The effect of composition on diffusion of macromolecules in a crowded environment.

abstract：:We report self-consistent Brownian dynamics simulations of a simple electrostatic model of the selectivity filters (SF) of calcium ion channels. They reveal regular structure in the conductance and selectivity as functions of the fixed negative charge Qf at the SF. With increasing Qf, there are distinct regions of hig...

journal_title：Physical biology

authors： Kaufman I,Luchinsky DG,Tindjong R,McClintock PV,Eisenberg RS

更新日期：2013-04-01 00:00:00

abstract：:We present a new particle tracking software algorithm designed to accurately track the motion of low-contrast particles against a background with large variations in light levels. The method is based on a polynomial fit of the intensity around each feature point, weighted by a Gaussian function of the distance from th...

journal_title：Physical biology

authors： Rogers SS,Waigh TA,Zhao X,Lu JR

更新日期：2007-10-09 00:00:00

abstract：:Particle-based simulators represent molecules of interest with point-like particles that diffuse and react in continuous space. These simulators are often used to investigate spatial or stochastic aspects of biochemical systems. This paper presents new particle-based simulation algorithms for modeling interactions bet...

journal_title：Physical biology

authors： Andrews SS

更新日期：2009-11-12 00:00:00

abstract：:Intermolecular interactions became an inherent part of the structure-function paradigm. Therefore, the generalized concept of protein stability and interactions should consider the balance of stabilizing forces working in different types of intermolecular interactions. We consider here two 'extremes' of protein intera...

journal_title：Physical biology

authors： Berezovsky IN

更新日期：2011-06-01 00:00:00

abstract：:We analyze theoretically the effects of excluded-volume interactions between motors on the dynamics of a cargo driven by multiple motors. The model considered shares much in common with others recently proposed in the literature, with the addition of direct interaction between motors and motor back steps. The cargo is...

journal_title：Physical biology

authors： Bouzat S,Falo F

更新日期：2010-11-22 00:00:00

abstract：:In the intracellular environment, the intrinsic dynamics of microtubule filaments is often hindered by the presence of barriers of various kind, such as kinetochore complexes and cell cortex, which impact their polymerisation force and dynamical properties such as catastrophe rate. We present a theoretical study of th...

journal_title：Physical biology

authors： Yadav V,Srinivas B,Gopalakrishnan M

更新日期：2020-10-12 00:00:00

abstract：:In addition to serving as structural elements and as tracks for motor proteins, microtubules use chemical energy derived from the hydrolysis of GTP to generate forces when growing and shrinking. These forces are used to push or pull on organelles such as chromosomes and the mitotic spindle. If an array of microtubules...

journal_title：Physical biology

authors： Howard J

更新日期：2006-02-28 00:00:00

abstract：:This report presents a simple model that describes the motion of a single Dictyostelium discoideum cell exposed to a traveling wave of cyclic adenosine monophosphate (cAMP). The model incorporates two types of responses to stimulation by cAMP: the changes in the polarity and motility of the cell. The periodic change i...

journal_title：Physical biology

authors： Ishiwata R,Iwasa M

更新日期：2015-03-19 00:00:00

abstract：:Calcium homeostasis is considered to be one of the most important factors for the contraction and relaxation of the heart muscle. However, under some pathological conditions, such as heart failure (HF), calcium homeostasis is disordered, and spontaneous waves may occur. In this study, we developed a mathematical model...

journal_title：Physical biology

authors： Lu L,Xia L,Ye X,Cheng H

更新日期：2010-05-26 00:00:00

abstract：:Tumors consist of multiple cell sub-populations including cancer stem cells (CSCs), transiently amplifying cells and terminally differentiated cells (TDCs), with the CSC fraction dictating the aggressiveness of the tumor and drug sensitivity. In epithelial cancers, tumor growth is influenced greatly by properties of t...

journal_title：Physical biology

authors： Kumar S,Kulkarni R,Sen S

更新日期：2016-04-29 00:00:00

abstract：:Cells of the immune system are confronted with opposing pro- and anti-inflammatory signals. Dendritic cells (DC) integrate these cues to make informed decisions whether to initiate an immune response. Confronted with exogenous microbial stimuli, DC endogenously produce both anti- (IL-10) and pro-inflammatory (TNFα) cu...

journal_title：Physical biology

authors： Marcou Q,Carmi-Levy I,Trichot C,Soumelis V,Mora T,Walczak AM

更新日期：2018-05-16 00:00:00

abstract：:This paper gives an overview of the coarse-grained models of phospholipids recently developed by the authors in the frame of a hybrid particle-field molecular dynamics technique. This technique employs a special class of coarse-grained models that are gaining popularity because they allow simulations of large scale sy...

journal_title：Physical biology

authors： Milano G,Kawakatsu T,De Nicola A

更新日期：2013-08-01 00:00:00

abstract：:Mucociliary clearance and cough are the two main natural mucus draining methods in the bronchial tree. If they are affected by a pathology, they can become insufficient or even ineffective, then therapeutic draining of mucus plays a critical role to keep mucus levels in the lungs acceptable. The manipulations of physi...

journal_title：Physical biology

authors： Mauroy B,Fausser C,Pelca D,Merckx J,Flaud P

更新日期：2011-10-01 00:00:00

abstract：:In many bacterial species, the protein FtsZ forms a cytoskeletal ring that marks the future division site and scaffolds the division machinery. In rod-shaped bacteria, most frequently membrane-attached FtsZ rings or ring fragments are reported and occasionally helices. By contrast, axial FtsZ clusters have never been ...

journal_title：Physical biology

authors： Fischer-Friedrich E,Friedrich BM,Gov NS

更新日期：2012-02-01 00:00:00

abstract：:Traditionally animal groups have been characterized by the macroscopic patterns that they form. It is now recognised that such patterns convey limited information about the nature of the aggregation as a whole. Aggregate properties cannot be determined by passive observations alone; instead one must interact with them...

journal_title：Physical biology

authors： Reynolds AM

更新日期：2019-04-23 00:00:00

abstract：:The field of tissue engineering aims to produce living, biological constructs which possess the appropriate spatial ordering of cells and their extra cellular matrix products. The complexity of a single cell and its interactions in a large collective have made development of useful models to assist in tissue culture d...

journal_title：Physical biology

authors： Pietak A,Waldman SD

更新日期：2008-04-01 00:00:00

abstract：:Efficient nucleotide import is critical to fuel the reverse DNA synthesis that takes place within the HIV-1 capsid. However, the mechanism by which the HIV-1 capsid imports nucleotides is presently unclear. In this work, we carry out a series of Brownian diffusion simulations to elucidate the nucleotide import process...

journal_title：Physical biology

authors： Song G

更新日期：2020-10-07 00:00:00

abstract：:The translocation of molecules across cellular membranes or through synthetic nanopores is strongly affected by thermal fluctuations. In this work we study how the dynamics of a polymer in a noisy environment changes when the translocation process is driven by an oscillating electric field. An improved version of the ...

journal_title：Physical biology

authors： Pizzolato N,Fiasconaro A,Adorno DP,Spagnolo B

更新日期：2010-08-04 00:00:00

abstract：:Electrostatic interaction is the driving force for the encapsulation by virus coat proteins of nanoparticles such as quantum dots, gold particles and magnetic beads for, e.g., imaging and therapeutic purposes. In recent experimental work, Daniel et al (2010 ACS Nano 4 3853-60) found the encapsulation efficiency to sen...

journal_title：Physical biology

authors： Lin HK,van der Schoot P,Zandi R

更新日期：2012-12-01 00:00:00

abstract：:Bistable regulatory elements enhance heterogeneity in cell populations and, in multicellular organisms, allow cells to specialize and specify their fate. Our study demonstrates that in a system of bistable genetic switch, the noise characteristics control in which of the two epigenetic attractors the cell population w...

journal_title：Physical biology

authors： Jaruszewicz J,Lipniacki T

更新日期：2013-06-01 00:00:00

abstract：:Surface plasmon resonance (SPR) chips are widely used to measure association and dissociation rates for the binding kinetics between two species of chemicals, e.g., cell receptors and ligands. It is commonly assumed that ligands are spatially well mixed in the SPR region, and hence a mean-field rate equation descripti...

journal_title：Physical biology

authors： Carroll J,Raum M,Forsten-Williams K,Täuber UC

更新日期：2016-12-06 00:00:00

abstract：:By combining optical tweezers-assisted dynamic force spectroscopy experiments with fluorescence activated cell sorting (FACS), we demonstrate a new approach to reducing the data variance in measuring receptor-ligand interactions on a single molecule level by ensuring similar coating densities. Therefore, the carboxyfl...

journal_title：Physical biology

authors： Stangner T,Singer D,Wagner C,Gutsche C,Ueberschär O,Hoffmann R,Kremer F

更新日期：2013-08-01 00:00:00

abstract：:Cancer cells are known to modify their micro-environment such that it can sustain a larger population, or, in ecological terms, they construct a niche which increases the carrying capacity of the population. It has however been argued that niche construction, which benefits all cells in the tumour, would be selected a...

journal_title：Physical biology

authors： Gerlee P,Anderson AR

更新日期：2015-08-12 00:00:00

abstract：:Based on recent experimental data, we design a model for neuronal membrane potentials that incorporates the influence of the surrounding glia (dressed neurons). A neurotransmitter released into the synaptic cleft triggers a Ca(2+) response in nearby glial cells that spreads as a Ca(2+) wave and interacts with other sy...

journal_title：Physical biology

authors： Nadkarni S,Jung P

更新日期：2004-06-01 00:00:00

abstract：:The controlling factors that underlie the growth of tumors have often been hard to identify because of the presence in this system of a large number of intracellular biochemical parameters. Here, we propose a simplifying framework to identify the key physical parameters that govern the early growth of tumors. We model...

journal_title：Physical biology

authors： Remy G,Cluzel P

更新日期：2016-04-04 00:00:00

abstract：:We propose a three-dimensional mechanical model of embryonic tissue dynamics. Mechanically coupled adherent cells are represented as particles interconnected with elastic beams which can exert non-central forces and torques. Tissue plasticity is modeled by a stochastic process consisting of a connectivity change (addi...

journal_title：Physical biology

authors： Czirok A,Isai DG

更新日期：2014-12-15 00:00:00

abstract：:In recent years, by using modern imaging techniques, scientists have found evidence of collaboration between different types of stem cells (SCs), and proposed a bi-compartmental organization of the SC niche. Here we create a class of stochastic models to simulate the dynamics of such a heterogeneous SC niche. We consi...

journal_title：Physical biology

authors： Shahriyari L,Komarova NL

更新日期：2015-07-31 00:00:00

abstract：:Messenger RNA (mRNA) encodes a sequence of amino acids by using codons. For most amino acids, there are multiple synonymous codons that can encode the amino acid. The translation speed can vary from one codon to another, thus there is room for changing the ribosome speed while keeping the amino acid sequence and hence...

journal_title：Physical biology

authors： Mitarai N,Pedersen S

更新日期：2013-10-01 00:00:00

abstract：:Host-to-host variability with respect to interactions between microorganisms and multicellular hosts are commonly observed in infection and in homeostasis. However, the majority of mechanistic models used to analyze host-microorganism relationships, as well as most of the ecological theories proposed to explain coevol...

journal_title：Physical biology

authors： Mukherjee S,Weimer KE,Seok SC,Ray WC,Jayaprakash C,Vieland VJ,Swords WE,Das J

更新日期：2014-12-04 00:00:00

abstract：:The tripartite synapse denotes the junction of a pre- and postsynaptic neuron modulated by a synaptic astrocyte. Enhanced transmission probability and frequency of the postsynaptic current-events are among the significant effects of the astrocyte on the synapse as experimentally characterized by several groups. In thi...

journal_title：Physical biology

authors： Nadkarni S,Jung P

更新日期：2007-01-09 00:00:00