甲基

The magnetic carboxymethylated chitosan-Fe3O4 nanocomposites were synthesized by one-step enwrapping method in which the magnetic Fe3O4 nanoparticles prepared via a modified co-precipitation method were enwrapped directly by carboxymethylated chitosan.

首先采用改进的共沉淀法制备四氧化三铁磁性纳米粒子，然后通过一步包埋法，将磁性纳米粒子用天然多糖物质－羧甲基壳聚糖直接进行包覆，制备出羧甲基壳聚糖磁性纳米复合物。

In order to utilize lignin effectively, base on the situation in China, the study was carried on systematically, centering around the topic of two step sulfomethylation of the soda lignin of wheat straw (the first step is methylolation, the second is sulfonation) and its application. The main purpose is to develop a heterogeneous catalytic system which not only catalyzes but also homogenizes the lignin molecule in the reaction.

为真正高效利用碱木素，木论文根据我国实情，紧紧围绕着麦草碱木素两步磺甲基化（第一步为羟甲基化，第二步为磺化）及其应用这一主题，以开发出在反应过程中既可催化反应又能使木素分子均一化的多相催化体系为主要目标，系统地展开了研究。

To investigate the characteristics of arsenic methylating metabolism in population in coal-burning type arsenism endemic area and in control area, and to explore the difference between the two population.

目的 描述燃煤型砷中毒病区人群与非病区人群砷甲基化代谢的特征，比较两区人群砷甲基化代谢水平的差异。

Recent progress of dimethyl carbonate which acted as methylating reagent in methylation reaction s that took place on carbon, oxygen, nitrogen and sulfur atoms was reviewed.

综述了碳酸二甲酯作甲基化试剂在碳、氧、氮和硫原子上进行甲基化反应的研究进展，提出了今后研究工作的发展方向。

In addition,we described an intriguing property of TR3 to inhibit the methyltransferase activity of PRMT1 by targeting to the PRMT1 catalytic region,resulting in the loss of the ability of PRMT1 for methylating its substrates.

我们还进一步发现，TR3不能被PRMT1甲基化的原因是TR3通过和PRMT1的催化区域直接结合抑制了PRMT1的甲基转移酶活性。

cDNA microarray was an effective and useful method to survey gene expression profiles in pancreatic carcinoma. MBD1、EDG1 and its hyper methylating modulation may play an important role in the pathogenesis of pancreatic cancer, among which the high expression of MBD1 in pancreatic cancer would be the key modulating point in the down regulation of multiple methylation related suppression genes transcription.

cDNA微列阵技术为胰腺癌相关基因表达谱的分析提供了有力的工具，MBD1、EDG1等基因过甲基化表达调控可能在胰腺癌发病机制中起着关键作用，而MBD1在胰腺癌中高表达可能是多个甲基化相关抑癌基因转录表达下降的关键调控点。

MBD1、EDG1 and its hyper methylating modulation may play an important role in the pathogenesis of pancreatic cancer,among which the high expression of MBD1 in pancreatic cancer would be the key modulating point in the down regulation of multiple methylation related suppression genes transcription.

cDNA 微列阵技术为胰腺癌相关基因表达谱的分析提供了有力的工具，MBD1、EDG1等基因过甲基化表达调控可能在胰腺癌发病机制中起着关键作用，而MBD1在胰腺癌中高表达可能是多个甲基化相关抑癌基因转录表达下降的关键调控点。

The specific inhibitor of DNA methylation that is available currently is 5-Aza-2'-deoxycytidine (5Aza-dc), which forms a covalent bond with the DNA methyltransferase, thus, limiting the number of free DMT molecules for methylating DNA and then decreasing its biology activity.

目前研究较多的甲基化抑制剂是胞苷类似物5-氮杂-2'-脱氧胞苷(5-Aza-2'-deoxycytidine， 5Aza-dc)。5Aza-dc的作用机制是与DNA甲基转移酶共价结合，降低酶的生物活性。

A DNA demethylating agent. This finding suggests that Met induce the flowering of detached cotyledon culture perhaps through acting as a methyl donor of DNA methylating not as the precursor of ethylene synthesis.

上述结果说明：10^(-5)M Met浸种3 h能显著促进子叶培养物的花芽形成，Met对离体子叶成花的诱导作用可能是作为甲基供体通过DNA甲基化途径来实现的。

The shorter variant mHemk2 is 1696 bp in length encoding a putative mouse protein of 14.7 kDa, consisting of 138 amino acid residues.In protein data bank annotations, Hemk has previously been classed among methyltransferases methylating N6-adenine or N4-cytidine in DNA because of the presence of S-adenosyl-L-methionine binding motif and of an NPPY motif in the protein.

在蛋白数据库的注释中，由于在Hemk蛋白中存在S-腺苷-L-甲硫氨酸结合基序和一个NPPY基序，因此，在蛋白库的说明中已经将Hemk蛋白归类于能甲基化DNA中N6-腺嘌呤或N4-胞嘧啶的甲基转移酶。

Now, however, all children continue in "comprehensive" schools, and the eleven-plus determines which courses of study the child will follow.

然而现在，所有的孩子都要在综合学校继续学习，所以这次考试只是决定他们将要学习哪些课程。

Cultivatable land , and led to a general recognition that development must not be carried at the cost of agriculture .

城区的迅速扩大在很多情况下侵占了宝贵的可耕地，使人们普遍认识到发展不能以牺牲农业为代价。