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Pterocephin A is a natural triterpenoid saponin isolated from Pterocephalus hookeri, a traditional Tibetan medicine with slight toxicity, which can induce liver injury in rats. This study aimed to establish a sensitive and reliable UPLC-MS/MS method for exploring the toxicokinetics and tissue distribution of pterocephin A following single intravenous and intragastric administration. Pterocephin A and prosapogenin 1C (internal standard, IS) were extracted using a simple protein precipitation technique with methanol as the precipitant for plasma samples and methanol/acetonitrile = 1:1 (v/v) for tissue samples. UPLC separation was achieved by gradient elution with 0.3 mL/min and a mobile phase consisting of 5 mM ammonium formate (A) and acetonitrile (B) (0–2 min 30% B; 2–4 min: 30–80% B; 4–5 min: 80–98% B; 5–6.5 min: 98% B; 6.5–7 min: 98–30% B; and 7–8 min: 30% B, v/v) with a column temperature of 35 °C. MS spectrometry adopted negative ion scanning mode, primary MS spectrometry adopted full scan monitoring mode, and secondary MS spectrometry adopted targeted MS2 scan monitoring mode. The assay exhibited a linear dynamic range of 0.02–15 μg/mL for pterocephin A in biological samples, with the low limit of quantification set at 0.02 μg/mL. Non-compartmental toxicokinetic parameters indicated that pterocephin A was well absorbed into the systemic circulation and had a long residual time after intravenous (10 mg/kg) and intragastric (60 mg/kg) administration, as it could still be detected after 72 h. Tissue distribution analysis revealed detectable levels of pterocephin A in various tissues, and a high concentration was maintained in the liver after intravenous (10 mg/kg) administration, with the highest concentration being 610.95 ± 25.73 ng/mL and a specific distribution pattern of liver > lung > kidney > intestine > spleen > testes > heart > stomach. The toxicokinetic process and tissue distribution characteristics of pterocephin A were expounded in this study, which can provide relevant data support for further research and clinical application of pterocephin A with its slight toxicity. [ABSTRACT FROM AUTHOR]

Digitization is the primary form of Metaverse art, making the Metaverse digitally re-enable the unfolding of art. First, as a digital art form, non-fungible token (NFT) art acts as a media technology object for digital subjects to seek an identity. It opens the potential to reflect on image ontology and image copies. Second, the development of Metaverse art is closely related to its media characteristics. The exploration of the attributes of Metaverse media can be divided into two approaches. One approach is to examine the characteristics of Metaverse media from the perspective of media archaeology and its association with cinema and games. The second approach lies in elucidating the temporal mechanism of modernity rooted in Metaverse media and rethinking the prominence and intervention of an “algorithmic timeline” in real time. Finally, the mediating properties of digital image ontology and the Metaverse’s temporal and spatiotemporal folding correspond to the two main characteristics of immersion and interactivity in a virtual space, which not only reflects the generation of an “external subject” but also triggers a crisis in the identification of the subject with the mirror image. [ABSTRACT FROM AUTHOR]

Direct oxidation of organic pollutants by manganese oxides is appealing for the removal of persistent organic pollutants (POPs) since it requires no chemical dosing. Rapid electron transfer and moderate adsorption are vital in manganese-induced oxidation. In this study, we used perovskite lanthanum manganate (LaMnO3) as a model to explore the relationship between bisphenol A (BPA) removal efficiency and metal–oxygen covalency, which is closely related to electron transfer and adsorption capacity, by introducing other metals or defects at the A-site. X-ray absorption spectra (XAS) and density functional theory (DFT) calculation showed that the charge migration rate and BPA adsorption capacity on manganese oxides increase with the increase of metal–oxygen covalency. The manganese oxides with medium metal–oxygen covalency have the strongest oxidation capability toward BPA. Our work provides new regulatory strategies for enhancing the oxidation ability of manganese oxides to directly decompose organic pollutants via interfacial electron transfer. [ABSTRACT FROM AUTHOR]

Economic and environmentally friendly strategies are needed to promote the bifunctional catalytic removal of carbonyl sulfide (COS) by hydrolysis and hydrogen sulfide (H 2 S) by oxidation. N doping is considered to be an effective strategy, but the essential and intrinsic role of N dopants in catalysts is still not well understood. Herein, the conjugation of urea and biochar during Cu/biochar annealing produced pyridine N, which increased the combined COS/H 2 S capacity of the catalyst from 260.7 to 374.8 mg·g -1 and enhanced the turnover frequency of H 2 S from 2.50 × 10 -4 to 5.35 × 10 -4 s -1 . The nucleophilic nature of pyridine N enhances the moderate basic sites of the catalyst, enabling the attack of protons and strong H 2 O dissociation. Moreover, pyridine N also forms cavity sites that anchor CuO, improving Cu dispersion and generating more reactive oxygen species. By providing original insight into the pyridine N-induced bifunctional catalytic removal of COS/H 2 S in a slightly oxygenated and humid atmosphere, this study offers valuable guidance for further C═S and C-S bond-breaking in the degradation of sulfur-containing pollutants.