独立于...之外

mitochondrial dnais the only inheritant substance except for the nuclear dna in a euˉkaryon cell,which is related to the oxidative phosphorylation of a cell.mitochondrial dna is the important target of carcinogens and is vulnerable because of its structure and function.the mutation of mtdna could reduce the nomal respitation and release large quantities of ros,whichincrease the danger of cancer happening.so,mtdna has been thought to be involved in carcinogenesis and recently more and more studies in this aspect have comeout.in this paˉper,we review the researches for relationship among mtdna mutation and tumors in digestion system,woman system,head and neck,urinary systemand blood system.

线粒体dna（mitochondrial dna，mt dna）是真核细胞中唯一存在的独立于核dna之外的遗传物质，与细胞的氧化磷酸化功能密切相关。mtdna自身的结构和功能特点决定了它是致癌物作用的重要靶点，易受致癌因素的损伤而发生突变。mtdna的突变可削弱正常的呼吸功能，释放高水平的活性氧，进而增加肿瘤发生的危险性，所以mtdna被认为与肿瘤发生有密切关系。近年来，这方面的研究越来越多，本文现就mtdna突变与消化系统肿瘤、妇科肿瘤、头颈部肿瘤、泌尿系统肿瘤等实体瘤以及血液系统恶性肿瘤之间的关系作一简单的综述。

B chromosomes do not pair with A chromosomes,they are inherited in a non-Mendelian way, exhibiting meiotic and mitotic instability andnondisjunction. Bs have little influence with the phenotype. DNA sequence differences in rye genomes (JNK population with similar geneticbackground) with and without B chromosomes were analyzed by random amplifiedpolymorphic DNA.

目前，已在约1300种植物和逾500种动物中发现了B染色体，实际含有B染色体的物种数远远不止这些。B染色体具有许多独特的性质：它独立于A染色体之外，不与任何A染色体配对，为非孟德尔遗传，具有不分离机制，不携带或极少携带核仁组织区，无影响表型的基因。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。