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.

Antipyrine reacts quickly with hydroxyl radicals to form para- and ortho-hydroxyantipyrine .
not found

A tendency towards increased plasma 6-keto-prostaglandin F1 alpha concentration and decreased serum thromboxane B2 concentration was found during the period of regular exercise , but prostaglandin E2 concentrations remained unchanged .
not found

A total of 57 consecutive patients with primary ureteropelvic junction obstruction were randomized to undergo 7/14Fr internal endopyelotomy stent placement for 2 ( group 1 ) and 4 ( group 2 ) weeks .

57 consecutive patients with primary ureteropelvic junction obstruction