期刊文献+
共找到146篇文章
< 1 2 8 >
每页显示 20 50 100
dbSCI:A manually curated database of SARS-CoV-2 inhibitors for COVID-19 被引量:1
1
作者 QIANG WANG GUO ZHAO +6 位作者 LONGXIANG XIE XUAN LI XIXI YU QIONGSHAN LI BAOPING ZHENG ZULIPINUER WUSIMAN XIANGQIAN GUO 《BIOCELL》 SCIE 2023年第2期367-371,共5页
Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is the pathogen of the ongoing coronavirus disease 2019(COVID-19)global pandemic.Here,by centralizing published cell-based experiments,clinical trials,and vir... Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is the pathogen of the ongoing coronavirus disease 2019(COVID-19)global pandemic.Here,by centralizing published cell-based experiments,clinical trials,and virtual drug screening data from the NCBI PubMed database,we developed a database of SARS-CoV-2 inhibitors for COVID-19,dbSCI,which includes 234 SARS-CoV-2 inhibitors collected from publications based on cell-based experiments,81 drugs of COVID-19 in clinical trials and 1305 potential SARS-CoV-2 inhibitors from bioinformatics analyses.dbSCI provides four major functions:(1)search the drug target or its inhibitor for SARS-CoV-2,(2)browse target/inhibitor information collected from cell experiments,clinical trials,and virtual drug screenings,(3)download,and(4)submit data.Each entry in dbSCI contains 18 types of information,including inhibitor/drug name,targeting protein,mechanism of inhibition,experimental technique,experimental sample type,and reference information.In summary,dbSCI provides a relatively comprehensive,credible repository for inhibitors/drugs against SARS-CoV-2 and their potential targeting mechanisms and it will be valuable for further studies to control COVID-19. 展开更多
关键词 SARS-CoV-2 COVID-19 INHIBITORS DRUGS database
暂未订购
Data Integration Strategy for Database Grids Based on P2P Framework 被引量:1
2
作者 WANG Guangqi SHEN Derong YU Ge ZHOU Wensheng LI Meifang 《Wuhan University Journal of Natural Sciences》 CAS 2006年第5期1182-1186,共5页
The differences between the data integration of a dynamic database grid (DBG) and that of a distributed database system are analyzed, and three kinds of data integration strategies are given on the background of DBG... The differences between the data integration of a dynamic database grid (DBG) and that of a distributed database system are analyzed, and three kinds of data integration strategies are given on the background of DBG based on Peer to Peer (P2P) framework, including the centralized data integration (CDI) strategy, the distributed data integration (DDI) strategy and the filter-based data integration (FDDI) strategy. CDI calls all the database grid services (DGSs) at a single node, DDI disperses the DGSs to multiple nodes, while FDDI schedules the data integration nodes based on filtering the keywords returned from DGSs. The performance of these three integration strategies are compared with and analyzed by simulation experiments. FDDI is more evident for filtering the keywords with data redundancy increasing. Through the reduction of large amount of data transportation, it effectively shortens the executing time for the task and improves its efficiency. 展开更多
关键词 database grid dada integration Peer to Peer (P2P)
在线阅读 下载PDF
Targeted screening and profiling of massive components of colistimethate sodium by two-dimensional-liquid chromatography-mass spectrometry based on self-constructed compound database
3
作者 Xuan Li Minwen Huang +11 位作者 Yue-Mei Zhao Wenxin Liu Nan Hu Jie Zhou Zi-Yi Wang Sheng Tang Jian-Bin Pan Hian Kee Lee Yao-zuo Yuan Taijun Hang Hai-Wei Shi Hongyuan Chen 《Journal of Pharmaceutical Analysis》 2025年第2期401-410,共10页
In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics.Similarities and variations of components present significant analytical challenges.A two-dimensional(2... In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics.Similarities and variations of components present significant analytical challenges.A two-dimensional(2D)liquid chromatography-mass spectrometry(LC-MS)method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium(CMS).A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated.For efficient and high-accuracy screening of CMS,a targeted method based on a self-constructed high resolution(HR)mass spectrum database of CMS components was established.The database was built based on the commercial MassHunter Personal Compound Database and Library(PCDL)software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening.On this basis,the unknown peaks in the CMS chromatograms were deduced and assigned.The molecular formula,group composition,and origins of a total of 99 compounds,of which the combined area percentage accounted for more than 95%of CMS components,were deduced by this 2D-LC-MS method combined with the MassHunter PCDL.This profiling method was highly efficient and could distinguish hundreds of components within 3 h,providing reliable results for quality control of this kind of complex drugs. 展开更多
关键词 Colistimethate sodium 2D-LC-MS PROFILING Targeted screening Component deduction database
在线阅读 下载PDF
Meta-analysis of CO_(2) conversion,energy efficiency,and other performance data of plasma-catalysis reactors with the open access PIONEER database 被引量:1
4
作者 Antoine Salden Maik Budde +28 位作者 Carolina A.Garcia-Soto Omar Biondo Jairo Barauna Marzia Faedda Beatrice Musig ChloéFromentin Minh Nguyen-Quang Harry Philpott Golshid Hasrack Domenico Aceto Yuxiang Cai Federico Azzolina Jury Annemie Bogaerts Patrick Da Costa Richard Engeln María Elena Gálvez Timo Gans Tomas Garcia Vasco Guerra Carlos Henriques Monika Motak Maria Victoria Navarro Vasile I.Parvulescu Gerard Van Rooij Bogdan Samojeden Ana Sobota Paolo Tosi Xin Tu Olivier Guaitella 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第11期318-342,I0007,共26页
This paper brings the comparison of performances of CO_(2)conversion by plasma and plasma-assisted catalysis based on the data collected from literature in this field,organised in an open access online database.This t... This paper brings the comparison of performances of CO_(2)conversion by plasma and plasma-assisted catalysis based on the data collected from literature in this field,organised in an open access online database.This tool is open to all users to carry out their own analyses,but also to contributors who wish to add their data to the database in order to improve the relevance of the comparisons made,and ultimately to improve the efficiency of CO_(2)conversion by plasma-catalysis.The creation of this database and database user interface is motivated by the fact that plasma-catalysis is a fast-growing field for all CO_(2)conversion processes,be it methanation,dry reforming of methane,methanolisation,or others.As a result of this rapid increase,there is a need for a set of standard procedures to rigorously compare performances of different systems.However,this is currently not possible because the fundamental mechanisms of plasma-catalysis are still too poorly understood to define these standard procedures.Fortunately however,the accumulated data within the CO_(2)plasma-catalysis community has become large enough to warrant so-called“big data”studies more familiar in the fields of medicine and the social sciences.To enable comparisons between multiple data sets and make future research more effective,this work proposes the first database on CO_(2)conversion performances by plasma-catalysis open to the whole community.This database has been initiated in the framework of a H_(2)0_(2)0 European project and is called the“PIONEER Data Base”.The database gathers a large amount of CO_(2)conversion performance data such as conversion rate,energy efficiency,and selectivity for numerous plasma sources coupled with or without a catalyst.Each data set is associated with metadata describing the gas mixture,the plasma source,the nature of the catalyst,and the form of coupling with the plasma.Beyond the database itself,a data extraction tool with direct visualisation features or advanced filtering functionalities has been developed and is available online to the public.The simple and fast visualisation of the state of the art puts new results into context,identifies literal gaps in data,and consequently points towards promising research routes.More advanced data extraction illustrates the impact that the database can have in the understanding of plasma-catalyst coupling.Lessons learned from the review of a large amount of literature during the setup of the database lead to best practice advice to increase comparability between future CO_(2)plasma-catalytic studies.Finally,the community is strongly encouraged to contribute to the database not only to increase the visibility of their data but also the relevance of the comparisons allowed by this tool. 展开更多
关键词 Open-access database on plasma-catalysis experiment CO_(2) conversion PLASMA-CATALYSIS Carbon capture and utilisation(CCU) Energy efficiency Specific energy input Dielectric barrier discharge Packed bed reactor METHANATION Dry reforming of methane
在线阅读 下载PDF
全球CO_(2)地质封存案例库选址决策平台研究及应用
5
作者 周银邦 王锐 +2 位作者 甄艳 代全齐 程传捷 《煤田地质与勘探》 北大核心 2026年第1期52-62,共11页
【目的】在“双碳”战略背景下,推进CO_(2)地质封存规模化部署亟需解决“封哪里”的核心问题。建立全球CO_(2)地质封存案例库与决策平台,可为选址工作提供关键数据支撑与历史经验借鉴,有效降低封存风险与成本,加速产业布局,并为相关政... 【目的】在“双碳”战略背景下,推进CO_(2)地质封存规模化部署亟需解决“封哪里”的核心问题。建立全球CO_(2)地质封存案例库与决策平台,可为选址工作提供关键数据支撑与历史经验借鉴,有效降低封存风险与成本,加速产业布局,并为相关政策制定与技术研发提供科学依据。【方法】提出并建立了一个综合的CO_(2)地质封存选址评估系统。该系统集成三项核心技术:基于改进余弦相似度的案例类比算法、依托模糊综合评价的适宜度评估模型,以及结合三维地质模型的有利地质体优选方法。通过构建定量化案例库并关联多源参数,建立了统一的空间数据库模型,并基于ArcGIS平台开发了集“案例比选-适宜度评价-地质体优选”于一体的系列功能模块,形成了系统的选址技术支撑体系。【结果和结论】基于该框架,研发了一套融合改进余弦相似度算法、随机森林适宜度评估模型及三维地质建模的封存靶区定量优选的决策平台。该平台通过算法驱动对全数据体进行系统扫描,提升了从定性经验到定量分析的案例匹配精度与地质体评价客观性,有效克服了传统人工方法的主观偏差与视野局限。平台实现了对背斜、断块等各类圈闭的统一量化评价与分级排序,大幅提高了封存体识别效率与结果可比性。以苏北盆地高邮凹陷为例的实践应用表明,该平台能为CO_(2)封存选址提供精准、高效且可直接支撑决策的数字化方案,有力增强了规模化封存部署的科学性与前瞻性。 展开更多
关键词 CO_(2)地质封存 CCUS案例库 余弦相似度 适宜度评价 有利地质体
在线阅读 下载PDF
Type-2 Neutrosophic Set and Their Applications in Medical Databases Deadlock Resolution
6
作者 Marwan H.Hassan Saad M.Darwish Saleh M.Elkaffas 《Computers, Materials & Continua》 SCIE EI 2023年第2期4417-4434,共18页
Electronic patient data gives many advantages,but also new difficulties.Deadlocks may delay procedures like acquiring patient information.Distributed deadlock resolution solutions introduce uncertainty due to inaccura... Electronic patient data gives many advantages,but also new difficulties.Deadlocks may delay procedures like acquiring patient information.Distributed deadlock resolution solutions introduce uncertainty due to inaccurate transaction properties.Soft computing-based solutions have been developed to solve this challenge.In a single framework,ambiguous,vague,incomplete,and inconsistent transaction attribute information has received minimal attention.The work presented in this paper employed type-2 neutrosophic logic,an extension of type-1 neutrosophic logic,to handle uncertainty in real-time deadlock-resolving systems.The proposed method is structured to reflect multiple types of knowledge and relations among transactions’features that include validation factor degree,slackness degree,degree of deadline-missed transaction based on the degree of membership of truthiness,degree ofmembership of indeterminacy,and degree ofmembership of falsity.Here,the footprint of uncertainty(FOU)for truth,indeterminacy,and falsity represents the level of uncertainty that exists in the value of a grade of membership.We employed a distributed real-time transaction processing simulator(DRTTPS)to conduct the simulations and conducted experiments using the benchmark Pima Indians diabetes dataset(PIDD).As the results showed,there is an increase in detection rate and a large drop in rollback rate when this new strategy is used.The performance of Type-2 neutrosophicbased resolution is better than the Type-1 neutrosophic-based approach on the execution ratio scale.The improvement rate has reached 10%to 20%,depending on the number of arrived transactions. 展开更多
关键词 Deadlock recovery type-2 neutrosophic set healthcare databases distributed deadlock detection
在线阅读 下载PDF
Databases of 2D material-substrate interfaces and 2D charged building blocks
7
作者 邓俊 潘金波 杜世萱 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期34-38,共5页
Discovery of materials using“bottom-up”or“top-down”approach is of great interest in materials science.Layered materials consisting of two-dimensional(2D)building blocks provide a good platform to explore new mater... Discovery of materials using“bottom-up”or“top-down”approach is of great interest in materials science.Layered materials consisting of two-dimensional(2D)building blocks provide a good platform to explore new materials in this respect.In van der Waals(vdW)layered materials,these building blocks are charge neutral and can be isolated from their bulk phase(top-down),but usually grow on substrate.In ionic layered materials,they are charged and usually cannot exist independently but can serve as motifs to construct new materials(bottom-up).In this paper,we introduce our recently constructed databases for 2D material-substrate interface(2DMSI),and 2D charged building blocks.For 2DMSI database,we systematically build a workflow to predict appropriate substrates and their geometries at substrates,and construct the 2DMSI database.For the 2D charged building block database,1208 entries from bulk material database are identified.Information of crystal structure,valence state,source,dimension and so on is provided for each entry with a json format.We also show its application in designing and searching for new functional layered materials.The 2DMSI database,building block database,and designed layered materials are available in Science Data Bank at https://doi.org/10.57760/sciencedb.j00113.00188. 展开更多
关键词 2D material-substrate interfaces charged building block database functional-oriented materials design layered materials density functional theory
原文传递
Analysis of E2F3 gene variants,expression and clinical significance in melanoma based on multiple databases
8
作者 HAN Li-min YE Gang +2 位作者 DENG Chuan DAI Jiao ZHAO Hai-long 《Journal of Hainan Medical University》 CAS 2023年第20期41-50,共10页
Objective:To investigate the variation,expression and clinical significance of E2F3 gene in melanoma.Methods:Firstly,cBioportal database,Oncomine database and GEO database were used to analyze the variation and expres... Objective:To investigate the variation,expression and clinical significance of E2F3 gene in melanoma.Methods:Firstly,cBioportal database,Oncomine database and GEO database were used to analyze the variation and expression level of E2F3 gene in melanoma.OSskcm database and TISIDB database were used to analyze the relationship between E2F3 and melanoma prognosis and tumor immune infiltrating cells.Then,the LinkedOmics database was used to identify the differential genes related to E2F3 expression in melanoma and analyze their biological functions.Finally,small molecule compounds for the treatment of melanoma were screened through the CMap database.Results:The mutation rate of E2F3 gene in melanoma is about 4%,and there are 21 mutation sites.Compared with normal skin tissues,the expression of E2F3 gene in melanoma was significantly increased(P<0.01).The mutation and increased expression of E2F3 gene were associated with the shortened overall survival(OS)of melanoma patients(P<0.05).The CNA level of E2F3 was negatively correlated with the expression levels of lymphocytes such as pDC,Neutrophil,Act DC and Th17,and negatively correlated with the expression levels of chemokines such as CXCL5,CCL13 and CCR1.The methylation level of E2F3 was positively correlated with the expression levels of Th1,Neutrophil,Act DC and other lymphocytes,and positively correlated with the expression levels of CXCL16,CXCL12,CCR1 and other chemokines.The expression level of E2F3 was negatively correlated with the expression levels of lymphocytes such as Th17,Tcm CD4 and Th1,and negatively correlated with the expression levels of chemokines such as CXCL 16,CCL 22 and CCL 2.The expression of 96 genes such as UHRF1BP1 in melanoma was significantly correlated with the expression of E2F3(|cor|0.5,P<0.05).The above genes were mainly related to RNA transport,eukaryotic ribosome biogenesis,cell cycle and other pathways.Among them,WDR12,WDR43,RBM28,UTP18,DKC1,PAK1IP1,DDX31,TEX10,TRUB1 and TRMT61B were the top 10 hub genes.YC-1,simvastatin,cytochalasin-d,Deforolimus and cytochalasin-b may be five small molecule compounds for the treatment of melanoma.Conclusion:The mutation and increased expression level of E2F3 gene are related to the poor prognosis of melanoma and participate in the occurrence and development of melanoma by affecting the expression of different tumor immune infiltrating cell subtypes,which may be a potential diagnostic marker and therapeutic target for melanoma. 展开更多
关键词 MELANOMA E2F3 database MUTATION Immune infiltration Prognosis
暂未订购
Application of Thermodynamic Database to Corrosion of ZrO_(2) Containing Submerged Entry Nozzle in Steel Continuous Casting Process
9
作者 In-Ho JUNG 《China's Refractories》 CAS 2024年第2期10-15,共6页
The CALPHAD thermodynamic databases are very useful to analyze the complex chemical reactions happening in high temperature material process.The FactSage thermodynamic database can be used to calculate complex phase d... The CALPHAD thermodynamic databases are very useful to analyze the complex chemical reactions happening in high temperature material process.The FactSage thermodynamic database can be used to calculate complex phase diagrams and equilibrium phases involving refractories in industrial process.In this study,the FactSage thermodynamic database relevant to ZrO_(2)-based refractories was reviewed and the application of the database to understanding the corrosion of continuous casting nozzle refractories in steelmaking was presented. 展开更多
关键词 thermodynamic database ZrO_(2)containing submerged entry nozzle continous casting
在线阅读 下载PDF
An Approach for Automatically Generating R2RML-Based Direct Mapping from Relational Databases
10
作者 Mohamed A.G. Hazber Ruixuan Li +1 位作者 Guandong Xu Khaled M. Alalayah 《国际计算机前沿大会会议论文集》 2016年第1期41-44,共4页
For integrating relational databases (RDBs) into semantic web applications, the W3C RDB2RDF Working Group recommended two approaches, Direct Mapping (DM) and R2RML. The DM provides a set of mapping rules according to ... For integrating relational databases (RDBs) into semantic web applications, the W3C RDB2RDF Working Group recommended two approaches, Direct Mapping (DM) and R2RML. The DM provides a set of mapping rules according to RDB schema, while the R2RML allows users to manually define mappings according to existing target ontology. The major problem to use R2RML is the effort for creating R2RML mapping documents manually. This may lead to appearance of many mistakes in the R2RML documents and requires domain experts. In this paper, we propose and implement an approach to generate an R2RML mapping documents automatically from RDB schema. The R2RML mapping reflects the behavior of the DM specification and allows any R2RML parser to generate a set of RDF triples from relational data.The input of generating approach is DBsInfo class that automatically generated from relational schema. An experimental prototype is developed and shows the effectiveness of our approach algorithms. 展开更多
关键词 RELATIONAL database to RESOURCE DESCRIPTION FRAMEWORK (RDB2RDF) Direct Mapping R2RML RELATIONAL database RESOURCE DESCRIPTION FRAMEWORK (RDF)
在线阅读 下载PDF
Unicenter Database Management for DB2 for z/OS v 8
11
作者 《软件世界》 2004年第5期95-95,共1页
关键词 数据库 事务处理 数据恢复 数据备份 UNICENTER database Management for DB2 for Z/OS V 8
在线阅读 下载PDF
MAD2L1和miR-28-5p在胃癌组织中的表达及临床意义
12
作者 崔广洁 刘袁明 +3 位作者 陈佳琪 陆杨 陶云霞 高超 《中国临床研究》 2026年第2期193-198,共6页
目的探讨胃癌组织中有丝分裂阻滞缺陷蛋白2同源蛋白1(MAD2L1)和微小RNA(miR)-28-5p的表达水平及其与胃癌患者临床病理特征的关系,以期为胃癌的早期诊断及治疗提供参考。方法从基因表达综合数据库(GEO)下载胃癌差异表达基因,确定MAD2L1... 目的探讨胃癌组织中有丝分裂阻滞缺陷蛋白2同源蛋白1(MAD2L1)和微小RNA(miR)-28-5p的表达水平及其与胃癌患者临床病理特征的关系,以期为胃癌的早期诊断及治疗提供参考。方法从基因表达综合数据库(GEO)下载胃癌差异表达基因,确定MAD2L1作为此次研究的靶基因。基于LinkedOmics网站,筛选MAD2L1相关miR,利用Targetscan验证MAD2L1与miR-28-5p有无靶向关系。收集2024年5月至11月徐州医科大学附属医院94例胃癌患者手术切除的肿瘤组织,同时获取距离肿瘤边缘5 cm及以上的对应癌旁组织。通过免疫组化和逆转录定量聚合酶链式反应(RT-qPCR)分别检测MAD2L1和miR-28-5p的表达水平,采用Spearman相关系数分析二者的相关性;通过χ^(2)检验分析MAD2L1和miR-28-5p的表达水平与胃癌患者临床病理特征之间的关系。结果生物信息学分析显示,在胃癌中,MAD2L1高表达,miR-28-5p低表达,MAD2L1与miR-28-5p具有靶向关系。免疫组化结果显示,胃癌组织中MAD2L1高表达率(56.38%)高于癌旁组织(39.36%)(χ^(2)=5.457,P<0.05)。RTqPCR结果显示,胃癌中miR-28-5p的表达水平(0.26±0.08)低于癌旁组织(1.14±0.53)(t=16.048,P<0.01)。胃癌组织中MAD2L1表达与miR-28-5p表达呈负相关(r=-0.369,P<0.01)。胃癌组织中MAD2L1表达与临床分期、淋巴结转移、分化程度、神经侵犯及脉管侵犯有关(P<0.05),miR-28-5p表达与分化程度有关(P<0.05)。结论MAD2L1和miR-28-5p表达与胃癌患者临床病理特征密切相关,两者可作为胃癌诊疗的潜在生物标志物。 展开更多
关键词 胃癌 有丝分裂阻滞缺陷蛋白2同源蛋白1 miR-28-5p 基因表达综合数据库 临床病理特征
原文传递
Effect of HITRAN Database Improvement on Retrievals of Atmospheric Carbon Dioxide from Reflected Sunlight Spectra in the 1.61-μm Spectral Window 被引量:1
13
作者 戴铁 石广玉 张兴赢 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2012年第2期227-235,共9页
A large number of experimental and theoretical investigations of carbon dioxide (CO 2 ) spectra have been conducted since the most recent update of the High-Resolution Transmission Molecular Absorption (HITRAN) da... A large number of experimental and theoretical investigations of carbon dioxide (CO 2 ) spectra have been conducted since the most recent update of the High-Resolution Transmission Molecular Absorption (HITRAN) database. To maintain optimal parameters, the HITRAN 2004 CO 2 line list has been completely replaced by HITRAN 2008 data in the near-infrared region from 4300 cm-1 to 7000 cm-1 . To examine the effect of this change on the retrieval of CO 2 vertical column data from reflected sunlight spectra in the 1.61-μm spectral window, synthetic measurements for a given atmospheric state and instrument setup were generated and compared using radiative transfer model with the line-transition parameters from the HITRAN 2004 and 2008 databases. Simulated retrievals were then performed based on the optimal estimation retrieval theory. The results show that large systematic errors in atmospheric CO 2 column retrievals were induced by the differences in the HITRAN laboratory line parameters in the 1.61-μm region. The retrieved CO 2 columns were underestimated by 10 ppm using the HITRAN 2004 data, and improvements resulting from the use of the improved HITRAN database were more pronounced at a higher spectral resolution. 展开更多
关键词 HITRAN database retrieval of CO 2 reflected sunlight spectra
在线阅读 下载PDF
A BiLSTM cardinality estimator in complex database systems based on attention mechanism 被引量:3
14
作者 Qiang Zhou Guoping Yang +6 位作者 Haiquan Song Jin Guo Yadong Zhang Shengjie Wei Lulu Qu Louis Alberto Gutierrez Shaojie Qiao 《CAAI Transactions on Intelligence Technology》 SCIE EI 2022年第3期537-546,共10页
An excellent cardinality estimation can make the query optimiser produce a good execution plan.Although there are some studies on cardinality estimation,the prediction results of existing cardinality estimators are in... An excellent cardinality estimation can make the query optimiser produce a good execution plan.Although there are some studies on cardinality estimation,the prediction results of existing cardinality estimators are inaccurate and the query efficiency cannot be guaranteed as well.In particular,they are difficult to accurately obtain the complex relationships between multiple tables in complex database systems.When dealing with complex queries,the existing cardinality estimators cannot achieve good results.In this study,a novel cardinality estimator is proposed.It uses the core techniques with the BiLSTM network structure and adds the attention mechanism.First,the columns involved in the query statements in the training set are sampled and compressed into bitmaps.Then,the Word2vec model is used to embed the word vectors about the query statements.Finally,the BiLSTM network and attention mechanism are employed to deal with word vectors.The proposed model takes into consideration not only the correlation between tables but also the processing of complex predicates.Extensive experiments and the evaluation of BiLSTM-Attention Cardinality Estimator(BACE)on the IMDB datasets are conducted.The results show that the deep learning model can significantly improve the quality of cardinality estimation,which is a vital role in query optimisation for complex databases. 展开更多
关键词 ATTENTION BiLSTM cardinality estimation complex database systems query optimiser Word2vec
在线阅读 下载PDF
面向HTTP/2流量多路复用特征的加密视频识别方法 被引量:2
15
作者 吴桦 罗浩 +3 位作者 赵士顺 刘嵩涛 程光 胡晓艳 《软件学报》 北大核心 2025年第7期3375-3404,共30页
视频应用平台的兴起使得视频得以快速传播并渗透社会生活的各个方面.网络中传播的视频也混杂了一些公害视频,因此网络空间安全监管迫切需要准确地识别网络中加密传播的公害视频.已有方法在网络主要接入点采集流量数据,提取加密视频流量... 视频应用平台的兴起使得视频得以快速传播并渗透社会生活的各个方面.网络中传播的视频也混杂了一些公害视频,因此网络空间安全监管迫切需要准确地识别网络中加密传播的公害视频.已有方法在网络主要接入点采集流量数据,提取加密视频流量的特征,基于公害视频库,通过流量特征的匹配识别出被传输的公害视频.然而随着视频加密传输协议的更新,使用新型多路复用技术的HTTP/2协议已经大规模部署应用,这导致传统的基于HTTP/1.1传输特征的流量分析方法无法识别使用HTTP/2传输的加密视频.此外,当前的研究大多针对的是播放时分辨率固定的视频,很少考虑到流媒体自适应播放时分辨率切换给识别带来的影响.针对以上问题,详细分析了视频平台使用HTTP/2协议传输视频时音视频数据长度发生偏移的原理,并提出了将多路复用的加密数据精准修正还原为组合音视频数据单元长度的方法,从而构建出精准还原的加密视频修正指纹.然后,利用加密视频修正指纹和大型视频明文指纹库,提出了视频修正指纹滑动匹配机制和以隐马尔可夫模型与维特比算法为基础的加密视频识别模型.该模型使用动态规划方法解决了视频分辨率自适应切换带来的问题,其在40万级的Facebook和Instagram真实指纹库场景中,对固定分辨率和自适应分辨率的加密视频的识别准确率分别达到了98.41%和97.91%.使用Triller、Twitter和芒果TV这3个视频平台进行了方法通用性和泛化性验证.与类似工作在识别效果、泛化性和时间开销方面的比较进一步验证了所提出的方法具有较高的应用价值. 展开更多
关键词 HTTP/2 DASH 大型数据集 修正指纹 HMM 加密视频识别
在线阅读 下载PDF
Stochastic simulation of ground motions based on NGA-West2 strong motion records
16
作者 Peng Tian Xiaodan Sun +1 位作者 Xin Li Keyu Wan 《Earthquake Science》 2019年第3期115-124,共10页
Stochastic modeling of ground motion is a simple tool to predict ground shaking level for future earthquake and less time consuming than physics-based deterministic modeling.In this paper,a record-based stochastic met... Stochastic modeling of ground motion is a simple tool to predict ground shaking level for future earthquake and less time consuming than physics-based deterministic modeling.In this paper,a record-based stochastic method that considers the time-and frequency-evolution of ground motion is used to estimate ground motion for scenario earthquakes in tectonic active region.The stochastic method employs a time-domain modulation function to describe the temporal nonstationarity and a filter impulse response function that describe the evolution of frequency content.For characterizing the modulation function and the filter impulse function,six parameters(Ia,D5-95,tmid,ωmid,ω',ξf)are defined,and 2,571 pairs of ground motion recording in the NGA-west2 database are selected to identify the six parameters.Probabilistic density function is assigned to each of the parameter by fitting the frequency distribution histogram.The parameters are then transformed into standard normal space where regression analysis is performed by considering each parameter as function of moment magnitude,rupture distance,vS30(The time-averaged shear wave velocity of the top 30 m of soil).The prediction equations are used to generate ground motions for several scenario earthquakes and compared to NGA-West2 GMPEs. 展开更多
关键词 stochastic modeling nonstationarity scenario earthquake nga-west2
在线阅读 下载PDF
利用癌症基因组图谱数据库分析miR-181a-2-3p在胃癌中的表达及预后意义
17
作者 王心平 郑侠 +1 位作者 韩玉洁 姜超 《现代医药卫生》 2025年第5期1057-1061,1066,共6页
目的探讨微小RNA-181a-2-3p(miR-181a-2-3p)在胃癌(GC)中的表达和预后预测价值。方法利用癌症基因组图谱数据库,从中筛选出GC患者的人口学、临床病理学、生存结局和miRNA测序数据,共纳入GC患者446例。采用配对样本t检验分析miR-181a-2-3... 目的探讨微小RNA-181a-2-3p(miR-181a-2-3p)在胃癌(GC)中的表达和预后预测价值。方法利用癌症基因组图谱数据库,从中筛选出GC患者的人口学、临床病理学、生存结局和miRNA测序数据,共纳入GC患者446例。采用配对样本t检验分析miR-181a-2-3p在GC组织和癌旁组织中的表达差异,绘制受试者工作特征曲线评估miR-181a-2-3p的诊断价值;采用Kaplan-Meier生存曲线比较不同miR-181a-2-3p表达水平患者无进展时间(PFI)和总生存期(OS)的差异,单因素和多因素COX回归分析筛选、预测PFI、OS的预后因子;利用基因本体和京都基因与基因组百科全书对miR-181a-2-3p潜在靶基因进行功能和信号通路富集分析。结果GC组织中miR-181a-2-3p表达水平(中位8.70)明显高于癌旁组织(中位7.97),差异有统计学意义(P<0.05)。miR-181a-2-3p对GC具有较好的诊断价值(ROC曲线下面积为0.748,95%可信区间0.689~0.808)。miR-181a-2-3p高表达患者PFI(中位25.5个月)、OS(中位20.3个月)均明显短于低表达者(中位分别为55.0、42.4个月),差异均有统计学意义(P<0.05)。miR-181a-2-3p是影响患者PFI、OS的独立预后因子之一(危害比=1.856、1.788,95%可信区间1.137~3.030、1.061~3.014,P=0.013、0.029)。miR-181a-2-3p靶基因的功能主要富集于调控细胞衰亡。结论GC组织miR-181a-2-3p明显高表达,与患者预后不良密切相关,可作为诊断GC和判断患者预后的生物标志物,其生物学功能主要与细胞衰亡相关。 展开更多
关键词 胃肿瘤 微小RNA-181a-2-3p 预后 表达 癌症基因图谱数据库
暂未订购
膳食类胡萝卜素摄入量与2型糖尿病的关系
18
作者 王思璐 王彦 +2 位作者 王煜增 谷婷钰 关兆娟 《山西医科大学学报》 2025年第8期945-953,共9页
目的 采用横断面分析和两样本孟德尔随机化(MR)探究类胡萝卜素摄入量与2型糖尿病(T2DM)的关系,为T2DM的预防提供新思路。方法 在横断面研究中,纳入NHANES数据库2007—2018年收录的17 384名成年人群,分为T2DM组和非T2DM组,通过多因素logi... 目的 采用横断面分析和两样本孟德尔随机化(MR)探究类胡萝卜素摄入量与2型糖尿病(T2DM)的关系,为T2DM的预防提供新思路。方法 在横断面研究中,纳入NHANES数据库2007—2018年收录的17 384名成年人群,分为T2DM组和非T2DM组,通过多因素logistic回归分析类胡萝卜素摄入量对T2DM的影响,并构建广义相加模型(GAM)和限制性立方样条图(RCS)以明确类胡萝卜素摄入量与T2DM的剂量-反应关系。在两样本MR分析中,以逆方差加权法(IVW)作为评估因果效应的主要方法,以MR-Egger回归、加权中位数法(WM)、简单中位数法(SM)和加权中值法作为补充,评估胡萝卜素摄入量与T2DM的因果关系,采用Cochran′Q检验、MR-Egger截距法、“留一法”和漏斗图进行敏感性分析。结果 横断面研究中共检出T2DM患者3 966名(22.83%)。多因素logistic回归分析显示,类胡萝卜素摄入量与T2DM呈负相关趋势(P<0.05);GAM和RCS分析显示,类胡萝卜素摄入量与T2DM呈非线性关系(P非线性<0.05),且当类胡萝卜素每日摄入量超过4 885μg/1 000 kcal时可能对T2DM具有保护作用。MR分析中共纳入10个与胡萝卜素摄入量相关的单核苷酸多态性(SNPs)作为工具变量,IVW分析显示类胡萝卜素摄入量与T2DM之间存在负向因果关联(P=0.002),加权中位数法(P=0.028)也支持该结果;异质性检验、MR-Egger截距法、“留一法”和漏斗图结果均表明MR分析结果可靠。结论 类胡萝卜素摄入量与T2DM存在一定的因果关系,合理增加类胡萝卜素摄入有助于降低T2DM的发生。 展开更多
关键词 类胡萝卜素 摄入量 2型糖尿病 NHANES数据库 横断面研究 孟德尔随机化 因果关系
暂未订购
基于FAERS数据库的钠-葡萄糖共转运蛋白2抑制剂与骨折及关节炎事件关联性分析
19
作者 周丽敏 谢保城 徐永祥 《中国医院药学杂志》 北大核心 2025年第13期1519-1523,1546,共6页
目的:挖掘与分析钠-葡萄糖共转运蛋白2抑制剂(sodium-glucose co-transporter 2 inhibitors,SGLT2i)与骨折及关节炎事件的关联性,为临床安全用药提供参考。方法:采用Open Vigil FDA分析工具提取美国食品药品管理局不良事件报告系统(FAE... 目的:挖掘与分析钠-葡萄糖共转运蛋白2抑制剂(sodium-glucose co-transporter 2 inhibitors,SGLT2i)与骨折及关节炎事件的关联性,为临床安全用药提供参考。方法:采用Open Vigil FDA分析工具提取美国食品药品管理局不良事件报告系统(FAERS)数据库中SGLT2i相关骨折及关节炎事件报告。提取时间范围为2004年1月1日至2024年8月31日。采用报告比值比法检测风险信号并评估潜在关联性。结果:共检索到SGLT2i相关骨折事件报告845份(达格列净271份,恩格列净385份、卡格列净184份、艾托格列净5份),关节炎事件报告1 098份(达格列净296份,恩格列净481份、卡格列净319份、艾托格列净2份),其中恒格列净和加格列净无相关报告。总体分析结果显示,骨折及关节炎事件在达格列净、恩格列净、卡格列净和艾托格列净中均未形成风险信号。根据骨折部位进行的亚组分析显示,恩格列净在股骨颈骨折事件中生成风险信号。根据关节炎类型进行的亚组分析显示,卡格列净在银屑病关节炎和细菌性关节炎事件中生成风险信号。结论:SGLT2i与骨折及关节炎事件总体上无显著相关性。恩格列净可能与股骨颈骨折事件存在关联,而卡格列净可能与银屑病关节炎、细菌性关节炎事件相关,但仍需进一步研究加以验证。 展开更多
关键词 钠-葡萄糖共转运蛋白2抑制剂 骨折 关节炎 药物不良事件 FAERS数据库
原文传递
膳食炎症指数与老年2型糖尿病肌少症的关联
20
作者 裔华 吴进 +1 位作者 陈晓艳 洪克霞 《东南大学学报(医学版)》 2025年第6期966-973,共8页
目的:基于美国国家健康与营养调查(NHANES)数据库分析膳食炎症指数(DII)与老年2型糖尿病(T2DM)肌少症的关联,以期为老年T2DM肌少症的临床防治提供参考。方法:本研究提取美国NHANES数据库1999—2020年的数据进行分析。收集参与者的一般... 目的:基于美国国家健康与营养调查(NHANES)数据库分析膳食炎症指数(DII)与老年2型糖尿病(T2DM)肌少症的关联,以期为老年T2DM肌少症的临床防治提供参考。方法:本研究提取美国NHANES数据库1999—2020年的数据进行分析。收集参与者的一般资料、血液学指标、DII、肌少症等数据。按DII四分位数将老年T2DM患者分为DII Q1组(DII<0.448,n=251)、DII Q2组(0.448≤DII<1.891,n=249)、DII Q3组(1.891≤DII<2.879,n=250)、DII Q4组(DII≥2.879,n=251)。比较不同DII分组的种族、肌少症患病率等的差异。采用Logistic回归分析DII与老年T2DM肌少症的关系,并行趋势分析和亚组分析。采用限制性立方样条图(RCS)分析DII与老年T2DM肌少症的非线性关系。结果:共纳入1001例老年T2DM患者,肌少症患病率为34.07%(341/1001)。不同DII分组老年T2DM患者的种族构成、性别构成、教育水平、饮酒比例、贫困指数、C反应蛋白水平,差异有统计学意义(P<0.05)。Logistic分析显示,校正后DII每增高1,肌少症风险增高0.671倍(OR=1.671,95%CI:1.179~2.368,P<0.05);相较DII Q1组,DII Q3组(OR=2.049,95%CI:1.362~3.101)、DII Q4组(OR=3.082,95%CI:2.042~4.651)老年T2DM患者患肌少症的风险增高1.049倍和2.082倍(P<0.05)。且在2个模型中,DII Q1、Q2、Q3、Q4组老年T2DM患者患肌少症的风险OR均呈增加趋势(P_(趋势)<0.05)。亚组分析显示,在不同种族、年龄、性别和饮酒情况的老年T2DM患者中,DII与肌少症风险关系基本一致,且DII与种族、年龄、性别和饮酒情况均不存在交互作用(P_(交互)>0.05)。RCS分析显示,在老年T2DM患者中,DII与肌少症风险呈负对数型曲线(P_(非线性)=0.041)。结论:在老年T2DM患者中,DII与肌少症风险呈负对数型曲线,随DII增加,老年T2DM肌少症的风险呈非线性增高趋势。 展开更多
关键词 2型糖尿病 肌少症 膳食炎症指数 NHANES数据库 老年
暂未订购
上一页 1 2 8 下一页 到第
使用帮助 返回顶部