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1.
本文报告应用致病性血清型丢失毒力质粒Y.e菌株439-80V-及82-140进行家兔体内感染,通过大体病变、组织病变和细胞病变的观察.研究其致病性及致病机理.结果表明:这两株Y.e.菌感染性与致病性明显弱于对照组──致病性血清型带毒力质粒Y.e菌株,其中.用439-80V-菌株接种的家兔不发生感染与致病.用LAB-B182菌株接种的家兔有排菌,肠粘膜上皮溃疡,急性脾炎病变.但无微脓肿及菌落形成.无组织细胞变性坏死.  相似文献   

2.
本文报告应用小肠结肠炎耶尔森氏菌以6×108的细菌数,经静脉注射家兔的病理学观察实验结果表明,致病性血清型带毒力质粒小肠结肠炎耶尔森菌菌株G151(血清型0:9)和LAB-8182(血清型0:3)引起家兔组织严重的病理学改变:血细胞渗出,微脓肿和菌落形成,组织变性坏死、溃疡.致病性血清型丢失毒力质粒的小肠结肠炎耶尔森氏菌菌株82-140(血清型0:8)注射的家兔组织病理学改变轻微.493-80V-(血清0:9)不引起家兔组织病理学改变.  相似文献   

3.
本文报告应用小肠结肠炎耶氏菌以6×10 ̄8的细菌数,经静脉注射家兔的大体病变观察。实验结果表明,致病性血清型带毒力质粒小肠结肠炎那氏菌G151(血清型0:9)和LAB-B182(血清型0:3)引起家兔严重感染及病变:排菌、食欲和体重减轻,肠、肝、脾组织脓肿和溃疡形成,LAB-B182菌株引起家兔肝和肠组织局灶性坏死。致病性血清型丢失毒力质粒的小肠结肠炎那氏茵茵株439-80V ̄-(血清型0:9)和82-140(血清型0:8)不引起家兔明显的感染及病变:不排菌或排菌时间短,腹腔脏器组织无大体病变或病变极其轻微。  相似文献   

4.
为了初步研究小肠结肠炎耶氏菌(Y.e.)致病机理,本文报告应用依钙、自凝、刚果红平板毒力试验和质粒DNA提取方法,进行Y.e.体外毒力探讨。结果表明:带毒力质粒的Y.e.菌株G151,920和LAB-B182依钙、自凝和刚果红平板毒力试验阳性;不带毒力质粒的Y.e.菌株82-140和439-80V ̄-依钙、自凝和刚果红平板毒力试验阴性。依钙、自凝、刚果红平板毒力试验阳性与携带毒力质粒的一致性以及依钙、自凝、刚果红平板毒力试验阴性与不携带毒力质粒的一致性表明:Y.e.的依钙、自凝和吸收刚果红特性是毒力质粒编码。  相似文献   

5.
用冻融法将含有绿色荧光蛋白基因的质粒pGL2-GS导入农杆菌菌株LBA4404 (pTOK233),两个质粒发生同源重组,形成一个新的二元载体pTOK233-GS.农杆菌菌株LBA4404 (pTOK233-GS) 经叶盘法转化烟草,筛选具有卡那霉素抗性的愈伤组织,诱导成苗.PCR 扩增发现,绿色荧光蛋白基因在90% 的再生植株中存在.在荧光显微镜下,使用蓝色激发光观察再生植株的徒手切片和压片发现,80 % 以上的再生植株都能不同程度地发出绿色荧光.多数植株的根尖和叶脉都发光,一些植株的气孔、叶表皮或叶绒毛也发光  相似文献   

6.
乙型肝炎病毒(HBV)DNA免疫的初步研究   总被引:1,自引:1,他引:0  
用聚合酶链反应(PCR)扩增了编码HBVsAg的基因序列,将其插入到pcDNA3载体中,位于人巨细胞病毒(CMV)早期启动子下游.重组质粒pcDNA3-sAg转染细胞后检测到HBsAg表达.用纯化后的重组质粒直接注射到BALB/C小鼠骨骼肌内,诱发实验小鼠产生了抗HBsAg特异性抗体.PCR扩增未检测到注射部位及肝脏细胞染色体中有外源HBVDNA整合  相似文献   

7.
产 PHB 重组大肠杆菌质粒稳定性的研究   总被引:2,自引:0,他引:2  
从工程应用的角度研究了重组E.coliHMS174(pTZ18U-PHB)的质粒稳定性,结果表明,质粒pTZ18U-PHB具有结构稳定性和分裂不稳定性,PHB在胞内的大量积累和重组菌较低的生长速率增加了质粒的分裂不稳定性。为了保证细胞的正常生长及表达,在种子培养基中必须添加氨苄青霉素(Ap);由于接种时种子带入的10mg/LAp足以杀死丢失了质粒的细胞,因而在摇瓶发酵阶段不必再添加Ap。在LB和LBG培养基中传代18次后,带质粒的菌分别为7.4%和3.5%;细胞每分裂一次,质粒的平均丢失率分别为0.96%和0.93%。并建立了野生菌的Ap敏感动力学方程和质粒丢失的动力学方程  相似文献   

8.
绿色荧光蛋白基因在烟草植株中的表达   总被引:3,自引:0,他引:3  
用冻融法将含有绿色荧光蛋白基因的质粒pGL2-GS导入农杆菌菌株LBA4404(pTOK233),两个质粒发生同源重组,形成一个元载体pTOK233-GS,农杆菌菌株LBA44024(pTOK233-GS)经叶盘法转化烟草,筛选具有卡霉素抗性的愈伤组织,诱导成苗、PCR扩增发现,绿色荧光蛋白基因在90%的再生存在,在荧光显微镜下,使用蓝色激发光观察再生植株的徒手切片和压片发现,80%以上的再生植株  相似文献   

9.
对本室筛选的高活性B.t.野生株进行了cry 基因检测,Southern杂交证明cryIAc和cry1C位于质粒上.利用接合转移和电穿孔转化等方法对这些菌株进行了遗传改良研究.结果表明:高效野生株7404、HD-1-X和9510 不易获得并表达外源cry 基因,而高效野生株Bti. t-1897 的电转化频率较高,并获得以Btit-1897 为受体,对甜菜夜蛾、棉铃虫、黏虫和淡色库蚊均有毒力,具有cryIAc、cryIC、cryIV及cyt多价基因的广谱工程菌株.  相似文献   

10.
以优选的合成抗原(H(ap)-BSA)免疫动物产生了滴度为1:55000(1号兔,Rt-1)的兔抗多克隆催化抗体.采用盐析和ProteinA-SephaxoseCL4B亲和层析法,从兔抗血清中分离出了具有电泳纯度的多克隆催化抗体.经SDS-PAGE检测,IgGs相对分子质量为148000.纯化后的多克隆抗体,经ELISA法测定,其最低检出活性为2×10(-6)~4×10(-6)g/L.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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