خيارات البحث
النتائج 3871 - 3880 من 4,043
Vitellogenin and vitellogenin receptor gene expression and 20-hydroxyecdysone concentration in Macrobrachium rosenbergii exposed to chlordecone النص الكامل
2016
Lafontaine, Anne | Hanikenne, Marc | Boulangé-Lecomte, Céline | Forget-Leray, Joëlle | Thomé, Jean-Pierre | Gismondi, Eric
Vitellogenin and vitellogenin receptor gene expression and 20-hydroxyecdysone concentration in Macrobrachium rosenbergii exposed to chlordecone النص الكامل
2016
Lafontaine, Anne | Hanikenne, Marc | Boulangé-Lecomte, Céline | Forget-Leray, Joëlle | Thomé, Jean-Pierre | Gismondi, Eric
Chlordecone is a persistent organochlorine pesticide widely used in Guadeloupe (French West Indies) to control the banana weevil Cosmopolites sordidus. Although it was previously highlighted that chlordecone may affect the reproduction and growth of vertebrate species, little information is available on the chlordecone effects in invertebrates. The present study investigated the effects of chlordecone on a hormone and a protein having key roles in reproduction and growth of the decapod crustacean Macrobrachium rosenbergii, by measuring the 20-hydroxyecdysone concentration, vitellogenin, and vitellogenin receptor gene expression, as well as the bioconcentration of chlordecone in exposed prawns. First, the results revealed that chlordecone was accumulated in M. rosenbergii. Then, it was found that Vg and VgR gene expression were increased in male and female M. rosenbergii exposed to chlordecone for 90 and 240 days, while the 20-hydroxyecdysone concentrations were decreased. This work suggests that chlordecone accumulates in prawn tissues and could affect key molecules involved in the reproduction and the growth of the invertebrate M. rosenbergii. However, many questions remain unresolved regarding the impacts of chlordecone on growth and reproduction and the signaling pathways responsible for these effects, as well as the potential role of confounding factors present in in situ studies.
اظهر المزيد [+] اقل [-]Vitellogenin and vitellogenin receptor gene expression and 20-hydroxyecdysone concentration in Macrobrachium rosenbergii exposed to chlordecone النص الكامل
2016
Lafontaine, Anne | Hanikenne, Marc | Boulangé-Lecomte, Céline | Forget-Leray, Joëlle | Thomé, Jean-Pierre | Gismondi, Eric
peer reviewed
اظهر المزيد [+] اقل [-]Composition of phosphorus in wetland soils determined by SMT and solution 31P-NMR analyses النص الكامل
2016
Zhang, Wenqiang | Jin, Xin | Ding, Yuekui | Zhu, Xiaolei | Rong, Nan | Li, Jie | Shan, Baoqing
In Eastern China, wetlands are common in the lower reaches of catchments or in coastal zones. Wetlands are at risk from eutrophication because of the large quantities of phosphorus (P) they receive from rivers. They are also decreasing in size. In this contribution, we present information about the composition of P in wetland soils, obtained using the Standards, Measurements, and Testing (SMT) protocol and ³¹P-nuclear magnetic resonance (NMR) spectroscopy. Average P concentrations varied in the different wetland soils and, in four of the five wetlands sampled, exceeded 500 mg∙kg⁻¹. HCl-inorganic P (Pi) was the main Pi fraction in wetland soils. The percentage contribution of Pi (89.7 %) to total P was the highest in the Yangtze River estuary wetland. Six P components were detected by ³¹P-NMR analysis. Mono-P was the main organic P (Po) in wetland soils. Orthophosphate (Ortho-P) was positively and negatively related to NaOH-Pi (R ² = 0.957, p < 0.001) and HCl-Pi (R ² = −0.689, p < 0.001), respectively. Orthophosphate monoesters (Mono-P) were positively related to Po (R ² = 0.617, p < 0.001) and ortho-P (R ² = 0.624, p < 0.001), respectively. The main Po component was Mono-P, and it may be mineralized to ortho-P under the frequently changing redox conditions in wetland soils. The information from this study will support the development of robust scientific and effective policy for P management in wetlands.
اظهر المزيد [+] اقل [-]Health risk equations and risk assessment of airborne benzene homologues exposure to drivers and passengers in taxi cabins النص الكامل
2016
Chen, Xiaokai | Feng, Lili | Luo, Huilong | Cheng, Heming
Interior air environment and health problems of vehicles have attracted increasing attention, and benzene homologues (BHs) including benzene, toluene, ethylbenzene, xylenes, and styrene are primary hazardous gases in vehicular cabins. The BHs impact on the health of passengers and drivers in 38 taxis is assessed, and health risk equations of in-car BHs to different drivers and passengers are induced. The health risk of in-car BHs for male drivers is the highest among all different receptors and is 1.04, 6.67, and 6.94 times more than ones for female drivers, male passengers, and female passengers, respectively. In-car BHs could not lead to the non-cancer health risk to all passengers and drivers as for the maximal value of non-cancer indices is 0.41 and is less than the unacceptable value (1.00) of non-cancer health risk from USEPA. However, in-car BHs lead to cancer health risk to drivers as for the average value of cancer indices is 1.21E-04 which is 1.21 times more than the unacceptable value (1.00E-04) of cancer health risk from USEPA. Finally, for in-car airborne benzene concentration (X, μg/m³) to male drivers, female drivers, male passengers, and female passengers, the cancer health risk equations are Y = 1.48E-06X, Y = 1.42E-06X, Y = 2.22E-07X, and Y = 2.13E-07X, respectively, and the non-cancer health risk equations are Y = 1.70E-03X, Y = 1.63E-03X, Y = 2.55E-04X, and Y = 2.45E-04X, respectively.
اظهر المزيد [+] اقل [-]A field pilot-scale study of biological treatment of heavy oil-produced water by biological filter with airlift aeration and hydrolytic acidification system النص الكامل
2016
Zhang, Min | Wang, Junming | Zhang, Zhongzhi | Song, Zhaozheng | Zhang, Zhenjia | Zhang, Beiyu | Zhang, Guangqing | Wu, Weimin
Heavy oil-produced water (HOPW) is a by-product during heavy oil exploitation and can cause serious environmental pollution if discharged without adequate treatment. Commercial biochemical treatment units are important parts of HOPW treatment processes, but many are not in stable operation because of the toxic and refractory substances, salt, present. Therefore, pilot-scale experiments were conducted to evaluate the performance of hydrolytic acidification-biological filter with airlift aeration (HA-BFAA), a novel HOPW treatment system. Four strains isolated from oily sludge were used for bioaugmentation to enhance the biodegradation of organic pollutants. The isolated bacteria were evaluated using 3-day biochemical oxygen demand, oil, dodecyl benzene sulfonic acid, and chemical oxygen demand (COD) removals as evaluation indices. Bioaugmentation enhanced the COD removal by 43.5 mg/L under a volume load of 0.249 kg COD/m³ day and hydraulic retention time of 33.6 h. The effluent COD was 70.9 mg/L and the corresponding COD removal was 75.0 %. The optimum volumetric air-to-water ratio was below 10. The removal ratios of the total extractable organic pollutants, alkanes, and poly-aromatic hydrocarbons were 71.1, 94.4, and 94.0 %, respectively. Results demonstrated that HA-BFAA was an excellent HOPW treatment system.
اظهر المزيد [+] اقل [-]Quinoline biodegradation by filamentous fungus Cunninghamella elegans and adaptive modifications of the fungal membrane composition النص الكامل
2016
Felczak, Aleksandra | Bernat, Przemysław | Różalska, Sylwia | Lisowska, Katarzyna
Quinoline, which belongs to N-heterocyclic compounds, occurs naturally in the environment and is used in numerous industrial processes. The structures of various chemicals, such as dyes and medicines, are based on this compound. Due to that fact, quinoline and its derivatives are widely distributed in environment and can exert toxic effects on organisms from different trophic levels. The ability of the filamentous fungus Cunninghamella elegans IM 1785/21Gp to degrade quinoline and modulate the membrane composition in response to the pollutant was studied. C. elegans IM 1785/21Gp removes quinoline with high efficiency and transforms the pollutant into two novel hydroxylated derivatives, 2-hydroxyquinoline and 3-hydroxyquinoline. Moreover, due to the disruption in the membrane stability by quinoline, C. elegans IM 1785/21Gp modulates the fatty acid composition and phospholipid profile.
اظهر المزيد [+] اقل [-]Enhanced textile dye decolorization by marine-derived basidiomycete Peniophora sp. CBMAI 1063 using integrated statistical design النص الكامل
2016
Bonugli-Santos, Rafaella C. | Vieira, Gabriela A. L. | Collins, Catherine | Fernandes, Thaís Cristina C. | Marin-Morales, Maria Aparecida | Murray, Patrick | Sette, Lara D.
In the present study, the biotechnological potential of the marine-derived fungus Peniophora sp. CBMAI 1063 was investigated in relation to Reactive Black 5 (RB5) dye decolorization and degradation using an integrated statistical design composed of Plackett-Burman design (P&B), central composite design (CCD), and response surface methodology (RSM). RB5 dye was effectively decolorized (94 %) in saline conditions, without any detection of mutagenic compounds, and simultaneously, 57 % of total organic carbon (TOC) was removed in 7 days. The activity of lignin peroxidase (LiP) was not detected during the process. The gene expression of laccase (Lac) and manganese peroxidase (MnP) enzymes produced during the process was evaluated, and results from this experiment coupled with LC-MS analyses revealed that in the early stage of dye decolorization, a higher MnP gene expression and significant enzymatic activity was detected in Peniophora sp. CBMAI 1063 with the formation of p-Base and TAHNDS compounds. This paper reports innovative data related to the textile dye decolorization by the marine-derived basidiomycete Peniophora sp. CBMAI 1063, showing the metabolites formed and enzymatic action throughout the process in saline condition. The strategy used showed to be an efficient statistical approach that provides an attractive solution for the screening and simultaneous optimization of the degradation process.
اظهر المزيد [+] اقل [-]Characteristics of size-segregated carbonaceous aerosols in the Beijing-Tianjin-Hebei region النص الكامل
2016
Guo, Yuhong
Mass concentrations of organic carbon (OC) and elemental carbon (EC) in size-resolved aerosols were investigated at four sites (three cities and one country) in the Beijing-Tianjin-Hebei region from September 2009 to August 2011. The size distributions of OC and EC presented large evolutions among rural and urban sites, and among four seasons, with highest peaks of OC and EC in fine mode in urban areas during winter. Geometric mean diameters (GMDs) of OC and EC in fine particles at urban sites during winter were lower than those at rural site mainly due to effects of fine particle coagulation and organic compound repartitioning. Fossil fuel emissions were a dominant source of OC and EC in urban areas, while biomass burning was a major source of OC and EC at rural site. Trajectory clustering and CWT analysis showed that regional transport was an important contributor to OC and EC in Beijing.
اظهر المزيد [+] اقل [-]Biomonitoring of tobacco smoke exposure and self-reported smoking status among general population of Tehran, Iran النص الكامل
2016
Hoseini, Mohammad | Yunesian, Masud | Nabizadeh, Ramin | Yaghmaeian, Kamyar | Parmy, Saeid | Gharibi, Hamed | Faridi, Sasan | Hasanvand, Mohammad Sadegh | Ahmadkhaniha, Reza | Rastkari, Noushin | Mirzaei, Nezam | Naddafi, Kazem
The present study aimed to find a correlation between the self-reported smoking status of the residents of Tehran, Iran, and the urine cotinine as a biomarker of exposure to tobacco smoke. The self-reported data was collected from 222 participants who were living in the urban area of Tehran. The urine samples of participants were collected for cotinine analysis. Urine cotinine was measured by an enzymatic immunoassay technique. Tobacco smoking was reported by 76 (34.23 %) participants as the self-reported data, and the number of males in this report was higher than of females (p < 0.001). By adding the number of the self-reported non-smokers with cotinine levels above the cutoff value of >100 ng/ml to self-reported smokers, the smoking prevalence increased from 34.23 % (95 % CI 28.01–40.88 %) to 36.48 % (95 % CI 30.14–43.19 %). Using the cutoff value, sensitivity and specificity of the self-reported smoking status were respectively 90.12 % (95 % CI 81.46–95.64 %) and 98 % (95 % CI 93.91–99.55 %). The levels of agreement between self-reported tobacco smoking and urinary cotinine concentrations was 95.1 % (k = 0.89, p < 0.001, 95 % CI = 0.81–0.95). Based on the results, self-reported smoking can be a valid marker for assessing the tobacco exposure, and it can be of use in large epidemiological studies.
اظهر المزيد [+] اقل [-]Isolation and characterization of two novel psychrotrophic decabromodiphenyl ether-degrading bacteria from river sediments النص الكامل
2016
Wang, Linqiong | Li, Yi | Zhang, Wenlong | Niu, Lihua | Du, Juan | Cai, Wei | Wang, Jing
Decabromodiphenyl ether (BDE-209) is a brominated flame retardant and a priority contaminant. Currently, little information is available about its significance in the environment, specifically about its susceptibility to aerobic biotransformation at low temperature. In this work, five phylogenetically diverse BDE-209-degrading bacterial strains were isolated from river sediments of northern China. These strains were distributed among four different genera—Acinetobacter, Pseudomonas, Bacillus and Staphylococcus. All five isolates were capable of growing on BDE-209, among which two isolates show better growth. By detailed morphological, physiological, and biochemical characteristics and 16S rDNA sequence analysis, the two strains were identified and named as Staphylococcus haemolyticus LY1 and Bacillus pumilus LY2. The two bacteria can grow in mineral salt medium containing BDE-209 substrate across the temperatures ranging from 2.5 to 35 °C, with an optimum temperature of 25 °C which could be considered as psychrotrophs accordingly. The degradation experiment showed that more than 70.6 and 85.5 % of 0.5 mg/L BDE-209 were degraded and the highest mineralization efficiencies of 29.8 and 39.2 % were achieved for 0.5 mg/L BDE-209 by S. haemolyticus LY1 and B. pumilus LY2, respectively. To the best of our knowledge, this is the first demonstration for the biodegradation of BDE-209 by two psychrotrophic bacteria isolated from environment.
اظهر المزيد [+] اقل [-]Reduction of disinfection by-product precursors in reservoir water by coagulation and ultrafiltration النص الكامل
2016
Wang, Feng | Gao, Baoyu | Ma, Defang | Yue, Qinyan | Li, Ruihua | Wang, Qianwen
In this study, reservoir water intended for drinking water supply was treated by (i) ultrafiltration (UF) (ii) coagulation (CW) (iii) coagulation combined with ultrafiltration (CW-UF). To probe the influences of three treatment processes on disinfection byproduct (DBP) precursors in source water, the changes of dissolved organic matter (DOM) amounts and physicochemical properties, and disinfection byproduct (DBP) formation characteristics during chlorine disinfection were investigated. Both carbonaceous DBP (C-DBP) and nitrogenous DBP (N-DBP) formation and speciation were analyzed. The influence of chlorine dose, contact time on DBP formation and speciation were also studied to optimize the disinfection conditions to minimize the DBP formation. Compared with UF and CW alone, CW-UF improved the dissolved organic carbon (DOC) removal from about 20 % to 59 %. The three-dimensional excitation and emission matrix (3DEEM) fluorescence spectroscopy analysis showed that CW-UF had high removal efficiency in microbial products (Region IV), fulvic acid-like (Region III) and humic acid-like (Region V). The total C-DBP was determined by the formation of trihalomethanes and trichloromethane was the most abundant species (40 %). The most abundant N-DBP species was dichloroacetonitrile (32.5 %), followed by trichloroactetonitrile. CW-UF effectively reduced the risk of DBPs in drinking water supply by reducing 30.8 % and 16.9 % DBPs formation potential compared with UF and CW alone. Increasing contact time improved the yields of both C-DBPs and N-DBPs. Chlorine dosage had slight influence on DBP yield in this study.
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