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Monkeypox virus (MPXV) can induce systemic skin lesions after infection. This research focused on studying MPXV proliferation and the response of keratinocytes. Using transmission electron microscopy (TEM), we visualized different stages of MPXV development in human immortalized keratinocytes (HaCaT). We identified exocytosis of enveloped viruses as the exit mechanism for MPXV in HaCaT cells. Infected keratinocytes showed submicroscopic changes, such as the formation of vesicle-like structures through the recombination of rough endoplasmic reticulum membranes and alterations in mitochondrial morphology. Transcriptome analysis revealed the suppressed genes related to interferon pathway activation and the reduced expression of antimicrobial peptides and chemokines, which may facilitate viral immune evasion. In addition, pathway enrichment analysis highlighted systemic lupus erythematosus pathway activation and the inhibition of the Toll-like receptor signaling and retinol metabolism pathways, providing insights into the mechanisms underlying MPXV-induced skin lesions. This study advances our understanding of MPXV's interaction with keratinocytes and the complex mechanisms leading to skin lesions. [ABSTRACT FROM AUTHOR]

In this study, chopped natural bamboo fibers were successfully added in the benzoxazine matrix by the hot-pressing method to fabricate environmentally friendly bio-composite. The mechanical behaviors and failure mechanisms of neat benzoxazine matrix and its bamboo fiber composite under different tensile strain rates (quasi-static, 35/s and 110/s) were comparatively investigated using SHTB device (split-Hopkinson tensile bar), high-speed camera, DIC method (digital image correlation), and SEM observation (scanning electron microscopy). The results showed the composite exhibited 30.02% and 25.21% higher strength than that of neat benzoxazine under strain rates of 35/s and 110/s, respectively. However, under quasi-static tensile loading, the tensile strength of the composite was not higher than that of neat benzoxazine. The SEM and high-speed camera images showed the bamboo fibers displayed different reinforcing mechanisms under different strain rates. The chopped bamboo fibers could strengthen the composite effectively under dynamic tensile loadings. However, under quasi-static loading, the tensile strength of the composite was largely determined by the potential defects (such as small bubbles, pores, and fiber agglomerations) in the composite. [ABSTRACT FROM AUTHOR]

As a type of environmentally-friendly and low-cost natural material, bamboo fibers exhibit excellent mechanical properties. In this study, a bamboo fiber reinforced polybenzoxazine composite was fabricated by an improved hot-pressing process. The dynamic compressive behaviors of neat benzoxazine and its composite were comparatively studied by an SHPB (split Hopkinson pressure bar) apparatus. SHPB tests showed that the benzoxazine matrix and its composite exhibited significantly positive strain rate sensitivity at nominal strain rates in the range of 0.006–2500/s. During the impact loadings, the progressive deformation and failure of neat benzoxazine and bamboo composite were investigated by capturing real-time images with a high-speed camera. In comparison with neat benzoxazine, the bamboo composite had slightly higher maximum compressive stress under the same strain rates. It is noteworthy that the crashworthiness of the composite was remarkably better than that of neat benzoxazine due to the incorporation of bamboo fibers. For example, the energy absorption of bamboo composite was 105.7% higher than that of neat benzoxazine at a strain rate of 2500/s. The dynamic compressive properties of benzoxazine resin were much better than most of the conventional thermosetting resins. These results could guide the future application of this kind of composites. [ABSTRACT FROM AUTHOR]