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Functional connectivity of paired default mode network subregions in patients with eye trauma
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作者 Zheng-Mao Xing Dan Song +12 位作者 Jin-Yu Hu Xian-Mei Zhou Xuan Liao Cheng Chen Hong Wei Min Kang Qian Ling Liang-Qi He Zhen-Zhe Liu Jie Zou Xu Chen Zhen-Kai Wu Yi Shao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第12期2248-2255,共8页
AIM:To study functional brain abnormalities in patients with eye trauma(ET)and to discuss the pathophysiological mechanisms of ET.METHODS:Totally 31 ET patients and 31 healthy controls(HCs)were recruited.The age,gende... AIM:To study functional brain abnormalities in patients with eye trauma(ET)and to discuss the pathophysiological mechanisms of ET.METHODS:Totally 31 ET patients and 31 healthy controls(HCs)were recruited.The age,gender,and educational background characteristics of the two groups were similar.After functional magnetic resonance imaging(fMRI)scanning,the subjects’spontaneous brain activity was evaluated with the functional connectivity(FC)method.Receiver operating characteristic(ROC)curve analysis was used to classify the data.Pearson’s correlation analysis was used to explore the relationship between FC values in specific brain regions and clinical behaviors in patients with ET.RESULTS:Significantly increased FC between several regions was identified including the medial prefrontal cortex(MPFC)and left hippocampus formations(HF),the MPFC and left inferior parietal lobule(IPL),the left IPL and left medial temporal lobe(MTL),the left IPL and right MTL,and the right IPL and left MTL.No decreased region-to-region connectivity was detected in default mode network(DMN)sub-regions in patients with ET.Compared with HCs,ET patients exhibited significantly increased FC between several paired DMN regions,as follows:posterior cingulate cortex(PCC)and right HF(HF.R,t=2.196,P=0.032),right inferior parietal cortices(IPC.R)and left MTL(MTL.L,t=2.243,P=0.029),and right MTL(MTL.R)and HF.R(t=2.236,P=0.029).CONCLUSION:FC values in multiple brain regions of ET patients are abnormal,suggesting that these brain regions in ET patients may be dysfunctional,which may help to reveal the pathophysiological mechanisms of ET. 展开更多
关键词 eye trauma functional connectivity brain region
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Integrity and Size of Green Spaces Are Critical for the Functional Di-versity of Birds:Evidence from the Eastern and Northwestern Regions of China
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作者 GONG Lingxuan WANG Lili +5 位作者 YAO Yao WU Linyi WANG Su TAN Bingchang YUAN Hongdan HU Runan 《Chinese Geographical Science》 SCIE CSCD 2024年第6期1073-1089,共17页
Urbanization often changes bird species richness and affects the functional diversity.Therefore,understanding these changes helps city planners improve green space design and land use planning.Our study used multiple ... Urbanization often changes bird species richness and affects the functional diversity.Therefore,understanding these changes helps city planners improve green space design and land use planning.Our study used multiple datasets to explore the effects of land-scape patterns and natural environments on the functional diversity of birds in urban parks and campuses in the eastern and northwest-ern regions of China.Firstly,we used the data to calculate birds of the functional richness(FRic),functional evenness(FEve),and func-tional divergence(FDiv)of 68 urban spaces in the eastern and northwestern regions of China.Further,we established generalized linear models of natural factors,human factors,and functional diversity.Results showed more bird species with unique traits were in the north-western region.This may be because the earlier urbanization in the eastern region filtered out urban-sensitive species,leaving behind urban adapters.Moreover,we found that the fractal dimension index was the most significant positive factor of FRic in the eastern re-gion but the most significant negative factor of FDiv.Elevation was the most significant negative influence factor of FEve in the eastern region,but it was the most potent positive influence factor of FRic in the northwestern region.Population density had a significant posit-ive effect on FDiv in the northwestern region.However,green space areas significantly negatively impacted FEve in the northwestern region.In addition,birds in parks in both regions had more functional traits than those on campuses,possibly because of the larger green space in parks,which may contain more fragments of native vegetation and reduce human interference.Our study suggests that pre-serving more original vegetation and reducing human disturbance in cities can increase the functional diversity of urban birds and im-prove urban ecosystem functions. 展开更多
关键词 BIRDS functional diversity green space the eastern and northwestern regions of China
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Functional regionalization with the restriction of ecological shelter zones: A case of Zhaotong in Yunnan 被引量:6
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作者 DU Yu WANG Chuansheng ZHAO Haiying YANG Xiaoguang 《Journal of Geographical Sciences》 SCIE CSCD 2007年第3期365-374,共10页
Ecological shelter zones reconstruction is an ecosystem restoration and conservation project aimed to the ecological safety of nations, regions and basins. Reconstruction of ecological shelter zones of the upper reach... Ecological shelter zones reconstruction is an ecosystem restoration and conservation project aimed to the ecological safety of nations, regions and basins. Reconstruction of ecological shelter zones of the upper reaches of the Yangtze River became one of the most important tasks of Western Development strategy. This article, taking Zhaotong as an example, studies the functional regionalization of ecological shelter zones. The study supplies a case for functional regionalization of small and medium regions whose main tasks are environment reservation. With the guidance of theories of functional regionalization, and based on the analysis of Zhaotong's natural, ecological and socioeconomic factors, the paper suggests five principles for factors selection. These principles include: (1) reversing order evaluation; (2) selecting main factors; (3) keeping the integrality of administrative regions of towns; and (4) making the products acceptable by local government. To analyze spatial status of selected factors, LUCC data in 2002, 1:50,000 relief maps and town-unit socioeconomic statistical data in 2004 are used. RS and GIS tools are also applied to melt traditional and modern geographical methods. This would be useful to functional regionalization research in mountainous areas. As a conclusion, the leading functional regions of ecological conservation or economic development are suggested, respectively. Zhaotong city is divided into two-level functional regions. The first-level includes three leading functional regions and they will lead developing direction of sub-regions. The second-level includes eight sub-regions, which are policy implemented regions, and will supply guidance to Zhaotong's ecological shelter zones reconstruction. 展开更多
关键词 ecological shelter zones functional regionalization Zhaotong
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Major Function Oriented Zone: New Method of Spatial Regulation for Reshaping Regional Development Pattern in China 被引量:30
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作者 FAN Jie SUN Wei +1 位作者 ZHOU Kan CHEN Dong 《Chinese Geographical Science》 SCIE CSCD 2012年第2期196-209,共14页
Newest planning methods implemented by Chinese government are promoting a coordinated regional development and shaping an orderly spatial structure by applying the regulation of territorial function. This article anal... Newest planning methods implemented by Chinese government are promoting a coordinated regional development and shaping an orderly spatial structure by applying the regulation of territorial function. This article analyzes the problems of spatial planning and regional strategy caused by the wrongly-set primary goal of economic development; it states that the three-fold objective of competitiveness, sustainability, and welfare fairness shall be the principal for China to implement the spatial regulation in the new era; it discusses about theoretical thoughts and technology framework of conducting the ′Major Function Oriented Zone′ based on their different major functions that each region plays in urbanization and industrialization, ecological constructions, grain productions, and protection of natural and cultural heritages; it introduces the new concept of ′Major Function Oriented Zone′ that include the major functions category, the stereo regional equilibrium mode, the two-level zoning specification, and the territorial development intensity; it offers a zoning scheme that defines development-optimized and development-prioritized zones as regions with massive urbanization and industrialization, development-restricted zones as ecological constructing or grain producing regions, development-prohibited zones as natural and cultural heritage protecting regions; and finally it addresses the main obstacle for implementing ′Major Function Oriented Zone′, which is the institutional arrangement of the supreme goal of high GDP growth rate that is currently being implemented. 展开更多
关键词 Major function Oriented Zone (MFOZ) spatial regulation regional development China
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Roles and Functions of Tourism Destinations in Tourism Region of South Anhui:A Tourist Flow Network Perspective 被引量:9
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作者 LIU Fajian ZHANG Jinhe +3 位作者 ZHANG Jie CHEN Dongdong LIU Zehua LU Song 《Chinese Geographical Science》 SCIE CSCD 2012年第6期755-764,共10页
Theoretic and practical significance has been highlighted in the research of the roles and functions of destinations,as destinations are restricted by the spatial structure based on tourist flow network from the persp... Theoretic and practical significance has been highlighted in the research of the roles and functions of destinations,as destinations are restricted by the spatial structure based on tourist flow network from the perspective of relationship.This article conducted an empirical analysis for Tourism Region of South Anhui(TRSA) and revealed the necessity and feasibility of studying the roles and functions of destinations from tourist flow network's perspective.The automorphic equivalence analysis and centrality analysis were used to classify 16 destinations in TRSA into six role types:tourist flow distribution center,hub of tourist flows,passageway destination,common touring destination,attached touring destination,and nearly isolated destination.Some suggestions were given on suitable infrastructure construction and destinations service designs according to their functions in network.This destination role positioning was based on tourist flow network structure in integral and macroscopic way.It provided an important reference for the balanced and harmonious development of all the destinations of TRSA.In addition,this article verified the applicability of social network analysis on tourist flow research in local scale,and expanded this method to destination role and function positioning. 展开更多
关键词 tourist flow network equivalence model ROLES functionS centrality analysis Tourism region of South Anhui
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CLASSES OF MEROMORPHIC FUNCTIONS ASSOCIATED WITH CONIC REGIONS 被引量:2
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作者 J.Dziok 《Acta Mathematica Scientia》 SCIE CSCD 2012年第2期765-774,共10页
The object of this article is to introduce new classes of meromorphic functions associated with conic regions. Several properties like the coefficient bounds, growth and distortion theorems, radii of starlikeness and ... The object of this article is to introduce new classes of meromorphic functions associated with conic regions. Several properties like the coefficient bounds, growth and distortion theorems, radii of starlikeness and convexity, partial sums, are investigated. Some consequences of the main results for the well-known classes of meromorphic functions are also pointed out. 展开更多
关键词 Meromorphic functions conic regions varying argument SUBORDINATION Hadamard product CONVOLUTION
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Economic polarized trends,function and expanded boundaries of the Yangtze Delta Region 被引量:5
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作者 段学军 虞孝感 Josef Nipper 《Journal of Geographical Sciences》 SCIE CSCD 2009年第6期733-749,共17页
In the era of economic globalization,the concept of Economic Polarized Area comes into being as an effective vehicle to agglomerate the economic elements and sustain the economic lifeline of the region. Based on the r... In the era of economic globalization,the concept of Economic Polarized Area comes into being as an effective vehicle to agglomerate the economic elements and sustain the economic lifeline of the region. Based on the region's specific development mode and construction form the concept is working in such a way that it will contribute to guide the economic development of the country and will play an important role in competing with other regions or countries in the world. Due to the high speed development of the last 30 years,the Yangtze Delta Region starts to show the features of Economic Polarized Area. But,compared with other world-class Economic Polarized Areas,the economic strength and the ability of the Yangtze Delta Region to drive the country's economic development is still very low and the competitive power is still very limited. Expanding the boundaries of the Economic Polarized Area of the Yangtze Delta may extend the economic hinterland of the core area of the Yangtze Delta Region,will lighten the pressures from the limited resource and promote the rationalization of the industrial structure in the Yangtze Delta Region's core area. With regard to the reasonable boundaries of the Yangtze Delta Region,there are different opinions and controversial arguments in political and academic circles. Starting from the idea of increasing the competitive power and improving the economic strength of the Yangtze Delta Region,the paper firstly is discussing the requirements to become a world-class Economic Polarized Area. In a second step an analysis of functional complementation and economic collaboration between the cities of an "extended" Yangtze Delta Region has been carried out by in particular considering the feasibility of integrating these "newly included" cities. The final result of the study is,that the Region should be expanded from the number of 16 cities to 37 cities,and the appended cities should be divided up into two categories:Wenzhou,Jinhua,Yancheng,Huaian,Maanshan,Wuhu,Tongling,Chaohu,Hefei,Chuzhou,Xuancheng should be taken as Preferred Extending Area,and Suqian,Xuzhou,Lianyungang,Lishui,Quzhou,Chizhou,Anqing,Bengbu,Huangshan,Suzhou (Anhui Province) should be taken as Retained Qualification Area. 展开更多
关键词 Economic Polarized Area function expanded boundaries Yangtze Delta region
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Speckle tracking echocardiography to assess regional ventricular function in patients with apical hypertrophic cardiomyopathy 被引量:8
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作者 María Cristina Saccheri Tomás Francisco Cianciulli +7 位作者 Luis Alberto Morita Ricardo JoséMéndez Martín Alejandro Beck Juan Enrique Guerra Alberto Cozzarin Luciana Jimena Puente Lorena Romina Balletti Jorge Alberto Lax 《World Journal of Cardiology》 CAS 2017年第4期363-370,共8页
AIM To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy(HCM).METHODS We prospectively assessed 20 patient... AIM To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy(HCM).METHODS We prospectively assessed 20 patients(mean age 53 ± 16 years,range:18-81 years,10 were male),with apical HCM. We measured global longitudinal peak systolic strain(GLPSS) in the midwall and endocardium of the left ventricle. RESULTS The diastolic thickness of the 4 apical segments was 16.25 ± 2.75 mm. All patients had a normal global systolicfunction with a fractional shortening of 50% ± 8%. In spite of supernormal left ventricular(LV) systolic function,midwall GLPSS was decreased in all patients,more in the apical(-7.3% ±-8.8%) than in basal segments(-15.5% ±-6.93%),while endocardial GLPPS was significantly greater and reached normal values(apical:-22.8% ±-7.8%,basal:-17.9% ±-7.5%). CONCLUSION This study shows that two-dimensional strain was decreased mainly confined to the mesocardium,while endocardium myocardial deformation was preserved in HCM and allowed to identify subclinical LV dysfunction. This transmural heterogeneity in systolic strain had not been previously described in HCM and could be explained by the distribution of myofibrillar disarray in deep myocardial areas. The clinical application of this novel finding may help further understanding of the pathophysiology of HCM. 展开更多
关键词 Apical hypertrophic cardiomyopathy Twodimensional strain Speckle tracking ENDOCARDIUM Midwall regional myocardial systolic function
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Determination of the degree 120 time-variable gravity field in the Sichuan-Yunnan region using Slepian functions and terrestrial measurements 被引量:5
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作者 Jiancheng Han Shi Chen +2 位作者 Zhaohui Chen Hongyan Lu Weimin Xu 《Earthquake Science》 2021年第3期211-221,共11页
The terrestrial time-variable gravity measurements are characterized by a high signal-to-noise ratio and sensitivity to the sources of mass change in the Earth's crust.These gravity data have many applications,suc... The terrestrial time-variable gravity measurements are characterized by a high signal-to-noise ratio and sensitivity to the sources of mass change in the Earth's crust.These gravity data have many applications,such as surface deformation,groundwater storage changes,and mass migration before and after earthquakes.Based on repeated terrestrial gravity measurements at 198 gravity stations in the Sichuan-Yunnan region(SYR)from 2015 to 2017,we determine a time series of degree 120 gravity fields using the localized spherical harmonic(Slepian)basis functions.Our results show that adopting the first 6 Slepian basis functions is sufficient for effective localized Slepian modeling in the SYR.The differences between two gravity campaigns at the same time of year show an obvious correlation with tectonic features.The degree 120 timevariable gravity models presented in this paper will benefit the study of the regional mass migration inside the crust of the SYR and supplement the existing geophysical models for the China Seismic Experimental Site. 展开更多
关键词 Sichuan-Yunnan region terrestrial gravity measurements time-variable gravity Slepian basis function regional gravity field
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Left Ventricular Regional Systolic Function in Patient with Hypertrophic Cardiomyopathy by Quantitative Tissue Velocity Imaging 被引量:3
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作者 李秀兰 邓又斌 杨好意 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2006年第1期153-156,共4页
The left ventricular regional systolic functions in patients with hypertrophic cardiomyopathy (HCM) were assessed by using quantitative tissue velocity imaging (QTVI). Left ventricular (LV) regional myocardial v... The left ventricular regional systolic functions in patients with hypertrophic cardiomyopathy (HCM) were assessed by using quantitative tissue velocity imaging (QTVI). Left ventricular (LV) regional myocardial velocity along long- and short-axis in 31 HCM patients and 20 healthy subjects were analyzed by QTVI, and the regional myocardial systolic peak velocities (MVS) were measured. Mean MVS at each level including mitral annular, basal, middle and apical segments were calculated. The ratio of MVS along long-axis to that along short-axis (Ri) at basal and middle segments of the LV posterior wall and ventricular septum were calculated. The results showed that mean MVS was slower at each level including mitral annular, basal, middle and apical segments in the HCM patients than that in the healthy subjects (P〈0.01). There were no significant differences in mean MVS between obstructive and non-obstructive groups in HCM patients. MVS of all regional myocardial segments along long-axis in the HCM patients were significantly slower than that in the healthy subjects (P〈0.05), but there was no significant difference in MVS of all regional myocardial segments along long-axis between hypertrophied and non-hypertrophied group in the HCM patients. Ri was significantly lower in the HCM patients than that in the healthy subjects. The LV regional myocardial contractility along long-axis was impaired not only in the hypertrophied wall but also in the non-hypertrophied one in patients with HCM, suggesting that QTVI can assess accurately LV regional systolic function in patient with HCM and provides a novel means for an early diagnosis before and independent of hypertrophy. 展开更多
关键词 quantitative tissue velocity imaging hypertrophic cardiomyopathy left ventricular regional systolic function
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Assessment of Regional Myocardial Function in Patients with Hypertrophic Cardiomyopathy by Tissue Strain Imaging 被引量:2
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作者 熊润青 谢明星 +1 位作者 王新房 吕清 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2006年第3期334-337,共4页
The value of tissue strain imaging (SI) in regional myocardial systolic and diastolic func tion assessment was studied. In 18 patients with nonobstructive hypertrophic cardiomyopathy (HCM) and 20 age-matched healt... The value of tissue strain imaging (SI) in regional myocardial systolic and diastolic func tion assessment was studied. In 18 patients with nonobstructive hypertrophic cardiomyopathy (HCM) and 20 age-matched healthy subjects, regional myocardial longitudinal peak systolic strain in eject time (represented by εet) was measured at basal, mid and apical segments of septal, lateral and posterior walls of the left ventricle (LV) and compared between groups, εet had no significant difference between segments in control group (P〉0.05), which displayed a decreasing trend from basal segments to apical ones. εet in the HCM group was significantly decreased (P(0. 05) as compared with that in the healthy group. In the HCM group, εet in the midseptum was significantly less than at the basal and apical septum, and was also less than at the rest LV walls in the same group (P〉0.01). The systolic reversed εet was noticed in 35% of the hypertrophic segments in HCM group. Significantly negative correlation existed between the absolute value of εet and wall thickness in the midseptum (r= -0.83). The post-systolic strain(PSS) segment number the and amplitudes in healthy group were significantly less than those in HCM group (P〈0.05). Both regional myocardial systolic and diastolic functions were impaired in hypertrophic or non-hypertrophic segments in patients with the HCM, especially in hypertrophic segments. Strain imaging technique is a sensitive and accura tool in myocardial dysfunction assessment. 展开更多
关键词 ECHOCARDIOGRAPHY tissue strain imaging hypertrophic cardiomyopathy regional myocardial function
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Ecological function regionalization of fluvial corridor landscapes and measures for ecological regeneration in the middle and lower reaches of the Tarim River, Xinjiang of China 被引量:2
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作者 Zhou, HuaRong Xia, DuNing 《Journal of Arid Land》 SCIE 2010年第2期123-132,共10页
The middle and lower reaches of the Tarim River are currently one of the main regions of ecological restoration in the arid areas of western China.Using the principles and method of landscape ecology,this study has ch... The middle and lower reaches of the Tarim River are currently one of the main regions of ecological restoration in the arid areas of western China.Using the principles and method of landscape ecology,this study has chosen the fluvial corridor landscape in the middle and lower reaches of the Tarim River,and discusses the region’s ecologically functional regionalization system and issues related to its practical classification.On this basis the corresponding regionalizing principles and standards were developed which were used to qualitatively divide the three main landscapes as the ecologically functional areas in the drainage basin.The paper has also analyzed the characteristic of the study areas,and has put forward the measures for its ecological restoration. 展开更多
关键词 fluvial corridor landscape ecological function regionalization ecological regeneration Tarim River
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Aging effects of regional activation in a spatial task A functional magnetic resonance imaging study 被引量:1
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作者 Jong-Rak Park Dae-Woon Lim +6 位作者 Mi-Hyun Choi Su-Jeong Lee Jin-Seung Choi Hyung-Sik Kim Jeong-Han Yi Gye-Rae Tack Soon-Cheol Chung 《Neural Regeneration Research》 SCIE CAS CSCD 2009年第9期663-667,共5页
BACKGROUND: An increasing number of studies have shown the effects of aging in basic cognitive processing and higher cognitive functions using functional magnetic resonance imaging (fMRI). However, little is known ... BACKGROUND: An increasing number of studies have shown the effects of aging in basic cognitive processing and higher cognitive functions using functional magnetic resonance imaging (fMRI). However, little is known about the aging effects in diverse cognitive abilities, such as spatial learning and reasoning. OBJECTIVE: To investigate the effect of aging on spatial cognitive performance and regional brain activation based on fMRI. DESIGN, TIME, AND SETTING: A block design for fMRI observation. This study was performed at the fMRI Laboratory, Brain Science Research Center, Korea Advanced Institute of Science and Technology from March 2006 to May 2009. PARTICIPANTS: Eight right-handed, male, college students in their 20s (mean age 21.5 years) and six right-handed, male, adults in their 40s (mean age 45.7 years), who graduated from college, participated in the study. All subjects were healthy and had no prior history of psychiatric or neurological disorders. METHODS: A spatial task was presented while brain images were acquired using a 3T fMRI system (ISOL Technology, Korea). The spatial tasks involved selecting a shape that corresponded to a given figure using four examples, as well as selecting a development figure of a diagram. MAIN OUTCOME MEASURES: The accuracy rate (number of correct answers/total number of items x 100%) of spatial tasks was calculated. Using the subtraction procedure, the activated areas in the brain during spatial tasks were color-coded by T-score. The double subtraction method was used to analyze the effect of aging between the two age groups (20s versus 40s). RESULTS: The cerebellum, occipital lobe, parietal lobe, and frontal lobe were similarly activated in the two age groups. Increased brain activations, however, were observed in bilateral parietal and superior frontal lobes of the younger group. More activation was observed in bilateral middle frontal and right inferior frontal lobes in the older group. Compared with the older group, the younger men exhibited greater spatial performance (P = 0.012). CONCLUSION: Reduced cognitive function correlated with decreased activation areas in the parietal lobe and altered activation in the frontal lobe. 展开更多
关键词 functional magnetic resonance imaging AGING regional activation spatial task
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Trade-off and Synergy of Rural Functions Under County Depopulation in the Typical Black Soil Region of Northeast China 被引量:2
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作者 LI Dongmei WEN Qing +1 位作者 QI Yue ZHANG Pingyu 《Chinese Geographical Science》 SCIE CSCD 2023年第4期616-633,共18页
As the population continues to shrink in the black soil region of Northeast China since 2000,it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainab... As the population continues to shrink in the black soil region of Northeast China since 2000,it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainable development.In this study,we focused on the impacts of depopulation on the evolution and interrelationship of rural subfunctions.Based on the rural function indexes system,the TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)method,spatial analysis method,and mathematical statistics analysis method were used to summarize the spatial and temporal characteristics of rural function development,as well as the effect of population shrinkage in the typical black soil region of Northeast China.The results showed that depopulation varied in the extent and duration between the forested region and plain areas,which both impacted the trajectories of rural subfunctions evolution.For the economic development function and ecological conservation function,the effect of continuous slight depopulation was beneficial,while the effect of rapid depopulation was adverse,which was exactly opposite to the agricultural production function.All forms of population shrinkage were conducive to the development of the social security function.With the deepening population shrinkage,depopulation mainly promoted the collaborative development between subfunctions in this study,except the relationship between agricultural production and social security function.But effects of depopulation on the interrelationship of rural subfunctions varied between the forested region and plain areas in some cases.The results provided evidence for the cognition that population shrinkage had complicated effects on rural subfunctions. 展开更多
关键词 rural function depopulation trade-off and synergy typical black soil region Northeast China
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Structural analysis and design of frost resistance function for subgrade of high-speed railway ballasted track in cold regions 被引量:1
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作者 Qiang Luo WenQiang Lv +1 位作者 QingZhi Ye RuiGuo Zhang 《Research in Cold and Arid Regions》 CSCD 2015年第5期594-604,共11页
According to the technical characteristics of short fixed wheelbase of a high-speed carriage, a subgrade-track integrated space mechanical response analysis model is proposed for trains under the action ofbiaxial load... According to the technical characteristics of short fixed wheelbase of a high-speed carriage, a subgrade-track integrated space mechanical response analysis model is proposed for trains under the action ofbiaxial load after the comparison of the stress distribution characteristics of the ballast track subgrade bed structures for high-speed railway under the action of uniaxial load and biaxial load. The loading threshold value (high-cycle long-term dynamic strength) under the circum- stance where the cumulative deformation of subgrade structure gradually develops and finally reaches the convergent state, and its relationship with the foundation coefficient K30 were deduced, based on the characteristics of cumulative defor- mation evolution obtained from the unit structure filling model test under the action of cyclic loading. In view of structure stability and frost resistance requirements of the railway subgrade in cold regions, technical conditions to maintain good service performance of subgrade structure of high-speed railway ballasted track are discussed and analyzed. Study results show that the additive effect manifests itself obviously for railway train bogies under the action of biaxial load than uni- axial load, which has a significant dynamic effect on the subgrade bed bottom and a slight effect on the surface layer. Thus, the adoption of a biaxial load model in the design of a high-speed railway subgrade accurately reflects the vehicle load. Pursuant to the structure design principle, the design method of the subgrade structure of high-speed railway ballasted track is proposed to meet the technical requirements such as structural strength, bearing stiffness and high-cyclic and long-term stability. Technical indicators are obtained for the variation of thickness of the surface layer of reinforced sub- grade bed in the double-layer subgrade mode along with the change of K30 at the subgrade bed bottom. The double-layer structure mode of "closure on the upper layer and drainage on the lower layer" was proposed in order to meet the water- proofing and drainage requirements of the upper layer of the subgrade bed in cold regions. A dense-framework graded gravel filler with weak water permeability at a coefficient of 10 4 cm/s is used on the upper layer and the void-framework graded gravel filler at the water permeability coefficient of 10 2 cm/s is adopted on the lower layer. 展开更多
关键词 high-speed railway in cold regions subgrade structure biaxial load mode structural analysis design of frostresistance function
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Effect of Salt Stress on Nitrogen Assimilation of Functional Leaves and Root System of Rice in Cold Region 被引量:1
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作者 Gu Jiao-jiao Zhao Hong-wei +4 位作者 Jia Yan Hu Bo-wen Wang Zhuo-qian Qu Zhao-jun Yu Feng-li 《Journal of Northeast Agricultural University(English Edition)》 CAS 2020年第2期9-16,共8页
The aims were to investigate the effect of salt stress on key enzyme activity of nitrogen metabolism and the concentration of nitrate nitrogen and ammonium nitrogen response to salt stress.Two rice cultivars,Mudanjian... The aims were to investigate the effect of salt stress on key enzyme activity of nitrogen metabolism and the concentration of nitrate nitrogen and ammonium nitrogen response to salt stress.Two rice cultivars,Mudanjiang 30(sensitive cultivar)and Longdao 5(salt-tolerant cultivar),were treated with different salt concentrations(CK 0%,S10.075%,S20.15%,S30.225%and S40.3%).The results showed that the activities of nitrate reductase(NR),glutamine synthase(GS),glutamate synthase(GOGAT)and glutamate dehydrogenase(GDH)in the functional leaves and roots of rice in cold region presented a single peak curve change and the peak occurred in the heading stage;compared with those of the CK,the activities of NR,GS and GOGAT of rice in cold region decreased,but the activity of GDH increased in the heading stage under salt stress.The variation for key enzyme activity of nitrogen metabolism was the highest under S4 treatment.The activities of NR,GS and GOGAT in the functional leaves significantly decreased compared with those in roots;the concentrations of nitrate nitrogen and ammonium nitrogen in the functional leaves and roots of rice in cold region presented a single peak curve change and the peak occurred in the heading stage;compared with that of the CK,the concentration of nitrate nitrogen decreased in leaves and roots,the concentration of ammonium nitrogen decreased and the concentration of ammonium nitrogen in roots increased under salt stress.The variations for the activities of NR,GS and GOGAT in the functional leaves and roots of Longdao 5 were less than those of Mudanjiang 30 under the same concentration of salt stress. 展开更多
关键词 rice in cold region salt stress functional leave root system nitrogen metabolism
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Altered spontaneous brain activity in patients with diabetic optic neuropathy:A resting-state functional magnetic resonance imaging study using regional homogeneity 被引量:1
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作者 Gui-Ying Guo Li-Juan Zhang +7 位作者 Biao Li Rong-Bin Liang Qian-Min Ge Hui-Ye Shu Qiu-Yu Li Yi-Cong Pan Chong-Gang Pei Yi Shao 《World Journal of Diabetes》 SCIE 2021年第3期278-291,共14页
BACKGROUND Diabetes is a common chronic disease.Given the increasing incidence of diabetes,more individuals are affected by diabetic optic neuropathy(DON),which results in decreased vision.Whether DON leads to abnorma... BACKGROUND Diabetes is a common chronic disease.Given the increasing incidence of diabetes,more individuals are affected by diabetic optic neuropathy(DON),which results in decreased vision.Whether DON leads to abnormalities of other visual systems,including the eye,the visual cortex,and other brain regions,remains unknown.AIM To investigate the local characteristics of spontaneous brain activity using regional homogeneity(ReHo)in patients with DON.METHODS We matched 22 patients with DON with 22 healthy controls(HCs).All subjects underwent resting-state functional magnetic resonance imaging.The ReHo technique was used to record spontaneous changes in brain activity.Receiver operating characteristic(ROC)curves were applied to differentiate between ReHo values for patients with DON and HCs.We also assessed the correlation between Hospital Anxiety and Depression Scale scores and ReHo values in DON patients using Pearson correlation analysis.RESULTS ReHo values of the right middle frontal gyrus(RMFG),left anterior cingulate(LAC),and superior frontal gyrus(SFG)/left frontal superior orbital gyrus(LFSO)were significantly lower in DON patients compared to HCs.Among these,the greatest difference was observed in the RMFG.The result of the ROC curves suggest that ReHo values in altered brain regions may help diagnose DON,and the RMFG and LAC ReHo values are more clinically relevant than SFG/LFSO.We also found that anxiety and depression scores of the DON group were extremely negatively correlated with the LAC ReHo values(r=-0.9336,P<0.0001 and r=-0.8453,P<0.0001,respectively).CONCLUSION Three different brain regions show ReHo changes in DON patients,and these changes could serve as diagnostic and/or prognostic biomarkers to further guide the prevention and treatment of DON patients. 展开更多
关键词 DIABETES Diabetic optic neuropathy regional homogeneity Resting state functional magnetic resonance imaging Brain activity
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Spatial Function Regionalization Based on an Ecological-economic Analysis in Wuxi City, China
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作者 SUN Wei CHEN Wen JIN Zhifeng 《Chinese Geographical Science》 SCIE CSCD 2019年第2期352-362,共11页
As a result of rapid urbanization in China, urban sprawl has increased rapidly, and land-use regulation and smart urban growth are equally important. Spatial function regionalization can provide the scientific groundw... As a result of rapid urbanization in China, urban sprawl has increased rapidly, and land-use regulation and smart urban growth are equally important. Spatial function regionalization can provide the scientific groundwork for the regulation of land use and protection. This paper probes the system of evaluation indices and applies the methods of spatial analysis and classification clustering to the calculation of the ecologically significant value and economically significant value in each evaluation unit. After use of a classification matrix integrated by the two significant values, city space can be divided into four functional types, namely, feasible development area, moderate development area, moderate conservation area and prohibited exploiting area, and these are the basis for spatial development and control. 展开更多
关键词 SPATIAL function regionALIZATION SPATIAL analysis ecologically SIGNIFICANT VALUE economically SIGNIFICANT VALUE urbanized region
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Functional magnetic resonance imaging of regional homogeneity changes in parkinsonian resting tremor
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作者 Xian Liu Bo Liu Jun Chen Zhiguang Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第11期811-815,共5页
Regional homogeneity analysis of low-frequency blood oxygenation level-dependent signals from neighboring voxels enables the analysis of local neuronal synchrony. Both structural magnetic resonance imaging and resting... Regional homogeneity analysis of low-frequency blood oxygenation level-dependent signals from neighboring voxels enables the analysis of local neuronal synchrony. Both structural magnetic resonance imaging and resting-state functional magnetic resonance imaging scans were collected from nine Parkinson's disease patients with right resting tremor, and from eight age-matched normal controls. Regional homogeneity was compared between Parkinson's disease patients and controls. The results revealed that regional homogeneity was increased in several brain regions, including the right precuneus, right superior parietal gyrus, left anterior cingulate cortex, right middle frontal gyrus and right inferior frontal gyrus. Conversely, regional homogeneity was decreased in the cerebellar vermis in Parkinson's disease patients compared with healthy controls. 展开更多
关键词 Parkinson's disease resting tremor regional homogeneity functional magnetic resonance imaging resting state brain activity
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Exploring the Abnormal Brain Regions and Abnormal Functional Connections in SZ by Multiple Hypothesis Testing Technique
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作者 Lan Yang Shun Qi +1 位作者 Chen Qiao Yanmei Kang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第10期215-237,共23页
Schizophrenia(SZ)is one of the most common mental diseases.Its main characteristics are abnormal social behavior and inability to correctly understand real things.In recent years,the magnetic resonance imaging(MRI)tec... Schizophrenia(SZ)is one of the most common mental diseases.Its main characteristics are abnormal social behavior and inability to correctly understand real things.In recent years,the magnetic resonance imaging(MRI)technique has been popularly utilized to study SZ.However,it is still a great challenge to reveal the essential information contained in the MRI data.In this paper,we proposed a biomarker selection approach based on the multiple hypothesis testing techniques to explore the difference between SZ and healthy controls by using both functional and structural MRI data,in which biomarkers represent both abnormal brain functional connectivity and abnormal brain regions.By implementing the biomarker selection approach,six abnormal brain regions and twenty-three abnormal functional connectivity in the brains of SZ are explored.It is discovered that compared with healthy controls,the significantly reduced gray matter volumes are mainly distributed in the limbic lobe and the basal ganglia,and the significantly increased gray matter volumes are distributed in the frontal gyrus.Meanwhile,it is revealed that the significantly strengthened connections are those between the middle frontal gyrus and the superior occipital gyrus,the superior occipital gyrus and the middle occipital gyrus as well as the middle occipital gyrus and the fusiform gyrus,and the rest connections are significantly weakened. 展开更多
关键词 Multiple hypothesis testing SCHIZOPHRENIA magnetic resonance imaging abnormal brain regions abnormal functional connectivity
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