Exclusion of BMP6 as a candidate gene for cleidocranial dysplasia

Cleidocranial dysplasia (CCD) is an autosomal dominant, generalized skeletal dysplasia in humans that has been mapped to the short arm of chromosome 6. We report linkage of a CCD mutation to 6p21 in a large family and exclude the bone morphogenetic protein 6 gene (BMP6) as a candidate for the disease by cytogenetic localization and genetic recombination. CCD was linked with a maximal two-point LOD score of 7.22 with marker D6S452 at theta = 0. One relative with a recombination between D6S451 and D6S459 and another individual with a recombination between D6S465 and CCD places the mutation within a 7 cM region between D6S451 and D6S465 at 6p21. A phage P1 genomic clone spanning most of the BMP6 gene hybridized to chromosome 6 in band region p23-p24 using FISH analysis, placing this gene cytogenetically more distal than the region of linkage for CCD. We derived a new polymorphic marker from this same P1 clone and found recombinations between the marker and CCD in this family. The results confirm the map position of CCD on 6p21, further refine the CCD genetic interval by identifying a recombination between D6S451 and D6S459, and exclude BMP6 as a candidate gene.     

Isolation of a genetic locus associated with metronidazole resistance in Helicobacter pylori

We examined the molecular mechanism of metronidazole resistance by constructing a lambda-Zap II phagemid expression library with genomic DNA from a metronidazole-resistance strain of Helicobacter pylori. Twenty-two clones were found to have elevated MTZ resistances in XLOLR strain of E. coli. Phagemids belonging to the twenty two clones were extracted and then retransformed into the XLOLR strain of E. coli. After MTZ selection, five clones could confer metronidazole resistance consistently. According to Southern hybridization and DNA sequencing, the five clones contained a same locus, recA. In addition, transforming the five clones into BL21 strain of E. coli produced a higher resistance to MTZ. Interestingly, electroporation of one of the five phagemid clones into two MTZ sensitive H. pylori yielded MTZ resistant strains. Comparing amino acid sequence in MTZ resistant with sensitive isolates revealed two point mutations at this locus. Above results suggest that mutation in recA may be associated with metronidazole resistance of H. pylori.     

一种多径环境下基于四阶累积量的阵列扩展测向方法

本文分析了基于四阶累积量的测向方法不能正确测量多径信号方向的原因，提出了一种多径环境下的基于四阶累积量的新型测向方法。该方法利用零点领处理方法抑制多径信号，然后采用四阶累积量进行阵列扩展测向。计算机模拟结果表明该方法在多径环境下具有良好的性能并且可能实现对足够多的信号进行测向。     

强折射轴对称流场的干涉再现方法

利用光学方法测量气体状态参数的关键在于确定气体折射率场的变化。光线通过稳定的非均匀折射率场时发生偏折，并且在强折射对称场中会产生交叉，使得条纹位移量的判读困难。本文首先分析了光线在轴对称折射率场中的偏折效应，在此基础上，给出了一种利用成像透镜对强折射轴对称场中折射率的干涉再现方法。该方法与其它方法相比较能够精确地确定折射率ｎ（ｒ）的值。     

角状螺旋固体激光器热畸变自补偿特性分析

利用张量方法对角状螺旋光路固体激光器作了分析，证实其在ｘ、ｙ两方向对激光介质的热畸变有自补偿作用，且ｘ、ｙ两方向呈对称性．     

磷酸盐玻璃中稀土离子的发光浓度效应研究

磷酸盐玻璃中稀土离子的发光浓度效应研究王民权，马立新，樊先平（浙江大学材料科学与工程系３１００２７）（南京航空航天大学）ＳｔｕｄｙｏｎＣｏｎｃｅｎｔｒａｔｉｏｎＥｆｆｅｃｔｓｏｆＲａｒｅＥａｒｔｈＩｏｎｓｉｎＰｈｏｓｐｈａｔｅＧｌａｓｓｅｓ￥Ｗａｎｇ...     

活塞综合检测仪的研制

介绍了活塞综合检测仪的功能、组成、检测过程、测量原理与方法和主要技术性能指标。该仪器是国内研制的第一台智能型活塞综合检测仪。实际应用表明,这是一台高精度、高稳定性和高效率的检测仪器。     

可编程控制器在化肥散运系统上的应用

整个散运系统采用３台ＦＸ２－１２８ＭＲＰＬＣ分块控制后，使得控制结构清楚，线路简单，工作可靠性大为提高，对所有控制柜元器件进行数据库管理，极大地提高图表的准确率。     

高镁瓷工艺特性研究和应用

本文总结了ＭｇＯ－ＳｉＯ２－Ａｌ２Ｏ３系的高镁瓷配方、增塑及烧成工艺特性的研究过程与应用结果；介绍了适应大生产的高镁瓷制作工艺。     

复印粉的粉碎分级技术

本文介绍了利用国产气流粉碎机和余气萃取分级制备复印粉的实用技术，并展示了粉碎分级系统和复印粉的电镜照片。