https://www.selleckchem.com/products/tecovirimat.html Simulation-based mastery learning (SBML) improves skill transfer to humans. However, limited data exist to support the practice of performing additional training attempts once mastery has been achieved. We explored whether implementing this concept in an SBML model improves skill transfer in ultrasound-guided peripheral intravenous (USGPIV) catheter placement from simulator to humans. Forty-eight first- and second-year medical students underwent SBML for USGPIV placement to mastery standards on a simulator once to achieve minimum passing standard based on a 19-item checklist. Next, they completed either 0, 4, or 8 additional mastery level simulated performances in nonconsecutive order before attempting USGPIV placement on a human. An unplanned post hoc retention phase occurred 6 months later where participants' USGPIV skills were reassessed on a second human volunteer using the same checklist. In this sample, the success rate among the 3 training cohorts did not improve as the number of additional train checklist performance. Neonatal endotracheal intubation is a critical skill that is difficult for learners to acquire even with simulation-based training (SBT). Trainees prefer clinical experiences over SBT. The objective of the study was to explore the differences between SBT and clinical practice in acquiring neonatal intubation skills to inform mannequin design and to improve fidelity. A basic qualitative study using semistructured interviews was conducted to determine the experience of newly competent trainees (second- and third-year neonatal-perinatal medicine fellows) and their instructors in developing intubation skills. Participants were asked to compare learning through SBT with clinical practice in terms of context, equipment, and environment. Their responses were analyzed using an inductive approach. Thirty-two participants (20 fellows and 12 faculty) indicated that SBT does not equal the real experienc