表面活性剂与耐热超氧化物歧化酶混合溶液的储存稳定性

通过考察表面活性剂-耐热超氧化物歧化酶TcSOD混合溶液在不同储存时间、不同复配组合、不同储存温度、不同质量分数、不同pH条件下的SOD保留活性,研究了表面活性剂对TcSOD储存稳定性的影响。90 d储存的结果表明,无论是30还是45℃,单一表面活性剂鲸蜡硬脂醇聚氧乙烯(25)醚(A25)、单硬脂酸甘油酯(GMS)、椰油酰胺丙基二甲基甜菜碱(CAB)以及复配表面活性剂脂肪醇聚氧乙烯醚硫酸钠(AES)或十二烷基硫酸钠(K12)+GMS,AES或K12+N-月桂酰谷氨酸钠(SG)对混合溶液SOD保留活性的影响最小;高温储存是加速多数混合溶液TcSOD失活的协助因素;与离子型表面活性剂相比,混合溶液的SOD保留活性随非离子型表面活性剂质量分数增加而显著下降;非离子型表面活性剂-TcSOD混合溶液SOD保留活性峰值出现在pH=6,阴离子型和两性离子型表面活性剂-TcSOD混合溶液SOD保留活性在pH=6～8时较高。     

氨基酸类表面活性剂的抗菌活性研究

研究了几种新合成的两性表面活性剂对几种微生物的抗菌活性，并研究了ｐＨ值，分子结构及Ｃａ＾２＋浓度对其抗菌活性的影响。     

表面活性剂对液体蛋白酶活性的影响

研究了常用表面活性剂LAS、AES、AOS、AEC、AEO9、MEE、TX 10、吐温80、APG等对液体蛋白酶活性的影响。结果表明:阴离子表面活性剂AEC的亲水基电荷强度较弱,与酶的作用最小,在考察条件下几乎不影响液体酶活性。非离子表面活性剂对液体蛋白酶酶活性影响不大;常用非离子表面活性剂AEO9与酶稳定剂共同作用,产生更强的稳定酶活性作用。LAS对酶活性的影响较大,但可以通过与AEO9等比例复配加以改善。     

混合表面活性剂的协同效应

不同类型表面活性剂的协同效应能够使原有表面活性剂的表面活性得到提高,甚至产生优异的性能及良好的经济效益。这种通过表面活性剂复配的协同效应来寻找新产品及寻找现有产品的新用途已越来越显示出其重要性。本文系统地介绍协同效应的基本理论和复配规律,以及此领域研究的一些新进展。     

两性表面活性剂（五）两性表面活性剂的生理活性

介绍了两性表面活性剂的生理活性,指出两性表面活性剂的毒性与非离子表面活性剂一样比离子型表面活性剂的低,甚至比乙醇的还要低,两性表面活性剂对高等生物的致突变作用不明显,但对低等生物却具有较强制 杀来作用,详细讨论他两性表面活性剂对皮肤和眼睛的刺激性,并指出利用两性表面活性剂对阴离子表面活性剂的争毒性是配制温和性配方的重要手段。     

用化学需氧量法测定表面活性剂活性物含量

通过对不同类型表面活性剂（SAA）在不同活性物含量下耗氧量（COD）的测定,SAA的活性物含量与COD存在线性关系,COD值随着活性物含量的增加而增大,且多组分SAA的活性物含量与COD的线性关系可以看成是多个单组分SAA的线性相加,表明,可以通过测定溶液COD值得到活性物含量。     

表面活性剂及其复配体系

本文主要介绍了表面活性的种类、特性以及复配方法。并着重介绍了复配体系的复配方法、性能以及应用用于学习交流。     

驱油表面活性剂界面活性的影响因素

国内大部分油田都进入到三次采油阶段,表面活性剂在油田上的应用越来越广泛。主要探索了矿化度、碱浓度、表面活性剂、复配活性剂、ASP复合驱油体系各组分及其协同效应等对界面张力的影响,考察了驱油体系经岩石吸附和热老化以后的界面张力特征。     

碱对阴-非离子表面活性剂的界面活性影响研究

以某油田作为油相,研究了不同浓度的碱(苛性碱与碳酸钠)与阴-非离子表面活性剂(AEC、AES)复配体系在55℃时与原油油水界面张力行为。首先通过阴-非离子表面活性剂与地层水的配伍性实验筛选合适的阴-非离子表面活性剂;然后通过碱与筛选出来的表面活性剂复配,研究不同浓度下碱对该表面活性剂的界面张力的影响效果。研究结果表明:0.01%~1.20%Na OH分别与0.1%AES和0.3%AEC组成的复配体系体系以及0.01%~1.20%Na2CO3分别与0.1%AES和0.3%AEC组成的复配体系体系能够产生一定的协同效应,使得油水界面张力逐渐降低,最终都能达到10-3m N/m的超低界面张力,而且在相同浓度的Na OH、Na2CO3下,含AES的复配体系要比含AEC的复配体系所得到界面张力低。考虑到碱耗以及对储集层伤害的影响,选择0.6%~1.2%Na2CO3与0.1%AES复配体系能更好的达到降低油水界面张力、提高油田采收率的目的。     

从大蒜萃余物中提取超氧化物歧化酶研究

通过对大蒜中优先提取超氧化物歧化酶(SOD)与超临界CO2萃取蒜油后提取SOD的对比实验,结果表明,从大蒜萃余物中提取的SOD相对于优先从新鲜大蒜中提取的SOD活力相差不到10%。说明萃余物仍有很大的利用价值。     

Serum levels of zinc and copper and erythrocyte superoxide dismutase activity in alcoholic patients

Serum Zn and Cu levels were measured in 18 chronic alcoholic patients, without clinical signs of hepatic failure, and in 10 control subjects. Low serum Zn levels were observed in the alcoholics, probably due to the low protein ingestion of these individuals. Unlike the control group, no correlation was found between serum Zn and albumin levels in the experimental subjects. High levels of dietary Cu, mostly derived from wine, resulted in hypercupremia in the alcoholic patients. No significant changes in the erthrocyte activity of superoxide dismutase were observed.     

Effects of natural oils and surfactants on cellulase production and activity

Emulsification of natural oils by a surfactant increases their efficiency as chemical antifoams. The presence of low concentrations of fatty acids or other surfactants have been reported to inhibit or stimulate microbial growth and/or product formation. The effects of different natural oils, Tween 80 and saponin on growth and cellulase production by T. reesei and S. pulverulentum have been investigated. It was found that in general, emulsification leads to higher cellulase activities in both cultures, though there are variations in enzyme levels depending on the presence or absence of Tween 80 and of different oils in growth media as well as the substrates used for cellulase assay.     

Purification and characterization of superoxide dismutase from garlic

An efficient and easily scaled up method to isolate superoxide dismutase from garlic is proposed. The separation and purification procedure consists of phosphate buffer extraction, heat treatment and a two-stage ultrafiltration process. The enzyme was purified 139-fold with a specific activity of 2867 U/mg protein and a yield of 91%. The native molecular mass of superoxide dismutase estimated by fast protein liquid chromatography on a Superose 6 column was 28 kDa. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed a single band near 14 kDa, suggesting that native enzyme was homo-dimeric. The optimal pH for enzyme activity was found to be 7.0, and at this pH the enzyme exhibited maximum activity at 50 °C in 50 mM sodium phosphate buffer. Among various metal ions examined, Cu²⁺ and Zn²⁺ exerted a positive effect on superoxide dismutase activity, whereas Hg²⁺ was found to be a strong inhibitor. The final purified enzyme had an isoelectric point of 5.1-5.4 and a sheet content of 46%, consistent with the literature values. This shows that the purified SOD folded with a reasonable secondary structure.     

Manganese superoxide dismutase: guardian of the powerhouse

The mitochondrion is vital for many metabolic pathways in the cell, contributing all or important constituent enzymes for diverse functions such as β-oxidation of fatty acids, the urea cycle, the citric acid cycle, and ATP synthesis. The mitochondrion is also a major site of reactive oxygen species (ROS) production in the cell. Aberrant production of mitochondrial ROS can have dramatic effects on cellular function, in part, due to oxidative modification of key metabolic proteins localized in the mitochondrion. The cell is equipped with myriad antioxidant enzyme systems to combat deleterious ROS production in mitochondria, with the mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD) acting as the chief ROS scavenging enzyme in the cell. Factors that affect the expression and/or the activity of MnSOD, resulting in diminished antioxidant capacity of the cell, can have extraordinary consequences on the overall health of the cell by altering mitochondrial metabolic function, leading to the development and progression of numerous diseases. A better understanding of the mechanisms by which MnSOD protects cells from the harmful effects of overproduction of ROS, in particular, the effects of ROS on mitochondrial metabolic enzymes, may contribute to the development of novel treatments for various diseases in which ROS are an important component.     

牛血超氧化物歧化酶的纯化

比较了几种初步纯化超氧化物歧化酶方法,并进行了优化组合。研究了用软基质阴离子交换柱（ＤＥＡＥ－ＳｅｐｈａｒｏｓｅＣＬ－６Ｂ）和凝胶柱（Ｓｅｐｈａｒｏｓｅ６Ｂ）分离纯化ＳＯＤ的工艺条件。利用建立的方法纯化了来自牛血的超氧化物歧化酶,整个工艺过程总活性回收率为６５％。比活为５４２３ｕ／ｍｇ,纯化倍数提高至６１．６倍。     

磁性壳聚糖复合微粒固定化SOD的研究

制备了磁性壳聚糖复合微粒(Fe3O4/CS),并以Fe3O4/CS为载体固定了超氧化物歧化酶(Superoxide Dismutase,SOD)。研究了温度、pH、储存时间、操作次数等对固定化SOD和游离SOD活性的影响。研究结果表明,固定化SOD的热稳定性、pH稳定性、储存稳定性等性能明显优于游离SOD,固定化SOD的操作稳定性良好。研究了固定化SOD和游离SOD的半衰期t1/2和动力学性质。固定化SOD的半衰期t1/2,1=35.7 d,游离SOD的半衰期t1/2,2=8.8 d;固定化SOD的米氏常数Km,1=0.04 mmol/L,最大反应速率Vm,1=40.19 mmol/min,游离SOD的米氏常数Km,2=0.19 mmol/L,最大反应速率Vm,2=85.76 mmol/min。