Application of tree cores to investigate the historical pollution trends of atmospheric polycyclic aromatic compounds: A case study in a typical coal-contaminated region of China

Article

作者: Wang, Shanshan ; Yuan, Zijiao ; Wu, Xiaoguo ; Du, Wanying

In this study, 76 polycyclic aromatic compounds (PACs) were detected in air, soil, and tree core samples from Huainan, a typical coal-contaminated region of China. Concentrations of ΣPACs in soil and air samples were 2400 ± 5100 ng/g and 150 ± 63 ng/m³, respectively. Priority PAHs were predominant in both air and soil samples, contributing over 50 % of ΣPACs. Source analysis indicated that PAC contamination in Huainan primarily originated from local coal-related activities. The benzo[a]pyrene (BaP)-toxic equivalent concentrations (TEQ_BaP) of PACs in the air samples (5.6 ± 5.3 ng/m³) exceeded the threshold of 1 ng/m³. Some PACs, such as benzo[e]pyrene (BeP) and Alk-BaPs, demonstrated significant toxicity and are recommended for consideration as priority pollutants. The historical pollution trends of atmospheric PACs were obtained based on the tree core samples. PAC concentrations in tree core segments showed a strong correlation with atmospheric PM₁₀ levels in Huainan. As air quality has improved in recent years, the PACs concentrations in tree core segments have also decreased. Historical fluctuations of atmospheric PACs were largely attributed to the changes in the gas treatment systems of a nearby coal-fired power plant and adjustments in environmental policies. By integrating trends observed in tree core segments with air concentrations, the historical atmospheric PAC concentrations were extrapolated. The extrapolated results showed similar concentration levels and trends when compared with historical data from other studies in China. Thus, tree cores can not only reflect the historical trends of atmospheric PACs with high temporal precision but also are feasible for extrapolating historical concentrations of airborne PACs.

2024-11-01·INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

Cold plasma irradiation of chitosan: A straight pathway to selective antitumor therapy

Article

作者: Marin, Luminita ; Sava, Ion ; Harabagiu, Valeria ; Kondo, Takashi ; Tartau, Liliana M. ; Fifere, Adrian ; Tanaka, Hiromasa ; Iftime, Manuela M. ; Motooka, Yashiro ; Iftime, Manuela M ; Mizuno, Masaaki ; Kumagai, Jun ; Tanaka, Ayako ; Hori, Masaru ; Andreica, Bianca ; Miron, Camelia ; Yamakawa, Taishi ; Tartau, Liliana M ; Toyokuni, Shinya ; Bejan, Andrei

Plasma-activated chitosan (PAC) colloids for cancer treatment were obtained by using the cold atmospheric plasma technique. Chitosan solutions were irradiated by plasma ignited in argon gas and in a mixture of argon with nitrogen and oxygen gases in certain ratios. The structural modifications of chitosan and the chemical species generated in plasma were investigated by EPR, LC-MS/MS, XRD, DLS, and TGA methods. The cell viability test showed a selective cytotoxic effect on human breast carcinoma cells (MCF-7), while the human mammary epithelial cells (MCF-10A) were left unharmed. The cytotoxic effect was attributed mainly to chitooligosaccharides, but also to a synergistic effect with other compounds generated in very low concentrations in plasma, such as glyceric acid, ethyl acetate, or tricarballylic acid. The plasma irradiation improved the antioxidant activity and mucoadhesivity, while not affecting the hemocompatibility investigated by a standard hemolysis ex vivo test on mice blood. Moreover, the in vivo biocompatibility investigation at intraperitoneal administration of PAC in mice showed no statistically significant changes in the hematologic, biochemical, and immune system parameters, and no morphologic alterations of the liver and kidney. All these data indicate the cold plasma activation of chitosan as a straight method to produce biocompatible, antitumor systems.

2024-05-01·AWWA water science

Impact of water quality and operational factors on microcystin removal by powdered activated carbon

Article

作者: Alexander, Matthew T. ; McNeely, Morgan ; Speth, Thomas F. ; Dugan, Nicholas R. ; Waters, Thomas E.

Abstract:

The feasibility of using a 26‐1 fractional factorial design to screen the relative importance of six water quality and operational factors in the removal of microcystin‐LR (MC‐LR) by powdered activated carbon (PAC) was evaluated through jar testing. The factors were: PAC type, PAC dose, total organic carbon (TOC) concentration, turbidity, alum dose, and timing of PAC versus coagulant application. Follow‐up tests were performed to examine the interaction of PAC dose and TOC concentrations. All MC‐LR analyses were performed by enzyme linked immunosorbent assay (ELISA) and liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). The top three effect magnitudes were the same by ELISA and LC/MS/MS:PAC dose > PAC type > PAC application time. Correlation coefficients between removals estimated by ELISA and LC/MS/MS were >0.9 (p « .05). With both methods, the effects of PAC type and dose were found to be markedly larger than the other factors. The follow‐up tests indicated a greater impact of PAC dose at higher natural organic matter concentrations. Factorial designs are not commonly used to plan drinking water jar test experiments. The results generated in this study were plausible with respect to the existing body of adsorption knowledge, thus helping to demonstrate the feasibility of the factorial approach.

100 项与 GPCRs PAC (Peptide Logic) 相关的药物交易

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