Diffusion of molecules in brain and other tissues is important in a wide range of biological processes, such as the delivery of drugs, and for measurements, such as diffusion-weighted magnetic resonance imaging. The time-dependent diffusion coefficient D(t) of mobile molecules confined in pores or cells carries information about the confining geometry. At early times, D(t) gives, irrespective o...

In this work a glass micromodel which its grains and pores are non-uniform in size, shape and distribution is considered as porous medium. A two-dimensional random network model of micromodel with non-uniform pores has been constructed. The non-uniformity of porous model is achieved by assigning parametric distribution functions to pores throat and pores length, which was measured using ima...

Recently, high attention has been paid to template synthesis as a method for obtaining nanostructures with predetermined shapes and sizes. This is an obvious approach, in which the size shape of pores limit geometry formed inside them. As result, completely repeat pores. However, some cases, morphology resulting structures may differ from template, often these differences are not explained. gap...

in this work a glass micromodel which its grains and pores are non-uniform in size, shape and distribution is considered as porous medium. a two-dimensional random network model of micromodel with non-uniform pores has been constructed. the non-uniformity of porous model is achieved by assigning parametric distribution functions to pores throat and pores length, which was measured using image a...

To heal tissue defects, cells have to bridge gaps and generate new extracellular matrix (ECM). Macroporous scaffolds are frequently used to support the process of defect filling and thus foster tissue regeneration. Such biomaterials contain micro-voids (pores) that the cells fill with their own ECM over time. There is only limited knowledge on how pore geometry influences cell organization and ...

Mycobacterium smegmatis porin A (MspA) forms an octameric channel and represents the founding member of a new family of pore proteins. Control of subunit stoichiometry is important to tailor MspA for nanotechnological applications. In this study, two MspA monomers were connected by linkers ranging from 17 to 62 amino acids in length. The oligomeric pore proteins were purified from M. smegmatis ...

Single- and multiple-nanopore membranes are both highly interesting for biosensing and separation processes, as well as their ability to mimic biological membranes. The density of pores, their shape, and their surface chemistry are the key factors that determine membrane transport and separation capabilities. Here, we report silicon nitride (SiN) membranes with fully controlled porosity, pore g...

Nano-porous silicon were simply prepared from p-type single crystalline silicon wafer by electrochemical etching technique via exerting constant current density in two different HF-Ethanol and HF-Ethanol-H2O solutions. The mesoporous silicon layers were characterized by field emission scanning electron microscopy and scanning electron microscopy. The results demonstrate that the width of nano-p...

Phenomena occurring in soil pores can best be studied if the geometry of the pore space is understood. A number of models for the pore space have been proposed. These have included a Boolean grain process, fractals, packed sphere and other grain models, bubble processes, cracking processes and a range of models based on simple geometrical objects. This paper considers the issues raised by these...

We propose a DNA sequencing scheme based on silicene nanopores. Using first principles theory, we compute the electrical properties of such pores in the absence and presence of nucleobases. Within a two-terminal geometry, we analyze the current-voltage relation in the presence of nucleobases with various orientations. We demonstrate that when nucleobases pass through a pore, even after sampling...