7561
In a previous study , a coarse - grained united - residue model and molecular dynamics simulations were used to model the growth mechanism of A beta amyloid fibrils .
 None
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:  
Answer:
 None