鸡BF1和BF2基因实时荧光定量PCR检测方法的建立

目的建立鸡主要组织相容性复合体(Major histocompatibility complex,MHC)BF1和BF2基因实时荧光定量PCR[Real-time fluorescent quantitative(FQ)-PCR]检测方法。方法从鸡外周血淋巴白细胞(Peripheral blood leuk-ocytes,PBLs)中提取细胞总RNA,以其为模板,根据BF1、BF2和GAPDH基因相对保守序列各设计一对引物,应用RT-PCR法扩增目的基因,分别克隆至pGM-T载体上,制备重组质粒标准品,经PCR、EcoRⅠ酶切及测序鉴定;优化反应体系及反应条件,绘制标准曲线,建立Real-time FQ-PCR检测方法,并验证其敏感性、特异性及重复性。结果重组质粒标准品经PCR、酶切及测序鉴定构建正确;建立的定量标准曲线临界循环数(Threshold cycle,Ct)与BF1、BF2和GAPDH起始质粒DNA拷贝数的对数之间线性关系良好,相关系数分别为1.00、0.98、0.99,扩增效率分别为0.8、1.1、1.1;该方法的敏感性可达101copies/μl;融解曲线分析表明扩增效率一致,特异性较好;质粒DNA标准品3次检测的CV值误差不超过0.5,均小于5%。结论已成功建立了鸡BF1和BF2基因实时荧光定量PCR检测方法,为下一步应用该法检测BF1和BF2基因的转录水平奠定了基础。     

PCR荧光探针法在检测分泌物沙眼衣原体、淋球菌及解脲支原体中的应用

目的评价PCR荧光探针法用于检测分泌物沙眼衣原体(Chlamydia trachomatis,CT)、淋球菌(Neisseria gonorrhoeae,NG)、解脲支原体(Ureaplasma urealyticum,UU)的适用性。方法热裂解法提取CT、NG、UU分泌物样本中病原微生物DNA,以其作为模板,采用PCR荧光探针法检测样本中CT、NG、UU的阳性率。同时采用乳胶法检测相应样本中CT的阳性率,培养法检测相应样本中NG及UU的阳性率,并将检测结果分别与PCR荧光探针法进行比较。结果 1 209份CT标本中,PCR荧光探针法阳性检出率(9.76%)显著高于乳胶法(2.64%),1 491份NG标本中,PCR荧光探针法阳性检出率(6.64%)显著高于培养法(4.16%),差异均有统计学意义(P0.05);1 260份UU标本中,PCR荧光探针法阳性检出率(37.6%)略高于培养法法(36.8%),但差异无统计学意义(P0.05)。结论与培养法和乳胶法比较,荧光探针PCR法对CT和NG的阳性检出率更高,而对UU的阳性检出率与培养法相近,适用于分泌物中CT、NG及UU的检测。     

乙型肝炎病毒基因组C区启动子突变位点新型检测方法的建立、验证及初步应用

目的利用错配扩增和荧光PCR技术,建立一种针对乙型肝炎病毒(hepatitis B virus,HBV)基因组C区启动子(basal core promoter,BCP)1762/1764突变位点的新型检测方法,并对该方法进行验证及临床评价。方法根据NCBI登录的HBV A-H型基因序列(以GenBank号为AB033556.1的C基因型作为标准参考序列)合成野生型和突变型标准品序列,测序后连接至pMD-18T载体上,构建质粒标准品,设计引物、探针及合适的突变检测体系,确定检测的线性范围;对建立的方法进行灵敏度、重复性、特异性、稳定性验证;分别用本实验建立的ARMS-PCR法和基因Sanger测序法(金标准)检测132份慢性乙型肝炎患者血液样本的基因位点是否发生突变,并分析ARMS-PCR法的灵敏度和特异度。结果 ARMS-PCR法能检测1×102~1×109 copies/ml的野生型和突变型质粒;野生型和突变型样本检测的Ct差值(ΔCt)在7以上,且能检出最低达1%突变含量的混合质粒和样本;该方法灵敏度较高,重复性、特异性、稳定性良好;其检测132份慢性乙型肝炎患者血液样本1762/1764位点突变阳性率为41.7%,明显高于Sanger测序法检测结果(P0.05)。结论建立的ARMS-PCR法能很好地用于评估乙肝患者患肝癌的风险,且较Sanger测序法检测精度更高,更适合于临床推广。     

FQ-PCR联合Sanger测序法检测结直肠癌患者表皮生长因子受体、KRAS及BRAF基因突变

目的建立实时荧光定量PCR(fluorescent quantitative PCR,FQ-PCR)联合Sanger测序法快速检测结直肠癌患者表皮生长因子受体(epidermal growth factor receptor,EGFR)、KRAS和BRAF基因突变的方法。方法根据结直肠癌中EGFR、KRAS和BRAF基因常见突变类型设计引物及其TaqMan探针序列,以提取的86份结直肠癌患者肿瘤组织DNA为模板,进行FQ-PCR扩增,PCR产物经SAP酶和EXOⅠ酶作用后,收集酶切产物,进行测序PCR扩增,扩增产物经乙醇/醋酸钠法纯化后进行测序,测序结果采用Bioedit软件进行分析;检测EGFR、KRAS及BRAF基因突变,并与FQ-PCR法检测KRAS12/13密码子突变进行比较。结果成功建立了FQ-PCR联合Sanger测序法检测结直肠癌患者样本中EGFR、KRAS和BRAF基因突变的方法,各基因PCR扩增曲线均为标准的"S"型荧光扩增曲线,测序峰图清晰、稳定。86份结直肠癌样本中,EGFR基因突变概率2.3%(2/86),均为第21号外显子点突变,突变类型为L858R和L861Q;KRAS基因突变概率33.7%(29/86),其中第12位密码子突变占79.3%(23/29),突变类型为G12D和G12V,第13位密码子突变占10.3%(3/29),突变类型为G13D,第12和13位密码子同时突变1例(3.4%),第61位密码子未检测到突变,第146位密码子仅检测到2例突变,占6.9%(2/29),突变类型均为A146V;BRAF基因未检测到突变。FQ-PCR法检测KRAS12/13密码子突变概率高于FQ-PCR联合Sanger测序法,但差异无统计学意义(P0.05),两种检测方法的总体符合率为97.7%(84/86)。结论实时FQ-PCR联合Sanger测序法可快速检测结直肠癌患者中EGFR、KRAS和BRAF基因突变,检测方法稳定、可靠。     

牛副流感病毒3型TaqMan-MGB荧光定量PCR检测方法的建立

目的建立检测牛副流感病毒3型(bovine parainfluenza virus type 3,BPIV3)的Taq Man荧光定量PCR方法。方法根据GenBank中公布的BPIV3序列,选取P基因上保守区域设计特异性引物及TaqMan-MGB探针。优化反应体系,建立实时荧光定量PCR方法,并对方法的特异性、重复性和敏感性进行验证。结果标准曲线在104~108copies/μl范围内具有良好的线性关系,R~2达到0.999,斜率为-3.203,扩增效率为105.2%。利用该方法对BPIV3a及BPIV3c进行检测,结果为阳性,对牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)、牛传染性鼻气管炎病毒(infectioils bovine rhinotraeheitis virus,IBRV)进行检测,结果呈阴性。3个浓度质粒标准品,重复3次检测,CV均小于1.5%。建立的方法对质粒的最小检出量为1.0×10~2 copies/μl。结论建立了能够检测BPIV3a及BPIV3c的TaqMan-MGB探针实时定量PCR方法,该方法特异性较强,重复性及敏感性良好,为早期诊断及定量分析提供了更快速、稳定、可靠的方法。     

人呼吸道合胞病毒荧光PCR检测方法的建立和评价

目的建立人呼吸道合胞病毒(hRSV)荧光PCR(FQ-PCR)检测方法,并确定其最低检出限。方法针对hRSVN基因相对高度保守的序列,采用引物和探针设计软件PrimerExpressv2.0,设计1对特异性引物和1条TaqMan荧光探针,组装成荧光PCR检测试剂。以此试剂检测345份咽拭子样品,与ELISA法检测hRSVIgM抗体比较,确定最低检出限。结果该方法的最低检出限是传统的病毒滴度测定的104.79倍。与IgM抗体检测法相比,对于感染早期患者具有更高的检出率。结论建立的hRSVFQ-PCR检测方法具有简便、快捷的特点,适用于hRSV感染的早期诊断。     

儿童呼吸道易感病原菌多重PCR检测方法的建立

目的建立儿童呼吸道5种易感病原菌多重PCR(Multiplex PCR,mPCR)检测方法,并应用该方法分析北京地区儿童呼吸道易感病原菌菌群分布情况。方法分别设计针对肺炎链球菌(Streptococcus pneumoniae,SP)自溶素基因(ply)、肺炎克雷伯杆菌(Klebsiella pneumoniae,KP)16S核糖体RNA基因(16S rRNA)、金黄色葡萄球菌(Staphylococcus aureus,SA)热核酸酶基因(nuc)、表皮葡萄球菌(Staphylococcus epidermidis,SE)特异性保守基因(SeS)、流感嗜血杆菌(Haemophilus influenzae,HI)16S rRNA基因的特异性引物,建立mPCR检测方法;验证该方法的特异性及敏感性;并采用该方法对北京地区128例呼吸道感染患儿和80名健康儿童咽拭子或痰标本进行检测,并与传统培养法检测结果进行比对。结果 mPCR法能对同一样品中5种病原菌的DNA模板同时进行PCR扩增;该方法检测5种病原菌之间及与呼吸道其他易感病原之间无交叉反应,敏感性可达5×10-10μg/μl;mPCR法检测128例呼吸道感染患儿的菌群分布情况为:HI 24.22%、SP 15.63%、KP 4.69%,SA 2.34%,未检出SE,与培养法相比,两种检测方法的总符合率为78.91%;感染患儿与健康儿童相比,HI和SP的感染率差异有统计学意义(P<0.01)。结论建立了从呼吸道标本中直接检测多病原儿童易感病原菌的mPCR检测方法,该方法特异性强、敏感性高,为临床正确诊断和治疗细菌感染性疾病提供了参考。     

多重荧光PCR方法在HPV基因分型中的应用

目的:探讨多重荧光PCR方法在HPV基因分型中的应用。方法:用已构建的18种中高危型HPV基因分型的多重荧光PCR方法检测510例临床样本,并与核酸测序法结果比较以考察该技术在HPV基因分型中应用的可行性。结果:临床研究表明,HPV 16、18、26、31、33、35、39、45、51、52、53、56、58、59、66、68、73、82共18种型别检测与核酸测序法结果几乎完全一致。结论:多重荧光PCR方法具有灵敏性高、特异性强、操作简单、通量高,耗样量少的特点,在中小规模临床样本检测中应用前景广阔。     

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。     

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.     

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.     

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.