The paper describes a method for experimental evaluation of molecular diffusion in aqueous solutions. is based on solving the equation non-stationary dimensionless form

The diffusion of fractal aggregates constructed with the method by Thouy and Jullien [J. Phys. A 27, 2953 (1994)] comprised of N(p) spherical primary particles was studied as a function of the aggregate mass and fractal dimension using molecular dynamics simulations. It is shown that finite-size effects have a strong impact on the apparent value of the diffusion coefficient (D), but these can b...

Heterocyst-forming cyanobacteria grow as filaments in which intercellular molecular exchange takes place. During the differentiation of N2-fixing heterocysts, regulators are transferred between cells. In the diazotrophic filament, vegetative cells that fix CO2 through oxygenic photosynthesis provide the heterocysts with reduced carbon and heterocysts provide the vegetative cells with fixed nitr...

tion. If the researcher offers to assist the Eye Bank in tissue procurement, a partnership is beginning. This might include going with an eye banker to present inservice programs to a group of doctors, nurses, hospital administrators, or others who are close to the supply of tissue. It may be appearing with the eye banker on a radio talk show to explain the need of eye donations. It may be that...

Transmembrane exchange of materials is a fundamental process in biology. Molecular dynamics provides a powerful method to investigate in great detail various aspects of the phenomenon, particularly the permeation of small uncharged molecules, which continues to pose a challenge to experimental studies. We will discuss some of the recent simulation studies investigating the role of lipid-mediate...

We performed ab initio molecular dynamics simulations of the C2c and Cmca-12 phases of hydrogen at pressures from 210 to 350 GPa. These phases were predicted to be stable at 0 K and pressures above 200 GPa. However, systematic studies of temperature impact on properties of these phases have not been performed so far. Filling this gap, we observed that on temperature increase diffusion sets in t...

Though flux freezing is a good approximation frequently assumed for molecular clouds, ambipolar diffusion (AD) is inevitable at certain scales. The scale at which AD sets in can be a crucial parameter for turbulence and the star formation process. However, both observation and simulation of AD are very challenging and our knowledge of it is very limited. We recently proposed (Li and Houde 2008)...

Random motion within the cytoplasm gives rise to molecular diffusion; this motion is essential to many biological processes. However, in addition to thermal Brownian motion, the cytoplasm also undergoes constant agitation caused by the activity of molecular motors and other nonequilibrium cellular processes. Here, we discuss recent work that suggests this activity can give rise to cytoplasmic m...

Diffusion of inner membrane proteins is a prerequisite for correct functionality of mitochondria. The complicated structure of tubular, vesicular or flat cristae and their small connections to the inner boundary membrane impose constraints on the mobility of proteins making their diffusion a very complicated process. Therefore we investigate the molecular transport along the main mitochondrial ...