The aluminum joints were prepared by overcasting liquid aluminum A356 onto 6101 aluminum extrusion bars. The microstructure, element distribution, hardness and tensile strength of the joint interface area were investigated, the mechanism of interface formation and fracture behavior were analyzed. The results show that good metallurgical bonding was formed in the joints by electro-plating the solid 6101 aluminum alloy with a layer of zinc coating and carefully controlling the overcasting process. There is a transition zone between the two bonded aluminum alloys, and the fine equiaxed grained structure in the transition zone is due to the high undercooling during solidification. The tensile strength of the joint interface is higher than that of the as-cast A356 aluminum alloy(about 145 MPa) and the final fracture is always located in the as-cast A356 material.
目的:探讨胃肠道弥漫性大B细胞淋巴瘤(diffuse large B-cell lymphoma,DLBCL)中之染色体t(14;18)(q32;q21)易位及Bcl-2基因扩增与DLBCL亚型分类及病人预后间的关系;探讨其在胃肠道DLBCL发病中的作用机制。方法:应用荧光原位杂交(fluorescence in situ hybridization,FISH)技术检测45例胃肠道DLBCL组织中之t(14;18)(q32;q21)染色体易位及Bcl-2基因扩增情况;应用免疫组化染色法检测该45例胃肠道DLBCL中之Bcl-2蛋白的表达。结果:在45例胃肠道DLBCL病人中,10例(22%)存在t(14;18)(q32;q21)易位,10例(22%)存在Bcl-2基因扩增。t(14;18)(q32;q21)易位阳性者与阴性者间的亚型分类比例差异有统计学意义(P<0.01)。Bcl-2基因扩增阳性者与阴性者间之生存时间差异有统计学意义(P<0.05)。而t(14;18)(q32;q21)染色体易位及Bcl-2基因扩增与Bcl-2蛋白表达间均属无关(P>0.05)。结论:t(14;18)(q32;q21)染色体易位与胃肠道DLBCL的免疫表型分类相关,生发中心B细胞(germinal center B cell-like,GCB)型与非GCB型间存在分子遗传学差异。而检测Bcl-2基因扩增对判断胃肠道DLBCL病人的预后具有重要意义。
