共查询到18条相似文献，搜索用时 93 毫秒
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生理学中“线粒体DNA(mtDNA)”研究近年来取得重大进展 ,学者们十分关注它的突变与人类疾病的关系。本文综述了mtDNA的结构 ,遗传特点 ,突变类型和几种常见的综合症及临床症状 ,力求展示出研究的新进展 相似文献
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线粒体与细胞凋亡及临床疾病 总被引：1，自引：0，他引：1
线粒体是哺乳动物细胞内唯一含有核外遗传物质的细胞器，由于其自身的特征及其所处的环境，使线粒体DNA(mtDNA)较核DNA(nDNA)更易损伤或突变：通过线粒体外膜释放凋亡活性物质和通透性转换孔开放，可促进细胞凋亡；mtDNA的损伤和突变与人类衰老、神经退行性疾病、糖尿病及肿瘤等疾病的发生均有关系。 相似文献
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线粒体是哺乳动物细胞内唯一含有核外遗传物质的细胞器,由于其自身的特征及其所处的环境,使线粒体DNA(mtDNA)较核DNA(nDNA)更易损伤或突变;通过线粒体外膜释放凋亡活性物质和通透性转换孔开放,可促进细胞凋亡;mtDNA的损伤和突变与人类衰老、神经退行性疾病、糖尿病及肿瘤等疾病的发生均有关系. 相似文献
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陈龙 《周口师范高等专科学校学报》1999,16(2):34-37
介绍了线粒体ＤＮＡ的遗传学特性,试从分子水平上探讨ｍｔＤＮＡ突变发生情况,阐明ｍｔＤＮＡ的突变与线粒体病和衰老的关系,简要说明了人类ｍｔＤＮＡ突变的类型和相应的线粒体病的特点。 相似文献
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罗育发 《赣南师范学院学报》2005,26(6):58-60
综述线粒体DNA(mtDNA)的特征、线粒体基因组遗传特性认识的改进和mtDNA分子标记技术在蛛形学研究中的应用;并探讨了线粒体DNA标记技术在蜘蛛分子系统学研究和基因组分析中的广泛应用前景. 相似文献
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线粒体基因（mtDNA）在系统学、系统地理学和物种鉴定等领域被广泛应用,线粒体假基因（nuclear mitochondrial pseudogenes,Numts）的存在会影响系统发生关系、生物多样性研究和种群遗传参数的推断,以及线粒体相关疾病的研究和诊断。该文对Numts的序列特征、分布规律、转入机制、联合扩增的降低措施以及应用前景进行综述,以期在mtDNA应用中降低Numts的影响和为Numts的研究应用提供参考。 相似文献
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哺乳动物细胞线粒体基因组的转录及调控机制研究进展 总被引：1，自引：0，他引：1
目的：系统的归纳和总结近年来哺乳动物线粒体基因组转录及调控机制研究的进展,以期为哺乳动物和人类线粒体疾病及相关医学领域的研究提供参考依据。方法：从哺乳动物线粒体DNA（mtDNA）的结构和转录过程,转录基本元件和转录机制等方面,检索和整理近年来关于哺乳动物细胞线粒体基因组的转录及调控机制的文献并进行总结。结果：线粒体是哺乳动物细胞中普遍存在的具有独立基因组的半自主性细胞器,其主要功能是通过氧化磷酸化为细胞提供ATP,同时对于物质代谢、细胞周期调控、细胞分化和凋亡、细胞信号传递等生理过程发挥着重要作用。近年来对线粒体基因组的转录及其调控机制的研究已取得了一些突破和成果。结论：哺乳动物线粒体基因组的转录与调控机制的研究不仅有助于深入阐明和理解线粒体基因组的表达调控机制,而且也助于揭示临床线粒体病的发病机制。 相似文献
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针对人类的线粒体疾病,阐述人类线粒体mtDNA的结构特点、线粒体疾病的定义及其遗传学特点;线粒体疾病的病因和发病几率以及常见的人类线粒体疾病;介绍了现已掌握的线粒体疾病的治疗方法,展望了线粒体疾病的未来研究方向。 相似文献
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Wang JY Gu YS Wang J Tong Y Wang Y Shao JB Qi M 《Journal of Zhejiang University. Science. B》2008,9(8):610-615
Objective:Leber's hereditary optic neuropathY (LHON)is a maternally inherited degeneration of the optic nerve caused by point mutations of mitochondrial DNA(mtDNA).Many unsolved questions regarding the penetrance and pathophysiological mechanism of LHON demand efficient and reliable mutation testing.This study aims to develop a minor groove binder(MGB) probe assay for rapid detection of mtDNA11778 mutation and heteroplasmy in Chinese LHON patients by real-time polymerase chain reaction(PCR).Methods:Forty-eight patients suspected of having LHON and their maternal relatives underwent a molecular genetic evaluation,with 20 normal individuals as a control group at the same time.A real-time PCR involving two MGB probes was used to detect the mtDNA 11778 mutation and heteroplasmy.A linear standard curve was obtained by pUCmLHONG and pUCmLHONA clones.Results:All 48 LHON patients and their matemal relatives were positive for mtDNA 11778 mutation in our assay,27 heteroplasmic and 21 homoplasmic.Eighteen cases did not show an occurrence of the disease,while 9 developed the disease among the 27 heteroplasmic mutation cases.Eleven did not show an occurrence of the disease,while 10 cases developed the disease among 21 homoplasmic mutation cases.There was a significant difierence in the incidence between the heteroplasmic and the homoplasmic mutation types.The time needed for running a real-time PCR assay was only 80 min.Conclusion:This real-time PCR assay is a rapid,reliable method for mtDNA mutation detection as well as heteroplasmy quantification.Detecting this ratio is very important for predicting phenotypic expression of unaffected carriers. 相似文献
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Wang Y Dong L Cui H Shen DH Wang Y Chang XH Fu TY Ye X Yao YY 《Journal of Zhejiang University. Science. B》2011,12(5):346-356
Objective
Recently, a high frequency of mutations in mitochondrial DNA (mtDNA) has been detected in ovarian cancer. To explore the alterations of proteins in mitochondria in ovarian cancer, a pair of human ovarian carcinoma cell lines (SKOV3/SKOV3.ip1) with different metastatic potentials was examined. 相似文献13.
Howard Woodhouse 《Interchange》1995,26(4):347-364
Alfred North Whitehead's theory of learning is best understood in the overall context of his process philosophy. The rhythmic cycles of growth forming the basis of human learning (romance, precision, and generalisation) are organically connected to the characteristics of life typifying all entities in the universe (self-enjoyment, creative activity, and aim).The kind of balanced education which best enhances growth and connectedness is one in which art and aesthetic appreciation in the broadest sense are dominant. By experiencing the beauty of the sunset, for example, children and adults have access to feelings that flow through them from the world and connect them to distant events taking place in space and time. These bodily feelings at the base of all experience provide concrete ways in which human beings can appreciate the intrinsic value of the world around them.By way of contrast, the methods of 17th century science replace our concrete experience of the sunset with abstract categories that are used to measure the phenomena in question and deny the importance of that experience in understanding the world. Schools' and universities' emphasis upon this methodology produces an imbalanced education with minds in a groove.A renewal of balance in education helps us to understand the false dichotomy between child-centered and and curriculum-centered education. Education for Whitehead must pay attention to both. Moreover, he understands that the academic freedom enjoyed by bands of imaginative scholars in universities is not an article of commerce to be sold to the highest corporate bidder but something to be valued for its intrinsic worth. 相似文献
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There are considerable differences among mathematics teachers with regard to the quatlity of their way of developing mathematical knowledge in the classroom. Such differences are analysed. To develop mathematical meaning requires both a consistent presentation of the mathematical symbols and of the referential meaning of these symbols with respect to the given task. On the basis of this conception we assume that the quality of teaching will differ according to how teachers cope with the relation between these two sides of meaning. From a sample of 26 teachers, an expert teacher and a non-expert teacher were selected by means of classroom observation with scales of instructional quality variables. For each of these two teachers, two lessons introducing probability (sixth grade) are analysed. For this purpose, teacher and student contributions are coded. For the expert teacher, graphic visualizations of the development of mathematical concepts across time show soft transitions between the different aspects of mathematical meaning. These transitions are made possible by a consistent explication of the relation between formal symbols and the given mathematical task. In the case of the other teacher, explication of the relationship between the object side and the symbol side of mathematical meaning is much rarer, and there are sudden switches from one aspect of meaning to another. Further differences concern the handling of student contributions.We gratefully acknowledge the help of Wolfgang Barz, Regina Dietrich and Claudia Krüger with recording, transcribing or coding lessons. For their comments on draft versions of the paper the authors thank Deborah Ball, Jere Brophy, Willibald Dörfler, Alexander Gruza and two anonymous reviewers. 相似文献
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蜜蜂（Apis）线粒体DNA（mtDNA）研究进展 总被引：1，自引：0，他引：1
综述蜜蜂线粒体DNA(mtDNA）的结构及其多态性在进化、分类、群体遗传结构和非洲化蜜蜂研究上的应用，蜜蜂mtDNA是一个裸露的闭合双链环状分子，长度在16，300-17，000bp之间，其中AT含量约占85%,线粒体基因组含有13个编码蛋白质的基因，22个tRNA左因，2个编码rRNA亚基基因和两个非编码区域，部分基因有重叠现象，根据mtRNA限制位点的多态性，可推断出四个蜜蜂的系统分化图为:Florea(dorsata (cerena,mellifera）；而西方蜜蜂在进行过程中形成三大分支：西欧型（M）、东欧型（C）、非洲型（A）、mtDNA多态性也是研究蜜蜂群体遗传结构和非洲化形成、扩散机制的有力工具。 相似文献
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Concept-Mapping as a Research Tool: A Study of Primary Children's Representations of Information and Communication Technologies (ICT) 总被引：1，自引：0，他引：1
This paper presents an approach to concept-mapping that was used in an EU-funded project to study ten year old pupils' representations of Information and Communication Technologies (ICT). The research task – to draw a concept map of computers in today's world – was administered to children in six EU countries twice. In England this took place immediately before and after the introduction of networked PCs in their schools. They were asked to use their maps to communicate their ideas through drawing to the researchers and other children who did not all speak the same language as them. The maps were analysed both quantitatively and qualitatively, using phenomenographic methods combined with semiotic interpretation. The maps showed that the children had well-developed mental representations (secondary artifacts) of the role of ICT in today's world, even when they had little or no practical experience of using the Internet. Psychological theories suggest that learning depends to a considerable extent on the development of secondary artifacts of this kind. The extent and variety of knowledge about computers demonstrated by all children in the cohort came as a surprise and suggested that they would be very well prepared to develop sophisticated ICT skills once they had good access to ICT tools. Current approaches to ICT use in primary schools, involving explicit, systematic teaching of ICT skills, may therefore not be making the most cost-effective use of scarce resources. Exploratory use of ICT within open-ended project work, reflecting the kind of use that computer-literate adults make of ICT, might be more likely to provide the context for children's rapid development of a complex range of ICT skills. 相似文献
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惠萍 《广东教育学院学报》2009,29(5):54-58
利用B样条技术计算类氢施主杂质量子环能级和束缚能的量子尺寸效应．计算结果表明：量子环的能级E1随着抛物势ωh的增加而增大．E1-R0曲线存在极小值,极小值的位置r00随着ωh的增加而减小．束缚能Eb随着量子环半径r0的增加而单调快速地下降．在r0〈60nm区域,E1和Eb的量子尺寸效应很明显．在r0〉60nm区域,E1和Eb的量子尺寸效应不明显;在r0〈70nm区域,随着角动量m。从0增加到3,E1-r0和Eb—r0曲线的斜率发生剧烈的变化,E1的极小值的位置r00随着mc的增加而快速增大．在r0〉80nm区域,E1-r0和Eb-r0曲线分别会聚成一条线,E1和Eb不依赖于mc值的变化而变化;随着施主杂质的电荷增大,能级E1快速下降,E1-r0曲线的极小值的位置r00明显减小．库仑能不可以作为微扰项来处理． 相似文献
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针对中石化济南分公司 1 4mt/aRFCCU在加工重劣原料过程中所遇到的问题及相关的工艺特点 ,并就有关的操作条件如反应压力控制、终止剂的作用、催化剂置换速率及剂油比的重要性等方面进行了分析和探讨 相似文献