Bioavailability is a critical factor for assessing the environmental risk of organic pollutants in soil. In this study, extractions with 3 different solvents, including 2 aqueous solutions, calcium chloride(CaCl_2) an...Bioavailability is a critical factor for assessing the environmental risk of organic pollutants in soil. In this study, extractions with 3 different solvents, including 2 aqueous solutions, calcium chloride(CaCl_2) and a phosphate buffer solution(PBS), and a mixture of aqueous solution and organic solvent, a PBS-methanol(8:2,volume/volume) mixture(PBS-M), were performed to assess the bioavailability of chlorimuron-ethyl in soil in comparison to a battery of toxicity tests in wheat seedlings. The results indicated that the peroxidase(POD) activity in wheat leaves after 7 d of exposure was one of the sensitive biomarkers of chlorimuron-ethyl in soil.The extractability of chlorimuron-ethyl by all the 3 solvents decreased with exposure time, and the rate of decrease of the PBS-M extraction between 1 and 7 d of exposure was substantially higher than those of the aqueous solution extractions. Chlorimuron-ethyl gradually changed from a water-soluble form into a soil organic matter(SOM)-bound form in the soil. The PBS extraction correlated best with the POD activity in the leaves after 7 d of exposure.展开更多
The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships＇ hull paint have been investigated by rotating cylinder tests. Additionally, ...The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships＇ hull paint have been investigated by rotating cylinder tests. Additionally, test paint panels were attached to a vessel and recovered after a certain period of voyage for the validation of the laboratory tests. In the initial period, the release rates are influenced by pH, dissolved ion content and water velocity, but once after a certain period of test, those effects become less significant. These phenomena can be explained when the paint film is fresh, the rate is controlled by chemical reaction, the surface and/or diffusion layer in the water phase governs the rate. After the antifouling substance in the paint film leached out from the near-surface region, a diffused layer （leached layer）, that has little antifouling agent remained, is formed at the surface of the coating, and the diffusion in that layer can be a rate-determining process. The development of the leached layer is affected by a balance between the leaching rate of the antifouling ingredient and paint resin determined by the chemical properties and speed of the water. Thus, the leaching rates of antifouling agents are affected by the history of the paint in the water.展开更多
The electrochemical behaviour of three duplex stainless steels,(SAF 2101,SAF 2304,SAF 2205)was investigated.Open circuit potential,EOC,measurements,and electrochemical impedance spectroscopy(EIS)were employed both in ...The electrochemical behaviour of three duplex stainless steels,(SAF 2101,SAF 2304,SAF 2205)was investigated.Open circuit potential,EOC,measurements,and electrochemical impedance spectroscopy(EIS)were employed both in phosphate-buffered saline solution(PBS,pH=7.2)and in PBS simulating in vitro inflammatory conditions(PBS+H2O2,pH=5.0).It has been established that the tendency of the investigated steel materials towards corrosion de-creases in the following order:SAF 2101<SAF 2304<SAF 2205 in both ag-gressive environments.The superior corrosion resistance exhibited by SAF 2205 is ascribed to the formation of a passive film with enhanced protective effectiveness than the one formed on SAF 2101 and SAF 2304,and this im-provement is ascribed to a synergistic effect of Mo+N owing to the high mo-lybdenum content in the alloy.展开更多
This study investigates the targeted imaging and tumor inhibition effects of a"signal-off"imaging-based activatable aptamer probe(I-AAP)for pancreatic cancer.AS1411,contained in the I-AAP probe,targets the n...This study investigates the targeted imaging and tumor inhibition effects of a"signal-off"imaging-based activatable aptamer probe(I-AAP)for pancreatic cancer.AS1411,contained in the I-AAP probe,targets the nucleolin and i-motifs on the membrane surfaces of pancreatic cancer cells(PANC-1)and has a dual response to pH and an acidic environment.In vitro,a"signal-off"type I-AAP probe was constructed that possesses a fluorescence effect in a phosphate buffer solution at pH 6.0 and 6.5.The probe has no fluorescence effect at pH 7.0 or 7.5;thus,the"signal-off"type I-AAP probe has a targeted acid-sensitive response in pancreatic cancer and a tumor microenvironment imaging effect.After incubation for 30 min,AS1411 was taken up by PANC-1 cells and reached its peak value within 2 h.AS1411 inhibited pancreatic cancer cells in a time-dependent manner.This"signal-off"I-AAP probe is expected to be suitable for a low-background and high-specificity molecular pathologic tracer technique,making use of the presence of nucleolins on the surface of pancreatic cancer cells and the low pH response of the tumor microenvironment.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41401565,41201520 and 20807046)
文摘Bioavailability is a critical factor for assessing the environmental risk of organic pollutants in soil. In this study, extractions with 3 different solvents, including 2 aqueous solutions, calcium chloride(CaCl_2) and a phosphate buffer solution(PBS), and a mixture of aqueous solution and organic solvent, a PBS-methanol(8:2,volume/volume) mixture(PBS-M), were performed to assess the bioavailability of chlorimuron-ethyl in soil in comparison to a battery of toxicity tests in wheat seedlings. The results indicated that the peroxidase(POD) activity in wheat leaves after 7 d of exposure was one of the sensitive biomarkers of chlorimuron-ethyl in soil.The extractability of chlorimuron-ethyl by all the 3 solvents decreased with exposure time, and the rate of decrease of the PBS-M extraction between 1 and 7 d of exposure was substantially higher than those of the aqueous solution extractions. Chlorimuron-ethyl gradually changed from a water-soluble form into a soil organic matter(SOM)-bound form in the soil. The PBS extraction correlated best with the POD activity in the leaves after 7 d of exposure.
文摘The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships＇ hull paint have been investigated by rotating cylinder tests. Additionally, test paint panels were attached to a vessel and recovered after a certain period of voyage for the validation of the laboratory tests. In the initial period, the release rates are influenced by pH, dissolved ion content and water velocity, but once after a certain period of test, those effects become less significant. These phenomena can be explained when the paint film is fresh, the rate is controlled by chemical reaction, the surface and/or diffusion layer in the water phase governs the rate. After the antifouling substance in the paint film leached out from the near-surface region, a diffused layer （leached layer）, that has little antifouling agent remained, is formed at the surface of the coating, and the diffusion in that layer can be a rate-determining process. The development of the leached layer is affected by a balance between the leaching rate of the antifouling ingredient and paint resin determined by the chemical properties and speed of the water. Thus, the leaching rates of antifouling agents are affected by the history of the paint in the water.
文摘The electrochemical behaviour of three duplex stainless steels,(SAF 2101,SAF 2304,SAF 2205)was investigated.Open circuit potential,EOC,measurements,and electrochemical impedance spectroscopy(EIS)were employed both in phosphate-buffered saline solution(PBS,pH=7.2)and in PBS simulating in vitro inflammatory conditions(PBS+H2O2,pH=5.0).It has been established that the tendency of the investigated steel materials towards corrosion de-creases in the following order:SAF 2101<SAF 2304<SAF 2205 in both ag-gressive environments.The superior corrosion resistance exhibited by SAF 2205 is ascribed to the formation of a passive film with enhanced protective effectiveness than the one formed on SAF 2101 and SAF 2304,and this im-provement is ascribed to a synergistic effect of Mo+N owing to the high mo-lybdenum content in the alloy.
基金This work was supported by the National Natural Science Foundation of China(No.82172953)the Fujian Natural Science Foundation(No.2021J01716)the National Key Clinical Specialty Construction Project Fund(No.2022YBL-ZD-02).
文摘This study investigates the targeted imaging and tumor inhibition effects of a"signal-off"imaging-based activatable aptamer probe(I-AAP)for pancreatic cancer.AS1411,contained in the I-AAP probe,targets the nucleolin and i-motifs on the membrane surfaces of pancreatic cancer cells(PANC-1)and has a dual response to pH and an acidic environment.In vitro,a"signal-off"type I-AAP probe was constructed that possesses a fluorescence effect in a phosphate buffer solution at pH 6.0 and 6.5.The probe has no fluorescence effect at pH 7.0 or 7.5;thus,the"signal-off"type I-AAP probe has a targeted acid-sensitive response in pancreatic cancer and a tumor microenvironment imaging effect.After incubation for 30 min,AS1411 was taken up by PANC-1 cells and reached its peak value within 2 h.AS1411 inhibited pancreatic cancer cells in a time-dependent manner.This"signal-off"I-AAP probe is expected to be suitable for a low-background and high-specificity molecular pathologic tracer technique,making use of the presence of nucleolins on the surface of pancreatic cancer cells and the low pH response of the tumor microenvironment.
