埃可病毒6型表面特异性抗原VP1的原核表达及其多克隆抗体的制备

目的原核表达埃可病毒6型表面特异性蛋白VP1,并制备其多克隆抗体。方法筛选VP1蛋白氨基酸序列中抗原性强的片段,优化基因序列,分别构建重组表达质粒p GEX-4T-2-vp1和p ET-28a-vp1。将经双酶切及测序鉴定正确的重组质粒转化E.coli BL21(DE3),IPTG诱导表达,进行15%SDS-PAGE鉴定。将融合蛋白VP1-GST及VP1-His分别用Glutathione resin和High Affinity Ni-NTA resin进行纯化。以纯化后的VP1-His融合蛋白作为免疫原免疫新西兰大耳白兔,制备多克隆抗体,以VP1-GST融合蛋白为检测抗原,间接ELISA法检测血清抗体效价,Western blot法检测血清抗体特异性。结果经双酶切及测序鉴定证明,重组质粒p GEX-4T-2-vp1和p ET-28a-vp1构建正确。VP1-GST和VP1-His融合蛋白的相对分子质量分别为38 000和19 000,两种融合蛋白分别以可溶性蛋白和包涵体形式表达,约占菌体总蛋白的60%和30%,纯化后的纯度均90%。兔抗VP1血清效价为1∶320 000,可与融合蛋白VP1-GST和VP1-His发生特异性结合。结论成功原核表达了融合蛋白VP1-His和VP1-GST,且VP1-His具有良好的免疫原性,其制备的多克隆抗体的特异性较好,为埃可病毒快速检测技术的建立奠定了基础。     

肺炎链球菌神经氨酸酶nanA蛋白的原核表达、纯化及其免疫保护效果

目的原核表达并纯化肺炎链球菌(Streptococcus pneumonia,S.pn)神经氨酸酶nan A蛋白,并在小鼠模型中检测其保护效果,评价其作为S.pn疫苗候选蛋白的可行性。方法构建重组原核表达质粒p ET28a(+)-nan A,重组nan A蛋白经IPTG诱导及Ni-NTA亲和层析柱纯化后,采用黏膜(与CT佐剂混合)和腹腔(与Alum佐剂混合)给药途径免疫BALB/c小鼠,建立相应的S.pn感染模型,同时设相应对照组(佐剂+PBS),ELISA法检测特异性抗体及亚型;小鼠鼻腔滴定试验检测主动免疫保护效果;体内抗定植试验检测nan A蛋白对19F型S.pn在鼻咽部定植的保护作用。结果重组表达质粒p ET28a(+)-nan A经双酶切(NdeⅠ/XhoⅠ)及测序鉴定证明构建正确;重组蛋白的相对分子质量为55 000,主要以可溶性形式表达,约占菌体总蛋白的55%,纯化后纯度达90%;黏膜免疫组小鼠唾液中Ig A及Ig G效价分别为1.6×103和3.2×102,血清中Ig G效价为2.0×106,亚型主要为Ig G2a;腹腔免疫组血清中Ig G效价为0.5×106,亚型主要为Ig G1;黏膜和腹腔免疫小鼠生存时间较相应对照组显著延长(P0.05),黏膜免疫组小鼠生存率较其对照组显著增加;黏膜免疫可显著降低S.pn 19F在宿主鼻咽部和肺部的定植。结论原核表达并纯化了nan A蛋白,诱导的小鼠免疫反应可有效抵抗S.pn的感染,并可显著降低S.pn在宿主鼻咽部及肺部的定植,表明nan A蛋白是较理想的S.pn疫苗候选蛋白。     

金黄色葡萄球菌表面蛋白的表达及其多克隆抗体的制备

目的在原核细胞中表达金黄色葡萄球菌纤连蛋白结合蛋白A(fibronectin-binding protein A,FnBPA),制备其多克隆抗体。方法筛选FnBPA抗原表位富集区,优化基因序列,分别克隆至质粒pGEX4T-2和pET-28a(+)中,构建重组表达质粒pGEX4T-2-fnbpa和pET-28a-fnbpa,分别转化大肠埃希菌(E.coli)BL21(DE3),经IPTG诱导表达后,分别用High Affinity GST-NTA resin和High Affinity Ni-NTA resin进行纯化。以纯化后的FnBPA-His融合蛋白为抗原免疫新西兰大白兔,制备多克隆抗体,以FnBPA-GST融合蛋白为检测抗原,采用间接ELISA法检测血清效价,Western blot法检测特异性。结果经双酶切及测序鉴定,证明质粒pGEX4T-2-fnbpa和pET-28a-fnbpa构建正确;在相对分子质量约42 000和19 000处,分别可见FnBPA-GST和FnBPA-His融合蛋白的表达,表达量分别约占菌体总蛋白的30%和20%,均以可溶性形式表达,纯度均在90%以上;免疫新西兰大白兔后获得高效价的特异性兔抗血清。结论2种标签的融合蛋白均具有较好的免疫原性和抗原性,所制备的多克隆抗体具有较好的特异性,为金黄色葡萄球菌检测方法的建立奠定了基础。     

小鼠脱氧核糖核酸酶Ⅱα融合基因的原核表达及多克隆抗体的制备

目的原核表达LHRH-TAT-DNaseⅡα融合基因(LTD),并制备多克隆抗体。方法采用PCR法克隆LTD基因片段,插入p ET-28a载体,构建重组原核表达质粒p ET-28a-LTD,转化大肠埃希菌BL21(Rossetta),经IPTG诱导表达。融合蛋白经电洗脱分离纯化后,免疫獭兔,制备LTD蛋白多克隆抗体,采用ELISA法检测抗血清效价。结果构建的重组原核表达质粒经PCR、双酶切及测序鉴定证明构建正确;纯化得到的融合蛋白相对分子质量为39 270,浓度为0.5 mg/ml,可被兔抗LTD抗体识别。血清抗体效价可达1∶6 400。结论成功原核表达了DNaseⅡ融合蛋白LTD,并制备了多克隆抗体,为进一步研究DNaseⅡ蛋白体内外抗肿瘤活性及作用机制奠定了基础。     

克罗诺杆菌IbpA蛋白的表达、纯化及其免疫原性

目的表达并纯化克罗诺杆菌Ibp A蛋白,检测其免疫原性。方法提取克罗诺杆菌菌株CMCC45402的基因组,经PCR获得ibp A基因片段,连接至表达载体p ET30a(+),构建重组质粒p ET30a(+)-ibp A。将重组质粒转化E.coli BL21(DE3)菌株,用不同终浓度的IPTG(0.1、0.2、0.5、0.8、1.0 mmol/L)分别于30和37℃诱导表达不同时间(2.5、4、5 h),进行SDS-PAGE及Western blot分析。表达产物经Ni凝胶亲和层析纯化后,经腹腔免疫BALB/c小鼠,每2周加强免疫1次,共2次,末次免疫1周后,经小鼠眼球采血,分离血清,ELISA法检测血清效价。同时检测热激对Ibp A蛋白表达水平的影响。结果重组质粒p ET30a(+)-ibp A经双酶切鉴定证明构建正确。最佳IPTG诱导终浓度为0.2 mmol/L,最佳诱导温度为30℃,最佳诱导时间为5 h。诱导表达产物相对分子质量约24 000,主要以可溶性形式存在,可与抗His-Tag单克隆抗体特异性结合;纯化蛋白的纯度可达96%;小鼠免疫血清效价均可达1:25 000以上。用小鼠血清可检测到热激后克罗诺杆菌Ibp A的表达。结论本实验成功构建了ibp A基因的高效原核表达系统,获得了高纯度重组蛋白,制备了高效价抗血清,为后续ibp A基因和克罗诺杆菌热抗性关系的研究奠定了基础。     

寨卡病毒E蛋白第三结构域的可溶性表达及多克隆抗体的制备

目的原核表达并纯化寨卡病毒(Zika virus)E蛋白第三结构域(ZK-EⅢ)重组蛋白,并制备其多克隆抗体。方法 PCR扩增ZK-E Ⅲ序列,经双酶切后将其插入原核表达载体p ET-32a(+)中,构建重组表达质粒pET-ZKE Ⅲ,转化至大肠埃希菌(E. coli)Rosetta2(DE3),经IPTG诱导,表达的重组蛋白经亲和层析和阴离子交换层析纯化后,免疫家兔,制备ZK-E Ⅲ多克隆抗血清,进行Western blot鉴定后,ELISA法检测该抗血清效价。结果经PCR及测序鉴定证明原核表达质粒pET-ZKE Ⅲ构建正确,表达的重组蛋白相对分子质量约31 000,主要以可溶性形式存在,表达量占菌体总蛋白的60%;用纯化的重组蛋白免疫家兔后,获得的血清特异性良好,血清效价为1∶51 200。结论 ZKE Ⅲ蛋白在E. coli中以可溶性形式表达,制备的抗血清特异性好,效价高,具有用于寨卡病毒诊断和进行重组亚单位疫苗开发的潜力。     

树鼩干细胞生长因子的原核表达、纯化及免疫原性

目的原核表达、纯化树鼩干细胞生长因子(stem cell factor,SCF),并检测其免疫原性。方法根据GenBank预测的树鼩SCF基因序列设计引物,PCR扩增SCF基因,克隆至原核表达载体p ET-30a(+)中,构建重组表达质粒pET-30a(+)-SCF,转化大肠埃希菌BL21(DE3),IPTG诱导表达。表达的融合蛋白经Ni柱纯化后,免疫家兔,Western blot和ELISA法检测其免疫原性,并检测SCF在树鼩不同组织中的分布情况。结果重组表达质粒pET-30a(+)-SCF经酶切及测序证实构建正确;表达的重组蛋白相对分子质量约为34 500,表达量约占菌体总蛋白的35. 6%,以包涵体形式存在;纯化后的重组蛋白纯度达90%以上,可与兔抗人SCF多克隆抗体特异性结合,且免疫原性良好,抗血清效价为1∶256 000。在鼻、气管、肺、脾、肾、食管中能检测到SCF的分布。结论在大肠埃希菌中高效表达了重组SCF蛋白,纯化复性后具有良好的免疫原性。     

猪干扰素γ的原核表达及抗血清的制备

目的原核表达猪干扰素γ(poIFNγ),并制备其抗血清。方法PCR扩增poIFNγ成熟多肽基因片段,克隆至原核表达载体pET-28a(+)中,构建重组表达质粒pET-28a-poIFNγ,转化大肠杆菌BL21(DE3),IPTG诱导表达。表达的蛋白纯化后免疫小鼠,制备抗血清,ELISA检测抗血清的效价。结果重组原核表达质粒pET-28a-poIFNγ经双酶切和测序证明构建正确;重组蛋白的表达量占菌体总蛋白的40%,主要以包涵体形式表达;纯化的重组蛋白纯度可达90%;制备的抗血清效价可达10-5。结论已成功地在大肠杆菌中表达了poIFNγ,并制备了较高效价的抗血清。     

牛Ⅱ型链球菌van B2蛋白的原核表达及纯化

目的原核表达并纯化牛Ⅱ型链球菌(Streptococcus bovis biotypeⅡ)van B2蛋白。方法采用PCR法从牛Ⅱ型链球菌基因组DNA中扩增van B2基因,克隆至原核表达载体pET-28a(+)中,构建重组表达质粒pET-28a-van B2,转化大肠杆菌Rossata(DE3),IPTG诱导表达。表达的重组蛋白经Ni柱亲和层析纯化后,进行SDS-PAGE及Westernblot分析。结果 PCR扩增获得597 bp的van B2基因片段;重组表达质粒pET-28a-van B2经双酶切及测序证明构建正确;表达的重组van B2蛋白相对分子质量约为29 000,主要以可溶性形式表达;纯化的重组蛋白纯度为70%,可被小鼠抗牛链球菌血清Ⅱ型多克隆抗体特异性识别。结论原核表达并纯化了牛Ⅱ型链球菌van B2蛋白,为van B2基因的耐药性研究奠定了物质基础。     

牛轮状病毒VP6蛋白的原核表达及其多克隆抗体的制备

目的原核表达牛轮状病毒(rotavirus,RV)VP6蛋白,并制备其多克隆抗体。方法根据Gen Bank中登录的牛RV UK株VP6基因序列(X53667.1)设计一对特异性引物,RT-PCR扩增牛RV UK株VP6全长编码区片段,克隆至载体p ET-28a,构建重组表达质粒p ET-28a-Bo-RV-VP6,转染至E.coli Rosetta(DE3),IPTG诱导表达,重组蛋白进行SDS-PAGE和Western blot分析。将重组蛋白与弗氏佐剂混合后免疫豚鼠,共免疫3次,每次间隔2周,末次免疫后2周,经心脏采血,分离血清,制备VP6多克隆抗体,Western blot法检测其与牛RV的反应原性。结果经双酶切和测序鉴定,重组表达质粒p ET-28a-Bo-RV-VP6构建正确。重组蛋白以包涵体的形式表达,表达产物分别为43 000、34 000、27 000和15 000 4种不同相对分子质量的重组蛋白,纯化后纯度可达95%以上,可与牛RV阳性血清发生特异性反应。制备的VP6蛋白多克隆抗体效价1∶7 000,且可识别RV天然VP6蛋白。结论原核表达了牛RV VP6蛋白,并制备了抗VP6多克隆抗体,为后续RV疫苗效力评价及RV侵入机理等方面的研究奠定了基础。     

乙苯,苯乙烯的生产及合成乙苯,苯乙烯催化剂的研究进展

苯乙烯是重要的石油化工原料。本文介绍了国内外苯乙烯生产的发展概况，合成乙苯，苯乙烯所用的催化剂种类，并就苯乙烯生产及催化剂的发展趋势提出了自己的观点。     

Synthesis and characterization of homopolymers and copolymers of various acrylates and acrylonitrile

Various homopolymers and copolymers of methyl acrylate, ethyl acrylate, butyl acrylate, and acrylonitrile in different feed ratios were synthesized. These were characterized by IR, ¹³C-NMR, DSC, DTA, and TGA. Spectroscopic characterization helped in differentiating copolymers of different mol ratios. Thermal analysis revealed different degradation patterns for homopolymers and copolymers. The temperature and energy changes associated with various phase transitions were dependent on the chemical composition of homo- and copolymers, as expected. © 1993 John Wiley & Sons, Inc.     

生物质气化及生物质与煤共气化技术的研发与应用

总结了生物质原料的特点及生物质单独气化的缺点;介绍了国内外生物质气化技术及生物质与煤共气化技术的研发与应用现状;分析了在此领域国内外的发展趋势与前景;概括了开展生物质与煤共气化技术研发的意义。     

Comparison of the Adhesion and Cohesion of Triblock and Random Copolymers of Styrene and Butadiene

A substantially greater detachment energy is required to strip a polyethylene tereph-thalate (Mylar) film from a styrene-butadiene-styrene (SBS) triblock copolymer compared to that for peeling from a random styrene-butadiene (SBR) copolymer. This is true even though the intrinsic interaction between the Mylar and each elastomer is expected to be similar because of their virtually identical chemical composition. It is proposed that this difference in peel strength (between the SBS and SBR) is a consequence of the much higher dissipative capacity of the former elastomer. Another manifestation of this is the higher cohesive tear strength of the SBS compared to the SBR. Extents of energy dissipation within each elastomer during detachment of the Mylar adherend are consistent with the hypothesis that the average maximum stress experience before detachment is some similar fraction of each elastomer's tensile strength.     

Electronic structures and reactivities of monometallic and bimetallic clusters of Au and Cu

The variation of the Au 4f binding energy of Au clusters with the cluster size has been established by measuring the binding energies of clusters whose size distributions were independently determined by HREM and STM. The binding energy increases significantly when the cluster size is less than 2 nm. Au-Cu bimetallic clusters of the composition Cu₃Au have been deposited for the first time on carbon substrates. The shifts in the core level binding energies of the bimetallic clusters show the effect of alloying in the case of large clusters, but show effects of both alloying and cluster size in the case of the small clusters. The interaction of CO with Cu₃Au clusters is stronger than with a bulk Cu metal. The interaction of CO with small Cu clusters also seems to be stronger than with bulk Cu or with large Cu clusters.     

钾盐资源及钾肥供需情况分析及预测

阐述了国内外钾盐资源及钾肥生产现状,对国内外钾盐的供需形势进行了分析及预测,从资源、原材料、国际市场三方面提出了解决我国钾盐短缺的措施。     

Kinetics and Mechanism of Oxidation of Mono- and Polyacetals

Abstract

Kinetics and mechanisms of oxidation of 6 acetals by molecular oxygen and ozone in liquid phase have been studied. Reaction with molecular oxygen (70°C, 15–16 hr) leads to the formation monoethers of the corresponding glycols with 68–90% selectivity. Salts of metals and complexes with crown-ethers have increased the reaction rate significally. Ozone have reacted with acetals with formation similar products. The mechanisms of intermediate stages have been proposed.     

责任和责任心的涵义与结构

责任是人应主动承担的角色义务和对其因过失所造成后果应承担的责罚.有两层涵义:一是义务;二是后果.责任心是个体自觉做好分内事务和履行道德义务的心理倾向,是个性心理品质成分中自我特征维度上的重要内容.责任心具有两个方面的涵义:一是角色分内职责;二是角色道德义务.责任心是一种通过责任认知、责任个性和责任适应的动态形式表现出来的静态品质,责任心是责任心过程结构与责任心关系结构相互制约、相互影响的统一体.     

二甲基二烯丙基氯化铵和丙烯酰胺的合成及应用

用复合引发体系(过硫酸盐-偶氮类引发剂)和脂肪胺类氧化还原体系引发,在实验室获得了单体转化率≥98%,特性粘数高于13.6 dL/g的阳离子共聚物PDA,探讨了控制聚合物分子量的影响因素.     

Wetting properties of homopolymers and copolymers of pentafluorostyrene and methylacrylate and homopolymer blends

Polypentafluorostyrene (PPFS), polymethylacrylate (PMA), and poly(pentafluorostyrene-co-methylacrylate), poly(PFS-co-MA) were prepared and the wetting characteristics of polymer blends of PPFS and PMA were compared with that of poly(PFS-co-MA) via contact angle measurements. The critical surface tension of polypentafluorostyrene was found to be 22.6 dyne/cm, which is comparable to the value reported for polytrifluoroethylene (22 dyne/cm). The critical surface tension of poly(PFS-co-MA) is not linearly related to its composition. The polymer blends of PPFS and PMA exhibit significant surface enrichment of the fluoropolymer. The harmonic-mean method¹ was employed to determine surface tensions of these polymers and many known polymers. It is found that the method produces useful surface tension data provided the contact angle values are derived from testing liquids of dissimilar polarity.