Polymer Release out of a Spherical Vesicle through a Pore

Translocation of a polymer out of curved surface or membrane is studied via mean first passage time approach. Membrane curvature gives rise to a constraint on polymer conformation, which effectively drives the polymer to the outside of membrane where the available volume of polymer conformational fluctuation is larger. Considering a polymer release out of spherical vesicle, polymer translocation time $\tau$ is changed to the scaling behavior $\tau\sim L^2$ for $R<R_G$, from $\tau\sim L^3$ for $R\gg R_G$, where $L$ is the polymer contour length and $R$, $R_G$ are vesicle radius and polymer radius of gyration respectively. Also the polymer capture into a spherical budd is studied and possible apparatus for easy capture is suggested.Comment: 14 pages RevTeX, 6 postscript figures, published in Phys. Rev. E 57, 730 (1998

Coarsening Dynamics of an Antiferromagnetic XY model on the Kagome Lattice: Breakdown of the Critical Dynamic Scaling

We find a breakdown of the critical dynamic scaling in the coarsening dynamics of an antiferromagnetic {\em XY} model on the kagome lattice when the system is quenched from disordered states into the Kosterlitz-Thouless ({\em KT}) phases at low temperatures. There exist multiple growing length scales: the length scales of the average separation between fractional vortices are found to be {\em not} proportional to the length scales of the quasi-ordered domains. They are instead related through a nontrivial power-law relation. The length scale of the quasi-ordered domains (as determined from optimal collapse of the correlation functions for the order parameter $\exp[3 i \theta (r)]$) does not follow a simple power law growth but exhibits an anomalous growth with time-dependent effective growth exponent. The breakdown of the critical dynamic scaling is accompanied by unusual relaxation dynamics in the decay of fractional ($3\theta$) vortices, where the decay of the vortex numbers is characterized by an exponential function of logarithmic powers in time.Comment: 13 pages, 26 figure

Response projected clustering for direct association with physiological and clinical response data

<p>Abstract</p> <p>Background</p> <p>Microarray gene expression data are often analyzed together with corresponding physiological response and clinical metadata of biological subjects, e.g. patients' residual tumor sizes after chemotherapy or glucose levels at various stages of diabetic patients. Current clustering analysis cannot directly incorporate such quantitative metadata into the clustering heatmap of gene expression. It will be quite useful if these clinical response data can be effectively summarized in the high-dimensional clustering display so that important groups of genes can be intuitively discovered with different degrees of relevance to target disease phenotypes.</p> <p>Results</p> <p>We introduced a novel clustering analysis approach, <it>response projected clustering </it>(RPC), which uses a high-dimensional geometrical projection of response data to the gene expression space. The projected response vector, which becomes the origin in the projected space, is then clustered together with the projected gene vectors based on their different degrees of association with the response vector. A bootstrap-counting based RPC analysis is also performed to evaluate statistical tightness of identified gene clusters. Our RPC analysis was applied to the <it>in vitro </it>growth-inhibition and microarray profiling data on the NCI-60 cancer cell lines and the microarray gene expression study of macrophage differentiation in atherogenesis. These RPC applications enabled us to identify many known and novel gene factors and their potential pathway associations which are highly relevant to the drug's chemosensitivity activities and atherogenesis.</p> <p>Conclusion</p> <p>We have shown that RPC can effectively discover gene networks with different degrees of association with clinical metadata. Performed on each gene's response projected vector based on its degree of association with the response data, RPC effectively summarizes individual genes' association with metadata as well as their own expression patterns. Thus, RPC greatly enhances the utility of clustering analysis on investigating high-dimensional microarray gene expression data with quantitative metadata.</p

On the effective plate thickness of monolayer graphene from flexural wave propagation

We utilize classical molecular dynamics to study flexural, or transverse wave propagation in monolayer graphene sheets and compare the resulting dispersion relationships to those expected from continuum thin plate theory. In doing so, we determine that regardless of the chirality for monolayer graphene, transverse waves exhibit a dispersion relationship that corresponds to the lowest order antisymmetric (A0) mode of wave propagation in a thin plate with plate thickness of h = 0.104 nm. Finally, we find that the achievable wave speeds in monolayer graphene are found to exceed those reported previously for single walled carbon nanotubes, while the frequency of wave propagation in the graphene monolayer is found to reach the terahertz range, similar to that of carbon nanotubes.open9

Role of PVDF in rheology and microstructure of NCM cathode slurries for lithium-ion battery

A binder plays a critical role in dispersion of coating liquids and the quality of coating. Poly(vinylidene fluoride) (PVDF) is widely used as a binder in cathode slurries; however, its role as a binder is still under debate. In this paper, we study the role of PVDF on the rheology of cathode battery slurries consisting of Li(Ni$_{1/3}$Mn$_{1/3}$Co$_{1/3}$)O$_{2}$ (NCM), carbon black (CB) and N-methyl-2-pyrrolidone (NMP). Rheology and microstructure of cathode slurries are systemically investigated with three model suspensions: CB/PVDF/NMP, NCM/PVDF/NMP and NCM/CB/PVDF/NMP. To highlight the role of PVDF in cathode slurries, we prepare the same model suspensions by replacing PVDF with PVP, and we compare the role of PVDF to PVP in the suspension rheology. We find that PVDF adsorbs neither onto NCM nor CB surface, which can be attributed to its poor affinity to NCM and CB. Rheological measurements suggest that PVDF mainly increases matrix viscosity in the suspension without affecting the microstructure formed by CB and NCM particles. In contrast to PVDF, PVP stabilizes the structure of CB and NCM in the model suspensions, as it is adsorbed on the CB surface. This study will provide a useful insight to fundamentally understand the rheology of cathode slurries