生物传感器

生物传感器(biosensor)是利用生物活性物质识别分子的能力,选择性地检测特定的生物化学物质的一种传感器。它的研究开始于60年代的酶电极,酶电报是将电化学反应与酶反应结合在一起,进行选择性测量的新型电极。     

改良的YSI膜在葡萄糖传感器中的作用

为提高葡萄糖传感器的稳定性、检测精度、抗干扰能力及改善电极输出电流与葡萄糖浓度间的线性相关。在ＹＳＩ膜上固植过氧化氢酶，并在不同浓度的葡萄糖液、抗环血酸液和醋氨酚液中进行体外实验。结果显示：此传感器的背景电流为０．３７±０．０６ｎＡ；漂移值在０ｍＭＧ．Ｓ．中为（０．２０±０．１４）％／３ｈｒ，在１０ｍＭＧ．Ｓ．中为（３．２２±０．４０）％／３０ｈｒ，单位浓度单位时间的均值为０．１０３％；电极输出电流与葡萄糖浓度间的线性相关系数均值为０．９８６，线性范围为０～２０ｍＭＧ．Ｓ．；低浓度的抗坏血酸不能干扰传感器，高浓度的抗坏血酸和醋氨酚仅产生很小的干扰电流。因此，改良的ＹＳＩ酶膜使整个葡萄糖传感器系统性能、检测精度、抗干扰能力得到较明显的改善。     

固化酶电极

一、前言:生物体内的反应几乎都是在酶的参与下完成的,这是由于酶具有高效的催化作用。它可以使一些很难进行的反应在常温常压下完成,并且,酶具备高度的选择性,某一种酶只能催化某一定底物的特殊反应。所谓酶电极就是利用酶的独特功能而制作的传感器。它可以有选择地对有机物进行检测,现在,世界各地对酶电极的研究风起云涌,有的已达实用程度,下     

基于碳纳米管修饰的无酶型新型甲胎蛋白安培免疫传感器研究

目的构建新型甲胎蛋白安培免疫传感器。方法首先在玻碳电极（GCE）表面修饰一层羧基化碳纳米管（CNTs）,然后利用带负电荷的DNA分子和带正电荷的硫堇之间的静电作用,层层自组装修饰硫堇以增强检测信号,然后利用硫堇的氨基固定纳米金,以便固定抗体,最后利用牛血清白蛋白封闭未结合位点。结果修饰的碳纳米管能够显著地提高电极的导电性,利用层层组装技术修饰了5层硫堇。在优化的条件下（pH7.0,温浴时间25min）,制作的甲胎蛋白免疫传感器线性范围在0.5～25ng/ml内,检测限0.02ng/ml。结论成功利用层层自组装技术构建新型基于碳纳米管修饰的无酶型甲胎蛋白安培免疫传感器,该传感器灵敏度高,特异性好,有望成为原发性肝癌早期诊断的新方法。     

医用针状电极电流场边界元计算方法及纯水实验研究

根据医用针状电极系上的电势，利用边界元积分方程建立以针状电极单位长度流入导电介质中的电流为未知量的离散方程，通过求解线性方程组计算针状电极上电流密度的不均匀分布。再由针状电极上的电流密度计算了导电介质中任意一点的场，实现针状电极电流场分布的数值计算。为检验方法的可靠性和准确度，通过实验测量纯水中两针状电极的电势分布，测量值与计算结果相吻合，表明边界元积分方程法能够较好地模拟针状电极的电流场，该方法可用于针状电极电流场分布的数值计算。     

生物燃料电池酶电极电化学性能研究

目的研究一种新型酶电极电化学性能,该电极能够被应用到生物燃料电池中。方法通过生物素-亲和素系统固定葡萄糖氧化酶,制备了生物燃料电池酶电极,应用循环伏安法研究了酶电极的电化学性能,并讨论了酶的层数、底物浓度、扫描速率和温度等条件对其性能的影响。结果通过生物素、亲和素间的特异性结合力固定化酶制备的生物燃料电池酶电极对葡萄糖有较好的电流响应。结论制备的酶电极能够满足生物燃料电池的要求,适合在人体环境中使用。     

人绒毛膜促性腺激素（HCG）的生物电化学免疫测定

本文介绍了在玻璃碳电极上共价结合HCG抗体的免疫电极。采用循环伏安法测定了免疫电极的循环伏安图谱。当电极上抗体与抗原发生反应，形成抗原-抗体络合物后，循环伏安曲线的阴极峰电流发生变化。根据阴极峰电流的变化，可以测定溶液中HCG的含量，测定的浓度范围为5．0×10^-8～5．0×10^-6。克／毫升。     

复合电极在电阻抗x线断层术中的应用

在电阻抗x线断层术中,通过引入电流和测量电压来估算客体的阻抗的分布。由于电极与皮肤的接触阻抗很高,且随电极位置的改变而改变,故电极构型对测得的电压数据有影响。作者设计了一种两电极组成的复合电极:大号外电极用来引入     

乙肝电化学免疫传感器阵列电极的研制

研制了以乙肝表面抗原为检测对象的电化学免疫传感器阵列,采用微电子平面加工技术制备了八通道金电极阵列,在金电极表面自组装半胱胺分子,戊二醛进行醛基化,最后通过竞争组装同时固定乙肝抗体和硫堇,以硫堇的还原峰电流的下降百分比对乙肝表面抗原进行定性和定量的检测.该传感器阵列可同步检测乙肝表面抗原,大大提高了检测的准确度和可靠性.应用于临床血清样品的检测,其结果与ELISA法相一致.     

生物传感器

1.序言最近,传感器技术的发展是惊人的,尤其是利用生物功能物质识别分子的能力,选择性地检测特定化学物质的生物传感器(Biosensor),由于它方法巧妙,有不可估量的潜在能力,因此,其发展动向为世界所关注,本文回顾生物传感器的变迁,归纳新传感器产生的条件,介绍最尖端的研究水平,并展望未来, 2.生物传感器研究的变迁生物传感器之源可追溯到六十年代发表的酶电极,它是将电化反应与酶反应巧妙地结合在一起,为进行选择性测量而设计的一种新型电极。其独特之处是将酶固定在膜载体上,但从传感器的角度来看,应称其为酶     

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.