游离基因

Beta-thalassemia major is a serious hereditary hemolytic anemia which does great harm to human being.It is a monogenic disease characterised by a reduced synthesis of beta-globin chains,which dues to the Doint mutation or deletion of beta-globin gene and its control region.It not only decreases the hemoglobin level,but breaks the balance of alpha/beta synthesis ratio.The major cellular pathogenetic mechanisms in beta thalassemia are based primarily on the deleterious effects produced by the accumulation of the excess alpha globin chain.These excess alpha-globin chains cannot form stable tetrameric structure and deposit in erythroid cells.They cause large ineffective erythropoiesis on their own,accelerate red cells destruction,and lead to hemolysis.

地中海贫血是一种对人类健康危害严重的遗传性溶血性贫血病，是因β-珠蛋白基因及其调控序列的点突变或缺失致使β-珠蛋白肽链合成减少或完全停止，这不仅使患者血红蛋白水平降低，而且使原来在数量上与之持平的α-珠蛋白肽链相对过剩，这些相对过剩的游离α-珠蛋白肽链并不能形成稳定的四聚体，它们沉积在红细胞中导致了大量无效红细胞生成和红细胞寿命缩短，引起了严重的溶血性贫血。

The results indicated non-organic insertion genes in the transgenic cottons had some influence on the synthesis of these sugars and free amino acids.

这表明外源基因的导入已经影响到了转基因棉花品种中主要糖分与游离氨基酸的合成。

Circulating nucleic acids are extracellular nucleic acids found in cell-free serum, plasma and other body fluids from healthy subjects as well as in patients. The ability to detect and quantitate specific DNA and RNA sequences has opened up the possibility of diagnosis and monitoring of diseases, especially in the field of cancer.

循环核酸(circulating nucleic acid， CNA)是指存在于血液等体液中的细胞外游离DNA和RNA，与生理和病理状态下的细胞代谢密切相关，循环DNA和RNA水平的检测及其在基因诊断等方面的应用对于恶性肿瘤等疾病的诊断和监测具有十分重要的意义。

These data suggest that the terminal hairpin structure and ITRs of PfDNV play a key role in the rescue and gene correction process: sequence at the junction of the terminal palindrome of PfDNV genome and the pUC119 can form typical Holliday structure, it can be cutted by the special endonuclease, then the exposed 3'hairpin structure serving for a self-primer to initiate viral DNA replication; and the intact extremity acting as a template to repair another altered end within inverted terminal repeats.

说明存在着一种拯救和基因修复机制，推测与PfDNV基因组末端结构（Hairpin、ITR）有密切关系：PfDNV基因组与pUC119质粒连接处可形成Holliday结构而被识别该结构的核酸内切酶所切割，游离下的基因组3'发夹结构作为引物起始复制，然后被置换链的完整的5'ITR作为模板修复部分缺失的另一端ITR，推测这个过程需要病毒NS蛋白以及细胞因子的参与。

Keywords: Human embryonic stem cells; EBV episomal vectors; Stable transgene transfer/expression; RNA interference

中文关键词：人胚胎干细胞；EBV游离体载体；稳定基因转染/表达；RNA干扰

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。