TJS全数字脑电工作站在空军招飞体检中的应用研究

随着科学技术的不断进步,为了尽快适应新形势的发展,招飞体检中我们在脑电图(dectroencephalogram,EEG)检测方面使用了电子计算机技术,并对新仪器应用于脑功能检测工作的价值进行了相关的研究,现报告如下:     

心率及重建相位窗对多层螺旋CT冠状动脉造影图像质量的影响

目的 探讨心率及重建相位窗对多层螺旋CT冠状动脉造影图像质量的影响。方法 80例健康体检者行16层螺旋CT回顾性心电门控条件下冠状动脉造影。结果 每位患者的4条冠状动脉分支(左冠状动脉主干、左前降支、左回旋支、右冠状动脉)分别用于图像质量分析。心率≤60次／min者，有82．1％(46／56支)的图像可用于诊断；心率61～70次／min者，有63．4％(104／164支)的图像可用于诊断；心率71～80次/min者，有41．20h，(28／68支)的图像可用于诊断；心率80次／min以上者有31．2％(10／32支)的图像可用于诊断。左冠状动脉前降支在60％～70％的重建相位窗时图像质量最佳，左冠状动脉回旋支在50％～60％时最佳，右冠状动脉重建相位窗为50％～70％较满意。结论心率及重建相位窗对多层螺旋CT冠状动脉造影图像质量有重要影响作用。     

HPCE法测定蛹虫草及其培养物中核苷类化合物的含量

目的　建立蛹虫草中核苷类化合物的高效毛细管电泳测定法 ,比较天然蛹虫草及其培养物中核苷类化合物的含量。方法　在HV - 30 1高效毛细管电泳仪上进行定量分析 ,采用石英毛细管柱 ,以pH9.0的 4 0mmol·L-1 硼砂溶液作为电极缓冲液 ;分离电压为 1 6KV ;检测波长为 2 5 4nm。结果　天然蛹虫草中核苷类化合物主要集中在子座部分。人工培养蛹虫草子座和菌丝中虫草素的含量分别是天然蛹虫草子座中的 5 .0 4倍和 1 0 .85倍 ;液体培养蛹虫草菌丝中腺嘌呤、腺苷、尿苷、鸟苷含量均高于固体培养蛹虫草子座。结论　天然蛹虫草及其培养物中核苷类化合物的种类和含量具有较大的差异。高效毛细管电泳法可以用于蛹虫草的定量分析 ,具有分离度高、简便、准确 ,样品消耗少等特点     

胎儿主要肢骨发育时间表──超声骨龄

用Ｂ超检测正常妊娠中的胎儿。选择受精龄为１２至３８整周（ｃｏｍｐｌｅｔｅｄｗｅｅｋ）的胎儿２９７例。测量其主要肢骨（干）长度。并将所测数据进行统计学处理。结果表明胎儿肢骨的生长发育与胎龄有显著的正相关关系。     

血液流变学因素对缺血心肌冠脉流量的影响

选用长白猪８只于麻醉下开胸，于在体猪心上探讨心肌缺血时冠脉仍保留有部分扩张储备，而未被充分利用的机理。实验结果表明：降低左冠状动脉前降支（ＬＡＤ）内压至４．６７ｋＰａ时，由ＬＡＤ分别输入腺苷、山莨菪碱、生理盐水（２ｍｌ／ｍｉｎ），皆能诱发出明显的ＬＡＤ流量增加（Ｐ＜０．０５）。在维持ＬＡＤ内压不变，并持续分别输入上述三种溶液的同时，从ＬＡＤ远端取血测血液流变学指标，结果显示，输入生理盐水和山莨菪碱使红细胞压积降低，血浆粘度和全血粘度下降；心肌缺血时，冠脉内输注药物所诱发出的“冠脉扩张储备”部分是由于此种给药方式所引起的血液稀释及血液粘度下降的结果。它提示在冠脉狭窄时，血液粘度对狭窄远端的心肌血供可能是一个相当重要的因素，降低血液粘度可能并不亚于扩血管药物的作用。     

多抗甲素对人NK细胞活性的作用机理研究

作者应用单细胞细胞毒试验及形态学观察，研究多抗甲素（ＰＡＡ）对人体自然杀伤（ＮＫ）细胞活性的作用机理。结果表明：ＰＡＡ能增强食道癌患者淋巴细胞（ＰＢＬ）明显低下的结合率（Ｂ％）和杀伤率（Ｋ％），也可增强正常人ＰＢＬ的Ｋ％，但对正常人ＰＢＬ的Ｂ％无影响。形态学观察发现：与靶细胞结合的ＰＢＬ除大颗粒ＰＢＬ外，尚有普通的非颗粒ＰＢＬ，结合的靶细胞损伤首先表现为线粒体肿胀、空泡变，然后核固缩，核膜损伤，细胞严重空泡变性等，偶见靶细胞与自然杀伤细胞结合部质膜破损的现象。经ＰＡＡ预处理的靶效细胞结合的形态改变无明显差异，但食道癌组的杀伤作用出现较早，且明显增强。     

Association of a 70-kDa tyrosine phosphoprotein with the CD16:ζ:γ complex expressed in human natural killer cells

The CD16: ζ: γ receptor complex allows natural killer (NK) cells to recognize and eliminate antibody-coated target cells. Whereas the ectodomain of CD16 is the receptor for Fcγ domains of immunoglobulins, disulfide-linked homo- and heterodimers composed of ζ and γ are required for the cell surface expression, and signal transduction properties of the complex. Engagement of CD16 activates the tyrosine kinase pathway, which induces the tyrosine phosphorylation of several substrates, including the ζ subunit and the phospholipase C γ-1 and γ-2 isoforms. Here we show that CD 16 stimulation of either peripheral blood NK cells, leukemic NK cells, or Jurkat transformants expressing a CD16:ζ:γ receptor complex, results in the tyrosine phosphorylation of a 70 kDa ζ-associated protein (pp70). Similarly, a 70-kDa ζ-associated phosphoprotein in T cells has been shown to be a tyrosine kinase (ZAP-70). Peptide mapping analysis indicates that the 70-kDa ζ-associated phosphoproteins from T cells and NK cells are structurally indistinguishable. We conclude that the CD16:ζ:γ complex may use a ZAP-70-related non-receptor tyrosine kinase, in the CD16 signaling cascade leading to NK cell activation.     

MR image segmentation using vector decomposition and probability techniques: A general model and its application to dual-echo images

A general model is developed for segmenting magnetic resonance images using vector decomposition and probabilfty techniques. Each voxel is assigned fractional volumes of q tissues from p differently weighted images (q ≤ p + 1) in the presence of partial-volume mixing, random noise, and other tissues. Compared wtth the eigenimage method, fewer differently weighted images are needed for segmenting the q tissues, and the contrast-to-noise ratio in the calculated fractional volumes is improved. The model can produce com-posrte tissue-type images similar to that of the probability methods, by comparing the fractional volumes assigned to different tissues on each voxel. A three-tissue (p = 2, q = 3) model is illustrated for segmenting three tissues from dual-echo images. M provides statistical analysis to the algebraic method. A three-compartment phantom is segmented for validation. Two clinical examples are presented.     

The Effect of Quisqualic Acid-Induced Lesions of the Nucleus Basalis Magnocellularis on Latent Inhibition

Latent inhibition (LI) is a reduction in the rate of acquisition of a Pavlovian conditioned response that results from prior nonreinforced preexposure to a conditioned stimulus (CS). LI has been suggested to reflect the operation of mechanisms involved in stimulus selection for subsequent cognitive processing. The present experiment was conducted to assess the effect of bilateral lesions of the nucleus basalis magnocellularis (NBM) on LI employing a conditioned emotional response paradigm. Bilateral lesions of the NBM were produced by administration of 0.12 M quisqualic acid and resulted in decreased cortical acetylcholinesterase staining, as well as a 40% reduction in cortical choline acetyltransferase activity. Following lever press training, preexposed animals received 40 presentations of a 60-s tone CS. Nonpreexposed animals received no tone presentations. Acquisition of conditioned suppression was then assessed over the course of 4 tone-shock (0.6 mA, 0.5 s) pairings. Control, preexposed animals displayed a retarded rate of acquisition in comparison to nonpreexposed controls, thereby demonstrating that the parameters used in the present experiment produced LI. In contrast, lesioned animals preexposed to the CS acquired conditioned suppression as readily as non-preexposed lesioned animals. However, the acquisition of conditioned suppression in both lesioned groups was found to be similar to that displayed in the preexposed control group. This pattern of results was interpreted as being attributable to a lesion-induced impairment in the ability to maintain stimulus processing, rather than a deficit in the ability to filter a stimulus. Copyright © 1996 Elsevier Science Inc.     

Advances in processing of surface myoelectric signals: Part 1

During sustained voluntary or electrically elicted muscle contractions the surface myoelectric signal is nonstationary and it undergoes progressive changes reflecting the modifications of the motor unit action potentials and their propagation velocity. In particular, during sustained electrical stimulation, the evoked signals show progressive amplitude, time scaling and shape modification. The quantitative evaluation of these changes is important for non-invasive muscle characterisation and may be performed in either the time or frequency domain using parametric and nonparametric spectral analysis as well as alternative methodologies. The paper introduces the detection techniques, reviews and compares the methods of spectral estimation based on FFT and autoregressive models, and discusses their applications and limitations in extracting information from the surface myoelectric signal with particular regard to myoelectric manifestations of localised muscle fatigue during sustained contractions.