What Does the Military Health System Need to Support Future Combat Operations? Lessons from Aeromedical Evacuations from 2008 to 2020.

INTRODUCTION: Aeromedical evacuations from the past few decades have yielded massive amounts of data that may inform the Military Health System (MHS) on patient needs, specifically for understanding the inpatient and outpatient needs of evacuees. In this study, we evaluate inpatient and outpatient trends based on aeromedical evacuation data from recent conflicts. We anticipate that evacuations requiring MHS inpatient beds are primarily trauma-related and necessitate an increased need for inpatient trauma care. MATERIALS AND METHODS: We conducted a descriptive analysis of aeromedical evacuations using the U.S. Transportation Command Regulating and Command & Control Evacuation System database. We queried the database for aeromedical evacuations originating from the U.S. EUCOM and ending in the CONUS, from January 1, 2008 to June 4, 2020. With the resultant data, evacuee demographics were characterized by gender, age, active duty (AD) versus non-AD, and branch of service. Following this, the proportion of battle injury to disease and non-battle injury was categorized by both patient age ranges and year. Additionally, evacuations were stratified by their ICD codes, as well as the primary specialty responsible for care. Lastly, evacuations were categorized by inpatient and outpatient care status. RESULTS: The final dataset yielded 32,485 unique patients. The majority of evacuees were male (86.9%) with a mean age of 29.0 ± 9.6 years. Evacuees were primarily AD Military (96.7%), with the majority of those personnel being in the Army (70.2%). The total number of evacuations steadily increased from 2008 (n = 3,703) until a peak in 2010 (n = 4,929), which was also the peak year for battle injury (n = 1,472). Battle injury was also most prevalent in the 21 to 24 age group (24.7%) and declined in older age groups. Regarding diagnoses, the leading categories were injury/poisoning (33.1%), psychiatric (28.1%), and musculoskeletal (12.1%). As for specialty care of evacuees, psychiatry received the largest share of total evacuations (28.1%), followed by orthopedic surgery (22.7%) and general surgery (8.6%). Looking at proportions of inpatient and outpatient care, the majority of evacuees required outpatient care (65.6%) with a sizable minority requiring inpatient care (34.4%). Inpatient evacuations peaked in 2010 (n = 2,013), accounting for 40.8% of all evacuations that year. Orthopedic surgery had the largest share of inpatient evacuations (27.3%), followed by psychiatry (21.5%) and general surgery (18.2%). As for outpatient care, the specialties with the largest proportion of outpatient evacuations were psychiatry (33.6%), orthopedic surgery (20.3%), and neurology (9.8%). CONCLUSIONS: The results of this study reveal what the MHS can expect in future conflicts. Most evacuations are for psychiatric-/injury-/musculoskeletal-related diagnoses, typically requiring care by psychiatrists, orthopedic surgeons, or general surgeons. Outpatient care is important, though it is critical to bolster inpatient care requirements as future conflicts may bring extensive numbers of inpatient casualties. The MHS should program and plan resources accordingly, planning for the care of surgical/injured and psychiatric patients.

Nanoscale Magnetization and Current Imaging Using Time-Resolved Scanning-Probe Magnetothermal Microscopy.

Magnetic microscopy that combines nanoscale spatial resolution with picosecond scale temporal resolution uniquely enables direct observation of the spatiotemporal magnetic phenomena that are relevant to future high-speed, high-density magnetic storage and logic technologies. Magnetic microscopes that combine these metrics has been limited to facility-level instruments. To address this gap in lab-accessible spatiotemporal imaging, we develop a time-resolved near-field magnetic microscope based on magnetothermal interactions. We demonstrate both magnetization and current density imaging modalities, each with spatial resolution that far surpasses the optical diffraction limit. In addition, we study the near-field and time-resolved characteristics of our signal and find that our instrument possesses a spatial resolution on the scale of 100 nm and a temporal resolution below 100 ps. Our results demonstrate an accessible and comparatively low-cost approach to nanoscale spatiotemporal magnetic microscopy in a table-top form to aid the science and technology of dynamic magnetic devices with complex spin textures.

Local Photothermal Control of Phase Transitions for On-Demand Room-Temperature Rewritable Magnetic Patterning.

The ability to make controlled patterns of magnetic structures within a nonmagnetic background is essential for several types of existing and proposed technologies. Such patterns provide the foundation of magnetic memory and logic devices, allow the creation of artificial spin-ice lattices, and enable the study of magnon propagation. Here, a novel approach for magnetic patterning that allows repeated creation and erasure of arbitrary shapes of thin-film ferromagnetic structures is reported. This strategy is enabled by epitaxial Fe0.52 Rh0.48 thin films designed so that both ferromagnetic and antiferromagnetic phases are bistable at room temperature. Starting with the film in a uniform antiferromagnetic state, the ability to write arbitrary patterns of the ferromagnetic phase is demonstrated by local heating with a focused laser. If desired, the results can then be erased by cooling below room temperature and the material repeatedly re-patterned.