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Resultados 3721-3730 de 7,290
A novel microRNA IamiR-4-3p from water spinach (Ipomoea aquatica Forsk.) increased Cd uptake and translocation in Arabidopsis thaliana Texto completo
2022
Shen, Chuang | Huang, Ying-Ying | Xin, Jun-Liang | He, Chun-Tao | Yang, Zhong-Yi
MicroRNAs (miRNAs) play important roles in plant response to Cd stress. In our previous study, we observed significant differences in the expression levels of IamiR-4-3p between high-Cd and low-Cd cultivars of water spinach. The function of IamiR-4-3p was investigated by using wild type Arabidopsis (WT), Arabidopsis transfected with empty vector pCambia1302 (CK), and Arabidopsis transfected with IamiR-4-3p + vector pCambia1302 (p35S::miR-4-3p) in this study. In p35S::miR-4-3p Arabidopsis, the expression levels of GST3 and AWPM19-like were reduced by 20% and 24%. Under Cd treatment, higher root and shoot Cd concentrations were detected in the transgenic p35S::miR-4-3p Arabidopsis. MDA and H₂O₂ concentrations were positively correlated with the Cd concentrations in all Arabidopsis. The elevated GSH pool in p35S::miR-4-3p Arabidopsis should compensate for its restricted GST3 expression in response to Cd-induced oxidative stress. Lower F1 (cell wall) and higher F2 (organelle) and F3 (soluble fraction) Cd concentrations were observed along with the reduced ABA level in p35S::miR-4-3p Arabidopsis, which could induce a weakened apoplastic barrier and higher Cd accumulation and translocation in roots. It is suggested that IamiR-4-3p is able to reduce the expression levels of GST3 and AWPM19-like, resulting in higher Cd uptake and translocation in Arabidopsis.
Mostrar más [+] Menos [-]Exploring the dilemma and influencing factors of ecological transformation of resource-based cities in China: perspective on a tripartite evolutionary game Texto completo
2022
Yang, Jingyuan | Wang, Yadong | Mao, Jinqi | Wang, Delu
The ecological transformation of the mineral resource-based cities (MRBCs) is the key to promoting the construction of ecological civilization and realizing the sustainable development of the social economy and society in China. Existing research ignores the influence of public participation on other subjects in the process of transformation, which is essential to solve the dilemma faced by the ecological transformation of MRBCs. In view of this, from the perspective of stakeholders, this study constructs a new evolutionary game model, which is jointly participated in by the government, enterprises, and social factors (SF) (including public, self-media, and non-governmental organizations). This paper discusses the interests of the main parties and their inter-relationships and reveals the causal mechanism and influencing factors of the dilemma of the ecological transformation of the MRBCs. Our results demonstrate that the evolution and convergence of strategies among the tripartite game agents exhibit strong interaction. First, the single industrial structure, low regulatory efficiency, and weak ecological awareness substantially increase the cost of transformation, thus exacerbating the dilemma of MRBC transformation. Second, the transformation intensity and comprehensive income are important factors affecting the transformation, and the effect intensity of influencing factors in different transition stages is different, which implies that the focus of policies in different stages is different. Third, in the process of promoting enterprise ecological transformation, government supervision and SF supervision have significant complementary effects. However, high-intensity supervision has a significant crowding-out effect on the willingness of SF to participate. Therefore, the government needs to balance the intensity of supervision and willingness of SF to participate. Compared with the existing research, this study comprehensively reflects the complex dynamic game process of the ecological transformation of MRBCs in China and can provide a reference for the policy of promoting the ecological transformation of MRBCs in China.
Mostrar más [+] Menos [-]A catalyzed method to remove polychlorinated biphenyls from contaminated transformer oil Texto completo
2022
Maghami, Arash | Gholipour-Zanjani, Nooshin | Khorasheh, Farhad | Arjumand, Mahdī
The disposal of polychlorinated biphenyls (PCBs) as persistent organic pollutants from the environment has been normally performed by isolation from soil or water because of their biological activity and toxic potential. In the present investigation, catalytic hydrodehalogenation was used to detoxify PCBs-contaminated transformer oil. All reactions were directed on an oil containing 11.09 wt% of PCBs utilizing palladium supported on multi-walled carbon nanotubes (Pd/MWCNTs). The amount of hexa-chlorine homologues reduced considerably from 5.07% to less than 800 ppm utilizing HDC at the atmosphere of argon. Moreover, the amounts of long half-lives and bioaccumulative congener of PCB 153 decreased considerably from 3.2% to less than 200 ppm. Besides, the quantity of some environmental pollutants like PCB 105 as a mono-ortho-substituted congener decreased considerably. The significant effects of reaction time, reaction temperature, and catalyst concentration on the efficiency were confirmed and modeled through Box–Behnken design. The optimal reaction condition with an efficiency of 96.67% was 70°C, with catalyst loading of 8 wt% and reaction time of 3.23 h. Furthermore, the quantity of turnover frequency of Pd/MWCNTs showed that it has more activity than palladium-carbon active supported in the ambient pressure without utilizing hydrogen gas in transformer oil complex. The study of the kinetic model revealed that the required activation energy (of 12.99 kJ/mol) to remove PCBs from transformer oil utilizing the present catalyst was lower than other catalyzed hydrodechlorination methods.
Mostrar más [+] Menos [-]Seasonal occurrence, source apportionment, and cancer risk assessment of PAHs in the second largest international holy metropolitan: Mashhad, Iran Texto completo
2022
Mahdad, Faezeh | Bakhtiari, Alireza Riyahi | Moeinaddini, Mazaher | Charlesworth, Susanne
Street dust resuspension is one of the main sources of particulate matter with impacts on air quality, health, and climate. This research was aimed to determine the concentration, source, and health risk of polycyclic aromatic hydrocarbons (PAHs) in street dust of Mashhad city. To this end, USEPA-regulated 16 PAHs were measured in 84 dust samples using gas chromatography coupled to mass spectrometry (GC-MS). The source of Σ16PAHs was identified using diagnostic ratios (DRs), positive matrix factorization (PMF), and principal component analysis (PCA). The measured Σ16PAHs demonstrated different spatial concentrations (from 1,005 to 9,138.96 μg kg⁻¹) and showed higher levels in summer (1,206.21–9,138.96 μg kg⁻¹), although 4-ring PAHs exhibited maximum levels in both summer and winter. The findings revealed that the dust-deposited PAHs are predominantly emitted through combustion of fossil fuels (such as diesel and gasoline) and natural gas. The total incremental lifetime cancer risk (ILCR) was assessed by considering three possible exposure routes separately for children and adults and calculated carcinogenic risk values of 2.24E−06 and 2.14E−06, respectively. ILCR is above the baseline value (1.0E-06) for children and adults in both seasons.
Mostrar más [+] Menos [-]Improving the Detrimental Aspects of Salinity in Salinized Soils of Arid and Semi-arid Areas for Effects of Vermicompost Leachate on Salt Stress in Seedlings Texto completo
2022
Cicek, Nuray | Erdogan, Muhterem | Yucedag, Cengiz | Cetin, Mehmet
The present study was performed to determine the effects of vermicompost leachate on growth, quality, and nutrients of Sedum album seedlings under salt stress. The study was carried out in Research and Practice Greenhouse of Cankırı Karatekin University in Central Anatolia of Turkey. One-month-old seedlings are treated with or without vermicompost leachate at five various NaCl applications (0, 50, 100, 150, and 200 mM). Shoot height, shoot fresh and dry weights, aesthetic appearance score, and crown widths of 10-week-old S. album seedlings and plant nutrients were evaluated. Salt stress x vermicompost leachate interaction had a significant effect on all studied traits (P < 0.05). The study revealed that vermicompost leachate–supplemented salt concentrations improved the harmful effects of salinity stress on growth and quality traits and macro- and micronutrients of S. album. The present study highlights the consideration of the regular application of vermicompost leachate, rich in nutrient content and microbial activity, to improve the detrimental aspects of salinity in salinized soils of arid and semi-arid areas and to improve the quality of soil and plant.
Mostrar más [+] Menos [-]Protective effects of propolis extract against nicotine-evoked pulmonary and hepatic damage Texto completo
2022
Khaled, Shimaa | Makled, Mirhan N. | Nader, Manar A.
There is increasing interest in the use of natural products to treat many diseases, considering the minimal toxicity, availability, and low cost. Propolis, a natural resinous product produced by honeybees, has been proven for its antioxidant and anti-inflammatory properties. Therefore, this study was designed to investigate the protective potential of propolis extract against nicotine-induced pulmonary and hepatic damage in rats. Sprague Dawley rats were divided into six groups: control, propolis (200 and 300 mg/kg, p.o.), nicotine (10 mg/kg, i.p), and nicotine plus propolis-treated groups. Nicotine and propolis were given every day for 8 weeks. Then, blood and bronchoalveolar lavage fluid (BALF) were collected for assessing liver and lung functions. Liver and lung tissues were also harvested to assess oxidative stress and inflammatory biomarkers in addition to histopathological and immunohistochemical analysis. Both doses of propolis significantly decreased AST, ALT, ALP, and total and differential cell counts in a dose-dependent manner. Propolis extract significantly attenuated oxidative stress in both lung and liver tissues. The restoration of antioxidant status (GSH level, SOD activities) and reduction of nitric oxide and MDA content was more so in propolis 300-treated than propolis 200-treated group. This was parallel to the improvement seen in histopathological examination. Propolis 200 and 300 significantly decreased Nrf2 expression and increased HO-1 expression in a dose-dependent manner. Moreover, immunohistochemical examination revealed that propolis 200 and 300 decreased the expression of iNOS in lung and liver tissues while decreased TNF-α expression in lung tissues only. Propolis extract could have a protective potential against nicotine-induced pulmonary and hepatic damage via activating Nrf2/HO-1 signaling.
Mostrar más [+] Menos [-]The preparation and properties of iron-walnut shell powder microelectrolytic spherical fillers Texto completo
2022
Ding, Shaolan | Yan, Saining | Li, Nannan | Ren, Huijun
In order to solve the issues of caking, loss, and effluent color reversion in the application of traditional microelectrolysis, the iron-walnut shell powder microelectrolytic spherical filler was developed in this paper. The filler was prepared by walnut shell powder, iron powder, sodium silicate, and sodium humate activated by ZnCl₂ as raw materials and calcined at high temperature. The effects of the mass ratios of Fe to walnut shell powder, sodium silicate content, sodium humate content, calcination temperature, and time on the removal rate of methylene blue by the spherical fillers were investigated, so as to determine the optimal preparation conditions of the spherical fillers. The pore-forming structure and the composition of the spherical fillers were also analyzed by an X-ray diffractometer (XRD), a scanning electron microscope (SEM), and an energy spectrometer (EDS). The results show that the optimal preparation conditions for the spherical fillers of 5 mm are as follows: the mass ratio of iron powder to walnut shell powder treated by 15% ZnCl₂ is 1:1, sodium silicate is 15%, sodium humate is 20%, the calcination temperature is 800 °C, and the calcination time is 3 h. Compared with the conventional microelectrolysis, the removal rate of methylene blue by the spherical fillers can finally reach the same level as it did, and the phenomena of the filler hardening and clogging can be avoided.
Mostrar más [+] Menos [-]Safety assessment of drinking water sources along Yangtze River using vulnerability and risk analysis Texto completo
2022
Yang, Jingjing | Liu, Yaxiu | Tan, Xiao | Xu, Congbon | Lin, Aijun
Recently, the safety of drinking water sources along Yangtze River Basin is received much attention. But few works have carried out large-scale and all-round safety assessment of drinking water sources on the main stream of the whole Yangtze River Basin. In this work, 97 drinking water sources in 8 provinces of the main stream of the Yangtze River were selected as the objects to clarify the spatial distribution of the safety risk levels of drinking water sources in the whole basin and analyze the causes of drinking water source risks. The results showed that 13.4%, 55.7%, 25.8%, 5.1%, and 0% of the 97 drinking water sources were classified as low, moderate, considerate, high, and very high respectively, according to the safety risk level. This indicated that the safety risk of drinking water sources in the mainstream of Yangtze River is generally low, but there are also a number of high safety risk drinking water sources. And the safety risk degree of the lower and upper reaches in the mainstream of Yangtze River is generally higher than that of the middle reaches. The current situation of drinking water sources along the mainstream of Yangtze River could be attributed to the superposition of human activities and natural background factors. This study could contribute to the government’s targeted management and control of safety risk sources for drinking water sources along the Yangtze River Basin.
Mostrar más [+] Menos [-]The asymmetric effect of technology shocks on CO2 emissions: a panel analysis of BRICS economies Texto completo
2022
Chen, Jingjing | Yang, Fuwei | Liu, Yicen | Usman, Ahmed
Technological innovation positively contributes to economic development in BRICS countries; their environmental consequences cannot be ignored. Thus, it is imperious to explore the impact of technological shocks on environmental quality. We used ARDL and NARDL models to draw empirical consensus on the data set from 1990 to 2019 for BRICS economies. The results of ARDL model reveal that technological shocks positively affect carbon emissions in the long-run and short-run. The findings of NARDL model reveal that positive shocks in technology positively affect carbon emissions in the long-run and short-run, implying that an increase in technological development triggers an increase in carbon emissions. However, the negative shocks in technology have a negative impact on carbon emissions in the long-run, inferring that a reduction in technological development leads to a decrease in carbon emissions. The negative shock in technology has no significant impact on carbon emissions in the short-run. The findings emphasize the importance of environmental friendly technology to achieving sustainable development goals.
Mostrar más [+] Menos [-]Oxidative stress is involved in the activation of NF-κB signal pathway and immune inflammatory response in grass carp gill induced by cypermethrin and/or sulfamethoxazole Texto completo
2022
Li, Baoying | Wang, Yu | Zhao, Hongjing | Yin, Kai | Liu, Yachen | Wang, Dongxu | Zong, Hui | Xing, Mingwei
At present, the concentration of environmental pollutants, such as pesticides and antibiotics exposed in environment, especially in aquatic environment is increasing. Research on environmental pollutants has exploded in the last few years. However, studies on the combined effects of pesticides and antibiotics on fish are rare, especially the toxic damage to gill tissue is vague. In this paper, cypermethrin (CMN) and sulfamethoxazole (SMZ) were analyzed and found that there was a strong correlation between the pathways affected by the first 30 genes regulated by CMN and SMZ, respectively. Therefore, the toxic effects of CMN (0.651 μg L⁻¹) and/or SMZ (0.3 μg L⁻¹) on grass carp gill were studied in this paper. Histopathology, quantitative real-time PCR, and other methods were used to detect the tissue morphology, oxidative stress level, inflammation, and apoptosis-related indicators of the fish gills after exposure of 42 days. It was found that compared with the single exposure (CMN/SMZ) group, the combined exposure (MIX) group had a more pronounced oxidative stress index imbalance. At the same time, nuclear factor-κB (NF-κB) signal pathway was activated and immuno-inflammatory reaction appeared in MIX group. The expression of tumor necrosis factor (TNF-α) in the rising range is 2.94 times that of the C group, while the expression of interleukin 8 (IL-8) is as high as 32.67 times. This study reveals the harm of CMN and SMZ to fish, and provides a reference and basis for the rational use of pesticides and antibiotics.
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