Research Themes and Trends of Hen of the Woods or Maitake Medicinal Mushroom Grifola frondosa (Agaricomycetes): A Bibliometric Analysis of the Knowledge Field.

This paper aims to characterize the knowledge field of Grifola frondosa and analyze its research themes and trends. CiteSpace, a powerful bibliometric analysis tool, was adopted to visualize the knowledge field of G. frondosa research for facilitating this current study. A total of 747 articles and reviews retrieved from the Web of Science Core Collection (WoSCC) database between 1998 and 2022 were analyzed by CiteSpace. It was found that China and Japan are the most influential countries in G. frondosa research. Secondly, polysaccharide, bioactivity, structural characterization, and submerged culture are the main themes of G. frondosa research, among which bioactivity and structural characterization are the current research hotspots. Finally, selenium polysaccharide and gut microbiota may be the emerging trends in G. frondosa research in the future. This study could help researchers discern the evolution and future trends of G. frondosa research and provide a reference for related research work.

Molecular mechanisms of integrin αvß8 activation regulated by graphene, boron nitride and black phosphorus nanosheets.

Integrin αvß8 is a heterodimeric transmembrane protein on macrophages. Nanosheets can activate the integrin and elicit immune responses, exhibiting adverse immunotoxicity. Understanding the mechanism of integrin activation regulated by nanosheets is crucial for safe and effective use of nanosheets in biomedical applications. Herein, we performed all-atom molecular dynamics simulations to clarify the interactions between integrin αvß8 in the cell membrane and three types of nanosheets, graphene (GRA), hexagonal boron nitride (BN), and black phosphorus (BP). We observed that BP could adsorb the intracellular end of αv monomer and thus break the inner membrane clasp, an important hydrophobic cluster for maintaining the inactive state of integrin. The association between αv and ß8 subunit is weakened, promoting the integrin activation. By contrast, GRA and BN exert little influence on the association state of the integrin. Interestingly, the puckered structure of BP affects the integrin activation, where BP with the armchair direction perpendicular to the membrane plane cannot unpack the integrin. Moreover, the perturbation effect of nanosheets on the membrane was also evaluated. BP shows a milder effect on membrane structures and lipid properties than GRA and BN. This work unravels the molecular basis on the activation of integrin mediated by three nanosheets, and suggests the toxicity and therapeutic effect of well-established nanomaterials in the immune system.

Monitoring and risk assessment of perchlorate in tea samples produced in China.

Accumulation of potentially perchlorate in tea is a new concern for tea consumers. The information on perchlorate contamination in tea is highly limited. This study aimed to investigate the occurrence and accumulation of perchlorate in tea samples from China and to assess human exposure risks. A total of 288 tea samples collected from 16 provinces of China were tested, and nearly 94.8% of the samples were found to have detectable perchlorate contamination. Concentrations of perchlorate ranged from below LOQ to 1274.3 µg/kg, with a mean value of 294.6 µg/kg. Tea samples collected from Central China had the highest mean perchlorate concentration (403.4 µg/kg). The mean and median perchlorate levels in the dark and black samples were much higher than that of other types of tea samples. After brewing tea, the dissolution rates of perchlorate from the dried tea ranged from 58.9% to 89.2%. For the worst-case scenario, the estimated daily intakes (EDIs) of tea samples in 16 investigated provinces ranged from 25.9 to 157.8 ng/kg bw/day and 29.7-180.7 ng/kg bw/day for male and female respectively, indicating no significant health risks to local residents via tea consumption.