Magnetic spectrometers: approximate and ideal designs.

A produce for determining spectrometer parameters on the basis of specified criteria is illustrated by the design of an energy loss spectrometer for The John Hopkins University high resolution scanning transmission electron microscope. The design tutorial not only includes general expressions for uniform field magnets but also shows how published first and second order transfer coefficients which are available for both uniform field and field gradient magnets may be applied. Within the context of the sharp cutoff fringe field approximation, expressions are derived which enable one to construct ideal pole contours for comparison with prospective second order designs.

Octopine as an end product of anaerobic glycolysis in the chambered nautilus.

The terminal step in the anaerobic glycolysis of muscle in the chambered nautilus, Nautilus pompilius, is not pyruvate reduction to lactate as in vertebrate muscle. Instead of lactate dehydrogenase, these organisms utilize octopine dehydrogenase (E.C.

Recurrent reciprocating tachycardias in the Wolff-Parkinson-White syndrome; control by the use of a scanning pacemaker.

Frequent episodes of arrhythmias in patients with the Wolff-Parkinson-White syndrome are sometimes unresponsive to medical management. Recent emphasis has been placed on the role of surgery as a means of effectively controlling these patients' tachyarrhythmias; however, in some patients the use of permanent pacing has been espoused as an effective means of controlling arrhythmias. This report documents the efficacy of a new pacemaker with rate-scanning features, which offers significant technical advantages.