用于无创伤测量主动脉血液流速及其变化率的连续波多普勒仪:对狗的实验

本文介绍了一种新的连续波多普勒仪,它能无创测量病人升主动脉的峰值主动脉血流速度和加速度。该仪器采用一般的连续波多普勒发射器与接收器,工作频率为3.0MHz,用一正交解调器处理多普勒频移信号,以便仅仅检测朝向传感器的血流信号,该定向信号经边带滤波器后送至自动增益电路,使多普勒信号具有等幅度,再送至描迹器,绘出瞬时频率与峰值速度的关系曲线,并将其中最大的速度值确定为峰值速度。为了检验该仪器的精度,对16条开胸的经麻醉的狗进行了实验,比较了用该多普勒仪与电磁血流计所测得的升主动脉血液     

浅表动脉超声血流仪的设计

本文介绍了一种便携式浅表动脉超声多普勒血流仪的研制.该仪器可以打印出平均血流速度曲线图,也可以对多普勒血流声进行监听.文章介绍了血流速度测量原理并给出了硬件结构图和程序框图.该仪器在临床上具有广泛的用途.     

眼部血流多普勒信号的检测研究

研制以超声波为载体的电路系统,探测眼部血流多普勒信号,并进行频谱分析。硬件设计包括:信号控制、超声波发射/接收、高频放大、正交检波以及距离选通等电路;将检测信号数字化后,进行数字信号处理并绘制频谱分析图。同时,构建物理仿真模型验证系统功能;对人体正常眼组织的检测,获得眼动脉中血流信号的频谱分析图。结果表明,系统有效实现了血流流速的检测、血流方向的辨别和距离选通等功能;对人体正常眼组织检测所获得的频谱分析图中三峰双切迹状明显,与正常人体眼动脉血流参数吻合。作为专用眼科超声多普勒诊断仪的前期探索性研究,本设计能够准确的提取被测血流的多普勒频移信号,具有很好的应用前景。     

彩色多普勒血流显像与彩色多普勒能量图在恶性滋养细胞肿瘤的应用

目的探讨彩色多普勒血流显像(CDFI)及彩色多普勒能量图(CDE)在恶性滋养细胞肿瘤(GTD)早期诊断及化疗监测中的应用价值. 方法对20例GTD进行CDFI、CDE检测,观察其血流情况及用PD检测病变区血流速度,测算RI值. 结果 CDFI显示病变区血流异常丰富,CDE显示更丰富的血流信号.PD检测出低阻血流,RI=0.41±0.07,化疗前后相比CDFI、CDE和PD改变明显,RI值差异有非常显著性意义(p<0.01). 结论 CDFI、C DE对恶性滋养细胞肿瘤诊断及观察疗效均有十分重要的价值.     

基于蓝牙通讯的便携式心电监护仪的研制

目的 研制一种具有无线传输功能的便携式心电监护仪.方法 以MSP430单片机为核心,控制心电采集、放大模块,并通过BCM-03蓝牙模块将心电数据发送到掌上电脑上进行监护.结果 实现了心电数据的采集及与PDA的蓝牙无线通讯,掌上电脑端能稳定地接收到心电数据并实现心电波形的实时显示、存储、判别及远程传输等功能.结论 该监护仪达到设计要求,实用性好,运行稳定.     

一种多普勒血流探测仪性能的测试方法

近年 ,超声多普勒技术广泛应用于医疗器械各领域 ,如胎儿监护、诊断设备、血流探测设备等。一般多普勒血流探测仪的工作原理[1] 是 :探测仪内部电路的高频振荡器产生高频电压 ,再进行功率放大 ,激励换能器 (压电晶体 )发出超声波 ,向病人体内直线传播的超声波 ,受运动物体 (血流、胎儿心搏 )反射后会产生多普勒效应 ,即反射回波的频率会在发出的超声波频率上产生一定的频率偏移 (即频率发生很小的改变 ) ,频移量与运动物体的速度成正比。接收回波的换能器 (压电晶体 )将回波接收后转换成电信号 ,先经过放大、检波 ,再经信噪比的改善消除噪声…     

正交相位检测相域处理型连续波超声多普勒血流仪的研制

正交相位检测法是目前在超声多普勒血流测量中应用较为广泛的方向信息检测方法.本文介绍的正交相位检测相域处理型连续波超声多普勒血流仪具有灵敏度高、失真小和血流方向分辨率高等特点.本文除了介绍原理框图及信号处理过程外,还给出了实际的电路及关键的安装调试工艺.     

彩色多普勒血流显像与彩色多普勒能量图在恶性滋养细胞肿瘤的应用

目的探讨彩色多普勒血流显像(CDFI)及彩色多普勒能量图(CDE)在恶性滋养细胞肿瘤(GTD)早期诊断及化疗监测中的应用价值.方法对20例GTD进行CDFI、CDE检测,观察其血流情况及用PD检测病变区血流速度,测算RI值.结果CDFI显示病变区血流异常丰富,CDE显示更丰富的血流信号.PD检测出低阻血流,RI=0.41±0.07,化疗前后相比CDFI、CDE和PD改变明显,RI值差异有非常显著性意义(p<0.01).结论CDFI、CDE对恶性滋养细胞肿瘤诊断及观察疗效均有十分重要的价值.     

多普勒频谱的分析方法和显示技术

由于声源和接收体之间的相对运动而引起声波频率发生改变的现象是奥地利物理学家克理斯琴·约翰·多普勒(Christian Johann Doppler)首先发现,后来把这一物理学效应命名为多普勒效应(Doppler effect).在医学诊断中利用这一效应可探查心脏、血管、横膈的活动以及血流速度和胎儿的呼吸等.超声脉冲波进入人体后,将产生一系列复杂的频移信号,这些信号被接收器接收并处理后,还须经过适当的频率分析和显示,才能转变为有用的血流信息.     

超声脉冲多普勒速度仪中频率混淆的分辨

导论在以往的十年中,由于仪器技术和信号处理技术取得的进展,市售专用设备的配备,脉冲多普勒超声在估算容积血流和血液动力学方面的应用,变得日益普遍。尽管取得了重大的进展,但对系统的最大工作距离和能检测的最大速度(最高的多普勒频移)仍有基本限制。为了避免距离模糊,脉冲重复频率(PRF)必须足够低,使得在发射另一个信号之前,测量的回波返回到换能器。然而,取样过程常常把最大的可分辨的多普勒频移限制到1/2取样率(PRF/2),这些条件可合并为确定脉冲多普勒速度仪的距离——速度乘积限度。 R max·Vmax相似文献   

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.     

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.     

What will studies of Fulani individuals naturally exposed to malaria teach us about protective immunity to malaria?

There are an estimated over 200 million yearly cases of malaria worldwide. Despite concerted international effort to combat the disease, it still causes approximately half a million deaths every year, the majority of which are young children with Plasmodium falciparum infection in sub-Saharan Africa. Successes are largely attributed to malaria prevention strategies, such as insecticide-treated mosquito nets and indoor spraying, as well as improved access to existing treatments. One important hurdle to new approaches for the treatment and prevention of malaria is our limited understanding of the biology of Plasmodium infection and its complex interaction with the immune system of its human host. Therefore, the elimination of malaria in Africa not only relies on existing tools to reduce malaria burden, but also requires fundamental research to develop innovative approaches. Here, we summarize our discoveries from investigations of ethnic groups of West Africa who have different susceptibility to malaria.     

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.     

The universal muscular chain reaction,muscle spasm,Torsions, ruptures and extravasations. Chameleons of pathology and some manifestations of simple muscular disorders

Most bodily functions require the coordinated actions of complementary and supplementary paired muscle groups. Where this essential muscular cooperation is lacking, hollow organs may burst and others become literally screwed up, giving rise to many similar spastic diseases such as Torticollis, Twisted ovarian cyst, Torsion of the Testis, Volvulus of the intestines, Varicose Veins, Megacolon, Aortamegaly, Scoliosis, Erb's Palsy, Peyronie's Disease, Main-en-Griffe, Undescended Foot (Pes Cavus), Talipes, Strabismus. Spasm is “panenepidemic” and unclassified examples of Torsion Dystonia and Dyskinesia really are as common as debt and taxes.     

Class II HLA in Georgia Caucasus Tbilisi Georgians and their Mediterranean ancestry: The Usko Mediterranean languages

Georgia (or Sakartvelo in its own language) is a South Caucasus Mts. country with its easternmost part is enigmatically named Iberia, like the Iberian Peninsula, which may refer to rivers “Kura” and “Ebro” or their valleys respectively. Most of their inhabitants speak Georgian which is included within Dene-Caucasian group and Usko-Mediterranean subgroup of languages. The latter includes Basque, Berber, ancient Iberian-Tartessian, Etruscan, Hittite, Minoan Lineal A and others. In the present paper, HLA class II -DRB1 and -DQB1 alleles has been studied and extended haplotypes calculated. Most frequent haplotypes are also of Mediterranean origin (i. e.: (A*02-B*51)-DRB1*11:01-DQB1*03:01, (A*02-B*51)-DRB1*13:01-DQB1*06:03, or (A*24-B*35)-DRB1*01:01-DQB1*05:01) and DA genetic distances show that closest world populations to Georgians are Mediterraneans. Georgians also show common extended haplotypes ((A*02-B*51)-DRB1*11:01-DQB1*03:01, (A*02-B*13)-DRB1*07:01-DQB1*02:01 and (A*03-B*35)-DRB1*11:01-DQB1*03:01) with Svan people, a secluded population in North Georgia mountains. We can conclude that Georgians belong to a very old Mediterranean substratum according to both linguistics (Usko Mediterranean languages) and HLA genetics.     

'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.