13439
The influence of changes in the chain conformation on the ( 13 ) C sigma ( ii ) NMR shielding parameters is shown .
 Chemical: ( 13 ) C
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: ( 13 ) C