Profile and removal of endocrine disrupting chemicals by using an ER/AR competitive ligand binding assay and chemical analyses

An estrogen receptor （ER）/androgen receptor （AR） ligand competitive binding assay （ER/AR-binding assay） and chemical analyses were used to evaluate the endocrine disrupting chemicals （EDCs） behavior of two municipal wastewater treatment plants （WWTPs） （K and S）. In the influents, estrone （E 1）, androsterone （A）, androstenedione （AD）, BPA （bisphenol A）, NP （nonylphenol） and daidzein （DZ） were detected in high amounts with subsequent 24 h-average concentrations of 350, 1000, 29, 1300, 3900, and 5700 ng/L in K-WWTP and of 310, 620, 59, 1600, 2600, and 8400 ng/L in S-WWTP. The estrogenic （androgenic） activity as 17β-estradiol （E2） equivalents （EEQ） or testosterone （Te） equivalents （TEQ） was consequently 620 ng E2/L （570 ng Te/L） and 580 ng E2/L （800 ng Te/L） for the two WWTPs. The removal efficiencies of the above mentioned sole target chemicals were 51%-100% for K-WWTP and 55.6%-100% for S-WWTP. The removal efficiencies of EEQ were about 73% for both WWTPs, while the removal efficiencies of TEQ were 62.1% for K-WWTP and 98.4% for S-WWTP. In addition, chemical-derived EEQ were about 1.2%-52.4% of those by ER-binding assay for K-WWTP and the corresponding ratios were 1.3%-83.3% for S-WWTP, while chemical derived TEQ were less than 3% of values measured by the AR-binding assay for both WWTPs.

Effects of Cu content on microstructure and mechanical properties of rheo-diecasting Al-6Zn-2Mg-xCu alloys

A systematic study on how Cu content affects the microstructure and mechanical properties of rheo-diecasting Al-6Zn-2Mg-xCu alloys during solution treatment and ageing heat treatment was conducted.The swirled enthalpy equilibrium device(SEED)was adopted to prepare the semi-solid slurry of Al-6Zn-2Mg-xCu alloys.The microstructure development and mechanical properties were studied using optical microscopy(OM),scanning electron microscopy(SEM),X-ray diffraction(XRD),differential scanning calorimetry(DSC),as well as hardness and tensile testing.The grain boundary and shape factor were calculated using image processing software(Image-Pro Plus 6.0).Results show that the alloys are composed of typical globular primaryα-Al grains,eutectic phases,and smaller secondaryα-Al grains.After solution and ageing heat treatment,the eutectic phases are dissolved into Al matrix when the Cu content is lower than 1.5wt.%,while some eutectic phases transform into Al_(2)CuMg(S)phases and remain at grain boundaries when Cu content reaches 2wt.%.T6 heat treatment significantly enhances the mechanical properties of rheo-diecasting Al-6Zn-2Mg-xCu alloys.When Cu concentration is 0.5wt.%-1.5wt.%,the ultimate tensile strength,yield strength and elongation of T6 treated alloys rise to around 500 MPa,420 MPa,and 18%,respectively.

Combination patterns of precipitation and its concentration degree determining the risk of dengue outbreaks in China

The amount and distribution of precipitation can determine dengue risk by affecting mosquito breeding;however,previous studies failed to incorporate this bivariate characteristic to examine dengue fever transmission.In the present research,nationwide data on daily dengue cases in China between January 2005 and December 2020 were obtained,and the top 12 cities accounting for 78%of total cases were selected for analysis.Precipitation patterns were quantified by weekly precipitation and precipitation concentration degree(PCD).On the basis of the combinations of both parameters,the exposure-response relationships of precipitation with dengue risk were established using generalised additive models,and the high-dengue-risk thresholds of precipitation patterns were further identified.Dengue burden was assessed by calculating attributable dengue cases.For the same amount of precipitation,the dispersed precipitation in the pre-summer rainy season leads to a higher dengue risk in autumn.The weekly precipitation of 100-150 mm and PCD of 0.2-0.4 constitute the highest risk scenario,and the average frequency of precipitation associated with dengue risk in 2013-2020 is 1.6 times higher than that in 2005-2012.A total of 3093 attributable dengue cases are identified.From 2005 to 2020,the amount of dispersed precipitation increased in southern and southwestern China and posed high dengue risks in central China.This study has improved the understanding of the health impacts of irregular rainfall under climate change.Our approach to identifying thresholds provides information for early warning systems and helps reduce the risk of dengue transmission in the long run.