FIA型微生物探针动态响应过程（Ⅱ）正交配点法的应用

在已建立的Ｌ－谷氨酸检测体系的基础上，为克服电极不稳定性给测量带来的误差，根据全混流型生物反应器的特点，建立了适用于固定化细胞柱的数学模型，采用正文配点法对数学模型进行了估算，并以Ｌ－谷氨酸微生物传感器为例，提出了浓度测量值的计算方法．     

苹果酸生产中残留富马酸转成天门冬氨酸的研究

建立了固定化细胞分离Ｌ－苹果酸生产中残留富马酸并将其转化成Ｌ－天门冬氨酸的新方法。对生成Ｌ－天门冬氨酸的工艺条件进行优化，结果表明，当Ｌ－苹果酸反应液ｐＨ调至８～９，Ｌ－天门冬氨酸添加量为６～８ｇ／Ｌ，碳酸铵加量为１５～２０ｇ／Ｌ，Ｍｇ￣（２＋）、Ｍｎ￣（２＋）、Ｃａ￣（２＋）等二价阳离子加量为１ｍｍｏｌ／Ｌ时，固定化细胞可将Ｌ－苹果酸反应液中残留的２０％左右的富马酸几乎全部转化成Ｌ－天门冬氨酸，且Ｌ－苹果酸含量的损失小于５％。     

新型L—乳酸盐酶电极的研制

本文研制一种新型乳酸盐酶生物传感器，此传感器以复合酶ＮＡＤ＾＋与ＬＤＨ共固定在经ＣＮＢｒ活化的琼脂糖上作为敏感膜。用厚为０．３ｍｍ的粒状琼脂糖制成的敏感膜电极，其响应性能最佳。此乳酸盐酶电极测试的最优条件是：在ｐＨ８．５的Ｔｒｉｓ－ＨＣｌ缓冲液中进行，温度２５℃，此缓冲液中含１．５ｍｍｏｌ·Ｌ＾－１ＶＫ３电子介体。此电极的线性反应范围为０．０４￣２．１μｍｏｌ·Ｌ＾－１，每μｍｏｌ·Ｌ＾－１乳酸盐     

用乳状液膜法分离浓缩L-苯丙氨酸

以煤油－Ｎ２０５－Ｐ２０４－ＨＣｌ组成的乳状液膜体系，在喷射提取柱内分别对Ｌ－苯丙氨酸及Ｌ－苯丙氨酸和Ｌ－天冬氨酸的混合溶液进行提取。实验结果表明，用１０００ｍＬ乳状液对初始浓度为２１．２５ｇ／Ｌ的单一Ｌ－苯丙氨酸水溶液提取３次后，外相浓度降到０．９５ｇ／Ｌ，内相最高浓度为１２６．１０ｇ／Ｌ；对Ｌ－苯丙氨酸浓度为８．６４ｇ／Ｌ的混合溶液提取两次后，外相Ｌ－苯丙氨酸浓度降至０．９０ｇ／Ｌ，内相Ｌ－苯     

壳聚糖凝胶材料固定葡萄糖氧化酶制电极的研究

以壳聚糖为载体研究凝胶法固定葡萄糖氧化酶制电极。试验研究了载体壳聚糖的降解性；交联剂戊二醛的浓度、用量；电极的载酶量等固定化条件对所组建的传感器性能的影响。通过影响规律的分析、优化固定化条件的研究，找出了根据壳聚糖溶液粘度适当调整交联剂成二醛的用量和铂丝在酶膜母液中浸涂时间，克服壳聚糖的降解性对酶电极性能的影响，建立了制备性能相近的GOD传感器的方法。     

微机械加工微型葡萄糖传感器

用微机械加工技术和微电子平面工艺制备了微型Ｃｌａｒｋ型氧电极。外型尺寸为１５×２×０７ｍｍ３，敏感面积为１×０５ｍｍ２。在敏感区固定葡萄糖氧化酶（ＧＯＤ），构成了微型葡萄糖传感器。传感器的主要性能：灵敏度２２ｎＡ／（ｍｍｏｌ／Ｌ）；响应时间＜１ｍｉｎ，线性范围０１～１０ｍｍｏｌ／Ｌ，变动系数９７％，稳定响应在二十天以上。     

卡车驾驶员的心理健康研究

运用症状自评量表（ＳＣＬ－９０）对１５１名男性卡车驾驶员的心理健康水平进行了测试。研究结果表明：①事故组、事故多发组与安全组驾驶员的ＳＣＬ－９０各因子均分及阳性项目数存在显著差异；②同一年龄组驾驶员，除５０～６０岁年龄组外，其他各年龄组的安全组和事故组驾驶员的ＳＣＬ－９０各因子均分及阳性项目数大部分差异显著；③不同年龄组驾驶员的ＳＣＬ－９０各因子均分及阳性项目数只有２０～２９岁与４０～４９岁年龄组驾驶员的偏执和精神病性两因子均分差异显著；④ＳＣＬ－９０的某些因子与Ｙ－Ｇ的某些特质存在显著相关。     

PEK－C、LCP及其共混物的流动性能

研究了含酚酞聚苯醚酮（ＰＥＫ－Ｃ）、液晶聚合物（ＬＣＰ）及其共混物的流动性能，测定了ηａ－γ曲线及流动活化能（△Ｅ）。结果表明，（１）ＰＥＫ－Ｃ、ＬＣＰ及其共混物均属假塑性流体；（２）ＬＣＰ可增加ＰＥＫ－Ｃ的流动性；（３）它们的粘度均随温度的升高而降低；（４）共混物的△Ｅ随ＬＣＰ含量的增加而下降。     

PEK—C,LCP及其共混物的流动性能

研究了含酚酞聚苯醚酮（ＰＥＫ－Ｃ）、液晶聚合物（ＬＣＰ）及其共混物的流动性能，测定了ηａ－γ曲线及流动活化能（△Ｅ）。结果表明，（１）ＰＥＫ－Ｃ、ＬＣＰ及其共混物均属假塑性流体；（２）ＬＣＰ可增加ＰＥＫ－Ｃ的流动性；（３）它们的粘度均随温度的升高而降低；（４）共混物的△Ｅ随ＬＣＰ含量的增加而下降。     

用于微光探测器的天文杜瓦

综述了天文用ＣＣＤ微光探测器对天文杜瓦的要求，介绍了研制的ＴＷＤ型杜瓦的特点和试验情况。试验结果表明，在无探测腔时，Ⅱ型和Ⅲ型杜瓦容器的技术指标分别达到：有效容积２．５Ｌ和１．２５Ｌ；质量２．０５ｋｇ和３．０２ｋｇ；液氮保存期１１０ｈ和１１６ｈ。真空寿命达２年以上。接探测腔后，Ⅱ型杜瓦液氮保存期为４０ｈ；ＣＣＤ冷盘温度可达到－１００～－１２０℃。     

PET膜表面光固定脲酶的研究

合成一种含芳香叠氮基的光活性酯,并利用该酯将脲酶用紫外光光固定在polyethylene terepthlalte(PET)膜的表面,X射线光电子能谱证明PET表面已经技枝脲酶,同时研究了紫外光辐照时间对固定化酶密度,固定化脲酶活性的影响,温度,pH值对游离酶,固定化酶相对活性的影响,并考察了固定化酶的相对活性随光活性酶沈度的变化及固定化酶的重复使用稳定性等性质。     

Amperometric biosensor for glutamate using prussian blue-based "artificial peroxidase" as a transducer for hydrogen peroxide

The specially deposited Prussian Blue denoted as "artificial peroxidase" was used as a transducer for hydrogen peroxide. The electrocatalyst was stable, highly active, and selective to hydrogen peroxide reduction in the presence of oxygen, which allowed sensing of H2O2 around 0.0 V (Ag/AgCl). Glutamate oxidase was immobilized on the surface of the Prussian Blue-modified electrode in a Nafion layer using a nonaqueous enzymology approach. The calibration range for glutamate in flow injection system was 1 x 10(-7)-1 x 10(-4) M. The lowest concentration of glutamate detected (1 x 10(-7) M) and the highest sensitivity in the linear range of 0.21 A M-1 cm-2 were achieved. The influence of reductants was practically avoided using the low potential of an indicator electrode (0.0 V Ag/AgCl). The attractive performance characteristics of the glutamate biosensor illustrate the advantages of Prussian Blue-based "artificial peroxidase" as transducer for hydrogen peroxide detection.     

Enzyme packed bed system for the on-line measurement of glucose, glutamate, and lactate in brain microdialysate.

Rapid measurement of glucose, glutamate, and lactate is important in understanding the dynamics of the energy balance of the brain. Glutamate is also the main excitatory neurotransmitter. A general immobilized enzyme-based flow injection assay system is described which uses oxidase and peroxidase enzymes to convert the analyte into an oxidized ferrocene species which is detected electrochemically by reduction. The enzymes glucose oxidase, glutamate oxidase, lactate oxidase, and horseradish peroxidase are immobilized with near 100% efficiency onto 10-microns tresyl-activated silica beads (1000- and 500-A pore size). The beads are slurry-packed into 2- x 20-mm columns to give beds for glucose, glutamate, or lactate which are stable for greater than 40 days. The flow injection assays described have detection limits from 1.8 to less than 20 pmol and have been configured to have linear calibration responses over the range of basal and stimulated levels of the three compounds found in 5-microL microdialysate samples from the rat striatum. The assays are used for automated on-line measurement of glucose, glutamate, and lactate in striatal microdialysate at 2.5-min intervals.     

Chemiluminometric sensor for simultaneous determination of L-glutamate and L-lysine with immobilized oxidases in a flow injection system

A chemiluminometric flow-through sensor for simultaneous determination of L-glutamate (Glu) and L-lysine (Lys) in a single sample has been developed. Immobilized uricase, immobilized peroxidase, support material, coimmobilized glutamate oxidase/peroxidase, support material, and coimmobilized lysine oxidase/peroxidase were packed sequentially in a transparent PTFE tube, and the tube was placed in front of a photomultiplier tube as a flow cell. A three-peak recording was obtained by one injection of the sample solution. The peak height of the first peak was due to the concentrations of urate and other reductants in the sample; the immobilized uricase was used to decompose urate, and the hydrogen peroxide produced was decomposed with a luminol-hydrogen peroxide reaction by immobilized peroxidase. The peak heights of the second and third peaks were free from the interferences from the reductants and were dependent only on the concentrations of Glu and Lys, respectively. Calibration graphs for Glu and Lys were linear at 40-1,000 and 50-1,200 nM, respectively. The sampling rate was 11/h without carryover. The sensor was stable for two weeks. The sensor system was applied to the simultaneous determination of Glu and Lys in serum.     

Synthesis of Pt-immobilized on silica and polystyrene-encapsulated silica and their applications as electrocatalysts in the proton exchange membrane fuel cell

Nano sized Pt particles were successfully immobilized onto SiO₂ and polystyrene-encapsulated silica core shell (SiO₂@PS). To make the immobilization of Pt onto both silica and polystyrene-encapsulated silica core shell, SiO₂ was first functionalized with -NH₂ using 3-amino propyl trimethoxysilane (APTMS) while for core shell, the negatively charged surface of polystyrene (PS) was changed with positive charge by cationic surfactant such as cetyltrimethylammonium chloride (CTACl) to make the formation of SiO₂ shell on preformed PS sphere. Transmission electron micrograph (TEM) images shows that Pt nanoparticles immobilized onto SiO₂ and SiO₂@PS were to be 3-4 nm without agglomeraiton. The energy dispersive spectroscope (EDS) shows that Pt contents on both SiO₂ and SiO₂@PS were to be 21.45% and 20.28%, respectively. In case of Pt-SiO₂@PS, it is believed that Pt should have been immobilized onto PS surface and pore within SiO₂ shell as well as SiO₂ surface. The MEA fabricated with Pt-SiO₂@PS shows better cell performance than of Pt-SiO₂.     

Vertically integrated human P450 and oxygen sensing film for the assays of P450 metabolic activities

An assaying method of cytochrome P450 (P450 or CYP) monooxygenase activities for toxicological evaluation of drugs and environmental pollutants was developed by immobilizing P450 on an oxygen sensoring layer. Membrane fractions from E. coli expressing human P450 were entrapped in agarose or silica-based gels and immobilized on 96-well microarrays having an oxygen sensing film at the bottom. The oxygen sensing film was made of an organically modified silica film (ORMOSIL) doped with Tris(4,7-diphenyl-1,10-phenanthroline) ruthenium dichloride (Ru(dpp)(3)Cl(2)). P450 activity toward the substrates was monitored through the fluorescence intensity enhancement due to the oxygen consumption by the metabolic reactions. For the metabolism of chlortoluron, a selective herbicide used to control grass weeds, CYP1A1 immobilized in agarose gel showed a higher activity and stability compared with those in silica gels and free suspensions. The luminescence changing rate evaluated by the dynamic transient method (DTM) could be correlated with the substrate concentration. We also compared the metabolic responses of human P450s (CYP1A1,CYP2C8, CYP2E1, CYP3A4) toward various substances. The use of immobilized P450 on an oxygen sensing layer provides a versatile assaying platform owing to the following features. First, the oxygen sensor can detect metabolic reactions of any P450 species, in contrast with assays using fluorogenic substrates. Second, vertical integration of the oxygen sensor and immobilized P450 enhanced the sensitivity because of the effective depletion of oxygen in the vicinity of the oxygen sensing layer. Third, immobilization enables repeated use of P450 by replacing the substrate solutions using a flow cell. Furthermore, the activity of immobilized P450 was retained at least for 3 weeks at 4 °C, suggesting its long-term stability, which is an additional attractive feature.     

Biosensor for asparagine using a thermostable recombinant asparaginase from Archaeoglobus fulgidus

Asparaginase from the hyperthermophilic microorganism Archaeoglobus fulgidus was cloned and expressed in Escherichia coli as a fusion protein with a polyhistidine tail. After heat treatment to denature most of the native E. coli proteins, the enzyme was purified by an immobilized metal ion affinity chromatography method. The activity of the enzyme was determined by monitoring the change in ammonium concentration in solution. It was found that the enzyme is thermostable at temperatures as high as 85 degrees C. The KM for L-asparagine was 8 x 10(-5) and 5 x 10(-6) M at 37 and 70 degrees C, respectively. The catalytic activity for L-asparagine was 5-fold higher than for D-asparagine. The enzyme was immobilized in front of an ammonium-selective electrode and used to develop a biosensor for asparagine. The biosensor had a detection limit of 6 x 10(-5) M for L-asparagine. Unlike a sensor based on asparaginase from E. coli, the biosensor based on recombinant asparaginase from A. fulgidus demonstrated higher stability.     

用神经网络对内燃机气门间隙的识别

由于内燃机的振动信号较复杂，用一般分类器来识别它的故障，不容易得到满意的效果。本文提出利用神经网络构成的分类器，对内燃机气门间隙进行识别，实验与计算机模拟，得到较满意的结果。     

增韧尼龙6的结晶,热行为和加工性能

对聚烯烃弹性体接枝物(E-g-MA)和尼龙6的共混物的结晶、热行为和加工性能等方面进行了研究。 对不同比例的Ny6/E、Ny6/E-g-MA二元共混物进行了熔融指数的测定,Ny6/E的MI的变化随弹性体含量增加而下降,而相同比例的Ny6/E-g-MA的MI值明显低于前者。 对纯Ny6和相同比例的Ny6/E、Ny6/E-g-MA共混物进行了等温结晶速度的测定。 共混物的DSC、WAXD测定结果表明:E-g-MA的加入不会影响Ny6的热行为、晶胞参数和γ晶型的形成,也不会产生新的晶型。增韧尼龙6比纯尼龙6更有利于加工成型。