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: Initial EEG showed epileptiform discharges in three patients ; run of triphasic waves in one patient and moderate degree diffuse generalized slowing .
### Output Text:
Initial EEG showed epileptiform discharges in three patients ; run of triphasic waves in one patient and moderate degree diffuse generalized slowing . 