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991.
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。 相似文献
992.
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。 相似文献
993.
Isolation of Nanjing local strains of HHV-7 and their biological and immunological characteristics 总被引:2,自引:0,他引:2
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. 相似文献
994.
Specific absorbed fractions from the image-based VIP-Man body model and EGS4-VLSI Monte Carlo code: internal electron emitters 总被引:6,自引:0,他引:6
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. 相似文献
995.
许彬 《中国优生与遗传杂志》2003,(Z1)
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。 相似文献
996.
997.
红霉素缓释微囊的制备及其释药机理的研究 总被引:3,自引:0,他引:3
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。 相似文献
998.
Acupoint-specific fMRI patterns in human brain 总被引:19,自引:0,他引:19
Specific central nervous system (CNS) responses to acupuncture have recently attracted attention. It is important to understand the differences in fMRI images of the brain evoked by acupuncture at an acupoint and at a nearby "sham" point. Here, we report analyses of fMRI images of the brains of 37 healthy volunteers in response to acupuncture at Liv3 (Taichong) and LI4 (Hegu) versus their sham points. We found common activation areas in response to Liv3 or LI4 acupuncture in the middle temporal gyrus and cerebellum, along with deactivation areas in the middle frontal gyrus and inferior parietal lobule, compared with the effects of acupuncture at sham points. Acupuncture at Liv3 evoked specific activation at the postcentral gyrus, posterior cingulate, parahippocampal gyrus, BA 7, 19 and 41, but deactivation at the inferior frontal gyrus, anterior cingulate, BA 17 and 18, compared with acupuncture at its sham point. Acupuncture at LI4 evoked specific activation at the temporal pole, but deactivation at the precentral gyrus, superior temporal gyrus, pulvinar and BA 8, 9 and 45, compared with acupuncture at its sham point. These observations reveal that acupuncture at acupoints induces specific patterns of brain activity, and these patterns may relate to the therapeutic effects of acupuncture. 相似文献
999.
Opiate abuse is associated with long-lasting neural adaptative changes in the brain. Increasing evidence demonstrates that opiates significantly alter the function of the glutamatergic system, while how the system is regulated still remains elusive. In the present study, we studied the effect of morphine on extracellular glutamate concentration in the hippocampus, a nucleus rich of the glutamatergic neurons. The results showed that glutamate concentration in the extracellular fluid of the hippocampus was decreased following either acute or chronic treatment of morphine. However, naloxone-induced withdrawal increased glutamate concentration significantly. These results suggest an adaptation of the glutamatergic neuronal transmission in the hippocampus after morphine treatment. 相似文献
1000.
对36例多发性骨髓瘤(MM)患者骨髓涂片,行酸性磷酸酶(ACP)染色。结果发现MM组的骨髓浆细胞ACP积分明显高于对照组。MM组初诊时、缓解期和复发期46人次检测结果表明,成MM病程中ACP积分病情变化而变化,缓解期的较初诊时降低,复发期的又复增高。这种变化有时较骨髓浆细胞比例的变化与病情的关系更为密切,提示ACP积分可作为MM病情监测的指标。 相似文献