机制

The research progress of monomeric isocitrate dehydrogenase was reviewed in this paper,including the spatial stru...

本文主要对单体IDH的空间结构、催化机制及分子进化机制等研究进展进行了综述。

Asymmetric dimethylarginine and monomethyl arginine are endogenously produced amino acids that inhibit all three isoforms of nitric oxide synthase.

点评：内皮一氧化氮以及一氧化氮合酶是目前门静脉高压症以及相关并发症的发病机制的研究热点之一，本文研究了抑制NOS的内源性氨基酸类化合物的清除酶—-二甲基精氨酸–二甲氨基水解酶，进一步的深入探究了这一发病机制，为今后治疗作用位点的选择、药物研发以及相关实验研究提供了一定的理论依据，个人认为该实验意义较大。

The main features of the river basin eco-economic system are as follows: it is an open and non-balanced complex system; there exist non-linear mechanisms; and there are lots of random fluctuations with their amplifying mechanism and mutative qualities inside and outside the system.

流域生态经济系统的特征主要表现为流域生态经济系统是一个开放的复杂系统；是一个非平衡和复杂系统；存在着非线性作用机制；并且系统内外存在着大量的随机涨落及其涨落的放大机制和突变性。

However, a successful plant-fungal endophyte interaction requires the fine tuning of antagonistic interactions, which implies the evolution of unique self-regulating mechanisms on both sides to maintain a mutualistic interaction.

但这种生理功能的实现有赖于双方精细的调控机制，表明宿主和真菌双方都进化形成特有的分子调控机制来维持这种互惠共生关系。

Majority of acute leukemias in infant, either acute lymphoblastic leukemia or acute myeloblastic leukemia, posses a chromosomal translocation affecting the 11q23 chromosome region which specifically inoles the mixed-lineage leukemia gene.1-3 Most pediatric leukemias with MLL rearrangement clearly hae a remarkably short latency.1,4 MLL gene rearrangement is also associated with secondary leukemias of patients preiously treated with the topoisomerase II inhibitors.4 The latency of these secondary leukemias is similarly ery short.4 Of note, the concordance rate of leukemia with MLL rearrangement in infant monozygotic twins approximates to 100%,1,4 and identical breakpoint in the MLL gene was shared in these pairs of identical twin infants with concordant ALL.1,4 Moreoer, the unique and clonotypic MLL fusion gene was detectable in neonatal blood spots for Guthrie cards from non-twined indiiduals who subsequently deeloped ALL.1,4 These obserations indicate not only that MLL fusion is generated in utero but also that MLL fusion proteins could be capable of inducing leukemic transformation with few, if any, secondary mutations.2,3,4 Greaes et al speculate that an MLL fusion protein somehow promotes rapid transition to full-blown disease in patients ia ery rapid clonal expansion, genetic instability, or inhibition of DNA damage repair.4 In general, for clonal expansion of malignancies, tumor cells often hae acquired strategies that escape immune sureillance of the hosts.5,6 Immune escape mechanisms also contribute to the failure of graft-ersus-leukemia effect after allogeneic hematopoietic stem cell transplantation.7 Therefore, leukemia cells could acquire some immune escape mechanisms during leukemogenesis.

绪论 绝大多数的婴儿白血病，不管是急性淋巴性白血病或是急性骨髓性白血病，在染色体11q23部位有染色体易位的情况；这个部位的染色体易位牵连了混合谱系白血病基因。大多数具有MLL基因重排的儿童白血病潜伏期明显短很多。MLL基因重排也和经拓扑异构酶II抑制剂治疗后的继发性白血病有关。这些继发性白血病的潜伏期类似地都非常的短。很重要的是，单卵双胞胎婴儿同时患有或同时免于MLL基因重排阳性的白血病的一致性接近100%；并且同样患有ALL的同卵双胞胎的MLL基因的断裂点是一致的。而且，这种独特的克隆特异性的MLL融合基因能够从那些得ALL的非双生个体出生时的血斑标本中检测到。这些发现表明MLL融合基因产生在胎儿还在子宫的是后，而且MLL融合蛋白能过和其他的基因突变一起诱导白血病的产生。Greaes 等推测MLL融合蛋白在某种情况下同过快速克隆增殖，遗传的不稳定性或是DNA损伤修复的抑制促使疾病迅速地全面爆发。恶性肿瘤细胞的克隆增殖通常已经获得了逃避机体免疫监视的能力。免疫逃避机制也归因于异体外周血干细胞移植后移植物抗白血病作用的失效。所以，白血病细胞在白血病的产生过程中可能获得了某些免疫逃脱机制。

Results: ApoD was observed positively expressed in type2 astrocytes and oligodendrocytes from O2A lineage, while it was not expressed in type1 astrocytes from T1A lineage. Accordingly, we can verify the phenomenon found in the study of T1A and T2A gene different expression profile that ApoD mRNA was highly expressed in T2A and lowly expressed in T1A. Conclusion: It can be concluded that lipid metabolism related genes such as ApoD play important roles in the generation and differentiation of O2A lineage, which closely correlate with internal mechanism of lipid metabolism in the brain and myelogenesis.［Key words］astrocyte(T1A, T2A); oligodendrocyte; O2A lineage; apolipoproteinApoD

我们已采用基因芯片技术在mRNA水平研究两型星形胶质细胞的基因表达谱差异，发现ApoD在2型星形胶质细胞中差异高表达，故本文拟用激光共聚焦双重免疫荧光标记技术进一步在蛋白质水平观察ApoD在体外分化成熟的两型星形胶质细胞以及少突胶质细胞中的表达情况，以期为我们深入研究ApoD等脂代谢相关基因在脑内脂质代谢和神经髓鞘发育机制中所起的作用提供有用的实验依据，依此探讨胶质细胞发生和分化的信号机制。

Background and ObjectiveVitiligo is a kind of disease characterized by the depigmentation of the skin and hair because of acquired melanocytes damage. At present, the pathogenesis of vitiligo remains unclear, but many domestic and abroad researches have proved that vitiligo may be related with heredity, immunity and nerval elements.

一、研究背景和目的白癜风是一种获得性黑素细胞破坏所致皮肤和毛发色素脱失，其发病机制目前尚不清楚，国内外大量研究表明，该病发病机制可能与遗传、免疫、神经等方面有关。

Besides, The nodulation with else host experiment told us that NWGX035 could nodulate with melilotus suaveolens Ledeb, sophora alopecuroides Linn, lotus corniculatus Linn, sophora viciifolia Hance, trifolium repens Linn. The property of powerful salt, alkali, high temperature endurance and wide nodulation could confirm this strain was a particular strain.

另外，回接其它寄主植物的试验表明， NWGX035能与草木樨、黄化苦豆子、百脉根、狼牙刺和白三叶共生结瘤，其广泛的共生结瘤范围和强的耐盐、碱和抗(来源：A9fBC论文网www.abclunwen.com)高温特性可以证明该菌株为一株性状优良的菌株，其共生结瘤机制和耐盐碱机制需进一步研究。

Given dividing campus culture into two kinds of cultures, namely, the academic culture and the nonacademic culture, the author discussed their medium function in affecting college students' quality respectively, coneluded the affecting mechanisms of campus culture and their cooperation characteristic the closed process mechanism and the open adjustment mechanism.

大学校园文化通过发挥内部教育功能，从意义表达和具体操作两个功能层面，直接与大学生素质培养活动相联系，影响大学生的培养和发展。 8、大学校园文化影响大学生素质的培养和发展，以大学办学思想为核心、大学教师文化主体为重要载体、通过学术性与非学术性文化活动两大基本途径，具有它自身的组织与运行原理；形成影响大学生素质的闭合过程机制和开合的调谐机制。

We summarize the main results appeared in literature related to the topic and study the performance of nonblocking packet switches with speedup mechanism and back-pressure scheme.

我们总结了文献中关于此问题的有关结果，分析了采用加速机制和反压机制的无阻塞交换机的性能。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。