7-Piperazine ethyl chrysin inhibits proliferation of lung cancer cells via induction of apoptosis

Purpose: To investigate the effect of 7-piperazine ethyl chrysin (PEC) on A-427 and A-549 lung cancer cell lines.Methods: The cell lines were incubated with PEC at doses of 2, 4, 6, 8 and 10 μM for 24, 48 and 72 h, and their viabilities at each time interval were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay. Cell apoptosis was evaluated with annexin V fluorescein isothiocyanate/propidium iodide staining, while the expression of ERK1/2 protein was determined using western blot. The involvement of ERK1/2 in the effect of PEC on viability and apoptosis was assessed by incubating the cells with PD98059 (an inhibitor of ERK1/2).Results: Exposure to PEC at doses ≥ 4 μM significantly reduced the viability of A-427 and A-549 cell lines in time- and concentration-dependent manners at 48 h (p < 0.02). The viability of A-427 and A-549 cells was reduced to 21 and 18 %, respectively, on treatment with 8 μM PEC for 48 h. Moreover, PEC treatment induced apoptosis in A-427 (59.67 %) and A-549 (61.37 %) cells after 48 h. Western blot data revealed that PEC also significantly inhibited phosphorylation of ERK1/2 in both cancer cell lines (p < 0.05). Incubation of A-427 and A-549 cells with PD98059 for 48 h also reduced their viability and induced their apoptosis (p < 0.05).Conclusion: These results indicate that PEC inhibits the viability of lung cancer cells via inhibition of ERK1/2 expression. Thus, PEC may be efective for the treatment of lung carcinoma but further studies are required to ascertain this.Keywords: 7-Piperazine ethyl chrysin, Lung cancer cells, Apoptosis, Viability, inhibitio

Bacterial Communities in Riparian Sediments: A Large-Scale Longitudinal Distribution Pattern and Response to Dam Construction

Sediment microbes play major roles in riparian ecosystems; however, little is known about their longitudinal distribution pattern and their responses to dam construction, the most severe human disturbance in river basins. Here, we investigated the variability of sediment bacterial communities along a large-scale longitudinal gradient and between dam-controlled and dam-affected sites in riparian zone of the Lancang River, China. The abundance, activity and diversity of sediment bacteria gradually increased in a downstream direction, but were significantly lower in the dam-affected sites than in the dam-controlled sites. The bacterial community compositions differed significantly between the upper-middle-reach and downstream sites at all control sites, and also between the dam-affected and dam-controlled sites. In the cascade dam area, the relative importance of spatial distance and environmental heterogeneity for bacterial distribution differed between the dam-controlled and dam-affected sites. Spatial distance was the primary cause of variations in bacterial community in dam-controlled site. By contrast, the environmental heterogeneity had more control over the bacterial communities than did the spatial distance in dam-affected site. Network analysis showed that the bacterial community in the dam-affected sites had lower connectivity and stability when compared with that in dam-controlled sites. These results suggest the distinct variations in sediment bacterial community in dam-affected sites, which could enhance our understanding of potential ecological effects caused by dam construction

Effects of Biofilms on Trace Metal Adsorption on Plastics in Freshwater Systems

The formation of plastisphere on plastics and their potential impact on freshwater ecosystems have drawn increasing attention. However, there is still limited information about the effects of plastisphere on the heavy metal adsorption capacity and the related mechanism of plastic debris in different freshwaters. Herein, the trace metal adsorption capacity, kinetics and adsorption mechanisms of virgin and biofilm-covered plastic debris were investigated. Polypropylene (PP) and polyethylene terephthalate (PET) plastic debris were placed in three freshwaters (Xuanwu Lake, Donghu Lake and the Qinhuai River) for 45 days to incubate biofilms. Batch adsorption experiments were performed to compare the adsorption processes of trace metal on virgin and biofilm-covered plastics. Results showed that biofilms increase the adsorption of metals on plastics, and the adsorption isotherms were well fitted by the Langmuir model. Furthermore, the adsorption capacities for lead (Pb(II)) were higher than that of cadmium (Cd(II)) and zinc (Zn(II)), with 256.21 and 277.38 μg/g (Pb(II)) adsorbed in biofilm-covered PP and PET, respectively, in Xuanwu Lake. The adsorption kinetics of metals on plastic debris were significantly affected by the biofilms, by switching the intraparticle diffusion for virgin plastic debris to film diffusion for the biofilm-covered plastic debris. Moreover, the complexation of functional groups within the biofilms might mainly contribute to the increases of metal adsorption, involving the participation of oxygen and nitrogen groups. Overall, these results suggested that biofilms reinforce the potential role of plastics as a carrier of trace metals in freshwaters

Unconventional casing programs for subsalt ultra-deep wells with a complex pressure system: A case study on Well Wutan 1 in the Sichuan Basin

Well Wutan 1 is a wildcat well deployed in the Dazhou–Kaijiang paleo-uplift, eastern Sichuan Basin and its design depth is 7570 m. The Cambrian and Sinian strata are its main exploration targets, and the strata below the Silurian in this well are geologically uncertain with a high risk. A large section of gypsum-salt layer may be encountered in the Cambrian and the longitudinal pressure system is complex. It is predicted that the bottom hole temperature is up to 175 °C, and the bottom hole liquid column pressure exceeds 140 MPa, and there is hydrogen sulfide. As a result, the casing program design is confronted with great challenges. In this paper, the difficulties and risks of drilling engineering were analyzed. Then, a casing program was designed and optimized referring to the successful drilling experience of subsalt ultra-deep wells at home and abroad, combined with the pressure system characteristics of Well Wutan 1 and the creep performance of gypsum-salt layers. Finally, the casing program was applied on site. And the following research results were obtained. First, in order to prevent lost circulation, blowout and differential pressure induced stuck pipe in the open hole section, it is determined that the casing program shall be in the pattern of six-section casing with 5 setting points. Second, no setting point is needed in the Carboniferous pressure depleted reservoir for it is lithologically tight and differential pressure induced stuck pipe and lost circulation are less risky. Third, to better isolate the salt layer, one section of casing is specially designed for the Cambrian gypsum-salt layer and its collapse strength is 160 MPa to prevent collapse by salt creep. Fourth, Well Wutan 1 is drilled successfully to the expected strata and its total depth is 8060 m. In conclusion, the unconventional six-section casing program with 5 setting points to ensure the subsalt drilling safety in the eastern Sichuan Basin is rational. The successful drilling of Well Wutan 1 provides experiences and references for the follow-up exploration of deep-seated gas in the Dazhou–Kaijiang paleo-uplift. Keywords: Ultra-deep well, Complex pressure system, Gypsum-salt layer, Hydrogen sulfide bearing, Casing program, Sichuan basin, Eastern sichuan basin, Dazhou–kaijiang paleo-uplift, Well wutan