ABSTRACT
The Tuojiang River and Fujiang River, two important tributaries of the upper reaches of the Yangtze River, have serious water pollution problems, among which nitrogen (N) and phosphorus (P) are the most important pollutants. Therefore, the aim of this study was to identify the influencing factors of water quality in different spaces and provide a scientific basis for the prevention and control of surface water pollution in the upper reaches of the Yangtze River and its tributaries. Water samples of trunk and tributaries in the Tuojiang River and Fujiang River were collected, and the spatial distribution characteristics of water N and P were analyzed. The results showed that the Tuojiang River and Fujiang River showed serious pollution of total nitrogen (TN), with a water quality worse â ¤-section proportion as high as 94% and 50%, respectively. Both rivers showed that TN and TP concentrations in the tributaries were higher than those in the main stream. For both rivers, total phosphorus (TP), with moderate pollution, was mainly concentrated in â ¡, â ¢, and â £ class water quality, whereas the P pollution was more serious for the Fujiang River compared to that of the Fujiang River. For the Tuojiang River, nitrate nitrogen (NN) concentration from upstream to downstream showed a trend of decreasing after the first increase, with the maximum concentration of ammonium nitrogen (AN) exhibiting at the upstream site. In particular, TP concentration increased significantly after rivers flowed through a city. For the Fujiang River trunk stream, TN and NN concentration exhibited a gradually increasing trend from the middle to lower reaches. Generally, our study revealed that TN, TP, and NN in the rivers were affected by water pH and water temperature (T). Therefore, the control of N and P pollution in rivers should pay attention to the influence of water environmental factors.
Subject(s)
Environmental Pollutants , Nitrates , Nitrogen , Nutrients , Phosphorus , Water PollutionABSTRACT
BACKGROUND: The aim of this study was to investigate the roles of cytochrome P450 2C19 (CYP2C19) polymorphisms in primary open-angle glaucoma (POAG) susceptibility and individual responses to drug treatment. MATERIAL/METHODS: This case-control study consisted of 93 cases with POAG and 125 controls. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to analyze CYP2C19 single-nucleotide polymorphisms (SNPs). After timolol treatment, patients were classified into side effect (SE) group and non-side effect (NSE) group. According to drug treatment responses, patients were divided into 3 groups: excellent group (Ex) (IOP ≥8 mm Hg); utility group (Ut) (5
Subject(s)
Cytochrome P-450 CYP2C19/genetics , Genetic Predisposition to Disease , Glaucoma, Open-Angle/drug therapy , Glaucoma, Open-Angle/genetics , Polymorphism, Single Nucleotide/genetics , Adult , Aged , Case-Control Studies , Female , Gene Frequency/genetics , Glaucoma, Open-Angle/enzymology , Humans , Male , Middle Aged , Phenotype , Timolol/adverse effects , Timolol/therapeutic use , Treatment Outcome , Young AdultABSTRACT
The diversity of sulfate-reducing bacteria (SRB) in the aquifer underlying the Laogang Landfill along the shore of the East China Sea was investigated. The DNA extracted from 15 groundwater samples was subjected to PCR amplification of the dissimilatory sulfite reductase (dsr) gene. Full-length dsrAB amplicons (approximately 1.9 kb) were then used to construct 4 clone libraries, while the dsrB amplicons (approximately 350 bp) were used for denaturing gradient gel electrophoresis (DGGE) analysis. The clones in the 4 libraries covered all cultured SRB lineages, as well as a deeply branching clade not affiliated with any cultured SRB. In addition, nearly 80% of the 388 clones in the 4 libraries were similar to sequences of the Deltaproteobacteria, Desulfobacteriaceae, Desulfovibrionales, Syntrophaceae, and Desulfobulbaceae. Furthermore, a wide variety of marine SRB was detected, which indicated that seawater has infiltrated the aquifer. Indeed, the DGGE profiles revealed obvious variations in SRB diversity among the 15 samples, which clustered in accordance with the sulfate concentration of the samples ([SO4(2-)]). Moreover, the sulfate concentrations and SRB diversity along the leachate plume did not show regular variation, which suggests the impact of both groundwater flow and seawater intrusion.