Perception of an Introductory Point-of-Care Ultrasound Course for Thai Medical Students on Emergency Medicine Rotation.

INTRODUCTION: Point-of-care ultrasonography (POCUS) is increasingly utilized in emergency departments (EDs) throughout Thailand. Although emergency medicine (EM) residents are trained in POCUS, Thai medical students receive limited training. An introductory POCUS course was implemented for medical students to prepare them for internships. OBJECTIVE: This study described the perception and use of POCUS by graduates of an introductory POCUS course. MATERIALS AND METHODS: Medical students who completed the POCUS course were surveyed during their intern year from 2012 to 2015. The survey collected demographic characteristics. The Likert Scale was used to assess POCUS practice patterns and perceptions of the course. RESULTS: There were 230 respondents (98% response rate). All thought that POCUS was important. Furthermore, 96% of respondents felt that the POCUS course meaningfully impacted their ability to deliver care. POCUS use was greatest for obstetrics/gynecology and trauma cases. Over half of respondents (55.2%) felt very confident with using extended-Focused Assessment with Sonography in Trauma. Most respondents (81.8%) were positively impacted by the course, and 61.7% were satisfied with the scope of the course. Recommendations for improvement included increasing the course length, the content, and the hands-on time for POCUS practice. CONCLUSION: Graduates positively perceived the course and felt it dramatically impacted their clinical practice as novice physicians. An introductory POCUS course should be incorporated into the medical school curriculum to prepare graduates for practice. Future goals include increasing the scope of POCUS practice to help guide interns and residents in emergency patient care such as lung ultrasound in COVID-19 or pneumonia patients and studying the impact this course has on patient outcomes.

Bubble Magnetometry of Nanoparticle Heterogeneity and Interaction.

Bubbles have a rich history as transducers in particle-physics experiments. In a solid-state analogue, we use bubble domains in nanomagnetic films to measure magnetic nanoparticles. This technique can determine the magnetic orientation of a single nanoparticle in a fraction of a second and generate a full hysteresis loop in a few seconds. We achieve this high throughput by tuning the nanomagnetic properties of the films, including the Dzyaloshinskii-Moriya interaction, in an application of topological protection from the skyrmion state to a nanoparticle sensor. We develop the technique on nickel-iron nanorods and iron-oxide nanoparticles, which delineate a wide range of properties and applications. Bubble magnetometry enables precise statistical analysis of the magnetic hysteresis of dispersed nanoparticles, and direct measurement of a transition from superparamagnetic behavior as single nanoparticles to collective behavior in nanoscale agglomerates. These results demonstrate a practical capability for measuring the heterogeneity and interaction of magnetic nanoparticles.

Room-Temperature Magnetic Order in Air-Stable Ultrathin Iron Oxide.

Manual assembly of atomically thin materials into heterostructures with desirable electronic properties is an approach that holds great promise. Despite the rapid expansion of the family of ultrathin materials, stackable and stable ferro/ferri magnets that are functional at room temperature are still out of reach. We report the growth of air-stable, transferable ultrathin iron oxide crystals that exhibit magnetic order at room temperature. These crystals require no passivation and can be prepared by scalable and cost-effective chemical vapor deposition. We demonstrate that the bonding between iron oxide and its growth substrate is van der Waals-like, enabling us to remove the crystals from their growth substrate and prepare iron oxide/graphene heterostructures.

Nanoscale imaging of magnetization reversal driven by spin-orbit torque.

We use scanning electron microscopy with polarization analysis to image deterministic, spin-orbit torque-driven magnetization reversal of in-plane magnetized CoFeB rectangles in zero applied magnetic field. The spin-orbit torque is generated by running a current through heavy metal microstrips, either Pt or Ta, upon which the CoFeB rectangles are deposited. We image the CoFeB magnetization before and after a current pulse to see the effect of spin-orbit torque on the magnetic nanostructure. The observed changes in magnetic structure can be complex, deviating significantly from a simple macrospin approximation, especially in larger elements. Overall, however, the directions of the magnetization reversal in the Pt and Ta devices are opposite, consistent with the opposite signs of the spin Hall angles of these materials. Our results elucidate the effects of current density, geometry, and magnetic domain structure on magnetization switching driven by spin-orbit torque.

Realization of ground-state artificial skyrmion lattices at room temperature.

The topological nature of magnetic skyrmions leads to extraordinary properties that provide new insights into fundamental problems of magnetism and exciting potentials for novel magnetic technologies. Prerequisite are systems exhibiting skyrmion lattices at ambient conditions, which have been elusive so far. Here, we demonstrate the realization of artificial Bloch skyrmion lattices over extended areas in their ground state at room temperature by patterning asymmetric magnetic nanodots with controlled circularity on an underlayer with perpendicular magnetic anisotropy (PMA). Polarity is controlled by a tailored magnetic field sequence and demonstrated in magnetometry measurements. The vortex structure is imprinted from the dots into the interfacial region of the underlayer via suppression of the PMA by a critical ion-irradiation step. The imprinted skyrmion lattices are identified directly with polarized neutron reflectometry and confirmed by magnetoresistance measurements. Our results demonstrate an exciting platform to explore room-temperature ground-state skyrmion lattices.

Higher success rates and satisfaction in difficult venous access patients with a guide wire-associated peripheral venous catheter.

STUDY OBJECTIVE: This study compares first pass success rates and patient and physician satisfaction scores of using a guide wire-associated peripheral venous catheter (GAPIV) vs a traditional peripheral venous catheter in difficult to obtain venous access patients. METHODS: A total of 200 patients were enrolled prospectively from a convenience sample in a large urban academic emergency department. Patients were included when they were deemed difficult access per study criteria. Patients were alternated to receiving either a traditional peripheral venous catheter or a GAPIV. The number of attempts, the number of catheters used, and patient and physician satisfaction scores were recorded. RESULTS: A total of 100 patients were enrolled into each group. First attempt success was 85% with GAPIV vs 22% with the traditional peripheral venous catheter (P < .0001). Sixty-two percent of patients required a second stick with the conventional catheter compared to 15% with the GAPIV. The average number of attempts overall for the GAPIV product was 1.2 with an SD of 0.4 attempts vs 1.9 and an SD of 0.6 attempts with the traditional peripheral venous catheter; P < .0001. Using a 5-point Likert scale, the GAPIV had a median patient satisfaction score of 5 at insertion compared with the traditional peripheral venous catheter score of 2; P < .0001. Median physician satisfaction with the GAPIV study device was 5 at time of insertion, compared to 3 for the traditional peripheral venous catheter. CONCLUSION: The GAPIV product demonstrated significantly higher first attempt success and patient satisfaction compared to a traditional peripheral venous catheter in difficult to obtain venous access patients. Physician satisfaction was also favorable due to ease of access, time, and efficiencies gained.

Kilohertz rotation of nanorods propelled by ultrasound, traced by microvortex advection of nanoparticles.

We measure the microvortical flows around gold nanorods propelled by ultrasound in water using polystyrene nanoparticles as optical tracers. We infer the rotational frequencies of such nanomotors assuming a hydrodynamic model of this interaction. In this way, we find that nanomotors rotate around their longitudinal axes at frequencies of up to ≈ 2.5 kHz, or ≈ 150 000 rpm, in the planar pressure node of a half-wavelength layered acoustic resonator driven at ≈ 3 MHz with an acoustic energy density of <10 J·m(-3). The corresponding tangential speeds of up to ≈ 2.5 mm·s(-1) at a nanomotor radius of ≈ 160 nm are 2 orders of magnitude faster than the translational speeds of up to ≈ 20 µm·s(-1). We also find that rotation and translation are independent modes of motion within experimental uncertainty. Our study is an important step toward understanding the behavior and fulfilling the potential of this dynamic nanotechnology for hydrodynamically interacting with biological media, as well as other applications involving nanoscale transport, mixing, drilling, assembly, and rheology. Our results also establish the fastest reported rotation of a nanomotor in aqueous solution.