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.

At present no study of gastric dysrhythmia , measured with epigastric impedance , has been presented , and the purpose of the present study was to investigate gastric rhythms by means of impedance gastrography in control infants , compared to infants with different gastrointestinal diseases , before and after treatment of their disease .
infants with different gastrointestinal diseases

Daily supplementation significantly increased plasma concentrations of alpha-tocopherol and beta-carotene in the supplemented group ( Delta 14.4 ( SE 3.2 ) and 0.4 ( se 0.1 ) micromol/l ; P < 0.001 and P < 0.01 ) .
not found

Quantitative muscle strength testing sum scores declined in both treatment groups , -0.2 % for methotrexate and -3.4 % for placebo ( 95 % confidence interval = -2.5 % to +9.1 % for difference ) .

not found

