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A spectroscopic and theoretical investigation of interaction mechanisms of tetracycline and polystyrene nanospheres under different conditions 全文
2019
Wan, Tian | Lu, Songhua | Cheng, Wen | Ren, Jiehui | Wang, Min | Hu, Baowei | Jia, Ziyi | Li, Ying | Sun, Yubing
Interaction mechanisms of tetracycline (TC, as a typical antibiotic) on polystyrene microsphere (PSs, as a typical nanoplastic) were conducted by the batch, spectroscopic and theoretical techniques. The batch results showed that Na+ and K+ had no obvious effects on TC adsorption towards PSs, whereas Mg2+ significantly inhibited TC adsorption at pH > 5.0 due to its induced aggregations of PSs. The maximum TC adsorption capacity of PSs in the presence of humic acid (50.99 mg/g) was higher than that of PSs (44.77 mg/g) at pH 6.0. The highly effective adsorption was attributed to electrostatic attraction, π-π interaction and hydrophobic effect, which was determined by FT-IR and XPS analysis. According to DFT (density functional theory) calculations, the adsorption energy of TC/TC+ on PSs (1.52 eV) was significantly higher than that of negative TC− (0.57 eV), whereas minimum distance of TC on PSs (3.684 Å) was shorter than that of TC− on PSs (3.988 Å). The results of theoretical calculations indicated that TC was more preferably adsorbed on PSs with more stable configuration compared to TC−. These findings indicated that PSs can be used as a promising adsorbent for immobilization and pre-concentration of TC from aqueous solutions.
显示更多 [+] 显示较少 [-]Characteristics of organic phosphorus fractions in soil from water-level fluctuation zone by solution 31P-nuclear magnetic resonance and enzymatic hydrolysis 全文
2019
Qu, Ying | Wang, Chao | Guo, Jinsong | Huang, Junjie | Fang, Fang | Xiao, Yan | Ouyang, Wenjuan | Lu, Lunhui
Phosphorus (P) is an essential nutrient element for biological growth that can contribute to eutrophication in aquatic ecosystems. Water trophic status and algae growth are primarily related to the content of bioavailable P, which is primarily related to enzymatically hydrolysable organic P(EHOP) and dissolved inorganic P(IP). In this study, soil samples from the water-level fluctuation zone (WLFZ) were collected from a tributary of the Three Gorges Reservoir (TGR) to characterize the properties of organic P(OP) fractions using solution ³¹P-nuclear magnetic resonance (NMR) and enzymatic hydrolysis. ³¹P-NMR showed that orthophosphate was the main part of the bioavailable P in the WLFZ soil and accounted for 80.4% of the NaOH-EDTA extractable total P (NaOH-EDTA TP), while phosphate monoester accounted for 60.5% of NaOH-EDTA extractable OP (NaOH-EDTA OP). The soil properties and replenishment from the mainstream of the Yangtze River to the Pengxi River have a certain effect on the content and distribution of P forms in the WLFZ soil of the tributary. The EHOP accounted for 28.1% of the NaOH-EDTA OP, and a significant positive correlation was observed between labile monoester P and EHOP and organic matter (OM). The water-soluble OP(H₂O-OP), bicarbonate-extractable OP(NaHCO₃-OP), and Fe- and Al-associated OP(Fe/Al-OP) were significantly hydrolyzed by phosphatase and thus exhibited great release potential. The ranking of the bioavailability of OP was Fe/Al-OP > H₂O-OP > NaHCO₃-OP. Phytate-like P were mainly found in H₂O-OP and NaHCO₃-OP, which indicated that periodic submersion–emersion cycles promoted the release of phytate-like P from Fe/Al-OP into the water column of the TGR. These observations suggest that when the external P input was effectively controlled, a huge risk of release of the internal OP from the WLFZ soil, and the biogeochemical cycling of the bioavailable P played an important role in maintaining the eutrophication of the reservoir.
显示更多 [+] 显示较少 [-]Dissolved organic phosphorus enhances arsenate bioaccumulation and biotransformation in Microcystis aeruginosa 全文
2019
Wang, Zhenhong | Gui, Herong | Luo, Zhuanxi | Zhen, Zhuo | Yan, Changzhou | Xing, Baoshan
Only limited information is available on the effects of dissolved organic phosphorus (DOP) on arsenate (As(V)) bioaccumulation and biotransformation in organisms. In this study, we examined the influence of three different DOP forms (β-sodium glycerophosphate (βP), adenosine 5′-triphosphate (ATP), and D-Glucose-6-phosphate disodium (GP) salts) and inorganic phosphate (IP) on As(V) toxicity, accumulation, and biotransformation in Microcystis aeruginosa. Results showed that M. aeruginosa utilized the three DOP forms to sustain its growth. At a subcellular level, the higher phosphorus (P) distribution in metal-sensitive fractions (MSF) observed in the IP treatments could explain the comparatively lower toxic stress of algae compared to the DOP treatments. Meanwhile, the higher MSF distribution of arsenic (As) in M. aeruginosa in the presence of DOP could explain the higher toxicity with lower 96-h half maximal effective concentration (EC50) values. Although we observed As(V) and P discrimination in M. aeruginosa under IP treatments with high intracellular P/As, we did not find this discrimination under the DOP treatments. As accumulation in algal cells was therefore greatly enhanced by DOP, especially βP, given its lower transformation rate to phosphate compared to ATP and GP in media. Additionally, As(V) reduction and, subsequently, As(III) methylation were greatly facilitated in M. aeruginosa by the presence of DOP, particularly GP, which was confirmed by the higher relative expression of its two functional genes (arsC and arsM). Our findings indicate that As(V) accumulation and its subsequent biotransformation were enhanced by organic P forms, which provides new insight into how DOP modulates As metabolism in algae.
显示更多 [+] 显示较少 [-]No radioactive contamination from the Chernobyl disaster in Hungarian white truffles (Tuber magnatum) 全文
2019
Büntgen, Ulf | Jaggi, Maya | Egli, Simon | Heule, Martin | Peter, Martina | Zagyva, Imre | Krusic, Paul J. | Zimermann, Stephan | Bagi, Istvan
Despite being one of the most expensive gourmet foods, it remains unclear if the iconic White Truffle (Tuber magnatum Pico; hereinafter WT) accumulates radioactivity at harmful levels comparable to other fungal species. Here, we measure the active radiocaesium-137 concentration (137Cs) in ten hypogeous WT fruitbodies from southern Hungary, and the soils in which they were growing. All WTs reveal non-significant 137Cs values, thus providing an ‘all clear’ for WT hunters in the species' northernmost habitats, where corresponding soil samples occasionally exhibit slight 137Cs concentrations. Our results are particularly relevant in the light of a rapidly increasing global demand for WTs and their subsequent trading extent and price inflation, because up to 600 kg of fresh fruitbodies are harvested each year in southern Hungary. Moreover, some of Europe's forest ecosystems, in which mushroom picking is common practise, are still contaminated with 137Cs from the Chernobyl fallout more than 30 years ago, posing a serious threat to human health.
显示更多 [+] 显示较少 [-]Bisphenol S-induced chronic inflammatory stress in liver via peroxisome proliferator-activated receptor γ using fish in vivo and in vitro models 全文
2019
Qiu, Wenhui | Yang, Ming | Liu, Jingyu | Xu, Hai | Luo, Shusheng | Wong, Minghung | Zheng, Chunmiao
Bisphenol S (BPS) has been widely used as a bisphenol alternative in recent few years. However, with mounting evidence suggesting that the presence of BPS in the environment also poses risks to ecosystems and human health, we decided to use the juvenile common carp (Cyprinus carpio) and its primary macrophages as in vivo and in vitro models to examine if BPS is a safe substitute of BPA. The present study evaluated the immune responses of chronic BPS exposure and their mechanisms of action associated with peroxisome proliferator-activated receptor (PPAR) signaling pathway. Potential oxidative stress and pro-inflammatory effects of BPS exposure were identified in fish liver after 60-day exposure, based on the increased reactive oxygen species (ROS) production, antioxidant capacity, NO production, lipid peroxidation, and induction of inflammatory cytokine expression, as well as acute phase protein levels of C-reactive protein, immunoglobulin M, lysozyme, and complement component 3. Moreover, pparγ, PPAR pathway-associated genes retinoid x receptor α (rxrα) and nuclear factor-κb (nfκb) presented a rough concentration-dependent alteration after BPS exposure. An acute BPS exposure to the isolated primary macrophages from juvenile common carp was performed to help elucidate gene expression patterns of pparγ, rxrα, and nfκb in a typical immune cell model, the results were consistent with what we found in vivo experiments for long-term BPS exposure. Furthermore, with coexposure to BPS and a PPARγ antagonist, the restriction of PPAR signaling pathway significantly inhibited the induction of ROS and the mRNA level of interleukin-1β, confirming the involvement of PPAR pathway in BPS-induced chronic inflammatory stress in liver.
显示更多 [+] 显示较少 [-]In utero exposure to bisphenol A disrupts fetal testis development in rats 全文
2019
Lv, Yao | Li, Lili | Fang, Yinghui | Chen, Panpan | Wu, Siwen | Chen, Xiuxiu | Ni, Chaobo | Zhu, Qiqi | Huang, Tongliang | Lian, Qingquan | Ge, Ren-Shan
Bisphenol A (BPA) is widely used in consumer products and is a potential endocrine disruptor linked with abnormal development of male reproductive tract. However, its action and its effects on the pathways in the development of male gonad are still unclear. Here we report that effects of BPA exposure during gestation on male gonad development. Sprague-Dawley rats were gavaged daily with BPA (0, 4, 40, and 400 mg/kg body weight) from gestational day 12 to day 21. BPA dose-dependently decreased serum testosterone levels (0.45 ± 0.08 ng/ml and 0.32 ± 0.08 ng/ml for 40 and 400 mg/kg BPA, respectively) versus the control level (1.11 ± 0.22 ng/ml, Mean ± SE). BPA lowered Leydig cell Insl3 and Hsd17b3 mRNA and their protein levels at doses of 40 and 400 mg/kg. BPA also lowered Leydig cell (Lhcgr, Cyp11a1, and Cyp17a1) and Sertoli cell (Amh) mRNA and their protein levels at 400 mg/kg. BPA decreased fetal Leydig cell number via inhibiting their proliferation, but it did not affect fetal Sertoli cell number. In conclusion, the current study shows that in utero exposure to BPA inhibits fetal Leydig and Sertoli cell differentiation, possibly disrupting the development of male reproductive tract.
显示更多 [+] 显示较少 [-]Fiproles in urban surface runoff: Understanding sources and causes of contamination 全文
2019
Cryder, Zachary | Greenberg, Les | Richards, Jaben | Wolf, Douglas | Luo, Yuzhou | Gan, Jay
Urban-use pesticides present a unique risk to non-target organisms in surface aquatic systems because impervious pavement facilitates runoff that may lead to serious contamination and ensuing aquatic toxicity. Fipronil is an insecticide used at high rates in urban environments, especially in regions such as California. This compound and its biologically active degradation products have been detected in urban runoff drainage and downstream surface water bodies at concentrations exceeding toxicity thresholds for sensitive aquatic invertebrates, necessitating a better understanding of the runoff sources and causes of this contamination at sites of application. In this study, we evaluated sorption of fipronil, fipronil desulfinyl, fipronil sulfide, and fipronil sulfone in urban dust, soil, and concrete, matrices commonly associated with the perimeter of a residential home. Samples were also collected from five single family homes treated with fipronil in Riverside, California, for five months to determine the occurrence of fipronil and its degradates in runoff water, urban dust, soil, and on concrete surfaces. Statistical analysis was performed to determine which urban matrices contributed more significantly to the contaminant levels in runoff water. Freundlich sorption coefficients for fipronil and its degradation products in dust were 3- to 9-fold greater than their values in soil. Fipronil and its degradates were detected in 100% of runoff samples and their presence was observed in dust, soil, and concrete wipe samples for 153 d after the treatment. Linear regression analysis showed that concrete surfaces were a primary source of all four compounds to runoff, and loose dust on concrete pavement also served as an important contributor. This study represents the first comprehensive investigation of the sources and causes for surface runoff contamination by fipronil and its degradation products. Findings highlight the importance to reduce fipronil residues on concrete surfaces through improved application methods and other mitigation practices.
显示更多 [+] 显示较少 [-]Characterization of a multianalyte GC-MS/MS procedure for detecting and quantifying polycyclic aromatic hydrocarbons (PAHs) and PAH derivatives from air particulate matter for an improved risk assessment 全文
2019
Mueller, Andrea | Ulrich, Nadin | Hollmann, Josef | Zapata Sanchez, Carmen E. | Rolle-Kampczyk, Ulrike E. | von Bergen, Martin
A correct description of the concentration and distribution of particle bound polycyclic aromatic hydrocarbons is important for risk assessment of atmospheric particulate matter. A new targeted GC-MS/MS method was developed for analyzing 64 PAHs including compounds with a molecular weight >300, as well as nitro-, methyl-, oxy- and hydroxyl derivatives in a single analysis. The instrumental LOD ranged between 0.03 and 0.7 pg/μL for PAHs, 0.2–7.9 pg/μL for hydroxyl and oxy PAHs, 0.1–7.4 pg/μL for nitro PAHs and 0.06–0.3 pg/μL for methyl-PAHs. As an example for the relevance of this method samples of PM₁₀ were collected at six sampling sites in Medellin, Colombia, extracted and the concentration of 64 compounds was determined. The 16 PAHs from the EPA priority list contributed only from 54% to 69% to the sum of all analyzed compounds, PAH with high molecular weight accounted for 8.8%–18.9%. Benzo(a)pyrene equivalents (BaPₑq) were calculated for the estimation of the life time cancer (LCR). The LCR according to the samples ranged from 2.75 × 10⁻⁵ to 1.4 × 10⁻⁴ by a calculation with toxic equivalent factors (TEF) and 5.7 × 10⁻⁵ to 3.8 × 10⁻⁴ with potency equivalent factor (PEF). By using the new relative potency factors (RPF) recommended by US Environmental Protection Agency (U.S.EPA) the LCR ranged from 1.3 × 10⁻⁴ to 7.2 × 10⁻⁴. Hence, it was around six times higher than the well-known TEF. The novel method enables the reliable quantification of a more comprehensive set of PAHs bound on PM and thus will facilitate and improve the risk assessment of them.
显示更多 [+] 显示较少 [-]Underwater noise level predictions of ammunition explosions in the shallow area of Lithuanian Baltic Sea 全文
2019
Bagočius, Donatas | Narščius, Aleksas
Among the noisiest man-made activities in the seas, emitting very high acoustic energy are the underwater explosions of various objects and ship shock trials. Sound energy emitted by high explosives can be predicted or measured at sea. Sometimes, it can be convenient to apply empirical formulas and scaling laws to approximate the energy of underwater explosions. In addition, at some instances the determination of the spectral properties of the explosions is useful, i.e. when possible animal exposure to impulsive noise has to be evaluated. This paper presents an example of an application of freely available scaling laws and equations for prediction of noise levels of underwater explosions of historical ordnance in the shallow sea environments.Main findings of the study: An available scaling laws applied to model underwater explosion properties; spatial extent of explosion mapped; arising issues of modelling of underwater explosions in the shallow marine areas discussed.
显示更多 [+] 显示较少 [-]Effects of cerium oxide on rice seedlings as affected by co-exposure of cadmium and salt 全文
2019
Wang, Yaoyao | Wang, Lingqing | Ma, Chuanxin | Wang, Kexiang | Hao, Yi | Chen, Qing | Mo, You | Rui, Yukui
Effects of CeO2 NPs (200 mg.L−1) on rice (Oryza sativa L.) alone or co-exposure with cadmium (Cd) and salt (sodium chloride, NaCl) were investigated in hydroponic systems for two weeks. Physiological results show that rice biomass was significantly inhibited when NaCl or CdCl2 added alone or in co-exposure treatment. CeO2 NPs significantly relieve the chlorophyll damage under CdCl2 environmental stress. The presence of CeO2 NPs alleviated both stressors induced damages to rice as indicated by the reduced proline level. Additionally, CeO2 NPs triggered the antioxidant defense systems to counteract the oxidative stress caused by NaCl and CdCl2. The level of 8-OHdG, one of the most important indicators for genotoxicity, in rice suggest that the presence of CeO2 NPs reduced the DNA damage in NaCl treated rice. Elemental analysis indicated that co-exposure to NaCl and CdCl2 slightly decreased the Cd content as compared to the one in the CdCl2 alone treatment, and this co-exposure also significantly reduced the Na content when comparing with the NaCl alone treatment. Taken together, our findings suggest that CeO2 NPs could alleviate the CdCl2 and NaCl stresses, but could not completely change the phenotype of both contaminants treated rice.
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