US – Page 432 – TechConnect Briefs

DNA Translocation Across Protein Channels: How does a polymer worm through a hole?

Muthukumar M., University of Massachusetts, US

Conformational entropy of a polymer is reduced when the polymer confronts a narrow path. The reduction in entropy and the consequent free energy barriers control the polymer's translocation through narrow channels. Recent results on our [...]

Molecular Modeling of Proton Conduction in Polymer Electrolyte Membranes of Nafion® Type

Paddison S.J., Eikerling M., Zawodzinski_Jr. T.A., Pratt L.R., Los Alamos National Laboratory, US

Molecular mechanisms of proton conduction in polymer electrolyte membranes are addressed by ab initio molecular dynamics calculations, utilizing the VASP program, on the model system trifluoromethane sulfonic acid monohydrate solid. After establishing that the experimental [...]

Macromolecules in Microdevices: Multiscale simulation of DNA dynamics in model microfluidic geometries

Jendrejack R.M., de Pablo J.J., Graham M.D., University of Wisconsin-Madison, US

Simple arguments predict that the dynamics of a dissolved macromolecule confined to a channel comparable to its equilibrium coi size (~1 um for viral DNA) are quite different from those in free solution, because of [...]

Biochemical Binding in Microspheres-Based-Imunoassays

Prabhakarpandian B., Shah K.B., Sundaram S., Makhijani V.B., CFD Research Corporation, US

Microspheres (referred commonly as beads) are being extensively used in biochemical assays as supports for proteins, DNA, etc. We have successfully developed |omputational models for simulating sample detection using flowing beads. The model fully integrates [...]

Squeezing Flow of Particles and Large Molecules Suspended in a Liquid Through Nanochannels

Acrivos A., Khusid B., Koplik J., Drazer G., New Jersey Institute of Technology, US

The presentation addresses the status of current understanding of the hydrodynamic phenomena accompanyin the motion of a nanometer-sized particle through a nanotube.

Direct Numerical Simulation of Moving Charged, Flexible Bodies with Thermal Fluctuations

Patankar N.A., Northwestern University, US

The interaction of sub-micron scale objects with fluids is an important problem encountered in miniaturized systems. Various physical phenomena should be modeled simultaneously for a fundamental investigation of these systems. Our objective is to develop [...]

Transient Analysis of Electroosmotic Flow in Nano-diameter Channels

Qiao R., Aluru N.R., University of Illinois at Urbana-Champaign, US

Transient analysis of electroosmotic flow in a nano-diameter channel is presented. The time for flow to reach steady state in a nano-diameter channel for various Debye lengths is investigated by solving the Navier-Stokes equations in [...]

Numerical and Analytical Studies of AC Electric Field in Dielectrophoretic Electrode Arrays

Feng J.J., Krishnamoorthy S., Chen Z.J., Makhijani V.B., CFD Research Corporation, US

Manipulation of micro-sized particles and biological cells using dielectrophoresis (DEP) is an emerging technique in MEMS and nano technology[3]. This paper presents an exact solution of dielectrophoretic motion of a polarized particle in the vicinity [...]

Nanomolecular Gravitational Interactions Causing Incrased Probability of Birth Defects in Humans During Period from Conception to Early Fetus Formation

Vezzoli G.C., The Franklin Institute of Technology, US

It is found that small decreases in gravity that are caused by planet syzygy, full moon presence, and cosmogonic events of deep space can cause a sufficient change in gravitational interactions to affect the nucleons [...]

Modeling of the Deformation of Living Cells Induced by Atomic Force Microscopy

Rudd R.E., McElfresh M., Baesu E., Balhorn R., Alleny M., Belak J., Lawrence Livermore National Lab., US

We describe finite element modeling of the deformation of living cells by atomic force microscopy (AFM). Cells are soft systems, susceptible to large deformations in the course of an AFM measurement. Often the local properties, [...]