声学密度技术在肾功能正常肾病患者中的应用

目的:探索声学密度技术在肾功能正常但肾组织活检发现异常的患者中的应用。方法:选取生化检查显示肾功能正常但是肾组织活检发现异常的患者50例,正常人22例(肾脏44只)。将正常对照组及病例组均分成<40岁,40～59岁及≥60岁三个年龄段,测量和分析各组肾皮质、髓质的IBS(Intergratedbackscatter,IBS)、校正的IBS(IBS%)。结果:①<40岁,40～59岁及≥60岁三个年龄段的病例组患者的肾皮质、髓质的IBS%与正常对照组相比均增高且具有统计学意义。②<40岁的病例组的患者与40～59岁及≥60岁组患者比较,其肾皮质、髓质的IBS%较低且具有统计学意义,后两个年龄段之间比较则无统计学差别。结论:①病例组患者的IBS%值已经发生了改变,利用声学密度技术可以早期发现此类患者,利于早期治疗。②年龄对肾脏的IBS%值具有较明显的影响,在分析肾脏的声学密度特点时应引入年龄因素。     

卡维地洛对急性心肌梗死大鼠血流动力学和心肌胶原含量的影响

目的研究卡维地洛(Carvedilol)对大鼠急性心肌梗死(AMI)后血流动力学的影响及其与心肌组织中胶原含量的关系。方法23只AMI术后存活的雄性SD大鼠随机分为AMI对照组(n=11)和卡维地洛治疗(Carvedilol)组(n=12),另设假手术组(n=11)。给药6周后测量室间隔超声背向散射参数(平均背向散射积分标化值IBS%,背向散射积分周期变化值CVIB)及血流动力学参数、心功能指标。结果(1)与假手术组相比,AMI组大鼠SBP、DBP、LVSP及±dp/dtmax及其校正值(±dp/dtmax/LVSP)均显著降低,LVEDP显著增高,高频超声检测显示IBS%显著升高,CVIB显著降低(均为P<0.05)。(2)与AMI组相比,Carvedilol治疗组大鼠SBP、DBP及LVSP均未进一步降低(P>0.05),LVEDP显著降低,±dp/dtmax及其校正值(±dp/dtmax/LVSP)显著升高,高频超声检测显示IBS%显著降低,CVIB显著升高(均P<0.05)。结论第3代β受体阻滞剂Carvedilol的干预有助于恢复AMI大鼠受损的左室功能,这可能与其抑制非梗死区心肌胶原过度沉积有关。     

Quantification and characterisation of IgG binding to mould spores by flow cytometry and scanning electron microscopy

The concentration of mould-specific IgG antibodies in serum may objectively indicate mould exposure and can help identifying exposed individuals. Although inhaled spores probably are the most important source of mould exposure, the commonly used methods for detecting mould-specific IgG antibodies are based on extracts from all mould components, with only low contribution from spores. We have developed a flow cytometric method using surface antigens on mould spores for quantifying mould-specific IgG antibodies in serum. Flow cytometric results were evaluated by comparison with ImmunoCap and ELISA measurements. The flow cytometric assay showed a broad linear dose-dependency and correlated moderately to strongly (r=0.41-0.97) with ImmunoCap and ELISA measurements. The IgG antibody binding was studied in detail by immunolabelling in scanning electron microscopy (SEM), revealing that morphology and IgG antibody binding differed among spores, both within and between mould strains. Germination studies by flow cytometry and SEM showed that IgG antibody binding to mould spores was altered during germination due to loss of coat. The present spore based antibody assay are simple and suitable for quantification of mould-specific IgG antibodies in serum, and includes specificity to other and possibly more relevant antigens than existing methods.     

Wire-Feeding Laser Welding of Copper/Stainless Steel Using Different Filler Metals

Ni-based filler metal and Ni-Cu-based filler metal were used to obtain copper/stainless steel (Cu/SS) joints through wire-feeding laser welding. Along the SS/weld interface, there exist different grain sizes (from coarse columnar grains to fine equiaxed grains). The heat affected zone (HAZ) on the copper side consisted of two areas with different grain sizes and the size of the grain in the Cu-HAZ of the Ni-Cu-based filled joint was much smaller than that of the Ni-based filled joint. Our results showed that grain refinement at the copper/weld (Cu/weld) interface of the Ni-Cu-based filled joint was observed through high-resolution electron backscattered diffraction (EBSD). There was a hardness elevation at the Cu/weld interface of the Ni-Cu-based filled joint due to the grain refinement on the weld of the copper side. The maximum tensile strength of the Ni-Cu-based filled joint was obtained and reached 91.2% of the tensile strength of the copper base metal (Cu-BM). Joints in this study were observed to fracture in a ductile mode. Furthermore, the Ni-Cu-based filled joint exhibited a higher plastic deformation, which was primarily caused by the large deformation of the weld zone and the large deformation of the Cu-BM due to the high plasticity of the weld, which alleviated the stress concentration, as indicated by 2D-digital image correlation (DIC) test results.     

背向散射技术与彩色室壁运动技术在高血压左室重构中的应用

目的 探讨背向散射和彩色室壁运动参数评估原发性高血压不同左室构型心肌病变程度和局部室壁运动的临床价值。方法 测定70例原发性高血压病患者和31例正常对照者室间隔及左室后壁的背向散射参数和局部室壁收缩期位移。共收入正常构型组18例，向心重构组17例，向心肥厚组23例，离心肥厚组12例。结果 高血压各组室间隔超声背向散射(IB％)均不同程度地增大，以向心性肥厚组和离心性肥厚组为著；左室后壁IB％在向心性肥厚组和离心性肥厚组增高，以离心性肥厚组为著；室间隔周期变化幅度(cvlB)在向心性肥厚组和离心性肥厚组减低；左室后壁的CVIB在离心性肥厚组显著减低；高血压各组均未出现明显的背向散射跨壁梯度的改变。室间隔和左室后壁的SEM在离心性肥厚组显著减低，其余各组间虽无明显统计学差异，但在向心性肥厚组呈现增加的趋势。在离心性肥厚组，收缩期CK色带变薄或消失，色带不完整。结论 心肌超声背向散射参数可用于判断高血压不同左室构型心肌病变的程度；彩色室壁运动技术可用于评估高血压不同左室构型局部室壁运动状态。     

高脂高糖、饮酒建立家兔脂肪肝模型及超声量化诊断

目的:模拟人类不良饮食结构建立家兔不同程度脂肪肝模型,进行肝脏背向散射积分 (integrated backscatter,IBS)和图像灰阶平均强度(gray scale,GS)测定,并结合临床研究,探讨具有病理基础的脂肪肝无创性超声量化诊断标准．方法:选用纯种新西兰家兔40只,采用高脂高糖饲料及乙醇饮料建立不同程度脂肪肝模型三组(每组n=10),设立对照组(n=10):临床病例同步进行肝组织病理学及超声检测．病理组织学检测采用苏丹Ⅳ,HE和Masson三色染色:应用HP Sonos 5500超声诊断仪实时检测肝脏IBS,包括图像平均强度(average image intensity,AII)、峰-峰强度及图像强度标准差; 采用Photo shop 7．0直方图分析超声图像GS．所得数据采用SAS8．2进行统计学分析．结果:肝脏AII随脂肪变加重呈递增趋势,正常肝<轻度脂肪肝<中度脂肪肝<重度脂肪肝,尤以近区各组间差异显著(P<0．0001);同等程度肝脂肪变AII随炎症的发生而增大．临床研究显示,IBS对脂肪肝诊断率及与病理组织学符合率(85．7％)较常规超声检测(57．1％) 明显增高,重度脂肪肝AII显著高于轻度脂肪肝(P<0．0001,0．001或0．05)．肝脏GS与AII相关,于肝左、右叶近区二者随病变加重呈一致性增高趋势(r1=0．442 21,P1=0．0012:r2= 0．335 73,P2=0．0160)．中重度脂肪肝伴炎症 GS显著高于正常肝及轻度脂肪肝(P<0．05)．结论:高营养及乙醇联合喂养家兔可快速建立不同程度脂肪性肝病模型;肝脏超声IBS及 GS强度可反映肝脂肪变、炎症和纤维化的病变程度,为脂肪肝无创性量化诊断提供可靠依据．     

超声背向散射积分评价颈动脉粥样硬化斑块的危险性

目的本研究通过测定颈动脉不同回声类型粥样硬化斑块背向散射积分(IBS)的变化特点,初步探讨其在评价颈动脉粥样硬化斑块危险性方面的价值。方法对30例急性脑梗死及30例无脑血管疾病患者的颈动脉硬化斑块进行IBS参数测定,对不同回声类型硬化斑块的IBS三项参数(PPI:最大值与最小值之差,AII:平均值,SDI:离散度)进行对比分析,采用TGC均值对AII进行标准化。结果(1)在均质性斑块中,弱、低及强回声斑块的标化AII呈递增趋势,分别为:(29.4±4.8)dB、(38.7±5.6)dB、(50.7±6.8)dB;非均质性斑块的标化AII变化较大,其PPI及SDI明显高于均质性斑块(P<0.001);(2)脑梗死组非均质性斑块及均质性弱回声斑块的检出率明显高于对照组(P<0.001),而均质性强回声斑块的检出率低于对照组。结论IBS参数为了解颈动脉硬化斑块的组织学特征提供了客观的定量依据,为预测颈动脉硬化斑块的危险性提供重要信息。     

基于反向滤波器的倒谱法估计平均骨小梁间距

目的 探讨用改进的倒谱方法估计平均骨小梁间距(mean trabecular bone spacing,MTBS)的可行性.方法 提出了一种基于反向滤波器的改进的倒谱分析方法用于估计MTBS,并将该方法应用于仿真及离体牛胫骨松质骨中的实验信号.结果 改进的倒谱方法能有效减少超声换能器脉冲响应和组织散射特性对倒谱的干扰,而且实现简单,计算量小.结论 相比于传统的倒谱方法,改进的倒谱方法在估计MTBS时, 对弥散散射和噪声有更强的鲁棒性,因此估计MTBS的精度更高.     

背向散射积分超声组织定征在心肌梗死患者中的临床应用研究

目的探讨心肌背向散射积分(IBS)参数评估心肌梗死患者心肌病变的价值及其与局部心肌收缩功能的关系。方法用背向散射联机分析技术,观测31例前间壁心肌梗死患者及27例正常人前间隔标化平均背向散射积分(AII%),背向散射积分周期变异幅度(CVIB);通过二维超声测算室壁增厚率(WT%)。结果与正常人相比,心肌梗死患者的AII%明显增加(2.2±0.3vs1.6±0.2,P＜0.01),CVIB明显减低(3.3±1.7vs7.9±1.3,P＜0.01)。CVIB与反映局部心肌收缩功能的指标(WT%)呈高度相关(r为0.78,P＜0.01),AII%和WT%呈一定程度相关(r为－0.56,P＜0.01)。结论IBS两个参数,即AII%和CVIB,可以区分正常心肌和梗死区心肌,并能反映局部心肌收缩功能,具有评估心肌存活性的潜力。     

超声背向散射积分和多普勒组织成像检测慢性心肌缺血的实验研究

目的 :建立心肌慢性缺血动物模型 ,探讨超声背向散射积分 (IBS)和多普勒组织成像 (DTI)技术检测慢性心肌缺血的价值。　方法 :健康家猪 5头。在猪冠状动脉左旋支放置Ameroid环 ,应用IBS检测置环后 2、4、6、8周左心室侧后壁标化平均IBS(%AⅡ )、IBS周期变化幅度 (CVIB)及CVIB跨壁梯度指数 (TGI)的变化 ;应用DTI检测各阶段左心室乳头肌短轴观和心尖四腔观左心室侧后壁DTI频谱 [收缩期峰值速度 (VS)、舒张早期峰值速度(VE)、舒张晚期峰值速度 (VA) ]的变化。　结果 :正常心肌 %AⅡ为 2 .2 9± 0 .32 ,CVIB为 (9.6 9± 2 .2 2 )dB ,TGI为0 .2 2± 0 .0 8。置环后 %AⅡ逐渐增加 ,CVIB逐渐减小 ,心内膜下CVIB减小幅度大于心外膜下 ,使TGI亦逐渐减小 ,置环后 2～ 4周减小幅度最大 ,至 8周跨壁梯度消失 (P <0 .0 1) ;正常心尖四腔观VS 大于左心室短轴观VS(P <0 .0 1) ,VE 小于左心室短轴观VE(P <0 .0 5 )。置环后 2周 ,两者VS、VE 均显著减小 (P <0 .0 5 ) ,心尖四腔观VS 减小幅度大于左心室短轴观VS。以后各阶段两者VS、VE 继续减小 ,仍以心尖四腔观VS 减小幅度最大。　结论 :用Ameriod环建立猪心肌慢性缺血模型 ,能很好模拟人类冠心病的病变过程 ;超声IBS和DTI技术从回声和心室壁运动等不同方面检测慢性心肌