Fragility fractures are a large source of morbidity and mortality in the elderly. Orthopaedic surgeons are regularly the main point of contact in patients with lateral compression type 1 pelvis ...fractures, despite many of these being treated non-operatively. This study aims to identify risk factors for mortality and elucidate which follow-up visits have the potential to improve care for these patients.
In all, 211 patients have been identified with fragility lateral compression type 1 fractures at a level 1 trauma centre over a 5-year period. For all patients, we recorded patient demographics, imaging data, hospital readmissions, medical complications and death dates if applicable.
Of the 211 patients identified, 56.4% had at least one orthopaedic follow-up, of which no patient had a clinically meaningful medical intervention initiated. 30-day readmission rate was 19%, and 1-year mortality was 24%. Male sex, need for an assist device, higher Charlson Comorbidity Index and increased age were found to be statistically associated with increased risk of mortality. Patients who followed up with their primary care physician were found to have a statistically lower risk of mortality. Computed tomography scans were obtained in 70% of patients and never limited patient weight-bearing status or found any additional injury not already identified on the radiograph.
For patients with lateral compression type 1 type fragility fractures, orthopaedic surgeons did not offer additional clinically meaningful intervention after the time of initial diagnosis in this patient cohort. The rate of clinical follow-up with a primary care physician is relatively low despite high rates of medical comorbidity. Computed tomography scans were utilised frequently but did not change recommendations. The high rate of medical complications and lack of orthopaedic intervention suggest that we should re-evaluate the role of the orthopaedic surgeon versus the primary care physician as the primary point of medical contact for patients with these injuries.
The National Institute of Standards and Technology (NIST) recently developed a new robotic scanning system for performing near-field measurements at millimeter-wave (mm-wave) frequencies above 100 ...GHz, the configurable robotic millimeterwave antenna (CROMMA) facility. This cost-effective system is designed for high-frequency applications, is capable of scanning in multiple configurations, and is able to track measurement geometry at every point in a scan. The CROMMA combines realtime six-degree-of-freedom optical spatial metrology and robotic motion to achieve antenna positioning to within 25 μm rms. A unified coordinated metrology approach is used to track all positional aspects of scanning. A vector network analyzer is used to capture amplitude and phase. We present spherical near-field measurements of the forward hemisphere of a 24-dBi standard gain horn at 183 GHz. Using the configurable scanning ability, two different scanning radii were used. Near-field data were taken at a 100-mm radius. Direct far-field measurements were also taken at 1000-mm radius. The E- and H-plane patterns are determined from the measurements and compared to theoretical patterns. We describe the system components of the CROMMA and the coordinated metrology approach used. An analysis of the positional repeatability and accuracy achievable is also presented.
Many proposed biomedical applications for engineered gold nanoparticles require their incorporation by mammalian cells in specific numbers and locations. Here, the number of gold nanoparticles inside ...of individual mammalian stem cells was characterized using fast focused ion beam–scanning electron microscopy based tomography. Enhanced optical microscopy was used to provide a multiscale map of the in vitro sample, which allows cells of interest to be identified within their local environment. Cells were then serially sectioned using a gallium ion beam and imaged using a scanning electron beam. To confirm the accuracy of single cross sections, nanoparticles in similar cross sections were imaged using transmission electron microscopy and scanning helium ion microscopy. Complete tomographic series were then used to count the nanoparticles inside of each cell and measure their spatial distribution. We investigated the influence of slice thickness on counting single particles and clusters as well as nanoparticle packing within clusters. For 60 nm citrate stabilized particles, the nanoparticle cluster packing volume is 2.15 ± 0.20 times the volume of the bare gold nanoparticles.
A resolution metric intended for resolution analysis of arbitrary spatially calibrated images is presented. By fitting a simple sigmoidal function to pixel intensities across slices of an image taken ...perpendicular to light–dark edges, the mean distance over which the light–dark transition occurs can be determined. A fixed multiple of this characteristic distance is then reported as the image resolution. The prefactor is determined by analysis of scanning transmission electron microscope high-angle annular dark field images of Si . This metric has been applied to optical, scanning electron microscope, and helium ion microscope images. This method provides quantitative feedback about image resolution, independent of the tool on which the data were collected. In addition, our analysis provides a nonarbitrary and self-consistent framework that any end user can utilize to evaluate the resolution of multiple microscopes from any vendor using the same metric.
Six types of commercially available multiwall carbon nanotube soot were obtained and prepared into buckypapers by pellet pressing and by filtration into a paper. These samples were evaluated with ...respect to thickness, compressibility and electrical conductivity. DC conductivity results by two-point and four-point (van der Pauw) measurement methods as a function of preparation parameters are presented. Topology was investigated qualitatively by way of scanning electron microscopy and helium ion microscopy and from this, some generalizations about the nanotube structural properties and manufacturing technique with respect to conductivity are given.
•30nm gold nanoparticles (AuNPs) are stable in low-serum culture medium for 10days.•Focused ion beam milling exposes AuNPs within cellular cross sections.•AuNPs can be individually resolved by helium ...ion microscopy.•0.5μg/mL AuNPs do not alter metabolism or neurite outgrowth after 10days exposure.•Cross-slide coefficient of variation for controls (Li+ or AuNPs) is less than 10%.
Gold nanoparticles (AuNPs) are promising candidates for medical diagnostics and therapeutics, due to their chemical stability, optical properties, and ease of functionalization. Citrate-stabilized reference materials also have potential as negative controls in toxicology studies of other nanoparticles. Here we examine the impact of 30nm particles on the in vitro development of rat-cortex neural progenitor cells (NPCs), which mimic aspects of the developing neurological environment. AuNPs dispersed in a low-serum culture medium initially agglomerated, but then remained stable during a three day incubation period, and agglomerated only slightly during a ten day incubation period, as determined by dynamic light scattering. Transmission electron microscopy indicated the presence of individual nanoparticles at all timepoints examined. Fixed cells were cross-sectioned by ion milling and imaged by scanning electron microscopy and helium-ion microscopy to evaluate particle incorporation. Individual nanoparticles could be resolved inside cross-sectioned cells. AuNPs were incubated with developing NPCs for ten days at concentrations of 0.5μg/mL Au, 0.1μg/mL Au, or 0.05μg/mL Au. Adenosine triphosphate levels, as determined by bioluminescence measurements sensitive to low cell numbers, were not affected by AuNPs and the particles did not interfere with the assay. Multiple endpoints of neurite outgrowth were not altered by AuNPs, in particular, total neurite outgrowth per cell, a sensitive measure of neuronal development. Slide-level comparisons demonstrated the consistent response of NPCs to gold nanoparticles and a positive control chemical, neuroactive lithium. These results indicate that 30nm citrate-stabilized AuNPs could serve as negative-control reference materials for in vitro measurements of neurite outgrowth.
In this work, we present a robust synthesis protocol for platinum nanoparticles that yields a monomodal dispersion of particles that are approximately 100 nm in diameter. We determine that these ...particles are actually agglomerates of much smaller particles, creating a “raspberry” morphology. We demonstrate that these agglomerates are stable at room temperature for at least 8 weeks by dynamic light scattering. Furthermore, we demonstrate consistent electrocatalytic activity for methanol oxidation. Finally, we quantitatively explore the relationship between dispersion solvent and particle agglomeration; specifically, particles are found to agglomerate abruptly as solvent polarity decreases.
The conference was preceded by a morning preconference short course "Core Knowledge and Assessment Strategies in Advanced Placement and Introductory University Courses on US and Comparative ...Government" sponsored by the APSA Committee on Teaching and Learning. The Community Legal Information Center (CLIC) at California State University, Chico provides a unique internship program for paralegal students, offering a hands-on experience in a law office environment assisting actual clients. While Simeone, Anderson, and Allen focused on encouraging long-term relationships with community partners outside the classroom, Ari Kohen discussed the importance of internal thought and reflection, testing the impact of personal narratives on student engagement in social justice education. While encouraging individual students to connect course material to their own lives can be empowering for the small number of students in these courses, Chad Litton and Mark Springer reminded us that the key to exposing all students to civic education and engagement opportunities is to incorporate civic education into the core curriculum.
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