The unilateral pectoralis major island flap, an efficient and straightforward procedure for reconstruction of full length sternal defects after postoperative mediastinal wound infection.

Male weanling Wistar rats were divided into four groups of eight. For six weeks they were fed diets containing 15% of either fresh or thermally oxidized canola oil (TOO) and distilled water or 5% ethanol in water (v/v). TOO was prepared by heating the oil at 180°C for 72 hours with three eight-hour periods of aeration. The dietary treatments did not significantly alter mean caloric intake and final body weights. Dietary TOO elevated relative liver weights and microsomal protein. Animals fed TOO exhibited increased catalase activity as well as greter amounts of cytochrome P-450 (P-450). The same rats showed a reduction in CuZn superoxide dismutase (CuZnSOD) activity, while no change was seen in MnSOD. Neither treatment affected serum glutamic-oxalacetic transaminase (SGOT) activity. Ethanol administration potentiated the oxidized oil induced catalase and depressed CuZnSOD activities, but had no effect on MnSOD or P-450. These data suggest that dietary TOO or some components therein present an oxidative load to the liver. A low level ethanol intake may intensify these responses.

A detailed description is given of the surface composition and morphology of D&I can surfaces. Surface analysis indicated that a protective film of tin was present over virtually the entire surface, albeit very thin in places. This finding is in contrast to the results of electrochemical porosity tests which normally indicate that the majority of can wall surfaces are exposed steel. Investigations, however, revealed that the widely used porosity tests cause substantial surface damage resulting in erroneously high exposed steel values. It is recommended that they not be used in heavily worked tinplate, such as that in D&I cans.

Surfaces of materials, the top few atomic layers, are of critical importance because it is here that a material interacts with its environment. The surface properties of materials dominate their corrosion behaviour, wettability, electrical contact resistance, frictional behaviour, adhesion properties and chemical reactivity. Over the last 25 years the vital role that surfaces play and the need to characterise them have been increasingly recognised and this has been paralleled by the development of many new surface analysis techniques. Of these, just a few have become pre-eminent for materials and devices characterisation: X-ray photoelectron spectroscopy, Auger electron spectroscopy and secondary ion mass spectrometry. The principles and capabilities of each of these techniques are briefly described. Application include the study of semiconductors, metallic and ceramic materials.

Canola oils were heated in the laboratory for 72 hours at 180°C with three periods of eight-hour aeration. These oils were included in the diet at a level of 15% and were fed adlibitum to rats for 4 weeks. The effects of the diets on growth-related parameters and on several hepatic enzymes and biomolecules associated with the glutathione redox cycle were investigated. Feeding of oxidized oils resulted in no appreciable decrease in body weight gain or food intake. Fat absorption was lower in all oxidized oil groups. The percentage of lipid in livers of rats fed oxidized oils was not significantly changed, but amounts of the fatty acids C18:2, C18:3, and C20:4 in the xxidized groups were substantially different from the fresh oil groups except for the trace amount of C18:3 in the corn oil. Liver weights were increased in rats fed oxidized oil. The activities of the hepatic enzymes glutathione peroxidase and glucose-6-phosphate dehydrogenase in the oxidized oil groups were decreased numerically while that of catalase was significantly increased. There were no changes in the activity of glutathione reductase, or in the concentrations of hepatic glutathione, malonaldehyde or cytosolic protein.

Silicon nitride films have been produced by plasma enhanced chemical vapour deposition using silane and ammonia as the reactant gases in a Plasma-Therm PK1250PD machine. The compositions of the films have been investigated as a function of the silane to ammonia flow rate ratio used for deposition, using infra-red transmission and Auger electron spectroscopies. These techniques indicated that the plasma deposited films were silicon-rich and contained hydrogen. The oxygen content of the films was below the detection limit of Auger electron spectroscopy implying that it was less than 1%. Silicon ion-implanted semi-insulating gallium arsenide has been annealed using an approximately 1000 Å thick film of plasma deposited silicon nitride as an encapsulant. This capped annealing technique has achieved 70% activations of 4×1012 cm−2, 200 keV silicon implants with sheet Hall mobilities of 4000 cm2 V−1 s−1 at room temperature. Free carrier concentration and Hall mobility profiles are presented. Unimplanted semi-insulating gallium arsenide samples have also been capped annealed in the same manner and maintained a sheet resistivity of greater than 107 ohm/square after annealing.

In this and a companion paper, we summarise the achievement of a metal-semiconductor contact whose electrical characteristics degrade only over tens of hours at 500°C. Although initially conceived as a barrier to Au diffusion, the thin amorphous metal film now fails because of out-diffusion of elements of the semiconductor. In this paper we summarise the rationale for using amorphous metal films, the choice of alloys, the fabrication of test structures, and the characterisation of these structures before and after exposure to temperatures as high as 700°C for 24 hr. The companion paper describes the thermal degradation of Schottky barrier characteristics of metal films on both Si and GaAs.

The process of “zone refining” or “zone melting” is described. By an analogous process, magma formed at great depth within the mantle and ascending by solution and crystallization, could become enriched in those elements unable to substitute in the mineral phases of the mantle. The geological possibility of the process and its application to potassic basalts are discussed. Some sodic basalts are attributed to fractional crystallization modified by reaction with mantle material.