Increment of antioxidase activity of transgenic tobacco with betaine aldehyde dehydrogenase

Superoxide dismutase (SOD) activity in the leaves of transgenic tobacco plants with betaine aldehyde dehydrogenase (BADH) gene was about 36% higher than that in the control plants (parent plants), activities of peroxidase (POD) and catalase (Cat) increased by about 62% and 88% respectively. Activities of ascorbate peroxidase (AsSPOD), dehydroascorbate redutase (DAsAR) and glutathione reductase (GR) in ascorbate-glutothion pathway located at chloroplasts increased by 67.7%, 47.9% and 38.8% respectively. These results indicated that the H₂O₂ produced by SOD catalyzing superoxide anion radicals (O^-₂) could be fully decomposed, and could not derive to form the strongest toxicant radicals ·OH. This is the first report to elucidate quantitatively that the activities of two kinds of antioxidative enzymes decomposed radicals and active oxygen were matched. Photoinhibition tolerant capacity of the transgenic tobacco plants was 35% higher than that in the parent plants. Increment of photoinhibition tolerant capacity in the transgenic tobacco plants might be due to increment of antioxidative enzymes activities, in turn being able to more effectively scavenge active oxygen and radicals, protect organization and function of chloroplasts. These results showed that the increment of antioxidative enzymes activities in the transgenic tobacco might be one of the reasons for the increment of resistance in the transgenic tobacco.     

Discovery of Ordovician acritarchs in Buqingshan ophiolite complex, East Kunlun Mountains and its significance

This note reports the first discovery of Middle-Late Ordovician acritarchs from the Buqingshan ophiolite complex of the southern ophiolite zone of East Kunlun. The acritarch assemblage is dominated with acanthomorphids (approx. 32%) and sphaeromorphds (approx. 63%) and contains more characteristic forms, such as Lophosphaeridium edenense, L. varum, Nothooidium sp.,? Buedingiisphaaeridium sp., Visbysphaera sp., Strophomorpha sp., etc. In addition, some tube-like fragments and tetrads, which are recognized as affinity to terrestrial plants and usual occurrence in Late Ordovician-Early Silurian strata, are preserved together with acritarchs. All the known fossil evidence indicates that the strata should be Middle-Late Ordovician in age. It not only provides paleontological proof for the existence of Ordovician ophiolite, but also challenges the usual ideas on strata composition of the studied area and the southern ophiolite zone of East Kunlun, and the models on tectonic framework and evolution of this area and the northern part of the Qinghai-Tibetan Plateau.     

Rate of decay in admixture linkage disequilibrium and its implication in gene mapping

Modeling linkage disequilibria (LD) between genes usually observed in admixed natural populations has been shown an effective approach in high-resolution mapping of disease genes in humans. A prerequisite to obtain accurate estimation of recombination fraction between genes at a marker locus and the disease locus using the approach is a reliable prediction of the proportion of the admixture populations. The present study suggested the use of gene frequencies to predict the estimate of the admixture proportion based on the observation that the gene frequencies are much more stable quantities than the haplotype frequencies over evolution of the population. In this paper, we advanced the theory and methods by which the decay rate of nonlinear term of LD in admixed population may be used to estimate the recombination fraction between the genes. Theoretical analysis and simulation study indicate that, the larger the difference of gene frequencies between parental populations and the more closely the admixture proportion approaches 0.5, the more important the nonlinear term of the LD in the admixed population, and hence the more informative such admixed populations in the high-resolution gene mapping practice.     

数值分类在藓类植物中的应用

根据数值分类学的基本原理,设计了一个实现藓类植物数值分类的算法,通过该算法对33种藓类植物孢子和孢蒴的主要性状进行了计算机数量化分析,根据距离系数验证了它们之间的相似性和区别,并与形态和细胞分类作了比较,从数值分类角度可以说明大帽藓属（Encalypta）、真藓属（Bryum）和金发藓属（Polytrichum）是属级的自然分类群,小金发藓属（Pogonatum）与金发藓属（Polytrichum）是科一级的自然分类群,有2个物种与所在属的其它物种距离系数相差相关稍大,原因有待进一步探讨。     

3个Ramsey数R(4,q)的新下界

使用新的方法搜索Ramsey数（R（4,q)的下界,获得R（4,20)≥234,R(4,22)≥314,R(4,25)≥458     

结构动态分析中的可视化技术

提出了结构动态分析的可视化思路,并在先进的图形开发环境下利用OpenGL作为三维图形的绘制引擎,实现了结构的动态模拟。     

新法合成环己烯

在一水硫酸氢钠存在下,将环己醇小心加热40min制得环己烯,其收率达62.8%。     

8407钢与4Cr5MoSiV1钢纵横向热疲劳性能研究

采用自约束热疲劳试验方法,在相同的热处理条件下,对比研究了8407,4Cr5MoSiV1钢的纵横向热疲劳特性,观察分析了两种钢的热 形貌及深度,并选择典型试样进行扫描电镜分析,结果表明,8507钢比4Cr5MoSiV1钢的碳化物颗粒较小,而且分布均匀,从而表现出较好的热疲劳性能,尤其是4Cr5MoSiV1钢的横纵向热疲劳性能差异较8407钢大,即8407钢的各向同性要优于4Cr5MoSiV1钢,与两种钢的横纵向冲击韧性的比值相对应。     

[Co(2，3tri)(pz)Cl]2+体系配合物水解-重排机理研空

本文提出了一个「Ｃｏ（三元胺）（二元胺）Ｃｌ」＾２＋型的配合物及其异构体的重排机理模型,它包含了所有异构体间的转换关系,这一模型表面式异构体在重排过程中的重要性,利用对映异构体旋光性质及其可能的变化提出了可能存在一与经典模式不同的中间体假设。     

[Co(2，6-二胺基甲基吡啶)(1，2-二胺基丙烷)Cl]ZnCl4体系配合物的合成及一异构体的晶体结构

用过氧化物法合成了 [Co(bamp) (cmen)Cl]ZnCl4(bamp =2 ,6 -二胺基甲基吡啶 ;cmen =1 ,2 -二胺基丙烷 ) ]中的两个经式异构体 ,解析了其中一个异构体阳离子的晶体结构为m1 .晶体学参数 :单斜晶系 ,空间群C2 /c,a =2 .0 1 2 0(6 )nm ,b =0 .940 8(3)nm ,c =2 .0 5 2 1 (6 )nm ,β =92 .0 45 (6 )° ,V =3.882 2(1 9)nm3,Dc =1 .786 g/cm3,Z =8,F0 0 0 =2 1 0 4,μ(MoKα) =2 7.83cm-1,R =0 .0 42 6 ,RW=0 .1 0 38.配合物离子中Co3 为六配位 .晶胞中含 4个配合物离子 ,对映体的比例为 1 :1