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正本文针对枯草芽孢杆菌Subtilis str. 168的Sec分泌途径Spase Ⅰ类和Ⅱ类蛋白进行预测和分析,有助于了解该菌与宿主之间的作用机制,为该菌的筛选和应用打下了基础,也丰富了基因组序列和原核生物数据库。枯草芽孢杆菌是一类广泛存在植物和土壤中的具有较强抗逆性的革兰氏阳性益生菌,具有繁殖快,能抑制有害菌的生长等特点,是研究菌种的典型菌株。蛋白的Sec分泌途径的分析能够认识该菌株的生理功能和与宿主之间的作用机理。方法:Sec途径分泌蛋白具有Ⅰ型信号肽的分泌蛋白Spase Ⅰ和Ⅱ型信号肽的分泌蛋白Spase Ⅱ。首先在NCBI(w- 相似文献
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近年来,由微生物及其产生的各类毒素引发的食品污染层出不穷,PCR技术以其高强的特异性和灵敏度以及检测速度快、准确性好等优点,广泛地应用在食品微生物检测的各个领域,尤其对培养困难的细茵检测和抗原结构复杂的细菌鉴定方面。简要介绍了几种PCR方法的原理,以及其在食品微生物检测中的应用情况。 相似文献
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粪便移植又被称作粪便微生物群移植,粪菌医治。目前在难辨梭状芽孢杆菌感染、溃疡性结肠炎、能量代谢相关疾病等的医治中得到成功的应用。本文较全面地对"粪便移植"产生背景、方法与途径、应用现状及未来进行了科学探究。 相似文献
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本研究检测了无患子皂苷对6种典型细菌和6种典型真菌的抗菌活性。提取无患子假种皮中总皂苷R1和R2,分离得到皂苷混合物样品R1-3、R1-4、R1-5、R1-6、R1-7、R2-5、R2-6、R2-7、R2-8、R2-9和R2-10;采用滤纸片琼脂扩散法对其抑菌活性进行检测,得出抑菌圈直径、MIC值和EC50值。抑菌活性物质主要集中在样品R1-5、R1-6、R2-7、R2-8、R2-9和R2-10中,这些样品对金黄色葡萄球菌、枯草芽孢杆菌、蜡状芽孢杆菌、大肠杆菌、巨大芽孢杆菌、白色念珠菌、黑曲霉和绿色木霉具有很强的抑菌活性。无患子总皂苷各组分中含有能够显著抑制供试细菌和真菌的活性物质,这为进一步开发利用无患子的药用价值提供了科学依据。 相似文献
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我国肉毒中毒的食品,主要是自制的食物,如臭豆腐、腌菜、变质豆芽、变质土豆、米糊等。由于这些食物蒸煮加热时间短,在坛内发酵多日后,肉毒梭菌及芽孢繁殖产生毒素的条件成熟,进食后容易中毒。不新鲜的肉,也会引起肉毒毒素食物中毒。食品中肉毒毒素的检测主要有胶体金法、反向乳胶凝集法。以及三种方法的操作步骤、结果判定、注意事项等。 相似文献
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幽门螺杆菌CagA蛋白与CTB融合基因的克隆及其植物表达载体的构建 总被引：2，自引：0，他引：2
目的 构建能在水稻胚乳中特异表达的幽门螺杆菌细胞毒素相关蛋白(CagA)和霍乱毒素B亚单位(CTB)的植物表达载体.方法 采用高保真PCR技术分别从质粒pGEM CTB和幽门螺杆菌基因组DNA中扩增出CTB和cagA基因,然后用PCR方法直接融合CTB基因和cagA基因.又用PCR法改造了水稻Wx启动子,在其3′端融合加入Ω序列和Kozak序列.通过一系列亚克隆最终将两个融合基因和NOS终止子插入根癌农杆菌双元载体pCAMBI A1300的表达框架内.结果 PCR验证和测序分析证明,CTB和cagA融合基因以正确的方向插入到载体pCAMBI A1300中,并位于水稻Wx启动子后.结论 成功构建CTB和cagA融合基因的植物表达载体,为幽门螺杆菌口服疫苗的研究奠定基础. 相似文献
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笔者结合了多年的工作经验,针对遗传工程微生物细胞间发生的自然遗传转化进行了初步探讨分析,主要是将两株不同DNA的枯草芽孢杆菌进行分别培养,认真观察其生长状态,并通过质粒检测、经选择平板筛选等数据分析得知,虽然这两株枯草芽孢杆菌的遗传基因不同,但是可以进行自然遗传转化的,实验证明,自然遗传转化是在物细胞中进行遗传基因的转移,这对于我国遗传工程微生物的使用质量有着至关重要的作用与意义。 相似文献
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Rapid concentration and detection of bacteria in integrated chips and microfluidic devices is needed for the advancement of lab-on-a-chip devices because current detection methods require high concentrations of bacteria which render them impractical. We present a new chip-scale rapid bacteria concentration technique combined with surface-enhanced Raman scattering (SERS) to enhance the detection of low bacteria count samples. This concentration technique relies on convection by a long-range converging vortex to concentrate the bacteria into a packed mound of 200 μm in diameter within 15 min. Concentration of bioparticle samples as low as 104 colony forming units (CFU)∕ml are presented using batch volumes as large as 150 μl. Mixtures of silver nanoparticles with Saccharomyces cerevisiae, Escherichia coli F-amp, and Bacillus subtilis produce distinct and noticeably different Raman spectra, illustrating that this technique can be used as a detection and identification tool. 相似文献
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《Information processing & management》2023,60(4):103354
The proliferation of false information is a growing problem in today's dynamic online environment. This phenomenon requires automated detection of fake news to reduce its harmful effect on society. Even though various methods are used to detect fake news, most methods only consider data-oriented text features; ignoring dual emotion features (publisher emotions and social emotions) and thus lack higher levels of accuracy. This study addresses this issue by utilizing dual emotion features to detect fake news. The study proposes a Deep Normalized Attention-based mechanism for enriched extraction of dual emotion features and an Adaptive Genetic Weight Update-Random Forest (AGWu-RF) for classification. First, the deep normalized attention-based mechanism incorporates BiGRU, which improves feature value by extracting long-range context information to eliminate gradient explosion issues. The genetic weight for the model is adjusted to RF and updated to achieve optimized hyper parameter values that support the classifiers' detection accuracy. The proposed model outperforms baseline methods on standard benchmark metrics in three real-world datasets. It outperforms state-of-the-art approaches by 5%, 11%, and 14% in terms of accuracy, highlighting the significance of dual emotion capabilities and optimizations in improving fake news detection. 相似文献
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《Information processing & management》2022,59(5):103011
Nowadays, stress has become a growing problem for society due to its high impact on individuals but also on health care systems and companies. In order to overcome this problem, early detection of stress is a key factor. Previous studies have shown the effectiveness of text analysis in the detection of sentiment, emotion, and mental illness. However, existing solutions for stress detection from text are focused on a specific corpus. There is still a lack of well-validated methods that provide good results in different datasets. We aim to advance state of the art by proposing a method to detect stress in textual data and evaluating it using multiple public English datasets. The proposed approach combines lexicon-based features with distributional representations to enhance classification performance. To help organize features for stress detection in text, we propose a lexicon-based feature framework that exploits affective, syntactic, social, and topic-related features. Also, three different word embedding techniques are studied for exploiting distributional representation. Our approach has been implemented with three machine learning models that have been evaluated in terms of performance through several experiments. This evaluation has been conducted using three public English datasets and provides a baseline for other researchers. The obtained results identify the combination of FastText embeddings with a selection of lexicon-based features as the best-performing model, achieving F-scores above 80%. 相似文献
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结合共词分析法与战略坐标对食品安全发展态势做战略情报分析,得到当前国内食品安全研究领域的8个热点,为进一步定量分析各热点的发展趋势绘制了战略坐标图,研究结果表明:食品卫生监督、食品安全管理及法律法规、食品安全体系建设、残留危害物质及检测是当前研究的中心内容;食物中毒及有害微生物的快速检测处于探索阶段;农产品安全及食品标准尚不成熟;食品污染和食品RFID追溯制度处于研究领域的边缘。 相似文献
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民以食为天,食以安为先,食品安全关系每个人的日常生活,是民生的基础和最重要的保障。本文以我国现行的食品安全监管机制为研究对象。分析我国食品安全监管中存在的问题。通过对比分析美国、欧盟、日本的食品安全监管体制,在总结较为成熟的经验基础上,结合我国当前运行的食品安全监管机制的现状,提出建立以政府监管为导向和全民社会化参与监督监管的思路,以进一步健全和完善我国食品安全监管发展对策。 相似文献
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N. Gaur S. Gautam M. Gaur P. Sharma G. Dadheech S. Mishra 《Indian journal of clinical biochemistry : IJCB》2008,23(4):307-327
The conclusive identification of specific etiological factors or pathogenic processes in the illness of schizophrenia has
remained elusive despite great technological progress. The convergence of state-of-art scientific studies in molecular genetics,
molecular neuropathophysiology, in vivo brain imaging and psychopharmacology, however, indicates that we may be coming much
closer to understanding the genesis of schizophrenia. In near future, the diagnosis and assessment of schizophrenia using
biochemical markers may become a “dream come true” for the medical community as well as for the general population. An understanding
of the biochemistry/ visa vis pathophysiology of schizophrenia is essential to the discovery of preventive measures and therapeutic
intervention. 相似文献
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在中等职业卫生学校中,病原微生物实验课属于一门比较重要的实践操作课程。该课程在实际的教学设计和具体的实施的过程中都存在着许多问题,这些问题的存在在一定程度上影响、阻碍了良好教学效果的实现。而解决这些问题的一条有效途径就是在综合分析课程本身、学生情况等基础上采用最优化的教学方法。在本文中,作者就是以发现问题、分析问题、解决问题为主线对能有效提高病原微生物实验课教学效果的教学方法进行了探究。 相似文献