The rate constants and kinetic isotope effects for the O(P) + CH reaction have been investigated with the quantum instanton method in full dimensionality. The calculated rate constants are in good agreement with the experimental values above 400 K, below which the measured values are scattered. Compared to other theoretical approaches, the quantum instanton method predicts the largest quantum tunneling effect, so it gives the largest rate constants at low temperatures. The calculated kinetic isotope effects are always much larger than 1 and increase with decreasing temperature, due to the zero-point energy and quantum tunneling. Our calculations on different potential energy surfaces demonstrate that the potential energy barrier shape dominates the magnitude of quantum tunneling and has a great effect on the kinetic isotope effect.
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http://dx.doi.org/10.1021/acs.jpca.6b07029 | DOI Listing |
Environ Sci Technol
January 2025
School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China.
Organophosphorus pesticides (OPs) pose significant environmental and health risks, and their detoxification through catalytic hydrolysis using zirconium-based metal-organic frameworks (Zr-MOFs) has attracted considerable interest due to the strong Lewis acid metal ions. Albeit important, the defects of the materials for OP hydrolysis (e.g.
View Article and Find Full Text PDFMicrobiol Spectr
January 2025
Department of Biology and Chemistry, Changwon National University, Changwon, South Korea.
Unlabelled: Global aquaculture production faces the challenge of biologically cycling nitrogenous waste. Biofloc technology (BFT) systems offer the potential to reduce water consumption and eliminate waste products by using beneficial microorganisms to convert waste into usable nutrients or non-toxic molecules. Unlike flow-through systems (FTS), which depend on continuous water exchange and result in higher operational costs as well as limited microbiome stability, BFT operates without the need for constant water exchange.
View Article and Find Full Text PDFActa Otolaryngol
January 2025
ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, PR China.
Background: Vestibular migraine (VM) and Menière's disease (MD) have numerous overlapping symptoms. Distinguishing the two common recurrent vestibulopathies was challenging.
Objectives: To assess the characteristics of hearing loss and the horizontal semicircular canal function in VM and MD.
The study aimed to verify the physiological and metabolic parameters associated with the time to task failure (TTF) during cycling exercise performed within the severe-intensity domain. Forty-five healthy and physically active males participated in two independent experiments. In experiment 1, after a graded exercise test, participants underwent constant work rate cycling efforts (CWR) at 115% of peak power output to assess neuromuscular function (Potentiated twitch) pre- and post-exercise.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106, India.
Estimating rare event kinetics from molecular dynamics simulations is a non-trivial task despite the great advances in enhanced sampling methods. Weighted Ensemble (WE) simulation, a special class of enhanced sampling techniques, offers a way to directly calculate kinetic rate constants from biased trajectories without the need to modify the underlying energy landscape using bias potentials. Conventional WE algorithms use different binning schemes to partition the collective variable (CV) space separating the two metastable states of interest.
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