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Construction of Recombinant Adenovirus Vector Containing CEVB2L Gene 被引量:2
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作者 邵洪泽 毛文智 +4 位作者 宋阳 李琳 程荣华 孙健 孙强 《Agricultural Science & Technology》 CAS 2010年第3期94-97,共4页
[Objective] Sheep contagious ecthyma virus B2L gene recombinant adenovirus was built by adenovirus vector system.[Method] Genome DNA extracted from sheep contagious ecthyma virus strain JLSY04 as a template,Gene fragm... [Objective] Sheep contagious ecthyma virus B2L gene recombinant adenovirus was built by adenovirus vector system.[Method] Genome DNA extracted from sheep contagious ecthyma virus strain JLSY04 as a template,Gene fragments obtained from B2L by PCR amplification;B2L gene cloning was cloned into PDNR-CMD vector,screening positive clones and plasmid CTC572-6 was obtained;CTC572-6 plasmid for homologous was recombined with the adenoviral vector.Screening positive clones and bacilli PCR,digestion and sequencing and so on were identified.[Result] After identified by enzyme digestion and gene sequencing,recombinant adenovirus vector CTC572Ade-30 of carrying sheep contagious ecthyma virus B2L gene was constructed successfully.[Conclusion] Which laid the foundation for sheep contagious ecthyma genetically engineered vaccine. 展开更多
关键词 CEV B2L gene Adenovirus vector
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Combination Computing of Support Vector Machine, Support Vector Regression and Molecular Docking for Potential Cytochrome P450 1A2 Inhibitors 被引量:1
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作者 陈茜 乔连生 +2 位作者 蔡漪涟 张燕玲 李贡宇 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第5期629-634,I0002,共7页
The computational approaches of support vector machine (SVM), support vector regression (SVR) and molecular docking were widely utilized for the computation of active compounds. In this work, to improve the accura... The computational approaches of support vector machine (SVM), support vector regression (SVR) and molecular docking were widely utilized for the computation of active compounds. In this work, to improve the accuracy and reliability of prediction, the strategy of combining the above three computational approaches was applied to predict potential cytochrome P450 1A2 (CYP1A2) inhibitors. The accuracy of the optimal SVM qualitative model was 99.432%, 97.727%, and 91.667% for training set, internal test set and external test set, respectively, showing this model had high discrimination ability. The R2 and mean square error for the optimal SVR quantitative model were 0.763, 0.013 for training set, and 0.753, 0.056 for test set respectively, indicating that this SVR model has high predictive ability for the biolog-ical activities of compounds. According to the results of the SVM and SVR models, some types of descriptors were identi ed to be essential to bioactivity prediction of compounds, including the connectivity indices, constitutional descriptors and functional group counts. Moreover, molecular docking studies were used to reveal the binding poses and binding a n-ity of potential inhibitors interacting with CYP1A2. Wherein, the amino acids of THR124 and ASP320 could form key hydrogen bond interactions with active compounds. And the amino acids of ALA317 and GLY316 could form strong hydrophobic bond interactions with active compounds. The models obtained above were applied to discover potential CYP1A2 inhibitors from natural products, which could predict the CYPs-mediated drug-drug inter-actions and provide useful guidance and reference for rational drug combination therapy. A set of 20 potential CYP1A2 inhibitors were obtained. Part of the results was consistent with references, which further indicates the accuracy of these models and the reliability of this combinatorial computation strategy. 展开更多
关键词 Support vector machine Support vector regression Molecular docking CYPIA2 inhibitor
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Cloning of Cotton Delta-12 Oleate Desaturase Gene FAD2-1 and Construction of Its ihpRNA and amiRNA Interference Vectors 被引量:1
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作者 赵立群 李红岺 +3 位作者 李仁 李蔚 华金平 郭仰东 《Agricultural Science & Technology》 CAS 2012年第11期2281-2283,2286,共4页
Delta-12 oleate desaturase gene (FAD2-1) which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cott... Delta-12 oleate desaturase gene (FAD2-1) which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cotton delta-12 oleate desat- urase gene GhFAD2-1 containing an open reading frame of 1 158 bp was cloned for constructing RNAi vector. A 515 bp long specific fragment of this gene was se- lected for constructing ihpRNA vector under the control of a seed-specific promoter NAPIN, named pFGC1008-NAPIN-FAD2-1; meanwhile miRNA gene-silencing vector pCAMBIA1302-amiRNA-FAD2-1 targeting GhFAD2-1 was also constructed. 展开更多
关键词 Cotton delta-12 oleate desaturase gene GhFAD2-1 ihpRNA interferencevector amiRNA interference vector High oleic acid contents
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1-Norm/2-Norm约束及小波多尺度2D体波走时成像 被引量:1
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作者 高级 方洪健 《物探化探计算技术》 CAS CSCD 2016年第6期765-772,共8页
在对浅地表复杂地下介质层析成像时,由于观测系统局限性及方法本身对特定岩石地球物理属性的不敏感性等因素,造成地球物理反演存在多解性。在地震走时成像中,地震射线数量在低速区域分布较少形成阴影区,造成其对低速区域成像分辨率较低... 在对浅地表复杂地下介质层析成像时,由于观测系统局限性及方法本身对特定岩石地球物理属性的不敏感性等因素,造成地球物理反演存在多解性。在地震走时成像中,地震射线数量在低速区域分布较少形成阴影区,造成其对低速区域成像分辨率较低。同时因为观测数据包含干扰信息以及不同反演方法的局限性等因素造成反演结果包含次生假异常。这里主要研究了空间域的L1-norm、L2-norm约束反演及小波域小波系数稀疏约束反演,对比不同反演方式及约束条件对地质模型的分辨能力。通过测试孤立异常模型、层状地层模型、倾斜地层模型,得出三种不同反演方式分别具有对不同特定模型的分辨特性。在实际资料成像中,可以通过使用多种反演方式,对比反演结果合理性以期达到更准确的地质构造解释。 展开更多
关键词 体波走时 层析成像 1-norm 2-norm 小波多尺度
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VECTOR2X电子罗盘OEM板及其应用
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作者 罗卫兵 马力男 王永生 《半导体技术》 CAS CSCD 北大核心 2001年第7期37-40,共4页
介绍了美国 PNI公司的一种 2轴电子罗盘及其单片机接口,并描述了一种利用该电子罗盘设计的自动定向天线伺服系统。
关键词 电子罗盘 姿态传感器 定向天线 单片机 vector2X 专用集成电路
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表达猪圆环病毒2d型Cap蛋白的重组猪伪狂犬病病毒的构建
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作者 焦显芹 马晓 +3 位作者 田润博 刘颖 马世杰 陈红英 《中国畜牧兽医》 北大核心 2025年第5期2278-2286,共9页
【目的】利用同源重组技术和CRISPR/Cas9基因编辑技术,获得表达猪圆环病毒2d型(PCV2d)Cap蛋白的重组猪伪狂犬病病毒(PRV),为开发预防和控制PCV2d和PRV感染的疫苗提供技术支持。【方法】基于PCV2d KF1株ORF 2基因序列设计1对特异引物,以P... 【目的】利用同源重组技术和CRISPR/Cas9基因编辑技术,获得表达猪圆环病毒2d型(PCV2d)Cap蛋白的重组猪伪狂犬病病毒(PRV),为开发预防和控制PCV2d和PRV感染的疫苗提供技术支持。【方法】基于PCV2d KF1株ORF 2基因序列设计1对特异引物,以PCV2d KF1株DNA为模板扩增ORF 2基因。经限制性内切酶Bam HⅠ酶切后将ORF 2基因引入到含有绿色荧光蛋白(EGFP)基因的PRV转移载体pG中,获得重组质粒pG-PCV2d-EGFP。运用转染试剂ZLip2000将质粒pG-PCV2d-EGFP和PRV三基因缺失毒株gE^(-)/gI^(-)/TK^(-)PRV NY DNA共转染至ST单层细胞中拯救重组病毒,并利用CRISPR/Cas9 EGFP基因双敲除质粒敲除重组病毒中EGFP基因。经EGFP基因测序、PCR和Western blotting对获得的重组病毒进行鉴定。【结果】经8轮绿色荧光蚀斑筛选,纯化得到重组病毒rPRV-PCV2d-EGFP。CRISPR/Cas9 EGFP基因双敲除质粒敲除EGFP基因后,经3轮筛选没有绿色荧光的蚀斑,获得重组病毒rPRV-PCV2d。EGFP基因测序结果表明,rPRV-PCV2d中EGFP基因被剪截了1251 bp,PCR和Western blotting结果显示,rPRV-PCV2d携带的ORF 2基因能在ST细胞中转录与表达。【结论】本研究成功构建表达PCV2d Cap蛋白的重组病毒rPRV-PCV2d,为进一步研制重组活载体疫苗奠定了基础。 展开更多
关键词 猪圆环病毒2 猪伪狂犬病病毒 重组病毒活载体疫苗
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基于Word2vector的文本特征化表示方法 被引量:22
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作者 周顺先 蒋励 +2 位作者 林霜巧 龚德良 王鲁达 《重庆邮电大学学报(自然科学版)》 CSCD 北大核心 2018年第2期272-279,共8页
针对基于词语统计的特征化表示无法有效提取文本的词义特征的问题,提出一种基于上下文关系的文本特征化表示方法。该方法利用Word2vector提取词义特征,获得词向量;再对词向量进行"最优适应度划分"的聚类,并根据聚类结果将词... 针对基于词语统计的特征化表示无法有效提取文本的词义特征的问题,提出一种基于上下文关系的文本特征化表示方法。该方法利用Word2vector提取词义特征,获得词向量;再对词向量进行"最优适应度划分"的聚类,并根据聚类结果将词语替代表示为聚类质心;根据质心及其所代表的词语的词频,构成词向量聚类质心频率模型(semantic frequency-inverse document frequency,SF-IDF),用于特征化表示文本。在不依赖语义规则的情况下,分别以路透社文本集Reuter-21578、维基百科(extensible markup language,XML)数据为文本数据集,采用神经网络语言模型(neural network language model,NNLM)算法进行文本分类实验,并采用F1-measure标准进行样本分类的效果评估,词向量聚类质心频率模型SF-IDF(semantic frequency-inverse document frequency,SF-IDF)向量与现有技术中词频-逆向文件频率(term frequency-inverse document frequency,TF-IDF)向量的分类效果对比,与TF-IDF模型进行对比实验;在Reuter-21578数据集上平均准确率由原有的57.1%提高到63.3%,在Wikipedia XML数据集上平均准确率由原有的48.7%提高到59.2%。SF-IDF模型可适用于现行的基于特征向量的信息检索算法,且较TF-IDF模型有更高的文本相似性分析效率,可提升文本分类准确率。 展开更多
关键词 Word2vector 上下文关系 特征化表示 文本分类
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Derivation of Cloud-Free-Region Atmospheric Motion Vectors from FY-2E Thermal Infrared Imagery 被引量:3
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作者 Zhenhui WANG Xinxiu SUI +5 位作者 Qing ZHANG Lu YANG Hang ZHAO Min TANG Yizhe ZHAN Zhiguo ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第2期272-282,共11页
The operational cloud-motion tracking technique fails to retrieve atmospheric motion vectors (AMVs) in areas lacking cloud; and while water vapor shown in water vapor imagery can be used, the heights assigned to the... The operational cloud-motion tracking technique fails to retrieve atmospheric motion vectors (AMVs) in areas lacking cloud; and while water vapor shown in water vapor imagery can be used, the heights assigned to the retrieved AMVs are mostly in the upper troposphere. As the noise-equivalent temperature difference (NEdT) performance of FY-2E split win- dow (10.3-11.5 μm, 11.6-12.8 μm) channels has been improved, the weak signals representing the spatial texture of water vapor and aerosols in cloud-free areas can be strengthened with algorithms based on the difference principle, and applied in calculating AMVs in the lower troposphere. This paper is a preliminary summary for this purpose, in which the principles and algorithm schemes for the temporal difference, split window difference and second-order difference (SD) methods are introduced. Results from simulation and cases experiments are reported in order to verify and evaluate the methods, based on comparison among retrievals and the "truth". The results show that all three algorithms, though not perfect in some cases, generally work well. Moreover, the SD method appears to be the best in suppressing the surface temperature influence and clarifying the spatial texture of water vapor and aerosols. The accuracy with respect to NCEP 800 hPa reanalysis data was found to be acceptable, as compared with the accuracy of the cloud motion vectors. 展开更多
关键词 atmospheric motion vector cloud-free area FY-2E IR split window imagery difference method
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基于ART-2人工神经网络算法的煤矿应急管理能力综合评价模型研究
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作者 张玉华 丁立培 王宇 《中国矿业》 北大核心 2025年第8期145-151,共7页
在评价煤矿应急管理能力时,为指标分配权重的过程易产生数据缺失值,导致指标计算精度较差,影响了评价结果的准确性。为此,构建基于ART-2人工神经网络算法的煤矿应急管理能力综合评价模型,以提升评价的客观性与准确性。首先,依据煤矿应... 在评价煤矿应急管理能力时,为指标分配权重的过程易产生数据缺失值,导致指标计算精度较差,影响了评价结果的准确性。为此,构建基于ART-2人工神经网络算法的煤矿应急管理能力综合评价模型,以提升评价的客观性与准确性。首先,依据煤矿应急管理体系结构,对打分数值进行规范化处理,将其转化为类别样本矢量集,为后续利用ART-2人工神经网络算法进行指标筛选提供标准化的数据输入。其次,运用ART-2人工神经网络算法对煤矿管理能力指标进行筛选。再次,组合网络层级中的元素,构建评价指标间相互影响的未加权矩阵。该矩阵全面反映了各评价指标之间的关联关系,为后续的权重分配提供依据。在目标层神经元节点处设置警戒数值,通过ART-2人工神经网络对未加权矩阵进行训练和优化。在此过程中,算法能够自动调整和修正指标权重,降低权重分配的主观性和模糊性。最后,根据修正后的权值,重新对各层神经元节点处的指标评分进行计算,得出最终的评价结果。研究结论表明,基于ART-2人工神经网络算法的煤矿应急管理能力评价模型,在解决传统评价方法中权重分配主观性强、数据易缺失等问题上具有显著优势,能够为煤矿应急管理决策提供更科学、合理的依据,有助于煤矿企业更好地评估和提升应急管理能力,从而保障煤矿的安全生产。 展开更多
关键词 ART-2人工神经网络 煤矿应急管理能力 类别样本矢量集 网络层级 警戒数值
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Edge Enhancement for Remote Sensing Image Using Norm Algorithm in L_2 Vector Space 被引量:1
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作者 CHEN Xue MAJianwen 《Geo-Spatial Information Science》 2007年第2期121-123,共3页
The Householder transformation-norm structure function in L2 vector space of linear algebra is introduced, and the edge enhancement for remote sensing images is realized. The experiment result is compared with traditi... The Householder transformation-norm structure function in L2 vector space of linear algebra is introduced, and the edge enhancement for remote sensing images is realized. The experiment result is compared with traditional Laplacian and Sobel edge enhancements and it shows that the effect of the new method is better than that of the traditional algorithms. 展开更多
关键词 image edge enhancement Householder-norm transformation L2 vector space
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Recombinant Vaccinia Virus is an Effective and Non-perturbing Vector for Human Dendritic Cells Transfected with Epstein-Barr Virus Latent Membrane Protein 2A 被引量:2
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作者 许继军 姚堃 +4 位作者 彭光勇 谢芳艺 丁传林 朱建中 秦健 《Journal of Nanjing Medical University》 2002年第1期1-5,共5页
ObjectiveTo study the effects of dendritic cells (DC) transfected with recombinant vaccinia virus encoding Epstein Barr virus (EBV) latent membrane protein 2A(LMP2A) gene,and to provide evidence for further investiga... ObjectiveTo study the effects of dendritic cells (DC) transfected with recombinant vaccinia virus encoding Epstein Barr virus (EBV) latent membrane protein 2A(LMP2A) gene,and to provide evidence for further investigation on the therapeutic vaccines against EBV associated malignancies. MethodsMature DC were transfected with EBV LMP2A recombinant vaccinia virus (rVV LMP2A). Before and after the transfection,the expression of surface antigens on mature DC including CD1a,CD83,CD40,CD80,HLA DR was measured by fluorescence activated cell sorter (FACS) and the function of DC to stimulate allogeneic T cells proliferation was measured by mixed leukocyte reactions (MLR). ResultsLMP2A protein was highly expressed (66.1 %) in DC after the transfection of rVV LMP2A. No significant changes in the primary surface antigens expression and in the MLR were detected during the transfection. Transfected DC still had strong potential in stimulating the proliferation of allogeneic T cells. ConclusionRecombinant vaccinia virus was an effective and non perturbing vector to mediate the transfection of LMP2A into DC. The functions of mature DC were not affected significantly by the transfection of Vac LMP2A. This study could provide evidence for the further immunotherapy of EBV associated malignancies,e.g. nasopharyngeal carcinoma (NPC). 展开更多
关键词 rcombinant vaccinia vector dendritic cells Epstein Barr virus latent membrane protein 2A
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CLASSIFICATION OF SKIN AUTOFLUORESCENCE SPECTRUM USING SUPPORT VECTOR MACHINE IN TYPE 2 DIABETES SCREENING 被引量:1
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作者 YUANZHI ZHANG LING ZHU +4 位作者 YIKUN WANG LONG ZHANG SHANDONG YE YONG LIU GONG ZHANG 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2013年第4期42-48,共7页
Advanced glycation end products(AGEs)are a complex and heterogencous group of compounds that have been implicated in diabetes related complfcations.Sk in autofluorescence was recently introduced as an altemative tool ... Advanced glycation end products(AGEs)are a complex and heterogencous group of compounds that have been implicated in diabetes related complfcations.Sk in autofluorescence was recently introduced as an altemative tool for skin AGEs accumulation assessment in diabetes.Sucossful optical diagnosis of diabetes requires a rapid and accurate classification algorithm.In order to improve the performance of noninvasive and optical diagnosis of type 2 diabetes,support vector machines(SVM)algorithm was implemented for the clasification of skin autofluorescence from diabetics and control subjects.Cross-validation and grid optimization methods were employed to calculate the optimal parameters that ma ximize classification accuracy.Classification model was set up according to the training set and then veri fied by the testing set.The results show that radical basis fiunction is the best choice in the four common kernels in SVM.Moreover,a diagnostic accuracy of 82.61%,a sensitivity of 69.57%,and a specificity of 95.65%for discriminating diabetics from control subjects were achieved using a mixed kemel function,which is based on liner kernel function and radical basis function.In comparison with fasting plasma glucose and HbAue test,the clasifcation method of skin autofuorescence spectrum based on SVM shows great potential in screening of diabetes. 展开更多
关键词 Skin autofuorescence support vector machines algorithm type 2 diabetes noninvasive screening
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Cloning the Promoter of BcNA1 from Brassica napus and Fad2 Gene from Arabidopsis thaliana and Construction of the Plant Expression Vector 被引量:1
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作者 石东乔 《High Technology Letters》 EI CAS 2000年第1期83-90,共8页
The upstream regulatory region of a seed specific gene was isolated from the genomic DNA of Brassica napus by PCR amplification. The cloned fragment contained 1755 nucleotides, and shared a sequence homology of 99.6%... The upstream regulatory region of a seed specific gene was isolated from the genomic DNA of Brassica napus by PCR amplification. The cloned fragment contained 1755 nucleotides, and shared a sequence homology of 99.6% with the reported data. The coding region of oleic acid desaturase gene was then cloned from Arabidopsis thaliana. The sequencing analysis indicated that the sequence of the PCR product was just the same as reported before. In addition, the plant expression vector harboring the seed specific promoter and trans Fad2 gene was constructed. 展开更多
关键词 BRASSICA NAPUS Arabidopsis THALIANA seed specific PROMOTER FAD2 gene plant expression vector
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CONSTRUCTION, EXPRESSION AND BIOLOGICAL ASSESSMENT OF BPI_(23)-Fcγ1 RECOMBINANT PROTEIN PROKARYOTIC EXPRESSION VECTOR 被引量:7
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作者 安云庆 管远志 +1 位作者 柯岩 杨贵贞 《Chinese Medical Sciences Journal》 CAS CSCD 2002年第3期140-147,共8页
关键词 pBV BPI600 Fcγ1700 recombinant expression vector BPI23 Fcγ1 recombinant protein Objective. To construct pBV BPI600 Fcγ1700 recombinant expression vector to transform it into Escherichia coli DH5α and to induce the expression of BPI2
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BCR免疫组库分析SARS-CoV-2疫苗同源及异源免疫B细胞应答差异 被引量:2
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作者 宋彦丽 孙誉芳 +3 位作者 鲍春婷 王浇磊 权娅茹 李长贵 《病毒学报》 北大核心 2025年第1期23-32,共10页
比较新型冠状病毒(Severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)灭活疫苗(Inactivated vaccine,In)和腺病毒载体疫苗(Adenoviral vector vaccine,Ad)同源和异源免疫引起的B细胞抗原受体(B-cell receptor,BCR)差异,探究... 比较新型冠状病毒(Severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)灭活疫苗(Inactivated vaccine,In)和腺病毒载体疫苗(Adenoviral vector vaccine,Ad)同源和异源免疫引起的B细胞抗原受体(B-cell receptor,BCR)差异,探究SARS-CoV-2疫苗异源加强引起的抗体应答增强的原因。分别给小鼠同源免疫灭活疫苗In~4In、异源免疫3InAd,并于每次免疫10 d后采外周血检测各组血清针对SARS-CoV-2原型株和XBB.1.16变异株的中和抗体水平;提取同源和异源免疫后小鼠脾脏RNA,逆转录为cDNA后,对BCR重链的CDR3区序列进行BCR免疫组库测序,分析同源和异源免疫策略中CDR3的氨基酸长度多样性、V基因使用频率、V-J基因配对频率、BCR克隆多样性和克隆扩增水平。结果显示,异源3InAd组引起的针对原型株和XBB.1.16毒株的中和抗体水平显著高于同源免疫组;3InAd组CDR3氨基酸长度分布与同源免疫In~4In组不同;3InAd组V基因IGHV11-1、IGHV4-2使用频率显著高于同源4In组,IGHV5-6基因的使用频率低于4In组,IGHV9-3基因的使用频率在同源和异源免疫组无差异;同源免疫In~4In后,BCR克隆种类逐渐丰富,但BCR top 50的频率逐渐降低;3InAd组BCR种类丰富性与4In组相比没有明显增加,BCR top 50的频率逐渐增加,表明异源免疫增加了主要BCR克隆的扩增。本研究发现SARS-CoV-2异源免疫改变了B细胞CDR3长度、V基因频率、V-J基因配对频率、BCR种类多样性和BCR克隆扩增水平。 展开更多
关键词 BCR免疫组库 同源免疫 异源免疫 SARS-CoV-2 灭活疫苗 腺病毒载体疫苗
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On Felbin-type Fuzzy 2-normed Spacesand Its Fuzzy I-topologies
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作者 Mohammad Janfada Abolfazl Nezhadali Baghan 《模糊系统与数学》 CSCD 北大核心 2012年第1期12-19,共8页
In this paper using the concept of Felbin-type fuzzy 2-norm ‖.,.‖ on a vector space,two I-topologies τ‖.,.‖ and τ*‖.,.‖ is constructed.After making our elementary observations on this fuzzy I-topologies,the co... In this paper using the concept of Felbin-type fuzzy 2-norm ‖.,.‖ on a vector space,two I-topologies τ‖.,.‖ and τ*‖.,.‖ is constructed.After making our elementary observations on this fuzzy I-topologies,the continuity of vector space operations is discussed and it is proved that the vector space with I-topology τ‖.,.‖ is not I-topological vector space but with τ*‖.,.‖ is I-topological vector space.Next we study the relationship between this two I-topologies and it is proved that τ*‖.,.‖■τ‖.,.‖. 展开更多
关键词 Fuzzy Topology Fuzzy 2-norm I-topology Fuzzy Itopological vector Spaces
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一种基于Word2Vector与编辑距离的句子相似度计算方法 被引量:4
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作者 陆尹浩 《电脑知识与技术(过刊)》 2017年第2X期146-147,共2页
随着各种问答系统的流行与聊天机器人的火热,对句子相似性的比较和处理越来越成为各类类似系统的核心部分。因此,研究并设计出一种好的句子相似性比较方法变得越来越关键。该文基于一种深度学习模型Word2Vector并且结合编辑距离算法提... 随着各种问答系统的流行与聊天机器人的火热,对句子相似性的比较和处理越来越成为各类类似系统的核心部分。因此,研究并设计出一种好的句子相似性比较方法变得越来越关键。该文基于一种深度学习模型Word2Vector并且结合编辑距离算法提出了一种句子相似度计算方法,给出了具体的设计思路,并且通过实验验证了该方法的有效性,最后总结了该方法的优缺点。 展开更多
关键词 句子相似度计算 Word2vector 编辑距离 Edit Distance
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Interleukin-2 expression and glioma cell proliferation following Vaccinia vector gene transfection in vivo
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作者 Xiaogang Wang Xuezhong Wei Jiangqiu Liu 《Neural Regeneration Research》 SCIE CAS CSCD 2008年第4期415-417,共3页
BACKGROUND: The effectiveness of gene therapy is closely related to the efficiency of vector transfection and expression. OBJECTIVE: This study was designed to transfect a human brain glioma cell line with recombina... BACKGROUND: The effectiveness of gene therapy is closely related to the efficiency of vector transfection and expression. OBJECTIVE: This study was designed to transfect a human brain glioma cell line with recombinant Vaccinia virus expressing the interleukin-2 (rVV-IL-2) gene, and to observe IL-2 expression and glioma cell proliferation potential after transfection. DESIGN: Experimental observation. SETTING: Department of Neurosurgery, Shenyang Military Area Command of Chinese PLA. MATERIALS: The rVV-IL-2 vectors were obtained through homologous recombination and screening in the Second Military Medical University of Chinese PLA. The human brain glioma cell line and IL-2-dependent cells were produced by the Second Military Medical University of Chinese PLA. Human IL-2 was produced by Genzyme Corporation. METHODS: At passage day l, Veto cells were amplified l ; 1 for virus and cells. A human brain glioma cell line was transfected using amplified Vaccinia viral vectors at varying multiplicities of infection (MOI). At 2, 4, 6, 8, 12, and 24 hours post-transfection, superuatant was collected to determine by MTT assay IL-2 expression levels in IL-2 dependent cells. The transfected and non-transfected cells were divided into 4 groups, namely MOI1 : 1, MOI 5 : 1, MOI 10 : 1, and control groups. MAIN OUTCOME MEASURES: IL-2 expression at different time points after transfection of human brain glioma cells with varying MOI of Vaccinia viral vectors; in vitro proliferation capacity of human brain glioma cells among the 4 groups. RESULTS: IL-2 expression was detectable 4 hours after Vaccinia viral vector transfection and reached 300 kU/L by 8 hours. There was no significant difference in the proliferating rate of human brain glioma cells among the 4 groups (P 〉 0.05). CONCLUSION: Vaccinia viral vectors can transfect human brain glioma cells in vitro and express high levels of IL-2. Vaccinia virus and high IL-2 expression do not influence the proliferation rate of human brain glioma cells in vitro. 展开更多
关键词 Vaccinia virus vector glioma cell proliferation potential in vitro INTERLEUKIN-2
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Comparison of Five Expression Vectors for the Ha Gene in Constructing a DNA Vaccine for H6N2 Influenza Virus in Chickens 被引量:1
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作者 Songhua Shan Trevor Ellis +2 位作者 John Edwards Stan Fenwick Ian Robertson 《Advances in Microbiology》 2016年第4期310-319,共10页
A number of eukaryotic expression vectors have been developed for use as DNA vaccines. They showed varying abilities to initiate immune responses;however, there is little data to indicate which of these vectors will b... A number of eukaryotic expression vectors have been developed for use as DNA vaccines. They showed varying abilities to initiate immune responses;however, there is little data to indicate which of these vectors will be the most useful and practical for DNA vaccines in different species. This report examines the use of five expression vectors with different promoters and Kozak sequence to express the same hemagglutinin (HA) protein of an H6N2 avian influenza virus for DNA vaccination in chickens. Although intramuscular vaccination with seven DNA constructs elicited no or limited measurable H6 HA antibody responses in Hy-Line chickens, variable reduction in virus shedding for either oropharyngeal or cloacal swabs post-virus challenge were observed. This indicated that all DNA constructs generated some levels of protective immunity against homologous virus challenge. Interestingly, lower dose (50 or 100 μg) of plasmid DNAs consistently induced better immune response than higher dose (300 or 500 μg). In the transfection experiments there appeared to be a hierarchy in the in vitro expression efficiency in the order of pCAG-optiHAk/ pCAG-HAk > pCI-HAk > VR-HA > pCI-HA > pCI-neo-HA > pVAX-HA. Since the level of in vitro expression correlates with the level of immune response in vivo, in vitro expression levels of the DNA constructs can be used as an indicator for pre-selection of plasmid vaccines prior to in vivo assessment. Moreover, our results suggested that the Kozak sequence could be used as an effective tool for DNA vaccine design. 展开更多
关键词 DNA Vaccine Multiple Expressing vectors H6N2 Avian Influenza a Virus CHICKENS
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Construction and identification of a retroviral vector of bcl-2 mRNA-cleaving ribozyme gene
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作者 赵永同 朱峰 王成济 《Journal of Medical Colleges of PLA(China)》 CAS 1997年第3期227-230,共4页
The bcl-2 mRNA-cleaving ribozyme (RZ) gene was synthesized with EcoRI and BamHI sites, each on one of the terminals. The synthesized gene was cloned to the HincII site of the plasmid pGEM-3Zf(-) and the recombinant pl... The bcl-2 mRNA-cleaving ribozyme (RZ) gene was synthesized with EcoRI and BamHI sites, each on one of the terminals. The synthesized gene was cloned to the HincII site of the plasmid pGEM-3Zf(-) and the recombinant plasmid was termed 3ZRZ (+)/(-). The gene was sequenced and found to be correct, and was used for in vitro transcription and in vitro cleaving of bcl-2 mRNA. The RZ gene was cut out from the plasmid and subcloned in a retroviral vector pDOR-neo at the BamHI and EcoRI sites, and the new recombinant retroviral vector was named pDOR-RZ. 展开更多
关键词 BCL-2 RNA catalytic RETROVIRAL vector
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