酶法制备植源性生物活性肽及其生理活性的研究进展

近年来,植源性生物活性肽因其种类丰富和较高的营养价值而备受关注。酶法制备生物活性肽条件温和、安全性高且在反应过程没有副反应发生,不会降低酶解产物的营养价值,利用该法制备生物活性肽在食品加工、医疗保健及化妆品开发等领域有良好的发展前景。综述了植源性生物活性肽的制备技术及其生理活性的最新研究进展,并对生物活性肽在人类生活中的应用前景进行了展望。     

固定化酶在仪器分析中的应用

对固定化酶的特点和制备方法，固定化酶反应器在高效液相色谱，流动注射分析和生物传感器中的应用作了介绍。引用文献４３篇。     

计算机在酶电极测定中的应用

一、前言: 由于Clark氧电极可用来检测酶反应产生或消耗的氧,因此,它不仅是一种普通的电化学传感器,而且被用来组装成多种生物传感器,在生物医学研究等方面起着重要作用。目前,随着计算机技术日新月异的发展,计算机在各领域中的应用也越来越广泛。     

高粱麸酶解条件的比较及响应面实验的优化

本研究以高粱麸为原料,采用了三种蛋白酶：碱性蛋白酶（Alcalase）、中性蛋白酶（Neutrase）、复合蛋白酶（Protamex）对高粱麸进行水解,根据单因素试验结果,采用响应面设计实验。运用Box—Benhnken的中心组合实验设计原理,选择对氮溶指数有显著影响的三个因素：加酶量、反应时间、水料比,做了3因素3水平的响应面分析实验,分别确定了各酶水解高粱麸的最佳工艺条件。研究结果表明,Alcalase蛋白酶的酶解效率最高,其次是Protamex蛋白酶,Neutrase蛋白酶酶解效率最低。     

酶在饲料工业中的应用进展

我国是一个饲料资源十分紧缺的国家,土地少、人口多,人畜争粮的矛盾十分突出。要保持我国饲料工业和畜牧业的持续发展,必须解决好饲料问题,否则将严重制约其发展。目前,饲用酶的研究开发和推广应用,已成为生物     

ITC在酶动力学研究中的应用

在酶动力学参数测量中，等温滴定微量热技术（ITC）是一种普适性酶分析方法，灵敏度高，快速精确，可用于活性筛选，无须化学标记，可以直接用于各种酶一底物体系。[第一段]     

胃泌素释放肽前体在小细胞肺癌诊断及治疗中应用

目的 :探讨胃泌素释放肽前体(Pro GRP31-98)在小细胞肺癌(SCLC)临床治疗中的价值。方法 :收集肺部肿瘤患者199例,健康对照人群84例,以ELISA方法检测血清Pro GRP31-98水平,并与NSE、CYFRA21-1、CEA进行联合检测并分析其诊断SCLC敏感度和特异度。结果 :结合病理及影像技术确诊肺癌患者142例,其中鳞癌52例,腺癌40例,未分化癌1例,小细胞癌49例,其他良性病变者57例;49例SCLC患者中,血清Pro GRP31-98中位值为610.94 pg/m L,明显高于非小细胞肺癌(NSCLC)组及健康对照组,差异均有统计学意义(P<0.01);49例SCLC中广泛期患者Pro GRP31-98水平高于局限期患者,二者中位值分别为959.83pg/m L和320.12pg/m L(P<0.01);Pro GRP31-98诊断敏感性为81.63%,特异性为94.62%,Pro GRP31-98+NSE+CYFRA21-1+CEA联合检测的敏感性为91.84%,特异性为95.57%,约登指数为87.41,四个指标联检敏感性特异性高于单独检测,但与Pro GRP13-98+NSE比较,差异无统计学意义。结论:血清Pro GRP31-98检测可作为SCLC诊断指标,其水平能为SCLC治疗效果、复发监测等提供数据;与NSE联合检测可进一步提高敏感性。     

膜分离技术及其装备在中药制药过程中的应用

主要介绍了膜分离技术及其原理和应用特点,综述了近些年膜分离装备系统在中药制药过程中的应用情况,为今后更好地研究和应用这一技术提供了参考。     

核酸适配体在酶固定化研究中的应用

本研究基于核酸适配体对胰蛋白酶的高特异性和高亲和力,通过在硅胶颗粒上固定核酸适配体,从而实现胰蛋白酶的间接固定,并以牛血清白蛋白（BSA）为研究对象,对固定化胰蛋白酶的酶解活性进行表征。结果表明,这种酶固定化方法对酶的活性几乎没有影响。与传统的固定方法相比,这种酶固定化方法在保证胰蛋白酶活性的基础上,也可以实现胰蛋白酶的洗脱和重新固载,达到固载基质重新利用的目的,为酶的固定化提供了一种新的研究思路。     

菌肽保在水稻上的应用效果研究

试验采用大区对比、小区对比的研究方法,主要分析水稻全生育期应用菌肽保抗菌肥和中化的各个处理对水稻生长、发育、产量及产量性状的影响.试验结果表明,不同处理对水稻生育期无明显差异;施用菌肽保的平方米穗数有所减少,穗粒数比中化处理高2粒,但千粒质量提高0.2 g,结实率提高0.2％;施用菌肽保的实收产量较中化处理增加20.2...     

Mass spectrometry for the quantification of bioactive peptides in biological fluids

The study of pharmacologically active peptides is central to the understanding of disease and development of novel therapies. It would be advantageous to monitor the fate of bioactive peptides in biological fluids and tissues following their in vivo administration (exogenous administration) or the modulation of endogenous factors (e.g., peptide hormones) affected by the administration of a pharmacological agent. Measurement of administered compounds (small molecules) in plasma is a mature field. However, measurement of pharmacologically active peptides presents particular problems for quantitative mass spectrometry, including challenges from selectivity and sensitivity perspectives. Current approaches towards peptide quantification in biological fluids include immunoassays and mass spectrometric techniques. Immunoassays, although sensitive, lack the necessary selectivity for distinction between peptide and metabolites. Modified molecules induced by metabolic transformations (e.g., N- or C-terminal truncation of the peptide) might not be differentiated by the antibody used in the assay, leading to cross-reactivity. However, although it is generally accepted that mass spectrometry is an ideal technique for the quantification of trace levels of analytes in biological fluids, immunological techniques are still characterized by better limits of peptide detection. In this review article, novel mass spectrometric approaches and strategies on peptide quantification will be described. The current capabilities and prospects for advances in this critical area of research will be examined.     

Natriuretic peptides in relation to the cardiac innervation and conduction system

During the past two decades, the heart has been known to undergo endocrine action, harbouring peptides with hormonal activities. These, termed "atrial natriuretic peptide (ANP)," "brain natriuretic peptide (BNP)," and "C-type natriuretic peptide (CNP)," are polypeptides mainly produced in the cardiac myocardium, where they are released into the circulation, producing profound hypotensive effects due to their diuretic, natriuretic, and vascular dilatory properties. It is, furthermore, well established that cardiac disorders such as congestive heart failure and different forms of cardiomyopathy are combined with increased expression of ANP and BNP, leading to elevated levels of these peptides in the plasma. Besides the occurrence of natriuretic peptides (NPs) in the ordinary myocardium, the presence of ANP in the cardiac conduction system has been described. There is also evidence of ANP gene expression in nervous tissue such as the nodose ganglion and the superior cervical ganglion of the rat, ganglia known to be involved in the neuronal regulation of the heart. Furthermore, in the mammalian heart, ANP appears to affect the cardiac autonomic nervous system by sympathoinhibitory and vagoexcitatory actions. This article provides an overview of the relationship between the cardiac conduction system, the cardiac innervation and NPs in the mammalian heart and provides data for the concept that ANP is also involved in neuronal cardiac regulation.     

Peptidomics: identification and quantification of endogenous peptides in neuroendocrine tissues

Neuropeptides perform a large variety of functions as intercellular signaling molecules. While most proteomic studies involve digestion of the proteins with trypsin or other proteases, peptidomics studies usually analyze the native peptide forms. Neuropeptides can be studied by using mass spectrometry for identification and quantitation. In many cases, mass spectrometry provides an understanding of the precise molecular form of the native peptide, including post-translational cleavages and other modifications. Quantitative peptidomics studies generally use differential isotopic tags to label two sets of extracted peptides, as done with proteomic studies, except that the Cys-based reagents typically used for quantitation of proteins are not suitable because most peptides lack Cys residues. Instead, a number of amine-specific labels have been created and some of these are useful for peptide quantitation by mass spectrometry. In this review, peptidomics techniques are discussed along with the major findings of many recent studies and future directions for the field.     

Recent progress in the preparation of AuNPs-PDMS composite membranes

Gold nanoparticles-dimethylsiloxane(AuNPs-PDMS) membrane is a novel composite material in biochemical technology an d micro-electro-mechanical system(MEMS) research.It is widely used in biomed ici ne,biochemical detection and en vironmental protection due to its biocompatibility,elasticity and electric char acteristics.In this paper,the characteristics of the composite membrane were d escribed,and four methods for fabricating AuNPs-PDMS composite membranes were reviewed in detail.Besides,the advantages and disadvantages of the four method s were summarized,and the present problems and future researches were proposed.     

造纸法再造烟叶浸提液处理技术的研究进展

造纸法再造烟叶的工艺过程是将烟梗、烟末及碎烟叶经浸泡提取后进行固液分离,固相按造纸工艺制成纸状基片,液相经浓缩后回涂在基片上,再经干燥和分切后得到再造烟叶。浸提液的处理方法包括离心分离、絮凝剂与吸附剂的添加、生物酶解及浓缩等,处理工艺可直接影响浸提液质量,并关系到再造烟叶的感官品质。本文对造纸法再造烟叶生产中浸提液处理技术的研究进展进行了综述,提出了可以借鉴的经验,并展望了研究趋势及发展方向。     

可控电抗器在特高压输电系统中的应用

分析了我国发展特高压输电的必要性，介绍了可控电抗器在特高压输电系统中的优异性能。可控电抗器能够随着传输功率的变化而自动平滑地调节本身的容量．因而能显著改善电网的无功补偿．减少电网损耗和提高输电质量。论文还介绍了两种最具应用前景的特高压可控电抗器的结构与功能。     

Transmission electron microscopic observations of membrane effects of antibiotic cecropin B on Escherichia coli

The pathway of cell membrane lysis by the peptide antibiotic cecropin B (CB), which contains both a hydrophobic and an amphipathic alpha-helix, was analysed by assessing the morphological changes of Escherichia coli following treatment with the peptide. Exposure of green fluorescent protein (GFP)-expressing E. coli to CB does not lead to an efflux of GFP. Moreover, transmission electron microscopic (TEM) examination of cecropin B-treated cells showed that severe swelling precedes cell death and that the outer membrane becomes distended away from the plasma membrane. Using immuno-gold staining and TEM of E. coli expressing the maltose-binding protein in the cytoplasm, it was apparent that the protein remains restricted to the cytoplasmic compartment. These observations suggest that CB causes gross disruption of the outer membrane of Gram-negative bacteria. Circular dichroism measurements of CB in the presence of cell membrane-mimicking liposomes showed that CB forms secondary structure dependent on the ratio of [lipid]/[peptide]. These observations from this study are important for the future design of custom antimicrobial peptides.     

防爆膜在安全阀中的使用

介绍了防爆膜的特点、类型、材料尺寸的计算及影响工作稳定性的因素。     

STD总线在LED光强自动分选控制中的应用

介绍STD总线在LED光强自动分选控制中的硬件配置、功能软件开发及应采取的各种抗干扰措施,实现了LED光电参数的在线测试。