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色谱 2017年第10期35卷 1042-1047页

作者： cheuk man-yung LO Yun-Chuen POON Wing-Tat Department of Pathology Pamela Youde Nethersole Eastern Hospital

The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for determining catecholamines and metanephrines in urine to replace an existing liquid chromatographic method using electrochemical detection.Urine samples were prepared using Oasis weak-cation-exchange cartridges.The eluate was analyzed on an Agilent ZORBAX Eclipse Plus Phenyl-Hexyl column in 3 min.Adrenaline,noradrenaline,dopamine,metanephrine,normetanephrine,and their deuterated internal standards were monitored in positive electrospray ionization mode by multiple reaction monitoring(MRM).No evidence of ion suppression was observed.The assay was linear up to 5μmol/L for adrenaline,5μmol/L for noradrenaline,6.1μmol/L for dopamine,5.6μmol/L for metanephrine,and 34.6μmol/L for normetanephrine,with lower limits of quantification of 5,5,12,6 and 7nmol/L,respectively.The intra-day and inter-day precisions for all analytes ranged from 0.59%to 4.64%and1.98%to 4.80%,respectively.External quality assurance samples were assayed and showed excellent agreement with the target values.This simple method provides an improved assay for determining urine catecholamines and metanephrines.

关键词： liquid chromatography-tandem mass spectrometry (LC-MS/MS) metanephrines catecholamines pheochromocytoma urine

Ensemble Wind Power Prediction Interval with Optimal Reserve Requirement

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 65-76页

作者： Hamid Rezaie cheuk Hei Chung Nima Safari the Saskatchewan Power Corporation(SaskPower) ReginaSaskatchewanCanada the Department of Electrical and Computer Engineering and Department of Human Biology University of TorontoTorontoON M5S 3G4Canada the Alberta Electric System Operator(AESO) CalgaryAlbertaCanada

Wind power prediction interval(WPPI)models in the literature have predominantly been developed for and tested on specific case studies.However,wind behavior and characteristics can vary significantly across regions.Thus,a prediction model that performs well in one case might underperform in another.To address this shortcoming,this paper proposes an ensemble WPPI framework that integrates multiple WPPI models with distinct characteristics to improve robustness.Another important and often overlooked factor is the role of probabilistic wind power prediction(WPP)in quantifying wind power uncertainty,which should be handled by operating reserve.Operating reserve in WPPI frameworks enhances the efficacy of WPP.In this regard,the proposed framework employs a novel bi-layer optimization approach that takes both WPPI quality and reserve requirements into account.Comprehensive analysis with different real-world datasets and various benchmark models validates the quality of the obtained WPPIs while resulting in more optimal reserve requirements.

关键词： Ensemble model linear programming operating reserve optimal reserve requirement prediction interval probabilistic prediction renewable integration uncertainty representation wind power prediction(WPP)

Atomscopic of ripple origins for two-dimensional monolayer transition metal dichalcogenides

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Nano Research 2024年第3期17卷 2136-2144页

作者： Haitao Yu Mingzi Sun Xiao Wu cheuk Hei Chan Bolong Huang Zhong Lin Wang CAS Center for Excellence in Nanoscience Beijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 100083China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049China Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina Research Centre for Carbon-Strategic Catalysis The Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGeorgia 30332USA

During the development of ultrathin two-dimensional(2D)materials,the appearance of ripples has been widely observed.However,the formation mechanisms and their influences are still rarely investigated,especially their contributions to the electronic structures and optical properties.To compensate for the knowledge gap,we have carried out comprehensive theoretical studies on the monolayer WSe_(2) with a series of ripple structures from 0 to 12Åin different lattice sizes.The sensitivity of the formation energy,band structures,electronic structures,and optical properties to the ripple structures have been performed systematically for the first time.The formation of ripples in Armchair and zigzag simultaneously are more energetically favorable,leading to more flexible optimizations of the optoelectronic properties.The improved charge-locking effect and extension of absorption ranges indicate the significant role of ripple structures.The spontaneous formation of ripples is associated with orbital rearrangements and structural distortions.This leads to the unique charge carrier correlate inversion between W-5d and Se-4p orbitals,resulting in the pinning of the Fermi level.This work has supplied significant references to understand ultrathin 2D structures and benefit their future developments and applications in high-performance optoelectronic devices.

关键词： two-dimensional(2D)materials ripples strain effect charge carrier correlation inversion optoelectronic properties

Combinatorial Optimization of Physics Parameterization Schemes for Typhoon Simulation Based on a Simple Genetic Algorithm(SGA)

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Journal of Meteorological Research 2024年第1期38卷 10-26页

作者： Zebin LU Jianjun XU Zhiqiang CHEN Jinyi YANG Jeremy cheuk-Hin LEUNG Daosheng XU Banglin ZHANG China Meteorological Administration–Guangdong Ocean University Joint Laboratory for Marine Meteorology South China Sea Institute of Marine MeteorologyGuangdong Ocean UniversityZhanjiang 524088 College of Ocean and Meteorology Guangdong Ocean UniversityZhanjiang 524088 Guangzhou Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction China Meteorological AdministrationGuangzhou 510640 Shenzhen Institute of Guangdong Ocean University Shenzhen 518120 College of Atmospheric Science Lanzhou UniversityLanzhou 730000

Each physical process in a numerical weather prediction(NWP)system may have many different parameterization schemes.Early studies have shown that the performance of different physical parameterization schemes varies with the weather situation to be simulated.Thus,it is necessary to select a suitable combination of physical parameterization schemes according to the variation of weather systems.However,it is rather difficult to identify an optimal combination among millions of possible parameterization scheme combinations.This study applied a simple genetic algorithm(SGA)to optimizing the combination of parameterization schemes in NWP models for typhoon forecasting.The feasibility of SGA was verified with the simulation of Typhoon Mujigae(2015)by using the Weather Research and Forecasting(WRF)model and Typhoon Higos(2020)by using the Coupled Ocean–Atmosphere–Wave–Sediment Transport(COAWST)modeling system.The results show that SGA can efficiently obtain the optimal combination of schemes.For Typhoon Mujigae(2015),the optimal combination can be found from the 1,304,576 possible combinations by running only 488 trials.Similar results can be obtained for Typhoon Higos(2020).Compared to the default combination proposed by the COAWST model system,the optimal combination scheme significantly improves the simulation of typhoon track and intensity.This study provides a feasible way to search for the optimal combinations of physical parameterization schemes in WRF and COAWST for more accurate typhoon simulation.This can help provide references for future development of NWP models,and for analyzing the coordination and adaptability of different physical process parameterization schemes under specific weather backgrounds.

关键词： simple genetic algorithm(SGA) combinatorial optimization typhoon forecast numerical weather prediction(NWP)

片仔癀通过调节小鼠的肠道菌群和代谢物抑制非酒精性脂肪性肝炎

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Engineering 2024年第4期35卷 257-269页

作者： Xianyi Zeng Xiang Zhang Hao Su Hongyan Gou Harry cheuk-Hay Lau Xiaoxu Hu Ziheng Huang Yan Li Jun Yu Shenzhen Research Institute The Chinese University of Hong KongShenzhen 518057China Department of Medicine and Therapeutics Institute of Digestive DiseaseState Key Laboratory of Digestive DiseaseLi Ka Shing Institute of Health SciencesThe Chinese University of Hong KongHong Kong 999077China

Non-alcoholic steatohepatitis(NASH)is a severe form of non-alcoholic fatty liver disease without effective treatment.The traditional Chinese medicine formulation Pien Tze Huang(PTH)can suppress inflammatory diseases.Here,we evaluate the effects of PTH on the evolution of NASH and its underlying mechanisms.We found that PTH prevented the development of steatohepatitis induced by various dietary models,including a high-fat high-cholesterol(HFHC)diet,choline-deficient high-fat diet(CD-HFD),and methionine-and choline-deficient(MCD)diet,along with significant suppression of liver injury,hepatic triglyceride,and lipid peroxidation.Moreover,ten days of PTH treatment after the onset of NASH significantly ameliorated MCD diet-induced steatosis and liver injury in mice.Through the metagenomic sequencing of stool samples,we found that PTH administration restored the gut microbiota with enrichment of probiotics including Lactobacillus acidophilus(L.acidophilus),Lactobacillus plantarum,Lactococcus lactis,and Bacillus subtilis.The enriched L.acidophilus prevented MCD diet-induced steatohepatitis.In addition,PTH restored the gut barrier function in mice with steatohepatitis,as evidenced by reduced intestinal permeability,decreased serum lipopolysaccharides(LPS)level,and increased epithelial tightjunction protein E-cadherin expression.Our metabolomic analysis via liquid chromatography-mass spectrometry profiling identified the alteration in the metabolism of bile acids in the portal vein of PTHtreated mice.We further confirmed that an intact gut microbiota is necessary for PTH to exhibit antisteatohepatitis effects.In conclusion,PTH protects against steatohepatitis development by modulating the gut microbiota and metabolites.PTH is a potential promising prophylactic and therapeutic option for patients with NASH.

关键词： Pien Tze Huang Non-alcoholic steatohepatitis Gut barrier function Gut microbiota

An Evaluation of Tropical Cyclone Genesis Forecast over the Western North Pacific and the South China Sea from the CMA-TRAMS

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Journal of Tropical Meteorology 2024年第1期30卷 20-28页

作者：李梦婕陈子通戴光丰田群梁卓轩林青张艳霞 Guangzhou Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction CMAGuangzhou 510641 China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081 China Guangdong Meteorological Observatory Guangzhou 510641 China

Tropical cyclone(TC) genesis forecasting is essential for daily operational practices during the typhoon season.The updated version of the Tropical Regional Atmosphere Model for the South China Sea(CMA-TRAMS) offers forecasters reliable numerical weather prediction(NWP) products with improved configurations and fine resolution. While traditional evaluation of typhoon forecasts has focused on track and intensity, the increasing accuracy of TC genesis forecasts calls for more comprehensive evaluation methods to assess the reliability of these predictions. This study aims to evaluate the effectiveness of the CMA-TRAMS for cyclogenesis forecasts over the western North Pacific and South China Sea. Based on previous research and typhoon observation data over five years, a set of localized, objective criteria has been proposed. The analysis results indicate that the CMA-TRAMS demonstrated superiority in cyclogenesis forecasts, predicting 6 out of 22 TCs with a forecast lead time of up to 144 h. Additionally, over 80% of the total could be predicted 72 h in advance. The model also showed an average TC genesis position error of 218.3 km, comparable to the track errors of operational models according to the annual evaluation. The study also briefly investigated the forecast of Noul(2011). The forecast field of the CMA-TRAMS depicted thermal and dynamical conditions that could trigger typhoon genesis, consistent with the analysis field. The 96-hour forecast field of the CMA-TRAMS displayed a relatively organized threedimensional structure of the typhoon. These results can enhance understanding of the mechanism behind typhoon genesis,fine-tune model configurations and dynamical frameworks, and provide reliable forecasts for forecasters.

关键词： CMA-TRAMS cyclogenesis numerical weather prediction tropical cyclone

On the question of quark confinement in the Abelian U(1)QED gauge interaction

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Frontiers of physics 2023年第6期18卷 39-91页

作者： cheuk-Yin Wong Physics Division Oak Ridge National Laboratory*Oak RidgeTN 37831USA

If we approximate light quarks as massless and apply the Schwinger confinement mechanism to light quarks,we will reach the conclusion that a light quark and its antiquark will be confined as a boson in the Abelian U(1)QED gauge interaction in(1+1)D,as in an open string.From the work of Coleman,Jackiw,and Susskind,we can infer further that the Schwinger confinement mechanism persists even for massive quarks in(1+1)D.Could such a QED-confined one-dimensional open string in(1+1)D be the idealization of a flux tube in the physical world in(3+1)D,similar to the case of QCD-confined open string?If so,the QED-confined bosons may show up as neutral QED mesons in the mass region of many tens of MeV[Phys.Rev.C 81,064903(2010)&J.High Energy Phys.2020(8),165(2020)].Is it ever possible that a quark and an antiquark be produced and interact in QED alone to form a confined QED meson?Is there any experimental evidence for the existence of a QED meson(or QED mesons)?The observations of the anomalous soft photons,the X17 particle,and the E38 particle suggest that they may bear the experimental evidence for the existence of such QED mesons.Further confirmation and investigations on the X17 and E38 particles will shed definitive light on the question of quark confinement in QED in(3+1)D.Implications of quark confinement in the QED interaction are discussed.

关键词： quark confinement QCD interaction QED interaction Schwinger model open string model of mesons QCD molecular states

Lycium barbarum polysaccharides and ferroptosis:jumping into the era of novel regulated cell death

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Neural Regeneration Research 2022年第7期17卷 1473-1474页

作者： Amy cheuk Yin Lo Ming Yang Department of Ophthalmology Li Ka Shing Faculty of MedicineThe University of Hong KongHong Kong Special Administrative RegionChina

Lycium barbarum polysaccharides(LBP)are the key bioactive components of Lycium barbarum(also named Gouqizi or Goji berry or wolfberry),a widely used Traditional Chinese herb for more than 2000 years.Believed to balanc... 详细信息

关键词： benefits consumed balance

Uncovering novel human gut virome using ultra-deep metagenomic sequencing

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Chinese Medical Journal 2022年第20期135卷 2395-2397页

作者： Harry cheuk Hay Lau Jun Yu Institute of Digestive Disease and Department of Medicine and Therapeutics State Key Laboratory of Digestive DiseaseLi Ka Shing Institute of Health Sciencesthe Chinese University of Hong KongHong Kong SARChina

Human gastrointestinal tract harbors trillions of commensal microbes including bacteria,viruses,and fungi to form an ecological community,commonly known as the gut microbiome.Being the second most dominant taxonomic kingdom in the gut(5.8%of total microbiome DNA),enteric viruses are increasingly acknowledged for their roles in shaping the overall composition of the gut microbiome and maintaining human health.[1,2]Recent advancements in metagenomic sequencing have brought breakthrough in deciphering the features and functions of the gut virome.

关键词： breakthrough harbor gut

Gut Microbiome in Colorectal Cancer:Clinical Diagnosis and Treatment

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Genomics, Proteomics & Bioinformatics 2023年第1期21卷 84-96页

作者： Yali Liu Harry cheuk-Hay Lau Wing Yin Cheng Jun Yu Institute of Digestive Disease and The Department of Medicine and Therapeutics State Key Laboratory of Digestive DiseaseLi Ka Shing Institute of Health SciencesCUHK Shenzhen Research InstituteThe Chinese University of Hong KongHong Kong Special Administrative Region 999077China

Colorectal cancer(CRC)is one of the most frequently diagnosed cancers and the leading cause of cancer-associated deaths.Epidemiological studies have shown that both genetic and environmental risk factors contribute to the development of CRC.Several metagenomic studies of CRC have identified gut dysbiosis as a fundamental risk factor in the evolution of colorectal malignancy.Although enormous efforts and substantial progresses have been made in understanding the relationship between human gut microbiome and CRC,the precise mechanisms involved remain elusive.Recent data have shown a direct causative role of the gut microbiome in DNA damage,inflammation,and drug resistance in CRC,suggesting that modulation of gut microbiome could act as a powerful tool in CRC prevention and therapy.Here,we provide an overview of the relationship between gut microbiome and CRC,and explore relevant mechanisms of colorectal tumorigenesis.We next highlight the potential of bacterial species as clinical biomarkers,as well as their roles in therapeutic response.Factors limiting the clinical translation of gut microbiome and strategies for resolving current challenges are further discussed.

关键词： Gut microbiome Colorectal cancer Diagnostic biomarker Immunotherapy Chemotherapy