專題演講

2018/05/22(Tue)     14:00 -15:00    3F Conference Room(Library)

Title

Restricted diffusion in soft matter and cells

Speaker

Prof. John Roy de Bruyn

Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, Canada

Abstract

Diffusion is an important physical process in many systems, from gases to biological cells. In the simplest case, a diffusing particle undergoes a random walk and its mean squared displacement increases linearly with time. In many cases, however, the diffusion is not ideal: The motion of the diffusing species can be restricted in a variety of ways, leading to “sub-diffusion” in which the mean squared displacement increases more slowly. I will discuss experiments on the restricted diffusion of tracer particles in soft-matter systems close to a gel transition, and on the diffusion of a transmembrane protein in the cell membrane. In the soft materials, we gain insight into the microstructure of the systems and their temporal evolution as they gel. The membrane diffusion results give us information about membrane microstructure and indicate that the protein we studied is continuously recycled by the cell.