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: Mean arterial blood pressure in mice treated with NIMO alone decreased from 88 . 1 + / - 3 . 8 mm Hg to 80 . 0 + / - 2 . 9 mm Hg .
### Output Text:
Mean arterial blood pressure in mice treated with <span class="chemical">NIMO</span> alone decreased from 88 . 1 + / - 3 . 8 mm Hg to 80 . 0 + / - 2 . 9 mm Hg . 