Table 1.

The description of features with an example that extracted from a biomedical sentence by an entity and relation extraction tool, PKDE4J

No	Biomedical features	Description	Example feature record
1	ID	Identifier number of an article	15248468
2	Sent ID	Sentence id of a sentence	0
		in the abstract of an article
3	Entity-L	Entity on the left side	dehydroepiandrosterone sulfate
4	Type-L	Type of the entity on the left side	COMPOUND
5	Context-L	Context of the entity on the left side	NA;
6	Entity-R	Entity on the right side	ubiquinone-9
7	Type-R	Type of the entity on the right side	COMPOUND
8	Context-R	Context of the entity on the right side	NA
9	Negation	Negativeness of the relation	POSITIVE
10	Tense	Tense of the relation	ACTIVE
11	Verb	Verb of the relation	increase
12	Relation	Reference word of the relation	LOCATION_OF
13	Context level	Level of the context in the relation	level=0
14	Verb phrase	Verb phrase	increases hepatic ubiquinone-9 in
			male F-344
15	Sentence	Raw text of a sentence	Dehydroepiandrosterone sulfate
			increases hepatic ubiquinone-9
			in male F-344 rats