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Biomedical subjects

L K Yong

Publications and source records attributed to L K Yong.

3 recordsLinked to original sources
PubMed1996

Applying task analysis in design specification: current problems and a solution.

This paper addresses the following criticisms of task analysis: its requirement for an existing system; its focus on analysis rather than design; its limited scope within the design cycle; its underspecification of the application domain; and its inadequate documentation of design outputs. Such criticisms constitute problems for the application of task analysis. Solutions to these problems have emerged indirectly from the development of a structured method intended to rectify the typically late involvement of human factors in system development, e.g. only at the evaluation stage. This paper describes how task analysis has been extended and incorporated throughout the design cycle.

Data Interpretation, Statistical↗
PubMed1989

Metabolic changes and mitochondrial dysfunction early following transthoracic countershock in dogs.

The mechanisms of myocardial injury and necrosis following transthoracic shocks from a direct current cardiac defibrillator were investigated in adult greyhounds. Myocardial lactate extraction became negative maximally at 1 minute, following two (mean -22% +/- SEM23) or five (-193% +/- 135) shocks and returned to baseline in 6-15 minutes. Myocardial necrosis assessed at 4 hours following the shock period was 0.05 g (+/- 0.03) after two shocks, 6.69 g (+/- 1.76) after five shocks and zero in controls. In further experiments, dogs received five or zero (dummy) shocks and mitochondria were isolated from their hearts following excision within 1 minute of receiving the final shock. Maximal oxygen consumption in right ventricular mitochondria was lower than the unshocked controls with both glutamate (66.9 +/- 9.4 nanoatoms of oxygen/mg per minute, n = 9 vs 86.6 +/- 13.6 nanoatoms/mg per minute, n = 7) and succinate (96.2 +/- 8.7 nanoatoms/mg per minute, n = 9 vs 119.5 +/- 14.4 nanoatoms/mg per minute, n = 7) as substrates. Using electron spin resonance spectroscopy, an increase in a peroxyl-free radical with g = 2.031 was detected in myocardial tissue after two internal shocks (50 joules stored energy, 0.5-minute intervals). We conclude that mitochondrial dysfunction and free-radical generation are likely contributors to cellular injury following multiple countershocks.

Animals↗