23422
Nanopore - spanning lipid bilayers on silicon nitride membranes that seal and selectively transport ions .
 Chemical: silicon nitride
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: silicon nitride 
Answer:
 Chemical: silicon nitride