PMC:7352545 / 19867-19970 JSONTXT

{"project":"LitCovid-sentences","denotations":[{"id":"T189","span":{"begin":31,"end":87},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"in multiple combinations [28]. Multiple enzymes are involved in the modifications [29]. Historically, t"}