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: Circadian phase-shifting effects of a laboratory environment: a clinical trial with bright and dim light. | Journal of Circadian Rhythms BioMed Central Research Open Access Circadian phase-shifting effects of a laboratory environment a clinical trial with bright and dim light Shawn D Youngstedt 1 Daniel F Kripke2 Jeffrey A Elliott2 and Katharine M Rex2 Address department of Exercise Science Norman J. Arnold School of Public Health University of South Carolina Columbia SC 29208 USA and department of Psychiatry and Sam and Rose Stein Institute for Research on Aging University of California San Diego USA Email Shawn D Youngstedt - syoungstedt@ Daniel F Kripke - dkripke@ Jeffrey A Elliott - jelliott@ Katharine M Rex - krex@ Corresponding author Published 09 September 2005 Received 30 August 2005 Accepted 09 September 2005 Journal of Circadian Rhythms 2005 3 11 doi 1740-3391-3-11 This article is available from http content 3 1 1 1 2005 Youngstedt 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 Our aims were to examine the influence of different bright light schedules on mood sleep and circadian organization in older adults n 60 ages 60-79 years with insomnia and or depression contrasting with responses of young healthy controls n 30 ages 20-40 years . Methods Volunteers were assessed for one week in their home environments. Urine was collected over two 24-hour periods to establish baseline acrophase of 6-sulphatoxymelatonin aMT6s excretion. Immediately following home recording volunteers spent five nights and four days in the laboratory. Sleep periods were fixed at eight hours in darkness consistent with the volunteers usual sleep periods. Volunteers were randomly assigned to one of three light treatments four hours per day within the wake period
