2,508 research outputs found

    Electro-oxidation of methanol on Pt particles dispersed on RuO2 nanorods

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    The successful attachment of 1-3 nm Pt nanoparticles to the surface of amine-functional RuO2 nanorods through a simple, two-step chemically controlled procedure is reported here. The nanocomposites were characterized by transmission electron microscopy (TEM) and X-ray diffraction. TEM images showed that the monodispersed Pt nanoparticles were highly stable against thermal treatment. The electro-oxidation of methanol in sulfuric acidic solution was studied on RuO2-supported Pt nanoparticles by cyclic voltammetry and chronoamperometry. All of the electrochemical results show that RuO 2/Pt catalysts exhibit high activity for methanol oxidation that results from the high electroactive surface area of Pt nanoparticles and the effect of RuO2. These results demonstrate the feasibility of using metal oxide nanorods in certain fuel cell applications. © 2006 The Electrochemical Society. All rights reserved.published_or_final_versio

    Effect of the sound of dental equipment on dental anxiety and noise control techniques

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    The dental office environment subjects both patients and dental professionals to the noises associated with dental equipment. The sound of the dental drill, for example, usually causes some discomfort and anxiety. Fear and anxiety due to these noises are among the major reasons why patients avoid dental visits. It is important that these fears are addressed and patients are encouraged to seek the oral healthcare treatment they need. Long-term exposure to these noises also puts dental professionals themselves at high risk of hearing loss. It is unclear about the psychological influence of the sound of dental equipment on dental anxiety. This paper presents a questionnaire survey previously conducted by the authors to study the effects of the sound of dental equipment on people’s perceptions and dental anxiety levels and discusses solutions to the problem by means of passive and active noise control technologies or a combination of both of them.published_or_final_versio

    Analytical prediction of armature-reaction field in disc-type permanent magnet generators

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    H. C. Wong, Industrial CentreAuthor name used in this publication: S. L. HoAuthor name used in this publication: H. C. WongVersion of RecordPublishe

    The effect of a pre-exercise carbohydrate meal on immune responses to an endurance performance run

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    2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Ormosils-PVA BOD sensing film based on oxygen luminescence quenching

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    2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Identification and Expression Profiling of MicroRNAs in the Brain, Liver and Gonads of Marine Medaka (Oryzias melastigma) and in Response to Hypoxia

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    The marine medaka (Oryzias melastigma) has been increasingly used as a fish model for detecting environmental stresses and chemical contaminants in the marine environment. Recent mammalian studies have shown that environmental stresses can alter the expression profiles of microRNAs (miRNAs), leading to transgenerational effects. Here, we use high-throughput Illumina RNA sequencing (RNA-Seq) for miRNA transcriptome analysis of brain, liver, and gonads from sexually mature male and female marine medaka. A total of 128,883,806 filtered sequence reads were generated from six small RNA libraries, identifying a total of 2,125,663 non-redundant sequences. These sequences were aligned and annotated to known animal miRNAs (miRBase) using the BLAST method. A total of 223 distinct miRNA types were identified, with the greatest number expressed in brain tissue. Our data suggested that 55 miRNA types from 34 families are common to all tested tissues, while some of the miRNAs are tissue-enriched or sex-enriched. Quantitative real-time PCR analysis further demonstrated that let-7a, miR-122, and miR-9-3p were downregulated in hypoxic female medaka, while miR-2184 was specifically upregulated in the testis of hypoxic male fish. This is the first study to identify miRNAs in O. melastigma using small RNA deep sequencing technology. Because miRNA expression is highly conserved between marine medaka and other vertebrates, marine medaka may serve as a good model for studies on the functional roles of miRNAs in hypoxia stress response and signaling in marine fish.published_or_final_versio

    Dramatic escalation in metabolic syndrome and cardiovascular risk in a Chinese population experiencing rapid economic development

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    Background Metabolic syndrome (MetSyn) increases the incidence of cardiovascular disease. Information on changes in prevalence of MetSyn in developing countries is limited. This study aims to compare MetSyn prevalence and its associated vascular risk over the period between 2002 and 2010 in a population which has had the world’s fastest economic development over the past three decades. Methods Two health surveys were conducted by using the multistage cluster random sampling method in a Chinese population of 85 million in southern China. The participants received a full medical check-up, including measurement of blood pressure (BP), obesity indices, fasting lipids and glucose levels. Data describing socio-economic status and lifestyle factors were also collected through interview. Metabolic syndrome was defined in accordance with the International Diabetes Federation criteria. Results A total of 3,561 participants from Survey 2010 were included in the data analysis. Women had a significantly higher prevalence of MetSyn than men. Comparison between the two surveys shows that age-standardized prevalence of MetSyn increased fourfold (from 5.4% in 2002 to 21.3% in 2010) in those ≧ 20 years. Among the MetSyn components, prevalence of hyperglycaemia has increased most (from 9.1% to 53.1%). The age-standardized prevalence of central obesity, hypertension, hypertriglyceridaemia and low HDL-cholesterol increased from 13.5% to 25.4%, from 23.6% to 40.8%, from 12.1% to 17.4% and from 32.1% to 71.1%, respectively. Differences between rural and urban residents in the prevalence in MetSyn and its components narrowed in 2010. Conclusions Cardiovascular risk escalated dramatically in this population between 2002 and 2010. The escalation may relate to the rapid economic development, which led to accelerating changes in nutrition, lifestyle, and socio-economic status. Our findings suggest that health transition in rapidly developing second- and third-world countries may be much faster than what has been observed in Western countries.published_or_final_versio

    COVID-19 In Children Across Three Asian Cosmopolitan Regions

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    As another wave of COVID-19 outbreak has approached in July 2020, a larger scale COVID-19 pediatric Asian cohort summarizing the clinical observations is warranted. Children confirmed with COVID-19 infection from the Republic of Korea, the Hong Kong Special Administrative Region (HKSAR) and Wuhan, China, during their first waves of local outbreaks were included. Their clinical characteristics and the temporal sequences of the first waves of local paediatric outbreaks were compared. Four hundred and twenty three children with COVID-19 were analyzed. Wuhan had the earliest peak, followed by Korea and HKSAR. Compared with Korea and Wuhan, patients in HKSAR were significantly older (mean age: 12.9 vs. 10.8 vs. 6.6 years, p < 0.001, respectively) and had more imported cases (87.5% vs. 16.5% vs. 0%, p < 0.001, respectively). The imported cases were also older (13.4 vs. 7.6 years, p < 0.001). More cases in HKSAR were asymptomatic compared to Korea and Wuhan (45.5% vs. 22.0% vs. 20.9%, p < 0.001, respectively), and significantly more patients from Wuhan developed fever (40.6% vs. 29.7% vs. 21.6%, p=0.003, respectively). There were significantly less imported cases than domestic cases developing fever after adjusting for age and region of origin (p = 0.046). 5.4% to 10.8% of patients reported anosmia and ageusia. None developed pediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PMIS-TS). In general, adolescents were more likely to be asymptomatic and less likely to develop fever, but required longer hospital stays. In conclusion, majority patients in this pediatric Asian cohort had a mild disease. None developed PIMS-TS. Their clinical characteristics were influenced by travel history and age
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