10521
Mesoporous metallic cells : design of uniformly sized hollow mesoporous pt - ru particles with tunable shell thicknesses .
 Chemical: pt; Chemical: ru
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: pt, ru 
Answer:
 Chemical: pt; Chemical: ru