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B.B.Brodie博土,一个先驱药理学家和美国国家科学院院士,1989年2月28日逝世。生前是美国国立卫生研究院心脏研究所化学药理实验室的创始人和第一任主任。  相似文献   

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The karyotypes in spermatogonial and leukocyte metaphases of the toads Bufo bufo, B. viridis and B. calamita (all 2n=22) were analysed and the DNA content of colchicine treated and Feulgen stained spermatogonial metaphase chromosomes measured microspectrophotometrically. The toad species possess similar karyotypes, but the chromosomes of B. bufo are somewhat longer than the chromosomes of B. viridis and B. calamita. All chromosomes of B. bufo contain significantly more than, but in no case twice as much DNA as their homologues in the other two species. Eight chromosomes of B. bufo contain 30–40%, three about 50% more DNA than their homologues in B. viridis. Exactly the same DNA-differences between both sets of chromosomes were found in B. bufo × B. viridis hybrids. Significant differences in the DNA amount of B. viridis and B. calamita exist only between the large chromosomes of these species. The ratio of the total DNA amount of the genomes in the three species is 1.49∶1.07∶1. These DNA-differences between the three toad species are confirmed by microspectrophotometric DNA measurements of their erythrocyte nuclei. It is supposed that these interspecific differences in DNA content of the toads are not a consequence of differential polyteny but are caused during the evolution process by local increase in DNA in all chromosomes of B. bufo and in the large chromosomes of B. viridis.  相似文献   

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B.B.R对严重烧伤大鼠肠道屏障功能的保护作用   总被引:3,自引:0,他引:3  
目的 :探索 B.B.R(复合生态制剂 )对严重烧伤早期肠道屏障功能的保护作用 ,为防治肠源性感染寻找新途径。方法 :选用健康 Wistar大鼠 13 0只 ,体重 180~ 2 2 0 g,雌雄各半 ,随机分为 B.B.R治疗组 ,BFL(单一双歧杆菌制剂 )治疗组 ,烧伤对照组 (BC)和正常对照组 (NC) ,建立 3 0 % °烫伤肠源性感染的动物模型 ,按时分批活杀取材 ,检测细菌易位率、盲肠膜菌群、血浆内毒素和肠粘膜 s Ig A的含量。结果 :B.B.R和 BFL 组 ,伤后 3 d肠道细菌易位率分别为 10 %、2 0 .7% ,与 BC组 (3 3 % )比较明显降低了细易位率。血浆内毒素 BC组明显高于 NC组 (P>0 .0 5 ) ,而 B.B.R组与 NC组比较 ,差异无显著性 (P<0 .0 1)。BC组盲肠中双歧杆菌数量与 BC组比较明显减少 ,而 B.B.R、BFL 组与 NC组比较差异无显著性 (P>0 .0 5 ) ;NC组肠道中酵母菌和大肠埃希菌与 NC比较明显增加 ,B.B.R组差异无显著性 ,肠粘液 s Ig A水平与上述指标有类似变化。结论 :3 0 % °烫伤大鼠肠道内容物双歧杆菌明显下降 ,大肠埃希菌、酵母菌迅速过度生长 ,导致肠道微生态失衡 ,应用 B.B.R治疗后 ,促进肠粘膜机械屏障功能的恢复 ,减少细菌和内毒素的易位 ,调整肠道微生态平衡 ,提高了肠道局部和全身免疫功能  相似文献   

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The amino acid sequence of the cytochrome c' from Alcaligenes sp. N.C.I.B. 11015 (Iwasaki's ;Pseudomonas denitrificans') has been determined. This organism is the only non-photosynthetic bacterium in which the protein has been found. The protein consists of a single polypeptide chain of 127 residues, with a single haem covalently attached to two cysteines. Unlike normal cytochromes c, the haem attachment site is very close to the C-terminus. The amino acid sequence around the haem attachment site is very similar to that of Chromatium vinosum D cytochrome c'. Detailed evidence for the amino acid sequence of the protein has been deposited as Supplementary Publication SUP 50022 at the British Library (Lending Division), (formerly the National Lending Library for Science and Technology), Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies may be obtained on the terms given in Biochem. J. (1973) 131, 5.  相似文献   

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李鹤  孙芳义 《生物技术》1992,2(4):43-43,24
(一)吸附剂1.炉灰渣和黄土按照规定的要求进行烘干,粉碎、过筛20—40目2.炉灰渣和黄土之间的配比为7:3(重量比)炉灰渣和黄土按配比称重后一定要混匀.3.B·T乳液按喷雾筛孔径进行过滤,按规定的质量标准和用量(10%)向吸附剂上喷雾,一定将吸附剂和B·T乳液拌匀.(二)烘干  相似文献   

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研究1株产氢细菌Ethanoligenens sp. B49利用废糖蜜为基本原料进行生物制氢的条件,及外加氮素营养物对废糖蜜生物制氢的影响。结果表明,在10.3~20.6 g·L-1的化学需氧量(COD)范围内,经过驯化的Ethanoligenens sp. B49细胞具有较好的生物利用能力,细胞生长量和产氢能力随着废糖蜜COD的提高而增加。当废糖蜜COD超过20.6 g·L-1Ethanoligenens sp. B49的细胞生长受到抑制,同时产氢能力下降,COD超过41.2 g·L-1时细胞基本不具有生长和产氢能力。Ethanoligenens sp. B49利用废糖蜜产氢的最佳COD为20.6 g·L-1。在20.6 g·L-1COD条件下外加有机氮源可以促进Ethanoligenens sp. B49利用废糖蜜制氢的能力,促进作用顺序为酵母粉>牛肉膏>蛋白胨>脲素。添加4 g·L-1的酵母粉时,Ethanoligenens sp. B49细胞具有最好的生长活性和产氢能力。优化营养条件后,单位体积产氢量从44.82 mmol·L -1提高到78.97 mmol·L-1,提高了76.2%。  相似文献   

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In the second part of the study on vegetation of village settlements at the territory of the Bohemian Karst, ecological and successional characteristics of communities are given. Ellenberg indicator values for temperature, morsture, nitrogen and soil reaction were used to investigate habitat conditions. Successional relations of communities are presented. Quantitative data on the composition of vegetation cover were obtained which made it possible to compare the study area with other regions.  相似文献   

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应用B.t.和SBTi基因提高水稻抗虫性的研究   总被引:21,自引:0,他引:21  
用基因枪法将单个B.t.基因或与SBTi基因一起导入到两个华南地区优良籼稻品种中,获得21个转B.t.单基因的植株系,4个转B.t.和SBTi双基因的植株系。对R1代植株的分子杂交和遗传分析表明,3个转双基因系中多个拷贝的B.t.和SBTi基因均是整合在植株基因组同一染色体上相同或相近位点。Northern blot证明在R2代转基因植株中B.t.基因稳定表达。对稻纵卷叶螟的抗性实验表明,转B.t.单基因或B.t.和SBTi双基因的转基因植株均较原种对照有更强的抗性,而转双基因植株较转单基因植株又有更强的抗性。  相似文献   

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为了探讨凝集素在豆科植物与根瘤菌的识别过程中的作用,用DEAE-32离子交换层析和SephadexG-150凝胶过滤分离、纯化格拉姆柱花草种子凝集素(SGL),其分子量约为45kD,由两个相同的亚基组成,等电点约pH5.8,它是一种糖蛋白,含糖量约为2.6%.SGL的热稳定性强.SGL的血凝活性能被甘露糖所抑制.SGL对红细胞的凝集作用可能具有种属专一性;SGL具有强的促有丝分裂作用;荧光标记实验显示:9株能与格拉姆柱花草植株结瘤的菌株有7株能与SGL结合,6株不能与之结瘤的菌株,只有1株能与SGL结合,这表明不同根瘤菌菌株对SGL的结合能力,和它们在格拉姆柱花草上结瘤能力之间可能具有一定的生物学相关性.  相似文献   

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农杆菌转化获得转B.t.基因水稻及其生物学鉴定   总被引:8,自引:0,他引:8  
黄健秋  卫志明 《植物生理学报》2000,26(6):519-524,T002
以水稻主栽品种“秀水11”和“春江11”预培养4d未成熟胚为转化受体,经农杆菌LBA4404/pGBI4A2B(含B.t.基因)感染后,筛选出抗性愈伤组织并获得转化植株。其中抗性愈伤组织产生频率达44% ̄70%,转化植株产生频率达27% ̄64%。转基因植物总DNA经PCR和Southern blot分子杂交试验表明,T-DNA上的外源基因已整合到水稻的基因组里。对转B.t.基因水稻植株进行了两种水  相似文献   

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周志炎院士获B.Sahni百年纪念奖中国科学院南京地质古生物研究所研究员周志炎院士获1995年度B.Sahni百年纪念奖,并于1996年1月25日在印度勒克垴市参加授奖大会。B.Sahni是世界著名的古植物学家,印度古植物学的创始人和奠基人,英国皇家...  相似文献   

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