Identification and characterization of a heat shock protein 70 family member in channel catfish (Ictalurus punctatus)

The primary objective of this study was to evaluate the electrophysiologic effects of large-dose propofol, used as the sole anesthetic in patients with epilepsy. Nine patients with medically intractable complex partial epilepsy undergoing a three-stage approach to the surgical management of epilepsy were recruited. State I involved placement of the intracranial electrode array, while Stage II consisted of extraoperative localization of the seizure focus. The patients were studied during induction of anesthesia for Stage III (removal of electrodes and resection of seizure focus). Unpremedicated patients were induced with a propofol infusion (0.5 mg.kg-1.min-1) until one of the following occurred: 1) electrical seizure activity, 2) burst suppression, or 3) total dose of 10 mg/mg. Electrocorticography (ECoG) was recorded continuously during this period. Two patients were excluded from the study after experiencing delayed awakening after the Stage I procedure. Both had received propofol along with other anesthetics. No ECoG evidence of seizure activity was detected in the seven patients completing the study. Burst suppression was attained in six patients using a mean dose of 5.7 mg/kg +/- 2.6. We conclude that large dose propofol alone does not trigger electrical epileptiform activity on the ECoG of seizure patients.     

Steady-state flux-line cutting in type II superconductors

Flux-line cutting (intersection and cross-joining of adjacent nonparallel vortices) has been suggested as a mechanism for steady-state dissipation in current-carrying, type II superconductors in longitudinal magnetic fields. In this paper a specific theoretical flux-line-cutting model is proposed which generates a constant steady-state electric field in a current-carrying, ideal, type II superconducting slab in a longitudinal field. The assumed model consists of parallel vortex planes at different angles which periodically shuttle back and forth between the regions in which flux-line cutting occurs. The resulting macroscopic electric current and magnetic flux density distributions are calculated. The model yields a nonlinear voltage-current characteristic and a longitudinal paramagnetic moment.This work was supported by the U.S. Department of Energy, contract No. W-7405-Eng-82, Division of Materials Sciences budget code AK-01-02-02-3.     

Geometrical Barriers and the Growth of Flux Domes in Thin Ideal Superconducting Disks

When an ideal (no bulk pinning) flat type-II superconducting disk is subjected to a perpendicular magnetic field H _a , the first vortex nucleates at the rim when H _a =H ₀, the threshold field, and moves quickly to the center of the disk. As H _a increases above H ₀, additional vortices join the others, and together they produce a domelike field distribution of radius b. In this paper I present analytic solutions for the resulting magnetic-field and sheet-current-density distributions. I show how these distributions vary as b increases with H _a , and I calculate the corresponding field-increasing magnetization.