The primary objective of this survey was to investigate the prevalence of insomnia among anaesthetists in Hong Kong. The use of sleeping aids, factors associated with insomnia and the effect of insomnia on work performance were also studied. We surveyed all locally registered anaesthesia specialists and trainees by post. The response rate was 50%. We found that the prevalence of insomnia among the respondents was 22.4% (95% confidence interval 16.7 to 28.1%). Insomnia was positively associated with the number of on-call shifts per month (P=0.002) and poor relationship with supervisors (P=0.009). Alcohol was the most frequently used aid to assist sleep, followed by Zolpidem. The majority of respondents using sleeping medication obtained the drug over-the-counter, by self-prescription or prescription by colleagues. Only 4.3% (95% confidence interval 0 to 10.2%) of respondents suffering from insomnia had formal medical consultation for sleep disturbance. Insomnia was associated with increased subjective sleepiness at work (P=0.007) and subjective decline in work performance during both daytime (P <0.001) and night-time (P <0.001). However, it was not associated with the tendency to fall asleep at work. The results of this survey suggest that insomnia is a common problem among the anaesthetists of Hong Kong. By restricting the amount of on-call duty and improving relationships with supervisors, the prevalence of insomnia may be reduced and the quality of patient care improved.

The temperature- and bias-dependent photocurrent spectra of very long wavelength GaAs/AlGaAs quantum well infrared photodetectors (QWIPs) are studied using spectroscopic measurements and corresponding theoretical calculations. It is found that the peak response wavelength will shift as the bias and temperature change. Aided by band structure calculations, we propose a model of the double excited states and explain the experimental observations very well. In addition, the working mechanisms of the quasi-bound state confined in the quantum well, including the processes of tunneling and thermionic emission, are also investigated in detail. We confirm that the first excited state, which belongs to the quasi-bound state, can be converted into a quasi-continuum state induced by bias and temperature. These obtained results provide a full understanding of the bound-to-quasi-bound state and the bound-to-quasi-continuum state transition, and thus allow for a better optimization of QWIPs performance.

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It is generally accepted that the major autoantigen for antiphospholipid antibodies (aPL) is beta(2)glycoprotein I (beta(2)GPI). Interestingly, some aPL bind to beta(2)GPI and the homologous enzymatic domains of several proteases involved in hemostasis and fibrinolysis, and correspondingly hinder anticoagulant regulation and resolution of clots. These findings are consistent with several early findings of aPL and provide a new perspective about some aPL in terms of their binding specificities and related functional properties in promoting thrombosis. In addition, homologous enzymatic domains of the involved proteases share conformation epitope(s) with beta(2)GPI, thus providing a possible structural basis for some non-mutually exclusive mechanisms of aPL-mediated thrombosis.

The body has an elaborate system that maintains blood circulation and rapidly stops bleeding when vessels are damaged. Abnormalities that disrupt this balance may lead to thrombosis. While beta(2)-glycoprotein I is generally accepted as the major antigen for antiphospholipid antibodies in the antiphospholipid syndrome, our accumulated studies show that some antiphospholipid antibodies bind homologous enzymatic domains of several serine proteases involved in hemostasis and fibrinolysis. Functionally, some of the protease-reactive antiphospholipid antibodies hinder anticoagulant regulation and resolution of clots, thus tip the balance toward thrombosis. Intriguingly, several serine protease-reactive antiphospholipid antibodies also react with beta(2)-glycoprotein I, and interactions between antiphospholipid antibodies and antigens are cross-inhibited, indicating that these antiphospholipid antibodies recognize conformational epitope(s) on beta(2)-glycoprotein I and target serine proteases. Viewed as a whole, these results extend previous reports that antiphospholipid antibodies bind to various hemostasis factors, and provide a new perspective about some antiphospholipid antibodies in terms of their binding specificities and related functional properties in promoting thrombosis.

Lactate dehydrogenase isoenzyme patterns in auricular pseudocyst fluid indicated higher percentage distributions of lactate dehydrogenase 4 and 5 and lower percentage distributions of lactate dehydrogenase 1 and 2. An effective laboratory method of evaluating the different lactate dehydrogenase isoenzyme components was developed; this method may improve the accuracy of auricular pseudocyst diagnosis.

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