加合化合物

However, there is no difference for NAT2 rapid and slow acetylator between two groups.

吃红烧鱼因素在NAT2的快速酶中，特别是在野生纯合型中直肠腺瘤复发的相对危险度有增高趋势，提示了NAT2〓4等位基因编码快酶型NAT，可能在红烧鱼产生的杂环胺类化合物中代谢中加速其N-乙酰基化代谢过程，从而加速其代谢为终致癌物而与肠粘膜上皮细胞的DNA产生加成物，损伤其遗传物质。

Nevertheless, Smoking could interact with wild type of NAT2 and increase the relative risk of rectal adenoma recurrence significantly. It is suggested that NAT2 might involve the metabolism of pre-carcinogen generating from tobacco and alter the susceptibility of cancer. Meanwhile, the NAT2〓4 alleles encode rapid acetylator of NAT2 would increase the risk of adenoma recurrence among those high-risk people with habit of fried fish intake.

吃红烧鱼因素在NAT2的快速酶中，特别是在野生纯合型中直肠腺瘤复发的相对危险度有增高趋势，提示了NAT2〓4等位基因编码快酶型NAT，可能在红烧鱼产生的杂环胺类化合物中代谢中加速其N-乙酰基化代谢过程，从而加速其代谢为终致癌物而与肠粘膜上皮细胞的DNA产生加成物，损伤其遗传物质。

Firstly, 3-ethylthiobutanal was prepared from crotonaldehyde reacting with ethanehiol in triethylamine with high yield. Secondly, methyl acetoacetate was converted to 6-ethylthiohept-3-en-2-one by three steps via hydrolysis, condensation with 3-ethyltio-butanal and dehydration, then 6-ethylthiohept-3-en-2-one was cycloco ndensed with dimethyl malonate by Michael addition and Claisen condensation, followed by saponification and decarboxylation to give the intermediate of 5-(2-ethylthiopropyl)-cyclohexane-1,3-dione.

首先，以巴豆醛与乙硫醇为原料，在三乙胺的催化作用下高收率制得3-乙硫基丁醛；然后从乙酰乙酸甲酯出发，通过碱水解、与3-乙硫基丁醛缩合、脱水三步反应合成6-乙硫基-3-烯-2-庚酮，接着6-乙硫基-3-烯-2-庚酮与丙二酸二甲酯通过Michael加成和Claisen缩合成环，再通过皂化和脱羧反应生成中间体5-[2-丙基]-1，3-环己二酮；再与丙酸酐反应丙酰化，最后与0-3-氯-2-丙烯基羟胺肟化，得到目标化合物烯草酮。

Recent advances in addition,reduction,and asymmetric reactions of imines were reviewed.

亚胺是一类羰基化合物与氨的缩合产物，作者综述了近年国内外亚胺在加成、还原和不对称反应等方面的研究进展

Knoevenagel condensations of aromatic aldehydes with active methylene compounds were performed in the presence of room temperature ionic liquid without any additional volatile organic solvents.

6利用室温离子液体作催化剂，在无另加有机溶剂的条件下，考察了芳香醛和活泼亚甲基化合物的Knoevenagel缩合反应。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。