PMC:7781502 / 13723-13954 JSONTXT

{"project":"TEST0","denotations":[{"id":"33409059-158-164-2309440","span":{"begin":158,"end":160},"obj":"[\"29632445\"]"}],"text":"First, we analyzed only articles accessible via PubMed, which include the MEDLINE database and papers included in the National Library of Medicine catalogue [21]. PubMed only recently started to include preprints in search results."}

{"project":"LitCovid-sentences","denotations":[{"id":"T141","span":{"begin":0,"end":231},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"First, we analyzed only articles accessible via PubMed, which include the MEDLINE database and papers included in the National Library of Medicine catalogue [21]. PubMed only recently started to include preprints in search results."}