PMC:7796291 / 17261-17474 JSONTXT

{"project":"LitCovid-sentences","denotations":[{"id":"T148","span":{"begin":0,"end":213},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"The surface charges of the filter media are not consistently positive or negative; instead, both positive and negative charges can exist simultaneously, compensating the overall charges on the filter surface [45]."}