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Atmospheric ice nucleation plays an important role in modulating the global hydrological cycle and atmospheric radiation balance. To date, few comprehensive field observations of ice nuclei have been carried out at high-altitude sites, which are close to the height of mixed-phase cloud formation. In this study, we measured the concentration of ice-nucleating particles (INPs) in the immersion freezing mode at the summit of the Changbai Mountains (2623 m above sea level), northeast Asia, in summer 2021. The cumulative number concentration of INPs varied from 1.6 × 10 -3 to 78.3 L -1 over the temperature range of - 5.5 to - 29.0 °C. Proteinaceous-based biological materials accounted for the majority of INPs, with the proportion of biological INPs (bio-INPs) exceeding 67 % across the entire freezing-temperature range, with this proportion even exceeding 90 % above - 13.0 °C. At freezing temperatures ranging from - 11.0 to - 8.0 °C, bio-INPs were found to significantly correlate with wind speed (r = 0.5–0.8, p < 0.05) and Ca 2+ (r = 0.6–0.9), and good but not significant correlation was found with isoprene (r = 0.6–0.7) and its oxidation products (isoprene × O 3) (r = 0.7), suggesting that biological aerosols may attach to or mix with soil dust and contribute to INPs. During the daytime, bio-INPs showed a positive correlation with the planetary boundary layer (PBL) height at freezing temperatures ranging from - 22.0 to - 19.5 °C (r > 0.7, p < 0.05), with the valley breezes from southern mountainous regions also influencing the concentration of INPs. Moreover, the long-distance transport of air mass from the Japan Sea and South Korea significantly contributed to the high concentrations of bio-INPs. Our study emphasizes the important role of biological sources of INPs in the high-altitude atmosphere of northeastern Asia and the significant contribution of long-range transport to the INP concentrations in this region. [ABSTRACT FROM AUTHOR]

Atmospheric ice nucleation plays an important role in modifying the global hydrological cycle and atmospheric radiation balance. To date, few comprehensive field observations of ice nuclei have been carried out at high-altitude sites, which is close to the height of mixed-phase cloud formation. In this study, we measured the concentrations of ice-nucleating particles (INPs) in the immersion freezing mode at the summit of Changbai Mountain (2623 m above sea level), Northeast Asia, in summer 2021. The cumulative number concentration of INPs varied from 3.8 × 10−3 L−1 to 2.3 L−1 over the temperature range from −20.5 °C to −5.5 °C. Proteinaceous-based biological materials accounted for the majority of INPs, with the proportion of biological INPs (bio-INPs) exceeding 75 % across the entire freezing temperature range, with this proportion even exceeding 90 % above −13.0 °C. At freezing temperatures ranging from −11 °C to −8 °C, bio-INPs were found to significantly correlate with wind speed and Ca2+, and weakly correlate with isoprene and its oxidation products (isoprene × O3), suggesting that biological aerosols may attach to soil dust surfaces and contribute to INPs. During the daytime, bio-INPs showed a positive correlation with the planetary boundary layer height, with the valley breezes from southwestern mountainous regions also influencing the concentration of INPs. Moreover, the long-distance transport of air mass from the Japan Sea and South Korea significantly contributed to the high concentrations of bio-INPs. Our study emphasizes the important role of biological sources of INPs in the high-altitude atmosphere of northeastern Asia, as well as the significant contribution of long-range transport to the INPs concentrations in this region. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Fructus Alpiniae oxyphyllae ( A. oxyphylla ) is a traditional herb which is widely used in East Asian for the treatment of dyspepsia, diarrhea, abdominal pain, poor memory, inflammatory conditions and cancer. Materials and methods The cytotoxic activities of ethanol extract (EE) and five extract layers including petroleum ether (PE), dichloromethane (DCLM), acetoacetate (EtOAc), n -Butanol (n-Bu) and water fractions (WF) of A. oxyphylla were tested on HepG2, SW480, MCF-7, K562 and HUVEC cell lines using MTT assay and LDH release assay. The component analysis was performed on HPLC with gradient elution. Hoechst 33342 staining, DCFH-DA fluorescence microscopy, flow cytometry analysis, western blot and migration assays were carried out to determine the anti-cancer mechanisms of PE. Results MTT analysis showed that EE, PE and DCLM could inhibit cell proliferation on HepG2, SW480, MCF-7, K562 and HUVEC cell lines, especially PE fraction. HPLC analysis pointed out five main components which may contribute to the anti-proliferative activity of PE. Further study showed that PE increased LDH release, induced apoptosis, disrupted mitochondrial membrane potential and elevated intracellular reactive oxygen species (ROS) in HepG2 cells, whereas the antioxidant N-acetyl-l-cysteine (NAC) prevented PE-induced ROS generation. The results of western blot revealed that PE induced apoptosis in HepG2 cells by enhancing Bax/Bcl-2 ratio, increasing cytochrome c in cytosol and activating caspase-3/9. Meanwhile, high levels of ROS could induce DNA damage-mediated protein expression, AKT, ERK inactivation and SAPKs activation. Furthermore, PE conspicuously blocked the migration of HUVEC cells. Conclusion The present results demonstrated that PE induced apoptosis in HepG2 cells may be via a ROS-mediated signaling pathway. [ABSTRACT FROM AUTHOR]