排序方式： 共有34条查询结果，搜索用时 15 毫秒
31.
为建立能同时检测鸡毒支原体(Mycoplasma gallisepticum, MG)和鸡滑液囊支原体(Mycoplasma synoviae,MS)的双重PCR诊断方法,该研究根据GenBank中登录的MG gapA基因序列和MS heat shock ATP-dependent protease基因序列,设计2对特异性引物,通过对PCR扩增条件的优化,建立了能够同时检测MG和MS的双重PCR诊断方法。特异性检测结果显示,该方法能够扩增出729 bp的MG和309 bp的MS特异性片段,对禽巴氏杆菌、大肠杆菌、鸡白痢沙门菌、副鸡禽杆菌核酸扩增均为阴性;敏感性检测结果显示,对MG和MS DNA的最低检出量均为5×10-2 ng/μL;临床样品的检测结果显示,所建立的双重PCR方法可同时有效地检测出MG、MS混合感染和单独感染。该研究建立的鸡毒支原体与鸡滑液囊支原体双重PCR方法具有良好的特异性、敏感性、重复性,为快速、高效检测MG和MS提供了技术支持。 相似文献
32.
Badii Gaaliche Sonia Chehimi Sana Dardouri Mohamed Rabeh Hajlaoui 《International Journal of Fruit Science》2018,18(1):85-98
ABSTRACTPears have great importance in Tunisia for their desirable taste and commercial value. Until 2012, the pear cultivation was protected against fire blight by the application of a rigorous quarantine system. Fire blight, caused by Erwinia amylovora, was outbreak in Tunisia in the spring of 2012 and has spread rapidly through the most important pear growing regions destroying several hundred hectares of pear plantations. Therefore, the total pear production has decreased from 60,000 metric tons in 2011 to less than 20,000 metric tons in 2016. In this study, collected data of pear culture and surveys were carried out during four years (2012–2016) in the main pear growing areas to evaluate the current situation of the disease in the country particularly in the damaged regions of the lower valley of Medjerda (Manouba, Ben Arous, Bizerte, and Beja). Samples collected from symptomatic trees were processed for the isolation and identification of the causal agent using microbiological and molecular techniques. The results indicate that the disease had destroyed more than 5500 hectares among a total of 8400 hectares of pear plantations area. Both provinces Manouba and Ben Arous were the most affected by fire blight disease resulting in the eradication of 350 and 325 hectares of pear plantations, i.e., 100% and 98% of the total infected area, respectively. All control attempts, including sanitary measures, the application of mineral oil and copper, growth regulators and biological control have failed to limit the spread of the disease. The presence of pathogen in the prospected regions was confirmed by pathogenicity and molecular tests, which are compatible with the symptoms observed throughout the surveys. The pear cultivation in Tunisia is threatened by fire blight due to the restriction tolerance of the available varieties and the climatic conditions favoring the staggered flowering of the species. Quarantine measures must be implemented to prevent the spread of this disease in a new disease-free areas. 相似文献
33.
Mehdi Alikhani Samaneh Saberi Maryam Esmaeili Valrie Michel Mohammad Tashakoripour Afshin Abdirad Arezoo Aghakhani Sana Eybpoosh Massoud Vosough Mohammad Ali Mohagheghi Mahmoud Eshagh Hosseini Eliette Touati Marjan Mohammadi 《Iranian Biomedical Journal》2021,25(5):323
Background:Variations in mtDNA-CN of PBLs, as a potential biomarker for GC screening has currently been subject to controversy. Herein, we have assessed its efficiency in GC screening, in parallel and in combination with sPG I/II ratio, as an established indicator of gastric atrophy. Methods:The study population included GC (n = 53) and non-GC (n = 207) dyspeptic patients. The non-GC group was histologically categorized into CG (n = 104) and NM (n = 103) subgroups. The MtDNA-CN of PBLs was measured by quantitative real-time PCR. The sPG I and II levels and anti-H. pylori serum IgG were measured by ELISA. Results:The mtDNA-CN was found significantly higher in GC vs. non-GC (OR = 3.0; 95% CI = 1.4, 6.4) subjects. Conversely, GC patients had significantly lower sPG I/II ratio than the non-GC (OR = 3.2; CI = 1.4, 7.2) subjects. The combination of these two biomarkers yielded a dramatic amplification of the odds of GC risk in double-positive (high mtDNA-CN-low sPGI/II) subjects, in reference to double-negatives (low mtDNA-CN-high sPGI/II), when assessed against non-GC (OR = 27.1; CI = 5.0, 147.3), CG (OR = 13.1; CI = 2.4, 72.6), or NM (OR = 49.5; CI = 7.9, 311.6) groups. Conclusion:The combination of these two biomarkers, namely mtDNA-CN in PBLs and serum PG I/II ratio, drastically enhanced the efficiency of GC risk assessment, which calls for further validations. Key Words: Biomarkers, DNA copy number variation, Mitochondrial DNA, Stomach neoplasms 相似文献
34.
Self-assembling protein cages have been exploited as templates for nanoparticle synthesis. The ferritin molecule, a protein cage present in most living systems, stores excess soluble ferrous iron in the form of an insoluble ferric complex within its cavity. Magnetic nanocores formed by loading excess iron within an engineered ferritin from Archaeoglobus fulgidus (AfFtn-AA) were studied as a potential magnetic resonance (MR) imaging contrast agent. The self-assembly characteristics of the AfFtn-AA were investigated using dynamic light scattering technique and size exclusion chromatography. Homogeneous size distribution of the assembled nanoparticles was observed using transmission electron microscopy. The magnetic properties of iron-loaded AfFtn-AA were studied using vibrating sample magnetometry. Images obtained from a 3.0 T whole-body MRI scanner showed significant brightening of T(1) images and signal loss of T(2) images with increased concentrations of iron-loaded AfFtn-AA. The analysis of the MR image intensities showed extremely high R(2) values (5300?mM(-1)?s(-1)) for the iron-loaded AfFtn-AA confirming its potential as a T(2) contrast agent. 相似文献