Spontaneous Cell Detachment and Reattachment in Cancer Cell Lines: An In Vitro Model of Metastasis and Malignancy

There is an unmet need for simplified in vitro models of malignancy and metastasis that facilitate fast, affordable and scalable gene and compound analysis. “Adherent” cancer cell lines frequently release “free-floating” cells into suspension that are viable and can reattach. This, in a simplistic way, mimics the metastatic process. We compared the gene expression profiles of naturally co-existing populations of floating and adherent cells in SW620 (colon), C33a (cervix) and HeLa (cervix) cancer cells. We found that 1227, 1367 and 1333 genes were at least 2-fold differentially expressed in the respective cell lines, of which 122 were shared among the three cell lines. As proof of principle, we focused on the anti-metastatic gene NM23-H1, which was downregulated both at the RNA and protein level in the floating cell populations of all three cell lines. Knockdown of NM23-H1 significantly increased the number of floating (and viable) cells, whereas overexpression of NM23-H1 significantly reduced the proportion of floating cells. Other potential regulators of these cellular states were identified through pathway analysis, including hypoxia, mTOR (mechanistic target of rapamycin), cell adhesion and cell polarity signal transduction pathways. Hypoxia, a condition linked to malignancy and metastasis, reduced NM23-H1 expression and significantly increased the number of free-floating cells. Inhibition of mTOR or Rho-associated protein kinase (ROCK) significantly increased cell death specifically in the floating and not the adherent cell population. In conclusion, our study suggests that dynamic subpopulations of free-floating and adherent cells is a useful model to screen and identify genes, drugs and pathways that regulate the process of cancer metastasis, such as cell detachment and anoikis.     

Fabrication of novel ZnTe-based photocatalyst: Synergistic effect of dye sensitization and bridge engineering for boosting hydrogen evolution over ZnTe

Herein, a novel ZnTe-based photocatalyst is successfully synthesized via a facile combination of water-bath and hydrothermal processes. Morphology characterization and X-ray diffraction analysis reveal that ZnTe presents irregular granular shape and cubic crystal structure. Moreover, Mott-Schottky measurement shows that the conduction band potential of ZnTe is ?0.84 V (vs NHE). With Eosin Y (EY) sensitization, ZnTe exhibits superior photocatalytic hydrogen evolution activity (223.5 μmol g^?1 h^?1). Meanwhile, WC-ZnTe heterojunction is constructed by depositing ZnTe nanoparticles on bulk WC and obtains the optimal H₂ generation rate (559.1 μmol g^?1 h^?1) under EY sensitization. Electrochemical and photoluminescence results further prove that WC as electron bridge could reduce the interfacial resistance and suppress e^?-h⁺ pairs recombination. This study explores the potential application of ZnTe as a newly active photocatalyst in photocatalytic water splitting, and emphasizes the synergistic effect of dye sensitization and bridge engineering.     

温州某公轨共建高架车站结构设计

为了解决城市廊道资源的紧张和公共交通发展需求的矛盾,出现了轨道交通和快速路的共建型式,即公轨共建的复合型交通模式,以温州市域铁路S2线一期工程的人民路站为例,研究公轨共建高架车站的结构设计要点。首先,为降低浅层气体对桩基的承载力及沉降影响,对遇到局部浅层气体发育的基础设计提供了合理的解决方案。然后针对公轨共建一体化车站分别进行了多遇和罕遇地震作用分析,研究表明构件及整体指标满足规范要求。最后针对工程的一些关键技术,如快速路桥面体系的选型、超长结构温度应力的控制措施、轨道梁挠度及应力的控制、快速路桥面振动对车站的影响等进行了分析,并给出了具体的解决方案和指导意见。     

一种基于实时几何测距的船桥主动防撞方法

本文提出一种基于实时几何测距的船桥主动防撞方法。该方法对船的改动量甚微,仅需维持多项距离矩阵,通过告警逻辑矩阵进行展示与告警,能起到很好的船桥防撞提示效果。     

潼湖特大桥跨潮莞高速(88+160+88)m连续刚构关键施工技术

随着交通的日益发展,大跨度跨线连续刚构桥梁修建越来越多。本文结合潼湖特大桥跨潮莞高速(88+160+88)m连续刚构施工的成功实践,详细阐述了该桥的施工关键及其梁体施工的线型控制,跨既有公路施工防护及混凝土施工等关键施工技术,可供类似工程参考。     

基于工程状态标定的诊断载荷试验识别方法及应用

针对在役公路梁式桥梁由于材料性能退化及外部环境等因素共同作用而导致承载力不足、耐久性降低等问题,开展旧桥力学性能的快速诊断试验研究。通过诊断性载荷试验的理论分析和有限元模型标定流程研究,快速、高效地完成在役公路桥梁的承载力性能测量和评估,从而为在役公路桥梁结构的养护管理提供可靠的技术支持。     

Breakage of wet flexible fiber agglomerates impacting a plane

The breakage of an agglomerate of wet flexible fibers impacting a plane is computationally investigated in this work using the discrete element method. In the agglomerate, the fibers stick together due to cohesive liquid bridge forces. Agglomerate breakage with various impact conditions, initial configurations, fiber properties, and liquid bridge properties is systematically investigated. The degree of breakage is governed by the impact energy, the cohesion energy due to liquid bridges, the energy dissipation/absorption through fiber–fiber contacts and fiber deformation, and the efficiency of force transmission within the agglomerate. More specifically, breakage is promoted by increasing impact velocity, decreasing agglomerate size, increasing initial compaction, increasing fiber bending modulus, decreasing liquid surface tension, and decreasing liquid-to-solid volume ratio. Breakage is strongly dependent on the modified Weber number, that is, the ratio of the Weber number to a dimensionless rupture distance, which is a measure of the impact energy relative to the cohesion energy.     

桥梁检测机器人作业规划与位姿优化方法研究

针对桥梁底部病害人工检测的作业难题,介绍了桥梁检测机器人的工作原理,结合桥梁的结构化特征和视觉检测拍摄参数约束,研究了桥梁检测机器人作业规划与位姿优化方法。首先,提出一种以最佳拍摄模型约束的桥梁检测机器人拍摄作业位姿规划方法。在最佳拍摄规划方法的基础上,针对小箱梁桥梁和T型梁桥梁底部的褶皱结构,研究了以安全拍摄模型为约束的拍摄位姿优化方法,设计了结合拍摄偏角和拍摄距离的权重函数,推导了优化算法公式并给出了收敛证明。通过对不同拍摄参数的配置,进行了针对空心板桥梁的拍摄作业位姿规划方法仿真;针对小箱梁桥梁的结构,在位姿规划仿真结果基础上进行了位姿优化方法的仿真。最后以研制的桥梁检测机器人为对象,进行了现场测试与验证,仿真和实验结果均表明,该规划和优化方法符合桥梁拍摄检测的要求,具有很好的鲁棒性和实时性。     

浅谈桥梁深基坑挡土墙防护施工方案

本文根据该项工程实际情况和相关技术标准、水文地质特征,对施工准备、测量放线、基坑开挖、挡土墙施工、基坑监测等关键部分进行深入研究。