Catalytic Hydrogenolysis by Atomically Dispersed Iron Sites Embedded in Chemically and Redox Non-innocent N-Doped Carbon.

Atomically dispersed first-row transition metals embedded in nitrogen-doped carbon materials (M-N-C) show promising performance in catalytic hydrogenation but are less well-studied for reactions with more complex mechanisms, such as hydrogenolysis. Their ability to catalyze selective C-O bond cleavage of oxygenated hydrocarbons such as aryl alcohols and ethers is enhanced with the participation of ligands directly bound to the metal ion as well as longer-range contributions from the support. In this article, we describe how Fe-N-C catalysts with well-defined local structures for the Fe sites catalyze C-O bond hydrogenolysis. The reaction is facilitated by the N-C support. According to spectroscopic analyses, the as-synthesized catalysts contain mostly pentacoordinated FeIII sites, with four in-plane nitrogen donor ligands and one axial hydroxyl ligand. In the presence of 20 bar of H2 at 170-230 °C, the hydroxyl ligand is lost when N4FeIIIOH is reduced to N4FeII, assisted by the H2 chemisorbed on the support. When an alcohol binds to the tetracoordinated FeII sites, homolytic cleavage of the O-H bond is accompanied by reoxidation to FeIII and H atom transfer to the support. The role of the N-C support in catalytic hydrogenolysis is analogous to the behavior of chemically and redox-non-innocent ligands in molecular catalysts based on first-row transition metal ions and enhances the ability of M-N-Cs to achieve the types of multistep activations of strong bonds needed to upgrade renewable and recycled feedstocks.

Association between availability of direct access to army occupational therapy with return to duty in active-duty soldiers.

BACKGROUND: Upper extremity musculoskeletal injuries are common with active-duty Army Soldiers and result in increased limited duty days. Patient satisfaction and surgery rates improve with direct access to occupational therapy in the civilian community. PURPOSE: Examine the amount of time from initial evaluation following an upper extremity musculoskeletal injury (MSKI) to return to full duty plus occupational therapy (OT) utilization in Army Soldiers. STUDY DESIGN: Retrospective observational. METHODS: Electronic health records and profiles from 18,206 US active-duty Army soldiers with MSKI and OT evaluation between 2017-2018 were examined. Repeated measures generalized estimating equations provided the rate ratios (RRs) for OT healthcare utilization (total number of OT evaluations and treatment visits) by days to first OT evaluation and limited duty profile (total days on profile). RESULTS: Soldiers were on average 32.0 (SD = 8.9) y/o, predominantly senior enlisted (45.7%), white (58.0%), male (81.4%), 10.0 (SD = 8.4) years of service, and high school or less educated (51.3%). There were 22,617 UE MSKIs with an OT evaluation and 4936 UE MSKIs with profiles. Compared with UE MSKIs with an OT evaluation on the same day, there was a significant increase in rates of OT utilization for 1-7 days (RR: 1.4, 95% CI: 1.3, 1.5), 8-14 days (RR: 1.3, 95% CI: 1.2, 1.4), 15-30 days (RR: 1.4, 95% CI: 1.3, 1.5), 31-60 days (RR: 1.5, 95% CI: 1.4, 1.6), and +60 days later (RR: 1.6, 95% CI: 1.5, 1.7). Similar differences in rates for limited duty profiles were found. CONCLUSION: A greater number of days between diagnosis of UE MSKI and OT evaluation results in greater rates of OT utilization and longer temporary profile. Results suggest that earlier intervention by OT may decrease recovery and healthcare utilization of soldiers.

Changes in Distal Tibial Microarchitecture During Eight Weeks of U.S. Army Basic Combat Training Differ by Sex and Race.

Basic combat training (BCT) is a physically rigorous period at the beginning of a soldier's career that induces bone formation in the tibia. Race and sex are determinants of bone properties in young adults but their influences on changes in bone microarchitecture during BCT are unknown. The purpose of this work was to determine the influence of sex and race on changes in bone microarchitecture during BCT. Bone microarchitecture was assessed at the distal tibia via high-resolution peripheral quantitative computed tomography at the beginning and end of 8 weeks of BCT in a multiracial cohort of trainees (552 female, 1053 male; mean ± standard deviation [SD] age = 20.7 ± 3.7 years) of which 25.4% self-identified as black, 19.5% as race other than black or white (other races combined), and 55.1% as white. We used linear regression models to determine whether changes in bone microarchitecture due to BCT differed by race or sex, after adjusting for age, height, weight, physical activity, and tobacco use. We found that trabecular bone density (Tb.BMD), thickness (Tb.Th), and volume (Tb.BV/TV), as well as cortical BMD (Ct.BMD) and thickness (Ct.Th) increased following BCT in both sexes and across racial groups (+0.32% to +1.87%, all p < 0.01). Compared to males, females had greater increases in Tb.BMD (+1.87% versus +1.40%; p = 0.01) and Tb.Th (+0.87% versus +0.58%; p = 0.02), but smaller increases in Ct.BMD (+0.35% versus +0.61%; p < 0.01). Compared to black trainees, white trainees had greater increases in Tb.Th (+0.82% versus +0.61%; p = 0.03). Other races combined and white trainees had greater increases in Ct.BMD than black trainees (+0.56% and + 0.55% versus +0.32%; both p ≤ 0.01). Changes in distal tibial microarchitecture, consistent with adaptive bone formation, occur in trainees of all races and sexes, with modest differences by sex and race. Published 2023. This article is a U.S. Government work and is in the public domain in the USA. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Electrospun drug-eluting sutures for local anesthesia.

We have developed a local anesthetic-eluting suture system which would combine the function and ubiquity of the suture for surgical repair with the controlled release properties of a biodegradable polymeric matrix. Drug-free and drug-loaded poly(lactic-co-glycolic acid) (PLGA) sutures were fabricated by electrospinning, with or without the local anesthetic bupivacaine. The tensile strength of the electrospun sutures decreased as drug content increased, but strains remained relatively similar across all groups. Sutures released their entire drug payload over the course of 12 days and maintained approximately 12% of their initial tensile strength after 14 days of incubation in vitro. In a rat skin wound model, local analgesia was achieved 1 day after surgery and lasted approximately 1 week in 90% of treated animals (n=10, p<0.05), and all wounds were able to heal normally without the need for further reinforcement. The sutures caused tissue reaction in vivo that was comparable to that seen with a commercially available suture composed of PLGA. Such sutures may enhance perioperative analgesia and mitigate the need for standard postoperative opioid analgesics.