血流的在线性因素与血流波的畸变

本文用血流波形畸变的实测资料和非线性动力学理论分析得出了血流波形畸变是较普遍的现象，其畸变的原因主要是非线性因素。     

白血病染色体畸变与脆性部位

染色体脆性部位在肿瘤发生中的意义,是当前肿瘤细胞遗传学研究的热门课题之一,而脆性部位与肿瘤特异性畸变断裂点及癌基因位点的定位关系尤其引人注目。目前,对这方面了解最多且较能说明问题的是对白血病、淋巴瘤的研究。本文综述了白血病有关的染色体脆性部位、特异断裂点及癌基因对应关系,对其在白血病发生中的影响进行了讨论。     

小鼠联会复合体超微结构畸变的观察与分析

目的 :用改进的微铺展技术观察分析小鼠联会复合体超微结构的畸变。材料和方法 :以滨州医学院实验动物室饲养的性成熟雄性小鼠为材料 ,制备小鼠精母细胞联会复合体样品 ,硝酸银染色 ,电镜观察、分析。结果 :有联会复合体结构畸变和配对异常的细胞占观察细胞总数的 1 2 4%。其中联会复合体断裂占异常联会复合体总数的5 2 1 7% ,侧生组分断裂 3 1 5 2 % ,易位 6 5 2 % ,联会紊乱 4 3 5 % ,不联会 3 2 6% ,圆环 2 1 7%。结论 :实验小鼠各类联会复合体畸变百分率均高于国内文献报道的正常小鼠的联会复合体畸变率。改进的微铺展制备联会复合体样品技术简便易行 ,效果良好     

生精障碍与染色体畸变的检测分析

男性的精子生成和精子输送是个复杂的生理过程。精子的发生受到诸多有序表达的基因控制 ,完成细胞分裂及形态改变 ,染色体结构数目的畸变可影响这些基因的功能进而影响精子的发生导致不育。本文对 89例无精子少精子症病人进行了细胞遗传学分析 ,共发现 8例染色件核型异常 :对其中 2例涉及Ｙ染色体结构异常的无精子症病人还进行了ＹＲＲＭ1ＤＹＳ2 40ＤＮＡ片段的检测 ,对 1例 46 ,ＸＸ男性无精子症病人进行ＳＲＹＤＮＡ片断和ＹＲＲＭ1ＤＹＳ 2 40ＤＮＡ的检测。以下从所涉及的染色体及其片段断裂点对精子发生的作用进行分析。资料与方法对 …     

癌症患者外周血染色体畸变的研究

应用TC199培养基培养外周血淋巴细胞,获取中期分裂的染色体,观察和分析了32例癌症患者及20例正常人外周血淋巴细胞染色体畸变的情况。结果表明,癌患者染色体畸变率及代表畸变率的三个参数:细胞断裂率、染色体断裂率、畸变细胞率均明显高于对照组,t检验有高度显著性差异。染色体畸变的现象说明,在体内有恶性肿瘤存在,血液淋巴细胞染色体是不稳定的,同时也表明,染色体不稳定的增高,可能导致个体对肿瘤易感性的增加。     

人直肠癌细胞的8号染色体畸变与癌变的关系

大肠癌细胞遗传学的研究表明,染色体不稳定性变化与大肠癌的发生有着十分密切的关系,我们通过2例经病理诊断为直肠高分化腺癌患者的癌实体,直接制备染色体,以探讨其细胞染色体畸变与癌变的关系。1 材料取自手术刚摘除的癌肿块菜花状部位,用PBS液漂洗2次,放在含100 g·L~(-1)小牛血清的TC199培养液中充分剪碎,置含50μg·L~(-1)秋水仙素和100g·L~(1-)小牛血清的TC199培养液中,37℃培养4h后,收     

胚胎期绒毛染色体畸变与不良生产史的关系

本文选择60例正常年孕妇女和13例有不良生产史的早孕妇女,分析其早孕绒毛染色体核型畸变率。研究结果表明:有不良生产史的孕妇,胚胎期绒毛染色体畸变发生率明显高于正常对照组,而且不良生产次数越多,再次妊娠绒毛染色体畸变率越高。因此,对既往有不良生产史的孕妇,再次妊娠后,有选择性的进行绒毛染色体分析,对探讨不良生产史的致病因素和确定是否保胎治疗等都有一定的指导意义。     

动脉血管中非线性压力波的传播

目的建立人体动脉血管中血液流动的力学模型,研究血管中非线性压力波的传播。方法采用H.Demiray建议的本构关系,计算大变形效应,在现时构形上建立径向运动方程。结果采用约化摄动法由支配血液流动与管壁耦合系统的非线性偏微分方程组得到了KdV方程。结论在一定条件下系统可能存在着精确周期波解或孤波解。     

脉搏波波形特征信息检测及与部分血流动力学变化相关分析

目的引入特征点——收缩期与舒张期分界点，提出脉搏波波形周期面积特征．讨论脉搏波波形周期面积特征量与血流动力学参数的相关关系。方法选择笔者所在医院门诊病人424例，采集桡动脉脉搏波信号，分析其波形周期面积特征（收缩期面积特征量K1和舒张期面积特征量K2）与血流动力学参数[心输出量（CO）、血流阻力（TPR）和血液黏度（V）]的相关性。结果脉压差与K1高度正相关（P〈0．01），与K2高度负相关（P〈0．01），与K1/K2，高度正相关（P〈0．01）。年龄与K1高度正相关（P〈0．01），与致高度负相关（P〈0．01），与K1/K2，高度正相关（P〈0．01）。K1与CO高度负相关（P〈0．01），K2与CO负相关（P〈0．05），K1/K2与CO无明显相关。K2、K2分别与TPR高度正相关（P〈0．01），K1/K2与11PR无明显相关。K1、K2分别与V高度正相关（P〈0．01），K1/K2，与V高度负相关（P〈0．01）。结论试验表明，脉搏波波形周期面积特征量代表人体心血管系统中最为重要的一些生理参数如血管外周阻力、血液黏性等的变化。     

HBsAg携带者外周血染色体畸变与SCE的研究

本文对２０例无症状ＨＢｓＡｇ携带者和３５例正常成人对照组的外周血淋巴细胞的染色体畸变频率和姐妹染色体单体互换频率进行了分析。结果表明,ＨＢｓＡｇ携带者的染色体畸变率和姐妹染色体互换频率均同于正常对照组,差异高度显著。并结合文献资料,对ＨＢＶ感染导致的染色何不稳定性与肝癌发生的关系进行了讨论。     

Memory Distortion and Dissociation: Exploring the Relationship in a Non-Clinical Sample

ABSTRACT

There is a growing interest in the relationship between the tendency to have dissociative experiences and performance on several cognitive tasks, in particular the susceptibility to memory distortions. Participants are shown a video of a crime and then are given a post-event questionnaire that has several misleading questions. Later, participants are questioned about the event. The sample showed a large range in susceptibility to the post-event misleading information. This susceptibility was related to their responses to a dissociative experiences questionnaire (based on the DES) adapted for non-clinical populations (DES C). The results are discussed in relation to theories of memory distortion.     

用双超声脉冲法测量生物介质的非线性参数B/A

利用生物介质的超声非线性参数B／A与温度的相关性可实现超声无创测温,本文介绍了一种用双超声脉冲法测量介质非线性参数B／A的方法,这种方法是把探测波叠加到泵波之上,利用这两个波的非线性作用来测出参数B／A。实验结果表明该方法切实可行,能准确地测得参数B／A,为实现高质量的超声无损伤测温提供了可能。     

乳腺钼靶X线影像中结构扭曲的特征提取研究

本研究以灰度共生矩阵描述乳腺钼靶X线影像中结构扭曲的纹理特征.对学习样本（乳腺结构扭曲样本44个,正常样本78个）,计算五个反映纹理性质的特征参数,根据相应的Fisher系数,确定最适合作为分类依据的特征参数或特征参数组合.用线性判别分析对测试样本（乳腺结构扭曲样本43个,正常样本78个）进行分类.分类结果表明本研究确定的纹理特征熵（ENT）是识别乳腺结构扭曲的最佳统计参数（分类正确率达78.5%、ROC曲线下的面积为0.786）.     

A Note on the Power to Detect Transmission Distortion in Parent-Child Trios via the Transmission Disequilibrium Test

Transmission distortion refers to deviation from the normal 50:50 transmission of alleles from parents to offspring. Identification of genomic regions which undergo distortion is necessary for the correct interpretation of linkage and association studies, since tests of linkage using affected relative pairs and family based tests of association will yield spurious results in the presence of transmission distortion. With the increasing availability of genome-wide high density SNP data (e.g. from the International HapMap project), identification of these loci is now a real possibility. Here we present an analytical formula which demonstrates that the power to detect transmission distortion is a simple function of the number of heterozygous parents in the sample and the level of distortion at the locus. Our results indicate that whilst it will be possible to identify loci undergoing major levels of distortion using tens or hundreds of trios, large sample sizes in the order of tens of thousands of trios will be necessary to detect minor levels of distortion with appreciable power. The corollary is that genome-wide searches are unlikely to identify loci where the level of distortion is small, although they may serve to identify interesting regions worthy of follow up.Edited by Stacey Cherny     

Impact of Plasma-Lyte pH 7.4 on acid-base status and hemodynamics in a model of controlled hemorrhagic shock

OBJECTIVE:

Intravenous infusion of crystalloid solutions is a cornerstone of the treatment of hemorrhagic shock. However, crystalloid solutions can have variable metabolic acid-base effects, perpetuating or even aggravating shock-induced metabolic acidosis. The aim of this study was to compare, in a controlled volume–driven porcine model of hemorrhagic shock, the effects of three different crystalloid solutions on the hemodynamics and acid-base balance.

METHODS:

Controlled hemorrhagic shock (40% of the total blood volume was removed) was induced in 18 animals, which were then treated with normal saline (0.9% NaCl), Lactated Ringer''s Solution or Plasma-Lyte pH 7.4, in a blinded fashion (n = 6 for each group). Using a predefined protocol, the animals received three times the volume of blood removed.

RESULTS:

The three different crystalloid infusions were equally capable of reversing the hemorrhage-induced low cardiac output and anuria. The Lactated Ringer''s Solution and Plasma-Lyte pH 7.4 infusions resulted in an increased standard base excess and a decreased serum chloride level, whereas treatment with normal saline resulted in a decreased standard base excess and an increased serum chloride level. The Plasma-Lyte pH 7.4 infusions did not change the level of the unmeasured anions.

CONCLUSION:

Although the three tested crystalloid solutions were equally able to attenuate the hemodynamic and tissue perfusion disturbances, only the normal saline induced hyperchloremia and metabolic acidosis.     

Nonlinear Forecasting Measurements of the Human EEG During Evoked Emotions

Forecasting ability applied to a single EEG time sequence may quantify loss of memory of past brain states. This fundamental property of complex dynamical systems could prove to be an important measure of current brain states. The present study examined nonlinear forecasting (or nonlinear predictability) estimates of the scalp-recorded EEG in 76 healthy volunteers in response to emotionally charged (negative, positive and control neutral) video-clip stimuli. EEG was recorded from 18 sites (10-20 system). The obtained results indicate that the negative emotional impact led to a more predictable EEG dynamics, compared with neutral or positive emotional video content, and this effect was restricted to the posterior cerebral sites. The studied signatures of EEG dynamics succeed also in specific discrimination between effects of positive and negative film categories: significantly more predictable dynamics over posterior cerebral sites in response to negative film category was accompanied by enhanced predictability in answer to positive film category over frontocortical loci. It is concluded that these findings suggest the association of basic cortical nonlinear mechanisms with the specific physiological processes of emotional processing.     

Principal Dynamic Mode Analysis of Nonlinear Transduction in a Spider Mechanoreceptor

The nonlinear dynamics of the mechanoelectrical transduction in an arthropod mechanoreceptor (cuticular slit sense organ of the spider Cupiennius salei) were studied using Volterra kernel measurements and the recently proposed method of principal dynamic modes. Since mechanoreceptors must operate with sufficient gain sensitivity to rapidly varying displacement stimuli over a broad bandwidth and for a wide range of amplitudes, the experimental data were generated by applying pseudorandom broadband mechanical displacements of various mean levels to the cuticular slits. The recorded response data were intracellular current and potential. The purpose of this paper is to demonstrate the use of the principal dynamic mode (PDM) methodology in elucidating the nonlinear dynamics of a spider mechanoreceptor. The results obtained demonstrate that two PDMs suffice to provide a complete nonlinear dynamic model of this insect mechanoreceptor. The first PDM resembles the first-order kernel and has a low pass characteristic (position dependent), while the second PDM has a high-pass characteristic (velocity-dependent) and resides entirely in the second-order kernel (nonlinear adaptation). This study may serve as an example of the proper use of this new methodology for the analysis of nonlinear physiological systems. © 1999 Biomedical Engineering Society. PAC99: 8719Bb, 8719Nn, 8716Uv     

基于图像非线性配准的MRI几何失真校正

采用图像非线性配准的方法,对MRI存在的几何失真进行校正,先选取与MRI具有共同解剖结构且基本无几何失真的CT图像,作为配准校正的目标基准图像,将MRI与CT图像进行刚体配准,然后采用人工选点的方法,寻找CT图像和MRI中的对应标记点集,用改进的弹体样条函数进行全局非线性配准.结果表明:弹体样条变换具有较强的非线性校正能力,较好地实现了二维MRI的几何失真校正.我们采用的变换模型有效可行,并可用于三维失真图像的校正.     

An acoustically matched high pressure chamber for control of cavitation in shock wave lithotripsy: Mechanisms of shock wave damage in vitro

Increased ambient pressure (excess hydrostatic pressure) was used to regulate cavitation in the aqueous media surrounding isolated red blood cells and aluminum foils used as targets in studies of the mechanisms of shock wave (SW) damage in shock wave lithotripsy (SWL). Foils or cells were placed in a cylindrical chamber (bronze-aluminum alloy) connected to a regulator and nitrogen source. The ends of the cylinder were capped with planar, plastic plates 12.7 mm thick. Tests performed with a PVDF membrane hydrophone showed that SW's passed through the plastic without significant loss of amplitude or change in waveform. Pitting of foils, a form of damage that can only be due to cavitation, was eliminated by very high (70 atm) added pressure. It took substantially greater added pressure to reduce damage to foils than has been reported to reduce damage to cells, suggesting differences in how cavitation is regulated in bulk fluid versus a solid surface. This report describes the design of the pressure chamber used in these studies and explains how SW exposures of isolated cells and foil targets were performed.     

三种波形磁场对大鼠成骨细胞增殖与分化的影响

目的：研究不同波形磁场辐照，对离体大鼠成骨细胞增殖与分化的影响。方法：用矩形、三角形和正弦三种典型波形磁场辐照离体成骨细胞。结果：频率15Hz，幅值5mT，矩形磁场促进细胞增殖（P〈0．01），抑制细胞分化（P〈0．01）;正弦磁场抑制细胞增殖（P〈0．01），促进细胞分化（P〈0．01）；三角彤磁场对细胞增殖和分化的影响尤显著性差异．结论：除强度和频率窗外，还需考虑波形的影响。