Human-derived cell lines to study xenobiotic metabolism

In vitro systems make for rapid identification of xenobiotic effects and can be used to study cellular and subcellular toxicity mechanisms. In this report the metabolic competence of two human-derived cell lines, a hepatic (Hep G2) and a pulmonary one (A549) was tested. In the two cell systems the capability to activate Benzo[a]Pyrene through the cytochrome P450 enzyme system and to form reactive metabolites was analysed. ³H-BaP and the scintillation counting analysis were used to show the differences of the metabolic activity in Hep G2 and A549. A similar time course of ³H-BaP uptake was observed in the cell systems. Nevertheless, in the two cell lines the distribution of radioactive metabolites seemed to reflect a specific tissue response to toxicity.     

TiO2光催化剂的改性研究

采用浸渍法制备了掺杂Fe3+ ,用NH4 Cl提高单分散性并且用稀H2 SO4 表面修饰的TiO2 粉体光催化剂 ,考察了它与TiO2 在紫外光和日光作用下对直接耐晒黑G的降解效果。结果表明 ,以TiO2 干凝胶为母体 ,依次浸渍Fe3+ 、NH+ 4以及SO2 - 4所制备的粉体光催化剂Fe3+ /SO2 - 4/TiO2 在紫外光作用下降解效果比纯TiO2 高 2 .1倍 ,在日光作用下比TiO2 高 1 .9倍。X射线衍射分析表明 ,该法制备的TiO2 粉体中锐钛矿相占 1 0 0 % ,没有金红石相 ,平均晶粒粒径为 4nm ;红外吸收光谱分析表明 ,无论是纯TiO2 还是经过掺杂Fe3+ 、用H2 SO4 进行表面修饰后的TiO2 ,红外吸收光谱图基本相似 ,说明掺杂和表面修饰并没有极大地改变TiO2 的化学结构 ,光催化性能的提高归属于杂质能级的电子捕获陷阱作用、有效光成分增加和光生电子向反应物的迅速转移     

全氟辛酸对斜生栅藻细胞膜特性影响研究(Effect of Perfluorooctane Acid on Cell Membrane Properties of Scenedesmus obliquus)

斜生栅藻暴露于全氟辛酸(PFOA)中,其细胞膜特性可通过不同荧光染料染色的荧光信号变化来反映.应用流式细胞仪检测荧光信号,研究了PFOA对斜生栅藻细胞膜的完整性、选择透过性和膜电位指标的影响效应.实验结果显示,全氟辛酸对表征细胞膜完整性的碘化丙啶(PI)染料荧光强度起到显著刺激作用,栅藻细胞膜受损几率随暴露浓度升高呈现上升趋势;低暴露浓度下栅藻细胞膜选择透过性增强,但在高浓度暴露下这一细胞膜特性受到明显抑制,具体表现为表征酯酶活性的二乙酸荧光素(FDA)荧光强度出现先升后降的变化;与FDA荧光强度变化趋势相反,反映膜电位的碘代3,3’-二己氧基羰花青(DIOC6(3))荧光强度则先降后升,预示高浓度PFOA暴露将导致细胞膜处于异常的生理状态.     

微囊藻毒素-LR通过线粒体途径诱导人支气管上皮细胞凋亡

探讨线粒体Caspase依赖性途径是否参与微囊藻毒素-LR(microcystin-LR,MC-LR)诱导人支气管上皮细胞(human bronchial epithelial cells,16HBE)凋亡过程。将处于对数生长期的16HBE分别暴露于终浓度为0(对照组)、2.5、5、10μg·m L-1的微囊藻毒素-LR和10μg·m L-1MC-LR+50μmol·L-1Caspase广谱抑制剂Z-VAD-FMK,持续24 h和48 h。检测细胞凋亡率,线粒体跨膜电位(ΔΨm),Caspase-3和Caspase-9相对表达量。结果显示,与对照组相比,各浓度染毒组细胞凋亡率和Caspase-3、Caspase-9相对表达量均升高,10μg·m L-1MC-LR染毒组线粒体膜电位降低;与10μg·m L-1MC-LR组相比,10μg·m L-1MCLR+50μmol·L-1Z-VAD-FMK组细胞凋亡率明显降低,Caspase-3和Caspase-9相对表达量降低,差异均有统计学意义(P0.05)。且随着MC-LR染毒浓度的升高或染毒时间的延长,16HBE细胞凋亡率和Caspase-3、Caspase-9相对表达量呈升高趋势。研究表明,MC-LR可以通过线粒体Caspase依赖性途径诱导16HBE细胞凋亡。     

Characterization and control of energetic deposits from hexachlorodisilane in process tool exhaust lines

This work aims to characterize and develop a disposal method for a gel-like deposit generated in a vacuum foreline of an atomic layer deposition (ALD) tool that is using hexachlorodisilane (Si₂Cl₆, HCDS) as a precursor. This ALD foreline gel was reproduced by replicating the ALD tool process conditions by using a benchtop system that was a 1/85 scale down of one user's process. All samples were tested for shock sensitivity using the Fall hammer apparatus. Extensive infrared studies were done for unhydrolyzed and hydrolyzed gel. Dissolution tests were conducted to develop a method for removing and disposing the gel off-site. Many different solutions such as solvent based solutions, water based alkaline solutions and alcohol based alkaline solutions were tested. It was found that alcohol based alkaline solutions produced only hydrogen as a byproduct and were considered satisfactory for off-site abatement of gel. Furthermore, in-situ cleaning gel of the foreline using a fluorine/N₂ mixture with a concentration of 1–10vol% was done. They were all effective in cleaning/removing the gel under the condition of ambient temperature and reduced pressure. Finally, recommended procedures were given for removing as well as disposing the ALD gel.     

Pesticide wastewater treatment using the combination of the microbial electrolysis desalination and chemical-production cell and Fenton process

• MEDCC combined with Fenton process was developed to treat real pesticide wastewater. • Pesticide removal was attributable to desalination in the MEDCC. • High COD removal was attributable to organic distributions in different chambers. The combination of the microbial electrolysis desalination and chemical-production cell (MEDCC) and Fenton process for the pesticide wastewater treatment was investigate in this study. Real wastewater with several toxic pesticides, 1633 mg/L COD, and 200 in chromaticity was used for the investigation. Results showed that desalination in the desalination chamber of MEDCC reached 78%. Organics with low molecular weights in the desalination chamber could be removed from the desalination chamber, resulting in 28% and 23% of the total COD in the acid-production and cathode chambers, respectively. The desalination in the desalination chamber and organic transfer contributed to removal of pesticides (e.g., triadimefon), which could not be removed with other methods, and of the organics with low molecular weights. The COD in the effluent of the MEDCC combined the Fenton process was much lower than that in the perixo-coagulaiton process (<150 vs. 555 mg/L). The combined method consumed much less energy and acid for the pH adjustment than that the Fenton.     

Transmembrane transport of polycyclic aromatic hydrocarbons by bacteria and functional regulation of membrane proteins

• Explaintheadsorption, uptake and transmembrane transport of PAHs by bacteria. • Analyze functional regulation of membrane proteins inthe transmembrane transport. • Proteomics technology such as iTRAQ labeling was used to access expressed proteins. • Single cell analysis technology wereused to study the morphological structure. In recent years, increasing research has been conducted on transmembrane transport processes and the mechanisms behind the microbial breakdown of polycyclic aromatic hydrocarbons (PAHs), including the role of membrane proteins in transmembrane transport and the mode of transmission. This article explains the adsorption, uptake and transmembrane transport of PAHs by bacteria, the regulation of membrane protein function during the transmembrane transport. There are three different regulation mechanisms for uptake, depending on the state and size of the oil droplets relative to the size of the microbial cells, which are (i) direct adhesion, (ii) emulsification and pseudosolubilization, and (iii) interfacial uptake. Furthermore, two main transmembrane transport modes are introduced, which are (i) active transport and (ii) passive uptake and active efflux mechanism. Meanwhile, introduce the proteomics and single cell analysis technology used to address these areas of research, such as Isobaric tags for relative and absolute quantitation (iTRAQ) technology and Nano Secondary ion mass spectrometry (Nano-SIMS). Additionally, analyze the changes in morphology and structure and the characteristics of microbial cell membranes in the process of transmembrane transport. Finally, recognize the microscopic mechanism of PAHs biodegradation in terms of cell and membrane proteins are of great theoretical and practical significance for understanding the factors that influence the efficient degradation of PAHs contaminants in soil and for remediating the PAHs contamination in this area with biotechnology.     

硅胶复合材料吸附重金属汞的研究进展

针对高毒性、易累积的重金属汞污染物,介绍了对硅胶基底材料进行化学改性的方法,从液相和气相两方面详述了硅胶复合材料(包括有机官能团改性硅胶材料和无机磁性硅胶复合材料)在汞吸附分离领域的研究和应用进展,分析了现有研究的不足之处,并对该领域未来的研究方向提出了建议。指出,研制出高效、高选择性、高稳定性、易回收的汞吸附剂是治理工业废水和燃煤烟气中汞污染的关键。     

磺胺与群体感应抑制剂对费氏弧菌发光和生长联合毒性效应对比研究

抗生素类药物在广泛应用的同时,也带来了细菌耐药性问题。因此,越来越多的抗生素替代品如群体感应抑制剂(QSIs)被研究和应用,在未来二者可能共存于环境之中。为了对它们混合物联合毒性评价进行系统的研究,本文选择费氏弧菌(Vibrio fischeri,V.fischeri)为受试生物,测定了5种磺胺类抗生素(SAs)与6种QSIs对V.fischeri的发光强度(HV)和生长量(OD600)的联合毒性作用,初步探讨了SAs与QSIs对V.fischeri发光联合毒性和生长联合毒性差异的原因。结果表明:SAs与QSIs联合作用于V.fischeri时,对发光的联合毒性表现为拮抗,对生长的联合毒性表现为拮抗或加和,且TUHVTUOD。这可能是由于QSIs对V.fischeri的发光的抑制作用可以削弱SAs对发光的促进作用,而SAs与QSIs对V.fischeri的生长都表现出抑制作用,两者没有互相削弱作用。同时,基于分子对接和回归分析法的研究表明了靶蛋白上结合的化合物有效浓度不同也可能是造成SAs与QSIs联合作用于V.fischeri时TUHVTUOD的主要原因。该研究可以为抗生素与QSIs联合暴露的生态风险评价提供借鉴。     

0,0-二甲基-(2,2,2-三氯-1-羟基乙基)磷酸酯对4种藻类生长的影响

0,0-二甲基-(2,2,2-三氯~(-1)-羟基乙基)磷酸酯(敌百虫)为广谱杀虫剂,用途广泛,但对藻类的毒理学效应研究还有待完善。采用4种受试藻样,设置5个敌百虫浓度组(1、5、10、50和100 mg·L~(-1))和对照组,实验周期40 d,藻细胞的初始接种密度106cells·m L~(-1),光暗比12 h/12 h,24 h曝气,24 h磁力搅拌,实验温度25℃,p H 6.8,每隔24 h取样。结果表明:5 mg·L~(-1)、10 mg·L~(-1)、50 mg·L~(-1)浓度的敌百虫对铜绿微囊藻和小球藻的生长有促进作用,其中以50 mg·L~(-1)浓度组的促进作用最为显著,促进作用主要表现在生长峰值的延后以及生长对数期的延长,而高剂量(100 mg·L~(-1))的敌百虫则有抑制藻生长的作用。取50 mg·L~(-1)敌百虫浓度组以及铜绿微囊藻和小球藻作进一步深入研究,结果表明:50 mg·L~(-1)敌百虫浓度组的叶绿素a含量峰值比对照组高30%,细胞体内的SOD、ATP含量都高于对照组。敌百虫的使用浓度通常在0.1~1.0 mg·L~(-1),低于本实验最佳浓度。本实验中1 mg·L~(-1)敌百虫对藻生长影响效果不明显。