Hippocampal Automatic Recognition and 3D Segmentation Based on Active Appearance Model in Brain MR Images for Early Diagnosis ofAlzheimer's Disease

目的:研究磁共振(MAgnETIC rESOnAnCE,Mr)脑图像中海马的自动分割方法及海马的形态学分析方法,为阿尔茨海默病(AlzHEIMEr'S dISEASE,Ad)的早期诊断提供依据。方法:对20例Ad患者和60名正常对照者行MrI T1 WI 3d容积扫描,建立海马的三维主动表观模型,并以此模型对每个个体脑部磁共振图像上的海马进行自动识别和三维分割,分别建立正常对照组和Ad组的海马统计形状模型,比较Ad组与正常对照组间海马形状的差异性。结果:海马三维分割方法与手动分割方法在海马体积测量上无统计学差别(P>0.05);Ad患者海马头部发生萎缩(P0.05).Hippocampal head atrophy was found in AD patients(P<0.05).Conclusions: Hippocampal three-dimensional segmentation and automatic identification method based on active appearance model in brain MR image is accurate and reliable;the feature of hippocampal head atrophy can be used as a basis for diagnosis of AD.哈尔滨医科大学研究生创新基金(HCXB2010019);国家自然科学基金(81071219

Effects of argon pressure on carbon spheres by ferrocene catalyzed CaC2-CHCl3 system

以电石和氯仿为碳源和反应物,以二茂铁为催化剂,研究不同压力对CaC2-CHCl3体系制备碳球的形貌和结构的影响。反应设备是100mL的不锈钢高压釜,充入的氩气压力为0.5~1.5MPa,在350℃进行化学反应并保温3h,制备不同类型的碳球。采用X线衍射仪、扫描电子显微镜、透射电子显微镜和激光拉曼光谱仪等手段分析碳球的物相、形貌和结构。探讨空心碳结构的CHCl3雾化小液滴生长机理。研究结果表明:CaC2-CHCl3体系制备的碳球主要由无定形炭组成,随着压力增加,结晶程度增大。空心碳球的形成与体系压力相关,当充入压力为0.5MPa时,合成直径为100~260nm的实心无定形碳球,具有向菜花结构转变的趋势;当充入的氩气压力为1.0MPa时,合成4种不同空心碳结构,即空心毛绒碳球、角状空心碳棒、空心光滑碳球或碳棒和多边形化的空心碳球;当充入的氩气压力为1.5MPa时,合成3种不同直径范围的碳球,相同直径的碳球团聚在一起。With calcium carbide and chloroform as carbon sourses, and ferrocene as catalyst, the effect of different argon pressures on morphology and microstructure of carbon spheres was studied. The reaction setup is 100 mL autoclave, and 0.5-1.5 MPa of argon pressure was filled into the autoclave, respectively. Chemical reaction of CaC2-CHCl3 system was carried out at 350 ℃ for 3 h, and different types of carbon spheres were fabricated. The phase, morphology and microstructure of carbon spheres were analyzed by XRD, SEM, TEM and Raman spectrum. At last, CHCl3 atomizating small droplet growth mechanism of hollow carbon structures was supposed. The results show that carbon spheres are mainly composed of amorphous carbon, and with the increase of the argon gas pressure, the crystallization degree enhances. The formation of hollow spherical carbon depends on the system pressure. Solid and amorphous carbon spheres form under 0.5 MPa of argon pressure, and the mierostructure is cauliflower-like. Under 1.0 MPa of argon pressure, four hollow carbon structures are fabricated; including hollow fluffy carbon spheres, horn hollow carbon spheres, smooth hollow carbon spheres and polygon-like and hollow carbon spheres with internal filament structure. Carbon spheres with three different diameters are synthesized under 1.5 MPa of argon pressure, and carbon spheres with the same diameter are prone to agglomerate.国家重点基础研究发展计划(“973”计划)项目(2006CB600901);广西科学基金资助项目(桂青科0991015);广西教育厅项目(200808MS083);广西民族大学科研基金资助项