The term “circadian rhythms” describes endogenous oscillations with ca. 24-h period
associated with the earth's daily rotation and light/dark cycle. Such rhythms reflect the …

The circadian clock evolved in diverse organisms to integrate external environmental
changes and internal physiology. The clock endows the host with temporal precision and …

Humans, like all mammals, partition their daily behaviour into activity (wakefulness) and rest
(sleep) phases that differ largely in their metabolic requirements. The circadian clock …

INTRODUCTION The interaction among cell-autonomous circadian oscillators—daily cycles
of activity–rest and feeding–fasting—produces diurnal rhythms in gene expression in almost …

Circadian clocks are endogenous oscillators that control 24-h physiological and behavioral
processes. The central circadian clock exerts control over myriad aspects of mammalian …

Hepatocytes operate in highly structured repeating anatomical units termed liver lobules.
Blood flow along the lobule radial axis creates gradients of oxygen, nutrients and hormones …

The Earth turns on its axis every 24 h; almost all life on the planet has a mechanism—
circadian rhythmicity—to anticipate the daily changes caused by this rotation. The molecular …

The mammalian circadian clock has evolved as an adaptation to the 24-h light/darkness
cycle on earth. Maintaining cellular activities in synchrony with the activities of the organism …

Aging is characterized by an increased vulnerability to infection and the development of
inflammatory diseases, such as atherosclerosis, frailty, cancer and neurodegeneration …

Abstract Circadian (∼ 24-hour) timing systems pervade all kingdoms of life and temporally
optimize behavior and physiology in humans. Relatively recent changes to our …