乳液PCR扩增复杂基因序列的方法建立及普通PCR的比较

该研究分析普通PCR的不足,通过较多实验研究初步建立乳液PCR方法,改善PCR实验技术.采用人工合成的乳酸杆菌质粒为模板,不同成分配比条件下的乳液PCR和普通PCR对质粒序列进行扩增,对扩增产物进行琼脂糖凝胶电泳,电泳结束后对凝胶进行Gelred染色并用GS-800灰度扫描仪成像.进一步分析乳液PCR和普通PCR扩增产物的特异性以及不同成分配比条件下乳液PCR的扩增质量.通过比较两种PCR方法的扩增结果可得,在相同条件下,乳液PCR扩增特异性高于普通PCR扩增,并确定当水相中加入100 g/L BSA,水油体积比在1∶2.5时,破乳水饱和乙醚体积比为1∶1时,水油相在1700 rpm条件下连续混合5 min时扩增效果最好.     

酸奶在储存过程中菌群结构变化研究

为了探究酸奶储存过程中微生物菌群结构的变化,为其长期贮存奠定理论基础.采用酚/氯仿法抽提细菌基因组DNA,以此作为PCR反应的模板,进行16S rDNA基因有效扩增,并将PCR扩增产物进行DGGE电泳.用Bionumerics软件对DGGE分子指纹图谱进行舌苔菌群结构相似性分析.实验结果表明,采用该方法成功地扩增出16S rDNA V3区片段,为230 bp.DGGE分子指纹图谱结果表明,1、2号酸奶样品高相似性为93%,1-3号与4-7号的相似仅为6%,表明酸奶贮存过程中,菌群结构发生了变化.     

基于PCR持续改进架构的情报泄密危机管理模型研究

当前的反竞争情报领域,学者主要关心情报保护问题,而忽视情报泄密后的危机管理问题。本文基于持续性管理的思维,提出了情报泄密危机的生命周期和危机管理模型(PECR),阐述了该模型各个阶段的任务重点及相互关系。本文认为情报泄密危机的管理比情报保护往往还要重要,这项研究可为企业反竞争情报研究提供新的思路,并为企业关键性情报泄密事故的处理提供理论和实践指导。     

使用免疫BMPs纯化细菌PCR反应模板的比较

目的:使用免疫BMPs,对含有大肠杆菌O157的粪便标本,进行目标病原菌的捕获和洗净,建立一种快速纯化细菌PCR反应模板的方法。方法:将大肠杆菌O157抗体接种于BMPs表面,制成免疫BMPs。使用免疫BMPs,对含有不同浓度大肠杆菌O157的粪便标本,进行目标病原菌的捕获、分离和洗净,再使用洗净的病原菌制备PCR反应模板。作为对照,对含有不同浓度大肠杆菌O157的粪便标本,常规进行增菌培养及鉴别培养后,制备细菌的PCR反应模板,或粪便标本直接制备PCR反应模板。结果:使用免疫BMPs处理后制备PCR反应模板,与通过常规增菌培养和鉴别培养后制备PCR反应模板,PCR检测结果一致。而粪便标本直接取样制备PCR反应模板,大肠杆菌O157低浓度时,PCR检测的阳性率较低。结论:利用免疫BMPs捕获自然标本(粪便)中的目标病原菌,通过分离和洗净,去除标本中存在的PCR反应抑制物等影响因素,可省略增菌培养及鉴别培养,快速纯化目标病原菌的PCR反应模板。     

蜡状芽孢杆菌毒株的致病机理及检测方法

蜡状芽孢杆菌系无荚膜的革兰氏阳性菌,是最常见的食源性病原菌之一。致病性菌株能产生呕吐毒素和肠毒素,临床上可分为致呕吐型和腹泻型。研究病原性蜡状芽孢杆菌的致病机理,有助于了解其致病途径,从而改进和完善检测方法和诊治途径。通过综述蜡状芽孢杆菌几种毒素的致病机理,整理了一套蜡状芽孢杆菌致病毒株的鉴定检测技术方法:用鉴定平板等传统的鉴定方法将蜡状芽孢杆菌检出,应用先进的PCR和免疫方法检测毒素基因及毒蛋白,通过荧光多重PCR提高灵敏度和准确性等,以期加强食品安全。     

Detection of Catabacter hongkongensis in polluted European water samples

The Catabacteriaceae is a new bacterial family with a unique member: Catabacter hongkongensis is a strictly anaerobic, non-sporulating, Gram-positive coccobacillus that is phylogenetically related to some clostridial clusters. Little is known of its epidemiology and environmental distribution, but the inclusion of its 16S rRNA gene sequence in GenBank has allowed it to be detected qualitatively. As a first approach for prospective surveys, a real-time polymerase chain reaction (PCR) procedure to identify C. hongkongensis has been developed. The presence of Catabacteriaceae in 29 water bodies subjected to possible human or animal impact has been investigated. Four of them were positive. The results confirm that highly polluted water can contain C. hongkongensis.     

Interaction of - α 3.7, ? Thalassemia Mutation IVS 1-5 and HbD Punjab in a Family: A Case Report

Hemoglobin D exist in four form; HbD trait, HbD-thalassemia, HbD sickle cell and HbD homozygous. HbD trait and HbD homozygous generally asymptomatic condition but when HbD co-inherit with thalassemia and sickle cell anemia, produces clinically significant conditions like chronic hemolytic anemia. Here we present a case of HbD Punjab with α 3.7 kb deletion and IVS-1-5 β-thalassemia across a family. Diagnosis of HbD patient was performed by high performance liquid chromatography and complete blood count was measured by automated cell analyzer. Molecular study for common alpha deletions done by Gap-PCR while beta thalassemia mutation identified by ARMS-PCR. Case was clinically significant due to the inheritance of HbD/β⁺thalassemia genotype. Thus observed case behaved like thalassemia intermedia due to co-existence of α 3.7 deletions with IVS 1-5 β-thalassemia mutation in HbD Punjab patient.     

BBO晶体光参量放大研究

The noncollinear optical parametric amplification in BBO crystal is theoretically investigated. The phase matching angle, gain bandwidth, optimal noncollinear angle and conversion efficiency for both type-Ⅰ and type-Ⅱ BBO are simulated. The numerical simulation results are important to the practical optical parametric amplification experiments with BBO crystal.     

Classrooms for Children with Developmental Disabilities: Sound‐field and public address amplification systems compared

Background noise poses adverse effects on speech sounds and affects student learning, especially for children with developmental disabilities. Sound‐field and public address amplification systems can help to solve this problem by amplifying speech sounds relative to background noise. This study surveyed school classrooms for children with special needs, and compared the performance of a sound‐field and a portable public address system in classroom environments. Unoccupied room noise levels and reverberation times were measured in eight classrooms at four Hong Kong schools for children with special needs. Speech levels in each classroom were measured under three conditions: without amplification, with public address system amplification, and with sound‐field amplification. Speech‐to‐noise ratios were calculated for each condition. Noise and unamplified speech‐to‐noise ratio values exceeded recommended acoustic standards in all classrooms. When sound‐field and public address amplification systems were installed, speech‐to‐noise ratios improved considerably. When either amplification system was used, a uniform sound‐field resulted. The applicability of both types of amplification system and their relative merits in special education classrooms are discussed.     

快速纯化高活力基因工程Taq DNA聚合酶

用含有TaqDNA聚合酶基因的pTaq表达质粒转化E.coli DH5α菌株，IPTG诱导表态TaqDNA聚合酶。利用该酶的热，经两轮－70℃深度冷冻和75℃水浴，细菌裂解释放内容物，以高速离心除去冻融变性的细胞碎片及核酸蛋白的复合以达到快速纯化Taq DNA聚合酶的目的。PCR扩增反应表明所制备的Taq DNA聚合酶的活力、敏感性、特异性均达到试验要求。该方法具有快速简便的优点。