Abstract:
:The formulation of Lorente de Nó for the potential distribution in a volume conductor due to a contained bioelectric source is reviewed. The aforementioned formula is based on data taken from the bioelectric source in air (excised). This work is extended to the derivation of a formula which depends upon quantities available from in situ measurements. The latter formula appears to simplify to the form[FORMULA: see text]where J(n) is the normal current density flow across the surface S(o) that bounds the bioelectric source. The simplification is considered in some detail for a hypothetical action potential on a circular cylindrical axon, and is shown to be adequately substantiated for this case.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
PLONSEY Rdoi
10.1016/s0006-3495(64)86785-0subject
Has Abstractpub_date
1964-07-01 00:00:00pages
317-28eissn
0006-3495issn
1542-0086pii
S0006-3495(64)86785-0journal_volume
4pub_type
杂志文章abstract::We develop a model of tyrosine phosphorylation and activation of the T-cell receptor (TCR) by localization to regions of close membrane-membrane proximity (close contact) that physically exclude tyrosine phosphatases such as CD45. Phosphatase exclusion generates regions of low phosphatase and high kinase activity and ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.080044
更新日期:2006-09-01 00:00:00
abstract::We simulate a simple phenomenological model describing phase behavior in a multicomponent membrane, a model capable of producing macroscopic phase separation, modulated phases, and microemulsions, all of which have been discussed in terms of raft phenomena. We show that one effect of thermal fluctuations on the mean-f...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.03.017
更新日期:2014-05-06 00:00:00
abstract::Recent experimental studies (Pusch and Neher, 1988) and theoretical studies (Oliva et al., 1988) have found that the pipette tip is a significant barrier to diffusion in the whole cell patch clamp configuration. In this paper, we extend the theoretical analysis of fluxes between the pipette and cell to include transme...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(90)82418-8
更新日期:1990-09-01 00:00:00
abstract::Voltage-sensitive fluorescent dyes are commonly used to measure cardiac electrical activity. Recent studies indicate, however, that optical action potentials (OAPs) recorded from the myocardial surface originate from a widely distributed volume beneath the surface and may contain useful information regarding intramura...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74690-6
更新日期:2003-10-01 00:00:00
abstract::The Ciona intestinalis voltage-sensitive phosphatase (Ci-VSP) represents the first discovered member of enzymes regulated by a voltage-sensor domain (VSD) related to the VSD found in voltage-gated ion channels. Although the VSD operation in Ci-VSP exhibits original voltage dependence and kinetics compared to ion chann...
journal_title:Biophysical journal
pub_type: 信件
doi:10.1016/j.bpj.2012.06.030
更新日期:2012-08-08 00:00:00
abstract::Characterizing the ionic distribution around chromatin is important for understanding the electrostatic forces governing chromatin structure and function. Here we develop an electrostatic model to handle multivalent ions and compute the ionic distribution around a mesoscale chromatin model as a function of conformatio...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.08.023
更新日期:2010-10-20 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
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.07.029
更新日期:2020-09-01 00:00:00
abstract::The gelation of sickle hemoglobin includes the formation of spherulitic arrays of polymers, known as polymer domains, which are an intrinsic result of the polymer formation mechanism. We have observed the diffusion of monomers into domains as they form, which substantially increases the total concentration of hemoglob...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(90)82449-8
更新日期:1990-10-01 00:00:00
abstract::A pulsed source neutron spectrometer has been used to measure vibrational spectra (20-4000 cm-1) of dry and hydrated type I collagen fibers, and of two model polypeptides, polyproline II and (prolyl-prolyl-glycine)10, at temperatures of 30 and 120 K. the collagen spectra provide the first high resolution neutron views...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(95)79942-8
更新日期:1995-08-01 00:00:00
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journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)74047-0
更新日期:1998-09-01 00:00:00
abstract::Cellular membranes are laterally organized into domains of distinct structures and compositions by the differential interaction affinities between various membrane lipids and proteins. A prominent example of such structures are lipid rafts, which are ordered, tightly packed domains that have been widely implicated in ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2018.03.020
更新日期:2018-04-24 00:00:00
abstract::Unlike most transmembrane proteins, phospholipids can migrate from one leaflet of the membrane to the other. Because this spontaneous lipid translocation (flip-flop) tends to be very slow, cells facilitate the process with enzymes that catalyze the transmembrane movement and thereby regulate the transbilayer lipid dis...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.01.016
更新日期:2019-03-05 00:00:00
abstract::Current analyses of protein sequence/structure relationships have focused on expected similarity relationships for structurally similar proteins. To survey and explore the basis of these relationships, we present a general sequence/structure map that covers all combinations of similarity/dissimilarity relationships an...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/s0006-3495(02)75287-9
更新日期:2002-11-01 00:00:00
abstract::Cardiomyocytes have intracellular diffusion restrictions, which spatially compartmentalize ADP and ATP. However, the models that predict diffusion restrictions have used data sets generated in rat heart permeabilized fibers, where diffusion distances may be heterogeneous. This is avoided by using isolated, permeabiliz...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.03.025
更新日期:2010-06-16 00:00:00
abstract::Long time series of monosynaptic Ia-afferent to alpha-motoneuron reflexes were recorded in the L7 or S1 ventral roots in the cat. Time series were collected before and after spinalization at T13 during constant amplitude stimulations of group Ia muscle afferents in the triceps surae muscle nerves. Using autocorrelatio...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80526-0
更新日期:1994-08-01 00:00:00
abstract::ATP, 2-deoxy ATP (dATP), CTP, and UTP support isometric force and unloaded shortening velocity (Vu) to various extents (Regnier et al., Biophys. J. 74:3044-3058). Vu correlated with the rate of cross-bridge dissociation after the power stroke and the steady-state hydrolysis rate in solution, whereas force was modulate...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)78013-0
更新日期:1998-06-01 00:00:00
abstract::If a branched multistep editing mechanism is implemented by an enzyme with a single site for the specific substrates, there is no reason to believe that the number of testing steps is fixed and cannot be controlled by some external factors. The paper considers the mechanisms of single- or multistep editing done in res...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(82)84469-X
更新日期:1982-11-01 00:00:00
abstract::It was previously reported (Chernomordik and Sowers, 1991) that erythrocyte ghosts which were exposed to a 42 degrees C, 10-min heat treatment would, upon electrofusion, produce over 15-20 s a fusion product with an "open lumen" (i.e., the fusion product became converted to one large sphere), while electrofusion of gh...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80762-3
更新日期:1994-01-01 00:00:00
abstract::A requirement for concentrated and chemically homogeneous pools of molecular building blocks would severely restrict plausible scenarios for the origin of life. In the case of membrane self-assembly, models of prebiotic lipid synthesis yield primarily short, single-chain amphiphiles that can form bilayer vesicles only...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.07.067
更新日期:2014-10-07 00:00:00
abstract::The cell membrane of Salinibacter ruber contains xanthorhodopsin, a light-driven transmembrane proton pump with two chromophores: a retinal and the carotenoid, salinixanthin. Action spectra for transport had indicated that light absorbed by either is utilized for function. If the carotenoid is an antenna in this prote...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.108.132175
更新日期:2008-09-01 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
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74915-7
更新日期:2003-02-01 00:00:00
abstract::Pyranine (8-hydroxy pyrene-1,3,6-trisulfonate) is a commonly used photoacid that discharges a proton when excited to its first electronic singlet state. Follow-up of its dissociation kinetics reveals the physicochemical properties of its most immediate environment. At vanishing ionic strength the dye adsorbs to the Es...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)76122-X
更新日期:2001-03-01 00:00:00
abstract::The endoplasmic reticulum (ER) is the major compartment for the processing and quality control of newly synthesized proteins. Green fluorescent protein (GFP) was used as a noninvasive probe to determine the viscous properties of the aqueous lumen of the ER. GFP was targeted to the ER lumen of CHO cells by transient tr...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)77438-2
更新日期:1999-05-01 00:00:00
abstract::In previous in vivo studies, amyloid fibers formed from a peptide ubiquitous in human seminal fluid (semen-derived enhancer of viral infection (SEVI)) were found to dramatically enhance the infectivity of the HIV virus (3-5 orders of magnitude by some measures). To complement those studies, we performed in vitro assay...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.08.034
更新日期:2009-11-04 00:00:00
abstract::Membrane fusion proceeds via formation of intermediate nonbilayer structures. The stalk model of fusion intermediate is commonly recognized to account for the major phenomenology of the fusion process. However, in its current form, the stalk model poses a challenge. On one hand, it is able to describe qualitatively th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)75450-7
更新日期:2002-02-01 00:00:00
abstract::The spermine-induced DNA condensation is a first-order phase transition. Here, we apply a novel technique fluorescence lifetime correlation spectroscopy to analyze this transition in a greater detail. We show that the method allows for the observation of the condensed and uncondensed molecules simultaneously based sol...
journal_title:Biophysical journal
pub_type: 信件
doi:10.1529/biophysj.107.122408
更新日期:2008-02-01 00:00:00
abstract::Articular cartilage is the connective tissue that lines joints and provides a smooth surface for joint motion. Because cartilage is avascular, molecular transport occurs primarily via diffusion or convection, and cartilage matrix structure and composition may affect diffusive transport. Because of the inhomogeneous co...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.108.137752
更新日期:2008-11-15 00:00:00
abstract::Cytochrome c3 (cyt c3) can mediate electron transport across phosphatidylcholine (PC)/cardiolipin (CL) and PC/phosphatidylglycerol (PG) membranes. A two-molecule process is involved in the electron transport across PC/CL membranes in the liquid-crystalline state. In contrast, a single-molecule process dominates the el...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.065359
更新日期:2006-01-15 00:00:00
abstract::In this paper, we report on the presence of cation binding areas on bovine serum amine oxidase, where metal ions of the groups IA and IIA, such as Na(+), K(+), Cs(+), Mg(2+), and Ca(2+), bind with various affinities. We found a cation-binding area that influences the enzyme activity if occupied, so that the catalytic ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)73983-0
更新日期:2002-10-01 00:00:00
abstract::Three-dimensional structures were determined for three crystal forms of the antigen binding fragment (Fab) of anti-fluorescein antibody 4-4-20 in complex with fluorescein. These included 1) a triclinic (P1) form crystallized in 47% (v/v) 2-methyl-2,4-pentanediol (MPD); 2) a triclinic (P1) form crystallized in 16% (w/v...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80738-6
更新日期:1994-12-01 00:00:00