TASK DEFINITION: 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.
PROBLEM: However , deterioration in some responders with time suggests the need for maintenance protocols .

SOLUTION: not found

PROBLEM: Seventeen patients on chronic digitalis and diuretic therapy were randomized to receive either flosequinan ( n = 9 ) or placebo ( n = 8 ) in a double-blind fashion .

SOLUTION: not found

PROBLEM: Age-matched boys with ADHD ( 15 ) , ASD ( 18 ) , and controls ( 21 ) were compared with functional magnetic resonance imaging ( fMRI ) during a reversal task .

SOLUTION:
15 ) , ASD, 18 ) , and controls, 21