南昌地区婴幼儿腹泻轮状病毒核酸电泳分析

应用核酸凝胶电泳法对49份婴幼儿急性腹泻粪便标本进行了分析研究。试验结果表明,其中34份呈现轮状病毒核酸电泳型。包括长型和短型两个亚群。在长型中有两种不同的电泳图型,并且对轮状病毒的实验诊断与电镜检测做了比较,结果证实二者的敏感性和特异性相似,而核酸电泳法具有更多的优点,便于推广应用。     

西藏北部中、晚侏罗世海娥螺类

一、前言本文记述的中侏罗世海娥螺类系采自西藏北部双湖县达尔沃错、阿木岗日以及索县以南的雁石坪群,而晚侏罗世的海娥螺类则采自拉萨附近的多底沟群(插图1)。双湖地区的标本是西藏地质科学研究所板块专题组于1983年8月采集的,索县及拉萨附近的标本是夏金宝、毛力等于1982年9月和1983年8月两次采集的。上述地区的海娥螺动物群经研究,共9属11种,其中2个新种。这一研究成果增添了我国侏罗纪海娥螺动物群新资料,并且对藏北和     

基因。(有效因子)模型及其辨识

数量性状受多基因控制且其表现型受环境影响较大。为了更加有效地分析数量性状的表现,本文构建了数量性状的基因模型。由于该模型既包含了基因的加性作用,也涉及到显性偏差和上位性偏差,从而能够比较全面地刻划数量性状群体的分布形态。文章还给出了辨识模型参数的方法及一些性质的讨论。通过对一系列实例的计算并与Castle-Wright公式的结果进行了比较。本文所构建的模型产生的误差明显比Castle-Wright公式的小。可见该模型确实能够提供更多有用的信息。     

噬菌体对产肠毒素大肠杆菌菌型的鉴别

从上海近郊采集的82份污水中,分离到产肠毒素(LT、ST、LT+ST)大肠杆菌噬菌体46株,根据噬菌体的特性,选择19株,试用为产肠毒素大肠杆菌菌型的鉴别,对世界卫生组织、卫生部药品生物制品检定所提供的产肠毒素大肠杆菌75株和福建省卫生防疫站提供的产肠毒素大肠杆菌51株进行了型别的分析,总分型率达98.41％。并研究排除分型试验中可能出现的假阳性结果。     

Identification of the nuclear matrix and chromosome scaffold in dinoflagellate Crypthecodinium cohnii~1

Dinoflagellate is one of the primitive eukaryotes,whosenucleus may represent one of the transition stages fromprokaryotic nucleoid to typical eukaryotic nucleus.Usingselective extraction together with embeddment-free sectionand whole mount electron microscopy,a delicate nuclearmatrix filament network was shown,for the first time,indinoflagellate Crypthecodinium cohnii nucleus.Chromosomeresidues are connected with nuclear matrix filaments to forma complete network spreading over the nucleus.Moreover,we demonstrated that the dinoflagellate chromosome retainsa protein scaffold after the depletion of DNA and solubleproteins.This scaffold preserves the characteristic mor-phology of the chromosome.Two dimensional elec-trophoreses indicated that the nuclear matrix and chromo- some scaffold are mainly composed of acidic proteins.Ourresults demonstrated that a framework similar to the nuclearmatrix and chromosome scaffold in mammalian cells appearsin this primitive eukaryote,suggesting that these structuresmay have been originated from the early stages of eukaryoteevolution.     

Halobacterium denitrificans sp. nov., an extremely halophilic denitrifying bacterium

Halobacterium denitrificans was one of several carbohydrate-utilizing, denitrifying, extremely halophilic bacteria isolated by anaerobic enrichment in the presence of nitrate. Anaerobic growth took place only when nitrate (or nitrite) was present and was accompanied by the production of dinitrogen. In the presence of high concentrations of nitrate (i.e., 0.5%), nitrous oxide and nitrite were also detected. When grown aerobically in a mineral-salts medium containing 0.005% yeast extract, H. denitrificans utilized a variety of carbohydrates as sources of carbon and energy. In every case, carbohydrate utilization was accompanied by acid production. A type culture has been deposited with the American Type Culture Collection, Rockville, Md. (ATCC 35960).     

John Reynolds克隆了一种可控制结缔组织分解的潜在抑制物

与Celltech有限公司(斯劳,英国)合作的Strangeways研究实验室(剑桥,英国)的John Reynolds分离出一种被认为是可控制结缔组织分解和再生的蛋白质,即金属蛋白酶组织抑制物(TIMP),并在细菌和动物细胞中得到表达。TIMP(存在于许多体液和组织中)能抑制金属蛋白酶类,这些酶是专门分解结缔组织的。在正常生长期,这些酶的受控制的活性是组织再生必不可少的一部分。但是,不受控制的金属蛋白酶的活性可能会破坏胶原蛋白