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Enhancing Hyper-Spectral Image Classification with Reinforcement Learning and Advanced Multi-Objective Binary Grey Wolf Optimization
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作者 Mehrdad Shoeibi Mohammad Mehdi Sharifi Nevisi +3 位作者 Reza Salehi Diego Martín Zahra Halimi Sahba Baniasadi 《Computers, Materials & Continua》 SCIE EI 2024年第6期3469-3493,共25页
Hyperspectral(HS)image classification plays a crucial role in numerous areas including remote sensing(RS),agriculture,and the monitoring of the environment.Optimal band selection in HS images is crucial for improving ... Hyperspectral(HS)image classification plays a crucial role in numerous areas including remote sensing(RS),agriculture,and the monitoring of the environment.Optimal band selection in HS images is crucial for improving the efficiency and accuracy of image classification.This process involves selecting the most informative spectral bands,which leads to a reduction in data volume.Focusing on these key bands also enhances the accuracy of classification algorithms,as redundant or irrelevant bands,which can introduce noise and lower model performance,are excluded.In this paper,we propose an approach for HS image classification using deep Q learning(DQL)and a novel multi-objective binary grey wolf optimizer(MOBGWO).We investigate the MOBGWO for optimal band selection to further enhance the accuracy of HS image classification.In the suggested MOBGWO,a new sigmoid function is introduced as a transfer function to modify the wolves’position.The primary objective of this classification is to reduce the number of bands while maximizing classification accuracy.To evaluate the effectiveness of our approach,we conducted experiments on publicly available HS image datasets,including Pavia University,Washington Mall,and Indian Pines datasets.We compared the performance of our proposed method with several state-of-the-art deep learning(DL)and machine learning(ML)algorithms,including long short-term memory(LSTM),deep neural network(DNN),recurrent neural network(RNN),support vector machine(SVM),and random forest(RF).Our experimental results demonstrate that the Hybrid MOBGWO-DQL significantly improves classification accuracy compared to traditional optimization and DL techniques.MOBGWO-DQL shows greater accuracy in classifying most categories in both datasets used.For the Indian Pine dataset,the MOBGWO-DQL architecture achieved a kappa coefficient(KC)of 97.68%and an overall accuracy(OA)of 94.32%.This was accompanied by the lowest root mean square error(RMSE)of 0.94,indicating very precise predictions with minimal error.In the case of the Pavia University dataset,the MOBGWO-DQL model demonstrated outstanding performance with the highest KC of 98.72%and an impressive OA of 96.01%.It also recorded the lowest RMSE at 0.63,reinforcing its accuracy in predictions.The results clearly demonstrate that the proposed MOBGWO-DQL architecture not only reaches a highly accurate model more quickly but also maintains superior performance throughout the training process. 展开更多
关键词 Hyperspectral image classification reinforcement learning multi-objective binary grey wolf optimizer band selection
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Non-Linear Matrix Completion
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作者 Fengrui Zhang Randy C. Paffenroth David Worth 《Journal of Data Analysis and Information Processing》 2024年第1期115-137,共23页
Current methods for predicting missing values in datasets often rely on simplistic approaches such as taking median value of attributes, limiting their applicability. Real-world observations can be diverse, taking sto... Current methods for predicting missing values in datasets often rely on simplistic approaches such as taking median value of attributes, limiting their applicability. Real-world observations can be diverse, taking stock price as example, ranging from prices post-IPO to values before a company’s collapse, or instances where certain data points are missing due to stock suspension. In this paper, we propose a novel approach using Nonlinear Matrix Completion (NIMC) and Deep Matrix Completion (DIMC) to predict associations, and conduct experiment on financial data between dates and stocks. Our method leverages various types of stock observations to capture latent factors explaining the observed date-stock associations. Notably, our approach is nonlinear, making it suitable for datasets with nonlinear structures, such as the Russell 3000. Unlike traditional methods that may suffer from information loss, NIMC and DIMC maintain nearly complete information, especially in high-dimensional parameters. We compared our approach with state-of-the-art linear methods, including Inductive Matrix Completion, Nonlinear Inductive Matrix Completion, and Deep Inductive Matrix Completion. Our findings show that the nonlinear matrix completion method is particularly effective for handling nonlinear structured data, as exemplified by the Russell 3000. Additionally, we validate the information loss of the three methods across different dimensionalities. 展开更多
关键词 Matrix Completion Data Pipeline Machine Learning
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Investigating the Air Quality Parameters in Louisiana’s Industrial Corridor: A Baton Rouge Case Study
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作者 Oluwafemi Awolesi Peter G. Oni +5 位作者 Oluwatoyin K. Adekoya Seyi B. Adekoya Oluwafeyikemi D. Ogunmusi Fatemeh Ghafari Abosede Oje Odunayo Lawal 《Journal of Geoscience and Environment Protection》 2024年第7期139-164,共26页
In a local context, sustainable development entails utilizing the current resources—material and immaterial, measurable and immeasurable, popular and unpopular—of the community in a manner that avoids overexploitati... In a local context, sustainable development entails utilizing the current resources—material and immaterial, measurable and immeasurable, popular and unpopular—of the community in a manner that avoids overexploitation and ensures intergenerational equity. This approach prioritizes the safety and health of local citizens, placing communal productivity above corporate profitability. This research aims to assess air quality surrounding 28 chemical industry sites in Baton Rouge, Louisiana, to understand the environmental and health impacts of industrial pollutants, with a focus on environmental justice. Air quality pollutants, including PM2.5, PM10, O3, NO2, CO, and SO2, were monitored for 75 days during the Summer, using the BreezoMeter app. Python, Mapize, and QGIS software technologies were utilized for data analysis and visualization. Findings indicate a reduction in NO2 and CO levels, compared to existing literature. However, the persistent challenge of particulate matter suggests areas for further environmental management efforts. Additionally, the research suggests a significant disparity in air pollution exposure, probably affecting marginalized communities. Although the nature of the study might not fully capture annual pollution trends, the findings highlight the urgent need for the chemical industry to adopt efficient production methods and for policymakers to enhance air quality standards and enforcement, particularly in pollution-sensitive areas. The disproportionate impact of air pollution on vulnerable communities calls for a more inclusive approach to environmental justice, ensuring equitable distribution of clean air benefits and community involvement in pollution management decisions. 展开更多
关键词 Air Quality Monitoring Chemical Industry Pollution Environmental Justice Health Implications Particulate Matter Case Study
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Introduction to the Special Issue on Blockchain Security
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作者 Zhihong Tian Yanhui Guo +1 位作者 Shen Su Hui Lu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第1期5-7,共3页
Motivated by the fast evolvement of blockchain technology,cloud-edge platforms,intelligent transportation systems,smart grid,vehicular networks,location based services,and other IoT applications have achieved signific... Motivated by the fast evolvement of blockchain technology,cloud-edge platforms,intelligent transportation systems,smart grid,vehicular networks,location based services,and other IoT applications have achieved significant breakthrough during recent years.Nowadays,blockchain based researches and projects are super-hot topics and focuses for both research and industrial communities.However,most of the current blockchain projects still suffer from insufficient security concerns.The defects of the underlying protocol make the node communication vulnerable to be hijacked,and further exacerbate the fork problem;smart contracts can hardly be fully tested before deployment because of the evolving blockchain platforms,while the smart contracts updating is impossible(or very complicated);current data privacy protection techniques are either inefficient or inaccurate;sharing and cross-chain schemes brought new security problems together with its TPS promotion.The intrinsic security vulnerabilities make the current blockchain based systems and architectures prone to be assaulted,and further do harm to the confidence of the investment on the blockchain industrial.Worse still,blockchain turns out to play a critical role in a lot of existing security solutions,which would be useless if the blockchain is insecure. 展开更多
关键词 SERVICES SMART BREAKTHROUGH
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PFAS: Ecological Implications, Remedial Actions and Ethical Considerations
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作者 Oluwafemi Awolesi Peter Oni +7 位作者 Abiodun Oshinowo Boluwatife S. Olubusoye Faustina Owusu Simeon Pama Sunday Temitope Osobamiro Acaye Ongwech Omotoyosi Awolesi Beatrice Arwenyo 《Health》 2023年第3期306-334,共29页
The C-F bond is one of the strongest in organic chemistry. It is responsible for the great stability of perfluoroalkyl and polyfluoroalkyl substances, commonly referred to as “PFAS”, a group of man-made chemicals th... The C-F bond is one of the strongest in organic chemistry. It is responsible for the great stability of perfluoroalkyl and polyfluoroalkyl substances, commonly referred to as “PFAS”, a group of man-made chemicals that include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). Thermal stability, surface activity, dielectric characteristics, chemical resistance, and inertness are just a few of the technical advantages that this group has over hydrocarbons, and since the 1950s, these chemicals have been largely utilized in a variety of domestic and industrial endeavors. The hydrophilic and lipophilic nature of this class of chemicals accounts for its uniqueness. Up until today, the chemistry and ecotoxicology of these chemicals continue to emerge. Issues concerning the destructive power of ignorance expedited by an ineffective regulatory institution continue to show that manufacturing chemicals are insufficient without giving serious thought to issues of openness and humanity’s awareness of its own safety. When discussing the nature of humanity and how it can be defined or redefined, it is important to allude to the significance of integrating business with ethics in its various forms. This paper highlights the importance of holding polluters accountable for PFAS contamination cleanup costs while emphasizing the need for chemical manufacturers to test and disclose the health and environmental effects of PFAS compounds. In addition, the sources, types, properties, applications, distribution, toxicological implications, regulations, and analytical methods associated with PFAS (per- and polyfluoroalkyl substances) are explored. The effectiveness of the remedial methods described in this paper needs to be progressively tested while exploring other sustainable approaches. 展开更多
关键词 Emerging Contaminants Per- and Polyfluoroalkyl Substances Non-Polymeric Chemicals REMEDIATION ETHICS Public Health
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Microplastics and Nano-Plastics: From Initiation to Termination
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作者 Oluwafemi Awolesi Peter Oni Beatrice Arwenyo 《Journal of Geoscience and Environment Protection》 2023年第1期249-280,共32页
Following the advent of the Industrial Revolution, plastic pollution has been a serious environmental issue while micro- and nano-plastics have been a cynosure of researchers’ attention in the twenty-first century. T... Following the advent of the Industrial Revolution, plastic pollution has been a serious environmental issue while micro- and nano-plastics have been a cynosure of researchers’ attention in the twenty-first century. This is due to the improved knowledge of its ecotoxicological effects and the global pushforward towards sustainability. There is a growing concern that the increasing presence of microplastics and nanoplastics (MNPs) in aquatic habitats poses a threat to marine life, and it is predicted that nanoplastics will be just as ubiquitous as macro- and micro-plastics, but far more destructive to living organisms due to their ability to infiltrate cells. Recent research has shown that marine and freshwater biota become entangled with plastic litter, which disrupts the ecosystem. Aquatic creatures are known to absorb and deposit these new pollutants in their digestive systems, as has been documented in several studies. More recent research has also examined their co-occurrence and toxicity with other emerging contaminants, including their prevalence and effects in food, air, and soil. Using articles extracted from a six-year period from Scopus, ACS Publications and Google Scholar, this review explores the origins, fates, occurrence in the food chain, exposure routes, cellular interactions of microplastics and nano-plastics, in addition to the ecotoxicological impacts, analytical methods, and the potential remedies for combating pollution and toxicity. Ultimately, this review is a comprehensive, updated addendum to available reviews on micro- and nano-plastics. 展开更多
关键词 Microplastics NANO-PLASTICS OCCURRENCE Transport TOXICITY Environmental Health REMEDIATION
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Understanding the Perceptions and Practices of Homeowners in the Event of Hurricane: A Case Study of University Employees in Louisiana
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作者 Oluwafemi Awolesi Natalie Matherne +3 位作者 Victoria Horton Mattie Prosser Peter Oni Odunayo Lawal 《Journal of Geoscience and Environment Protection》 2023年第5期226-242,共17页
The purpose of this qualitative study is to explore and gain an understanding of Louisiana homeowners’ perceptions and practices in preparing for hurricanes;contribute to academic research and student learning, while... The purpose of this qualitative study is to explore and gain an understanding of Louisiana homeowners’ perceptions and practices in preparing for hurricanes;contribute to academic research and student learning, while guiding the development of future projects. We focused specifically on how homeowners in Louisiana would protect their important documents and possessions. These documents and possessions include but are not limited to photographs, social security cards, birth certificates, and insurance paperwork. We collected the data throughout the fall semester of 2022 at Louisiana State University (LSU) by conducting a focus group and in-depth interviews. We collected a variety of answers, but most participants expressed a strong need to have their important documents and possessions protected and gave different strategies for how this was carried out, such as digitizing or protective storage. Participants also expressed a strong need for more information to be delivered to residents to talk more about ways they can protect their own documents and possessions. Emphases were also made on the need for: leaders of large institutions to be especially concerned with preparedness for vulnerable populations;outreach programs to be put in place to spread awareness of the importance of protecting important documents and possessions during a disaster;news outlets to switch their focus from normal survival tips to discussions on the importance of protecting documents and possessions;government and non-profit agencies to work together to share tips and information through social media and other forms of handouts. 展开更多
关键词 Hurricanes Disaster Preparedness Environmental Education Climate Change
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PFAS: Ecological Implications, Remedial Actions and Ethical Considerations
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作者 Oluwafemi Awolesi Peter Oni +7 位作者 Abiodun Oshinowo Boluwatife S. Olubusoye Faustina Owusu Simeon Pama Sunday Temitope Osobamiro Acaye Ongwech Omotoyosi Awolesi Beatrice Arwenyo 《Journal of Agricultural Chemistry and Environment》 2023年第3期306-334,共29页
The C-F bond is one of the strongest in organic chemistry. It is responsible for the great stability of perfluoroalkyl and polyfluoroalkyl substances, commonly referred to as “PFAS”, a group of man-made chemicals th... The C-F bond is one of the strongest in organic chemistry. It is responsible for the great stability of perfluoroalkyl and polyfluoroalkyl substances, commonly referred to as “PFAS”, a group of man-made chemicals that include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). Thermal stability, surface activity, dielectric characteristics, chemical resistance, and inertness are just a few of the technical advantages that this group has over hydrocarbons, and since the 1950s, these chemicals have been largely utilized in a variety of domestic and industrial endeavors. The hydrophilic and lipophilic nature of this class of chemicals accounts for its uniqueness. Up until today, the chemistry and ecotoxicology of these chemicals continue to emerge. Issues concerning the destructive power of ignorance expedited by an ineffective regulatory institution continue to show that manufacturing chemicals are insufficient without giving serious thought to issues of openness and humanity’s awareness of its own safety. When discussing the nature of humanity and how it can be defined or redefined, it is important to allude to the significance of integrating business with ethics in its various forms. This paper highlights the importance of holding polluters accountable for PFAS contamination cleanup costs while emphasizing the need for chemical manufacturers to test and disclose the health and environmental effects of PFAS compounds. In addition, the sources, types, properties, applications, distribution, toxicological implications, regulations, and analytical methods associated with PFAS (per- and polyfluoroalkyl substances) are explored. The effectiveness of the remedial methods described in this paper needs to be progressively tested while exploring other sustainable approaches. 展开更多
关键词 Emerging Contaminants Per- and Polyfluoroalkyl Substances Non-Polymeric Chemicals REMEDIATION ETHICS Public Health
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Microplastics in Marine Environment: Occurrence, Distribution, and Extraction Methods in Marine Organisms
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作者 Boluwatife S. Olubusoye Peter Oni +6 位作者 Faustina Owusu Oluwatoyin Adekoya Acaye Ongwech Daniel A. Odogwu Oluwafemi Awolesi Ayobami Oje Beatrice Arwenyo 《Open Journal of Ecology》 2023年第12期931-955,共25页
The pervasive presence of microplastics in marine environments has raised significant concerns. This review addresses the pressing issue of microplastic pollution in marine ecosystems and its potential implications fo... The pervasive presence of microplastics in marine environments has raised significant concerns. This review addresses the pressing issue of microplastic pollution in marine ecosystems and its potential implications for both the environment and human health. It outlines the current state of microplastic occurrence, distribution, and extraction methods within marine organisms. Microplastics have emerged as a significant environmental concern due to their harmful effects on ecosystems and their potential human health risks. These particles infiltrate marine environments through runoff and atmospheric deposition, ultimately contaminating beaches and posing threats to marine life. Despite the gravity of this issue, there has been limited research on the presence and distribution of microplastics in marine organisms. This review aims to bridge this knowledge gap by comprehensively examining the occurrence, distribution, and various extraction methods used to detect microplastics in marine organisms. It emphasizes the urgent need for targeted measures to manage microplastic pollution, highlights the significant role of human activities in contributing to this problem, and underscores the importance of reducing human-induced pollution to safeguard marine ecosystems. While this paper contributes to the understanding of microplastic pollution in marine environments and underscores the critical importance of taking action to protect marine organisms and preserve our oceans for future generations, it also emphasizes that, in effectively tackling the microplastic problem, a well-coordinated approach is essential, involving research initiatives, policy adjustments, public involvement, and innovative technologies. Crucially, prompt and resolute responses must exist to counteract the escalating peril posed by microplastics to the oceans and the global environment. 展开更多
关键词 Microplastics Marine Environment Marine Organisms Extraction Methods Ecological Impact Ocean Pollution
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X型分子筛膜的制备及渗透性能的改善 被引量:7
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作者 许中强 陈庆龄 +1 位作者 卢冠忠 马忆华 《石油炼制与化工》 CAS CSCD 北大核心 2001年第9期43-48,共6页
采用在多孔载体上预投分子筛晶种 ,再用水热晶化的二次生长的成膜方法合成X型分子筛膜。通过三次晶化操作 ,SEM显示多孔载体上负载生长的分子筛膜厚约 1 5μm。分子筛膜的He和N2 的渗透率下降为载体渗透率的 1 %以下 ,纯三丁胺与全氟三... 采用在多孔载体上预投分子筛晶种 ,再用水热晶化的二次生长的成膜方法合成X型分子筛膜。通过三次晶化操作 ,SEM显示多孔载体上负载生长的分子筛膜厚约 1 5μm。分子筛膜的He和N2 的渗透率下降为载体渗透率的 1 %以下 ,纯三丁胺与全氟三丁胺的渗透率之比为 2 1 ( 3 50℃ )。但表征结果显示 ,膜层内存在缺陷。本研究采用了化学沉积与积炭处理相结合的二步修饰法来消除缺陷。结果表明 ,经二步修饰后 ,X型分子筛膜用三丁胺和全氟三丁胺的蒸气测试其渗透率 ,发现渗透侧全氟三丁胺几乎收集不到 ,比未修饰的膜的渗透率有很大提高 ,说明修饰对X型分子筛膜的非沸石孔道的消除很明显。 展开更多
关键词 X型分子筛膜 制备 沉积 积炭 渗透性
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在多孔陶瓷载体上X型分子筛生长成膜的研究 被引量:6
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作者 许中强 陈庆龄 +1 位作者 卢冠忠 MA Yi-hua 《石油化工》 EI CAS CSCD 北大核心 2000年第8期578-581,共4页
研究X型分子筛在多孔陶瓷载体上的生长条件 ,合成膜的晶化液组成n(SiO2 ) /n(Al2 O3) =3 .0~ 5 .0 ,n(Na2 O) /n(SiO2 ) =1.3~ 9.8,n(H2 O) /n(SiO2 ) =12 0~ 80 0 ;晶化温度 85~ 10 5℃ ;晶化时间 2 4~ 96h。SEM显示多孔陶瓷载体... 研究X型分子筛在多孔陶瓷载体上的生长条件 ,合成膜的晶化液组成n(SiO2 ) /n(Al2 O3) =3 .0~ 5 .0 ,n(Na2 O) /n(SiO2 ) =1.3~ 9.8,n(H2 O) /n(SiO2 ) =12 0~ 80 0 ;晶化温度 85~ 10 5℃ ;晶化时间 2 4~ 96h。SEM显示多孔陶瓷载体上负载生长分子筛膜要经过 6~ 7次涂膜操作 ,才能获得较理想的均匀连续的顶膜 ,膜厚 10~ 2 5 μm。考察了晶化液的配方、合成条件及晶化次数对分子筛负载量的影响 ,多孔载体的表面形貌及规格对表面膜均匀连续性的影响等。结果表明 ,成膜的渗透通量下降为载体的 7%~ 9% ,分子筛膜选透率用 (C4H9) 3N和 (C4F9) 3N的纯蒸汽表征 ,在 3 5 0℃下 (C4H9) 3N对 (C4F9) 3N的选透率达到 69。 展开更多
关键词 X型分子筛 分子筛膜 膜选透率 多孔陶瓷载体
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人巨细胞病毒临床分离株感染血管内皮细胞伴肾素基因表达
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作者 程远 李多多 +6 位作者 程计林 程新 刘宝玲 王海滨 金壮 张杰林 Crumpacker Clyde 《中国分子心脏病学杂志》 CAS 2009年第4期193-198,共6页
目的探讨巨细胞病毒(Cytomegalovirus,CMV)是否感染血管内皮细胞伴肾素表达。方法(1)用107pfu(空斑形成单位)/ml CMV临床分离株BI-5和实验室型CMV AD169分别与106腹主动脉内皮细胞和人脐静脉内皮细胞共同孵育,在23小时后、第3天、第7天... 目的探讨巨细胞病毒(Cytomegalovirus,CMV)是否感染血管内皮细胞伴肾素表达。方法(1)用107pfu(空斑形成单位)/ml CMV临床分离株BI-5和实验室型CMV AD169分别与106腹主动脉内皮细胞和人脐静脉内皮细胞共同孵育,在23小时后、第3天、第7天、第10天和第14天分别收集培养上清200μl,第14天用PBS缓冲液洗细胞3次,收获细胞。每组实验均设培养液代替病毒液的无感染对照;(2)COBAS定量PCR检测培养上清中CMV DNA拷贝数;(3)PCR检测感染细胞中CMVpol基因;(4)RT-PCR、Real time RT-PCR和Western blot检测肾素在感染细胞内的表达。结果(1)BI-5和AD169感染静脉和动脉细胞后,其形态学变化相似,无细胞裂解病理效应;(2)AD169感染细胞不同时间培养上清中CMV DNA拷贝数无明显增加,BI-5呈增殖趋势;(3)BI-5感染动脉细胞CMV DNA拷贝数和肾素表达量均大于静脉细胞。结论临床分离株CMV以非裂解形式在血管内皮细胞持续存在并诱导肾素基因表达,血管内皮细胞分泌肾素可能是CMV感染引起心血管疾病的新机制。 展开更多
关键词 巨细胞病毒 血管内皮细胞 肾素
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巨细胞病毒临床分离株感染血管内皮细胞伴肾素基因表达
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作者 李多多 程远 +6 位作者 程计林 程新 刘宝玲 王海滨 金壮 张杰林 Crumpacker Clyde 《公共卫生与临床医学》 2009年第3期164-169,共6页
目的探讨巨细胞病毒(Cytomegalovirus,CMV)是否感染血管内皮细胞伴肾素表达。方法①用10^7pfu(空斑形成单位)/mLCMV临床分离株BI-5和实验室型CMVA D169分别与10^6腹主动脉内度细胞和人脐静脉内皮细胞共同孵育,在23h后、d3、d7、... 目的探讨巨细胞病毒(Cytomegalovirus,CMV)是否感染血管内皮细胞伴肾素表达。方法①用10^7pfu(空斑形成单位)/mLCMV临床分离株BI-5和实验室型CMVA D169分别与10^6腹主动脉内度细胞和人脐静脉内皮细胞共同孵育,在23h后、d3、d7、d10和d14分别收集培养上清200μL,d14用PBS缓冲液洗细胞3次,收获细胞。每组实验均设培养液代替病毒液的无感染对照;②COBAS定量PCR检测培养上清中CMV DNA拷贝数;③PCR检测感染细胞中CMVpol基因;@RT-PCR、Real time RT-PCR和Western blot检测肾素在感染细胞内的表达。结果①BI-5和AD169感染静脉和动脉细胞后,其形态学变化相似,无细胞裂解病理效应;②AD169感染细胞不同时间培养上清中CMVDNA拷贝数无明显增加,BI-5呈增殖趋势;③BI-5感染动脉细胞CMVDNA拷贝数和肾素表达量均大于静脉细胞。结论临床分离株CMV以非裂解形式在血管内皮细胞持续存在并诱导肾素基因表达,血管内皮细胞分泌肾素可能是CMV感染引起心血管疾病的新机制。 展开更多
关键词 巨细胞病毒 血管内皮细胞 肾素
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共混比及聚合物浓度对PVC/PVB相容性及超滤膜性能结构的影响 被引量:3
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作者 朱晶逸 迟莉娜 +2 位作者 张遥遥 Anil Saddat 张振家 《净水技术》 CAS 2012年第5期46-54,共9页
通过混合焓的计算,对不同共混比和聚合物浓度的聚氯乙烯(PVC)/聚乙烯醇缩丁醛(PVB)共混比体系的相容性进行预测,并通过稀溶液黏度(DSV)法、运动黏度法和目视法进行相应验证;以N,N-二甲基乙酰胺(DMAc)为溶剂,通过湿相转换法(NIPS)制备PVC... 通过混合焓的计算,对不同共混比和聚合物浓度的聚氯乙烯(PVC)/聚乙烯醇缩丁醛(PVB)共混比体系的相容性进行预测,并通过稀溶液黏度(DSV)法、运动黏度法和目视法进行相应验证;以N,N-二甲基乙酰胺(DMAc)为溶剂,通过湿相转换法(NIPS)制备PVC/PVB共混平板超滤膜,并对超滤膜的性能和结构进行测试,系统地研究了PVC/PVB共混铸膜液的组成对平板超滤膜的结构及其分离性能的影响,为通过PVB共混改性PVC膜材料制备超滤膜提供了理论依据。 展开更多
关键词 共混改性 聚氯乙烯(PVC) 聚乙烯醇缩丁醛(PVB) 超滤膜
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大型土壤源热泵系统的地下热平衡与运行策略优化(英文)
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作者 陈义波 陈九法 +2 位作者 Umberto Berardi 乔未来 陈军伟 《Journal of Southeast University(English Edition)》 EI CAS 2013年第1期92-98,共7页
冬夏季取热散热不等导致的地下热环境的不平衡严重影响了土壤源热泵系统(GSHP)的性能.以某居住建筑为对象,采用数值模拟结合实验验证的方法,对建筑内采用的天棚辐射末端和置换新风系统进行研究,该空调系统的冷热源采用土壤源热泵.考虑... 冬夏季取热散热不等导致的地下热环境的不平衡严重影响了土壤源热泵系统(GSHP)的性能.以某居住建筑为对象,采用数值模拟结合实验验证的方法,对建筑内采用的天棚辐射末端和置换新风系统进行研究,该空调系统的冷热源采用土壤源热泵.考虑循环水泵、风机、热泵机组运行中向地下排出的产热量,采用Energy Plus模拟软件对建筑物进行能耗模拟,获得地下取热散热量及其比值.利用这一取热散热量,采用Fluent模拟软件建立系统模型,模型经实验验证后,研究3种典型控制策略下的地下热交换规律.得到南京地区地下每年的制冷负荷和供热负荷比为5.08∶1,并研究指出与温度和温度差控制策略相比,定时开启策略具有更好的效能和可靠性. 展开更多
关键词 土壤源热泵 民用建筑 热平衡 控制策略
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铁素体渗氮工艺模拟 被引量:1
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作者 M.Yang B.Yao +2 位作者 Y.H.Sohn R.D.Sisson Jr 顾剑锋 《热处理》 CAS 2015年第1期46-50,共5页
纯铁的莱勒图被广泛用于选择合金钢的渗氮工艺。本文首次采用计算热力学来确定AISI 4140钢的莱勒图。研究表明,AISI 4140钢的莱勒图与纯铁的存在明显差异。对AISI 4140钢进行了渗氮试验,目的是验证计算热力学的预测结果。扫描电镜结果... 纯铁的莱勒图被广泛用于选择合金钢的渗氮工艺。本文首次采用计算热力学来确定AISI 4140钢的莱勒图。研究表明,AISI 4140钢的莱勒图与纯铁的存在明显差异。对AISI 4140钢进行了渗氮试验,目的是验证计算热力学的预测结果。扫描电镜结果显示化合物层中存在两种相,利用透射电镜对化合物层与扩散层界面的研究结果证实了γ'-Fe4N和ε-Fe2-3(C,N)相的共存。这些试验结果与用计算热力学建立的AISI 4140钢莱勒图高度吻合。 展开更多
关键词 渗氮工艺 莱勒图 相图计算 AISI4140钢 AISI 4140
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Surface effects on in-shoe plantar pressure and tibial impact during running 被引量:4
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作者 Weijie Fu Ying Fang +3 位作者 David Ming Shuo Liu Lin Wang Sicong Ren Yu Liu 《Journal of Sport and Health Science》 SCIE 2015年第4期384-390,共7页
目的:探讨在不同表面上跑步对足底压力和胫骨加速度的影响。方法:13位男性跑步者被要求分别在水泥地、塑胶跑道、天然草地、跑步机以及配备EVA缓冲衬垫物的跑步机上以12 km/h的速度进行慢跑。用足底压力测试系统和安放在胫骨粗隆的加速... 目的:探讨在不同表面上跑步对足底压力和胫骨加速度的影响。方法:13位男性跑步者被要求分别在水泥地、塑胶跑道、天然草地、跑步机以及配备EVA缓冲衬垫物的跑步机上以12 km/h的速度进行慢跑。用足底压力测试系统和安放在胫骨粗隆的加速度计,记录和分析足底压力与胫骨冲击的特点。结果:第一和第二足底压力峰值(发生时间)、压力时间积分、峰值压力分布在混凝土、塑胶、草地和正常的跑步机的表面间没有明显差异。在5种不同测试表面下,峰值加速度正值也无显著差异。但相比于混凝土表面,在配备EVA缓冲衬垫物的跑步机上跑步能明显减小在冲击阶段的足底压力第一峰值和压力积分(p<0.05)。上述结果可进一步归因为足后跟区域峰值压力下降(P<0.05)。结论:运动表面和下肢冲击之间也许并无必然关系。然而值得注意的是,在解释足底压力的表现及将其运用到陆地表面的跑步运动中时应考虑不同跑步机表面的影响。 展开更多
关键词 足底压力 表面效应 跑步机 胫骨 乙烯-醋酸乙烯酯 压力峰值 混凝土表面 运行过程
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基于血管内超声(IVUS)的人体冠状动脉随心动周期形变的流固耦合数值模拟与分析
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作者 王梁 杨淳 Dalin TANG 《北京师范大学学报(自然科学版)》 CAS CSCD 北大核心 2013年第4期335-343,共9页
人体动脉血管内粥样斑的受损和破裂与血管内的受力等力学情况密切相关.基于各种医学成像数据建立的血管数值模拟模型能很好的考察血管内的受力及血流情况,已成为对血管内粥样斑的受损和破裂作出评估和预测的有力工具.本文利用一位患者... 人体动脉血管内粥样斑的受损和破裂与血管内的受力等力学情况密切相关.基于各种医学成像数据建立的血管数值模拟模型能很好的考察血管内的受力及血流情况,已成为对血管内粥样斑的受损和破裂作出评估和预测的有力工具.本文利用一位患者的血管内超声(IVUS)图像数据建立了其冠状动脉血管的三维流固耦合数值模拟模型,并根据患者CT造影的动态影像数据模拟了冠状动脉在人体内随心脏搏动而产生的周期性运动过程.模型中冠状动脉血管采用各向异性Mooney-Rivlin材料模型,其材料参数是由冠状动脉血管样本的双轴加载拉伸实验获得的拉伸比率———应力数据拟合得到的,血压数据也采用了患者自身的数据,因而本文建立的数值模型真实模拟了人体内冠状动脉的实际运动情况.本文给出了血管内的应力应变分布、血流速度、血液最大剪切应力等数值模拟结果,并比较了血管的周期弯曲和血压变化的相位差的影响.结果表明:血管内部的脂肪斑对血管的应力应变分布有显著的影响;就该患者个体而言,血管弯曲程度对血管内部的应力应变分布的影响要强于血压的影响.而相比于血管的弯曲程度,血管内的血流速度和流通量受血压的影响较为显著.本文建立的模拟冠状动脉周期运动的数值方法可以进一步地应用于大量冠状动脉粥样硬化患者的病例研究.随着患者数量的积累,通过分析可以更精确地评估和预测粥样斑的受损性和破裂发生可能性. 展开更多
关键词 IVUS 冠状动脉 流固耦合 动脉粥样斑
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Magnetic iron oxide nanoparticles: Synthesis and surface coating techniques for biomedical applications 被引量:2
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作者 孙圣男 魏超 +3 位作者 朱赞赞 侯仰龙 Subbu S Venkatraman 徐梽川 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第3期13-31,共19页
Iron oxide nanoparticles are the most popular magnetic nanoparticles used in biomedical applications due to their low cost, low toxicity, and unique magnetic property. Magnetic iron oxide nanoparticles, including magn... Iron oxide nanoparticles are the most popular magnetic nanoparticles used in biomedical applications due to their low cost, low toxicity, and unique magnetic property. Magnetic iron oxide nanoparticles, including magnetite (Fe304) and maghemite (γ-Fe203), usually exhibit a superparamagnetic property as their size goes smaller than 20 nm, which are often denoted as superparamagnetic iron oxide nanoparticles (SPIONs) and utilized for drug delivery, diagnosis, therapy, and etc. This review article gives a brief introduction on magnetic iron oxide nanoparticles in terms of their fundamentals of magnetism, magnetic resonance imaging (MRI), and drug delivery, as well as the synthesis approaches, surface coating, and application examples from recent key literatures. Because the quality and surface chemistry play important roles in biomedical applications, our review focuses on the synthesis approaches and surface modifications of iron oxide nanopar- ticles. We aim to provide a detailed introduction to readers who are new to this field, helping them to choose suitable synthesis methods and to optimize the surface chemistry of iron oxide nanoparticles for their interests. 展开更多
关键词 FE3O4 γ-Fe203 SYNTHESIS surface coating biomedical application
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Patient-Specific Echo-Based Fluid-Structure Interaction Modeling Study of Blood Flow in the Left Ventricle with Infarction and Hypertension 被引量:2
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作者 Longling Fan Jing Yao +2 位作者 Chun Yang Di Xu Dalin Tang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2018年第2期221-237,共17页
Understanding cardiac blood flow behaviors is of importance for cardiovascular research and clinical assessment of ventricle functions.Patient-specific Echo-based left ventricle(LV)fluid-structure interaction(FSI)mode... Understanding cardiac blood flow behaviors is of importance for cardiovascular research and clinical assessment of ventricle functions.Patient-specific Echo-based left ventricle(LV)fluid-structure interaction(FSI)models were introduced to perform ventricle mechanical analysis,investigate flow behaviors,and evaluate the impact of myocardial infarction(MI)and hypertension on blood flow in the LV.Echo image data were acquired from 3 patients with consent obtained:one healthy volunteer(P1),one hypertension patient(P2),and one patient who had an inferior and posterior myocardial infarction(P3).The nonlinear Mooney-Rivlin model was used for ventricle tissue with material parameter values chosen to match echo-measure LV volume data.Using the healthy case as baseline,LV with MI had lower peak flow velocity(30%lower at beginejection)and hypertension LV had higher peak flow velocity(16%higher at begin-filling).The vortex area(defined as the area with vorticity>0)for P3 was 19%smaller than that of P1.The vortex area for P2 was 12%smaller than that of P1.At peak of filling,the maximum flow shear stress(FSS)for P2 and P3 were 390%higher and 63%lower than that of P1,respectively.Meanwhile,LV stress and strain of P2 were 41%and 15%higher than those of P1,respectively.LV stress and strain of P3 were 36%and 42%lower than those of P1,respectively.In conclusion,FSI models could provide both flow and structural stress/strain information which would serve as the base for further cardiovascular investigations related to disease initiation,progression,and treatment strategy selections.Large-scale studies are needed to validate our findings. 展开更多
关键词 Fluid-structure interaction model VENTRICLE flow fluid dynamic VENTRICLE material properties VENTRICLE mechanics
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