正常人肺静脉管径及其血流频谱的研究

肺静脉血流和肺静脉管径的变化与左房压力及左心室舒张功能密切相关 [1 ,4 ] 。超声心动图可以直接、动态观察肺静脉内径及血流频谱变化 ,但是目前超声尚无健康人肺静脉内径正常值。我们应用彩色超声多普勒技术对正常人及孕周 2 4周以上的妊娠妇女进行肺静脉内径及血流频谱研究 ,以探索正常人肺静脉的显示率、内径正常值、血流频谱特点。观察高动力状态及呼吸对肺静脉管径和血流频谱的影响。1　材料与方法1.1　研究对象　 16 9例排除心肺疾患的健康人分组进行研究。其中成年男性组 4 4例、成年女性组 4 6例、儿童组 14例、中期妊娠组 (中妊 …     

The effects of THA on scopolamine and nucleus basalis lesion-induced EEG slowing

The effectiveness of THA (an anticholinesterae) on scopolamine (0.4 mg/kg) and nucleus basalis (NB) lesion-induced change in neocortical spectral electroencephalography (EEG) were investigated. Scopolamine increased the amplitudes of all the spectral components in waking-immobility. In the movement-related EEG spectral values, only the alpha power was increased. THA 7.5 mg/kg, but not THA 3 mg/kg, could reverse scopolamine-induced amplitude change. NB lesioning increased delta and theta amplitudes, but decreased beta amplitude. Delta amplitude was increased during movement recordings in NB-lesioned rats. THA 7.5 mg/kg and pilocarpine 10 mg/kg, but not THA 3 mg/kg, could partially reverse the increase of delta and theta amplitudes induced by NB lesions. However, the beta power decrease could not be restored with cholinomimetics. This study demonstrates that quantitative EEG activity analysis may reflect the THA-induced restoration of the function of the cholinergic nucleus basalis.     

High-quality recording of bioelectric events

A multichannel instrumentation amplifier, developed to be used in a miniature universal eight-channel amplifier module, is described. After discussing the specific properties of a bioelectric recording, the difficulties of meeting the demanded specifications with a design based on operational amplifiers are reviewed. Because it proved impossible to achieve the demanded combination of low noise and low power consumption using commercially available operational amplifiers, an amplifier equipped with an input stage with discrete transistors was developed. A new design concept was used to expand the design to a multichannel version with an equivalent input noise voltage of 0·35 μV RMS in a bandwidth of 0·1–100 Hz and a power consumption of 0·6 mW per channel. The results of this study are applied to miniature, universal, eight-channel amplifier modules, manufactured with thick-film production techniques. The modules can be coupled to satisfy the demand for a multiple of eight channels. The low power consumption enables the modules to be used in all kinds of portable and telemetry measurement systems and simplifies the power supply in stationary measurement systems.     

以乙二胺为核心的聚酰胺-胺树形高分子的合成及毛细管电泳分离研究

在-30℃下合成了1．0G～6.0G聚酰胺．胺(PAMAM)树形高分子，并采用核磁共振、元素分析对其进行了表征；采用毛细管电泳对1．0GPAMAM进行了分离。结果表明：在该温度下合成的PAMAM具有较好的结构完整性，而毛细管电泳是一种有效的分离提纯PAMAM树形高分子的方法。     

1000例正常人发电子自旋共振（ESR）波谱的饱和特性研究

本文报道1000例正常人发自由基的电子自旋共振波谱饱和功率(ESR-SP)的检测结果。所得正常值的全组中位数为2.496mw;95％上下限分别为2.989及1.720mw。如按性别统计,则女性下限(1.617mw)较男性(1.983mw)为低,(P<0.05)。按年龄分别统计,则40岁以上的中位数(2.376mw)及其下限(2.009mw)高于40岁以下的中位数(2.548mw)及其下限(1.597mw),两者差异有显著性(P<0.05)及极显著性(P<0.01)。因此在使用此正常值指标时,必须注意性别与年龄因素。     

Counter Intuitive Relations Between in vivo RF Lesion Size, Power, and Tip Temperature

Background: Radiofrequency (RF) lesion size in vitro is positively correlated with applied power and catheter tip temperature. However, the relation between RF lesion size, power, and tip temperature in vivo remains unclear. We hypothesized that due to flow, anatomy and tip contact effects in vivo, increased tip temperature would be inversely related to applied power and RF lesion size. Methods: RF lesions were created on the endocardium of 16 pigs using 5, 6, and 7 Fr catheters. The ablation generator was set to achieve a temperature of 70°C. RF lesions were created in different regions of the heart so as to encompass a wide range of blood flow and catheter movement conditions. RF lesions were measured acutely (DIMEN, mm) and correlated with average power applied (POWER, W), and average tip temperature (TEMP, °C). The POWER and TEMP relation was also examined. Results: For TEMPs below 55°C, the power output from the generator was typically maximized at 50 W. At TEMPs above 55°C, POWER decreased exponentially with increasing TEMP {POWER = 50 – exp(-((41-TEMP)/7)), r = 0.98, p < 0.05}. Further, DIMEN tended to be inversely related to TEMP (Slope: –0.07 ± 0.04, r = –0.15, p = 0.07); but, was positively related to POWER (Slope: 0.04 ± 0.02, r = 0.23, p < 0.05). These relations varied by tip size and estimated local blood flow characteristics. Conclusion: In vivo, variable tissue contact and flow yield DIMEN-POWER-TEMP relations opposite to those found in vitro. These counterintuitive results suggest that maximum in vivo RF lesion size is achieved when power is maximized at tip temperatures between 50 and 60°C.     

S波段高功率微波辐射对原代培养乳鼠心肌细胞的影响

目的研究S波段高功率微波（HPM）辐射后乳鼠心肌细胞的损伤效应及其机制。方法采用平均功率密度为5～30mW/cm^2的S波段HPM模拟源辐射原代培养的乳鼠心肌细胞，应用流式细胞术、原子力显微镜观察辐射后心肌细胞凋亡和坏死率、[Ca^2＋]。及细胞膜形态。结果10—30mW／cm^2的S波段HPM辐射后6h，心肌细胞凋亡和坏死率增加（P〈0．05或P〈0．01），且随辐射剂量增大，坏死细胞增多；30mW/cm^2 HPM辐射后即刻[Ca^2＋]i升高（P〈0．01），细胞膜发生穿孔。结论10—30mW/cm^2的S波段HPM辐射可造成心肌细胞凋亡和坏死，[Ca^2＋]；升高以及细胞膜穿孔，是S波段HPM辐射致心肌细胞损伤的重要机制。     

Study on Singularity of Chaotic Signal Based on Wavelet Transform

INTRODUCTION The significant information of a signal is often carried by singular characteristics or irregular struc-tures of the signal, for example, the most important information of ECG(electrocardiogram) or EEG isoften presented at the transient points of a signal, such as those points near peaks. The singular charac-teristics of these transient points are more obvious than the smooth parts of signals. Therefore,to studythe singularity of a signal is a meaningful work. Those analysi…