抑制薇甘菊生长的日本菟丝子化感物质研究

采用制备型高效液相色谱、重结晶等方法从有害植物日本菟丝子（Cuscuta japonica Choisy）的水浸液有机萃取物中分离出能显著抑制薇甘菊（Mikania micrantha H.B.K.）种子萌发的化感物质,并采用核磁共振（1HNMR、13CNMR）法、质谱（MS）法等对其结构进行分析和鉴定。结果表明：能显著抑制薇甘菊种子萌发的日本菟丝子化感物质为桂皮酸（cinnamicacid）和3-苯基丙酸（3-phenylpropanoic acid）。这2种化合物在菟丝子属的植物中属首次分离鉴定。这2种化感物质具有开发为生物源农药（如除草剂）的潜力。研究结果为入侵植物薇甘菊的防治提供了参考依据,也为日本菟丝子的开发利用开辟了一条新途径。     

Acute toxicity of industrial endocrine-disrupting chemicals,natural and synthetic sex hormones to the freshwater planarian,Dugesia japonica

Many chemicals commonly occurring in surface water are found to be hormonally active. Fourteen compounds including four sex hormones, three synthetic hormones, one non-steroidal anti-androgen, and six industrial endocrine-disrupting chemicals were selected to examine their acute toxicities on the freshwater planarian, Dugesia japonica. Among all test chemicals, diethylstilbestrol had the highest toxicity. Relatively, the toxicities of the synthetic hormones were higher than the natural ones. Among the six industrial endocrine-disrupting chemicals tested, bisphenol A was the most toxic, with a 48-h LC₅₀ of 8.3 mg L^?1. Overall, the natural or synthetic hormones, other than estrone and estriol, were more acutely toxic to planarians than the industrial endocrine disruptors tested. The acute toxicities of the test chemicals to Dugesia japonica were in the same order of magnitude as those to Daphnia magna based on available published data. Despite this study used non-environmentally relevant levels, such kinds of chemicals do not exist singly in the aquatic environment, but typically act in synergistic and/or additive ways in the complex environmental mixtures, and the total estrogen equivalents are much higher than a single chemical. This study stands as a starting point for other acute and chronic assays, namely using mixtures.     

Effects of perfluorooctanoic acid on neural genes expression and neuronal morphology in the planarian Dugesia japonica

Perfluorooctanoic acid (PFOA) is an emerging persistent organic pollutant that is considered as a neurotoxicant in animal studies. However, these neurotoxicological studies did not evaluate potential neural deficits in aquatic animals associated from PFOA exposure. In this study, the effects of PFOA on neural genes expression and neuronal morphology in the planarian Dugesia japonica have been investigated. The results show that PFOA exposure results in neural-related genes expression alteration and neuronal morphology defects in planarians. These results suggest that the planarian D. japonica is a good bioindicator for the detection and evaluation of PFOA effects on freshwater invertebrates. The basal phylogenetic position of planarians makes them a good indicator species that can predict toxicity for higher taxa, providing information for the overall ecological toxicity of PFOA in aquatic environment.     

城市空气中铅在国槐树体内的积累

研究了山西省太原市、榆次市和太谷县城3个规模大小和污染程度不同的城市,主要街道两侧行道树国槐杖叶内铅内铅的含量．结果表明：国槐对街道污染空气中的铅有很强的吸收和富集作用．枝条内含铅量与街道上交通车辆密度呈正相关,最高含铅量区域在太原市火车站和五一广场一带从市区中心向郊外延伸空气污染强度减弱,国槐枝叶内含铅量也呈梯度降低趋势3个城市的国槐枝叶内含铅量与其污染强度相吻合一年四季国槐都能通过枝、叶吸收和积累铅污染物,但其含量与树木生理活动、生长周期密切相关     

铜、汞、铅对涡虫的急性毒性作用

在恒温 (2 0± 1)℃条件下研究了铜、汞、铅离子对东亚三角头涡虫 (Dugesiajaponica)的急性毒性作用 .结果为Cu2 、Hg2 和Pb2 对涡虫 2 4h半致死浓度 (LC50 )分别是 :1.5 6 3mgL-1、0 .70 4mgL-1和 188.16mgL-1;4 8h的LC50 分别是 :0 .888mgL-1、0 .6 6 6mgL-1和 171.5 7mgL-1;72h的LC50 分别是 :0 .786mgL-1、0 .6 6 2mgL-1和 14 0 .94mgL-1;96h的LC50 分别是 :0 .779mgL-1、0 .6 4 7mgL-1(Pb2 无此值 ) .试验结果表明 :这些重金属的作用应属于3种类型 ,涡虫作为重金属污染的指示生物基本可行 .图 2表 1参 18     

Effects of bisphenol A,two synthetic and a natural estrogens on head regeneration of the freshwater planarians,Dugesia japonica

Regeneration is a vital physiological process for survival of adult organisms. Bisphenol A (BPA), diethystilbestrol (DES), 17α-ethinylestradiol (EE2), and 17β-estradiol (E2) were examined for their effects on head formation in decapitated freshwater planarians (Dugesia japonica). The median lethal concentration of the test chemicals and the median inhibitory concentration for decapitated planarians and different regenerative endpoints, were determined for 3–7 d of exposure. For planarian head regeneration, the no-observed-effect level of BPA and DES was 0.05 mg L^?1 and 1 mg L^?1 for EE2 and E2. The effects of BPA, DES, and EE2 on asexual planarian regeneration did not correspond with the order of their estrogenic potencies, suggesting that the effects, at least partially, were due to general toxicity rather than their estrogenicity. In view of the published data on concentrations of xenoestrogens in water bodies versus the nominal levels tested here, this study suggests that the current environmental levels of BPA, DES, EE2, and E2 have no immediate adverse effects on freshwater planarian regeneration.     

高羊茅和结缕草对地下渗滤系统中氮磷的去除研究

研究了高羊茅和结缕草覆盖的地下渗滤系统处理生活污水过程两种草坪草对氮、磷的去除作用。研究结果表明:高羊茅含有的总氮浓度在46.8～52.7 g/kg变化,且显著高于结缕草的总氮浓度;高羊茅含有的总磷浓度在4.64～5.89 g/kg之间变化,两种草坪草之间没有显著差异;高羊茅的日平均氮带出量在不同的月份分别为0.237,0.180,0.118 g/(m2.d),显著高于结缕草的日平均氮带出量;高羊茅对生活污水中的氮去除率在2011年9月、10月及11月分别为21.4%,、13.1%和11.8%;高羊茅的日平均磷带出量在不同的月份分别为23.4,15.1,13.8 mg/(m2.d),显著高于结缕草的日平均磷带出量;高羊茅对生活污水中的磷去除率在2011年9月、10月及11月分别为30.2%、24.4%和22.4%。     

干旱胁迫过程中外源钙对忍冬光合生理的影响

以不同浓度Ca2＋对干旱胁迫处理下的忍冬进行化学调控,研究外源Ca2＋对干旱胁迫处理下忍冬叶片中叶绿素含量、可溶性糖含量、游离脯氨酸含量、过氧化氢酶活性以及光合速率的影响,以探讨外源Ca2＋对缓解干旱胁迫下忍冬光合作用下降的作用机制。结果表明,干旱胁迫下,忍冬的正常生理代谢明显受到抑制,叶绿素质量分数、可溶性糖质量分数、游离脯氨酸质量分数、过氧化氢酶活性以及光合速率分别降低到0.4 mg·g-1、0.06~0.1 mg·g-1、0.8 mg·g-1、0.25 u.mg-1和12~14μmol·m-2.s-1;当施入钙离子后,干旱胁迫对忍冬的伤害得到不同程度的缓解,并在最大程度上稳定叶绿素含量和CAT活性;并能使脯氨酸和可溶性糖的积累显著减少。说明外源Ca2＋能够在一定程度上弥补干旱胁迫导致的Ca2＋亏缺,使植物维持较正常的生理活动,稳定细胞膜结构,维持体内离子吸收平衡,维持较高的光合速率并保护光合结构。     

海洋沉积物中Zn对底栖端足类生物的毒性

通过分析Zn加标沉积物中酸溶挥发性硫化物与同步提取金属的摩尔浓度差值解释Zn对底栖生物的毒性作用,受试生物种选择端足类底栖生物日本大螯蜚(Grandidierella japonica),使用实验室沉积物10-day急性毒性生物检验方法进行检验分析结果表明,当酸溶挥发性硫化物与同步提取金属的差值＜0μmol/g干重时,Zn在沉积物间隙水中的浓度非常低,而且在生物急性毒性试验中也很少发现生物致死的现象相反,当二者的差值＞0μmol/g时,Zn在沉积物间隙水中的浓度则明显升高,而且在生物急性毒性试验中受试生物致死率迅速增加.本研究通过将化学数据与生物短期暴露的观察结果相比较,支持了使用酸溶挥发性硫化物作为归一化因子预测金属沾污沉积物毒性的方法.