模板甲基化水平对鼠肝RNA聚合酶体外转录活性的影响

利用３Ｈ－ＵＴＰ同位素参入法，研究了大鼠肝细胞ＲＮＡ聚合酶在核内外的转录活性，结果表明：在细胞核内的转录活性明显低于在无核抽提物中的转录活性。利用自身的ＤＮＡ模板，优于利用外加的ＤＮＡ模板。并比较了不同ＤＮＡ甲基化水平的模板对ＲＮＡ聚合酶体外转录活性的影响，发现模板的甲基化水平与其体外转录水平呈反相关。     

乙烯调控果实成熟的分子生物学研究进展

乙烯是一种可促进果实成熟的内原植物激素．随着分子生物学的发展，已克隆出几个与乙烯合成有关的果实成熟基因，并获得了反义基因转化植株。本文简要综述了用基因工程手段调控果实的成熟，基因工程技术对认识果实成熟机理的贡献，以及乙烯调控果实成熟的分子机理．     

人乳头瘤病毒感染的宫颈癌组织的病理形态学观察

应用核酸杂交技术结合组织病理学的光镜和电镜观察、检测８０例子宫颈癌、４２例正常宫颈组织、３３例宫颈非典型增生组织和１０例宫颈尖锐湿疣组织中的ＨＰＶｓ基因组相关序列。结果表明：（１）４２例正常宫颈组织ＤＮＡ无一例检出ＨＰＶ，而在宫颈癌组织、宫颈非典型增生组织和宫颈尖锐湿疣组织中，ＨＰＶ检出率分别达４３．７５％、４５．４５％和８０％；（２）宫颈癌组织中阳性３５例，阳性率为４３．７５％；ＨＰＶ型别分布主要为ＨＰＶ１６型（１８例，５１．４３％）和ＨＰＶＲ型（８例，２２．８６％）；（３）１８例ＨＰＶ１６型和３例ＨＰＶ１１／６型均为鳞癌，８例ＨＰＶＲ型中有６例也为鳞癌。ＨＰＶ１６型的１８例中有１２例为低分化癌，ＨＰＶＲ型的８例中有５例也为低分化癌；（４）不同型别ＨＰＶ感染的宫颈癌组织，其病理形态学特征有所不同。研究表明，广西地区相当部分宫颈癌的发生与ＨＰＶ感染有关，其感染的宫颈癌组织具有一定的病理形态学特征。     

RNAi-mediated knockingdown of rlpk2 gene retarded soybean leaf senescence

Leaf senescence that occurs in the last stage of leaf development is a genetically programmed process. It is very significant to elucidate the molecular mechanisms that control the initiation and progression of leaf senescence and the way the senescence signal is transduced. In a previous study on artificially induced soybean leaf senescence, we cloned a novel gene designated rlpk2 (Genbank Accession No. AY687391) that encodes a leucine-rich repeat (LRR) receptor like protein kinase. The expression level of rlpk2 gene was shown to be strongly up-regulated during both the natural leaf senescence process in this report and the artificially induced primary-leaf-senescence process in our previous work. The RNA interference (RNAi)-mediated knocking-down of rlpk2 dramatically retarded both the natural and nutrient deficiency-induced leaf senescence in transgenic soybean. The transgenic leaves showed more cell-aggregated surface structure and higher content of chlorophyll.     

Comparative analysis of A,B,C and D genomes in the genus Oryza with C_0t-1 DNA of C genome

The genus Oryza includes two cultivated species, O. sativa L. and O. glaberrima Steud. and comprises more than 20 species[1]. The genomes of Oryza are classified into 10 types: AA, BB, CC, BBCC, CCDD, EE, FF, GG, HHJJ and HHKK[2,3]. Morphological variatio…     

Gene flow from genetically modified herbicide-resistant rapeseed to cruciferous weeds

The sexual compatibility between genetically modified (GM) glyphosate-resistant rapeseed variety Q3 (Brassica napus L.) and 5 cruciferous weeds is studied through the observation of fluorescence microscopy and cross-fertility after manual pollination. The results indicated that Q3 (as male) was highly incompatible with Thlaspi arvense L., Capsella bursa?pastoris (L.) Medic, Cardamine hirsuta L. and Rorippa palustris (L.) Besser (as female). Fluorescence microscopic observation showed that growing of pollen tubes terminated on the stigma surface or at the upper 1/3 part of the style. However, B. juncea×Q3 was compatible, and the compatibility index was 1.65. Under the neighboring growth and natural pollination conditions, the rates of gene flow from Q3 to T. arvense, C. bursa-pastoris, C. hirsute and R. palustris were all 0, while it was 0.86% for B. juncea. These results indicate that there is difference in the rate of gene flow between GM rapeseed and cruciferous wild weeds, and frequency of gene flow is highly correlated with sexual compatibility.     

线阵CCD图像减影技术实现抛射物体轨迹实时检测

为对抛射物体的运动进行分析 ,克服使用高速录像并逐帧分析像片图像的方法需要较长的后期分析时间 ,不便于对结果进行自动快速分析的缺点 ,论文基于抛射物体的运动学规律 ,通过在抛射曲线上的两个固定点的高度和跨越时间的检测 ,获得了抛射物的初始角度和初始速度。对高度和时间的检测 ,采用了线阵电荷耦合器件 (CCD)为图像传感器进行摄像并采用图像减影的方法识别抛射物体。在对系统进行静态标定的基础上 ,在抛射架上进行了抛射实验检测。用该文提供的方法和用录像检测方法对不同条件下的初始发射角和初速度进行检测 ,二者数据符合得很好     

利用椭圆偏振光谱法研究硅片上DNA分子杂交

将单晶硅片硅烷化后，用戊二醛做醛基修饰，将5′端氨基修饰寡核苷酸探针片段通过醛－氨共价键结合在硅片上，然后用椭圆偏振光谱法对探针和不同序列样品的杂交反应进行了研究。结果表明该方法能在不对样品进行荧光标记的情况下直接研究杂交反应的效率，从而得知样品的序列信息。     

一种基于主元递归分析法的多模糊逻辑系统的组合形式

根据多个模型相加可以提高整体预测精度和鲁棒性的思想，提出了一种具有递阶特点的模糊逻辑模型。该模型采用基于山峰函数的减法聚类算法，将样本数据集分成多组来进行局部模糊模型的建立和训练，大大提高了组合模糊逻辑模型的训练效率。各局部模糊系统的预测输出通过主元递归分析法（PCR）连接，解决了模型之间的严重相关性问题，增强了模型的预测能力，提高了模型的鲁棒性。仿真结果表明，组合多个模糊逻辑模型能够达到比局部模型更好的建模效果，并能有效的改善模型的预测能力和泛化能力。