Is Routine Chest X-Ray After Ultrasound-Guided Central Venous Catheter Insertion Choosing Wisely?: A Population-Based Retrospective Study of 6,875 Patients.

Background: A routine chest radiograph (CXR) is recommended as a screening test after central venous catheter (CVC) insertion. The goal of this study was to assess the value of a routine postprocedural CXR in the era of ultrasound-guided CVC insertion.

Methods: This population-based retrospective cohort study was performed to review the records of all adult patients who had a CVC inserted in the operating room in a tertiary institution between July 1, 2008, and December 31, 2015.

Simplification of stochastic chemical reaction models with fast and slow dynamics.

Biological systems often involve chemical reactions occurring in low-molecule-number regimes, where fluctuations are not negligible and thus stochastic models are required to capture the system behaviour. The resulting models are generally quite large and complex, involving many reactions and species. For clarity and computational tractability, it is important to be able to simplify these systems to equivalent ones involving fewer elements.

Systematic reduction of a stochastic signalling cascade model.

Biochemical systems involve chemical reactions occurring in low-number regimes, wherein fluctuations are not negligible and thus stochastic models are required to capture the system behaviour. The resulting models are often quite large and complex, involving many reactions and species. For clarity and computational tractability, it is important to be able to simplify these systems to equivalent ones involving fewer elements.