False negative tests for SARS-CoV-2 are common and have important public health and medical implications. We tested the hypothesis of diurnal variation in viral shedding by assessing the proportion of positive versus negative SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) tests and cycle time (Ct) values among positive samples by the time of day. Among 86,342 clinical tests performed among symptomatic and asymptomatic patients in a regional health care network in the southeastern United States from March to August 2020, we found evidence for diurnal variation in the proportion of positive SARS-CoV-2 tests, with a peak around 1400 h and 1.7-fold variation over the day after adjustment for age, sex, race, testing location, month, and day of week and lower Ct values during the day for positive samples. These findings have important implications for public health testing and vaccination strategies.
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http://dx.doi.org/10.1177/07487304211051841 | DOI Listing |
Bone Res
January 2025
Department of Orthodontics, State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.
Circadian rhythm is ubiquitous in nature. Circadian clock genes such as Bmal1 and Clock form a multi-level transcription-translation feedback network, and regulate a variety of physiological and pathological processes, including bone and cartilage metabolism. Deletion of the core clock gene Bmal1 leads to pathological bone alterations, while the phenotypes are not consistent.
View Article and Find Full Text PDFNeuroscience
January 2025
Laboratory of Epileptogenesis, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur St, 02-093 Warsaw, Poland. Electronic address:
Our previous in silico data indicated an overrepresentation of the ZF5 motif in the promoters of genes in which circadian oscillations are altered in the ventral hippocampus in the pilocarpine model of temporal lobe epilepsy in mice. In this study, we test the hypothesis that the Zbtb14 protein oscillates in the hippocampus in a diurnal manner and that this oscillation is disrupted by epilepsy. We found that Zbtb14 immunostaining is present in the cytoplasm and cell nuclei.
View Article and Find Full Text PDFPLoS One
January 2025
UCL Institute of Ophthalmology, University College London, London, United Kingdom.
The outer retina (OR) is highly energy demanding. Impaired energy metabolism combined with high demands are expected to cause energy insufficiencies that make the OR susceptible to complex blinding diseases such as age-related macular degeneration (AMD). Here, anatomical, physiological and quantitative molecular data were used to calculate the ATP expenditure of the main energy-consuming processes in three cell types of the OR for the night and two different periods during the day.
View Article and Find Full Text PDFJ Am Heart Assoc
January 2025
Center for Coronary Artery Disease, Division of Cardiology Beijing Anzhen Hospital, Capital Medical University Beijing China.
Background: The circadian rhythm of myocardial infarction (MI) in patients with obstructive sleep apnea (OSA) remains disputable and no studies have directly evaluated the relationship between nocturnal hypoxemia and the circadian rhythm of MI. The aim of the current study was to evaluate the association of OSA and nocturnal hypoxemia with MI onset during the night.
Methods: Patients with MI in the OSA-acute coronary syndrome (ACS) project (NCT03362385) were recruited.
Food Funct
January 2025
College of Food Science and Technology, Yunnan Agricultural University, Kunming, 650201, China.
The intestinal microbiota undergoes diurnal compositional and functional oscillations within a day, which affect the metabolic homeostasis of the host and exacerbate the occurrence of obesity. TB has the effect of reducing body weight and lipid accumulation, but the mechanism of improving obesity caused by a high-fat diet based on the circadian rhythm of intestinal microorganisms has not been clarified. In this study, we used multi-omics and imaging approaches to investigate the mechanism of TB in alleviating obesity in mice based on the circadian rhythm of gut microbiota.
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