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The main phase transition (Tm) of 100 nm large unilamellar vesicles (LUVs) of 1,2-dipalmitoylphosphatidylcholine (DPPC) was investigated using 1H NMR (proton magnetic resonance) in deuterium oxide, and both DSC (differential scanning calorimetry) and IR (infrared) spectroscopy in water and deuterium oxide. The ability of 1H NMR to determine Tm was demonstrated and the values obtained were in general agreement with those observed with DSC and IR. However, the temperature range of the transition observed by NMR was significantly broader than that observed with either DSC or IR. The effect of deuterium oxide on Tm was studied by comparing results obtained in water and deuterium oxide with DSC and IR. The results showed no significant difference in Tm or temperature range of transition determined in these solvents.
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http://dx.doi.org/10.1081/lpr-120014759 | DOI Listing |
Nat Chem
September 2025
Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA.
Proton transfer plays an important role in both hydrogen and oxygen evolution reactions during electrocatalytic water splitting to produce green hydrogen. However, directly adapting the conventional proton/deuterium kinetic isotope effect to study proton transfer in heterogeneous electrocatalytic processes is challenging. Here we propose using the shift in the Tafel slope between protic and deuteric electrolytes, or the Tafel slope isotope effect, as an effective probe of proton transfer characteristics.
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
September 2025
Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX.
The purpose of this study was to investigate the sex-specific differences in how late-midlife adults respond to short term disuse and rehabilitation. Sixteen, late-midlife adults, who were free of overt disease (8 males; 58±2 yr; BMI 29.4±0.
View Article and Find Full Text PDFAm J Clin Nutr
September 2025
Population Policy and Practice Department, University College London, Great Ormond Street Institute of Child Health, London, United Kingdom.
Background: Total body water (TBW) is commonly used to derive estimates of body composition. The deuterium oxide dose-to-mother (DTM) technique for measuring breast milk intake requires an estimate of infant TBW. The DTM calculation employs a prediction equation for estimating infant TBW from body weight (TBW), but the general validity of this equation is unknown.
View Article and Find Full Text PDFSensors (Basel)
August 2025
Department of Exercise Science and Sport Management, Kennesaw State University, Kennesaw, GA 30144, USA.
Background: Multifrequency bioelectrical impedance devices such as the InBody 770 (IB770) offer faster measurements and lower costs compared with other body composition assessments. This study validated measures from IB770 against the deuterium oxide dilution technique (D2O) and DXA and compared a four-compartment (4C) model using total body water (TBW) derived from IB770 compared with D2O.
Methods: A total of 55 adult females (mean ± SD, age: 21.
Molecules
August 2025
College of Biological Science, University of Guelph, Guelph, ON N1G 2W1, Canada.
Metabolite fingerprint profiling is a robust tool for verifying suppliers of authentic botanical ingredients. While comparative studies exist, few apply identical conditions across multiple species; this study utilized a cross-species comparison to identify versatile solvents despite biochemical variability. Multiple solvents were used for sample extraction prior to analysis by proton NMR and liquid chromatography-mass spectrometry (LC-MS) for multiple botanicals including , , , , , , , , and .
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