EMERGY analysis for sustainability evaluation of the Baiyangdian wetland ecosystem in China

This study presents a quantitative and ecological benefit evaluation of the Baiyangdian wetland in China between the years 2000 and 2006. Methods of EMERGY analysis were applied to illustrate the wetland ecosystem, to evaluate the economic and environmental inputs and consequent yields, and to assess the sustainability of the Baiyangdian wetland. The indicators for the integrated ecological and economic system, such as EMERGY yield ratio (EYR) (7.51), EMERGY investment ratio (EIR) (4.52), environmental loading ratio (ELR) (2.92), EMERGY exchange ratio (0.41), and EMERGY sustainable indicator (ESI) (2.57) were calculated, compared, analyzed, and discussed. The non-renewable investment in Baiyangdian was greater than renewable investment, leading to the unsustainable development of the system. High EYR indicated that the Baiyangdian integrated system had created huge profits for its people, while ELR and ESI revealed that human behavior has been a heavy burden on the environment, and countermeasures should be taken by the Chinese government to relieve and resolve these problems. Potential management methods were also proposed in this paper.     

重庆市男性PAHs和PAEs暴露与男性精液质量的相关性分析

多环芳烃(polycyclic aromatic hydrocarbons,PAHs)和邻苯二甲酸酯(phthalate esters,PAEs)是三峡库区水中主要有机污染物。为探讨这2类化学物对三峡库区男性精液质量的影响,课题组于2007年在三峡库区6个区县进行了男性生殖健康的流行病学调查。调查中共收集到有效样本1 346例,对所有样本进行了精液常规检测,选取了冬季采样的232例标本进行了尿液中4种PAHs代谢产物和5种PAEs代谢产物含量的检测,并对这些样本的精子细胞凋亡(Annexin V/PI双标法)和精子脱氧核醣核酸(DNA)损伤(彗星电泳法)进行了检测。运用Spearman等级相关,多元线性回归和logisitic回归分析等方法分析了PAHs和PAEs代谢产物与精液常规指标、精子细胞凋亡、精子DNA损伤的相关关系。结果显示,1 346名三峡库区健康男性精液常规5项指标全部达到世界卫生组织(WHO)标准的比率仅为38.9%。PAHs代谢产物的含量与男性精液常规指标间未发现相关关系,但某些PAHs代谢产物水平与精子凋亡参数及精子DNA损伤指标有一定的关联性,随着尿中PAHs代谢产物浓度的增加,正常未发生凋亡的精子减少,精子DNA的损伤增加。未发现PAEs代谢产物与精液各项参数间的相关关系。本研究结果表明,在重庆市健康育龄男性中PAHs与PAEs的暴露与精液常规指标间没有明确的相关关系,但PAHs暴露与精子DNA损伤显著相关。为明确PAHs的暴露对精子DNA的损伤作用,有必要进行较大规模的队列研究以进行验证。     

戊吡虫胍对几种非靶标生物的急性毒性

戊吡虫胍是一种从烟碱类和缩胺脲类杀虫剂活性结构拼接而成的系列化合物中筛选出来的新型杀虫剂,目前戊吡虫胍对非靶标生物的毒性研究报道较少。为探究戊吡虫胍的环境安全性,采用生物毒性试验方法测定了其对斜生栅藻(Scenedesmus obliquus)、大型溞(Daphnia magna)、家蚕(Bombyx mori)、斑马鱼(Brachydanio rerio)、赤子爱胜蚯蚓(Eisenia fetide)、非洲爪蟾(Xenopus laevis)、赤眼蜂(Trichogramma nubilale)、意大利蜜蜂(Apis mellifera)、日本鹌鹑(Coturnix coturnix japonica)共9种非靶标生物的急性毒性。结果显示戊吡虫胍对斜生栅藻和大型溞的半数有效浓度(EC50)分别为8.79 mg·L~(-1)和10.97 mg·L~(-1),对家蚕、斑马鱼、赤子爱胜蚯蚓和非洲爪蟾的半数致死浓度(LC50)分别为2.32 mg·L~(-1)、13.74 mg·L~(-1)、100 mg·kg~(-1)和19.30mg·L~(-1),对赤眼蜂的安全系数为0.16~0.031,对蜜蜂急性触杀和急性摄入毒性分别为51.82μg·bee~(-1)和10.8×10~3mg·L~(-1),对鹌鹑的急性经口和急性饲喂毒性LC50分别为1 000 mg·kg~(-1)和2×103mg·kg~(-1)。按照最新国标(GB/T31270—2014)化学农药环境安全评价准则的毒性等级划分,戊吡虫胍除了对家蚕和赤眼蜂为高毒和极高风险外,对其余非靶生物均为低毒。     

Effects of ethyl 2-methyl acetoacetate (EMA) on the growth of Phaeodactylum tricornutum and Skeletonema costatum

We investigated the effects of ethyl 2-methyl acetoacetate (EMA) on growth of the marine diatom algae Phaeodactylum tricornutum (P. tricornutum) and Skeletonema costatum (S. costatum). Growth of P. tricornutum was significantly inhibited by the minimum concentration (3.5 mmol·L ^?1) of EMA at lower initial algal densities (IADs) (3.6×10⁴ and 3.3×10⁵ cells·mL ^?1). However, at the highest IAD, significant growth inhibition was found at above 7 mmol·L ^?1 of EMA exposure. In S. costatum, EMA concentrations of 10.5 mmol·L ^?1 or more significantly inhibited growth at lower IAD (3×10⁴ and 1.8×10⁵ cells·mL ^?1); at the highest IAD, only EMA concentrations above 14 mmol·L ^?1 obviously inhibited the growth of S. costatum. Changes in specific growth rates and pigment were consistent with algal growth, but only at higher EMA concentrations or lower IAD values was the ratio of chlorophyll a (Chla) to carotenoid significantly lower than the control. Medium effective concentration (EC ₅₀) values were in the order 4.07, 8.03 and 12.27 mmol·L ^?1 for P. tricornutum and 7.48, 11.92 and 17.22 mmol·L ^?1 for S. costatum. All these results show that the effect of EMA on the growth of algae was species specific and mainly depended on IAD, which might be an important factor to influence algal growth.     

Ecotoxicity of silver nanoparticles on earthworm Eisenia fetida: responses of the antioxidant system,acid phosphatase and ATPase

Ecotoxicity of nanoparticles has received growing attention in recent years. This study investigated the influence of silver nanoparticles (Ag-NP) on earthworm Eisenia fetida. The experiment was performed with five test groups: control (without Ag-NP), 10?nm Ag-NP groups (20, 100 or 500?mg?kg^?1) and positive control (787?mg?kg^?1 AgNO₃). After 14-day acute exposure, activities of various enzymes, including glutathione S-transferase (GST), glutathione reductase (GR), acid phosphatase (AP), and Na⁺, K⁺-ATPase were determined. Effects of Ag-NP with different sizes (10 and 80?nm) were also tested. Data showed that the activity of GR was significantly lower at 500?mg?kg^?1. The activities of AP and Na⁺, K⁺-ATPase were inhibited following the increase of Ag-NP concentration. When treated with Ag-NP with different sizes, activities of AP and Na⁺, K⁺-ATPase of the 10?nm group were significantly lower than the control group, but those of the 80?nm group were similar to the control group. Data indicate that Ag-NP may be harmful to the earthworm E. fetida at 500?mg?kg^?1, and the toxicity of Ag-NP with 10?nm size is greater than 80?nm. In addition, AP and Na⁺, K⁺-ATPase are sensitive biomakers to the effects of Ag-NP.     

Protoplast fusion between Saccharomyces cerevisiae and Rhodobacter sphaeroides for the treatment of soybean wastewater

The kinetic parameters and the purification rates of the hybrid cell Foaz in soybean processing wastewater (SPW) were measured through a shaking reaction and in two automatic regulated control stable fermentation systems (ARCSFS). The maximum specific growth rate of Foaz was 0.576 h^‐1, higher than that of one of its parental strains Rhodobacter sphaeroides P9479 and lower than that of another parental strain Saccharomyces cerevisiae Y9407. The BOD₅ removal rate of Foaz in the No. 1 system was 61.3%, higher than those of both its parental strains when the influent BOD₅ concentration was 4600 mg/L. The results of this study suggest that the hybrid Foaz has a better capacity of the degradation of organic pollutants in SPW than its parental strains and it may be applicable to the treatment of high concentration organic wastewater.     

脱氧雪腐镰刀菌烯醇毒理作用研究进展

脱氧雪腐镰刀菌烯醇(DON)是人畜食品中检出率和超标率最高的一种真菌毒素。与核糖体60s亚基的肽基转移酶活性中心结合后会引发核糖体应激反应,诱导细胞凋亡等作用,对肠道、免疫系统造成破坏,并且具有遗传毒性。为今后的研究工作提供参考,笔者将从DON的毒理学机制和对机体的影响角度入手对近几年新的研究成果做综合论述。     

流域河口湿地生态健康与湿地发育关系研究

河口湿地作为一个独立的＂活体＂,有着其自身的地理发育、成熟和衰老的生长过程。以大洋河河口湿地为例,运用面积积分曲线和分维度指数计算大洋河流域发育阶段及河口湿地生长过程,得出如下结论,（1）在河流流域地貌发育早期,河流底蚀、侧蚀、溯源侵蚀强烈,河流含沙量高,泥沙在河口地区沉降而易形成河口湿地;随着流域地貌发育到壮年期,河流泥沙含量输出稳定,河口湿地面积继续扩张;到流域地貌发育晚期,侵蚀减弱,河流含沙量减少,河口湿地缺乏稳定的泥沙供应,在河湾水动力作用下逐渐萎缩、直至消亡。（2）人类活动直接影响河口湿地环境的物理、化学和生物组份,改变了河口泥沙的输入量及沉积环境,人类活动实际上是直接或间接地缩短了河口湿地的发育时间,加速了其发育进程。（3）针对不同发育阶段的河流,在制定河口湿地保护政策和修复措施时,必须充分考虑其地质历史发育特征,政策的制定要符合其生长规律。     

o-Coumaric acid from invasive Eupatorium adenophorum is a potent phytotoxin

A phytochemical study of the invasive Eupatorium adenophorum indicated that the plant was rich in a phenolic compound o-coumaric acid (or 2-hydroxycoumaric acid). Biological investigations with the model plant Arabidopsis thaliana and crop plants showed that o-coumaric acid strongly inhibited seed germination, plant growth and root elongation, reduced the photosynthesis in old leaves, and induced the root cell death and the expression of genes related to senescence, oxidative stress, and systemic acquired resistance. The phytotoxic effects of o-coumaric acid exhibit selectivity between under- and above-ground parts of test plants and between E. adenophorum and other plants. These results indicate that o-coumaric acid is a potent toxin that might play an important role in the competition of E. adenophorum with its neighboring plants during its invasion and establishment.     

Sediment microbial fuel cell with floating biocathode for organic removal and energy recovery

A sediment microbial fuel cell (SMFC) with three dimensional floating biocathode (FBC) was developed for the electricity generation and biodegradation of sediment organic matter in order to avoid negative effect of dissolved oxygen (DO) depletion in aqueous environments on cathode performance and search cost-effective cathode materials. The biocathode was made from graphite granules with microbial attachment to replace platinum (Pt)-coated carbon paper cathode in a laboratory-scale SMFC (3 L in volume) filled with river sediment (organic content 49±4 g·kg^-1 dry weight). After start-up of 10 days, the maximum power density of 1.00W·m^-3 (based on anode volume) was achieved. The biocathode was better than carbon paper cathode catalyzed by Pt. The attached biofilm on cathode enhanced power generation significantly. The FBC enhanced SMFC performance further in the presence aeration. The SMFC was continuously operated for an over 120-day period. Power generation peaked within 24 days, declined gradually and stabilized at a level of 1/6 peak power output. At the end, the sediment organic matter content near the anode was removed by 29% and the total electricity generated was equal to 0.251 g of chemical oxygen demand (COD) removed.