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Function of Slit/Robo signaling in breast cancer

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《医学前沿（英文）》 2015年第9卷第4期页码 431-436 doi: 10.1007/s11684-015-0416-9

摘要：

Slit and Robo are considered tumor suppressors because they are frequently inactivated in various tumor tissue. These genes are closely correlated with CpG hypermethylation in their promoters. The Slit/Robo signaling pathway is reportedly involved in breast cancer development and metastasis. Overexpression of Slit/Robo induces its tumor suppressive effects possibly by inactivating the β-catenin/LEF/TCF and PI3K/Akt signaling pathways or by altering β-catenin/E-cadherin-mediated cell-cell adhesion in breast cancer cells. Furthermore, loss of Slit proteins or their Robo receptors upregulates the CXCL12/CXCR4 signaling axis in human breast carcinoma. In addition, this pathway regulates the distant migration of breast cancer cells not only by mediating the phosphorylation of the downstream molecules of CXCL12/CXCR4 and srGAPs, such as PI3K/Src, RAFTK/ Pyk2, and CDC42, but also by regulating the activities of MAP kinases. This review includes recent studies on the functions of Slit/Robo signaling in breast cancer and its molecular mechanisms.

关键词： Slit/Robo hypermethylation β-catenin CXCL12/CXCR4 migration

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Cyclic behavior of prefabricated reinforced concrete frame with infill slit shear walls

Kui XIAO,Qilin ZHANG,Bin JIA

《结构与土木工程前沿（英文）》 2016年第10卷第1期页码 63-71 doi: 10.1007/s11709-015-0294-x

摘要： A composite structural system consisting of prefabricated reinforced concrete frame with infill slit shear walls (PRCFW), with good ductility, is a new type of earthquake resistant structure. Pseudo-static tests were performed to evaluate the seismic behavior of the PRCFW system. Two one-bay, two-story PRCFW specimens were both built at one-half scale. Additional computational research is also conducted to enhance the nonlinear analytical capabilities for this system. Combined with the concrete damaged plastic (CDP) model provided by finite element program ABAQUS and the constitutive model of concrete proposed by Chinese code, the damage process of the PRCFW structure under cyclic load is simulated. The simulated results show a good agreement with the test data, the dynamic behavior of the PRCFW system can be simulated sufficiently accurate and efficient to provide useful design information. The experimental and numerical study show that this system has the potential to offer good ductility and energy absorption capacity to dissipate input energy, and stiffness adequate for controlling drift for buildings located in earthquake-prone regions.

关键词： slit shear wall constitutive model cyclic seismic damage

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Morphologies of diblock copolymer confined in a slit with patterned surfaces studied by dissipative particle

FENG Jian, HUANG Yongmin, LIU Honglai, HU Ying

《化学科学与工程前沿（英文）》 2007年第1卷第2期页码 132-139 doi: 10.1007/s11705-007-0025-5

摘要： Diblock copolymers with ordered mesophase structures have been used as templates for nano-fabrication. Unfortunately, the ordered structure only exists at micrometer-scale areas, which precludes its use in many advanced applications. To overcome this disadvantage, the diblock copolymer confined in a restricted system with a patterned surface is proved to be an effective means to prohibit the formation of defects and obtain perfect ordered domains. In this work, the morphologies of a thin film of diblock copolymer confined between patterned and neutral surfaces were studied by dissipative particle dynamics. It is shown that the morphology of the symmetric diblock copolymer is affected by the ratio of the pattern period on the surface to the lamellar period of the symmetric diblock copolymer and by the repulsion parameters between blocks and wall particles. To eliminate the defects in the lamellar phase, the pattern period on the surface must match the lamellar period. The difference in the interface energy of different compartments of the pattern should increase with increasing film thickness. The pattern period on the surface has a scaling relationship with the chain length, which is the same as that between the lamellar period and the chain length. The lamellar period is also affected by the polydispersity of the symmetric diblock copolymer. The total period is the average of the period of each component multiplied by the weight of its volume ratio. The morphologies of asymmetric diblock copolymers are also affected by the pattern on the surface, especially when the matching period of the asymmetric diblock copolymer is equal to the pattern period, which is approximately equal to the lamellar period of a symmetric diblock copolymer with the same chain length.

关键词： weight nano-fabrication morphology matching dissipative particle

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Evaluation of measurement uncertainty of the high-speed variable-slit system based on the Monte Carlo

Yin ZHANG, Jianwei WU, Kunpeng XING, Zhongpu WEN, Jiubin TAN

《机械工程前沿（英文）》 2020年第15卷第4期页码 517-537 doi: 10.1007/s11465-020-0589-z

摘要： This paper presents a dynamic and static error transfer model and uncertainty evaluation method for a high-speed variable-slit system based on a two-dimensional orthogonal double-layer air-floating guide rail structure. The motion accuracy of the scanning blade is affected by both the moving component it is attached to and the moving component of the following blade during high-speed motion. First, an error transfer model of the high-speed variable-slit system is established, and the influence coefficients are calculated for each source of error associated with the accuracy of the blade motion. Then, the maximum range of each error source is determined by simulation and experiment. Finally, the uncertainty of the blade displacement measurement is evaluated using the Monte Carlo method. The proposed model can evaluate the performance of the complex mechanical system and be used to guide the design.

关键词： air-floating guide rail error transfer model driving and following structure dynamic error uncertainty evaluation Monte Carlo method