Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Diffusion

Diffusion

Diffusion is a type of passive transport. In passive transport, a substance tends to move from an area of high concentration to an area of low concentration until the concentration is equal across the space. For example, take the diffusion of substances through the air. When someone opens a perfume bottle in a room filled with people, the perfume is at its highest concentration in the bottle and is at its lowest at the edges of the room. The perfume vapor will diffuse, or spread away, from the...

Diffusion

Diffusion

Diffusion is the passive movement of substances down their concentration gradients—requiring no expenditure of cellular energy. Substances, such as molecules or ions, diffuse from an area of high concentration to an area of low concentration in the cytosol or across membranes. Eventually, the concentration will even out, with the substance moving randomly but causing no net change in concentration. Such a state is called dynamic equilibrium, which is essential for maintaining overall...

Protein Diffusion in the Membrane

Protein Diffusion in the Membrane

Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...

Theories of Dissolution: Diffusion Layer Model

Theories of Dissolution: Diffusion Layer Model

Dissolution, the process by which drug particles dissolve in a solvent, is explained by the diffusion layer model, a theoretical framework that simulates the absorption of oral drugs and allows us to analyze experimental data.
This process starts with a thin layer, saturated with the drug, forming at the interface between the solid and liquid. The solute then diffuses from this layer into the main solution. The Noyes-Whitney equation suggests that the rate of dissolution relies on the diffusion...

Behavior of Gas Molecules: Molecular Diffusion, Mean Free Path, and Effusion

Behavior of Gas Molecules: Molecular Diffusion, Mean Free Path, and Effusion

Although gaseous molecules travel at tremendous speeds (hundreds of meters per second), they collide with other gaseous molecules and travel in many different directions before reaching the desired target. At room temperature, a gaseous molecule will experience billions of collisions per second. The mean free path is the average distance a molecule travels between collisions. The mean free path increases with decreasing pressure; in general, the mean free path for a gaseous molecule will be...

Passive Diffusion: Overview and Kinetics

Passive Diffusion: Overview and Kinetics

Passive diffusion is a critical process that allows small lipophilic drugs to cross the cell membrane along a concentration gradient. This mechanism's efficiency depends on four primary factors: the membrane's surface area, the drug's lipid-water partition coefficient, the concentration gradient, and the membrane's thickness.
When administered orally, drugs establish a substantial concentration gradient between the gastrointestinal (GI) lumen and the bloodstream, expediting their diffusion into...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Collinear velocity relaxation of two spheres in a viscous incompressible fluid.

Physical review. E·2020

Same author

Vanishing mean volume velocity in isothermal isobaric diffusion of a binary fluid mixture.

The Journal of chemical physics·2018

Same author

Generalized Einstein relation for the mutual diffusion coefficient of a binary fluid mixture.

The Journal of chemical physics·2017

Same author

Effect of fluid inertia on the motion of a collinear swimmer.

Physical review. E·2017

Same author

Swimming of a deformable slab in a viscous incompressible fluid with inertia.

Physical review. E, Statistical, nonlinear, and soft matter physics·2016

Same author

Effect of inertia on laminar swimming and flying of an assembly of rigid spheres in an incompressible viscous fluid.

Physical review. E, Statistical, nonlinear, and soft matter physics·2015

Search research articles

Related Experiment Video

Updated: Jun 20, 2026

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

Published on: September 26, 2016

Fluctuation theory of single-file diffusion.

B U Felderhof¹

¹Institut für Theoretische Physik A, RWTH Aachen, Templergraben 55, 52056 Aachen, Germany. ufelder@physik.rwth-aachen.de

The Journal of Chemical Physics

|August 21, 2009

Summary

In single-file systems, particle displacement grows with the square root of time, not linearly. This study derives single-file mobility using fluctuation theory and relates it to collective diffusion and compressibility.

Area of Science:

Physics
Statistical Mechanics
Soft Matter

Background:

Brownian motion describes random particle movement.
In one-dimensional systems, particles cannot pass each other, altering diffusion dynamics.
Previous models, like the generalized Smoluchowski equation, have explored these systems.

Purpose of the Study:

To investigate the anomalous diffusion of Brownian particles in a one-dimensional single-file system.
To derive the single-file mobility coefficient using fluctuation theory.
To connect single-file mobility to fundamental physical quantities.

Main Methods:

Analysis of mean square displacement in a one-dimensional Brownian particle suspension.
Application of fluctuation theory, including velocity time scale and fluctuation-dissipation theorem.

More Related Videos

A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts

A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts

Published on: December 1, 2018

Spot Variation Fluorescence Correlation Spectroscopy for Analysis of Molecular Diffusion at the Plasma Membrane of Living Cells

Spot Variation Fluorescence Correlation Spectroscopy for Analysis of Molecular Diffusion at the Plasma Membrane of Living Cells

Published on: November 12, 2020

Related Experiment Videos

Last Updated: Jun 20, 2026

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

Published on: September 26, 2016

A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts

A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts

Published on: December 1, 2018

Spot Variation Fluorescence Correlation Spectroscopy for Analysis of Molecular Diffusion at the Plasma Membrane of Living Cells

Spot Variation Fluorescence Correlation Spectroscopy for Analysis of Molecular Diffusion at the Plasma Membrane of Living Cells

Published on: November 12, 2020

Expressing single-file mobility in terms of collective diffusion and isothermal osmotic compressibility.

Main Results:

Mean square displacement exhibits a square root of time dependence at long times, deviating from linear behavior.
The single-file mobility coefficient was successfully derived from fluctuation theory.
The derived single-file mobility is consistent with previous findings based on the generalized Smoluchowski equation.

Conclusions:

Single-file dynamics lead to sub-diffusive behavior (square root of time dependence).
Fluctuation theory provides a robust framework for understanding single-file mobility.
The study confirms the relationship between single-file mobility, collective diffusion, and compressibility.