LED exposure and study groups rule is as following,
The 40
mice were randomly split into four groups (each contained 10
mice), including (1) white family LED irradiation for a consecutive 2-week period (2 hr/day), (2) white LED irradiation for a consecutive 4-week period (2 hr/day), (3) environmental light source with white family LED lamps (the illuminated light of 12-hr light/ 12-hr dark cycle with white family LED lamps), and (4) blank control (no LED exposure).