蝮蛇抗栓酶治疗小儿脑炎致急性偏瘫血中6—K—PGF1α,TXB2的变化

应用蝮蛇抗栓酶治疗小儿脑炎致急性偏瘫共25例。沿疗前后检测血中的6-K-PGF_1x及 TXB_2.结果表明:治疗后血中 6-酮-前列腺素 F_1x 明显增高,血栓素 B_2明显降低。推测蝮蛇抗栓酶之所以具有去纤、溶栓、扩血管等作用,可能与血中前列腺素、血栓素 B_2水平变化有关。     

油茶籽饼抗真菌活性成分的研究

从油茶籽饼中已经分离得到一种新的抗真菌活性成分油茶皂甙A,被鉴定为齐墩果烷型的五环三萜皂甙,它的mp为258～260℃,[α]_D~(27)=-20°(C=1％,80％EtOH),体外试验研究表明油茶皂甙A有较强的抑制真菌作用,对红包毛癣菌、石膏样癣菌、断发癣菌、黄癣菌、紫色癣菌、絮状表皮癣菌的MIC为0.125～1.000mg/ml,对白色念珠菌的MIC为0.0625～0.2500mg/ml。     

免疫反应动力学的几个数学模型

免疫系统对抗原刺激的应答过程非常复杂,由抗原刺激导致抗体产生的现象,可借助数学模型的研究获得有意义的结果。本文讨论有关抗体产生与免疫反应的动力学的问题,介绍有关的数学模型,并根据近斯免疫学研究的进展分析了若干模型。     

A Wuchiapingian (Late Permian) brachiopod fauna from an exotic block in the Indus–Tsangpo suture zone, southern Tibet, and its palaeobiogeographical and tectonic implications

A brachiopod fauna including 19 species of 17 genera from an exotic block in the Indus–Tsangpo suture zone in southern Tibet is described and illustrated. The brachiopod fauna is dominated by Martinia elegans and two new taxa: Jinomarginifera lhazeensis gen. et sp. nov. and Zhejiangospirifer giganteus sp. nov. The fauna is closely comparable with those from the middle and upper parts of the Wargal Formation and the Chhidru Formation in the Salt Range of Pakistan, the Chitichun Limestone in southern Tibet, and the Basleo area of West Timor, and these correlations suggest a Wuchiapingian age. The fauna exhibits substantial links with both peri–Gondwanan and Cathaysian faunas, which may imply that it is a seamount biota originally located in the southern margin of the Neotethys during the Late Permian, and was later (in the early Cenozoic) displaced and became sandwiched into younger marine deposits in the collision process between India and Eurasia.     

大肠杆菌rpoH基因的克隆,表达及其产物的纯化

本文用ＰＣＲ方法获得大肠杆菌热休克蛋白转录因子σ３２的编码基因ｒｐｏＨ,并克隆在含有ｔａｃ启动子的表达载体ｐＵＨＥ中,经ＩＰＴＧ诱导,在大肠杆菌中表达了Ｃ端融合有６个寡聚组氨酸的σ３２。表达产物经金属螯合层析一步纯化,达到ＳＤＳ－ＰＡＧＥ银染一条带纯度,氨基酸组成分析及Ｎ端序列分析结果与文献报道一致。３５Ｓ细胞内参入实验表明：即使在较低的温度下,表达产物σ３２（Ｈｉｓ）６也能导致热休克蛋白如ＧｒｏＥｌ、ＤｎａＫ、Ｈｔｐ的大量合成．     

四膜虫(Tetrahymena shanghaiensis)大核核仁与去膜大核能诱导非细胞体系核重建

外源DNA或染色质在非洲爪蟾卵提取物中可以诱导细胞核样结构的重建。重建核除不具有核仁样结构外,在其它形态结构上与真核细胞核十分相似。前人的工作表明在重建核中具有核仁前体结构。但可能是由于缺少活性核仁组织者的缘故,这些核仁前体不能相互融合形成新生核仁。那么活性核仁组织者在重建核中是否能发挥其功能呢?为了研究这一问题,我们提取纯化了四膜虫的大核与大核的周边核仁。进一步去除大核的核被膜,并将去除核被膜的大核与大核核仁分别加入非洲爪赡卵非细胞体系中。通过电镜超薄切片观察,我们发现无论是与大核染色质相连的周边核仁还是分离纯化的核仁结构在非洲爪赡卵非细胞体系中都不能保持其原有结构特征,而是发生了典型核重建变化,并且在诱导形成的重建核中也看不到核仁样结构。这些结果说明具有活性的核仁组织者在加入非洲爪蟾卵提取物后既不能继续保持其原有的RNA转录功能也不能诱导新的核仁的出现。     

Insect-resistant transgenic cabbage plants and their progenies

An insecticidal crystal protein gene of Bacillus thuringiensis was transferred into cabbage genome with the method of Agrobacterium infection. Cotyledons with petioles as explants were cocultivated with Agrobacterial suspension. Calli generated at the basis of petiole were subjected to selection on the MS medium containing 15-30 mg/L kanamycin (Km). About 5% explants produced calli growing continuously on the selective medium. Green shoots appeared on these calli when they were transplanted onto medium with Km and 6-BA for plant differentiation. The shoots were separated and cultivated on medium with kanamycin. About 80% shoots were rooted. Non-transformed control calli could not give normal shoots and roots and brownized and died gradually. Larvae of Pieris rapae showed poisonous symptoms: growth inhibition and mortality when fed with the leaf of the transgenic plants. About 80% of regenerated plants showed positive hybridization bands when their DNA were probed with crystal protein sequence of Bacillu     

具有竞争指针的短时记忆神经网络模型

在我们以前提出的短时记忆神经网络模型基础上［３］,我们在新模型中引入突触竞争机制,提出了一个新的短时记忆神经网络模型。模型仍由两个神经网络所组成;其一为与长时记忆共有的信息内容表达网络,另一个为指针神经元环路。由于表达区神经元与指针神经元间的突触权重的竞争,使得模型可以表现出由干扰引起的短时记忆的遗忘。相应于自由回忆序列位置效应和汉字组块两个心理学实验,对模型做了计算机仿真。仿真结果显示模型的行为与两个心理实验定量地符合得很好。由此表明现在的模型更合适于作为短时记忆的模型。