PMC:7543426 / 506-548 JSONTXT

{"project":"LitCovid-sentences","denotations":[{"id":"T8","span":{"begin":17,"end":24},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"ve been sparse.\n\nMethods\nTo further define"}