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Breast cancer resistance protein （Bcrp） and the testis--an unexpected turn of events

Asian Journal of Andrology 2013年第4期15卷 455-460,I0006页

作者： Xiaojing Qiin yan-Ho cheng Dolores D Mruk C yan cheng The Mary M. Wohlford Laboratory for Male Contraceptive Research Center for Biomedical Research Population Council New York NY 10065 USA Department of Anatomy Histology and Embryology School of Basic Medicine Peking Union Medical College Beijing 100005 China and Richmond University Medical Center Staten Island NY 10301 USA

Breast cancer resistance protein （Bcrp） is an ATP-dependent efflux drug transporter. It has a diverse spectrum of hydrophilic and hydrophobic substrates ranging from anticancer, antiviral and antihypertensive drugs, to organic anions, antibiotics, phytoestrogens （e.g., genistein, daidzein, coumestrol）, xenoestrogens and steroids （e.g., dehydroepiandrosterone sulfate）. Bcrp is an integral membrane protein in cancer and normal cells within multiple organs （e.g., brain, placenta, intestine and testis） that maintains cellular homeostasis by extruding drugs and harmful substances from the inside of cells. In the brain, Bcrp is a major component of the blood- brain barrier located on endothelial cells near tight junctions （TJs）. However, Bcrp is absent at the Sertoli cell blood-testis barrier （BTB）; instead, it is localized almost exclusively to the endothelial TJ in microvessels in the interstitium and the peritubular myoid cells in the tunica propria. Recent studies have shown that Bcrp is also expressed stage specifically and spatiotemporally by Sertoli and germ cells in the seminiferous epithelium of rat testes, limited only to a testis-specific cell adhesion ultrastructure known as the apical ectoplasmic specialisation （ES） in stage VI-early VIII tubules. These findings suggest that Bcrp is equipped by late spermatids and Sertoli cells to protect late-stage spermatids completing spermiogenesis. Furthermore, Bcrp was found to be associated with F （filamentous）-actin and several actin regulatory proteins at the apical ES and might be involved in the organisation of actin filaments at the apical ES in stage VII-VIII tubules. These findings will be carefully evaluated in this brief review.

关键词： actin filaments breast cancer resistant protein ectoplasmic specialisation effux drugtransporter germ cells Sertoli cells spermatids spermatogenesis spermiogenesis testis

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Synthesis and Crystal Structure of a Coordination Polymer {[Co(phth)(phen)(H_2O)]·(C_2H_5OH)}_n

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Chinese Journal of Structural Chemistry 2006年第10期25卷 1193-1196页

作者： Gao Ling cheng Qing-yan WANG yan-Ji Hebei University of Technology Tianjin 300130 China

The coordination polymer {[Co（phth）（phen）（H2O）]·（C2H5OH）}n （phth = phthalate, phen = 1,10-phenanthroline） with formula C22H2OCoN2O6 （Mr = 467.33） was synthesized by the solvothermal method under low temperature, and its crystal structure was determined by singlecrystal X-ray diffraction. The complex belongs to monoclinic system, space group P21/n with a = 12.7352（16）, b = 8.8125（11）, c = 18.677（2） °A, β= 102.633（2）°, V = 2045.3（4）°A^3 Z = 4, Dc= 1.518 g/cm^3,μ = 0.882 mm^-1, F（000） = 964, S = 1.053, the final R = 0.0401 and wR = 0.0984 for 3135 observed reflections （I〉 2σ（I））. Single-crystal X-ray analysis revealed that the Co（Ⅱ） ion is six-coordinated. The cobalt complex forms a one-dimensional chain structure via phthalate bridging ligand. In the cobalt complex, a 3D network structure is formed by π-π stacking interaction of 1,10-phenanthroline as well as intermolecular hydrogen bonding interactions.

关键词： cobalt complex solvothermal method π-π stacking hydrogen bond

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Effects of coal seam dip angle on the outburst in coal roadway excavation

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International Journal of Mining Science and Technology 2019年第5期29卷 757-764页

作者： cheng Hou Yinghua Zhang Yi yan University of Science and Technology Beijing Beijing 100083China Department of Mechanical Engineering McGill UniversityMontrealQC H3A 0C3Canada

The prevention and forecast of coal and gas outburst has always been one of the key issues in coal mining *** simulating the process of tunneling in coal seam with different dip angle through FLAC3D software,the dangerous zone in which outburst may occur and the probability of outburst near the working face were predicted through the distribution of stress,displacement and plastic *** we discussed the size of unstable area in the surrounding rock through the distribution of stress and the variation curve of the displacement on the roadway *** results show that,with an increase of the coal seam dip angle,the risk of outburst in the working face rises *** the dangerous areas in which may outburst occur moves to the upper part of coal *** size of unstable area in the surrounding rock increases with the increase of coal seam dip angle.

关键词： Dip angle Stress concentration Plastic zone Displacement Coal and gas outburst

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“Capture-activation-recapture” mechanism-guided design of double-atom catalysts for electrocatalytic nitrogen reduction

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Journal of Energy Chemistry 2024年第9期96卷 437-447页

作者： cheng He Shiqi yan Wenxue Zhang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina School of Materials Science and Engineering Chang’an UniversityXi’an 710064ShaanxiChina

Compared with the traditional industrial nitrogen fixation, electrocatalytic methods, especially those utilizing double-atom catalysts containing nonmetals, can give good consideration to the economy and environmental protection. However, the existing “acceptance-donation” mechanism is only applicable to bimetallic catalysts and nonmetallic double-atom catalysts containing boron atoms. Herein, a novel “capture-activation-recapture” mechanism for metal-nonmetal double-atom catalyst is proposed to solve the problem by adjusting the coordination environments of nonmetallic atoms and utilizing the activation effect of metal atoms on nitrogen. Based on this mechanism, the nitrogen reduction reaction (NRR) activity of 48 structures is calculated by density functional theory calculation, and four candidates are selected as outstanding electrocatalytic nitrogen reduction catalysts: Si-Fe@NG (U_(L) = –0.14 V), Si-Co@NG (U_(L)= –0.15 V), Si-Mo@BP1 (U_(L) = 0 V), and Si-Re@BP1 (U_(L) = –0.02 V). The analyses of electronic properties further confirm “capture-activation-recapture” mechanism and suggest that the difference in valence electron distribution between metal and Si atoms triggers the activation of N≡N bonds. In addition, a machine learning approach is utilized to generate an expression and an intrinsic descriptor that considers the coordination environment to predict the limiting potential. This study offers profound insight into the synergistic mechanism of TM and Si for NRR and guidance in the design of novel double-atom nitrogen fixation catalysts.

关键词： "Capture-activation-recapture"mechanism Double-atom catalyst Nitrogen reduction reaction Density functional theory

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A semi-implicit three-step method based on SUPG finite element formulation for flow in lid driven cavities with different geometries

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第1期12卷 33-45页

作者： cheng HUAN Dai ZHOU yan Bao School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

A numerical algorithm using a bilinear or linear finite element and semi-implicit three-step method is presented for the analysis of incompressible viscous fluid problems. The streamline upwind/Petrov-Galerkin (SUPG) stabilization scheme is used for the formulation of the Navier-Stokes equations. For the spatial discretization, the convection term is treated explicitly, while the viscous term is treated implicitly, and for the temporal discretization, a three-step method is employed. The present method is applied to simulate the lid driven cavity problems with different geometries at low and high Reynolds numbers. The results compared with other numerical experiments are found to be feasible and satisfactory.

关键词： Semi-implicit three-step method Streamline upwind/Petrov-Galerkin (SUPG) finite element method (FEM) Unsteady incompressible flows Lid driven cavity problem

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Design and Implementation of a Driver's Eye State Recognition Algorithm Based on PERCLOS

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Chinese Journal of Electronics 2014年第4期23卷 669-672页

作者： PENG yan DONG yan cheng Du School of Management Capital Normal University Beijing Institute of Control Engineering

In order to improve the general detection accuracy of eye state, this paper puts forward an innovative method for judging human eye state based on PERCLOS. After pretreatment of the eye image, Hough transformation is used for ellipse detection and pupil position. The gray projection variance threshold analysis is then used to help make the final detection. Freeman chain and the Snake model algorithm are used for the corner detection and precise calculation of the height of an open eye. Thus the PERCLOS value and the eye state can be figured out. The performance of our eye state recognition algorithm is validated by more than 1000 images within product database. The statistics result shows that the fatigue detection accuracy rate can meet the need of usage in complex environment.

关键词： Eye state detection Freeman chain code Snake model Hough circle Ellipse detection

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Three-dimensional visualization and quantification of microporosity in aluminum castings by X-ray micro-computed tomography

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Journal of Materials Science & Technology 2021年第6期65卷 99-107页

作者： cheng Gu yan Lu Alan A.Luo Department of Materials Science and Engineering The Ohio State University2041 College Rd N.ColumbusOhio 43210USA Department of Integrated Systems Engineering The Ohio State University1971 NeilAve.ColumbusOhio 43210USA

Porosity is a major issue in solidification processing of metallic *** this work,wedge die casting experiments were designed to investigate the effect of cooling rate on microporosity in an aluminum alloy *** information including dendrites and porosity were measured and observed by optical microscopy and X-ray micro-computed tomography(XMCT).The effects of cooling rate on secondary dendrite arm spacing(SDAS)and porosity were *** relationship between SDAS and cooling rate was established and validated using a mathematical ***-dimensional(3-D)porosity information,including porosity percentage,pore volume,and pore number,was determined by *** the cooling rate decreasing from a lower to a higher position of the wedge die,the observed pore number decreases,the porosity percentage increases,and the equivalent pore radius *** of the pores was discussed as an empirical criterion to distinguish the types of *** different cooling rates,the larger the equivalent pore radius is,the lower the sphericity of the *** research suggests that XMCT is a useful tool to provide critical 3-D porosity information for integrated computational materials engineering(ICME)design and process optimization of solidification products.

关键词： X-ray computed tomography Casting micropore Quantitative evaluation Al alloy

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Model-driven path planning for robotic plasma cutting of branch pipe with single Y-groove based on pipe-rotating scheme

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Advances in Manufacturing 2024年第1期12卷 94-107页

作者： yan Liu Qiu Tang Xin-cheng Tian School of Control Science and Engineering Shandong UniversityJinan250061People’s Republic of China Engineering Research Center of Intelligent Unmanned System Ministry of EducationJinan250061People’s Republic of China School of Mechanical and Electronic Engineering Shandong Jianzhu UniversityJinan250101People’s Republic of China

The automatic cutting of intersecting pipes is a challenging task in *** improved automation and accuracy,this paper proposes a model-driven path planning approach for the robotic plasma cutting of a branch pipe with a single ***,it summarizes the intersection forms and introduces a dual-pipe intersection *** on this model,the moving three-plane structure(a description unit of the geometric characteristics of the intersecting curve)is constructed,and a geometric model of the branch pipe with a single Y-groove is ***,a novel mathematical model for plasma radius and taper compensation is ***,the compensation model and groove model are integrated by establishing movable ***,to prevent collisions between the plasma torch and workpiece,the torch height is planned and a branch pipe-rotating scheme is *** the established models and moving frames,the planned path description of cutting robot is provided in this novel *** accuracy of the proposed method is verified by simulations and robotic cutting experiments.

关键词： Automatic groove cutting of intersecting pipes Model-driven robot path planning Plasma beam radius and taper compensation

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Preparation of yttrium oxide coating with enhanced thermal shock resistance on refractories used for titanium alloy melting and casting

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Journal of Iron and Steel Research International 2024年第6期31卷 1411-1422页

作者： ao Chen yan Ma Zhou-fu Wang Hao Liu Xi-tang Wang Sen-na Chen Chen-xin Zhang Zi-yi Tang Wei-dong Fu Wei cheng The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Xiangyang Juli High Technology Material Co. Ltd.Xiangyang 441705HubeiChina Xiangyang Public Inspection and Testing Center Xiangyang 441000HubeiChina

In order to enhance the service life of refractories for melting and casting of titanium alloy,preparation of yttrium oxide coatings on the refractories surface is an effective *** improvement of thermal shock stability of the coating is beneficial to its spalling resistance during the high-temperature service,and the available slurry with good performance is the *** effects of the varieties and contents of dispersant(sodium tripolyphosphate,sodium hexametaphosphate,sodium pyrophosphate,citric acid and polycarboxylate ammonium salt)and binder(aluminum dihydrogen phosphate,zirconium acetate and yttria sol)on the stability,rheological and thixotropic properties of yttrium oxide waterbased slurry were investigated,and the effects of slurry composition design on the thermal shock resistance of the coating were *** results showed that the introduction of polycarboxylate ammonium salt as dispersant significantly improved the stability of the slurry,and the varieties of the binders had significant effects on the dispersibility of the *** aluminum dihydrogen phosphate and polycarboxylate ammonium salt were used as binder and dispersant,respectively,the slurry had better stability,suitable rheological and thixotropic *** using aluminum dihydrogen phosphate as binder,the coating had good thermal shock resistance and no obvious cracks were observed for the coating after thermal shock,which was attributed to the yttrium aluminate binding phase generated in the *** effective method was provided for preparing yttrium oxide coatings with enhanced thermal shock resistance applied in the process of titanium alloy melting and casting.

关键词： Yttrium oxide-Slurry Stability Rheological property Thixotropic property-Coating Thermal shock resistance

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Fermion dynamical symmetry and strongly-correlated electrons:A comprehensive model of high-temperature superconductivity

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Frontiers of physics 2020年第4期15卷 35-99页

作者： Mike Guidry yang Sun Lian-ao Wu cheng-Li Wu Department of Physics and Astronomy Universilty of TenesseeKnorilleTN 37996USA School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai 200240China IKERBASQUE Basque Foundation for Science48011 BilbaoSpainand Department of Theoretical Physics and History of ScienceBasque Country University(EHU/UPV)Post Office Bor 64448080 BilbaoSpain Department of Physics Chung-Yuan Christian UniversityChungliTaiwan 320China

We review application of the SU(4)model of strongly-correlated electrons to cuprate and iron-based superconductors.A minimal self-consistent generalization of BCS theory to incorporate antiferromag-netism on an equal footing with pairing and strong Coulomb repulsion is found to account system-atically for the major features of high-temperature superconductivity,with microscopic details of the parent compounds entering only *** provides a systematic procedure to separate es-sential from peripheral,suggesting that many features exhibited by the high-Te data set are of interest in their own right but are not central to the superconducting *** generally,we propose that the surprisingly broad range of conventional and unconventional superconducting and superfluid behavior observed across many fields of physics results from the systemnatic appearance of similar al-gebraic structures for the emergent ffoctive Harmiltonians,even though the microscopic Harmiltonians of the corresponding parent states may differ radically from each other.

关键词： strongly-correlated electrons SU(4)model fermian dynamical symmetry high-temperature superconductivity

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