固相化学发光免疫分析法在病毒性肝炎病原分型上的应用

化学发光免疫分析方法是近十年发展的新技术,国内正在建立这一技术。由于化学发光免疫分析的敏感性可与放射免疫分析相比,而且无放射免疫试剂的半衰期限制和辐照污染的弊病,是一项很有前途的实验技术。为此,我们研究了固相化学发光免疫分析(SPCLIA),并用此技术做了病毒性肝炎病原分型的应用。为了比较     

最新的光纤医疗诊断技术

光学纤维(简称光纤)由于在尺寸大小、柔软性和抗电磁干扰等方面具有独特的优点,因而被用来制成各种传感器以解决医疗诊断的许多难题。因为光纤的尺寸细小,构成的传感器亦小,可以伸入体内,而且需要的取样物质(如:血)亦少。光纤传感器的柔软性好且细小,便于与内窥镜结合使用,可以测量组织、器官和血管内的参数。抗电磁干扰也很强,这样同时可以运用于高压或高温的电子探测仪器。医疗诊断光纤技术的应用大致可以分为三类:1.物理量探测,如压力、温度、血流速度和流量;2.化学量探测、如氧饱和、PH、Pco_2、Po_2测量;3.免疫反应探测。前面二类光纤传感器,将入射光送到试     

魔芋

魔芋又名蒟蒻、鬼芋、南星等等。中药称“蛇六谷”。属天南星科魔芋属,是一种多年生宿根草本植物,它的地下球状茎呈扁圆球形,肉质,暗红褐色。它原产印度、斯里兰卡,我国种植很早,远在一千多年前的宋朝所编的《开宝重室本草》中就有详细的记载。主要产区分布在四川、云南、贵州、广西、广东、湖南、湖北、安徽等地,有野生和栽培。魔芋球状块茎含萄萄甘露糖为50％,蛋白质为30％,多种氨基酸、微量元素和食物纤维,经常食用对人体好处甚多,并可调剂人体内部的酸碱度,但因它含有毒生物碱,不能生     

红花种子的研究与利用

一、概况红花(carthamus tinctorous zinn)又叫红蓝花、草红花等,是一种有多种用途的植物,属菊科(compositae)。红花原产埃及、印度,现分布全世界30多个国家,以印度、加拿大、墨西哥、美国、澳大利亚等十多个国家产量较多,近年来是国外发展较快的新的油料。联合国粮农组织正式把红花籽油作为一种油料作物列入《生产年鉴》的统计项目之内。     

甘松油生产技术

一、甘松与甘松油简介甘松属败酱科甘松香属多年生草本植物。分为中华甘松(Nardostachys Chinensis Batalin)和长匙甘松(Nardostachys jtamansi),是一种珍贵的经济植物,其主要分布我国四川、云南、甘肃、青海、西藏等省(区),以及印度、尼泊尔等国家。生长于阴湿山坡及湿     

人体心电物理模型的构造和应用

心脏生物电过程与心脏组织的生物化学过程、收缩松弛过程以及心脏组织的变异、控制心脏活动的有关神经系统有着密切的关系,它们之间存在着错综复杂的内在联系。研究心电过程以及心电过程在人体表面的电位分布——心电图,对于推断心脏生理的正常或异常,具有极其重要的价值。人体心脏生物电的活体测量是非常困难的,其过程的测定更是几乎不可能的,最好的办法是根据某些心脏生物电的实测结果,凭藉电学普遍原理,得出人类心     

A new batch calorimeter for aerobic growth studies

A microcalorimeter for aerobic growth studies, derived from a Tian Calvet differential apparatus, was successfully constructed. The calorimetric vessel was a short cylinder, which permitted a good exchange between the surface area and the gas phase. The time constant of the calorimeter was 3.6 min and the sensitivity 234 V/W. The thermochemical aspect of the aerobic growth of Escherichia coli on succinate, acetate, and glucose was investigated. This analysis revealed that the contribution of biosynthetic reactions varied with the substrate used and strongly influenced the heat evolution. The experimental metabolic enthalpy change was in good agreement with the predicted value for succinate and glucose growth. To explain the discrepancy between the two values observed for acetate growth we suggest that acetate metabolism may generate a by-product which was not further oxidized.     

Induction of NADPH-linked D-xylose reductase and NAD-linked xylitol dehydrogenase activities in Pachysolen tannophilus by D-xylose, L-arabinose, or D-galactose

Considerable interest in the D-xylose catabolic pathway of Pachysolen tannophilus has arisen from the discovery that this yeast is capable of fermenting D-xylose to ethanol. In this organism D-xylose appears to be catabolized through xylitol to D-xylulose. NADPH-linked D-xylose reductase is primarily responsible for the conversion of D-xylose to xylitol, while NAD-linked xylitol dehydrogenase is primarily responsible for the subsequent conversion of xylitol to D-xylulose. Both enzyme activities are readily detectable in cell-free extracts of P. tannophilus grown in medium containing D-xylose, L-arabinose, or D-galactose and appear to be inducible since extracts prepared from cells growth in media containing other carbon sources have only negligible activities, if any. Like D-xylose, L-arabinose and D-galactose were found to serve as substrates for NADPH-linked reactions in extracts of cells grown in medium containing D-xylose, L-arabinose, or D-galactose. These L-arabinose and D-galactose NADPH-linked activities also appear to be inducible, since only minor activity with L-arabinose and no activity with D-galactose is detected in extracts of cells grown in D-glucose medium. The NADPH-linked activities obtained with these three sugars may result from the actions of distinctly different enzymes or from a single aldose reductase acting on different substrates. High-performance liquid chromatography and gas-liquid chromatography of in vitro D-xylose, L-arabinose, and D-galactose NADPH-linked reactions confirmed xylitol, L-arabitol, and galactitol as the respective conversion products of these sugars. Unlike xylitol, however, neither L-arabitol nor galactitol would support comparable NAD-linked reaction(s) in cellfree extracts of induced P. tannophilus. Thus, the metabolic pathway of D-xylose diverges from those of L-arabinose or D-galactose following formation of the pentitol.     

Startup of anaerobic downflow stationary fixed film (DSFF) reactors

One of the serious problems limiting the application of full-scale anaerobic fixed film processes is reactor startup. To better understand startup, studies with downflow stationary fixed film (DSFF) reactors were conducted to characterize the effects of influent concentration, support material, and surface-to-volume ratio on biofilm development and overall reactor performance. Materials with roughened surfaces gave the best startup performance and as expected increased surface area in the reactors led to more rapid increases in loading rates and higher ultimate loadings. Soluble influent COD concentrations between 5 x 10(3) and 2 x 10(4) mg/L influenced the rate of biofilm development. Lower COD concentrations resulted in faster development of the biofilm, even though ultimate loadings were not necessarily achieved as rapidly as in reactors fed higher strength wastes. No decrease in specific activity of the biofilms in each reactor was observed as the thickness of the biofilms increased to their maximum value at the ultimate loadings. The operation of reactors fed lower strength wastes was more stable than reactors receiving higher strength feeds at comparable loadings. Biofilm yield and activity, COD removals, suspended growth and activity, and other system parameters are discussed.     

Design of a system for the control of low dissolved oxygen concentrations: critical oxygen concentrations for Azotobacter vinelandii and Escherichia coli

The physiological activity of microorganisms in environments with low dissolved oxygen concentrations often differs from the metabolic activity of the same cells growing under fully aerobic or anaerobic conditions. This article describes a laboratory-scale system for the control of dissolved oxygen at low levels while maintaining other parameters, such as agitator speed, gas flowrate, position of sparger outlet, and temperature at fixed values. Thus, it is possible to attribute in dilute nonviscous fermentations all physiologic changes solely to changes in dissolved oxygen. Experiments were conducted with Azotobacter vinelandii and Escherichia coli. Critical oxygen concentrations for growth (that value of oxygen allowing growth at 97% of mu max) were measured as 0.35 +/- 0.03 mg/L for A. vinelandii and 0.12 +/- 0.03 mg/L for E. coli. These values are significantly different from the commonly quoted values for critical oxygen concentrations based on respiration rates. Because of the superior dissolved oxygen control system and an improved experimental protocol preventing CO2 limitation, we believe that the values reported in this work more closely represent reality.