scholarly journals A first-passage algorithm for the hydrodynamic friction and diffusion-limited reaction rate of macromolecules

1997 ◽  
Vol 106 (9) ◽  
pp. 3761-3771 ◽  
Author(s):  
James A. Given ◽  
Joseph B. Hubbard ◽  
Jack F. Douglas
Keyword(s):  
Reaction Rate ◽  
First Passage ◽  
Hydrodynamic Friction ◽  
Diffusion Limited ◽  
And Diffusion ◽  
Diffusion Limited Reaction

Diffusion-limited reaction rate theory for two-dimensional systems

1983 ◽  
Vol 387 (1792) ◽  
pp. 147-170 ◽  
Keyword(s):  
Reaction Rate ◽  
Rate Function ◽  
Three Dimensions ◽  
Square Lattice ◽  
Rate Theory ◽  
Two Dimensional ◽  
Irreversible Reaction ◽  
Diffusion Limited ◽  
Condensed Phase Reactions ◽  
Diffusion Limited Reaction

The Noyes and Smoluehowski diffusion-limited reaction rate theories are proved to be equivalent on a lattice. The Noyes theory is analysed and used to predict the kinetics of the two-dimensional irreversible reaction A + B → P. Only condensed phase reactions with molecules of A and B undergoing Brownian motion (diffusion) are discussed. For comparison, all calculations are done in both two and three dimensions. The two-dimensional rate function k N ( t ) in the equation d[A]/d t = d[B]/d t = - k N ( t ) [A] [B] asymptotically goes to zero as (In t ) -1 as t increases; the asymptotic expansion of k N ( t ) is derived from the expansion for the first-return probability in a random walk on a square lattice. The theoretical rate function is determined as a function of the probability α of reaction given an encounter. Although k N ( t ) is not significantly different from ‘empirical’ rate functions in a Monte Carlo simulation of a two-dimensional chemical reaction, it does differ from the rate function in a two-dimensional fluorescence quenching experiment.

TOF-SIMS Evidence of Intercalated Molecular Gases and Diffusion-Limited Reaction Kinetics in an α Particle-Irradiated PTFE Matrix

2006 ◽  
Vol 110 (4) ◽  
pp. 1820-1829 ◽  
Author(s):  
Gregory L. Fisher ◽  
Christopher Szakal ◽  
Christopher J. Wetteland ◽  
Nicholas Winograd
Keyword(s):  
Reaction Kinetics ◽  
Molecular Gases ◽  
Diffusion Limited ◽  
Tof Sims ◽  
And Diffusion ◽  
Diffusion Limited Reaction

A large portion of the astrocyte proteome is dedicated to perivascular endfeet, including critical components of the electron transport chain

2021 ◽  
pp. 0271678X2110041
Author(s):  
Jesse A Stokum ◽  
Bosung Shim ◽  
Weiliang Huang ◽  
Maureen Kane ◽  
Jesse A Smith ◽  
...  
Keyword(s):  
Electron Transport ◽  
Electron Transport Chain ◽  
Glycogen Storage ◽  
Subcellular Compartment ◽  
Diffusion Limited ◽  
Transport Chain ◽  
Critical Components ◽  
And Diffusion ◽  
Ubiquitous Presence ◽  
Astrocyte Endfeet

The perivascular astrocyte endfoot is a specialized and diffusion-limited subcellular compartment that fully ensheathes the cerebral vasculature. Despite their ubiquitous presence, a detailed understanding of endfoot physiology remains elusive, in part due to a limited understanding of the proteins that distinguish the endfoot from the greater astrocyte body. Here, we developed a technique to isolate astrocyte endfeet from brain tissue, which was used to study the endfoot proteome in comparison to the astrocyte somata. In our approach, brain microvessels, which retain their endfoot processes, were isolated from mouse brain and dissociated, whereupon endfeet were recovered using an antibody-based column astrocyte isolation kit. Our findings expand the known set of proteins enriched at the endfoot from 10 to 516, which comprised more than 1/5th of the entire detected astrocyte proteome. Numerous critical electron transport chain proteins were expressed only at the endfeet, while enzymes involved in glycogen storage were distributed to the somata, indicating subcellular metabolic compartmentalization. The endfoot proteome also included numerous proteins that, while known to have important contributions to blood-brain barrier function, were not previously known to localize to the endfoot. Our findings highlight the importance of the endfoot and suggest new routes of investigation into endfoot function.

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