Theory of threshold fluctuations in nerves. I. Relationships between electrical noise and fluctuations in axon firing.

abstract：:The molecular weight of single-stranded DNA from the slime mold Physarum polycephalum has been determined by alkaline gradient centrifugation. The average molecular weight during DNA synthesis ( approximately 1.5 x 10(7) D) is less than that observed in nonsynthetic periods ( approximately 4 x 10(7) D). On the basis o...

journal_title：Biophysical journal

authors： McGrath RA,Williams RW

更新日期：1967-05-01 00:00:00

abstract：:The [FeFe] hydrogenase from the green alga Chlamydomonas reinhardtii can catalyze the reduction of protons to hydrogen gas using electrons supplied from photosystem I and transferred via ferredoxin. To better understand the association of the hydrogenase and the ferredoxin, we have simulated the process over multiple ...

journal_title：Biophysical journal

authors： Long H,Chang CH,King PW,Ghirardi ML,Kim K

更新日期：2008-10-01 00:00:00

abstract：:The glycocalyx is a thick coat of proteins and carbohydrates on the outer surface of all eukaryotic cells. Overproduction of large, flexible or rod-like biopolymers, including hyaluronic acid and mucins, in the glycocalyx strongly correlates with the aggression of many cancer types. However, theoretical frameworks to ...

journal_title：Biophysical journal

authors： Gandhi JG,Koch DL,Paszek MJ

更新日期：2019-02-19 00:00:00

abstract：:We introduce the use of microfabrication techniques to construct on a silicon wafer a synthetic capillary bed with 2.5- to 4-micron (mu)-wide channels. Establishment of a fluid pressure gradient allowed us to observe simultaneously using optical microscopy hundreds of cells flowing through the bed at physiological spe...

journal_title：Biophysical journal

authors： Brody JP,Han Y,Austin RH,Bitensky M

更新日期：1995-06-01 00:00:00

abstract：:Multiple data are available on the self-assembly of mixtures of bilayer-forming amphiphiles, particularly phospholipids and micelle-forming amphiphiles, commonly denoted detergents. The structure of such mixed assemblies has been thoroughly investigated, described in phase diagrams, and theoretically rationalized in t...

journal_title：Biophysical journal

authors： Lichtenberg D,Ahyayauch H,Goñi FM

更新日期：2013-07-16 00:00:00

abstract：:The sarcoplasmic reticulum channel (ryanodine receptor) from cardiac myocytes was reconstituted into planar lipid bilayers consisting of 1-palmitoyl-2-oleoyl-phosphatidylethanolamine (POPE) and 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) in varying ratios. The channel activity parameters, i.e., open probability an...

journal_title：Biophysical journal

authors： Cannon B,Hermansson M,Györke S,Somerharju P,Virtanen JA,Cheng KH

更新日期：2003-08-01 00:00:00

abstract：:We present a minimal model of plasma membrane heterogeneity that combines criticality with connectivity to cortical cytoskeleton. The development of this model was motivated by recent observations of micron-sized critical fluctuations in plasma membrane vesicles that are detached from their cortical cytoskeleton. We i...

journal_title：Biophysical journal

authors： Machta BB,Papanikolaou S,Sethna JP,Veatch SL

更新日期：2011-04-06 00:00:00

abstract：:Here we model the Alzheimer beta-peptide ion channel with the goal of obtaining insight into the mechanism of amyloid toxicity. The models are built based on NMR data of the oligomers, with the universal U-shaped (strand-turn-strand) motif. After 30-ns simulations in the bilayer, the channel dimensions, shapes and sub...

journal_title：Biophysical journal

authors： Jang H,Zheng J,Nussinov R

更新日期：2007-09-15 00:00:00

abstract：:Immature human immunodeficiency virus (HIV) virions have a lattice of Gag and Gag-Pol proteins anchored to the lumen of their envelope. Using electron microscopy, we demonstrate that HIV virus-like particles (VLPs) assembled by the viral protein Gag and tagged at its C-terminus with the fluorescent protein Dendra2 hav...

journal_title：Biophysical journal

authors： Saha I,Saffarian S

更新日期：2020-08-04 00:00:00

abstract：:Sedimentation velocity analytical ultracentrifugation is an important tool in the characterization of macromolecules and nanoparticles in solution. The sedimentation coefficient distribution c(s) of Lamm equation solutions is based on the approximation of a single, weight-average frictional coefficient of all particle...

journal_title：Biophysical journal

authors： Brown PH,Schuck P

更新日期：2006-06-15 00:00:00

abstract：:Protein/lipid coassembly is an understudied phenomenon that is important to the function of antimicrobial peptides as well as the pathological effects of amyloid. Here, we study the coassembly process of PAP248-286, a seminal peptide that displays both amyloid-forming and antimicrobial activity. PAP248-286 is a peptid...

journal_title：Biophysical journal

authors： Vane EW,He S,Maibaum L,Nath A

更新日期：2020-09-01 00:00:00

abstract：:A useful technique in studying the saturation of hemoglobin in erythrocytes or myoglobin in tissue is cryophotometry, in which tissue is frozen for later spectrophotometric analysis. A general question associated with this technique is whether the freezing process alters the chemical state. This paper presents a theor...

journal_title：Biophysical journal

authors： Clark A Jr,Clark PA

更新日期：1983-04-01 00:00:00

abstract：:We explore the means by which immobilization of a substrate on a surface can increase the rate of a diffusion-controlled enzymatic reaction. A quasichemical approach is developed and compared with Brownian dynamics simulations. We use these methods to show that restricting only the orientation of the enzyme by long-ra...

journal_title：Biophysical journal

authors： Nag A,Dinner AR

更新日期：2006-02-01 00:00:00

abstract：:The influence of basic open-loop synaptic connections on the firing of simultaneously recorded neurons has been investigated with auto- and cross-correlation histograms, using experimental records and computer simulations. The basic connections examined were direct synaptic excitation, direct synaptic inhibition, and ...

journal_title：Biophysical journal

authors： Moore GP,Segundo JP,Perkel DH,Levitan H

更新日期：1970-09-01 00:00:00

abstract：:Helical beta-peptides have been shown to fold into well-defined structures. In aqueous solution, some beta-peptides self-assemble into nanoscale fibers, aggregates, and liquid crystalline phases. Molecular simulations, at an atomistic level, are used to examine, in a systematic manner, the interactions between distinc...

journal_title：Biophysical journal

authors： Miller CA,Gellman SH,Abbott NL,de Pablo JJ

更新日期：2009-06-03 00:00:00

abstract：:The rotation of human red blood cells (RBC) as they flow in the shear field established by a Coulter type orifice is modeled. This model, based on hydrodynamics of ellipsoid rotation in laminar creeping flow, is used to calculate the probability of the cells entering the orifice with a specific orientation. The electr...

journal_title：Biophysical journal

authors： Breitmeyer MO,Lightfoot EN,Dennis WH

更新日期：1971-02-01 00:00:00

abstract：:A detailed electron spin resonance (ESR) study of mixtures of 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) and phosphatidylserine (POPS) in oriented multilayers in the liquid crystalline phase is reported with the purpose of characterizing the effects of headgroup mixing on the structural and dynamical properties o...

journal_title：Biophysical journal

authors： Ge M,Budil DE,Freed JH

更新日期：1994-05-01 00:00:00

abstract：:A general analytical description of the equilibrium and reaction kinetics of DNA multiplex hybridization has been developed. In this approach, multiplex hybridization is considered to be a competitive multichannel reaction process: a system wherein many species can react both specifically and nonspecifically with one ...

journal_title：Biophysical journal

authors： Horne MT,Fish DJ,Benight AS

更新日期：2006-12-01 00:00:00

abstract：:The properties of vesicle membranes prepared from 16:0-SM, 16:0-DHSM, or DPPC were characterized using steady-state and time-resolved fluorescence spectroscopy and different fluorescent reporter molecules. The acyl-chain region was probed using free and phospholipid-bound 1,6-diphenyl-1,3,5-hexatriene. 16:0-DHSM was f...

journal_title：Biophysical journal

authors： Nyholm T,Nylund M,Söderholm A,Slotte JP

更新日期：2003-02-01 00:00:00

abstract：:In many situations, cell-cell adhesion is mediated by multiple ligand-receptor pairs. For example, the interaction between T cells and antigen-presenting cells of the immune system is mediated not only by T cell receptors and their ligands (peptide-major histocompatibility complex) but also by binding of intracellular...

journal_title：Biophysical journal

authors： Coombs D,Dembo M,Wofsy C,Goldstein B

更新日期：2004-03-01 00:00:00

abstract：:Profiles of negatively stained gap junctions have been measured by grid sectioning. After normal levels of electron irradiation, the membrane thickness shrinks to about half that of unirradiated controls, but no shrinkage occurs in the hexagonal lattice plane. Even under low irradiation conditions, there is significan...

journal_title：Biophysical journal

authors： Sosinsky GE,Jésior JC,Caspar DL,Goodenough DA

更新日期：1988-05-01 00:00:00

abstract：:Single-molecule methods provide direct measurements of macromolecular dynamics, but are limited by the number of degrees of freedom that can be followed at one time. High-resolution rotor bead tracking (RBT) measures DNA torque, twist, and extension, and can be used to characterize the structural dynamics of DNA and d...

journal_title：Biophysical journal

authors： Ivanov IE,Lebel P,Oberstrass FC,Starr CH,Parente AC,Ierokomos A,Bryant Z

更新日期：2018-01-23 00:00:00

abstract：:The separation method, flow field-flow fractionation (flow FFF), is coupled on-line with multiangle laser light scattering (MALLS) for simultaneous measurement of the size and concentration of vesicles eluting continuously from the fractionator. These size and concentration data, gathered as a function of elution time...

journal_title：Biophysical journal

authors： Korgel BA,van Zanten JH,Monbouquette HG

更新日期：1998-06-01 00:00:00

abstract：:Activation of the photoreceptor G protein transducin (Gt) by opsin, the ligand-free form of rhodopsin, was measured using rod outer segment membranes with densities of opsin and Gt similar to those found in rod cells. When GTPgammaS was used as the activating nucleotide, opsin catalyzed transducin activation with an e...

journal_title：Biophysical journal

authors： Melia TJ Jr,Cowan CW,Angleson JK,Wensel TG

更新日期：1997-12-01 00:00:00

abstract：:It is shown that alpha-helical content of eleven proteins is well correlated with alanine plus leucine content. These residues, taken singly or together, are to a first approximation randomly distributed in the four proteins whose tertiary structures have been determined (i.e., myoglobin, lysozyme, ribonuclease, alpha...

journal_title：Biophysical journal

authors： Prothero JW

更新日期：1968-11-01 00:00:00

abstract：:Hormones are released from neuroendocrine cells by passing through an exocytotic pore that forms after vesicle and plasma membrane fusion. An elegant way to study this process at the single-vesicle level is to use styryl dyes, which stain not only the membrane, but also the matrix of individual vesicles in some neuroe...

journal_title：Biophysical journal

authors： Stenovec M,Poberaj I,Kreft M,Zorec R

更新日期：2005-04-01 00:00:00

abstract：:The solution structures of the N-terminal domains of protein S, a plasma vitamin K-dependent glycoprotein, and its homolog growth arrest specific protein 6 (Gas6) were predicted by molecular dynamics computer simulations. The initial structures were based on the x-ray crystallographic structure of the corresponding re...

journal_title：Biophysical journal

authors： Perera L,Li L,Darden T,Monroe DM,Pedersen LG

更新日期：1997-10-01 00:00:00

abstract：:We study a Brownian dynamics simulation model of a biopolymeric shell deformed by axial forces exerted at opposing poles. The model exhibits two distinct, linear force-extension regimes, with the response to small tensions governed by linear elasticity and the response to large tensions governed by an effective spring...

journal_title：Biophysical journal

authors： Banigan EJ,Stephens AD,Marko JF

更新日期：2017-10-17 00:00:00

abstract：:Fluorescence detection, either involving propagating or near-field emission, is widely being used in spectroscopy, sensing, and microscopy. Total internal reflection fluorescence (TIRF) confines fluorescence excitation by an evanescent (near) field, and it is a popular contrast generator for surface-selective fluoresc...

journal_title：Biophysical journal

authors： Oheim M,Salomon A,Brunstein M

更新日期：2020-05-19 00:00:00

abstract：:Low-power continuous-wave laser radiation is used to form a very stable microbubble at the end of a specially etched and metalized optical fiber probe. We demonstrate that the microbubble, which is firmly attached to the fiber probe, can be used to benignly trap and manipulate living swine sperm cells as well as human...

journal_title：Biophysical journal

authors： Diop M,Taylor R

更新日期：2006-05-15 00:00:00