A study on the prospects of vacuum gamma irradiation to enhance crosslinking for 3D-Printing PLA/MCC biocomposite filaments

3D-printing or Additive Manufacturing (AM) has been growing as a rapid manufacturing process for many different applications, with Poly (Lactic Acid) as one of the most used materials for 3D-printing. PLA shows great promise for many applications to achieve the goals of the SDGs due to its biodegradability and biocompatibility but lacks when it comes to mechanical strength and thermal resistance. In this study, microcrystalline cellulose (MCC) fibers were introduced as a reinforcement to PLA. The biocomposite filaments were irradiated in a vacuum to enhance the crosslinking. Gamma-ray irradiation in a vacuum has successfully shown signs of crosslinking by increasing the tensile strength and thermal stability of the biocomposite, indicating an enhancement for PLA/MCC for various applications. On the other hand, changes in thermal properties also indicated that irradiation may reduce the processability of the composite, so it is necessary to study the conditions under which the mechanical properties and processability are compatible

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population