Dynamic Properties of Entangled Polymers: The Reptation Model

This review concerns modeling studies of the fundamental problem of entangled (reptational) homopolymer diffusion in melts and nanocomposite materials in comparison to experiments. In polymer melts, the developed united atom and multibead spring models predict an exponent of the molecular weight dependence to the polymer diffusion very similar to experiments and the tube reptation model. There are rather unexplored parameters that can influence polymer diffusion such as polymer semiflexibility or polydispersity, leading to a different exponent. Models with soft potentials or slip-springs can estimate accurately the tube model predictions in polymer melts enabling us to reach larger length scales and simulate well entangled polymers. However, in polymer nanocomposites, reptational polymer diffusion is more complicated due to nanoparticle fillers size, loading, geometry and polymer-nanoparticle interactions.

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A thermodynamically admissible reptation model for fast flows of entangled polymers

Journal of Rheology ◽

10.1122/1.551055 ◽

1999 ◽

Vol 43 (6) ◽

pp. 1461-1493 ◽

Cited By ~ 62

Author(s):

Hans Christian Öttinger

Keyword(s):

Entangled Polymers ◽

Reptation Model

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The distribution of antigen on the surface of RBL-2H3 rat basophilic leukemia cells observed by back-scattered electron imaging

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100142992 ◽

1986 ◽

Vol 44 ◽

pp. 274-275

Author(s):

R.F. Stump ◽

J.R. Pfeiffer ◽

JC. Seagrave ◽

D. Huskisson ◽

J.M. Oliver

Keyword(s):

Cell Surface ◽

Dynamic Properties ◽

Leukemia Cells ◽

Antigen Binding ◽

Scattered Electron ◽

Ige Receptor ◽

Receptor Complexes ◽

Rat Basophilic Leukemia Cells ◽

Electron Imaging ◽

Basophilic Leukemia

In RBL-2H3 rat basophilic leukemia cells, antigen binding to cell surface IgE-receptor complexes stimulates the release of inflammatory mediators and initiates a series of membrane and cytoskeletal events including a transformation of the cell surface from a microvillous to a lamellar topography. It is likely that dynamic properties of the IgE receptor contribute to the activation of these responses. Fewtrell and Metzger have established that limited crosslinking of IgE-receptor complexes is essential to trigger secretion. In addition, Baird and colleagues have reported that antigen binding causes a rapid immobilization of IgE-receptor complexes, and we have demonstrated an apparent increase with time in the affinity of IgE-receptor complexes for antigen.

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Nucleosome dynamics

Biochemical Society Symposium ◽

10.1042/bss0730109 ◽

2006 ◽

Vol 73 ◽

pp. 109-119 ◽

Cited By ~ 2

Author(s):

Chris Stockdale ◽

Michael Bruno ◽

Helder Ferreira ◽

Elisa Garcia-Wilson ◽

Nicola Wiechens ◽

...

Keyword(s):

High Resolution ◽

Chromatin Structure ◽

Current Knowledge ◽

Dynamic Properties ◽

Structure And Dynamics ◽

Nucleosome Dynamics ◽

Sharp Focus ◽

Recent Advances ◽

Insight Into ◽

Chromatin Structure And Dynamics

In the 30 years since the discovery of the nucleosome, our picture of it has come into sharp focus. The recent high-resolution structures have provided a wealth of insight into the function of the nucleosome, but they are inherently static. Our current knowledge of how nucleosomes can be reconfigured dynamically is at a much earlier stage. Here, recent advances in the understanding of chromatin structure and dynamics are highlighted. The ways in which different modes of nucleosome reconfiguration are likely to influence each other are discussed, and some of the factors likely to regulate the dynamic properties of nucleosomes are considered.

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