单作用

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。

ResultsIn contrast with model group, Myricetin Dispersible Tablets(140 mg/kg,70 mg/kg and 35 mg/kg could significantly decrease the cerebral water content, MDA and LA contents, as well as the weight of venous thrombus , suppress MAO activity, and significantly increase SOD activity.

结果与模型组相比，杨梅素分散片各剂量组(140，70，35 mg/kg)均可显著改善脑水肿、减少过氧化脂质的形成，减少乳酸的聚积，并对单胺氧化酶有抑制作用；显著减轻大鼠静脉血栓重量；显著抑制ADP诱导的血小板聚集。

The Arabidopsis CYP81F2 gene encodes a P450 monooxygenase that is essential for the pathogen-induced accumulation of 4-methoxyindol-3-ylmethyl glucosinolate, which in turn is activated by the atypical PEN2 myrosinase (a type of β-thioglucoside glucohydrolase) for antifungal defense.

拟南芥CYP81F2基因能都编码一种P450单加氧酶，这对4甲氧基-3二甲胺基芥子油甙的病原体诱导积累物是十分重要的。反过来，它也能被非典型PEN2黑芥子酶激活，以产生抗真菌的防御作用。

Bioinformatics studies of the functional impact of alternative splicing have revealed a wide range of regulatory mechanisms, from NAGNAG sites that add a single amino acid; to short peptide segments that can play surprisingly complex roles in switching protein conformation and function (as in the Piccolo C2A domain); to events that entirely remove a specific protein interaction domain or membrane anchoring domain.

选择性剪切的功能性影响的生物信息学研究揭示了各式各样的调控机制，从添加一个单氨基酸的NAGNAG位点；到可以在开关蛋白质构象和功能(如在Piccolo C2A区域)中起到惊人地复杂作用的短肽片段；到完全移除一个特定蛋白质相互作用区域或膜锚定区域的事件。

The results suggest it be possible to establish the recombination bacteria of Nitrosomonas to oxidize the ammonia in wastewater.

第二步 ，由亚硝酸盐氧化成硝酸盐；其中第一步较慢，是限制性步骤，通过亚硝酸细菌完成，而在此过程中直接起作用的酶是氨单加氧酶(ammoniummonooxygenase，AMO)。

Results showed that the combined effect of Streptomyces and Nocardia sp markedly increased the corrosion tendency of steel A3, decreased the impedance value and increased the corrosion current density of the electrode after 21 days of exposure.

结果表明，与单种菌相比，混合菌作用下试样表面的腐蚀倾向增大，阻抗值降低，腐蚀电流密度增加。

Recent studies have shown single-section helical CT to be useful in differentiating perforated from nonperforated appendicitis, the authors explain, but the accuracy was not high for any single finding.

作者指出：近期的研究显示，单节螺旋CT可以对阑尾穿孔的诊断有一定作用，但其准确性一直不尽如人意。

Based on some related concepts of shock disturbed system, weakening buffer operators with variable weights and strengthening ones with variable weights are established respectively. This subject defines buffer operator regulation degree which reflects effect strength to original sequence caused by buffer operator, and also studie the relationship between buffer operator regulation degree and variable weight. Consequently, the monotonicity nonvariable axim of buffer operator is put forward.

基于冲击扰动系统的相关概念，提出了变权缓冲算子的概念，分别构造了变权弱化缓冲算子和变权强化缓冲算子，定义了缓冲算子调节度来反映缓冲算子对原始序列的作用强度，并研究了缓冲算子调节度与可变权重之间的关系，在此基础上提出了缓冲算子的单调性不变公理。

Single and double octyl phosphate are important anionic surfactants and corrosion inhibitors, which play very important role in the fine chemical and petroleum chemical industry.

磷酸单、双辛酯是重要的阴离子表面活性剂和缓蚀阻垢剂，在精细化工和石油化工行业起着非常重要的作用。

Neighbor-joining and Bayesian show Pslosium, Ophioglossum, and Selaginella are monophyletic group. Most parsimony analysis shows Lycopodiella are monophyletic group with Pslosium, Ophioglossum, and Selaginella.

高度简约分析则显示过山龙和其他的拟蕨共同形成一个单源群，本论文的结果和前人研究不同，推测是原始陆生植物之matK演化速率太快、造成谱系分析长枝吸引的作用。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。