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排序方式: 共有31条查询结果,搜索用时 15 毫秒
1.
利用端粒重复序列扩增(TRAP)法进行了山羊卵母细胞和附植前胚胎的端粒酶活性的测定;结果表明,山羊卵母细胞和早期胚胎的端粒酶活性都为阳性。TPG定量比较发现,卵母细胞的TPG最低,为25.348U;4-细胞的TPG为273.832U,至8-细胞时,TPG又降低到56.117U,随后快速升高,桑椹胚的TPG为251.111U;囊胚的端粒酶活性最高,TPG为519.46U。  相似文献   
2.
为了建立适于鸭瘟病毒(DPV)弱毒增殖的细胞系,利用4个主要组织相容性复合体(MHC)单倍型鸭品系,体外分离鸭胚肝细胞,在干细胞因子、白细胞抑制因子和成纤维细胞生长因子诱导下,获得鸭胚肝间充质干细胞(DuLMSC)。接种DPV疫苗株C-KCE后,结果显示:F1~F10代均能稳定出现CPE;将F10病毒接种细胞24 h后,通过扫描电镜在胞质、胞核及细胞间隙均能够观察到典型的疱疹病毒粒子;F1至F10代均能扩增出DPV UL2基因片段,序列测定结果表明F1、F5、F10代的扩增产物与NCBI中公布的DPV株(EU082088)的核苷酸同源性为100%;组织培养半数感染量和一步生长曲线结果表明,源自B4系单倍型鸭的DuLMSC细胞系增殖DPV的病毒含量明显高于B1、B2和B3系。本研究为稳定培养鸭瘟病毒提供了优良稳定的实验材料。  相似文献   
3.
This article examines how the recently introduced law on assisted reproduction in Italy, which gives symbolic legal recognition to the embryo, came about, and how a referendum, which would have repealed large sections of it, failed. The occupation of the legal space by the embryo is the outcome of a crusade by a well-organised alliance of theo-conservatives. These groups see in reproductive medicine an uncontrolled interference with their notion of the natural order of things. Such a worldview requires a total ban on stem cell research, limitation of access to reproductive technologies and repressive laws to govern the area. This conservative dream scenario has come closer to being realised by the introduction of a law doing all of these things in the name of the protection of “Life”. In the case of this law, the “life” to be protected is the embryo. In the name of “Life”, scientific advances and individual liberty have been curbed. The politics of embryo citizenship is a politics which values the yet to come over the here and now, purgation over pleasure, and the transcendent over the material.  相似文献   
4.
根据鸡胚致死孤儿(CELO)病毒Phelps株的fiber1基因(GenBank序列号U46933)序列设计了1对引物,采用PCR扩增CELO病毒fiber1基因C端(包含Knobs区)的部分片段,并将其克隆到质粒表达载体pGEX6p1,获得的阳性克隆命名为pGEXAF807。序列分析表明,所获得的DNA片段核苷酸序列与CELO病毒Phelps株的fiber1基因序列完全一致。将pGEXAF807转化大肠埃希氏菌DH5α,经37℃、0.6mmol/LIPTG诱导表达5h,SDSPAGE分析超声裂解后的上清和沉淀。结果显示,目的蛋白以包涵体形式存在,蛋白分子质量约为54.6ku,目的蛋白量占菌体总蛋白的35.7%。用CELO病毒多克隆血清做Westernblotting试验,结果表明目的蛋白具有较好的抗原活性。  相似文献   
5.
选用氮酮和丙二醇作促渗透剂,观察2种渗透剂在气室膜对台盼蓝的促渗透作用及对鸡胚的毒性作用.结果表明,10、20和40 g/L氮酮均有明显的促渗透作用,且其间差异不显著,但随其浓度升高,对鸡胚的毒性作用增强.  相似文献   
6.
The possibility of an emancipated politics in chick lit novels remains a contested question among postfeminist critics. Drawing on definitions of postfeminism as a transnational sensibility, this article examines South African chick lit in relation to what has been termed post-truth or trickster politics in the context of the rise of politicians, such as Donald Trump. I read Angela Makholwa’s novel The Blessed Girl as an example of African chick lit that features a blessee narrator, a young woman who lives a luxurious lifestyle financed by older men, who is deeply influenced by a Trumpian mode of self-making. By employing a trickster aesthetic and narrative strategies, such as unreliable narration and reader address, the novel, I argue, however also unsettles established parameters of neoliberal girlpower, moving beyond its assumed anti-politicalness, as well as a simple understanding of the blessee figure through either a lens of victimhood or amorality.  相似文献   
7.
为探讨FSH的种类、剂量及注射次数和注射季节对绵羊超数排卵的影响,采用中国科学院动物所、宁波、加拿大生产的FSH对206只无角道塞特绵羊进行了超排处理,观察了供体发情率、回收胚胎数、可用胚胎数、退化胚及未受精卵比率以及供体的表现。结果,无论那种FSH,在适当的剂量范围都可有效进行超排,中国科学院FSH与宁波FSH联合使用可提高回收胚胎数和可用胚胎数;与6次递减注射相比,7次或8次递减注射的结果更为理想;秋季的超排效果优于春、夏和冬季。供体对激素处理表现复杂多变的超排反应,同时也出现卵子受精失败现象。结果表明,外源FSH只能在一定程度上控制超排反应,进一步的研究应考虑外源性FSH与内分泌反应的关系。  相似文献   
8.
鸡胚免疫器官组织学发育过程观察   总被引:2,自引:0,他引:2  
通过对孵化至 12~ 2 1日龄鸡胚的免疫器官胸腺、脾及腔上囊进行组织学连续性观察 ,较为详细地描述了鸡胚免疫器官的组织发育过程。观察结果显示 ,胸腺的组织结构发育和形成较早 ,自 12日龄起胸腺就已形成原始的胸腺小叶 ;虽然脾在 12日龄时就已初具轮廓 ,但脾直到 18日龄才开始隐约形成形态可辨的红髓和白髓 ;腔上囊淋巴滤泡自鸡胚发育到 17日龄时即渐趋明显 ,但完整的滤泡皮质和髓质结构在出壳前仍然处于分化成熟阶段。  相似文献   
9.
为探讨唾液酸(SA)、糖胺多糖(GAG)在鸡慢性氟中毒早期诊断中的意义,以期筛选出诊断慢性氟中毒早期的敏感指标,选用250只1日龄罗曼蛋鸡,随机分为5组,每组50只,饲喂相同的全价日粮.Ⅰ组为正常对照组,Ⅱ~Ⅴ组在日粮中添加不同水平的氟化钠,使日粮中氟含量分别为500、1000、1500和2000mg/kg,试验期为150 d,每隔30 d采集血样1次,测定血清中氟、SA、GAG的含量,观察试验鸡的临床表现.结果,试验成功地复制出不同程度的鸡慢性氟中毒模型;饲料中所加氟量与血清中氟含量呈明显的剂量-效应关系;氟中毒组鸡血清中SA含量均低于对照组,而血清中GAG含量则均高于对照组;血清中氟含量与SA含量呈显著的负相关(r=-0.773,P<0.01),与GAG含量则呈显著的正相关(r=0.798,P<0.01);各中毒组SA/GAG值与正常值相比降低30%以上.由此可见,氟中毒可明显影响机体内SA、GAG的代谢,血清中SA、GAG含量的变化可灵敏地反映氟对机体的损伤情况.可将SA/GAG值降低30%或更多作为鸡慢性氟中毒的敏感、可靠的早期诊断指标.  相似文献   
10.
Legal limits on the psychoactive tetrahydrocannabinol (THC) content in Cannabis sativa plants have complicated genetic and forensic studies in this species. However, Cannabis seeds present very low THC levels. We developed a method for embryo extraction from seeds and an improved protocol for DNA extraction and tested this method in four hemp and six marijuana varieties. This embryo extraction method enabled the recovery of diploid embryos from individual seeds. An improved DNA extraction protocol (CTAB3) was used to obtain DNA from individual embryos at a concentration and quality similar to DNA extracted from leaves. DNA extracted from embryos was used for SSR molecular characterization in individuals from the 10 varieties. A unique molecular profile for each individual was obtained, and a clear differentiation between hemp and marijuana varieties was observed. The combined embryo extraction–DNA extraction methodology and the new highly polymorphic SSR markers facilitate genetic and forensic studies in Cannabis.  相似文献   
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