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421.
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为探讨铅暴露对小鼠胸腺微环境阳性选择相关分子表达的影响,将24只健康初断乳21日龄清洁级雄性KM小鼠随机分为4组,分别为对照(蒸馏水)组和低(200 mg·L-1)、中(400 mg·L-1)、高(800 mg·L-1)剂量乙酸铅染毒组,每组6只.采用自由饮水方式进行染毒,连续染毒12周.染毒结束后,采用流式细胞技术检测小鼠胸腺细胞和胸腺上皮细胞阳性选择相关膜分子的表达.结果发现,与对照组比较,各剂量乙酸铅染毒组小鼠胸腺细胞膜分子CD4、CD8、CD28和LFA-1及胸腺上皮细胞H2-A、H2-K、B7和ICAM-1的表达均明显下降,差异显著(p<0.05);且随着乙酸铅染毒剂量的升高,小鼠胸腺细胞膜分子CD4、CD8、CD28、LFA-1的表达及胸腺上皮细胞膜分子H2-A、H2-K、B7、ICAM-1的表达均呈下降趋势. 相似文献
423.
本文构建了2.0L具有微生物隔膜的模块化生物阴极微生物燃料电池(MFC),以实际生活污水为底物,在连续流运行模式中,系统考察了微生物隔膜(MS)在MFC长期运行过程中的功能特征.结果表明:发育成熟的微生物隔膜可以稳定维持MFC阴阳极室间的溶解氧(DO)浓度梯度,使阳极室平均DO浓度低于0.5mg/L,同时使完全混合的阴极室COD浓度低于50mg/L,避免了电解液性质对于电极反应的抑制.微生物隔膜可以实现离子的跨隔膜迁移,进而平衡阴阳极室间的pH值;阴阳极室间存在的跨隔膜离子梯度意味着微生物隔膜完全分隔了两极室内不同的微生物代谢类型,阴极快速的好氧代谢可能导致了阴极室离子强度的降低.微生物隔膜对于MFC中COD和DO梯度的保持以及pH值的平衡起到了决定性作用,这将严格保证MFC的正常运行.同时,本文论述了在面向规模化应用的MFC中装配微生物隔膜的巨大技术与经济优势,综合评价了微生物隔膜的效能特征,为进一步推广面向实际废水处理的微生物电化学设备提供了技术支撑. 相似文献
424.
Daniel L. Long Randel L. Dymond 《Journal of the American Water Resources Association》2014,50(4):977-987
This study examines the use of bioretention as a strategy to reduce the thermal impact associated with urban stormwater runoff in developing cold water stream watersheds. Temperature and flow data were collected during 10 controlled runs at a bioretention facility located in Blacksburg, Virginia. It was determined that bioretention has the ability to reduce the temperature of thermally charged stormwater runoff received from an asphalt surface. Significant reductions in peak and average temperatures (p < 0.001) were observed. However, this facility was unable to consistently reduce the temperature below the threshold for natural trout waters in Virginia. The ability of bioretention to reduce runoff volume and peak flow rate also serves to reduce the hydrothermal impact. An average thermal pollution reduction of nearly 37 MJ/m3 was calculated using an adopted threshold temperature of 20°C. Based on the results of this study, it was concluded that properly designed bioretention systems have the capability to reduce the thermal impact of urban stormwater runoff on cold water stream ecosystems. 相似文献
425.
Brant A. Peppley 《International Journal of Green Energy》2013,10(2):201-218
Fuel cells can be highly efficient energy conversion devices. However, the environmental benefit of utilising fuel cells for energy conversion is completely dependent on the source of the fuel. Hydrogen is the ideal fuel for fuel cells but the current most economical methods of producing hydrogen also result in the production of significant amounts of carbon dioxide. Utilising biomass to produce the fuel for fuel cell systems offers an option that is technically feasible, potentially economically attractive and greenhouse gas neutral. High-temperature fuel cells that are able to operate with carbon monoxide in the feed are well suited to these applications. Furthermore, because they do not require noble metal catalysts, the cost of high-temperature fuel cells has the greatest potential to become competitive in the near future compared to other types of fuel cells. It is, however, extremely difficult to assess the economic feasibility of biomass-fuelled fuel cell systems because of a lack of published cost information and uncertainty in the predicted cost per kW of the various types of fuel cells for large volume production methods. From the scant information available it appears that the current cost for fuel-cell systems operating on anaerobic digester gas is about US$2,500 per kW compared to a target price of US$1,200 required to compete with conventional technologies. 相似文献
426.
《International Journal of Green Energy》2013,10(3):353-364
Abstract CdO thin films which can be used in photovoltaic solar cells as window material were obtained on glass substrates at 250°C and 300°C substrate temperatures using Ultrasonic Spray Pyrolysis (USP) technique. The electrical, optical, structural, and surface properties of the films were investigated for two different substrate temperatures. After all investigations, it is concluded that, the CdO thin films can be used in photovoltaic solar cells as window materials and cell efficiencies can be increased using different growth parameters. 相似文献
427.
428.
Abhilasha Singh Mathuriya 《环境科学学报(英文版)》2016,28(4):105-111
A novel single cathode chamber and multiple anode chamber microbial fuel cell design(MAC-MFC)was developed by incorporating multiple anode chambers into a single unit and its performance was checked.During 60 days of operation,performance of MAC-MFC was assessed and compared with standard single anode/cathode chamber microbial fuel cell(SC-MFC).The tests showed that MAC-MFC generated stable and higher power outputs compared with SC-MFC and each anode chamber contributed efficiently.Further,MAC-MFCs were incorporated with different wastewaters in different anode chambers and their behavior in MFC performance was observed.MAC-MFC efficiently treated multiple wastewaters simultaneously at low cost and small space,which claims its candidature for future possible scale-up applications. 相似文献
429.
为探讨入侵植物加拿大蓬(Erigeron canadensis L.)的化感作用机制,以蚕豆(Vicia faba L.)叶下表皮为材料,研究了营养期和生殖期加拿大蓬挥发油各1μL、2μL、3μL、4μL、5μL分别处理保卫细胞10 min、20 min、30 min后产生的毒性效应。结果表明:挥发油处理后保卫细胞大量死亡,核形态发生较大改变;细胞死亡率和核异常率显著上升(p0.05),与处理剂量和时间呈正相关(p0.01);营养期挥发油处理后细胞的死亡率和核异常率总体高于生殖期;加入泛Caspase抑制剂后,细胞死亡率显著降低(p0.05)。研究表明,加拿大蓬挥发油引起的保卫细胞死亡为Caspase依赖性的细胞凋亡,营养期挥发油的化感胁迫效应比生殖期更强。结合GC-MS分析可见,不同生长期加拿大蓬挥发油毒性的差异可能与其化感物质的组成和含量差异有关。 相似文献
430.