The relationship between the expression of vascular endothelial growth factor（VEGF） and microvascular density（MVD） marked by CD105（CD105-MVD）,and that between CD105-MVD and the clinicopathological characteristic...The relationship between the expression of vascular endothelial growth factor（VEGF） and microvascular density（MVD） marked by CD105（CD105-MVD）,and that between CD105-MVD and the clinicopathological characteristics of primary pterygium were investigated.The streptavidin-biotin complex（SABC） immunohistochemical staining in paraffin-embedded tissues was used to detect the expression of VEGF in 23 cases of primary pterygia and 7 normal conjunctival specimens.The antibody against CD105 was used to display vascular endothelial cells,and MVD was examined by counting the CD105-positive vascular endothelial cells.The correlations of VEGF and CD105-MVD,and those of CD105-MVD and clinicopathological data were analyzed by using SPSS 12.0.The expression of VEGF was significantly increased in epithelia（P=0.000）,endothelia and stroma cells（P=0.005） in primary pterygia as compared with normal conjunctivae.The CD105-MVD in pterygia（mean 19.22±6.68） was higher than that in normal conjunctivae（mean 4.00±2.15,P=0.000）.MVD in pterygia was significantly associated with the Tan classification（P=0.000） and the VEGF expression level in the stroma（P=0.020）,but not with sex（P=0.61）,age（P=0.150） or the VEGF expression level in the epithelia（P=0.518）.Our results suggest that over-expression of VEGF and high CD105-MVD in primary pterygium may contribute to the progression by increasing angiogenesis and growth of primary pterygium.展开更多
Nonlocal self-similarity is an important property of Synthetic Aperture Radar(SAR)images to characterize the repetitiveness of features embodied by SAR images within nonlocal areas and has been used for enhancement of...Nonlocal self-similarity is an important property of Synthetic Aperture Radar(SAR)images to characterize the repetitiveness of features embodied by SAR images within nonlocal areas and has been used for enhancement of SAR images.Existing SAR ship detectors often independently handle small sub-images cropped from a large marine SAR image and do not exploit the nonlocal self-similarity therein.In this paper,we propose a new ship detector from the perspective of nonlocal self-similarity in SAR images to improve the ship detection performance,basically including three stages:prescreening,intra-cue calculation,and inter-cue calculation.In the prescreening stage,we design a new Histogram-based Density(HD)feature to rapidly select candidate sub-images potentially containing ship targets from a large SAR image.In the intra-cue calculation stage,target cues within a single candidate sub-image are extracted.In the inter-cue calculation stage,thanks to the nonlocal self-similarity among different candidate sub-images in terms of density features,we innovatively extract a weighted superpixel-HD map to obtain accumulated intracues across all the candidate sub-images.Finally,for each candidate sub-image,we fuse its inter-cue and intra-cue to obtain final detection results.Experimental results based on real SAR images show that our newly proposed method provides a better target-to-clutter contrast and ship detection performance than those of other state-of-the-art detection approaches.展开更多
区别于经典的基于Parzen窗口法的概率密度函数估计器构建策略,提出了基于近邻误差度量函数的启发式核密度估计器(Heuristic kernel density estimator,HKDE),用以提升对模相近数据概率密度函数拟合的准确性。首次从数据不确定性和模型...区别于经典的基于Parzen窗口法的概率密度函数估计器构建策略,提出了基于近邻误差度量函数的启发式核密度估计器(Heuristic kernel density estimator,HKDE),用以提升对模相近数据概率密度函数拟合的准确性。首次从数据不确定性和模型不确定性的角度分析了传统核密度估计器解决模相近数据概率密度函数估计问题时的缺陷:利用概率密度值对于直方图箱宽参数的收敛性确定观测数据的启发式概率密度值,降低数据概率密度值计算的不确定性;基于启发式概率密度值构建用于确定核密度估计器最优带宽的目标函数,降低最优带宽优化过程中的不确定性。在18个模相近数据集上对新估计器HKDE的可行性、合理性和有效性进行了系统性的验证。实验结果表明,与7种具有代表性的概率密度函数估计器相比,HKDE能够获得更加优异的概率分布近似表现,具有比其他估计器更低的估计误差,能够确定出更接近真实值的概率密度函数估计值。展开更多
文摘The relationship between the expression of vascular endothelial growth factor（VEGF） and microvascular density（MVD） marked by CD105（CD105-MVD）,and that between CD105-MVD and the clinicopathological characteristics of primary pterygium were investigated.The streptavidin-biotin complex（SABC） immunohistochemical staining in paraffin-embedded tissues was used to detect the expression of VEGF in 23 cases of primary pterygia and 7 normal conjunctival specimens.The antibody against CD105 was used to display vascular endothelial cells,and MVD was examined by counting the CD105-positive vascular endothelial cells.The correlations of VEGF and CD105-MVD,and those of CD105-MVD and clinicopathological data were analyzed by using SPSS 12.0.The expression of VEGF was significantly increased in epithelia（P=0.000）,endothelia and stroma cells（P=0.005） in primary pterygia as compared with normal conjunctivae.The CD105-MVD in pterygia（mean 19.22±6.68） was higher than that in normal conjunctivae（mean 4.00±2.15,P=0.000）.MVD in pterygia was significantly associated with the Tan classification（P=0.000） and the VEGF expression level in the stroma（P=0.020）,but not with sex（P=0.61）,age（P=0.150） or the VEGF expression level in the epithelia（P=0.518）.Our results suggest that over-expression of VEGF and high CD105-MVD in primary pterygium may contribute to the progression by increasing angiogenesis and growth of primary pterygium.
基金supported by National Key R&D Program of China(No.2021YFA0715201)in part by National Natural Science Foundation of China(Nos.61925106,62022092,and 62101303)in part by Autonomous Research Project of Department of Electronic Engineering at Tsinghua University。
文摘Nonlocal self-similarity is an important property of Synthetic Aperture Radar(SAR)images to characterize the repetitiveness of features embodied by SAR images within nonlocal areas and has been used for enhancement of SAR images.Existing SAR ship detectors often independently handle small sub-images cropped from a large marine SAR image and do not exploit the nonlocal self-similarity therein.In this paper,we propose a new ship detector from the perspective of nonlocal self-similarity in SAR images to improve the ship detection performance,basically including three stages:prescreening,intra-cue calculation,and inter-cue calculation.In the prescreening stage,we design a new Histogram-based Density(HD)feature to rapidly select candidate sub-images potentially containing ship targets from a large SAR image.In the intra-cue calculation stage,target cues within a single candidate sub-image are extracted.In the inter-cue calculation stage,thanks to the nonlocal self-similarity among different candidate sub-images in terms of density features,we innovatively extract a weighted superpixel-HD map to obtain accumulated intracues across all the candidate sub-images.Finally,for each candidate sub-image,we fuse its inter-cue and intra-cue to obtain final detection results.Experimental results based on real SAR images show that our newly proposed method provides a better target-to-clutter contrast and ship detection performance than those of other state-of-the-art detection approaches.
文摘区别于经典的基于Parzen窗口法的概率密度函数估计器构建策略,提出了基于近邻误差度量函数的启发式核密度估计器(Heuristic kernel density estimator,HKDE),用以提升对模相近数据概率密度函数拟合的准确性。首次从数据不确定性和模型不确定性的角度分析了传统核密度估计器解决模相近数据概率密度函数估计问题时的缺陷:利用概率密度值对于直方图箱宽参数的收敛性确定观测数据的启发式概率密度值,降低数据概率密度值计算的不确定性;基于启发式概率密度值构建用于确定核密度估计器最优带宽的目标函数,降低最优带宽优化过程中的不确定性。在18个模相近数据集上对新估计器HKDE的可行性、合理性和有效性进行了系统性的验证。实验结果表明,与7种具有代表性的概率密度函数估计器相比,HKDE能够获得更加优异的概率分布近似表现,具有比其他估计器更低的估计误差,能够确定出更接近真实值的概率密度函数估计值。
