Biomedical subjects

A Fuliński

Publications and source records attributed to A Fuliński.

5 recordsLinked to original sources

PubMed2005

Asymmetric nanodiffusion.

The asymmetric diffusion through conical nanopores is described by the diffusional model. Diffusion is several times faster; when the concentration gradient points from the wide towards the narrow opening of the cone than in the opposite direction. The asymmetric diffusion appears either when the diffusion coefficient depends on the concentration or when the diffusing substances interact with the channel (i.e., ions moving through channels with charged walls). These results suggest that asymmetric nanopores can act as molecular (ionic) filters which could be used for retrieving the molecules of a given component from solutions in which its concentration fluctuates strongly, and only occasionally attains high values.

Journal Article↗

PubMed2005

Asymmetric diffusion through synthetic nanopores.

We show that diffusion currents for a membrane containing a single conical nanopore with a fixed surface charge and small enough opening diameter depend on the concentration gradient direction. We interpret the results based on the effect of salt concentration on the thickness of the electrical double layer within the nanopore associated with the nanopore's surface charge and the distribution of electric fields inside the pore. The experimental observations are described by a diffusional model based on the Smoluchowski-Nernst-Planck equation.

Chlorine↗

PubMed2002

Fabrication of a synthetic nanopore ion pump.

We present a synthetic nanodevice, which transports potassium ions against their concentration gradient if stimulated with external field fluctuations. It consists of a single, conical pore, created in a thin polyethylene terephthalate film. The pumping mechanism is similar to one of longitudinally oscillating deterministic ratchets.

Journal Article↗

PubMed2002

Origin of 1/f(alpha) noise in membrane channel currents.

The transport characteristics of nanofabricated synthetic pores of similar dimensions to those of biological channels is reported. By comparison of the ion current through single synthetic and biological channels we show that the 1/f(alpha) noise indeed originates from the channel's opening-closing process. Strong evidence has been provided that the latter is related to the underlying motions of channel wall constituents.

Animals↗

PubMed2001

Constructive role of noise in signal transmissions by biomembrane proteins.

We discuss new examples of the constructive role of environmental fluctuations in biophysical processes, namely quantitative enhancement and qualitative sharpening of the outgoing signal in the intercellular signal transduction, e.g., in the synaptic links. An experimental check in a chemical flow reactor is suggested.

Biocompatible Materials↗