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 this study , long - term cardiac transplant patients were switched from cyclosporine to Srl - based IS .
### Output Text:
In this study , long - term cardiac transplant patients were switched from <span class="chemical">cyclosporine</span> to <span class="chemical">Srl</span> - based IS . 