Kinetics of acetyl CoA: Arylamine N‐acetyltransferase from rapid and slow acetylator fish tissues

N‐acetyltransferase (NAT) activity was determined in 100 fish (Oreochromis mossambicus) livers using 2‐aminofluorene and p‐aminobenzoic acid as substrates. Overall, the liver NAT activity of the 50 females was higher than the liver NAT activity of the 50 males. The activities (mean ± SD) of NAT from kidney, blood, intestine, and liver of males was 0.42 ± 0.11, 0.12 ± 0.03, 0.12 ± 0.08, and 1.56 ± 0.54 nmol/min/mg protein for the acetylation of 2‐aminofluorene and 0.36 ± 0.09, 0.09 ± 0.01, 0.11 ± 0.04, and 0.46 ± 0.15 nmol/min/mg protein for the acetylation of p‐aminobenzoic acid. In kidney, blood, intestine, and liver from female fish, the activities obtained were 1.60 ± 0.12, 0.35 ± 0.07, 0.15 ± 0.09, and 1.89 ± 0.50 nmol/min/mg protein for 2‐aminofluorene and 0.95 ± 0.11, 0.27 ± 0.03, 0.13 ± 0.09, and 0.57 ± 0.12nmol/min/mg protein for p‐aminobenzoic acid. Kinetic constants for arylamine N‐acetyltransferase activity in kidney, blood, intestine, and liver from fish with rapid, intermediate, and slow acetylator activity were determined. Apparent K _m and V _max values for 2‐aminofluorene were 5.5 and 7‐fold higher for liver than for the other tissues. Apparent K _m and V _max values for p‐aminobenzoic acid were 3.5 and 4.7‐fold higher for liver than for the other tissues. Based on the 2‐aminofluorene NAT activity of liver, there appears to be a polymorphism in NAT activity with 16 rapid, 28 intermediate, and 56 slow acetylators among the 100 fish assayed. This is the first demonstration of acetyl CoA: arylamine N‐acetyltransferase activity in fresh water fish and could lead to the development of a fish model for monitoring the effect of pollution of water environments on native species.     

基于RS与GIS混合编程的公路水毁灾情信息提取

研究了基于高分辨率卫星遥感影像的公路水毁灾情信息提取模型,通过解决跨软件环境的开发问题,实现了基于遥感与地理信息系统混合编程的公路水毁灾情信息提取系统。使用高分辨率卫星遥感数据形成融合数据,通过分析融合图像的光谱、几何、纹理特征,建立了公路信息提取规则,构建了面向对象的公路信息提取模型。根据水在近红外和中红外波长范围内反射率极低的特性,同时考虑不同环境背景造成的信息提取复杂性,研究了具有自适应特点的水面提取模型。通过建立组件式地理信息系统和遥感应用环境之间的通信和数据共享机制,实现了模型运行的交互式用户界面,并提供叠置空间分析功能,从灾后公路边界提取结果中去除水面部分,获得公路水毁信息。实际应用表明,系统可以满足相关工作对公路水毁灾情信息提取技术的要求。     

电动力修复铅镉复合污染土壤

采用电动力修复技术处理Pb、Cd复合污染土壤,考察了柠檬酸和乙二胺四乙酸二钠（EDTA）作为电解液对棕壤（ZR）和红壤（HR）两种我国典型壤质中Pb、Cd去除效果的影响。实验结果表明：在电压梯度为2 V/cm,修复时间为4 d的条件下,ZR的最佳电解液为EDTA,Pb、Cd平均去除率为13.2%和17.8%,HR的最佳电解液为柠檬酸,Pb、Cd的平均去除率为20.0%和33.8%;延长修复时间至10 d能显著提高HR中Pb、Cd的去除率,电解液为柠檬酸时Cd平均去除率达91.1%,电解液为EDTA时Pb平均去除率达63.2%,修复后土壤中Cd和Pb含量均低于建筑用地土壤污染风险筛选值。综合考虑能耗及修复效果,EDTA是高效且经济的修复电解液。     

The first monoclonal antibody-based,matrix-resistant immunoassay for the carbamate herbicide asulam,in water

To date, no ligand binding assay has been described for the carbamate herbicide asulam, although a variety of physical methods, dependent on pre-concentration of water samples, have been documented for its assessment. However, asulam is increasingly used in sensitive agricultural areas, and statutory regulations concerning its monitoring will undoubtedly become more stringent. Antibodies are optimal partners in ligand binding assays, but it is commonly understood by immunological researchers that where no antibody reactive with a particular antigen has yet been described, the immunogenicity of the antigen may be particularly restricted. By the expedient of employing a specialised approach to final immunisation with an asulam-protein conjugate, prior to the immortalisation of a specific anti-asulam antibody-producing cell, we have succeeded in generating a monoclonal antibody reactive specifically with asulam that can be configured in a convenient immunoassay. This antibody may be used flexibly in a number of ways: small sample volumes of 10 microl can be assessed to sensitivities of 4.35 x 10(-7) M (10 microg L(-1)) while avoiding discrepancies contributed by the assay matrix; this antibody-based assay can also be formatted to deliver sensitivities at levels stipulated by regulatory authorities (e.g., 4.35 x 10(-9) M or 0.1 microg L(-1)) directly from a water sample, without prior pre-concentration.     

Transfer of dioxin risk between nine major municipal waste incinerators in Taiwan

The objective of this study was to assess site-specific carcinogenic risks of incinerator-emitted dioxins and risk transfers among the areas covered by nine municipal incinerators in Taiwan. We used actual emission data and the industrial source complex short-term model (ISCST3) to determine the dioxin impact areas within the 8 x 8-km simulation regions surrounding the incinerators. We then used multimedia model to estimate cancer risks in individual impact areas for two exposure scenarios, which were sufficient (SFP) and insufficient food production (IFP) for residents' consumption in each impact area. We also used information of food supply and consumption between impact areas to calculate risk transfers among these nine incinerators. We found that dioxins' carcinogenic risks ranged from 1.4 x 10(-8) (Incinerator F) to 7.1 x 10(-5) (Incinerator A) for the nine incinerators under the exposure scenario of SFP, and ranged from 8.7 x 10(-8) (Incinerator D) to 1.1 X 10(-6) (Incinerator E) under the exposure scenario of IFP. The food ingestion was the main exposure pathway, which accounted for 64-99% of total dioxin risks among nine impact areas. For the nine major food items consumed by residents in the impact areas, eggs (14-35%) and chicken (11-26%) were two main routes of dioxin exposure in the SFP scenario, while chicken (8-78%) and vegetables (0.2-81%) were two main routes of dioxin exposure in the IFP scenario. Significant risks of dioxins were transferred among incinerators, which accounted for up to 88% among the incinerators. Incinerator E was the major risk-exporting source to six Incinerators C, D, F, G, H, and I. For these six incinerators, Incinerator E accounted for their 51-88% imported risks. We concluded that risk transfers among incinerators through routes of food consumption should be considered in assessing health risks associated with incinerator-emitted dioxins in Taiwan. We should place high priority on implementing control measures to lower dioxin emissions in important food-exporting areas like Incinerator E. We should also emphasize analyzing dioxin contents in eggs, chicken, and vegetables in order to improve dioxin-related health risk assessments in the future.     

Photocatalytic degradation of Rhodamine B bymicrowave-assisted hydrothermal synthesized N-doped titanate nanotubes

Microwave-induced nitrogen-doped titanate nanotubes（NTNTs） were characterized by transmission electron microscopy（TEM）, X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, Fourier transform infrared spectroscopy（FT-IR）, Zeta potential analysis,specific surface area（SBET）, and UV-Visible spectroscopy. TEM results indicate that NTNTs retain a tubular structure with a crystalline multiwall and have a length of several hundred nanometers after nitrogen doping. XRD findings demonstrate that the crystalline structure of NTNTs was dominated by anatase, which is favored for photocatalytic application. The Ti-O-N linkage observed in the XPS N 1s spectrum is mainly responsible for narrowing the band gap and eventually enhancing the visible light photoactivity. FT-IR results demonstrated the existence of H3O＋, which could be excited by photo-generated holes to form hydroxyl radicals and degrade environmental pollutants. After sintering at 350°C, the UV-Vis absorbance edges of NTNTs significantly shift to the visible-light region, which indicates N atom doping into the nanotubes. Photocatalytic degradation of Rhodamine B（RhB） via NTNTs show good efficiency, with pseudo first-order kinetic model rate constants of 3.7 × 10-3, 2.4 × 10-3and 8.0 × 10-4sec-1at pH 3, 7, and 11, respectively.     

Review of the progress in preparing nano TiO2: An important environmental engineering material

TiO2 nanomaterial is promising with its high potential and outstanding performance in photocatalytic environmental applications, such as CO2 conversion, water treatment, and air quality control. For many of these applications, the particle size, crystal structure and phase,porosity, and surface area influence the activity of TiO2 dramatically. TiO2 nanomaterials with special structures and morphologies, such as nanospheres, nanowires, nanotubes, nanorods,and nanoflowers are thus synthesized due to their desired characteristics. With an emphasis on the different morphologies of TiO2 and the influence factors in the synthesis, this review summarizes fourteen TiO2 preparation methods, such as the sol–gel method, solvothermal method, and reverse micelle method. The TiO2 formation mechanisms, the advantages and disadvantages of the preparation methods, and the photocatalytic environmental application examples are proposed as well.     

Extraction of 17β-estradiol in water using non-imprinted polymer submicron particles in membrane filters

17β-Estradiol (E2) is an endocrine disrupting chemical of harm to both animals and human beings at a low concentration level (ng/L). It cannot be completely removed by wastewater treatments, and is often detected in both environment and drinking waters. The purpose of this feasibility study, towards environmental engineering in the field of water analysis and treatment, was to remove E2 by extraction using non-imprinted polymer (NIP) submicron particles. Experimental results showed that 0.5 mg/L of E2 could be completely extracted by adding 10 mg of NIP particles directly into 10 mL of water. However, the extraction efficiency decreased to 64% for 100 mL of water. prefilling the NIP particles inside a membrane filter showed a potential for water treatment of a large volume, requiring no effort to distribute the particles uniformly in the water. High extraction efficiency (80 ± 10)% for E2 was achieved for 100 mL of water. A total mass of 0.29 mg E2 was extracted from 1000 mL of water containing 0.8 mg/L E2 (by using only 10 mg of NIP particles). Both efficiency and mass capacity can be increased, by scaling up the amount of NIP particles, towards environmental engineering applications.     

Extraction of 17p-estradiol in water using non-imprinted polymer submicron particles in membrane filters

17β-Estradiol (E2) is an endocrine disrupting chemical of harm to both animals and human beings at a low concentration level (ng/L).It cannot be completely removed by wastewater treatments,and is often detected in both environment and drinking waters.The purpose of this feasibility study,towards environmental engineering in the field of water analysis and treatment,was to remove E2 by extraction using non-imprinted polymer (NIP) submicron particles.Experimental results showed that 0.5 mg/L of E2 could be completely extracted by adding 10 mg of NIP particles directly into 10 mL of water.However,the extraction efficiency decreased to 64% for 100 mL of water.prefilling the NIP particles inside a membrane filter showed a potential for water treatment of a large volume,requiring no effort to distribute the particles uniformly in the water.High extraction efficiency (80±10)% for E2 was achieved for 100 mL of water.A total mass of 0.29 mg E2 was extracted from 1000 mL of water containing 0.8 mg/L E2 (by using only 10 mg of NIP particles).Both efficiency and mass capacity can be increased,by scaling up the amount of NIP particles,towards environmental engineering applications.     

煤层对CO_2处置能力评价的修正方法与应用

煤等温吸附气体实验中的煤体变形效应会造成CO2在煤层中吸附量评价结果的偏差,通过对气体吸附模拟方法进行修正,应用修正的Langmuir和Dubinin-Astakhov模型对CO2、CH4吸附实验结果进行重新拟合,获得准确的吸附量计算方法。结果表明,吸附实验中煤主要表现为膨胀变形,且煤吸附CO2的膨胀量高于吸附CH4的膨胀量,煤膨胀造成CO2实测过剩吸附量较真实过剩吸附量偏低4.4%~43.8%,修正后CO2吸附拟合效果大大提高,Langmuir和D-A模型拟合曲线与实测数据吻合的相关系数分别从0.978、0.995提高到修正后的0.997、0.999,D-A模型对CO2吸附数据的拟合效果优于Lang-muir模型,CH4吸附模拟效果的改善程度不及CO2。