Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Phase delaying the human circadian clock with a single light pulse and moderate delay of the sleep/dark episode: no influence of iris color. | Journal of Circadian Rhythms BioMed Central Research Phase delaying the human circadian clock with a single light pulse and moderate delay of the sleep dark episode no influence of iris color Jillian L Canton1 Mark R Smith1 Ho-Sun Choi2 and Charmane I Eastman 1 Open Access Address biological Rhythms Research Laboratory Department of Behavioral Sciences Rush University Medical Center Chicago IL USA and 2Department of Ophthalmology Rush University Medical Center Chicago IL USA Email Jillian L Canton - jlcanton7@ Mark R Smith - Ho-Sun Choi - Ho_S_Choi@ Charmane I Eastman - ceastman@ Corresponding author Published 17 July 2009 Received 3 June 2009 Journal of Circadian Rhythms 2009 7 8 doi 1740-3391-7-8 Accepted I7 July 2009 This article is available from http content 7 1 8 2009 Canton et al licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background Light exposure in the late evening and nighttime and a delay of the sleep dark episode can phase delay the circadian clock. This study assessed the size of the phase delay produced by a single light pulse combined with a moderate delay of the sleep dark episode for one day. Because iris color or race has been reported to influence light-induced melatonin suppression and we have recently reported racial differences in free-running circadian period and circadian phase shifting in response to light pulses we also tested for differences in the magnitude of the phase delay in subjects with blue and brown irises. Methods Subjects blue-eyed n 7 brown eyed n 6 maintained a regular sleep schedule for 1 week before coming to the laboratory for a baseline phase assessment during which saliva was .
