基于实测高光谱数据的太湖悬浮物浓度与透明度分区

通过实地测量太湖水体的反射光谱和表层水质,利用实测数据以及水-气界面辐射传输模型计算其遥感反射率,并根据太湖的实际水质状况将其划分为3个区域,分别分析太湖总体和分区的反射光谱曲线,建立太湖不同区域水体悬浮物浓度和透明度的反演模型。结果表明,就悬浮物浓度和透明度而言,太湖3个区域中以东太湖水质最佳,贡湖、梅梁湖和竺山湖次之,南部和西部最差;对太湖进行分区研究能够更好地反应太湖水质的差异性,拟合各区域的水质状况,分区模型精度较全湖区模型高,误差也普遍较小,能够提高研究结果的可信度和可行性。     

再生水中弗氏柠檬酸杆菌生物膜特性研究

从使用再生水的某电厂冷却塔粘泥中分离出一株具有硫酸盐还原功能的弗氏柠檬酸杆菌.利用扫描电子显微镜（SEM）和能谱仪（EDS）对再生水中HSn70-1A和BFe30-1-1两种合金表面弗氏柠檬酸杆菌生物膜结构和成分进行表征,结果表明HSn70-1A成膜特性好于BFe30-1-1,两种合金表面生物膜中C、O等无机元素含量较...     

New cytochrome P450 1B1, 1C1, 2Aa, 2Y3, and 2K genes from Chinese rare minnow (Gobiocypris rarus): Molecular characterization,basal expression and response of rare minnow CYP1s and CYP2s mRNA exposed to the AHR agonist benzo[a]pyrene

Cytochrome P450 (CYP450) genes play an important role in catalyzing oxidative metabolism of toxicants. Recently, CYP1 subfamily were discovered and reported in fish, however, little is known regarding the CYP2 isoforms in fish. In the present study, the cDNA fragments of CYP 1B1 and 1C1 and CYP2Aa, 2Y3, and 2K of rare minnow were cloned and exhibited a high amino acid sequence identity compared with their zebrafish orthologs. Basal expression showed CYP1C1 and CYP 2Aa expression were observed in all eight tissues analyzed (liver, gill, intestine, kidney, spleen, brain, skin, and muscle). CYP 1A, and 1B1 expression was found in all tissues except for muscle and skin. However, CYP 2Y3 was expressed in liver, spleen, intestine and muscle whereas CYP 2 K in liver, kidney and intestine. 4 and 100 μg L⁻¹ Benzo[a]pyrene (BaP) induced patterns showed that CYP 1A, 1B1 and 1C1 expression in liver, gill, and intestine was strongly up-regulated (p < 0.05). Furthermore, CYP 2Y3 was strongly induced in liver from BaP treatments (p < 0.05). The high induction on mRNA level of CYP1s and CYP 2Y3 by BaP could be associated with catalyzing detoxification and indicated that CYP2s may also be potential biomarker to screen AHR agonist. The high responsiveness of CYP1 and 2 genes suggested Chinese rare minnow is feasible to screen and assess pollution with AHR agonist.     

Subacute effects of a phosphorothionate pesticide on mixed function oxidases of wistar rats

Abstract

Subacute oral toxicity of a newly developed phosphorothionate insecticide (2‐butenoic acid‐3‐(diethoxy‐phosphinothioyl) methyl ester), coded as RPR‐2, was studied in male rats by oral (multiple) intubation of low (0.014 mg kg^‐1 day^‐1), medium (0.028 mg kg^‐1 day^‐1), and high (0.042 mg kg^‐1 day^‐1) dose for 90 days. The medium and high dose produced toxic symptoms along‐with some mortality (20%) occurred in the high dose treated rats. The medium and high doses caused significant inhibition in cytochrome P‐450 activity in liver, lung, kidney and brain tissues at 45 and 90 days. The high dose caused significant decrease in cyt.b₅ activity of all the four tissues at 45 and 90 days. Whereas, medium dose brought such effect in liver and lung at 45 and 90 days. Kidney and brain cyt.b₅ activity decreased significantly at 90^th day due to medium dose. Low dose also caused inhibition in cyt.b₅ activity in brain at 90^th day. Cytochrome P‐450 reductase activity was decreased significantly in liver, lung, kidney and brain at 45 and 90^th by the medium and high dose. The results indicated that RPR‐2 had potential to modulate hepatic and extra‐hepatic cyt.P‐450 dependent monooxygenase system of rat due to subacute exposure. These metabolic alterations were quite reversible after 28 days withdrawal of treatment.     

An evaluation of the cytochrome P450 inhibition potential of selected pesticides in human hepatic microsomes

The goal of this work was to study the ability of 18 pesticides to inhibit selective model activities for all major xenobiotic-metabolizing enzymes, namely CYP1A1/2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4. Generally organophosphorus insecticides were the most potent and extensive inhibitors, especially towards CYP1A1/2 (IC₅₀ values of chlorpyrifos, fenitrothion and profenofos ～3 μ M), CYP2B6 (IC₅₀ values of chlorpyrifos and fenitrothion 2.5 μ M), CYP2C8 (fenitrothion 4.3 μ M), CYP2C9 (fenitrothion and malathion 4.8 and 2.5 μ M, respectively), CYP2D6 (chlorpyrifos and phenthoate ～ 3 μ M) and CYP3A4 (chlorpyrifos, fenitrothion and phenthoate 3–4 μ M). Otherwise there were quite considerable differences in potency and extent of inhibition between different organophosphates. Pyrethroids were in general very weak or inactive. Deltamethrin and fenvalerate were potent inhibitors of CYP2D6 (IC₅₀ values of ～ 3 μ M) while lambda-cyhalothrin potently inhibited both CYP2D6 and CYP3A4-mediated activities (IC₅₀'s about 3–4 μ M). Some pesticides caused relatively potent inhibitions sporadically (carbendazim, CYP2D6, IC₅₀ = 12 μ M; atrazine, CYP3A4, IC₅₀ = 2.8 μ M; glyphosate, CYP2C9, IC₅₀ = 3.7 μ M; hexaflumuron, IC₅₀ = 6.0 μ M). With the exceptions of alpha-cypermethrin, cypermethrin, isoproturon, carbaryl and abamectin, most pesticides inhibited relatively potently at least one CYP-selective activity, which may have relevance for potential interactions in occupational exposures and for further studies on the CYP-associated metabolism of respective pesticides.     

Characterization of an adsorbed humin-like substance on an allophanic soil formed via catalytic polycondensation between catechol and glycine, and its adsorption capability to pentachlorophenol

An allophanic soil (AS) catalyzed the formation of dark-colored polymers via polycondensation reactions between catechol and glycine. The organic carbon content of the AS was increased from 0.16% to 1.3%, indicating that some of the dark-colored polymers had been adsorbed to the AS. The characteristics of the dark-colored polymers adsorbed on the AS were similar to those of a humin that is not extractable with an aqueous alkaline solution. Such a humin-like substance (HuLS) was separated from the AS by treatment with a mixture of HF and HCl. The HuLS and humic acid-like substance (HaLS), comprising the acid-insoluble fraction in the reaction mixture, were characterized by elemental analysis, size exclusion chromatography, pyrolysis-GC/MS and ¹³C NMR. However, the structural features of HaLS and HuLS had many points in common. These results suggest that HuLS-AS can be regarded as an organo-clay complex formed by the strong adsorption of HaLS to the AS. The adsorption of pentachlorophenol (PCP) to AS and HuLS-AS was examined at pH 5.5. At this pH, the zeta potential of the HuLS-AS showed a negative value. It would, therefore, be expected that pentachlorophenolate anions would adsorb with difficulty to HuLS-AS because of electrostatic repulsion. Nevertheless, the adsorption coefficient for PCP to HuLS-AS, as estimated by the Freundlich isotherm, was seven times larger than that for AS. These results show that HuLS, when adsorbed on the AS surface, has the capability to enhance the adsorption of PCP.     

A transgenic approach to enhance phosphorus use efficiency in crops as part of a comprehensive strategy for sustainable agriculture

Concerns about phosphorus (P) sustainability in agriculture arise not only from the potential of P scarcity but also from the known effects of agricultural P use beyond the field, i.e., eutrophication leading to dead zones in lakes, rivers and coastal oceans due to runoffs from fertilized fields. Plants possess a large number of adaptive responses to P_i (orthophosphate) limitation that provide potential raw materials to enhance P_i scavenging abilities of crop plants. Understanding and engineering these adaptive responses to increase the efficiency of crop capture of natural and fertilizer P_i in soils is one way to optimize P_i use efficiency (PUE) and, together with other approaches, help to meet the P sustainability challenge in agriculture. Research on the molecular and physiological basis of P_i uptake is facilitating the generation of plants with enhanced P_i use efficiency by genetic engineering. Here we describe work done in this direction with emphasis on the up-regulation of plant proton-translocating pyrophosphatases (H⁺-PPases).     

Assessment of typical pollutants in waterborne by combining active biomonitoring and integrated biomarkers response

Organic pollutants, heavy metals and pharmaceuticals are continuously dispersed into the environment and have become a relevant environmental emerging concern. In this study, a situ assay to assess ecotoxicity of mixed pollutants was carried out in three typical sites with different priority contaminations in Guangzhou, China. Chemical analysis of organic pollutants, metals and quinolones in three exposure sites were determined by GC-ECD/MS, ICP-AES and HPLC, as well as, a combination of biomarkers including: ethoxyresorufin O-deethylase (EROD); aminopyrine N-demethylase (APND); erythromycin N-demethylase (ERND); glutathione S-transferase (GST); malondialdehyde (MDA); CYP1A; and P-glycoprotein (P-gp) mRNA expressions were evaluated in Mugilogobius abei. Results of chemical analysis in sediment samples revealed that the dominant chemicals were organic pollutants and heavy metals in Huadi River while quinolones in the pond. Bioassays indicated that differences among sites were in relation to some specific biomarkers. EROD and GST activities significantly increased after 72 h in situ exposure, but no difference was observed among the exposure sites. APND, ERND and MDA exhibited dissimilar change patterns for different priority pollutants. CYP1A and P-gp mRNA expressions were significantly induced at all exposure sites, whilst P-gp activity was typical for S2 with the highest levels of quinolones. The molecular biomarkers seemed to be more susceptible than enzyme activities. These assays confirmed the usefulness of applying a large array of various combined biomarkers at different levels, in assessing the toxic effects of mixed pollutants in a natural aquatic environment.     

光催化电化学联合降解水中苯酚的研究

采用电化学、光催化联合工艺降解水中苯酚,在对其降解机理、反应动力学进行分析的基础上,考察了电解质浓度、电流密度及溶液pH等控制因素对降解速率的影响。实验结果表明：电化学和光催化同时作用时,产生了协同作用;以氯化钠为电解质可增强协同作用;光电联合工艺降解苯酚符合准一级反应动力学;弱酸性环境有利于降解反应的进行。在电流密度...     

关于滤纸可溶物对测定悬浮物影响的探讨

针对滤纸可溶物对测定悬浮物结果的影响作了定量和研究。