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Selenium (Se) reduces Sclerotinia stem rot disease incidence of oilseed rape by increasing plant Se concentration and shifting soil microbial community and functional profiles 全文
2019
Liu, Kang | Cai, Miaomiao | Hu, Chengxiao | Sun, Xuecheng | Cheng, Qin | Jia, Wei | Yang, Tao | Nie, Min | Zhao, Xiaohu
Sclerotinia stem rot (SSR), a soil-borne plant disease, cause the yield loss of oilseed rape. Selenium (Se), a beneficial element of plant, improves plant resistance to pathogens, and regulates microbial communities in soil. Soil microbial communities has been identified to play an important role in plant health. We studied whether the changes in soil microbiome under influence of Se associated with oilseed rape health. SSR disease incidence of oilseed rape and soil biochemical properties were investigated in Enshi district, “The World Capital of Selenium”, and soil bacterial and fungal communities were analyzed by 16S rRNA and ITS sequencing, respectively. Results showed that Se had a strong effect on SSR incidence, and disease incidence inversely related with plant Se concentration. Besides, soil Se enhanced the microbiome diversities and the relative abundance of PGPR (plant growth promoting rhizobacteria), such as Bryobacter, Nitrospirae, Rhizobiales, Xanthobacteraceae, Nitrosomonadaceae and Basidiomycota. Furthermore, Soil Se decreased the relative abundance of pathogenic fungi, such as Olpidium, Armillaria, Coniosporium, Microbotryomycetes and Chytridiomycetes. Additionally, Se increased nitrogen metabolism, carbohydrate metabolism and cell processes related functional profiles in soil. The enrichment of Se in plants and improvement of soil microbial community were related to increased plant resistance to pathogen infection. These findings suggested that Se has potential to be developed as an ecological fungicide for biological control of SSR.
显示更多 [+] 显示较少 [-]Short-term exposure to air pollution and conjunctivitis outpatient visits: A multi-city study in China 全文
2019
Lü, Peng | Zhang, Yongming | Xia, Guoxin | Zhang, Wenyi | Li, Shanshan | Guo, Yuming
Conjunctivitis has hazardous effects on patients’ quality of life through influencing school performance, work productivity, and daily activities such as driving. However, limited evidence is available on the contributory role of air pollution on conjunctivitis, particularly in China.We obtained data of 81,351 conjunctivitis outpatients from the largest comprehensive hospitals of four cities, China, between Jan 1, 2013 and Dec 31, 2014. Data on air pollutants, including particulate matter ≤2.5 μm in diameter (PM₂.₅), particulate matter ≤10 μm in diameter (PM₁₀), nitrogen dioxide (NO₂), ozone (O₃) and sulphur dioxide (SO₂) were collected from China National Environmental Monitoring Centre. Conjunctivitis outpatient visits were linked with air pollution concentrations by the visiting dates. A time-stratified case-crossover design with conditional logistic regression model was used to examine the effect of short-term exposure to air pollution on conjunctivitis outpatient visits.We found that the associations between air pollutants (per 10 μg/m³ increase) and hospital outpatient visits for asthma were [odds ratios (ORs) and 95% confidence intervals]: 1.004(1.002–1.007) for PM₂.₅, 1.004 (1.002–1.005) for PM₁₀, 1.012(1.005–1.020) for NO₂, 1.006 (1.001–1.011) for SO₂, and 1.007 (1.003–1.010) for O₃, respectively at lag0 day. Outpatients aged 35–64 years showed significant associations with exposure to PM₂.₅ (1.005, 1.001–1.010), PM₁₀ (1.005, 1.002–1.008), NO₂ (1.014, 1.003–1.026), and O₃ (1.005, 1.000–1.011), while those aged 15–34 years showed significant associations with exposure to O₃ (1.010, 1.004–1.017).Short-term exposure to air pollution has impacts on outpatient visits for conjunctivitis in China. This study suggests that improving air quality could protect eye health.
显示更多 [+] 显示较少 [-]The upper size limit of the dust samples in road dust heavy metal studies: Benefits of a combined sieving and air classification sample preparation procedure 全文
2019
Lanzerstorfer, Christof | Logiewa, Agata
The concentrations of heavy metals and other components in road dust from a Polish coal mining district were investigated. The sample was split into eight size fractions ranging from <5 μm to 1–2 mm applying the combined classification procedure of dry sieving and air classification. For most elements, significantly higher concentrations were found in the finest size fractions. In combination with the mass fractions of the various size fractions the concentrations of the components were calculated for this road dust assuming different upper size limits. The results demonstrate the important influence of the upper size limit applied on the composition of road dust. An analysis of the composition of road dust by particle size, instead of analysing whole road dust samples, proves to have several advantages. On the one hand, a reliable comparison of the results with the concentration data available in the literature is possible and on the other hand, the results can be used in assessments, for example resuspension or wash-off by rainfall, which require different upper size limits.Upper size limit applied in road dust sampling significantly influences the results. Combined sieving and air classification sample preparation procedure allows flexible use of the results.
显示更多 [+] 显示较少 [-]Locating and quantifying multiple landfills methane emissions using aircraft data 全文
2019
Gasbarra, D. | Toscano, P. | Famulari, D. | Finardi, S. | Di Tommasi, P. | Zaldei, A. | Carlucci, P. | Magliulo, E. | Gioli, B.
A mass balance approach to quantify methane (CH4) emission of four co-located landfills by means of airborne measurements and dispersion modelling was proposed and assessed. By flying grids at different heights above the landfills, atmospheric CH4 densities and wind components were measured along the edges and inside the study atmospheric volume, in order to calculate mass flows in the along- and across-wind directions. A steady-state Gaussian dispersion model was applied to build the concentration fields associated to unit emission from each landfill, while the contribution of each one to the total emission was assessed using a General Linear Model approach, minimizing the difference between measured and modeled mass flows. Results showed that wind spatial and temporal variability is the main factor controlling the accuracy of the method, as a good agreement between measured and modeled mass flows was mainly found for flights made in steady wind conditions. CH4 emissions of the entire area ranged from 213.5 ± 33.5 to 317.9 ± 90.4 g s−1 with a mean value of 252.5 ± 54.2 g s−1. Contributions from individual sources varied from 17.5 to 40.1 g m−2 day−1 indicating a substantial heterogeneity of the different landfills, which differed in age and waste composition. The proposed method was validated against tower eddy covariance flux measurements made at one of the landfills, revealing an overall agreement within 20%.
显示更多 [+] 显示较少 [-]Environmentally relevant concentrations of arsenite induces developmental toxicity and oxidative responses in the early life stage of zebrafish 全文
2019
Sun, Hong-Jie | Zhang, Jing-Ying | Wang, Qiang | Zhu, Engao | Chen, Wenrong | Lin, Hongjun | Chen, Jianrong | Hong, Huachang
Arsenic (As) present in water is a nonignorable environmental issue, even at low concentrations (≤150 μg L⁻¹). To evaluate the toxic effect of low concentrations of As, zebrafish at early life stage were exposed to 0, 25, 50, 75, or 150 μg L⁻¹ AsIII for 120 h. Our results indicated that low concentration of AsIII decreased zebrafish larvae’s survival rate to 85%, 89% and 86% at 50, 75 and 150 μg L⁻¹. Furthermore, low concentrations of AsIII exposure caused oxidative stress (elevated superoxide dismutase (SOD) activity and influenced the mRNA transcriptional levels of Cu/ZnSOD and MnSOD) and damage (increased malondialdehyde levels). Meanwhile, zebrafish larvae regulated the mRNA transcription of metallothionein and heat shock protein 70 to alleviate toxicity caused by AsIII. These results revealed lower concentrations (≤150 μg L⁻¹) of AsIII had a detriment effect on the survival of fish at early life stage, moreover, oxidative stress caused by AsIII posed potential risk for the zebrafish. This study provides novel insight into low concentration AsIII-induced toxicity in zebrafish.
显示更多 [+] 显示较少 [-]Neuroimaging signatures of brain plasticity in adults with prenatal exposure to polychlorinated biphenyls: Altered functional connectivity on functional MRI 全文
2019
Chu, Chih-Pang | Wu, Shao-Wei | Huang, Yi-Jie | Chiang, Ming-Chang | Hsieh, Sung-Tsang | Guo, Yue Leon
Prenatal exposure to polychlorinated biphenyls (PCBs), persistent organic pollutants in food chains and environment, exerts negative effects on children's cognitive function. To study the long-term effects, we examined cognitive functions in the male children of women with substantial PCB exposure in Taiwan during 1978–1979 and investigated neural basis of cognitive function changes through structural magnetic resonance imaging (MRI) and functional MRI (fMRI), which included resting-state and task-activated fMRI with two paradigms: a 2-back task and a picture rotation task. Ten men aged 30.0 ± 3.7 years with prenatal exposure to PCBs and 11 unexposed controls aged 28.1 ± 3.1 years participated. Both groups had similar cognitive phenotypes and behavioral results. Structural MRI analysis results showed that the PCB group had increased cortical thickness over the right inferior parietal lobule. In the resting-state study, the PCB group showed alterations in the default mode network. During the tasks, the PCB group showed decreased task-induced deactivation signals in cognition–associated brain areas during the 2-back task but enhanced deactivations during the picture rotation task. This study demonstrated altered structural MRI as well as resting and task-related fMRI in men with prenatal PCB exposure, suggesting altered brain plasticity and compensatory neuropsychological performance.
显示更多 [+] 显示较少 [-]Effects of interactions between humic acid and heavy metal ions on the aggregation of TiO2 nanoparticles in water environment 全文
2019
Wang, Dongxu | Wang, Peifang | Wang, Chao | Ao, Yanhui
Nanoparticles (NPs), heavy metal and natural organic matter (NOM) may simultaneously exist in the aquatic environment, where they will affect the behavior of each other and may enhance their toxicities. Studies on the influences of interactions between NOM and heavy metal ions on the behavior of NPs are scarce. In this study, combined effects of Pb²⁺ and HA on the aggregation behavior of TiO₂ NPs in water environment were investigated by Dynamic light scattering (DLS) and Nanoparticle tracking analysis (NTA). The results illustrated that interactions between Pb²⁺ and HA could case the aggregation of TiO₂ NPs obviously. The concurrence of Pb²⁺ and HA resulted in decreased critical coagulation concentration (CCC) and increased attachment efficiencies. Meanwhile, we found that the addition sequences of HA and heavy metal clearly influenced the aggregation kinetics of TiO₂ NPs. At different addition sequences, the complex reaction between Pb²⁺ and HA changed the surface charge of TiO₂ NPs, and caused the different aggregation behavior which depended on the complex locations and complex sites. Furthermore, the excitation-emission-matrix (EEM) fluorescence spectra was used to verify the significant effects of the complex interactions between Pb²⁺ and HA on the aggregation of TiO₂ NPs. Our results would be significant for interpreting TiO₂ behavior in the complicated water system.The complexation between Pb²⁺ and HA promoted the aggregation of TiO₂ NPs, meanwhile, complex locations and complex sites played an important role.
显示更多 [+] 显示较少 [-]Toxicokinetic−toxicodynamic modeling of cadmium and lead toxicity to larvae and adult zebrafish 全文
2019
Gao, Yongfei | Zhang, Yan | Feng, Jianfeng | Zhu, Lin
Toxicity of hazard materials to organism is different between larvae and adult zebrafish. However, this different effect was seldom considered in toxicological modeling. Here, we measured Cd and Pb toxicity for larvae and adult zebrafish (Danio rerio) and assessed whether metal toxicity can be better simulated by the one-compartment or two-compartment toxicokinetic (TK) and toxicodynamic (TD) models with assumption of stochastic death (SD) and individual tolerance (IT), respectively. Results showed that, for larvae, the one-compartment model generally fitted the observed accumulation and survival better than two-compartment model. In contrast, for adult, the two-compartment model simulation satisfied the observed accumulation and survival better than one-compartment model. In addition, both the SD and the IT models generally described the Cd or Pb toxicity well, although the IT model predictions were slightly better than the SD model in adult fish, the opposite phenomenon was observed in larvae. Our results suggested that variations in both TK and TD parameters might be needed to quantify the toxicity sensitivity in larvae and adult zebrafish, and accounting these variations in mechanistic toxicological effect models (e.g. TK-TD) will allow more accurate predictions of hazard materials effects to organisms.
显示更多 [+] 显示较少 [-]Effects of biochar on uptake, acquisition and translocation of silver nanoparticles in rice (Oryza sativa L.) in relation to growth, photosynthetic traits and nutrients displacement 全文
2019
Abbas, Qumber | Liu, Guijian | Yousaf, Balal | Ali, Muhammad Ubaid | Ullah, Habib | Ahmed, Rafay
Rapid development in nanotechnology and incorporation of silver nanoparticles (AgNPs) in wide range of consumer products causing the considerable release of these NPs in the environment, leading concerns for ecosystem safety and plant health. In this study, rice (Oryza sativa) was exposed to AgNPs (0, 100, 200, 500 and 1000 mg L−1) in biochar amended (2 %w/v) and un-amended systems. Exposure of plants to AgNPs alone reduced the root and shoot length, biomass production, chlorophyll contents, photosynthesis related physiological parameters as well as macro-and micronutrients in a dose dependent manner. However, in case of biochar amendment, physiological parameters i.e., net photosynthesis rate, maximum photosynthesis rate, CO2 assimilation, dark respiration and stomatal conductance reduced only 16, 6, 7, 3 and 8%, respectively under AgNPs exposure at 1000 mg L−1 dose. Meanwhile, biochar at all exposure level of AgNPs decreased the bioaccumulation of Ag in rice root and shoot tissues, thus alleviated the phyto-toxic effects of NPs on plant growth. Moreover, results showed that biochar reduced the bioavailability of AgNPs by surface complexation, suppressing dissolution and release of toxic Ag+ ions in the growth medium. The presence of biochar at least decreased 2-fold tissue contents of Ag even at highest AgNPs (1000 mg L−1) concentration. These finding suggested that biochar derived from waste biomass resources can be used effectively to prevent the bioaccumulation and subsequent trophic level transfer of emerging Ag nano-pollutant in the environment.
显示更多 [+] 显示较少 [-]Potential reductions in premature mortality attributable to PM2.5 by reducing indoor pollution: A model analysis for Beijing-Tianjin-Hebei of China 全文
2019
Ji, Wenjing | Zhou, Bin | Zhao, Bin
China has one of the highest PM2.5 (particulate matter with an aerodynamic diameter smaller than 2.5 μm) pollution levels in the world. It might still be long before air quality reaches the National Class II standard of 35 μg/m3.We aim to estimate the potential reduction in premature mortality by reducing indoor PM2.5 levels in the Beijing-Tianjin-Hebei (BTH) region and compare it with reducing outdoor levels.We combined PM2.5 transport model and the Global Burden of Disease (2016) methodology to estimate potential reductions in premature mortality attributable to PM2.5 by reducing indoor PM2.5 to National Class I standard of 15 μg/m3, and compared with reducing outdoor PM2.5 to Government 2020 Interim target of 64 μg/m3 or National Class II standard of 35 μg/m3.A total of 74,000 (95% confidence interval (CI): 43,000–111,000) premature deaths were attributable to PM2.5 exposure in 2013. Thirty percent, or 22,000 (95% CI: 17,000–32,000) deaths, would have been averted if indoor PM2.5 had reached the National Class I standard. The benefit is greater than that from reaching the Government 2020 Interim target for outdoor PM2.5 [22%, or 16,000 (95% CI: 12,000–23,000), deaths], although still smaller than that from reaching the National Class II standard [42%, or 31,000 (95% CI: 24,000–45,000), deaths].Reaching the National Class I level of indoor PM2.5 at current outdoor pollution levels could bring considerable health benefits, which are comparable to those from reaching the Government 2020 Interim target for outdoor PM2.5.The avertable premature deaths gained from cleaning indoor PM2.5 to National Class I standard level would be greater than reducing outdoor PM2.5 to Government 2020 Interim target.
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