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Background The aim of this study is to address the paucity of epidemiological data regarding the characteristics, treatment patterns and survival outcomes of Chinese glioblastoma patients. Methods This was a population-level study of Hong Kong adult (>18 years) Chinese patients with newly diagnosed histologically confirmed glioblastoma between 2006 and 2019. The age standardized incidence rate (ASIR), patient-, tumor- treatment-related characteristics, overall survival (OS) as well as its predictors were determined. Results One thousand and ten patients with a median follow-up of 10.0 months were reviewed. The ASIR of glioblastoma was 1.0 per 100 000 population with no significant change during the study period. The mean age was 57 + 14 years. The median OS was 10.6 months (IQR: 5.2–18.4). Independent predictors for survival were: Karnofsky performance score >80 (adjusted OR: 0.8; 95% CI: 0.6–0.9), IDH-1 mutant (aOR: 0.7; 95% CI: 0.5–0.9) or MGMT methylated (aOR: 0.7; 95% CI: 0.5–0.8) glioblastomas, gross total resection (aOR: 0.8; 95% CI: 0.5–0.8) and temozolomide chemoradiotherapy (aOR 0.4; 95% CI: 0.3–0.6). Despite the significant increased administration of temozolomide chemoradiotherapy from 39% (127/326) of patients in 2006–2010 to 63% (227/356) in 2015–2019 (P-value < .001), median OS did not improve (2006–2010: 10.3 months vs 2015–2019: 11.8 months) (OR: 1.1; 95% CI: 0.9–1.3). Conclusions The incidence of glioblastoma in the Chinese general population is low. We charted the development of neuro-oncological care of glioblastoma patients in Hong Kong during the temozolomide era. Although there was an increased adoption of temozolomide chemoradiotherapy, a corresponding improvement in survival was not observed.

Background Young people are most vulnerable to suicidal behaviours but least likely to seek help. A more elaborate study of the intrinsic and extrinsic correlates of suicidal ideation and behaviours particularly amid ongoing population-level stressors and the identification of less stigmatising markers in representative youth populations is essential. Methods Participants (n = 2540, aged 15–25) were consecutively recruited from an ongoing large-scale household-based epidemiological youth mental health study in Hong Kong between September 2019 and 2021. Lifetime and 12-month prevalence of suicidal ideation, plan, and attempt were assessed, alongside suicide-related rumination, hopelessness and neuroticism, personal and population-level stressors, family functioning, cognitive ability, lifetime non-suicidal self-harm, 12-month major depressive disorder (MDD), and alcohol use. Results The 12-month prevalence of suicidal ideation, ideation-only (no plan or attempt), plan, and attempt was 20.0, 15.4, 4.6, and 1.3%, respectively. Importantly, multivariable logistic regression findings revealed that suicide-related rumination was the only factor associated with all four suicidal outcomes (all p < 0.01). Among those with suicidal ideation (two-stage approach), intrinsic factors, including suicide-related rumination, poorer cognitive ability, and 12-month MDE, were specifically associated with suicide plan, while extrinsic factors, including coronavirus disease 2019 (COVID-19) stressors, poorer family functioning, and personal life stressors, as well as non-suicidal self-harm, were specifically associated with suicide attempt. Conclusions Suicide-related rumination, population-level COVID-19 stressors, and poorer family functioning may be important less-stigmatising markers for youth suicidal risks. The respective roles played by not only intrinsic but also extrinsic factors in suicide plan and attempt using a two-stage approach should be considered in future preventative intervention work.

In 2017, there are over six hundreds social enterprises in Hong Kong. Among them, approximately 70% are work integration social enterprises (WISEs) primarily aiming at creating employment and/or pr...

Aims Brief measurements of the subjective experience of stress with good predictive capability are important in a range of community mental health and research settings. The potential for large-scale implementation of such a measure for screening may facilitate early risk detection and intervention opportunities. Few such measures however have been developed and validated in epidemiological and longitudinal community samples. We designed a new single-item measure of the subjective level of stress (SLS-1) and tested its validity and ability to predict long-term mental health outcomes of up to 12 months through two separate studies. Methods We first examined the content and face validity of the SLS-1 with a panel consisting of mental health experts and laypersons. Two studies were conducted to examine its validity and predictive utility. In study 1, we tested the convergent and divergent validity as well as incremental validity of the SLS-1 in a large epidemiological sample of young people in Hong Kong (n = 1445). In study 2, in a consecutively recruited longitudinal community sample of young people (n = 258), we first performed the same procedures as in study 1 to ensure replicability of the findings. We then examined in this longitudinal sample the utility of the SLS-1 in predicting long-term depressive, anxiety and stress outcomes assessed at 3 months and 6 months (n = 182) and at 12 months (n = 84). Results The SLS-1 demonstrated good content and face validity. Findings from the two studies showed that SLS-1 was moderately to strongly correlated with a range of mental health outcomes, including depressive, anxiety, stress and distress symptoms. We also demonstrated its ability to explain the variance explained in symptoms beyond other known personal and psychological factors. Using the longitudinal sample in study 2, we further showed the significant predictive capability of the SLS-1 for long-term symptom outcomes for up to 12 months even when accounting for demographic characteristics. Conclusions The findings altogether support the validity and predictive utility of the SLS-1 as a brief measure of stress with strong indications of both concurrent and long-term mental health outcomes. Given the value of brief measures of mental health risks at a population level, the SLS-1 may have potential for use as an early screening tool to inform early preventative intervention work.

Background Intracoronary imaging during percutaneous coronary intervention (PCI) allows better delineation of lesion characteristics and more accurate vessel sizing compared with angiogram alone. However, the benefit and safety of its use in primary percutaneous coronary intervention (PPCI) is uncertain. Purpose To determine whether the use of intracoronary imaging with intravascular ultrasound (IVUS) or optical coherence tomography (OCT)/ optical frequency domain imaging (OFDI) in PPCI is associated with better outcome. Method From Jan 2014 to Dec 2018, all patients with PPCI performed in our hospital were retrospectively studied. Baseline and procedural characteristics of angiographic-guided versus imaging-guided PCI were analyzed. Primary endpoint was target vessel failure, and procedural outcomes were contrast volume, number of stents implanted, mean stent length and diameter and use of post-dilatation. Safety outcomes were post-operative acute kidney injury (AKI), need for renal replacement therapy (RRT) and occurrence of no/slow reflow. Results A total of 408 patients were included, of which 223 (54.7%) used IVUS (n=176 80.3%) or OCT/OFDI (n=44 19.7%) during the procedure. Baseline and procedural characteristics were similar between both groups except more patients had history of PCI (12.6% vs 4.3% p=0.004) and left-main/ bifurcation lesions (12.6% vs 2.7% p Conclusion Use of intra-vascular imaging during PPCI was associated with less target vessel failure, longer and more stents implanted and more frequent use of post-dilatation. Further prospective randomized controlled trial is suggested to confirm this benefit. Funding Acknowledgement Type of funding source: None

Esophageal cancer is one of the most lethal cancers worldwide with poor survival and limited therapeutic options. The discovery of microRNAs created a new milestone in cancer research. miR-377 is located in chromosome region 14q32, which is frequently deleted in esophageal squamous cell carcinoma (ESCC), but the biological functions, clinical significance and therapeutic implication of miR-377 in ESCC are largely unknown. In this study, we found that miR-377 expression was significantly downregulated in tumor tissue and serum of patients with ESCC. Both tumor tissue and serum miR-377 expression levels were positively correlated with patient survival. Higher serum miR-377 expression was inversely associated with pathologic tumor stage, distant metastasis, residual tumor status and chemoradiotherapy resistance. The roles of miR-377 in suppressing tumor initiation and progression, and the underlying molecular mechanisms were investigated. Results of in vitro and in vivo experiments showed that miR-377 overexpression inhibited the initiation, growth and angiogenesis of ESCC tumors as well as metastatic colonization of ESCC cells, whereas silencing of miR-377 had opposite effects. Mechanistically, miR-377 regulated CD133 and VEGF by directly binding to their 3′ untranslated region. Moreover, systemic delivery of formulated miR-377 mimic not only suppressed tumor growth in nude mice but also blocked tumor angiogenesis and metastasis of ESCC cells to the lungs without overt toxicity to mice. Collectively, our study established that miR-377 plays a functional and significant role in suppressing tumor initiation and progression, and may represent a promising non-invasive diagnostic and prognostic biomarker and therapeutic strategy for patients with ESCC.

On Behalf Cardiac Team, Department of Medicine, Queen Elizabeth Hospital Background Management of significant pericardial effusion in cancer patients is controversial. These patients have poor prognosis, and avoiding unnecessary intervention is important. Close monitoring of symptoms and echocardiogram is often a reasonable option, but inherits risk of cardiac tamponade. Whether pericardial drainage by means of percutaneous pericardiocentesis or surgical pericardiotomy could prevent future deterioration or affect survival is unknown. Purpose To evaluate the benefit of elective pericardial drainage in malignancy associated pericardial effusion without echocardiographic or clinical evidence of tamponade effect. Methods From 1st Jul 2014 to 31st Dec 2017, all patients with new onset malignancy-associated pericardial effusion with size more than 1cm were retrospectively analyzed. Patients with clinical or echocardiographic evidence of cardiac tamponade were excluded. We compared pericardial drainage versus monitoring for short-term (30-day), mid-term (90-day) and long term (1 year) survival without need for drainage. Results 101 patients were retrospectively analyzed. 40 (39.6%) patients underwent drainage. Overall median survival free from drainage was 4 months. There were no significant difference in short-term (30-day), mid-term (90-day) and long term (1-year) survival free from drainage or mortality between treatment and monitoring group. Size of pericardial effusion did not predict mortality or future need of drainage. Chemotherapy was associated with improved 30-day mortality (RR 0.53 CI 0.32-0.87 p = 0.025) but not survival free from drainage or longer term mortality. Conclusion Close monitoring could be a feasible strategy in cancer patients with significant pericardial effusion without tamponade effect. Baseline characteristics Factor Drainage (n = 40) monitoring (n = 61) p-value method of drainage pericardiocentesis alone 17 NA pericardiotomy alone 13 both 10 Male 19 (47.5%) 27 (44.3%) 0.749 mean size (cm) 1.93 2.77 Abstract 224 Figure. Survival free from drainage

ObjectivesIndividual neuroimaging features of small vessel disease (SVD) have been reported to influence poststroke cognition. This study aimed to investigate the joint contribution and strategic distribution patterns of multiple types of SVD imaging features in poststroke cognitive impairment.MethodsWe studied 145 first-ever ischaemic stroke patients with MRI and Montreal Cognitive Assessment (MoCA) examined at baseline. The local burdens of acute ischaemic lesion (AIL), white matter hyperintensity, lacune, enlarged perivascular space and cross-sectional atrophy were quantified and entered into support vector regression (SVR) models to associate with the global and domain scores of MoCA. The SVR models were optimised with feature selection through 10-fold cross-validations. The contribution of SVD features to MoCA scores was measured by the prediction accuracy in the corresponding SVR model after optimisation.ResultsThe combination of the neuroimaging features of SVD contributed much more to the MoCA deficits on top of AILs compared with individual SVD features, and the cognitive impact of different individual SVD features was generally similar. As identified by the optimal SVR models, the important SVD-affected regions were mainly located in the basal ganglia and white matter around it, although the specific regions varied for MoCA and its domains.ConclusionsMultiple types of SVD neuroimaging features jointly had a significant impact on global and domain cognitive functionings after stroke on top of AILs. The map of strategic cognitive-relevant regions of SVD features may help clinicians to understand their complementary impact on poststroke cognition.

Post-transplantation primary central nervous system lymphoma is an uncommon and fatal post-transplant lymphoproliferative disorder. Such lymphomas have been described in only a few case series in the literature. The incidence of this condition is rising with improved survival after organ transplantation. A case of post-transplantation primary central nervous system lymphoma in a young Chinese woman with systemic lupus erythematosus is described here. She presented with right-sided weakness and memory loss after tooth extraction 2 weeks before admission. Contrast computed tomography of the brain demonstrated a contrast rim-enhancing lesion over the left frontal lobe. With a history of recent dental procedure, long-term immunosuppressive therapy and computed tomography findings, cerebral abscess was highly suspected. Emergency operation was performed. Histopathology showed post-transplantation primary central nervous system lymphoma, with cells positive for B-cell marker CD20. Immunosuppressant was stopped and she was treated with radiotherapy and rituximab (anti-CD20 monoclonal antibody). She remained disease-free at 16 months. Post-transplantation primary central nervous system lymphoma is rare with variable presentation and radiological features. We believe rituximab may have a role in the treatment of such lymphomas.

The performance variation caused by the stress field near a through-silicon via (TSV) is measured using 28-nm node devices across 12-in wafers. The TSV is fabricated by a via-last process. The back-end-of-line dielectrics on TSV cause the asymmetric stress field, i.e., the absolute value of radial stress ( $\vert \sigma _{r}\vert )$ does not equal to that of tangential stress ( $\vert \sigma _{\theta }\vert )$ on silicon and leads to the asymmetric keep-out zone (KOZ), different from previously reported. A modified KOZ model with the asymmetric radial and tangential stress field is proposed and verified by 3-D finite-element analysis simulation and experiment data. The physics behind the asymmetry is also described. Comparable KOZ size for nFETs and pFETs is observed.

PurposeAs part of a study that aimed at enhancing the future roles and functions of building services (BS) engineers in Hong Kong, a survey was carried out to obtain demographic information about BS practitioners as well as their views and opinions on a range of issues which affect professional practices of BS engineers and recognition of their contributions by others. The purpose of this paper is to give a portrait of BS engineers in Hong Kong.Design/methodology/approachA series of statistical analyses were conducted based on the responses given by the BS practitioners, which included their qualifications, experience, job field, annual income and the number of trades of BS systems that they are competent in and responsible for.FindingsThe statistics show that: competence gap exists in that BS engineers are required to handle more trades of BS systems than those they are competent in; and the academic and professional qualifications, years of experience and job position are the key influential factors to the annual income of BS engineers but little differences exist in the average annual income of engineers in different job fields.Originality/valueThe competence gap is a concern that needs to be addressed to ensure BS engineers are competent in handling the common trades of BS systems, which is increasingly important for them to perform effectively in integrated professional teams for turning out holistic solutions for sustainable building developments.

A two-step pseudo isothermal plane model is used to calculate the thermal resistance of BEOL (Rth, beol). The intrinsic thermal resistances of 14nm FinFETs (Rth0, Device) are extracted with face-up (conventional measurement, heat flow from the channel to substrate) and face-down (flip-chip, heat flow from the channel to metal contact) configurations. Since the free convection of air has a large thermal resistance, the heat flow direction affects Rth0, Device. The face-up Rth0, Device is higher than face-down Rth0, Device. This is more significant for multi-finger FinFETs. The volume of hot spot affects the cooling time. In an inverter, the maximum temperature (Tmax) of pFET is higher than nFET due to the low thermal conductivity of SiGe S/D. Tmax and the high temperature duration can be controlled by the current and output capacitive loading of the inverter. The residual temperature in the channel and the temperatures of M1 layer are found too low to reflect the real device temperature, which may lead to an underestimation of device temperature with transient AC input.

Impact of via-last through-silicon via (TSV) on 28nm node devices is investigated. The stress field of TSV is affected by the back-end-of-line (BEOL) dielectrics. The absolute value of radial stress (|σr|) is different from that of tangential stress (|σθ|) on silicon, which leads to the asymmetric keep-out zone (KOZ). The physics behind the asymmetry is also described. A modified KOZ model considering the asymmetric stress field is proposed and verified by experiment data.

It remains unanswered whether persistent allergic inflammation in nasal mucosa alters bacterial colonization and infection. The aim of this study was to investigate the bacterial flora in the nasal cavity of patients with persistent allergic rhinitis (PAR) and to correlate the bacteriological findings with presence of nasal symptoms, nasal eosinophil and neutrophil counts. A total of 255 subjects, aged between 6 - 74 years (mean 33.9 years) was randomly selected from a population-based rhinitis survey study in Singapore. All subjects went through a thorough medical history and nasal examinations. Serum specific IgE to a panel of common house dust mites, nasal cytological and microbiological examinations were performed. PAR was diagnosed in 107 patients and none of them had received previous regular therapy. There is a significant relationship between PAR and eosinophil grades, but not with neutrophil count. No statistically significant difference was found in quantitative and qualitative bacterial flora in nasal cavity between PAR patients and subjects with non-rhinitis or with non-allergic rhinitis. There is a significant inverse correlation between ongoing rhinorrhoea and quantitative bacterial load, and between signs of nasal mucosa (pale and edema) and the presence and type of bacterial pathogens. In conclusion, our study demonstrates that patients with untreated (or using PRN medicine) PAR do not result in a significant change in bacterial flora in their nasal cavity.

This article reports on a performance evaluation on the knowledge management system (KMS) developed for a short-term food assistance program in Hong Kong the authors have conducted. DeLone and McLean's (1992) widely accepted model on information system success is adopted as the evaluative framework. Instead of just another revalidation of the model on KMS evaluation in social services, this study attempts to discuss the effectiveness of the system across different hierarchal levels in the organizations involved. This has remained an unexplored aspect in previous related studies, and the article suggests that the results have implications for further KMS development in human and social services.

PurposeThe purpose of this paper is to narrow the diverse views of the industry stakeholders on two controversial issues, namely the scope of core competence of building services engineers (BSEs) and the statutory role that they should play, which were encountered in an extensive research study on the building services profession of Hong Kong.Design/methodology/approachAn expert panel was formed and the Delphi method was applied to resolve the controversies. In the Delphi process, every panel member was provided with complete opinions expressed by all other panel members in each round of the deliberation.FindingsSufficient support was found for the proposition that professional BSEs should be competent in handling air‐conditioning, electrical, fire services, and plumbing & drainage works, and that the government authorities should mandate the design and compliance certification of electrical and fire services installations by BSEs.Research limitations/implicationsAlthough the Delphi method has not been hitherto applied to resolve the controversies addressed in the study, it was proven to be a very effective tool in seeking majority opinions from a group of experts. The same approach may be taken in similar studies in future.Practical implicationsThe core competence identified should be made as a minimum requirement for practitioners who wish to practise as professional BSEs. The views and comments given by the expert panel members are informative references to public policy makers.Originality/valueThis was the first ever study conducted in an attempt to identify the core competence and statutory role of BSEs in Hong Kong.

As the nano-motor becomes a mechanical reality, its prototype can be envisaged as nano-sized rotating machinery at a situation, albeit for different purposes, like that in the first half of the 20th century during which rotor dynamics has contributed to boosting machine power capacity. Accordingly, we take the benefit of hindsight to develop a classical framework of vibration analysis. Essentially, the equations of motion are formulated to cope with both the special carbon-nanotube properties and the first author's previously developed spinning beam formalism, establishing a model satisfactorily verified by some available molecular dynamics (MD) data and classical spinning beam results extracted from the literature. The model is inexpensive based on continuum mechanics as an alternative to the less-flexible MD method for simulating wave motion of the spinning single-walled carbon nanotube, yielding several interesting phenomena, including the fall-off and splitting of the wave characteristic curves and the unexpected gyroscopic phase property. Potential applications are proposed.

PurposeThe survey reported here is intended to obtain an understanding of the general public's perception about building services and building services practitioners in Hong Kong.Design/methodology/approachTargeting a sampling error of within ±1 per cent at a confidence level of 95 per cent, a team of six surveyors conducted face‐to‐face interviews with 751 laypersons at places around 11 residential estates.FindingsOver 90 per cent of the general public know the presence of various building services installations in buildings and 12 per cent know that building services is the collective name of such installations. The general public are satisfied with the operability and reliability of building services installations but are just marginally satisfied with their performance at higher levels, such as energy conservation and indoor air quality control.Research limitations/implicationsA paucity of teenagers know about building services, which is a concern to the future development of both the building services profession and the facilities management (FM) industry in Hong Kong. Future work may investigate the situation in other regimes with a similar FM setting and study on how the profession is perceived for buildings with restricted access to the general public. Operation and maintenance personnel of the FM offices, who are approached by most people when problems with building services installations arise, are the key on the perceived image of building services professionals.Originality/valueIn addition to informing higher educational institutes the need to reinforcing promotion of building services engineering to school leavers, the findings can help professional institutions in formulating how the social status of building services engineers may be raised.

A speckle shearing interferometer with a simple setup is designed and tested for full-field characterization of the elastic properties of isotropic and orthotropic composite plates. The technique is straightforward and provides comparable results obtained by standard methods. The proposed method has the advantages of being noncontact and full field in nature. Beam specimens cut from the plate were loaded under the standard four-point bending configuration. Gradients of bending deformation are measured by the speckle shearing interferometer directly. Curvature of each bended beam is calculated from the slope of the fitted line of the gradient data. The elastic moduli and Poisson's ratios of the plate material are determined from the curvature of the beam specimens. Comparing the present approach to other full-field techniques reported in literature that are mostly based on deformation measurement of a specimen subjected to a complicated load field, the present method is much easier to apply, and the image analysis procedure is much simpler.

A wave mechanics approach is used to solve the Timoshenko beam equation, revealing that two waves exist. One is called the s a –wave and the other the s b –wave. These two waves are found to be the basic constituent components of the mode shapes of the beam. An experiment was carried out and the measured mode shapes of a free–free beam are shown to consist of one s a –wave and one s b –wave in superposition for each of the modes. The measured s a –wave and s b –wave exhibit the Rayleigh–Lamb first (with anomalous dispersion) and Rayleigh–Lamb second (with normal dispersion) flexural modes, respectively. The issue of the second spectrum is addressed and it is shown that, within the measurable frequency range, Rayleigh–Lamb second flexural modes are present in the free–free beam. The s b –wave is identified as the second–spectrum mode. The role of shear deformation is also investigated in explaining the basic difference in the behaviour of the s a – and s b –waves. This paper also contributes to a physical interpretation of the hyperbolic functions in the classical solution of beam vibration problems.

It is difficult to properly assess whether energy has been used efficiently and effectively in a commercial building that is equipped with a central air-conditioning system and houses a mix of premises of largely different energy characteristics. Due to the inter-relationship between the energy use of individual tenants and of the central air-conditioning system, a building that consumes a large amount of energy may not be inefficient if a substantial portion of its area is occupied by premises that have intensive cooling requirements. The paper describes a proposed method for establishing energy consumption benchmarks for assessing the energy performance of this type of buildings, which are the dominant energy consumers in Hong Kong. The key feature of the method is that the benchmarks to be established would be specific to each individual building, dependent on the mix of premises in the building and an those characteristics of the building and its air-conditioning system that are unlikely to be changea...

This paper presents the energy characteristics Of hotel operation. The energy sources, apportionment of energy use and energy indices are reported based on findings of an extensive energy scrutiny and on-site measurement in the studied hotel. Hourly power Intensity of guestrooms and daily load profiles of electricity and fuel use are presented. Energy performance lines showing the dependence Of fuel consumption on outdoor air temperature, hotel occupancy rates and number of food covers are established and discussed. These energy Indices and performance lines will provide a basis for hotel environmental management and for engineers in setting energy saving measures and designing services systems in hotels.

Primary, high density bovine articular chondrocyte (BAC) cultures, stimulated with transforming growth factor-beta-1, elaborated a high molecular weight anionic glycoconjugate, kDa 540, which does not contain glycosaminoglycan chains (Chan and Anastassiades, 1996). The effect of exogenously added transforming growth factor-beta-1 on the elaboration of the high molecular weight glycoconjugate and of proteoglycans was studied during dedifferentiation of the chondrocytes, utilizing a serial subculture technique under anchorage-dependent conditions, up to four subcultures. The high molecular weight glycoconjugate was detected in the media of all growth-factor-stimulated chondrocyte subcultures, as well as stimulated primary cultures, but not in unstimulated primary cultures or subcultures. By contrast, a large proteoglycan, was only secreted by primary cultures and first subcultures, whether treated with transforming growth factor-beta-1 or untreated. This proteoglycan contained mostly chondroitin sulfate chains, whose hydrodynamic size was increased by the addition of transforming growth factor-beta-1. Further, the pattern of the proteoglycans appearing in the media of subcultures 2-4 was influenced by the addition of transforming growth factor-beta-1, so that while these control subcultures elaborated both the large and small chondroitin sulfate proteoglycans, the equivalent stimulated subcultures elaborated only intermediate sized chondroitin sulfate proteoglycan(s). These results suggest that while dedifferentiation of articular chondrocytes, achieved by subculturing, strongly modulates the effect of exogenously added transforming growth factor-beta-1 on the type of proteoglycan elaborated, the process of dedifferentiation does not influence the transforming-growth-factor-beta-dependent synthesis of the high molecular weight anionic glycoconjugate.

Electrical wavelength switching of picosecond pulses was demonstrated in an actively mode-locked Er-doped fiber ring laser with fiber gratings by changing the electrical driving frequency of the modulator. Laser pulses switchable between two wavelengths spaced from 0.5 to 18 nm apart were achieved. The switching speed between the two wavelengths was of the order of several hundred kilohertz.

A random series of impacts method was introduced for vibration test on tube bundles of coolers. A non-normal Poisson process was employed to establish a model for the method. Experimental analysis of the forcing functions showed good agreement with the model. The method was found to be appropriate for extracting modal parameters of such tube structure. Site investigation on power station coolers proved this method to be convenient and reliable. Tube-to-baffle impactions created nonlinear effects which were shown to be of hard-spring type. A piecewise linear system method was used to handle such situation. The theoretical results were closely correlated with the experimental results.

The time averaged frame subtraction technique is improved by subtracting two Bessel fringe patterns at two different force levels. The technique enables significant enhancement of fringe contrast and increased measurement sensitivity. The contrast and sensitivity of the fringes obtained at different force ratios are investigated. Both theoretical and experimental results are presented.

An all-optical fiber nonlinear Fabry-Perot resonator is proposed. The steady-state model for describing this resonator is developed. The transmission and refection bistabilities are shown numerically. Our results show that the bistability in this system is similar to that in a normal nonlinear Fabry-Perot etalon, except that the characteristics of the bistability can be changed not only by the cavity length but also by the phase shifts of the fiber loop mirrors.

The influence of polystyrene beads (80 μm) and nylon fibres on the water permeability of bleached kraft wood pulp fibre pads was measured and the results were regressed to the Kozeny-Carman equation. SEM micrographs of pad cross sections showed that the beads, which were uniformly distributed, had little effect on pad structure whereas the long rigid nylon fibres made the pads more difficult to compress. The pad specific surface areas and swollen volumes were linear functions of the content of beads or nylon fibres. This suggests that the fibre pad permeability characteristics could be adequately modeled from the linear superposition of geometric properties of the pad constituents. L'influence des billes de polystyrene (80 μm) et des fibres de nylon sur la permeabilite a l'eau de tampons de fibre de pǎte a papier Kraft blanchie a ete mesuree, et les resultats sont traites avec l'equation de Kozeny-Carman. Des micrographies SEM (microscopie electronique a balayage) de sections transversales des tampons montrent que les billes, qui sont uniformement distribuees, ont peu d'effet sur la structure des tampons, alors que les fibres de nylon rigides longues rendent les tampons plus difficiles a comprimer. La surface specifique des tampons et les volumes gonfles sont des fonctions lineaires de la teneur en billes ou en fibres de nylon. Ceci suggere que les caracteristiques de permeabilite des tampons de fibres pourrait ětre adequatement modelisees par la superposition lineaire des proprietes geometriques des constituants des tampons.

Hourly global (total of direct and diffuse horizontal) solar radiation data for Hong Kong can be obtained from the Royal Observatory of Hong Kong. However, data on intensities of direct and diffuse radiation, which are required in detailed calculation of energy transport across building envelopes, are not available. To address to this need, a correlation between diffuse and global solar radiation for Hong Kong has been established, on the basis of global and diffuse solar radiation intensities measured at the Hong Kong Polytechnic from October 1990 to July 1994. Further analysis has been carried out to accertain the accuracy of prediction of this correlation and to see if the accuracy will vary with seasonal changes and solar altitude angle. In this paper, the correlation and the results of the analysis are presented. Application of the correlation to estimate the direct and diffuse radiation intensities from known global intensities is described. Also, the correlation is compared with the measured data a...

Indoor air quality (IAQ) has been a matter of public concern. In the peacetime, a quite number of civil air defense works have been reconstructed to serve for commercial purposes. Good indoor air quality is essential to occupants. In order to characterize the IAQ in underground shopping malls, the IAQ was investigated in an underground shopping mall. The concentration of carbon dioxide (CO2) is widely used as an indicator of IAQ and ventilation effectiveness. In this paper, the concentrations of CO2 were investigated, and the indoor temperature and relative humidity were measured. The concentrations of CO2 in some area of the underground shopping mall exceeded 1500 ppm. The excessive levels of CO2 could result from high occupancy combined with insufficient ventilation. The influence on the room air environment by introducing internal partitioning was also studied. To assess the IAQ comprehensively, the subjective investigation was conducted with questionnaire survey. The survey revealed that the ventilation should be enhanced to improve IAQ in the underground shopping mall.

The isochronal and isothermal annealing characteristics of acceptor‐doped GaAs:Be grown at low substrate temperatures (300 °C) by molecular‐beam epitaxy (LTMBE) have been studied. The Be was introduced in a range of concentrations from 1016 to 1019 cm−3. Electrical measurements of as‐grown material up to the highest Be concentration of 1019 cm−3 show that no free holes are contributed to the valence band even though Raman spectroscopy of the Be local vibrational mode indicates that the majority of the Be impurities occupy substitutional sites. It is proposed that Be acceptors are rendered inactive by the high concentration of AsGa‐related native donor defects present in LTMBE material. The concentration of AsGa‐related defects in the neutral charge state was estimated from infrared absorption measurements to be as high as 3×1019 cm−3. A distinct annealing stage at 500 °C, similar to that found in irradiation‐damaged and plastically deformed GaAs, marks a rapid decrease in the concentration of AsGa‐related...

The Overall Thermal Transfer Values (OTTVs) of building envelopes in Hong Kong have been considered. Parametric studies on a centrally air-conditioned building were performed. The DOE-2 program, developed at the US Department of Energy, has been used as the energy behaviour simulation tool. The year 1980 is taken as the reference weather year for Hong Kong. The window-to-wall ratio as well as the orientation of the windows for the example building were varied. Two values of OTTV, one for summer and the other for winter, have been established for accounting for seasonal changes in Hong Kong. The summer OTTV, calculated from the heat gain in the hot season, is recommended as the more important value for evaluating the thermal performance of building envelopes in Hong Kong.

In the dormitories of universities, the indoor air quality (IAQ) is especial concern, which greatly affects the learning efficiency and students' physical and mental health. In order to improve the IAQ of student dormitories, the present characteristics of IAQ should be investigated. In this paper, the measurement of the IAQ was conducted in student dormitories on a campus in Chongqing. The investigation includes two parts: site measurement and subjective questionnaire investigations. The measured indexes include air temperature, relative humidity, the concentration distribution of carbon dioxide (CO 2 ), carbon monoxide (CO), sulfur dioxide (SO 2 ), nitrogen dioxide (Nox), respirable suspended particulates (PM10), total number of bacteria (TNB), etc. The measured data showed that the concentration of CO 2 , SO 2 , PM10 and total number of bacteria were beyond the amount stipulated in related standards, and the thermal environment needed improved. For the sake of reflecting the IAQ comprehensively, the subjective investigation was also conducted with questionnaires. The site measurement and questionnaire investigation showed that it was necessary to improve the IAQ of student dormitories, which could be done by increasing the ventilation rate by means of a mechanical system.

1. A recombinant adenovirus encoding SARS coronavirus(SARS-CoV) nucleocapsid protein (rAd-N) was constructed. 2. The ability of the rAd-N to induce anti-SARS-CoV N antibody production and cellular immune responses was evaluated in an HLA-A2.1/Kb transgenic mouse model.

A wavelength-tunable actively mode-locked erbium fiber ring laser was demonstrated using a Fabry–Perot semiconductor modulator. The modulator played the simultaneous roles of an intensity mode locker and a tunable optical filter. Stable single- or dual-wavelength nearly transform-limited picosecond pulses at gigabit repetition rates were generated. Continuous wavelength tuning was achieved by simply controlling the temperature of the modulator. Pulse train with a repetition rate up to 19.93 GHz (eight times the driving frequency) was obtained by using rational harmonic mode-locking technique.

1. A novel HLA-A2.1-specific SARS coronavirus (SARS-CoV) nucleocapsid (N) protein epitope (N220-N228 LALLLLDRL) able to activate cytotoxic T cells in vitro has been identified. 2. When used with a single-chain-trimer system, the SARS-CoV N protein epitope (N220-N228 LALLLLDRL) can stimulate a cytotoxic T-cell response against N-protein expressing cells in the HLA-A2.1K(b) transgenic mouse model.

A novel compact planar bandstop filter with deep stopband rejection and ultra-wide passband bandwidth is introduced for worldwide interoperability microwave access (WiMAX) test equipment. The physical based equivalent circuited model is introduced and investigated. A 2.5GHz bandstop filter is designed and used for worldwide interoperability microwave access (WiMAX) test equipment. The designed fifth-order bandstop filter covers rejection band of 2.3GHz∼2.85GHz with rejection more than 60dB and insertion loss less than 2dB. The center frequency of the second stopband appears as high as 5.8 times (15GHz) of that of the fundamental stopband.

For organometallic vapor phase epitaxial (OMVPE) grown InP, the change in lattice constant is measured as a function of tellurium (Te) dopant concentration. We observe ~0.15% dilation in the InP lattice constant at a Te concentration of ~1020 cm-3. Our measurements are compared to predictions from Vegard’s Law.

We have successfully grown bulk In0.53Ga0.47As on InP using tertiarybutylarsine (TBA), trimethylindium and trimethylgallium. The growth temperature was 602° and the V/III ratio ranged from 19 to 38. Net carrier concentrations were 2 – 4 × 1015 cm-3, n-type, with a peak 77 K mobility of 68,000 cm2/V. sec. Increasing compensation was observed in In0.53Ga0.47As grown at higher V/III ratios. PL spectra taken at 5 K revealed strong near bandgap emission at 0.81 eV—with the best sample having a FWHM of 2.5 meV. At lower energies, donor-acceptor pair transitions were evident. Strong and sharp 5 K PL emission was observed from InP/In0.53Ga0.47As/InP quantum wells grown with TBA.

We present a highly sensitive fiber temperature sensor based on a gain-switched Fabry–Perot semiconductor laser self-seeded from a linearly chirped fiber Bragg grating. A temperature resolution of better than 0.1 °C was demonstrated. This sensor not only has the advantage of robustness against fluctuating light levels, but also obviates the need for fine wavelength discrimination.