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1.
采用PCR方法,克隆得到3.5kb的开放阅读框架(ORF),其包括Bti的杀虫蛋白基因,cryIVB结构基因各部分上游启动区。将结构基因亚克隆到高表达载体pQE52中,构建了高表达质粒pQE52B。在E.coli SG13009(pREP)中,130kD的蛋白得到表达,其对韭菜迟眼蕈蚊(Bradysia odoriphaga)三龄幼虫具有较强的毒杀作用。  相似文献   

2.
含多种抗真菌病基因植物表达载体的构建   总被引:9,自引:2,他引:7  
含有大麦核糖体失活蛋白(BRIP) 编码序列的质粒pRC24/BRIP改造后, 依次与含有水稻碱性几丁质酶基因RCH10 和水稻酸性几丁质酶基因RAC22 编码序列的质粒pABC2 以及含有苜蓿β1 , 3葡聚糖酶编码序列的质粒pAAG89 连接, 得到了中间载体pRAS10 .pRAS10再与根癌农杆菌双元载体pCAMBIA1300 连接, 得到了适合水稻转化的双元载体pRAS1300 . 利用冻融法将此表达载体导入根癌农杆菌LBA4404 中, 并准备将pRAS1300 转入水稻, 以期获得对真菌病有广泛且较强抗性的水稻品种  相似文献   

3.
THECURRENTDENSITYDEPENDENCEOFACTIVATIONENERGYINHIGH-TcSUPERCONDUCTORHgBa_2Ca_2Cu_3O_(8+x)INLOWCURRENTDENSITYTHECURRENTDENSITYDE...  相似文献   

4.
PHOTOLUMINESCENCESPECTRAOFC_(60)MOLECULESEMBEDDEDINPOROUSSIYanFeng;BacXimao;WuXiaowei;ChenHuilan(DepartmentofPhysicsandInstit?..  相似文献   

5.
hSOD基因在大白鼠肺上皮细胞中的表达   总被引:1,自引:1,他引:0  
本文以哺乳动物细胞表达载体pRc/CMV为运载体,构建了受控于CMV启动子的hSOD基因的表达载体pRc/CMV_SOD,用脂质体转染法转染大白鼠肺上皮细胞L2细胞后,经抗生素G418选择性培养,获得与细胞染色体DNA稳定整合的hSODcDNA导入细胞,经SouthernBlots和WesternBlots分析,结果表明,hSOD在细胞中得到稳定表达,同时测定细胞SOD酶活性,hSODcDNA导入细胞的SOD酶活性是空载体导入细胞和父本细胞的约2倍,并且在选择细胞克隆之后的60天内是持续的.  相似文献   

6.
简易多用微型实验装置邹荣贤(四川师范学院化学系,南充637002)ASIMPLEBUTMULTI-PURPOSEMINI-EXPERIMENTDEVICE¥ZhouRongxian(Dept.ofChemistry,SichuanTeachersCi...  相似文献   

7.
ONTHEEXPONENTSETOFPRIMITIVELOCALLYSEMICOMPLETEDIGRAPHS¥ZhangKeming1);BuYuehua2)(1)DepartmentofMathcmaties,NanjingUniversity,N...  相似文献   

8.
Ti鱼蛋白酶水解物的营养评价   总被引:8,自引:0,他引:8  
对Ti鱼蛋白酶水解物EAPH进行评价。EAPH蛋白质含量88.26%,氨基酸比例合理,必需氨基酸占总氨基酸43.6%,并含丰富的水溶性维生素和微量元素。EAPH对动物的生长效果、饲料效率(FE)、蛋白质效率(PER)、净蛋白质效率(NPR)均与对照乳粉蛋白相近;表征其消化吸收利用率的真消化率(TD)、生物价(BV)、蛋白质净利用率(NPU)均略高于对照乳粉蛋白;小麦粉蛋白经EAPH强化后,其蛋白质  相似文献   

9.
MICROSPHERULESINSUZHOUGRANITE:ABLATEDPRODUCTSOFACOMETARYEXPLOSIONHuZhongwei1)WanYuqiu2)WangErkang2)(1)DepartmentofAstronomy,...  相似文献   

10.
精馏与渗透汽化复合生产ETBE的过程   总被引:5,自引:0,他引:5  
为了分离乙基叔丁基醚(ETBE)和乙醇混合物,得到ETBE产品,研究了乙酸丙酸纤维素膜(CAP)的渗透汽化过程,讨论了温度、浓度等因素对渗透通量和选择性的影响。结果表明,CAP膜的渗透通量随温度和乙醇在混合物中的浓度增加而增加,渗透通量与温度的关系满足Arrhenius形式的方程。在此基础上,提出了精馏与渗透汽化复合生产ETBE的过程,并运用ASPENPLUS软件对该过程进行了设计计算,汽液相平衡采用UNIFAC法进行预测。  相似文献   

11.
采用溶胶-凝胶法(Sol-gel法)制备镧钴掺杂的纳米锶铁氧体(Sr1-xLaxFe12-yCoyO19),使用X射线衍射仪、振动样品磁强计、阻抗自动测量仪(LCR电桥)对掺杂的锶铁氧体进行表征,对其结构、相变进行研究。实验结果表明,温度高于850℃时样品为稳定的M相结构,在掺杂的样品中发现了磁导率减落现象,证实了Co^2+离子进入到六角晶体的晶位中。  相似文献   

12.
The cephalosporin acylases are a group of enzymes that hydrolyze cephalosporin C and/or glutaryl 7-aminocephalosporanic acid to produce ?-aminocephalosporanic acid. The cephalosporin acylase from Pseudomonas sp. strain 130 was crystallized in two different forms suitable for structural studies. A tetragonal crystal form diffracted to 0.24 nm belonged to the space group P41212. There was one αβ heterodimer per asymmetric unit. A second crystal form diffracted to 0.21nm belonged to the space group P21. There was four αβ heterodimers per asymmetric unit. The tetragonal crystal structure of CA-130 was determined using the multiwavelength anomalous diffraction method and the P21 crystal structure was then determined using the molecular replacement method.  相似文献   

13.
Neodymium substituted Li_2MnO_3 samples were prepared by the solid-state reaction method. The crystal and electronic structure properties of the prepared samples were investigated by x-ray based techniques. According to the analysis, it was determined that Nd atoms did not sit in to the Cr coordinations in Nd substituted samples and built up a different crystal structure. To support the analysis of the crystal structure study of the samples,electronic structure properties of the Nd substituted samples were studied via the collected data by x-ray absorption fine structure(XAFS) spectroscopy from the Mn K-edge. The results of the data analysis revealed that due to the misfit with the ionic radii and also the oxidation states, substituted neodymium atoms built up isolated crystal domains in Li_8Mn_5Nd_(18) O_(39) cubic crystal structure. The symmetry in Mn K-edge absorption data of the sample both in parent Li_2MnO_3 and Nd substituted samples confirmed that Mn coordinations has not been influenced by the Nd substitution.  相似文献   

14.
本文合成了数种2位不同取代基的螺[异苯并呋喃-1(3H),9'-(9H)-占吨]-酮-3类化合物,并进行了红外、紫外光谱分析,对代表性化合物用X-射线衍射的方法测定了晶体结构,讨论了该类化合物的显色机理.  相似文献   

15.
用固相反应法制备了二元稀土掺杂的La1/3Ndl/3Ba1/3Mn03多晶庞磁电阻块材.x射线衍射分析表明在1200℃烧结的样品具有立方对称的晶格结构.热磁曲线显示材料在低温处于自旋冰状态.自旋冰的熔点随着外磁场的增大而降低.在磁场达到40kOe时,自旋冻结现象消失.材料的居里温度为-250K,但室温磁化曲线中出现由微弱不均匀品格畸变造成的寄生铁磁性行为.电阻率一温度曲线出现双峰现象.在居里温度附近出现的电阻率峰由晶体的本征特性贡献,在低于居里温度的~190K附近出现的电阻率峰由界面隧穿效应贡献.电阻率在~40K附近出现极小值.经过曲线拟合证实,其行为与近藤效应相似.研究结果较为全面地分析了单相多晶CMR材料的基本磁电相关特性.  相似文献   

16.
In order to obtain phase information for the X-ray diffraction of tabtoxin resistance protein (TTR) crystal using the MAD phasing method, a selenomethionine (Se-Met) derivative of TTR was overexpressed in E. coli strain M15, with pQE-30 plasmid, through IPTG induction in M9 medium containing Se-Met. The product was purified to an estimated homogeneity of greater than 95% according to SDS-PAGE, by a Ni-NTA metal affinity followed by a Mono Q anion exchange column chromatography. The successful substitution of Se-Met for methionine (Met) was confirmed by MALDI-TOF and ESI-Quadrupole Mass Spectrometry analysis. The derivative crystal was obtained using similar conditions as those for the native.  相似文献   

17.
为原核表达免疫缺陷病毒(human immunodeficiency virus,HIV)外膜蛋白,对HIV-1外膜蛋白的基因进行了修饰,并利用PCR技术克隆env基因,将env基因克隆到原核表达载体中,利用大肠杆菌表达系统表达外膜蛋白,应用Western blotting检测其表达情况.结果表明:酶切鉴定证实正确地构建了pRSETB表达质粒,Western blotting和SDS-PAGE试验检测结果表明,构建后的env基因能在低温诱导的条件下表达.产物的相对分子质量为50000和33000,表达的env蛋白具有较好的免疫原性.  相似文献   

18.
Janssen BJ  Read RJ  Brünger AT  Gros P 《Nature》2007,448(7154):E1-2; discussion E2-3
Activation of the protein C3 into C3b in the complement pathway is a crucial step in the complement immune response against pathogenic, immunogenic and apoptotic particles. Ajees et al. describe a crystal structure for C3b that deviates from the one reported by Janssen et al. and by Wiesmann et al.. We have reanalysed the data deposited by Ajees et al. and have discovered features that are inconsistent with the known physical properties of macromolecular structures and their diffraction data. Our findings therefore call into question the crystal structure for C3b reported by Ajees et al..  相似文献   

19.
 采用基于密度泛函理论(DFT)框架下的第一性原理平面波赝势(PWP)方法,计算了闪锌矿结构ZnSe晶体的晶格常数、能带结构、态密度以及电荷布居,计算结果表明,闪锌矿结构的ZnSe是一种直接带隙半导体材料,其下价带主要由Zn 3d电子贡献,上价带主要由Se 4p电子形成,导带主要来自于Zn 4s电子以及Se原子最外层电子,Zn原子与Se原子之间形成的是包含弱离子键的共价键,净电荷值分别为0.14e和-0.14e。  相似文献   

20.
The structural characteristics and optical and electrical properties of molecular-beam-epitaxy (MBE) grown ZnS0.8Se0.2 thin films on indium-tin-oxide (ITO) glass substrates were investigated in this work. The X-ray diffraction (XRD) results indicated that high quality polycrystalline ZnS0.8Se0.2 thin film grown at the optimized temperature had a preferred orientation along the (111) planes. The transmission electron microscopy (TEM) cross-sectional micrograph of the sample showed a well defined columnar structure with lateral crystal dimension in the order of a few hundred angstroms. Ultraviolet(UV) photoresponsivity as high as 0.01 A/W had been demonstrated and for wavelengths longer than 450 nm, the response was down from the peak response by more than 3 orders of magnitude. The thin ZnS0.8Se0,2 photosensor layer, with a wide energy gap and anisotropic electrical property, makes a transmission UV liquid crystal light valve (LCLV) with high resolution feasible.  相似文献   

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