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| 1 | Layer-by-layer deposition of bioactive layers on magnesium alloy stent materials to improve corrosion resistance and biocompatibility显示文摘Magnesium alloy is considered as one of the ideal cardiovascular stent materials owing to its good mechanical properties and biodegradability.However,the in vivo rapid degradation rate and the insufficient biocompatibility restrict its clinical applications.In this study,the magnesium alloy(AZ31B)was modified by combining the surface chemical treatment and in-situ self-assembly of 16-phosphonyl-hexadecanoic acid,followed by the immobilization of chitosan-functionalized graphene oxide(GOCS).Heparin(Hep)and GOCS were alternatively immobilized on the GOCS-modified surface through layer by layer(LBL)to construct the GOCS/Hep bioactive multilayer coating,and the corrosion resistance and biocompatibility were extensively explored.The results showed that the GOCS/Hep bioactive multilayer coating can endow magnesium alloys with an excellent in vitro corrosion resistance.The GOCS/Hep multilayer coating can significantly reduce the hemolysis rate and the platelet adhesion and activation,resulting in an excellent blood compatibility.In addition,the multilayer coating can not only enhance the adhesion and proliferation of the endothelial cells,but also promote the vascular endothelial growth factor(VEGF)and nitric oxide(NO)expression of the attached endothelial cells on the surfaces.Therefore,the method of the present study can be used to simultaneously control the corrosion resistance and improve the biocompatibility of the magnesium alloys,which is expected to promote the application of magnesium alloys in biomaterials or medical devices,especially cardiovascular stent. | Fan Gao Youdong Hu Guicai Li Sen Liu Li Quan Zhongmei Yang Yanchun Wei Changjiang Pan | 2020 | Bioactive Materials2020，5，3： | 12 |
| 2 | The diurnal and seasonal characteristics of urban heat island variation in Beijing city and surrounding areas and impact factors based on remote sensing satellite data显示文摘Based on the land surface temperature (LST), the land cover classification map,vegetation coverage, and surface evapotranspiration derived from EOS-MODIS satellite data, and by the use of GIS spatial analytic technique and multivariate statistical analysis method, the urban heat island (UHI) spatial distribution of the diurnal and seasonal variabilities and its driving forces are studied in Beijing city and surrounding areas in 2001. The relationships among UHI distribution and landcover categories, topographic factor, vegetation greenness, and surface evapotranspiration are analyzed. The results indicate that: (i) The significant UHI occur in Beijing city areas in the four seasons due to high heat capacity and multi-reflection of compression building, as well as with special topographic features of its three sides surrounded by mountains,especially in the summer. The UHI spatial distribution is corresponding with the urban geometry structure profile. The LST difference is approximately 4-6℃ between Beijing city and suburb areas, comparatively is 8- 10℃ between Beijing city area and outer suburb area in northwestern regions. (ii) The UHI distribution and intensity in daytime are different from nighttime in Beijing city area, the nighttime UHI is obvious. However, in the daytime, the significant UHI mainly appears in the summer, the autumn takes second place, and the UHI in the winter and the spring seem not obvious. The surface evapotranspiration in suburb areas is larger than that in urban areas in the summer, and high latent heat exchange is evident, which leads to LST difference between city area and suburb area. (iii) The reflection of surface landcover categories is sensitive to the UHI, the correlation between vegetation greenness and UHI shows obviously negative.The scatterplot shows that there is the negative correlation between NDVI and LST (R2 = 0.6481).The results demonstrate that the vegetation greenness is an important factor for reducing the UHI,and large-scale construction of greenbelts can considerably reduce the UHI effect. | ZHANG Jiahua, HOU Yingyu, LI Guicai, YAN Hao YANG Limin & YAO Fengmei The Chinese Academy of Meteorological Sciences, Beijing 100081, China The National Meteorological Center, Beijing 100081, China The National Satellite Meteorological Center, Beijing 100081, China Joint Laboratory for Geoinformation Science, The Chinese University of Hong Kong, Hong Kong, China Department of Geosciences, Graduate School of Chinese Academy of Sciences, Beijing 100039, China | 2005 | Science China Earth Sciences2005，48，z2： | 11 |
| 3 | Forest canopy height mapping over China using GLAS and MODIS data显示文摘The Geoscience Laser Altimeter System(GLAS)accurately detects the vertical structural information of a target within its laser spot and is a promising system for the inversion of structural features and other biophysical parameters of forest ecosystems.Since the GLAS footprints are discontinuously distributed with a relativity low density,continuous vegetation height distributions cannot be mapped with a high accuracy using GLAS data alone.The MODIS BRDF product provides more forest structural information than other optical remote sensing data.This study aimed to map forest canopy heights over China from the GLAS and MODIS BRDF data.Firstly,the waveform characteristic parameters were extracted from the GLAS data by the method of wavelet analysis,and the terrain index was calculated using the ASTER GDEM data.Secondly,the model reducing the topographic influence was constructed from the waveform characteristic parameters and terrain index.Thirdly,the final canopy height estimation model was constructed from the neural network combining the canopy height estimated with the GLAS point and the MODIS BRDF data,and applied to get the continuous canopy height map over China.Finally,the map was validated by the measured data and the airborne Li DAR data,and the validation results indicated that forest canopy heights can be estimated with high accuracy from combined GLAS and MODIS data. | YANG Ting WANG Cheng LI GuiCai LUO SheZhou XI XiaoHuan GAO Shuai ZENG HongCheng | 2015 | Science China Earth Sciences2015，58，1： | 8 |
| 4 | Empirical Analysis of City Contact in Zhujiang(Pearl) River Delta, China显示文摘In traditional urban geography, city contact research is a classic study element in city research. In general, researchers use the traditional gravity model to characterize the contacts that exist between two cities. The traditional gravity model assumes ideal conditions, but these preconditions and their results often do not exist in realistic conditions. Thus, we used a modified gravity model to characterize the city contacts within a specific region. This model considers factors such as intercity complementarities, government intervention, and the diversity of the transportation infrastructure which is characterized as the transportation distance instead of the traditional Euclidean distance. We applied this model to an empirical study of city contact in the Zhujiang(Pearl) River Delta(PRD) of China. The regression results indicated that the modified gravity model could measure city contact more accurately and comprehensively than the traditional gravity model, i.e., it yielded a higher adjusted R2 value(0.379) than the traditional gravity model result(0.259). Our study also suggests that, in addition to urban-regional and metropolitan development, the complementarities of the basic functions of cities at the administrative and market levels, as well as the corporeal and immaterial levels, play very significant roles in the characterization of city contact. Given the complexity of city contact, it will be necessary to consider more relevant influential factors in the modified gravity model to characterize the features of city contact in the future. | TONG De LIU Tao LI Guicai YU Lei | 2014 | Chinese Geographical Science2014，24，3： | 7 |
| 5 | Positioning localities from spatial assertions based on Voronoi neighboring显示文摘With the rapid development of Internet,much spatial information contained in non-structured or semi-structured documents is available on the World Wide Web.In such documents,localities are always textually described using spatial relationships and named places,instead of numerical coordinates.Hence,extracting positional information from locality descriptions is an important task.In this paper,we bridge two aspects of locality descriptions,namely generating locality descriptions and positioning localities,and provide a method to compute probability density according to the selection probability of a reference object to describe the position of the target object.Refinement operation on uncertainty field is used to deal with locality description involving multiple reference objects.Three metrics are introduced to measure the results of positioning localities.We choose the mixed selection probability function based on Euclidean distance and Voronoi stolen-area to compute probability density function.Finally,we use three cases to demonstrate the proposed methods. | GONG YongXi 1,2,3,LI GuiCai 1,LIU Yu 2 & YANG Jian 1 1 Shenzhen Key Lab of Recycling Economy,Peking University Shenzhen Graduate School,Shenzhen 518055,China 2Institute of Remote Sensing and Geographical Information Systems,Peking University,Beijing 100871,China 3College of Urban and Environmental Science,Peking University,Beijing 100871,China | 2010 | Science China(Technological Sciences)2010，53，S1： | 4 |
| 6 | Low gas-liquid ratio foam flooding for conventional heavy oil显示文摘The recovery of heavy oil by water flooding is 10% lower than that of conventional crude oil,so enhanced oil recovery (EOR) is of great significance for heavy oil.In this paper,foam flooding with a gas-liquid ratio (GLR) of 0.2:1 for the Zhuangxi heavy oil (325 mPa·s at 55 °C) was performed on cores,sand packs and plate model.In sand pack tests,polymer enhanced foam flooding increased oil recovery by 39.8%,which was 11.4% higher than that for alkali/surfactant/polymer (ASP) flooding under the same conditions.Polymer enhanced foam flooding in plate models shows that the low GLR foam flooding increased oil recovery by about 30%,even when the extended water flooding was finished at 90% water cut.Moreover,it was discovered by microscopy that foam was more stable in heavy oil than in light oil.These results confirm that low GLR foam flooding is a promising technology for displacing conventional heavy oil. | Wang Jing Ge Jijiang Zhang Guicai Ding Baodong Zhang Li Jin Luchao | 2011 | Petroleum Science2011，8，3： | 3 |
| 7 | Nanoparticle mediated controlled delivery of dual growth factors显示文摘Peripheral nerve functional recovery after nerve injury generally requires multiple growth factors by synergistic effect.However,the optical combination of multiple synergistic growth factors for axonal regeneration has been scarcely considered up to now.Meanwhile,the use of growth factors in promoting nerve regeneration was limited by its short biological half-life in vivo,its vulnerability to structure disruption or hydrolyzation,leading to loss of bioactivity.Herein,a novel polymeric nanoparticle delivery system composed of heparin andε-poly-L-lysine(PL)was prepared for control release of nerve growth factor(NGF)and basic fibroblast growth factor(bFGF).The nanoparticles were synthesized by polyelectrolyte complexation in aqueous solution at room temperature,followed by cross-linking with biological genipin.The obtained nanoparticles had a spherical shape,with a mean diameter of about 246 nm,and high growth factors encapsulation efficiency as well as good stability.NGF and bFGF were encapsulated in the nanoparticles and showed a continuous and slow release behavior in vitro.The bioactivities of the released growth factors were evaluated,and exhibited the synergistic effect.The controlled release of the dual synergistic growth factors would improve the treatment of peripheral nerve injury to mimic the natural cellular microenvironments. | ZHANG LuZhong ZHOU YouLang LI GuiCai ZHAO YaHong GU XiaoSong YANG YuMin | 2014 | Science China(Life Sciences)2014，57，2： | 3 |
| 8 | Co-culture of Schwann cells and endothelial cells for synergistically regulating dorsal root ganglion behavior on chitosan-based anisotropic topology for peripheral nerve regeneration显示文摘Background:Anisotropic topologies are known to regulate cell-oriented growth and induce cell differentiation,which is conducive to accelerating nerve regeneration,while co-culture of endothelial cells(ECs)and Schwann cells(SCs)can significantly promote the axon growth of dorsal root ganglion(DRG).However,the synergistic regulation of EC and SC co-culture of DRG behavior on anisotropic topologies is still rarely reported.The study aims to investigate the effect of anisotropic topology co-cultured with Schwann cells and endothelial cells on dorsal root ganglion behavior for promoting peripheral nerve regeneration.Methods:Chitosan/artemisia sphaerocephala(CS/AS)scaffolds with anisotropic topology were first prepared using micro-molding technology,and then the surface was modified with dopamine to facilitate cell adhesion and growth.The physical and chemical properties of the scaffolds were characterized through morphology,wettability,surface roughness and component variation.SCs and ECs were co-cultured with DRG cells on anisotropic topology scaffolds to evaluate the axon growth behavior.Results:Dopamine-modified topological CS/AS scaffolds had good hydrophilicity and provided an appropriate environment for cell growth.Cellular immunofluorescence showed that in contrast to DRG growth alone,co-culture of SCs and ECs could not only promote the growth of DRG axons,but also offered a stronger guidance for orientation growth of neurons,which could effectively prevent axons from tangling and knotting,and thus may significantly inhibit neurofibroma formation.Moreover,the co-culture of SCs and ECs could promote the release of nerve growth factor and vascular endothelial growth factor,and up-regulate genes relevant to cell proliferation,myelination and skeletal development via the PI3K-Akt,MAPK and cytokine and receptor chemokine pathways.Conclusions:The co-culture of SCs and ECs significantly improved the growth behavior of DRG on anisotropic topological scaffolds,which may provide an important basis for the development of nerve grafts in peripheral nerve regeneration. | Tiantian Zheng Linliang Wu Shaolan Sun Jiawei Xu Qi Han Yifan Liu Ronghua Wu Guicai Li | 2022 | Burns & Trauma2022，10，1： | 2 |
| 9 | Construction of Dual-Biofunctionalized Chitosan/Collagen Scaffolds for Simultaneous Neovascularization and Nerve Regeneration显示文摘Biofunctionalization of artificial nerve implants by incorporation of specific bioactive factors has greatly enhanced the success of grafting procedures for peripheral nerve regeneration.However,most studies on novel biofunctionalized implants have emphasized the promotion of neuronal and axonal repair over vascularization,a process critical for long-term functional restoration.We constructed a dual-biofunctionalized chitosan/collagen composite scaffold with Ile-Lys-Val-Ala-Val(IKVAV)and vascular endothelial growth factor(VEGF)by combining solution blending,in situ lyophilization,and surface biomodification.Immobilization of VEGF and IKVAV on the scaffolds was confirmed both qualitatively by staining and quantitatively by ELISA.Various single-and dual-biofunctionalized scaffolds were compared for the promotion of endothelial cell(EC)and Schwann cell(SC)proliferation as well as the induction of angiogenic and neuroregeneration-associated genes by these cells in culture.The efficacy of these scaffolds for vascularization was evaluated by implantation in chicken embryos,while functional repair capacity in vivo was assessed in rats subjected to a 10mm sciatic nerve injury.Dual-biofunctionalized scaffolds supported robust EC and SC proliferation and upregulated the expression levels of multiple genes and proteins related to neuroregeneration and vascularization.Dual-biofunctionalized scaffolds demonstrated superior vascularization induction in embryos and greater promotion of vascularization,myelination,and functional recovery in rats.These findings support the clinical potential of VEGF/IKVAV dual-biofunctionalized chitosan/collagen composite scaffolds for facilitating peripheral nerve regeneration,making it an attractive candidate for repairing critical nerve defect.The study may provide a critical experimental and theoretical basis for the development and design of new artificial nerve implants with excellent biological performance. | Guicai Li Qi Han Panjian Lu Liling Zhang Yuezhou Zhang Shiyu Chen Ping Zhang Luzhong Zhang Wenguo Cui Hongkui Wang Hongbo Zhang | 2020 | Research2020，，1： | 2 |
| 10 | Modelling carbon fluxes of different forests by coupling a remote-sensing model with an ecosystem process model显示文摘 | Junbang Wang Jiyuan Liu Mingkui Cao Yunfeng Liu Guirui Yu Guicai Li Shuhua Qi Kerang Li | 2011 | International Journal of Remote Sensing2011，，21： | 1 |
| 11 | Tailoring of the Titanium Surface by Immobilization of Heparin/Fibronectin Complexes for Improving Blood Compatibility and Endothelialization: An in Vitro Study显示文摘 | Li Guicai Yang Ping Liao Yuzhen | 2011 | Biomacromolecules2011，12，4： | 1 |
| 12 | Modeling a web-based remote monitoring and fault diagnosis system with UML and component technology显示文摘 | Xing Wu Jin Chen Ruqiang Li Weixiang Sun Guicai Zhang Fucai Li | 2006 | Journal of Intelligent Information Systems2006，，1： | 1 |
| 13 | A vector-based algorithm to generate and update muhiplieatively weighted Voronoi diagrams for points, polylines, and polygons 显示文摘 | GONG YONGXI LI GUICAI TIAN YUAN | 2011 | Computers & Geosciences2011，42，9： | 1 |
| 14 | A vector-based algorithm to generate and update multiplicatively weighted voronoi diagrams for points,polylines,and polygons显示文摘 | Gong Yongxi Li Guicai Tian Yuan | 2012 | Computers&Geosciences2012，42，： | 1 |
| 15 | Modeling a web-based remote monitoring and fault diagnosis system with UML and component technology显示文摘 | Xing Wu Jin Chen Ruqiang Li Weixiang Sun Guicai Zhang Fucai Li | 2006 | Journal of Intelligent Information Systems2006，，1： | 1 |
| 16 | Functionality of Ti-O thin films doped by phosphorus: wettability, semiconductor performance and blood compatibility显示文摘 | WANG Jinbiao YANG Ping LI Guicai | 2009 | Materials Science Forum Volumes2009，，： | 1 |
| 17 | Extracting gear fault features using maximal bispectrum显示文摘 | Zhang Guicai Chen Jin Li Fucai | 2005 | Key Engineering Materials2005，，： | 1 |
| 18 | Value capture beyond municipalities: transit-oriented development and inter-city passenger rail investment in China's Pearl River Delta显示文摘 | Li Guicai Luan Xiaofan Yang Jiawen | 2013 | Journal of Transport Geography2013，33，： | 1 |
| 19 | 显示文摘 | Weng Yajun Hou Ruixia Li Guicai | 2008 | Applied Surface Science2008，254，9： | 1 |
| 20 | Spatial Pattern Evolution and Industrial Characteristics of Economic and Technological Development Zones and High-tech Industrial Zones in China显示文摘Economic and technological development zone and high-tech industrial zone are important types of development zone in China,and there are differences in their connotation and goal setting.In this paper,basic data of national and provincial economic and technological development zones and high-tech industrial zones in China were collected and arranged.Kernel density analysis and other GIS spatial analysis techniques were used to analyze the evolution laws of spatial patterns of economic and technological development zones and high-tech industrial zones in cities from 2006 to 2018.First,the agglomeration intensity was compared by measuring the degree of regional agglomeration and dispersion on the two time nodes.Next,kernel density method was used to explore the evolution of the two in the spatial layout and location,and analyze development commonness and difference of economic and technological development zones and high-tech industrial zones.Finally,the trend and reason of spatial evolution of development zones with different leading industries were explored.Research results show that:①the agglomeration degree of layout of high-tech industrial zones is stronger than that of economic and technological development zones,and there are similarities and differences in distribution trend of spatial patterns of the two types of development zones;②the distribution of labor-intensive,capital-intensive and technology-intensive development zones is concentrated at smaller scales and dispersed at larger ones;③although there are differences between the economic and technological development zones and the high-tech industrial zones in the goal,support,structure and function,management system and so on,their spatial development presents a trend of convergence.In the future,when enhancing urban-rural planning and public administration,governments should combine the trend of industrial transformation and upgrading,and optimize spatial layout of development zones by adjusting industrial structure,layout,transportation and land use. | LI Jingxian LIU Qing LI Guicai | 2021 | Journal of Landscape Research2021，13，2： | 1 |
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