硒缺乏豚鼠心肌细胞膜的通透性和超微结构变化

硒缺乏与克山病发病有关,亚硒酸钠能预防克山病新发,虽得到公认,但机制不清。为了探索硒在克山病发病中的作用机制,本研究用人工半合成低硒饲料喂养豚鼠,电镜观察了低硒豚鼠心肌细胞膜的通透性和超微结构变化。断奶后雄性豚鼠20只,分别喂低硒和相同饲料组份的补硒半合成饲料,硒合量为0.013ppm,0.37ppm。饲料配方见文献1。实验二个月期满,测定两组动物血硒含量。用硝酸镧显示心肌细胞膜通透性变化的电镜技术制制片,并做常规切片。H—600—4型电镜观察。结果表明,低硒和补硒组豚鼠血硒含量分别为0.039±0.0006ppm,0.093±0.014ppm。补硒组豚鼠心肌     

串珠镰刀菌素引起小鼠及大鼠心肌损伤的超微结构研究

串珠镰刀菌素Moniliformin是从串珠镰刀菌Fusarium monilifome的培养物中提取的毒素。此毒素可以引起大鼠急性心力衰竭及心肌损伤。88年医科院药物所姬政等从云南及陕西克山病病区粮食中分离到此毒素,含量为40-252μg/kg。并用化学方法合成了此毒素。范礼理等观察到此毒素可以引起在体及离体大鼠心肌收缩功能显著减弱及心律失常。我们对串珠镰刀菌素引起小鼠及大鼠的急性及慢性心肌损伤进行了超微结构的研究,以便进一步探讨此毒素与克山病之间的关系。     

脾主肌肉的超微结构研究

运用电子显微学和超微结构定量计测技术探讨了中医脾主肌肉的超微结构基础。对骨骼肌和心肌单位视野的线粒体数进行了计测和分析。研究结果表明脾气虚证大白鼠结构正常的线粒体数显著减少,而结构异常的线粒体数显著增加。这些改变提示降低了肌肉中的能量供给。四君子汤(健脾中药)治疗后的数据与正常大白鼠无显著差异。认为线粒体的结构改变是脾主肌肉的超微结构基础之一。     

急性硒中毒后肝损伤的电镜观察

急性硒中毒后肝损伤的电镜观察曹晓哲高自芳邢传平刘华福（兰州军区总医院病理科，兰州７３００５０）作为必需营养元素—硒，各国学者对其缺乏的研究进展迅速，发现硒缺乏与克山病、白肌病、缺血性心肌病、高血压、关节炎、衰老、白内障、不孕、肿瘤等疾病有关［１］。随...     

人心肌细胞线粒体的电镜观察

一些病变的人心肌细胞线粒体,如心肌梗死患者,克山病患者以及因饥饿而死的婴儿,电镜观察到在心肌细胞线粒体上存在着电子密度较高的团状无定形物质,这无疑是病变所引起的。那么健康人心肌细胞线粒体上是否也存在着这类物质呢?我们对八例、年令均在20岁左右的非正常死亡的健康人心肌作常规电镜超薄切片观察,发     

脾气虚证大白鼠血管平滑肌超微结构研究

运用电子显微学和超微结构定量计测技术探讨中医脾主肌肉的超微结构基础,对脾气虚证动物骨骼肌和心肌以及十二指肠平滑肌进行了超微结构观察和定量计测研究。本研究目的是按中医理论复制大白鼠脾气虚证模型,观察研究脾气虚证时,血管平滑肌的超微结构变化。实验实物Wistar雄性大白鼠,复制脾气虚证模型时用厚朴、枳实、大黄按3:3:2的比例混合制成100％煎剂,每天4毫升灌胃,隔日一次,给药当天禁食,次日给足量食物,共42天。对照组灌等量水,正常饲养。经中医确认为脾气虚证,用加味四君子汤使其复健,基本方的组成是炙黄芪、党参、茯苓、炒白术、炙甘草,以2:2:2:2:1制成100％煎剂,每只大白鼠隔日灌胃4毫升,正常饲养,共21天。自然恢复组灌等量水,正常饲养。     

心内膜心肌活检组织的超微结构研究—106例分析

近年,心内膜心肌活检技术在医学临床诊断上的应用日益广泛,为了探讨由不同病因引起的心肌超微结构形态变化,以及其对临床诊断的意义,我室从1986年开始累积了106例资料。透射电镜观察的结果表明:不同病因的心肌组织其超微结构病变部位主要在心肌细胞和心肌间质。一心肌细胞损伤根据损伤程度分为:(一)重度损伤;心肌细胞正常结构丧失,显示细胞坏死的特征。含此种变化的有15例。(二)轻度损伤:心肌细胞的结构存在,损害程度不一,主要改变有1.细胞器变性,其中较显著和普遍的是线粒体和内质网。2.局部肌原纤维、肌丝排列紊乱,灶性肌丝溶解。Z线形态和位置异常往往与肌丝紊     

海洛因成瘾复吸大鼠脑组织神经元超微结构和神经递质变化的研究

目的：模仿人类吸毒成瘾→脱毒治疗→又吸毒成瘾→又脱毒治疗→再吸毒成瘾→再脱毒治疗的大量临床实例,建立海洛因成瘾复吸大白鼠模型,对三个阶段海洛因成瘾和复吸成瘾大白鼠脑神经元超微结构和脑部分种类神经递质的含量作比较研究,了解海洛因致各阶段大白鼠脑损害的动态趋势。方法：采用递增法人为地给大白鼠皮下注射海洛因造成动物成瘾,用美沙酮—丁丙诺啡—可乐定脱毒治疗。尔后再按上法皮下注射海洛因造成动物复吸成瘾→再脱毒治疗→又再复吸成瘾,又再脱毒治疗。动物设对照组和模型组,取各阶段各组大白鼠多部位脑组织电镜下观察神经元超微结构变化,用荧光分光度法测定各阶段各组大白鼠脑(不含脑垂体)NA、DA、5—HT等神经递质的含量。结果：三个阶段海洛因成瘾和复吸成瘾大白鼠脑内多部位神经元胞体、轴突、树突都出现变性、凋亡、胀亡等超微病理结构改变,而且随复吸次数增多病变呈加重趋势。第二、三个阶段成瘾大鼠下丘脑病变比前额皮质、海马重。正常对照组电镜超微结构影像正常。三个阶段成瘾大鼠脑NA、DA、5—HT含量比正常对照组升高,而随复吸次数增加。神经递质含量增高幅度呈现下降的趋势。结论：海洛因成瘾、复吸成瘾大白鼠脑组织神经元出现广泛性损害,以变性为主。凋亡是海洛因成瘾致脑神经元死亡的主要形式,本实验也提示海洛因成瘾致脑损害中有部位上的特异性。脑神经递质含量也出现相应变化。随复吸次数增加,脑损害呈加重趋势。     

脾气虚证大白鼠膈肌的超微结构研究

利用现代科学技术不断获得新的微观观测结果,将能对我们前人干百年来积累的生活和医疗实践所概括的中医理论,赋予更丰富的不同层次细节的内容。关于中医脾主肌肉论述的超微结构基础,已进行了骨骼肌和心肌以及平滑肌的超微结构观察和定量计测研究。中医《内经》有“隔有上下,知气之所在。”的论述。本研究是观察按中医理论复制的大白鼠脾气虚证模型膈肌的超微结构变化,并与正常组、加味四君子汤复健组和自然恢复组进行比较。     

锌元素对大剂量VD3所致心肌损伤保护作用的研究

锌元素对大剂量ＶＤ３所致心肌损伤保护作用的研究＊陆炎迟月明康向华（哈尔滨医科大学附属二院核医学科克山病研究所病理教研室，哈尔滨１５００８６）目前，ＶＤ３阿霉素等药物对心肌的慢性毒副作用已日益受到重视，许多专家学者致力于对心肌具有保护作用药物的研究［１...     

实验性缺氧性肺动脉高压肺腺泡内动脉的超微结构观察

目的:观察实验性缺氧性肺动脉高压肺腺泡内动脉的超微结构变化并探讨其发生机理。方法:将Wistar大鼠随机分成对照组(n=9)及肺动脉高压组(n=9)。以右心导管法测定肺动脉平均压力(mPAP)。用透射电镜观察肺腺泡内动脉超微结构。结果:肺动脉高压组大鼠mPAP较对照组明显增高(P<0 01)。超微结构观察,肺动脉高压组大鼠肺腺泡内动脉内皮细胞增生、变性。内弹力膜厚薄不均。呼吸性细支气管水平小动脉中层平滑肌细胞增生;呼吸性细支气管水平及肺泡水平小动脉肌化。中间型细胞及血管周细胞增生。胶原原纤维增多。结论:肺腺泡内动脉平滑肌细胞增生及动脉肌化是缺氧性肺动脉高压特征性的超微结构变化。肺血管结构重建是缺氧性肺动脉高压形成的病理基础。     

芪桃片治疗糖尿病鼠周围神经病变的电镜研究

用中药芪桃片对糖尿病鼠周围神经病变进行了实验性研究，利用电子显微镜观察病鼠坐骨神经的超微结构变化。发现病鼠坐骨神经纤维轴索内大多数肿胀的线粒体都恢复正常结构，髓 板层分离，变形和肿胀或萎缩的轴索都明显减少，郎飞结肿胀的结旁区得以改善，雪旺氏细胞内粗面内质肉扩张的现象也消失。     

A rigorous analysis of a microstripline fed patch antenna

A rigorous solution to the problem of a rectangular microstrip antenna fed by a microstripline is presented. The currents on the feed line and the patch are expanded in a suitable set of modes, and a moment method solution is formulated in the spectral domain. Three special feed cases are treated: a patch fed at a radiating edge; a patch fed at a nonradiating edge; and a proximity coupled patch. Good results are obtained for the radiating edge fed case and the proximity coupled case. The nonradiating edge fed case results were not as good; reasons for this discrepancy are discussed. Calculations are compared with measurements for high and low dielectric constant substrates.     

Proteinous amino acids in muscle cytosol of rats' heart after exercise and hypoxia

Levels of 19 proteinous amino acids and of total free amino acids were assayed by gas-liquid chromatography in cytosols of rat atrial and ventricular heart muscle cardiomyocytes. These amino acids were assayed after the rats had been exposed to either exercise (swimming) or hypoxia (hypobaric pressure of 686 hectoPascals). Out of the total free amino acids levels of arginine, glutamine and cysteine in atrial and ventricular cardiac muscle cytosols of control rats were the highest of all amino acids assayed. The control levels of all other amino acids assayed in atrial or ventricular cardiac muscles ranged from 0.1% to 10.6% of the total free amino acids in the control rats. Physical stress (exercise and hypoxia) significantly reduced the total amount of cytosolic free amino acids in both heart muscles. While hypoxia decreased the levels of arginine in both heart muscles, exercise abolished the level of cysteine in the atrial heart muscle. Decrease in arginine levels, and elimination of cysteine from the heart's atrial muscle after physical stress, may be attributed to its utilization of nitric oxide and to its synthesis of atriopeptin and/or endothelin during stress. No change was recorded in either experimental group in the level of glutamine in heart muscle cytosol. Exercise and hypoxia affect, in different modes, the levels of all other amino acids assayed, except for tryptophan, tyrosine, and histidine, which are precursors of endogenous neurotransmitters. The impact of proteinous amino acids on some bodily functions is discussed.     

长期低铅染毒大鼠脾脏超微结构的观察

目的：探讨长期低铅染毒对大鼠脾脏免疫细胞超微结构的影响。方法：建立低铅染毒的大鼠模型,８周后测定血铅并应用透射电镜技术观察大鼠脾脏免疫细胞的超微结构。结果：①电镜观察,脾脏免疫细胞出现不同程度的线粒体肿胀、空泡化或固缩;内质网肿胀、脱颗粒;②以上变化均随着铅染毒剂量的增加而加重。讨论：长期低铅染毒即可导致脾脏免疫细胞的损伤,为进一步研究铅对机体免疫系统的毒性作用提供了形态学依据。     

一种空气同轴馈电的X波段低副瓣阵列天线

设计了一种应用于雷达系统中的低成本低副瓣阵列天线, 该天线阵包含256个辐射单元, 由四个64单元的子阵组成, 采用波导合成网络进行功率合成.天线单元采用空气同轴馈电的角锥喇叭, 空气同轴馈线内外导体呈方型结构, 其终端为短路馈电方式, 实现了内导体的自支撑设计和较低的传输损耗, 并依据综合幅度分布采用若干数量的不等功分器进行低副瓣设计.测试结果表明, 小于2的驻波带宽为0.5 GHz, 相对带宽为7.5%.另外, 中心频率的增益为30 dB, 增益大于29.5 dB的带宽为0.2 GHz, E面和H面的旁瓣电平为28.5 dB和29 dB.     

Broadband Stacked Patch Antenna with Low VSWR and Low Cross‐Polarization

A low cross‐polarization broadband stacked patch antenna is proposed. By means of the stacked patch configuration and probe‐fed strip feed technique, the VSWR 1.2:1 bandwidth of the patch antenna is enhanced to 22% from 804 MHz to 1,002 MHz, which outperforms the other available patch antennas (<10%). Furthermore, the antenna has a cross‐polarization level of less than ?20 dB and a gain level of about 9 dBi across the operating bandwidth. Simulation results are compared with the measurements, and a good agreement is observed.     

心脏移植受体的超微结构改变

目的：观察心脏移植标本的超微结构变化。方法：通过移植后心脏的心内膜活检，经固定、常规则超薄切片制备，JEM－2000EX透射电镜检查。结果：移植后的早期阶段，未见明显移植排斥反应的心脏心内膜活检显示间质水肿，偶尔可见毛细血管内皮细胞的肿胀。心肌细胞和内皮细胞内溶酶体明显增多。在早期细胞排斥反应阶段，电镜检查可发现显著的心肌细胞坏死和变性，并可确定浸润炎细胞的性质。在血管排斥反应阶段，辨认内皮细胞增生、内皮细胞损伤和基底膜的改变，在患有移植性冠状动脉病的病人，其缺血性心脏具有显著特点：肌动蛋白丝的缺失比肌球蛋白丝更明显，肌微丝相对较粗大。结论：这些改变对于进一步确诊心脏移植受体的排斥和局部缺血是有用的形态学特征。     

Monomolecular layer epitaxy of GaAs for ideal static induction transistor

An ideal static induction transistor (ISIT) structure was fabricated using molecular layer epitaxy (MLE). The doping method of MLE enabled us to achieve a sufficiently high level of doping for ISIT fabrication. In the fabrication process a low growth temperature was very important for the device structure, which requires very sharp dopant profiles. For the ISIT, two MLE processes, namely source–drain growth and gate regrowth, were required. The electrical characteristics of the source–drain were changed after heat treatment at a temperature higher than 480°C. The effect of the redistribution of dopants of the source–drain structure (n⁺⁺–i–p⁺⁺–i–n⁺) during gate regrowth was clearly shown by SIMS (secondary ion mass spectroscopy) measurements for various temperatures of heat treatment. As a result the doped Se diffused from the n⁺⁺ source region to the other layers and the doped Zn diffused from the p⁺⁺ layer to the i-layers. The source was a heavily Se-doped layer at the doping level of (2–3)×10¹⁹ cm⁻³ containing a larger amount of interstitial Se atoms in the lattice. The redistribution of Se from the heavily doped region was detectable even after heat treatment at 480°C for 30 min. For the p⁺⁺ layer the profile of the C-doped layer was stable even after heat treatment at 620°C for 30 min, but the profile of Zn changed markedly after heat treatment at 480°C for 30 min. In addition, the carbon-doped p⁺⁺ layer acted as a gettering layer for diffused interstitial Se from the source region. The driving force of the redistribution of dopants results in the electric field in the device structures. © 1997 John Wiley & Sons, Ltd.     

STACS: new active contour scheme for cardiac MR image segmentation

The paper presents a novel stochastic active contour scheme (STACS) for automatic image segmentation designed to overcome some of the unique challenges in cardiac MR images such as problems with low contrast, papillary muscles, and turbulent blood flow. STACS minimizes an energy functional that combines stochastic region-based and edge-based information with shape priors of the heart and local properties of the contour. The minimization algorithm solves, by the level set method, the Euler-Lagrange equation that describes the contour evolution. STACS includes an annealing schedule that balances dynamically the weight of the different terms in the energy functional. Three particularly attractive features of STACS are: 1) ability to segment images with low texture contrast by modeling stochastically the image textures; 2) robustness to initial contour and noise because of the utilization of both edge and region-based information; 3) ability to segment the heart from the chest wall and the undesired papillary muscles due to inclusion of heart shape priors. Application of STACS to a set of 48 real cardiac MR images shows that it can successfully segment the heart from its surroundings such as the chest wall and the heart structures (the left and right ventricles and the epicardium.) We compare STACS' automatically generated contours with manually-traced contours, or the "gold standard," using both area and edge similarity measures. This assessment demonstrates very good and consistent segmentation performance of STACS.