Direct detection of brown adipose tissue thermogenesis in UCP1-/- mice by hyperpolarized Xe MR thermometry.

Brown adipose tissue (BAT) is a type of fat specialized in non-shivering thermogenesis. While non-shivering thermogenesis is mediated primarily by uncoupling protein 1 (UCP1), the development of the UCP1 knockout mouse has enabled the study of possible UCP1-independent non-shivering thermogenic mechanisms, whose existence has been shown so far only indirectly in white adipose tissue and still continues to be a matter of debate in BAT. In this study, by using magnetic resonance thermometry with hyperpolarized xenon, we produce the first direct evidence of UCP1-independent BAT thermogenesis in knockout mice.

Calibration of methylene-referenced lipid-dissolved xenon frequency for absolute MR temperature measurements.

Purpose: Absolute MR temperature measurements are currently difficult because they require precalibration procedures specific for tissue types and conditions. Reference of the lipid-dissolved Xe resonance frequency to temperature-insensitive methylene protons (rLDX) has been proposed to remove the effect of macro- and microscopic susceptibility gradients to obtain absolute temperature information. The scope of this work is to evaluate the rLDX chemical shift (CS) dependence on lipid composition to estimate the precision of absolute temperature measurements in lipids.

Emergency Department Intubation Success With Succinylcholine Versus Rocuronium: A National Emergency Airway Registry Study.

Study Objective: Although both succinylcholine and rocuronium are used to facilitate emergency department (ED) rapid sequence intubation, the difference in intubation success rate between them is unknown. We compare first-pass intubation success between ED rapid sequence intubation facilitated by succinylcholine versus rocuronium.

Methods: We analyzed prospectively collected data from the National Emergency Airway Registry, a multicenter registry collecting data on all intubations performed in 22 EDs.

Simple and robust referencing system enables identification of dissolved-phase xenon spectral frequencies.

Purpose: To assess the effect of macroscopic susceptibility gradients on the gas-phase referenced dissolved-phase Xe (DPXe) chemical shift (CS) and to establish the robustness of a water-based referencing system for in vivo DPXe spectra.

Methods: Frequency shifts induced by spatially varying magnetic susceptibility are calculated by finite-element analysis for the human head and chest. Their effect on traditional gas-phase referenced DPXe CS is then assessed theoretically and experimentally.

Prehospital Administration of Tranexamic Acid by Ground Forces in Afghanistan: The Prehospital Trauma Registry Experience.

Background: Tranexamic acid (TXA) was shown to reduce overall mortality and death secondary to hemorrhage in a large prospective study. This intervention is time sensitive. As such, the Tactical Combat Casualty Care (TCCC) guidelines recommend use of this low-cost, safe intervention among patients with possible hemorrhagic shock, penetrating trauma to the thorax or trunk, or extremity amputation.

QuikClot® Combat Gauze® Use by Ground Forces in Afghanistan The Prehospital Trauma Registry Experience.

Background: QuikClot® Combat Gauze® (QCCG) was fielded in 2008 to replace previous generations of hemostatic products. To the best of our knowledge, despite nearly a decade of use, there are no published data on use among US combatant forces. We describe the use of QCCG by ground forces in Afghanistan and compare patients who received QCCG compared with the remaining population in the database who did not receive QCCG.

Depolarization of nuclear spin polarized Xe gas by dark rubidium during spin-exchange optical pumping.

Continuous-flow spin-exchange optical pumping (SEOP) continues to serve as the most widespread method of polarizing Xe for magnetic resonance experiments. Unfortunately, continuous-flow SEOP still suffers from as-yet unidentified inefficiencies that prevent the production of large volumes of xenon with a nuclear spin polarization close to theoretically calculated values. In this work we use a combination of ultra-low field nuclear magnetic resonance spectroscopy and atomic absorption spectroscopy (AAS) measurements to study the effects of dark Rb vapor on hyperpolarized Xe in situ during continuous-flow SEOP.

Utilization and effectiveness of an emergency department initiated smoking cessation program.

OBJECTIVE: To determine which method of intervention will best assist ED patients who smoke and are interested in quitting. METHODS: This was a prospective, controlled randomized survey of patients seen at a military ED with an annual census of approximately 30,000. All patients 18 years old or older who were medically stable and who admitted to smoking were eligible.