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Science China Chemistry 2024年第11期67卷 3791-3797页

作者： Debasis Pal Kirana DVeeranna Yuk fai wong PAndrew Evans Department of Chemistry Queen’s University90 Bader LaneKingstonK7L 3N6Canada Xiangya School of Pharmaceutical Sciences Central South UniversityChangsha410013China

The Reformatsky reagent derived from ethyl bromoacetate circumvents the challenge associated with the direct regio-and enantioselective iridium-catalyzed allylic alkylation with an unstabilized aliphatic ester enolate. Notably, this work represents the first example of using a Reformatsky reagent in a metal-allyl reaction, which permits the direct construction of enantioenriched β-stereogenic homoallylic esters without preactivation of the pronucleophile or post-reaction modification of the product(e.g., thermal decarboxylation of a 1,3-dicarbonyl). Moreover, the process allows the coupling of a broad range of sterically and electronically diverse electrophiles bearing aryl, heteroaryl and alkenyl derivatives, including the significantly more challenging alkyl-substituted allylic carbonates. The versatility of the ester product is exemplified by a series of functional group manipulations and the development of a concise and efficient enantioselective total synthesis of the natural product,(+)-descurainolide A. Finally, mechanistic studies indicate that the zinc enolate behaves as a soft nucleophile that undergoes outer-sphere alkylation.

关键词： allylic substitution asymmetric catalysis mechanistic studies natural product synthesis Reformatsky reagent

On limit behavior of quasi-local mass for ellipsoids at spatial infinity

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Communications in Theoretical Physics 2020年第1期72卷 102-110页

作者： Xiaokai He Leong-fai wong Naqing Xie School of Mathematics and Computational Science Hunan First Normal UniversityChangsha 410205China School of Mathematical Sciences Fudan UniversityShanghai 200433China

We discuss the spatial limit of the quasi-local mass for certain ellipsoids in an asymptotically flat static spherically symmetric *** ellipsoids are not nearly round but they are of interest as an admissible parametrized foliation defining the Arnowitt–Deser–Misner *** Hawking mass of this family of ellipsoids tends to-∞.In contrast,we show that the Hayward mass converges to a finite ***,a positive mass type theorem is *** limit of the mass has a uniform positive lower bound no matter how oblate these ellipsoids *** result could be extended for asymptotically Schwarzschild *** numerical simulation in the Schwarzschild spacetime illustrates that the Hayward mass is monotonically increasing near infinity.

关键词： quasi-local mass asymptotically flat limit behavior

A Survey on Recent Advances and Challenges in Reinforcement Learning Methods for Task-oriented Dialogue Policy Learning

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Machine Intelligence Research 2023年第3期20卷 318-334页

作者： Wai-Chung Kwan Hong-Ru Wang Hui-Min Wang Kam-fai wong The Systems Engineering and Engineering Management Department The Chinese University of Hong KongHong Kong 999077China

Dialogue policy learning(DPL)is a key component in a task-oriented dialogue(TOD)*** goal is to decide the next action of the dialogue system,given the dialogue state at each turn based on a learned dialogue *** learning(RL)is widely used to optimize this dialogue *** the learning process,the user is regarded as the environment and the system as the *** this paper,we present an overview of the recent advances and challenges in dialogue policy from the perspective of *** specifically,we identify the problems and summarize corresponding solutions for RL-based dialogue policy *** addition,we provide a comprehensive survey of applying RL to DPL by categorizing recent methods into five basic elements in *** believe this survey can shed light on future research in DPL.

关键词： Dialogue policy learning(DPL) task-oriented dialogue system(TOD) reinforcement learning(RL) dialogue system Markov decision process

Molecular dynamics-driven exploration of peptides targeting SARS-CoV-2,with special attention on ACE2,S protein,M^(pro),and PL^(pro):A review

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BIOCELL 2023年第8期47卷 1727-1742页

作者： MOHAMAD ZULKEFLEE SABRI JOANNA BOJARSKA fai-CHU wong TSUN-THAI CHAI Green Chemistry and Sustainable Technology Cluster Bioengineering SectionUniversiti Kuala LumpurMalaysian Institute of Chemical and Bioengineering Technology(UniKL MICET)Alor Gajah78000Malaysia Institute of General and Ecological Chemistry Faculty of ChemistryLodz University of TechnologyLodz90-924Poland Department of Chemical Science Faculty of ScienceUniversiti Tunku Abdul RahmanKampar31900Malaysia Center for Agriculture and Food Research Universiti Tunku Abdul RahmanKampar31900Malaysia

Molecular dynamics(MD)simulation is a computational technique that analyzes the movement of a system of particles over a given *** can provide detailed information about the fluctuations and conformational changes of biomolecules at the atomic level over *** recent years,MD has been widely applied to the discovery of peptides and peptide-like molecules that may serve as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)*** review summarizes recent advances in such explorations,focusing on four protein targets:angiotensin-converting enzyme 2(ACE2),spike protein(S protein),main protease(M^(pro)),and papain-like protease(PL^(pro)).These four proteins are important druggable targets of SARS-CoV-2 because of their roles in viral entry,maturation,and infectivity of the virus.A review of the literature revealed that ACE2,S protein,and M^(pro) have received more attention in MD research than PL^(pro).Inhibitors of the four targets identified by MD simulations included peptides derived from food and other bioresources,peptides designed using the targets as templates,and peptide-like molecules retrieved from *** of the inhibitors have yet to be validated in experimental assays for ***,the role of MD simulation as an efficient tool in the early stages of anti-SARS-CoV-2 drug discovery agents has been demonstrated.

关键词： COVID-19 Anti-SARS-CoV-2 agent Receptor binding domain Computational screening Drug discovery

Extended social force model with a dynamic navigation field for bidirectional pedestrian flow

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Frontiers of physics 2017年第5期12卷 181-189页

作者： Yan-Qun Jiang Bo-Kui Chen Bing-Hong Wang Weng-fai wong Bing-Yang Cao School of Science Southwest University of Science and Technology Mianyang 621000 China School of Computing National University of Singapore Singapore 117417 Singapore Department of Modern Physics and Nonlinear Science Center University of Science and Technology of China Hefei 230026 China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering Mechanics Tsinghua University Beijing 100084 China

An extended social force model with a dynamic navigation field is proposed to study bidirectional pedestrian movement. The dynamic navigation field is introduced to describe the desired direction of pedestrian motion resulting from the decision-making processes of pedestrians. The macroscopic fundamental diagrams obtained using the extended model are validated against camera-based observations. Numerical results show that this extended model can reproduce collective phenomena in pedestrian traffic, such as dynamic multilane flow and stable separate-lane flow. Pedestrians＇ path choice behavior significantly affects the probability of congestion and the number of self-organized lanes.

关键词： bidirectional pedestrian flow social force model dynamic navigation field collective phenomena complex systems

Molecular diagnosis of hepatocellular carcinoma:trends in biomarkers combination to enhance early cancer detection

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Hepatoma Research 2019年第3期5卷 20-33页

作者： Tiong Sun Chia Kwong fai wong John M.Luk Arbele Limited Hong Kong Science&Technology ParkShatinNew TerritoriesHong Kong

Despite of the advances in clinical imaging and applied research in proteomic biomarkers,liver cancer,especially hepatocellular carcinoma remains detected at the very late and advanced stages when curable treatments are unavailable and *** this regard,there are still huge unmet medical needs in developing and clinically validating those high-potential protein biomarkers preferably in liquid biopsy *** review provides a glimpse of emerging biomarkers together with detection tools and techniques which are potentially commercially available to the *** also discuss several diagnostic biomarkers having therapeutic potential for developing first-in-class medicines.

关键词： Hepatocellular carcinoma biomarkers targets α-fetoprotein cadherin-17 Yes-associated protein AXL Trop2

Seagrass proteins: Sources of health-promoting agents awaiting exploration?

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Food Innovation and Advances 2023年第1期2卷 18-20页

作者： Tsun-Thai Chai Jillian Lean Sim Ooi fai-Chu wong Department of Chemical Science Faculty of ScienceUniversiti Tunku Abdul Rahman31900 KamparMalaysia Center for Agriculture and Food Research Universiti Tunku Abdul Rahman31900 KamparPerakMalaysia Department of Geography Faculty of Arts and Social SciencesUniversiti Malaya50603 Kuala LumpurMalaysia

Seagrasses are marine plants that form economically and ecologically important ecosystems in coastal seas around the *** seaweeds,another group of marine flora,seagrasses are flowering and seed-bearing ***,there are only 72 known species of seagrasses,distributed over six bioregions,spanning from the Temperate North Atlantic to the Temperate Southern Ocean[1].This contrasts with 295,383 species of terrestrial flowering plants[2]and 225,000 species of seaweeds known to science[3].

关键词： ecosystems coastal marine

Time trend and characteristics of prostate cancer diagnosed in Hong Kong(China)in the past two decades

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Asian Journal of Andrology 2019年第1期21卷 104-106页

作者： Ho-fai wong Chi-Hang Yee Jeremy YC Teoh Samson YS Chan Peter KF Chiu Ho-Yuen Cheung Simon SM Hou Chi fai Ng S H.Ho Urology Centre Department of SurgeryThe Chinese University of Hong KongHong KongChina

Dear Editor, Prostate cancer is an important disease worldwide)In 2015 it was the third most common cancer diagnosed in male in Hong Kong (China) and the incidence of prostate cancer has been rising in the past 15 years. Meanwhile,with increasing public awareness,health education, presentation,and detection of prostate cancer maybe ***, we would like to review how the epidemiology of prostate cancer in Hong Kong (China)had changed in the past two decades.

关键词： prostate cancer Time trend

Antiviral activity of traditional Chinese medicinal plants Dryopteris crassirhizoma and Morus alba against dengue virus

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Journal of Integrative Agriculture 2020年第4期19卷 1085-1096页

作者： Maqsood MARYAM Kian Keong TE fai Chu wong Tsun Thai CHAI Gary K K LOW Seng Chiew GAN Hui Yee CHEE Department of Medical Microbiology and Parasitology Faculty of Medicine and Health SciencesUniversiti Putra MalaysiaSerdang 43400Malaysia Faculty of Natural Sciences SBK Women's University QuettaBalochistan 87300Pakistan Department of Chinese Medicine Faculty of Medicine and Health SciencesUniversiti Tunku Abdul RahmanSungai Long CampusKajang 43000Malaysia Department of Chemical Science Faculty of ScienceUniversiti Tunku Abdul Rahman(Kampar Campus)Kampar 31900Malaysia Department of Population Medicine Faculty of Medicine and Health SciencesUniversiti Tunku Abdul Rahman(Sungai Long Campus)Kajang 43000Malaysia Department of Pre-Clinical Sciences Faculty of Medicine and Health SciencesUniversiti Tunku Abdul Rahman(Sungai Long Campus)Kajang 43000Malaysia

Dengue virus(DENV) has emerged as a major virus that is spread by mosquitoes. Recently, it has spread to more than a hundred nations but continues to lack specific treatable medication. Many traditional Chinese medicinal(TCM) plants are in practice for dengue fever in dengue endemic regions. These traditional medicines persevere with treatments, which modern medicines lack. The study aims to substantiate the anti-dengue potential of some traditional herbs and make them available for further studies to facilitate TCM users. Twelve TCM plants aqueous extracts were evaluated, which are described as cool herbs used for the diseases with high fever. Lead plants were established through detailed in vitro foci forming unit reduction analysis(FFURA) against all four serotypes and validated through quantitative real-time RT-PCR(q RT-PCR). Four plants potentially inhibited the virus in primary phenotypic in vitro evaluation. Two lead plants Dryopteris crassirhizoma(DC) and Morus alba(MA) were identified with half minimal inhibitory concentration(IC50) 130 and 221 μg m L^-1, respectively, while the selectivity indices(SI) were 4.21 and 4.62, respectively. Lead plants equally inhibited all four serotypes of DENV. Time-of-addition analysis suggested that, DC was active at later stages of viral replication, whereas MA was active during the early stages and even showed some prophylactic activity. Liquid chromatography-mass spectrometry(HPLC/MS) analysis revealed presence of flavonoids. DC and MA are identified as potential anti-dengue plants, active against varied stages of dengue virus replication cycle. These results may serve as the base knowledge for further investigation on their combined treatments or integrative treatment with western medicines, which may improve the overall anti-dengue activity in future.

关键词： dengue virus traditional Chinese medicines TCM complementary medicines plant extracts anti-dengue

Impact of disease severity on gastric residual volume in critical patients

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World Journal of Gastroenterology 2011年第15期17卷 2007-2012页

作者： Chien-Wei Hsu Shu-Fen Sun David Lin Lee Shoa-Lin Lin Kam-fai wong Hsiu-Hua Huang Hung-Ju Li Department of Medicine School of Medicine National YangMing University Taipei Taiwan China Intensive Care Unit Department of Medicine Kaohsiung Veterans General Hospital Kaohsiung City 813 Taiwan China Department of Physical Medicine and Rehabilitation Kaohsiung Veterans General Hospital Kaohsiung City 813 Taiwan China Institute of Statistics National University of Kaohsiung Kaohsiung City 813 Taiwan China Department of Nutrition Kaohsiung Veterans General Hospital Kaohsiung City 813 Taiwan China

AIM: To investigate whether illness severity has an impact on gastric residual volume (GRV) in medical critically ill patients. METHODS: Medical intensive care unit (ICU) patients requiring nasogastric feeding were enrolled. Sequential Organ failure Assessment (SOFA) score was assessed immediately preceding the start of the study. Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱ scores were recorded on the first, fourth, seventh, and fourteenth day of the study period. GRV was measured every 4 h during enteral feeding. The relationship be-tween mean daily GRV and SOFA scores and the correlation between mean daily GRV and mean APACHE Ⅱ score of all patients were evaluated and compared. RESULTS: Of the 61 patients, 43 patients were survivors and 18 patients were non-survivors. The mean daily GRV increased as SOFA scores increased (P < 0.001, analysis of variance). Mean APACHE Ⅱ scores of all patients correlated with mean daily GRV (P = 0.011, Pearson correlation) during the study period. Patients with decreasing GRV in the first 2 d had better survival than patients without decreasing GRV (P = 0.017, log rank test). CONCLUSION: GRV is higher in more severely ill medical ICU patients. Patients with decreasing GRV had lower ICU mortality than patients without decreasing GRV.

关键词： Critical care Outcome Residual volume Severity of illness index Tube feeding