PMC:7796344 / 21849-22032 JSONTXT

{"project":"LitCovid-sentences","denotations":[{"id":"T150","span":{"begin":0,"end":74},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"However, the effectiveness depended largely on adherence to mask use [30]. Hoang et al. (2019 and 2020) noted the complexity of the bacterial and viral RTIs [18] and high transmission"}