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.     

钢板弹簧三连杆模型参数辨识研究

钢板弹簧三连杆模型结构能够准确描述悬架垂直刚度特性,适用于计算路面载荷及平顺性分析.应用有限元软件计算钢板弹簧悬架刚度特性及导向特性,以此为基础通过集成优化方法及逆向求解方法辨识三连杆模型参数,并通过纵向力工况验证了模型的正确性.     

Simple adaptive filtering scheme to improve measurement accuracy of gyroscope on angular motion base

The objective of this work is to improve the measurement accuracy of a gyroscope on a angular motion base with a simple adaptive filter scheme. Two main topics are highlighted in this work. The first topic is to show building a dual-process model employed for the conventional Kalman filter. The second topic is to show developing a modified noise adaptive algorithm when measurement noise and process noise are unknown. The experimental results are presented to show that the simple adaptive filtering scheme outperforms the other conventional scheme in this paper in terms of noise reduction.     

轮胎胎面特性对侧偏模型预测精度影响分析

胎面花纹是影响轮胎性能的重要因素。文中以模态参数模型的稳态侧偏模型为基础,从理论推导和实际计算两方面说明胎而花纹刚度的重要性,其对侧偏模型计算结果的影响要大大高于对垂直模型的影响。因此,在确定轮胎解析模型中胎面花纹参数时应首先考虑其对侧偏模型的影响。     

轮胎原地转向离散仿真模型

建立了轮胎印记范围内的原地转向物理模型,对印记内的胎面进行了离散处理,分析了胎面单元的变形和滑移情况,通过胎体上下表面的力矩平衡,得到轮胎所受回正力矩,并对计算过程进行了详细说明。给出不同工况下原地转向时轮胎所受回正力矩,并进行了试验验证。结果表明,该离散仿真模型能较好的反应轮胎的原地转向特性,能方便地分析轮胎结构参数及印迹内压力分布对原地转向特性的影响。     

非饱和黄土结构强度特性的试验研究

分析了非饱和黄土强度的组成和结构强度的来源,通过常规三轴试验对非饱和黄土的结构强度和抗剪强度规律进行了研究。结果表明:非饱和黄土的结构强度可用其天然结构破坏时所丧失的强度表示;同一含水率下结构强度随围压的增大而增大,在同一围压下结构强度随含水率的增加而逐渐减小,呈较好的幂函数关系;结构强度与其粘聚力之间有显著的线性相关关系。     

~（131）I治疗Graves’病的突眼症状的疗效分析

对４８０例经１３１Ⅰ治疗的甲亢患者的疗效与是否伴突眼以及突眼症状是否有改善等系列问题进行了分析研究。结果表明：４８０例甲亢患者中２３３例伴突眼，其发病率为４９％，２３３例突眼患者中，９０例突眼恢复（３９％），好转９６例（４１％）．未变化４５例（１９％），加重２例（０．８５％），总有效率８０％。认为甲亢的治疗效果与有无伴发突眼关系不密切，１３１Ⅰ治疗甲亢伴突眼者可使大部分突眼症状得到明显改善。据此，我们认为在甲亢伴突眼的治疗中１３１Ⅰ应视为一种有效和较好的治疗方法。     

深孔注浆止水帷幕技术在地铁明挖车站中的应用

文章对北京地铁14号线某车站在深基坑土方开挖施工中应用深孔注浆止水帷幕技术进行基坑水处理施工的实例做了介绍,包括注浆孔布置、注浆加固设计参数、质量控制、注浆止水帷幕效果等。该项技术在北京地铁基坑降水施工中首次大面积应用,并取得了成功的经验。     

戈壁强风区CRTSⅠ型双块式无砟轨道混凝土养护应用试验研究

新建兰新铁路第二双线LXTJ7标段工程,地处"三十里风区"和"达坂城风区",为大风易发区(Ⅴ和Ⅳ区),属于戈壁强风区,大风频繁,气候干燥,昼夜温差变化大,春、秋季多风,夏季短促,冬季寒冷,掌握并应用好无砟轨道的养护技术,是保证道床板混凝土质量的一个重要条件。对传统的养护方式进行对比分析,提出了适合本标段较为特殊的养护方式,有效解决了道床板混凝土前期裂缝的产生。     

戈壁强风区CRTSI型双块式无砟轨道混凝土养护应用试验研究

新建兰新铁路第二双线LXTJ7标段工程,地处“三十里风区”和“达坂城风区”,为大风易发区(V和Ⅳ区),属于戈壁强风区,大风频繁,气候干燥,昼夜温差变化大,春、秋季多风,夏季短促,冬季寒冷,掌握并应用好无砟轨道的养护技术,是保证道床板混凝土质量的一个重要条件.对传统的养护方式进行对比分析,提出了适合本标段较为特殊的养护方式,有效解决了道床板混凝土前期裂缝的产生.