20353
In this study , the force and the frequency generated by the spontaneously contracting zebrafish heart , isolated in saline , were found to be 0 . 87 +/- 0 . 05mN and 1 . 54 +/- 0 . 03Hz ( n = 6 ) respectively within the first hour of recording .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None