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Recent observations suggest a large and unknown daytime source of nitrous acid (HONO) to the atmosphere. Multiple mechanisms have been proposed, many of which involve chemistry that reduces nitrogen dioxide (NO2) on some time scale. To examine the NO2 dependence of the daytime HONO source, we compare weekday and weekend measurements of NO2 and HONO in two U.S. cities. We find that daytime HONO does not increase proportionally to increases in same-day NO2, i.e., the local NO2 concentration at that time and several hours earlier. We discuss various published HONO formation pathways in the context of this constraint.
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http://dx.doi.org/10.1021/acs.est.5b02511 | DOI Listing |
ACS Sens
September 2025
School of Electronic Information, Northwest University, Xi'an 710127, China.
High-sensitivity, multiparameter sensing is increasingly critical for environmental monitoring and electronics. Existing sensing platforms struggle to integrate precise, rapid, and stable monitoring of parts per billion-level hazardous gases and temperature within a single miniaturized device. This study developed a novel sensor based on two-dimensional (2D) indium selenide (InSe), complemented by first-principles density functional theory calculations elucidating the layer-dependent NO adsorption mechanism.
View Article and Find Full Text PDFArch Gerontol Geriatr
August 2025
Aging and Later Life, Amsterdam Public Health Research Institute, Amsterdam, the Netherlands; Amsterdam UMC location Vrije Universiteit Amsterdam, Epidemiology and Data Science, Amsterdam, the Netherlands. Electronic address:
Background: Ageing in place has been promoted in the Netherlands to encourage optimal functional ability (FA) and independent living among older adults. FA is likely dependent on intrinsic capacity (IC), a composite measure of an individual's mental and physical capacities-and its interaction with the physical environment in which people live. This study aimed to examine the association between IC and FA, as well as to explore how the physical environment may modify this relationship in older adults.
View Article and Find Full Text PDFJ Phys Chem A
September 2025
National Key Laboratory of Solid Propulsion, School of Astronautics, Northwestern Polytechnical University, Xi'an 710072, China.
Unsymmetrical dimethylhydrazine (UDMH) is a widely used hypergolic rocket fuel. It is one of the most commonly used fuels for attitude control engines, such as those in missiles, satellites, spacecraft, and launch vehicles. We conducted a high-level theoretical study to develop a detailed combustion kinetic mechanism for UDMH, focusing on crucial elementary reactions.
View Article and Find Full Text PDFJ Mater Chem B
September 2025
Guangdong Key Laboratory of Nanomedicine, CAS-HK Joint Lab of Biomaterials, CAS Key Laboratory of Biomedical Imaging Science and System, Shenzhen Key Laboratory of Metabolic Halth, Shenzhen Metabolism and Reproductive Targeted Delivery Proof-of-Concept Center, Shenzhen Engineering Laboratory of Nano
Bacterial infections pose significant challenges in clinical diagnostics and microbiological research due to the need for rapid, sensitive, and specific detection methods. Herein, we report the development of Cy5-NO2, a novel nitro-containing fluorescent probe designed for real-time monitoring of bacterial nitroreductase (NTR) activity. Cy5-NO2 is synthesized through a streamlined, high-yield process without chromatography, yielding a stable compound confirmed by X-ray crystallography and spectroscopic methods.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
August 2025
School of Biological Engineering, Dalian Polytechnic University, Dalian 116034, PR China. Electronic address:
In this study, the influence of various substituents on the fluorescence properties and excited-state intramolecular proton transfer (ESIPT) process of 2-hydroxy-3-phenyliminomethyl-10-butyl phenothiazine (Ph) were systematically investigated using density-functional theory (DFT) and time-dependent density-functional theory (TD-DFT). Five Ph derivatives were strategically designed by incorporating two electron-donating groups (NH, MeO) and three electron-withdrawing groups (CN, CHO, NO). Analysis the structural parameters and IR spectra revealed that the intramolecular hydrogen bonding in Ph and its derivatives was enhanced in the S state.
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