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: Dose - related beneficial and adverse effects of dietary corticosterone on organophosphorus - induced delayed neuropathy in chickens .
### Output Text:
Dose - related beneficial and adverse effects of dietary <span class="chemical">corticosterone</span> on <span class="chemical">organophosphorus</span> - induced delayed neuropathy in chickens . 