No abstract

Herein, we report a series of carboxyl-grafted metal–organic frameworks (UiO-66-(COOH) n , n = 0,1,2,4) for Pb2+ removal and the important role of carboxyl groups in capture of Pb2+. Among these materials, UiO-66-(COOH)2 exhibits a large adsorption capacity of 420.2 mg g–1, superior to that of other metal–organic frameworks and most of reported adsorbents. Besides, 99.99% of Pb2+ can be removed from water in the concentration range of <100 ppm with the UiO-66-(COOH)2 dosage of 0.5 mg mL–1. Furthermore, UiO-66-(COOH)2 can be easily regenerated through a simple method. Mechanism analysis (Fourier transform infrared, X-ray photoelectron spectroscopy, and density functional theory calculation) indicates that the synergy effect of rich carboxyl groups and proper pore structure plays a critical role in the capture of Pb2+. This work may provide a guideline to design high-efficiency adsorbents for Pb2+ from water.

No abstract

Ligustrazine (Tetramethylpyrazine, TMP) is an active substance extracted from the Umbelliferae plant Ligusticum chuanxiong. It has been proven to have antioxidant and inflammation effects. The study was designed to explore the efficacy and specific mechanism of TMP for ALI/ARDS treatment. Here, we confirmed that TMP decreased the infiltration of inflammatory cells in alveoli and the secretion of pro-inflammatory factors, which is comparable to glucocorticoids in vivo. In vitro, TMP inhibited the polarization of M1-type macrophages, and to a certain extent, promoted M2-type repolarization, thus reducing LPS-induced massive transcription and secretion of IL-1β, IL-18, TNF-ɑ and other inflammatory factors. Besides, TMP reduced expression of NLRP3, inhibited the formation of inflammasome complexes, and decreased the cleavage of caspase-1, leading to reduced cell pyroptosis and accompanying inflammation. TMP also inhibited apoptosis through caspase-8/caspase-3 signaling pathways. Our study indicates that TMP improved ALI through inhibiting the TLR4/TRAF6/NFκB/NLRP3/caspase-1 and TLR4/caspase-8/caspase-3 signaling pathways, which reversed macrophages polarization, reduced cell pyroptosis and apoptosis, which provides a theoretical basis of using TMP in treating ALI in the future.