保护层厚度对受拉与受压粘结强度的影响

针对不同混凝土保护层厚度,分别进行了12个拔出试验和18个推出试验,并对试验结果进行了对比与分析.结果表明：当保护层厚度较小时,无论是拔出试件还是推出试件,均发生劈裂破坏;当保护层厚度较大时,推出试件钢筋被缓缓推出,混凝土没有开裂;增加混凝土保护层厚度既可以提高钢筋的受拉粘结强度,也可以提高钢筋的受压粘结强度;混凝土保护层厚度在一定限值范围内对钢筋受拉粘结强度影响较大.     

Innate partnership of HLA-B and KIR3DL1 subtypes against HIV-1

Allotypes of the natural killer (NK) cell receptor KIR3DL1 vary in both NK cell expression patterns and inhibitory capacity upon binding to their ligands, HLA-B Bw4 molecules, present on target cells. Using a sample size of over 1,500 human immunodeficiency virus (HIV)+ individuals, we show that various distinct allelic combinations of the KIR3DL1 and HLA-B loci significantly and strongly influence both AIDS progression and plasma HIV RNA abundance in a consistent manner. These genetic data correlate very well with previously defined functional differences that distinguish KIR3DL1 allotypes. The various epistatic effects observed here for common, distinct KIR3DL1 and HLA-B Bw4 combinations are unprecedented with regard to any pair of genetic loci in human disease, and indicate that NK cells may have a critical role in the natural history of HIV infection.