Long-term variation of black carbon and PM2.5 in Beijing, China with respect to meteorological conditions and governmental measures.

Black carbon (BC) and PM2.5 were studied for nine years from 2005 to 2013 in the Beijing urban area. The overall weekly average mass concentrations of BC and PM2.5 were 4.3 and 66.8 µg/m³. PM2.5 annual means of the nine years are around 2 times of the standard (GB3095-2012) in China, and are 5-7 times higher than the WHO standard. The Beijing Olympic Games in 2008 was a milestone to mitigate aerosol pollution. Temporal distribution of BC shows a distinct declining trend, and annual mean mass concentrations of PM2.5 after 2008 were lower than those before 2008 but increased from 2011 to 2013. Wind rose plots show that high BC concentrations are usually associated with low wind speed of northeastern or southwestern winds, generally causing poor visibility. Governmental mitigation measures such as traffic restriction despite increased motor vehicle numbers and gasoline consumption and industry relocation with declining consumption of coal and coke were successful in reducing BC emissions. Annual mean of BC was reduced by 38% in 2013 compared to 2005. However, BC contamination in Beijing is still severe when compared to other urban areas around the world.

[Assessment on the COD discharge status of municipal wastewater treatment plant in a city of China].

Based on the statistical theory, the paper collected routine monitoring data for 3 years of 11 municipal wastewater treatment plants with secondary treatment or enhanced secondary treatment in a northern city in China, and analysis of the discharge concentration distribution of COD showed a Delta-lognormal distribution. On this basis, referring to the formulation methods of water pollutant discharge limits used in the USA, the paper studied and assessed the discharge status of COD of the municipal wastewater treatment plants in the city, including the daily maximum and the monthly average discharge status, and came to the conclusion that the daily maximum discharge status met the first grade A class discharge standard (50 mg · L(-1)) required by the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002). Meanwhile, the assessment conclusion was obtained for the monthly average discharge status, and the conclusions were discussed. The assessment method and the conclusions in this paper might provide reference for formulation and revision of water discharge standards.

Glycogen Synthase Kinase 3ß Inhibitor (2'Z,3'E)-6-Bromo-indirubin- 3'-Oxime Enhances Drug Resistance to 5-Fluorouracil Chemotherapy in Colon Cancer Cells.

OBJECTIVE: To explore the effects and mechanism of glycogen synthase kinase 3ß (GSK-3ß) inhibitor (2'Z,3'E)-6-bromo-indirubin-3'-oxime (BIO) on drug resistance in colon cancer cells. METHODS: The colon cancer SW480 and SW620 cells were treated with BIO, 5-fluorouracil (5-FU) and BIO/5-FU, separately. Cell cycle distribution, apoptosis level and efflux ability of rhodamine 123 (Rh123) were detected by flow cytometry. The protein expressions of P-glycoprotein (P-gp), multidrug resistance protein 2 (MRP2), thymidylate synthase (TS), ß-catenin, E2F-1 and Bcl-2 were detected by Western blot. ß-catenin and P-gp were stained with double immunofluorescence and observed under a confocal microscope. RESULTS: BIO up-regulated ß-catenin, P-gp, MRP2 and TS, enhanced the efflux ability of Rh123, decreased Bcl-2 protein and gave the opposite effect to E2F-1 protein in SW480 and SW620 cells. Furthermore, BIO significantly inhibited cell apoptosis, increased S and G(2)/M phase cells, and reduced the cell apoptosis induced by 5-FU in SW480 cells, whereas the effects were slight or not obvious in SW620 cells. CONCLUSION: GSK-3ß was involved in drug resistance regulation, and activation of ß-catenin and inhibition of E2F-1 may be the most responsible for the enhancement of 5-FU chemotherapy resistance induced by GSK-3ß inhibitor BIO in colon cancer.