滋养层的

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastocysts followed by fusion of cytoplasm and nucleus and cleavage in vitro. During the fusion of cytoplasm, the DNA methylation levels of the fused embryos are as high as these of two-cell diploid embryos in vivo Then the embryos are rapidly demethylated when the nucleus begin to fuse, resulting in the lowest DNA methylation levels when the nucleus are fused completely. After that, the DNA methylation levels of the fused embryos are gradually increased until the morula stage. However, whereas an asymmetric distribution of DNA methylation is established in vivo-derived blastocysts with a higher methylation level in the inner cell mass than that in the trophectoderm, we can not detect the asymmetric distribution in most in vitro-derived tetraploid blastocysts.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在桑葚胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastocysts followed by fusion of cyto-plasm and nucleus and cleavage in vitro. During the fusion of cytoplasm, the DNA methylation levels of the fused embryos are as high as these of two-cell diploid embryos in vivo Then the embryos are rapidly demethylated when the nucleus begin to fuse, resulting in the lowest DNA methylation levels when the nucleus are fused completely. After that, the DNA methy-lation levels of the fused embryos are gradually increased until the morula stage. However, whereas an asymmetric distribu-tion of DNA methylation is established in vivo-derived blastocysts with a higher methylation level in the inner cell mass than that in the trophectoderm, we can not detect the asymmetric distribution in most in vitro-derived tetraploid blastocysts.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在桑葚胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastcysts fellowed by fusion of cytoplasm and nucleus and cleavage in vitro.After fusion of cytoplasm, the DNA methylation levels of the fused embryos was very high as well as two-cell diploid embryos in vivo.Then the embryos was rapiddly demethylated when the nucleus begin to fuse, resulting the lowest DNA methylation levels when the nucleus fused completely.After that, the DNA methylation levels of fused embryos were gradually increased until the blastocysts stage.However, whereas an asymmetric distribution of DNA methylation was established in an vivo-derived blastocysts with a higher methylation level in the inner cell mass than in the trophectoderm, in most vitro-derived tetraploid blastocysts, we can not detect the asymmetric distribution.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在囊胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Embryonic germ layer on ventral aspect of the bilaminar disk that gives rise to endoderm.

双层椎间盘腹侧形成滋养层细胞的三个胚层组织引起的内胚层。

Objective To study the relationship between postdate labor and the trophoblast apoptosis by observing the expression of Survivin protein in the trophoblasts of placenta.

目的 通过观察过期妊娠患者凋亡抑制蛋白Survivin在胎盘滋养细胞层的表达，探讨滋养细胞凋亡与过期妊娠的关系。

In order to avoid the shortcomings of cytotrophoblasts from early first trimester or term villous cytotrophoblast, the differentiated RS366. 4 was used as new early cytotrophoblast model.

为避免由早期胚胎标本或胎盘来源的细胞滋养层细胞模型的不足，本实验选用由猕猴RS366.4 ES细胞来源的早期分化滋养层细胞为模型进行研究。

As we know that human placentalsyncytiotrophoblast cell derlves from the fused cytotrophoblast cell and fetal calfserum can be able to induce the term placental cytotrophoblast cell fusion in vitro.

妊娠过程中，合体滋养层细胞分泌的hCG可促进卵巢黄体和胎盘分泌孕酮，在维持妊娠中起着重要的作用；然而未分化的细胞滋养层细胞不能合成hCGβ。

Through upregulating the production of MMPs in deciduas and chorionic villi, the upregulation of the expression of EMMPRIN in syncytiotrophoblast and cytotrophoblast column of the villi in the threatened abortion can degenerate deciduas and denudates embryo.

发生先兆流产时合体滋养细胞、细胞滋养层柱所表达的EMMPRIN增强可能通过上调绒毛及蜕膜组织中基质金属蛋白酶的水平，降解细胞外基质，使绒毛剥离、蜕膜组织剥脱。

The trophoblast blood flow spectrum could be easily detected with the guide of CDE.The ultrasonic findings were characterized by broad arterial flow spectrum,high diastolic component of the low resistance trophoblastic flow,RI＝0.40～0.51 with single or biphasic spectrum.The salpingian ring with high blood flow indicated early and complete salpingian pregnancy.

结果：①异位妊娠包块血流信号丰富，血管连续性好，能较完整显示血管床、血管网及范围广的低流速血流信号；②脉冲多普勒取样为滋养层周围性血流频谱，其特征为：频谱增宽、单相或双相持续存在、阻力降低(RI＝0.44±0.04)、舒张期血流丰富的动脉频谱；③具有鲜明丰富的滋养层周围性彩色血流频谱特征的&输卵管环&是早期输卵管妊娠的特征性表现，并提示是输卵管完整存在的标志。

The a -Gal remarkably positive staining was appeared in membrane and plasm on ES cell, but nuclear is negative. It indicates that we must pay attention to HAR in cell xenotransplantation, especially differentiation ES cell in vivo.

筛选过程中在选择性培养基中添加LIF和BMP一2替代滋养层细胞，发现ES细胞的生长没有受到影响，提示在做基因敲除胚胎干细胞的筛选中可以不需要制备Nco抗性的滋养层细胞。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐