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: RESULTS : From April 2 , 2005 , through October 30 , 2008 , a total of 114 patients were randomized .
### Output Text:
RESULTS : From April 2 , 2005 , through October 30 , 2008 , a total of 114 patients were randomized . 