Showing papers in "Biophysical Journal in 1995"

TL;DR: Applying the idea of self-similar dynamics, a fractal scaling model is derived that results in an equation in which the time derivative is replaced by a differentiation (d/dt)beta of non-integer order beta ofNon- integer order beta.

TL;DR: Both the theoretical simulation and experimental data show that photobleaching of fluorescein in microscopy is, in general, not a single-exponential process.

TL;DR: The passive tension-sarcomere length relation of rat cardiac muscle was investigated by studying passive (or not activated) single myocytes and trabeculae and the contribution of collagen, titin, microtubules, and intermediate filaments to tension and stiffness was investigated.

TL;DR: It is demonstrated that monitoring fluctuations in probe position at low transducer stiffness enhances detection of molecular adhesion and activation of cytoskeletal structure and can be measured at a displacement resolution set by structural fluctuations.

TL;DR: In this article, two photon molecular excitation was applied to fluorescence correlation spectroscopy to measure translational mobility in the cytoplasm of living cells, and the results showed that the translational diffusion coefficient for 7 and 15-nm radius latex beads stuck to the cells and slowed down 10 to 100 times after a few hours.

TL;DR: Measurement of neuronal growth cone membrane mechanical properties through the extension of filopodia-like tethers with IgG-coated beads indicates that the actin cytoskeleton affects the membranes mechanical properties, including the force required for membrane extension and the viscoelastic behavior.

TL;DR: Pressure-distance relations have been measured by X-ray diffraction analysis of liposomes subjected to known applied osmotic pressures to take into account the effects of polymer polydispersity and the possibility that, at low grafting densities, polymers from apposing bilayers surfaces can interpenetrate or interdigitate.

TL;DR: The resolution is best in pure propanol, on the order of 20 nm, and becomes worse for the softer samples, and the degradation in resolution can be understood by considering the elastic indentation of the gelatin caused by the AFM tip, which becomes larger the softer the sample is.

TL;DR: The results confirm the concept that, for appropriately matched temperature and surface pressure, a monolayer is a close approximation to one-half of a bilayer and suggest that the surface area per phospholipid molecule for fluid phosphatidylcholine bilayer membranes is smaller than has generally been assumed in computational studies at constant volume.

TL;DR: Epifluorescence imaging of the transmembrane potential during and after stimulation of both refractory and excitable tissue shows distinctive regions of simultaneous depolarization and hyperpolarization during stimulation that act as virtual cathodes and anodes that confirm bidomain model predictions that the onset of a stimulus induces propagation from the virtual cathode.

TL;DR: A simulation approach to the study of the effects of pharmacological agents on cellular processes was introduced and the results are qualitatively consistent with experimental observations and help resolve contradictory conclusions in the literature regarding the mechanism of EADs.

TL;DR: The confinement of liposomes and Chinese hamster ovary cells by infrared (IR) optical tweezers is shown to result in sample heating and temperature increases by several degrees centigrade, as measured by a noninvasive, spatially resolved fluorescence detection technique.

TL;DR: Purple membranes adsorbed to mica were imaged in buffer solution using the atomic force microscope and individual bacteriorhodopsin molecules consistently exhibited a distinct substructure.

TL;DR: The concentric ring model is consistent with the observation that the diameters of collagen fibrils are restricted to discrete values, and energy minimization results in radially oriented crystalline domains separated by disordered grain boundaries.

TL;DR: An expression for the C-C bond order parameter, SCC, of membrane hydrocarbon chains has been derived from the observed C-D bond order parameters, thereby affording the calculation of accurate hydrophobic bilayer thicknesses.

TL;DR: In this article, the calmodulin-binding properties of the rabbit skeletal muscle Ca2+ release channel (ryanodine receptor) and the channel's regulation by Calmodulin were determined.

TL;DR: Transepithelial impedance of Madin-Darby canine kidney cell layers is measured by a new instrumental method, referred to as electric cell-substrate impedance sensing, and shows that reduction of Ca2+ concentration causes junction resistance between cells to drop and the distance between the basal cell surface and substratum to increase.

TL;DR: The introduction of the exciton-radical-pair equilibrium, for both the open and closed states of the trap, is shown to be equivalent to an irreversible trapping scheme with modified parameters and variation of the interunit transfer rate allows continuous modulation from the case of separated units to the pure lake model.

TL;DR: Electron cryo-microscopy was used to determine the three-dimensional structure of bovine rhodopsin from tilted two-dimensional crystals embedded in vitrified water and the overall density distribution in the low resolution map shows an arrangement of the helices in which the "arc-shaped" feature is extended by a fourth, less tilted helix.

TL;DR: Results suggest that formation of an intermediate with a high beta-sheet content is a controlling step in Abeta-amyloid peptide self-assembly.

TL;DR: A method was developed to detect temporary confinement in the trajectories of membrane proteins that cannot be accounted for by Brownian motion, and the results were compared with those for simulated random walks.

TL;DR: The hippocampal nicotinic acetylcholine- and NMDA-activated whole-cell currents were determined and it was found that the neuronal alpha-BGT-sensitive nAChR is a cation channel considerably selective to Ca2+ and may mediate a fast rise in intracellular Ca2+.

TL;DR: Results are consistent with protonation of histidine residue 37 as an essential step in the activation of the wild-type M2 ion channel.

TL;DR: The absorption and spreading behavior of lipid vesicles composed of either palmitoyloleoylphosphatidylcholine (POPC) or Escherichia coli lipid upon contact with a glass surface was examined, and supported planar bilayers were found to be permeable for small molecules, whereas supported vesicle layers were impermeable and thus represented immobilized, topologically separate compartments.

TL;DR: resolution on exceptional images of DNA appears to be approximately 2 nm, sufficient to see helix turns in detail, but the smallest substructures typically seen on DNA in propanol are approximately 6-10 nm in size.

TL;DR: The results indicate that nonspecific adsorption of single-stranded DNA on the surface and subsequent two-dimensional diffusion can significantly enhance the overall reaction rate and suggest that there is an optimal surface probe density when 2D diffusion occurs.

TL;DR: A biologically realistic cell-chemotaxis model to describe the self-organization of bacteria is developed and numerical and analytical investigations of the model mechanism show how the two types of observed geometric patterns can be generated by the interaction of the cells with chemoattractant they produce.

TL;DR: The intermediates of hemifusion and fusion pores in phospholipid membranes involve different membrane monolayers and may have opposite net curvatures, Biological fusion may proceed through similar intermediates.

TL;DR: A theoretical study of the free energy contributions to nucleic acid base stacking in aqueous solution and qualitatively reproduce the experimental dependence of stacking free energy on purine-pyrimidine composition.

TL;DR: The structure and phase behavior of fully hydrated DSPC suspensions containing PEG-lipids composed of distearoylphosphatidylethanolamine with attached PEGs of molecular weights ranging from 350 to 5000 are determined.