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Surface water quality assessment in a semiarid Mediterranean region (Medjerda, Northern Tunisia) using partial triadic analysis 全文
2020
Slimani, Noura | Jiménez, Juan José | Guilbert, Éric | Boumaïza, Moncef | Thioulouse, Jean
A range of methods have been developed specifically to analyze several tables of data simultaneously (variable × space × time) in the field of ecological research, although they have been less widely used to examine water quality. In this study, we assessed the spatiotemporal variability of water quality in the Medjerda River basin (Northern Tunisia). Partial triadic analysis (PTA) provides an effective framework for the assessment of spatiotemporal variability of water quality in the Medjerda River basin (Northern Tunisia). Fourteen physicochemical variables were monitored from 12 sampling sites monthly during 2013. PTA allowed correlations among different physicochemical parameters to be identified and to assess overall water quality in the Medjerda River. Salinity (S), Cl⁻, SO₄²⁻, Ca²⁺, and Mg²⁺ ions were associated with intensive agricultural activities (agricultural pollution sources) leading to salinization. However, NH₄⁺, PO₄³⁻, chemical oxygen demand (COD), and biochemical oxygen demand (BOD₅) we more strongly associated with polluted urban sites. PTA helped illustrate that strong links exist between land uses and adjacent water quality. The advantages of this multi-table method approach for water quality monitoring include as follows: (1) identifying common multivariate spatial structures and problems associated with maintaining water quality, (2) allowing identification of consistent patterns in water chemistry, and (3) allowing analysis on the temporal variability of water chemistry.
显示更多 [+] 显示较少 [-]Characteristics of water-soluble organic acids in PM2.5 during haze and Chinese Spring Festival in winter of Jinan, China: concentrations, formations, and source apportionments 全文
2020
Tang, Shuting | Zhou, Xuehua | Zhang, Jingzhu | Xue, Likun | Luo, Yuanyuan | Song, Jie | Wang, Wenxing
PM₂.₅ aerosols from Jinan (36°256′N, 117°106′E) in the North China Plain region were investigated for water-soluble organic acids (WSOAs, i.e., oxalic acid, formic acid, acetic acid, methanesulfonic acid (MSA), and lactic acid) during 30 December 2016 to 21 February 2017. The average PM₂.₅ concentration was 168.77 μg/m³ with about 90.74% samples beyond the National Ambient Air Quality (NAAQ) standards (Grade II). The total concentration of the measured WSOAs averaged at 1.34 μg/m³, contributing to 0.80% of PM₂.₅ mass. In the observation, acetic acid was the most abundant WSOA, followed by oxalic acid, lactic acid, formic acid, and MSA. During the period, serious haze events frequently happened. The average concentrations of PM₂.₅ and every WSOA species were higher in haze than those in non-haze. The correlations among species suggested that WSOAs in haze had complicated sources and secondary pathways, especially aqueous-phase reactions which played an important role on WSOAs. The concentrations of WSOAs declined in the Spring Festival compared with those in the non-Spring Festival due to holiday effect. Fireworks burning during the Spring Festival had different influences on WSOAs with slight increases for acetic acid and lactic acid. Five source factors were identified by positive matrix factorization (PMF) model for five WSOAs, respectively, and the results revealed that secondary reactions were the main sources of WSOAs in haze.
显示更多 [+] 显示较少 [-]Chitosan nanoparticles from Artemia salina inhibit progression of hepatocellular carcinoma in vitro and in vivo 全文
2020
Elkeiy, Mai M. | Khamis, Abeer A. | El-Gamal, Mona M. | Abo Gazia, Maha M. | Zalat, Zeinb A. | El-Magd, Mohammed A.
This study was conducted to evaluate the effect of chitosan nanoparticles (CNPs) isolated from Artemia salina against hepatocellular carcinoma (HCC) both in vitro (HepG2) and in vivo (diethylnitrosamine-induced HCC in rats) and to investigate the involved underlying mechanisms. Administration of CNPs decreased HCC progression as evidenced by (1) induced HepG2 cell death as detected by MTT assay; (2) induced necrosis as indicated by acridine orange/propidium iodide (AO/PI) red staining, annexin V/7-AAD positive staining (detected by flow cytometry), and upregulated expression of necrosis markers (PARP1 and its downstream target, RIP1 genes), but no effect on apoptosis as revealed by insignificant changes in caspase 3 activity and mRNA levels of Bax and AIF; (3) increased intracellular ROS and decreased mitochondrial membrane potential in HepG2; (4) decreased liver relative weight, serum levels of liver enzymes (ALT, AST, and ALP), total bilirubin, and cancer markers (AFP and GGT), number and area of GST-P positive tumor nodules; and (5) reduced oxidative stress (decrease in MDA levels) and increased activities of SOD, CAT, and GPx enzymes in rat liver. The preventive (pre-treatment) effect of CNPs was better than the therapeutic (post-treatment) effect. Collectively, administration of CNPs inhibited HCC progression in vitro and in vivo, possibly through induction of necrosis, rather than apoptosis, and induction of antioxidant enzyme activities in vivo, but with stimulation of ROS production in vitro. Thus, CNPs could be used as a promise agent for treating HCC after application of further confirmatory clinical trials.
显示更多 [+] 显示较少 [-]The role of shadow economies in ecological footprint quality: empirical evidence from Turkey 全文
2020
Köksal, Cihat | Işik, Mehtap | Katircioğlu, Salih
The purpose of this research study is to investigate the role of shadow economies in the levels of ecological footprint for the case of Turkey. Annual data set ranging from 1961 to 2014 was used with this respect. The results of this study verify the long-term and positively elastic impact of shadow economic activities on the level of ecological footprint in Turkey; that is, 1 % change in shadow economic activities results in a 1.008% change in ecological footprint in the same direction. This study, therefore, reaches a significant conclusion that in Turkey, shadow economies are long-term and essential drivers of environmental pollution.
显示更多 [+] 显示较少 [-]Heat treatment and protective potentials of luteolin-7-O-glucoside against cisplatin genotoxic and cytotoxic effects 全文
2020
Maatouk, Mouna | Abed, Besma | Bouhlel, Ines | Krifa, Mounira | Khlifi, Rihab | Ioannou, Irina | Ghedira, Kamel | Ghedira, Leila Chekir
Cisplatin is an effective chemotherapeutic agent that has pronounced adverse effects. Using flavonoids is currently eliciting considerable interest. During extraction and conditioning, they usually undergo several physical treatments such as heat treatment, although it is not known whether thermal treatment might influence the pharmacological effects of flavonoids such as luteolin-7-O-glucoside (L7G). This study was undertaken to explore the protective role of native and heated L7G against DNA damage and oxidative stress induced by cisplatin. Balb/c mice were administered L7G before a single intraperitoneal injection of cisplatin (10 mg/kg). Animals were sacrificed 24 h after treatment with drugs. The geno-protective role of native and heated L7G was evaluated by comet assay. In addition to monitoring the activities of antioxidant enzymes, levels of malondialdehyde and reduced glutathione were assessed in the liver, kidney, brain, and spleen tissues. The results of the present study demonstrate that both heated and native L7G, at a dose of 40 mg/kg b.w, were able to reduce the genotoxicity of cisplatin. They attenuate the oxidative stress (malondialdehyde, catalase, GPx, SOD, and GSH) and tissue damage (creatinine, IFNγ). Heat treatment did not alter the antigenotoxic effect observed for native L7G and showed similar effects to those of native L7G for all of the evaluated parameters. Our study reveals that L7G attenuates the side effects of anticancer drug and heat treatment did not alter his antigenotoxic and antioxidant the potential.
显示更多 [+] 显示较少 [-]Effect of diurnal temperature range on outpatient visits for common cold in Shanghai, China 全文
2020
Ma, Yuxia | Yang, Sixu | Yu, Zhiang | Jiao, Haoran | Zhang, Yifan | Ma, Bingji | Zhou, Ji
To evaluate the correlations between diurnal temperature range (DTR) and the number of outpatient visits for common cold from Jan. 1, 2008, to Dec. 31, 2010, in the Shanghai metro area; we used a distributed lag non-linear model together with a Poisson regression model. The controlling factors included long-term trends and day of the week in outpatient visits for common cold and the selected weather elements. The entire study group was divided into three different age subgroups, including ≤ 15, 15–65, and ≥ 65 years old. We found some non-linear J-patterns between DTR and daily outpatient visits for common cold. At lag 0 day, the number of outpatient visits for common cold would increase by 11.1% per 1 °C increase in DTR. The greater the DTR, the more it affects outpatient visits for common cold, especially for the ≥ 65 years age group. In addition, DTR plays a more important role in outpatient visits for common cold in spring and winter compared with other seasons of the year. Our study showed that DTR is a risk factor that contributes to common cold. Results in this study can provide scientific evidence for the local authorities in improving preventive measures of the healthcare system.
显示更多 [+] 显示较少 [-]Assessment and source quantification of heavy metal(loid)s in surface water using multivariate analyses from the Saigon River, Vietnam 全文
2020
Nguyen, Binh Thanh | Nguyen, Vinh Ngoc | Truong, Huong Thu Thi | Do, Dung Doan | Nguyen, Tong Xuan | Nguyen, Duong Thuy Phuc | Nguyen, My Hoang | Dong, Hao Phu | Le, Anh Hung | Bach, Quang-Vu
The metal concentration in surface water of a river could be affected by season, position, and oceanic process such as tide. The current study aimed to (1) examine the heavy metal(loid) concentration in surface water from the Saigon River as affected by the combination of season, tide, and position and (2) apportion and quantify pollution sources. Ninety-six surface water samples were collected from 13 sites on the River in four campaigns (rainy season + ebb tide, rainy season + flood tide, dry season + ebb tide, and dry season + flood tide). Eight heavy metal(loid)s (Al, B, Bi, Fe, Mn, Pb, Sr, and Zn) were measured and subjected to multivariate analyses. Three-way ANOVA showed that in the rainy season, the total concentration of the metal(loid)s (TCM) in two tides was not clearly different from each other while in the dry season the TCM was significantly higher during the ebb tide than during the flood tide. Principal component analysis/factor analysis and Pearson correlation matrix showed that the TCM could be derived from three main sources, grouped into anthropogenic activities such as industrial, agricultural, and domestic wastes from inside Ho Chi Minh city, and natural origins from lowland area and acid sulfate soil. Three pollution sources explained 70% and 68% of the total variance of TCM in the rainy and dry seasons, respectively. In brief, the metal(loid) concentration was significantly affected by the season and tide and the pollution sources could be derived from inside Ho Chi Minh City and from lowland areas beyond the river estuary.
显示更多 [+] 显示较少 [-]Ultrasonic-assisted synthesis of natural clay/Fe3O4/graphene oxide for enhance removal of Cr (VI) from aqueous media 全文
2020
Esmaeili, Hossein | Tamjidi, Sajad
In this study, Fe₃O₄/graphene oxide (GO)/clay composite was used to remove chromium (VI) ion from aqueous media. The structure and characteristics of the Fe₃O₄/GO/clay composite were investigated using FT-IR, SEM, EDX/Map, VSM, BET, and XRD analyses. The BET analysis indicated that the specific surface area and mean pore size of the Fe₃O₄/GO/clay composite were calculated as 61.64 m²/g and 16.2 nm respectively, which indicate that the composite has a mesoporous structure. Also, the VSM analysis showed that the Fe₃O₄/GO/clay composite has a superparamagnetic property. Moreover, the highest removal efficiency of Cr (VI) from aqueous media was obtained to be 98.84%, which achieved at pH 3, Cr (VI) ion concentration of 10 mg/L, the composite dosage of 1 g/L, contact time of 60 min, and temperature of 25 °C. Furthermore, the kinetic and equilibrium studies showed that the quasi second-order kinetic model and the Langmuir model could better describe the sorption behavior of the clay and the Fe₃O₄/clay composite, while the behavior of the Fe₃O₄/GO/clay composite can be better explained by the Freundlich model. Besides, the maximum sorption capacities of the clay, Fe₃O₄/clay, and Fe₃O₄/GO/clay composite were obtained to be 49.61, 62.26, and 71.47 mg/g, respectively, which shows that the maximum sorption capacity of the clay increases with improving the surface properties of the clay. Also, the thermodynamic study indicated that the Cr (VI) sorption process was exothermic and spontaneous in nature. In general, the results indicated that the Fe₃O₄/GO/clay composite was more effective than the clay and the Fe₃O₄/clay in Cr (VI) ion removal.
显示更多 [+] 显示较少 [-]Spirulina platensis as renewable accumulator for heavy metals accumulation from multi-element synthetic effluents 全文
2020
Cepoi, Liliana | Zinicovscaia, Inga | Rudi, Ludmila | Chiriac, Tatiana | Miscu, Vera | Djur, Svetlana | Strelkova, Ludmila | Grozdov, Dmitrii
Metal accumulation by Spirulina platensis from synthetic effluents with the following chemical composition: Cr/Fe, Cr/Fe/Ni, Cr/Fe/Ni/Zn, and Cr/Fe/Ni/Zn/Cu during repeated cultivation cycle was investigated. Metal ions in different concentrations were added to the culture medium at the exponential and stationary phases of biomass growth and their uptake by biomass was traced using neutron activation analysis. The effect of metal ions on biomass and main biochemical components (proteins, carbohydrates, lipids, phycobilins, and β-carotene) was monitored. S. platensis keeps high metal accumulation capacity during 2–3 cultivation cycles, while the metal ions were added in the stationary phase of its growth. By adding metals in the exponential phase of growth in the following concentrations: 10 mg/L of chromium (VI), 5 mg/L of iron, 2 mg/L of zinc, nickel, and copper, Spirulina platensis acted as renewable accumulator only in Cr/Fe system. It maintained the accumulation capacity during three cultivation cycles when exposed to lower concentrations of metal ions. Its ability to accumulate metal ions during several cultivation cycles was ensured by the maintenance of the optimal level of proteins and lipid in biomass.
显示更多 [+] 显示较少 [-]Atmospheric mercury accumulation rate in northeastern China during the past 800 years as recorded by the sediments of Tianchi Crater Lake 全文
2020
Zhan, Tao | Zhou, Xin | Cheng, Wenhan | He, Xiaoqing | Tu, Luyao | Liu, Xiaoyan | Ge, Junyi | Xie, Yuanyun | Zhang, Jun | Ma, Yongfa | Li, E. | Qiao, Yansong
An evaluation of the history of anthropogenic mercury (Hg) emissions is needed to quantify total atmospheric Hg emissions since the Industrial Revolution. Thus more long-term records of Hg accumulation rate from natural archives are needed. In the present study, a sediment core from Tianchi Lake, a crater lake in northeastern China, was used to reconstruct atmospheric Hg accumulation rates during the past 800 years. The results show that both Hg concentration and Hg accumulation rate began to increase from 29.5 to 40.2 ng g⁻¹ and from 1.44 to 2.26 μg m⁻² yr⁻¹, respectively, at ~ 1750 AD, synchronous with the initiation of the Industrial Revolution. The Hg accumulation rate and Hg concentration increased significantly at ~ 1850 AD, and subsequently, there were two prominent peaks, at ~ 1940 AD and ~ 1980 AD, which are temporally consistent with the Second World War and the peak in commercial usage of Hg, respectively. The Hg accumulation rate and Hg concentration decreased after ~ 1980 AD, possibly because of the decrease in the global Hg background at that time. Differences in regional Hg emissions and atmospheric circulation may be responsible for the different trends in Hg accumulation rate after ~ 1980 AD in the Tibetan Plateau and northeastern China. Our results provide new data for evaluating natural and anthropogenic Hg emissions to the atmosphere in China.
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