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Результаты 2671-2680 из 4,937
Fluorene-9-bisphenol inhibits epithelial-mesenchymal transition of human endometrial cancer Ishikawa cells by repressing TGF-β signaling pathway Полный текст
2019
Wang, Lingjuan | Zhuang, Taifeng | Li, Fangzhou | Wei, Wei
Fluorene-9-bisphenol (BHPF), a new derivative of bisphenol A (BPA), has been introduced for treatment with estrogen-related tumors, such as endometrial cancer. This study investigated the potential mechanism underlying the action of BHPF against endometrial cancer in vitro. We used the cell counting kit-8 (CCK8) method on Ishikawa cells to screen sub-lethal doses of BHPF and established the optimal concentration at which BHPF influenced the proliferation of Ishikawa cells. Effect of BHPF on cell migration and invasion was investigated by cell scratch assay and transwell assay, respectively. Expression levels of epithelial-mesenchymal transition (EMT)–related proteins were detected by Western blot analysis. BHPF was found to inhibit the proliferation of Ishikawa cells, whose migration and invasion abilities were also reduced. Western blot indicated that BHPF can significantly inhibit the EMT process of Ishikawa cells by blocking transforming growth factor-β (TGF-β) signaling pathway. This is the first report of the effect of BHPF on the biological behavior of endometrial cancer cells and its inhibition of endometrial cancer progression by repressing both endometrial cell proliferation and epithelial-mesenchymal transition, hence suggesting it as a novel anti-cancer drug. Graphical abstract Schematic representation of the molecular basis underlying BHPF treatment. BHPF repressed the EMT process by regulating EMT-related genes, such as E-cadherin, N-cadherin, and vimentin as well as the TGF-β signaling pathway–related genes, including p-Smad2/3 and slug, in a BHPF-dependent manner.
Показать больше [+] Меньше [-]Effects of detergents on natural ecosystems and wastewater treatment processes: a review Полный текст
2019
Mousavi, Seyyed Alireza | Khodadoost, Farank
Among the different contaminants, detergent as an important pollutant has serious risks to natural ecosystems. Furthermore, detergents can pass into the wastewater treatment plants and have bad effect on their performance. They are part of human life and consumed for different aims especially hygienic purposes. Therefore, detergent components can enter to soil and water bodies from different sources. Detergents affect fauna and flora, and they have direct and indirect effects on ecosystems. Eutrophication, foaming, and altering parameters such as temperature, salinity, turbidity, and pH are more important, and their effects need to be managed and controlled. Researchers confirmed that aerobic processes are able to degrade the most of detergents but anaerobic degradation is not possible because of restricted metabolic pathways and toxicity of them. Therefore, production of environment-friendly detergent is an important issue around the world. Graphical abstract
Показать больше [+] Меньше [-]Evaluation of hematological, biochemical parameters and thiol enzyme activity in chrome plating workers Полный текст
2019
Lacerda, Larissa Machado | Garcia, Solange Cristina | da Silva, Luciano Basso | de Ávila Dornelles, Mariana | Presotto, Anelise Teresinha | Lourenço, Eloir Dutra | de Franceschi, Itiane Diehl | Fernandes, Elissa | Wannmacher, Clovis Milton Duval | Brucker, Natália | Sauer, Elisa | Gioda, Adriana | Machado, Aline Belem | Oliveira, Evandro | Trombini, Thereza Luciano | Feksa, Luciane Rosa
The most commonly used solution in chrome plating bath is chromic acid (hexavalent Cr), and a considerable amount of mists is released into the air and consequently produce hazards to workers. Thus, the aim of this study was to evaluate whether the biomarker of exposure to metals, specially Cr levels, presents associations with hematological and biochemical parameters and if they can alter the activity of enzymes that contain thiol groups such as pyruvate kinase, creatine kinase, adenylate kinase, and δ-aminolevulinate dehydratase. Fifty male chrome plating workers were used for exposed group and 50 male non-exposed workers for control group. For that, biological monitoring was performed through quantification of metals on total blood and urine by inductively coupled plasma mass spectrometry (ICP-MS) and enzyme activity was performed by spectrometry in erythrocytes. In addition, chromium levels in water was quantified and ecotoxicology assay was performed with Allium cepa test. The results demonstrated that blood and urinary chromium levels in exposed group were higher than the control group (p < 0.0001). Furthermore, decreased activity of enzymes was found in those that contain thiol groups from exposed group when compared with the control group (p < 0.001). The water analysis did not present a statistical difference between control and exposed groups (p > 0.05), demonstrating that water did not seem to be the source of contamination. In summary, our findings indicated some toxicology effects observed in the exposed group, such as thiol enzyme inhibition, mainly associated with occupational exposure in chrome plating and besides the presence of other metals, and Cr demonstrated to influence the activity of the enzymes analyzed in this research.
Показать больше [+] Меньше [-]Importance of Organic Matter to the Retention and Transport of Bisphenol A and Bisphenol S in Saturated Soils Полный текст
2019
Shi, Yanfeng | Sun, Yuanyuan | Gao, Bin | Xu, Hongxia | Wu, Jichun
Bisphenol A (BPA) and bisphenol S (BPS) are frequently detected in soils and groundwater, which may pose threats to public health and the environment. However, the fate and transport of BPA/BPS in the subsurface media are still not clear. In this study, the retention and transport of BPA/BPS in three different natural soils were investigated with column experiments and mathematical modeling. The results showed that both BPA and BPS had high mobility in saturated soil A (Xinjiang soil), medium mobility in soil B (Changshu soil) media, and no mobility in the soil C (Jilin soil). There was a negative correlation between the mobility of BPA/BPS and soil organic matter (SOM) content because of the strong sorption of BPA/BPS on SOM. BPS showed higher mobility than BPA in the three soils. In addition, with the reduction of SOM of the soil B and C (after H₂O₂-treatment), the mobility of BPA/BPS enhanced dramatically. All these suggest that SOM played a significant role in controlling the retention and transport of BPA/BPS in the soil. Furthermore, the two-site kinetic model simulated the BPA/BPS transport experiment results very well.
Показать больше [+] Меньше [-]Assessment of Pollution Sources, Fate of Pollutants, and Potential Instream Interventions to Mitigate Pollution of Earthen Canals of Urban to Rural-Urban Fringe Полный текст
2019
Gomes, Pattiyage I. A. | Fernando, Bothalage A. V. W. | Dehini, Ganegeoda K.
Three representative earthen canals from urban, peri-urban, and rural-urban fringe of Sri Lanka were studied for a 2-year period against different seasons to capture insights important in ecological rehabilitation. Only the canal from rural-urban fringe showed a better water quality in wet season; elucidating, the impact of contaminated catchment runoff in the other canals. At a given sampling session, one or two peaks (relative maxima) were observed in urban and peri-urban canals for pollution representative parameters such as nitrate nitrogen and soluble reactive phosphorus. Those peaks were highly localised, an indication of poor advection. In general, two-dimensional variations of electrical conductivity and turbidity in dry season were uniform in urban and peri-urban canals, an indication of dominant molecular diffusion. This was further evidenced via physical models for different flow stages (low, high, and bankfull). Therefore, fate of contaminants had to be mainly governed by assimilation via sediments. However, grey water footprint analyses showed urban and peri-urban canals have over utilised the natural assimilation capacity of many water quality parameters by several folds. This study proved the importance of inducing attenuation by instream physical heterogeneity similar to natural streams or naturalised canals such as the canal from the rural-urban fringe of this study.
Показать больше [+] Меньше [-]Direct and indirect photolysis of the antibiotic enoxacin: kinetics of oxidation by reactive photo-induced species and simulations Полный текст
2019
Lastre-Acosta, Arlen Mabel | Barberato, Bruna | Parizi, Marcela Prado Silva | Teixeira, Antonio Carlos Silva Costa
The purpose of this study was to investigate the aqueous phase photochemical behavior of enoxacin (ENO), an antibiotic selected as a model pollutant of emerging concern. The second-order reaction rate constants of ENO with hydroxyl radicals (HO●) and singlet oxygen (¹O₂) were determined at pH 3, 7, and 9. Also, the rate constants of the electron transfer reaction between ENO and triplet states of chromophoric dissolved organic matter (³CDOM*) are reported for the first time, based on anthraquinone-2-sulfonate (AQ2S) as CDOM proxy. The sunlight-driven direct and indirect ENO degradation in the presence of dissolved organic matter (DOM) is also discussed. The results show that direct photolysis, which occurs more rapidly at higher pH, along with the reactions with HO● and ³AQ2S*, is the key pathway involved in ENO degradation. The ENO zwitterions, prevailing at pH 7, show kENO, HO●, kENO,₁O₂, and kENO,₃AQ₂S* of (14.0 ± 0.8) × 10¹⁰, (3.9 ± 0.2) × 10⁶, and (61.5 ± 0.7) × 10⁸ L mol⁻¹ s⁻¹, respectively, whose differences at pH 3, 7, and 9 are due to ENO pH-dependent speciation and reactivity. These k values, along with the experimental ENO photolysis quantum yield, were used in mathematical simulations for predicting ENO persistence in sunlit natural waters. According to the simulations, dissolved organic matter and water depth are expected to have the highest impacts on ENO half-life, varying from a few hours to days in summertime, depending on the concentrations of relevant waterborne species (organic matter, NO₃⁻, NO₂⁻, HCO₃⁻).
Показать больше [+] Меньше [-]Asymmetric causality among renewable energy consumption, CO2 emissions, and economic growth in KSA: evidence from a non-linear ARDL model Полный текст
2019
Toumi, Saïd | Toumi, Hassen
This study applies asymmetric causality to renewable energy (REC), carbon dioxide emissions (CE), and real GDP using non-linear broadcasting between these variables through the non-linear autoregressive distributed lag model (NARDL) to examine the short- and long-run asymmetries in the inconsistency of greenhouse gas emissions among the variables and to unpack the asymmetric causality of selective variables through positive and negative shocks for time series data from the Kingdom of Saudi Arabia between 1990 and 2014. The bounds cointegration test shows the existence of long-term dealings among all considered variables in the presence of asymmetry. The non-linear asymmetric causality test shows that negative shocks in carbon dioxide emissions had only positive impacts on real GDP in the long-term but are unobservable in the short-term. Additionally, the short- and the long-term incidences of positive shocks on real GDP are not similar to the negative shock to REC, implying the existence of asymmetric impacts on REC in both short- and long-term forms. Finally, the asymmetric causal relationship from carbon dioxide emissions to REC is neutral in the long-term. Both positive and negative shocks to REC consistently had an adverse effect on CE in the long-term. The presence of asymmetry between economic growth, CE, and REC could be of major substantial for more helpful policymakers and the action plan of sustainable development goals (SDGs) in Saudi Arabia.
Показать больше [+] Меньше [-]Acetone adsorption capacity of sulfur-doped microporous activated carbons prepared from polythiophene Полный текст
2019
Zhu, Junchao | Chen, Ruofei | Zeng, Zheng | Su, Changqing | Zhou, Ke | Mo, Yamian | Guo, Yang | Zhou, Fan | Gao, Jie | Li, Liqing
Sulfur-doped activated carbons (SACs) with high sulfur content and large specific surface area were synthesized from polythiophene for acetone removal. The sulfur content of carbons (3.10–8.43 at.%) could be tunable by adjusting the activation temperature. The BET surface area and pore volume of the obtained samples were 916–2020 m² g⁻¹ and 0.678–1.100 cm³ g⁻¹, with a significant proportion of microporosity (up to 84% and 72% for BET surface area and pore volume, respectively). The resulting SACs show a superior acetone adsorption capacity (i.e., 716.4 mg g⁻¹ at 15 °C and 705 mg g⁻¹ at 25 °C for SAC700). In terms of the adsorption behavior of acetone on the activated carbons, compared to the Langmuir model, the Langmuir-Freundlich model showed better agreement with the adsorption amount. The results reveal that the surface area and micropore volume are the key factors for acetone adsorption, while the sulfur-doped functional groups, especially oxidized sulfur functional groups, can enhance the acetone adsorption capacity at a certain low pressure. Temperature programmed desorption (TPD) experiments were performed to get desorption activation energy of acetone on SAC samples, and the results ranged from 23.54 to 38.71 kJ mol⁻¹. The results of the molecular simulation show that the introduction of sulfur element can increase the binding energy between acetone molecule and carbon surface, and the tri-oxidized sulfur (sulfonic acid) functional group has the highest binding energy of − 0.4765 eV. Graphical abstract
Показать больше [+] Меньше [-]Decomposition of 2-Propanol in the Liquid Phase Using a Photocatalyst Immobilized on Nonwoven Fabric and Ozone Microbubbles Полный текст
2019
Yasui, Fumio | Sekiguchi, Kazuhiko | Tamura, Hajime
2-Propanol (IPA) is a highly water-soluble volatile organic compound that is used in the cleaning and drying processes during semiconductor fabrication. IPA is also used as a disinfectant in the pharmacy field. Water scrubber processing is one of the methods used for IPA collection. However, water scrubbing requires wastewater treatment. In this study, we propose a decomposition system for IPA in the liquid phase based on a TiO₂ photocatalyst immobilized on nonwoven fabric (TiO₂ nonwoven fabric) and ozone microbubbles (MBs). The thick nonwoven fabric with immobilized TiO₂ exhibits a higher IPA removal rate than that exhibited by the pleated fabric. IPA decomposes to produce acetone, which can be further decomposed and possibly undergo mineralization. The entire water tank can be supplied with ozone by introducing the MB-forming ozone, which considerably affects the decomposition of IPA. The efficient decomposition of IPA was achieved by combining ozone MBs, TiO₂ nonwoven fabric, and ultraviolet irradiation, presumably because the photocatalyst promotes the mineralization of the decomposition product. Thus, the OH radicals from the O₃ MBs competitively captured in the decomposition product strongly promote the decomposition of IPA, enhancing the IPA decomposition rate.
Показать больше [+] Меньше [-]Simultaneous removal of nitrate/phosphate with bimetallic nanoparticles of Fe coupled with copper or nickel supported on chelating resin Полный текст
2019
Shen, Zhanhui | Dong, Xinyi | Shi, Jialu | Ma, Yuanhao | Liu, Daoru | Fan, Jing
Given the prevalence of nitrate and phosphate in surface and groundwater, it is important to develop technology for the simultaneous removal of nitrate and phosphate. In this study, we prepared the bimetallic nanoparticles of Fe coupled with copper or nickel supported on chelating resin DOW 3N (D-Fe/Ni and D-Fe/Cu) for removing nitrate and phosphate simultaneously. XPS profiles revealed that Cu has better ability than Ni to increase the stability of Fe nanoparticles and prevent nZVI from oxidation. The results showed that nitrate removal efficiencies by D-Fe/Ni and D-Fe/Cu were 98.7% and 95.5%, respectively and the phosphate removal efficiencies of D-Fe/Cu and D-Fe/Ni were 99.0% and 93.0%, respectively. Besides adsorption and coprecipitation as reported in previous studies, the mechanism of phosphate removal also includes the adsorption of the newly formed polymeric ligand exchanger (PLE). Moreover, in previous studies, the presence of phosphate had significant negative effects on the reduction of nitrate. However, in this study, the removal efficiency of nitrate was less affected with the increasing concentration of phosphate for D-Fe/Cu. This was mainly because D-Fe/Cu had higher adsorption capacity of phosphate due to the newly formed PLE according to the XPS depth profile analysis.
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