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: Light microscopic evidence of renal damage was seen above a dose of 0 . 5 mg doxorubicin / kg , which resulted in albuminuria and very low serum albumin levels .
### Output Text:
Light microscopic evidence of renal damage was seen above a dose of 0 . 5 mg <span class="chemical">doxorubicin</span> / kg , which resulted in albuminuria and very low serum albumin levels . 