Models for the gating of ion channels usually assume that the rate constants for leaving any given kinetic state are independent of previous channel activity. Although such discrete Markov models have been successful in describing channel gating, there is little direct evidence for the Markov assumption of time-invariant rate constants for constant conditions. This paper tests the Markov assump...

We have measured gating currents from the squid giant axon using solutions that preserve functional K channels and with experimental conditions that minimize Na channel contributions to these currents. Two pharmacological agents were used to identify a component of gating current that is associated with K channels. Low concentrations of internal Zn2+ that considerably slow K channel ionic curre...

objective(s): in positron emission tomography (pet) studies, thoracic movement under free-breathing conditions is a cause of image degradation. respiratory gating (rg) is commonly used to solve this problem. two different methods, i.e., phase-gating (pg) and amplitude-gating (ag) pet, are available for respiratory gating. it is important to know the strengths and weaknesses of both methods when...

We consider an exactly tractable model of the Kramers type for the voltage-dependent gating dynamics of single ion channels. It is assumed that the gating dynamics is caused by the thermally activated transitions in a bistable potential. Moreover, the closed state of the channel is highly degenerate and embraces the whole manifold of closed substates. Opening of the ion channel is energetically...

This paper represents a review of some existing clock gating techniques for low power dissipation in digital circuitry designs. In this paper, the clock gating techniques are used which reduces the power consumption from the normal implementation of the same design. The 16 bit ALU (arithmetic logical unit) is used for reducing the dynamic power consumption through gating techniques by shutting ...

The gating charge and voltage dependence of the open state to the inactivated state (O-->I) transition was measured for the voltage-dependent mammalian cardiac Na channel. Using the site 3 toxin, Anthopleurin-A (Ap-A), which selectively modifies the O-->I transition (see Hanck, D. A., and M. F. Sheets. 1995. Journal of General Physiology. 106:601-616), we studied Na channel gating currents (Ig)...

background: in radiation treatment of moving targets located in thorax region of patient body, the delivered dose does not match with the planned treatment, resulting in some over and under dosage in the tumor volume, as a function of motion magnitude and frequency. several efforts have been done to investigate the target motion effects on dose distribution in the target and surrounding normal ...