PMC:7780429 / 5603-5714 JSONTXT

{"project":"LitCovid-sentences","denotations":[{"id":"T41","span":{"begin":0,"end":111},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"This involved the use of different types of more or less tight-fitting masks, and sometimes glasses or screens."}