X60钢在CO2饱和盐水中缓蚀作用的研究

本文采用动电位极化、线性极化、电偶电流和高压釜挂片失重等法,研究了含氮、硫有机缓蚀剂和/或Me~(2+)对X60钢在CO_2饱和的盐水溶液中的缓蚀作用。结果表明,含氮、硫的有机缓蚀剂在缓蚀过程中,开始是以抑制阳极过程为主,随后是以抑制阴极过程为主的混合型缓蚀剂。如与Me~(2+)复配使用,能明显地提高缓蚀效能。     

A Screening Procedure for Heavy Metals in Soil Extracts by Alcohol Dehydrogenase and Urease Inhibition Eine Screening-Methode für Schwermetalle in Extrakten aus Bodenproben,basierend auf der Inhibierung der Enzyme Alkoholdehydrogenase und Urease

A screening method for heavy metals in aqueous extracts of soil is presented which is based on inhibition of the enzymes urease and alcohol dehydrogenase. The method is suitable to detect cupric and mercury ions in concentrations below 0.01 mg/L and several other heavy metal ions in 1000 fold higher concentration. It is shown that the test may be used for screening of mercury ion concentrations exceeding 0.03 mg/L in aqueous solution when copper chelators are added to the test system. The usefulness of the presented tests to detect heavy metals eluted from soil was verified with samples from ore mining waste. The concentration of copper, lead, and zinc eluted from these samples to different amount was determined by atomic absorption spectrometry and was in good agreement with the enzyme inhibition data obtained with these samples.     

Urease-Hemmtest für wirkungsbezogene Untersuchungen der Bindungsformen von Kupfer in Wässern und Bodeneluaten

Urease Inhibition Test for Effect-related Investigations of Copper Speciation in Water and Soil Extracts In 80 different water samples, the inhibition effect of cupric ions was measured by application of a simple urease inhibition test. In relation to the total copper concentration, the inhibition permits an effect-related classification of drinking water, rain water, spring water, surface water, leakage water, wastewater, and soil extracts. Drinking water contains high parts of cupric ions in the free hydrated form. Their copper content results in high urease inhibition and is caused by using copper pipes in house plumbing. In leakage water, wastewater, and soil extracts, cupric ions are mainly complexed by organic compounds in the sample matrix. Hence, the inhibition effects are low. In soil extracts, the urease inhibition increased after an UV-decomposition procedure, but a decreasing effect was observed for a surface and a drinking water sample, respectively. The chemical oxygen demand and UV-absorbance at 255 nm measured before and after the procedure were correlated to the content of organic compounds, i.e., humic acid. In most samples, the organic matrix was not decomposed completely. The oxidizing decomposition apparently forms further complexing agents, which suppress the inhibition effect of cupric ions. In the rain water samples investigated, the content of organic compounds depended on rain intensity. The chemical oxygen demand and UV-absorbance, respectively, were low for rain water collected during strong rain periods and increased with decreasing rain intensity. The rain water trickled over sheet-lead roof showed an increase of urease inhibition compared with the simultaneously collected rain. Consequently, a decomposition of organic matrix could be demonstrated in rain water by use of the urease inhibition test.     

Toxicity-directed Fractionation of Tannery Wastewater Using Solid-phase Extraction and Luminescence Inhibition in Microtiter Plates

A four-step solid-phase extraction (SPE) method is presented for toxicity-directed fractionation of industrial wastewater. This fractionation procedure serves as a key step for identifying unknown organic toxicants in complex samples. Toxicity was determined as luminescence inhibition of Vibrio fischeri using microtiter plates. This method was compared to standard tests in glass cuvettes using both 37 standard chemicals and 24 wastewater fractions with EC₅₀ values covering five orders of magnitude. Results of both methods correlated well. 22 tannery wastewater samples were sequentially extracted using C₁₈e and polystyrene-divinylbenzene phases in combination with pH-changes. Final solid-phase filtrates showed low inhibition, so toxicity of inorganics could be neglected. Using 1/EC₅₀ values, the SPE eluates showed clearly different toxicity patterns. Even in eluates of the fourth extraction step, high toxic effects could be observed. In several cases, luminescence inhibition was increasing at the anaerobic treatment step compared to the corresponding untreated samples. After aerobic treatment, toxicity of most wastewater fractions was greatly diminished. HPLC/DAD analyses of the wastewater fractions showed a fair separation concerning compound polarity. However, the samples were still too complex to identify single compounds responsible for the detected toxicity. Therefore, a further clean-up step accompanied with toxicity testing is needed.     

Gewässergütebewertung und Bewertung von Abwasserfahnen in Rhein und Main auf der Basis mikrobieller Enzymaktivitäten

Quality Mapping of Surface Water and Assessment of Treated and Untreated Waste-water Inputs into the Rhine and Main River Based on Microbial Enzyme Activities Microbial enzyme activities are used for an extension of the traditional quality mapping of surface water. In the following study, the enzymatic parameters were proved and validated on samples from various creeks and rivers in Baden-Württemberg and on samples gathered from the Rhine and Main Rivers (Germany). The test parameters should also be used for the control and the preservation of the capacity of the biological self-purification, which is the only natural and essential process in drinking-water conditioning of surface water. Main subject of the surveys was the development of criteria for an assessment of the measured enzymatical inhibition effects. Therefore, classes of inhibition and indices of inhibition are defined.     

化感物质抑制短裸甲藻的机理研究

文章通过研究邻苯二甲酸二丁酯(DBP)对短裸甲藻的活性氧自由基(ROS,主要为H_2O_2)水平、过氧化标志产物丙二醛(MDA)含量以及对细胞亚显微结构的影响,初步揭示DBP抑制短裸甲藻的机理,为沿海赤潮的控制和有效防治提供有力的支持。研究结果表明,DBP通过引起短裸甲藻细胞内活性氧自由基的过度积累而引起膜质过氧化,与不添加DBP的对照组相比,在低浓度DBP(0.1mg/L)的影响下,H_2O_2含量前48h变化比较平稳,48h以后逐渐下降。而在高浓度DBP(10mg/L)的影响下,H_2O_2含量变化波动明显,暴露72h后,H_2O_2含量达到248.24nmol·(10~7cells)~(-1),约是对照组的4.67倍。过氧化标志产物MDA在低浓度DBP(0.1mg/L)处理后暴露24h分别出现峰值0.23μmol·(10~9cells)~(-1)、0.28μmol·(10~9cells)~(-1),高浓度DBP(10 mg/L)处理MDA含量24h后持续上升,72h时高达0.351μmol·(10~9 cells)-1,约是对照组的2.32倍。同时DBP可以引起短裸甲藻细胞结构受损,表现在叶绿体、线粒体等细胞器变模糊,细胞空泡化,原生质膜皱缩,细胞脂质体(黑色颗粒)明显增多等,初步认为过氧化损伤为化感物质作用机理。     

Sample preparation methods for quantitative detection of DNA by molecular assays and marine biosensors

The need for quantitative molecular methods is growing in environmental, food, and medical fields but is hindered by low and variable DNA extraction and by co-extraction of PCR inhibitors. DNA extracts from Enterococcus faecium, seawater, and seawater spiked with E. faecium and Vibrio parahaemolyticus were tested by qPCR for target recovery and inhibition. Conventional and novel methods were tested, including Synchronous Coefficient of Drag Alteration (SCODA) and lysis and purification systems used on an automated genetic sensor (the Environmental Sample Processor, ESP). Variable qPCR target recovery and inhibition were measured, significantly affecting target quantification. An aggressive lysis method that utilized chemical, enzymatic, and mechanical disruption enhanced target recovery compared to commercial kit protocols. SCODA purification did not show marked improvement over commercial spin columns. Overall, data suggested a general need to improve sample preparation and to accurately assess and account for DNA recovery and inhibition in qPCR applications.     

11种天然药物对弧菌的体外抑制效果的观察

于１９９１年３－４月应用纸片法定量测定了海洋及陆地来源的１１种天然药物提取物地中国对虾的主要致病菌－弧菌的体外抑制效果，结果表明，对弧菌高度敏感的药物有５种，中度敏感的药物有３种，不敏感药物有３种，并且５种高度敏感药物的抑菌效果均优于绝大多数抗菌素。为在对虾养殖中选择高效，低毒的天然抗菌药物提供科学依据。     

Kinetics of ammonia and ammonium ion inhibition of the atmospheric oxidation of aqueous sulfur dioxide by oxygen

This is the first study, which shows both NH₃ and NH₄⁺ to inhibit the autoxidation of aqueous SO₂ in the pH range 7.0–8.5. The rate of the autoxidation, R _aut , in both buffered and unbuffered media at a fixed pH is in conformity with the rate law: