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Circle of Willis atherosclerosis, Alzheimer's disease and the Dean number
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作者 Rovshan M Ismailov 《World Journal of Cardiology》 CAS 2013年第10期394-396,共3页
The important role of atherosclerosis in pathophysiology of Alzheimer's Disease has become evident.Mechanisms such as hyperlipidemia,inflammation,abdominal obesity and insulin resistance are important yet they may... The important role of atherosclerosis in pathophysiology of Alzheimer's Disease has become evident.Mechanisms such as hyperlipidemia,inflammation,abdominal obesity and insulin resistance are important yet they may not fully explain the specific involvement of the Circle of Willis in these pathologies.The Circle of Wills is a complex geometrical structure which has several areas with different curvature as well as various branching angles of vessels composing the circle.The hemodynamics in this region should take into account the Dean number which indicates the influence of curvature on the resistance to blood flow.Thus,areas with various curvature and angles may have different hemodynamics and there are certain areas in the Circle of Willis that are more likely to develop atherosclerotic changes.Therefore,this could suggest the novel pathophysiological pathway resulting from the geometric peculiarities of the Circle of Willis.One of the directions of future research is to examine whether specific areas of the Circle of Willis are more likely to develop atherosclerotic changes compared to other ones.Selective areas of the Circle of Willis affected by atherosclerotic changes could indicate the primary role of atherosclerosis promoting Alzheimer's disease although other pathophysiological mechanisms suggesting the opposite direction should be also examined in prospective studies. 展开更多
关键词 circle of willis Alzheimer’ s disease ATHEROSCLEROSIS MECHANISM The Dean number
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Variability of the Circle of Willis in North American Caucasian and Middle East Arabic Cohorts
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作者 Maryna Kornieieva Azmy Hadidy +1 位作者 Ashirbad Panta Melody Abadpour 《Open Journal of Modern Neurosurgery》 2021年第1期7-19,共13页
The cerebral arterial circle (circle of Willis) plays an important role in the redistribution of the blood flow between the anterior and posterior territories and maintains the plasticity of the cerebral blood circula... The cerebral arterial circle (circle of Willis) plays an important role in the redistribution of the blood flow between the anterior and posterior territories and maintains the plasticity of the cerebral blood circulation. The anatomical variability of the vascular circle often alters the cerebral hemodynamics and determines the outcomes of acute and chronic cerebrovascular disease. The heritability and prevalence of certain variants of the circle of Willis in different ethnic and racial groups are frequently disputed by authors. Our cross-sectional retrospective study aims to compare the patterns of the cerebral arterial circle in 64 Caucasian cadavers with 64 Arabic living individuals, by methods of anatomic dissection and magnetic resonance angiography, respectively. The typical structure of the circle of Willis was revealed in 8.3% of the Caucasian study group, and in 22.2% of the Arabic one. The anterior part of the circle of Willis was incomplete in 6 out of 64 of the Caucasian specimens, where the anterior communicating artery was hypoplastic (6.3%) or absent (3.1%). The posterior part of the circle of Willis had hypoplastic or absent posterior communicating artery on one side in 20, and on both sides in 12 out of 64 Caucasian specimens. In the Arabic cohort, the posterior part of the circle of Willis was incomplete in 17 out of 64 specimens, with absence of the posterior communicating artery unilaterally (in 11 cases) or bilaterally (in 6 cases). The present study reveals that the configuration of the cerebral arterial circle and distribution of the blood flow between the anterior and posterior territories have certain differences in the Caucasian study group versus the Arabic one. 展开更多
关键词 Arterial Cerebral circle Anterior Circulation Posterior Circulation Fetal Cerebral Circulation
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Willis环变异与缺血性卒中相关性的研究进展
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作者 曾潮坤 赵振强 《中国卒中杂志》 北大核心 2024年第2期213-218,共6页
通过尸体解剖和MRA等影像学技术,学者们发现Willis环存在变异,并将其分为不同类型。依托MRA技术,根据Willis环不同动脉段直径大小,可将Willis环分为4种类型。研究发现不同类型的Willis环与缺血性卒中的发病、发生部位及复发有关,然而不... 通过尸体解剖和MRA等影像学技术,学者们发现Willis环存在变异,并将其分为不同类型。依托MRA技术,根据Willis环不同动脉段直径大小,可将Willis环分为4种类型。研究发现不同类型的Willis环与缺血性卒中的发病、发生部位及复发有关,然而不同类型的Willis环与缺血性卒中的严重程度及预后的相关性存在一定的争议。本文就Willis环变异与缺血性卒中的相关性进行综述。 展开更多
关键词 willis 缺血性卒中 侧支循环
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Circle社交网络系统衍生的社区互助模式探究
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作者 黄浩 张华 《工业工程设计》 2024年第4期100-106,共7页
探究Circle社区网络系统衍生的社区互助模式并总结传统设计与协同创新设计对于协同设计者的职能要求。从多元主体、理念衍生与模式思辨三个层次梳理Circle服务系统流程及利益相关者,剖析Circle社区网络系统的设计模式。基于此,文章从行... 探究Circle社区网络系统衍生的社区互助模式并总结传统设计与协同创新设计对于协同设计者的职能要求。从多元主体、理念衍生与模式思辨三个层次梳理Circle服务系统流程及利益相关者,剖析Circle社区网络系统的设计模式。基于此,文章从行为认同、情感互动及体验价值三个层面建构了社区协同互助模式的设计策略,并进一步扩展出协同设计者的四条职能:思辨设计思维、跨学科知识体系、能级导向设计及协调创新。Circle社交网络系统衍生的社区协同互助模式在一定程度上能够引导和优化本土化社区的弹性和韧性,朝着更加有利于社会创新模式的方向不断发展。 展开更多
关键词 协同设计 社区互助模式 circle 协同设计者职能
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基于Circle映射和自适应t分布变异改进的鹈鹕优化算法
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作者 高猛 曾宪文 《计算机与现代化》 2024年第9期69-73,共5页
针对传统鹈鹕优化算法(POA)存在收敛速度慢、易陷入局部最优解等缺陷,提出一种基于Circle映射初始化和自适应t分布变异的改进的鹈鹕优化算法(IPOA)。首先,在种群初始化阶段,采用Circle映射生成具有高度多样性的初始解,并结合反向学习策... 针对传统鹈鹕优化算法(POA)存在收敛速度慢、易陷入局部最优解等缺陷,提出一种基于Circle映射初始化和自适应t分布变异的改进的鹈鹕优化算法(IPOA)。首先,在种群初始化阶段,采用Circle映射生成具有高度多样性的初始解,并结合反向学习策略,提高种群多样性,增强种群的探索能力。其次,在迭代过程中,采用自适应t分布变异操作对个体进行扰动,有助于鹈鹕优化算法跳出局部最优解并提高收敛速度。另外,在鹈鹕优化算法的探索阶段引入自适应因子和改进惯性权重,更好地平衡算法全局探索能力和局部开发能力。最后,在多个测试函数上将IPOA与其他4种经典算法进行比较。实验结果表明,IPOA在收敛速度、全局搜索能力和收敛鲁棒性方面均有显著提升。 展开更多
关键词 鹈鹕优化算法 circle映射 自适应因子 自适应t分布变异
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Comprehensive evaluation and spatial-temporal evolution characteristics of urban resilience in Chengdu-Chongqing Economic Circle
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作者 Xin Li Shuyi Zhang +1 位作者 Rongxi Ren Yafei Wang 《Chinese Journal of Population,Resources and Environment》 2024年第1期58-67,共10页
To clarify the connotations and extensions of urban resilience,this study focuses on the Chengdu-Chongqing Economic Circle with 16 cities as research subjects.A comprehensive evaluation index system was constructed to... To clarify the connotations and extensions of urban resilience,this study focuses on the Chengdu-Chongqing Economic Circle with 16 cities as research subjects.A comprehensive evaluation index system was constructed to measure the resilience of each city from 2003 to 2020.The spatial-temporal evolution characteristics were analyzed using Kernel density estimation,standard deviation ellipse,and spatial Markov chain analysis,and the spatial Tobit model was introduced to discover the influencing factors.The results indicate the following:①Urban resilience in the Chengdu-Chongqing Economic Circle displays an upward trend,with the center of gravity moving to the southwest,and the polarization phenomenon intensifying.②The urban resilience level in a region has certain spatial and geographical dependence,while the probability of urban resilience transfer differs in adjacent cities with different resilience levels.③Urban centrality,economic scale,openness level,and financial development promote urban resilience,whereas government scale significantly inhibits it.Finally,this paper proposes countermeasures and suggestions to improve the urban resilience of the Chengdu-Chongqing Economic Circle. 展开更多
关键词 Chengdu-chongqing Economic circle Urban resilience Spatial-temporal evolution Driving factor
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Research on the Evolution Structure of Fragment Disordering Public Opinion in College Students’ Network Circle Group
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作者 Huawei Zhi Yan Qiao 《Social Networking》 2024年第4期45-65,共21页
Clarifying the evolution structure of public opinion induced and spread by fragmentation in college students’ network circle group is the key to understanding college students’ online social psychological demands, g... Clarifying the evolution structure of public opinion induced and spread by fragmentation in college students’ network circle group is the key to understanding college students’ online social psychological demands, grasping the development trend of public opinion, and designing targeted public opinion governance strategies. On the basis of identifying the key variables in the process of public opinion communication, DEMATEL-ISM model is used to explore the attribute positioning, relative importance level and hierarchical association mechanism of ante-variable and result variable, and then the governance strategies for fragment disordering public opinion in network circle groups of college students is designed. According to the study, exogenous stimuli, the uniqueness of discourse system, the number of spectacular texts and micro-narrative mode constituted the deep-rooted causes of fragment disordering public opinion. The unique situational and information attributes of network circle groups often become an important “booster” of disordered public opinion. The topic deviation is often accompanied with the formation of negative emotions. The corresponding public opinion governance strategies are sought from the aspects of shaping the network environment, adjusting the operation mechanism of the network circle group, improving the efficiency of using fragmented information, and optimizing the human resources of colleges. 展开更多
关键词 College Students’ Network circle Group Fragment Disordering Public Opinion Governance DEMATEL ISM
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The Impact of Digital Finance on High-Quality Development of the Chengdu-Chongqing Economic Circle
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作者 Wei Liangyi Bai Xiaobo Li Qin 《Contemporary Social Sciences》 2024年第2期1-15,共15页
This paper developed a comprehensive evaluation system that was able to quantify the levels of high-quality development across the cities within the Chengdu-Chongqing economic circle,and investigate the impact that di... This paper developed a comprehensive evaluation system that was able to quantify the levels of high-quality development across the cities within the Chengdu-Chongqing economic circle,and investigate the impact that digital finance had on the cities’high-quality development and the underlying mechanisms through which it achieved this.This comprehensive evaluation system was constructed using statistical data from these cities for the period 2014 to 2020 while also taking China’s high-quality development philosophy into account.The key findings revealed that:(a)Digital finance was able to significantly promote high-quality development in the Chengdu-Chongqing economic circle;(b)Digital finance had a significant positive effect in promoting innovative,coordinated,green,open,and shared development;(c)Digital finance was able to stimulate the high-quality development in the Chengdu-Chongqing economic circle by boosting entrepreneurial dynamism;(d)Digital finance had a significant impact on the high-quality development of the axis areas,while its impact was less discernible in non-axis areas.The insights from this research offer a deeper understanding of the factors that drive high-quality development,the role digital finance plays,and the mechanisms through which digital finance is able to propel high-quality development at the city cluster scale. 展开更多
关键词 digital finance Chengdu-Chongqing economic circle high-quality development
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Coupling coordinated development among digital economy,regional innovation,and talent employment:A case study in the Hangzhou Metropolitan Circle,China
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作者 QIU Luyi Sharina OSMAN HUA Yidi 《Regional Sustainability》 2024年第1期93-106,共14页
Coordinative development across various systems,particularly the economic,social,cultural,and human resources subsystems,is a key aspect of urban sustainability and has a direct impact on the quality of urbanization.T... Coordinative development across various systems,particularly the economic,social,cultural,and human resources subsystems,is a key aspect of urban sustainability and has a direct impact on the quality of urbanization.The Hangzhou Metropolitan Circle,comprising Hangzhou City,Huzhou City,Jiaxing City,and Shaoxing City,was the first metropolitan circle approved by the National Development and Reform Commission(NDRC)as a demonstration of economic transformation in China.To evaluate the coupling coordination degree of the four cities and analyze the coordinative development in three systems(including digital economy,regional innovation,and talent employment),we collected panel data during 2015–2022 from these four cities.The development level of the three systems was evaluated by the standard deviation method and comprehensive development index.The results are as follows:(1)the level of coupling coordinated development of the three systems in the Hangzhou Metropolitan Circle was relatively low;(2)the coupling coordination degree of the four cities in the Hangzhou Metropolitan Circle showed significant regional differences,among which Hangzhou City was in the leading position,and Huzhou,Jiaxing,and Shaoxing cities made steady but slow progress in the coupling development of the three systems;and(3)the development of digital economy and talent employment needs to be strengthened.This study contributes to the coordinative development of Hangzhou Metropolitan Circle by innovatively focusing on the coupling coordination relationship among digital economy,regional innovation,and talent employment,which also meets the industrial layout of Hangzhou Metropolitan Circle.In this way,the optimal allocation and sustainable development of digital economy,regional innovation,and talent employment in the Hangzhou Metropolitan Circle can be achieved. 展开更多
关键词 Digital economy Regional innovation Talent employment Coupling coordination degree Hangzhou Metropolitan circle
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Enhancing Women's Well-being and Self-Confidence through Fragrance Cosmetics:Perceptions within Close and Broader Social Circles
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作者 Yang Fan Guo Miao +1 位作者 Zhou Ziyan Abriat Anne 《China Detergent & Cosmetics》 CAS 2024年第2期69-78,共10页
Mental and physical stress can affect people's self-confidence and happiness.The primary objective of this study is to develop an active fragrance that has been proved to have a positive effect on happiness and se... Mental and physical stress can affect people's self-confidence and happiness.The primary objective of this study is to develop an active fragrance that has been proved to have a positive effect on happiness and self-confidence based on the latest research results of aroma components and fragrance innovation.The active fragrance is applied to the cream formula to study the emotions it brings to the user and extend the research scope of the active emotion to the close and extensive social circle of users to see whether it can perceive it.This study provides a reference cosmetic solution for emotional regulating active fragrance. 展开更多
关键词 FRAGRANCE emotion CREAM social circle
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Identification and Optimisation of Cycling Life Circle in High Density Communities with Public Health Support: A Case Study of Tiantongyuan in Beijing
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作者 LIANG Weinan HUANG Yi +1 位作者 WANG Zilin ZHOU Xuan 《Journal of Landscape Research》 2024年第5期27-32,37,共7页
In recent years,the compact development of high-density cities has sparked ongoing interest in healthy urban environments and public well-being.This study examines the relationship between cycling behaviors and the bu... In recent years,the compact development of high-density cities has sparked ongoing interest in healthy urban environments and public well-being.This study examines the relationship between cycling behaviors and the built environment of streets in Tiantongyuan Community,a typical high-density area in Beijing,China.By observing street spaces and summarizing residents’travel modes and behaviors,the study evaluates the impact of street design on cycling habits.In order to reveal the riding behavior characteristics of residents in different time periods and different street spaces,tools such as track recording APPs and the Gopro Motion Camera are employed to collect street view pictures and riding track data comprehensively,analyzing the various travel purposes of residents in Tiantongyuan community and the riding OD activity tracks of the main entrances and exits of the community.Meanwhile,by conducting the questionnaire survey of residents’travel demands and OD data of Baidu,and utilizing geographic information system(GIS)for data visualization,this study further investigates the distribution characteristics of cycling hotspots,cycling paths and cycling space,accurately identifies the cycling life circle of this community based on the spatial and temporal scales,and further puts forward the optimization strategy of the cycling network.Some cycling-friendly street space optimization strategies are suggested to deeply analyze the mechanism of the built environment of street space in high-density communities on the cycling activities and health of urban residents,with a view to provide accurate data support for the renewal of street cycling space. 展开更多
关键词 Public health High-density neighbourhoods Cycling life circle Precision update Tiantongyuan community
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Spatial Distribution Characteristics and Coverage Rate of Commercial Facilities in 15-minute Radius Livelihood Service Circles of Chunshu Street
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作者 HAN Qiqi YANG Kaitai 《Journal of Landscape Research》 2024年第1期17-21,共5页
Building a 15-minute radius livelihood service circle from the needs of residents is a topdown process of optimizing urban layout and promoting high-quality development implemented by the government.In September 2022,... Building a 15-minute radius livelihood service circle from the needs of residents is a topdown process of optimizing urban layout and promoting high-quality development implemented by the government.In September 2022,Xicheng District of Beijing served as a national pilot of the 15-minute radius livelihood service circle.Based on the data of POI,urban walking network and building outline,this paper studies the coverage of commercial service facilities in the 15-minute radius livelihood service circle of Chunshu Street by using kernel density analysis and urban network analysis tools.The research shows that the commercial facilities are concentrated in Zhuangsheng Square and Dazhalan commercial district.There are large gaps in housekeeping and couriers logistics facilities,which need to be further improved. 展开更多
关键词 Chunshu Street 15-minute radius livelihood service circle POI Historic urban areas Community business
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Everything Is a Circle: A New Universal Orbital Model
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作者 Asli Pinar Tan 《Advances in Aerospace Science and Technology》 2024年第3期94-116,共23页
Based on measured astronomical position data of heavenly objects in the Solar System and other planetary systems, all bodies in space seem to move in some kind of elliptical motion with respect to each other. Accordin... Based on measured astronomical position data of heavenly objects in the Solar System and other planetary systems, all bodies in space seem to move in some kind of elliptical motion with respect to each other. According to Kepler’s 1st Law, “orbit of a planet with respect to the Sun is an ellipse, with the Sun at one of the two foci.” Orbit of the Moon with respect to Earth is also distinctly elliptical, but this ellipse has a varying eccentricity as the Moon comes closer to and goes farther away from the Earth in a harmonic style along a full cycle of this ellipse. In this paper, our research results are summarized, where it is first mathematically shown that the “distance between points around any two different circles in three-dimensional space” is equivalent to the “distance of points around a vector ellipse to another fixed or moving point, as in two-dimensional space”. What is done is equivalent to showing that bodies moving on two different circular orbits in space vector-wise behave as if moving on an elliptical path with respect to each other, and virtually seeing each other as positioned at an instantaneously stationary point in space on their relative ecliptic plane, whether they are moving with the same angular velocity, or different but fixed angular velocities, or even with different and changing angular velocities with respect to their own centers of revolution. This mathematical revelation has the potential to lead to far reaching discoveries in physics, enabling more insight into forces of nature, with a formulation of a new fundamental model regarding the motions of bodies in the Universe, including the Sun, Planets, and Satellites in the Solar System and elsewhere, as well as at particle and subatomic level. Based on the demonstrated mathematical analysis, as they exhibit almost fixed elliptic orbits relative to one another over time, the assertion is made that the Sun, the Earth, and the Moon must each be revolving in their individual circular orbits of revolution in space. With this expectation, individual orbital parameters of the Sun, the Earth, and the Moon are calculated based on observed Earth to Sun and Earth to Moon distance data, also using analytical methods developed as part of this research to an approximation. This calculation and analysis process have revealed additional results aligned with observation, and this also supports our assertion that the Sun, the Earth, and the Moon must actually be revolving in individual circular orbits. 展开更多
关键词 Solar System Planetary System PLANET Satellite Earth MOON Topology circle Sun ELLIPSE ORBIT TRAJECTORY Orbital Mechanics
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Progress of International Meridian Circle Program
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作者 WANG Chi BLANC Michel +13 位作者 ZHANG Shunrong DENARDINI Clezio Marcos LIU William SHEN Xuhui WU Jian XU Jiyao LI Hui ZHANG Qinghe REN Liwen ZHU Yajun LI Guozhu DING Zonghua LIU Zhengkuan YANG Fang 《空间科学学报》 CAS CSCD 北大核心 2024年第4期741-745,共5页
In 2024,the Chinese Meridian Project(CMP)completed its construction,deploying 282 instruments across 31 stations.This achievement not only provides a robust foundation but also serves as a reference template for the I... In 2024,the Chinese Meridian Project(CMP)completed its construction,deploying 282 instruments across 31 stations.This achievement not only provides a robust foundation but also serves as a reference template for the International Meridian Circle Program(IMCP).The IMCP aims to integrate and establish a comprehensive network of ground-based monitoring stations designed to track the propagation of space weather events from the Sun to Earth.Additionally,it monitors various disturbances generated within the Earth system that impact geospace.Over the past two years,significant progress has been made on the IMCP.In particular,the second phase of construction for the China-Brazil Joint Laboratory for Space Weather has been completed,and the North Pole and Southeast Asia networks are under active construction.The 2024 IMCP joint observation campaign was successfully conducted.To facilitate these developments,the scientific program committee of IMCP was established,following the success of 2023 IMCP workshop and the space weather school,which was co-hosted with the Asia-Pacific Space Cooperation Organization(APSCO)and sponsored by Chinese Academy of Sciences(CAS)and Scientific Committee on Solar-Terrestrial Physics(SCOSTEP).Preparations are now underway for the 2024 workshop in collaboration with the National Institute for Space Research(INPE)in Brazil. 展开更多
关键词 Chinese Meridian Project(CMP) International Meridian circle Program(IMCP) China-Brazil Joint Laboratory for Space Weather North Pole and Southeast Asia networks
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Research on the Application of Evidence-Based Quality Control Circle to Improve the Implementation Rate of Airway Management Measures in Adult Critically Ill Patients
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作者 Yujiao Yan Jing Wu +4 位作者 Juan Liu Yanting Yuan Lixin Liu Huaxin Ye Juan Ding 《Yangtze Medicine》 2024年第1期8-19,共12页
Objective: To explore the effect of evidence-based quality control circle (QCC) in improving the implementation rate of airway management measures in adult critically ill patients. Methods: Based on the Joanna Briggs ... Objective: To explore the effect of evidence-based quality control circle (QCC) in improving the implementation rate of airway management measures in adult critically ill patients. Methods: Based on the Joanna Briggs Institute (JBI) evidence-based health care model, the best evidence of airway management in adult critically ill patients was obtained and applied to the clinic. Results: The total implementation rate of airway management measures in adult critically ill patients increased from 23.62% before the implementation of quality control circle to 88.82%, and the pulmonary infection rate in critically ill patients decreased from 42.31% to 21.74%, with statistical significance between the two groups (P 0.05). Conclusion: Evidence-based quality control circle activities can standardize the practice standards of airway management in critically ill patients, reduce the occurrence of patients’ airway related complications, and improve clinical outcomes. 展开更多
关键词 Critically Ill Patients Airway Management Be Evidence-Based Quality Control circle Intensive Care Unit (ICU)
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Research on Sports Public Service Supply in the Chengdu-Chongqing Twin-City Economic Circle under the Background of Regional Economic Development
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作者 Yiming Yang Yun Liu Yu Huang 《Proceedings of Business and Economic Studies》 2024年第2期106-113,共8页
Using literature,questionnaires,interviews,and mathematical statistics to investigate the current situation of sports public services in the Chengdu-Chongqing Twin-city Economic Circle.The results show that there are ... Using literature,questionnaires,interviews,and mathematical statistics to investigate the current situation of sports public services in the Chengdu-Chongqing Twin-city Economic Circle.The results show that there are some problems in Chengdu-Chongqing sports public services,such as big difference in the development level of supply between urban and rural areas,low supply level,low efficiency,supply mechanism defect,lack of social sports instructors,an outstanding contradiction between the quality of sports public service and residents’demand.To address the problems,government departments should accelerate the transformation of government functions,improve the relevant regulations and systems,increase the investment in sports public services,improve the quality of supply,cultivate the backbone team,integrate resources,and combine the national characteristics with regional characteristics,take into account the personalized needs of the residents,combine the sports public services with intelligence,and build the service system of“Internet+Fitness.” 展开更多
关键词 Regional economy Chengdu-Chongqing Twin-city Economic circle Sports demand Sports public service Current supply situation
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正常国人Willis环形态的MRA研究 被引量:37
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作者 陈述花 于铁链 +3 位作者 张云亭 刘国栋 陆国庆 范红 《临床放射学杂志》 CSCD 北大核心 2003年第9期732-736,共5页
目的 联合运用多种MRA序列和 /或 3DFSPGR序列观察正常国人的Willis环形态及其类型。资料与方法 行MRA检查的正常国人 16 7例。图像分析采用联合分析方法 ,根据Willis环完整情况将Willis环形态分为Ⅰ型 (Willis环完整 )、Ⅱ型 (Willi... 目的 联合运用多种MRA序列和 /或 3DFSPGR序列观察正常国人的Willis环形态及其类型。资料与方法 行MRA检查的正常国人 16 7例。图像分析采用联合分析方法 ,根据Willis环完整情况将Willis环形态分为Ⅰ型 (Willis环完整 )、Ⅱ型 (Willis环前循环完整后循环不完整 )、Ⅲ型 (Willis环前循环不完整后循环完整 )、Ⅳ型 (Willis环前、后循环均不完整 ) ,然后根据组成血管发育情况 ,各类型又分成典型型、变异型、发育不良型和混合型 4种亚型。结果  16 7例正常国人中 ,Ⅰ型占 44 .31%(74/16 7) ,Ⅱ型占 41.92 %(70 /16 7) ,Ⅲ型占 6 .5 9%(11/16 7) ,Ⅳ型占7.19%(12 /16 7)。后交通动脉显示率为 6 4.97%(2 17/334 ) ,前交通动脉显示率为 87.43%(146 /16 7) ,A1段发育不良者占 5 .6 9%(19/334 ) ,未显示者占 1.80 %(6 /334 )。P1段发育不良者占 12 .87%(43/334 ) ,未显示者占 1.2 0 %(4/334 )。结论 利用MRA对正常国人Willis环形态进行分型 ,可为今后有关研究提供依据。 展开更多
关键词 willis 形态 磁共振血管成像 正常人 脑血管 图像分析 诊断
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Willis环三维时间飞跃法磁共振成像的形态、解剖变异及脑底动脉直径测量 被引量:30
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作者 何杰 刘怀军 +1 位作者 黄勃源 池琛 《生物医学工程学杂志》 EI CAS CSCD 北大核心 2007年第1期39-44,共6页
通过三维时间飞跃法磁共振成像建立正常国人Willis环的形态、解剖变异及各组成血管直径的正常参考值,探讨其临床意义,决定在Willis环的解剖中是否存在年龄或性别差异。153例健康志愿者和体检者做头MRA检查,显示Willis环,根据其完整情况... 通过三维时间飞跃法磁共振成像建立正常国人Willis环的形态、解剖变异及各组成血管直径的正常参考值,探讨其临床意义,决定在Willis环的解剖中是否存在年龄或性别差异。153例健康志愿者和体检者做头MRA检查,显示Willis环,根据其完整情况分为I型(Willis环完整)、II型(Willis环前循环完整后循环不完整)、III型(Willis环前循环不完整后循环完整)、IV型(Willis环前后循环均不完整),根据各血管发育情况,各型又分为典型型、变异型、发育不良型和混合型4种亚型,并对各组成血管直径进行测量。结果表明:153例中,I型占34.64%,II型占47.71%,III型占5.23%,IV型占12.42%。各型及各亚型的年龄、性别差异无显著性。前交通动脉显示率为87.58%,后交通动脉显示率为65.34%,胚胎型大脑后动脉出现率为20.92%。MRA评价Willis环的形态和变异有重要的临床意义,脑底动脉MRA正常值可作为临床判断脑血管疾病的参考。 展开更多
关键词 磁共振血管成像 willis 形态 影像解剖学 摄影测量法
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颈内动脉严重狭窄时脑部症状与Willis环侧支循环建立的关系 被引量:34
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作者 惠品晶 陈谋森 +3 位作者 刘春风 张丽 王之敏 张世明 《中风与神经疾病杂志》 CAS CSCD 北大核心 2002年第5期278-280,共3页
目的 应用经颅超声多普勒 (TCD)检测颈内动脉 (ICA )严重狭窄 ,探讨 Willis环的侧支循环与临床症状之间的相关性。方法 分析 34例 ICA严重狭窄患者 (其中有症状组 16例和无症状组 18例 )侧支循环的类型、大脑中动脉 (MCA)的平均血流速... 目的 应用经颅超声多普勒 (TCD)检测颈内动脉 (ICA )严重狭窄 ,探讨 Willis环的侧支循环与临床症状之间的相关性。方法 分析 34例 ICA严重狭窄患者 (其中有症状组 16例和无症状组 18例 )侧支循环的类型、大脑中动脉 (MCA)的平均血流速度 (Vm)、脉动指数 (PI)及频谱改变 ,并与 30例正常人进行对照。结果 存在 3种侧支循环类型 :前交通动脉 (ACOA)型 ,后交通动脉 (PCOA)型 ,眼动脉 (OA)型。无症状组的侧支循环中 ,ACOA型占 88.9% ,狭窄侧 MCA Vm为 5 9.1± 8.7cm / s;有症状组 ACOA型占 5 0 % ,有 4例未检出侧支循环 ,狭窄侧 MCAVm为 4 8.6± 7.3cm/ s(P<0 .0 0 1)。所有患者狭窄侧的 MCA PI减低 (P<0 .0 0 1) ,且频谱低平呈波浪状 ,波峰变钝 ,失去收缩峰的特征。结论  TCD可以发现 ICA严重狭窄患者 Willis环侧支循环的显著异常改变 ,研究 Willis环的侧支循环对 ICA严重狭窄患者治疗和预后的判断具有重要的临床价值。 展开更多
关键词 颈内动脉狭窄 willis 侧支循环 经颅多普勒超声 TCD
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CT灌注成像联合CT血管造影评价颈内动脉或大脑中动脉狭窄患者脑血流灌注及Willis环结构对灌注分布的影响 被引量:26
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作者 颜利辉 戴真煜 +2 位作者 姚立正 李新 周桂龙 《中国医学影像技术》 CSCD 北大核心 2012年第3期435-438,共4页
目的探讨脑CT灌注(CTP)成像联合CTA检查颈内动脉或大脑中动脉狭窄患者脑血流灌注情况及Willis环结构对脑血流灌注分布影响的价值。方法对经颅多普勒(TCD)诊为单侧颈动脉狭窄的42例患者行CTP联合CTA检查,观察血管狭窄部位、程度、Willis... 目的探讨脑CT灌注(CTP)成像联合CTA检查颈内动脉或大脑中动脉狭窄患者脑血流灌注情况及Willis环结构对脑血流灌注分布影响的价值。方法对经颅多普勒(TCD)诊为单侧颈动脉狭窄的42例患者行CTP联合CTA检查,观察血管狭窄部位、程度、Willis环形态及脑血流灌注情况。结果经CTP联合CTA检查,29例为颈内动脉狭窄,13例为大脑中动脉狭窄;轻度狭窄11例,中度狭窄13例,重度狭窄14例,闭塞4例。狭窄侧与对侧血管相比,轻度狭窄患者各灌注参数差异均无统计学意义(P均>0.05);中度狭窄患者狭窄侧MTT、TTP高于对侧(P均<0.05);重度狭窄或闭塞患者狭窄侧CBF低于对侧,CBV、MTT、TTP高于对侧(P均<0.05)。42例中21例存在灌注异常,颈内动脉与大脑中动脉狭窄患者间异常灌注区分型差异有统计学意义(P<0.05)。结论CTP联合CTA检查可较好地评价颈内动脉或大脑中动脉狭窄患者脑血流动力学及Willis环血管形态。 展开更多
关键词 体层摄影术 X线计算机 灌注成像 willis 血流动力学
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