冠心病人心电图信号的非线性动力学特性

采用非线性动力学方法对冠心病人的同步十二导联常规心电信号（Electrocardiogram:ECG)进行了研究,计算了每一导联心电图信号的关联维数D2,并与正常对照组进行对比,发现不论冠心病人（CHD）还是健康人,心电图信号均表现出强烈的混沌动力学特征,从不同导联得出的D2值不同,同一导联相比较,除Ⅰ,Ⅱ,Ⅲ导联外,冠心病人的D2显著低于正常人的D2值,显示在心肌缺血的情况下,心脏ECG吸引子的复杂程度降低了。结果表明,D2可以区别正常人与冠心病人,也可以为确定病变部位提供有价值的诊断信息。     

Characteristics of magnetocardiography and electrocardiography in the time-frequency domain

As the carriers of electromagnetic information about the cardiac system,both magnetocardiography(MCG) and electrocardiography(ECG) are non-stationary signals(NSS).The essential and crucial features of NSS are the local time-frequency characteristics(LTFCH).Under the constraint of the uncertainty principle in the time-frequency domain(TFD),the LTFCH of those non-stationary signals can be determined by evolutionary spectrum analysis(ESA).In this paper,by analyzing the QRS complexes of both MCG and ECG data from healthy volunteers,we have derived some characteristic parameters(CHPs) in the TFD,such as the quality factor(Q) and center frequency(fz).According to the experiment results,we believe that there are threshold ranges of Q and fz values in the dynamic behavior of the cardiac system for healthy projects.If the CHPs are in the proper ranges,the cardiac system is in a normal condition and homeostasis can be self-correcting.In contrast,if the values of the CHPs are less than the proper ranges,the homeostasis of the cardiac system is lost and some cardiac diseases may result.The assumption of the threshold ranges is verified by sample data from different cardiac diseases,and the results support the assumption.The CHPs are not only a kind of new reference criterion for ECG in clinical diagnosis,but also afford a technological route for the application of MCGs in cardiology.     

Correlation between platelet gelsolin levels and different types of coronary heart disease

Gelsolin is an important cytoskeletal protein of platelets and studies have shown a close relationship between gelsolin and cardiovascular disease.However,the role of gelsolin in the development of coronary heart disease(CHD) is unclear.In this study,we record the distribution of gelsolin in human platelets and plasma and its association with different types of CHD.This study included 114 cases,with 33 stable angina pectoris(SAP) cases,81 acute coronary syndrome(ACS) cases—composed of 39 unstable angina pectoris(UAP) and 42 acute myocardial infarction(AMI) cases,and 31 healthy control participants.Gelsolin concentration in platelet rich plasma(PRP) and platelet poor plasma(PPP),actin filament(F-actin) and Gc-globulin of PPP were determined by enzyme-linked immunoadsorbent assay(ELISA).The fluorescence intensity of CD62p and cytoplasmic calcium([Ca2+] i) in human platelets measured by flow cytometry.We also used turbidimetry to detect the platelet aggregation rate(PAR).We analyzed the correlation between platelet gelsolin concentration and CD62p or plasma F-actin levels among each different patient group.Compared with the control group,the gelsolin level in PRP of UAP and AMI groups increased significantly(P<0.01),while the gelsolin level in PPP of all the three patient groups decreased markedly(P<0.01),and the CD62p,PAR,[Ca2+] i of platelets,F-actin and Gc-globulin of the UAP and AMI groups increased significantly(P<0.01).Compared with the SAP group,the gelsolin level in PRP,the PAR,[Ca2+] i of platelets and CD62p of other two groups increased significantly(P<0.01),F-actin of the AMI group increased markedly(P<0.01).Platelet cytoskeleton protein dynamics vary among the different types of CHD.Platelet gelsolin levels are markedly increased and accompanied by increased platelet activity,F-actin and [Ca2+] i of ACS patients,while gelsolin levels in PPP are markedly lower.Abnormally increased platelet gelsolin levels show high positive correlation with the level of platelet activity.Therefore,platelet gelsolin might be a novel molecular marker and/or a new potential therapeutic target of anti-platelet therapy of ACS.     

Investigation of gene expression profiles in coronary heart disease and functional analysis of target gene

The research outlined here includes constitution of the differential gene expression profile by means of oligonucleotide gene microarray and functional analysis of the target gene for coronary heart disease (CHD). In a microarray screening experiment, the predominance of inflammation- and immune-related genes is presented in the expression profile of 107 differential genes based on the analysis of gene ontology and gene pathway. IL-8, an inflammatory factor, is identified as one of the genes that were markedly up-regulated in CHD. The plasma level of IL-8 is significantly raised in patients with CHD (n = 30) compared with healthy controls (n = 40), which underscores the clinical relevance of the in vitro finding. The further functional analysis shows that IL-8 affects platelet aggregation percentage, expression of CD62p and platelet aggregation morphology in 12 healthy volunteers to some extent. These findings suggest the relevance of inflammation and immune responses to CHD at the DNA level. Moreover, IL-8 may be involved in the pathogenesis of CHD through the pathway of platelet activation. Supported by the National Natural Science Foundation of China (Grant No. 90409021)     

基于多尺度熵的心电图ST段研究

首次用多尺度熵的理论研究了心电图的ST段,并将心电图ST段多尺度熵分析结果和ECG多尺度分析结果进行比较.我们发现:健康人和冠心病人心电图的样本熵值接近,它们都要高于心梗病人的样本熵值;而健康人心电图ST段的样本熵值最小,冠心病人的最高,心梗病人的样本熵值在两者之间,并给出了合理的解释.心电曲线复杂度变化的这些特点对于早期临床诊断具有重要的意义.     

A high-Tc dc-SQUID-based single-channel MCG and its performance

A single-channel high-Tc dc-SQUID magnetometer and gradiometer have been developed to record the magnetic field component perpendicular to the human chest generated by heart-beat. Magnetocardiogram (MCG) measurements have been carried out inside a magnetically shielded room. By sequentially adjusting a non-magnetic patient table with 5 cm pitch in X and Y directions, the field signals on a rectangle grid 5 × 5 over the chest area were registered in real time trace point by point with a typical dwell time over 30 cardiocycles each. Utilizing standard electrocardiogram (ECG) recordings as timing reference measured simultaneously with the MCG signals, the MCG data were then averaged and combined to form magnetic field patterns every 10 ms or so. Both the current dipole, which is parallel to MCG measuring plane and produces the vertical magnetic field, and its depth were determined as a function of time in a standard way. We have compared the MCG of healthy hearts with that of a heart with right bundle branch block. Significant differences between their MCGs have been observed.     

通管汤盆腔灌注对大鼠输卵管炎性阻塞性不孕模型病理及BCL-2、EGFR蛋白表达的影响

目的研究自拟通管汤(简称通管汤)盆腔灌注对大鼠输卵管炎性阻塞的作用及机制。方法选用体重为(200±20)g,鼠龄8~12周的SD雌性大鼠130只,用混合菌制造大鼠输卵管炎性阻塞模型114只,随机分为正常对照组(A)、模型组(B)、兔耳风胶囊组(C)、通管汤组(低剂量组D_1、中剂量组D_2、高剂量组D_3)。采用输卵管通液观察输卵管通畅,HE染色观察输卵管组织形态学变化,免疫组化检测输卵管上皮细胞Bcl-2、EGFR的表达。结果 (1)治疗组输卵管通畅率D_3、D_2、C组与B、D_1组比较有非常显著性差异(P0.01);(2)D_3组与D_2、C组比较有较显著差异(P0.05);中高剂量治疗组(D_3、D_2)输卵管组织形态好转明显好于模型组(B)与低剂量组(D_1);治疗组输卵管上皮细胞Bcl-2、EGFR表达(P0.05-P0.01),差异有显著性,15 d与30 d比较无明显差异。结论通管汤高剂量组能缓解输卵管肿胀、减轻炎性细胞浸润、增加管腔纤毛数量和恢复输卵管通畅性;并通过下调Bcl-2、EGFR的过度表达,抑制输卵管上皮细胞凋亡和炎症反应,达到治疗输卵管炎性阻塞的作用。     

Lyapunov exponents for synchronous 12-lead ECG signals

The Lyapunov exponents of synchronous 12-lead ECG signals have been investigated for the first time using a multi-sensor (electrode) technique. The results show that the Lyapunov exponents computed from different locations on the body surface are not the same, but have a distribution characteristic for the ECG signals recorded from coronary artery disease (CAD) patients with sinus rhythms and for signals from healthy older people. The maximum Lyapunov exponent L1 of all signals is positive. While all the others are negative, so the ECG signal has chaotic characteristics. With the same leads, L1 of CAD patients is less than that of healthy people, so the CAD patients and healthy people can be classified by L1, L1 therefore has potential values in the diagnosis of heart disease.     

Relation of chaos activity characteristics of the cardiac system with the evolution of species

According to the nonlinear theory, the experiments have been conducted on sample ECG (electrocardiogram) signals of healthy human beings, coronary heart disease patients and adult canines. On the basis of the analyses of the power spectra, the computation of the correlation dimension and the Lyapunov exponent to a large number of ECG signals, the following conclusions are shown: through the comparative research, (1( the analyses of the power spectra, the computation of the correlation dimension and the Lyapunov exponent to the ECG signals reflect the whole dynamic characteristics of the hearts, and they may become a new method of researching ECG quantitatively to an early diagnose of heart disease. (2( Under normal physiological conditions the cardiac activities are chaotic, while under pathologic conditions the cardiac activities approach regularity. (3( On the basis of the comparative research of human beings and canines, it is revealed that chaos may be a quantitative index to measure the evolution of species. This conclusion would supply a new cut-in point to elaborate the Darwin theory, and it would enable us to explain the life theory renewably using the basic principle of nonlinear theory.     

Functional Imaging of Breast Tissue and Clinical Application

0Introduction Near infrared(NIR)techniquesarebasedonsensitive,quantitativemeasurementsoffunctionalcontrastbe tweenhealthyanddiseasedtissue.Recently,researchersshowgreatinterestinmeasuringfunctionalpropertiesofbreasttis suesuchashemoglobinconcentrationoroxygensaturationbyNIRspectroscopyandNIRimaging[1,2].NIRlightcanpene trateseveralcentimetersintotissuebeforeitisattenuatedbe lowdetection.ThemainintrinsicmechanismsofNIRlightat tenuationintissuearethescatteringduetoindexofrefractionvariatio…     

Evidence for hydrogen-deuterium exchange in viral particles

Heavy water (D2O) could enhance thermostability of some viruses. However, the underlying mechanism is not clear. Here we report the development of a matrix-aided gas-isotope-ratio mass spectrometry method that allows direct determination of deuterium/hydrogen (D/H) ratio in D2O-treated Japanese encephalitis virus (JEV), hepatitis A virus (HAV) and RNA from D2O-treated HAV. The D/H ratiowas expressed as δDSMOW. Our experiments showed that δDSMOW values increased significantly in D2O-treated viral samples compared to normal controls, and increment in δDSMOW of D2O, treated viral samples was in a fine linear relationship with increment in amount of samples loaded in BSA matrix. Our experiments also indicated that increased δDSMOW of D2O-treated virus correlated well with its enhanced thermostability. The results suggested that hydrogen-deuterium exchange occurred in viral particles and its RNA structure as a result of D2O-treatment. Furthermore,such exchange could cause changes in viral phenotype, such as enhanced thermostability.     

Trichloroacetate affects the EPR Signal IIslow and Signal I in the thylakoid ofChlamydomonas reinhardtii

One electron paramagnetic resonance (EPR) signal, named Signal II_slow, originates from the oxidized Tyrosine 160 (Y_D) of D2 polypeptide of photosystem II reaction center. After adding high concentration trichloroacetate (TCA) to theChlamydomonas reinhardtii thylakoid suspension, this signal was abolished in a minute. Treatment of TCA also removes a few of polypeptides, including three extrinsic polypeptides of oxygen-evolving complex, from the thylakoid membrane. Based upon the analysis of the microenvironment around Y_D with a three-dimensional model, it is indicated that relatively high hydrophobicity of this microenvironment may be the essential prerequisite for TCA to affect Y_D. It has been observed that TCA treatment also retards the decay of the Signal 1, produced by the oxidized reaction center chlorophyll dimer (P700⁺) of photosystem I.     

健康恒河猴心电图研究

目的研究健康恒河猴在清醒状态下的心电图特点。方法选择60只2-3岁健康恒河猴,体重2-3．5kg; 雌雄各30只;在环境安静、动物清醒状态下,测定I、Ⅱ、Ⅲ、aVR、aVL、aVF六个导联的心电图变化,并计算平均心 率,平均心电轴,P波、QRs波群和T波的振幅,PR间期、QT问期等指标。结果60只恒河猴均为窭性心律,并发 现在肢体Ⅱ导联中,P波均为向上直立波,Ⅱ、Ⅲ、aVF导联中大部分恒河猴没有s波,aVR导联中大部分恒河猴没 有Q波。雌性恒河猴R波电压平均值明显高于雄性恒河猴平均值(P<0．005)。恒河猴P波较尖,QRs波群多样 化,QT问期的K值范围是0．298 4-0．030,ST段位于等电位线,T波以圆滑为主,Ⅱ导联中绝大部分为直立。结论 此研究建立了恒河猴心电图相关基础数据,为相关的研究提供了参考。     

ST/HR斜率与单光子发射计算机断层摄影术心肌灌液显像

分析了ST/HR斜率对冠心病(CHD)的诊断价值,应用ST/HR斜率计算机自动分析系统与运动介入单光子发射型计算机断层摄影术(SPECT)心肌显像同时进行,检测60例临床怀疑CHD患者,并对30例健康正常人进行了ST/HR斜率检测。结果表明:ST/HR斜率与SPECT心肌显像二者结果有良好的相关性(r=0.58,P<0.005),符合率为80%,SPECT阳性者其斜率值高于SPECT阴性者及正常人群(均P<0.05);若以SPECT为标准,ST/HR斜率与普通运动试验诊断CHD的敏感性分别为81.6%和73.9%(P>0.05),特异性分别为77.3%和45.5%(P<0.05),以正常人为ST/HR斜率与普通运动试验的特异性分别为93.3%和70.0%(P<0.05);SPECT显示2个以上节段心肌缺血者,其斜率值明显高于单一节段缺血者(P<0.05)。     

急性正后壁心肌梗死采用常规导联与头胸导联心电图定位诊断比较

目的对急性正后壁心肌梗死的患者及健康人,分别采用常规12导联和头胸导联对其进行心电图定位诊断的比较。方法选取心内科急性正后壁心肌梗死的患者36例和健康人52例,分别应用常规12导联和头胸导联心电图进行同步记录,后参照冠状动脉造影确诊结果对两份心电图检查结果进行对比,经计算得出两种导联的心电图对急性正后壁心肌梗死诊断的确诊率和假阳性率,应用χ2检验作出统计学分析。结果常规12导联心电图对急性正后壁心肌梗死36例患者中,32例可确诊,确诊率为88.8%;对52例健康人做出了7例假阳性诊断,假阳性率为13.4%;头胸导联对急性正后壁心肌梗死患者有35例可确诊,确诊率为97.22%,对52例健康人做出了2例假阳性诊断,假阳性率为3.85%。差异具有统计学意义(P<0.05)。结论急性正后壁心肌梗死的临床诊断,头胸导联优于常规12导联,值得临床推广。     

Investigation on the explosive welding mechanism of corrosion-resisting aluminum and stainless steel tubes through finite element simulation and experiments

To solve the difficulty in the explosive welding of corrosion-resistant aluminum and stainless steel tubes, three technologies were proposed after investigating the forming mechanism through experiments. Then, a 3D finite element model was established for systematic simulations in the parameter determination. The results show that the transition-layer approach, the coaxial initial assembly of tubes with the top-center-point the detonation, and the systematic study by numerical modeling are the key technologies to make the explosive welding of LF6 aluminum alloy and 1Cr18Ni9Ti stainless steel tubes feasible. Numerical simulation shows that radial contraction and slope collision through continuous local plastic deformation are necessary for the good bonding of tubes. Stand-off distances between tubes (D₁ and D₂) and explosives amount (R) have effect on the plastic deformation, moving velocity, and bonding of tubes. D₁ of 1 mm, D₂ of 2 mm, and R of 2/3 are suitable for the explosive welding of LF6-L2-1Cr18Ni9Ti three-layer tubes. The plastic strain and moving velocity of the flyer tubes increase with the increase of stand-off distance. More explosives (R>2/3) result in the asymmetrical distribution of plastic strain and non-bonding at the end of detonation on the tubes.     

维生素E和疏血通注射液联用对不稳定型心绞痛患者的影响

目的观察维生素E和疏血通注射液联用对不稳定型心绞痛(UAP)患者的疗效及其时血浆一氧化氮、内皮素的影响.方法将70例符合WHO不稳定型心绞痛诊断标准的患者随机分为两组,对照组30例,常规抗心绞痛治疗,实验组在对照组治疗基础上加用维生素E100mg,1次/d口服,疏血通注射液6mL加入5%葡萄糖注射液250 mL中静点,1次/d.测定治疗前及治疗1,2,3,4周时的NO,ET-1水平及4周时的心绞痛症状、心电图的变化情况.另测30例体检健康者的ET-l,NO水平作为阴性对照.结果冠心痛心绞痛患者与健康体检者比较NO水平降低,ET-1水平增高.实验组第3,4周时与对照组比较ET-1水平降低,NO水平增高.实验组治疗前后差异有显著性,对照组治疗前后无差异显著性.治疗4周后实验组总有效率明显优于对照组.结论维生素E和疏血通注射液联用,可明显改善不稳定型心绞痛患者的血管内皮功能,提高治疗效果.     

直径图为11圈的7距离集研究

如果平面点集X中的任意两点确定的互异距离数为k,则称X为k距离集。用d(x,y)表示平面上互异两点x,y之间的距离,记X中的最大距离为直径D=D(X)。直径图DG(XD)是由X中所有直径构成的图,XD表示其顶点集。讨论了当X是一个7距离集时,直径图DG(XD)的构型。利用DG(XD)中最多包含一个圈,且只能为奇圈的特性,以及直径所具有的特殊性,证得当直径图为11圈时,其顶点集XD恰好为某正十一边形的顶点集。     

Fractal Characteristics of Soil under Different Land-Use Patterns in the Arid and Semi-Arid Region of the Western Tibet Plateau, China

0Introduction Changesinsoilstructureoftenaccompanychangesinmanagementpracticesandmayaffecttheeffectivenessofthesepractices.Parametersareneededto quantifythesechanges.Sizedistributionsofsoilparticleandmicroaggregatehavebeenfoundtobeagood indicatorofchanges…     

铝药型罩环形聚能射流的数值模拟

基于一种药型罩材料为铝的环形聚能装药结构,通过Autodyn软件模拟不同起爆方式（起爆环直径D₁）和不同长径比（L/D）的装药,计算得到环形射流的成型过程和速度分布曲线.分析数值模拟结果发现:环形射流成型过程主要受长径比影响,长径比较小时射流发生内偏,长径比较大时射流发生外偏;射流轴向速度主要受长径比影响,长径比越大轴向速度越大,头部轴向速度最大相差约700 m/s;射流径向速度主要受起爆方式影响,平均径向速度最大相差为220 m/s,起爆环直径和长径比在较小或较大时,射流径向速度梯度较大;结合射流成型和速度结果,D₁=0.5D、L/D=1.0时射流综合性能较好.侵彻混凝土板试验的通孔直径为装药直径的2.6倍,数值模拟结果与试验结果误差为7.7%,验证了计算模型及算法的合理性.