PMC:7696151 / 5817-5925 JSONTXT

{"project":"LitCovid-sentences","denotations":[{"id":"T49","span":{"begin":7,"end":62},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"study. In total, 133 papers were selected for data extraction. A flowchart illustrating the steps of the stu"}