N95 respirator decontamination: a study in reusability.

The coronavirus disease 2019 (COVID-19) pandemic had caused a severe depletion of the worldwide supply of N95 respirators. The development of methods to effectively decontaminate N95 respirators while maintaining their integrity is crucial for respirator regeneration and reuse. In this study, we systematically evaluated five respirator decontamination methods using vaporized hydrogen peroxide (VHP) or ultraviolet (254 nm wavelength, UVC) radiation. Through testing the bioburden, filtration, fluid resistance, and fit (shape) of the decontaminated respirators, we found that the decontamination methods using BioQuell VHP, custom VHP container, Steris VHP, and Sterrad VHP effectively inactivated Cardiovirus (3-log10 reduction) and bacteria (6-log10 reduction) without compromising the respirator integrity after 2-15 cycles. Hope UVC system was capable of inactivating Cardiovirus (3-log10 reduction) but exhibited relatively poorer bactericidal activity. These methods are capable of decontaminating 10-1000 respirators per batch with varied decontamination times (10-200 min). Our findings show that N95 respirators treated by the previously mentioned decontamination methods are safe and effective for reuse by industry, laboratories, and hospitals.

One-stop microfiber spinning and fabrication of a fibrous cell-encapsulated scaffold on a single microfluidic platform.

This paper provides a method for microscale fiber spinning and the in situ construction of a 3D fibrous scaffold on a single microfluidic platform. This platform was also used to fabricate a variety of fibrous scaffolds with diverse compositions without the use of complicated devices. We explored the potential utility of the fibrous scaffolds for tissue engineering applications by constructing a fibrous scaffold encapsulating primary hepatocytes. The cells in scaffold were cultured over seven days and maintained higher viability comparing with 3D alginate non-fibrous block. The main advantage of this platform is that the fibrous structure used to form a scaffold can be generated without damaging the mechanically weak alginate fibers or encapsulated cells because all procedures are performed in a single platform without the intervention of the operator. In addition, the proposed fibrous scaffold permitted high diffusion capability of molecules, which enabled better viability of encapsulated cells than non-fibrous scaffold even in massive cell culture.

Acidogenic pretreatment of wastewaters containing 2-nitrophenol.

Anaerobic Toxicity Assay (ATA) tests were conducted on acidogenic cultures to assess the feasibility of using acidogenic processes to treat wastewaters containing 2-nitrophenol. Results indicated 2-nitrophenol could be removed with a removal efficiency of more than 98%. 2-aminophenol was identified as the major metabolite of the biotransformation of 2-nitrophenol. Reduction in inhibition potential of acidogenic pretreated effluent was observed in the aerobic process. EC50 values of 2-nitrophenol and 2-aminophenol were found to be 0.065 mM and 1.83 mM respectively.