MPEG-2TS信息提取和一致性测试研究

阐述了对MPEG-2TS流进行测试的必要性,提出了对TS流进行信息提取和一致性测试的方法,给出了关键部分缓冲区测试和PCR测试的详细的设计思想。该方法应用在系统中被证明是完全可行的。

Establishment of a Multiplex PCR System for Detecting Transgenic Ingredients from Citrus

[Objective] This study aimed to establish a multiplex PCR system for de- tecting transgenic ingredients from Citrus. [Method] Based on the pBI121 plasmid sequences published in GenBank and actin gene sequence of Citrus, the primers specific to CaMV35S promoter, NOS promoter, NOS terminator and actin gene were designed, to establish a multiple PCR system which could detect four types of sequences. In addition, orthogonal tests were performed to determine the optimal concentrations of all the components in PCR reaction system, as well as the optimal PCR cycle parameters. [Result] The optimal PCR reaction system should contain 2.5μl of 10xPCR buffer, 2.0μl of MgCI2 （25 mmol/L）, 2.0 μl of dNTP mixture （2.5 mmol/L of each dNTP）, 1.0 μl of actin gene primers （10μmol/L）, 1.0μl of 35S promoter primers （10 μmol/L）, 1.5 μl of NOS promoter primers （10 μmol/L） and 0.5 μl of NOS terminator primers （10μmol/L）, 0.1 μg of template DNA, 1.25 U of Taq DNA polymerase; ddH20 was added to the total reaction system of 25μl. The PCR reaction program consisted of pre-denaturing at 94℃ for 5 min; 31 cycles of denaturing at 94℃ for 30 s, annealing at 64.1℃ for 45 s and extension at 72℃ for 50 s; final extension at 72℃ for 10 min. The reaction system optimized with the orthogonal tests could detect as less as 0.1% transgenic component in the tested samples. [Conclusion] The MPCR detection system established in this study can meet the requirements in theory for detecting the genetically modified ingredients in Citrus or the deep-processed products.

一种新型的美白牙膏去除牙齿外源性色斑的系统功效评价方法研究

具有美白功效的口腔护理产品一直是消费者的首选,而如何对美白口腔护理产品进行更好更快的功效评价也一直是口腔行业的研究热点。本研究以舒客白牙素牙膏作为研究对象,分别采用体外PCR清洁力试验与临床试验研究对其开展去除牙齿外源性色斑的功效评价。结果表明,无论是体外PCR清洁力试验还是临床功效研究,舒客白牙素牙膏均具有良好的去除牙齿外源性色斑的效果。同时,在常规采用Lobene色斑指数进行临床功效评价的基础上,结合图像分析法评价牙齿三维颜色的变化,可更加直观显性地看到产品去除外源性色斑的变化,缩短临床试验的周期。

Exploring valid internal-control genes in Porphyra yezoensis(Bangiaceae) during stress response conditions

To screen the stable expression genes related to the stress （strong light, dehydration and temperature shock） we applied Absolute real-time PCR technology to determine the transcription numbers of the selected test genes in Porphyra yezoensis, which has been regarded as a potential model species responding the stress conditions in the intertidal. Absolute real-time PCR technology was applied to determine the transcription numbers of the selected test genes in Porphyra yezoensis, which has been regarded as a potential model species in stress responding. According to the results of photosynthesis parameters, we observed that Y（II） and Fv/Fm were significantly affected when stress was imposed on the thalli of Porphyra yezoensis, but underwent almost completely recovered under normal conditions, which were collected for the following experiments. Then three samples, which were treated with different grade stresses combined with salinity, irradiation and temperature, were collected. The transcription numbers of seven constitutive expression genes in above samples were determined after RNA extraction and cDNA synthesis. Finally, a general insight into the selection of internal control genes during stress response was obtained. We found that there were no obvious effects in terms of salinity stress （at salinity 90） on transcription of most genes used in the study. The 18S ribosomal RNA gene had the highest expression level, varying remarkably among different tested groups. RPS8 expression showed a high irregular variance between samples. GAPDH presented comparatively stable expression and could thus be selected as the internal control. EF-la showed stable expression during the series of multiple-stress tests. Our research provided available references for the selection of internal control genes for transcripts determination of P. yezoensis.

Rapid Detection of Filoviruses by Real-time TaqMan Polymerase Chain Reaction Assays

Ebola virus （EBOV） and Marburg virus （MARV） are causative agents of severe hemorrhagic fever with high mortality rates in humans and non-human primates and there is currently no licensed vaccine or therapeutics. To date, there is no specific laboratory diagnostic test in China, while there is a national need to provide differential diagnosis during outbreaks and for instituting acceptable quarantine procedures. In this study, the TaqMan RT-PCR assays targeting the nucleoprotein genes of the Zaire Ebolavirus （ZEBOV） and MARV were developed and their sensitivities and specificities were investigated. Our results indicated that the assays were able to make reliable diagnosis over a wide range of virus copies from 103 to 109, corresponding to the threshold of a standard RNA transcript. The results showed that there were about 101 RNA copies per milliliter of virus culture supernatant, equivalent to 10,000 RNA molecules per infectious virion, suggesting the presence of many non-infectious particles. These data indicated that the TaqMan RT-PCR assays developed in this study will be suitable

Cardiac Lesions in Naturally Infected Dogs with Trypanosoma cruzi

With the purpose to determine the frequency and type of cardiac lesions in naturally exposed dogs to Trypanosoma cruzi, ninety one stray dogs, capture by the Canine and Feline Control Center （dog pound） from the municipality of Merida, were studied. Before euthanasia, blood samples were taken to detect 72 cruzi antigens by indirect immunofluorescence antibody test and Western Blot and to detect the genome of parasite by Polymerase Chain Reaction. Immediately after euthanasia, hearts were macroscopically evaluated and a sample of the middle right atrial wall of each dog was taken for histopathological analyses. DNA was also obtained from paraffin blocks of seropositives animals with microscopic lesions to detect 72 cruzi genome. Of ninety one dogs, thirteen were seropositive. All seropositive dogs showed an association （P 〈 0.05） with lymphocytoplasmatic myocarditis. The presence of the 72 cruzi genome was also detected by PCR in cardiac septum tissue of seropositive dogs and in all the cases with microscopic lesions indicating the high pathogenicity of the local circulating strain. No association with macroscopic lesions was observed in seropositive dogs. Also, the presence of Dirofilaria immitis （D. immitis） was found in 6% of dogs evaluated. This study demonstrates a high tropism to cardiac tissue and virulence of the strains of 72 cruzi circulating in the studied dog population.