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Wong YK, Lui CT, Li KK, Wong CY, Lee MM, Tong WL, Ong KL, Tang SYH. Prediction of en-route complications during interfacility transport by outcome predictive scores in ED. Am J Emerg Med 2016; 34:877-82. [PMID: 26947612 DOI: 10.1016/j.ajem.2016.02.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 02/06/2016] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE The objective was to determine the accuracy of the outcome predictive scores (Modified Early Warning Score [MEWS]; Hypotension, Low Oxygen Saturation, Low Temperature, Abnormal ECG, Loss of Independence [HOTEL] score; and Simple Clinical Score [SCS]) in predicting en-route complications during interfacility transport (IFT) in emergency department. DESIGN This was a retrospective cohort study. METHODS All IFT cases by ambulances with either nurse-led or physician-led escort, occurring between 1 January 2011 and 31 December 2012, were included. Obstetric and pediatric cases (age < 18 years) were excluded. The condition of patients was quantified by using the predictive scores (MEWS, HOTEL, and SCS) at triage station and on ambulance departure. The accuracy of predictive scores was compared by the receiver operating characteristic (ROC) curves. RESULTS A total of 659 cases were included. Seventeen cases had en-route complications (2.6%). The complication rate in physician-escorted transport (2.2%) was similar to that in nurse-escorted transport (2.6%). None of the 57 intubated cases had en-route complications. The area under the ROC curve for MEWS was 0.662 (triage) and 0.479 (departure). The accuracy of MEWS at triage was better than that at departure (P = .049). The area under the ROC curve for HOTEL was 0.613 (triage) and 0.597 (departure), and that for SCS was 0.6 (triage) and 0.568 (departure). In general, the predictive scores at triage were better than those on departure. CONCLUSION None of the scores had good accuracy in prediction of en-route complications during IFT. MEWS at triage was among the best one already but was not ideal.
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Wong YK, Ho KC, Tsang YF, Wang L, Yung KKL. Cultivation of Chlorella vulgaris in Column Photobioreactor for Biomass Production and Lipid Accumulation. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2016; 88:40-46. [PMID: 26803025 DOI: 10.2175/106143015x14362865227553] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Microalgae have been used as energy resources in recent decades to mitigate the global energy crisis. As the demand for pure microalgae strains for commercial use increases, designing an effective photobioreactor (PBR) for mass cultivation is important. Chlorella vulgaris, a local freshwater microalga, was used to study the algal biomass cultivation and lipid production using various PBR configurations (bubbling, air-lift, porous air-lift). The results show that a bubbling column design is a better choice for the cultivation of Chlorella vulgaris than an air-lift one. The highest biomass concentration in the bubbling PBR was 0.78 g/L while the air-lift PBR had a value of 0.09 g/L. Key operating parameters, including draft-tube length and bubbling flowrate, were then optimized based on biomass production and lipid yield. The highest lipid content was in the porous air-lift PBR and the air-lift PBR with shorter draft tube (35 cm) was also better than a longer one (50 cm) for algal cultivation, but the microalgae attachment on the inner tube of PBR always occurred. The highest biomass concentration could be produced under the highest gas flowrate of 2.7 L/min, whereas the lowest dry cell mass was under the lowest gas flowrate of 0.2 L/min.
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Wong YK, Yung KKL, Tsang YF, Xia Y, Wang L, Ho KC. Scenedesmus quadricauda for Nutrient Removal and Lipid Production in Wastewater. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2015; 87:2037-2044. [PMID: 26652116 DOI: 10.2175/106143015x14362865227193] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Scenedesmus quadricauda, a local freshwater microalga, was used to treat primary settled and filtrate wastewater and to produce algal lipid. For the primary settled wastewater, the maximum biomass concentrations of acclimated and unacclimated microalgae were 0.995 g/L and 0.940 g/L, respectively. Over 90% orthophosphate and 95% ammonia nitrogen in the acclimated and unacclimated cultures, respectively, were removed after five days. The lipid contents of the microalgae were higher than 13% in all cultures. The highest growth rate occurred in the 25% filtrate culture. Over 80% phosphate was removed under the 25% and 50% filtrate cultures within six days, while over 90% ammonia nitrogen was removed within five days under both conditions. The lipid content was the highest (18.1%) under the 50% filtrate condition. C16:0, C18:2n6, and C18:3n3 were dominant fatty acids. In conclusion, S. quadricauda is a viable candidate for wastewater treatment and lipid production.
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Leung HM, Leung SKS, Au CK, Cheung KC, Wong YK, Leung AOW, Yung KKL. Comparative assessment of water quality parameters of mariculture for fish production in Hong Kong Waters. MARINE POLLUTION BULLETIN 2015; 94:318-322. [PMID: 25697818 DOI: 10.1016/j.marpolbul.2015.01.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 01/27/2015] [Accepted: 01/29/2015] [Indexed: 06/04/2023]
Abstract
The objective of the study is to evaluate the effect of fish cultivation on water quality in fish culture zone (FCZ) and analysed by Principle Component Analysis (PCA). 120 surface water samples were collected from Hong Kong Waters (60 samples in Victoria Harbour and another 60 in Ma Wan FCZ). Significant difference was found in dissolved oxygen (MW: 59.6%; VH: 81.3%), and Escherichia coli (MW: 465 CFU/100 ml; VH: 162.5 CFU/100 ml). Three principle components are responsible for water quality variations in the studying sites. The first component included E. coli (0.625) and dissolved oxygen (0.701). The second included E. coli (0.387) and ammonical-nitrogen (0.571). The third included E. coli (0.194) and ammonical-nitrogen (0.287). This framework provides information to assess the relative contribution of eco-aquaculture to nutrient loads and the subsequent risk of eutrophication. To conclude, a rigorous monitoring of water quality is necessary to assess point and nonpoint source pollution. Besides, appropriate remediation techniques should be used to combat water pollution and achieve sustainability.
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Lau KK, Wong YK, Chan YH, Li OY, Lee PYS, Yuen GG, Wong YK, Tong S, Wong D, Chan KH, Cheung RTF, Siu CW, Ho SL, Tse HF. Mediterranean-style diet is associated with reduced blood pressure variability and subsequent stroke risk in patients with coronary artery disease. Am J Hypertens 2015; 28:501-7. [PMID: 25352231 DOI: 10.1093/ajh/hpu195] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND AND PURPOSE The Mediterranean-style diet is widely advocated for the prevention of cardiovascular diseases (CVD). Meanwhile, blood pressure variability (BPV) is a novel risk factor for CVD. It is unknown whether dietary pattern plays a role in modulating BPV. METHODS We prospectively followed-up 274 consecutive patients with stable coronary artery disease (CAD). The Mediterranean diet score (MDS) was derived for all individuals upon recruitment, blood pressure (BP) was measured during each subsequent clinic visit and the visit-to-visit BPV was calculated. The occurrence of major adverse cardiovascular events (MACEs) and all-cause mortality was monitored. RESULTS After a mean follow-up of 77±12 months, 16.1% of the study population developed MACEs. About 11.3% died from all causes. Patients who developed MACEs or all-cause mortality had a greater systolic BPV compared to those who did not develop an adverse event. Patients who developed a MACE had a lower MDS and further analysis revealed those who developed a stroke had a lower MDS compared with those who did not develop a stroke, but there were no significant differences in MDS between CAD patients with or without subsequent acute coronary syndrome, cardiovascular, or all-cause mortality. After adjusting for confounding variables, a high MDS was an independent predictor for low systolic BPV (B -0.74, 95% confidence interval -1.27 to -0.21, P < 0.01) and was noted to be protective against subsequent development of stroke (hazards ratio 0.48, 95% confidence interval 0.24 to 0.94, P = 0.03). CONCLUSIONS Among patients with CAD, a higher MDS is associated with a lower visit-to-visit BPV and with lower stroke risk.
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Lau KK, Wong YK, Teo KC, Chang RSK, Chan KH, Hon SFK, Wat KL, Cheung RTF, Li LSW, Siu CW, Tse HF. Long-term prognostic implications of visit-to-visit blood pressure variability in patients with ischemic stroke. Am J Hypertens 2014; 27:1486-94. [PMID: 24842389 DOI: 10.1093/ajh/hpu070] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Blood pressure (BP) variability (BPV) is a novel risk factor for the development of atherosclerotic diseases. High BPV has recently been shown to predict all-cause and cardiovascular mortality in patients with lacunar infarct. Whether BPV has prognostic implications in patients with ischemic stroke subtypes, other than those due to small-vessel occlusion, remains uncertain. METHODS We prospectively followed up the clinical outcome of 632 consecutive ischemic stroke patients without atrial fibrillation. The average BP and BPV, as determined by the coefficient of variation of the systolic and diastolic BP, were recorded during a mean 12 ± 6 outpatient clinic visits. RESULTS The average age of the population was 71 ± 11 years. After a mean of 76 ± 18 months of follow-up, 161 patients died (26%); 35% (n = 56 of 161) of these deaths were due to cardiovascular causes. Sixteen percent and 5% developed recurrent stroke and acute coronary syndrome (ACS), respectively. After adjusting for mean systolic BP and confounding variables, patients with high systolic BPV were at significantly greater risk of cardiovascular mortality (hazards ratio (HR) = 2.36; 95% confidence interval (CI) = 1.02-5.49; P < 0.05). High systolic BPV also predicted all-cause mortality after adjusting for mean systolic BP (HR = 1.79; 95% CI = 1.16-2.75; P < 0.05). There was no association between systolic BPV and nonfatal recurrent stroke or nonfatal ACS. Raised diastolic BPV did not predict recurrent nonfatal stroke, nonfatal ACS, or mortality. CONCLUSIONS Visit-to-visit systolic BPV predicts long-term all-cause and cardiovascular mortality in patients with ischemic stroke without atrial fibrillation, independent of other conventional risk factors, including average BP control.
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Lau KK, Wong YK, Teo KC, Chang RSK, Hon SFK, Chan KH, Cheung RTF, Li LSW, Tse HF, Ho SL, Siu CW. Stroke patients with a past history of cancer are at increased risk of recurrent stroke and cardiovascular mortality. PLoS One 2014; 9:e88283. [PMID: 24523883 PMCID: PMC3921146 DOI: 10.1371/journal.pone.0088283] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 01/07/2014] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE Cancer patients are at increased risk of cardiovascular and cerebrovascular events. It is unclear whether cancer confers any additional risk for recurrent stroke or cardiovascular mortality after stroke. METHODS This was a single center, observational study of 1,105 consecutive Chinese ischemic stroke patients recruited from a large stroke rehabilitation unit based in Hong Kong. We sought to determine whether patients with cancer are at higher risk of recurrent stroke and cardiovascular mortality. RESULTS Amongst 1,105 patients, 58 patients (5.2%) had cancer, of whom 74% were in remission. After a mean follow-up of 76 ± 18 months, 241 patients developed a recurrent stroke: 22 in patients with cancer (38%, annual incidence 13.94%/year), substantially more than those without cancer (21%, 4.65%/year) (p<0.01). In a Cox regression model, cancer, age and atrial fibrillation were the 3 independent predictors of recurrent stroke with a hazard ratio (HR) of 2.42 (95% confidence interval (CI): 1.54-3.80), 1.01 (1.00-1.03) and 1.35 (1.01-1.82) respectively. Likewise, patients with cancer had a higher cardiovascular mortality compared with those without cancer (4.30%/year vs. 2.35%/year, p = 0.08). In Cox regression analysis, cancer (HR: 2.08, 95% CI: 1.08-4.02), age (HR: 1.04, 95% CI 1.02-1.06), heart failure (HR: 3.06, 95% CI 1.72-5.47) and significant carotid atherosclerosis (HR: 1.55, 95% CI 1.02-2.36) were independent predictors for cardiovascular mortality. CONCLUSIONS Stroke patients with a past history of cancer are at increased risk of recurrent stroke and cardiovascular mortality.
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Lau KK, Wong YK, Chang RSK, Teo KC, Hon SFK, Chan KH, Wat KL, Cheung RTF, Li LSW, Siu CW, Ho SL, Tse HF. Visit-to-visit systolic blood pressure variability predicts all-cause and cardiovascular mortality after lacunar infarct. Eur J Neurol 2013; 21:319-25. [PMID: 24267182 DOI: 10.1111/ene.12310] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Accepted: 10/21/2013] [Indexed: 11/26/2022]
Abstract
BACKGROUND AND PURPOSE Both blood pressure (BP) and its variability (BPV) are established risk factors for development of atherosclerotic disease and are associated with an increased risk for cardiovascular and all-cause mortality. The prognostic implications of outpatient clinic visit-to-visit BPV amongst patients with lacunar infarction are nevertheless unknown. METHODS The clinical outcome of 281 patients with lacunar infarction was prospectively followed up. The average BP and BPV, as determined by the standard deviation of the systolic and diastolic BP, were recorded during a mean 13 ± 6 outpatient clinic visits. RESULTS The mean age of the population was 70 ± 10 years. After a mean 78 ± 18 months follow-up, 65 patients died (23%), 31% (20/65) due to cardiovascular causes; 14% and 7% developed recurrent stroke and acute coronary syndrome. After adjusting for age, sex, mean systolic and diastolic BP, cardiovascular risk factors and comorbidities, patients with a systolic BPV of the third tertile had significantly higher risk of all-cause mortality [hazard ratio (HR) 1.97, 95% confidence interval (CI) 1.02-3.80, P = 0.04) and cardiovascular mortality (HR 7.64, 95% CI 1.65-35.41, P < 0.01) than those with systolic BPV of the first tertile. Nevertheless, systolic BPV did not predict recurrent stroke or acute coronary syndrome. Diastolic BPV did not predict various adverse clinical outcomes. CONCLUSIONS Visit-to-visit systolic BPV predicts long-term all-cause and cardiovascular mortality after lacunar infarct, independent of conventional risk factors including average BP control.
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Diamond T, Wong YK, Golombick T. Effect of oral cholecalciferol 2,000 versus 5,000 IU on serum vitamin D, PTH, bone and muscle strength in patients with vitamin D deficiency. Osteoporos Int 2013; 24:1101-5. [PMID: 22422304 DOI: 10.1007/s00198-012-1944-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2011] [Accepted: 02/06/2012] [Indexed: 10/28/2022]
Abstract
UNLABELLED Treatment of vitamin D deficiency for 3 months with oral cholecalciferol 5,000 IU daily was more effective than 2,000 IU daily in achieving optimal serum 25-hydroxyvitamin D (25OHD) concentrations. Optimal 25OHD serum level calculated to be 63.8 nmol/L. All parameters of muscle strength improved following administration of cholecalciferol for 3 months. INTRODUCTION The aim of this study was to determine the optimal dose of cholecalciferol required to achieve target serum 25OHD level ≥ 75 nmol/L and its relationship to both bone turnover and muscle strength. METHODS Thirty deficient patients (serum 25OHD ≤ 50 nmol/L) were randomly assigned into two groups-i.e. 2,000 and 5,000 IU/day. Data were collected at baseline, at 2 and 3 months post-therapy: (a) clinical demographics, (b) dietary calcium recall, (c) physical tests of muscle function and (d) biochemistry. Statistical analysis used paired student t test and analysis of variance. Regression analysis was used to determine relationship between serum 25OHD and parathyroid hormone (PTH). RESULTS Twenty-six (87%) patients completed 3 months of therapy. The percent increase in serum 25OHD (compared to baseline) was 82.7% in 2,000-IU group and 219.5% in 5,000-IU group. All participants (100%) achieved a serum 25OHD concentration >50 nmol/L; only 5 subjects (45.4%) in 2,000-IU group compared to 14 subjects (93.3%) in 5,000-IU group achieved final 25OHD concentration ≥ 75 nmol/L (p < 0.01). In the regression analysis, the reflexion point at which the PTH level increased above the normal range was calculated to be 63.8 nmol/L 25OHD. All parameters of muscle strength showed trends in improvements following the administration of both the 2,000 and 5,000 IU doses. No patient reported untoward side effects and no patient developed hypercalcaemia. CONCLUSION Treatment for 3 months with oral cholecalciferol 5,000 IU daily may be more effective than 2,000 IU daily in achieving optimal serum 25OHD concentrations in vitamin D-deficient patients.
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Lau KK, Wong YK, Chan YH, Yiu KH, Teo KC, Li LSW, Ho SL, Chan KH, Siu CW, Tse HF. Prognostic implications of surrogate markers of atherosclerosis in low to intermediate risk patients with type 2 diabetes. Cardiovasc Diabetol 2012; 11:101. [PMID: 22900680 PMCID: PMC3444371 DOI: 10.1186/1475-2840-11-101] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 08/11/2012] [Indexed: 11/24/2022] Open
Abstract
Background Type 2 diabetes mellitus (T2DM) patients are at increased risk of developing cardiovascular events. Unfortunately traditional risk assessment scores, including the Framingham Risk Score (FRS), have only modest accuracy in cardiovascular risk prediction in these patients. Methods We sought to determine the prognostic values of different non-invasive markers of atherosclerosis, including brachial artery endothelial function, carotid artery atheroma burden, ankle-brachial index, arterial stiffness and computed tomography coronary artery calcium score (CACS) in 151 T2DM Chinese patients that were identified low-intermediate risk from the FRS recalibrated for Chinese (<20% risk in 10 years). Patients were prospectively followed-up and presence of atherosclerotic events documented for a mean duration of 61 ± 16 months. Results A total of 17 atherosclerotic events in 16 patients (11%) occurred during the follow-up period. The mean FRS of the study population was 5.0 ± 4.6% and area under curve (AUC) from receiver operating characteristic curve analysis for prediction of atherosclerotic events was 0.59 ± 0.07 (P = 0.21). Among different vascular assessments, CACS > 40 had the best prognostic value (AUC 0.81 ± 0.06, P < 0.01) and offered significantly better accuracy in prediction compared with FRS (P = 0.038 for AUC comparisons). Combination of FRS with CACS or other surrogate vascular markers did not further improve the prognostic values over CACS alone. Multivariate Cox regression analysis identified CACS > 40 as an independent predictor of atherosclerotic events in T2DM patients (Hazards Ratio 27.11, 95% Confidence Interval 3.36-218.81, P = 0.002). Conclusions In T2DM patients identified as low-intermediate risk by the FRS, a raised CACS > 40 was an independent predictor for atherosclerotic events.
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Yu H, Wang J, Deng B, Wei X, Wong YK, Chan WL, Tsang KM, Yu Z. Chaotic phase synchronization in small-world networks of bursting neurons. CHAOS (WOODBURY, N.Y.) 2011; 21:013127. [PMID: 21456841 DOI: 10.1063/1.3565027] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We investigate the chaotic phase synchronization in a system of coupled bursting neurons in small-world networks. A transition to mutual phase synchronization takes place on the bursting time scale of coupled oscillators, while on the spiking time scale, they behave asynchronously. It is shown that phase synchronization is largely facilitated by a large fraction of shortcuts, but saturates when it exceeds a critical value. We also study the external chaotic phase synchronization of bursting oscillators in the small-world network by a periodic driving signal applied to a single neuron. It is demonstrated that there exists an optimal small-world topology, resulting in the largest peak value of frequency locking interval in the parameter plane, where bursting synchronization is maintained, even with the external driving. The width of this interval increases with the driving amplitude, but decrease rapidly with the network size. We infer that the externally applied driving parameters outside the frequency locking region can effectively suppress pathologically synchronized rhythms of bursting neurons in the brain.
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Ho HF, Wong YK, Rad AB. Adaptive fuzzy approach for a class of uncertain nonlinear systems in strict-feedback form. ISA TRANSACTIONS 2008; 47:286-299. [PMID: 18482726 DOI: 10.1016/j.isatra.2008.03.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Revised: 01/07/2008] [Accepted: 03/17/2008] [Indexed: 05/26/2023]
Abstract
Adaptive fuzzy control is proposed for a class of affine nonlinear systems in strict-feedback form with unknown nonlinearities. The unknown nonlinearities include two types of nonlinear functions: one satisfies the "triangularity condition" and can be directly approximated by fuzzy logic system, while the other is assumed to be partially known and consists of parametric uncertainties. Takagi-Sugeno type fuzzy approximators are used to approximate unknown system nonlinearities and the design procedure is a combination of adaptive backstepping and generalized small gain design techniques. It is proved that the proposed adaptive control scheme can guarantee the uniformly ultimately bounded (UBB) stability of the closed-loop systems. Simulation studies are shown to illustrate the effectiveness of the proposed approach.
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Yu IH, Wong YK. Evaluation of mandibular anatomy related to sagittal split ramus osteotomy using 3-dimensional computed tomography scan images. Int J Oral Maxillofac Surg 2008; 37:521-8. [PMID: 18450425 DOI: 10.1016/j.ijom.2008.03.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Revised: 01/07/2008] [Accepted: 03/07/2008] [Indexed: 12/01/2022]
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Wong YK, Hui E, Woo J. A community-based exercise programme for older persons with knee pain using telemedicine. J Telemed Telecare 2005; 11:310-5. [PMID: 16168168 DOI: 10.1258/1357633054893346] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We explored the feasibility and efficacy of an exercise programme for elderly people with knee pain conducted via videoconferencing. Twenty-two community-dwelling subjects aged 60 years or above with knee pain were recruited from two community centres in Hong Kong. A 12-week exercise programme, including strengthening and balance training, was given via videoconferencing to subjects at both centres, in conjunction with a home-based exercise programme. The outcome measures included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), quadriceps muscle strength, Berg's Balance Scale (BBS) and subjects' degree of acceptance of videoconferencing. Twenty subjects completed the 12-week programme and significant improvements occurred in all domains of the WOMAC score (P <0.003). There was a 44% and a 13% increase in quadriceps muscle strength (P <0.001) and BBS (P <0.001), respectively. Over 80% of the elderly subjects who joined the programme agreed or strongly agreed about all aspects of using videoconferencing. Most of them felt that the system was user-friendly and convenient. Videoconferencing appears to be a useful method of delivering a resistance-training programme for community-dwelling elderly persons with knee pain.
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Lo CH, Wong YK, Rad AB. Model-based fault diagnosis in continuous dynamic systems. ISA TRANSACTIONS 2004; 43:459-475. [PMID: 15272799 DOI: 10.1016/s0019-0578(07)60161-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Traditional fault detection and isolation methods are based on quantitative models which are sometimes difficult and costly to obtain. In this paper, qualitative bond graph (QBG) reasoning is adopted as the modeling scheme to generate a set of qualitative equations. The QBG method provides a unified approach for modeling engineering systems, in particular, mechatronic systems. An input-output qualitative equation derived from QBG formalism performs continuous system monitoring. Fault diagnosis is activated when a discrepancy is observed between measured abnormal behavior and predicted system behavior. Genetic algorithms (GA's) are then used to search for possible faulty components among a system of qualitative equations. In order to demonstrate the performance of the proposed algorithm, we have tested it on a laboratory scale servo-tank liquid process rig. Results of the proposed model-based fault detection and diagnosis algorithm for the process rig are presented and discussed.
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Wong YK, Dawkins S, Grimes R, Smith F, Dawkins KD, Simpson IA. Improving the positive predictive value of exercise testing in women. BRITISH HEART JOURNAL 2003; 89:1416-21. [PMID: 14617551 PMCID: PMC1767962 DOI: 10.1136/heart.89.12.1416] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To identify exercise test variables that can improve the positive predictive value of exercise testing in women. DESIGN Cohort study. SETTING Regional cardiothoracic centre. SUBJECTS 1286 women and 1801 men referred by primary care physicians to a rapid access chest pain clinic, of whom 160 women and 406 men had ST depression of at least 1 mm during exercise testing. The results for 136 women and 124 men with positive exercise tests were analysed. MAIN OUTCOME MEASURES The proportion of women with a positive exercise test who could be identified as being at low risk for prognostic coronary heart disease and the resulting improvement in the positive predictive value. RESULTS Independently of age, an exercise time of more than six minutes, a maximum heart rate of more than 150 beats/min, and an ST recovery time of less than one minute were the variables that best identified women at low risk. One to three of these variables identified between 11.8% and 41.2% of women as being at low risk, with a risk for prognostic disease of between 0-11.5%. The positive predictive value for the remaining women was improved from 47.8% up to 61.5%, and the number of normal angiograms was potentially reducible by between 21.1-54.9%. By the same criteria, men had higher risks for prognostic disease. CONCLUSIONS A strategy of discriminating true from false positive exercise tests is worthwhile in women but less successful in men.
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Cheng KY, Cheng PG, Mak KT, Wong SH, Wong YK, Yeung EW. Relationships of perceived benefits and barriers to physical activity, physical activity participation and physical fitness in Hong Kong female adolescents. J Sports Med Phys Fitness 2003; 43:523-9. [PMID: 14767415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
AIM Previous studies that examined participation in physical activity suggested that female adolescents were less active compared with males. However, the relationship between physical fitness, physical activity participation, and perceived benefits and barriers for physical activity to adolescents, irrespective of gender, has not been made clear. This study examines the association of these factors in female adolescents. METHODS Physical activity participation and perceived benefits and barriers to physical activity were determined in 206 secondary school female subjects (aged 11 to 18) using a validated questionnaire. RESULTS Subjects with a correct concept about optimal physical activity participation to maintain health engaged in an activity level higher than the group without a correct concept (t=2.37, p=0.02). A significant correlation was established between the physical activity participation with "health" (r=0.22, p<0.001) and "body image" (r=0.17, p=0.02) in the perceived benefit category. The individual factor, "make me feel better in general" in the "health" category (p=0.04) and the intention to participate (p<0.001) were shown to be significant predictors for physical activity participation. The combined effects of the regression model explained 35.9% of the variance in participation in physical activity. CONCLUSION Policies to support regular physical activity participation at school and out-of-school should be strategically developed and promoted, highlighting the promotion of health benefits in exercise and the reinforcement of initial intent towards exercise.
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Ho HF, Rad AB, Wong YK, Lo WL. On-line lower-order modeling via neural networks. ISA TRANSACTIONS 2003; 42:577-593. [PMID: 14582882 DOI: 10.1016/s0019-0578(07)60007-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This paper presents a novel method to determine the parameters of a first-order plus dead-time model using neural networks. The outputs of the neural networks are the gain, dominant time constant, and apparent time delay. By combining this algorithm with a conventional PI or PID controller, we also present an adaptive controller which requires very little a priori knowledge about the plant under control. The simplicity of the scheme for real-time control provides a new approach for implementing neural network applications for a variety of on-line industrial control problems. Simulation and experimental results demonstrate the feasibility and adaptive property of the proposed scheme.
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Lo CH, Wong YK, Rad AB, Chow KM. Fusion of qualitative bond graph and genetic algorithms: a fault diagnosis application. ISA TRANSACTIONS 2002; 41:445-456. [PMID: 12398276 DOI: 10.1016/s0019-0578(07)60101-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this paper, the problem of fault diagnosis via integration of genetic algorithms (GA's) and qualitative bond graphs (QBG's) is addressed. We suggest that GA's can be used to search for possible fault components among a system of qualitative equations. The QBG is adopted as the modeling scheme to generate a set of qualitative equations. The qualitative bond graph provides a unified approach for modeling engineering systems, in particular, mechatronic systems. In order to demonstrate the performance of the proposed algorithm, we have tested the proposed algorithm on an in-house designed and built floating disc experimental setup. Results from fault diagnosis in the floating disc system are presented and discussed. Additional measurements will be required to localize the fault when more than one fault candidate is inferred. Fault diagnosis is activated by a fault detection mechanism when a discrepancy between measured abnormal behavior and predicted system behavior is observed. The fault detection mechanism is not presented here.
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Wong YK, Dawkins KD, Ward ME. The association between deaths from myocardial infarction and household size in England and Wales. JOURNAL OF CARDIOVASCULAR RISK 2001; 8:159-63. [PMID: 11455848 DOI: 10.1177/174182670100800307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Chronic infection with organisms such as Chlamydia pneumoniae is thought to cause coronary heart disease. We investigated whether myocardial infarction deaths are associated with large household size and overcrowding, as these are factors that may facilitate the transmission of infection. DESIGN Ecological study of England and Wales. METHODS Population data were obtained from the 1991 National Census and mortality data were obtained from the Office of National Statistics. For various categories of household size and overcrowding, we calculated mortality rates standardized for age, sex and deprivation. RESULTS Standardized mortality rates for acute respiratory infections were associated with household size and overcrowding, while rates for myocardial infarction and gastric carcinoma, both putatively associated with chronic infection, were associated with household size. For combined deaths from causes other than myocardial infarction, there were small associations with household size and overcrowding. In the case of myocardial infarction, the association was generally strongest in the age group 45-54.9 years. For this age group, the standardized mortality rate ratio for the category of largest size household was 2.7 in the year 1991. CONCLUSIONS There is an association between household size and mortality from myocardial infarction. Chronic infection is a possible cause.
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Wong YK, Tang KT, Wu JC, Hwang JJ, Wang HS. Stimulation of hyaluronan synthesis by interleukin-1beta involves activation of protein kinase C betaII in fibroblasts from patients with Graves' ophthalmopathy. J Cell Biochem 2001; 82:58-67. [PMID: 11400163 DOI: 10.1002/jcb.1118] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Hyaluronan accumulation in the retroorbital connective tissue is one of the pathological features of Graves' ophthalmopathy. Interleukin-1beta (IL-1beta) is known to stimulate hyaluronan synthesis in orbital fibroblasts. In the present study, the intracellular signal transduction pathways involved in this stimulatory effect were investigated in cultured human retroorbital fibroblasts from patients with Graves' ophthalmopathy. IL-1beta-induced hyaluronan synthesis was significantly inhibited by pretreatment of the cells with two protein kinase C (PKC) inhibitors, chlerythrine chloride and H-7. In addition, treatment with phorbol 12-myristate 13-acetate (PMA), a direct PKC activator, also resulted in increased hyaluronan production. IL-1beta- or PMA-stimulated hyaluronan synthesis was blocked by the protein synthesis inhibitor, cycloheximide. Moreover, the intracellular Ca(2+) concentration of the orbital fibroblasts was also involved in the IL-1beta induced transduction pathway, the effect being completely inhibited by BAPTA, an internal calcium chelator. In addition, A23187, a calcium ionophore, increased hyaluronan synthesis in unstimulated cells. These results suggest that the Ca(2+)-dependent PKC signal transduction pathway plays an important role in the IL-1beta-induced hyaluronan synthesis. Moreover, IL-1beta treatment resulted in increased PKC activity and the rapid translocation of PKC betaII from the cytoplasm to the plasma membrane. These results indicate that cytosolic Ca(2+) and PKC betaII are involved in IL-1beta-induced hyaluronan synthesis in cultured orbital fibroblasts from patients with Graves' ophthalmopathy.
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Chang KW, Lin SC, Chao SY, Kwan PC, Chiu CP, Wong YK. Establishment and characterization of an oral melanoma cell line (ME). Oral Oncol 2001; 37:301-7. [PMID: 11287286 DOI: 10.1016/s1368-8375(00)00116-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A new cell line, ME, has been established from a melanoma of the palatal mucosa. The cultured monolayer of cells was fusiform and melanin-producing. The cells were highly tumorigenic and metastatic in nude mice. The xenographic tumors resembled the original tumor in morphology, melanin production, and the expression of S-100 and HMB-45 antigens. The metaphase karyotype of ME indicated multiple aberrations of chromosomes 2, 3, 5, 7-11, 13, 19, 21 and X. A homozygous loss of the p16/MTS1 gene during the establishment of ME correlated with karyotypic evidence of chromosome 9 abnormalities. Absence of nm23 protein expression and elevated expression of CD44 protein (indicative of metastatic phenotypes) were demonstrated in primary and xenographic tumors. ME cells could be valuable in developing novel therapeutic strategies for oral melanoma.
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Lin SC, Chang KW, Chang CS, Yu SY, Chao SY, Wong YK. Establishment and characterization of a cell line (HCDB-1) derived from a hamster buccal pouch carcinoma induced by DMBA and Taiwanese betel quid extract. PROCEEDINGS OF THE NATIONAL SCIENCE COUNCIL, REPUBLIC OF CHINA. PART B, LIFE SCIENCES 2000; 24:129-35. [PMID: 10943946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
This study identified that the carcinogenesis of hamster buccal pouch (HBP) induced by 7,12-dimethylbenz[a]anthracene (DMBA) was greatly enhanced (18 folds) by a combination treatment with Taiwanese betel quid (BQ) extract. A new cell line, HCDB-1, has been established from induced carcinomas. The cultured monolayer cells were epithelioid in shape with irregular nuclei. They demonstrated abundant cytokeratin and tonofilaments; however, ultrastructural well-organized desmosomes were lacking. The HCDB-1 cell exhibited population doubling in 19 h and was highly tumorigenic in nude mice. A C-->T transition at codon 141 (Ala to Val) of the p53 gene was detected in this cell. This mutation is equivalent to a specific temperature-sensitive mouse p53Ala135Val mutant that causes transformation by shifting to 37.5 degrees C. HCDB-1 is the first cell line established from the HBP model of oral carcinogenesis induced by DMBA/Taiwanese BQ extract. It might be valuable for exploring the molecular pathogenesis of oral cancer.
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MESH Headings
- 9,10-Dimethyl-1,2-benzanthracene
- Animals
- Areca
- Carcinoma, Papillary/chemically induced
- Carcinoma, Papillary/genetics
- Carcinoma, Papillary/pathology
- Carcinoma, Papillary/ultrastructure
- Cell Division
- Cricetinae
- Genes, p53
- Mice
- Mouth Neoplasms/chemically induced
- Mouth Neoplasms/genetics
- Mouth Neoplasms/pathology
- Mouth Neoplasms/ultrastructure
- Plant Extracts/toxicity
- Plants, Medicinal
- Polymerase Chain Reaction
- Polymorphism, Single-Stranded Conformational
- Taiwan
- Tumor Cells, Cultured
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Lin SC, Chang KW, Chang CS, Liu TY, Tzeng YS, Yang FS, Wong YK. Alterations of p16/MTS1 gene in oral squamous cell carcinomas from Taiwanese. J Oral Pathol Med 2000; 29:159-66. [PMID: 10766393 DOI: 10.1034/j.1600-0714.2000.290403.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
To determine the alterations of the p16/MTS1 gene in oral squamous cell carcinoma (OSCC), we examined in Taiwanese patients the mutation, deletion and methylation of p16/MTS1 in primary OSCCs associated mostly with betel quid (BQ)/tobacco use. Among 110 tumors undergoing mutational analyses, seven (6%) showed mutations in exon 2 or the intron 1/exon 2 splice site. All but one mutation disrupted the encoded proteins. Base transitions represented the vast majority (6/7) of the mutations identified in BQ/tobacco consuming subjects. It was noted that 15/56 (27%) tumors examined by restriction fragment methylation analysis revealed a significant level of methylation in different loci of exon 1 as compared with the respective non-cancerous tissue. Mutation of p16/MTS1 was exclusively identified in carcinomas of buccal mucosa, whereas methylation of the p16/MTS1 promoter region occurred preferentially in carcinomas of the tongue (54%) rather than at other sites (22%). Homozygous deletion was not found in 56 paired samples examined, nor was hemizygous deletion indicated in 12 informative cases. The results indicated aberrant methylation and mutation as the molecular abnormality of p16/MTS1 in the OSCC from Taiwanese.
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Chang KW, Lin SC, Kwan PC, Wong YK. Association of aberrant p53 and p21(WAF1) immunoreactivity with the outcome of oral verrucous leukoplakia in Taiwan. J Oral Pathol Med 2000; 29:56-62. [PMID: 10718400 DOI: 10.1034/j.1600-0714.2000.290202.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The expression of p53 and p21WAF1 in 53 oral verrucous leukoplakias (OVLs), mostly non-dysplastic lesions, was investigated to ascertain the role of such events in malignant conversion. Immunohistochemical analysis revealed aberrant p53 and p21WAF1 immunoreactivity in 51% (27 cases) and 75% (40 cases), respectively. After an average follow-up period of three and a half years, histopathological examination revealed that 22 (42%) cases had developed oral squamous cell carcinoma (OSCC), 14 (26%) cases had undergone recurrence, and 17 (32%) cases were free of disease. The oncogenic potential of this subset of premalignant lesions warrants attention. A significant difference in the frequency of OSCC progression/recurrence was noted in lesions bearing aberrant immunoreactivity of either p53 (93% vs 42%; P=0.00008) or p21WAF1 (80% vs 32%; P=0.002) in comparison with lesions without immunoreactivity. This study suggested that the aberrant immunoreactivity of p53 and p21WAF1 may represent important alterations of OVL and could affect the outcome of this lesion.
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