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文章从三叶虫的头尾搭配问题的讨论对"也论Protaitzehoia Yang三叶虫的分类位置"一文中置于原太子河虫属的某些尾部的可靠性提出了质疑,认为插图2中的尾(K),由于缺少宽而下凹的尾边缘,应属于Stephanocare Monke,1903一属的尾部;插图2中的尾(L)的归属尚难定论.将原太子河虫属的头盖、活动颊、尾部、唇瓣与Cheilocephalus Berkey,1898属的头盖、活动颊、尾部、唇瓣对比后,认为原太子河虫属应归属Cheilocephalidae Shaw,1956.  相似文献   

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A computer-based technique is described for calculating the survival of normal and malignant cell populations during and after chemotherapy or radiotherapy. For exponentially growing cells, cell sensitivity as a function of the position in the cell cycle (age response function) is considered and survival calculated by means of a method discussed previously (Hahn, 1966; Hahn & Kallman, 1967). It is shown how the age response function is obtained from experimental data. Two examples of the application of the computer-based technique are given. As one example, the technique is used to 'optimize' the scheduling of fractionated irradiations to differentially kill one cell line over another using as a basis for optimization differences in their age response functions. the second example illustrates the use of the technique to determine the relative advantage of different chemotherapy protocols. Here the survival of cycling and noncycling bone marrow stem cells, and resistant and sensitive malignant cells, is calculated. It is suggested that the technique may have direct relevance for the chemotherapy of some leukemias.  相似文献   

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中国茴香属的比较研究及分类处理意见   总被引:2,自引:0,他引:2  
范昌发  何兴金  贾敬芬  李存勇  冯陪章 《植物研究》2001,21(3):350-355,T001
从细胞学、孢粉学、形态学角度,并辅以解剖学和胚胎学方法,对茴香属Foeniculum Miller植物球茎茴香F.vulgare subsp.copillaceum var.azoricum(Miller)Thellung与茴香F.vulgare Miller进行了比较研究。结果表明,孢粉学特征差异表现在花粉粒类型、球状、大小、萌发孔、纹饰等方面;细胞学特征差异表现在核型不对称系数、染色体组成、最长染色体与最短染色体之比值等方面;形态学特征差异包括基部茎、基部叶叶鞘及果实主棱的圆钝等方面;解剖学上发现数量性状差异;胚胎学方面则表现在珠被上。就上述对应特征而言,茴香均表现出比球茎茴香更为进化的特性。据此,支持Miller(1768)将球茎茴香均作为等级的处理意见,而不支持将球茎茴香视为茴香变种,以及为茴香异名的观点,并恢复其名称为Foeniculum azoricum Miller。  相似文献   

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