Various methods for peripheral nerve and epidural catheter location assessment exist, with varying degrees of ease of use, utility, and accuracy. Pulsed wave Doppler (PWD) evaluates the presence of fluid flow and is possible modality to assess the location of a percutaneously inserted perineural catheter.A retrospective chart review was conducted in which PWD ultrasonography was used to confirm the position of nerve catheters for regional anesthesia. Data was collected to assess 24-hour postoperative pain scores, opioid consumption, complications, and the incidence of catheter replacement.Eighty-six patients were included; average age was 58 years and a 27% incidence of chronic pain. These catheters were left in place based on the PWD images. Three catheters failed and a total of 16 catheters were repositioned. In the first 24 hours average pain scores ranges between 3.5 to 5.9 and median postoperative opioid consumption range was 11.3 mg to 60.8 mg. For epidural catheters, PWD changes were more obvious with air injection and there was only one episode of hemodynamic instability.Our preliminary experience with PWD ultrasonography suggests that they may offer the ability to selectively assess flow at different locations to identify the proper location of epidural and perineural catheters. Future randomized, controlled investigations are warranted to further evaluate the effectiveness and safety of this modality.

© 2017 The Author(s). Lithium-rich layered transition metal oxide positive electrodes offer access to anion redox at high potentials, thereby promising high energy densities for lithium-ion batteries. However, anion redox is also associated with several unfavorable electrochemical properties, such as open-circuit voltage hysteresis. Here we reveal that in Li1.17-xNi0.21Co0.08Mn0.54O2, these properties arise from a strong coupling between anion redox and cation migration. We combine various X-ray spectroscopic, microscopic, and structural probes to show that partially reversible transition metal migration decreases the potential of the bulk oxygen redox couple by > 1 V, leading to a reordering in the anionic and cationic redox potentials during cycling. First principles calculations show that this is due to the drastic change in the local oxygen coordination environments associated with the transition metal migration. We propose that this mechanism is involved in stabilizing the oxygen redox couple, which we observe spectroscopically to persist for 500 charge/discharge cycles.

© 2016 IEEE. NERSC has partnered with 20 representative application teams to evaluate performance on the Xeon-Phi Knights Landing architecture and develop an application-optimization strategy for the greater NERSC workload on the recently installed Cori system. In this article, we present early case studies and summarized results from a subset of the 20 applications highlighting the impact of important architecture differences between the Xeon-Phi and traditional Xeon processors. We summarize the status of the applications and describe the greater optimization strategy that has formed.

This report documents the physics case for building a 2 MW, 8 GeV superconducting linac proton driver at Fermilab.