基于多分辨分析与连续小波变换提取和分析兔体感诱发电位

研究单次提取兔体感诱发电位,并定位和分析诱发电位波形成分。麻醉兔,以0.5Hz频率电脉冲刺激兔下肢隐神经,3764Hz采样率收集兔头皮电位。采用一维多分辨分析提取兔体感诱发电位,并用连续小波变换定位和分析诱发电位波形成分。单次诱发电位的小波变换与叠加平均诱发电位比较,表明Daubechies小波多分辨分析可以单次提取诱发电位。连续小波变换能够精确定位诱发电位中波形成分,并可采用连续小波变换分析诱发成分的频域特性。连续小波变换技术把一维时域信号投影到二维时频空间研究将成为医学信号处理的一个有用方法。     

ERP单次提取中的小波变换模极大值恢复算法

自发脑电的频谱不规则,与有效信号ＥＲＰ频谱相重叠,传统滤波方法难以奏效。但由于随机噪声奇异性指数与有效信号奇异性指数大小不一样,小波变换模极大值在不同尺度下传播行为也不一样,据此可将有效信号从随机噪声中提取出来。我们发现利用小波变换模极大值算法可以提取出单次ＥＲＰ,并将此方法用于１１名被试听觉的实时提取研究。     

基于小波和卡尔曼平滑的事件相关电位单次提取

本研究提出一种事件相关电位单次提取方法,可有效减少实验次数,并可探索实验之间ERP的变异性。此方法基于小波和卡尔曼平滑,首先利用小波变换考察ERP平均信号的时频特性,根据ERP不同分量出现的时间位置,在不同尺度上选取特定的单次实验ERP小波系数构成观测向量,其为真实ERP小波系数状态向量与噪声之和,然后对观测向量进行卡尔曼平滑,最后对卡尔曼平滑后的小波系数进行小波重构,得到单次提取的ERP信号。仿真实验表明,基于小波和卡尔曼平滑的方法不仅信噪比提高约16~18 dB,优于30次叠加平均、简单小波方法和基于高斯基函数的卡尔曼滤波方法,还可以跟踪ERP的幅度趋势变异性。与基于高斯基函数的卡尔曼滤波方法相比,所提方法降低了计算量。真实脑电ERP提取实验表明本方法较好地从单次记录中提取出了事件相关电位,并可解释ERP因适应和应激引起的趋势变异性。     

噪声中EP信号的提取算法及研究进展

诱发电位的提取是脑电信号处理领域的前沿课题近年来 ,通过少次甚至单次试验提取诱发电位已经成为研究的主流。本文对近年来提取诱发电位的信号处理方法进行了简要的回顾 ,并分别从小波变换、神经网络、高阶累积量、独立分量分析等四个方面对算法进行了介绍     

基于小波多分辨分析的脑干听觉诱发电位特征提取

本文应用小波变换方法从背景噪声中提取出脑干听觉诱发电位(BAEP)信号并进行特征识别。首先我们讨论了母小波和小波变换算法的选择,发现双正交母小波bior5.5和稳定离散小波变换(SWT)最适合BAEP信号的小波多分辨分析。通过D6尺度小波系数的相关性分析,发现相关性大于0.4的单次刺激记录具有较高的信噪比,使得仅数次刺激的叠加平均就能清晰地识别出BAEP信号的各个波。最后我们用此方法来挑选各次刺激记录,对每10次记录进行叠加平均和小波滤波结合消噪,并正确识别和计算出BAEP信号各个波的潜伏期。实验证明本方法通过小波系数相关性分析能有效选取单次刺激的BAEP记录,在大大减少刺激次数的同时,达到了更好的消噪效果。     

结合小波分解和径向基神经网络进行事件相关电位的单次提取

从单次实验记录中提取事件相关电位，无论在临床诊断上还是在大脑高级功能的研究中都起着重要的作用。介绍了一种将小波多分辨率分解和重建与径向基神经网络结合起来进行事件相关电位单次提取的方法。它基于事件相关电位主要是低频信号的事实，发挥径向基神经网络对连续函数的逼近能力，从信号的小波分解系数中提取出与低频响应相关的成分，构造了一种新的时频域滤波的方法，实验表明本方法较好地从单次记录中提取出了事件相关电位。     

提升小波在诱发电位提取中的应用研究

目的诱发电位信号的少次甚至单次提取一直是信号处理领域关注的热点问题之一,探讨如何利用提升小波有效提取诱发电位信号。方法首先基于仿真脑电数据,比较提升小波方法与多孔算法的去噪效果,选出具有最优小波基和分解层数的提升小波方法,再应用提升小波方法提取实际诱发电位信号。结果提升小波方法提取诱发电位信号波形特征明显,提高了信噪比,且其运算量只有传统方法的一半左右。结论提升小波的方法在诱发电位的应用中效果明显,有应用前景。     

心房活动电生理信号特征提取

为从12导联体表心电图中有效地提取反映心房活动的电生理信号,构造一种稀疏表示下的独立成分分析模型。首先,对采集到的12导联体表心电信号进行预处理,然后通过小波变换,实现心电信号小波域的稀疏表示形式,对变换后的心电信号进行独立成分分析,并通过频谱分析确定出反映心房活动的电生理信号源。讨论了平均房颤周长的这一测量指标在房颤患者中的具体应用。实验表明,该方法可以有效提取心房活动的电生理信号,将对心房活动电生理的深入研究产生积极影响。     

诱发电位快速提取方法及进展

每次刺激所产生的诱发电位的峰值和潜伏期以至波形是时变信号。随着信号处理技术的发展,诱发电位的提取方法由传统的平均叠加方法,向逐步减少累加次数,最终实现单次提取诱发响应波形,实现动态提取诱发电位的方向发展,因此对诱发电位的少次以至单次提取成为生物医学信号处理领域备受关注的一个研究课题。对近年来快速提取诱发电位的信号处理方法进行了简要的回顾,并分别从自适应滤波、小波变换、神经网络及独立成分分析等4个方面对算法进行了介绍。     

基于小波分析方法的脑电诱发电位单导少次提取

脑电诱发电位(EP)的单导少次提取具有重要的临床意义.本研究提出一种基于小波分析的方法,用于EP信号的单导少次提取.该算法首先将检测得到的信号经过白化滤波器进行滤波,将自发脑电预白化为白噪声,目的是使噪声的小波系数均匀分布在所有尺度和位移上,而期望信号的小波系数只在少数尺度上为非零值.进而对滤波后的信号的小波系数进行加权处理,再通过反变换得到期望信号,恢复出EP信号.在不同初始信噪比条件下仿真,进行算法测试和性能分析.结果表明,该算法能够抑制自发脑电的干扰,使信噪比提高13 dB,相当于20次叠加平均效果,从而可以实现EP信号的单导快速提取.     

Schizophrenia in a North Swedish geographical isolate, 1900–1977. Epidemiology, genetics and biochemistry

Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc² (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.     

HLA in North Colombia Chimila Amerindians

HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.     

The universal muscular chamber. A basic unit of the genitourinary, cardiovascular, gastro-intestinal, skeletal, cutaneous, respiratory and other systems, endocameral hypertension; and spasm, the key to their idiopathic diseases and arthropathies

Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.     

Der Einfluß von Nahrungsmitteln und Rauchen auf die klinisch-chemische Diagnostik von Phäochromozytom,Neuroblastom und Karzinoid-Syndrom

Zusammenfassung Der Einfluß von verschiedenen Nahrungsmitteln auf Methoden zur Bestimmung von Adrenalin (AD), Noradrenalin (NA), Vanillinmandelsäure (VMS), Metanephrinen (MN), Homovanillinsäure (HVS) und 5-Hydroxyindolessigsäure (5-HIE) im 24 h-Harn zur Diagnose des Phäochromozytoms bzw. Karzinoid-Syndroms wurde untersucht. Die in die Untersuchung einbezogenen Nahrungsmittel waren: Tee, Kaffee, Mandeln, Ananas, Käse, Walnüsse, Vanillepudding, Bananen, Tomaten und Milchschokolade. Außerdem wurde der Einfluß des Zigarettenrauchens auf die Bestimmung von AD, NA, VMS und MN untersucht.Walnüsse führten zu einer starken Erhöhung der 5-HIE-Ausscheidung. Bananen erhöhten die Ausscheidung von AD, NA, VMS, MN und 5-HIE. Kaffee und Ananas bewirkten eine geringe Zunahme der MN-Werte. Rauchen von 20–30 Zigaretten/Tag beeinflußte keine der vier Variablen.Wenn die beschriebenen Methoden benutzt werden, sollte lediglich auf den Verzehr von Bananen und Walnüssen vor und während der Harnsammelperioden verzichtet werden, da die oberen Normgrenzen im Harn überschritten werden könnten. Ein Verzicht auf Kaffee und Ananas in normalen Mengen ist nicht erforderlich. Es besteht kein Anlaß, weiterhin die bisherigen umfangreichen Restriktionen der übrigen Nahrungsmittel beizubehalten.     

A comparative study of the effects of dimebon,obsidan, finoptin,and cordaron on the functional state of ischemic focus and size of necrotic zone in experimental myocardial infarction

Dimebon, an antihistamine agent, exerts a moderate antianginal effect, improving the function of ischemic focus in the myocardium and decreasing the necrotic zone in experimental myocardial infarction. Dimebon is less active than obsidan, finoptin (except for the size of the necrotic zone), and cordaron. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 12, pp. 642–644, December, 1996     

Effects of sex steroid hormones on lipid peroxidation and glutathione antioxidant system in rat skin

Effects of estradiol and testosterone on the intensity of lipid peroxidation and contents of glutathione redox system components in the dermis and epidermis of rat skin were studied. Only estradiol induced considerable dose-dependent and tissue-specific biphasic antioxidant effects on the skin. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 12, pp. 663–666, December, 1999     

Adhesion and growth of CaCo2 cells on surface-modified PEEK substrata

A series of surface-functionalized poly(ether ether ketone) (PEEK) films has been prepared by selective wet-chemistry; they are hydroxylated polymer (PEEK-OH) obtained by reduction, aminated polymer (PEEK-[]-NH2) prepared by coupling a diisocyanate reagent to PEEKOH (PEEK-[]-NCO) followed by hydrolysis, and carboxylated and aminocarboxylated polymers (PEEK-[]-GABA and PEEK-Lysine) resulting from the coupling of aminoacids to PEEK-[]-NCO. The aminated and carboxylated substrata promoted the adhesion and growth of CaCo2 cells in the presence of serum. Fibronectin (FN), an extra-cellular matrix protein, has been covalently fixed and/or adsorbed on various PEEK substrata, in the presence or not of a polymeric surfactant (Pluronic F68). The performances of the FN-grafted substrata (PEEK-[]-FN(1) and PEEK-[]-FN(2)) were significantly higher than those of reference substrata simply coated with FN (PEEK-OH(+FN)(1) and (2), PEEK-[]-NH2(+FN)(1) and (2)), considering the adhesion and spreading of CaCo2 cells in the absence of serum. Moreover, the stability of the adherent cells on the FN-adsorbed substrata dramatically depended on the experimental conditions applied during the PEEK coating with FN.     

THE ODYSSEY – A JUNGIAN PERSPECTIVE: INDIVIDUATION AND MEETING WITH THE ARCHETYPES OF THE COLLECTIVE UNCONSCIOUS

Homer's epic tale of the 20-year return of Odysseus from the Trojan War is investigated with particular reference to Jung's theory of individuation. Odysseus' meetings with 'the anima' in the form of goddesses, sirens and female monsters and his visit to Hades demonstrate the confrontation and humanization of aspects of the archetypal level of the psyche, central to Jung's theories of psychic growth and development. Jung's important ideas of the psychoid level and the transcendent function are explored and linked both to his investigations into medieval alchemy and with findings from contemporary neuroscience. The importance of Jung's constructive method of the interpretation of dreams and myths is shown to be central.