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: Both effects ( better survival and nephrosis ) are most probably related to an enhanced capture of DXNP by cells of the mononuclear phagocyte system , including mesangial cells .
### Output Text:
Both effects ( better survival and nephrosis ) are most probably related to an enhanced capture of DXNP by cells of the mononuclear phagocyte system , including mesangial cells . 