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Acta Pharmacologica Sinica 2007年第10期28卷 1559-1565页

作者： Po-yee CHIU Hoi-yan LEUNG Ada HL SIU Michel KTPOON kam-ming ko Department of Biochemistry Hong kong University of Science and Technology Hong kong SAR China

Aim:In order to elucidate the molecular mechanism underlying the cardioprotectionafforded by schisandrin B （Sch B）,the effect of Sch B treatment on the sensitivityof mitochondria to Ca2+-stimulated permeability transition （PT） was investigatedin rat hearts under normal and ischemia-reperfusion （I-R） ***:Myocardial I-R injury caused an increase in the sensitivity of mitochondria toCa2+-stimulated PT in *** enhanced sensitivity to mitochondrial PT wasassociated with increases in mitochondrial Ca2+content as well as the extent ofreactive oxidant species production in vitro and cytochrome c release in *** cardioprotection afforded by Sch B pretreatment against I-R-induced injurywas paralleled by the decrease in the sensitivity of myocardial mitochondria toCa2+-stimulated PT,particularly under I-R ***:The resultssuggest that Sch B treatment increases the resistance of myocardial mitochondriato Ca2+-stimulated PT and protects against I-R-induced tissue injury.

关键词： schisandrin B mitochondria permeability transition calcium myocardial ischemiareperfusion

A Comparative Study of Finite Element and Finite Difference Methods for Two-Dimensional Space-Fractional Advection-Dispersion Equation

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Advances in Applied Mathematics and Mechanics 2016年第1期8卷 166-186页

作者： Guofei Pang wen Chen kam Yim Sze Institute of Soft Matter Mechanics Department of Engineering MechanicsHohai UniversityNanjing 210098China Department of Mechanical Engineering The University of Hong KongPokfulamHong Kong

The paper makes a comparative study of the finite element method(FEM)and the finite difference method(FDM)for two-dimensional fractional advectiondispersion equation(FADE)which has recently been considered a promising tool in modeling non-Fickian solute transport in *** to the non-local property of integro-differential operator of the space-fractional derivative,numerical solution of FADE is very challenging and little has been reported in literature,especially for highdimensional *** order to effectively apply the FEM and the FDM to the FADE on a rectangular domain,a backward-distance algorithm is presented to extend the triangular elements to generic polygon elements in the finite element analysis,and a variable-step vector Gr¨unwald formula is proposed to improve the solution accuracy of the conventional finite difference *** investigation shows that the FEM compares favorably with the FDM in terms of accuracy and convergence rate whereas the latter enjoys less computational effort.

关键词： Space-fractional derivative advection-dispersion finite element finite difference

Incremental expectation maximization principal component analysis for missing value imputation for coevolving EEG data

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第8期12卷 687-697页

作者： Sun Hee KIM Hyung Jeong YANG kam Swee NG Department of Computer Science Chonnam National University

Missing values occur in bio-signal processing for various reasons,including technical problems or biological *** missing values are then either simply excluded or substituted with estimated values for further *** the missing signal values are estimated for electroencephalography (EEG) signals,an example where electrical signals arrive quickly and successively,rapid processing of high-speed data is required for immediate decision *** this study,we propose an incremental expectation maximization principal component analysis (iEMPCA) method that automatically estimates missing values from multivariable EEG time series data without requiring a whole and complete data *** proposed method solves the problem of a biased model,which inevitably results from simply removing incomplete data rather than estimating them,and thus reduces the loss of information by incorporating missing values in real *** using an incremental approach,the proposed method alsominimizes memory usage and processing time of continuously arriving *** results show that the proposed method assigns more accurate missing values than previous methods.

关键词： Electroencephalography (EEG) Missing value imputation Hidden pattern discovery Expectation maximization Principal component analysis

Generating Electricity from Mechanical Vibrations:Optimization of Linear a Generator

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Instrumentation 2021年第2期8卷 34-39页

作者： MAA KARUNARATHNA kam DHANURANGA Department of Electronics Faculty of Applied SciencesWayamba University of Sri LankaSri Lanka

Energy preservation is one of the key components in developing eco-friendly *** industry,the majority of machines lose a considerable amount of energy through mechanical ***,the wasted energy through vibration can be utilized as a renewable energy source to compensate for the overall energy *** research work presented in this paper discusses the ability to design a linear power generator utilizing Nd Fe-B magnets,which can generate energy through mechanical vibrations.A pilot model was developed and simulated to understand the efficiency and *** results showed that the model could reduce 14% rotor bulk with a marginal impact on the current generation.

关键词： Mechanical Vibrations Linear Generator Sustainable Energy Energy Production

On the first negative Hecke eigenvalue of an automorphic representation of GL_(2)(A_(Q))

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Science China Mathematics 2021年第11期64卷 2381-2394页

作者： Yuk-kam Lau Ming Ho Ng Hengcai Tang Yingnan Wang Department of Mathematics The University of Hong KongHong KongChina Department of Mathematics The Chinese University of Hong KongHong KongChina Institute of Modern Mathematics School of Mathematics and StatisticsHenan UniversityKaifeng 475004China Shenzhen Key Laboratory of Advanced Machine Learning and Applications College of Mathematics and StatisticsShenzhen UniversityShenzhen 518060China

Letπbe a self-dual irreducible cuspidal automorphic representation of GL_(2)(A_(Q))with trivial central *** Hecke eigenvalue λπ(n)is a real multiplicative function in *** show that λπ(n)<0 for some n< 详细信息

关键词： automorphic representation Hecke eigenvalue Maass cusp form sign change

EVALUATION OF QUARTZ CRYSTALS IN RAT LUNGS BY X-RAY DIFFRACTOMETRY

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Scientia Sinica 1981年第10期24卷 1448-1449页

作者： JOHN KAI-HONG kam University of California BerkeleyCaliforniaUSA

The NIOSH（National Institute of Occupational Safety and Health）-recommended pro-cedure of determining quartz through X-ray diffractometry was applied to rat lungs. Usinga compressed air nebulizer inside a closed chamber, 150 male Sprague-Dawley rats were ex-posed to monodisperse particles of quartz for varying time intervals. The rats were subse-quently sacrificed by cervical dislocation and their lungs were removed for ashing inside amuffle furnace at 600℃ for 4 hr. The ashed materials were then filtered onto silver mem-branes and scanned by an X-ray diffractometer. The results, expressed in mg SiO2 were com-pared to standard values derived from PVC filters. The values suggested that the NIOSHmethod could be used by biochemists to quantify minerals and crystalline structures in organicmaterials.

关键词： EVALUATION OF QUARTZ CRYSTALS IN RAT LUNGS BY X-RAY DIFFRACTOMETRY RAT

On the Distributions of Two Classes of Multiple Dependent Aggregate Claims

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Acta Mathematicae Applicatae Sinica 2008年第4期24卷 655-668页

作者： Rong-ming Wang kam C. Yuen Li-xing Zhu School of Finance and Statistics East China Normal University Shanghai 200241 China Department of Statistics and Actuarial Science The University of Hong Kong Department of Mathematics Hongkong Baptist University Kowloon Tong Hong Kong

In this paper we examine two classes of correlated aggregate claims distributions, with univariate claim counts and multivariate claim sizes. Firstly, we extend the results of Hesselager [ASTIN Bulletin, 24： 19-32（1994）] and Wang ＆ Sobrero＇s [ASTIN Bulletin, 24：161-166 （1994）] concerning recursions for compound distributions to a multivariate situation where each claim event generates a random vector. Then we give a multivariate continuous version of recursive algorithm for calculating a family of compound distribution. Especially, to some extent, we obtain a continuous version of the corresponding results in Sundt [ASTIN Bulletin, 29：29-45 （1999）] and Ambagaspitiya [Insurance： Mathematics and Economics, 24：301-308 （1999）]. Finally, we give an example and show how to use the algorithm for aggregate claim distribution of first class to compute recursively the compound distribution.

关键词： Compound distribution recursive algorithm collective risk model aggregate claim distribution,absolutely continuous

A Traditional Chinese Medicine Approach in Treating Depression by Promoting Liver Qi Circulation: A western Medicine Perspective

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Chinese Medicine 2015年第4期6卷 187-195页

作者： Raphaella Wai Lam So Hoi Shan Wong kam Ming ko Division of Life Science Hong Kong University of Science & Technology Hong Kong China

Depression is a prevalent mental illness in developed countries. In western medicine, experimental and clinical investigations have demonstrated that depression is associated with the dysregulation of neurotransmitter signaling, and symptoms of depression can be alleviated by therapeutic intervention. However, patients taking antidepressant drugs often experience serious side effects and high relapse rates. On the other hand, traditional Chinese medicine (TCM) views depression as a manifestation of liver qi stagnation. Practitioners of TCM have long been treating depression with herbs that promote qi circulation in the liver. In this article, we offer a hypothesis stating the biochemical basis of the linkage between liver qi stagnation and depression. Liver qi is involved in the processing of macronutrients into molecules to fuel energy metabolism in brain neurons, as well as the synthesis of plasma proteins that maintain blood circulation to the brain, thereby enabling these fuel molecules to be delivered to the brain. In cases of liver qi stagnation, the failure in delivering sufficient fuel molecules to the brain disrupts mitochondrial ATP production in neurons. Because neurotransmitter release and neurotropin transport are driven by ATP, the deficiency in release and transport processes resulting from insufficient ATP production could lead to depression. Therefore, if liver qi stagnation is causally related to the pathogenesis of depression, the promotion of liver qi circulation by Chinese herbs might offer a promising prospect for the effective treatment of depression.

关键词： Mitochondrial ATP Liver “Qi” Stagnation Depression Traditional Chinese Medicine

Investigation of in Vitro and in Vivo Metabolism of Schisandrin B from Schisandrae Fructus by Liquid Chromatography Coupled Electrospray Ionization Tandem Mass Spectrometry

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Pharmacology & Pharmacy 2015年第8期6卷 363-373页

作者： Tianxiu Qian Pou Kuan Leong kam Ming ko Wan Chan Department of Chemistry The Hong Kong University of Science and Technology Hong Kong SAR Chin Department of Chemistry The Hong Kong University of Science and Technology Hong Kong SAR China Institute of Medicinal Plant Development Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China Division of Life Science The Hong Kong University of Science and Technology Hong Kong SAR China

Schisandrin B (Sch B) is one of the active dibenzocyclooctadiene lignans found in the Schisandrae Fructus. Experimental studies have shown that Sch B possesses various pharmacological properties, including anti-cancer, neuroprotective and nephroprotective activities. However, no detailed information on its biotransformation was reported in the literature. Here, we investigated the in vitro and in vivo metabolism of Sch B by using ultra-performance liquid chromatography coupled with tandem mass spectrometry. In vitro study detected and identified one oxygenated metabolite. Four metabolites were detected and identified from the in vivo study. The results indicated that the metabolism of Sch B mainly involved the demethylation of methoxy groups, the opening of five-member ring and the glucuronidation of metabolites in rats. The metabolites were identified for the first time by MS/MS analyses.

关键词： Schisandrin B Metabolism Disposition UPLC-MS/MS

‘Yang-Invigorating’ Chinese Tonic Herbs Enhance Mitochondrial ATP Generation in H9c2 Cardiomyocytes

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Chinese Medicine 2011年第1期2卷 1-5页

作者： Hoi Shan Wong Hoi Yan Leung kam Ming ko 不详

‘Yang-invigorating’ Chinese tonic herbs have been shown to enhance the myocardial mitochondrial ATP generation capacity in mice ex vivo. In the present study, we examined the effect of treatment with the methanol extract of ‘Yang-invigorating’ herbs on mitochondrial ATP generation capacity in H9c2 cardio-myocytes. The effect of ‘Yin-nourishing’ herbs was also investigated for comparison. The results indicated that all ‘Yang-invigorating’ Chinese tonic herbs dose-dependently enhanced the mitochondrial ATP genera-tion capacity in H9c2 cardiomyocytes. Three out of nine ‘Yin-nourishing’ herbs produced a dose-dependent stimulatory effect on ATP generation, but to lesser extents than those of Yang herbs. Results obtained from activity-directed fractionation of the three most potent ‘Yang-invigorating’ herbs suggested that the ATP-stimulating ingredients were rather water insoluble and largely resided in the butanol fraction. In con-clusion, ‘Yang-invigorating’ herbs invariably stimulated mitochondrial ATP generation capacity in H9c2 cardiomyocytes. The cell-based assay of ATP generation capacity may be used as pharmacological test for ‘Yang-invigorating’ Chinese tonic herbs.

关键词： Yang Yin Chinese Medicine ATP Mitochondria Cardiomyocytes