癫痫脑电信号符号动力学分析

癫痫是大脑神经元异常放电所引起的常见神经系统疾病,其发作具有突然性和反复性特点,因此,提前预测发作以便对患者及时采取措施具有重要意义。本文引入符号动力学方法分析癫痫大鼠失神性发作时脑电(EEG)信号的特性,并对影响符号统计量的关键参数的选取进行讨论,计算癫痫发作不同时期EEG信号的符号熵和时间不可逆转性。研究发现正常发作间隙期,符号熵和时间不可逆转性指标值较大;从发作间隙期向发作期的转化阶段,即发作前期,二者明显减小;发作时维持较低水平。研究结果表明符号动力学方法能够揭示癫痫EEG动力学特征变化,符号熵和时间不可逆转性两个指标是表征癫痫发作不同阶段的敏感特征量,具有重要的潜在临床应用价值。     

基于经验模式分解与样本熵的癫痫预测方法

本研究提出一种基于经验模式分解（empirical mode decomposition，EMD）与样本熵的癫痫预测方法；该方法首先对原始信号进行了经验模态分解，将其分解为多个平稳的固有模态函数（intrinsic mode function，IMF）之和，再选取若干个包含主要癫痫预报信息的IMF分量，将其求和后，计算其样本熵（sample entropy，SampEn）。结果表明，癫痫发作前期样本熵呈减小趋势，基于EMD的样本熵其减小幅度显著增加，同时抑制了伪差对实验结果的影响。基于经验模式分解与样本熵的癫痫预测方法能够很好的对癫痫进行预测。     

样本熵及在脑电癫痫检测中的应用

对癫痫进行检测和预报具有非常重要的临床意义。首先采用近似熵对癫痫患者的脑电信号进行分析，探索运用近似熵进行癫痫检测的可行性。针对近似熵存在的问题，选用一种与近似熵类似但精度更好的方法一样本熵，并同近似熵就在癫痫脑电信号中的应用进行了比较分析。结果显示癫痫发作时脑电信号的近似熵和样本熵均明显低于发作前和发作后。样本熵的变化幅度明显大于近似熵，样本熵的变化幅度相对于近似熵提高了约10％～25％。     

基于样本熵与小波包能量特征提取和Real AdaBoost算法的正常期、癫痫间歇与发作期的脑电自动检测

脑电图(EEG)分析已被广泛应用于疾病的诊断,针对癫痫患者的脑电检测可及时对患者的发病情况作出判断,具有很强的实用价值,因此急需癫痫脑电自动检测、诊断分类技术。为实现患者正常期、癫痫发作间期和发作期各时段脑电的快速、高精度自动检测分类,本文提出一种基于样本熵(SampEn)与小波包能量特征提取结合纠错编码(ECOC)Real AdaBoost算法的脑电自动分类识别方法。将输入信号的样本熵值和4层小波包分解后的部分频段能量作为特征,并用纠错编码和Real AdaBoost算法相结合的方式对其进行分类。本文采用德国波恩大学癫痫数据库实验数据(含正常人清醒、睁眼与清醒、闭眼,癫痫患者间歇期致痫灶外与致痫灶内及癫痫发作期5组脑电信号)进行了方法有效性检验。研究结果表明,该方法有较强的脑电特征分类识别能力,尤其对癫痫间歇期脑电信号识别率提升显著,上述5组3个时期不同特征脑电信号的平均识别率可达96.78%,优于文献已报道的多种算法且有较好稳定性与运算速度及实时应用潜力,可在临床上对癫痫疾病的预报及检测起到良好的辅助决策作用。     

基于近似熵的癫痫发作预测研究

临床采用诱发方法检测获得的失神发作患者EEG信号,研究其发作前脑电信号的动力学变化的规律,寻找预测癫痫失神发作一般规律和方法。我们选择合适的电极对,使用非线性动力学的方法,采用复杂度变化度量的近似熵指标,通过闪光刺激癫痫患者获得的EEG信号进行动力学特征研究,根据EEG信号表现出的同步情况实现对癫痫发作的预测。结果表明,本研究可以实现对临床光刺激进行诱发的癫痫失神患者的发作进行预测。研究中采用优化电极的方法优于采用固定电极对。     

基于脑电棘波频次的癫痫发作预测算法

癫痫发作预测是近年来在神经科学领域中备受关注的课题.预测癫痫发作可以使医护人员或患者提前采取有效措施来预防和控制癫痫发作,在临床上具有重要意义.棘波是最基本的阵发性异常脑电活动,在分析和统计癫痫发作前期和发作期棘波频次不同表现的基础上,首次提出一种基于脑电棘波频次的癫痫预测算法.对脑电进行滤波以去掉高频干扰后,采用形态学滤波器检测脑电棘波数目,并计算各段脑电中棘波出现的频次,最后根据棘波频次的变化预测癫痫的发作.采用本算法对21例癫痫患者长程颅内脑电进行癫痫预测,准确率达到74.7％,每小时错误预测次数仅为0.111次.结果表明,所提出算法能够有效地预测癫痫发作.     

基于Android系统的便携式癫痫发作智能监控系统

临床上基于个人电脑的脑电监护系统不适用于便携和家庭的监测,并且癫痫患者长期住院检测会增加医疗负担。为此本文设计了一种基于Android智能手机的16导便携式、网络化监控系统。整个系统采用了主动电极技术、WiFi无线传输技术、多尺度排序熵算法、反向传播(BP)神经网络优化算法等,并基于Android手机应用软件实现对脑电数据的处理、分析、显示、报警等功能。系统在多台Android 2.3以上系统的手机上测试后运行稳定、可靠,为医护人员和患者提供了一种便携、可靠、实用的癫痫发作监控解决方案。     

基于近似熵的癫痫发作预测研究

临床采用诱发方法检测获得的失神发作患者EEG信号,研究其发作前脑电信号的动力学变化的规律,寻找预测癫痫失神发作一般规律和方法.我们选择合适的电极对,使用非线性动力学的方法,采用复杂度变化度量的近似熵指标,通过闪光刺激癫痫患者获得的EEG信号进行动力学特征研究,根据EEG信号表现出的同步情况实现对癫痫发作的预测.结果表明...     

基于C-FFuzzyEn的神经电生理信号同步性分析

基于传统互模糊熵,结合分数阶微积分提出分数阶互模糊熵（C-FFuzzyEn）,并基于该算法分析混沌耦合系统的同步性,进行健康对照者和癫痫患者不同脑区脑电信号的耦合性对比。结果表明,与传统互模糊熵相比,C-FFuzzyEn提高了不同耦合度模型的区分能力;与健康对照者相比,癫痫患者在癫痫发作时不同通道脑电信号之间C-FFuzzyEn较小,与癫痫发作时各神经元同步放电现象相吻合;相比互模糊熵,C-FFuzzyEn区分健康对照者与癫痫患者脑区之间脑电信号同步性的效果更好。C-FFuzzyEn可应用于脑电信号等神经电生理信号的同步性分析。     

基于加权复杂网络度熵和的癫痫发作检测方法

癫痫发作检测一直是一项富有挑战性的工作,随着癫痫发病率的增加,高性能癫痫自动检测算法在临床上可以减轻医务工作者的工作量,具有重要的临床医学研究意义。提出基于加权水平可视图的癫痫检测新方法。首先利用加权水平可视图将单通道脑电信号转化为复杂网络,并提取生成的复杂网络的度的平方和权重度分布熵两个特征;最后将两个特征之和作为单特征输入到线性分类器中,用来识别癫痫间歇期和发作期信号。对波恩大学的癫痫脑电数据集进行实验,评价所提出的检测算法的性能。使用该癫痫脑电数据集间歇期和发作期各100个实验样本,样本长度为1 024。实验结果表明,所提出的方法具有较高的分类精度,可达到98.5%。由于分类的特征为单特征,所以更加简单高效,可用于癫痫发作在线自动检测。     

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.     

Renal dysplasia and asplenia in two sibs

A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.     

The dominant diseases of modernized societies as omega-3 essential fatty acid deficiency syndrome: Substrate beriberi

About 1900, modern food selection and processing caused widespread $\text{epidemics}$ of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a $\text{panh}$ypovitaminosis B, i.e., a mixture of $\text{substrate}$ beriberi and $\text{substrate}$ pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse $\text{endemic}$ disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for $\text{primates}$. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.     

'Very sore nights and days': the child's experience of illness in early modern England, c.1580-1720

Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.     

Guidelines for the Validation and Use of Immunoassays for Determination of Introduced Proteins in Biotechnology Enhanced Crops and Derived Food Ingredients

Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.     

Ultracryotomy: development and application (with examples from the yeast cytology) (author's transl)

The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.     

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 case for allele‐specific recognition by the TCR

There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable.     

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.