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Diffusive flux into a stochastically gated tube
1Department of Mathematics, University of Utah, Salt Lake City, Utah 84112, USA.
The Journal of Chemical Physics
|May 12, 2026
Summary
This study extends flux estimates for diffusion-influenced reactions with stochastically gated entrances. The new formula accurately models complex geometries and varying diffusivities, improving predictions in biophysical systems.
Area of Science:
- Physical Chemistry
- Biophysics
- Chemical Kinetics
Background:
- Diffusion-influenced reactions are crucial in biophysical and biochemical processes.
- Previous estimates for diffusive flux through gated entrances were limited to narrow tubes.
- Stochastic gating introduces complexity in modeling reaction dynamics.
Purpose of the Study:
- To extend existing diffusive flux estimates for stochastically gated systems.
- To develop a formula applicable to non-narrow tubes and heterogeneous diffusivity.
- To validate the extended formula using stochastic simulations.
Main Methods:
- Derivation of an explicit flux estimate formula.
- Mathematical analysis to prove exactness in specific parameter regimes.
- Stochastic simulations to assess accuracy across broad parameter ranges.
Main Results:
- An explicit formula for diffusive flux through stochastically gated entrances was derived.
- The formula is valid for tubes of arbitrary width and differing bulk/tube diffusivities.
- Stochastic simulations confirmed the estimate's accuracy across a wide parameter space.
Conclusions:
- The derived flux estimate provides a more general and accurate model for diffusion-influenced reactions with stochastic gates.
- This work overcomes limitations of previous models concerning tube geometry and diffusivity variations.
- The findings offer improved predictive power for complex biophysical and chemical systems.
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