The mammalian circadian system consists of a master clock in the brain that synchronizes subsidiary oscillators in peripheral tissues. The master clock maintains phase coherence in peripheral cells through systemic cues such as feeding-fasting and temperature cycles. Here, we examined the role of oxygen as a resetting cue for circadian clocks. We continuously measured oxygen levels in living animals and detected daily rhythms in tissue oxygenation. Oxygen cycles, within the physiological range, were sufficient to synchronize cellular clocks in a HIF1α-dependent manner. Furthermore, several clock genes responded to changes in oxygen levels through HIF1α. Finally, we found that a moderate reduction in oxygen levels for a short period accelerates the adaptation of wild-type but not of HIF1α-deficient mice to the new time in a jet lag protocol. We conclude that oxygen, via HIF1α activation, is a resetting cue for circadian clocks and propose oxygen modulation as therapy for jet lag.
Aim: Intraoperative lung-protective ventilation strategies (LPVS) have been shown to improve lung oxygenation and prevent postoperative pulmonary problems in surgical patients. However, the application of positive end-expiratory pressure (PEEP)-based LPVS in emergency traumatic brain injury (TBI) has not been thoroughly explored. The purpose of this study is to evaluate the effects of drive pressure-guided individualized PEEP on perioperative pulmonary oxygenation, postoperative pulmonary complications, and recovery from neurological injury in patients with TBI.
Human mesenchymal stromal cells (MSCs) are attractive for both medical practice and biomedical research. Nonfreezing short-term storage may provide safe and simple transportation and promote the practical use of MSCs. We aimed to determine the duration of efficient storage at ambient temperature (22°C) of human dermal MSCs in different three-dimensional organization and to investigate the role of cell metabolic mode in the resistance to the ambient storage damaging factors.
Sperm cryopreservation is a useful storage technique in artificial insemination. Nanoparticles and nanovesicles such as exosomes are widely used in sperm cryopreservation procedures to alleviate cold-induced injury inflicted during sperm freezing. The objective of the present study was to examine the impact of varying concentrations of exosomes derived from seminal plasma added to a freezing extender on the quality of post-thawed bull sperm.
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
Introduction: The striped hamster, often parasitized by ectoparasites in nature, is an ideal model for studying host-ectoparasite molecular interactions. Investigating the response to ectoparasites under laboratory conditions helps elucidate the mechanism of host adaptations to ectoparasite pressure.
Methods: Using transcriptome sequencing, we analyzed gene expression in striped hamsters after short-term (3 days) and long-term (28 days) flea () parasitism.
Anaerobic ammonium oxidation coupled with Fe(III) reduction (Feammox) is an essential process in the geochemical iron and nitrogen cycling. This study explores Feammox-based nitrogen removal in a continuous laboratory up-flow bioreactor stimulated by intermittently adding 5 mM Fe(OH) at intervals of approximately two months. The feed was synthetic wastewater with a relatively low ammonium concentration (∼100 mg N/L), yet without organic carbon in order to test its autotrophic nitrogen removal performance.
