Underlying Roles of Polyol Additives in Promoting CO2 Capture in PEI/Silica Adsorbents.

Solid-supported amines having low molecular weight branched poly(ethylenimine) (PEI) physically impregnated into porous solid supports are promising adsorbents for CO2 capture. Co-impregnating short-chain poly(ethylene glycol) (PEG) together with PEI alters the performance of the adsorbent, delivering improved amine efficiency (AE, mol CO2 sorbed / mol N) and faster CO2 uptake rates. To uncover the physical basis for this improved gas capture performance, we probed the distribution and mobility of the polymers in the pores via small angle neutron scattering (SANS), solid-state NMR, and molecular dynamic (MD) simulation studies. SANS and MD simulations reveal that PEG displaces wall-bound PEI, making amines more accessible for CO2 sorption. Solid-state NMR and MD simulation suggest intercalation of PEG into PEI domains, separating PEI domains and reducing amine-amine interactions, providing potential PEG-rich and amine-poor interfacial domains that bind CO2 weakly via physisorption while providing facile pathways for CO2 diffusion. Contrary to a prior literature hypothesis, no evidence is obtained for PEG facilitating PEI mobility in solid supports. Instead, the data suggest that PEG chains coordinate to PEI, form larger bodies with reduced mobility compared to PEI alone. We also demonstrate promising CO2 uptake and desorption kinetics at varied temperatures, given by favorable amine distribution.

Probing the neurocardiac circuit in trauma and posttraumatic stress.

The neurocardiac circuit is integral to physiological regulation of threat and trauma-related responses. However, few direct investigations of brain-behavior associations with replicable physiological markers of PTSD have been conducted. The current study probed the neurocardiac circuit by examining associations among its core regions in the brain (e.g., insula, hypothalamus) and the periphery (heart rate [HR], high frequency heart rate variability [HF-HRV], and blood pressure [BP]). We sought to characterize these associations and to determine whether there were differences by PTSD status. Participants were N = 315 (64.1 % female) trauma-exposed adults enrolled from emergency departments as part of the prospective AURORA study. Participants completed a deep phenotyping session (e.g., fear conditioning, magnetic resonance imaging) two weeks after emergency department admission. Voxelwise analyses revealed several significant interactions between PTSD severity 8-weeks posttrauma and psychophysiological recordings on hypothalamic connectivity to the prefrontal cortex (PFC), insula, superior temporal sulcus, and temporoparietaloccipital junction. Among those with PTSD, diastolic BP was directly correlated with right insula-hypothalamic connectivity, whereas the reverse was found for those without PTSD. PTSD status moderated the association between systolic BP, HR, and HF-HRV and hypothalamic connectivity in the same direction. While preliminary, our findings may suggest that individuals with higher PTSD severity exhibit compensatory neural mechanisms to down-regulate autonomic imbalance. Additional study is warranted to determine how underlying mechanisms (e.g., inflammation) may disrupt the neurocardiac circuit and increase cardiometabolic disease risk in PTSD.

A Second Space Age Spanning Omics, Platforms, and Medicine Across Orbits.

The recent acceleration of commercial, private, and multi-national spaceflight has created an unprecedented level of activity in low Earth orbit (LEO), concomitant with the highest-ever number of crewed missions entering space and preparations for exploration-class (>1 year) missions. Such rapid advancement into space from many new companies, countries, and space-related entities has enabled a"Second Space Age." This new era is also poised to leverage, for the first time, modern tools and methods of molecular biology and precision medicine, thus enabling precision aerospace medicine for the crews. The applications of these biomedical technologies and algorithms are diverse, encompassing multi-omic, single-cell, and spatial biology tools to investigate human and microbial responses to spaceflight. Additionally, they extend to the development of new imaging techniques, real-time cognitive assessments, physiological monitoring, and personalized risk profiles tailored for astronauts. Furthermore, these technologies enable advancements in pharmacogenomics (PGx), as well as the identification of novel spaceflight biomarkers and the development of corresponding countermeasures. In this review, we highlight some of the recent biomedical research from the National Aeronautics and Space Administration (NASA), Japan Aerospace Exploration Agency (JAXA), European Space Agency (ESA), and other space agencies, and also detail the commercial spaceflight sector's (e.g. SpaceX, Blue Origin, Axiom, Sierra Space) entrance into aerospace medicine and space biology, the first aerospace medicine biobank, and the myriad upcoming missions that will utilize these tools to ensure a permanent human presence beyond LEO, venturing out to other planets and moons.

Treatment strategy and clinical outcomes of surgically managed hip periprosthetic fractures: analysis from a high-volume centre.

BACKGROUND: Hip periprosthetic fractures (PPF) after total hip arthroplasty (THA) are becoming increasingly prevalent. Their management is secondary to the fracture type and the stability of the implant. This study aimed to provide the outcomes of operatively managed PPF from a high-volume centre to help guide future decision making. METHODS: This was a retrospective study of prospectively collected data from January 2008 to January 2021. Patient demographics, implant specific details, and fixation strategy were collected. Complications including infection, reoperation, re-fracture, re-revision, were collected. Short-term mortality was evaluated at 3 months and 1 year. P-values <0.05 were considered significant. RESULTS: 282 surgically managed PPF were identified. Vancouver B2 were predominant in 52% of the cases. Revision alone and revision with additional fixation were the most frequent strategies in 168 cases (60%). Complications requiring reoperation occurred in 20% of the cases, with infection as the most frequent (8.5%). Mortality rate was 7.8% at 3 months and 15.7% at 1 year, with significantly lower rates in B2 type. B2 fractures treated with cemented stems had a significantly lower 1-year mortality than distal fit revisions. CONCLUSIONS: PPF is associated with a high complication rate. Revision alone and revision with additional fixation remain the preferred method in B2/B3 type fractures, however, cemented revision can yield similar outcomes with lower short-term mortality. Considering the high-risk elderly and frail category of patients, a multidisciplinary team is necessary to improve outcomes and reduce mortality.

Catalytic Upgrading of a Mixed Hydroxy Acid Feedstock Derived from Kraft Black Liquor.

Lignocellulosic feedstocks are widely studied for sustainable liquid fuel and chemical production. The pulp and paper industry generates large amounts of kraft black liquor (BL) from which a high volume of hydroxy acids (HAs) can be separated for further catalytic processing. Here, we explore the catalytic upgrading of HAs, including the conversion of (1) a model HA, gluconic acid; (2) a model mixture of HAs, and (3) a real mixture of HAs derived from kraft BL on M/Nb2O5 (M = Pd, Pt, Rh, and Ru). The hydrodeoxygenation of model gluconic acid reveals that "volatile" carboxylic acids (mainly C2 and C3), levulinic acid, and cyclic esters are significant products over all the catalysts, with Pd/Nb2O5 showing superior activity and selectivity toward valuable intermediates. The model mixture of HAs shows a wide range of reactivity over the supported metal catalyst, with the product selectivity strongly correlating to reaction temperature. Utilizing a 0.25% Pd/Nb2O5 catalyst, a real mixture of HAs derived from kraft BL is successfully dehydroxylated to produce a mixture rich in C3-C8 carboxylic acids that may be amenable for further upgrading, e.g., catalytically to ketones with high carbon chain lengths. Despite the feedstock complexity, we selectively cleaved the C-OH bonds of HAs, while successfully preserving most of the -COOH groups and minimizing C-C and C=O bond scission reactions under the operating conditions tested. The BL-derived HA stream is thus proposed to be a suitable platform for producing mixed carboxylic acid products from an overoxygenated byproduct feed.

Emergency department staff compassion is associated with lower fear of enacted stigma among patients with opioid use disorder.

OBJECTIVES: Fear of enacted stigma (fear of discrimination or being treated unfairly) is associated with decreased health care-seeking behaviors among patients with opioid use disorder (OUD). We sought to describe the prevalence of fear of enacted stigma among patients presenting to the emergency department (ED) with OUD and to test whether experiencing greater compassion from ED staff is associated with lower fear of enacted stigma. METHODS: We conducted a cross-sectional study in the ED of an academic medical center between February and August 2023. We included adult patients with OUD presenting to the ED and assessed patient experience of compassion from ED staff using a previously validated 5-item compassion measure (score range 5-20). The primary outcome measure was fear of enacted stigma in the ED, measured using the validated 9-item subscale of the Substance Abuse Self-Stigma Scale (score range 9-45). RESULTS: Of the 116 subjects enrolled, 97% (95% confidence interval [CI] 91%-99%) reported some degree of stigma, with a median (interquartile range) score of 23 (16-31). In a multivariable model adjusting for potential confounders, patient experience of greater ED compassion was independently associated with lower fear of enacted stigma, ß = -0.66 (95% CI -1.03 to -0.29), suggesting that every 1-point increase in the 5-item compassion measure score is associated with a 0.66-point decrease in the fear of enacted stigma score. CONCLUSIONS: Among ED patients with OUD, fear of enacted stigma is common. Patient experience of compassion from ED staff is associated with lower fear of enacted stigma. Future research is warranted to test if interventions aimed at increasing compassion from ED staff reduce patient fear of enacted stigma among patients with OUD.

Intensive longitudinal assessment following index trauma to predict development of PTSD using machine learning.

There are significant challenges to identifying which individuals require intervention following exposure to trauma, and a need for strategies to identify and provide individuals at risk for developing PTSD with timely interventions. The present study seeks to identify a minimal set of trauma-related symptoms, assessed during the weeks following traumatic exposure, that can accurately predict PTSD. Participants were 2185 adults (Mean age=36.4 years; 64% women; 50% Black) presenting for emergency care following traumatic exposure. Participants received a 'flash survey' with 6-8 varying symptoms (from a pool of 26 trauma symptoms) several times per week for eight weeks following the trauma exposure (each symptom assessed ∼6 times). Features (mean, sd, last, worst, peak-end scores) from the repeatedly assessed symptoms were included as candidate variables in a CART machine learning analysis to develop a pragmatic predictive algorithm. PTSD (PCL-5 ≥38) was present for 669 (31%) participants at the 8-week follow-up. A classification tree with three splits, based on mean scores of nervousness, rehashing, and fatigue, predicted PTSD with an Area Under the Curve of 0.836. Findings suggest feasibility for a 3-item assessment protocol, delivered once per week, following traumatic exposure to assess and potentially facilitate follow-up care for those at risk.

Sex-dependent differences in vulnerability to early risk factors for posttraumatic stress disorder: results from the AURORA study.

BACKGROUND: Knowledge of sex differences in risk factors for posttraumatic stress disorder (PTSD) can contribute to the development of refined preventive interventions. Therefore, the aim of this study was to examine if women and men differ in their vulnerability to risk factors for PTSD. METHODS: As part of the longitudinal AURORA study, 2924 patients seeking emergency department (ED) treatment in the acute aftermath of trauma provided self-report assessments of pre- peri- and post-traumatic risk factors, as well as 3-month PTSD severity. We systematically examined sex-dependent effects of 16 risk factors that have previously been hypothesized to show different associations with PTSD severity in women and men. RESULTS: Women reported higher PTSD severity at 3-months post-trauma. Z-score comparisons indicated that for five of the 16 examined risk factors the association with 3-month PTSD severity was stronger in men than in women. In multivariable models, interaction effects with sex were observed for pre-traumatic anxiety symptoms, and acute dissociative symptoms; both showed stronger associations with PTSD in men than in women. Subgroup analyses suggested trauma type-conditional effects. CONCLUSIONS: Our findings indicate mechanisms to which men might be particularly vulnerable, demonstrating that known PTSD risk factors might behave differently in women and men. Analyses did not identify any risk factors to which women were more vulnerable than men, pointing toward further mechanisms to explain women's higher PTSD risk. Our study illustrates the need for a more systematic examination of sex differences in contributors to PTSD severity after trauma, which may inform refined preventive interventions.

Fine-scale foraging ecology and habitat use of sympatric green and hawksbill turtles in the Western Indian ocean.

Using stable isotope analysis of carbon and nitrogen of turtle tissues and putative prey items, we investigated the diet of immature green turtles and hawksbill turtles foraging in the lagoon of Aldabra Atoll, a relatively undisturbed atoll in the southern Seychelles. Aldabra offers a unique environment for understanding sea turtle ecology. Green turtles mostly consumed seagrass and brown algae while hawksbill turtles mainly consumed mangroves and invertebrates. Green turtles showed a dietary shift with size (a proxy for age). There was minimal niche overlap between species and evidence of small-scale foraging site fidelity with turtle tissue reflecting site-specific prey. This highlights the ecological importance of seagrass and mangrove habitats and suggests that turtles play a role in controlling algal biomass at Aldabra. This study is the first to closely examine the foraging ecology of these sympatric turtle species in the Western Indian Ocean, a globally important region for both species.

Alumina Incorporation in Self-Supported Poly(ethylenimine) Sorbents for Direct Air Capture.

Self-supported branched poly(ethylenimine) scaffolds with ordered macropores are synthesized with and without Al2O3 powder additive by cross-linking poly(ethylenimine) (PEI) with poly(ethylene glycol) diglycidyl ether (PEGDGE) at -196 °C. The scaffolds' CO2 uptake performance is compared with a conventional sorbent, i.e., PEI impregnated on an Al2O3 support. PEI scaffolds with Al2O3 additive show narrow pore size distribution and thinner pore walls than alumina-free materials, facilitating higher CO2 uptake at conditions relevant to direct air capture. The PEI scaffold containing 6.5 wt % Al2O3 had the highest CO2 uptake of 1.23 mmol/g of sorbent under 50% RH 400 ppm of CO2 conditions. In situ DRIFT spectroscopy and temperature-programmed desorption experiments show a significant CO2 uptake contribution via physisorption as well as carbamic acid formation, with lower CO2 binding energies in PEI scaffolds relative to conventional PEI sorbents, likely a result of a lower population of primary amines due to the amine cross-linking reactions during scaffold synthesis. The PEI scaffold containing 6.5 wt % Al2O3 is estimated to have the lowest desorption energy penalty under humid conditions, 4.6 GJ/tCO2, among the sorbents studied.

The dynamic responses of mood and sleep physiology to chronic sleep restriction and subsequent recovery sleep.

Healthy sleep of sufficient duration preserves mood and disturbed sleep is a risk factor for a range of psychiatric disorders. As adults commonly experience chronic sleep restriction (SR), an enhanced understanding of the dynamic relationship between sleep and mood is needed, including whether susceptibility to SR-induced mood disturbance differs between sexes. To address these gaps, data from N=221 healthy adults who completed one of two multi-day laboratory studies with identical 9-day SR protocols were analyzed. Participants randomized to the SR (n=205) condition underwent 5 nights of SR to 4 h time-in-bed and were then randomized to one of seven sleep doses that ranged from 0 h to 12 h in 2 h increments; participants randomized to the control (n=16) condition received 10 h time-in-bed on all study nights. The Profile of Mood States (POMS) was used to assess mood every 2 h during wakefulness and markers of sleep homeostasis (EEG slow-wave activity) were derived via polysomnography. Mood progressively deteriorated across SR with marked disturbances in somatic mood components. Altered sleep physiology contributed to mood disturbance whereby increased EEG slow-wave activity was associated with increased POMS Total Mood Disturbance scores, a finding specific to males. Mood was restored in a dose-response fashion where improvements were greater with longer sleep doses. These findings suggest that when lifestyle and environmental factors are inhibited in the laboratory, the affective consequences of chronic sleep loss are primarily somatic mood disturbances. Altered sleep homeostasis may contribute to mood disturbance, yet sleep-dependent mechanisms may be sex-specific.

Sex Differences in Response Inhibition-Related Neural Predictors of Posttraumatic Stress Disorder in Civilians With Recent Trauma.

BACKGROUND: Females are more likely to develop posttraumatic stress disorder (PTSD) than males. Impaired inhibition has been identified as a mechanism for PTSD development, but studies on potential sex differences in this neurobiological mechanism and how it relates to PTSD severity and progression are relatively rare. Here, we examined sex differences in neural activation during response inhibition and PTSD following recent trauma. METHODS: Participants (n = 205, 138 female sex assigned at birth) were recruited from emergency departments within 72 hours of a traumatic event. PTSD symptoms were assessed 2 weeks and 6 months posttrauma. A Go/NoGo task was performed 2 weeks posttrauma in a 3T magnetic resonance imaging scanner to measure neural activity during response inhibition in the ventromedial prefrontal cortex, right inferior frontal gyrus, and bilateral hippocampus. General linear models were used to examine the interaction effect of sex on the relationship between our regions of interest and the whole brain, PTSD symptoms at 6 months, and symptom progression between 2 weeks and 6 months. RESULTS: Lower response inhibition-related ventromedial prefrontal cortex activation 2 weeks posttrauma predicted more PTSD symptoms at 6 months in females but not in males, while greater response inhibition-related right inferior frontal gyrus activation predicted lower PTSD symptom progression in males but not females. Whole-brain interaction effects were observed in the medial temporal gyrus and left precentral gyrus. CONCLUSIONS: There are sex differences in the relationship between inhibition-related brain activation and PTSD symptom severity and progression. These findings suggest that sex differences should be assessed in future PTSD studies and reveal potential targets for sex-specific interventions.

Post-traumatic stress and future substance use outcomes: leveraging antecedent factors to stratify risk.

Background: Post-traumatic stress disorder (PTSD) and substance use (tobacco, alcohol, and cannabis) are highly comorbid. Many factors affect this relationship, including sociodemographic and psychosocial characteristics, other prior traumas, and physical health. However, few prior studies have investigated this prospectively, examining new substance use and the extent to which a wide range of factors may modify the relationship to PTSD. Methods: The Advancing Understanding of RecOvery afteR traumA (AURORA) study is a prospective cohort of adults presenting at emergency departments (N = 2,943). Participants self-reported PTSD symptoms and the frequency and quantity of tobacco, alcohol, and cannabis use at six total timepoints. We assessed the associations of PTSD and future substance use, lagged by one timepoint, using the Poisson generalized estimating equations. We also stratified by incident and prevalent substance use and generated causal forests to identify the most important effect modifiers of this relationship out of 128 potential variables. Results: At baseline, 37.3% (N = 1,099) of participants reported likely PTSD. PTSD was associated with tobacco frequency (incidence rate ratio (IRR): 1.003, 95% CI: 1.00, 1.01, p = 0.02) and quantity (IRR: 1.01, 95% CI: 1.001, 1.01, p = 0.01), and alcohol frequency (IRR: 1.002, 95% CI: 1.00, 1.004, p = 0.03) and quantity (IRR: 1.003, 95% CI: 1.001, 1.01, p = 0.001), but not with cannabis use. There were slight differences in incident compared to prevalent tobacco frequency and quantity of use; prevalent tobacco frequency and quantity were associated with PTSD symptoms, while incident tobacco frequency and quantity were not. Using causal forests, lifetime worst use of cigarettes, overall self-rated physical health, and prior childhood trauma were major moderators of the relationship between PTSD symptoms and the three substances investigated. Conclusion: PTSD symptoms were highly associated with tobacco and alcohol use, while the association with prospective cannabis use is not clear. Findings suggest that understanding the different risk stratification that occurs can aid in tailoring interventions to populations at greatest risk to best mitigate the comorbidity between PTSD symptoms and future substance use outcomes. We demonstrate that this is particularly salient for tobacco use and, to some extent, alcohol use, while cannabis is less likely to be impacted by PTSD symptoms across the strata.

Isomorphous Substitution in ZSM-5 in Tandem Methanol/Zeolite Catalysts for the Hydrogenation of CO2 to Aromatics.

Intensified reactors for conversion of CO2 to methanol (via hydrogenation) using metal oxide catalysts coupled with methanol conversion to aromatics in the presence of zeolites (e.g., H-ZSM-5) in a single step are investigated. Brønsted acid sites (BAS) in H-ZSM-5 are important sites in methanol aromatization reactions, and correlations of the reactivity with zeolite acid properties can guide reaction optimization. A classical way of tuning the acidity of zeolites is via the effect of the isomorphous substitution of the heteroatom in the framework. In this work, H-[Al/Ga/Fe]-ZSM-5 zeolites are synthesized with Si/T ratios = 80, 300, affecting the acid site strength as well as distribution of Brønsted and Lewis acid sites. On catalytic testing of the H-[Al/Ga/Fe]-ZSM-5/ZnO-ZrO2 samples for tandem CO2 hydrogenation and methanol conversion, the presence of weaker Brønsted acid sites improves the aromatics selectivity (CO2 to aromatics selectivity ranging from 13 to 47%); however, this effect of acid strength was not observed at low T atom content. Catalytic testing of H-[B]-ZSM-5/ZnO-ZrO2 provides no conversion of CO2 to hydrocarbons, showing that there is a minimum acid site strength needed for measurable aromatization reactivity. The H-[Fe]-ZSM-5-80/ZnO-ZrO2 catalyst shows the best catalytic activity with a CO2 conversion of ∼10% with a CO2 to aromatics selectivity of ∼51%. The catalyst is shown to provide stable activity and selectivity over more than 250 h on stream.

Utilizing Stems in Primary Total Knee Arthroplasty: Analysis of the Australian Orthopaedic Association National Joint Replacement Registry Data.

BACKGROUND: We compared revision rates and reasons for revision for primary total knee arthroplasty (TKA) performed for osteoarthritis with and without tibial stem extensions. METHODS: Data from the Australian Orthopaedic Association National Joint Replacement Registry were used to compare all-cause revision, reason, and type of revision between primary TKA using stemmed tibial prostheses and non-stemmed prostheses. RESULTS: All-cause revision for TKA with stem extension was higher for the first 6 months (hazard ratio [HR] 1.47; 95% confidence interval [CI]1.19 to 1.82; P < .001); while after 1.5 years TKA with stem extension had a lower rate of revision (HR 0.84; 95% CI 0.73 to 0.97; P = .01). Stemmed components were more likely to be revised for infection between 3 months and 1.5 years after surgery (HR 1.39; 95% CI 1.05 to 1.83; P = .02). The revision rate for aseptic loosening was lower in the stemmed group beyond 2 years (HR = 0.45; 95% CI 0.31 to 0.63; P < .001). Insert-only revision was higher in the stemmed group at all times (HR = 1.42; 95% CI 1.21 to 1.66, P < .001). Isolated tibial component revision was lower in the stemmed group at all times (HR 0.47; 95% CI 0.29 to 0.74; P = .001). Aseptic loosening for tibial component-only revision was significantly lower in the stemmed group at all times (HR 0.23; 95% CI 0.11 to 0.50; P < .001). CONCLUSIONS: Patients undergoing primary stemmed TKA have lower rates of all-cause revision beyond 1.5 years and tibial component-only revision at all times. Further investigation is required to preoperatively select patients that benefit from augmentation with stems.

Endoscopic Tendon Release for Iliopsoas Impingement After Total Hip Arthroplasty-Excellent Clinical Outcomes and Low Failure Rates at Short-Term Follow-Up.

PURPOSE: To investigate the clinical effectiveness of endoscopic iliopsoas tendon release (IPR) at the lesser trochanter (LT) in patients with iliopsoas impingement (IPI) after total hip arthroplasty (THA). METHODS: Between November 2017 and March 2021, a consecutive series of 36 patients were treated with endoscopic IPR for diagnosed IPI. Patients included had acetabular cup position confirmed by functional imaging (OPS, Corin, Pymble, NSW), typical clinical symptoms of IPI, and a positive response to diagnostic injection. Clinical assessment included validated patient-reported outcome measures (PROMs) along with hip flexion strength and active range of motion at different time marks up to 2-year follow-up, as well as surgical complications. RESULTS: Overall, 36 consecutive patients (11 males) with a mean age of 62 ± 12 years were included. All patients had failed nonoperative management. Dynamic computed tomography assessment was available in 89% of the patients, edge loading was reported in 10%, and variable cup overhang was reported in 50%. Clinically, PROMs were significantly improved at every time mark when compared with preoperative values (P < .001), showing the biggest improvement within the first 4 weeks after surgery. At the 6-month follow-up, peak isometric hip flexion strength on the operated side was 20% lower than the contralateral side (P < .001). Failure rate of the procedure was 2.8% (1 case). Linear regression showed no association between cup overhang and clinical outcomes. CONCLUSIONS: Endoscopic IPR at the LT is a safe and reproducible technique associated with significant and immediate improvement in pain, functional outcomes, and high patient satisfaction. With minimal short-term weakness, no complications, and only a single revision, even in cases with cup malposition and/or edge loading, we believe that endoscopic IPR can be considered as one of the first-line operative options in patients with symptomatic IPI, irrespective of component position. LEVEL OF EVIDENCE: Level IV, case series.

Stemmed Tibial Fixation for Primary Total Knee Arthroplasty in Obese Patients-A National Registry Study.

BACKGROUND: We investigated if the use of augmented tibial fixation with stems in primary total knee arthroplasty (TKA) in obese patients was associated with a difference in reason for revision, type of revision, or overall revision rate. METHODS: Data from the Australian Orthopaedic Association National Joint Replacement Registry compared reason for revision, rate, and type of revision between primary TKA using stemmed tibial prostheses to nonstemmed prostheses, stratified by body mass index (BMI) and obesity. The cumulative percent revision was obtained using the Kaplan-Meier method, and Cox proportional hazards models estimated hazard ratios (HRs) adjusted for age and sex with 95% confidence intervals (CIs). All tests were 2-tailed at 5% statistical significance (P < .05). There were 66,508 procedures available for analyses. RESULTS: Obese class 2 (BMI 35 to 39.99) had higher rates of revision in the stemmed group compared to the nonstemmed group (HR 1.44, 95% CI 1.00, 2.05, P = .047). There was no significant difference in revision rates between stemmed and nonstemmed tibial prostheses in any other BMI group. Primary TKA in obese patients (BMI ≥30) with a stem extension had a significantly higher rate of minor revisions compared to no stem extension (HR 1.31, 95% CI 1.03, 1.66, P = .025). There was no significant difference between stemmed and nonstemmed groups for major revision in obese patients and for minor or major revision in nonobese patients. CONCLUSION: Using a tibial stem during primary TKA in obese patients is not associated with a lower rate of revision.

Associations of alcohol and cannabis use with change in posttraumatic stress disorder and depression symptoms over time in recently trauma-exposed individuals.

BACKGROUND: Several hypotheses may explain the association between substance use, posttraumatic stress disorder (PTSD), and depression. However, few studies have utilized a large multisite dataset to understand this complex relationship. Our study assessed the relationship between alcohol and cannabis use trajectories and PTSD and depression symptoms across 3 months in recently trauma-exposed civilians. METHODS: In total, 1618 (1037 female) participants provided self-report data on past 30-day alcohol and cannabis use and PTSD and depression symptoms during their emergency department (baseline) visit. We reassessed participant's substance use and clinical symptoms 2, 8, and 12 weeks posttrauma. Latent class mixture modeling determined alcohol and cannabis use trajectories in the sample. Changes in PTSD and depression symptoms were assessed across alcohol and cannabis use trajectories via a mixed-model repeated-measures analysis of variance. RESULTS: Three trajectory classes (low, high, increasing use) provided the best model fit for alcohol and cannabis use. The low alcohol use class exhibited lower PTSD symptoms at baseline than the high use class; the low cannabis use class exhibited lower PTSD and depression symptoms at baseline than the high and increasing use classes; these symptoms greatly increased at week 8 and declined at week 12. Participants who already use alcohol and cannabis exhibited greater PTSD and depression symptoms at baseline that increased at week 8 with a decrease in symptoms at week 12. CONCLUSIONS: Our findings suggest that alcohol and cannabis use trajectories are associated with the intensity of posttrauma psychopathology. These findings could potentially inform the timing of therapeutic strategies.