Modeling and computing transport in the subsurface is a difficult problem that requires good understanding of the relations among different processes at various different length and time scales, and their effective properties. Already at the pore scale, ranging from a few micrometers to millimeters, direct flow simulation in a detailed medium geometry assuming Stokes flow is extremely costly. N...

We use the bond fluctuation model (BFM) to study the pore-blockade times of a translocating polymer of length N in two dimensions, in the absence of external forces on the polymer (i.e., unbiased translocation) and hydrodynamic interactions (i.e., the polymer is a Rouse polymer), through a narrow pore. Earlier studies using the BFM concluded that the pore-blockade time scales with polymer lengt...

The GINS complex, which contains the four subunits Sld5, Psf1, Psf2, and Psf3, is essential for both the initiation and progression of DNA replication in eukaryotes. GINS associates with the MCM2-7 complex and Cdc45 to activate the eukaryotic minichromosome maintenance helicase. It also appears to interact with and stimulate the polymerase activities of DNA polymerase epsilon and the DNA polyme...

The partition function of two hard spheres in a hard-wall pore is studied, appealing to a graph representation. The exact evaluation of the canonical partition function and the one-body distribution function in three different shaped pores are achieved. The analyzed simple geometries are the cuboidal, cylindrical, and ellipsoidal cavities. Results have been compared with two previously studied ...

We investigate the problem of polymer translocation through a nanopore in the absence of an external driving force. To this end, we use the two-dimensional fluctuating bond model with single-segment Monte Carlo moves. To overcome the entropic barrier without artificial restrictions, we consider a polymer which is initially placed in the middle of the pore and study the escape time tau required ...

MCM-48 and SBA-1 samples were characterized using powder X-ray diffraction and nitrogen adsorption in a wide range of relative pressures. X-ray diffraction provided direct evidence for the high degree of pore structure ordering for the materials under study. Nitrogen adsorption showed that highly ordered MCM-48 materials exhibited sharp steps of capillary condensation and narrow pore size distr...

Physical properties affecting transport processes inside the gas diffusion layer (GDL) in fuel cells mainly depend on the microscopic structure of its pore space. The presented characterization of the pore space is based on geometric 3D graphs, representing the complex microscopic structure. This description of the open volume contains the essential information on the geometrical structure of t...

BACKGROUND Innate immune response amplification is achieved by leukocyte expression of the purinergic nucleotide receptor P2X7, an extracellular nucleotide-gated pore. Previously, low P2X7 pore activity in whole blood was associated with loss-of-function genotypes in correlation with a decreased ratio of lipopolysaccharide-stimulated tumor necrosis factor-alpha to interleukin-10, of relevance t...

bilayer as two abutted monolayers, each with a neutral surface. The constraint imposed by mathematically placing two monolayers in apposition causes minimal energy to be larger than that predicated by (incorrectly) assuming that the elastic properties of a bilayer can be quantitatively captured through a single surface. Independent of pore size, the deformation of tilt did not appreciably affec...