8960
New , more extensive multicentre studies are underway which aim at better selection and stratification of patients in order to further evaluate the safety and effectiveness of these techniques , before wider use of this revolutionary approach for severe lung emphysema can be advocated .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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