Effects of age, breast density, ethnicity, and estrogen replacement therapy on screening mammographic sensitivity and cancer stage at diagnosis: review of 183,134 screening mammograms in Albuquerque, New Mexico

PURPOSE: To examine how common patient factors affect screening mammographic sensitivity and cancer stage at diagnosis. MATERIALS AND METHODS: The authors used a population-based database of 183,134 screening mammograms and a statewide tumor registry to identify 807 breast cancers detected at screening mammography. RESULTS: Sensitivity varied significantly with ethnicity, use of estrogen replacement therapy, mammographic breast density, and age. Sensitivity was 54% (13 of 24) in women younger than 40 years, 77% (121 of 157) in women aged 40-49 years, 78% (224 of 286) in women aged 50-64 years, and 81% (277 of 340) in women older than 64 years. Sensitivity was 68% (162 of 237) for dense breasts and 85% (302 of 356) for nondense breasts and 74% (180 of 244) in estrogen replacement therapy users and 81% (417 of 513) in nonusers. Sensitivity was most markedly reduced with the combination of dense breasts and estrogen replacement therapy use; there was little difference when only one factor was present. Median cancer size and the percentage of early cancers showed little change with any factors. CONCLUSION: Age is a minor determinant of mammographic sensitivity in women aged 40 years or older. Sensitivity is substantially decreased with the combination of higher breast density and estrogen replacement therapy use. There was not a notable shift in cancer outcomes in the groups with lower mammographic sensitivity. These data do not support different screening recommendations in women aged 40-49 years or in estrogen replacement therapy users.     

机构影响系数和并联机器人雅克比矩阵的研究

基于刚体运动学的原理，对机构影响系数进行了研究，用运动坐标系和拟牵连速度的概念给出了机构速度影响系数求解公式，揭示了机构影响系数的物理意义，明确地论证了机构速度影响系数只与机构瞬时位姿有关而与机构的真实速度无关的结论。并将该方法用于并联机器人的运动学研究，由此而给出了求解并联机器人的雅克比矩阵的方法。     

于锁集合算法的增强型数据竞争检测方法

针对锁集合算法误报率高的缺点,采用增强型数据竞争检测方法对锁集合算法及算法实现两方面进行改进.增强型锁集合算法提出了更强必要条件的检测算法.该算法通过分析线程结束情况和理解变量的线程信息,精化数据竞争检测条件.算法实现采用系统体系结构扩展的方法,通过扩展锁表部件,将集合操作精确映射到位图操作,进一步提高检测精度和减少误报.实现了无干扰免插桩检测技术,避免了二进制代码插桩带来的干扰性和不确定性问题.与同类系统的对比实验结果表明,该方法能够有效地将误报率减小到0.67,并且具有很高的检测效率.     

基于TCP／IP协议的网络教学系统设计

通过对高校网络教学现状的调查与分析，提出了总体的设计目标以及设计方案，包括系统运行环境以及系统展现内容．系统采用C／S模式，通过主机与客户机发送数据包，利用网络包截获的相应技术以及包过滤等策略，对特定的数据包进行分析，将各类协议首部用的二进制代码展现，可更直观的看到网络传输的具体方式，同时可将二进制代码转换为十进制，使系统具有更强的可视性．     

论邓小平发展科学技术的创新思想

全面地阐述了邓小平关于发展科学技术的思想.从发展科学技术的重要性与发展科学技术的方法、目标、前提、核心等方面,将邓小平关于我国发展科学技术的论述,概括为科的论述,概括为科技关键论、引进吸收创新论、科技前沿论、教育基础论和人才为本论.     

基于Cross-EKF定位的多机器人协作围捕策略研究

针对目前多机器人协作围捕过程中收敛速度慢、稳定性差、定位精度低的问题,提出一种新的围捕策略.设计出Cross-EKF定位算法,对目标位置的后验估计协方差进行交叉计算,以取得最小协方差区域.以区域边缘点到均值中心最大距离为半径,构建收敛圆,将对动态点的收敛扩展为对动态面的收敛.实验结果表明,系统能快速平稳地收敛该圆,从而实现对目标的精确围捕,该方法具有较高的实用价值.     

RF/wireless-interconnect: The next wave of connectivity

In the era of the nanometer CMOS technology, due to stringent system requirements in power, performance and other fundamental physical limitations (such as mechanical reliability, thermal constraints, overall system form factor, etc.), future VLSI systems are relying more on ultra-high data rates (up to 100 Gbps/pin or 20 Tbps aggregate), scalable, re-configurable, highly compact and reliable interconnect fabric. To overcome such challenges, we first explore the use of multiband RF/wireless-interconnects wh...     

人体压力分布测量及其传感技术

体压分布测量系统是测试病人坐卧时,人体与接触面之间压力的可视化工具.介绍了人体压力分布测量系统的一般结构,对其关键点--传感器技术作了较为详细的叙述.它们分别是电容式压力传感器;用电阻油墨制成的电阻式压力传感器阵列;压电电阻传感器等.有针对的介绍了国外三种典型的人体压力测试产品,Xsensor、Tekscan和FSA;论述了它们的主要特点及优缺点,并对其主要性能作了对比.最后介绍了自行设计的体压分布测量系统,并给出了实测结果.     

Centriacinar remodeling and sustained procollagen gene expression after exposure to ozone and nitrogen dioxide

Sprague-Dawley rats were exposed to 0.8 ppm ozone (O3), to 14.4 ppm nitrogen dioxide (NO2), or to both gases simultaneously for 6 h per day for up to 90 d. The extent of histopathologic changes within the central acinus of the lungs was compared after 7 or 78 to 90 d of exposure using morphometric analysis by placement of concentric arcs radiating outward from a single reference point at the level of the bronchiole- alveolar duct junction. Lesions in the lungs of rats exposed to the mixture of gases extended approximately twice as far into the acinus as in those exposed to each individual gas. The extent of tissue involvement was the same at 78 to 90 d as noted at 7 d in all exposure groups. At the end of exposure, in situ hybridization for procollagen types I and III demonstrated high levels of messenger RNA within central acini in the lungs of animals exposed to the combination of O3 and NO2. In contrast, animals exposed to each individual gas had a similar pattern of message expression compared with that seen in control animals, although centriacinar histologic changes were still significantly different from control animals. We conclude that the progressive pulmonary fibrosis that occurs in rats exposed to the combination of O3 and NO2 is due to sustained, elevated expression of the genes for procollagen types I and III. This effect at the gene level is correlated with the more severe histologic lesions seen in animals exposed to both O3 and NO2 compared with those exposed to each individual gas. In contrast, the sustained expression of the procollagen genes is not associated with a shift in the distribution of the lesions because the area of change in each group after 7 d of exposure was the same as after 78 to 90 d of exposure.