共查询到19条相似文献，搜索用时 265 毫秒
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小鼠和猪的克隆比较简单，而大鼠比较难，人类更难，但不会比猴子还难。没人知道为什么有些物种比其他物种更难克隆。但是，对小鼠的研究正帮助人们阐释这些差异，最终促使研究者在利用人类胚胎干细胞治疗疾病及移植器官方面获得更大的成功。在治疗性克隆(又名核移植)方面，迄今为止值得注意的成就是由韩国汉城国立大学的黄武树(Woo Suk Hwang)做出的。 相似文献
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据新华社2月3日报道,继美国科研人员去年首次宣布由人体细胞成功克隆人体胚胎后,我国科研人员利用不同来源的人类成体细胞成功克隆出5枚符合国际公认技术鉴定指标的人类囊胚。克隆和干细胞领域国际权威学术期刊《克隆和干细胞》杂志网络版1月27日发表了这一研究成果。就在国内众多媒体纷纷转载这条消息的同时,一些质疑的声音也出现了…… 相似文献
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近日,国家畜禽分子遗传育种中心宣布,世界首例体细胞克隆兔在北京诞生。这只小免目前健康状况良好,体重已经达到了2公斤。从此克隆家族又添新丁,针对人类疾病的治疗又增添了一份新生力量。体细胞克隆一向被视为克隆技术的一大"门槛",当年"多利"从成年母羊乳腺细胞克隆成功后,轰动了世界。克隆兔虽然一直有科学家在研究,但这次诞生在北京的却是全球第一只体细胞克隆兔,可谓"世界最牛"! 相似文献
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《中国科学院院刊》1993,(4):357-360
王壬学 男 34岁 1982年毕业于山东海洋学院,1986年在该校获硕士学位.1989年在中国科学院海洋研究所获博士学位,现为该所副研究员.从事发育生物学和遗传学研究.对中国北方盐场的孤雌生殖卤虫进行了细胞学研究及克隆分析,在国际上首先发现在中国存在五倍体孤雌生殖卤虫,发现华北孤雌生殖二倍体卤虫染色体有典型的减数分裂行为.在鱼类基因转移研究工作中,解决了金鱼体外成熟卵母细胞的授精难题,对体外成熟的金鱼卵母细胞进行抗冻蛋白基因转移,成功地获得转抗冻蛋白基因的转基因金鱼,证实了外源基因在寄主基因组中的整合和表达以及在子代中的稳定遗传.主要论文有:“从体外成熟卵母细胞获得转基因金鱼的研究”、“华北盐场孤雌生殖卤虫及其染色体的研究”、“The Study of opAFP Gene Transfer in Goldfish”． 相似文献
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朱效民 《科学对社会的影响》2006,(3):62-64
近两年来干细胞研究领域里最为上镜的人物当非韩国“克隆之父”黄禹锡莫属了。2005年5月黄禹锡宣布,其研究小组已经成功地利用克隆技术培育出人类胚胎,并从中提取了世界上首批与病人基因相符的胚胎干细胞系,从而一举成为基因研究领域里的领军人物,随后其研究成果发表在世界权威 相似文献
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Yu-Hsiang Chung Yi-Hsing Hsiao Wei-Lun Kao Chia-Hsien Hsu Da-Jeng Yao Chihchen Chen 《Biomicrofluidics》2015,9(2)
A vital aspect affecting the success rate of in vitro fertilization is the culture environment of the embryo. However, what is not yet comprehensively understood is the affect the biochemical, physical, and genetic requirements have over the dynamic development of human or mouse preimplantation embryos. The conventional microdrop technique often cultures embryos in groups, which limits the investigation of the microenvironment of embryos. We report an open microwell platform, which enables micropipette manipulation and culture of embryos in defined sub-microliter volumes without valves. The fluidic environment of each microwell is secluded from others by layering oil on top, allowing for non-invasive, high-resolution time-lapse microscopy, and data collection from each individual embryo without confounding factors. We have successfully cultured mouse embryos from the two-cell stage to completely hatched blastocysts inside microwells with an 89% success rate (n = 64), which is comparable to the success rate of the contemporary practice. Development timings of mouse embryos that developed into blastocysts are statistically different to those of embryos that failed to form blastocysts (p–value < 10−10, two-tailed Student''s t-test) and are robust indicators of the competence of the embryo to form a blastocyst in vitro with 94% sensitivity and 100% specificity. Embryos at the cleavage- or blastocyst-stage following the normal development timings were selected and transferred to the uteri of surrogate female mice. Fifteen of twenty-two (68%) blastocysts and four of ten (40%) embryos successfully developed into normal baby mice following embryo transfer. This microwell platform, which supports the development of preimplanted embryos and is low-cost, easy to fabricate and operate, we believe, opens opportunities for a wide range of applications in reproductive medicine and cell biology. 相似文献
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New forms of life produced by biomedical research, such as human embryonic stem cells (hESC), have been the object of public debate beyond the scientific fields involved. This article brings to light the case of Brazil, where recently passed federal legislation has authorized research with in vitro human embryos. It focuses on the legislative debate in the Brazilian National Congress between 2003 and 2005 on the Biosafety Bill of Law, which cleared for hESC research a certain share of supernumerary and unviable human embryos frozen in the country's assisted reproduction clinics. The passing of this Bill triggered other public reactions, chiefly a Direct Action of Unconstitutionality in Brazil's Federal Supreme Court. This study adopts an anthropological perspective for describing and analyzing the chief arguments in both debates, in terms of how the notion of 'life' was deployed and negotiated by contending parties. If, on the one hand, the definition of life appeared firmly attached to a conception of both the in vitro embryo and the fetus as a human person, on the other a movement towards breaking down life along utilitarian lines was found when the potential beneficiaries of stem cell therapy came into the equation. In all cases, however, notions of life were negotiated from a hybrid continuum of (biological) facts and (religious, moral and juridical) values, and resonated in different ways with the idea of the individual as privileged mode of constructing personhood in the context of modern nation states. 相似文献
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Kirejczyk M 《Social studies of science》1999,29(6):889-912
Twenty years ago, the technology of in vitro fertilization created a new artefact: the human embryo outside the woman's body. In many countries, political debates developed around the artefact. One of the central questions in these debates is whether it is permissible to use human embryos in research and, if so, under what conditions. To date, no uniform answer to this question has been given by the governments and parliaments of the different nation states. This highlights the importance of national cultures and local dynamics in the process of crafting the space for human embryo research. In this paper I approach the issue of the national context by comparing the Dutch and British parliamentary debates on human embryos. Though some arguments used in both debates were similar, the outcomes were very different. In the UK, the Human Fertilisation and Embryology Act was passed in 1990. In the Netherlands, several bills on human embryos have been drafted, but each of them was withdrawn from the proceedings before reaching Parliament. To understand the processes which led to these different outcomes, I scrutinize the roles in the Netherlands of the political parties, of the scientists' lobby and of women speakers, and compare them with the findings of the UK debate. I also reflect upon the role played by gender in these two culturally different political contexts. 相似文献
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Simin Sohrabi Azim Akbarzadeh Dariush Norouzian Ali Farhangi Mehri Mortazavi Mohammad Reza Mehrabi Mohsen Chiani Zahra Saffari Soheil Ghassemi 《Indian journal of clinical biochemistry : IJCB》2011,26(4):354-359
The attempt is made to produce recombinant factor VIII but the first step in producing such product is production and purification
of rabbit’s polyclonal antibody against factor VIII. The second and third steps involve monoclonal antibody and recombinant
factor VIII production. Factor VIII is one of the most important coagulating factor where its deficiency leads to diseases
like hemophilia type A or classic. It is an inherited disease. Previously, it was obtained through fractionation of blood
plasma of blood donors. After processing, factor VIII could be used to manage such patients. Due to transfer of viral disease
like hepatitis and HIV through factor VIII obtained by fractionation, high cost of production, insufficiency of the donors
and the process of virus removal, thus production of factor VIII through recombinant technology can be useful and helpful.
The reaction between antibody and antigen is one the most specific reaction; therefore, such reaction can be employed to identify
factor VIII. Thereby, rabbits were injected several times with adjuvant-linked antigen to produce antibody. The antibody was
separated from the blood sample, purified and used to identify factor VIII in the research. 相似文献
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耕地资源既能产生生态效益,为整个社会提供生态福利,具有正外部性,同时也会因为不合理利用而损坏人类的福利,产生负外部效应。仅仅估算耕地的正外部性价值量,可能会高估耕地保护经济补偿额,不利于耕地保护政策的实施。本文以湖北省102个县(市、区)为例,分别测算了耕地的正外部性和负外部性价值量,进而得出耕地的净外部性价值量;此外,通过测算各区域内部的外部性需求量得出耕地保护的外部性盈亏水平,并据此实施跨区域的财政转移支付,以均衡各区域的发展。研究结果表明:①湖北省大部分地区的耕地对外界环境均起到了正面影响,但省内耕地资源的净外部性水平差异明显;②扣除区域内部的外部性需求量,湖北省共有41个县(市、区)耕地保护的外部性有盈余,属于财政转移支付受偿区;同时,共有61个县(市、区)耕地资源的外部性处于亏损状态,属于财政转移支付支付区;③财政转移支付行为具有一定的现实可操作性。各个县(市、区)的转移支付额占当年地方政府财政收入的比例较低,约为0.007%~5.030%,均在政府可承受的范围内。研究成果为耕地保护经济补偿政策的实施提供了一定的理论依据。 相似文献
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长期以来,国际科学界在体外人胚胎研究领域所遵循的“14天规则”,将人胚胎体外研究时间限制在受精后的14天内,这是该研究领域最重要的伦理规则。随着胚胎培养技术的发展,这一伦理规则受到前所未有的挑战。2021年,国际干细胞研究学会（ISSCR）在《干细胞研究和临床转化指南》中建议有条件地放宽这一限制,科学界重启关于“14天规则”的讨论。文章以“14天规则”为切入点,系统梳理人胚胎研究伦理规制的历史背景和现实挑战,围绕人胚胎的道德地位、尊严和法律地位等关键伦理问题进行分析,全面分析各界利益相关者的观点和态度,从而结合实际做出评估,明确提出审慎、适当延长“14天规则”的政策建议和具体措施。 相似文献
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促进高校科研人力资本合理迁移和配置是激发社会创新创业活力的重要举措。基于计划行为理论构建了高校科研人力资本迁移意愿影响因素结构方程模型,并通过内蒙古295名高校科研人才的调查数据进行实证检验。研究表明科研人才的行为态度、主观规范和知觉行为控制三个维度均对迁移意愿有显著的正向影响,具体来说家庭、高校、政府政策、能力素质以及资源整合程度等因素影响较大。因此,建议政府、高校等从建立风险保障机制、完善人力资本迁移制度实施细则、积极为科研人才提供创新创业资源入手,提高科研人力资本迁移意愿。 相似文献
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脑疾病是我国乃至全球人口健康领域正面临的重大挑战。尽快部署脑疾病研究的中长期战略具有重大意义,将显著提升我国在该领域的国际竞争力,促进相关学科的发展以及新技术和新治疗途径的开发,实现脑疾病的精准医疗。脑疾病的研究正在从分子细胞机理、介观网络机制、生物标记物与分子分型、影像诊断和治疗策略研发等多个层面推进,其中介观网络研究是当前脑科学研究的新焦点,将填补分子细胞机理和宏观疾病症状之间的鸿沟。基于脑疾病的复杂性,非人灵长类动物可能是研究人类脑疾病的最优模型,我国在该领域具有明显优势;而脑疾病的早期诊断和早期干预是脑疾病治疗的关键,我国有丰富的临床资源库,亟需建立国际规范化、全国统一化的采样、处理、分析标准和共享的规则。此外,单细胞和单分子技术是微观研究的新趋势,也是精准医疗的关键技术,在解析复杂脑疾病机理方面具有重要的价值。 相似文献