Mixed data rate and format transmission (40-Gbit/s non-return-to-zero, 40-Gbit/s duobinary, and 10-Gbit/s non-return-to-zero) by mid-link spectral inversion.

A polarization-diverse subsystem based on periodically poled lithium niobate waveguides is used as an optical phase conjugator for compensation for linear and nonlinear distortion. We show successful transmission formats of 13 x 40 Gbit/s non-return-to-zero mixed with 6 x 10 Gbit/s non-return-to-zero and 40-Gbit/s duobinary over 8 x 100 km of standard single-mode fiber. A single phase conjugator is used to conjugate all data formats, including the alternative duobinary format, simultaneously.

Sonic vibrational analysis provides continuous measurement of arterial properties.

OBJECTIVE: We describe a new technology for measuring artery mechanical properties, called Sonic Vibrational Analysis (SVA). We utilize SVA to study the changes in radial artery smooth muscle tone caused by intravenous infusion of vasoactive agents. METHODS: Six healthy volunteers were monitored with a radial intra-arterial catheter and an SVA sensor during progressively increasing doses of nitroglycerin (NTG), phenylephrine, sodium nitroprusside (SNP), dobutamine, and nicardipine. In SVA, the propagation velocity of an audio-frequency vibration is measured over a short segment of the radial artery. The measurement has sufficient temporal resolution to track the continuous changes in arterial properties that occur due to the natural blood pressure pulse. RESULTS: Coupled with the measurement of radial blood pressure, SVA allowed determination of the physiological/mechanical state of the artery within a single cardiac cycle. NTG, SNP, and phenylephrine caused significant changes in both blood pressure and the physiological state of the radial artery. Nicardipine and dobutamine altered blood pressure without change in the state of the radial artery. CONCLUSIONS: The current results are consistent with previous studies of the effects of vasoactive agents on the radial artery. SVA is non-invasive, continuous, localized to a well-defined section of artery, and suitable for the collection of large volumes of time-resolved data in a laboratory or clinical setting.

Saturation of the Xe III 109-nm laser using traveling-wave laser-produced-plasma excitation.

We describe the construction and operation of a 109-nm, photoionization-pumped, single-pass laser in Xe III. The laser is pumped by soft x rays emitted from a laser-produced plasma in a traveling-wave geometry. Using a 3.5-J, 300-psec, 1064-nm laser pump pulse, we measure a small-signal gain coefficient of 4.4 cm(-1) and a total small-signal gain of exp(40). The laser is fully saturated and produces an output energy of 20 microJ in a beam with 10-mrad divergence.

Slow dose ketamine - a new technique.

A technique using a very low dose infusion of ketamine to provide intense analgesia without loss of consciousness as an alternative to general or regional anaesthesia during selected surgical operations is described and illustrated with three case reports.

Transcatheter thromboembolectomy of acute renal artery occlusion.

Direct surgery of the renal artery has been performed for the relief of acute thrombotic or embolic occlusion of the renal artery to restore adequate renal perfusion and prevent irreversible renal failure. Occasionally, severe medical disease may increase surgical risk to a prohibitive level. An angiographic technique has been devised to provide an alternative approach and has been successfully used on five occluded renal arteries in four patients, with measurable benefit.

Principles in the management of arterial injuries associated with fracture/dislocations.

Ten out of 355 patients admitted with fracture and/or dislocations of long bones secondary to blunt trauma had associated vascular injuries. The clinical recognition of the associated vascular injury and its vertification of arteriography, Doppler study or surgical exploration resulted in early vascular repair and limb salvage. The controversial aspects of bone stabilization followed by vascular repair versus primary vascular repari, skeletal traction and delayed internal fixation together with fasciotomy-fibulectomy are discussed. Our results with the injuries seen justify the principle of bone stabilization followed by vascular repair, particularly since a team effort resulted in little time lost prior to circulatory restoration. The problems following vascular repair-namely anterior compartment snydrome, acute renal failure and cardiac arrest are present with their principles of management.