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The use of peripheral nerve blocks to control pain is an increasing practice. Many techniques include the use of stimulating needles to locate the nerve of interest. Though success rates are generally high, difficulties still exist. In certain deeper nerve blocks, two needles of different geometries are used in the procedure. A smaller needle first locates a nerve bundle, and then is withdrawn in favor of a second, larger needle used for injection. The distinct geometries of these needles are shown to generate different electric field distributions, and these differences may be responsible for failures of the second needle to elicit nerve stimulation when placed in the same location as the first. A 3-D finite-difference method has been employed to numerically calculate the electric field distributions for a commercial set of stimulating needles. Index Terms--Anesthesiology, electric fields, finite-difference methods.

An approach to describe the behavior of superconducting transmission line using the magnetic vector potential (A) is presented and examined. The results suggest that for device level formulation, the magnetic vector potential is a mathematically simpler quantity to deal with than the combination of magnetic flux density and electric field intensity and still contains all the electromagnetic information of the junction under construction.

The use of peripheral nerve blocks to control pain is an increasing practice. Many techniques include the use of stimulating needles to locate the nerve of interest. Though success rates are generally high, difficulties still exist. In certain deeper nerve blocks, two needles of different geometries are used in the procedure. A smaller needle first locates a nerve bundle, and then is withdrawn in favor of a second, larger needle used for injection. The distinct geometries of these needles are shown to generate different electric field distributions, and these differences may be responsible for failures of the second needle to elicit nerve stimulation when placed in the same location as the first. A 3-D finite-difference method has been employed to numerically calculate the electric field distributions for a commercial set of stimulating needles. [ABSTRACT FROM AUTHOR]

Abstract: Films of the photomagnetic Prussian blue analogue Rb0.7Co4(Fe(CN)6)3.0(Co–Fe PBA) were deposited onto a Melinex® substrate using two different multiple sequential adsorption methods. Film thickness, measured using atomic force microscopy, was controlled by the number of deposition cycles. The photoinduced magnetism known for the bulk Co–Fe PBA at low temperatures is also seen in the thin films, although the response is anisotropic. A photoinduced increase in magnetization is observed when the film is parallel (∥) to the applied magnetic field (H E), while a photoinduced decrease is observed when the film is perpendicular (⊥) to a weak H E. The relationship between the film thickness and the photoinduced decrease in magnetization is explored in this article. The photoinduced decrease is observed for films less than ∼200nm thick. The behavior is explained by invoking a dipolar interaction between primordial ferrimagnetic domains and the photoswitchable pairs arrayed in the quasi-2D thin film. [Copyright &y& Elsevier]