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Evolution of microstructure and tensile properties of cold-drawn hyper-eutectoid steel wires during post-deformation annealing

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Journal of Materials Science & Technology 2020年第6期41卷 1-11页

作者： Majid Jafari chan-Woo Bang Jong-chan Han Kyeong-Min Kim Seon-Hyeong Na chan-Gyung Park Byeong-Joo Lee Department of Materials Science and Engineering POSTECH Pohang 37673 South Korea

Manufacturing temperatures of severely cold-drawn hyper-eutectoid steel wires are sufficiently high to influence the mobility of dislocations and alloy elements,thereby affecting the materials’mechanical ***,we describe the evolution of microstructure and tensile strength of the as-drawn 3.45 GPa steel wire during post-deformation annealing for 30 min at 150-450℃.Annealing at 150℃raised the strength to 3.77 GPa by age-hardening through activation of dislocations pinning by carbon,while further temperature rising up to 450℃caused a severe loss of *** was proved that annealing at 300 and 450℃destabilizes the lamellar microstructure,promoting the formation of carbon-deficient(Fe,Mn,Cr)3 C-type cementite particles with preferentially rounded and partially faceted *** at 450℃yielded the accumulation of Mn and Cr at the ferrite/particle interfaces,and their concentrations at the interfaces were dependent on the interface structure;i.e.,lower concentrations at rounded interfaces(formed through capillarity–driven coarsening of the spheroidized cementite),and higher concentrations at faceted interfaces(that are initially existing in the as-drawn state).Our proof-of-principle observations,supported by thermodynamic calculations and kinetic assessments,provide a pathway for understanding the changes in microstructural and tensile properties during manufacturing of the hyper-eutectoid steel wires.

关键词： Three-dimensional atom probe(3DAP) High resolution transmission electron microscopy(HRTEM) Nano-grained low-carbon steel Annealing Tensile behavior

Urocortin and cardiovascular protection

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Acta Pharmacologica Sinica 2004年第3期25卷 3-11页

作者： Chi-wai LAU,Yau-chi chan,Suk-ying TSANG,Franky Leung chan The Chinese University of Hong Kong Hong Kong China Department of Anatomy The Chinese University of Hong Kong Hong Kong China Department of Anatomy The Chinese University of Hong Kong Hong Kong China Department of Anatomy The Chinese University of Hong Kong Hong Kong China Department of Anatomy

Urocortin and other hypothalamus corticotropin-releasing factor (CRF) polypeptides play biologically diverse roles in the stress, cardiovascular and inflammatory responses by acting on central and peripheral CRF receptors. Urocortin shows a significantly high sequence homology to CRF, and the concurrent expression of type-2 CRF (CRF2) receptors with urocortin in the heart suggests that urocortin may play a physiological role in the cardiac function. Urocortin is thought to be the endogenous agonist producing the cardiovascular actions previously attributed to CRF. This review highlights the current novel findings on the molecular and cellular mechanisms by which urocortin may exert its cardiovascular protective action.

关键词： urocortin corticotropin-releasing hormone vascular smooth muscle heart vasodilaion second messenger system protein kinases

An overview on the chemistry, pharmacology and anticancer properties of tetrandrine and fangchinoline(alkaloids) from Stephania tetrandra roots

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Journal of Integrative Medicine 2021年第4期19卷 311-316页

作者： Eric Wei Chiang chan Siu Kuin Wong Hung Tuck chan Faculty of Applied Sciences UCSI UniversityKuala Lumpur 56000Malaysia School of Foundation Studies Xiamen University MalaysiaSelangor 43900Malaysia Secretariat of the International Society for Mangrove Ecosystems(ISME) Faculty of AgricultureUniversity of the RyukyusOkinawa 903-0129Japan

Tetrandrine(TET) and fangchinoline(FAN) are dominant bisbenzylisoquinoline(BBIQ) alkaloids from the roots of Stephania tetrandra of the family Menispermaceae. BBIQ alkaloids comprise two benzylisoquinoline units linked by oxygen bridges. The molecular structures of TET and FAN are exactly the same, except that TET has a methoxy(-OCH3) group, while FAN has a hydroxyl(-OH) group at C7. In this overview,the current knowledge on the chemistry, pharmacology and anticancer properties of TET and FAN have been updated. The focus is on colon and breast cancer cells, because they are most susceptible to TET and FAN, respectively. Against colon cancer cells, TET inhibits cell proliferation and tumor growth by inducing apoptosis and G1 cell cycle arrest, and suppresses adhesion, migration and invasion of *** breast cancer cells, FAN inhibits cell proliferation by inducing apoptosis, G1-phase cell cycle arrest and inhibits cell migration. The processes involve various molecular mechanisms and signaling pathways. Some insights on the ability of TET and FAN to reverse multi-drug resistance in cancer cells and suggestions for future research are provided.

关键词： Tetrandrine Fangchinoline Alkaloids Pharmacology Anticancer Multi-drug resistance

Differentially weighted operator splitting Monte Carlo method for simulating complex aerosol dynamic processes

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Particuology 2018年第1期16卷 114-126页

作者： Hongmei Liu Tat Leung chan Department of Mechanical Engineering The Hong Kong Polytechnic University Kowloon Hong Kong China

A differentially weighted operator splitting Monte Carlo （DWOSMC） method is developed to solve com- plex aerosol dynamic processes by coupling the differentially weighted Monte Carlo method and the operator splitting technique. This method is validated by analytical solutions and a sectional method in different aerosol dynamic processes. It is first validated in coagulation and condensation processes, and nucleation and coagulation processes, and then validated through simultaneous nucleation, coagulation, and condensation processes. The results show that the DWOSMC method is a computationally efficient and quantitatively accurate method for simulating complex aerosol dynamic processes.

关键词： Differentially weighted Monte Carlo Operator splitting Aerosol dynamics Particle size distribution

Progress in self-powered sensors—Moving toward artificial intelligent and neuromorphic system

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Nano Research 2023年第9期16卷 11801-11821页

作者： Feng Wen chan Wang Chengkuo Lee Department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore Center for Intelligent Sensors and MEMS(CISM) National University of SingaporeSingapore 117608Singapore National University of Singapore Suzhou Research Institute(NUSRI) Suzhou 215123China NUS Graduate School-Integrative Sciences and Engineering Programme(ISEP) National University of SingaporeSingapore 119077Singapore

Wearable and flexible electronics are shaping our life with their unique advantages of light weight,good compliance,and desirable *** marching into the era of Internet of Things(IoT),numerous sensor nodes are distributed throughout networks to capture,process,and transmit diverse sensory information,which gives rise to the demand on self-powered sensors to reduce the power ***,the rapid development of artificial intelligence(AI)and fifth-generation(5G)technologies provides an opportunity to enable smart-decision making and instantaneous data transmission in IoT *** to continuously increased sensor and dataset number,conventional computing based on von Neumann architecture cannot meet the needs of brain-like high-efficient sensing and computing applications *** electronics,drawing inspiration from the human brain,provide an alternative approach for efficient and low-power-consumption information ***,this review presents the general technology roadmap of self-powered sensors with detail discussion on their diversified applications in healthcare,human machine interactions,smart homes,*** leveraging AI and virtual reality/augmented reality(VR/AR)techniques,the development of single sensors to intelligent integrated systems is reviewed in terms of step-by-step system integration and algorithm *** order to realize efficient sensing and computing,brain-inspired neuromorphic electronics are next briefly ***,it concludes and highlights both challenges and opportunities from the aspects of materials,minimization,integration,multimodal information fusion,and artificial sensory system.

关键词： wearable and flexible electronics self-powered sensors virtual reality/augmented reality(VR/AR)and artificial intelligence(AI)-enhanced system neuromorphic electronics

Does the gamma-ray signal from the central Milky Way indicate Sommerfeld enhancement of dark matter annihilation?

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Research in Astronomy and Astrophysics 2016年第10期16卷 116-120页

作者： Man-Ho chan Department of Science and Environmental Studies The Education University of Hong Kong

Recently, some studies showed that the GeV gamma-ray excess signal from the central Milky Way can be explained by the annihilation of -40 GeV dark matter through the bb channel. Based on the morphology of the gamma-ray flux, the best-fit inner slope of the dark matter density profile is γ = 1.26. However, recent analyses of the Milky Way dark matter profile favor γ = 0.6 - 0.8. In this article, we show that the GeV gamma-ray excess can also be explained by the Sommerfeld-enhanced dark matter annihilation through the bb channel with γ = 0.85 - 1.05. We constrain the parameters of the Sommerfeld-enhanced annihilation by using data from Fermi-LAT. We also show that the predicted gamma-ray fluxes emitted from dwarf galaxies generally satisfy recent upper limits on gamma-ray fluxes detected by Fermi-LAT.

关键词： (cosmology): dark matter

Casticin from Vitex species: a short review on its anticancer and anti-inflammatory properties

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Journal of Integrative Medicine 2018年第3期16卷 147-152页

作者： Eric Wei Chiang chan Siu Kuin Wong Hung Tuck chan Faculty of Applied Sciences UCSI University School of Science Monash University Secretariat of International Society for Mangrove Ecosystems Faculty of Agriculture University of the Ryukyus

This short review provides an update of the anticancer and anti-inflammatory properties of casticin from Vitex species. Casticin is a polymethylflavone with three rings, an orthocatechol moiety, a double bond,two hydroxyl groups and four methoxyl groups. Casticin has been isolated from various tissues of plants in the Vitex genus： fruits and leaves of V. trifolia, aerial parts and seeds of V. agnus-castus and leaves of ***. Studies have reported the antiproliferative and apoptotic activities of casticin from Vitex *** compound is effective against many cancer cell lines via different molecular mechanisms. Studies have also affirmed the anti-inflammatory properties of casticin, with several molecular mechanisms identified. Other pharmacological properties include anti-asthmatic, tracheospasmolytic, analgesic, antihyperprolactinemia, immunomodulatory, opioidergic, oestrogenic, anti-angiogenic, antiglioma, lung injury protection, rheumatoid arthritis amelioration and liver fibrosis attenuation activities. Clinical trials and commercial use of the casticin-rich fruit extract of V. agnus-castus among women with premenstrual syndrome were briefly discussed.

关键词： Vitexicarpin Polymethylflavone Apoptosis Molecular mechanisms

(-)Epicatechin induces and modulates endothelium-dependent relaxation in isolated rat mesenteric artery rings

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Acta Pharmacologica Sinica 2002年第12期23卷 135-139页

作者： chan Franky Leung China Chinese University of Hong Kong Department of Anatomy

AIM: The present study was aimed to examine the role of endothelial nitric oxide in the relaxant response to green tea (-)epicatechin and its modulation of endothelium-mediated relaxation in the isolated rat mesenteric artery rings. METHODS: changes in the isometric tension were measured with Grass force-displacement transducers. RESULTS: The (-)epicatechin-induced relaxation was largely dependent on the presence of intact endothelium and was re-versed by NG-nitro-L-arginine methyl ester 10 μmol/L or methylene blue 10 μmol/L, the inhibitors of nitric oxide-mediated relaxation. L-Arginine at 1 mmol/L antagonized the effect of L-NAME or methylene blue. Pretreatment of endothelium-intact rings with (-)epicatechin 10 μmol/L enhanced the relaxation induced by endothelium-dependent vasodilator, acetylcholine, while this concentration did not influence the endothelium-independent relaxation in-duced by sodium nitroprusside in the endothelium-denuded artery rings. CONCLUSION: The results indicate that the en

关键词： (-)epicatechin vascular endothelium nitric oxide muscle relaxation mesenteric artery rats

Relationship between the zonal displacement of the western Pacific subtropical high and the dominant modes of low-tropospheric circulation in summer

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Progress in Natural Science:Materials International 2008年第2期18卷 161-165页

作者： chan-Su Ryu Center for Asian Monsoon and Climate Environment Research Chosun University Gwangju Republic of Korea

The zonal displacement of the western Pacific subtropical high remarkably influences the climate anomalies in China. In this paper,a new zonal index of the subtropical high is defined by modifying previous indices,and is used to investigate the relationship between the zonal displacement of the subtropical high and the dominant modes of 850-hPa circulations. It is found that the zonal displacement of the subtropical high is significantly correlated with the first two leading modes of circulations. In particular,the correlation coefficient between the index and the time series associated with the second mode is as high as 0.78 in 1958-2003 (46 years). Since the second mode is not associated with significant anomalies of sea surface temperatures,the above results imply the diffculty in seasonal forecasting of the zonal displacement of the subtropical high. In addition,the interannual variability in the zonal displacement of the subtropical high has been considerably enhanced since 1978,due to the effects of both dominant modes,especially the second mode. This is likely to account for the frequent occurrence of anomalous climate in China during the recent two decades.

关键词： Western Pacific subtropical high General circulation Dominant mode Interannual variability Interdecadal variation