桂竹糖芥强心甙G及其制剂HPLC分析

应用高效液相色谱法（ＨＰＬＣ法），以挂竹糖芥甙Ｇ为对照标准品，测定制剂中甙Ｇ的含量．采用μ－ＢｏｎｄａｐａｋＣ１８柱、流动相：乙腈－甲醇－水系统，线性范围：（２．６～７．８）μｇ，变异系数０．９（％），回归方程：ｙ＝１４１５７９２ｘ＋５２６２４．６，相关系数ｒ＝０．９９９９，方法灵敏、准确。     

二元压缩映象对和映象列的公共耦合不动点及重合点

在一致凸Ｂａｎａｃｈ空间中,获得了二元非线性压缩映象对和映象列的公共耦合不动点的存在与唯一性定量,并对已有的结果进行了推广。     

单调半凝聚映射与半紧1—集压缩映射

给出了半凝聚映射的概念,讨论了单调半凝聚映射与半紧1-集压缩映射不动点存在的条件及不动点集{x(λ)}的性质。在两种意义下改进了已有的结果。     

一类Lazer—Mckenna吊桥方程的周期解

通过Banach不动点定理。得到了关于Lazer-Mckenna吊桥方程分别在所谓对称和非对称无理周期边界条件之下解的存在唯一性定理。     

特发性室性心律失常的射频消融治疗

评价特发性室性心律失常(室性心动过速和室性早搏)经导管射频消融治疗的临床疗效.10例患者(男4例,女6例),平均年龄42.5±17.3岁.其中频发室早5例,室速5例,采用激动标测法与起搏标测法相结合来确定起源点.4例心律失常位于右室流出道,5例位于左室中后间隔区,1例左室流出道室早位于左冠窦内.10例患者均获得良好效果,即刻成功率100%.随访期间(2～30个月)停用抗心律失常药物无心律失常复发.     

大学生适宜运动负荷强度的实验研究

通过对62例大学生心输出量、最大吸氧量等指标在递增负荷后的变化，讨论SV(每搏输出量)、CO(每分输出量)、VO2max(最大摄氧量)、VAT(通气无氧阈)、HR(心率)等有关指标变化规律及影响因素，探讨了男子大学生适宜的运动负荷强度及不同体能受试者在不同负荷状态下的机能反映。普通大学生适宜的运动负荷强度值为最大心率的51％～88％之间，此范围是最大摄氧量的34％-70％，是最适宜的运动负荷强度。大学生运动员组的适宜负荷强度高于普通大学生，而且大学生运动员在每分输出量后的心力储备仍有一定水平，建议普通男子大学生以心输出量开始下降时心率为安全运动的限度。     

New dynamic model for non-Fickian diffusion of calcium spark in cardiac myocytes

A new dynamic model for non-Fickian diffusion of calcium spark in cardiac myocytes was developed by introducing time lags on the basis of the microscale mass transport theory. Numerical simulation showed that the size of the calcium spark produced by the new dynamic model was larger than that of Fick diffusion and was in more agreement with experimental results. In addition, the time lags of the calcium spark in cardiac myocytes were about 0.1--0.8 ms. These results can be used to understand the mechanism of calcium spark diffusion in cardiac myocytes.     

心电图数据的非线性动力学研究

本文介绍了几种非线性动力学处理信息的方法,它们也比较适合对心电图信息进行非线性研究,并得到了一些结果。为此首先要对ＥＣＧ进行预处理,以获得更有效的便于分析的信息,用非线性动力学的方法从中提取动力学特征,为进一步早期临床诊断疾病提供依据。     

Relationship between action potential, contraction-relaxation pattern, and intracellular Ca2+ transient in cardiomyocytes of dogs with chronic heart failure

Abnormalities of contractile function have been identified in cardiomyocytes isolated from failed human hearts and from hearts of animals with experimentally induced heart failure (HF). The mechanism(s) responsible for these functional abnormalities are not fully understood. In the present study, we examined the relationship between action potential duration, pattern of contraction and relaxation, and associated intracellular Ca²⁺ transients in single cardiomyocytes isolated from the left ventricle (LV) of dogs (n = 7) with HF produced by multiple sequential intracoronary microembolizations. Comparisons were made with LV cardiomyocytes isolated from normal dogs. Action potentials were measured in isolated LV cardiomyocytes by perforated patch clamp, Ca²⁺ transients by fluo 3 probe fluorescence, and cardiomyocyte contraction and relaxation by edge movement detector. HF cardiomyocytes exhibited an abnormal pattern of contraction and relaxation characterized by an attenuated initial twitch (spike) followed by a sustained contracture ('dome') of 1 to 8 s in duration and subsequent delayed relaxation. This pattern was more prominent at low stimulation rates (58% at 0.2 Hz, n = 211, 21% at 0.5 Hz, n = 185). Measurements of Ca²⁺ transients in HF cardiomyocytes at 0.2 Hz manifested a similar spike and dome configuration. The dome phase of both the contraction/relaxation pattern and Ca²⁺ transients seen in HF cardiomyocytes coincided with a sustained plateau of the action potential. Shortening of the action potential duration by administration of saxitoxin (100 nM) or lidocaine (30 μM) reduced the duration of the dome phase of both the contraction/relaxation profile as well as that of the Ca²⁺ transient profile. An increase of stimulation rate up to 1 Hz caused shortening of the action potential and disappearance of the spike-dome profile in the majority of HF cardiomyocytes. In HF cardiomyocytes, the action potential and Ca²⁺ transient duration were not significantly different from those measured in normal cells. However, the contraction-relaxation cycle was significantly longer in HF cells (314 ± 67 ms, n = 21, vs. 221 ± 38 ms, n = 46, mean ± SD), indicating impaired excitation-contraction uncou pling in HF cardiomyocytes. The results show that, in cardiomyocytes isolated from dogs with HF, contractile abnormalities and abnormalities of intracellular Ca²⁺ transients at low stimulation rates are characterized by a spike-dome configuration. This abnormal pattern appears to result from prolongation of the action potential. Received 22 January 1998; received after revision 16 March 1998; accepted 27 March 1998     

关于一类隐式微分方程的初值问题

应用压缩映象原理证明了一类一阶隐式微分方程的初值解的存在唯一性定理，此定理可以看成是经典的Ｐｉｃａｒｄ存在唯一性定理的推广。