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: The US FDA - recommended argatroban dose in HIT is 2 microg / kg / min ( reduced in patients with hepatic impairment and in paediatric patients ) , adjusted to achieve activated partial thromboplastin times ( aPTTs ) 1 . 5 - 3 times baseline ( not > 100 seconds ) .
### Output Text:
The US FDA - recommended <span class="chemical">argatroban</span> dose in HIT is 2 microg / kg / min ( reduced in patients with hepatic impairment and in paediatric patients ) , adjusted to achieve activated partial thromboplastin times ( aPTTs ) 1 . 5 - 3 times baseline ( not > 100 seconds ) . 