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1.
Cd和表面活性剂复合污染对小麦叶片若干生理状性的影响   总被引:18,自引:7,他引:11  
研究了溶液培养条件下Cd-直链十二烷基苯磺到钠(LAS)、Cd-二六烷基三甲基溴化铵(CTAB)和Cd-聚氧乙烯山梨醇月桂酸酯(Tween-80)3种复合污染对小麦生理状态的影响。结果表明,表面活性剂促进Cd在小麦叶中的积累,其效应顺序为CTAB〉LAS〉Tween80.Cd和表面活性剂复合污染条件下,小麦叶中Cd的大量积累导致的细胞膜脂过氧化水平大大高于单纯Cd污染下的水平。细胞中SH基含量降低  相似文献   

2.
利用顺磁性自旋标记技术,探测在表面活性剂CHAPS(3-〔(3-Cholamidopropyl)dimethyl-ammonio〕propanesulfonic acid)作用下,紫膜脂双层微环境的物理参数(序参数S和旋转相关不同。表层序参数S值随CHAPS浓度的增加而逐渐减小;深层旋转相关时间τc值开始随CHAPS浓度的增加而增大,在CHAPS浓度为5mmol/L时,τc值呈现最大值,随着CHA  相似文献   

3.
黑曲霉产木聚糖酶发酵条件的研究   总被引:17,自引:0,他引:17  
正交设计试验结果表明,黑曲霉(Aspergillus niger m12)产木聚糖酶活力达76.60u/ml,合适的产酶发酵条件如下,培养基(g/L):麸皮40,尿素6.67,KH2PO4 1.0,MgSO4.7H2O0.5,NaCl0.3,Tween-80 3.0,CaCO3 2.0,28℃,120r/min水浴振荡培养5.5d。  相似文献   

4.
三唑酮对绿豆幼苗叶片衰老的延缓作用   总被引:26,自引:0,他引:26  
三唑酮处理可提高离体绿豆(PhaseolusradiatusL.)幼苗叶片叶绿素和蛋白质含量。叶片衰老过程中超氧物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(AsAPOD)活性及抗坏血酸(AsA)和还原型谷胱甘肽(GSH)含量降低。20mg/L三唑酮可提高POD、AsAPOD活性和AsA、GSH含量,对SOD、CAT活性无影响。丙二醛(MDA)含量在叶片衰老过程中提高,并与POD、AsAPOD活性和AsA、GSH含量呈显著负相关,三唑酮可降低MDA含量。表明三唑酮有提高植物对膜脂过氧化作用的保护能力,延缓叶片的衰老作用。  相似文献   

5.
动脉平滑肌细胞(SMC)的增殖在动脉粥样硬化(AS)的形成过程中极其重要。我们在建立人主动脉SMC体外培养方法的基础上,观察了LDL,VLDL及HDL和相应的氧化修饰型脂蛋白对培养人SMCsis,jun,H-ras原癌基因及Rb抗癌基因转录表达的影响。结果表明:(1)HDL对SMCsis,jun,ras基因表达无影响;(2)LDL和VLDL有使这些基因表达增加的趋势;(3)ox-LDL,ox-VLDL和ox-HDL具有使SMCsis,jun,和ras基因表达显著增强的作用(P<0.01),且其作用较相应的天然脂蛋白大(P<0.01);(4)天然和氧化修饰型脂蛋白对Rb基因表达均无影响。据上述结果推测:LDL,VLDL,ox-LDL,ox-VLDL和ox-HDL的致AS作用可能与刺激SMCsis,jun和ras原癌基因表达增加有关。  相似文献   

6.
动脉平滑肌细胞(sm ooth m uscle cell,SMC)是动脉粥样硬化(atherosclerosis,AS)斑块中的主要细胞,它的增殖在AS形成过程中极其重要.利用体外培养的人主动脉SMC,观察了天然高密度脂蛋白(native high density lipoprotein,N-HDL)及氧化修饰HDL(oxidized HDL,OX-HDL)对培养人主动脉SMC cyclin D1(细胞周期蛋白D1)基因转录表达的影响.结果表明:(1)N-HDL对SMCcyclin D1基因表达无影响(P> 0.05);(2)OX-HDL使SMCcyclin D1基因表达显著增强(P<0.01),其表达量随时间(2、12、24 h)延长而增加.上述结果表明,OX-HDL的致AS作用可能与其刺激SMCcyclin D1基因表达增加有关.  相似文献   

7.
钙对水稻幼苗抗冷性的影响   总被引:3,自引:0,他引:3  
CaCl2浸种提高水稻幼苗叶片中结合态钙、内源抗氧化剂(GSH、AsA)含量和膜保护酶(CAT、SOD和POD)活性,也增加可溶性蛋白质中煮沸稳定蛋白质(boiling-stableprotein)的含量。冷胁迫期间,CaCl2并能减少因冷胁迫引起的GSH、AsA含量,CAT、SOD和POD活性以及煮沸稳定蛋白质下降的程度。在恢复期间,经CaCl2处理的幼苗其GSH、ASA、CAT、SOD和POD以及煮沸稳定蛋白质水平均有回升。  相似文献   

8.
动脉平滑肌细胞(SMC)是动脉粥样硬化(AS)斑块中的主要细胞,它的增殖在AS形成过程中极其重要。脂蛋白和氧化修饰型脂蛋白对SMC增殖的影响以及SMC增殖与原癌基因异常表达的关系是当前AS发病机制研究的热点之一。我们在建立人主动脉SMC体外培养方法的基础上,观察了LDL,VLDL及HDL和相应的氧化修饰型脂蛋白对培养人SMCfos,myc,erb-B原癌基因转录表达的影响。结果表明:①HDL对SMCfos,myc基因表达无影响;②LDL和VLDL有使这些基因表达增加的趋势,但与对照比较差异不显著(P>0.05);③OX-VLDL,OX-VLDL和OX-HDL有使SMCfos,myc基因表达显著增强的作用(P<0.01),且其作用较相应的天然脂蛋白大(P<0.01).上述结果说明:LDL,VLDL,OX-LDL,OX-VLDL和0X-HDL的致AS作用可能与刺激SMCfos和myc癌基因表达增加有关。  相似文献   

9.
峨眉山艾纳香属一新种   总被引:2,自引:0,他引:2  
祝正银   《广西植物》1997,17(1):16-18
峨眉山艾纳香属一新种祝正银(四川省中药学校,四川峨眉山614201)ANEWSPECIESOFBLUMEAFROMEMEISHANZhuZhengyin(SichuangcholofChineseMateriaMedica,Emeishan,Sich...  相似文献   

10.
从人正常胸主动脉分离硫酸乙酰肝素蛋白聚糖(HSPG),观察其对体外培养的人主动脉平滑肌细胞(HASMC)合成PG的影响。HASMC在不加(对照)或加HSPG(19μg醛酸/ml)的 ̄(35)S-硫酸钠培养液中培养,以标记PG。继之,培养液及细胞层的4mol/L盐酸胍提取液中的PGs经离子交换及凝胶过滤柱层析分离,发现加HSPG后,培养液中的HSPG,硫酸软骨素PG(CSPG)及硫酸皮肤素-硫酸软骨素PG(DSCSPG)均明显增高,而细胞层中仅HSPG和CSPG增高,且加HSPG后细胞层的DSCSPG分子大小有所不同,进一步分析DSCSPG中DS及CS含量发现加HSPG组HASMC细胞层中的DS%含量略低于对照组。结果提示HSPG可刺激HASMC的PG合成,其可能与血管壁修复及动脉壁脂质沉积有关。  相似文献   

11.
The interactions between the polysaccharide alginate with charged ionic surfactants (anionic and cationic) in aqueous solution have been investigated using pyrene as a photophysical probe. Static fluorescence determinations have been used to obtain information about the new microenvironments arising by these interactions. Micropolarity studies using the I(1)/I(3) ratio of the vibronic bands and I(E)/I(M) ratio between the excimer and monomer emissions of pyrene shows the formation of hydrophobic domains. The interactions between the natural polyelectrolytes and the oppositely charged surfactants lead to the formation of pre-micelles at surfactant concentrations lower than the CMC of the surfactants. The aggregation process is assumed to be due to electrostatic attraction. On the other side, systems containing an anionic surfactant do not show the same behaviour at low concentrations.  相似文献   

12.
A variety of commercial surfactants were tested to determine their effect on polychlorinated biphenyl (PCB) transformation by Pseudomonas LB400. Initial tests determined that most surfactants were fully or partially able to solubilize the PCB congeners 2,5,2′-chlorobiphenyl (CBP), 2,4,2′,4′-CBP, 2,3,5,2′,5′-CBP and 2,4,5,2′,4′,5′-CBP, at concentrations above the surfactants' critical micelle concentration (CMC). Surfactants were also found to have no negative effect on bacterial survival, as cell numbers were the same or higher after incubation in the presence of surfactants than after incubation without surfactants. A comparison of the extent of biotransformation of single PCB congeners by the bacterium revealed that, at surfactant concentrations above the CMC, the presence of an anionic surfactant promoted while nonionic surfactants inhibited PCB transformation, compared to a control with no surfactant. The rates of transformation of PCB congeners were also higher in the presence of the anionic surfactant compared to the control. The inhibitory effects of a nonionic surfactant, Igepal CO-630 at a concentration above its CMC, on transformation of 2,4,5,2′,5′-CBP could be eliminated by diluting the surfactant/PCB solution to a concentration close to the surfactant CMC. Received: 26 October 1998 / Received revision: 5 March 1999 / Accepted: 14 March 1999  相似文献   

13.
Four surfactants were tested at five concentrations to determine their abilities to solubilize soil-adsorbed pyrene. Inoculation with pyrene degraders in the presence of the surfactant Witconol SN70 was the most effective treatment for pyrene mineralization (46 to 80%) under unsaturated conditions, but the surfactant inhibited the effectiveness of these inoculants in soil slurries.  相似文献   

14.
Nonionic and ionic surfactants diminish the initial rate of proteolysis of aqueous bovine serum albumin (BSA) by subtilisin Carlsberg. Surfactants studied include: nonionic tetraethylene glycol monododecyl ether (C12E4); anionic sodium dodecyl sulfate (SDS), anionic sodium dodecylbenzenesulfonate (SDBS), and cationic dodecyltrimethylamonium bromide (DTAB). Kinetic data are obtained using fluorescence emission. Special attention is given to enzyme kinetic specificity determined by fitting initial-rate data to the Michaelis-Menten model. All surfactants reduce the rate of proteolysis, most strongly at concentrations near and above the critical micelle concentration (CMC). Circular dichroism (CD), tryptophan/tyrosine fluorescence spectra, and tryptophan fluorescence thermograms indicate that BSA partially unfolds at ionic surfactant concentrations near and above the CMC. Changes in BSA conformation are less apparent at ionic surfactant concentrations below the CMC and for the nonionic surfactant C12E4. Subtilisin Carlsberg activity against the polypeptide, succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, decreased due to enzyme-surfactant interaction. At the concentrations and time frames studied, there was no enzyme autolysis. Importantly, aqueous proteolysis rates are significantly reduced at high surfactant concentrations where protein-micellar-surfactant aggregates occur. To explain the negative effect of surfactant on subtilisin Carlsberg proteolytic activity against BSA, we propose that micelle/protein complexes hinder enzyme access.  相似文献   

15.
The effects of the non-ionic surfactant Triton X-100, the cationic surfactant cetyltri-methylammonium bromide (CTAB) and the anionic surfactant sodium N-lauroyl sarcosinate (SLS) on the decolorization of the reaction medium containing the monoazo dye Acid Orange 7 (AO7) by Alcaligenes faecalis and Rhodococcus erythropolis were studied. It was found that the surfactants influenced in different ways the rate of decolorization. At all concentrations tested the non-ionic surfactant Triton X-100 decreased the decolorization rate of R. erythropolis. At concentrations above the critical micelle concentration (CMC) Triton X-100 upset the usually observed exponential decay of the dye with A. faecalis due probably to the existence of an outer membrane in this organism. In concentrations above the CMC the anionic surfactant SLS inhibited the decolorization and, at prolonged incubation, caused partial release of the bound dye. The cationic surfactant CTAB in concentrations above and below the CMC accelerated drastically the binding of AO7 to the cells causing a rapid staining of the biomass and complete decolorization of the reaction medium. An attempt was made for explanation of the observed differences by the negative electrostatic charge of the living bacterial cell.  相似文献   

16.
植物对水中菲和芘的吸收   总被引:14,自引:0,他引:14  
凌婉婷  高彦征  李秋玲  谢正苗  熊巍 《生态学报》2006,26(10):3332-3338
以菲和芘为多环芳烃(PAHs)代表物,采用水培体系研究了黑麦草(Lolium multiflorum Lam)对水中PAHs的吸收作用,重点研究了植物吸收菲和芘的时间动态.水中菲和芘起始浓度分别为1.00mg/L和0.12mg/L.0~288h内,黑麦草根和茎叶中菲和芘含量均先快速增加而后降低,积累量不断增大,植物根系和茎叶富集系数则先快速升高而后趋于稳定.茎叶中菲和芘含量、茎叶对菲和芘的富集系数比根低1~3数量级,积累量也明显小于根系.黑麦草根系对水中芘有更强的富集能力,其根系富集系数比菲大85%~179%;而其茎叶对菲的富集作用则略强.菲和芘在植物体内有明显的传导作用.0~288h,传导系数(TF)先显著升高而后趋于恒定;但实验条件下,菲和芘的TF值均很小,分别不高于0.031和0.009,且芘的TF值明显小于菲,表明供试植物对芘的传导能力更弱.  相似文献   

17.
The efficiency of several chemical treatments as potential enhancers of the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil was evaluated by analyzing the mineralization of 14C-labeled phenanthrene, pyrene, and benzo(a)pyrene. The effect of nonionic surfactants with Fenton oxidation and combinations of surfactants with the Fenton oxidation was evaluated in a microtiter plate assay. The surfactants selected for the study were Tween 80, Brij 35, Tergitol NP-10, and Triton X-100. The addition of Fentons reagent significantly enhanced the mineralization of pyrene at the two concentrations studied: 2.8 M H2O2 with 0.1 M FeSO4 and 0.7 M H2O2 with 0.025 M FeSO4. Phenanthrene mineralization was also positively induced by the Fenton treatments. However, none of the treatments had a significant effect on benzo(a)pyrene mineralization. Surfactant additions at concentrations of 20% and 80% of the aqueous critical micelle concentration did not significantly affect the mineralization rates. When surfactant addition was combined with the Fenton oxidation, reduced mineralization rates were obtained when compared with mineralization after Fentons treatment alone. The results indicate that the addition of Fentons reagent may enhance the mineralization of PAHs in contaminated soil, whereas the addition of surfactants has no significant beneficial effect. The efficiency of the Fenton oxidation may decrease when surfactants are added simultaneously with Fentons reagent to contaminated soil.  相似文献   

18.
表面活性剂对分枝杆菌KR2菌株降解菲的影响   总被引:2,自引:0,他引:2  
采用同位素示踪方法,从表面活性剂的浓度、离子类型和直链长度三方面研究了表面活性剂对分枝杆菌KR2菌株降解菲的影响。结果表明,表面活性剂的存在不能促进KR2菌对菲的降解;高浓度表面活性剂(≥20mg·L-1)的存在,使菲的降解出现延迟期,非离子表面活性剂Tween80在低浓度时(≤10mg·L-1)可以优先作为营养基质被分枝杆菌KR2菌株利用,表面活性剂的离子类型对菲降解的抑制作用的顺序为阳离子表面活性剂TDTMA>阴离子表面活性剂LAS>非离子表面活性剂Tween80,表面活性剂的直链长度对菲降解的影响为直链越短,对微生物的毒性越大,菲降解得越不完全。  相似文献   

19.
In arthropods, the determination of two important parameters of digestive juices, i.e. the total surfactant concentration and the critical micelle concentration (CMC), is challenging due to small sample volumes and low surfactant concentrations. In this work, we report a successful implementation of potentiometric titrations using the surfactant ion-selective electrode (SISE) and the pyrene fluorescence method (PFM) for the determination of the total surfactant concentration and CMC in the digestive juice of terrestrial isopod crustaceans Porcellio scaber. Pooled digestive juice extracts of four (SISE) or two (PFM) animals were used per measurement run. In both cases, digestive juice extracts in 100 μL of deionized water were sufficient for one measurement run. The total surfactant concentration of P. scaber digestive juice was determined to be 9.2 ± 3.5 mM and the CMC was approximately 90 μM. Our work presents an important improvement towards easy CMC determination in small volume samples in comparison with the commonly used stalagmometric technique, where much larger sample volumes are usually needed. To date, the total surfactant concentration was not measured in the digestive juices of arthropods other than Homarus vulgaris, Astacus leptodactylus and Cancer pagurus, for which complex separation and analytical techniques were required. Our results obtained by SISE and PFM therefore present the first successful quantification of surfactants and their CMC in small volumes of arthropod digestive juice without prior separation or purification techniques.  相似文献   

20.
Continuing our earlier study of the retention behaviour in reversed-phase systems with aqueous mobile phases containing surfactants in concentrations lower (submicellar systems) and higher (micellar systems) than the critical micellar concentration (CMC), we investigated the chromatographic behaviour of various non-ionic solutes in mixed aqueous-organic micellar and submicellar mobile phases and their dependence on the methanol concentration. CMC values were measured for two cationic surfactant and one anionic surfactant in mixed aqueous-methanolic solvents, and were found to increase slightly with increasing methanol concentration. Depending on the character of the surfactant, a limiting concentration of methanol was found, above which micelles do not occur anymore. Sorption isotherms of the surfactants on an octylsilica gel column were measured as a function of the concentration of methanol in aqueous-methanolic solvents. A modified Langmuir equation was used to describe the distribution of the surfactants between the stationary and the mobile phases in the concentration range below CMC. The retention of several polar solutes was measured on an octylsilica gel column both in micellar and submicellar mobile phases containing methanol. The dependencies of the capacity factors of the solutes studied on the concentration of methanol in the mobile phase can be suitably described by the same form of equation as that conventionally used for aqueous-organic mobile phases that do not contain surfactants, but the slopes of the dependencies for a given solute are different in the two ranges of surfactant concentrations. The ratio of the two slopes is controlled by the interaction with micelles and is approximately equal to, below or above 1, depending on whether the solutes do or do not associate with the micelles, or are repulsed from them. Simultaneous control of the concentrations of the organic solvent and of the surfactant in the mobile phase can be used for fine tuning the selectivity of separation as a complement to commonly used adjusting concentrations of two organic solvents in ternary aqueous-organic mobile phases. These effects are illustrated by practical examples of submicellar HPLC with mobile phases containing methanol.  相似文献   

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