Development of microporous materials with hierarchical structures of both micro/mesopores leads to molecular transport at nanometer length scales. For novel microporous materials including three-dimensionally ordered mesoporous imprinted (3DOm-i) zeolites and zeolite nanosheets, particle dimensions are below 35 nm resulting in surface-dominated structures. At the same time, the existence of sur...

The lessons learned from p-octiphenyl beta-barrel pores are applied to the rational design of synthetic multifunctional pore 1 that is unstable but inert, two characteristics proposed to be ideal for practical applications. Nonlinear dependence on monomer concentration provided direct evidence that pore 1 is tetrameric (n = 4.0), unstable, and "invisible," i.e., incompatible with structural stu...

The outer vestibule of voltage-gated Na(+) channels is formed by extracellular loops connecting the S5 and S6 segments of all four domains ("P-loops"), which fold back into the membrane. Classically, this structure has been implicated in the control of ion permeation and in toxin blockage. However, conformational changes of the outer vestibule may also result in alterations in gating, as sugges...

Based on direct numerical simulations of the coupled motion of particles and fluid, this study analyzes the collective hydrodynamic and colloidal effects of flowing microparticles during the formation of different 3D clogging patterns at a pore entrance. Simulations of flowing suspensions through a pore with various simulation conditions show that particle concentration and surface interactions...

Bacillus anthracis secretes three polypeptides: protective antigen (PA), lethal factor (LF), and edema factor (EF), which interact at the surface of mammalian cells to form toxic complexes. LF and EF are enzymes that target substrates within the cytosol; PA provides a heptameric pore to facilitate LF and EF transport into the cytosol. Other than administration of antibiotics shortly after expos...

In this study, we develop a lab-on-a-chip approach to study pore-scale salt precipitation dynamics during CO2 sequestration in saline aquifers-a challenge with this carbon management strategy. Three distinct phases-CO2 (gas), brine (liquid), and salt (solid)-are tracked through microfluidic networks matched to the native geological formations. The resulting salt formation dynamics indicate poro...

Upon stimulation by odorants, Ca(2+) and Na(+) enter the cilia of olfactory sensory neurons through channels directly gated by cAMP. Cyclic nucleotide-gated channels have been found in a variety of cells and extensively investigated in the past few years. Glutamate residues at position 363 of the alpha subunit of the bovine retinal rod channel have previously been shown to constitute a cation-b...

In the Lyme disease spirochete Borrelia burgdorferi, the outer membrane protein P66 is capable of pore formation with an atypical high single-channel conductance of 11 nS in 1 M KCl, which suggested that it could have a larger diameter than 'normal' Gram-negative bacterial porins. We studied the diameter of the P66 channel by analyzing its single-channel conductance in black lipid bilayers in t...

In this study vertically aligned carbon nanotubes (VA-CNT) was grown on anodized aluminum oxide (AAO) substrate. The synthesized AAO-CNT membrane was characterized using Raman spectroscopy, field emission scanning electron microscopy (FESEM), contact angle and BET. The pure water flux, humic acid (HA) (as representative of natural organic matters) rejection and fouling mechanism were also evalu...