34 research outputs found

    Pulsed laser deposition of nanostructured indium-tin-oxide films

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    Effects of O2, N2, Ar and He on the formation of micro- and nanostructured indium tin oxide (ITO) thin films were investigated in pulsed Nd:YAG laser deposition on glass substrate. For O2 and Ar, ITO resistivity of ≤ 4 × 10-4 Ωcm and optical transmittance of \u3e 90% were obtained with substrate temperature of 250 °C. For N2 and He, low ITO resisitivity could be obtained but with poor optical transmittance. SEM images show nano-structured ITO thin films for all gases, where dense, larger and highly oriented, microcrystalline structures were obtained for deposition in O2 and He, as revealed from the XRD lines. EDX results indicated the inclusion of Ar and N2 at the expense of reduced tin (Sn) content. When the ITO films were applied for fabrication of organic light emitting devices (OLED), only those deposited in Ar and O2 produced comparable performance to single-layer OLED fabricated on the commercial ITO. © 2010 SPIE

    Sentinel surveillance for human enterovirus 71 in Sarawak, Malaysia: lessons from the first 7 years

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    BACKGROUND: A major outbreak of human enterovirus 71-associated hand, foot and mouth disease in Sarawak in 1997 marked the beginning of a series of outbreaks in the Asia Pacific region. Some of these outbreaks had unusually high numbers of fatalities and this generated much fear and anxiety in the region. METHODS: We established a sentinel surveillance programme for hand, foot and mouth disease in Sarawak, Malaysia, in March 1998, and the observations of the first 7 years are described here. Virus isolation, serotyping and genotyping were performed on throat, rectal, vesicle and other swabs. RESULTS: During this period Sarawak had two outbreaks of human enterovirus 71, in 2000 and 2003. The predominant strains circulating in the outbreaks of 1997, 2000 and 2003 were all from genogroup B, but the strains isolated during each outbreak were genetically distinct from each other. Human enterovirus 71 outbreaks occurred in a cyclical pattern every three years and Coxsackievirus A16 co-circulated with human enterovirus 71. Although vesicles were most likely to yield an isolate, this sample was not generally available from most cases and obtaining throat swabs was thus found to be the most efficient way to obtain virological information. CONCLUSION: Knowledge of the epidemiology of human enterovirus 71 transmission will allow public health personnel to predict when outbreaks might occur and to plan interventions in an effective manner in order to reduce the burden of disease

    Systematic comparison of plasma EBV DNA, anti-EBV antibodies and miRNA levels for early detection and prognosis of nasopharyngeal carcinoma

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    Nasopharyngeal carcinoma (NPC) is originated from the epithelial cells of nasopharynx, Epstein-Barr virus (EBV)-associated and has the highest incidence and mortality rates in Southeast Asia. Late presentation is a common issue and early detection could be the key to reduce the disease burden. Sensitivity of plasma EBV DNA, an established NPC biomarker, for Stage I NPC is controversial. Most newly reported NPC biomarkers have neither been externally validated nor compared to the established ones. This causes difficulty in planning for cost-effective early detection strategies. Our study systematically evaluated six established and four new biomarkers in NPC cases, population controls and hospital controls. We showed that BamHI-W 76 bp remains the most sensitive plasma biomarker, with 96.7% (29/30), 96.7% (58/60) and 97.4% (226/232) sensitivity to detect Stage I, early stage and all NPC, respectively. Its specificity was 94.2% (113/120) against population controls and 90.4% (113/125) against hospital controls. Diagnostic accuracy of BamHI-W 121 bp and ebv-miR-BART7-3p were validated. Hsa-miR-29a-3p and hsa-miR-103a-3p were not, possibly due to lower number of advanced stage NPC cases included in this subset. Decision tree modeling suggested that combination of BamHI-W 76 bp and VCA IgA or EA IgG may increase the specificity or sensitivity to detect NPC. EBNA1 99 bp could identify NPC patients with poor prognosis in early and advanced stage NPC. Our findings provided evidence for improvement in NPC screening strategies, covering considerations of opportunistic screening, combining biomarkers to increase sensitivity or specificity and testing biomarkers from single sampled specimen to avoid logistic problems of resampling

    Investigation Of Plume Dynamics, Phase Explosion And Droplets In Pulsed Laser Ablation And Deposition Of Materials

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    The basic concept of pulsed laser ablation lies in the laser-matter interactions and phenomena related to the materials removal. While the former concern with the photo-induced ablation mechanisms, the latter are often related to the propagation behavior of the photo-ablated materials, which is generally known as the plume. The plume can be collected on a substrate, hence giving rise to the pulsed laser deposition technique which is widely used for preparation of many types of thin-film materials. These thin films, however, often contain commonly-known particulates (for example, droplets) of size ranging from nanometer (nm) to micrometer (mm)

    Digital content on mobile devices (a music perspective).

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    This project focuses on the value proposition of digital music content in the context of a wireless mobile world. Three forces, namely technology, law and human behavior are defined which will impact the music and wireless industry in the near future. The focus of music is chosen because the uptake of digital music media is leading the technology field as compared to other media forms

    Triggered Spark Gap Command Charger for High Repetition Rate Applications

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    A normal de resonant charger was transformed into a command-mode charger by connecting a spark gap at its output terminal, prior to the load circuit. This charging spark gap was triggered by a transformer connected in series, pulsed by a fast spark gap circuit. Noise suppression schemes were implemented throughout the command charger, in particular around the charging spark gap to order prevent misfiring. The ringing noise and spikes from the capacitor discharge and those of the stray capacitance of coaxial cable were strongly suppressed by a simple LCR circuit so that these would hot induce self-breakdown in the charging spark gap. This triggered spark gap command charger was tested to 2 kHz and < 10 kV with a resistive load. A transversely excited atmospheric CO2 laser was operated up to 300 Hz and (10-15) kV that was limited only by the flow rate of the laser gas mixture
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