instruction:
In medical studies, treatments are tested within a group of study participants. You will be given a sentence of a study report in which your task is to list the phrases that give information about the participants of the study. You should list the phrases in the same order that they appear in the text, separated by commas. If no information about the participants is mentioned, just output "not found". Relevant information about participants include: gender, medical conditions, location, number of people participating. Do not contain participant mentions without relevant information.
question:
Cardiovascular reactivity to psychological stress may be one mechanism for the enhanced risk , but the small number of studies examining whether OC users who smoke have greater reactivity have produced mixed results .
answer:
OC users who smoke


question:
Short-term phasic activity was only found in 13 out of 40 of the normal infants ( 32.5 % ) .
answer:
40 of the normal infants


question:
Children presenting with GABHS pharyngitis were randomised to oral amoxicillin 1500 mg QD ( or 750 mg if bodyweight was < or=30 kg ) or to oral penicillin V 500 mg BID ( or 250 mg if bodyweight was < or=20 kg ) for 10 days .
answer:

not found