变异发生

As showed above, we could draw the conclusion that H3 viruses could cause outbreaks or local epidemics in Shanghai for the immune of population to the new emerging antigenic drift was still unknown though there was strong immune barrier to the previous vaccine strain, H1 viruses also may caused epidemics as the population had a weak immune protection to the previous reference strains A/New Caledonia/20/99-like and part of the recent isolates were distingwishing from them and continued to evolute on the new reference strain, and H5N1 HPAI activities has expanded its geographical range thus increasing the size of the population at risk as the continuing emergence of human cases which give the virus an opportunity to evolve towards a fully transmissible pandemic strain. We should keep eyes on the human cases of avian influenza virus an its variation for the H5 isolates in Shanghai also has the possibility to infect human directly and the infection of H5, H9 viruses had previously occurred in the population especially in those contacting with animals.

综合上述分析结果，我们认为上海地区人群虽然对原有的H3亚型参考病毒株有较高的免疫保护，但H3亚型病毒HA已出现新的抗原漂移，人群现在对新变异株的保护水平尚未知，有可能在未来引起局限性暴发甚至地方性流行；人群对H1亚型流感病毒免疫保护水平低，同时H1亚型流感病毒株部分与原推荐疫苗株抗原性差别较大，并在现推荐疫苗株基础上继续变异，需警惕发生流行的可能性；H5N1亚型高致病性禽流感地域范围扩大，人间病例不断发生，存在演变成大流行株的威胁，上海市H5亚型禽流感病毒株存在跨宿主屏障感染人类的可能性，而且已发现人群尤其禽、畜类动物接触人群中存在H5、H9亚型流感病毒的既往感染，应警惕禽流感病毒的变异和人间病例的发生。

YMDD mutation: HBV YMDD mutation were developed in 12 lamivudine recipients, whereas the treated group had no incidence of HBV YMDD variation, there were significant difference between two groups (p=0.000). YMDD mutation resulted in increase of the mean HBVDNA levels (p=0.000), but no contribution to serum ALT diversification (p＞0.05). 2. Precore nt1896 mutation: Precore nt1896 mutation incidence had no difference between lamivudine recipients and objects who received combination therapy of Kidney-invigorating Granule and Marine Injection, and patients of HBeAg negative and HBeAg positive had a close incidence of precore mutation as well as. Precore nt1896 mutation had no influence on serum ALT level. The occurrence of precore nt1896 mutation contributed to serum HBVDNA load increased and worse response of HBVDNA extenuation. 3. HBV genotype: The baseline of serum HBVDNA gradually increase in turn of genotype B, genotype C and genotype B/C. Genotype B seemed to obtain higher rate of serum HBVDNA loss and HBeAg/anti-HBe seroconversion after combination therapy of Kidney-invigorating Granule and Marine Injection, differencing with lamivudine therapy.

疗效相关因素研究：1YMDD变异：对照组有12例检出YMDD变异，治疗组无1例检出，两组比较有显著性差异（P=0.000）；发生YMDD变异者血清HBVDNA和ALT水平均有所升高，HBVDNA平均水平高于非变异者（P=0.000）；血清ALT与非变异者无明显差异（P＞0.05）。2前C区nt1896变异：前C区nt1896变异发生率在治疗组和对照组以及HBeAg阴性和HBeAg阳性患者之间均无明显差异（P＞0.05）；1896c变异对血清ALT水平无明显影响；治疗组发生1896c变异者，其HBVDNA平均水平较之未变异者明显升高（P＜0.05），治疗后HBVDNA下降幅度明显低于未发生1896c变异者（P=0.000）。3HBV基因型：血清HBVDNA基础水平在B、C、B/C混合型间存在明显差异（P＜0.05），按B型、C型、B/C混合型依次升高；治疗组HBVDNA阴转率、HBeAg/抗-HBe血清转换率，B型似乎高于C型和B/C混合型，但无统计学意义（P＞0.05）；对照组HBVDNA阴转、HBeAg/抗-HBe改变在B、C、B/C混合型间无明显差异（P＞0.05）。

That is why we are interested in genetic variation.

这就是为什么我们对遗传变异发生兴趣。

The present thesis is intended to approach several aspects on the mechanism of plant somaclonal variation by cytological methods.

本论文拟从细胞学的角度探讨植物体细胞无性系变异发生机理方面的几个根本问题。

OBJECTIVE ①To compare the sequences of the ribosomal rDNA-ITS2, 28S-D3 and mitochondrial mtDNA-COII in the different origins of Anopheles minimus for detecting the intra-and inter-specific variation of the sibling species of the Minimus Complex;②To reconstruct phylogenetic trees of the Minimus Complex and Myzomyia Series for determining the position of An. minimus A and C;③To establish specific methods for differentiation of two sibling species, An. minimus A and An. minimus C, of the Minimus Complex.

中文题名微小按蚊种群变异与分子鉴别研究副题名外文题名论文作者周水森导师汤林华研究员学科专业分子流行病学研究领域\研究方向学位级别博士学位授予单位中国预防医学科学院学位授予日期2002 论文页码总数98页关键词蚊微小按蚊馆藏号BSLW /2003 /R384 /3 目的①比较微小按蚊核糖体rDNA-ITS2、28S-D3基因和线粒体mtDNA-COII基因的序列差异，阐明微小按蚊复合体亲缘种种间和种内变异；②根据基因变异重建微小按蚊复合体及迈蚊系成员的种系发生关系，以确立微小按蚊亲缘种变异的种系地位；③建立微小按蚊复合体亲缘种A和C的分子鉴别方法。

At the same time, the relationship between genera Machilus and Persea was also discussed. The result of chloroplast DNA analysis indicated that C. philippinense was closer to Machilus than to Cinnamomum. There was no difference between C. philippinense, Machilus thunbergii, M.

上述3个叶绿体DNA片段的定序结果显示菲律宾樟较靠近桢楠属，在3个片段多达31处变异处可供辨识的位置上菲律宾樟与桢楠属植物序列之间没有任何变异，而两者与樟树有15处发生序列变异或插入缺失，与酪梨亦有14处发生变异或缺失。

With the growth of age, the ulnar variance tends to change dynamically.

2随着年龄的增长，尺骨变异发生动态变化。

Objective: To investigate genotype and drug resistance in HIV/AIDS infectors in Henan Province.

目的：检测研究河南省艾滋病病毒基因型耐药变异发生的情况。

It was thought that these variations took place at the stage of forming flower organ subregions, and could not be interpreted by "ABC model" for flower organ development, nor by the advanced "ABCD model" and "ABCDE model".

分析认为：韭兰的花形变异发生在花亚区的形成期，不能用花器官发育的&ABC模型&以及由&ABC模型&为基础发展而来的&ABCD模型&和&ABCDE模型&解释。

The published Kentucky bluegrass transformation system has many disadvantages including the diffculty of regeneration, high frequency of somaclonal, long-time transformation period and low efficiency of transformation.

现有的草地早熟禾遗传转化体系存在着植株再生困难、体细胞无性系变异发生频率高以及转化周期长、效率低等缺点，严重制约了早熟禾基因工程育种研究的发展。

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。