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Answering Reachability Queries on Incrementally Updated Graphs by Hierarchical Labeling Schema

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Journal of Computer Science & Technology 2016年第2期31卷 381-399页

作者： Tak-lam wong Department of Mathematics and Information Technology The Hong Kong Institute of Education Hong Kong China

we proposed a novel solution schema called the Hierarchical Labeling Schema （HLS） to answer reachability queries in directed graphs. Different from many existing approaches that focus on static directed acyclic graphs （DAGs）, our schema focuses on directed cyclic graphs （DCGs） where vertices or arcs could be added to a graph incrementally. Unlike many of the traditional approaches, HLS does not require the graph to be acyclic in constructing its index. Therefore, it could, in fact, be applied to both DAGs and DCGs. when vertices or arcs are added to a graph, the HLS is capable of updating the index incrementally instead of re-computing the index from the scratch each time, making it more efficient than many other approaches in the practice. The basic idea of HLS is to create a tree for each vertex in a graph and link the trees together so that whenever two vertices are given, we can immediately know whether there is a path between them by referring to the appropriate trees. we conducted extensive experiments on both real-world datasets and synthesized datasets. we compared the performance of HLS, in terms of index construction time, query processing time and space consumption, with two state-of-the-art methodologies, the path-tree method and the 3-hop method. we also conducted simulations to model the situation when a graph is updated incrementally. The performance comparison of different algorithms against HLS on static graphs has also been studied. Our results show that HLS is highly competitive in the practice and is particularly useful in the cases where the graphs are updated frequently.

关键词： graph indexing reachability query Hierarchical Labeling Schema (HLS) incremental update directed cyclic graph

Design and mathematical analysis of activating transcriptional amplifiers that enable modular temporal control in synthetic juxtacrine circuits

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Synthetic and Systems Biotechnology 2023年第4期8卷 654-672页

作者： Calvin lam Department of Biochemistry and Molecular Biology University of Nebraska Medical CenterOmahaNE68198USA.

The ability to control mammalian cells such that they self-organize or enact therapeutic effects as desired has incredible *** only would it further our understanding of native processes such as development and the immune response,but it would also have powerful applications in medical fields such as regenerative medicine and *** control is typically obtained by synthetic circuits that use synthetic receptors,but control remains *** synthetic juxtacrine receptors(SJRs)are widely used as they are fully modular and enable spatial control,but they have limited gene expression amplification and temporal *** these are integral facets to cell control,I therefore designed transcription factor based amplifiers that amplify gene expression and enable unidirectional temporal control by prolonging duration of target gene *** a validated in silico framework for SJR signaling,I combined these amplifiers with SJRs and show that these SJR amplifier circuits can direct spatiotemporal patterning and improve the quality of self-organization.I then show that these circuits can improve chimeric antigen receptor(CAR)T cell tumor killing against various heterogenous antigen expression *** amplifiers are flexible tools that improve control over SJR based circuits with both basic and therapeutic applications.

关键词： Synthetic biology Synthetic development Synthetic immunotherapy synNotch SNIPR Amplifiers Self-organization Temporal control Spatiotemporal control CAR T cell Synthetic receptors

Restriction of Intramolecular Motion(RIM):Investigating AIE Mechanism from Experimental and Theoretical Studies

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Chemical Research in Chinese Universities 2021年第1期37卷 1-15页

作者： ZHANG Jianyu ZHANG Haoke lam Jacky w.Y. TANG Ben Zhong Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and ReconstructionInstitute for Advanced Studyand Department of Chemical and Biological EngineeringThe Hong Kong University of Science&TechnologyClear Water BayKowloonHong KongP.R.China MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou310027P.R.China Center for Aggregation-Induced Emission SCUT-HKUST Joint Research InstituteState Key Laboratory of Luminescent Materials and DevicesSouth China University of TechnologyGuangzhou510640P.R.China Guangzhou Development District AIE InstituteGuangzhou510530P.R.China

Mechanistic studies promote scientific development from phenomena to ***-induced emission(AIE),as an unusual photophysical phenomenon,builds the bridge between molecular science and aggregate *** the twenty-year development of AIE,restriction of intramolecular motion(RIM)has been verified as the working mechanism of AIE *** this review,these mechanistic works about RIM are summarized from experimental and theoretical ***,the experimental studies are introduced from three parts:external rigidification,structural modification and structural *** the theoretical part,calculations on the low-frequency motion of AIEgens have been performed to prove the RIM *** virtue of the theoretical calculations,some new mechanisms are proposed to supplement the RIM,such as restriction of access to conical intersection,suppression of Kasha transition,restriction of access to dark state,*** is foreseeable that the RIM mechanism will unify the photophysical theories for both molecules and aggregates,and inspire more progress in aggregate science.

关键词： Aggregation-induced emission(AIE) Restriction of intramolecular motion Photophysical mechanism Aggregate science

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单核细胞增多性李斯特氏菌的分离

广东畜牧兽医科技 1987年第2期 44-46页

作者： JACOB w.lam 何美联美国Lowell大学健康职业学院 Ph.D

在牛奶的调查研究中发现,用选择性肉汤标明Stuart转移培养基在阳性牛奶样品中没有统计学显著差异。同样,当阳性牛奶样品用于两种倒平板的培养基时,也没有统计

关键词：李斯特氏菌食物牛肉琼脂 LEB 肉类李斯特氏菌病单核细胞增多

CARBAZOLE-CONTAINING HYPERBRANCHED POLY(ARYLENEETHYNYLENE)S:SYNTHESIS,CHARACTERIZATION,ANDPROPERTIES

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Chinese Journal of Polymer Science 2007年第6期25卷 641-649页

作者： Han Peng Xiu-wen Zheng Jacky w. Y. lam Ben-zhong Tang Institute of Material Science and Engineering South China University of Technology Guangzhou 510640 China Department of Chemistry Hong Kong University of Science ＆ Technology Clear Water Bay Kowloon Hong Kong China

New hyperbranched poly（aryleneethynylene）s containing carbazole moieties are synthesized in high yields （up to 87%） by polycyclotrimerization of 3,6-bis（4-ethynylphenyl）-9-octylcarbazole and its copolymerization with 1-octyne catalyzed by CpCo（CO）2 in THF. The structures and properties of the polymers are characterized and evaluated by IR, NMR, TGA, UV, photoluminescence, and cyclic voltammetry analyses. All the polymers are soluble in common organic solvents and show outstanding thermal stability （≥ 430℃）. They graphitize in high yields （up to 79%） when pyrolyzed at 800℃. Upon photoexcitation, the polymers emit a strong deep blue light of ca. 400 nm with quantum yields larger than 60%.

关键词： Acetylenes Carbazole Cyclopolymerization Hyperbranched Luminescence.

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Human induced pluripotent stem cell-derived therapies for regeneration after central nervous system injury

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Neural Regeneration Research 2025年第11期20卷 3063-3075页

作者： Stephen Vidman Yee Hang Ethan Ma Nolan Fullenkamp Giles w.Plant Department of Neuroscience Ohio State UniversityColumbusOHUSA

In recent years,the progression of stem cell therapies has shown great promise in advancing the nascent field of regenerative *** the non-regenerative nature of the mature central nervous system,the concept that“blank”cells could be reprogrammed and functionally integrated into host neural networks remained *** work has also demonstrated the ability of such cells to stimulate intrinsic growth programs in post-mitotic cells,such as *** embryonic stem cells demonstrated great potential in treating central nervous system pathologies,ethical and technical concerns *** barriers,along with the clear necessity for this type of treatment,ultimately prompted the advent of induced pluripotent stem *** advantage of pluripotent cells in central nervous system regeneration is multifaceted,permitting differentiation into neural stem cells,neural progenitor cells,glia,and various neuronal *** precise spatiotemporal application of extrinsic growth factors in vitro,in addition to microenvironmental signaling in vivo,influences the efficiency of this directed *** the pluri-or multipotency of these cells is appealing,it also poses the risk of unregulated differentiation and teratoma *** of the neuroectodermal lineage,such as neuronal subpopulations and glia,have been explored with varying degrees of *** the risk of cancer or teratoma formation is greatly reduced,each subpopulation varies in effectiveness and is influenced by a myriad of factors,such as the timing of the transplant,pathology type,and the ratio of accompanying progenitor ***,successful transplantation requires innovative approaches to develop delivery vectors that can mitigate cell death and support ***,host immune responses to allogeneic grafts must be thoroughly characterized and further developed to reduce the need for *** to a clinical setting wi

关键词： axon regeneration central nervous system regeneration induced pluripotent stem cells neurotrauma regenerative medicine spinal cord injury stem cell therapy

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Long-term temporal-spatial dynamics of marine coastal water quality in the Tolo Harbor,Hong Kong,China

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Journal of Environmental Sciences 2004年第1期16卷 161-166页

作者： XUFu-liu K.C.lam R.w.Dawson TAOShu Y.D.CHEN DepartmentofUrbanandEnvironmentalSciences＆MOELaboratoryforEarthSurfaceProcess PekingUniversityBeijing100871China DepartmentofGeographyandResourceManagement TheChineseUniversityofHongKongShatinNewTerritoriesHongKongChina

The long-term temporal and spatial dynamics of marine coastal water quality in Tolo Harbor, Hong Kong were explored. The Harbor is divided into three zones represented as Harbor, Buffer, and Channel Subzones. The time range for the study covers the period from the 1970s to the 1990s. The selected indicators for the comprehensive assessment of water quality consist of physical, chemical and biological aspects, including suspended solids(SS), Secchi disk depth(SD), 5-day biochemical oxygen demand(BOD\-5), total nitrogen(TN), total phosphorus(TP), faecal coliform, chlorophyll-a(Chl-a), and the number of red tide occurrences. The results indicated the presence of obvious temporal and spatial trends with regard to changes in water quality. Spatially, water quality in the Channel Subzone is the best, while that in the Harbor Subzone is the worst. On a temporal basis, the average trend from bad to good was 1980s>1990s>1970s as indicated by most of the selected water quality indicators. water quality during the late 1980s reached its worst level with the lowest SD, the highest BOD\-5, TN, TP, Chl-a concentrations, and the number of red tide occurrences. These long-term temporal-spatial water quality trends were also found in other studies of the Tolo Harbor. The large quantity of pollutants produced as a result of increasing population, industrial and commercial actives, and urbanization and industrialization trends in both Shatin and Tai Po seem to be primarily responsible for the changes in marine coastal water quality.

关键词： temporal-spatial dynamics water quality indicators pollution load Tolo Harbor

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Role of the forkhead transcription factor FOXO-FOXM1 axis in cancer and drug resistance

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Frontiers of Medicine 2012年第4期6卷 376-380页

作者： Fung Zhao Eric w.-F.lam Department of Surgery and Cancer Imperial College LondonHammersmith Hospital CampusLondon W120NNUK

The forkhead transcription factors FOXO and FOXM1 have pivotal roles in tumorigenesis and in mediating chemotherapy sensitivity and *** research shows that the forkhead transcription factor FOXM1 is a direct transcriptional target repressed by the forkhead protein FOXO3a,a vital downstream effector of the PI3K-AKT-FOXO signaling ***,FOXM1 and FOXO3a also compete for binding to the same gene targets,which have a role in chemotherapeutic drug action and *** understanding of the role and regulation of the FOXO-FOXM1 axis will impact directly on our knowledge of chemotherapeutic drug action and resistance in patients,and provide new insights into the design of novel therapeutic strategy and reliable biomarkers for prediction of drug sensitivity.

关键词： FOXO3a FOXM1 transcription factor cancer drug resistance tumorigenesis

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Phase change memory

Science China(Information Sciences) 2011年第5期54卷 1061-1072页

作者： lam Chung IBM Research T.J. Watson Research Center Yorktown Heights New York 10598 USA

Phase change memory (PCM) is a non-volatile solid-state memory technology based on the large resistivity contrast between the amorphous and crystalline states in phase change materials. we present the physics behind this large resistivity contrast and describe how it is being exploited to create high density PCM. we address the challenges facing this technology, including the design of PCM cells, fabrication, device variability, thermal cross-talk and write disturb. we discuss the scalability, assess the performance, and examine the reliability of PCM including data retention, multi-bit storage and endurance.

关键词： solid state memory non-volatile DRAM flash phase change resistive memory data retention write endurance solid-state drive computer memory