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The structure of DNA in the nucleosome core particle is studied using an elastic model that incorporates anisotropy in the bending energetics and twist-bend coupling. Using the experimentally determined structure of nucleosomal DNA [T.J.…

Biomolecules · Quantitative Biology 2009-11-13 Farshid Mohammad-Rafiee , Ramin Golestanian

Rapid and cost-effective DNA sequencing at the single nucleotide level might be achieved by measuring a transverse electronic current as single-stranded DNA is pulled through a nano-sized pore. In order to enhance the electronic coupling…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 X. Chen , I. Rungger , C. D. Pemmaraju , U. Schwingenschlogl , S. Sanvito

We present a numerical study of the effect of knotting on the ejection of flexible and semiflexible polymers from a spherical, virus-like capsid. The polymer ejection rate is primarily controlled by the knot, which moves to the hole in the…

Biomolecules · Quantitative Biology 2009-02-23 R Matthews , A. A. Louis , J. M. Yeomans

We present a simplified model of the dynamics of translocation of RNA through a nanopore which only allows the passage of unbound nucleotides. In particular, we consider the disorder averaged translocation dynamics of random, two-component,…

Biomolecules · Quantitative Biology 2007-05-23 J. B. Lucks , Y. Kafri

We consider the dynamics of pore-driven polymer translocation through a nanopore to semi-infinite space when the chain is initially confined and equilibrated in a narrow channel. To this end, we use Langevin dynamics (LD) simulations and…

Soft Condensed Matter · Physics 2025-03-11 Soheila Emamyari , Jalal Sarabadani , Ralf Metzler , Tapio Ala-Nissila

We review recent progress on the theory of dynamics of polymer translocation through a nanopore based on the iso-flux tension propagation (IFTP) theory. We investigate both pore-driven translocation of flexible and a semi-flexible polymers,…

Soft Condensed Matter · Physics 2018-10-16 Jalal Sarabadani , Tapio Ala-Nissila

It is a standard exercise in mechanical engineering to infer the external forces and torques on a body from its static shape and known elastic properties. Here we apply this kind of analysis to distorted double-helical DNA in complexes with…

Biomolecules · Quantitative Biology 2009-11-13 Nils B. Becker , Ralf Everaers

Polymer composites are ubiquitous in biology and industry alike, owing to their emergent desirable mechanical properties not attainable in single-species systems. At the same time, polymer topology has been shown to play a key role in…

The molecular dynamics of deep eutectic solvents (DESs) are complex, characterized by nanoscale spatial and temporal heterogeneity. Understanding these dynamics is crucial for tailoring transport properties like diffusion, viscosity and…

Soft Condensed Matter · Physics 2025-02-05 T. Rinesh , H. Srinivasan , V. K. Sharma , V. García Sakai , S. Mitra

Simulations of knotting and unknotting in polymers or other filaments rely on random processes to facilitate topological changes. Here we introduce a method of \textit{topological steering} to determine the optimal pathway by which a…

Geometric Topology · Mathematics 2025-04-18 Agnese Barbensi , Alexander R. Klotz , Dimos Gkountaroulis

We study the dynamics of the passage of a polymer through a membrane pore (translocation), focusing on the scaling properties with the number of monomers $N$. The natural coordinate for translocation is the number of monomers on one side of…

Soft Condensed Matter · Physics 2009-11-07 Jeffrey Chuang , Yacov Kantor , Mehran Kardar

DNA regulation and repair processes require direct interactions between proteins and DNA at specific sites. Local fluctuations of the sugar-phosphate backbones and bases of DNA (a form of DNA "breathing") play a central role in such…

The genomic DNA of most bacteria is significantly underwound, which constrains the DNA molecule to adopt a branched plectoneme geometry. Moreover, biological functions like replication and transcription require that the two DNA strands be…

Biological Physics · Physics 2025-11-04 Marc Joyeux

Methods for reducing and directly controlling the speed of DNA through a nanopore are needed to enhance sensing performance for direct strand sequencing and detection/mapping of sequence-specific features. We have created a method for…

Biological Physics · Physics 2018-11-28 Xu Liu , Yuning Zhang , Roland Nagel , Walter Reisner , William B. Dunbar

The passage of DNA through a nanopore can be effectively decomposed into two distinct phases, docking and actual translocation. In experiments each phase is characterized by a distinct current signature which allows the discrimination of…

A hydrodynamic model for determining the electrophoretic speed of a polyelectrolyte through a nanopore is presented. It is assumed that the speed is determined by a balance of electrical and viscous forces arising from within the pore and…

Chemical Physics · Physics 2011-11-09 Sandip Ghosal

The diffusion of molecules (penetrants) of variable size, shape, and chemistry through dense crosslinked polymer networks is a fundamental scientific problem that is broadly relevant in materials, polymer, physical and biological chemistry.…

Polymer brush-grafted nanoparticles have significant application value in fields such as gene therapy and targeted drug delivery. A profound understanding of the interaction mechanisms between these particles and cell membranes represents a…

Soft Condensed Matter · Physics 2025-12-16 Shuai He , Junxing Pan , Jinjun Zhang

A theory is presented for the binding of small molecules such as surfactants to semiflexible polymers. The persistence length is assumed to be large compared to the monomer size but much smaller than the total chain length. Such polymers…

Soft Condensed Matter · Physics 2009-09-25 Haim Diamant , David Andelman

Diatoms are characterised by silica cell walls (frustules), which have highly ordered micro-/nano-structures. As the synthesis of such structures remains challenging, diatom frustules offer a promissing alternative to conventional porous…

Mesoscale and Nanoscale Physics · Physics 2024-10-24 Naoki Tomioka , Yusaku Abe , Yu Matsuda