PMC:1359071 / 654-663 JSONTXT

{"project":"craft-ca-core-ex-dev","denotations":[{"id":"T512","span":{"begin":1,"end":2},"obj":"SO_EXT:sequence_nullness_or_absence"}],"text":"/−) backg"}

{"project":"craft-sa-dev","denotations":[{"id":"T642","span":{"begin":0,"end":1},"obj":"HYPH"},{"id":"T643","span":{"begin":1,"end":2},"obj":"SYM"},{"id":"T644","span":{"begin":2,"end":3},"obj":"-RRB-"}],"text":"/−) backg"}