VCF (voltage clamp fluorimetry) provides a powerful technique to observe real-time conformational changes that are associated with ion channel gating. The present review highlights the insights such experiments have provided in understanding Kv (voltage-gated potassium) channel gating, with particular emphasis on the study of mammalian Kv1 channels. Further applications of VCF that would contri...

A wavelength-independent method for optical gating, based on the optical Kerr effect, has been demonstrated. Using this method, we produced 100-ps, 10-kW, two-wavelength pulses (10.3 and 10.6 microm) with a signal-to-background ratio contrast of 10(5) by slicing a long CO2 pulse. The capability of gating consecutive pulses separated on a picosecond time scale with this method is also shown.

Nonlinear capacitative current (charge movement) was compared to the Ca current (ICa) in single guinea pig ventricular myocytes. It was concluded that the charge movement seen with depolarizing test steps from -50 mV is dominated by L-type Ca channel gating current, because of the following observations. (a) Ca channel inactivation and the immobilization of the gating current had similar voltag...

Before treatment delivery of respiratory-gated radiation therapy (RT) in patients with implanted fiducials, both the patient position and the gating window thresholds must be set. In linac-based RT, this is currently done manually and setup accuracy will therefore be dependent on the skill of the user. In this study, we present an automatic method for finding the patient position and the gating...

specific steps in voltage-activation path of an ion channel are altered by a potent allosteric inhibitor. The Kþ channel peptide inhibitor guangxitoxin-1E (GxTX) is partial inverse agonist of the voltage gated potassium channel subtype Kv2.1 from rat. At saturating concentrations of GxTX, Kv2.1 requires higher voltages to activate. The GxTX modulated conductance requires more voltage to activat...

AbstractBackground and purpose Both gating tracking can mitigate the deteriorating dosimetric impact of intrafraction translation during prostate stereotactic body radiotherapy (SBRT). However, their ability to manage rotation has not yet been thoroughly investigated. The accuracy gating, MLC couch was Materials methods Treatment plans for end-to-end tests SBRT with f...

OBJECTIVES The purpose of this study was to validate cardiac measurements derived from real-time cardiac magnetic resonance imaging (MRI) as compared with well-validated conventional cine MRI. BACKGROUND Although cardiac MRI provides accurate assessment of left ventricular (LV) volume and mass, most techniques have been relatively slow and required electrocardiogram (ECG) gating over many hea...

We demonstrate the validity of the Shackled-frequency-resolved-optical-gating technique for the complete characterization, both in space and in time, of ultrashort optical pulses that present strong angular dispersion. Combining a simple imaging grating with a Hartmann-Shack sensor and standard frequency-resolved-optical-gating detection at a single spatial position, we are able to retrieve the...

Low threshold Ca2+ currents mediated by T-type channels underlie burst spike activities of relay neurons in the thalamus. We have previously reported that knock-out mice for T-type channels show an enhanced nociceptive response to visceral pain, accompanied by an increase in tonic spikes in the absence of burst spikes in thalamic relay neurons. These results raised a possibility that T-type cha...