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131.
132.
Quantum dots enhance Cu2+-induced hepatic L02 cells toxicity 总被引:1,自引:0,他引:1
As a new class of xenogenous nanoparticle,quantum dots (QDs) possess the potential to co-exist with Cu2+ in human liver.The combined toxicity is thus concerned.Considering QDs and Cu2+ are known ROS (reactive oxygen species) inducer,we investigated the combined oxidative stress and corresponding protective strategy using human hepatic L02 cells.The results demonstrated that the presence of a small amount of MPA-CdTe QDs (2 μg/mL) in a Cu2+ solution (2.5-20 μg/mL) resulted in a higher toxicity with up to 8-fold cell viability decrease,which was accompanied by cell morphology changes.The combined toxicity was then confirmed as ROS associated oxidative stress with up to 300% and 35% increase of the intracellular ROS level and glutathione S-transferase (GST) activity,respectively.N-acetylcysteine (NAC) can also provide almost complete protection against the induced toxicity.Therefore,the ROS associated oxidant injury might be responsible for the QDs-Cu2+/Cu2+ induced toxicity and could be balanced through cytoprotective antioxidant enzyme GST. 相似文献
133.
Efficiency of white lupin in the removal of mercury from contaminated soils: Soil and hydroponic experiments 总被引:1,自引:0,他引:1
Pilar Zornoz Roc′?o Mill′an M. Jos′e Sierr Almudena Seco Elvira Esteban 《环境科学学报(英文版)》2010,22(3):421-427
This study examined the ability of the white lupin to remove mercury (Hg) from a hydroponic system (Hg concentrations 0, 1.25, 2.5, 5 and 10 μmol/L) and from soil in pots and lysimeters (total Hg concentration (19.2 ± 1.9) mg/kg availability 0.07%, and (28.9 ± 0.4) mg/kg availability 0.09%, respectively), and investigated the accumulation and distribution of Hg in different parts of the plant. White lupin roots efficiently took up Hg, but its translocation to the harvestable parts of the plant was low. The Hg concentration in the seeds posed no risk to human health according to the recommendations of the World Health Organization, but the shoots should not be used as fodder for livestock, at least when unmixed with other fodder crops. The accumulation of Hg in the hydroponically-grown plants was linear over the concentration range tested. The amount of Hg retained in the roots, relative to the shoots, was almost constant irrespective of Hg dose (90%). In the soil experiments, Hg accumulation increased with exposure time and was the greater in the lysimeter than in the pot experiments. Although Hg removal was the greater in the hydroponic system, revealing the potential of the white lupin to extract Hg, bioaccumulation was the greatest in the lysimeter-grown plants; the latter system more likely reflects the true behaviour of white lupin in the field when Hg availability is a factor that limits Hg removal. The present results suggest that the white lupin could be used in long-term soil reclamation strategies that include the goal of profitable land use in Hg-polluted areas. 相似文献
134.
Variations between rice cultivars in iron and manganese plaque on roots and
the relation with plant cadmium uptake 总被引:4,自引:0,他引:4
To understand certain mechanisms causing variations between rice cultivars with regard to cadmium uptake and tolerance, pot soil
experiments were conducted with two rice cultivars of di erent genotypes under di erent soil Cd levels. The relationships between
plant Cd uptake and iron/manganese (Fe/Mn) plaque formation on roots were investigated. The results showed that rice cultivars
di ered markedly in Cd uptake and tolerance. Under soil Cd treatments, Cd concentrations and accumulations in the cultivar Shanyou
63 (the genotype indica) were significantly higher than those in the cultivar Wuyunjing 7 (the genotype japonica) (P < 0.01, or P <
0.05), and Shanyou 63 was more sensitive to Cd toxicity than Wuyunjing 7. The di erences between the rice cultivars were the largest
at relatively low soil Cd level (i.e., 10 mg/kg). Fe concentrations in dithionite-citrate-bicarbonate root extracts of Shanyou 63 were
generally lower than that of Wuyunjing 7, and the di erence was the most significant under the treatment of 10 mg Cd/kg soil. The
results indicated that the formation of iron plaque on rice roots could act as a barrier to soil Cd toxicity, and may be a “bu er” or a
“reservoir” which could reduce Cd uptake into rice roots. And the plaque may contribute, to some extent, to the genotypic di erences
of rice cultivars in Cd uptake and tolerance. 相似文献
135.
矿山强酸性多金属污染土壤修复及麻疯树植物复垦条件研究 总被引:5,自引:0,他引:5
采用温室盆栽实验,研究了在不同剂量(质量分数分别为0、0.10%、0.25%、0.5%和1.0%)石灰石改良条件下,大宝山矿强酸性多金属不同污染程度土壤中麻疯树的生长状况和吸收金属特征,并探讨了麻疯树在酸性土壤中生长的抑制因素和石灰石改良适宜剂量.研究表明,在低污染酸性土壤中,Cu和Pb的高活性可能是抑制麻疯树生长的主要因素;而在高污染酸性土壤中,Cd、Cu、Zn等金属的高活性及由强酸引起的Al毒也可能是抑制麻疯树生长的主要因素;石灰石通过提高土壤pH值和降低多金属的生物有效态含量,促进了麻疯树在低污和高污土壤中的生长,其最佳剂量分别为0.25%和0.5%;石灰石可以不同程度地降低麻疯树地上部和地下舔的Cd、Cu、Pb、Zn和Al含量,同时随石灰石用量的增加,其金属含量基本呈降低趋势;麻疯树地下部金属含量高于地上部,且石灰石对麻疯树地下部金属(除Cd外)含量降低幅度较地上部大.因此,种植麻疯树与石灰石改良是联合修复大宝山矿酸性多金属污染土壤的有效措施之一. 相似文献
136.
Decabromodiphenyl ether (BDE-209) is a prevalent polybrominated diphenyl ether (PBDE) congener known to have neurotoxicity. Effects of BDE-209 on Neuro-2a cells were performed in the present study and the possible apoptotic pathway was discussed. Results indicated that BDE-209 induced Neuro-2a cell apoptosis, increased the protein expression of Fas and Fas-associated death domain-containing protein (FADD) and activated the caspase-8 and -3 activities in a concentration-dependent manner, inferring the death-receptor pathway was involved in the apoptotic process. Meanwhile, BDE-209 exposure increased the Bax/Bcl-2 ratio and decreased the cellular mitochondrial membrane potential (MMP) which led to cytochrome C released to the cytoplasm. The intracellular caspase-9 was elevated simultaneously, which caused downstream caspase cascade and triggered cell apoptosis. Moreover, BDE-209 exposure increased cellular reactive oxygen species (ROS) level in a concentration-dependent manner and the addition of N-acetyl-l-cysteine (NAC), known as ROS scavengers, obviously reduced the apoptotic rate and a positive relationship was observed between the degree of apoptosis blocking and the loss of MMP and ROS production. We thus concluded that BDE-209 induced Neuro-2a cell apoptosis via the combination of the death-receptor signaling pathway and the mitochondrial signaling pathway. The elevated ROS production was considered to magnify the intracellular apoptosis signal and played a crucial role in apoptosis of Neuro-2a cells induced by BDE-209. 相似文献
137.
为揭示南海北部表层海水中参与卡尔文循环的固碳基因多样性及其与环境因子的关系,本研究以卡尔文循环中的关键酶核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubis CO)的Ⅰ、Ⅱ型基因(cbbL、cbbM)作为分子标记,采用Illumina Miseq高通量测序技术对海水中的固碳基因多样性进行分析,并结合多元统计分析的方法,探讨了固碳基因多样性与环境因子的关系.结果显示,在南海北部表层海水中,含cbbL基因固碳基因主要归属于变形菌门(Proteobacteria)、蓝藻门(Cyanobacteria)和厚壁菌门(Firmicutes),其中,优势亚群分别是γ-变形菌亚门(45.3%)、蓝细菌(30.9%)和β-变形杆菌亚门(23.8%);而含cbbM基因的固碳菌群未检测到;近岸的A9站位与其他站位物种组成有一定的差异,异着色菌属(Allochromatium)、硫杆菌属(Thiobacillus)和硫单胞菌属(Thiohalomonas)为其特有菌属.相关性和冗余分析(RDA)结果显示,含cbbL基因的固碳基因丰度与水温、盐度呈显著负相关(p0.01),与硝酸盐、亚硝酸盐、硅酸盐呈显著正相关(p0.01). 相似文献
138.
139.
140.
To overcome adoption barriers and promote battery electric vehicles (BEVs) as an energy efficient consumer transportation option, a number of states offer subsidies to consumers for BEVs. We use a national data set of vehicle registrations and state-level financial incentives to assess the impact of vehicle purchase subsidies on adoption using both difference-in-differences and synthetic controls methods. We find that incentives offered as direct purchase rebates generate increased levels of new BEV registrations at a rate of approximately 8 percent per thousand dollars of incentive offered. Between 2011 and 2015, vehicle rebate incentives are associated with an increase in overall BEV registrations of approximately 11 percent. Our findings indicate incentives offered as state income tax credits do not have a statistically significant effect on BEV adoptions, though we caution this may be a result of limited temporal variation in BEV incentives across our sample. Responses to rebate incentives do not differ significantly by the make of the vehicle purchased (i.e., Tesla and non-Tesla vehicles). We combine our results with recent assessments of marginal environmental costs of electric vehicle charging and measure net welfare effects of BEV subsidy programs. Our analysis indicates these programs are not welfare-improving if only considering benefits associated with avoided emissions. Additional benefits associated with long-term market growth, production cost savings, network externalities, or accelerated innovation could substantially impact the net welfare outcomes. 相似文献