微机心电场仿真模型与仿真研究

心电场仿真是心电理论研究的前沿课题。本文讨论首次在IBM-PC/AT微机上实现的一个完整的心电场仿真模型。其中,人体和心脏的单元分割精度与国外最近的研究相同,采用边界元法求解心电场电位,并提出一种新的心脏兴奋传播仿真算法,提高了仿真速度。应用该模型对正常心脏和病变心脏进行了仿真研究,仿真结果与临床测量结果是一致的。     

血脂与体外血栓形成的关系

应用国产ＤＪＨ－Ｉ型调速单型血栓形成仪，对４７４名４５岁以上成人体外血栓形成进行了检测，同时检查血脂水平。另外对部分隐性体外血栓阳性者及正常人的红细胞膜荧光偏振度（Ｐ）和微粘度（η）进行比较。结果表明：隐性体外血栓阳性者中血脂增高者为５７／１０９（５４．１２％），其中一级血栓３２／７５（４２．６％），二级血栓１１／１６（６８．７％），三级血栓１４／１８（７７．７％）。红细胞膜Ｐ和η在隐性体外血栓阳性者与正常人之间有显著差异（Ｐ＜０．０５）。提示：隐性体外血栓检测对临床心脑血管的血栓性疾病的早期预防、治疗有较大的参考价值     

PII component of the toad electroretinogram.

1. The PII component of the electroretinogram (ERG) is comprised of the b-wave and the DC component and is thought to reflect bipolar cell activity. Although the b-wave is generated in large part by a K+/Müller cell mechanism, the origin of the DC component is unclear. In this paper we detail our investigation of the origin of the DC component. We hypothesize that the DC component is generated by a K+/Müller cell mechanism identical to that involved in b-wave generation. 2. We studied the ERG in the dark-adapted, isolated retina preparation of the toad, Bu fo marinus. We used K+ ion-sensitive microelectrodes (K+ISM), as well as conventional intra- and extracellular microelectrodes, to record [K+]o changes, the vitreal ERG, and Müller cell responses. 3. We used the excitatory amino acid receptor agonist N-methyl-DL-aspartate (NMDLA) to inhibit light responses of third-order neurons and thereby eliminate most of the ERG M-wave. In the absence of the M-wave, the ERG consisted of PII and PIII. We then superfused the retina with a solution containing both kynurenic acid (KYN) and 2-amino-4-phosphonobutyric acid (APB), which together inhibit all retinal responses proximal to the photoreceptors. In the presence of KYN and APB, the ERG consisted only of PIII. Using digital subtraction, we reconstructed PII. To our knowledge, this is the first report of the isolation of a PII component in the ERG of a nonmammalian species. 4. Using K+ISMs, we recorded the distal K+ changes in the outer plexiform layer (OPL).(ABSTRACT TRUNCATED AT 250 WORDS)     

使用自相关和时间序列检测的方法检测心室纤颤信号

心室纤颤信号必须准确而及时地识别,如果不使用除颤器及时进行除颤,病人会迅速死亡。另一方面,如果心室纤颤信号没有发生,而误判为心室纤颤信号,给予电击,则病人的心脏受到不应有的损伤,这也属于严重的医疗事故。因此快速与准确的识别显得十分重要。自70年代以来,世界上许多科学家都在探讨各种方法,以期望使用计算机自动识别心室纤颤信号,但均因达不到实时判别的要求或准确率不够高而不能用于自动除颤器检测的设计方案。本文介绍了一种准确率高而又较简易的快速识别法。这一方法是取一秒心电信号,进行有限长度离散信号的自相关,然后对该自相关函数作零切割,让自相关函数变成一串二进制脉冲串,接着以一秒信号的脉冲串数作为特征参数,设计分类器。经证明,心室纤颤信号(VF信号)(Ventricular Fibrillation)和心动过速信号(VT信号)(Ventricular Tachycar-dia)的特征参数均属于高斯分布。因此可用Wald时间序列检测方法对VF信号和VT信号分类。这个算法可用于计算机进行实时处理和分析,同时此法与取样率无关,适用于各种取样系统,是一个较理想的方法。     

蛇毒抗栓酶对氧自由基致血小板变化的影响

次黄嘌呤／黄嘌呤氧化酶体系产生的氧自由基在体外能明显增加血中板膜微粘度，脂质过氧化代射产物丙二醛含量，血小板胞内游离钙浓度和血小板５－羟色胺的释放量。０．０３ｕ／ｍｌ的蛇毒抗栓酶明显抑制前二种效应，但促进血小板释放５－羟色胺，增加血小板胞内游离钙浓度，结果表明蛇毒抗栓酶对血小板膜有保护作用。     

Isolation of Nanjing local strains of HHV-7 and their biological and immunological characteristics

To investigate the biological and immunological characteristics of the Nanjing local strains of HHV-7,fourstrains of herpesvirus were isolated from saliva specimens of one healthy individual and three childrensuffering from a kidney disease in Nanjing.The viruses were identified by transmission electron microscopy(EM),indirect immunofluorescence assay(IFA) with a specific monoclonal antibody;nested polymerase chainreaction,restriction mapping and DNA sequencing.The virus-infected cells showed the typical cytophathiceffect(CPE) under microscopy and could be detected by IFA with the human herpesvirus-7(HHV-7) specificantibody.Under EM,herpesvirus-like and virions capsids could be found in their cytoplasm or nucleoplasm.HHV-7 DNA fragments amplified from infected cells by nested PCR were confirmed by restriction mappingand DNA sequencing.Similarly to DC strain,an known HHV-7 strain used in the present study as the positivecontrol,the virus could be inactivated by ultraviolet irradiation for 10 min,heated at 45℃ for 30 min,pH<5or>9 at 4℃ for 2 h and ether or chloroform for 10 h.The virus induced the production of TNF-α,IL-10 andIL-12p70 while inhibited IFN-γ secretion,increased the percentage of CD2~+ cells while decreased that of CD4~+or CD45RA~+ cells.The results indicate that the viruses isolated in Nanjing are HHV-7,which has similarbiological characteristic to the known HHV-7 strain,DC.Infection with HHV-7 in vitro could affect immunefunction of lymphocytes by disturbing cytokine production and CD antigen expression.Cellular & MolecularImmunology.2004;1(5):367-372.     

Specific absorbed fractions from the image-based VIP-Man body model and EGS4-VLSI Monte Carlo code: internal electron emitters

VIP-Man is a whole-body anatomical model newly developed at Rensselaer from the high-resolution colour images of the National Library of Medicine's Visible Human Project. This paper summarizes the use of VIP-Man and the Monte Carlo method to calculate specific absorbed fractions from internal electron emitters. A specially designed EGS4 user code, named EGS4-VLSI, was developed to use the extremely large number of image data contained in the VIP-Man. Monoenergetic and isotropic electron emitters with energies from 100 keV to 4 MeV are considered to be uniformly distributed in 26 organs. This paper presents, for the first time, results of internal electron exposures based on a realistic whole-body tomographic model. Because VIP-Man has many organs and tissues that were previously not well defined (or not available) in other models, the efforts at Rensselaer and elsewhere bring an unprecedented opportunity to significantly improve the internal dosimetry.     

异位妊娠危险因素分析

目的 分析、研究异位妊娠相关因素,早期发现及时诊治。方法 收集异位妊娠64例,与同期正常妊娠62例对照,两组就相关危险因素进行对比分析。结果 感染、手术、尤其是输卵管手术、不孕症、多次流产、IUD等同异位妊娠密切相关,与正常妊娠组在统计学上差异显著(P<0.001)。结论 近年来,异位妊娠发生率呈明显上升趋势,大出血仍是早孕妇女死亡的重要原因。各种危险因素的增加同其发病率的不断上升密切相关。应重视异位妊娠的相关因素。早期发现、早期诊断、早期治疗。     

应用威布尔分布函数研究红霉素微囊的溶出度

本文测定了红霉素微囊在人工肠液中的溶出度，并用威布尔分布函数求出了溶出百分率与时间的关系。     

红霉素缓释微囊的制备及其释药机理的研究

本文旨在探讨红霉素微囊的制备及体外缓释机理。以明胶等为囊材,用红霉素制成微囊,研究微囊的厚度及孔隙度对药物释放速率的影响。进行理论分析,与实验结果相符性较好。