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Detection of estrogenic disrupting compounds (EDCs) in drinking waters around China has led to rising concerns about health risks associated with these compounds. There is, however, a paucity of studies on the occurrence and identification of the main compounds responsible for this pollution in the source waters. To fill this void, we screened estrogenic activities of 23 source water samples from six main river systems in China, using a recombinant two-hybrid yeast assay. All sample extracts induced significant estrogenic activity, with E2 equivalents (EEQ) of raw water ranging from 0.08 to 2.40 ng/L. Additionally, 16 samples were selected for chemical analysis by gas chromatography-mass spectrometry. The EDCs of most concern, including estrone (E1), 17β-estradiol (E2), 17α-ethinylestradiol (EE2), estriol (E3), diethylstilbestrol (DES), estradiol valerate (EV), 4-t-octylphenol (4-t-OP), 4-nonylphenols (4-NP) and bisphenol A (BPA), were determined at concentrations of up to 2.98, 1.07, 2.67, 4.37, 2.52, 1.96, 89.52, 280.19 and 710.65 ng/L, respectively. Causality analysis, involving comparison of EEQ values from yeast assay and chemical analysis identified E2, EE2 and 4-NP as the main responsible compounds, accounting for the whole estrogenic activities (39.74% to 96.68%). The proposed approach using both chemical analysis and yeast assay could be used for the identification and evaluation of EDCs in source waters of China.

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Seismic, sonic logging and geothermal data are analyzed to show the distribution of gas hydrates in the Dongsha region north of the South China Sea. Bottom simulating reflectors (BSRs) and amplitude blanking zones are revealed in seismic profiles. A high velocity interval and a velocity reverse are distinguished by sonic logging.The BSR depth is compared with thickness of gas hydrate stability zone from geothermal gradient data. The BSR at ODP sites 1144 and 1148 occur at 654 and 475 meters below sea floor respectively. The top of the amplitude blanking zone may be related to gas hydrate bearing strate in a region adjacent to ODP site 1144, at about 450 meters below the sea floor.

Superparamagnetic iron oxide nanoparticles (SPIONs) have been the subject of extensive research due to their potential biomedical applications. In the present investigation, superparamagnetic FA-PEI-Fe 3 O 4 were successfully prepared and evaluated as a targeted MRI contrast agent. FTIR characteristics, TGA, VSM, and MR imaging confirmed the composition and magnetic properties of the synthesized nanoparticles. TEM showed that FA-PEI-Fe 3 O 4 were spherical in shape and well dispersed. The nanoparticles were superparamagnetic at room temperature with a saturation magnetization value of 67.1 emu/g. The nanoparticles showed higher uptake efficiency due to receptor-mediated endocytosis. Moreover, specificity of FA-PEI-Fe 3 O 4 to target tumor cells was demonstrated by the increased nanoparticle uptake and significant contrast enhancement of KB cells over MCF7 cells. The competitive inhibition of FA-PEI-Fe 3 O 4 by free FA further confirmed the specific interaction of this conjugate with FA receptors. In vivo MR imaging studies showed a decreased signal intensity and enhanced tumor contrast post-injection of FA-PEI-Fe 3 O 4 . These results indicate that FA-PEI-Fe 3 O 4 can be used as a promising tumor-targeting agent as well as a T 2 negative-contrast agent in MR imaging applications.

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In light with Bouguer gravity data, various information on faults were obtained by means of analytical continuation, target field extraction, arbitrary horizontal direction derivative processing and discrete wavelet transform processing. According to synthetic analyses with geologic data, the 123°E longitude was chosen as a typical profile, then initial models were established based on seismic data to perform gravitational inverse iterative fitting, and finally density parameters of various modules and their distribution were given. Based upon which the geologic and geophysical properties of the principal faults of the study area were analyzed, resulting in fault zone and block binding distribution maps. The paper focuses on the discussion of west marginal fault zone of the Korean Peninsula and Wulian– Qingdao–Rongcheng fault zone in the study area and points out that Wulian–Qingdao– Rongcheng fault zone did not intrude Korean Peninsula to connect with Imjinhang fault zone. It also holds that northward translational movement of the portion belonging to the Yangtze Plate at the west side of west marginal fault zone of the Korean Peninsula once occurred under the action of northward stress. Only the fault zones consisting of Wulian– Qingdao–Rongcheng fault zone along with northern fault zone of South Yellow Sea, west marginal fault zone of the Korean Peninsula, and south marginal fault zone of Cheju Island should be the binding site of Sino‐Korean and Yangtze Plates.