实时三维超声心动图在诊断心脏肿瘤中的应用价值

目的探讨实时三维超声心动图对心脏肿瘤的诊断价值.方法对7例心脏肿瘤患者进行二维、实时三维超声心动图检查,测量其左右径、上下径、及前后径,结果与手术或MRI对照.结果实时三维超声心动图可实时显示心脏肿瘤的空间位置、形态、大小以及与周围结构的关系.与手术或MRI结果的相比较,左右径r=0.99,SEE=2mm;上下径r=0.97,SEE=2.2mm;前后径r=0.98,SEE=2.1mm.二维超声测得的结果与手术或MRI结果相比较,左右径r=0.89,SEE=6mm;上下径r=0.91,SEE=4mm;前后径r=0.89,SEE=5mm.结论实时三维超声心动图操作简单、应用方便,可显示心脏肿瘤的整体形态,为心脏肿瘤患者的定性和定量诊断提供了可靠的新方法.     

实时三维超声心动图评价房间隔缺损的收缩形式及其影响因素

目的应用实时三维超声心动图(RT-3DE)技术评价继发孔型房间隔缺损(ASD)在心动周期中的收缩变化特征并探讨其可能的影响因素.方法对36例继发孔型ASD患者进行实时三维成像,3例患者因图像质量欠佳而剔除,在其余33例病例,结合三维数据工作站,分别测量缺损面积,缺损长轴及短轴上的最大及最小径,平行及垂直于三尖瓣水平的最大及最小径.计算上述测值的变化率,并将缺损面积的变化率与缺损最大径、年龄、心率、肺循环与体循环血流量之比(Qp/Qs)进行相关分析.结果缺损面积在心动周期的收缩变化显著,变化率从15.2%到76.9%,平均变化率为49.0%.缺损呈对称性收缩且与缺损最大径、心率、Qp/Qs无相关性,与年龄呈轻微负相关.结论RT-3DE可清晰显示ASD缺损的动态收缩变化特征,有助于理解心房水平分流的病理生理学改变.     

B13 先天性二尖瓣狭窄(瓣膜型)超声心动图

冠状动脉瘘是一种罕见的先天性心脏病,在先心中占0.3%,常被误诊为动脉导管未闭等,本文应用超声心动图探讨其诊断此病的价值。研究对象分对照组及研究组,前者中,正常人20例,室缺及动脉导管未闭患者各20例。后者中包括冠状动脉瘘患者7名。仪器应用Hewlett Packard公司SONOS1000型彩色多普勒超声心动图仪,经胸壁探头频率2.5及3.5MHz,经食道探头频率5MHz。患者取平卧位及半左侧卧位。结果显示所有对照组人员的左、右冠状动脉主干直径均小于0.6cm,7例冠状动脉瘘患者左室内径均不同程度扩大,主动脉稍宽、肺动脉不宽,冠状动脉瘘引流终止的腔扩…     

从超声心动图探讨二尖瓣病变的病因及手术指证

慢性二尖瓣狭窄（ＭＳ）及关闭不全（ＭＲ）是累及青中年患者的一种常见的心血管疾病，其病因以风湿性为多见，严重者导致心脏功能不全，危及生命，二尖瓣的人工瓣置换术能使患者的临床情况明显改善，但亦有一定的死亡率，故选择合适的手术时机是决定病人存活的重要因素，本文就１９８８年１２月～１９９２年１１月住院的１００例二尖瓣置换术患者，对术前超声检查、手术时发现及术后患者的临床改善作一分析。取彩色多普勒超声显象仪经胸壁作常规切面，用多普勒压差减半时间测算二尖瓣口面积；根据彩色多普勒信号在收缩期自左室反流入左房的…     

三维超声地震模型实时成像系统

室内水槽实验是研究地质沉积过程及其演化规律的重要手段,高精度获取沉积过程中的地质体的变化是这类模拟实验非常关键的环节。文章介绍了新研制的三维超声地震模型实时成像系统的主要组成及关键技术。该系统用于模拟海上地震,可以在沉积实验后通过快速测量及对数据的实时偏移处理与成像可以获取变化的多层复杂地质模型动态图像,极大地提高了实验效率和成像精度。该系统具有良好的实时性、成像质量以及探测范围,在对研究地质沉积、海洋地质以及三维地震模型研究等方面有着广泛应用前景。     

三维超声心动图评价基因转染骨髓干细胞移植治疗慢性缺血心肌价值

目的探讨动态三维超声心动图(DTDE)评价基因转染自体骨髓基质干细胞移植治疗慢性缺血心肌的价值.方法在猪冠脉左旋支放置Ameroid环建立慢性心肌缺血模型;4周后分组注射编码血管生长素(ANG)基因的腺病毒转染的自体骨髓基质干细胞(组Ⅰ)、编码ANG基因的腺病毒液(组Ⅱ)、单纯自体骨髓基质干细胞(组Ⅲ)和空腺病毒磷酸盐缓冲液(组Ⅳ、对照组);再4周后行病理学检查.应用脱机DTDE重建和分析技术,观测正常、置环后4周及注射后4周左室形状、容积和收缩功能的变化.结果慢性缺血心肌左室舒张和收缩末期容积(LVEDV、LVESV)增大,射血分数(LVEF)降低(P<0.01).注射后,对照组LVEDV、LVESV较其它各组明显增大(P<0.05),射血分数(LVEF)明显降低(P<0.05),与缺血时无明显差异(P>0.05).组Ⅰ～Ⅲ较慢性缺血时LVEDV和LVESV均缩小(P<0.05),LVEF均增大(P<0.05),各治疗组比较,左室重构现象均不同程度地减轻,组Ⅰ较其它组,左室容积减小及收缩功能改善最为显著.组Ⅱ和Ⅲ间测值比较无统计学差异.结论DTDE对评价基因转染自体骨髓基质干细胞移植治疗慢性缺血性心脏病具有重要价值.     

基于实时三维超声造影对于输卵管源性不孕症的诊断评价研究

目的:探讨实时三维子宫输卵管超声造影对于输卵管源性不孕症的诊断评价.方法:随机抽取在我院进行治疗的输卵管源性不孕症患者80名,按照统计学规则将抽取的样本分成对照组和研究组.对照组患者接受腹腔镜检查以及子宫输卵管碘油造影检查,研究组患者接受腹腔镜检查以及实时三维子宫输卵管超声造影检查,子宫输卵管碘油造影的结果接近金标准....     

超声心动图评价左室舒张功能的临床价值

目的：探讨超声心动图评价左室舒张功能的临床价值,为临床诊断治疗提供一定的依据。方法：选择我院来进行超声心动图检查的患者97例．其中正常人31例。高血压患者36例,冠心病患者30例,应用彩色多普勒超声心动图测定所选患者的E峰速度、A峰速度、E／A比值、E峰减速时间（DT）等,并比较。结果：冠心病组与高血压组间的E峰速度、A峰速度、E／A比值、E峰减速时间（DT）无明显差异（P〉0．05）,冠心病组、高血压组的E峰速度、E／A比值明显低于正常对照组．A峰速度及E峰减速时间（DT）明显高于正常对照组,差异显著（P〈0．05）。结论：超声心动图在临床诊断左室舒张功能上有一定的价值,E峰速度、A峰速度、E／A比值、E峰减速时间（DT）等指标与左室舒张功能障碍有明显的相关性．值得临床关注。     

晶体生长三维实时观察技术研究

最近建立一套用干晶体三维实时观察的装置,主要分为光学观察部分,晶体生长部分,结果处理部分．采用二目观察法记录晶体生长和流体运动．设计并制造适于Ｂｒｉｄｇｍａｎ法晶体生长的生长炉和坩埚．初步观察到ＮａＮＯ_３晶体的固液界面形貌,并通过图像处理软件还原为三维真实图像．     

实时三维彩色多普勒血流显像定量评估主动脉瓣反流的初步探讨

目的探讨实时三维彩色多普勒血流显像(RT3D CDFI)定量评估主动脉瓣反流的价值.方法应用实时三维超声心动图技术采集23例单纯性主动脉瓣反流患者的全容积数据库和三维彩色血流信号数据库,利用TomTec三维图像处理工作站分别测量左室舒张末期容积(LVEDV)、左室收缩末期容积(LVESV)和主动脉瓣彩色反流束容积(regurgitant jet volume,RJV),计算出反流束分数(RJF%).在二维超声心动图上用脉冲多普勒(PD-2D)测量计算反流容积(RV)和反流分数(RF%).对RT3D CDFI和PD-2D的测量值进行相关性分析.结果RT3D CDFI和PD-2D两种方法评价主动脉瓣反流的测值相关性良好,其中RT3D CDFI测得的RJV与PD-2D测得的RV相关性为r=0.93,Y=0.89X+3.9,SEE=8.6ml,P<0.001,二者间的均数差为-1.5ml,标准差为9.8ml;RT3D CDFI测得RJF%与PD-2D测得的RF%的相关性为r=0.88,Y=0.71X+14.8,SEE=6.4%,P<0.001,二者间的均数差为-1.2%,标准差为7.9%.结论RT3D CDFI可从三维空间对主动脉瓣反流进行评价,为临床定量评估主动脉反流提供了一种新方法.     

Late onset of clinically apparent central vein stenosis due to previous central venous catheter in a patient with inherited thrombophilia

We describe a case of a patient with a functional kidney transplant who was admitted to our department with clinically evident central vein stenosis (CVS) 7 years after the removal of a central venous catheter (CVC) from the right internal jugular vein. The catheter was used as a hemodialysis access for a 2‐month period. In the interval before his last admission, the patient suffered two episodes of deep vein thrombosis. Investigation revealed heterozygosity for factor V Leiden, the most common inherited thrombophilia encountered in 5% of Caucasians, and anticoagulation treatment was started. Magnetic resonance angiography showed stenosis just after the convergence of the right subclavian vein with the internal jugular vein to the innominate vein. Transluminal angioplasty restored venous patency and right upper arm edema resolved. Coexistence of CVS, accompanied by hemodynamic changes and endothelial dysfunction, with thrombophilia fulfill all the elements of the Virchow's triad. Therefore, the patient was at great risk for central vein thrombosis, from which he was possibly protected by the early administration of anticoagulant treatment. This case indicates that CVS can be asymptomatic for several years after CVC removal and also raises the question if thrombophilia workup and investigation for CVS may be beneficial in every patient with CVC placement in order to avoid any harmful outcomes.     

Real-time performance evaluation and improvement of assembly systems with Bernoulli machines and finite production runs

Extensive research has been investigated in the past several decades to evaluate the performance of manufacturing systems under rigid production mode. Based on the deployment of the new manufacturing strategies (e.g. smart manufacturing), real-time performance analysis, continuous improvement and efficient production management of flexible production systems are urgently to be investigated. Therefore, we study the problems of real-time performance evaluation and bottleneck of assembly systems in this paper. The system is assumed to have Bernoulli machines and finite production runs. We first derive the mathematical model of the system and then, derive the analytical formulas for performance evaluation of systems with three Bernoulli machines. In addition, we propose a decomposition and aggregation-based algorithm to approximate the system performances with high accuracy and computational efficiency. The idea is then extended to generalised assembly systems. Finally, the method of bottleneck analysis by using completion time bottleneck indicator is introduced and evaluated by numerical justification.     

Enhanced expression of hemoglobin scavenger receptor and heme oxygenase‐1 is associated with aortic valve stenosis in patients undergoing hemodialysis

A high prevalence and a rapid progression of aortic valve stenosis (AS) in patients undergoing hemodialysis (HD) has been reported. In these circumstances, intraleaflet hemorrhage of aortic valve may be related to the development of AS in HD patients. We immunohistochemically examined the relationship among intraleaflet hemorrhage, neovascularization, hemoglobin scavenger receptor (CD163), and heme oxygenase‐1 (HO‐1) using surgically resected aortic valve specimens from AS patients undergoing HD. The study population consisted of 26 HD patients and 25 non‐HD patients with severe AS who had undergone aortic valve replacement. Frozen aortic valve samples surgically obtained from AS patients were stained immunohistochemically with antibodies against smooth muscle cells, macrophages, glycophorin‐A (a protein specific to erythrocyte membranes), CD31, CD163, and HO‐1. Morphometric analysis demonstrated that the CD163‐positive macrophage score, the number of CD31‐positive microvessels, and the percentage of glycophorin‐A and HO‐1‐positive area were significantly higher in HD patients than in non‐HD patients (CD163‐positive macrophage score, P < 0.0001; CD31‐positive microvessels, P < 0.0001; glycophorin‐A, P < 0.0001; HO‐1, P < 0.0001). Double immunostaining for CD163 or HO‐1 and macrophages revealed that the majority of CD163‐ or HO‐1‐positive cells were macrophages. Furthermore, CD163‐positive macrophage score was positively correlated with glycophorin‐A, HO‐1‐positive area, and the number of CD31‐positive microvessels (glycophorin‐A, R = 0.66, P < 0.0001; HO‐1, R = 0.50, P < 0.0005; microvessels, R = 0.38, P < 0.01). These findings suggest a positive association among intraleaflet hemorrhage, neovascularization, and enhanced expression of CD163 and HO‐1 as a response to intraleaflet hemorrhage in stenotic aortic valves in AS patients undergoing HD.     

A formulation of arbitrarily shaped surface elements for three-dimensional large deformation contact with friction

The paper introduces a general theory for the numerical simulation of large deformation contact problems. The contacting bodies under consideration may be of two- or three-dimensional shape modelled by finite elements. A contact finite element which can be applied to handle multi-body contact as well as contact with rigid bodies is developed. The element is universal in the sense that it can be used as a surface element for any known finite element model and includes friction. The frictional behaviour of the model obeys Coulomb's law of friction distinguishing between sticking and sliding contact. The algorithmic treatment is based on a penalty formulation for the normal and sticking contact. The corresponding consistent tangential stiffness matrices are derived, leading to an overall quadratic convergence behaviour for the method. This feature is demonstrated in a number of representative examples. © 1997 by John Wiley & Sons, Ltd.     

Real-time scheduling in manufacturing system with machining and assembly operations: a state of art

Manufacturing systems producing multiple products are common in many industries, where products are made from several parts and/or sub-assemblies that require machining operations in first stage and assembly operations at later stage. Several scheduling techniques are proposed in the literature for such manufacturing system to develop near optimal schedule. A disruption in the manufacturing necessitates adjusting previously planned schedule which is known as real-time scheduling. This paper presents a comparative evaluation of different scheduling methods proposed by different investigators for dealing such situations. The literature indicates that real-time scheduling of manufacturing system with machining and assembly operations is hardly attempted. The paper offers a framework for developing rescheduling methodologies for such manufacturing situations.     

活性炭在三维电极法处理染料废水中的应用

采用活性炭作为自制三维电极反应器中的第三极，并用此电极反应器对甲基橙模拟染料废水的降解进行了实验研究。重点讨论了电压、电解质浓度以及溶液pH等因素对CODCr去除率和甲基橙去除率的影响。研究结果表明：活性炭作为第三极的三维电极反应器对甲基橙模拟染料废水进行降解，甲基橙浓度去除率到达90％，CODCR去除率达到80％。并由此展望了活性炭在三维电极处理染料废水的应用前景。     

Dipyridamole stress echocardiography in diagnosis and prognosis of hemodialysis patients with asymptomatic coronary disease

The prevalence of coronary artery disease (CAD) is high in hemodialysis (HD) patients. The aim of the study was to assess the diagnostic and prognostic value of dipyridamole stress echocardiography (DSE) in nondiabetic HD patients without signs or symptoms of CAD. In 51 out of 158 evaluated HD patients (21 females, age 67 [33–85] years, HD duration 38 [9–271] months), resting echocardiography and DSE were performed. Exclusion criteria were known CAD, diabetes mellitus, and pulmonary and oncologic pathologies. Logistic regression analysis was carried out to identify predictors of abnormal DSE response, while Cox regression analysis was performed to determine variables associated with total and cardiovascular mortality, after 43.3 (11–60) months of follow‐up. Seven patients (14%) showed a positive response to DSE (DSE+). In 5/7, CAD was documented by angiography: All of them underwent coronary revascularization. DSE+ patients had significantly smaller body mass index than patients with a negative response (DSE‐): 21.7 ± 1.9 vs. 25.1 ± 3.4 kg/m² (p = 0.018). During follow‐up, 16 (31%) patients died. Older age hazard ratio [HR = 1.07; confidence interval (CI) = 1.01–1.12; p = 0.02] and higher plasma phosphate levels (HR = 10.41; CI = 2.30–47.17; p < 0.01) were predictors of total mortality. Male gender (HR = 22.7; CI = 1.45–354.4; p = 0.03), older age (HR = 1.24; CI = 1.03–1.50; p = 0.02), longer HD duration (HR = 1.13; CI = 1.01–1.26; p = 0.04), and positive response to DSE (HR = 5.82; CI = 1.04–32.65; p = 0.04) were associated with cardiovascular mortality. Ten percent of asymptomatic HD patients had significant CAD, but timely diagnosis did not seem to improve their prognosis. Total survival was associated with age and higher levels of plasma phosphate, while male gender, older age, longer HD duration, and DSE+ were predictors of cardiovascular mortality.     

半椭圆形罩LSC的准三维和三维数值模拟对比

为了得到半椭圆形罩线型聚能装药(LSC)射流成型的特点和规律,利用ANSYS/LS-DYNA软件分别建立了半椭圆形罩LSC的准三维和三维数值计算模型,对射流成型过程进行了数值模拟,获得了射流成型过程的特点和典型时刻沿对称面射流速度梯度分布及射流最大速度随时间的变化关系。从横断面看,形成的射流较长且均匀,相对质量和速度均较大,速度梯度呈现明显的三段特征;杵体短而粗,相对质量和速度均较小;两种数值计算模型获得的射流最大速度出现的时刻、杵体断裂时刻和射流断裂时刻以及典型时刻沿对称面射流速度梯度分布均有所差别。结果对比分析表明,三维数值计算模型比准三维计算模型能更全面准确地模拟出射流的成型过程,获得的结果更可靠。     

半椭圆形罩LSC的准三维和三维数值模拟对比

为了得到半椭圆形罩线型聚能装药(LSC)射流成型的特点和规律,利用ANSYS/LS-DYNA软件分别建立了半椭圆形罩LSC的准三维和三维数值计算模型,对射流成型过程进行了数值模拟,获得了射流成型过程的特点和典型时刻沿对称面射流速度梯度分布及射流最大速度随时间的变化关系。从横断面看,形成的射流较长且均匀,相对质量和速度均较大,速度梯度呈现明显的三段特征;杵体短而粗,相对质量和速度均较小;两种数值计算模型获得的射流最大速度出现的时刻、杵体断裂时刻和射流断裂时刻以及典型时刻沿对称面射流速度梯度分布均有所差别。结果对比分析表明,三维数值计算模型比准三维计算模型能更全面准确地模拟出射流的成型过程,获得的结果更可靠。     

Collagen gel three-dimensional matrices combined with adhesive proteins stimulate neuronal differentiation of mesenchymal stem cells

Three-dimensional gel matrices provide specialized microenvironments that mimic native tissues and enable stem cells to grow and differentiate into specific cell types. Here, we show that collagen three-dimensional gel matrices prepared in combination with adhesive proteins, such as fibronectin (FN) and laminin (LN), provide significant cues to the differentiation into neuronal lineage of mesenchymal stem cells (MSCs) derived from rat bone marrow. When cultured within either a three-dimensional collagen gel alone or one containing either FN or LN, and free of nerve growth factor (NGF), the MSCs showed the development of numerous neurite outgrowths. These were, however, not readily observed in two-dimensional culture without the use of NGF. Immunofluorescence staining, western blot and fluorescence-activated cell sorting analyses demonstrated that a large population of cells was positive for NeuN and glial fibrillary acidic protein, which are specific to neuronal cells, when cultured in the three-dimensional collagen gel. The dependence of the neuronal differentiation of MSCs on the adhesive proteins containing three-dimensional gel matrices is considered to be closely related to focal adhesion kinase (FAK) activation through integrin receptor binding, as revealed by an experiment showing no neuronal outgrowth in the FAK-knockdown cells and stimulation of integrin β1 gene. The results provided herein suggest the potential role of three-dimensional collagen-based gel matrices combined with adhesive proteins in the neuronal differentiation of MSCs, even without the use of chemical differentiation factors. Furthermore, these findings suggest that three-dimensional gel matrices might be useful as nerve-regenerative scaffolds.