Small field measurements using electronic portal imaging device.

Purpose/Objective Small-field measurement poses challenges. Although many high-resolution detectors are commercially available, the EPID for small-field dosimetry remains underexplored. This study aimed to evaluate the performance of EPID for small-field measurements and to derive tailored correction factors for precise small-field dosimetry verification. Material/Methods Six high-resolution radiation detectors, including W2 and W1 plastic scintillators, Edge-detector, microSilicon, microDiamond and EPID were utilized. The output factors, depth doses and profiles, were measured for various beam energies (6 MV-FF, 6 MV-FFF, 10 MV-FF, and 10 MV-FFF) and field sizes (10 x 10 cm2, 5 x 5 cm2, 4 x 4 cm2, 3 x 3 cm2, 2 x 2 cm2, 1 x 1 cm2, 0.5 x 0.5 cm2) using a Varian Truebeam linear accelerator. During measurements, acrylic plates of appropriate depth were placed on the EPID, while a 3D water tank was used with five-point detectors. EPID measured data were compared with W2 plastic scintillator and measurements from other high-resolution detectors. The analysis included percentage deviations in output factors, differences in percentage for PDD and for the profiles, FWHM, maximum difference in the flat region, penumbra, and 1D gamma were analyzed. The output factor and depth dose ratios were fitted using exponential functions and fractional polynomial fitting in STATA 16.2, with W2 scintillator as reference, and corresponding formulae were obtained. The established correction factors were validated using two Truebeam machines. Results When comparing EPID and W2-PSD across all field-sizes and energies, the deviation for output factors ranged from 1% to 15%. Depth doses, the percentage difference beyond dmax ranged from 1% to 19%. For profiles, maximum of 4% was observed in the 100% - 80% region. The correction factor formulae were validated with two independent EPIDs and closely matched within 3%. Conclusion EPID can effectively serve as small-field dosimetry verification tool with appropriate correction factors.

Assessing the Impact of Adlayer Description Fidelity on Theoretical Predictions of Coking on Ni(111) at Steam Reforming Conditions.

Methane steam reforming is an important industrial process for hydrogen production, employing Ni as a low-cost, highly active catalyst, which, however, suffers from coking due to methane cracking. Coking is the accumulation of a stable poison over time, occurring at high temperatures; thus, to a first approximation, it can be treated as a thermodynamic problem. In this work, we developed an Ab initio kinetic Monte Carlo (KMC) model for methane cracking on Ni(111) at steam reforming conditions. The model captures C-H activation kinetics in detail, while graphene sheet formation is described at the level of thermodynamics, to obtain insights into the "terminal (poisoned) state" of graphene/coke within reasonable computational times. We used cluster expansions (CEs) of progressively higher fidelity to systematically assess the influence of effective cluster interactions between adsorbed or covalently bonded C and CH species on the "terminal state" morphology. Moreover, we compared the predictions of KMC models incorporating these CEs into mean-field microkinetic models in a consistent manner. The models show that the "terminal state" changes significantly with the level of fidelity of the CEs. Furthermore, high-fidelity simulations predict C-CH island/rings that are largely disconnected at low temperatures but completely encapsulate the Ni(111) surface at high temperatures.

Toward a new definition of surface energy for late transition metals.

Surface energy is a top-importance stability descriptor of transition metal-based catalysts. Here, we combined density functional theory (DFT) calculations and a tiling scheme measuring surface areas of metal structures to develop a simple computational model predicting the average surface energy of metal structures independently of their shape. The metals considered are W, Ru, Co, Ir, Ni, Pd, Pt, Cu, Ag and Au. Lorentzian trends derived from the DFT data proved effective at predicting the surface energy of metallic surfaces but not for metal clusters. We used machine-learning protocols to build an algorithm that improves the Lorentzian trend's accuracy and is able to predict the surface energies of metal surfaces of any crystal structure, i.e., face-centred cubic, hexagonal close-packed, and body-centred cubic, but also of nanostructures and sub-nanometer clusters. The machine-learning neural network takes easy-to-compute geometric features to predict metallic moieties surface energies with a mean absolute error of 0.091 J m-2 and an R2 score of 0.97.

Impact on an Urgent Care Clinic of a New Freestanding Emergency Department in a Resource-Scarce Area.

Background: Convenience clinics-such as urgent care centers (UCCs), retail clinics, and freestanding emergency departments (FSEDs)-where patients can receive treatment for a variety of medical conditions have increased in number and popularity. We quantify the impact an FSED had on UCC visits in an underserved area in North Baton Rouge, Louisiana. Methods: All FSED and UCC visits were abstracted from 2015 to 2020. Visits were classified using International Classification of Diseases, Tenth Revision codes. We used a time series analysis to evaluate the association of nonemergent and emergent visits to the UCC after the opening of the FSED. Visits were also aggregated at the census block group (neighborhood) level. Demographic characteristics and the neighborhood Area Deprivation Index were used to compare UCC utilization before and after the FSED opened and to describe the visits to the UCC and the FSED. Results: We found a difference in the demographic composition of patients presenting to the UCC after the FSED opened. Emergent visits decreased at the UCC, but nonemergent visits did not change after the FSED opened. The majority of visits to the FSED were nonemergent, and the proportion of nonemergent visits to the FSED increased during the hours that the UCC was closed. The majority of visits to the FSED came from neighborhoods with a high Area Deprivation Index. Conclusion: The opening of an FSED resulted in a reduction of emergent visits to the UCC without impacting the number of nonemergent visits. The opening of an FSED in a poor, healthcare-resource-scarce area resulted in significantly more patients from deprived neighborhoods being treated at the FSED and UCC.

Early occlusal caries detection using targeted fluorescent starch nanoparticles.

OBJECTIVES: We have previously shown fluorescent cationic starch nanoparticles (FCSNs) penetrate enamel surface porosity of active carious lesions, potentially aiding their detection. Here, we evaluate the in vitro diagnostic accuracy of FCSNs in detecting occlusal caries compared to histologic reference standard. METHODS: 100 extracted human teeth were selected with sound (50), or either non-cavitated (25) or cavitated (25) lesions. A region of interest (ROI) on the occlusal surface was assessed for fluorescence by two independent examiners, after immersion in FCSN solution, water rinse, and illumination by dental curing lamp viewed through orange UV-filter glasses. ROIs were sectioned and evaluated by histology (Downer Criteria) as a gold standard for caries presence. Cohen's Kappa was determined for inter- and intra-examiner agreement, and sensitivity, specificity, and area under the curve of Receiver Operator Curves (ROCAUC) were calculated. The analysis was repeated for the subset of "early" lesions, defined as being limited to enamel. RESULTS: FCSN use resulted in substantial inter-user (k=0.74±0.07), and high intra-user agreement (k=0.80±0.06; 0.94±0.03, by examiner). Sensitivity, specificity and ROCAUC for FCSNs were 88.9%; 94.6%; 0.92±0.06 for all, and 76.9%, 94.6%, and 0.86±0.10 for early lesions. In post hoc analysis, sensitivity seemed to be greater with the FCSN than the expert visual exam, particularly for early lesions. CONCLUSIONS/CLINICAL SIGNIFICANCE: FCSNs are a reproducible and accurate novel technology for occlusal caries detection, with high sensitivity and specificity compared to histology. Future clinical validation is necessary. FCSNs can improve early caries detection and shift treatment towards non-invasive approaches, improving oral health.

Effect of Medicaid Expansion on Visit Composition in a Louisiana Health Care System.

Background: In 2016, Louisiana expanded Medicaid to low-income adults under the Patient Protection and Affordable Care Act. By 2020, the uninsured rate of adults in Louisiana had dropped from 22.7% to 8.9%; however, few reports describe the effect Medicaid expansion has had on access and utilization of health care services in Louisiana. Methods: For this study, we collected all-payer emergency department and clinic visits from one health care system in Louisiana from 2015 to 2019. We used a time series analysis to compare trends before and after Medicaid expansion in health insurance coverage and emergency department visit type. Results: The changes in payer mix in the urgent care and primary care clinics and emergency departments after Medicaid expansion was driven by the uptake of Medicaid coverage in the previously uninsured. Medicaid expansion had a limited impact on the number of urgent care and emergent and nonemergent emergency department visits, but an increase in primary care visits was observed. Conclusion: Medicaid expansion reduced uncompensated care in our patient population and expanded the access to primary care clinics. Ongoing research is needed to understand the effect of nonfinancial barriers to care on access to and utilization of services in Louisiana.

Using natural language processing to compare task-specific verbal cues in coached versus noncoached cardiac arrest teams during simulated pediatrics resuscitation.

OBJECTIVES: Coaches improve cardiopulmonary (CPR) outcomes in real-world and simulated settings. To explore verbal feedback that targets CPR quality, we used natural language processing (NLP) methodologies on transcripts from a published pediatric randomized trial (coach vs. no coach in simulated CPR). Study objectives included determining any differences by trial arm in (1) overall communication and (2) metrics over minutes of CPR and (3) exploring overall frequencies and temporal patterns according to degrees of CPR excellence. METHODS: A human-generated transcription service produced 40 team transcripts. Automated text search with manual review assigned semantic category; word count; and presence of verbal cues for general CPR, compression depth or rate, or positive feedback to transcript utterances. Resulting cue counts per minute (CPM) were corresponded to CPR quality based on compression rate and depth per minute. CPMs were compared across trial arms and over the 18 min of CPR. Adaptation to excellence was analyzed across four patterns of CPR excellence determined by k-shape methods. RESULTS: Overall coached teams experienced more rate-directive, depth-directive, and positive verbal cues compared with noncoached teams. The frequency of coaches' depth cues changed over minutes of CPR, indicating adaptation. In coached teams, the number of depth-directive cues differed among the four patterns of CPR excellence. Noncoached teams experienced fewer utterances by type, with no adaptation over time or to CPR performance. CONCLUSION: NLP extracted verbal metrics and their patterns in resuscitation sessions provides insight into communication patterns and skills used by CPR coaches and other team members. This could help to further optimize CPR training, feedback, excellence, and outcomes.

Association of Alopecia Areata With Attention-Deficit/Hyperactivity Disorder Stimulant Medication: A Case-Control Study.

Background: Both psychiatric disorders and diverse medications used to treat them have been associated with alopecia. The objective of our study was to investigate the existence of an association between attention-deficit/hyperactivity disorder (ADHD) stimulant medication (ASM) and various types of alopecia. Methods: We conducted a retrospective case-control medical record review of patients between the ages of 6 and 18 years seen in dermatology clinics during a 10-year period. Cases included patients diagnosed with alopecia areata (AA), alopecia totalis (AT), or alopecia universalis (AU). We matched 3 controls on age and sex to each case. We reviewed patients' medical records for the following medications: lisdexamfetamine, amphetamine/dextroamphetamine, dexmethylphenidate, and methylphenidate. We examined the association between medications used to treat ADHD and diagnoses of AA, AT, and/or AU by calculating a series of odds ratios and 95% CIs. Results: We identified 124 cases (110 with AA, 11 with AT, and 3 with AU) and 372 controls. We found a strong association between AU and ASM use (P<0.0071). No relationship between ASM use and other types of hair loss was found. Conclusion: Although the sample size of cases with AU was small, we found a significant association between AU and ASM. While further study is needed, practitioners may consider close monitoring of patients with AA who use ASM for the development of worsening disease and discontinue the medication if the patient experiences an increase in hair loss that appears to be progressing to AU.

DFT benchmark studies on representative species and poisons of methane steam reforming on Ni(111).

Ni catalysts used in methane steam reforming (MSR) are highly susceptible to poisoning by carbon-based species, which poses a major impediment to the productivity of industrial operations. These species encompass graphitic carbon-like formations that are typically modelled as graphene. First principles-based approaches, such as density functional theory (DFT) calculations, can provide valuable insight into the mechanism of graphene growth in the MSR reaction. It is, however, critical that a DFT model of this reaction can accurately describe the interactions of Ni(111) with the MSR intermediates as well as graphene. In this work, a systematic benchmark study has been carried out to identify a suitable DFT functional for the graphene-MSR system. The binding energies of graphene and important MSR species, as well as the reaction energies of methane dissociation and carbon oxidation, were computed on Ni(111) using GGA functionals, DFT-D and van der Waals density functionals (vdW-DF). It is well-established that the GGA functionals are inadequate for describing graphene-Ni(111) interactions. In the case of vdW-DF, the optPBE-vdW functional predicts the binding energies of graphene and several important MSR species with reasonable accuracy; however, it provides poor estimates of CO and O binding energies. Among the DFT-D functionals, PBE-D3 and PBE-dDsC have been found to exhibit acceptable accuracy for graphene and most MSR species (excluding adsorbed CO), and therefore, both functionals are promising for elucidating carbon-based catalytic poisoning in the MSR reaction. Overall, no single DFT functional could estimate the binding energies of all the species with equally high accuracy.

Difficulties in Accessing Cancer Care in a Small Island State: A Community-Based Pilot Study of Cancer Survivors in Saint Lucia.

Developing robust systems for cancer care delivery is essential to reduce the high cancer mortality in small island developing states (SIDS). Indigenous data are scarce, but community-based cancer research can inform care in SIDS where formal research capacity is lacking, and we describe the experiences of cancer survivors in Saint Lucia in accessing health services. Purposive and snowball sampling was used to constitute a sample of survivors for interviews. Subjects were interviewed with a questionnaire regarding socio-demographics, clinical characteristics, health services accessed (physicians, tests, treatment), and personal appraisal of experience. We recruited 50 survivors (13 men, 37 women). Only 52% of first presentations were with general practitioners. The mean turnaround for biopsy results in Saint Lucia was three times longer than overseas (p = 0.0013). Approximately half of survivors commenced treatment more than one month following diagnosis (median of 32 days, IQR 19-86 days), and 56% of survivors traveled out-of-country for treatment. Most survivors (60%) paid for care with family/friends support, followed by savings and medical insurance (38% each). In conclusion, cancer survivors in Saint Lucia are faced with complex circumstances, including access-to-care and health consequences. This study can guide future research, and possibly guide practice improvements in the near term.

The impact of the COVID-19 pandemic and governor mandated stay at home order on emergency department super utilizers.

BACKGROUND: Despite the trend of rising Emergency Department (ED) visits over the past decade, researchers have observed drastic declines in number of ED visits due to the COVID-19 pandemic. The purpose of the current study was to examine the impact of the COVID-19 pandemic and governor mandated Stay at Home Order on ED super utilizers. METHODS: This was a retrospective chart review of patients presenting to the 12 emergency departments of the Franciscan Mission of Our Lady Hospital System in Louisiana between January 1, 2018 and December 31, 2020. Patients who were 18 years of age or older and had four ED visits within a one-year period (2018, 2019, or 2020) were classified as super-utilizers. We examined number and category of visits for the baseline period (January 2018 - March 2020), the governor's Stay at Home Order, and the subsequent Reopening Phases through December 31, 2020. RESULTS: The number of visits by super utilizers decreased by over 16% when the Stay at Home Order was issued. The average number of visits per week rose from 1010.63 during the Stay at Home Order to 1198.09 after the Stay at Home Order was lifted, but they did not return to Pre-COVID levels of approximately 1400 visits per week in 2018 and 2019. When categories of visits were examined, this trend was found for emergent visits (p < 0.001) and visits related to injuries (p < 0.001). Non-emergent visits declined during the Stay at Home Order compared to the baseline period (p < 0.001), and did not increase significantly during reopening compared to the Stay at Home Order (p = 0.87). There were no changes in number of visits for psychiatric purposes, alcohol use, or drug use during the pandemic. CONCLUSIONS: Significant declines in emergent visits raise concerns that individuals who needed ED treatment did not seek it due to COVID-19. However, the finding that super utilizers with non-emergent visits continued to visit the ED less after the Stay at Home Order was lifted raises questions for future research that may inform policy and interventions for inappropriate ED use.

Simulation-Based Education Enhances Patient Safety Behaviors During Central Venous Catheter Placement.

OBJECTIVE: We describe the effect of simulation-based education on residents' adherence to protocols for and performance of central venous access. METHODS: Internal medicine and emergency medicine residents underwent a central venous access course that included a lecture, video presentation, readings, and simulation demonstrations presented by faculty. Baseline data were collected before the course was initiated. After a skills session where they rehearsed their ultrasound-guided central venous access skills, residents were evaluated using a procedural checklist and written knowledge exam. Residents also completed questionnaires regarding confidence in performing ultrasound-guided central venous access and opinions about the training course. RESULTS: Residents demonstrated significant improvement on the written knowledge exam (P < 0.0001) and Standard Protocol Checklist (P < 0.0001) after the training course. Training improved a number of patient safety elements, including adherence to sterile technique, transparent dressing, discarding sharps, and ordering postprocedure x-rays. However, a number of residents failed to wash their hands, prepare with chlorhexidine, drape the patient using a sterile technique, anesthetize the site, and perform a preprocedure time-out. Significant improvement in procedural skills was also noted for reduction in skin-to-vein time (P < 0.003) as well as a reduction in number of residents who punctured the carotid artery (P < 0.02). CONCLUSIONS: Simulation-based education significantly improved residents' knowledge and procedural skills along with their confidence. Adherence to the protocol also improved. This study illustrates that simulation-based education can improve patient safety through training and protocols.

Computed Tomography for Pediatric Pelvic Fractures in Pediatric Versus Adult Trauma Centers.

BACKGROUND: Pediatric pelvic fractures are a significant source of morbidity for children in the United States. In the era of specialized care, the relationship between trauma center designation and outcomes remains unknown. We hypothesized that there would be no difference in patient outcomes when treated at adult trauma centers (ATCs), pediatric trauma centers (PTCs), or dual trauma centers (DTCs). MATERIALS AND METHODS: We used the National Trauma Data Bank to identify pediatric (≤14 y) patients suffering pelvic fractures in 2013-2015. DTCs were defined as centers with level I or II trauma designation for both pediatric and adult care. Primary outcomes included mortality, complications, and computed tomography (CT) utilization. RESULTS: There were 4260 patients who met study criteria. Of these, 1290 (22%) were treated at ATCs, 1332 (30%) at PTCs, and 2120 (48%) at DTCs. Pediatric patients treated at ATCs were more likely to suffer a complication or receive a CT scan. On multivariate analysis, patients treated at PTCs and DTCs were significantly less likely to have a recorded complication or receive head, thoracic, or whole-body CT scans compared with ATCs. DTCs, but not PTCs, used fewer abdominal CT scans. Mortality rates were not predicted by center designation. CONCLUSIONS: For pediatric pelvic fractures, centers with pediatric trauma designation (PTCs and DTCs) appear to have better outcomes despite significantly less use of CT scans. Further studies are needed to determine optimal management of pediatric pelvic fractures while minimizing exposure to ionizing radiation. LEVEL OF EVIDENCE: Level III Retrospective.

Adsorbate-Induced Segregation of Cobalt from PtCo Nanoparticles: Modeling Au Doping and Core AuCo Alloying for the Improvement of Fuel Cell Cathode Catalysts.

Platinum, when used as a cathode material for the oxygen reduction reaction, suffers from high overpotential and possible dissolution, in addition to the scarcity of the metal and resulting cost. Although the introduction of cobalt has been reported to improve reaction kinetics and decrease the precious metal loading, surface segregation or complete leakage of Co atoms causes degradation of the membrane electrode assembly, and either of these scenarios of structural rearrangement eventually decreases catalytic power. Ternary PtCo alloys with noble metals could possibly maintain activity with a higher dissolution potential. First-principles-based theoretical methods are utilized to identify the critical factors affecting segregation in Pt-Co binary and Pt-Co-Au ternary nanoparticles in the presence of oxidizing species. With a decreasing share of Pt, surface segregation of Co atoms was already found to become thermodynamically viable in the PtCo systems at low oxygen concentrations, which is assigned to high charge transfer between species. While the introduction of gold as a dopant caused structural changes that favor segregation of Co, creation of CoAu alloy core is calculated to significantly suppress Co leakage through modification of the electronic properties. The theoretical framework of geometrically different ternary systems provides a new route for the rational design of oxygen reduction catalysts.

Machine learning to extract communication and history-taking skills in OSCE transcripts.

OBJECTIVES: Observed Structured Clinical Exams (OSCEs) allow assessment of, and provide feedback to, medical students. Clinical examiners and standardised patients (SP) typically complete itemised checklists and global scoring scales, which have known shortcomings. In this study, we applied machine learning (ML) to label some communication skills and interview content information in OSCE transcripts and to compare several ML methodologies by performance and transferability. METHODS: One-hundred and twenty-one transcripts of two OSCE scenarios were manually annotated per utterance across 19 communication skills and content areas. Utterances were converted to two types of numeric sentence vector representations and were paired with three types of ML algorithms. First, ML models (MLMs) were evaluated using a five K-fold cross-validation technique on all transcripts in one scenario to generate precision and recall, and their harmonic mean, F1 scores. Second, ML models were trained on all 101 transcripts from scenario 1 and tested for transferability on 20 scenario 2 transcripts. RESULTS: Performance testing in the K-fold cross-validation demonstrated relatively high mean F1 scores: median 0.87 and range 0.53-0.98 across all 19 labels. Transferability testing demonstrated success: F1 median 0.76 and range 0.46-0.97. The combination of a bi-directional long short-term memory neural network (biLSTM) algorithm with GenSen numeric sentence vector representations was associated with greater F1 scores across both performance and transferability (P < .005). CONCLUSIONS: We report the first application of ML in the context of student-SP OSCEs. We demonstrated that several MLMs automatically labelled OSCE transcripts for a range of interview content and some clinical communications skills. Some MLMs achieved greater performance and transferability. Optimised MLMs could provide automated and accurate assessment of OSCEs with potential to track student progress and identify areas for further practice.

Mesospheric Bore Evolution and Instability Dynamics Observed in PMC Turbo Imaging and Rayleigh Lidar Profiling Over Northeastern Canada on 13 July 2018.

Two successive mesospheric bores were observed over northeastern Canada on 13 July 2018 in high-resolution imaging and Rayleigh lidar profiling of polar mesospheric clouds (PMCs) performed aboard the PMC Turbo long-duration balloon experiment. Four wide field-of-view cameras spanning an area of ~75 × 150 km at PMC altitudes captured the two evolutions occurring over ~2 hr and resolved bore and associated instability features as small as ~100 m. The Rayleigh lidar provided PMC backscatter profiling that revealed vertical displacements, evolving brightness distributions, evidence of instability character and depths, and insights into bore formation, ducting, and dissipation. Both bores exhibited variable structure along their phases, suggesting variable gravity wave (GW) source and bore propagation conditions. Both bores also exhibited small-scale instability dynamics at their leading and trailing edges. Those at the leading edges comprised apparent Kelvin-Helmholtz instabilities that were advected downward and rearward beneath the bore descending phases extending into an apparently intensified shear layer. Instabilities at the trailing edges exhibited alignments approximately orthogonal to the bore phases that resembled those seen to accompany GW breaking or intrusions arising in high-resolution modeling of GW instability dynamics. Collectively, PMC Turbo bore imaging and lidar profiling enabled enhanced definition of bore dynamics relative to what has been possible by previous ground-based observations, and a potential to guide new, three-dimensional modeling of bore dynamics. The observed bore evolutions suggest potentially important roles for bores in the deposition of energy and momentum transported into the mesosphere and to higher altitudes by high-frequency GWs achieving large amplitudes.

The Association of Payer Status and Injury Patterns in Pediatric Bicycle Injuries.

BACKGROUND: Bicycle injuries continue to cause significant morbidity in the United States. How insurance status affects outcomes in children with bicycle injuries has not been defined. We hypothesized that payer status would not impact injury patterns or outcomes in pediatric bicycle-related accidents. METHODS: The National Trauma Data Bank was used to identify pediatric (≤18 y) patients involved in bicycle-related crashes admitted in year 2016. Patients with private insurance were compared with all others (uninsured, Medicaid, and Medicare). RESULTS: There were 5619 patients that met study criteria. Of these, 2500 (44%) had private insurance. Privately insured were older (12 y versus 11, P < 0.001), more likely to be white (77% versus 56%, P < 0.001), and more likely to wear a helmet (26% versus 9%, P < 0.001). On multivariate analysis, factors associated with traumatic brain injury included age (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.06-1.08; P < 0.001) and helmet use (OR, 0.64; 95% CI, 0.55-0.74; P < 0.001). Patients without private insurance were significantly less likely to wear a helmet (OR, 0.52; 95% CI, 0.44-0.63; P < 0.001). Uninsured patients had significantly higher odds of a fatal injury (OR, 4.43; 95% CI, 1.52-12.92; P = 0.006). CONCLUSIONS: Uninsured children that present to a trauma center after a bicycle accident are more likely to die. Although helmet use reduced the odds of traumatic brain injury, minorities and children without private insurance were less likely to be helmeted. Public health interventions should increase helmet access to children without private insurance, especially uninsured children.

Impact of trauma center volume on major vascular injury: An analysis of the National Trauma Data Bank (NTDB).

BACKGROUND: The association of procedure volume and improved outcomes has been established with infrequently performed elective operations. However, effect of trauma center volume on outcomes in emergency surgery has not been defined. We hypothesized that high volume centers (HVC) would provide better outcomes for operative major vascular injuries (MVI) than low volume centers (LVC). METHODS: The NTDB was queried from 2010 to 2014. Patients with MVI were identified and HVC were compared to LVC. HVC were defined as >480 patients per year with ISS≥15. RESULTS: There were 37,125 patients with MVI, with 16,461 (44.3%) managed operatively. Of these, 15,965 (97%) underwent surgery at HVC and 496 (3%) at LVC. There was no difference in shunt utilization, however, HVC were more likely to utilize endovascular repair (31.0% vs. 21.9%, p < 0.001). Rates of death, amputation, and compartment syndrome were similar. HVC were more likely to develop pneumonia or sepsis. On logistic regression, HVC was not associated with survival (OR: 0.90, 95%CI: 0.60-1.34, p = 0.60). Variables associated with mortality for HVC and LVC included thoracic arterial injury (OR: 1.57, 95%CI: 1.27-1.94, p < 0.001), penetrating mechanism (OR:1.84, 95%CI: 1.57-2.15, p < 0.001), and open repair (OR: 1.95, 95%CI: 1.69-2.26, p < 0.001). Lower ISS (OR: 0.29, 95%CI: 0.24-0.34, p < 0.001) and higher presenting blood pressure (OR: 0.99, 95%CI: 0.99-1.00, p < 0.001) were associated with survival. CONCLUSIONS: Although LVC may have less proficiency with endovascular techniques, trauma center volume does not influence survival in emergency surgery for MVI.

The PMC Turbo Balloon Mission to Measure Gravity Waves and Turbulence in Polar Mesospheric Clouds: Camera, Telemetry, and Software Performance.

The Polar Mesospheric Cloud Turbulence (PMC Turbo) instrument consists of a balloon-borne platform which hosts seven cameras and a Rayleigh lidar. During a 6-day flight in July 2018, the cameras captured images of Polar Mesospheric Clouds (PMCs) with a sensitivity to spatial scales from ~20 m to 100 km at a ~2-s cadence and a full field of view (FOV) of hundreds of kilometers. We developed software optimized for imaging of PMCs, controlling multiple independent cameras, compressing and storing images, and for choosing telemetry communication channels. We give an overview of the PMC Turbo design focusing on the flight software and telemetry functions. We describe the performance of the system during its first flight in July 2018.