Background Pneumothorax (PTX) is a potentially life-threatening condition encountered by U.S. Army combat medics on the battlefield.
View Article and Find Full Text PDFThe high-pressure compaction of three dimensional granular packings is simulated using a bonded particle model (BPM) to capture linear elastic deformation. In the model, grains are represented by a collection of point particles connected by bonds. A simple multibody interaction is introduced to control Poisson's ratio and the arrangement of particles on the surface of a grain is varied to model both high- and low-frictional grains.
View Article and Find Full Text PDFStatic structure factors are computed for large-scale, mechanically stable, jammed packings of frictionless spheres (three dimensions) and disks (two dimensions) with broad, power-law size dispersity characterized by the exponent -β. The static structure factor exhibits diverging power-law behavior for small wave numbers, allowing us to identify a structural fractal dimension d_{f}. In three dimensions, d_{f}≈2.
View Article and Find Full Text PDFThe use of nucleic acids (NAs) has revolutionized medical approaches and ushered in a new era of combating various diseases. Accordingly, there is an increasing demand for accurate identification, localization, quantification, and characterization of NAs encapsulated in nonviral or viral vectors. The vast spectrum of molecular dimensions and intra- and intermolecular interactions presents a formidable obstacle for NA analytical development.
View Article and Find Full Text PDFMed J (Ft Sam Houst Tex)
April 2023
Background: Tension pneumothorax is a prominent cause of potentially survivable death on the battlefield. Field management for suspected tension pneumothorax is immediate needle thoracostomy (NT). Recent data noted higher NT success rates and ease of insertion at the fifth intercostal space, anterior axillary line (5th ICS AAL), leading to an amendment of the Committee on Tactical Combat Casualty Care recommendations on managing suspected tension pneumothorax to include the 5th ICS AAL as a viable alternative site for NT placement.
View Article and Find Full Text PDFBackground: Controversy exists regarding the optimal methods of employing ultrasound to enhance vascular access. A novel user interface which dynamically displays transverse (short) and longitudinal (long) planes simultaneously was developed to optimize ultrasound-guided vascular access. This study aimed to assess the impact of this novel biplane axis technology on central venous access performance.
View Article and Find Full Text PDFExplicit simulations of fluid mixtures of highly size-dispersed particles are constrained by numerical challenges associated with identifying pair-interaction neighbors. Recent algorithmic developments have ameliorated these difficulties to an extent, permitting more efficient simulations of systems with many large and small particles of disperse sizes. We leverage these capabilities to perform molecular dynamics simulations of binary sphere mixtures with elastically stiff particles approaching the hard sphere limit and particle size ratios of up to 50, approaching the colloidal limit.
View Article and Find Full Text PDFDue to significant computational expense, discrete element method simulations of jammed packings of size-dispersed spheres with size ratios greater than 1:10 have remained elusive, limiting the correspondence between simulations and real-world granular materials with large size dispersity. Invoking a recently developed neighbor binning algorithm, we generate mechanically stable jammed packings of frictionless spheres with power-law size distributions containing up to nearly 4 000 000 particles with size ratios up to 1:100. By systematically varying the width and exponent of the underlying power laws, we analyze the role of particle size distributions on the structure of jammed packings.
View Article and Find Full Text PDFNanoporous materials relying on supramolecular liquid crystals (LCs) are excellent candidates for size- and charge-selective membranes. However, whether they can be manufactured using printing technologies remained unexplored so far. In this work, we develop a new approach for the fabrication of ordered nanoporous microstructures based on supramolecular LCs using two-photon laser printing.
View Article and Find Full Text PDFMarfan syndrome is a genetic connective tissue disorder that is a frequent cause of aortic dissection in younger patients. We report a case of a patient with a history of ectopia lentis in his third decade and abdominal striae since adolescence, who presented with Stanford type A dissection at age 48.
View Article and Find Full Text PDFObjective: Point-of-care ultrasound (POCUS) has rapidly emerged as a valuable tool in the bedside assessment of patients. This scoping review summarizes existing literature covering clinical use and educational integration of POCUS by physician assistants (PAs), with the overall goal of identifying gaps in POCUS research involving the PA profession.
Methods: Keyword searches of PubMed, EMBASE, Medline, and Google Scholar were conducted.
Phytocannabinoid derivatives are among the several compounds found in the cannabis plant. The phytocannabinoid chemicals Δ9-tetrahydrocannabinol (THC) and cannabidiol are mostly responsible for the drug's behavioral effects. Chronic cannabis administration has been shown to disrupt circadian rhythms and reduce the duration of the deepest phase (stage N3) of nonrapid eye movement sleep.
View Article and Find Full Text PDFMelanin concentrating hormone (MCH) is a sleep-promoting neuromodulator synthesized by neurons located in the postero-lateral hypothalamus and incerto-hypothalamic area. MCHergic neurons have widespread projections including the serotonergic dorsal (DR) and median (MnR) raphe nuclei, both involved in the control of wakefulness and sleep. In the present study, we explored in rats the presence of the MCH receptor type 1 (MCHR-1) in serotonergic neurons of the MnR by double immunofluorescence.
View Article and Find Full Text PDFBackground: Extended Focused Assessment with Ultrasonography in Trauma (eFAST) reliably identifies noncompressible torso hemorrhage (NCTH), a major cause of battlefield death. Increased portability of ultrasound enables eFAST far forward on the battlefield, and published data demonstrate combat medics can learn and reliably perform ultrasound exams. One medical company developed an ultrasound device with an intuitive graphical user interface (GUI) and novel, finger-worn transducer with built-in linear and phased arrays, referred to as the novel device.
View Article and Find Full Text PDFIntroduction: The Department of Defense spends more than $3 billion annually on medical costs of lifestyle-related morbidity. Military service members and veterans engage in unhealthy behaviors at a higher rate than the civilian population. Lifestyle medicine may mitigate lifestyle-related chronic diseases and increase medical readiness in the U.
View Article and Find Full Text PDFResolving atomic scale details while capturing long-range elastic deformation is the principal difficulty when solving contact mechanics problems with computer simulations. Fully atomistic simulations must consider large blocks of atoms to support long-wavelength deformation modes, meaning that most atoms are far removed from the region of interest. Building on earlier methods that used elastic surface Green's functions to compute static substrate deformation, we present a numerically efficient dynamic Green's function technique to treat realistic, time-evolving, elastic solids.
View Article and Find Full Text PDFObjectives: Acute otitis media (AOM) is the most-common indication for antibiotics in children. Delayed antibiotic prescribing for AOM can significantly reduce unnecessary antibiotic use and is recommended by the American Academy of Pediatrics for select children. We sought to improve delayed prescribing for AOM across 8 outpatient pediatric practices in Colorado.
View Article and Find Full Text PDFAn American Academy of Pediatrics State Chapter organized a 6-month, mostly online quality improvement learning collaborative to improve antibiotic prescribing and patient education for upper respiratory infection (URI) and acute otitis media (AOM). Practices submitted data on quality measures at baseline, monthly, and 4 months post-project. Fifty-three clinicians from 6 independent, private primary care pediatric practices participated.
View Article and Find Full Text PDFJ Am Coll Emerg Physicians Open
December 2020
Objective: Emergency physicians routinely encounter stressful clinical situations, including treating victims of crime, violence, and trauma; facing the deaths of patients; and delivering bad news. During a pandemic, stress may be increased for healthcare workers. This study was undertaken to identify symptoms of post-traumatic stress disorder (PTSD) among emergency physicians during the coronavirus disease 2019 (COVID-19) pandemic.
View Article and Find Full Text PDFDisorder in the contact between an amorphous slider and a crystalline substrate leads to a cancellation of lateral forces. Atomically flat, rigid surfaces exhibit structural superlubricity, with the frictional stress in circular contacts of radius vanishing as 1/. The inclusion of elasticity allows relative motion of domains on the surface in response to the random interfacial forces.
View Article and Find Full Text PDFThe acid sphingomyelinase (ASM)/ceramide system exhibits a crucial role in the pathology of major depressive disorder (MDD). ASM hydrolyzes the abundant membrane lipid sphingomyelin to ceramide that regulates the clustering of membrane proteins via microdomain and lipid raft organization. Several commonly used antidepressants, such as fluoxetine, rely on the functional inhibition of ASM in terms of their antidepressive pharmacological effects.
View Article and Find Full Text PDFObjective: We previously showed that the change in amplitude of a finger photoplethysmography waveform during the Valsalva maneuver reflects cardiac filling pressure. However, the automated determination of peaks and valleys to calculate amplitude is limited in significant arrhythmias such as atrial fibrillation and premature ventricular complexes, which are common in heart failure. The purpose of this study was to assess the change in size of the waveform by calculating the change in root mean square (RMS) of the signal, thereby utilizing the entire cardiac cycle, and to compare it to change in size of peak-to-valley amplitude.
View Article and Find Full Text PDFBackground: Ultrasound, due to recent advances in portability and versatility, has become a valuable clinical adjunct in austere, resource-limited settings and is well demonstrated to be an accurate/efficient means to detect pneumothorax. The purpose of this study was to evaluate the impact of hands-on ultrasound training on ultrasound-naive US Army combat medics' ability to detect sonographic findings of pneumothorax with portable ultrasound in a cadaver model.
Methods: Ultrasound-naive US Army combat medics assigned to conventional military units were recruited from a single US Army installation and randomized to receive either didactic training only, or "blended" (didactic and hands-on) training on ultrasound detection of pneumothorax.
Objective: On-scene prehospital conditions and patient instability may warrant a during-transport ultrasound (US) exam. The objective of this study was to assess the effect of ambulance turbulence on the performance of the Focused Assessment with Sonography in Trauma (FAST) with a handheld US device.
Methods: This was a randomized controlled trial in which participants were randomized to perform a FAST in either a stationary or an in-motion military ambulance.