甲基化的

During the two critical periods—gametogenesis and preimplantation development, there are genome-wide epigenetic reprogramming in gametes and embryos, which plays important roles in the erasion or creation of imprinting, gene silencing and tissue-specific gene expression.

其中关键时期是配子形成期和胚胎植入前期，最主要内容是全基因组DNA"CpG岛"甲基化和染色质组蛋白乙酰化的有规律变化，结果是配子遗传印记的消除与重建、植入前胚胎大范围基因的静默和组织特异性基因表达的确定。

Recombination suppression in the sex-determining region and accumulation of deleterious mutations lead to degeneration of the Y chromosomes in many species with heteromorphic X/Y chromosomes.

这个问题一直困扰着科学家，在2008年最后一期的世界著名杂志《基因组研究》上，王秀娥和张文立博士发表了《番木瓜原始Y染色体的雄性特异区中DNA甲基化和异染色质化》的研究论文，初步揭示了性染色体的起源变化机制。

The results indicated that Kail/CD82 is higher expressed in HT29 and SW480 than in LoVo and HCT116 whatever in mRNA or protein level.The possible mechanism of down regulation of Kail was also analyzed. By PCR-SSCP,8 exons of Kail,exon 3 to exon 10,were screened in LoVo and HCT116 cell lines. The methylation of CpG islands in promoter region was analyzed,and the expression level of p53 was detected by IH and Western Blot.

为进一步探讨Kai1基因表达下调的机制，本研究用PCR-SSCP技术分析了Kai1／CD82表达较低的LoVo与HCT116细胞系的Kai1基因第3～10外显子是否存在点突变，检测Kai1基因启动子区域CpG岛的甲基化状况，并用免疫组化与Western Blot等方法研究Kai1基因表达与p53异常之间的相关性。

Noma de México and the Instituto Nacional de Cancerolog?a, Mexico, demonstrate, for the first time, that a combination of a DNA methylation and a histone deacetylase inhibitor, can reactivate the expression of more than a thousand genes in primary tumours of breast cancer patients.

在PLoS ONE开始的一期，来自墨西哥国家癌症研究所和国家Aut大学Investi gaciones Biomédicas研究所的Due馻s-Gonzalez博士领导研究组第一次证明DNA甲基化和组蛋白去乙酰化的抑制物联合可以使乳腺癌患者在初期肿瘤时超过一千个基因的表达失活

Noma de México and the Instituto Nacional de Cancerolog?a, Mexico, demonstrate, for the first time, that a combination of a DNA methylation and a histone deacetylase inhibitor, can reactiate the expression of more than a thousand genes in primary tumours of breast cancer patients.

在PLoS ONE开始的一期，来自墨西哥国家癌症研究所和国家Aut大学Inesti gaciones Biomédicas研究所的Due as-Gonzalez博士领导研究组第一次证明DNA甲基化和组蛋白去乙酰化的抑制物联合可以使乳腺癌患者在初期肿瘤时超过一千个基因的表达失活

The calculational results are in good agreement with the X-ray data and show that different substitute group results in different charge distribution, the exocyclic sulfur atom has the biggest negative charge value and this site is the most likely site of protonation and methylation as well as the potential coordination site with metallic ions.

计算结果与X-射线衍射数据相符合，并显示虽然不同的取代基导致了不同的电荷分布，但四唑环外的硫原子总是具有最大的负电荷分布，从而使其成为最有可能的质子化、甲基化及与金属离子进行反应的点位。

Four new salicylaldehyde derivatives with a glucose or mannose moiety were synthesized with 2-tert-butylphenol or 4-tert-butylphenol as the starting material, followed by the formylation, chloromethylation, nucleophilic substitution reaction with the desired carbohydrate. The salicylaldehyde derivatives condensed with ethylenediamine to give the Schiff bases, which coordinated with Mn to afford four novel sugar-based Salen Mn complexes.

首先，分别以2-叔丁基苯酚和4-叔丁基苯酚为起始原料，经过甲酰化反应、氯甲基化反应、和糖类衍生物的亲核取代反应制得了四种新型并入葡萄糖基或甘露糖基的水杨醛衍生物，将它们与乙二胺缩合生成希夫碱配体，得到的配体与过渡金属Mn~(3+)配位制备出四种新型含糖基的Salen Mn配合物。

As our studies showed, silylation of mesoporous molecular sieves with alkoxysilane was an usual method of linking desired organical groups. However, as a result, the a lot of silanol groups still existed on the surface of mosoporous molecular sieves after silylation, which maybe affect the interface property and its catalystic activity. Based on this consideration, a novel method was proposed that a mixture of trichlorosilanes was used to silylate mesoporous molecular sieves, introducing both the further reactive group and hyhrophobic methyl group in one pot.

正如研究表明，通过硅氧烷与介孔分子筛表面的硅羟基反应是常见的键连有机基团的方法，但表面仍会剩余较多的硅羟基，硅羟基的存在会严重影响到介孔分子筛表面性质及催化活性，为此笔者提出采用混合的三氯化硅烷一步硅烷化介孔分子筛，在孔道内同时引入可进一步功能化的氯丙基或氯苄基和疏水性的甲基。

A novel polymer of Poly(diglycidyl maleate-co-stearyl methacrylate) was synthesized and its structure was characterized by ~1H NMR. Its self-assembly behavior was studied in different solvents. It was found that vesicles and tubule-liked aggregates can be obtained through self-assembly of P(DGMA-co-SMA)/THF/EtOH system. And spheral aggregates were obtained in P(DGMA-co-SMA)/THF/H_2O system while the spheral aggregates were converted into rod-liked aggregates and line-liked aggregates after aged for different time.

合成了带含环氧基侧链和十八烷基侧链的聚(马来酸二缩水甘油酯-co-甲基丙烯酸十八酯)，用~1H NMR对所得的共聚物进行了表征；研究了其在选择性溶剂中的自组装行为，发现P(DGMA-co-SMA)／THF／EtOH体系可以通过自组装形成囊泡形自组装体和支化的管状自组装体，P(DGMA-co-SMA)／THF／H_2O体系最初自组装形成球形自组装体，随着陈化时间的延长，球形自组装体逐渐融合成长条形自组装体和线形自组装体；探讨了自组装过程的机理，建立了可能的自组装过程模型。

Studies on many aspects show that there are four main reasons which cause the epigenetic effects;the methylation of DNA,the acetylation of histones,the change of chromatin structure and the alteration of protein configuration.

多方面的研究表明，导致后生效应的可能原因主要有四个方面：DNA的甲基化、组蛋白的乙酰化、染色质结构背景的改变和蛋白质构型的变化。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。