Objectives: Photobiomodulation (PBM) is widely used in clinical therapy, and is an effective approach to resist the bacterial infection of the cutaneous wound and modulate the wound healing process. Due to the several detriments of lasers, Red & Blue LED light (RBLL) may be a more viable light source. This study is aimed to evaluate and compare the therapeutic effect of RBLL light on different multidrug resistant (MDR) bacteria in vitro and male Sprague-Dawley (SD) rat refractory MDR infection wound model in vivo. Materials and Methods: Methicillin-resistant Staphylococcus aureus (MRSA), Extended-spectrum β-lactamases -producing Escherichia coli (ESBLs-Eco), and the MDR Pseudomonas aeruginosa (MDR-Pae) were employed to evaluate the antibacterial effects of the Blue LED light in vitro. Effects of RBLL on in vivo wound healing were evaluated by analyzing time to closure, wound score, semiquantitative test for bacterial culture, histopathological examination and Masson staining of skin tissue, immunohistochemical (IHC) staining, and western blot analysis (WB) of wound tissue. Results: Blue LED light inhibited MRSA, ESBLs-Eco, and MDR-Pae in vitro study. In vivo, RBLL accelerated wound healing, reduced levels of pathogenic bacteria on the wound surface while increasing the blood supply to the wound surface and inhibiting the excessive inflammatory response. Conclusion: RBLL showed a great potential gain for the treatment of MDR bacterial infected wounds, suggesting PBM therapy is an inexpensive, convenient, pain-free, and safe therapeutic intervention for refractory MDR infection wounds.

A low-quality unwinding process of the unwinding machine can lead to downtime of the knitting machine and loss of fabric quality. To address this issue, we studied the tension and vibration of carbon fiber yarns during unwinding. Based on the theory of axially moving strings, the dynamic model of carbon fiber yarn was established during the unwinding process, bringing the parameters into the simulation. According to the simulation results, the yarn tension in the unwinding process is closely related to the spring preload, which needs control within a certain range. When the unwinding speed increases, the fluctuation amplitude, lateral vibration amplitude, and axial vibration amplitude of the yarn tension gradually increase, causing friction and wear of the carbon fiber yarn. By controlling factors such as spring preload, unwinding speed, and the number of bobbins unwound simultaneously, one can effectively control the yarn’s vibration and improve the quality of the yarn.

Refractory wounds present a complex and serious clinical dilemma in plastic and reconstructive surgery. However, there are currently no standard guidelines for the treatment of refractory wounds. Artificial dermis (AD) has achieved some satisfactory results, but also has some limitations. Autologous platelet-rich plasma (PRP), as a cell-therapy material, was a valuable and safe treatment dressing for chronic non-healing wounds. This study aimed to evaluate the efficacies of artificial dermis (AD) with and without autologous platelet-rich plasma (PRP) in patients with refractory wounds. Sixteen patients with refractory wounds were randomly allocated to autologous PRP therapy combined with artificial dermis (PRP + AD [N = 8]) or an artificial dermis program only (AD [N = 8]). We compared the efficacies of the two methods in terms of times to wound healing, infection control, and AD vascularization, as well as hospitalization days and eventual clinical outcomes.13 patients achieved complete healing, including seven (87.5%) in the PRP + AD group and six (75.0%) in the AD group (P > .05). The times to wound healing, infection control, and AD vascularization, and hospitalization time after transfer were significantly shorter in the PRP + AD group compared with the AD group (P < .05). In conclusion, the combination of AD and PRP promoted refractory wound healing and shortened waiting times compared with simple dermal grafts.

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