PMC:7417187 / 24455-24496
Annnotations
LitCovid-sentences
{"project":"LitCovid-sentences","denotations":[{"id":"T218","span":{"begin":0,"end":41},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"Each mask is used maximum for five times."}