The role of the pineal hormone melatonin in human physiology is uncertain. Previous studies correlated plasma melatonin levels with several physiological parameters or determined the responses to pharmacological doses of melatonin during daylight hours. We established an acute model that is more rigorously physiological. Constant nocturnal bright light in sleep-deprived normal men resulted in low plasma melatonin levels throughout the night, in contrast to sleep in the dark and dim light sleep deprivation nights. Subsequently, melatonin was infused during bright light exposure to approximate physiological levels. Plasma GH and PRL measurements in these four conditions revealed an effect of sleep deprivation independent of the presence or absence of melatonin. A subsample of these men had an intermediate level of melatonin suppression with 500 lux light intensity, relative to those during sleep and bright light. The results suggest that melatonin has no acute modulatory effect on the secretion of these two sleep-related hormones.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1210/jcem-65-5-847 | DOI Listing |
PLoS Biol
January 2025
Department of Pharmacology and Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America.
Pathogenic mutations that cause rhodopsin misfolding lead to a spectrum of currently untreatable blinding diseases collectively termed retinitis pigmentosa. Small molecules to correct rhodopsin misfolding are therefore urgently needed. In this study, we utilized virtual screening to search for drug-like molecules that bind to the orthosteric site of rod opsin and improve its folding and trafficking.
View Article and Find Full Text PDFMater Horiz
January 2025
Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Beijing Advanced Innovation Center for Imaging Theory and Technology, Capital Normal University, Beijing 100048, P. R. China.
Linearly-polarized organic electroluminescent devices have gained significant attention due to their potential applications across various fields. However, traditional thin-film organic light-emitting diodes (OLEDs) face significant challenges, primarily due to the necessity of incorporating complex optical elements. In this study, we present linearly-polarized OLEDs (LP-OLEDs) based on organic single crystals that we have designed and prepared.
View Article and Find Full Text PDFCell-type-specific activation of parvalbumin (PV)-expressing neurons in the external globus pallidus (GPe) through optogenetics has shown promise in facilitating long-lasting movement dysfunction recovery in mice with Parkinson's disease. However, its translational potential is hindered by adverse effects stemming from the invasive implantation of optical fibers into the brain. In this study, we have developed a non-invasive optogenetics approach, utilizing focused ultrasound-triggered mechanoluminescent nanotransducers to enable remote photon delivery deep in the brain for genetically targeted neuromodulation.
View Article and Find Full Text PDFNanoscale
January 2025
Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085, India.
Sub-cellular organelle anomalies are frequently observed in diseases such as cancer. Early and precise diagnosis of these alterations can be crucial for patient outcomes. However, current diagnostic tools using conventional organic dyes or metal quantum dots face limitations, including poor biocompatibility, stringent storage conditions, limited solubility in aqueous media, and slow staining speeds.
View Article and Find Full Text PDFMolecules
December 2024
Department of Science and Humanities, School of Engineering and Technology, CHRIST University, Bangalore 560029, Karnataka, India.
Using the solid-state reaction technique, varied YSiO phosphors activated by europium (Eu) ions at varied concentrations were made at calcination temperatures of 1000 °C and 1250 °C during sintering in an air environment. The XRD technique identified the monoclinic structure, and the FTIR technique was used to analyze the generated phosphors. Photoluminescence emission and excitation patterns were measured using varying concentrations of Eu ions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!