Toward Circular Recycling of Polyurethanes: Depolymerization and Recovery of Isocyanates.

We report a depolymerization strategy to nearly quantitatively regenerate isocyanates from thermoplastic and thermoset polyurethanes (PUs) and then resynthesize PUs using the recovered isocyanates. To date, chemical/advanced recycling of PUs has focused primarily on the recovery of polyols and diamines under comparatively harsh conditions (e.g., high pressure and temperature), and the recovery of isocyanates has been difficult. Our approach leverages an organoboron Lewis acid to depolymerize PUs directly to isocyanates under mild conditions (e.g., ∼80 °C in toluene) without the need for phosgene or other harsh reagents, and we show that both laboratory-synthesized and commercially sourced PUs can be depolymerized. Furthermore, we demonstrate the utility of the recovered isocyanate in the production of second-generation PUs with thermal properties and molecular weights similar to those of the virgin PUs. Overall, this route uniquely provides an opportunity for circularity in PU materials and can add significant value to end-of-life PU products.

Hyaluronic Acid Allows Enzyme Immobilization for Applications in Biomedicine.

Enzymes are proteins that control the efficiency and effectiveness of biological reactions and systems, as well as of engineered biomimetic processes. This review highlights current applications of a diverse range of enzymes for biofuel production, plastics, and chemical waste management, as well as for detergent, textile, and food production and preservation industries respectively. Challenges regarding the transposition of enzymes from their natural purpose and environment into synthetic practice are discussed. For example, temperature and pH-induced enzyme fragilities, short shelf life, low-cost efficiency, poor user-controllability, and subsequently insufficient catalytic activity were shown to decrease pertinence and profitability in large-scale production considerations. Enzyme immobilization was shown to improve and expand upon enzyme usage within a profit and impact-oriented commercial world and through enzyme-material and interfaces integration. With particular focus on the growing biomedical market, examples of enzyme immobilization within or onto hyaluronic acid (HA)-based complexes are discussed as a definable way to improve upon and/or make possible the next generation of medical undertakings. As a polysaccharide formed in every living organism, HA has proven beneficial in biomedicine for its high biocompatibility and controllable biodegradability, viscoelasticity, and hydrophilicity. Complexes developed with this molecule have been utilized to selectively deliver drugs to a desired location and at a desired rate, improve the efficiency of tissue regeneration, and serve as a viable platform for biologically accepted sensors. In similar realms of enzyme immobilization, HA's ease in crosslinking allows the molecule to user-controllably enhance the design of a given platform in terms of both chemical and physical characteristics to thus best support successful and sustained enzyme usage. Such examples do not only demonstrate the potential of enzyme-based applications but further, emphasize future market trends and accountability.

Enhancing nursing practice by utilizing voice recognition for direct documentation.

Innovative strategies that preserve nursing time for direct patient care activities are needed. This study examined the utility, feasibility, and acceptability of voice recognition (VR) software to document nursing care and patient outcomes in an electronic health record in a simulated nursing care environment. A phase 1 trial included 5 iterative experiments with observations and nurse participant feedback to allow enhancements to the speech detection capabilities and refinement of the technology, software, and processes. Utility ratings improved over time; however, interference on nursing care remained a concern throughout. Nurse participants favored keyboard entry electronic health record, largely due to software and technical issues, but also relative to the culture shift the new technology brings to nursing practice. Successful adoption of VR technology by nursing will be dependent on receptiveness of the nurses and perceived benefits, timely access to education and training, and minimization of barriers to using the software.

The successful application of simulation-based training in thoracic surgery residency.

OBJECTIVE: We developed and tested a clinical simulation program in the principles and conduct of cardiopulmonary bypass with the aim of improving confidence and proficiency in this critical aspect of cardiac surgical care. METHODS: Fifteen residents from 6 resident-training programs who reported no prior cardiopulmonary bypass observation or simulation-based perfusion experience participated in a cardiopulmonary bypass course involving both didactic lectures and hands-on simulation. A computer-controlled hydraulic model of the human circulation was used in a specifically designed multidisciplinary simulation center environment to give the participants hands-on training with both basic operations and specific perfusion crisis scenarios. Pretraining and posttraining assessments concerning confidence, knowledge, and applications with regard to cardiopulmonary bypass were administered and compared. RESULTS: Likert scale scores on confidence-related items increased significantly (P < .001), from 59% +/- 16% to 92% +/- 8%. Pretraining versus posttraining scores (72% +/- 14%) on similar cognitive items were not significantly different (P=.3636). Scores on similar open-ended application items before and after training improved from 62% +/- 25% to 85+/-10% (P < .0001). All subjects agreed that simulation-based cardiopulmonary bypass training was superior to classroom- and clinic-based education and that the scenarios enhanced their learning experience. CONCLUSIONS: Simulation-based cardiopulmonary bypass training appears to be an effective technique to build the confidence of thoracic surgery residents regarding knowledge and applications. Scenario-based practice in a specifically designed simulated environment is a valuable adjunct to traditional educational methods and has the potential to improve the training of thoracic residents.