Association between the -1562 C/T polymorphism in the MMP-9 promoter and phenotype of esophageal squamous cell carcinoma in northern Chinese population

Objective To conduct a case-control study on the association of the nucleotide polymorphisms in the promoter region of the matrix metalloproteinase-9 (MMP-9) gene with phenotype of esophageal cancer. Methods All subjects were unrelated residents in northern regions of China. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was used to determine the MMP-9 genotypes. Results The overall distribution of genotypes in the patients was not different from that in the controls (OR=0.77, 95% CI=0.45-1.34; P=0.36). There were no significant differences between the patients and the control subjects in terms of the distributions of sex and age, smoking status, alcohol dependence, pickled diet status, or history of environmental exposure. The patients were further examined with stratifications by age, sex, grade, depth of tumor invasion, lymphatic invasion, venous invasion and TNM staging. The results showed no pronounced association among the stratifications. Conclusion There is no significant association between the MMP-9 single nucleotide polymorphism genotypes and phenotype of esophageal cancer.     

一种计算自锚式悬索桥吊杆成桥张拉力的方法研究

确定自锚式悬索桥吊杆合理张拉力是自锚式悬索桥设计施工要解决的关键问题。基于吊杆在施工张拉过程中主缆位移具有弱相干性原理,将加劲梁视为连续梁结构,根据能量最小原理及变形协调原理,可确定吊杆的成桥张拉力。     

MVBC02一类设备主/从帧数据收发实现方法

本文从TCN标准出发,着重论述多功能车辆总线控制器MVBC内部编程模块的具体功能及主控MVBC在一类设备模式下的初始化配置流程,并在此基础上阐明MVBC一类设备模式下的主/从数据帧的基本组成、帧格式配置、功能码、端口属性定义以及实现数据帧收发的具体方法.通过对MVBC一类模式下的主/从数据帧收发具体流程的详细分析,为进一步开展直接针对MVBC控制器底层硬件的数据通信编程打下基础.     

S355J2W耐候钢焊接接头显微组织与力学性能

通过拉伸、疲劳和金相检验试验,对S355J2W耐候钢、空冷状态焊接接头和退火状态焊接接头进行了显微组织和力学性能的研究.结果表明：两种状态焊接接头的力学性能都达到了要求,S355J2W耐候钢退火状态焊接接头的强度低于空冷状态焊接接头的强度;退火状态焊接接头的塑性好于空冷状态焊接接头的塑性;退火状态焊接接头的疲劳寿命低于空冷状态焊接接头的疲劳寿命;退火状态焊接接头与空冷状态焊接接头相比,每个区域的晶粒都有明显的细化和均匀化,空冷状态的焊接接头显微组织的晶界比较清晰.     

青藏铁路格拉段交通重点目标战时保障对策研究

在未来信息化条件下局部战争中,青藏铁路格拉段桥隧等交通重点目标直接面临精确制导武器的威胁,高寒缺氧条件下,传统交通保障技术面临全新挑战。在分析青藏铁路格拉段交通保障面临问题的基础上,提出了建立联合保障机制、提升冻土基础抗打击能力、深化高寒缺氧条件下交通保障技术研究等建议与对策,以期使整个青藏铁路的交通保障问题能够引起更多的关注。     

高速公路建设贯彻国防要求研究初探

从分析我国高速公路建设贯彻国防要求存在的问题入手,探讨了加强高速公路建设贯彻国防要求工作的突破点,提出应从加强目录管理工作和技术标准建设两方面推进高速公路建设贯彻国防要求工作,以期解决当前我国高速公路建设贯彻国防要求工作存在的问题。     

公路隧道巷道式施工通风瓦斯分布研究

为探究瓦斯公路隧道巷道式施工通风中瓦斯的体积分数分布规律,利用流体力学研究软件FLUENT建立三维隧道模型并进行了数值仿真计算,通过对隧道内部整体、掌子面附近和主洞与横通道连接处瓦斯体积分数分布的研究,分析了隧道内部瓦斯分布的具体特点并深入探讨了内部回流区、涡流区和瓦斯容易聚集的位置。模拟结果表明： 瓦斯从一侧主洞涌出后,不会对另一侧造成污染; 涡流区瓦斯体积分数明显大于周围区域; 风管所在一侧截面上瓦斯体积分数分布明显低于异侧。     

"十四五"期我国城市交通无障碍发展需求和政策建议

为促进"十四五"期我国城市交通无障碍环境建设,系统梳理我国城市交通无障碍发展的现状和问题,基于对"十四五"期城市交通无障碍发展形势需求的分析研判,提出相应的政策建议.研究认为:"十四五"期,我国城市交通无障碍发展将面临人口老龄化、新型城镇化、需求品质化、交通智能化的多重趋势叠加,需坚持新发展理念,加快供给侧改革和需求侧管理双向发力,从完善顶层制度设计、推广普及通用设计、完善慢行交通体系、推动无障碍公交认证、加强日常维护管理、提升出行服务水平、加大资金用地保障和营造无障碍出行文化等方面采取对策,推进城市交通无障碍建设高质量发展.     

Introduction to the special issue on maritime security

The terrorist attacks of 11 September 2001 heightened awareness about the vulnerability of all modes of transportation to terrorist attack. The issue of maritime security has therefore become a major concern in the international maritime sector over the past several years. Globalization has led to a strong growth in seaborne trade; however, it simultaneously increases vulnerability to not only terrorism but also international criminal activities that threaten the world's supply chain. For example, in 2008, the rise in piracy activities in the Gulf of Aden brought the issue of maritime security to the forefront of international debate. In addition to the direct impact on ships, crews and cargoes, and on the maritime industry and governments, piracy also threatens global seaborne trade, and has an impact on energy security and the environment [UNCTAD, 2009, Review of Maritime Transport 2009 (New York: United Nations)]. Maritime piracy can pose substantial risks to seaborne trades, with considerable commodities, ranging between raw materials and energy to high-value manufactured products, being shipped between global economic powerhouses [FU, X. W., NG, A. K. Y., LAU, Y. Y., forthcoming, The impacts of maritime piracy on global economic development: The case of Somalia. Maritime Policy and Management]. Maritime security management, including the definition of security, maritime risk assessment, security measures, the regulation and policy of maritime security in shipping and port-related business operations has been receiving growing attention, both in practice and research.