خيارات البحث
النتائج 5271 - 5280 من 6,560
SLC16A1-AS1 enhances radiosensitivity and represses cell proliferation and invasion by regulating the miR-301b-3p/CHD5 axis in hepatocellular carcinoma النص الكامل
2020
Pei, Shenglin | Chen, Zuyi | Tan, Huajun | Fan, Liwei | Zhang, Baina | Zhao, Chang
Hepatocellular carcinoma (HCC), a common type of human malignancies, leads to increasing incidence and fairly high mortality. An increasing number of studies have verified that long noncoding RNAs (lncRNAs) played key roles in the development of multiple human cancers. As a biomarker, SLC16A1-AS1 has been reported in non-small cell lung cancer (NSCLC) and oral squamous cell carcinoma (OSCC). Thus, we decided to investigate whether SLC16A1-AS1 exerts its biological function in HCC. In this study, we discovered that SLC16A1-AS1 was obviously downregulated in HCC tissues and cells. Overexpression of SLC16A1-AS1 inhibited HCC cell proliferation, invasion, and epithelial-mesenchymal transition (EMT) process as well as promoted cell apoptosis. Moreover, SLC16A1-AS1 was confirmed to enhance the radiosensitivity of HCC cells. Molecular mechanism exploration suggested that SLC16A1-AS1 served as a sponge for miR-301b-3p and CHD5 was the downstream target gene of miR-301b-3p in HCC cells. Rescue assays implied that CHD5 knockdown could recover the effects of SLC16A1-AS1 overexpression on HCC cellular processes. In brief, our study clarified that SLC16A1-AS1 acted as a tumor suppressor in HCC by targeting the miR-301b-3p/CHD5 axis, which may be a promising diagnostic biomarker and provide promising treatment for HCC patients.
اظهر المزيد [+] اقل [-]Influence of weather and air pollution on the occurrence of idiopathic pulmonary embolism in the region of Sousse (Tunisia) النص الكامل
2020
Kacem, Imène | Kahloul, Mohamed | Hafsia, Meriam | Aroui, Haifa | Maoua, Maher | Ajmi, Mohamed | Jedidi, Maher | Gouider, Jridi | Ghannouchi, Neirouz | Laouani, Chadia | Chouchane, Imed | Taieb, Dalila | Chaouch, Ajmi | Naija, Walid | Mrizak, Nejb
Pulmonary embolism (PE) is the most serious manifestation of thromboembolic conditions. Its incidence varies considerably between countries, suggesting its interaction with the external environment. To analyze the influence of climate and air pollution on the occurrence of idiopathic PE in the region of Sousse (Tunisia). A total of 142 patients with idiopathic PE at two academic hospitals in Sousse (Tunisia) were enrolled in the study over a 7-year period. An analysis of two time series (environmental data and PE cases) was performed. Climatic data were collected from the National Institute of Meteorology. Air pollution data were obtained from the modeling platform of the National Agency for Protection of the Environment. The year 2015 was marked by the occurrence of the highest number of cases (24.6%). A statistically significant decrease in PE risk of 41.9% was observed during the summer with an OR of 0.59 (95% CI [0.36–0.94] and p = 0.026), compared with other seasons. Poisson GLM regression showed a significant increased risk of PE of 3.3% for each 1 °C temperature drop. After multiple binary logistic regression, the elevation of PM₁₀ concentration was independently associated with an increased risk of PE (p < 10⁻³, OR 79.55, 95% CI [42.28–149.6]). Some environmental parameters may predispose to the onset of idiopathic PE. Understanding their accurate influence may have preventive and curative implications.
اظهر المزيد [+] اقل [-]N2O profiles in the enhanced CANON process via long-term N2H4 addition: minimized N2O production and the influence of exogenous N2H4 on N2O sources النص الكامل
2020
Xiao, Pengying | Ai, Shuo | Zhou, Jing | Luo, Xiaojing | Kang, Baowen | Feng, Li | Zhao, Tiantao
Production of the greenhouse gas nitrous oxide (N₂O) from the completely autotrophic nitrogen removal over nitrite (CANON) process is of growing concern. In this study, the effect of added hydrazine (N₂H₄) on N₂O production during the CANON process was investigated. Long-term trace N₂H₄ addition minimized N₂O production (0.018% ± 0.013% per unit total nitrogen removed) and maintaining high nitrogen removal capacity of CANON process (nitrogen removal rate and TN removal efficiency was 450 ± 60 mg N/L/day and 71 ± 8%, respectively). Ammonium oxidizing bacteria (AOB) was the main N₂O producer. AOB activity inhibition by N₂H₄ decreased N₂O production during aeration, and the N₂H₄ concentration was negatively correlated with N₂O production rate in NH₄⁺ oxidation via AOB, whereas N₂O production was facilitated under anaerobic conditions because hydroxylamine (NH₂OH) production was accelerated due to anammox bacteria (AnAOB) activity strengthen via N₂H₄. Added N₂H₄ completely degraded in the initial aeration phases of the CANON SBR, during which some N₂H₄ intensified anammox for total nitrogen removal to eliminate N₂O production from nitrifier denitrification (ND) by anammox-associated, while the remaining N₂H₄ competed with NH₂OH for hydroxylamine oxidoreductase (HAO) in AOB to inhibit intermediates formation that result in N₂O production via NH₂OH oxidation (HO) pathway, consequently decreasing total N₂O production.
اظهر المزيد [+] اقل [-]Anthracene-induced DNA damage and oxidative stress: a combined study at molecular and cellular levels النص الكامل
2020
Sun, Kailun | Song, Yan | Zong, Wansong | Tang, Jingchun | Liu, Rutao
At present, research progress of anthracene’s toxicity lags far behind the pollution caused on its application fields such as petroleum and minerals. In this paper, anthracene-induced oxidative stress effects and genetic toxicity were investigated at both the molecular and cellular levels. The intracellular oxidative stress effect of anthracene on earthworm primary coelomocyte was confirmed by the detection of reactive oxygen species, antioxidant enzymes activity, and malondialdehyde content. Moreover, after anthracene exposure, the decrease in the mitochondrial membrane potential and cell viability also indicated the adverse effects of anthracene on earthworm coelomocyte. The comet assay proved the break in DNA strand, revealing the anthracene-induced DNA damage. On the molecular level, we revealed that anthracene caused the shrinkage of the catalase skeleton and altered the microenvironment of chromophores of catalase by multi-spectral methods. Molecular simulation results indicated that anthracene interacted with His74 by “arene-arene” force and the dominant binding site between anthracene and catalase was close to the active site of catalase. In addition, anthracene was shown to bind to the DNA molecule by groove binding mode. This study proposed a new combined analysis method for the toxicity evaluation of anthracene at the cellular and molecular levels. Graphical abstract This study creatively proposed a new combined analysis for the toxicity evaluation of ANT at the cellular and molecular levels.
اظهر المزيد [+] اقل [-]Characterization of particulate matter emissions in urban train braking - An investigation of braking conditions influence on a reduced-scale device النص الكامل
2020
Octau, Charlene | Meresse, Damien | Watremez, Michel | Schiffler, Jesse | Lippert, Marc | Keirsbulck, Laurent | Dubar, Laurent
The particulate matter emissions related to the braking of railway rolling stock are investigated using a reduced scale braking device. Samples of organic materials and cast iron discs are tested for different nominal contact pressures and disc surface temperatures, representative of real conditions. The aim of this work is to investigate the influence of braking conditions on the global amount of particles emitted, their distribution in number and size, and their morphological and chemical characteristics. To be representative, the tested conditions are designed to dissipate the same amount of energy for all the braking events by adjusting the pad application duration. The results show that for the same dissipated energy, a temperature increase above a transition value in the range of 230–280 ∘C depending on the braking conditions modifies the size and number distributions of the generated particles. The results obtained are of interest to better represent their propagation through CFD modelling according to the characteristic of the particle emission.
اظهر المزيد [+] اقل [-]Enhanced biodiesel production from waste cooking palm oil, with NaOH-loaded Calcined fish bones as the catalyst النص الكامل
2020
Chinglenthoiba, Chingakham | Das, Anu | Vandana, Sajith
The present work mainly focuses on the development of heterogeneous catalysts from fishbone, loaded with sodium hydroxide for transesterification of biodiesel. The catalyst was developed using a two-step process involving the calcination of fishbone at 900 °C, followed by a hydrothermal process with a sodium hydroxide-loaded (NaOH) solution. The synthesized heterogeneous catalyst was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and BET surface area analysis. The transesterification of waste cooking palm oil (WCO) with BC-NaOH shows a maximum yield of up to 98% for 2.5 wt.% catalyst loading, 1:9 oil:methanol molar ratio at a temperature of 65 °C for a reaction time of 1.5 h. The enhanced catalytic activity is due to the high base active site density of hydroxyl groups from hydroxyapatite, β- tricalcium phosphate, and sodium hydroxide. A gas chromatography-mass spectroscopy (GC-MS) was performed to determine the conversion of oil to biodiesel. The reusability of the catalyst was confirmed from the consistency in the biodiesel yield obtained in up to 7 cycles.
اظهر المزيد [+] اقل [-]Evaluating provincial eco-efficiency in China: an improved network data envelopment analysis model with undesirable output النص الكامل
2020
Yu, Shiwei | Liu, Jie | Li, Longxi
In this study, an improved matrix-type network data envelopment analysis (NDEA) model with undesirable output was developed to evaluate the eco-efficiency of China’s 30 provinces. The proposed model considered three linked but independent subsystems of the economy–society–environment cyclic system. Additionally, to allocate the weights of the NDEA model among the three subsystems (environment, economy, and society) of the eco-environment, a new relative reduction of the input-based method was proposed. The results show that, from 2003 to 2016, the average eco-efficiency of China’s 30 provinces was low, ranging in [0.59, 0.73]. Qinghai and Hainan ranked first and second, respectively, in average eco-efficiencies, while both Shaanxi and Xinjiang had the lowest average eco-efficiencies. Affected by the low social subsystem efficiency, the eco-efficiency of 18 provinces decreased, but the range of the decrease was smaller than that of the increase in 11 other provinces in which the eco-efficiency improved. The average efficiency of the environmental subsystem is the highest among the three subsystems benefiting from reducing the emissions of “three industrial wastes,” while economic subsystem owns the lowest average efficiency due to the input redundancy of total fixed assets and energy consumption. Compared with variables’ projection, for most provinces, the undesirable output of the three industrial wastes should be reduced by more than 88.0%, while the positive outputs of atmospheric quality and per capita years of education should be increased by at least 61.0%.
اظهر المزيد [+] اقل [-]Salinity profile in coastal non-agricultural land in Gaza النص الكامل
2020
El-Nahhal, Yasser | Safi, Mohamed | Safi, Jamal
The objectives of this study were to characterize the electric conductivity (EC), total dissolved salts (TDS), highly soluble salts (HSS), less soluble salts (LSS), cations (Na⁺, K⁺, Ca⁺⁺ and Mg⁺⁺) and anions (Cl⁻, NO⁻₃, SO⁻⁻₄, PO⁻⁻⁻₄) profiles in non-agricultural coastal land in Gaza Strip and to evaluate the effect of trees in salinity. Six locations were selected randomly in coastal zone in Gaza Strip and used for soil profile digging. Soil samples were collected from different layers between 0 and 150 cm depth, air dried and kept in plastic bags at lab temperature. Ten grams of soil were mixed with 25 mL distilled water and kept under shaking for 24 h, then EC, pH and TDS were determined. Then additional 25 ml distilled water was added to each bottle and kept for additional 24 h of shaking. EC and TDS were determined again. Then the soil filtrates were collected by centrifugation and used to determine cations and anions. Results showed that concentrations of TDS, HSS and LSS were higher at the top soil layer than at deeper soil layers. Concentrations of cations and anions have similar trends to TDS, HSS and LSS. Behavior of cations and anions in the soil profiles under trees were different from those in open field. Comparing between the data of soil profiles under trees (site 2 and 5) and those in the open field (sites 1, 3, 4 and 6) showed slight effects on availability of cations and anions. Strong correlations were found between cations and anions in soil profiles under trees, and week correlations were found in soil profile in open field. In conclusion the coastal soil profiles are characterized with elevated levels of TDS, HSS and LSS in the top soil layers. Accumulations of salts were more pronounced in top soil layers. These properties suggest high potential damage to the ecosystem.
اظهر المزيد [+] اقل [-]Emerging trends in municipal solid waste incineration ashes research: a bibliometric analysis from 1994 to 2018 النص الكامل
2020
Wong, Syieluing | Mah, Angel Xin Yee | Nordin, Abu Hassan | Nyakuma, Bemgba Bevan | Ngadi, Norzita | Mat, Ramli | Amin, Nor Aishah Saidina | Ho, Wai Shin | Lee, Ting Hun
The rapidly increasing generation of municipal solid waste (MSW) threatens the environmental integrity and well-being of humans at a global level. Incineration is regarded as a technically sound technology for the management of MSW. However, the effective management of the municipal solid waste incineration (MSWI) ashes remains a challenge. This article presents the global dynamics of MSWI ashes research from 1994 to 2018 based on a bibliometric analysis of 1810 publications (research articles and conference proceedings) extracted from the Web of Science database, followed by a comprehensive summary on the research developments in the field. The results indicate the rapid growth of annual publications on MSWI ashes research, with China observed as the most productive country within the study period. Waste Management, Journal of Hazardous Materials, Chemosphere and Waste Management & Research, which accounted for 35.42% of documents on MSWI research, are the most prominent journals in the field. The most critical thematic areas on this topic are MSWI ashes characterisation, dioxin emissions from fly ash, valorisation of bottom ash and heavy metal removal. The evolution of MSWI ashes treatment technologies is also discussed, together with the challenges and future research directions. This is the first bibliometric analysis on global MSWI ashes research based on a sufficiently large dataset, which could provide new insights for researchers to initiate further research with leading institutions/authors and ultimately advance this research field.
اظهر المزيد [+] اقل [-]Relationship embedding and environmental governance performance research of pollution in a mining area, China النص الكامل
2020
Mi, Jun | Bian, Jie | Liu, Yaru | Guo, Wenxia
The aim of this study was to explore the enterprises in the mining area, in the face of environmental pollution, to use relationship embedding to acquire new key knowledge from the external network, and to improve environmental governance performance. In this paper, a model between relationship embedding and environmental governance performance was established, and five main hypotheses were proposed. Luliang Mountain Area is a typical mining area in China. And this study used 310 sample datum and regression analysis to empirically test the mechanism, taking Luliang Mountain Area as an example. First, SPSS statistical software was used for reliability and validity analysis of the questionnaire, and the results showed good. Then regression analysis was performed to test the hypothesis. The results showed that relationship embedding has a significant positive impact on environmental governance performance, and enterprises in the mining area use relationship embedding to obtain key knowledge, which can enhance environmental governance performance. Internal social capital has a positive adjustment effect on the relationship between relationship embedding and knowledge acquisition. In order to control environmental pollution in the mining area, enterprises should make full use of the relationship embedding, acquire new key knowledge, improve environmental governance capacity, and improve the environmental governance performance of enterprises.
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