甲基

They were eucalyptol, bicyclo［2.2.1］heptan-2-one,1,7,7-trimethyl-,(1R)-, borneol, 1-methyl-2-(1-methyl ethenyl)-(1R-cis)-cyclobutaneethanol, limonene, 1-hydroxymethyl-7,7-dimethy lbicyclo［2.2.1］heptan-2-one,-spathulenol, 3,7,11,15-Tetramethyl-2-hexadecen-1-ol, isocitronellol,-9-Octadecenoic acid, heneicosane, respectively.

阿给中共有11个阿给炭没有检测出的成分，包括桉油精、D-樟脑、冰片、(1R-cis)- 1-甲基-2-(1-甲基乙烯基)环丁基乙醇、二戊烯、1-羟甲基-7，7-二甲基-双环［2.2.1］庚-2-酮、-匙叶桉油烯醇、3，7，11，15-四甲基-2-十六碳烯-1-醇、异香茅醇、-9-十八碳烯酸和廿一烷。

The types of histone methyltransferases, the relationship between methylation of Lysine 9 of H3 and the formation of heterochromatin, gene regulation in euchromatin, and that with DNA methylation, were mainly introduced.

主要阐述了组蛋白甲基转移酶的类型，组蛋白H3中第9位赖氨酸甲基化与异染色质的形成、常染色体中基因表达的调控，以及与DNA甲基化之间的关系，说明了组蛋白甲基化与组蛋白乙酰化、磷酸化的相互关系，指出组蛋白甲基化对维持细胞各种状态的平衡起到极其重要的作用。

N,N-dimethyl-N'-(2-trifluorometyl-1-pentafluoroethyl) perfluoro propenyl propane diamine and N,N-dimethyl N'-(2-trifluorometyl-1-pentafluoroethyl) perfluoro propene propane diamine were prepared by the reaction of hexafluoropropene dimer and N,N-dimethyl propanediamine in the molar ratio 1:1.0 at about 35℃for 8h, and the structures of I were identified by IR and NMR spectra.

本文以六氟丙烯二聚体和N，N-二甲基丙二胺为主要原料合成了两种含氟中间体叔胺——N，N-二甲基-N'-(2-三氟甲基-1-五氟乙基)全氟丙烯基丙二胺和N，N-二甲基-N'-(2-三氟甲基-1-五氟乙基)全氟烯丙基丙二胺，用薄层色谱和柱色谱等方法对产品进行分离提纯，并运用红外光谱和核磁共振等分析手段对其结构进行了表征。

In the process of laboratory study, oxycodone was prepared by oxidating thebaine at 6,14-position under oxydol, hydrodeoxidizing 7,8-position double bond and 14-position ether under palladium catalyst. Furthermore, N-methyl of oxycodone was isolated byα-chloro-ethyl chloroformate under anhydrous condition and protection of 14-position hydroxyl to obtain noroxycodone, which was further converted into methylnaltrexone by N-alkylation in presence of cyclopropyl bromomethane, then by isolating 3-position methyl of methylnaltrexone under boron tribromide, becoming hydrochloride to prepare target compound, natrexone hydrochloride.

实验室工艺方面，本文首先用双氧水氧化蒂巴因的6-位和14-位、在钯炭催化下加氢还原7-8位双键和14-位醚合成羟考酮，然后提出并优化了在无水和14-位保护的情况下，用氯甲酸-α-氯乙酯脱去羟考酮的N-位甲基合成去甲羟考酮，再用环丙甲基溴将去甲羟考酮的N-位烷基化合成甲基纳曲酮，最后采用三溴化硼脱去甲基纳曲酮的3-位甲基和成盐酸盐合成盐酸纳曲酮。

In the case of coat color, cells descended from a particular precursor stay together and thus form a patch of the same color, creating the pattern of visible variegation.

甲基化状况可以因两种方式而丧失。甲基可能被一种去甲基酶主动除去，或者甲基化在复制产生的半甲基化位点不能发生。

Chemiluminescent immunoassay is one of the advanced immunoassay ofnon-radioisotopic immunoassay because of its high sensitivity, wide dynamic range,high accuracy, stable labeled protein, full automation and extensive application field.CLIA using acridinium ester derivatives as chemiluminescent label has advantages oflow background, high signal-to-noise ratio, no need of catalyst and simpleluminescence system. Different aspects associating the DMAE·NHS-based CLIA were studied in thisthesis, including synthesis of acridinium ester, chemiluminescentcharacteristics of DMAE·NHS, labelling antibody or streptavidin with DMAE·NHS,two-site sandwich chemiluminescent immunoassay for TSH, two-sitesandwich chemiluminescent immunoassay involved biotin-streptavidinsystem for TSH, and competitive chemiluminescent immunoassay usingbiotin-streptavidin system for TT〓. The desired acridinium ester, DMAE·NHS, was synthesized according to thereference method with some modifications. The products were identified by IR, NMR,MS and elemental analysis. In our method, KOH was used in place of NaOH tosynthesize benzyl ester of 3,5-dimethyl-4-hydroxybenzoic acid,2',6'-dimethyl-4'-(n-succinimidyloxycarbonyl) phenyl-acridinium-9-carboxylate waspurified on a silica gel column with chloroform/ethylacetate(4:1, v/v) as eluent andfurther purified by triturating with hexane/acetone(2:1, v/v).

DMAE·NHS的合成是本论文的关键和难点，我们对文献方法进行改进：文献方法用氢氧化钠与3，5-二甲基-4-羟基苯甲酸反应制得3，5-二甲基-4-羟基苯甲酸钠，再用3，5-二甲基-4-羟基苯甲酸钠与苄氯作用制备3，5-二甲基-4-羟基苯甲酸苄酯，我们用氢氧化钾代替氢氧化钠，使合成取得成功；在合成2'，6'-二甲基-4'-苯基-吖啶-9-甲酸酯时，文献方法对粗产品进行两次硅胶柱层析纯化，第一次柱层析用氯仿／乙酸乙酯(4∶1，V∶V)作溶剂和淋洗剂，第二次柱层析用己烷／丙酮(2∶1，V∶V)作溶剂和淋洗剂，按照文献方法得到的不是所需要的化合物，我们只进行第一次柱层析纯化，然后用己烷／丙酮(2∶1，V∶V)进行研磨，过滤，洗涤，除去溶于己烷／丙酮(2∶1，V∶V)的部分，得到所需要的产品。

Although the biological significance of DNA methylation has been recognized to some extent, the mechanisms of DNA methylation regulation and of the establishment of tissue-specific DNA methylation pattern in somatic cells are still unclear, since the knowledge of the enzymes responsible for de novo DNA methylation and demethylation of DNA is very limited and up to now only two functional DNA methyltransferases in mammals have been cloned.

目前，虽然对DNA甲基化的作用已有一定认识，但DNA甲基化的调节以及发育过程中组织特异的DNA甲基化谱的建立机制还不清楚。问题主要在于对催化重新甲基化和去甲基化反应的酶的了解很少。至今仅克隆出两种有功能的哺乳动物DNA甲基转移酶。

Methyl-5-ethyl-2-thiouracil,m.p.211°,was prepared according to the direc- tions of Johnson and Baily.4-Methyl-5-ethyl-uracil,m.p.236°,was formed in a 81% yield from 4-methyl-5-ethyl-2-thiouracil by boiling the latter with an aqueous solution of monochloroacetic acid.4-Methyl-5-ethyl-uracil reacted with phosphorous oxychloride and phosphorous pentachloride,giving 4-methyl-5-ethyl-2,6-dichloropy- rimidine in a 79% yield.

14-甲基5-乙基-2，6-二氯代嘧啶曾用磷醯氯和五氯化磷与其相应的2，6-二羟基嘧啶作用制取。(2)4-甲基-5-乙基-2，6-二氯代嘧啶与醇钠作用，极易转变成4-甲基-5-乙基-2，6-二烷氧基嘧啶。(3)4-甲基-5-乙基-2，6-二甲氧基嘧啶和2-氧代-3，4-二甲基-5-乙基-6-甲氧基嘧啶在高温时重排成其稳定构型的的异构体：1，3，4-三甲基-5-乙基-2，6-二氧代嘧啶。

RESULTS: APC promoter 1A was methylated in NCI-H460 cells, and unmethylated in NCI-H446 and SPC-A1 cells. Hypermethylation was detected in all 5 CpG islands (687, 707, 714, 719, 726) of APC promoter 1A in NCI-H460 cells. The expression of APC in NCI-H460 cells was decreased by 26.04% of that in NCI-H446 cells and by 32.36% of that in SPCA1 cells. After treatment of 1, 5, 10, 15μmol/L 5-aza-dC, the expression of APC promoter 1A in NCI-H460 cells was enhanced by 4.59, 5.78, 9.58, 5.98 folds, respectively.

结果：SPC-A1和NCI-H446细胞APC甲基化阴性，NCI-H460细胞APC甲基化阳性；甲基化芯片检测Ncl-H460细胞在APC启动子1A 5个CpG位点均存在甲基化(687、707、714、719、726)，SPC-A1和NCI-H446甲基化阴性，荧光定量结果NCI-H460的APC转录较SPC-A1和NCI-H446有明显的下降，仅为二者平均的30.04%；经5-aza-dC脱甲基化作用后，NCI-H460细胞的APC表达增加了约5~10倍，其中10μmol/L浓度作用下，APC表达增加最多。

There is not a significant difference in these groups by one-way analysis of variance. 2 Among 51 cases with lung cancer, 7 specimens showed malignant cells in bronchial lavages, including 4 cases in central lung cancer and 3 cases in peripheral lung cancer. Concordant results were observed in 20 cases. 6 specimens showed malignant cells on cytological analysis, and NMSP was positive in at least one gene tested. 14 samples did not show malignant cells on cytological analysis, and the NMSP results were correspondingly negative. The results of cytology and NMSP were discordant in 31 samples. 30 samples were cytologically negative, but NMSP positive in one or more genes. In addition, there was one case that the cytology was positive for malignant cells, but the NMSP was negative in all of the three gene tested.

51例肺癌患者支气管灌洗液细胞学检查发现肺癌细胞7例，其中27例中心型肺癌患者4例支气管灌洗液发现肺癌细胞，24例周围型肺癌患者3例支气管灌洗液发现肺癌细胞。20例支气管灌洗液细胞学检查和过甲基化检测得到一致结论。6例支气管灌洗液发现肿瘤细胞，过甲基化分析至少一个基因阳性。14例灌洗液未发现肿瘤细胞，三个基因过甲基化分析均为阴性。31例支气管灌洗液细胞学检查和过甲基化检测得到不一致结论，30例细胞学检查为阴性，但过甲基化分析一个或一个以上基因为阳性。1例细胞学检查阳性但过甲基化分析阴性。

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。