The nuclear envelope and associated structures from Xenopus laevis oocytes (stage VI) have been examined with the high resolution scanning electron microscope (SEM). The features of the inner and outer surfaces of the nuclear surface complex were revealed by manual isolation , whereas the membranes facing the perinuclear space (the space between the inner and outer nuclear membranes) were obser...

Previous micro-scale studies of the effect pore structure on spontaneous imbibition are mainly limited to invariable-diameter capillaries. However, in real oil and gas reservoir formations, capillary diameters changing interconnected. Applying lattice Boltzmann color gradient two-phase flow model parallel computation CPUs, we simulated variable-diameter We explored reasons for nonwetting phase ...

Electrochemical etching of semiconductors, apart frommany technical applications, provides an interesting experimental setup for self-organized structure formation capable e.g. of regular, diameter-modulated, and branching pores. The underlying dynamical processes governing current transfer and structure formation are described by the CurrentBurst-Model: all dissolution processes are assumed to...

A model to estimate the extent of intraparticle, or perfusive, electroosmotic flow (EOF) in CEC capillaries packed with macroporous particles has been developed. Nucleosil packings (d(p) = 7 microm) having nominal pore sizes of 500, 1000, and 4000 A were studied. Intraparticle pores ranging from 50 to 10000 A in diameter were partitioned into 995 intervals of 10 A. Using pore size distribution ...

Mesoporous carbons prepared by an inverse replica technique have been used as electrodes for electrochemical capacitors. Such well sized carbons were prepared from mesostructured SBA-16 silica materials that served as templates whereas polyfurfuryl alcohol was the carbon precursor. Two highly mesoporous carbons characterized by 3 and 8 nm average pore diameter were tested in various electrolyti...

Polymer translocation through a nanopore in a membrane is investigated theoretically. Recent experiments on voltage-driven DNA and RNA translocations through a nanopore indicate that the size and geometry of the pore are important factors in polymer dynamics. A theoretical approach is presented which explicitly takes into account the effect of the nanopore length and diameter for polymer motion...

Pvlercury porosimetry was used to measure the bulk and real densities, pore volumes and pore size distributions of compacts of hydroxyapatite before and after sintering. The hydroxyapatites were prepared by two different methods and had widely different surface areas. The properties were determined as a function of compaction force and sintering temperature. Densities from porosimetry were in g...

A study of reflective interference spectroscopy [RIfS] properties of nanoporous anodic aluminium oxide [AAO] with the aim to develop a reliable substrate for label-free optical biosensing is presented. The influence of structural parameters of AAO including pore diameters, inter-pore distance, pore length, and surface modification by deposition of Au, Ag, Cr, Pt, Ni, and TiO2 on the RIfS signal...

It is now possible to slow and trap a single molecule of double-stranded DNA (dsDNA), by stretching it using a nanopore, smaller in diameter than the double helix, in a solid-state membrane. By applying an electric force larger than the threshold for stretching, dsDNA can be impelled through the pore. Once a current blockade associated with a translocating molecule is detected, the electric fie...

Dynamic Monte Carlo simulations are used to study coupled transport (co-transport) through sub-nanometer-diameter pores. In this classic Hodgkin-Keynes mechanism, an ion species uses the large flux of an abundant ion species to move against its concentration gradient. The efficiency of co-transport is examined for various pore parameters so that synthetic nanopores can be engineered to maximize...