Ching C.T.-S.,National Chi Nan University |
Ching C.T.-S.,Asia University, Taiwan |
Yong K.-K.,Puli Christian Hospital |
Yao Y.-D.,Hong Kong Community College |
And 6 more authors.
International Journal of Nanomedicine | Year: 2014
The aims of this study were to investigate the most effective combination of physical forces from laser, electroporation, and reverse iontophoresis for noninvasive transdermal extraction of uric acid, and to develop a highly sensitive uric acid biosensor (UAB) for quantifying the uric acid extracted. It is believed that the combination of these physical forces has additional benefits for extraction of molecules other than uric acid from human skin. A diffusion cell with porcine skin was used to investigate the most effective combination of these physical forces. UABs coated with ZnO2 nanoparticles and constructed in an array configuration were developed in this study. The results showed that a combination of laser (0.7 W), electroporation (100 V/cm2), and reverse iontophoresis (0.5 mA/cm2) was the most effective and significantly enhanced transdermal extraction of uric acid. A custom-designed UAB coated with ZnO2nanoparticles and constructed in a 1×3 array configuration (UAB-1×3-ZnO2) demonstrated enough sensitivity (9.4 μA/mM) for quantifying uric acid extracted by the combined physical forces of laser, electroporation, and RI. A good linear relationship (R2=0.894) was demonstrated to exist between the concentration of uric acid (0.2-0.8 mM) inside the diffusion cell and the current response of the UAB-1×3-ZnO2. In conclusion, a new approach to noninvasive transdermal extraction and quantification of uric acid has been established. © 2014 Ching et al.
PubMed | University of Science Vietnam National University of Hochiminh City, National Chi Nan University, Hong Kong Community College, Asia University, Taiwan and Taichung Veterans General Hospital
Type: Journal Article | Journal: Sensors (Basel, Switzerland) | Year: 2015
Regular monitoring of blood -fetoprotein (AFP) and/or carcino-embryonic antigen (CEA) levels is important for the routine screening of liver cancer. However, AFP and CEA have a much lower specificity than des--carboxyprothrombin (DCP) to detect liver cancer. Therefore, the study reported here was designed, to develop a screen-printed DCP immunosensor incorporating zinc oxide nanoparticles, for accurate determination of DCP. The designed immunosensor shows low detection limits for the detection of DCP: 0.440 ng/mL (based on impedance measurement), 0.081 ng/mL (based on real part of impedance measurement) and 0.078 ng/mL (based on imaginary part of impedance measurement), within the range of 3.125 ng/mL to 2000 ng/mL. In addition, there was little interference to DCP determination by molecules such as Na, K, Ca(2+), Cl(-), glucose, urea, and uric acid. It is therefore concluded that the DCP immunosensor developed and reported here is simple, inexpensive and effective, and shows promise in the rapid screening of early-stage liver cancer at home with a point-of-care approach.
Tse W.S.,City University of Hong Kong |
Tse W.S.,Hong Kong Community College |
Lu Y.,City University of Hong Kong |
Bond A.J.,King's College London |
And 3 more authors.
International Journal of Social Psychiatry | Year: 2011
Background: Patients with schizophrenia consistently show deficits in facial affect perception and social behaviours. It is illusive to suggest that these deficits in facial affect perception cause poor social behaviours. Aim: The present research aims to study how facial affects influence ingratiation, cooperation and punishment behaviours of the patients. Methods: Forty outpatients with paranoid schizophrenia, 26 matched depressed patients and 46 healthy volunteers were recruited. After measurement of clinical symptoms and depression, their facial emotion recognition, neurocognitive functioning and the facial affects dependent cooperative behaviour were measured using a modified version of Mixed-Motive Game. Results: The depressed control group showed demographic characteristics, depression levels and neurocognitive functioning similar to the schizophrenic group. Patients with schizophrenia committed significantly more errors in neutral face identification than the other two groups. They were significantly more punitive on the Mixed-Motive Game in the neutral face condition. Conclusion: Neutral face misidentification was a unique emotion-processing deficit in the schizophrenic group. Their increase in punitive behaviours in the neutral face condition might confuse their family members and trigger more expressed emotion from them, thus increasing the risk of relapse. Family members might display more happy faces to promote positive relationships with patients. © The Author(s) 2010.
Yu F.W.,Hong Kong Community College |
Chan K.T.,Hong Kong Polytechnic University
5th Asian Conference on Refrigeration and Air Conditioning, ACRA 2010 - Green Breeze from Asia: Frontiers of Refrigerants, Heat Transfer and System | Year: 2010
This study investigates how the environmental performance of water-cooled chiller systems can be optimized by applying load-based speed control to all the system components. New chiller and cooling tower models were developed using a transient systems simulation program called TRNSYS 15 in order to assess the electricity and water consumption of a chiller plant operating for a building cooling load profile. The chiller model was calibrated using manufacturer's performance data and used to analyze the coefficient of performance when the design and control of chiller components are changed. The NTU-effectiveness approach was used for the cooling tower model to consider the heat transfer effectiveness at various air-to-water flow ratios and to identify the makeup water rate. Applying load-based speed control to the cooling tower fans and pumps could save an annual plant operating cost by around 15% relative to an equivalent system with constant speed configurations. Copyright © 2010 by the Japan Society of Refrigeration and Air Conditioning Engineering (JSRAE).
Chen Q.,Hong Kong Polytechnic University |
Hu Z.,Hong Kong Polytechnic University |
Hu Z.,South China Agricultural University |
Yao F.Y.D.,Hong Kong Community College |
Liang H.,Hong Kong Polytechnic University
LWT - Food Science and Technology | Year: 2016
Pomelo peels were first processed by a solvent-free microwave extraction (SFME) for essential oils, then by a hot-solvent microwave extraction (HSME) for pectin. SFME was superior to the conventional hydrodistillation (HD) method for essential oil extraction and HSME was better than acidic solution method for pectin extraction in terms of extraction efficiency and yield of targeted component. Chemical composition analysis by GC-MS showed that SFME did not affect the quality of essential oils. By using the response surface methodology, the optimal conditions of HSME for pectin was found at microwave power of 520 W, solvent pH value of 1.5 and extraction time of 5.6 min. Surface view by optical microscope (OM) and cross sectional view by scanning electron microscope (SEM) of the peels suggested that microwave can enhance the extraction process by two distinct mechanisms: one attributes to the diffusion across the intact oil gland while the other involves the convection through the broken oil gland. © 2015 Elsevier Ltd.
Chan J.Y.-Y.,Hong Kong Polytechnic University |
Chan E.,Hong Kong Polytechnic University |
Chan S.-W.,Hong Kong Polytechnic University |
Chan S.-W.,State Key Laboratory of Chinese Medicine and Molecular Pharmacology |
And 7 more authors.
Pharmaceutical Biology | Year: 2011
Context: Grifola frondosa (Polyporaceae), maitake, is a widely consumed edible mushroom in some Asian countries. The fruit bodies and mycelia of maitake have shown different bioactive compounds with anticancer and other therapeutic properties. Objective: This study evaluated three chemically modified maitake polysaccharide-peptides' (MPSP) adjuvant effect (in vivo) and anticancer activity (in vitro growth inhibitory effect) compared with crude MPSP from G. frondosa. Materials and methods: We investigated the possibility of enhancing the adjuvant effect and anticancer effect of crude MPSP by using simple chemical modification methods to convert crude MPSP to phosphorylated, acetylated or esterified MPSPs. The adjuvant effect and growth inhibitory effect were evaluated by C6 cell inoculated rat model with cyclophosphamide (CPA) treatment and in vitro cell viability assay, respectively. Results: All four tested MPSPs showed significant adjuvant effect to CPA treatment on rats inoculated with C6 cancer cells. In addition, an obvious growth inhibitory effect was observed in C6 cancer cells but not in normal brain cells treated with various forms of MPSPs. Only phosphorylation could significantly (p<0.05) improve the adjuvant effect (in vivo) and growth inhibitory effect. A same rank order (phosphorylated MPSP > esterified MPSP ≥ acetylated MPSP ≥ crude MPSP) of efficacy was observed in both the in vivo and in vitro assays. Discussion and conclusion: This study showed chemical phosphorylation could markedly enhance both adjuvant effects and growth inhibitory effects. This study demonstrated the feasibility of enhancing the efficacy of MPSP by using a simple chemical modification method, and this provides a foundation for future study in this area. © 2011 Informa Healthcare USA, Inc.
Hunga W.-T.,Hong Kong Polytechnic University |
Mak K.-L.,Hong Kong Community College
INTER-NOISE 2015 - 44th International Congress and Exposition on Noise Control Engineering | Year: 2015
The paper describes the development of a simple statistical model to estimate tyre/road noise. For the first time, a total number of 5744 tyre/road noise measurements were collected using a Close-proximity vehicle, from 870 trials along 28 selected road sections on five surface material pavements between 2009 and 2012, to develop such a model in Hong Kong. Six parameters were found to be principle factors of tyre/road noise and were subsequently adopted in the model for predicting tyre/road noise. These parameters include vehicle speed, acceleration, ambient temperature, road temperature, road surface age and road gradient. Further analysis found that vehicle speed and absolute acceleration are the most significant factors at sound frequencies below 1000 Hz. For frequencies between 1250 Hz and 2000 Hz, the road gradient and surface age become more significant. Interaction effects between vehicle speed and absolute acceleration are found to be important for noise levels at frequencies below 1250 Hz. This statistical model was compared to a traditional logarithm speed model in estimating the instantaneous tyre/road noise level. The results show that the new model has more accurate prediction ability than the traditional logarithm speed model, especially for lower frequencies. © 2015 by ASME.
Chan J.Y.-Y.,Hong Kong Polytechnic University |
Tsui H.-T.,Hong Kong Polytechnic University |
Chung I.Y.-M.,Hong Kong Community College |
Chan R.Y.-K.,BNU HKBU United International College |
And 2 more authors.
International Journal of Food Sciences and Nutrition | Year: 2014
Oxidative stress is considered an important factor that promotes cell death in response to a variety of pathophysiological conditions. This study investigated the antioxidant properties of allicin, the principle ingredient of garlic, on preventing oxidative stress-induced injury. The antioxidant capacities of allicin were measured by using 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay and hydrogen peroxide (H2O2)-induced cell damage on H9c2 cardiomyoblasts. Allicin (0.3-10μM) pre-incubation could concentration-dependently attenuate the intracellular reactive oxygen species (ROS) increase induced by H2O2 on H9c2 cells. It could also protect H9c2 cells against H2O2-induced cell damage. However, the DPPH free radical scavenging activity of allicin was shown to be low. Therefore, it is believed that the protective effect of allicin on H9c2 cells could inhibit intracellular ROS production instead of scavenging extracellular H2O2 or free radicals. For the observed protective effect on H9c2 cells, allicin might also be effective in reducing free radical-induced myocardial cell death in ischemic condition. © 2014 Informa UK Ltd. All rights reserved.
Cheng C.,Hong Kong Community College
Proceedings of 2012 International Symposium on Information Technologies in Medicine and Education, ITME 2012 | Year: 2012
This article describes the author's experiences with facilitating an ePortfolio project in a Hong Kong Higher Education Institution (HEI) as well as her reflections on this project. Firstly, the impact on Hong Kong HEIs brought about by various educational policies in recent years is described. Next, the major types of ePortfolios in the Higher Education sector are examined as discovered in existing literature. The last section deals with the backgrounds of the College and the ePortfolio project, the challenges that the author as the project-manager has faced, as well as the rewards brought to both the students and the faculty through the implementation of this project. It is hoped that this article could help stimulate discussions of how ePortfolios could benefit and play a key role in enhancing the learning environment of both teachers and students under the new educational reform in Hong Kong. © 2012 IEEE.
Chan K.T.,Hong Kong Polytechnic University |
Yang J.,Hong Kong Polytechnic University |
Yu F.W.,Hong Kong Community College
Proceedings of Building Simulation 2011: 12th Conference of International Building Performance Simulation Association | Year: 2011
This paper reports how the coefficient of performance (COP) of air-cooled chillers can be improved by adopting variable condensing setpoint temperature control and using mist evaporation to pre-cool ambient air entering the condensers to trigger a lower condensing temperature. Chiller models without and with water mist system were established, and the former was validated by using measured operating data of an installed screw chiller. With the validated model, the energy performance of air-cooled screw chillers with twin refrigeration circuits and water mist system serving a representative commercial building was studied. The results reveal that the chiller COP can be changed by various degrees from -0.3% up to +72% depending on the weather and load conditions, and the annual energy consumption can be reduced by 10.9% for a commercial building in subtropical climate.