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1.
利用一对带有Tat在序列的Bcl-x专一性引物从BEAS-2B细胞中扩增出比bcl-XL和bcl-XscDNA,并将它们克隆入pGEX-5X-3载体进行表达。用IPTG诱导表达的融合蛋白占菌体蛋白总量的30%,经谷胱甘肽-Sepharose亲和层析,蛋白纯度达90%。这些结果为进一步研究Bcl-x在编程性细胞死亡中的作用奠定了基础。  相似文献   

2.
从大量繁殖的D73杂交瘤细胞中提取制备其基因组mRNA,并以此为模板,经反转录途径获得基因组cDNA,随后将其插入到λgt11中,构建了马铃薯Y病毒小鼠单克隆抗体cDNA基因文库。经免疫原位杂交,从该基因文库中筛选出30个含抗体轻链基因和10个含抗体重链基因的阳性克隆,进一步将其插入到nGEM-7Z(+)质粒中,经酶切分析和电泳检测,证实在获得的轻链和重链阳性克隆中各有一个质粒(K6和G9)具有较长的外源DNA插入(分别为1Kb和1.6Kb),它们可能编码完整的抗体轻链和重链蛋白。  相似文献   

3.
采用PCR方法从BMP-1的cDNA中克隆了BMP-1成熟肽的编码基因,删除了BMP-1前体分子N端的信号肽序列和C端的其他序列。用HindⅢ消化1.3Kb的PCR产物,将0.84和0.46Kb两片段分别克隆到pUC载体中进DNA序列分析。分别酶切回收EcoR-HindⅢ和HindⅢ-BamHⅠ两目的基因片段,与大肠杆菌表达载体pBV-220进行退火连接,使插入基因受控于P_RP_L启动子。将含有BMP-1成熟肽编码基因重组表达质粒pBVBMP-1转化大肠杆菌宿主细胞进行温度诱导表达。结果表明,经42℃热诱导后,大肠杆菌能以包涵体形式表达BMP-1成熟肽,其分子量约为52kDa。  相似文献   

4.
利用一对带有Tat序列的Bcl-专一性引物从BEAS-2B细胞中扩增出bcl-XL和bcl-Xs cDNA,并将它们克隆入pGEX-5X-3载体进行表达,用IPTG诱导表达的融合蛋白占菌体蛋白总量的30%,经谷胱甘胱-Sepharose亲和层析,蛋白纯度达90%,这些结果为进一步研究Bcl-x在编程性细胞死亡中的作用奠定了基础。  相似文献   

5.
从大量繁殖的D73杂交瘤细胞中提取制备其基因组mRNA,并以此为模板,经反转录途径获得基因组cDNA,随后将其插入到λgt11中,构建了马铃薯Y病毒小鼠单克隆抗体cDNA基因文库。经免疫原位杂交,从该基因文库中筛先出30个含抗体轻链基因和10个含抗体重链基因的阳性克隆,进一步将其插入到pGEM-7Z(+)质粒中,经酶切分析和电泳检测,证实在获得的轻链和重链阳性克隆中各有一个质粒具有较长的外源DNA  相似文献   

6.
赵明  刘莉 《高技术通讯》1995,5(4):41-45
采用PCR方法从BMP-1的cDNA中克隆了BMP-1成熟肽的编码基因,删除了BMP-1前体分子N端的信号肽序列和C端的其他序列。用HindⅢ消化1.3Kb的PCR产物,将0.84和0.46Kb两片段分别克隆到PUC载体中进DNA序列分析。分别酶切回收EcoR-HindⅢ-BamHⅠ两目的基因片段,与大肠杆菌表达载体PBV-220进行退火连接,使插入基因受控于PRPL启动子。将含有BMP-1成熟肽  相似文献   

7.
mRNA差异显示阳性cDNA克隆的快速筛选与鉴定   总被引:13,自引:0,他引:13  
建立了一种快速筛选差异显示阳性cDNA克隆的方法,该方法利用两轮ReverseNorthern杂交,结合质粒酶切图谱分析,从30个DDRT差异cDNA片段中筛选鉴定出两个阳性cDNA克隆,对其中一个克隆进行的Northern分析证实了筛选方法的可靠性。  相似文献   

8.
利用RT-PCR技术,检测了BMP-3及BMP-5在不同组织中的表达,并将PCR扩增出的bmp-3和bmp-5cDNA克隆入pGEX表达载体.在大肠杆菌中得到高效表达。  相似文献   

9.
P190是恶性疟原虫裂殖子表面抗原,是很有希望的疟疾疫苗候选抗原。采用PCR方法克隆了我国海南省FCC1/HN株P190抗原基因的3个保守区片段,连接到pUC18载体上进行DNA序列测定,然后分别与表达载体pGEX-2T连接,经双酶切鉴定后转化感受态JM109大肠杆菌进行高效融合表达。  相似文献   

10.
人血小板生成素(hTPO)的cDNA克隆与序列测定   总被引:1,自引:0,他引:1  
由于人血小板生成素cDNA的阅读框架较长而且序列中无合适的酶切位点,因此,我们利用一个同义突变创造的KpnI酶切位点人为将hTPO cDNA分成N-端和C-端两个片段。首先利用反转录聚合酶链式反应从人胎肝mRNA中分别扩增出两个cDNA片段,于EcoRI,KpnI位点分别克隆入测序载体pUC19中。  相似文献   

11.
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.  相似文献   

12.
13.
A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.  相似文献   

14.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

15.
A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.  相似文献   

16.
On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……  相似文献   

17.
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill.  相似文献   

18.
Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.  相似文献   

19.
The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……  相似文献   

20.
Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.  相似文献   

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