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.

Example Input: In conclusion , in 60-year-old subjects antioxidant supplementation had no effect on the exercise-induced increase in oxidative stress as measured by free radical products of antipyrine .
Example Output: 60-year-old subjects

Example Input: Ramipril reduced the risk for any progression ( OR , 0.87 ; 95 % CI , 0.78 to 0.97 ; P = 0.0146 ) .
Example Output: not found

Example Input: 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 .
Example Output:
OC users who smoke