . 05 ) with cure . 