hiu laam wong - Academia.edu (original) (raw)

Papers by hiu laam wong

Translational gastrointestinal cancer, 2012

Gastric cancer (GC) is a heterogeneous disease with large variations across geographical regions.... more Gastric cancer (GC) is a heterogeneous disease with large variations across geographical regions. Although the global incidence of GC is declining, it remains highly prevalent in Asia as compared to the West (1). China is one of the countries with the highest incidence of GC, and accounts for over 40% of all new GC cases in the world (2). GC is the third leading cause of cancer mortality in China (3).

Sensors and Actuators A: Physical, 2002

This paper presents the development of a vibration-induced power generator with total volume of 1... more This paper presents the development of a vibration-induced power generator with total volume of 1 cm 3 which uses laser-micromachined springs to convert mechanical energy into useful electrical power by Faraday's law of induction. The goal of this project is to create a minimally sized electric power generator capable of producing enough voltage to drive low-power ICs and/or microsensors for applications where ambient mechanical vibrations are present. Thus far, we have fabricated generators with total volume of 1 cm 3 that are capable of producing up to 4.4 V peak-to-peak, which have a maximum RMS power of 830 mW with loading resistance of 1000 O. The mechanical vibration required to generate this electrical energy has frequencies ranging from 60 to 110 Hz with 200 mm amplitude. The generator was shown to generate suf®cient power at different resonating modes. We have demonstrated that this generator can drive an infrared (IR) transmitter to send 140 ms pulse trains every minute, and also a 914.8 MHz FM wireless temperature sensing system.

Winner of the French writing contest organized by French Consulate-General in Hong Kong in collab... more Winner of the French writing contest organized by French Consulate-General in Hong Kong in collaboration with the consulate of Belgium, Canada, Laos,Switzerland and Vietnam in 2006.

Conclusion: Stories that Never End 299 Works Cited and Consulted 305 Acknowledgement First of all... more Conclusion: Stories that Never End 299 Works Cited and Consulted 305 Acknowledgement First of all, I would like to express my heartfelt gratitude to Professor Michael Bell, my thesis supervisor, for his invaluable advice, insightful recommendations, constructive criticism, continual patience and support, and endless motivation throughout the completion of this thesis. I would also like to thank the staff of the Department of English and Comparative Literary Studies for helping me one way

Scientific Reports, 2015

Cochlear hair cell loss results in secondary regression of peripheral auditory fibers (PAFs) and ... more Cochlear hair cell loss results in secondary regression of peripheral auditory fibers (PAFs) and loss of spiral ganglion neurons (SGNs). The performance of cochlear implants (CI) in rehabilitating hearing depends on survival of SGNs. Here we compare the effects of adeno-associated virus vectors with neurotrophin gene inserts, AAV.BDNF and AAV.Ntf3, on guinea pig ears deafened systemically (kanamycin and furosemide) or locally (neomycin). AAV.BDNF or AAV.Ntf3 was delivered to the guinea pig cochlea one week following deafening and ears were assessed morphologically 3 months later. At that time, neurotrophins levels were not significantly elevated in the cochlear fluids, even though in vitro and shorter term in vivo experiments demonstrate robust elevation of neurotrophins with these viral vectors. Nevertheless, animals receiving these vectors exhibited considerable re-growth of PAFs in the basilar membrane area. In systemically deafened animals there was a negative correlation between the presence of differentiated supporting cells and PAFs, suggesting that supporting cells influence the outcome of neurotrophin over-expression aimed at enhancing the cochlear neural substrate. Counts of SGN in Rosenthal's canal indicate that BDNF was more effective than NT-3 in preserving SGNs. The results demonstrate that a transient elevation in neurotrophin levels can sustain the cochlear neural substrate in the long term. C ochlear implants (CI) restore the hearing sense by directly stimulating remnant auditory neural structures in ears in which hair cells are absent or dysfunctional. CIs have been very successful in restoring the recipient's ability to understand speech in quiet settings. However, they have had more limited benefit in restoring the ability to clearly perceive more complex acoustic stimuli, such as speech in background noise or music. Current CIs typically have 8-22 electrodes, but some studies have shown an effective functional yield of only 4-10 perceptual channels, which is likely due to current spread and the deterioration of auditory neuronal structures 1,2. A greater number of functional perceptual channels are required to optimize speech understanding in noise (up to 20) and music appreciation (32 or more) 1,3,4. Advances in CI technology, alone, cannot provide the necessary additional perceptual channels, as the improved technology does not address the issue of compromised auditory neural targets. To address this issue, it is likely that advances in biotherapies will be key to further enhancing CI outcomes. It is through biotherapies, such as the delivery of neurotrophins to the inner ear, that auditory neural substrate survival and health may be improved, thereby increasing the number of perceptual channels rendered by our current CI electrode technology. Neurotrophins are a family of molecules essential in the development and maintenance of neural systems throughout the body. Neurotrophin-3 (NT-3) and brain derived neurotrophic factor (BDNF) are the two neurotrophins critical for the normal development and function of the peripheral auditory nervous system 5. Studies using null mutant mice have demonstrated that NT-3 is essential for the normal development of the majority of spiral ganglion neurons (SGNs) and afferent peripheral auditory fibers (PAFs) 6,7 , whereas BDNF is critical in the development of primarily vestibular ganglion cells and a minority of afferent PAFs 7. Additional null mutant mouse studies have suggested that there is a gradient of neurotrophin expression within the cochlea that changes over the course of development. BDNF is initially expressed primarily in the apex of the cochlea, with progressively increased expression in the base later in development 8. In contrast, NT-3 is primarily expressed in the cochlear base early in development, and expression progresses apically in post-natal and adult mice 8,9. Within the adult inner ear, NT-3 is primarily expressed by inner hair cells and supporting cells within the cochlear apex 9 , and BDNF is primarily expressed within the vestibular system 5 .

IEDM Technical Digest. IEEE International Electron Devices Meeting, 2004.

The impact of oxygen vacancies in Hf-based gate dielectrics is discussed. Generation of oxygen va... more The impact of oxygen vacancies in Hf-based gate dielectrics is discussed. Generation of oxygen vacancies in HfO 2 is thermodynamically driven and causes Si interfacial layer formation and gate Fermi-level pinning in MOS devices. Hence, it is necessary to prevent oxygen transport across both top and bottom gate-dielectric interfaces through careful design of material system and thermal processing steps.

Proceedings 2002 IEEE Hong Kong Electron Devices Meeting (Cat. No.02TH8616)

In this paper, simulation results of the gate misalignment effects on the sub-threshold character... more In this paper, simulation results of the gate misalignment effects on the sub-threshold characteristics of asymmetric (ADC) and symmetric (SDG) double-gate MOSFET (DG-MOSFET) in the sub-100nm regime are presented. Gates alignment in DG-MOSFETs becomes more and more difficult as devices are scaling down in non-self-aligned doublegate processes. The results show that gate misalignment effects are not as serious as generally expected and 60.80% misalignment is considered to he tolerable in some circuit applications.

Proceedings of the 43rd IEEE Midwest Symposium on Circuits and Systems (Cat.No.CH37144)

Abstruct-This paper presents the development of a vibration-induced power generator with total vo... more Abstruct-This paper presents the development of a vibration-induced power generator with total volume of -lcm3 that uses laser-micromachined springs to convert mechanical energy into useful electrical power. The goal of this project is to create a minimally sized electric power ...

International Journal of Nonlinear Sciences and Numerical Simulation, 2000

The dynamical motion of laser-micromachined copper springs used for a meso-scale vibration-based ... more The dynamical motion of laser-micromachined copper springs used for a meso-scale vibration-based power generator was successfully modeled using ANSYS to reveal 3 modes of multi-directional vibratory motion due to a pure vertical input vibration. A MATLAB simulation was also used to predict the voltage output of the micro power generator system with coupled electrical and mechanical damping effects. The simulated output matched experimental results closely. These capabilities are essential for the successful design and development of a miniature, low-frequency, and robust micro energy generator that could be potentially used to convert human mechanical energy into usefully electrical power to operate devices such as mobile phones and heart-pacers. Thus far, 1cm 1 meso-scale generators are demonstrated capable of producing up to 4V AC with instantaneous peak power of 80mW, at input frequencies ranging from 60 to 120Hz with ~200μηι input vibration amplitude. A generator capable of producing 2V DC output with 40μ\ν power after voltage rectification, and able to drive a commercial infrared wireless signal transmitter to send 140ms pulse trains with ~60sec power generation time was also demonstrated. The ANSYS model and MATLAB simulation results are presented and compared with the experimental results in this paper.

Transducers ’01 Eurosensors XV, 2001

This paper presents the development of a vibration-induced power generator with total volume of ~... more This paper presents the development of a vibration-induced power generator with total volume of ~1cm 3 which uses laser-micromachined springs to convert mechanical energy into useful electrical power by Faraday's Law of Induction. The goal of this project is to create a minimally sized electric power generator capable of producing enough voltage to drive low-power ICs and/or micro sensors for applications where ambient mechanical vibrations are present. Thus far, we have fabricated generators with total volume of 1cm 3 that are capable of producing up to 4.4V peak-to-peak, which have a maximum rms power of ~680ìW with loading resistance of 1500Ù. The mechanical vibration required to generate this electrical energy has frequencies ranging from 60 to 110Hz with ~200µm amplitude. We have demonstrated that this generator can drive an IR transmitter to send 140ms pulse trains every minute, or a 914.8MHz FM wireless temperature sensing system.

Water Research, 2005

A membrane bioreactor (MBR) may serve as a pre-disinfection or disinfection unit, in addition to ... more A membrane bioreactor (MBR) may serve as a pre-disinfection or disinfection unit, in addition to its solid/liquid separation and biological conversion functions, to produce sewage effluent of high quality. This bench-scale pilot study focuses on investigating the performance of a submerged MBR in pathogen removal and the factors affecting the removal, using a 0.4-mm hollow-fiber membrane module submerged in an aeration tank and bacteriophage MS-2 as the indicator organism. Removal of the MS-2 phage was found to be contributed by physical filtration by the membrane itself, biomass activity in the aeration tank and bio-filtration achieved by the biofilm developed on the membrane surface. The membrane alone gave poor virus removal (0.470.1 log) but the overall removal increased substantially with the presence of biomass and the membrane-surface-attached biofilm. The contributions of the suspended biomass and attached biofilm to the phage removal are dependent on the interrelated parameters including the concentration of mixed liquor suspended solids (MLSS), the sludge retention time (SRT) and the food to mass (F/M) ratio. The correlations between effluent flux/trans-membrane pressure and virus removal give evidence that phage removal in the MBR is most likely susceptible to both biological and physical factors including the quantity and property of the biomass and the biofilm and the membrane pore size reduction.

The Laryngoscope, 2012

Canal switch is a complication following canalith repositioning procedure (CRP) for posterior can... more Canal switch is a complication following canalith repositioning procedure (CRP) for posterior canal benign paroxysmal positional vertigo (BPPV). Instead of being returned to the utricle, the loose otoconia migrate into the superior or horizontal semicircular canal. Patients remain symptomatic, and treatment can be ineffective unless the switch is recognized and additional repositioning maneuvers directed toward the appropriate semicircular canal are performed. This report provides the first videographic documentation of canal switch involving conversion of unilateral posterior semicircular canal BPPV to geotropic horizontal canalithiasis.

PEDIATRICS, 2006

Here we report a familial cluster of 3 cases of coxsackievirus B3 infection: a recent history of ... more Here we report a familial cluster of 3 cases of coxsackievirus B3 infection: a recent history of illness in a woman's 3-year-old son with a coxsackievirus B3–positive stool culture indicated that he probably infected his mother at home during her last week of pregnancy. Consequently, she delivered an infected neonate who developed severe hepatitis, disseminated intravascular coagulation, and bilateral intracranial hemorrhage. The neonate remained well for the first 2 days of life. On the third day, he developed fever (39°C) and poor peripheral circulation. On the fourth day, he developed petechiae and bruises over his chest wall and extremities, and prolonged bleeding was observed over venipuncture sites. Investigations revealed severe thrombocytopenia (platelets: 41 × 109/L) and a markedly deranged coagulation profile (prothrombin time: 19 seconds [reference: <10 seconds]; activated partial thromboplastin time: >120 seconds [reference: 24.2–37.0 seconds], serum D-dimers: ...

Pediatrics, 2009

OBJECTIVES. To assess (1) the differences in attitudes toward disabilities of 3 groups of subject... more OBJECTIVES. To assess (1) the differences in attitudes toward disabilities of 3 groups of subjects involved in neonatal care decision-making: health care workers, mothers of term infants, and parents of preterm infants, and (2) the impact of subject characteristics on these attitudes including parental education level, religion, and severity of disability. METHODS. Five hundred seventy-eight subjects were interviewed, of whom 135 were health care workers, 155 were mothers of term infants, and 288 were parents of preterm infants. We assessed between-group differences of the (1) health state ranking permutations, (2) proportion of subjects willing to save the infant at all costs, (3) pivotal risks of each group to the 5 health states comprising varying combinations of mental, physical, and social disabilities, and (4) impact of personal characteristics on decision-making. RESULTS. Most health care workers ranked the most severe disability health state as worse than death, whereas most...

Molecular Therapy, 2014

The mammalian auditory epithelium (AE) cannot replace supporting cells and hair cells once they a... more The mammalian auditory epithelium (AE) cannot replace supporting cells and hair cells once they are lost. Therefore, sensorineural hearing loss associated with missing cells is permanent. This inability to regenerate critical cell types makes the AE a potential target for cell replacement therapies such as stem cell transplantation. Inserting stem cells into the AE of deaf ears is a complicated task due to the hostile, high potassium environment of the scala media in the cochlea, and the robust junctional complexes between cells in the AE that resist stem cell integration. Here, we evaluate whether temporarily reducing potassium levels in the scala media and disrupting the junctions in the AE make the cochlear environment more receptive and facilitate survival and integration of transplanted cells. We used sodium caprate to transiently disrupt the AE junctions, replaced endolymph with perilymph, and blocked stria vascularis pumps with furosemide. We determined that these three steps facilitated survival of HeLa cells in the scala media for at least 7 days and that some of the implanted cells formed a junctional contact with native AE cells. The data suggest that manipulation of the cochlear environment facilitates survival and integration of exogenously transplanted HeLa cells in the scala media.

Journal of Wind Engineering and Industrial Aerodynamics, 1982

Three main types of aerod~cnamic damping devices, namely, a perforated shroud, helical strakes, a... more Three main types of aerod~cnamic damping devices, namely, a perforated shroud, helical strakes, and longitudinal slats, have been fitted on a circular cylinder for study in the same wind tunnel and under similar conditions. The drag coefficient of each device has also been determined at Reynolds numbers up to 1.5 X l0 s. Notation CD D k M N Re V Yr z0 7?0 5s P 0 /; drag coefficient based on D diameter of cylinder non~limensional damping coefficient. 2MSs/pD 2 mass per unit length frequency of oscillation Reynolds number, VD/v flow velocity reduced velocity, V/ND peak-to-peak amplitude of oscillation of free end of model non<limensional amplitude of oscillation, zo/D logarithmic decrement of oscillating system in still air fluid density opening angle at front and rear of slat system kinematic viscosity of fluid

Journal of Medical Virology, 1996

The BMRF1 protein is an Epstein-Barr virus (EBV) DNA polymerase accessory protein that forms part... more The BMRF1 protein is an Epstein-Barr virus (EBV) DNA polymerase accessory protein that forms part of the early antigen diffuse (EA-D) component. An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of IgA antibody to the BMRF1 protein of EBV in saliva and serum samples. The assay was shown to be specific for nasopharyngeal carcinoma (NPC) patients and, when used with saliva alone, to have a sensitivity comparable to an existing indirect immunoperoxidase assay for early antigens. The sensitivity of the assay could be significantly enhanced to 86% by the use of paired saliva and serum samples.