纤蚤属一新种及一新纪录（蚤目：多毛蚤科）

本文报道纤蚤属１９１２ １新种及１新纪录：蔡氏纤蚤和五侧纤蚤似邻近亚种。     

蚊幼对狼蛛的营养作用研究

研究蚊子幼虫（子孓）以拟水狼蛛（Ｐｉｒａｔａｓｕｂｐｉｒａｔｉｃｕｓ）的营养,繁殖作用,结果表明狼蛛对蚊幼的捕食符合ＨｏｌｌｉｎｇⅡ型功能反应,喂以蚊幼和不喂蚊幼处理狼蛛的体重增长率和生殖有极显著差异,在相同蚊幼密度下,狼蛛初始体重越小,增长率越大,经计算狼蛛每增重１ｍｇ,需消耗１０．５８ｍｇ蚊幼,这基本符合生态系统营养级能量流动的１／１０法则,狼蛛体重大小对褐飞虱的捕食量有明显差异,体重大的个体     

大气-土壤-小麦生态系统中铅的分布和迁移规律研究

研究铅在国道附近大气－土壤－小麦生态系统中的分布及其迁移规律。结果表明,大气中铅浓度与汽车流量成正比,而与风速、温度等相关性不明显;距公路越远,土壤及小麦中铅的含量越高,含是与距离呈一定的匀相关性,５ｍ及６０ｍ为其转折点;铅在土壤中由上上及在小麦体中由根向茎、穗的迁移较小;小麦各器官中铅含量大小依次为根〉叶〉穗〉茎〉籽。叶片、穗尚从大气中直接部分铅。在小麦不同生长阶段中,各器官积累铅量不同,其积累     

PSⅡ反应中心D1蛋白的小肽抗体的制备和鉴定

用人工合成的PSⅡ反应中心D1蛋白中(229～240)的12肽,与牛血清白蛋白偶联后做为抗原免疫家兔, 获得抗菠菜D1蛋白抗体. 免疫双扩散法测得其具较高的效价,蛋白印迹检测结果显示该抗体仅与D1蛋白有免疫亲和反应. 表明此抗体可作为检测D1蛋白及其光抑制时降解产物的探针.     

GI双突变体GIK253RA198C的构建及其性质分析

以双引物法对葡萄糖异构酶（GI）基因进行定点突变,将突变体基因于大肠杆菌中表达,获得了GI双点突变体GIK253RA198C.研究K253R和A198C双点突变对GI的结构和性质的作用,结果表明GIK253RA198C的热稳定性明显下降,最适反应温度降低5℃.文章从结构和机制上解释了为何同是K253R突变,对SM33 GI和密苏里游动放线菌GI的热稳定性产生不同的影响,认为这是由于Lys253在两种GI结构的位置上存在微小差异,从而使引入的Arg对亚基间的相互作用产生了相反效应所引起.     

Matching models of left ventricle and systemic artery

To reveal how the matching models of the left ventricle and its afterload affect the pressure and flow in the aortic root, the differences between the measured pressure and flow waveforms and those determined by three kinds of matching model were compared. The results showed that, compared with the results by both matching models 1 and 2, the pressure and flow waveforms determined by matching model 3 established in this work were in the closest agreement with the corresponding experimental waveforms, therefore indicating that matching model 3 was a matching model that closely and rationally characterized the match between the left ventricle and the systemic artery.     

Construction of a trivalent candidate Shigella vaccine strain with host-vector balanced-lethal system

A trivalent liveShigella vaccine candidate FSD01 against S.flexneri 2a, S.sonnei and S.dysenteriae I was constructed. This candidate strain was based on the S.flexneri 2a vaccine T32. By homologous recombination exchange, the chromosomalasd gene of T32 was site-specifically inactivated, resulting in the strain unable to grow normally in LB broth, while anotherasd gene of S.mutans was employed to construct an Asd⁺ complementary vector. This combination ofasd ^- host/Asd⁺ vector formed a balanced-lethal expression system in T32 strain. By use of this system, two important protective antigen genes coding for S.sonnei Form I antigen and Shiga toxin B subunit were cloned and expressed in T32, which led to the construction of trivalent candidate vaccine FSD01. Experimental results showed that this strain was genetically stable, but its recombinant plasmid was non-resistant. Moreover, it was able to effectively express trivalent antigens in one host and induce protective responses in mice against the challenges of the above threeShigella strains.     

Sequence analysis of lacZ- mutations induced by ion beam irradiation in double-stranded M13mp18DNA

While M13mp18 double-stranded DNA was irradiated with ion beam, and transfected intoE. coli JM103, a decrease of transfecting activity was discovered. The lacZ^- mutation frequency at 20% survival could reach (3.6–16.8) × 10⁴, about 2, 3–10 times that of unirradiated M13DNA. Altogether, 27 IacZ^-mutants were selected, 10 of which were used for sequencing. 7 of the sequenced mutants show base changes in 250-bp region examined (the remaining 3 mutants probably have base changes outside the regions sequenced). 5 of the base-changed mutants contain more than one mutational base sites (some of them even have 5–6 mutational base sites in 250-bp region examined); this dense distribution of base changes in polysites has seldom been seen in X-rays, Y-rays or UV induced DNA mutations. Our experiments also showed that the types of base changes include transitions(50%), transversions (45%) and deletion (5%); no addition or duplication was observed. The transitions were mainly C→T and A→G; the transversions were mainly C→A and C→G. The mutations involving cytosine residue (in the template strand) constitute about 60% of all the base changes observed. In comparison with the surrounding sequences of mutational base sites, the base located between TG and CT is found to be easily substituted.     

猫纹状皮层神经元整合野的形状和范围

用正弦调制的移动光栅测量了１２０个猫纹状皮层神经元在长度和宽度方向上的空间整合特性。结果表明：（１）大多数细胞的传统感受野具有长宽相近的结构,然而它们的整合野多数是宽而短或者窄而长的长条形。（２）整合野大小为传统感受野的２—７倍,平均为３．７倍。简单细胞与复杂细胞整合野的大小没有显著差别。（３）随着感受野的视网膜偏心度的增加,整合野大小有逐渐增大的趋势。（４）感受野靠近视网膜垂直中线的细胞,其整合野可以跨越中线进入同侧视野;在两半视野中整合野的范围没有显著差异,但是同侧视野整合野的作用强度明显弱于对侧视野。以上结果提示,初级视皮层神经元能够对大范围内的图形特征进行整合,这种整合作用来自两侧视野。     

中国主要五针松群落学特征及其生物量的研究

本文根据现有的文献资料,系统地分析了中国五针松的分布．群落学特征,按不同分布区、不同群落类型探讨了中国五针松的群落生物量和年净生产量及在群落的不同层次上的分布．比较分析了不同分布区五针松的年干物质累积速度（ＮＰ／Ｂ）．结果表明：１１５─１３５ａ生的阔叶红松林群落生物量在９７．０９─１２０．５１ｔ／ｈｍ￣２之间,年净生产量在８．６９８─１０．３４ｔ／ｈｍ￣２．ａ之间,年净生产量长白山山脉沙松、鹅耳枥红松林＞小兴安岭南坡枫桦、水曲柳红松林＞小兴安岭北坡云杉、冷杉红松林;３０─３６ａ生的华山松林群落生物量在７８．７５─９４．７３ｔ／ｈｍ￣２之间,年净生产量在４．９９３─５．５３７ｔ／ｈｍ￣２．ａ之间,年净生产量贵州山地常绿阔叶华山松林＞秦岭中山地阔叶华山松林＞甘肃小陇山针阔叶华山松林．ＮＰ／Ｂ值：长白山山脉的阔叶红松林＞小兴安岭山脉的阔叶红松林;秦岭中山地阔叶华山松林＞甘肃小陇山针阔华山松林＞贵州中山地常绿阔叶华山松林．