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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

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

Synthesis and properties of poly(1-phenyl-1-octyne)s containing stereogenic and chromophoric pendant groups

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Science China Chemistry 2009年第10期52卷 1691-1702页

作者： lam Jacky W.y. JIM Cathy K.W. KWOK Hoi Sing Department of Chemistry The Hong Kong University of Science & Technology Center for Display Research The Hong Kong University of Science & Technology

poly(1-phenyl-1-octyne)s containing different stereogenic and chromophoric pendants {-[(C6H13)C= C(C6H4-p-CO2-R)] n -R = [(1S)-endo]-(?)-borneyl (P3), (1R,2S,5R)-(?)-menthyl (P4), -C6H4-p-(1R,2S,5R)-(?)-menthyl (P5), 2-napthyl (P6), 4-biphenylyl (P7)} have been designed and synthesized. The polymers are prepared in moderate yields by WCl6-Ph4Sn and possess high molecular weights (M w up to 64000). The structures and properties of the polymers are characterized and evaluated by NMR, TGA, UV, CD, PL, and EL analyses. All the polymers are thermally stable and their temperatures for 5% weight loss locate in the range of 300 to 416°C under nitrogen. The energy band gaps of all the polymers are ～3.0 eV. polymers P4 and P5 show CD absorptions associated with the helicity of the polymer segments. Excitation of the THF solutions of P3–P7 by UV irradiation gives strong blue lights of ～485 nm with quantum yields higher than 20%. The thin films of the polymers also emit in the same spectral region, indicative of little aggregation-caused quenching of light emission. Multilayer EL devices with a configuration of ITO/polymer:PVK/BCP/Alq3/LiF/Al are constructed, which emit blue lights of ～487 nm. The maximum luminance and external quantum efficiency vary with the pendant groups, with P6 exhibiting the highest external quantum efficiency of 0.16%. The spectra stability of the EL devices is outstanding and the EL peak maximum experiences little change with the applied voltage.

关键词： chiral photoluminescence polyacetylene electroluminescence helicity

An AlGaN/GaN HEMT with a reduced surface electric field and an improved breakdown voltage

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Chinese Physics B 2012年第8期21卷 360-364页

作者：谢刚 Edward Xu Niloufar Hashemi 张波 Fred y.Fu Wai Tung ng The Edward S.Rogers Sr.Electrical and Computer Engineering Department University of Toronto State key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China Crosslight Software Inc.Burnaby BCCanada

A reduced surface electric field in an AlGaN/GaN high electron mobility transistor （HEMT） is investigated by employ.ng a localized Mg-doped layer under the two-dimensional electron gas （2-DEG） channel as an electric field shaping layer. The electric field strength around the gate edge is effectively relieved and the surface electric field is distributed evenly as compared with those of HEMTs with conventional source-connected field plate and double field plate structures with the same device physical dimensions. Compared with the HEMTs with conventional sourceconnected field plates and double field plates, the HEMT with a Mg-doped layer also shows that the breakdown location shifts from the surface of the gate edge to the bulk Mg-doped layer edge. By optimizing both the length of Mg-doped layer, Lm, and the doping concentration, a 5.5 times and 3 times the reduction in the peak electric field near the drain side gate edge is observed as compared with those of the HEMTs with source-connected field plate structure and double field plate structure, respectively. In a device with VGS = -5 V, Lm 1.5 m, a peak Mg doping concentration of 8×10^17 cm-3 and a drift region length of 10 m, the breakdown voltage is observed to increase from 560 V in a conventional device without field plate structure to over 900 V without any area overhead penalty.

关键词： AlGaN/GaN HEMT reduced surface electric field Mg-doped layer breakdown voltage

Clinically relevant factors associated with quantitative optical coherence tomography angiography metrics in deep capillary plexus in patients with diabetes

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Eye and Vision 2020年第1期7卷 64-74页

作者： Fang yao Tang Erica O.Chan Zihan Sun Raymond Wong Jerry Lok Simon Szeto Jason C.Chan Alexander lam Clement C.Tham Danny S.ng Carol y.Cheung Department of Ophthalmology and Visual Sciences The Chinese University of Hong KongHong Kong Special Administrative RegionKowloonChina Hong Kong Eye Hospital Hong Kong Special Administrative RegionKowloonChina CUHK Eye Centre Hong Kong Eye Hospital147K Argyle StreetKlnKowloonHong KongChina

Background:To test clinically relevant factors associated with quantitative artifact-free deep capillary plexus(DCP)metrics in patients with diabetes mellitus(DM).Methods:563 eligible eyes(221 with no diabetic retinopathy[DR],135 with mild DR,130 with moderate DR,and 77 with severe DR)from 334 subjects underwent optical coherence tomography-angiography(OCT-A)with a swept-source OCT(Triton DRI-OCT,Topcon,Inc.,Tokyo,Japan).Strict criteria were applied to exclude from analysis those DCP images with artifacts and of poor quality,including projection artifacts,motion artifacts,blurriness,signal loss,B-scan segmentation error,or low-quality score.A customized MATLAB program was then used to quantify DCP morphology from the artifact-free DCP images by calculating three metrics:foveal avascular zone(FAZ),vessel density(VD),and fractal dimension(FD).Results:166(29.5%)eyes were excluded after quality control,leaving in the analysis 397 eyes(170 with no DR,101 with mild DR,90 with moderate DR,36 with severe DR)from 250 *** the multiple regression models,larger FAZ area was associated with more severe DR(β=0.687;p=0.037),shorter axial length(AL)(β=−0.171;p=0.003),thinner subfoveal choroid thickness(β=−0.122;p=0.031),and lower body mass index(BMI)(β=−0.090;p=0.047).Lower VD was associated with more severe DR(β=−0.842;p=0.001),shorter AL(β=0.107;p=0.039),and poorer visual acuity(VA)(β=−0.133;p=0.021).Lower FD was associated with more severe DR(β=−0.891;py,AL,subfoveal choroidal thickness,age,and BMI in diabetic *** effects of ocular and systemic factors should be considered for meaningful interpretations of DCP changes in DM patients.

关键词： Optical coherence tomography angiography Diabetic retinopathy Deep capillary plexus Visual acuity

On business cycle forecasting

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Frontiers of Business Research in China 2020年第3期14卷 324-349页

作者： Huiwen Lai Eric C.y.ng School of Accounting and Finance Faculty of BusinessHong Kong Polytechnic UniversityHong KongChina Department of Economics Hong Kong University of Science and TechnologyHong KongChina

We develop a recession forecasting framework using a less restrictive target variable and more flexible and inclusive specification than those used in the *** target variable captures the occurrence of a recession within a given future period rather than at a specific future point in time(widely used in the literature).The modeling specification combines an autoregressive Logit model capturing the autocorrelation of business cycles,a dynamic factor model encompassing many economic and financial variables,and a mixed data sampling regression incorporating common factors with mixed sampling *** model gene rates significantly more accurate forecasts for *** with smaller forecast errors and stronger early signals for the turning points of business cycles than those gene rated by existing models.

关键词： Recession forecasting Business cycle Autoregressive Logit Dynamic factor Mixed data sampling(MIDAS)regression

Impact of microbiota on female fertility and gynecological problems

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生殖与发育医学(英文) 2024年第4期8卷 242-251页

作者： Kumar Manish Jiang Luhan Lai Hoi-lam Lee Cheuk-Lun ng Ernest H. y. yeung William S. B. Lee Kai-Fai Department of Obstetrics and Gynaecology LKS Faculty of Medicine The University of Hong Kong Hong Kong SAR China Shenzhen Key Laboratory of Fertility Regulation. The University of Hong Kong-Shenzhen Hospital Shenzhen China

The uterus was previously considered a sterile environment for embryo implantation and fetal growth; however, evidence showed that different microorganisms in the female reproductive tract may regulate human fertility. TheLactobacillus family is among the most prevalent bacteria in the vagina and uterus of the female reproductive system. Interestingly, aLactobacillus-dominated (LD) uterine environment is associated with better pregnancy outcomes. Nevertheless, the mechanism by which an LD environment improves pregnancy outcomes is unknown. In the uterus, many commensal bacteria (eg,Bifidobacterium, Prevotella,Enterobacter,Streptococcus, andStaphylococcus) produce short-chain fatty acids (SCFAs), including acetate, butyrate, and propionate. SCFAs are crucial in modulating cytokine production (eg, IL-6 and IL-10) and immune cell populations (eg, T cells and macrophages) during embryo implantation and gynecological diseases. This minireview provides an overview of the roles of lactobacilli and SCFAs in female fertility and related diseases.

关键词： Endometrial receptivity Embryo implantation Lactobacillus Short-chain fatty acids Infertility Gynecological diseases

Synthesis, Crystal and Molecular Structure and Biological Activity of Dimethyl Trans-3-(2-bromophenyl)-2-methylisoxazolidine-4,5-dicarboxylate

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Chinese Journal of Structural Chemistry 2012年第9期31卷 1251-1262页

作者： yÜKSEKTEPE Çigdem ÖZKAN Hamdi yAVUZ Serkan yANMAZ Volkan DISLI Ali BÜyÜKGÜngÖR Orhan Department of Physics Faculty of ScienceCankiri Karatekin University Department of Chemistry Faculty of ScienceCankiri Karatekin University Department of Chemistry Faculty of Arts and SciencesGazi University Department of Physics Faculty of Arts and SciencesOndokuz Mayis University

The compound of dimethyl trans-3-（2-bromophenyl）-2-methylisoxazolidine-4,5-dicarboxylate has been synthesized and characterized by IR, 1H-NMR, 13C-NMR, 2D-NMR （COSy, NOESy, HMQC, HMBC） and UV-vis. spectroscopy techniques and single-crystal X-ray diffraction （XRD）. The biological activities of the title compound have been investigated in detail. The new compound crystallizes in monoclinic, space group C2/c with a = 26.9263（10）, b = 7.0970（2）, c = 19.8554（7）？, and β = 126.630（2）. In addition to the single crystal structure, the molecular geometry, vibrational frequencies, chemical shifts, molecular electrostatic potential and frontier molecular orbital analysis of the title compound in the ground state have been calculated by Density Functional Theory （DFT） method.

关键词： ab initio calculations isoxazolidine spectroscopy X-ray structure determination

Packing and film thickness theories for the mix design of high-performance concrete

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2016年第10期17卷 759-781页

作者： Pui-lam ng Albert Kwok-Hung KWAN Leo Gu LI Department of Civil Engineering The University of Hong Kong Pokfulam Hong Kong China Faculty of Civil Engmeering Vilnius Gediminas Technical University Vilnius Lithuania Schoo of Cicil and Transportation Engmeering Guangdong University of Technology Guangzhou 510006 China

A high-performance concrete （HPC） is required to have superior performance in various aspects such as workability,strength, durability, dimensional stability, segregation stability, and passing ability. The mix design of HPC is rather complicatedbecause the number of ingredients in HPC is usually more than those in conventional concrete and some of the required propertiesare conflicting with each other in the sense that improvement in one property would at the same time cause impairment of anotherproperty. However, there is still lack of understanding regarding how the various mix parameters should be optimised forachieving best overall performance. Most practitioners are still conducting mix design primarily through trial concrete mixing,which is laborious, ineffective, and often unable to timely respond to fluctuations in the properties of raw materials. To addressthese issues, the authors have been developing the packing and film thickness theories of concrete materials, in order to revamp themix design philosophy of HPC in terms of the water film thickness （WFT）, paste film thickness （PFT）, and mortar film thickness（MFT） in the concrete. Based on the findings from an extensive experimental programme, suitable ranges ofWFT, PFT, and MFThave been recommended.

关键词： Concrete mix design, Concrete science, Film thickness, High-performance concrete, Packing density, Sustainability

Precision Bionanomaterials Made from Biomacromolecules

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Precision Bionanomaterials Made from Biomacromolecules