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SIRTain regulators of premature senescence and accelerated aging

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Protein & Cell 2015年第5期6卷 322-333页

作者： Shrestha Ghosh Zhongjun Zhou Department of Biochemistry The University of Hong Kong Hong Kong China Shenzhen institute of Innovation and Technology The University of Hong Kong Hong Kong China

The sirtuin proteins constitute class III histone deacetylases （HDACs）. These evolutionarily conserved NAD＋-dependent enzymes form an important component in a variety of cellular and biological processes with highly divergent as well as convergent roles in maintaining metabolic homeostasis, safeguarding genomic integrity, regulating cancer metabolism and also inflammatory responses. Amongst the seven known mammalian sirtuin proteins, SIRT1 has gained much attention due to its widely acknowledged roles in pro- moting longevity and ameliorating age-associated pathologies. The contributions of other sirtuins in the field of aging are also gradually emerging. Here, we summarize some of the recent discoveries in sirtuins biology which clearly implicate the functions of sirtuin proteins in the regulation of premature cellular senescence and accelerated aging. The roles of sirtuins in various cellular processes have been extrapolated to draw inter-linkage with anti-aging mechanisms. Also, the latest findings on sirtuins which might have potential effects in the process of aging have been reviewed.

关键词： sirtuins senescence premature aging longevity

A real-time forecast of tunnel fire based on numerical database and artificial intelligence

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Building Simulation 2022年第4期15卷 511-524页

作者： Xiqiang Wu Xiaoning Zhang Xinyan Huang Fu Xiao Asif Usmani Department of Building Services Engineering Hong Kong Polytechnic UniversityHong KongChina Research institute for Sustainable Urban Development Hong Kong Polytechnic UniversityHong KongChina

The extreme temperature induced by fire and hot toxic smokes in tunnels threaten the trapped personnel and *** alleviate the potential casualties,fast while reasonable decisions should be made for rescuing,based on the timely prediction of fire development in *** paper targets to achieve a real-time prediction(within 1 s)of the spatial-temporal temperature distribution inside the numerical tunnel model by using artificial intelligence(Al)methods.A CFD database of 100 simulated tunnel fire scenarios under various fire location,fire size,and ventilation condition is *** proposed Al model combines a Long Short-term Memory(LSTM)model and a Transpose Convolution Neural Network(TCNN).The real-time ceiling temperature profile and thousands of temperature-field images are used as the training input and *** show that the predicted temperature field 60 s in advance achieves a high accuracy of around 97%.Also,the Al model can quickly identify the critical temperature field for safe evacuation(i.e.,a critical event)and guide emergency responses and firefighting *** study demonstrates the promising prospects of Al-based fire forecasts and smart firefighting in tunnel spaces.

关键词： tunnel fires smart firefighting critical event CFD deep learning LSTM/TCNN

Energy performance analysis of multi-chiller cooling systems for data centers concerning progressive loading throughout the lifecycle under typical climates

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Building Simulation 2024年第10期17卷 1693-1708页

作者： Yingbo Zhang Hangxin Li Shengwei Wang Department of Building Environment and Energy Engineering The Hong Kong Polytechnic UniversityHong KongChina Research institute for Smart Energy The Hong Kong Polytechnic UniversityHong KongChina

The increasing demand for cooling energy in data centers has become a global *** studies lack a comprehensive analysis of the energy performance of widely used multi-chiller cooling systems in air-cooled data centers throughout their lifecycle,especially concerning progressive *** bridge this gap,this study conducts a thorough assessment of the energy performance of multi-chiller cooling systems throughout the entire ***,the impact of climate conditions on the energy efficiency of the cooling systems is analyzed,considering design variations for typical ***-chiller cooling system models are developed using the test data of cooling equipment and typical control *** energy performance of the cooling system is thoroughly analyzed under full-range cooling loads and climate *** show that free cooling time could differ up to 1442 hours at different part load ratios in the same ***,the cooling system’s coefficient of performance(COP)varies significantly,by up to 6,at different part load ratios,corresponding to a difference in power usage effectiveness(PUE)up to ***,the average cooling system COP throughout the lifecycle loading is found to be only 11.7,2.9 lower than the design system COP.

关键词： data center cooling system energy performance life-cycle operation power usage effectiveness(PUE) coefficient of performance(COP)

A gigaparsec-scale local void and the Hubble tension

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Science China(Physics,Mechanics & Astronomy) 2020年第9期63卷 7-15页

作者： QianHang Ding Tomohiro Nakama Yi Wang Department of Physics The Hong Kong University of Science and TechnologyHong KongChina Jockey Club institute for Advanced Study The Hong Kong University of Science and TechnologyHong KongChina

We explore the possibility of using a gigaparsec-scale local void to reconcile the Hubble *** a gigaparsec-scale void can be produced by multi-stream inflation where different parts of the observable universe follow different inflationary *** trajectories become different parts of the observable universe after inflation,when these scales return to the *** these trajectories have different e-folding numbers,these parts of the universe have different energy densities,possibly creating a local large *** impacts of such a void for cosmological observations are studied,especially those involving supernovae,Baryon Acoustic Oscillations(BAO)and the kinetic Sunyaev-Zel’dovich(kSZ)*** show that with the presence of the void,supernovae observations may be more consistent with the *** also estimate the impacts of a local large void on BAO *** addition,we show that a local large void and hence its capabilities to ease the Hubble tension is limited by the kSZ *** a benchmark model,a 1.7 Gpc scale void with boundary width 0.7 Gpc and density contrast-0.14 may ease the Hubble tension,evading the kSZ limit.

关键词： Hubble tension void cosmology inflation

SHAPE MEMORY EFFECT OF PU IONOMERS WITH IONIC GROUPS ON HARD-SEGMENTS

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Chinese Journal of Polymer Science 2006年第2期24卷 173-186页

作者：胡金莲 Kwok-wing Yeung institute of Textiles and Clothing hong kong Polytechnic University Hung HomHong KongChina

SMPU （shape memory polyurethane） non-ionomers and ionomers, synthesized with poly（c-caprolactone）（PCL）, 4, 4＇-diphenylmethane diisocyanate （MDI）, 1,4-butanediol （BDO）, dimethylolpropionic acid （DMPA） were measured with cyclic tensile test and strain recovery test. The relations between the structure and shape memory effect of these two series were studied with respect to the ionic group content and the effect of neutralization. The resulting data indicate that, with the introduction of asymmetrical extender, the stress at 100% elongation is decreased for PU non-ionomer and ionomer series, especially lowered sharply for non-ionomer series; the fixation ratio of ionomer series is not affected obviously by the ionic group content; the total recovery ratio of ionomer series is decreased greatly. After sufficient relaxation time for samples stretched beforehand, the switching temperature is raised slightly, whereas the recovery ratio measured with strain recovery test method is lowered with increased DMPA content. The characterization with FT-IR, DSC, DMA elucidated that, the ordered hard domain of the two series is disrupted with the introduction of DMPA which causes more hard segments to dissolve in soft phase; ionic groups on hard segment enhance the cohesion between hard segments especially at high ionic group content and significantly facilitate the phase separation compared with the corresponding non-ionomer at moderate ionic group content.

关键词： Polyurethane Ionomers Cyclic thermo-mechanical investigations Shape memory effect Cyclic tensile test Strain recovery test.

Structure and species composition of tree stands on verges and slopes along a major highway in hong kong

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Journal of Forestry Research 2023年第5期34卷 1347-1358页

作者： Louis Shing Him Lee Hao Zhang Kathy Tze Kwun Ng Shun Cheong Lo Alan Siu Lun Yu Faculty of Design and Environment Technological and HigherEducation Institute of Hong KongHong KongPeople’s Republic of China Landscape Division Highways DepartmentHong KongPeople’s Republic of China Greening Landscape and Tree Management SectionDevelopment BureauHong KongPeople’s Republic of China

Arboricultural research focusing on transport land use was lacking in hong *** highway slopes were registered in the Systematic Identification of Maintenance Responsibility of Slopes in the Territory(SIMAR),abbreviated as SIMAR *** aimed to analyze patterns in the structure and species composition of the tree stock along a highway in hong kong and examined how a slope registration system could help explain the characteristics of urban *** 53 slopes and 52 verges along San Tin Highway,hong kong were randomly *** trees on each slope and verge were collectively sampled as a tree *** variables,namely tree abundance,species richness,maximum tree height,Shannon-Wiener diversity,Simpson's dominance,and Pielou's evenness were measured for each *** addition,a limited visual tree risk assessment was *** 7,209 trees in 23 species were *** richness was low,ranging from one to eight species per *** and non-SIMAR slopes were *** slopes had significantly higher species richness,diversity,evenness but lower dominance,with mean difference of 1.41 species,0.17,0.17 *** slopes were associated with lower tree risk *** training regression models,boosting as an ensemble method arbitrarily raised the explanatory power and the predictive accuracy of some *** height,length,angle and area could be significant predictors of the biodiversity-related *** research can sample more habitat characteristics related to the structure and species composition of slopes and verges which were important components of urban forestry.

关键词： Highway greenery Roadside tree management Tree risk assessment Monospecific urban forest Slope geophysical environment Urban forests

Simultaneously improving mechanical properties and oxidation resistance of Ti-bearing high-entropy superalloys at intermediate temperature via silicon addition

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Journal of Materials Science & Technology 2023年第26期157卷 30-41页

作者： Shaofei Liu Weicheng Xiao Bo Xiao Jiang Ju Yinghao Zhou Yilu Zhao Zengbao Jiao Junhua Luan Qian Li Jinxiong Hou Ji-jung Kai Tao Yang Department of Mechanical Engineering City University of Hong KongHong Kong 999077China Center for Advanced Nuclear Safety and Sustainable Development City University of Hong KongHong Kong 999077China Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China School of Materials Science and Engineering Harbin Institute of TechnologyShenzhen 518055China Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China hong kong institute for Advanced Study City University of Hong KongHong Kong 999077China

Ti-bearing high-entropy superalloys(HESAs)often suffer from severe intergranular embrittlement and terrible oxidation degradation at intermediate *** we showcase that minor Si addition can effectively mitigate the intergranular embrittlement and improve the oxidation resistance of the a(Ni_(2)Co_(2)FeCr)_(92) Ti_(4)Al_(4) HESA at 700℃ *** analysis revealed that the intergranu-lar G phase induced by 2 at%Si addition can effectively suppress the inward diffusion of oxygen along grain boundaries at 700℃,thus enhancing the tensile ductility of the alloy from∼8.3%to∼13.4%.Be-sides,the 2 at%Si addition facilitated the formation of a continuous Al_(2)O_(3) layer during oxidation,con-tributing to a remarkable reduction in the growth rate of the oxide scale to a quarter of the Si-free *** results demonstrate that Si can be a favorable alloying element to design advanced HESAs with syn-ergistically improved thermal-mechanical performance.

关键词： High-entropy superalloy Mechanical property Oxidation behavior Intermediate temperature Silicon addition

Arabidopsis EXTRA-LARGE G PROTEIN 1(XLG1) functions together with XLG2 and XLG3 in PAMP-triggered MAPK activation and immunity

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Journal of Integrative Plant Biology 2023年第3期65卷 825-837页

作者： Yiping Wang Hailei Zhang Pengxi Wang Huan Zhong Wuzhen Liu Shoudong Zhang Liming Xiong Yingying Wu Yiji Xia Department of Biology Hong Kong Baptist UniversityHong Kong 999077China institute for Research and Continuing education Hong Kong Baptist UniversityShen Zhen 518057China State Key Laboratory of Agrobiotechnology The Chinese University of Hong KongHong Kong 999077China State Key Laboratory of Biological and Environmental Analysis Hong Kong Baptist UniversityHong Kong 999077China

Pattern-triggered immunity(PTI) is an essential strategy used by plants to deploy broad-spectrum resistance against pathogen attacks. Heterotrimeric G proteins have been reported to contribute to *** the three non-canonical EXTRA-LARGE G PROTEINs(XLGs) in Arabidopsis thaliana, XLG2 and XLG3 were shown to positively regulate immunity,but XLG1 was not considered to function in defense,based on the analysis of a weak xlg1 *** this study, we characterized the xlg1 xlg2 xlg3 triple knockout mutants generated from an xlg1 knockout allele. The strong xlg1 xlg2 xlg3 triple mutants compromised pathogen-associated molecular pattern(PAMP)-triggered activation of mitogen-activated protein kinases(MAPKs) and resistance to pathogen infection. The three XLGs interacted with MAPK cascade proteins involved in defense signaling, including the MAPK kinase kinases MAPKKK3 and MAPKKK5, the MAPK kinases MKK4 and MKK5, and the MAPKs MPK3 and MPK6. Expressing a constitutively active form of MKK4 restored MAPK activation and partially recovered the compromised disease resistance seen in the strong xlg1 xlg2 xlg3 triple mutant. Furthermore, mutations of all three XLGs largely restored the phenotype of the autoimmunity mutant bak1-interacting receptor-like kinase 1. Our study reveals that all three XLGs function redundantly in PAMP-triggered MAPK activation and plant immunity.

关键词： Arabidopsis heterotrimeric G protein MAPK cascade plant immunity XLG1 XLG2

The Tribulations of a Chinese in China:Verne and the Celestial Empire

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外国语 2006年第5期29卷 63-79页

作者： William Butcher the Language Centres at the hong kong institute for Vocational education

In Around the World in Eighty Days, Jules Verne presents chapters describing nineteenth-century hong kong. In the pioneering Tribulations of a Chinese in China he creates a complex Chinese hero and provides a relatively accurate description of contemporary conditions, based on first-hand sources. Verne’s manuscript and correspondence with his publisher show, however, that this novel underwent considerable changes before publication.

关键词： Jules Verne China French literature literary criticism inception