Mathematical principle of planar Z-plasty

To extend the work of precursors attempting to use Z-plasties with angles that have arbitrary degrees and may or may not be equal in size, a comprehensive study was done to clarify and simplify the correlation among the angles, limbs, and diagonals of the geometrical construction of Z-plasties. In geometry, the truth of a proposition must be proved; it is a question to which the answer must be found. By law and formula, a ternary trigonometric equation was derived from a simplified geometric diagram by a trigonometric approach. A procedure declaration accompanies this formula; neither was previously mentioned in the literature.

Novel pulse-delayed scheme for degenerate optical parametric amplification in chi((3)) waveguides

We describe a novel pulse-delayed scheme to realize degenerate optical parametric amplification in chi((3)) planar waveguides. The scheme utilizes two identical birefringent plates placed before and after a chi((3)) planar waveguide to implement a single-arm, pulse-multiplexed nonlinear Mach-Zehnder interferometer. Using this scheme, we demonstrate ultrafast degenerate optical parametric amplification in AlGaAs waveguides.

Predicting survival in AIDS patients with respiratory failure. Application of the APACHE II scoring system

This article describes the APACHE II classification system as a measure of severity of illness applied to AIDS patients with respiratory insufficiency. Among 82 patients, observed mortality in patients with high APACHE II scores (greater than 30) and those with low scores (less than 18) was significantly higher than predicted. There was variable correlation between predicted and observed mortality in the other APACHE II score ranges. The usefulness of the APACHE II scoring system is reviewed as limited and inaccurate in predicting survival rates in AIDS patients with respiratory failure.

An acrylic head appliance for craniomaxillary fixation

An acrylic head appliance for the treatment of LeFort fractures is described. The appliance remains stable and effective during the course of treatment. When immobilization is no longer needed, it may be removed without anesthetizing the patient.

Congenital liver cyst presenting as congenital diaphragmatic hernia

A 5-day-old infant was found to have an unusual presentation of a congenital liver cyst. The cyst arose from the left lobe of the liver and herniated into the left thoracic cavity through a congenital defect at the central tendinous portion of the diaphragm. The association between a congenital liver cyst and the location of the diaphragmatic hernia suggests that the abnormality occurred during very early embryonic development when the liver rapidly expands and extends into the septum transversum at the base of the heart. A small amount of liver tissue might well have perforated through the thinnest central portion of the septum transversum and underwent cystic degeneration due to incarceration.