共查询到20条相似文献,搜索用时 62 毫秒
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目前,转基因动物技术发展迅速并广泛应用于食品、医药、农业和生物材料等众多领域,带来了巨大的经济效益和社会效益,且发展潜力巨大。同时,转基因动物及其产品的安全性问题也日益突出,表现在转基因动物本身及产品安全性和环境安全性两个主要方面。"实质等同性原则"是国际上转基因动物安全性评价的基本原则。从转基因动物及其产品作为食品、药品等的安全性评估;从转基因动物对生态环境安全和影响的评估和非预期效应的评估等三个方面进行了阐述,并对我国转基因动物评价体系的构建提出建议。 相似文献
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转基因作物安全性的解决方法研究进展 总被引:1,自引:0,他引:1
随着转基因技术的不断发展,转基因作物的种植面积逐年扩大.转基因技术在解决全球不断增长的粮食需求和保障农业的可持续发展等方面发挥了重要作用.然而,人们对转基因作物和转基因食品的安全性一直存在争议.为了解决这个问题,科学家研究出了多项分子技术来消除转基因带来的潜在威胁,尤其是近几年出现的"外源基因清除技术",有望成为解决该问题的有力工具.综述了几种解决转基因作物安全性问题的方法及其最新进展,并对几种方法进行了优缺点分析. 相似文献
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自转基因技术研发和商业化生产以来,针对转基因作物的食用安全性和环境安全性问题一直是公众争论的焦点。面对全球粮食安全形势的严峻压力,如何使公众对转基因技术及其产品的客观性保持一种科学性的认识,是摆在各国(特别是发展中国家)政府和科学家面前不可忽视的课题。本文从食品和环境两个方面简要介绍了转基因作物的安全性问题,旨在还原转基因技术的科学真实性,并简要提出转基因作物的安全性对策。 相似文献
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转基因技术对粮食生产的影响 总被引:10,自引:0,他引:10
介绍了转基因技术对粮食生产的诸多影响,尤其强调了转基因技术在解决日益膨胀的人口吃饭问题上的重要作用。应该坦然面对转基因技术,在津津乐道转基因技术给我们带来的种种好处的同时,也必须对其安全性给予足够的关注。 相似文献
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转基因产品的安全性及其对应策略 总被引:22,自引:1,他引:22
目前,生物安全性问题已成为转基因技术及其产品能否获得足够的研究空间和良好开发市场的关键所在。然而,在重视安全性的同时,也必然认识到转基因技术及其产品的出现乃是人类社会发展的客观必然。当务之急不应该是简单地反对或赞成,而是必须对转基因产品进行全面、充分的研究和客观、具体的评价,从而使其在造福于人类的同时,能有效地减少或避免对人类健康及其生存环境可能产生的潜在危害。当然,对社会公众进行科学宣传和指导,从而使其在对转基因产品具有客观了解的基础上培养一种健康的接受心态也是必需的。本在简述转基因产品安全性及其研究现状的基础上,提出若干对应策略,希望能引起社会各界的共识。 相似文献
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Although the importance of the endosperm as a food store inmany angiosperm seeds is well known, its significance duringearly embryogenesis has been neglected. In many interspecifichybrids, and in some other situations, embryos do not developfully and abort. It has often been stated that this is causedby the endosperm failing to conduct sufficient nutrients tothe embryo, but seldom has it been suggested that the endospermactively controls most of the early stages of morphogenesisof the embryo. Information gleaned from a broad survey of theliterature, combined with additional evidence presented here,obtained fromSolanum incanumand interspecific hybrids, indicatethat the endosperm is dynamic and very active in regulatingearly embryo development. This requires highly integrated geneticcontrol of rapidly changing metabolism in the endosperm. Ininterspecific hybrids, lack of coordination may cause unbalancedproduction of growth regulating substances by the endospermand hence abortion of the embryo, or even unregulated productionof nucleases and proteases resulting firstly in autolysis ofthe endosperm and then digestion of the embryo. The endospermmay thus serve to detect inappropriate hybridization of speciesor ploidy levels and so prevent waste of resources by producingseeds that would result in sterile hybrids or unthrifty subsequentgenerations. This discriminatory function of the endosperm hasdiminished during evolution and domestication of the crop plantSolanummelongenaL.Copyright 1998 Annals of Botany Company Solanum, embryo morphogenesis, endosperm, hybrid, seed development. 相似文献
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Michele Rivkin-Flsh 《Medical anthropology quarterly》2000,14(1):119-120
Pragmatic Women and Body Politics. Margaret Lock and Patricia A. Kaufert. eds. Cambridge, UK: Cambridge University Press, 1998. xii +364 pp.
Maternities and Modernities: Colonial and Postcolonial Experiences in Asia and the Pacific. Kalpana Ram and Margaret Jolly. eds. Cambridge, UK: Cambridge University Press, 1998. xiv. 305 pp. 相似文献
Maternities and Modernities: Colonial and Postcolonial Experiences in Asia and the Pacific. Kalpana Ram and Margaret Jolly. eds. Cambridge, UK: Cambridge University Press, 1998. xiv. 305 pp. 相似文献
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Höpfl G Ogunshola O Gassmann M 《American journal of physiology. Regulatory, integrative and comparative physiology》2004,286(4):R608-R623
For most organisms oxygen is essential fo life. When oxygen levels drop below those required to maintain the minimum physiological oxygen requirement of an organism or tissue it is termed hypoxia. To counter act possible deleterious effects of such a state, an immediate molecular response is initiated causing adaptation responses aimed at cell survival. This response is mediated by the hypoxia-inducible factor-1 (HIF-1), which is a heterodimer consisting of an alpha- and a beta-subunit. HIF-1 alpha protein is stabilized under hypoxic conditions and therefore confers selectivity to this response. Hypoxia is characteristic of tumors, mainly because of impaired blood supply resulting from abnormal growth. Over the past few years enormous progress has been made in the attempt to understand how the activation of the physiological response to hypoxia influences neoplastic growth. In this review some aspects of HIF-1 pathway activation in tumors and the consequences for pathophysiology and treatment of neoplasia are discussed. 相似文献
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环腺苷酸应答元件结合蛋白与学习记忆 总被引:2,自引:0,他引:2
环腺苷酸(cAMP)应答元件结合蛋白(cAMP response element binding protein,CREB)是一种核转录因子,可与cAMP反应元件结合,调节基因转录,具有调节精子生成,昼夜节律,学习记忆等功能.近年来关于其在学习记忆中的作用成为医学研究热点.CREB是神经元内多条信息传递途径的汇聚点,参与长时记忆形成和突触可塑性.长时记忆(long-term memory)形成需依赖CREB介导的基因转录,干扰或抑制CREB活性可破坏长时记忆.长时程增强(long-term potentiation,LTP)是研究学习记忆的理想模型,在LTP诱导和维持过程中均可观察到CREB活性持续升高.但增龄过程中,海马CREB活性下降,影响学习记忆功能,与许多神经退行性疾病发生有关. 相似文献
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Studies of human constitution and mental features are traditionally among the main concepts of anthropological research. In
this research, we attempted to discover connections between morphological and constitutional features and self-esteem in children
and adolescents. Such a connection was discovered in some studied age groups. The obtained results could serve as a basis
for further studies in this field. 相似文献