没食子酸丙酯对K562细胞的增殖抑制和诱导凋亡作用

观察没食子酸丙酯(Propyl gallate,PG)对人慢性髓系白血病K562细胞株的增殖抑制及诱导凋亡作用.采用倒置显微镜观察细胞形态及数目的变化,乳酸脱氢酶(Lactate dehydrogenase,LDH)释放检测细胞活性,流式细胞术PI染色法及DNA倍体分析检测细胞凋亡作用.结果表明,没食子酸丙酯能有效地抑制K562细胞增殖,药物处理24 h时细胞形态发生变化,细胞数目减少;细胞培养液中LDH活性分析显示,20~300μg/mL没食子酸丙酯处理24 h对细胞毒性作用不明显;但处理时间达48 h时,没食子酸丙酯对细胞毒性明显增加;亚二倍体峰(凋亡峰)的出现及DNA片段化分析表明,200μg/mL PG处理细胞24 h时,能引起K562细胞凋亡.结果表明,PG具有明显的体外抗肿瘤活性,其抗癌活性与其抑制细胞增殖、诱导细胞凋亡有关.图5参18     

天然提取物抗PM2.5诱导A549细胞凋亡的作用

采集北京城区大气可吸人颗粒物中的细颗粒物(PM25),用其对人肺腺癌A549细胞染毒,探讨PM25对细胞增殖的毒性和诱导细胞凋亡的作用,并且考察了加入不同浓度的红豆越橘提取物和竹叶提取物对其的抗性作用.实验采用MTT法检测细胞增殖作用,采用Annexi V-FITC/PI双染法和流式细胞仪检测细胞凋亡.结果显示:PM2...     

Synergistic cytotoxicity of binary combinations of inorganic and organic disinfection byproducts assessed by real-time cell analysis

Chlorine, chlorine dioxide, and ozone are widely used as disinfectants in drinking water treatments. However, the combined use of different disinfectants can result in the formation of various organic and inorganic disinfection byproducts (DBPs). The toxic interactions, including synergism, addition, and antagonism, among the complex DBPs are still unclear. In this study, we established and verified a real-time cell analysis (RTCA) method for cytotoxicity measurement on Chinese hamster ovary (CHO) cell. Using this convenient and accurate method, we assessed the cytotoxicity of a series of binary combinations consisting of one of the 3 inorganic DBPs (chlorite, chlorate, and bromate) and one of the 32 regulated and emerging organic DBPs. The combination index (CI) of each combination was calculated and evaluated by isobolographic analysis to reflect the toxic interactions. The results confirmed the synergistic effect on cytotoxicity in the binary combinations consisting of chlorite and one of the 5 organic DBPs (2 iodinated DBPs (I-DBPs) and 3 brominated DBPs (Br-DBPs)), chlorate and one of the 4 organic DBPs (3 aromatic DBPs and dibromoacetonitrile), and bromate and one of the 3 organic DBPs (2 I-DBPs and dibromoacetic acid). The possible synergism mechanism of organic DBPs on the inorganic ones may be attributed to the influence of organic DBPs on cell membrane and cell antioxidant system. This study revealed the toxic interactions among organic and inorganic DBPs, and emphasized the latent adverse outcomes in the combined use of different disinfectants.     

微氧环境中电化学活性微生物的分离与鉴定

电化学活性微生物在金属、碳等元素的生物地球化学循环,以及生物能源合成中具有重要作用.与微生物燃料电池厌氧阳极相比,微氧阳极能够捕集更多电能.但是相比于厌氧阳极中功能微生物的广泛研究,微氧阳极中的功能微生物还未被分离和研究.本研究采用传统好氧分离技术从微生物燃料电池微氧阳极分离获得3株纯菌Aeromonas sp.WS-XY2、Citrobacter sp.WS-XY3和Bacterium strain WS-XY4,其中WS-XY2和WS-XY3属于变形菌门,WS-XY4初步鉴定为新种.循环伏安、计时电流结果表明3株菌均具有电化学活性,且具有相似的直接胞外电子传递机制.3株菌在微生物分类学和电化学性质上的异同,表明微氧阳极能够定向筛选具有相似电化学性质的电化学活性微生物.微生物燃料电池微氧阳极具有更高效多样的功能微生物,可能是微氧阳极性能优于厌氧阳极的一个原因.因此,进一步针对微生物燃料电池微氧阳极中功能微生物的研究,将有助于阐明微氧阳极提高微生物燃料电池电能捕集的微生物机制.     

活性氧和钙离子参与镉诱导的酵母细胞死亡过程调节

以酵母为实验材料,研究了镉(以CdCl2形式添加)对细胞的毒性作用机制.结果显示,浓度为0.25~5 mmol·L-1的镉可降低酵母细胞活性,诱导细胞死亡;随着镉浓度的提高和处理时间的延长,细胞死亡率增高.凋亡抑制剂Z-Asp-CH2-DCB与镉共同作用后,细胞死亡率明显低于镉单独处理组.经镉处理后,酵母细胞内的活性氧(ROS)水平显著升高;外源抗氧化剂抗坏血酸和过氧化氢酶能降低镉引发的细胞死亡,特异性Ca2+螯合剂EGTA或Ca2+通道特异性抑制剂LaCl3亦可明显降低镉诱发的细胞死亡率.研究表明,镉诱发的酵母细胞死亡过程存在依赖于caspase途径的细胞凋亡途径;镉诱发的死亡与镉处理组胞内ROS和Ca2+水平升高有关,ROS可能通过增加胞内Ca2+水平,继而激活相关下游信号导致细胞死亡.     

Immunotoxic effects of an industrial waste incineration site on groundwater in rainbow trout (Oncorhynchus mykiss)

The discharge of organic waste from the petrochemical industry into the Mercier lagoons caused major groundwater contamination. The objective of this study was to determine the immunotoxic potential of three groundwater wells at increasing distance from the incinerator dumping site （1.17, 2.74 and 5.40 km）. Rainbow Trout were exposed to increasing concentrations of water from three groundwater wells for 14 days. Immunocompetence was characterized by phagocytosis, mitogen-stimulated proliferation of lymphocytes, cell cycle analysis and apoptosis. A significant increase in innate （phagocytosis） and specific immune response （B lymphocyte proliferation） was observed in trout exposed to water collected from the well at 2.74 km. However, phagocytosis activity was suppressed in groups at 1.17 and 5.40 km. The proportion of lymphocytes in S phase was significantly increased in groups at 2.74 and 5.40 kin, while lymphocytes in G0/G1 phase were decreased in all three exposure groups. Additionally, dexamethasone （DEX）-induced apoptosis of lymphocytes was significantly reduced in the group at 2.74 km, which suggests decreased lymphocyte turnover. Furthermore, the ratio of DEX- induced apoptosis/apoptosis was lower in the groups at 2.74 and 5.40 km. In summary, our experiments have shown that exposure to the mixture of organic compounds present in Mercier groundwater modulates phagocytosis and cell proliferation, disrupts the cell cycle and reduces the ratio of DEX- induced apoptosis/apoptosis. It is concluded that groundwater collected in the vicinity of an incinerator containment field could impact immunocompetence in fish.     

长江口邻近海域赤潮水体浮游植物光吸收特性分析

根据2013年8月对长江口邻近海域赤潮水体浮游植物优势物种及光吸收特性进行调查,在34个调查站位中,共10个站位发生赤潮,其中,6个站位发生硅藻赤潮,3个站位发生甲藻赤潮.赤潮水体和非赤潮水体浮游植物吸收系数变化很大,440 nm处吸收系数范围分别为0.199~0.832 m-1和0.012~0.109 m-1;而比吸收系数变化相对较小,440 nm处比吸收系数在赤潮和非赤潮水体的平均值分别为0.023 m2·mg-1和0.035 m2·mg-1.从赤潮水体向非赤潮水体过渡,大粒径浮游植物所占比例减小,小粒径浮游植物所占比例上升,打包效应减小,因而比吸收系数升高.浮游植物粒径指数的变化对440 nm和675nm处的比吸收系数变化的贡献可分别达到43%和25%.不同类型赤潮(如硅藻和甲藻赤潮)在浮游植物粒级结构接近的情况下吸收光谱仍具有明显差异,这是色素组成不同的结果.甲藻赤潮中硅甲藻黄素和叶绿素c2的浓度之和与叶绿素a浓度的比值大于硅藻赤潮,是甲藻在465 nm附近出现吸收肩峰的重要原因.     

Fluid Mechanics of Serpentine Flow Fields on a Porous Media

Laminar flows are investigated in single and double parallel serpentine channels mounted on a porous media and it is found that significant convective transport occurs in porous media for practical fuel cell conditions. This transport increases with increasing flow Reynolds number, with decreasing land width, and most significantly with increasing channel length.

Increasing the number of parallel channels significantly decreases the pressure drop across the fuel cell, but also significantly decreases the magnitude of convective transport in the porous media. Increased parasitic loads must be put in the context of the change in electrochemical performance.

This paper presents both data and a methodology for beginning to think about flow field design from a hydrodynamic perspective.     

硫酸盐对微生物燃料电池脱氮的影响

构建了双室型微生物燃料电池(MFC),探讨了硫酸盐对MFC阴极脱氮效果和产电性能的影响。实验结果表明:缺氧阴极室中,硝酸盐氮、硫酸盐的还原存在一定的竞争关系,且硫酸盐对电子的竞争能力比硝酸盐氮强;当S与N的质量比(记为S/N)为2∶1时,72 h后的硫酸根去除率达96.41%,而硝酸盐氮去除率仅为36.86%;在S/N为2∶1的条件下,当电压达307.6 m V时,功率密度达最大值15.77 W/m2,电池内阻为100Ω,与未加入硫酸盐时相比产电性能明显提高。