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关键词： 心理学原理   组织胚胎学教学   运用   学习兴趣   学习心理   学习效果  

摘要： 作为一名教师,除了要精通业务知识,具备灵活运用教学方法的能力之外,还要掌握一定的心理学知识,恰如其份地运用一些心理学原理指导日常的教学工作,往往会收到事半功倍的效果.

关键词： 生长发育   广西大学   胚胎细胞   克隆兔   实验  

关键词： arrhythmia   bradycardia   embryoid body   embryonic cardiomyocyte   propagation failure   spontaneous electrical activity   tissue hypoxia   velocity of conduction  

摘要： The influence of tissue hypoxia on the generation and propagation of excitation was studied in spontaneously beating embryonic cardiomyocyte clusters grown in eight 9-12 days old embryoid bodies. Within the embryoid bodies one to three separately active clusters of cardiomyocytes were found. each having its own pacemaker cell. Lowering of tissue PO2 caused bradycardia as well as arrhythmia in all embryoid bodies investigated. The mean frequency of the extracellularly recorded action potentials decreased under conditions of pronounced hypoxia from a mean of 1.4-1.8 Hz to below 0.8 Hz. In three embryoid bodies hypoxia-sensitive as well as hypoxia-tolerant cardiomyocyte clusters were found. The hypoxia-insensitive cardiomyocytes showed a low frequency of spontaneous activity. In addition to the observed changes in the generation of excitation, tissue hypoxia caused an approximately 60% reduction in the velocity of conduction within the cardiomyocyte clusters. Moreover, in at least one of the eight experiments propagation failure with an incomplete block in spread of excitation was observed. All hypoxia-induced effects on generation and propagation of embryonic cardiomyocyte excitation were completely reversible after reoxygenation. (C) 2002 Elsevier Science Inc. All rights reserved.

关键词： 茎尖   组织培养   胚状体   玉米   体细胞胚胎   组织细胞学  

摘要： 以玉米茎尖分生组织为外植体 ,在离体培养条件下诱导体细胞胚胎 (胚状体 )发生。组织细胞学观察表明 ,玉米茎尖分生组织在离体培养条件下可直接产生胚性愈伤组织 ,后者在继代培养中发生胚状体。多数胚状体起源于愈伤组织的表层细胞和表层之下的几层细胞 ,少数产生于愈伤组织的较深层。胚状体发生于单细胞 ,发育过程与合子胚大致相似。多数胚状体发育正常 ,具有一个芽端和一个胚根端。少数胚状体形成具多个芽端而共用一个胚根端的次生连体胚。胚状体发生不同步。胚状体只有在分化培养基上才能发育成熟。

关键词： 胚胎组织   特异性转基因技术   电穿孔  

关键词： anteroposterior specification   Cynops pyrrhogaster   head organizer   trunk-tail organizer   urodele  

摘要： The dorsal marginal zone (DMZ) of an amphibian early gastrula is thought to consist of at least two distinct domains: the future head and trunk-tail organizers. We studied the mechanism by which the organizing activities of the lower half of the DMZ (LDMZ) of the urodelean (Cynops pyrrhogaster) embryo are changed. The uninvoluted LDMZ induces the notochord and then organizes the trunk-tail structures, whereas after cultivation in vitro or suramin treatment, the same LDMZ loses the notochord-inducing ability and organizes the head structures. A cell-lineage experiment indicated that the change in the organizing activity of the LDMZ was reflected in the transformation of the inductive ability: from notochord-inducing to neural-inducing activity. Using RT-PCR, we showed that the LDMZ expressed gsc, lim-1, chordin, and noggin, but not the mesoderm marker bra. In the sandwich assay, the LDMZ induced bra expression in the animal cap ectoderm, but the inductive activity was inhibited by cultivation or suramin treatment. The present study indicates that the change in the organizing activity of the LDMZ from trunk-tail to head is coupled with the loss of notochord-inducing activity. Based on these results, we suggest that this change is essential for the specification of the head and trunk-tail organizers during gastrulation. (C) 2002 Elsevier Science (USA).

关键词： 组织学与胚胎学专业   隐性教学工具   黑板报   学习动机  

摘要： 怎样利用课间休息十分钟来激发高校学生对专业课程学习兴趣很容易被高校教师忽视。通过五年多来组织学生出组织学与胚胎学专业黑板报 ,并以不记名问卷调查的方式收集学生反馈意见 ,笔者认为专业黑板报形式灵活多样 ,是一种很好的隐性教学工具。

关键词： 多媒体教学   医学教育   制作方法   制作工具   组织胚胎学教学   课件制作  

摘要： 随着计算机技术的飞速发展和多媒体教室的普及 ,多媒体教学在高等教育中的应用成为必然的趋势 ,多媒体教学课件的开发与应用成为当务之急 ,课件制作既要有本专业的专业知识 ,又要有多媒体技术的基础知识 ,还要有一定的审美眼光。近两年我校开始应用多媒体教学 ,在短时间内要求各教研室教师制作出符合本专业教学需要的多媒体课件 ,给各位教师提出了严峻的挑战。笔者在组织胚胎学教学中应用多媒体课件 ,受到学生的普遍好评。现就课件的制作与应用谈谈体会。一、制作工具的选择目前有多种软件可进行多媒体教学课件的制作 ,教师可根据教学目的 ,主、客观条件等加以选择。1 .主要考虑方便学生学习的教学课件。这类课件主要是学生

关键词： Olea europaea L.   bud explants   embryo germination   in vitro culture   mannitol   sucrose  

摘要： The influence of sucrose or mannitol on in vitro zygotic embryo germination, seedling development and explant propagation of olive tree (Olea europaea L.) was compared. Embryos germinated without sucrose in the medium but for adequate development of the seedlings to yield viable plants, a carbohydrate supply was necessary;both sucrose and mannitol were equally suitable for this purpose. However, when explants obtained from in vitro germinated embryos were cultured with mannitol or sucrose, then the polyalcohol promoted significantly more growth than sucrose by increasing shoot length, pairs of leaves formed, and breaking apical dominance. This improved the in vitro culture of olive plant material, thus allowing new olive clonal lines to be obtained in shorter times. This will assist in future breeding experiments with the species.

关键词： erythropoiesis   terminal differentiation   adaptation   gene expression  

摘要： During avian embryonic development, terminal erythroid differentiation occurs in the circulation. Some of the key events, such as the induction of erythroid 2,3-bisphosphoglycerate (2,3-BPG), carbonic anhydrase (CAII), and pyrimidine 5'-nucleotidase (P5N) synthesis are oxygen dependent (Baumann R, Haller EA, Schoning U, and Weber M, Dev Biol 116: 548-551, 1986;Dragon S and Baumann R, Am J Physiol Regulatory Integrative Comp Physiol 280: R870-R878, 2001;Dragon S, Carey C, Martin K, and Baumann R, J Exp Biol 202: 2787-2795, 1999;Dragon S, Glombitza S, Gotz R, and Baumann R, Am J Physiol Regulatory Integrative Comp Physiol 271: R982-R989, 1996;Dragon S, Hille R, Gotz R, and Baumann R, Blood 91: 3052-3058, 1998;Million D, Zillner P, and Baumann R, Am J Physiol Regulatory Integrative Comp Physiol 261: R1188-R1196, 1991) in an indirect way: hypoxia stimulates the release of norepinephrine (NE)/adenosine into the circulation (Dragon et al., J Exp Biol 202: 2787-2795, 1999;Dragon et al., Am J Physiol Regulatory Integrative Comp Physiol 271: R982-R989, 1996). This leads via erythroid beta-adrenergic/adenosine A(2) receptor activation to a cAMP signal inducing several proteins in a transcription-dependent manner (Dragon et al., Am J Physiol Regulatory Integrative Comp Physiol 271: R982-R989, 1996;Dragon et al., Blood 91: 3052-3058, 1998;Glombitza S, Dragon S, Berghammer M, Pannermayr M, and Baumann R, Am J Physiol Regulatory Integrative Comp Physiol 271: R973-R981, 1996). To understand how the cAMP-dependent processes are initiated, we screened an erythroid cDNA library for cAMP-regulated genes. We detected three genes that were strongly upregulated (>5- fold) by cAMP in definitive and primitive red blood cells. They are homologous to the mammalian Tob, Ifr1, and Fos proteins. In addition, the genes are induced in the intact embryo during short-term hypoxia. Because the genes are regulators of proliferation and differentiation in other cell types, we suggest that cAMP might p