| 1. |
- Gao, Kai, et al.
(författare)
-
Application of Rainbow Trout CYP1 Gene Expression Patterns in Gill and Liver for Haihe River Bio-monitoring
- 2015
-
Ingår i: Huanjing Kexue. - 0250-3301. ; 36:10, s. 3878-3883
-
Tidskriftsartikel (refereegranskat)abstract
- CYP1 subfamily genes in gills and liver of rainbow trout as biomarkers were studied to establish methods for quantitative mRNA expression analysis of these genes and to determine their expression pattern. Fish caged in various waters in the Haihe River (Tianjin) were analyzed. The mRNA expression patterns observed in Machangjian River and estuary site of Haihe River were markedly similar but at different levels, reflecting that those sites shared the similar pollution components but with different local pollution load. CYP1C1 and 1C3 were only induced at Gegu site and estuary site of Haihe River, indicating different types of CYP1 agonists in Machangjian River. Response patterns of multiple CYP1 genes in gills and liver could be applied in the monitoring strategy. The response patterns of CYP1 genes could be used for better understanding the relationship between complex mixtures of pollutants and biological response of organisms in aquatic environments.
|
|
| 2. |
- Jiang, Tao
(författare)
-
Simulated desorption kinetics of lead by the dominant plant roots released low molecular weight organic acids from the water-level-fluctuating zone in the Three Gorges Reservoir
- 2017
-
Ingår i: Huan Jing Ke Xue. - 0250-3301. ; 38, s. 600-607
-
Tidskriftsartikel (refereegranskat)abstract
- Vegetations grow vigorously in the water-level-fluctuating zone (WLFZ) of Three Gorges Reservoir (TGR) during the non-flooded period. Low molecular weight organic acids (LMWOAs) excreted from the roots of these plants may active the heavy metals in soil. In order to investigate the desorption kinetics of Pb in the vegetation covered soil of TGR, the LMWOAs released from Cynodon dactylon and Echinochloa crusgalli roots, which are the dominant species in WLFZ, were analyzed both qualitatively and quantitatively. Furthermore, single and mixed species of LMWOAs were also used in the simulation. The results showed that the variety and content of LMWOAs secreted from Cynodon dactylon roots were larger and higher than those of Echinochloa crusgalli. Citric acid, malonic acid, acetic acid and malic acid were the same LMWOAs released from the two types of plants. The contents of acetic acid were the highest among all LMWOAs, which were 0.765 and 0.261 mmol·kg-1in Cynodon dactylon and Echinochloa crusgalli roots, respectively.Citric acid, malonic acid and acetic acid were the same LMWOAs detected from their rhizosphere soils. In the citric acid, malonic acid and acetic acid desorption test, the desorption captivities of Pb were inhibited when the concentration of LMWOAs was lower than 1 mmol·L-1. The desorption ability displayed a decreasing order of malonic acid>citric acid>acetic acid. However, the three LMWOAs promoted the desorption of Pb in soil when their concentrations were higher than 1 mmol·L-1, respectively. The desorption ability displayed a decreasing order of citric acid>malonic acid>acetic acid. During the entire process of desorption, 0-240 min was the fast reaction stage, and the remaining time was the slow reaction stage. The pseudo-second order kinetics equation could fit best for the kinetic process.
|
|
| 3. |
- Jiang, Tao
(författare)
-
Use of the Nitrogen/Carbon Ratio (N/C) and Two End-Member Sources Mixing Model to Identify the Origins of Dissolved Organic Matter from Soils in the Water-Level Fluctuation Zones of the Three Gorges Reservoir
- 2019
-
Ingår i: Huan Jing Ke Xue. - 0250-3301. ; 40, s. 2647-2656
-
Tidskriftsartikel (refereegranskat)abstract
- Soil dissolved organic matter (soil DOM) plays a crucial role in the environmental fate of pollutants because of its exceptional biogeochemical reactivity. Therefore, tracing the sources and understanding the properties of DOM through chemical characterization is important for clarifying the "structure-reactivity" of DOM in the environment. In this study, traditional elementary analysis methods including nitrogen/carbon ratio (N/C) determinations and derived two end-member source-loads mixing models were applied to soil DOM extracted from the water-level fluctuation zones of the Three Gorges Reservoir (TGR) area. The results were further compared to other characterization techniques that operate on the molecular scale (e. g., FTIR and analytical pyrolysis techniques). The ultimate objective was to assess the performance of N/C ratio and two end-member modeling for identifying the DOM sources. Additionally, a photo-bleaching kinetic experiment was conducted to test the correlation between DOM reactivity and its source-loadings. Results showed, based on the N/C ratio and mixing modeling, all soil DOM samples in the TGR area share "dual-source" characteristics, namely, allochthonousness (e. g., terrestrial) and autochthonousness (e. g., internal) attributes, which is in agreement with other advanced characterization tools. The traditional method results were comprehensible in light of the data from molecular techniques, but the information revealed only reflects certain aspects of DOM compositional characteristics. It can be concluded that the N/C ratio and mixing modeling can validate general sources of soil DOM, but not information about specific components. Meanwhile, the significant correlation between the photo-bleaching kinetic constant and N/C and source-loadings indicated that these two parameters can be used as rapid indicators to estimate soil DOM reactivity in photochemical processes. However, it should be emphasized that it remains essential to employ multiple characterization methods to investigate the biogeochemistry of soil DOM, so as to increase the characterization resolution with regard to the heterogeneity of DOM.
|
|
