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Hydrologic, terrestrial, and biologic disturbances influence stream channel conditions that are important to the persistence of aquatic biota. Past studies of how disturbance events alter streams have focused on fires, floods, and debris torrents as the magnitude of these events make them easy to detect. This approach has led to a bias in understanding which disturbances are likely to affect stream conditions. To address this concern, we used stream habitat data to identify where a substantial change in stream conditions had occurred and then used photographs of the evaluated reach to determine the disturbance that potentially caused those changes. We evaluated conditions in over 2,000 stream reaches and found that nearly a quarter of them had seen a substantial change in at least one of the five stream channel characteristics (bank‐full width, wood frequency, median particle size, pool depth, and bank stability) in the two decades that these streams were monitored. Although many stream reaches were affected by charismatic disturbance events such as fires, floods, and mass wasting, the majority of the substantial changes we observed in channel conditions were related to small‐scale disturbances. Mechanisms such as beavers, tree fall, vegetative growth, grazing, and active restoration all played an important role in bringing about large changes in stream channel conditions. While the majority of the disturbances were natural, some channel changes remain tied to anthropogenic activities. Our results suggest that no single sampling approach can be used to evaluate how stream conditions respond to all disturbances as they vary in intensity, over space and time, and based on which stream attribute is measured. By better understanding the full range of possible disturbances, managers should be better able to use such events to improve outcomes for streams and aquatic biota. [ABSTRACT FROM AUTHOR]

Surgical site infections (SSIs) are a persistent clinical challenge. Local antimicrobial delivery may reduce the risk of SSI by increasing drug concentrations and distribution in vulnerable surgical sites compared to what is achieved using systemic antimicrobial prophylaxis alone. In this work, we describe a comprehensive in vivo evaluation of the safety and efficacy of poly(N‐isopropylacrylamide‐co‐dimethylbutyrolactone acrylamide‐co‐Jeffamine M‐1000 acrylamide) [PNDJ], an injectable temperature‐responsive hydrogel carrier for antimicrobial delivery in surgical sites. Biodistribution data indicate that PNDJ is primarily cleared via the liver and kidneys following drug delivery. Antimicrobial‐loaded PNDJ was generally well‐tolerated locally and systemically when applied in bone, muscle, articulating joints, and intraperitoneal space, although mild renal toxicity consistent with the released antimicrobials was identified at high doses in rats. Dosing of PNDJ at bone‐implant interfaces did not affect normal tissue healing and function of orthopedic implants in a transcortical plug model in rabbits and in canine total hip arthroplasty. Finally, PNDJ was effective at preventing recurrence of implant‐associated MSSA and MRSA osteomyelitis in rabbits, showing a trend toward outperforming commercially available antimicrobial‐loaded bone cement and systemic antimicrobial administration. These studies indicate that antimicrobial‐loaded PNDJ hydrogels are well‐tolerated and could reduce incidence of SSI in a variety of surgical procedures. [ABSTRACT FROM AUTHOR]

A biodegradable, shape memory polymer (SMP) scaffold based on poly(ε-caprolactone) (PCL) represents an attractive alternative therapy for the repair of critically sized bone defects given its ability to press-fit within irregular defects. Clinical translation of SMP scaffolds requires successful movement beyond proof-of-concept rodent studies through a relevant large-animal model and into the clinical setting. In addition to representing a clinical veterinary population, the canine species is a strong translational model for humans due to similarities in orthopedic disorders, biomechanics, and bone healing. The present study was performed to assess in vitro cytocompatibility and osteogenic differentiation of canine multipotent stromal cells (cMSCs) cultured on SMP scaffolds in preparation for future canine in vivo studies. Two different SMP scaffold compositions were utilized: a "PCL-only" scaffold prepared from PCL-diacrylate (PCL-DA) and a semi-interpenetrating network (semi-IPN) formed from PCL-DA and poly(L-lactic acid) (PCL:PLLA). The PCL:PLLA scaffolds degrade faster and are more mechanically rigid versus the PCL scaffolds. Canine bone marrow-derived MSCs (cMSCs) were evaluated in terms of attachment, proliferation, and osteogenic differentiation. cMSCs exhibited excellent cytocompatibility, attachment, and proliferation on both SMP scaffold compositions. PCL scaffolds were more conducive to both early- and late-stage in vitro osteogenesis of cMSCs versus PCL:PLLA scaffolds. However, cMSCs deposited mineralized extracellular matrix over 21 days when cultured on both SMP scaffold compositions. These results demonstrate that the SMP scaffolds are suitable for in vitro cMSC attachment, proliferation, and osteogenic differentiation, representing a significant step toward canine in vivo studies and potential translation to human patients., (© 2024 Wiley Periodicals LLC.)

Biodegradable, shape memory polymer (SMP) scaffolds based on poly(ε-caprolactone) (PCL) offer unique advantages as a regenerative treatment strategy for critical-sized bone defects. In particular, a conformal fit may be achieved following exposure to warm saline, thereby improving osseointegration and regeneration. Advancing the clinical translation of these SMP scaffolds requires establishment of efficacy not only in non-loading models, but also load-bearing or load-sharing models. Thus, the present study evaluated the biocompatibility and bone regeneration potential of SMP scaffolds in a rabbit distal femoral condyle model. Two distinct SMP scaffold compositions were evaluated, a "PCL-only" scaffold formed from PCL-diacrylate (PCL-DA) and a semi-interpenetrating network (semi-IPN) formed from PCL-DA and poly(L-lactic acid) (PCL:PLLA). Semi-IPN PCL:PLLA scaffolds possess greater rigidity and faster rates of degradation versus PCL scaffolds. In vivo biocompatibility was assessed with a rat subcutaneous implantation model, whereas osseointegration was assessed with a 4 mm × 8 mm rabbit distal femoral condyle defect model. Both types of SMP scaffolds exhibited excellent biocompatibility marked by infiltration with fibrous tissue and a minimal inflammatory response. When implanted in the rabbit distal femur, both SMP scaffolds supported bone ingrowth. Collectively, these results demonstrate that the SMP scaffolds are biocompatible and integrate with adjacent host osseous tissues when implanted in vivo in a load-sharing environment. This study provides key proof-of-concept data necessary to proceed with large animal translational studies and clinical trials in human subjects., (© 2024 Wiley Periodicals LLC.)

Introduction: Point-of-care ultrasound (POCUS) is increasingly being employed in family medicine. Residency tracks can be an effective way to increase mastery in a specific subdiscipline for interested residents, but no studies exist on the implementation of a POCUS track in family medicine. We address this gap in the literature by assessing POCUS use by POCUS track residents compared to non-POCUS track residents and faculty in an academic family medicine department., Methods: We performed a retrospective review of all POCUS scans completed in the first year after implementation of a family medicine residency POCUS track. Scans were analyzed by two reviewers. We compared scan volume and type between POCUS track residents, non-POCUS track residents, and faculty. A blinded quality analysis was performed on each group of scans., Results: A total of 572 scans were completed on 536 patients over 1 year. POCUS track residents scanned significantly more than non-POCUS track residents (mean difference of 72.2, CI 59.1 to 85.4; P <.0001). The most common scan types across groups were musculoskeletal and soft tissue. POCUS track residents showed statistically improved scan quality in all scan types, while non-POCUS track residents showed statistical improvement only in soft tissue, shoulder, and abdominal aortic aneurysm scans., Conclusions: This is the first longitudinal study of a novel academic family medicine residency POCUS track. Participation in a POCUS track can increase the number, variety, and quality of scans performed. Our curriculum can be a model for family medicine residency programs that wish to provide robust POCUS training., (© 2024 by the Society of Teachers of Family Medicine.)

Dreaming and insomnia are important markers of distress in times of crisis. Here, we present a longitudinal, mixed-methods study examining changes in dreaming between individuals with and without insomnia symptoms and their relationship to mental health during the COVID-19 pandemic. A global survey examining insomnia symptoms, dreams and mental health was launched in April 2020 and followed participants over 12 months. Of 2240 participants, 1009 (45%) reported dream changes at baseline. A higher proportion of participants with new-onset insomnia reported dream changes (55%) than those with pre-existing insomnia (45%) or good sleepers (36%). Overall, thematic analysis identified key dream change themes of increased dream activity, with participants dreaming vividly, in high-definition, and with a strong negative charge. Themes around survival, adjusting to pandemic life, meaning-making and poor sleep quality were also noted. Linguistic Inquiry Word Count showed that individuals with insomnia used more negative words to describe their dream changes than good sleepers. Specifically, the new-onset insomnia group used more anxious and death-related words than those who slept well. Notably, all groups experienced a significant reduction in dream activity by 3-month follow-up. Lastly, dream changes were associated with worse mental health symptoms over time, and this effect was more pronounced in individuals with insomnia. Our results highlight that insomnia symptoms, especially new-onset insomnia, are associated with more negative dream changes during collective stressful events, potentially compounding daytime distress and mental health symptoms over time. During times of crisis, dreaming and insomnia may reveal an important target for mental health interventions., (© 2022 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.)