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: CONCLUSIONS : The incidence of HIT in patients with end - stage hepatic failure is , with about 1 . 95 % , rare .
### Output Text:
CONCLUSIONS : The incidence of HIT in patients with end - stage hepatic failure is , with about 1 . 95 % , rare . 