We prove rigorously and demonstrate in simulations that, for a potential system staying initially at the bottom of a well, the escape flux over the barrier grows on times of the order of a period of eigenoscillation in a stepwise manner, provided that friction is small or moderate. If the initial state is not at the bottom of the well, then, typically, some of the steps transform into oscillations. The stepwise/oscillatory evolution at short times appears to be a generic feature of a noise-induced flux.
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http://dx.doi.org/10.1103/PhysRevLett.86.1665 | DOI Listing |
Phys Chem Chem Phys
January 2025
Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
One of the most subtle steps in the single-molecule approach to the flux through the membrane channel, which uses the one-dimensional Smoluchowski equation, is to describe the molecule's "behavior" at the contacts between the channel openings and the bulk. Earlier, to handle this issue, we introduced the so-called "radiation boundary conditions" that account for the interplay between the two types of trajectories of the molecules starting at the openings, specifically, the ones that eventually return to the channel and the ones that escape to infinity. The latter trajectories represent the true translocation events on the condition that initially the molecule entered the channel from the opposite side.
View Article and Find Full Text PDFEnviron Sci Technol
December 2024
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Tire and road wear particles (TRWPs) are an appreciable source of microplastics (MPs); however, knowledge of their large-scale occurrence and mass flux based on robust sampling and quantification is limited. Herein, the first city-wide survey of TRWPs across environmental compartments (road dust, snowbank, water, and sediment from rivers and lakes) along four ring roads (beltways) in Beijing was performed. TRWP concentrations ( = 74) were quantified using bonded-sulfur as a marker to reveal the city-wide spatial distributions and adopted to establish a framework estimating TRWP emission factors (EFs) and mass flux from generation to remote atmospheric, terrestrial, and aquatic transport.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Department of Medical Biochemistry and Microbiology, The Biomedical Center, Uppsala University, Uppsala, 75123, Sweden.
The high transmissibility and mutation ability of coronaviruses enable them to easily escape existing immune protection and also pose a challenge to existing antiviral drugs. Moreover, drugs only targeting viruses cannot always attenuate the "cytokine storm". Herein, a synthetic heparan sulfate (HS) mimetic, HMSA-06 is reported, that exhibited antiviral activities against both the SARS-CoV-2 prototype and Omicron strains by targeting viral entry and replication.
View Article and Find Full Text PDFSci Bull (Beijing)
December 2024
Engineering Research Center of Solar Power and Refrigeration (MOE), Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address:
Solar evaporation is a sustainable pathway for diverse water treatment technologies. The contactless evaporation stands out for its superior anti-contamination property. However, the evaporation performance is significantly limited by the non-contact heat transport, which is more pronounced in scalable applications with suppressed vapor escaping and tilted solar irradiation.
View Article and Find Full Text PDFMicrob Pathog
February 2025
Center of Clinical Laboratory, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China; Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, 361004, China; Xiamen Clinical Laboratory Quality Control Center, Xiamen, Fujian, China. Electronic address:
Increasing evidence suggests that immune cell clearance is closely linked to cellular metabolism. Neurosyphilis, a severe neurological disorder caused by Treponema pallidum (T. pallidum) infection, significantly impacts the brain.
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