We investigated the imp silicon microelectrodes and co electrodes in rat cerebral cortex. were performed in which the insertion/retraction into brain tiss 2 mm/s, 2 repetitions) were measu tine VSAMUEL microelectrode sectional area = 950 μm2) with a single tine microelectrodes (ope sectional area = 750-1962 μm2). In of the brain surface before the mN). The force maintained to inc advancement ha...

The way that contractility varies between beats—the force-frequency relationshipwas determined for rabbit papillary muscles held at different lengths. When the maximum rate of rise of tension in a contraction, Fmai, was used as a measure of contractility, the way contractility changed between contractions was independent of length. That is, when the values of Fmax obtained at one length were mu...

Motivated by recent experiments, we develop a model for DNA toroids under external tension. We find that tori are the equilibrium states for our model up to a critical tension, above which they become only metastable. Above this tension, we find a cascade of transitions between discrete toroid states that successively lower the winding number, until the ground state (rod) is reached. In this pr...

Matar, W., T. M. Nosek, D. Wong, and J.-M. Renaud. Pinacidil suppresses contractility and preserves energy but glibenclamide has no effect during muscle fatigue. Am. J. Physiol. Cell Physiol. 278: C404–C416, 2000.—The effects of 10 μM glibenclamide, an ATP-sensitive K1 (KATP) channel blocker, and 100 μM pinacidil, a channel opener, were studied to determine how the KATP channel affects mouse ex...

Dyssynchronous activation of the heart leads to abnormal regional systolic stretch. In vivo studies have suggested that the timing of systolic stretch can affect regional tension and external work development. In the present study, we measured the direct effects of systolic stretch timing on the magnitude of tension and external work development in isolated murine right ventricular papillary mu...

The molecular determinants of the high efficiency of biological machines like unfoldases (e.g., the proteasome) are not well understood. We propose a model to study protein translocation into the chamber of biological unfoldases represented as a funnel. It is argued that translocation is a much faster way of unfolding a protein than end-to-end stretching, especially in a low-force regime, becau...

When tensioned, ordinary materials expand along the direction of the applied force. Here, we explore network concepts to design metamaterials exhibiting negative compressibility transitions, during which a material undergoes contraction when tensioned (or expansion when pressured). Continuous contraction of a material in the same direction of an applied tension, and in response to this tension,...

The way that contractility varies between beats—the force-frequency relationshipwas determined for rabbit papillary muscles held at different lengths. When the maximum rate of rise of tension in a contraction, Fmai, was used as a measure of contractility, the way contractility changed between contractions was independent of length. That is, when the values of Fmax obtained at one length were mu...

Controlled-length quick releases were applied to cat papillary muscle at various times during an isometric contraction to study the series elasticity of cardiac muscle relative to time. Force and length were measured continuously during the course of constant-velocity releases. Series elastic compliance was evaluated from semilogarithmic plots with force referred to plateau levels. The force-ex...