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Toxic effect of Atalantia monophylla essential oil on Callosobruchus maculatus and Sitophilus oryzae 全文
2017
Nattudurai, Gopal | Baskar, Kathirvelu | Paulraj, Micheal Gabrial | Islam, Villianur Ibrahim Hairul | Ignacimuthu, Savarimuthu | Duraipandiyan, Veeramuthu
The hydrodistillated essential oil of Atalantia monophylla was subjected to GC-MS. Forty compounds were presented in the essential oil. Eugenol (19.76 %), sabinene (19.57 %), 1,2-dimethoxy-4-(2-methoxyethenyl) benzene (9.84 %), beta-asarone (7.02 %) and methyl eugenol (5.52 %) were found the predominant compounds. The oil was tested for fumigant toxicity and repellent activity against Callosobruchus maculatus and Sitophilus oryzae. The development stage of C. maculatus fecundity, adult emergence and also ovicidal activities were studied by the treatment of A. monophylla oil. The oil exhibited considerable fumigation toxicity (70.22 %), repellent activity (85.24 %) and ovicidal activity (100 %) against C. maculatus. The oil significantly reduced the protein, esterase, acetylcholinesterase and glutathione S-transferase on C. maculatus and S. oryzae. It can be considered that A. monophylla has a potential insecticide against stored product pests.
显示更多 [+] 显示较少 [-]Degradation of 3,4-dichlorobenzotrifluoride by the Fenton-like process using zirconia-coated magnetite magnetic nanoparticles as an effective heterogeneous catalyst 全文
2017
Chen, Hai | Sun, Zhengnan | Yang, Zhilin | Zhang, Zhonglei | Wang, Jianlong | Feng, Mingbao | Yang, Qi
In this study, zirconia-coated magnetite magnetic nanoparticles (ZrO₂/Fe₃O₄ MNPs) were prepared, characterized, and used as an effective and reusable heterogeneous catalyst for 3,4-dichlorobenzotrifluoride (3,4-DCBTE) degradation. The catalytic potential of the Fe₃O₄/ZrO₂-H₂O₂ system for the removal of 3,4-DCBTE was tested in comparison with several other systems, and the effects of various operating parameters, including initial solution pH, catalyst addition, H₂O₂ concentrations, and reaction temperature, were also evaluated with respect to the degradation efficiency of 3,4-DCBTE. Results showed that the Fe₃O₄/ZrO₂ composite could effectively enhance the oxidation of 3,4-DCBTE by the Fenton-like process, and there might be a synergetic effect in the Fe₃O₄/ZrO₂ composite. When the mass ratio of Fe₃O₄ and ZrO₂ was 1:1, the Fe₃O₄/ZrO₂ exhibited the best catalytic activity, and the catalyst-driven Fenton process achieved high removal of 3,4-DCBTE (98.5%) and total organic carbon (TOC) (52.7%) at the operating conditions: pH 3.0, catalyst 2.0 g/L, H₂O₂ 30 mM, temperature 30 °C, and reaction time 1 h. Furthermore, five successive runs of the Fenton oxidation using the same Fe₃O₄/ZrO₂ composite resulted in the steady removal of 3,4-DCBTE, further confirming the high stability of the catalyst. In addition, the possible catalytic mechanism and degradation pathways of 3,4-DCBTE were also investigated.
显示更多 [+] 显示较少 [-]Alleviative effect of licorice on copper chloride-induced oxidative stress in the brain: biochemical, histopathological, immunohistochemical, and genotoxic study 全文
2017
Mostafa, Heba El-Sayed | Alaa-Eldin, Eman Ahmad | El-Shafei, Dalia Abdallah | Abouhashem, Nehal S.
Although copper is an essential micronutrient involved in a variety of biological processes indispensable for sustaining life, it can be toxic when administered in excess. Licorice (Glycyrrhizaglabra) has been used in Chinese folk medicine for the treatment of various disorders. Licorice has the biological capabilities of detoxication, antioxidation, and antiinfection. Here, we test the hypothesis that licorice could ameliorate copper-induced neurotoxic and genotoxic effects in adult male albino rats. For this purpose, 48 adult male albino rats were randomized into five groups: group I (8 rats), untreated control; group II (16 rats), subdivided into; vehicle control IIa (8 rats) which received 1 mL saline twice weekly intraperitoneally for 8 weeks and vehicle control IIb (8 rats) received 0.5 mL distilled water/day orally gavaged for 8 weeks; group III (8 rats), treated with licorice dissolved in 0.5 mL of distilled water, 50 mg/kg b.w./day orally gavaged for 8 weeks; group IV (8 rats), copper chloride (CuCl₂) dissolved in 0.5 mL saline, 7 mg/kg b.w. twice weekly intraperitoneal for 8 weeks; and group V (8 rats), CuCl₂ + licorice (the same previously mentioned doses) licorice extract were orally given for 10 days before treatment was initiated then followed by CuCl₂ intraperitoneally for 8 weeks. We found that CuCl₂ exposure significantly increased brain oxidative stress as manifested by elevated malondialdehyde levels, decreased reduced glutathione content, and depressed antioxidant enzyme activities in brain tissues when compared with control groups. This was accompanied by histopathological changes in the form of increased cellularity and swelling of astrocytes that showed dense eosinophilic cytoplasm, pyknotic nuclei, and multiple apoptotic bodies that associated with degenerated neurons with deep eosinophilic cytoplasm. Also, strong Bax immunoreactions in the brain were detected. Furthermore, comet assay results confirmed CuCl₂-related oxidative DNA damage. Notably, all these changes were partially ameliorated in rats treated concomitantly with licorice and CuCl₂. Our results showed that licorice exerts protective effects against CuCl₂-induced neuro- and genotoxicities. These effects may be attributed to the antioxidative property of licorice.
显示更多 [+] 显示较少 [-]Emission analysis on the effect of nanoparticles on neat biodiesel in unmodified diesel engine 全文
2017
Pandian, Amith Kishore | Ramakrishnan, Ramesh Bapu Bathey | Devarajan, Yuvarajan
Biodiesels derived from the mahua seeds are established as a promising alternative for the diesel fuel owing to its non-edible nature and improved properties. TiO₂ nanoparticle in powder form is added to neat mahua oil biodiesel (BD100) to examine its effect on emission characteristics. TiO₂ nanoparticle is chosen as an additive owing to its catalytic effect, higher surface energy, and larger surface to volume ratio. TiO₂ nanoparticle with an average size of 60 nm was synthesized by sol-gel route. TiO₂ nanoparticles are added with mahua biodiesel (BD100) at 100 and 200 ppm. Mahua oil biodiesel doped with 100 and 200 ppm of TiO₂ nanoparticles are referred as BD100T100 and BD100T200. A constant speed diesel engine is employed for the experimental trail. Engine is fueled with diesel, BD100, BD100T100, and BD100T200, respectively. Experimental result confirmed that the modified fuels (BD100T200 and BD100T100) showed a significant reduction in all the emissions. Further, the addition of TiO₂ nanoparticle (200 ppm) to mahua biodiesel gave respective reduction of 9.3, 5.8, 6.6, and 2.7% in carbon monoxide, hydrocarbon, nitrogen oxide, and smoke emissions when compared to neat mahua biodiesel.
显示更多 [+] 显示较少 [-]Toxic evaluations of sediments in Tokyo Bay, Japan, using Japanese medaka embryos 全文
2017
Uno, Seiichi | Kokushi, Emiko | Kawano, Machi | McElroy, Anne E. | Koyama, Jiro
Toxic risks of sediments collected from seven sites in Tokyo Bay were evaluated using Japanese medaka embryos. Those sediments with slight pore water were placed in grass petri dishes without overlying water. The most remarkable effect in the field sediment was to cause hatching delay in embryos, and the longest time until hatching took was 12.5 ± 1.6 days post-fertilization (dpf), although that in control group was 10.1 ± 0.7 dpf. A significant delay in hatching was observed at four sites. Because total carbon concentrations were relatively high in sediments at three of these four sites, several chemicals were expected to be residues in these sites and could cause their delay. Although extreme mortality was not observed at all sites, sediments collected from the site close to Kawasaki city induced 10 % mortality. Polycyclic aromatic hydrocarbon (PAH) concentrations were remarkably high at this site compared with other sites, and thus PAH toxicities could be causing the mortality. Concentration of heavy metals such as cadmium, copper, lead, and zinc in sediments were also determined, but no clear relationship was found between toxicities to embryos and the distribution of their concentrations.
显示更多 [+] 显示较少 [-]Effect of an alkaline environment on the engineering behavior of cement-stabilized/solidified Zn-contaminated soils 全文
2017
Liu, Jingjing | Zha, Fusheng | Deng, Yongfeng | Cui, Kerui | Zhang, Xueqin
Although the stabilization/solidification method has been widely used for remediation of heavy metal-contaminated soils in recent decades, the engineering behavior and mobility of heavy metal ions under alkaline groundwater conditions are still unclear. Therefore, the unconfined compressive strength test (UCS) combined with toxicity characteristic leaching procedure (TCLP) and general acid neutralization capacity (GANC) was used to investigate the effects of alkalinity (using NaOH to simulate alkalinity in the environment) on the mechanical and leaching characteristics of cement-solidified/stabilized (S/S) Zn-contaminated soils. Moreover, the microstructure was analyzed using the scanning electron microscope (SEM) technology. The results indicated that alkaline environment could accelerate the UCS development compared with specimens without soaking in NaOH solution,, regardless of whether the specimens contained Zn²⁺ or not. And the UCS varied obviously attributed to the variations of both NaOH concentration and soaking time. Except for the specimens soaked for 90 days, the leached Zn²⁺ concentrations were higher than that of without soaking. However, the leachability of Zn²⁺ in all the stabilized specimens is in the regulatory level. ANC results indicated that the Zn²⁺ leaching behavior can be divided into three stages related to the initial leachate pH. Moreover, SEM results proved that the alkaline environment could actually facilitate the cement hydration process. The results proved in the present paper could be useful in treating the heavy metal-contaminated soils involved in the solidification/stabilization technology under alkaline environment.
显示更多 [+] 显示较少 [-]Investigation of the removal mechanism of Cr(VI) in groundwater using activated carbon and cast iron combined system 全文
2017
Huang, Dandan | Wang, Guangcai | Li, Zhihong | Kang, Fei | Liu, Fei
Zero-valent iron (Fe⁰) has been widely used for Cr(VI) removal; however, the removal mechanisms of Cr(VI) from aqueous solution under complex hydrogeochemical conditions were poorly understood. In this research, the mixed materials containing cast iron and activated carbon were packed in columns for the treatment of aqueous Cr(VI)-Cr(III) in groundwater with high concentration of Ca²⁺, Mg²⁺, HCO₃ ⁻, NO₃ ⁻, and SO₄ ²⁻. We investigate the influences of those ions on Cr(VI) removal, especially emphasizing on the reaction mechanisms and associated precipitations which may lead to porosity loss by using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) techniques. The results show that the precipitations accumulated on the material surface were (Fe/Cr) (oxy)hydroxide, mixed Fe(III)-Cr(III) (oxy)hydroxides, Fe₂O₃, CaCO₃, and MgCO₃. During these reactions, the Cr(VI) was reduced to Cr(III) coupled with the oxidated Fe⁰ to Fe(II) through the galvanic corrosion formed by the Fe⁰-C and/or the direct electron transfer between Fe⁰ and Cr(VI). In addition, Cr(VI) could be reduced by aqueous Fe(II), which dominated the whole removal efficiency. The primary aqueous Cr(III) was completely removed together with Cr(III) reduced from Cr(VI) even when Cr(VI) was detected in the effluent, which meant that the aqueous Cr(III) could occupy the adsorption sites. In general, the combined system was useful for the Cr(VI)-Cr(III) treatment based on galvanic corrosion, and the hardness ions had a negative effect on Cr(VI) removal by forming the carbonates which might promote the passivation of materials and decrease the removal capacity of the system.
显示更多 [+] 显示较少 [-]Evaluation of organic amendment on the effect of cadmium bioavailability in contaminated soils using the DGT technique and traditional methods 全文
2017
Lin, Wanjing | Sun, Qin | Wang, Chao | Wang, Pei-fang | Ding, Shi-ming
Organic amendments have been widely proposed as a remediation technology for metal-contaminated soils, but there exist controversial results on their effectiveness. In this study, the effect of pig manure addition on cadmium (Cd) bioavailability in Cd-contaminated soils was systematically evaluated by one dynamic, in situ technique of diffusive gradients in thin films (DGT) and four traditional methods based on the equilibrium theory (soil solution concentration and the three commonly used extractants, i.e., acetic acid (HAc), ethylenediamine tetraacetic acid (EDTA), and calcium chloride (CaCl₂). Wheat and maize were selected for measurement of plant Cd uptake. The results showed that pig manure addition could promote the growth of two plants, accompanied by increasing biomasses of shoots and roots with increasing doses of pig manure addition. Correspondingly, increasing additions of pig manure reduced plant Cd uptake and accumulation, as indicated by the decreases of Cd concentrations in shoots and roots. The bioavailable concentrations of Cd in Cd-contaminated soils reflected by the DGT technique obviously decreased with increasing doses of pig manure addition, following the same changing trend as plant Cd uptake. Changes in soil solution Cd concentration and extractable Cd by HAc, EDTA, and CaCl₂ in soils were similar to DGT measurement. Meanwhile, the capability of Cd resupply from solid phase to soil solution decreased with increasing additions of pig manure, as reflected by the decreases in the ratio (R) value of C DGT to C ₛₒₗ. Positive correlations were observed between various bioavailable indicators of Cd in soils and Cd concentrations in the tissues of the two plants. These findings provide stronger evidence that pig manure amendment is effective in reducing Cd mobility and bioavailability in soils and it is an ideal organic material for remediation of Cd-contaminated soils.
显示更多 [+] 显示较少 [-]Short-term effects of air pollution on daily hospital admissions for cardiovascular diseases in western China 全文
2017
Ma, Yuxia | Zhang, Haipeng | Zhao, Yuxin | Zhou, Jianding | Yang, Sixu | Zheng, Xiaodong | Wang, Shigong
Controlling the confounding factors on cardiovascular diseases, such as long-time trend, calendar effect, and meteorological factors, a generalized additive model (GAM) was used to investigate the short-term effects of air pollutants (PM₁₀, SO₂, and NO₂) on daily cardiovascular admissions from March 1st to May 31st during 2007 to 2011 in Lanzhou, a heavily polluted city in western China. The influences of air pollutants were examined with different lag structures, and the potential effect modification by dust storm in spring was also investigated. Significant associations were found between air pollutants and hospital admissions for cardiovascular diseases both on dust event days and non-dust event days in spring. Air pollutants had lag effects on different age and gender groups. Relative risks (RRs) and their 95% confidence intervals (CIs) associated with a 10 μg/m³ increase were 1.14 (1.04~1.26) on lag1 for PM₁₀, 1.31 (1.21~1.51) on lag01 for SO₂, and 1.96 (1.49~2.57) on lag02 for NO₂ on dust days. Stronger effects of air pollutants were observed for females and the elderly (≥60 years). Our analysis concluded that the effects of air pollutants on cardiovascular admissions on dust days were significantly stronger than non-dust days. The current study strengthens the evidence of effects of air pollution on health and dust-exacerbated cardiovascular admissions in Lanzhou.
显示更多 [+] 显示较少 [-]Simultaneous adsorption of Remazol brilliant blue and Disperse orange dyes on red mud and isotherms for the mixed dye system 全文
2017
Gadigayya Mavinkattimath, Ratnamala | Shetty Kodialbail, Vidya | Govindan, Srinikethan
The paper presents the adsorption of Remazol brilliant blue (RBB) and Disperse orange 25 (DO25) dyes from aqueous solution of the mixture of dyes onto concentrated sulphuric acid-treated red mud (ATRM). First-order derivative spectrophotometric method was developed for the analysis of RBB and DO25 in mixed dye aqueous solution to overcome the limitations arising due to interference in the zero-order spectral method. The optimum conditions to maximize RBB adsorption favoured the adsorption of RBB, and those for DO25 favoured DO25 adsorption from the mixed dye aqueous solutions. Presence of a second dye always inhibited the adsorption of a target dye. The uptake and percentage adsorption of each of the dyes onto ATRM from the aqueous solution of the mixture of dyes decreased considerably with increasing concentrations of the other dye showing the antagonistic effect. Monocomponent Langmuir isotherm fitted the mixed dye adsorption equilibrium data better than the monocomponent Freundlich isotherm. However, monocomponent models are suitable for the fixed concentration of the other dye. Modified Langmuir isotherm model adequately predicted the multi-component adsorption equilibrium data for RBB-DO25-ATRM adsorption system with a good accuracy and is more generic from the application point of view.
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