Search

Synthetic hormones in wastewater effluents released into the aquatic environments may interfere with the normal endocrine systems of fish in receiving streams. Norgestrel (NGT) is a synthetic progestin widely used in oral contraceptives and frequently detected in wastewater effluents. In this study, adult female mosquitofish (Gambusia affinis) were exposed to three environmentally relevant concentrations of norgestrel (NGT) (i.e., 3.6, 35.8, and 368.0 ng L-1) for 42 d, fin morphology, histology of the ovary, and reproductive behaviors were evaluated. The results showed that NGT at all three concentrations caused an increased frequency of atretic follicular cells in ovaries and impaired mating behaviors exhibited by males toward the NGT-exposed females. In mosquitofish exposed to NGT at 35.8 and 368 ng L-1, the anal fin of females had an increased length ratio of ray4/ray 6, an increased width of ray 3, and increased number of segments in ray 3. The histopathological analysis showed that exposure to NGT increased the incidence of spermatogenesis in ovaries. Mating behavior was impaired 58.4%, 65.7%, and 76.4% (P

Novel mesoporous B–N–O–H nanofoam was prepared using CuB23 and ammonium chloride precursors under O2 in ionic liquids via a solution plasma technique. It had a large specific surface area of 1023 m2 g−1, and exhibited high electrical conductivity of 20.8 S m−1 and good specific capacity of 184 F g−1 in 600 mg L−1 methylene blue aqueous solution at a current density of 0.2 mA cm−2. Furthermore, the nanofoam exhibited a high adsorption capacity for cationic dyes, especially methylene blue, with well-controlled recycling behavior. Meanwhile, the methylene blue/acid orange 7 mixture could be easily separated for reuse by the strong electrostatic interaction. The good separation of methylene blue/Rhodamine B was attributed to the stronger coordination between methylene blue and the B–N–O–H nanofoams in comparison with that of Rhodamine B, and the advantage of the smaller methylene blue in competitive adsorption at higher flow rates. These results indicate that the present B–N–O–H nanofoam may have promising applications in the field of water purification, including enrichment or even total separation of dyes during wastewater treatment for reuse. [ABSTRACT FROM AUTHOR]

An amorphous graphene-like CuB23 alloy with a sheet height of 1.033 nm and a high specific surface area of 674.88 m2 g−1 was prepared via a solution plasma technique with the assistance of polyvinylpyrrolidone. It exhibited a fast, stable and highly selective response to H2S at room temperature with a 1 ppb detection limit. [ABSTRACT FROM AUTHOR]

In this study, the luminescent macromolecular lanthanide complexes with the copolymers of styrene (St) and 2-butenedioic acid (z)-mono-ethyl ester (BAME) have been synthesized, and an extensive characterization has been carried out by means of elemental analysis, FTIR, thermal analysis, and fluorescence determination. The results showed that the carboxylic groups on the chain of the polymers acted as bidentate ligands coordinated to lanthanide ions; and the coordination degree of -COO−/Ln3+ in the macromolecular complexes was closely dependent on both the pH value of the solution and the molar ratio of St to BAME in the polymeric ligands. Thermal analysis manifested that the macromolecular complexes Ln-PSt/BAME (Ln = Y, Sm, Dy, Eu, and Tb) were highly crosslinked and had high thermal stability and solvent resistance. The fluorescence determination indicated that Ln-PSt/BAME complexes could emit characteristic fluorescence with comparatively high brightness and good monochromaticity, and the fluorescence intensity increased with an increasing of lanthanide content. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

The drastic changes or threshold phenomena of ecosystems in response to environmental changes are main research focuses in ecology. However, the difficulty in quantitative detection of ecological thresholds hinders the further research progress and application of this topic. Based on typical cases, we analzyed the driving-response mechanism of S-shaped curve type, subsidy-stress type, step type of the potential ecological thresholds. Seven methods to determine ecological thre-shold were summarized, including locally weighted scatterplot smoothing, piecewise regression, Gaussian model, change-point analyzer, regime shift detection, threshold indicator taxa analysis and system dynamics simulation model. The advantages, disadvantages and applicability of those methods were also addressed. This study could provide references for quantitative detection of ecological threshold.

Non-linear changes widely occur in ecosystems, which manifest as sudden changes in system state with increasing pressure. To explain these changes, ecologists proposed the concepts of ecological threshold and regime shift, and continuously improved the theory and method system. Mechanistic and empirical studies further deepen our understanding for evolution mechanism of the complex system, which begun to be implemented into the environmental management. In recent decades, a large number of quantitative studies on stress-response in various types of ecosystems in China. Results from those studies are closely related to the theory paradigms of ecological threshold and regime shift in essence. Based on the "China Ecological Thresholds and Alternative Stable States Database", we screened and summarized the relevant ecological thresholds and explained the mechanisms underlying regime shift for 10 ecosystem types, including river, lake, wetland, forest, grassland, estuary and ocean, farmland, desert, city, and tundra. We linked case studies with theory paradigms of ecological threshold and regime shift with the aim to integrate multi-field scientific achievements and resources as the basis for ecosystem complexity research, and promote their application in ecological monitoring, ecological security early warning, and ecological standards innovation.

Objective: To study the effect of Bushen Tongdu Capsule (BTC) on RANK/RANKL/ OPG pathway of collagen induced arthritis (CIA) rats, thereby laying theoretic evidence for treating rheumatic arthritis (RA) by Chinese medicine., Methods: RA model was induced by CIA. Totally 42 rats were randomly divided into six groups, i.e., the normal control group, the model group, the low dose BTC (BSL) group, the medium dose BTC (BSM) group, the high dose BTC (BSH) group, and the Tripterygium Glycosides (TG) group, 7 in each group. BTC at the daily dose of 120, 240, and 480 mg/kg was given by gastrogavage to rats in the BSL, BSM, and BSH group respectively from the 13th day of modeling. TG at the daily dose of 24 mg/kg was given by gastrogavage to rats in the TG group. All medication was given once daily, 2 mL each time. Two mL normal saline was administered to rats in the normal control group and the model group. All medication lasted for 18 days. Samples were taken at day 31. The TRAP section of the ankle joint was fixed in 10% formalin for TRAP stain. Serum levels of osteoprotegerin (OPG), receptor activator of nuclear factor-κB ligand (RANKL), and macrophage colony-stimulating factor (M-CSF) were detected using ELISA., Results: Compared with the normal control group, positive reactions of pathological ankle joint section, inflammation, and osteoclasia degree were significantly improved in the model group, serum levels of RANKL and M-CSF were up-regulated, levels of OPG and OPG/RANKL were significantly lowered (all P < 0.01). Compared with the model group, positive reactions of pathological ankle joint section, inflammation, and osteoclasia degree also significantly decreased in the BSH group and the TG group (all P < 0.01). RANKL and M-CSF were significantly down-regulated in each medicated group, while levels of OPG and OPG/RANKL were significantly up-regulated (all P < 0.01). Compared with the TG group, M-CSF was lower, but levels of OPG and OPG/RANKL were significantly up-regulated in the normal control group (all P < 0.01). RANKL and M-CSF were significantly up-regulated, while levels of OPG and OPG/RANKL were significantly down-regulated in the model group and each BS group (all P < 0.01)., Conclusion: BTC could relieve bone damage of CIA rats possibly through regulating and controlling osteoclasts.