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: No adverse effects of eslicarbazepine acetate were observed in the behavioral / EEG patterns studied , including sleep / wakefulness cycle , at the doses studied .
### Output Text:
No adverse effects of <span class="chemical">eslicarbazepine acetate</span> were observed in the behavioral / EEG patterns studied , including sleep / wakefulness cycle , at the doses studied . 