خيارات البحث
النتائج 5431 - 5440 من 6,560
Renal protective effects of grape seed extract treatment against Eltroxin-induced hyperthyroidism, kidney damage, and oxidative stress in male mice النص الكامل
2020
Albrahim, Tarfa | Robert, Alwin
The present study aimed to investigate the influence of grape seed extract (GSE) in renal toxicity, oxidative stress, and Bcl-2 expressions in Eltroxin-induced hyperthyroidism to male mice. GSE was evaluated through oral administration to male mice at dose 50 mg/kg daily for 3 consecutive weeks. Eltroxin (100 μg/kg) was administered to mice for 3 weeks, and the mice were posttreated with GSE for another 3 weeks. Results revealed that GSE administered to normal mice did not produce any signs of toxicity and did not cause any biochemical or histopathological changes. Posttreatment of Eltroxin-induced hyperthyroidism mice with GSE daily for 3 weeks improved all examined biochemical or histopathological features. Oral GSE can significantly normalize the elevated level of T3 and T4 in hyperthyroidism animals and elevated the reduced levels of TSH. Moreover, serum urea, creatinine, and electrolyte levels were significantly improved. GSE showed a potent antioxidant capacity in all oxidative stress markers assays (TBARS, reduced GSH, GST, SOD, and CAT) of kidney tissue homogenates. Furthermore, histopathological examination of kidney tissue of Eltroxin + GSE-treated group confirms the potential nephroprotective effect of GSE through increasing the anti-apoptotic marker Bcl-2.
اظهر المزيد [+] اقل [-]Hyperspectral inversion of mercury in reed leaves under different levels of soil mercury contamination النص الكامل
2020
Liu, Weiwei | Li, Mengjie | Zhang, Manyin | Long, Songyuan | Guo, Ziliang | Wang, Henian | Li, Wei | Wang, Daan | Hu, Yukun | Wei, Yuanyun | Yang, Si
High mercury (Hg) affects biochemical-physiological characteristics of plant leaves such as leaf chlorophyll, causing refractive discontinuity and modifications in leaf spectra. Furthermore, the hyperspectroscopy provides a potential tool for fast non-destructive estimation of leaf Hg. However, there are few studies that have investigated Hg for wetland plants via hyperspectral inversion. In this study, reeds (Phragmites australis) leaf Hg concentration and hyperspectra were measured under different soil Hg treatment. Hg-sensitive parameters were identified by basic spectral transformations and continuous wavelet transformation (CWT). Inversion models were developed using stepwise multiple linear regressions (SMLR), partial least square regression (PLSR), and random forest (RF) to estimate leaf Hg. The results indicated that CWT improved the correlation of hyperspectra and leaf Hg by 0.020–0.227, and R² of the CWT-related model increased by 0.0557–0.2441. In addition, Hg-sensitive bands were predominant at 600–750 (visible region) and 1500–2300 nm (mid-infrared), and Hg might modify leaves spectra primarily by affecting chlorophyll and water contents. Of the studied models, SMLR using normalized transformation (NR) and CWT (NR-CWT-SMLR) model (R² = 0.8594, RMSE = 0.0961) and RF using NR and CWT (NR-CWT-RF) model (R² = 0.8560, RMSE = 0.1062) suited for leaf Hg inversion. For Hg content < 1.0 mg kg⁻¹, the former model was more reliable and accurate. This study provided a method for the estimation of Hg contamination in wetland plant and indicated that model-based hyperspectral inversion was feasible for fast and non-destructive monitoring.
اظهر المزيد [+] اقل [-]Advanced landfill leachate biochemical effluent treatment using Fe-Mn/AC activates O3/Na2S2O8 process: process optimization, wastewater quality analysis, and activator characterization النص الكامل
2020
Liu, Zhanmeng | Pan, Liang | Hu, Fengping | Hu, Yunqi
A novel catalyst of Fe-Mn/AC was prepared and used as a heterogeneous catalyst to activate O₃/Na₂S₂O₈ for landfill leachate biochemical effluent treatment. The experimental results indicated that the highest COD (84%) and color (98%) removal was obtained at Fe-Mn/AC dosage 1.2 g/L, O₃ concentration 1.2 g/L, Na₂S₂O₈ dosage 6 g/L, initial pH 10, and reaction time 100 min. Three-dimensional and excitation emission matrix (3D-EEM) fluorescence spectrometry, Fourier transform infrared spectroscopy (FTIR), and gas chromatography mass spectrometry (GC/MS) of wastewater samples before and after treatment demonstrated that the leachate biochemical effluent contained a large amount of humic and fulvic acid organic compounds. After treatment with this coupling system, both the pollution level of dissolved organic matter (DOM) and the fluorescence intensity declined. The micro morphology of Fe-Mn/AC was characterized using scanning X-ray diffraction patterns (XRD), electron microscope spectra (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. It can be concluded that the microscopic morphology of the catalyst is porous. The main active components are amorphous MnO₂ and multivalent iron oxides. Furthermore, the Fe-Mn/AC catalyst showed great reusability; the removal efficiency of COD was only reduced from 84% to 79% at the fourth reaction. Moreover, the COD removal efficiency could recover to 81% after catalyst regeneration.
اظهر المزيد [+] اقل [-]LINC01133: an emerging tumor-associated long non-coding RNA in tumor and osteosarcoma النص الكامل
2020
Li, Zheng | Xu, Derong | Chen, Xin | Li, Shugang | Chan, Matthew T. V. | Wu, William K. K.
Emerging evidence suggested that long non-coding RNAs (lncRNAs) play pivotal roles in tumorigenesis. LINC01133 is a newly identified lncRNA first discovered as an oncogene in lung squamous cell carcinoma. Subsequent studies further demonstrated this lncRNA was deregulated in a wide spectrum of tumors, including colorectal, gastric, lung, and pancreatic ductal adenocarcinoma as well as osteosarcoma and hepatocellular carcinoma. Intriguingly, this lncRNA exerted oncogenic or tumor-suppressive action in a tissue-dependent manner. This review sought to summarize our current understanding concerning the deregulation of LINC01133 in human tumors in relation to its molecular mechanisms and cellular functions. The clinical utilization of LINC01133 as a potential prognostic biomarker and a treatment target is also discussed.
اظهر المزيد [+] اقل [-]Phytotoxicity and cytogenotoxicity of composted tannery sludge النص الكامل
2020
de Moraes Cunha Gonçalves, Matheus | de Almeida Lopes, Angela Celis | Gomes, Regina Lucia Ferreira | de Melo, Wanderley José | Araujo, Ademir Sergio Ferreira | Pinheiro, José Baldin | Marin-Morales, Maria Aparecida
Tannery sludge (TS) contains high levels of organic matter and chemical elements, mainly chromium (Cr). This can increase its toxicity, rendering it unsuitable for application to soil. However, composting has been proposed as an alternative method for detoxifying TS before its addition to soil. Thus, the aim of this study was to evaluate the phytotoxic and cytogenotoxic potential of untreated (TS) and composted (CTS) tannery sludge in solid and solubilized samples. Seed germination and root growth bioassays were performed with Lactuca sativa, while chromosomal aberrations were assessed using the Allium cepa bioassay. In solid samples, the L. sativa bioassay showed that TS adversely affected germination and root growth, while CTS had a negative affect only on root growth. In solubilized samples, only TS showed significant adverse effects on seed germination and root growth. In both solid and solubilized samples, TS and CTS showed cytotoxic, genotoxic, and mutagenic effects on A. cepa. Thus, results demonstrated that the composting of TS does not result in its complete detoxification. For this reason, TS and CTS cannot be recommended for agricultural use, since they may increase the risk of environmental contamination and crop damage.
اظهر المزيد [+] اقل [-]What factors influence PM2.5 emissions in China? An analysis of regional differences using a combined method of data envelopment analysis and logarithmic mean Divisia index النص الكامل
2020
Xu, Shi-Chun | Zhou, Yi-Feng | Feng, Chao | Wang, Yan | Li, Yun-Fan
This study uses a combined data envelopment analysis and logarithmic mean Divisia index (DEA-LMDI) method to decompose affecting factors for PM₂.₅ emissions into effects related to the potential emission intensity (PEI), environmental efficiency and technology, production efficiency and technology, regional economic structure, and national economic growth, and investigates differences in the effects on PM₂.₅ emissions, considering the diversity among different areas and periods in China. This study provides a new insight in the decomposition method, which can decompose the emissions into new effects compared with the exiting studies. This study reveals that the regional environmental-based technology (EBT) effect is the key curbing factor for PM₂.₅ emissions, followed by the regional PEI effect. The curbing effect of regional EBT on PM₂.₅ emissions is strong in East China and weak in Northeast China. The environment-oriented scale efficiency (ESE), environment-oriented management efficiency (EME), production-oriented scale efficiency (PSE), production-oriented management efficiency (PME), and production-based technology (PBT) had relatively small effects on PM₂.₅ emissions on the whole. The effects differ among different areas and periods in China. The emission reduction potential of these efficiency effects has not been realized. The national economic growth greatly promotes PM₂.₅ emissions. The regional economic structure effect slightly increases PM₂.₅ emissions because of the unbalanced development of regional economy. The relative policy suggestions are put forward based on the findings of this study.
اظهر المزيد [+] اقل [-]Urinary bisphenol A, phthalate metabolites, and obesity: do gender and menopausal status matter? النص الكامل
2020
Lim, Jung-eun | Choi, BongKyoo | Jee, Sun Ha
Previous studies of urinary bisphenol A (BPA), phthalate metabolites, and obesity risk have shown inconsistent results. Menopausal status is one of the main factors that affect hormone secretion change in women. In this study, we examined whether urinary BPA and phthalate metabolite levels are associated with obesity and whether the associations differ by sex and menopausal status in a sample of Korean adult populations. We recruited participants at three branches (Yeouido, Gangnam, and Gwanghwamun) of the Korea Medical Institute, a nationwide health check-up center, from 2015 to 2016. Urinary BPA level was measured by high-performance liquid chromatography–tandem mass spectrometry (Agilent 6490 Triple Quad LC-MS/MS; Agilent Technologies, CA, USA). Urinary six phthalate metabolites were analyzed with ultra-high-performance liquid chromatography–tandem mass spectrometry (TSQ Quantum Access Mass; Thermo Fisher Scientific, MA, USA). Participants with body mass index ≥ 25 kg/m² were defined as general obesity group. Men with waist circumference (WC) ≥ 90 cm and women with WC ≥ 85 cm were defined as abdominal obesity group. Age, sex, alcohol intake, smoking, and exercise were considered in multivariate logistic regression models. Among the total of 702 participants, 211 participants were classified into the general obesity group, and 131 participants were classified into the abdominal obesity group. Urinary phthalate metabolite levels were not associated with general and abdominal obesity in men and women. However, in women, urinary BPA concentration was positively associated with abdominal obesity (OR = 1.50, 95% CI 1.00–2.26). Also, the association was stronger in postmenopausal women (OR = 2.23, 1.01–4.92), while it was weak in premenopausal women (OR = 1.31, 0.78–2.20). In this study, urinary BPA concentration was associated with abdominal obesity in women, especially postmenopausal women. Future studies should consider sex and menopausal status when investigating associations between urinary BPA, phthalate metabolites levels, and obesity.
اظهر المزيد [+] اقل [-]Environmental and economic assessment of Enhanced Landfill Mining in Tehran النص الكامل
2020
Sabour, Mohammad Reza | Alam, Ehsan | Mostafa Hatami, Amir
Landfilling brings many difficulties such as leaching of hazardous substances, methane gas production, loss of land, and natural resources such as groundwater, soil, and minerals. Enhanced landfill mining (ELFM) gives an opportunity to deal with such related problems. This study aimed to assess the environmental performance of ELFM through the application of life cycle assessment (LCA). SimaPro (v 8.5) was utilized to model the consequential life cycle assessment. Moreover, a comprehensive cost-benefit analysis was applied to assess the economic performance along with the Monte Carlo simulation to address the related uncertainties. In addition, the indicator of net present value (NPV) was adopted to understand the economic feasibility of the project. The case study landfill was the closed 55-hectare dumpsite of the municipality of Tehran in Kahrizak due to the need for further landfilling space in the future. The results of this study indicated that ELFM could lead to remarkable environmental benefits compared with the landfill’s current status (the do-nothing scenario). The ELFM project reduced the impact of global warming by 1,759,790 ton CO₂ eq, equaling to 134% reduction in comparison with the do-nothing scenario. Moreover, the potential profitability of the project was calculated to be 370 million $. Among the processes, recycling and thermal treatment of waste significantly dominated the environmental results of the project. Although the research was based on a case study landfill, the methodology can be applied to similar projects worldwide.
اظهر المزيد [+] اقل [-]Effect of Moringa oleifera Lam. methanolic extract on lead-induced oxidative stress-mediated hepatic damage and inflammation in rats النص الكامل
2020
Albasher, Gadah | Al Kahtani, Saad | Alwahibi, Mona S. | Almeer, Rafa
This experiment explored the potential hepatic protective effect of Moringa oleifera Lam. methanolic extract (MOE) against lead-induced hepatotoxicity. Thirty-two adult Wistar albino rats were allocated randomly equally into four groups, seven rats each. The control group received intraperitoneal (i.p.) injections of physiological saline (0.9% NaCl); the lead acetate (Pb) group was i.p. injected with 20 mg/kg of Pb; the MOE group was orally administered with 250 mg/kg of MOE; and the MOE+ Pb group was orally treated with 250 mg/kg of MOE 3 h before receiving i.p. injections of 20 mg/kg Pb. All rats received their treatment for 14 days. Results revealed that Pb(II) intoxication induced liver injury accompanied by elevated levels of liver function markers (ALT and AST), oxidative stress markers (MDA and NO), and proinflammatory cytokines (NF-κB p65, TNFα, and IL-1β as well iNOS expression) in addition to the pro-apoptotic-related proteins such as Bax and caspase-3. Meanwhile, significantly depleted GSH content, suppressed activity of antioxidant enzyme activity, and anti-apoptotic protein Bcl-2 were also manifested in the liver tissue. Interestingly, concurrent treatment of rats with MOE ameliorated liver markers, prevented tissue injury, and inhibited oxidative stress, apoptosis, and NF-κB. In addition, MOE activated the detoxifying enzyme system in Pb(II)-intoxicated rats. Therefore, the obtained results in the present experiment provide evidence that MOE concurrent administration has the potential to protect the liver tissues in Pb(II)-intoxicated rats by preventing oxidative stress, inflammation, and apoptosis, via attenuation of NF-κB signaling pathway.
اظهر المزيد [+] اقل [-]The critical role of the dispersant agents in the preparation and ecotoxicity of nanomaterial suspensions النص الكامل
2020
Andreani, Tatiana | Fernandes, Paula M. V. | Nogueira, Verónica | Pinto, Vera V. | Ferreira, Maria José | Rasteiro, Maria Graça | Pereira, Ruth | Pereira, Carlos M.
This work reports the role of different dispersants, namely, polyethylene glycol (PEG 200 2%), ethylene glycol 5%, ethanol 2%, dimethyl sulfoxide (DMSO 5%), and polyvinyl alcohol (PVA 5%) in the toxicity profile of several commercial nanomaterials (NM), such as hydrophilic and hydrophobic TiO₂, hydrophilic SiO₂, SiO₂ in aqueous suspension (aq), and ZnO towards the bioluminescent bacterium Aliivibrio fischeri. The majority of NM showed tendency to form agglomerates in the different dispersants. Although some particle agglomeration could be detected, DMSO at 5% was the best dispersant for hydrophobic TiO₂ NM while PVA at 5% was the most effective dispersant for the other types of NM. Average size was not the most relevant aspect accounting for their toxicity. A remarkable reduction in average size was followed by a decrease in NM toxicity, as demonstrated for SiO₂ aq. in PVA 5%. Contrarily, despite of high particle agglomeration, ZnO NM showed a higher toxicity to bacteria when compared with other tested NM. Independently of the average particle size or surface charge, the dispersant either enhanced the toxicity to bacteria or acted as physical barrier decreasing the NM harmful effect to A. fischeri.
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