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The relationship between compartment models and their stochastic counterparts:A comparative study with examples of the COVID-19 epidemic modeling
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作者 Ziyu Zhao Yi Zhou +6 位作者 Jinxing Guan Yan Yan Jing Zhao Zhihang Peng Feng Chen Yang Zhao Fang Shao 《Journal of Biomedical Research》 CAS CSCD 2024年第2期175-188,I0016-I0018,共17页
Deterministic compartment models(CMs)and stochastic models,including stochastic CMs and agent-based models,are widely utilized in epidemic modeling.However,the relationship between CMs and their corresponding stochast... Deterministic compartment models(CMs)and stochastic models,including stochastic CMs and agent-based models,are widely utilized in epidemic modeling.However,the relationship between CMs and their corresponding stochastic models is not well understood.The present study aimed to address this gap by conducting a comparative study using the susceptible,exposed,infectious,and recovered(SEIR)model and its extended CMs from the coronavirus disease 2019 modeling literature.We demonstrated the equivalence of the numerical solution of CMs using the Euler scheme and their stochastic counterparts through theoretical analysis and simulations.Based on this equivalence,we proposed an efficient model calibration method that could replicate the exact solution of CMs in the corresponding stochastic models through parameter adjustment.The advancement in calibration techniques enhanced the accuracy of stochastic modeling in capturing the dynamics of epidemics.However,it should be noted that discrete-time stochastic models cannot perfectly reproduce the exact solution of continuous-time CMs.Additionally,we proposed a new stochastic compartment and agent mixed model as an alternative to agent-based models for large-scale population simulations with a limited number of agents.This model offered a balance between computational efficiency and accuracy.The results of this research contributed to the comparison and unification of deterministic CMs and stochastic models in epidemic modeling.Furthermore,the results had implications for the development of hybrid models that integrated the strengths of both frameworks.Overall,the present study has provided valuable epidemic modeling techniques and their practical applications for understanding and controlling the spread of infectious diseases. 展开更多
关键词 compartment models agent-based models compartment-agent mixed models comparative study COVID-19
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Integrated Machine Learning and Deep Learning Models for Cardiovascular Disease Risk Prediction: A Comprehensive Comparative Study
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作者 Shadman Mahmood Khan Pathan Sakan Binte Imran 《Journal of Intelligent Learning Systems and Applications》 2024年第1期12-22,共11页
Cardiovascular Diseases (CVDs) pose a significant global health challenge, necessitating accurate risk prediction for effective preventive measures. This comprehensive comparative study explores the performance of tra... Cardiovascular Diseases (CVDs) pose a significant global health challenge, necessitating accurate risk prediction for effective preventive measures. This comprehensive comparative study explores the performance of traditional Machine Learning (ML) and Deep Learning (DL) models in predicting CVD risk, utilizing a meticulously curated dataset derived from health records. Rigorous preprocessing, including normalization and outlier removal, enhances model robustness. Diverse ML models (Logistic Regression, Random Forest, Support Vector Machine, K-Nearest Neighbor, Decision Tree, and Gradient Boosting) are compared with a Long Short-Term Memory (LSTM) neural network for DL. Evaluation metrics include accuracy, ROC AUC, computation time, and memory usage. Results identify the Gradient Boosting Classifier and LSTM as top performers, demonstrating high accuracy and ROC AUC scores. Comparative analyses highlight model strengths and limitations, contributing valuable insights for optimizing predictive strategies. This study advances predictive analytics for cardiovascular health, with implications for personalized medicine. The findings underscore the versatility of intelligent systems in addressing health challenges, emphasizing the broader applications of ML and DL in disease identification beyond cardiovascular health. 展开更多
关键词 Cardiovascular Disease Machine Learning Deep Learning Predictive modeling Risk Assessment comparative Analysis Gradient Boosting LSTM
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Comparative transcriptome analysis between rhesus macaques(Macaca mulatta) and crab-eating macaques(M. fascicularis) 被引量:1
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作者 Yu-Xiang Mao Yamei Li +6 位作者 Zikun Yang Ning Xu Shilong Zhang Xuankai Wang Xiangyu Yang Qiang Sun Yafei Mao 《Zoological Research》 SCIE CSCD 2024年第2期299-310,共12页
Understanding gene expression variations between species is pivotal for deciphering the evolutionary diversity in phenotypes. Rhesus macaques(Macaca mulatta, MMU)and crab-eating macaques(M. fascicularis, MFA) serve as... Understanding gene expression variations between species is pivotal for deciphering the evolutionary diversity in phenotypes. Rhesus macaques(Macaca mulatta, MMU)and crab-eating macaques(M. fascicularis, MFA) serve as crucial nonhuman primate biomedical models with different phenotypes. To date, however, large-scale comparative transcriptome research between these two species has not yet been fully explored. Here, we conducted systematic comparisons utilizing newly sequenced RNA-seq data from84 samples(41 MFA samples and 43 MMU samples)encompassing 14 common tissues. Our findings revealed a small fraction of genes(3.7%) with differential expression between the two species, as well as 36.5% of genes with tissue-specific expression in both macaques. Comparison of gene expression between macaques and humans indicated that 22.6% of orthologous genes displayed differential expression in at least two tissues. Moreover,19.41% of genes that overlapped with macaque-specific structural variants showed differential expression between humans and macaques. Of these, the FAM220A gene exhibited elevated expression in humans compared to macaques due to lineage-specific duplication. In summary,this study presents a large-scale transcriptomic comparison between MMU and MFA and between macaques and humans. The discovery of gene expression variations not only enhances the biomedical utility of macaque models but also contributes to the wider field of primate genomics. 展开更多
关键词 Crab-eating macaques Rhesus macaques comparative transcriptomics Biomedical models Nonhuman primates RNA-SEQ Duplicated genes
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A Comparative Study on Factors Influencing Food Security in China and India
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作者 Shaowen YANG Meixue QIU 《Asian Agricultural Research》 2024年第2期12-15,共4页
This paper analyzes and compares the key factors influencing food security in two populous countries(China and India),and cate-gorizes them into three types:agricultural production,economic development and income leve... This paper analyzes and compares the key factors influencing food security in two populous countries(China and India),and cate-gorizes them into three types:agricultural production,economic development and income level,and income distribution.Using the prevalence of undernourishment as an indicator of food security,the paper empirically tests the degree of impact of various factors on food security in both countries using Tobit regression and Newey regression methods.The study finds that improving the level of economic development can significantly enhance food security in both countriesꎻreducing the Gini coefficient has a significant impact on India,but not on Chinaꎻincreasing the agricultural production per capita has a much greater effect on China than on India.Therefore,both countries should take measures that are both similar and different according to their national conditions to improve their food security level. 展开更多
关键词 Food security Influencing factors comparative study Econometric model
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Research on Comparative Advantage and Typical Models of Circular Agriculture Economy in Eastern and Mid-China Region
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作者 周颖 周清波 甘寿文 《Agricultural Science & Technology》 CAS 2015年第11期2573-2580,共8页
Developing agricultural circular economy is the important measures of relieving the pressure on agricultural resources, preserving the ecological environment and promoting the sustainable development of agriculture an... Developing agricultural circular economy is the important measures of relieving the pressure on agricultural resources, preserving the ecological environment and promoting the sustainable development of agriculture and rural economy. Based on the idea of circulation of agricultural research as the breakthrough point, the research firstly detailed the concept and scientific connotation of circular egdculture in an all-round way and described and analyzed the advantages and conditions of the development of circular agriculture in eastern and middle regions of China from three aspects including resources endowment, conditions of economic development and industrial base conditions. Furthermore, the research analyzed the model char- actedstics and summarized the successful ex^dence to provide a reference for promoting the models with consideration of Taihu Lake Basin in South of Jiangsu, Yi- meng mountain areas in Southeast of Shandong and hills and mountains region in northwest Henan. Finally, the reseach put forward the development orientation of agricultural circular economy and countermeasures and suggestions to further enhance the level of development. 展开更多
关键词 Agricultural circular economy comparative advantages Typical model Mid-Eastem China
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A Comparative Study of the Jerome Model and the Horace Model 被引量:1
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作者 黄淋 唐学琳 《科技信息》 2012年第6期179-180,共2页
This paper will try to compare the Jerome model with the Horace model to look into advantages, shortages and relationship be-tween them. It mainly discusses the important roles of the Jerome model and the Horace model... This paper will try to compare the Jerome model with the Horace model to look into advantages, shortages and relationship be-tween them. It mainly discusses the important roles of the Jerome model and the Horace model in turning Chinese from their translation ef-fects. The present article comes to a conclusion that they are opposite, related, complementary, melting and permeating. And it gives us anidea that we should neither praise nor censure either of them, and we should adopt a correct method according to the concrete conditions toachieve a perfect translation effect. 展开更多
关键词 英语教学 教学方法 阅读教学 阅读知识
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24Model与LCM原因因素定义对比研究 被引量:2
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作者 袁晨辉 傅贵 +1 位作者 吴治蓉 赵金坤 《中国安全科学学报》 CAS CSCD 北大核心 2024年第1期27-34,共8页
为探究损失致因模型(LCM)原因因素定义与事故致因“2-4”模型(24Model)存在的异同和优缺点,梳理2个模型各层面原因和结果的定义,对比定义内容及其对事故原因分析等安全实务的指导作用,并以一起瓦斯爆炸事故为例加以实证分析,获得二者分... 为探究损失致因模型(LCM)原因因素定义与事故致因“2-4”模型(24Model)存在的异同和优缺点,梳理2个模型各层面原因和结果的定义,对比定义内容及其对事故原因分析等安全实务的指导作用,并以一起瓦斯爆炸事故为例加以实证分析,获得二者分析结果之间的差异。研究结果表明:LCM是首个将管理因素纳入事故致因分析的一维事件序列模型,可明确各层面原因因素的定义和因素间的逻辑关系,但部分定义存在交叉重复的问题,并没有揭示安全工作指导思想等深层次事故致因因素;24Model作为系统性事故致因模型,对各类因素的定义均以组织为主体,描述事件、事故、安全的概念内涵,划分个体安全动作、安全能力和组织安全管理体系的类别并给出含义解析,探究组织安全文化层面的问题并以32个元素体现;2个模型的事故原因分析方法均建立在对各层级原因因素定义的基础上,并适用于模型理论体系本身。 展开更多
关键词 “2-4”模型(24model) 损失致因模型(LCM) 事故致因模型 原因因素定义 对比研究
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Comparative study of HFACS and the 24Model accident causation models 被引量:7
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作者 Gui Fu Jia-Lin Cao +1 位作者 Lin Zhou Yuan-Chi Xiang 《Petroleum Science》 SCIE CAS CSCD 2017年第3期570-578,共9页
A comparative study is conducted to compare the theory and application effect of two accident causation models, the human factors analysis and classification system(HFACS) and the accident causation "2-4" model(2... A comparative study is conducted to compare the theory and application effect of two accident causation models, the human factors analysis and classification system(HFACS) and the accident causation "2-4" model(24 Model), as well as to provide a reference for safety researchers and accident investigators to select an appropriate accident analysis method. The two models are compared in terms of their theoretical foundations, cause classifications, accident analysis processes, application ranges, and accident prevention strategies. A coal and gas outburst accident is then analyzed using both models, and the application results are compared. This study shows that both the 24 Model and HFACS have strong theoretical foundations, and they can each be applied in various domains. In addition, the cause classification in HFACS is more practical, and its accident analysis process is more convenient. On the other hand, the 24 Model includes external factors, which makes the cause analysis more systematic and comprehensive. Moreover, the 24 Model puts forward more corresponding measures to prevent accidents. 展开更多
关键词 HFACS Accident causation "2-4" model comparative study Unsafe acts External causes Coaland gas outburst accident
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Comparative systems biology between human and animal models based on next-generation sequencing methods
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作者 Yu-Qi ZHAO Gong-Hua LI Jing-Fei HUANG 《Zoological Research》 SCIE CAS CSCD 北大核心 2013年第S02期35-41,共7页
Animal models provide myriad benefits to both experimental and clinical research.Unfortunately,in many situations,they fall short of expected results or provide contradictory results.In part,this can be the result of ... Animal models provide myriad benefits to both experimental and clinical research.Unfortunately,in many situations,they fall short of expected results or provide contradictory results.In part,this can be the result of traditional molecular biological approaches that are relatively inefficient in elucidating underlying molecular mechanism.To improve the efficacy of animal models,a technological breakthrough is required.The growing availability and application of the high-throughput methods make systematic comparisons between human and animal models easier to perform.In the present study,we introduce the concept of the comparative systems biology,which we define as“comparisons of biological systems in different states or species used to achieve an integrated understanding of life forms with all their characteristic complexity of interactions at multiple levels”.Furthermore,we discuss the applications of RNA-seq and ChIP-seq technologies to comparative systems biology between human and animal models and assess the potential applications for this approach in the future studies. 展开更多
关键词 Animal models comparative systems biology Next-generation sequencing RNA-SEQ CHIP-SEQ
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Comparative systems biology between human and animal models based on next-generation sequencing methods
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作者 Yu-Qi ZHAO Gong-Hua LI Jing-Fei HUANG 《Zoological Research》 CAS CSCD 北大核心 2013年第2期J0001-J0007,共7页
Animal models provide myriad benefits to both experimental and clinical research. Unfortunately, in many situations, they fall short of expected results or provide contradictory results. In part, this can be the resul... Animal models provide myriad benefits to both experimental and clinical research. Unfortunately, in many situations, they fall short of expected results or provide contradictory results. In part, this can be the result of traditional molecular biological approaches that are relatively inefficient in elucidating underlying molecular mechanism. To improve the efficacy of animal models, a technological breakthrough is required. The growing availability and application of the high-throughput methods make systematic comparisons between human and animal models easier to perform. In the present study, we introduce the concept of the comparative systems biology, which we define as "comparisons of biological systems in different states or species used to achieve an integrated understanding of life forms with all their characteristic complexity of interactions at multiple levels". Furthermore, we discuss the applications of RNA-seq and ChIP-seq technologies to comparative systems biology between human and animal models and assess the potential applications for this approach in the future studies. 展开更多
关键词 Animal models comparative systems biology Next-generation sequencing RNA-SEQ ChlP-seq
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Comparative Study on Diagonal Strut Model of Infill Wall
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作者 Zhenling Chai Zixiong Guo +1 位作者 Xiaojuan Liu Yunfan Jiang 《Structural Durability & Health Monitoring》 EI 2018年第3期169-187,共19页
The equivalent diagonal strut models of infill wall mainly include the single strut model and multi-strut model.Firstly,several equivalent strut models and their characteristics are introduced in this paper.Then,model... The equivalent diagonal strut models of infill wall mainly include the single strut model and multi-strut model.Firstly,several equivalent strut models and their characteristics are introduced in this paper.Then,model analysis and pushover analysis are carried out on infilled frame models with the aid of the software SAP2000.Two typical single strut models and a typical three-strut model are used to simulate the panel of the frames respectively.It is indicated that the period reduction factor of the frame with a three-strut model is close to the value recommended by the current code.The infill wall has great influence on the overall stiffness,bearing capacity and weak position of the structure.The stiffness and the bearing capacity of the infilled frame increase with the increase of the number of the infill walls.The unfilled story is the weak position of the infilled frame,and when the unfilled story at the bottom of the infilled frame,the seismic response of the upper infill layer decreases with the increasing of the number of unfilled story. 展开更多
关键词 Infill wall equivalent strut model comparative study pushover analysis
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Objective Model Selection in Physics: Exploring the Finite Information Quantity Approach
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作者 Boris Menin 《Journal of Applied Mathematics and Physics》 2024年第5期1848-1889,共42页
Traditional methods for selecting models in experimental data analysis are susceptible to researcher bias, hindering exploration of alternative explanations and potentially leading to overfitting. The Finite Informati... Traditional methods for selecting models in experimental data analysis are susceptible to researcher bias, hindering exploration of alternative explanations and potentially leading to overfitting. The Finite Information Quantity (FIQ) approach offers a novel solution by acknowledging the inherent limitations in information processing capacity of physical systems. This framework facilitates the development of objective criteria for model selection (comparative uncertainty) and paves the way for a more comprehensive understanding of phenomena through exploring diverse explanations. This work presents a detailed comparison of the FIQ approach with ten established model selection methods, highlighting the advantages and limitations of each. We demonstrate the potential of FIQ to enhance the objectivity and robustness of scientific inquiry through three practical examples: selecting appropriate models for measuring fundamental constants, sound velocity, and underwater electrical discharges. Further research is warranted to explore the full applicability of FIQ across various scientific disciplines. 展开更多
关键词 comparative Uncertainty Finite Information Quantity Formulating a model Measurement Accuracy Limit Objective model Selection
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IFAM与24Model的对比研究
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作者 刘晓露 严玉琼 +2 位作者 张苏 高梦瑶 聂晓琴 《中国安全生产科学技术》 CAS CSCD 北大核心 2024年第9期233-240,共8页
为完善和推动事故致因理论的发展,提高事故防控水平,在对信息流事故致因模型(IFAM)和事故致因2-4模型(24Model)理论基础、组成要素和分析过程对比研究的基础上,通过实例分析辨识二者之间的异同。研究结果表明:IFAM与24Model都有较强的... 为完善和推动事故致因理论的发展,提高事故防控水平,在对信息流事故致因模型(IFAM)和事故致因2-4模型(24Model)理论基础、组成要素和分析过程对比研究的基础上,通过实例分析辨识二者之间的异同。研究结果表明:IFAM与24Model都有较强的理论基础,部分组成要素存在对应关系,但原因类别划分存在差异。IFAM以信息流和组织为研究对象,研究过程相对复杂,更适用于分析单起事故;24Model以组织为研究对象,事故原因模块通用性和逻辑性强,适用于分析单起或某类事故。在实际应用中,IFAM与24Model均可用于事故调查分析和事故分级定责,具有一定的理论和实践价值。IFAM通过信息流表征事故致因,直观描述组织外部原因因素,但对个体能力的深入研究欠缺;而24Model认为组织外部因素需要通过组织内部原因模块的欠缺体现,认为个体能力是引发事故的间接原因并进行细致分析,但对组织间相关关系的探究欠缺。研究结果可为事故预防工作提供新视角和理论支撑。 展开更多
关键词 信息流事故致因模型(IFAM) 事故致因2-4模型(24model) 事故致因 道路交通事故 对比研究
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Comparison of different methods of intestinal obstruction in a rat model 被引量:10
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作者 Meng-Lang Yuan Zheng Yang +10 位作者 Yu-Cheng Li Lan-Lan Shi Jia-Ling Guo Yu-Qin Huang Xia Kang Jing-Jing Cheng Yang Chen Ting Yu De-Qi Cao Huan Pang Xiao Zhang 《World Journal of Gastroenterology》 SCIE CAS 2013年第5期692-705,共14页
AIM:To investigate different methods of creating incomplete intestinal obstruction in a rat model and to compare their electrophysiologic,morphologic and histologic characteristics. METHODS:Rat ileum was partially obs... AIM:To investigate different methods of creating incomplete intestinal obstruction in a rat model and to compare their electrophysiologic,morphologic and histologic characteristics. METHODS:Rat ileum was partially obstructed by the respective application of:braided silk(penetrated the mesentery and surrounded intestine);half ligation (penetrated directly and ligated 1/2 cross-section of the intestine);wide pipe(6 mm in width,surrounded the intestine);narrow pipe(2 mm in width,surrounded the intestine).A control was also included(no obstruction). Various behavioral and electrophysiologic variables, as well as morphologic and immunohistochemical observations were recorded by blinded investigators at different time points(12,24,48,72 h),including daily general condition,ileal wet weight and circumference, macromorphous and micromorphous intestine,bowel movement capability in vivo and in vitro,slow wave and neural electrical activity,and the number of c-Kit positive interstitial cells of Cajal(ICC). RESULTS:Despite being of a similar general condition, these methods resulted in different levels of obstruction in each group compared with the control at different time points(12,24,48,72 h).However,these fields of the wide pipe rat showed significantly differences when compared with the other three obstructed groups at 12 to 72 h,including macroscopic and histological presentation,intestinal transit ratio and contractility,circumference and wet weight,amplitude and frequency of nerve electrical discharge and slow wave,and ICC numbers(all P<0.01). CONCLUSION:The wide pipe rat method is significantly more reliable and stable than the other methods of obstruction,demonstrating that use of the wide pipe method can be a useful model of incomplete intestinal obstruction. 展开更多
关键词 INTESTINAL OBSTRUCTION model comparative study ELECTROPHYSIOLOGY Morphology INTERSTITIAL cells of CAJAL
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Multi-model comparison of CO2 emissions peaking in China:Lessons from CEMF01 study 被引量:6
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作者 Oleg LUGOVOY FENG Xiang-Zhao +4 位作者 GAO Ji LI Ji-Feng LIU Qiang TENG Fei ZOU Le-Le 《Advances in Climate Change Research》 SCIE CSCD 2018年第1期1-15,共15页
The paper summarizes results of the China Energy Modeling Forum's(CEMF)first study.Carbon emissions peaking scenarios,consistent with China's Paris commitment,have been simulated with seven national and indust... The paper summarizes results of the China Energy Modeling Forum's(CEMF)first study.Carbon emissions peaking scenarios,consistent with China's Paris commitment,have been simulated with seven national and industry-level energy models and compared.The CO2 emission trends in the considered scenarios peak from 2015 to 2030 at the level of 9e11 Gt.Sector-level analysis suggests that total emissions pathways before 2030 will be determined mainly by dynamics of emissions in the electric power industry and transportation sector.Both sectors will experience significant increase in demand,but have low-carbon alternative options for development.Based on a side-by-side comparison of modeling input and results,conclusions have been drawn regarding the sources of emissions projections differences,which include data,views on economic perspectives,or models'structure and theoretical framework.Some suggestions have been made regarding energy models'development priorities for further research. 展开更多
关键词 Carbon EMISSIONS projections Climate change CO2 EMISSIONS peak China’s Paris commitment Top-Down ENERGY modelS BOTTOM-UP ENERGY modelS Multi model comparative STUDY China ENERGY modeling Forum(CEMF)
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Comparison of a new stent and Wallstent for transjugular intrahepatic portosystemic shunt in a porcine model 被引量:4
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作者 MichaelA.Bettmann P.JackHoopes 《World Journal of Gastroenterology》 SCIE CAS CSCD 2001年第1期74-79,共6页
AIM: To evaluate a new balloon-expandable stainless steel stent (Cordis stent) in a transjugular intrahepatic portosystemic shunt (TIPS) porcine model and compared with Wallstent. METHODS: TIPS was performed in 26 nor... AIM: To evaluate a new balloon-expandable stainless steel stent (Cordis stent) in a transjugular intrahepatic portosystemic shunt (TIPS) porcine model and compared with Wallstent. METHODS: TIPS was performed in 26 normal domestic pigs weighing 20 kg-30 kg using a Cordis stent or Wallstent (13 pigs in each stent). All pigs were sacrificed at the 14th day after TIPS. The stent deployment delivery system, stent patency, and stent recoil after placement were evaluated.Proliferative response in representative histological sections from the center,hepatic and portal regions of the two stent designs were quantified. RESULTS: The shunt was widely patent in 4 pigs in the Cordis stent group (4/12, premature dead in 1 pig), and in 5 pigs in the Wallstent group (5/13). All remaining stents of both designs were occluded or stenotic. The mean quantified proliferation including thickness of the proliferation and the ratio of proliferation: total area in three assayed regions in Cordis stent and Wallstent was 2.18 mm:2.00 mm, and 59.18 mm2:51.66 mm2, respectively (P 】 0.05). The delivery system and mechanical properties of the Cordis stent functioned well. CONCLUSION: The new Cordis stent is appropriate for TIPS procedure. 展开更多
关键词 STENTS ANIMALS Balloon Dilatation Cell Division comparative Study models Animal Portal Vein Portasystemic Shunt Transjugular Intrahepatic SWINE Tunica Intima
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Comparative multi-locus assessment of modern Asian newts(Cynops, Paramesotriton, and Pachytriton:Salamandridae) in southern China suggests a shared biogeographic history 被引量:2
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作者 Zhi-Yong Yuan Yun-Ke Wu +5 位作者 Fang Yan Robert W.Murphy Theodore J.Papenfuss David B.Wake Ya-Ping Zhang Jing Che 《Zoological Research》 SCIE CAS CSCD 2022年第5期706-718,共13页
Evolutionary biologists are always interested in deciphering the geographic context of diversification,therefore they introduced the concept of comparative phylogeography, which helps to identify common mechanisms tha... Evolutionary biologists are always interested in deciphering the geographic context of diversification,therefore they introduced the concept of comparative phylogeography, which helps to identify common mechanisms that contribute to shared genetic structures among organisms from the same region.Here, we used multi-locus genetic data along with environmental data to investigate shared phylogeographic patterns among three Asianendemic newt genera, Cynops, Paramesotriton and Pachytriton, which occurred in montane/submontane streams or ponds in southern China. Our 222samples from 78 localities covered the entire range of the three genera and represented the largest dataset of this group to date. We reconstructed matrilineal genealogies from two protein-coding,mitochondrial genes, and gene network from two nuclear genes. We also estimated divergence times of major cladogenetic events and used occurrence data to evaluate niche difference and similarity between lineages. Our results revealed a common basal split in all three genera that corresponds to the separation of two geographic terrains of southern China.Those ancient divergence occurred during middle to late Miocene and likely correlate with paleoclimatic fluctuations caused by the uplift of the Qinghai-Xizang (Tibet) Plateau (QTP).Particularly,the strengthening and weakening of Asian summer monsoons during the Miocene may have profoundly impacted southern China and led to repeatedly vicariance in those newts.However,despite differences in realized niches between lineages,there is no evidence for divergence of fundamental niches.Preservation of old newt matriline lineages in mountains of southern China suggests that the region acts as both museums and cradles of speciation.Based on those results,we advocate a multi-pronged protection strategy for newts in the three genera. 展开更多
关键词 AMPHIBIAN comparative phylogeography Qinghai-Xizang(Tibet)Plateau East Asian monsoons Ecological niche modeling Species museums and cradles
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Comprehensive Assessment and Promotion Policy of Producer Services' Competitiveness in Beijing City:A Comparative Analysis among Beijing,Tianjin,Shanghai,Guangzhou and Shenzhen 被引量:1
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作者 Qiu Ling Fang Chuanglin +1 位作者 Shen Yuming Liu Xiaoli 《Chinese Journal of Population,Resources and Environment》 2011年第4期82-89,共8页
The five central cities-Beijing,Tianjin,Shanghai,Guangzhou and Shenzhen-of the three most important strategic regions in China,namely Beijing-Tianjin-Hebei metropolitan region,the Yangtze River Delta and the Pearl Riv... The five central cities-Beijing,Tianjin,Shanghai,Guangzhou and Shenzhen-of the three most important strategic regions in China,namely Beijing-Tianjin-Hebei metropolitan region,the Yangtze River Delta and the Pearl River Delta,are taken as a comparative analysis on urban producer services' competitiveness,especially focusing on the comparative advantages and disadvantages of producer services in Beijing.Firstly,based on an integrated indicator system including one objective hierarchy,four standard hierarchies and 35 indicator hierarchies,the study applies factor analysis model and analytic hierarchy process model reformed by entropy technology to measure the comprehensive competitiveness of producer services in the above five cities.Secondly,Beijing has comparative advantages of capital resource,industrial base,scientific research resource and market scale,since it takes the first place of the five cities in the comprehensive competitiveness of producer services,the competitiveness of industrial development,business environment and living environment,only inferior to Shanghai in the competitiveness of talent capital.Thirdly,Beijing has comparative disadvantages in the level of producer services development,urban innovation capability and living environment.Finally,five proposals are put forth to enhance the competitiveness of producer services in Beijing,namely perfecting the system of laws and statutes,supporting the development of industry association,implementing scientific development planning,introducing preferential fiscal and taxation policies and strengthening human capital reserve. 展开更多
关键词 producer services COMPETITIVENESS comparative analysis factor analysis model Beijing City
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Comparing of Aviation Network Structure of Mid-south,Northwest and Southwest of China Based on Hierarchical Index Model 被引量:1
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作者 Cheng Xiangjun Yang Fang Xie Li 《Journal of Traffic and Transportation Engineering》 2020年第1期14-19,共6页
In order to compare the aviation network of mid-south,northwest and southwest of China to reveal the structure similarity and difference for providing quantitative evidence to construct regional aviation network and i... In order to compare the aviation network of mid-south,northwest and southwest of China to reveal the structure similarity and difference for providing quantitative evidence to construct regional aviation network and improve its structure,hierarchical index model of regional aviation network was established through dividing the aviation network into layers to research its structure characters.Data matrixes were defined to record the basic state of regional aviation network.Index matrixes were constructed to describe the quantitative features of regional aviation network.On the basis of these indexes,several structure indexes of all layers of aviation network were calculated to show the structure features of aviation network,such as ratio of passenger volume within the region with across the region,share rate of passenger volume among layers,ratio of average number of airline for each airport,ratio of average passenger volume for each airline and ratio of airline rate.According to the statistical data,similar structure of share rate of passenger volume among layers and average passenger volume for each airline in their regional aviation network was found after calculating.But on the side of ratio of passenger volume within the region with across the region,ratio of average number of airlines for each airport and ratio of airline rate were different. 展开更多
关键词 Regional aviation network comparing of structure hierarchical index model index matrix structure index
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CLASSIFICATION AND COMPARISON OF WOOD DRYING MODELS
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作者 Chang Jianmin Dai Fangtian Northeast Forestry University 《Journal of Northeast Forestry University》 SCIE CAS CSCD 1993年第2期112-117,共6页
The Various models established by many scholar in the near years areclassified and compared between them.
关键词 WOOD drying. model. Classify compare.
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