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: Importantly , a decrease in glutamate uptake correlates negatively with an increase in the incidence of orofacial diskinesia .
### Output Text:
Importantly , a decrease in <span class="chemical">glutamate</span> uptake correlates negatively with an increase in the incidence of orofacial diskinesia . 