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1.
用化学方法测定了乙酰胆碱脂酶(AchE)活性,阵发性睡眠性血红蛋白尿症(PNH)红细胞远低于正常红细胞。为了进一步研究PNHAchE(—)的红细胞,采用Protein A Sepharose 6MB结合AchE单抗亲和层析法分离出PNHAchE(—)的红细胞。用间接免疫荧光流式细胞术检测,PNH细胞AchE低于正常,而PNHAchE(—)红细胞未能检出AchE。3H-肌醇标记实验证明,正常红细胞膜区带4.1处有较高的放射活性,而PNH红细胞极低,PNHAchE(—)红细胞完全无放射活性。用AchE抗体做免疫印渍实验证明了AchE存在区带4.1部位。DMPC诱导正常和PNH红细胞,检测二者囊泡化的程度,发现PNH病人红细胞远比正常人红细胞易于囊泡化。  相似文献   

2.
《生物物理学报》1999,15(1):25-32
nnature,agroupofprokaryoticorganismshastheabilitytoreducedinitrogentoammonia,whichcanbeusedbyotherorganisms.Thefunctionalmach...  相似文献   

3.
用月桂酸对人红细胞超氧化物歧化酶(h-SOD)进行化学修饰得到酰化h-SOD(Ac-hSOD),并对Ac-hSOD和h-SOD的稳定性进行了比较。结果表明:Ac-hSOD活力为h-SOD的72%。比活力为4000U/mg,Ac-hSOD的热稳定性、酸碱稳定性及抗蛋白酶水解能力均比天然酶提高。  相似文献   

4.
阵发性睡眠性血红蛋白尿症红细胞乙酰胆碱酯酶的研究   总被引:1,自引:0,他引:1  
用化学方法测定了乙酰胆碱脂酶(AchE)活性,阵发性睡眠性血红蛋白尿症(PNH)红细胞远低于正常红细胞。为了进一步研究PNH AchE(一)的红细胞,采用Protein A Sepharose 6MB结合AchE单抗亲和层析法分离出PNHAchE(一)的红细胞。同间接免疫荧光流式细胞术检测,PNH细胞AchE低于正常,而PNH AchE(一)红细胞未能检出AchE。^3H-肌醇标记实验证明,正常  相似文献   

5.
人类血细胞及其他细胞有IgG-Fc受体(hFcrR)表达,即hFcrR Ⅰ、hFcrR Ⅱ和hFcrR Ⅲ。它们的表达表现明显的多态性,并能介导多种生物学活性,如吞噬、ADCC、增强抗原提呈、促进细胞因子释放、调节免疫球蛋白产生等。细菌感染过程中hFcrR表达增高,提示这类抗体在抗细菌性感染免疫中起一定作用。  相似文献   

6.
Scaffoldassociatedregion(SAR)andmatrixattachmentregion(MAR)areknownascisactingDNAelements,whichspecificallybindtonuclearscaffoldornuclearmatrix.SAR/MARareusually300—1000bplong,ATrich,andcontainingtopoisomeraseIIconsensussequenceandotherATrichsequencemotifs[1].…  相似文献   

7.
Littersizeisaveryimportantquantitativetraittopigproductionanddifficulttoimprovebytraditionalbreedingtechnologyduetoitslowheritability.Markerassistedselection(MAS)isthoughtasanewapproach,whichcanbeusedtoimproveproductiontraitsoflowheritabilityeffectivel…  相似文献   

8.
Amolecularmarkercanbedesignatedascodominantordominanttypeaccordingtothegenotypicinformationprovided[1—4].Foracodominantmarker,threebandpatternscanbeobservedinelectrophoreticgels,whichcorrespondtotwocopiesoftheDNAsegmentsonthislocusbeinghomozygousP1type,h…  相似文献   

9.
用月桂酸对人红细胞超氧化物歧化酶进行化学修饰处到酰化h-SOD,并对Ac-hSOD和h-SOD的稳定性进行了比较。结果表明:Ac-hSOD活力为h-SOD的72%,比活力为4000U/mg,Ac-hSOD的热稳定性,酸碱稳定性及抗蛋白酶水解能力均比天然酶提高。  相似文献   

10.
洞庭湖滨湖湿地平原农村生态工程初步研究严斧,游有林,刘劲凡,卢源德,周为民(中国科学院生态环境研究中心系统生态室沅江课题组,大庸市416600)RuralEcologicalEngineeringonWetlandPlainofDongtingLakeside¥.YanFu;YouYoulin;LiuJinfan;LuYuande;ZhouWeimin(YuanjiangResearchGroup,ResearchCenterforEco-environmentalScience,A-cademiaSinica,Dayong416600).ChineseJournalofEcology,1993,12(2):45—48.AccordingtothemaintypesofresourcecombinationsonwetlandplainofDongtinglakeside,severaleco-logicalengineeringsincludinglakesidereed-forest,lowlandrice-fish-ramie,rnanure-forage-fuel,fish-pig-duckandf  相似文献   

11.
通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.  相似文献   

12.
The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.  相似文献   

13.
青蒿素生物合成机理研究现状   总被引:10,自引:1,他引:9  
赵兵  王玉春  欧阳藩   《广西植物》1999,19(2):154-158
本文总结了目前有关青蒿素生物合成机理方面的研究,主要包括青蒿素生物合成中生理因子的影响,青蒿素生物合成中间体及前体,青蒿素生物合成细胞定位等。指出了存在的一些问题及今后的研究发展前景。  相似文献   

14.
The main purpose of this study was to determine whether the magnitude effect is present in cases where delayed sequences of rewards are discounted. The magnitude effect refers to the inverse relationship between the amount of a reward and the steepness of temporal discounting. This study was conducted with a computer program to estimate the indifference points, which served as indicators of the present subjective value of delayed sequences of small and large rewards. In the indifference point the subjective value of a single, immediate reward was equal to the subjective value of the delayed sequence (or to the value of a single delayed reward). As a control condition, we added an experimental task involving choices between single immediate and single delayed rewards. The experiment showed that the sequences of large rewards are discounted less steeply than are the sequences of small rewards. This finding suggests that the magnitude effect is present within the delayed sequences of rewards. In addition, when outcomes are relatively large, the results suggest that a single reward is discounted less steeply than the sequence of a total nominal value equal to this single reward. However, for relatively small rewards, the difference is not statistically significant. The less steep discounting of sequences of large rewards may explain the reward-bundling effect, which refers to less steep discounting of longer sequences than of shorter ones: longer sequences usually have greater overall nominal value. The present study was conducted on hypothetical rewards, and the results should be validated using real rewards.  相似文献   

15.
目的:分析激光联合注射曲安奈德治疗婴幼儿血管瘤的疗效。方法:将120例处于增殖期血管瘤患儿分成观察组和对照组各60例,观察组给予激光联合注射曲安奈德治疗,对照组采用激光治疗,比较两组患者的治疗疗效。结果:观察组和对照组的总有效率分别为96.7%和66.7%,两组比较具有显著差异,P〈0.05;对于表浅病灶,观察组治疗的有效率为96.8%,对照组为84.8%,两组之间无差异,P〉0.05;对于深部病灶,观察组和对照组的总有效率分别为96.6%和44.4%,具有显著差异(P〈0.05)。结论:激光联合注射曲安奈德治疗婴幼儿血管瘤具有较好的疗效,尤其对深部增殖期的血管瘤具有较好的效果,适合在临床推广应用。  相似文献   

16.
Analysis of evolution of exon-intron structure of eukaryotic genes   总被引:10,自引:0,他引:10  
The availability of multiple, complete eukaryotic genome sequences allows one to address many fundamental evolutionary questions on genome scale. One such important, long-standing problem is evolution of exon-intron structure of eukaryotic genes. Analysis of orthologous genes from completely sequenced genomes revealed numerous shared intron positions in orthologous genes from animals and plants and even between animals, plants and protists. The data on shared and lineage-specific intron positions were used as the starting point for evolutionary reconstruction with parsimony and maximum-likelihood approaches. Parsimony methods produce reconstructions with intron-rich ancestors but also infer lineage-specific, in many cases, high levels of intron loss and gain. Different probabilistic models gave opposite results, apparently depending on model parameters and assumptions, from domination of intron loss, with extremely intron-rich ancestors, to dramatic excess of gains, to the point of denying any true conservation of intron positions among deep eukaryotic lineages. Development of models with adequate, realistic parameters and assumptions seems to be crucial for obtaining more definitive estimates of intron gain and loss in different eukaryotic lineages. Many shared intron positions were detected in ancestral eukaryotic paralogues which evolved by duplication prior to the divergence of extant eukaryotic lineages. These findings indicate that numerous introns were present in eukaryotic genes already at the earliest stages of evolution of eukaryotes and are compatible with the hypothesis that the original, catastrophic intron invasion accompanied the emergence of the eukaryotic cells. Comparison of various features of old and younger introns starts shedding light on probable mechanisms of intron insertion, indicating that propagation of old introns is unlikely to be a major mechanism for origin of new ones. The existence and structure of ancestral protosplice sites were addressed by examining the context of introns inserted within codons that encode amino acids conserved in all eukaryotes and, accordingly, are not subject to selection for splicing efficiency. It was shown that introns indeed predominantly insert into or are fixed in specific protosplice sites which have the consensus sequence (A/C)AG|Gt.  相似文献   

17.
目的 针对医疗机构的合理用药水平进行评价研究。方法 根据医疗机构合理用药的具体要求,构建医疗机构合理用药评价指标体系,采用基于模糊群决策的方法和多指标评价分析法构建医疗机构合理用药评价模型。结果 构建了基于模糊群决策的医疗机构合理用药评价模型,并通过实例分析证明了评价模型的可行性。结论 建立的基于模糊群决策的医疗机构合理用药评价模型能够对医疗机构的合理用药水平进行科学评价,为提高医疗机构合理用药水平奠定基础。  相似文献   

18.
山黧豆叶片蛋白质双向电泳技术的建立   总被引:11,自引:1,他引:10  
以山黧豆叶片为材料,比较分析了蛋白质的不同提取方法,在此基础上着重于样品制备。对IPG胶条的选择,第一向等电聚焦和第二向SDS-聚丙烯酰胺凝胶电泳的电泳程序及参数、染色方法等相关技术进行了比较和条件优化。结果显示:采用TCA-丙酮沉淀法提取蛋白质,裂解液中加入Tris-base作为蛋白酶抑制剂,等电聚焦电泳时延长低电压的电泳时间(30V、12h,500V、1h,1000V、2h)以促进盐离子泳出的方法对山黧豆叶片蛋白质进行双向电泳,并用考马斯亮蓝和银染复合染色法进行凝胶染色,能够获得蛋白点清晰的双向电泳图谱,说明用优化后的方法建立起的山黧豆叶片蛋白质双向电泳技术,蛋白质样品制备质量好,电泳分辨率高,完全适合于进一步的蛋白质组学研究。  相似文献   

19.
20.
Nine of 10 genera and 119 of approximately 240 species of the Pinaceae occur in China, including 67 endemic species and two endemic genera. In this paper, the distributional maps of all the genera of the Pinaceae are presented (fig. 1-8). The horizontal and vertical distributions of species in each genus are discussed. The analysis of the distribution patterns of the genera indicates that some genera, such as Keteleeria, Tsuga, Pseudotsuga, Cathaya and Pseudolarix, are restricted to the area south of the Qinling Mountains and the Huaihe River, and the others, i. e. Picea, Abies, Larix and Pinus, extend northward to northeastern China. However, all of the genera except Keteleeria and Pinus are not found in very dry areas and tropical mountainous regions of China. The monotypic genera, Cathaya and Pseudolarix, are distributed in eastern and central China. The genus Keteleeria consists of 10 species, 7 of which are concentrated in southern Guizhou, northern Guangxi, southwestern Hunan and easternmost Yunnan. The distribution of the remaining 6 genera shows the maximum concentration in western Sichuan and northwestern Yunnan. (Figs. 2-8). Furthermore, more than third of species of the Pinaceae (37.8%) are also concentrated in western Sichuan and northwestern Yunnan. where a great variety of habitats and different topographic features occur. It is apparent that to conduct our systematic and evolutionary studies on this family in these region is especially needed. The relations between the areal size and the tolerance of species are discussed. The distributions of macrofossils and microfossils of the genera of the Pinaceae ia China are given, and it has been proved that areas of most genera of the family were considerably larger in the past. than at present.  相似文献   

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