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the evolution and refinement of vasoepididymostomy techniques

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Asian Journal of Andrology 2013年第1期15卷 49-55页

作者： Peter t chan Department of Urology Royal Victoria Hospital McGill University Health Center Montreal Quebec H3A 1A1 Canada

Obstructive azoospermia secondary to epididymal obstruction can be corrected by microsurgical reconstruction with vasoepididymostomy （VE）. Although alternative management such as epididymal or testicular sperm aspiration in conjunction with intracytoplasmic sperm injection is feasible, various studies have established the superior cost-effectiveness of VE as a treatment of choice. Microsurgical VE is considered one of the most technically challenging microsurgeries. Its success rate is highly dependent on the skills and experience of the surgeons. Various techniques have been described in the literature for VE. We have pioneered a technique known as longitudinal intussusception VE （LIVE） in which the epididymal tubule is opened longitudinally to obtain a larger opening to allow its tubular content to pass through the anastomosis. Our preliminary data demonstrated a patency rate of over 90%. this technique has been widely referenced in the recent literature including robotic-assisted microsurgery. the history of the development of different VE approaches, the oreoDerative evaluation along with the techniaues of various VE will be described in this article.

关键词： longitudinal intussusception vasoepididymostomy (LIVE) intracytoplasmic sperm injection (ICSI) male infertility microsurgery obstructive azoospermia vasoepididymostomy (VE)

Dirac-like cone-based electromagnetic zero-index metamaterials

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Light(Science & Applications) 2021年第11期10卷 2048-2066页

作者： Yang Li C.t.chan Eric Mazur State Key Laboratory of Precision Measurement technology and Instrument Department of Precision InstrumentTsinghua UniversityBeijingChina Department of Physics Hong Kong University of Science and TechnologyKowloonHong KongChina John A.Paulson School of Engineering and Applied Sciences Harvard UniversityCambridgeMAUSA

Metamaterials with a Dirac-like cone dispersion at the center of the Brillouin zone behave like an isotropic and impedance-matched zero refractive index material at the Dirac-point *** metamaterials can be realized in the form of either bulk metamaterials with efficient coupling to free-space light or on-chip metamaterials that are efficiently coupled to integrated photonic *** materials enable the interactions of a spatially uniform electromagnetic mode with matter over a large area in arbitrary *** unique optical property paves the way for many applications,including arbitrarily shaped high-transmission waveguides,nonlinear enhancement,and phase mismatch-free nonlinear signal generation,and collective emission of many *** review summarizes the Dirac-like cone-based zero-index metamaterials’fundamental physics,design,experimental realizations,and potential applications.

关键词： index collective realization

Systemic treatment for inoperable pancreatic adenocarcinoma: review and update

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Chinese Journal of Cancer 2014年第6期33卷 267-276页

作者： Stephen L.chan Sin t.chan Eric H.chan Zhe-Xi He State Key Laboratory in Oncology in South China Sir YK Pao Center for Cancer Department of Clinical Oncology and Hong Kong Cancer Institute and Prince of Wales Hospital The Chinese University of Hong Kong the Faculty of Medicine The Chinese University of Hong Kong

there have been many clinical trials conducted to evaluate novel systemic regimens for unresectable pancreatic cancer. However, most of the trial results were negative, and gemcitabine monotherapy has remained the standard systemic treatment for years. A number of molecular targeted agents, including those against epidermal growth factor receptor and vascular endothelial growth factor receptors, have also been tested. In recent years, there have been some breakthroughs in the deadlock: three regimens, namely gemcitabine-erlotinib, FOLFIRINOX, and gemcitabine-nab-paclitaxel, have been shown to prolong the overall survival of patients when compared with gemcitabine monotherapy. In addition, emerging data suggested that the membrane protein human equilibrative nucleotide transporter 1 is a potential biomarker with which to predict the efficacy of gemcitabine. Here we review the literature on the development of systemic agents for pancreatic cancer, discuss the current choices of treatment, and provide future directions on the development of novel agents.

关键词：全身治疗胰腺癌审查血管内皮生长因子受体表皮生长因子受体手术临床试验靶向药物

Hidden-symmetry-enforced nexus points of nodal lines in layer-stacked dielectric photonic crystals

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Light(Science & Applications) 2020年第1期9卷 315-324页

作者： Zhongfei Xiong Ruo-Yang Zhang Rui Yu C.t.chan Yuntian Chen School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China Department of Physics The Hong Kong University of Science and TechnologyClear Water BayHong KongChina School of Physics and technology Wuhan UniversityWuhan 430072China Wuhan National Laboratory of Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China

It was recently demonstrated that the connectivities of bands emerging from zero frequency in dielectric photonic crystals are distinct from their electronic counterparts with the same space *** discover that in an AB-layerstacked photonic crystal composed of anisotropic dielectrics,the unique photonic band connectivity leads to a new kind of symmetry-enforced triply degenerate points at the nexuses of two nodal rings and a Kramers-like nodal *** emergence and intersection of the line nodes are guaranteed by a generalized 1/4-period screw rotation symmetry of Maxwell’s *** bands with a constant kz and iso-frequency surfaces near a nexus point both disperse as a spin-1 Dirac-like cone,giving rise to exotic transport features of light at the nexus *** show that spin-1 conical diffraction occurs at the nexus point,which can be used to manipulate the charges of optical *** work reveals that Maxwell’s equations can have hidden symmetries induced by the fractional periodicity of the material tensor components and hence paves the way to finding novel topological nodal structures unique to photonic systems.

关键词： symmetry nodal dielectric

Long-term survival after intraluminal brachytherapy for inoperable hilar cholangiocarcinoma: A case report

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World Journal of Gastroenterology 2005年第20期11卷 3161-3164页

作者： Siu-Yin chan Ronnie t. Poon Kelvin K. Ng Chi-Leung Liu Raymond t. chan Sheung-tat Fan Centre for the Study of Liver Disease and Department of Surgery the University of Hong Kong PokfulamHong Kong China Department of Clinical Oncology the University of Hong Kong Pokfulam Hong Kong China

Surgical resection with a tumor-free margin is the onlycurative treatment for hilar cholangiocarcinoma (Klatskin tumor). However, over half of the patients present late with unresectable tumors. Radiotherapy using external beamirradiation or intraluminal brachytherapy (ILBt) has been used to treat unresectable hilar cholangiocarcinoma with satisfactory outcome. We reported a patient with unresectable hilar cholangiocarcinoma surviving more than 6 years after combined external beam irradiation and ILBt.

关键词： Brachytherapy Hilar cholangiocarcinoma

Computing Quantum Bound States on triply Punctured two-Sphere Surface

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Chinese Physics Letters 2016年第9期33卷 1-4页

作者： K.t.chan H.Zainuddin K.A.M.Atan A.A.Siddig Department of Physics Faculty of ScienceUniversiti Putra Malaysia Institute for Mathematical Research Universiti Putra Malaysia Department of Physics and Astronomy College of ScienceKing Saud University

We are interested in a quantum mechanical system on a triply punctured two-sphere surface with hyperbolic metric. the bound states on this system are described by the Maass cusp forms （MCFs） which are smooth square integrable eigenfunctions of the hyperbolic Laplacian. their discrete eigenvalues and the MCF are not known analytically. We solve numerically using a modified Hejhal and then algorithm, which is suitable to compute eigenvalues for a surface with more than one cusp. We report on the computational results of some lower-lying eigenvalues for the triply punctured surface as well as providing plots of the MCF using GridMathematica.

关键词： of in for Computing Quantum Bound States on triply Punctured two-Sphere Surface is on MCF

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桥梁时变移动车载的间接识别

振动工程学报 2005年第1期18卷 99-102页

作者：余岭 chan t H t 长江科学院爆破与振动研究所湖北武汉430010 Department of Civil and Structural Engineering theHong Kong Poly technic University Hung HomKowloonHong Kong

针对桥梁上时变移动车载 ,提出了两种桥梁模型、四种移动车载间接识别方法和两种不同解决方案 ,并通过模型实验对上述不同桥梁移动车载解决方案进行验证。仿真和试验结果表明 :虽然各种车桥参数对识别结果都有不同程度的影响 ,但每种解... 详细信息

针对桥梁上时变移动车载 ,提出了两种桥梁模型、四种移动车载间接识别方法和两种不同解决方案 ,并通过模型实验对上述不同桥梁移动车载解决方案进行验证。仿真和试验结果表明 :虽然各种车桥参数对识别结果都有不同程度的影响 ,但每种解决方案都能有效识别桥梁移动车载且以“时域法”和“频时域法”识别精度较高、实用性较强 ,可推荐用于现场桥梁移动车载识别。

关键词：动车桥梁车桥车载时变时域法模型实验移动解决方案识别

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阿司匹林用于结直肠癌预防(英文)

化学进展 2013年第9期25卷 1450-1453页

作者： Andrew t.chan Division of Gastroenterology Massachusetts General Hospital

一直以来,实验室研究、流行病学调查和最近的随机对照临床试验都表明阿司匹林可以降低结直肠癌的风险。出于对潜在的副作用如胃肠道出血的考虑,此前美国预防医学工作组的专家曾经建议对于处于平均风险的普通人群不要常规使用阿司匹林来... 详细信息

一直以来,实验室研究、流行病学调查和最近的随机对照临床试验都表明阿司匹林可以降低结直肠癌的风险。出于对潜在的副作用如胃肠道出血的考虑,此前美国预防医学工作组的专家曾经建议对于处于平均风险的普通人群不要常规使用阿司匹林来预防结直肠癌。然而,最近的高质量证据表明,阿司匹林不仅可以预防结直肠癌,对其它癌症也有预防作用。因此,值得重新考虑阿司匹林是否可常规用于癌症预防这个问题。本文总结了这些支持阿司匹林化学预防功效的有力证据,认为阿司匹林广泛的抗癌效应加上它在预防心血管疾病中的作用可能推动阿司匹林在众多患者中的长期应用。

关键词：阿司匹林结直肠癌随机对照试验非阿司匹林非甾体抗炎药化学预防

Separation and extraction of bridge dynamic strain data

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Frontiers of Structural and Civil Engineering 2009年第4期3卷 395-400页

作者： Baijian WU Zhaoxia LI Ying WANG t.H.t.chan Department of Engineering Mechanics Southeast UniversityNanjing 210018China Department of Civil and Structural Engineering the Hong Kong Polytechnic UniversityHong KongChina

through comparing the measured data of dynamic strains due to loading and temperature by the stain gauge and temperature sensor at the same location,the information in the strain data was divided into three parts in the frequency domain by using the defined index named power spectral density(PSD)-ratio *** three parts are dominated respectively by temperature varying,stresses,and noises and thus can be distinguished from the determined the separatrix ***,a simple algorithm was developed to separate the three types of information and to extract the strain caused mainly by structural *** an application of the proposed method,the effect of strain deformation and noises on the fatigue assessment was investigated based on the separated *** results show that,the determined values of separatrix frequencies are valuable for the monitoring data from other *** algorithm is a multiresolution and hierarchical method,which has been validated as a simple and effective method for data analyses,and is suitable for the compression and preprocessing of the great amount monitoring data and easy to be integrated into the structural health monitoring(SHM)soft *** strain due to temperature varying attributes a little to the errors of fatigue assessment;however,the noises or random disturbance existed in the monitoring data have much responsibility for the errors,and the main reason is that the random disturbance shifts the real strain/stress amplitude picked up by real structural stress or strain.

关键词： structural health monitoring(SHM) structural strain information separation information extraction fatigue assessment