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Abstract A reduction in the thickness and volume of the brain entorhinal cortex (EC), together with changes in blood arachidonic acid (AA) and docosahexaenoic acid (DHA), are associated with Alzheimer’s disease (AD) among apolipoprotein E ε4 carriers. Magnetic Resonance Imaging (n = 631) and plasma lipidomics (n = 181) were performed using the LIMBIC/CENC cohort to examine the influence of ε4 on AA- and DHA-lipids and EC thickness and volume in relation to mild traumatic brain injury (mTBI). Results showed that left EC thickness was higher among ε4 carriers with mTBI. Repeated mTBI (r-mTBI) was associated with reduced right EC thickness after controlling for ε4, age and sex. Age, plus mTBI chronicity were linked to increased EC White Matter Volume (WMV). After controlling for age and sex, the advancing age of ε4 carriers with blast mTBI was associated with reduced right EC Grey Matter Volume (GMV) and thickness. Among ε4 carriers, plasma tau and Aβ40 were associated with mTBI and blast mTBI, respectively. Chronic mTBI, ε4 and AA to DHA ratios in phosphatidylcholine, ethanolamides, and phosphatidylethanolamine were associated with decreased left EC GMV and WMV. Further research is needed to explore these as biomarkers for detecting AD pathology following mTBI.

The extracellular matrix (ECM) is the naturally secreted biomaterial scaffold that provides support and regulates key aspects of cell behavior. This dynamic and complex network of structural proteins, proteoglycans, and soluble cues defines the cell microenvironment and is essential for tissue homeostasis. Because tissue engineering approaches aim to recapitulate aspects of the microenvironment to instruct tissue regeneration, ECM‐inspired or ‐derived scaffolds are some of the earliest tissue‐engineered constructs reported. However, conventional single‐protein constructs fail to provide the biochemical and structural complexity of the native ECM. Decellularized ECM is under investigation to improve cell adhesion, cell remodeling, migration, proliferation, and differentiation within tissue‐engineered constructs. However, challenges associated with poor mechanical properties and inherent chemical instability compared to synthetic or other natural polymers require additional considerations. This review describes the bioactive properties of ECM, current strategies to efficiently decellularize cell‐secreted and tissue‐derived ECM, standard fabrication techniques for ECM constructs, and current developments in the field of ECM‐based musculoskeletal platforms.

This paper describes and analyzes the Reed–Jablonowski (RJ) tropical cyclone (TC) test case used in the 2016 Dynamical Core Model Intercomparison Project (DCMIP2016). This intermediate-complexity test case analyzes the evolution of a weak vortex into a TC in an idealized tropical environment. Reference solutions from nine general circulation models (GCMs) with identical simplified physics parameterization packages that participated in DCMIP2016 are analyzed in this study at 50 km horizontal grid spacing, with five of these models also providing solutions at 25 km grid spacing. Evolution of minimum surface pressure (MSP) and maximum 1 km azimuthally averaged wind speed (MWS), the wind–pressure relationship, radial profiles of wind speed and surface pressure, and wind composites are presented for all participating GCMs at both horizontal grid spacings. While all TCs undergo a similar evolution process, some reach significantly higher intensities than others, ultimately impacting their horizontal and vertical structures. TCs simulated at 25 km grid spacings retain these differences but reach higher intensities and are more compact than their 50 km counterparts. These results indicate that dynamical core choice is an essential factor in GCM development, and future work should be conducted to explore how specific differences within the dynamical core affect TC behavior in GCMs.

Abstract Cultivated meat production requires bioprocess optimization to achieve cell densities that are multiple orders of magnitude higher compared to conventional cell culture techniques. These processes must maximize resource efficiency and cost-effectiveness by attaining high cell growth productivity per unit of medium. Microcarriers, or carriers, are compatible with large-scale bioreactor use, and offer a large surface-area-to-volume ratio for the adhesion and proliferation of anchorage-dependent animal cells. An ongoing challenge persists in the efficient retrieval of cells from the carriers, with conflicting reports on the effectiveness of trypsinization and the need for additional optimization measures such as carrier sieving. To surmount this issue, edible carriers have been proposed, offering the advantage of integration into the final food product while providing opportunities for texture, flavor, and nutritional incorporation. Recently, a proof of concept (POC) utilizing inactivated mycelium biomass derived from edible filamentous fungus demonstrated its potential as a support structure for myoblasts. However, this POC relied on a model mammalian cell line combination with a single mycelium species, limiting realistic applicability to cultivated meat production. This study aims to advance the POC. We found that the species of fungi composing the carriers impacts C2C12 myoblast cell attachment—with carriers derived from Aspergillus oryzae promoting the best proliferation. C2C12 myoblasts effectively differentiated on mycelium carriers when induced in myogenic differentiation media. Mycelium carriers also supported proliferation and differentiation of bovine satellite cells. These findings demonstrate the potential of edible mycelium carrier technology to be readily adapted in product development within the cultivated meat industry.

We present an atmospheric characterization and orbital analysis of HD 206893 B, an exceptionally red, L/T-transition substellar companion in a multiplanetary system, via Keck Planet Imager and Characterizer (KPIC) high-resolution ( R ∼ 35,000) K- band spectroscopy. Using PHOENIX atmospheric models in a forward-model framework that fits the spectrum of the companion and diffracted starlight simultaneously, we detect HD 206893 B at >8 σ significance via cross correlation in two epochs. We find an effective temperature for the companion of 1634 ${}_{-38}^{+72}$ K and a $\mathrm{log}\,g$ of 4.55 ${}_{-0.22}^{+0.17}$ . Only accounting for statistical uncertainties, we measure the carbon-oxygen ratio (C/O) of this companion to be 0.57 ± 0.02, or near-solar while assuming solar metallicity. The C/O ratio we measure fits the tentative trend of >4 M _Jup companions having near-solar C/O ratios while less massive companions have greater-than-solar C/O ratios. Using substellar evolution models, we find an age of 112 ${}_{-22}^{+36}$ Myr, a mass of 22.7 ${}_{-1.7}^{+2.5}$ M _Jup , and a radius of 1.11 ± 0.03 R _Jup for this companion. We also use KPIC radial velocity data to fit the orbit of HD 206893 B and analyze the orbital stability of this system. We find that the orbital stability is relatively independent of the mass of HD 206893 B, and favors an orbital configuration where B and its interior planetary companion, HD 206893 c, are coplanar. The measured C/O ratio coupled with the current architecture of the system cannot rule out the core accretion scenario, nor the disk fragmentation scenario regarding the formation pathway of HD 206893 B.

We present Keck/KPIC Phase II K -band observations of the nontransiting hot Jupiter HD 143105 b. Using a cross-correlation approach, we make the first detection of the planetary atmosphere at ${K}_{{\rm{p}}}=18{5}_{-13}^{+11}$ km s ^−1 and an inferior conjunction time 2.5 hr before the previously published ephemeris. The retrieved K _p value, in combination with the orbital period, mass of the host star, and lack of transit detection, give an orbital inclination of $7{8}_{-12}^{\circ +2}$ and a true planet mass of 1.23 ± 0.10 M _J . While the equilibrium temperature of HD 143105 b is in the transition regime between noninverted and inverted atmospheres, our analysis strongly prefers a noninverted atmosphere. Retrieval analysis indicates the atmosphere of HD 143105 b is cloud free to approximately 1 bar and dominated by H _2 O absorption ( ${\mathrm{logH}}_{2}{{\rm{O}}}_{\mathrm{MMR}}=-3.{9}_{-0.5}^{+0.8}$ ), placing only an upper limit on the CO abundance ( ${\mathrm{logCO}}_{\mathrm{MMR}}\lt -3.7$ at 95% confidence). We place no constraints on the abundances of Fe, Mg, or ^13 CO. From these abundances, we place an upper limit on the carbon-to-oxygen ratio for HD 143105 b, C/O

Abstract Background Osteosarcoma (OS) survival rates and outcome have not improved in 50 years since the advent of modern chemotherapeutics. Thus, there is a critical need for an improved understanding of the tumor microenvironment to identify better therapies. Extracellular matrix (ECM) deposition and hypoxia are known to abrogate the efficacy of various chemical and cell‐based therapeutics. Here, we aim to mechanistically investigate the combinatorial effects of hypoxia and matrix deposition with the use of OS spheroids. Methods We use two murine OS cell lines with differential metastatic potential to form spheroids. We form spheroids of two sizes, use ascorbate‐2‐phosphate supplementation to enhance ECM deposition, and study cell response under standard (21% O2) and physiologic (5% O2) oxygen tensions. Finally, we examine chemotherapeutic responses to doxorubicin treatment. Results ECM production and oxygen tension are key determinants of spheroid size through cell organization based on nutrient and oxygen distribution. Interestingly, highly metastatic OS is more susceptible to chemotherapeutics compared to less metastatic OS when matrix production increases. Together, these data suggest that dynamic interactions between ECM production and oxygen diffusion may result in distinct chemotherapeutic responses despite inherent tumor aggressiveness. Conclusion This work establishes OS spheroids as a valuable tool for early OS tumor formation investigation and holds potential for novel therapeutic target and prognostic indicator discovery.

The Proton Power Upgrade initiative at Oak Ridge National Lab’s Spallation Neutron Source aims to greatly boost the capability of proton beam power. This upgrade involves the integration of seven additional cryomodules, each housing four six-cell high-beta (β=0.81) superconducting radio frequency cavities. These cavities, manufactured and processed by Research Instruments in Germany, underwent meticulous treatment, including electropolishing as the bulk and final vital step. Upon delivery to Jefferson Lab, a total of 28 cavities for seven cryomodules, along with an additional four cavities for a spare cryomodule, underwent thorough vertical qualification tests, meeting the required specifications. Following cavity tanking and subsequent rf testing, the assembly of eight cryomodules was successfully executed, with all 32 cavities demonstrating compliance with acceptance criteria. The transportation of the cryomodule to SNS for high-power testing in the tunnel yielded exceptional results. Notably, the performance surpassed specifications, in terms of quality factor and accelerating gradient.

We demonstrate that LFRic-Atmosphere, a model built using the Met Office's GungHo dynamical core, is able to reproduce idealised large-scale atmospheric circulation patterns specified by several widely used benchmark recipes. This is motivated by the rapid rate of exoplanet discovery and the ever-growing need for numerical modelling and characterisation of their atmospheres. Here we present LFRic-Atmosphere's results for the idealised tests imitating circulation regimes commonly used in the exoplanet modelling community. The benchmarks include three analytic forcing cases: the standard Held–Suarez test, the Menou–Rauscher Earth-like test, and the Merlis–Schneider tidally locked Earth test. Qualitatively, LFRic-Atmosphere agrees well with other numerical models and shows excellent conservation properties in terms of total mass, angular momentum, and kinetic energy. We then use LFRic-Atmosphere with a more realistic representation of physical processes (radiation, subgrid-scale mixing, convection, clouds) by configuring it for the four TRAPPIST-1 Habitable Atmosphere Intercomparison (THAI) scenarios. This is the first application of LFRic-Atmosphere to a possible climate of a confirmed terrestrial exoplanet. LFRic-Atmosphere reproduces the THAI scenarios within the spread of the existing models across a range of key climatic variables. Our work shows that LFRic-Atmosphere performs well in the seven benchmark tests for terrestrial atmospheres, justifying its use in future exoplanet climate studies.

The ability of regional air quality models to skilfully represent pollutant distributions throughout the atmospheric column is important to enabling their skilful prediction at the surface. This provides a requirement for model evaluation at elevated altitudes, though observation datasets available for this purpose are limited. This is particularly true of those offering sampling over extended time periods. To address this requirement and support evaluation of regional air quality models such as the UK Met Offices Air Quality in the Unified Model (AQUM), a long-term, quality-assured dataset of the three-dimensional distribution of key pollutants was collected over the southern United Kingdom from July 2019 to April 2022. Measurements were collected using the Met Office Atmospheric Survey Aircraft (MOASA), a Cessna 421 instrumented for this project to measure gaseous nitrogen dioxide, ozone, sulfur dioxide and fine-mode (PM2.5) aerosol. This paper introduces the MOASA measurement platform, flight strategies and instrumentation and is not intended to be an in-depth diagnostic analysis but rather a comprehensive technical reference for future users of these data. The MOASA air quality dataset includes 63 flight sorties (totalling over 150 h of sampling), the data from which are openly available for use. To illustrate potential uses of these upper-air observations for regional-scale model evaluation, example case studies are presented, which include analyses of the spatial scales of measured pollutant variability, a comparison of airborne to ground-based observations over Greater London and initial work to evaluate performance of the AQUM regional air quality model. These case studies show that, for observations of relative humidity, nitrogen dioxide and particle counts, natural pollutant variability is well observed by the aircraft, whereas SO2 variability is limited by instrument precision. Good agreement is seen between observations aloft and those on the ground, particularly for PM2.5. Analysis of odd oxygen suggests titration of ozone is a dominant chemical process throughout the column for the data analysed, although a slight enhancement of ozone aloft is seen. Finally, a preliminary evaluation of AQUM performance for two case studies suggests a large positive model bias for ozone aloft, coincident with a negative model bias for NO2 aloft. In one case, there is evidence that an underprediction in the modelled boundary layer height contributes to the observed biases at elevated altitudes.

Mesenchymal stromal cells (MSCs) are widely used in cell-based therapies and tissue regeneration for their potent secretome, which promotes host cell recruitment and modulates inflammation. Compared to monodisperse cells, MSC spheroids exhibit improved viability and increased secretion of immunomodulatory cytokines. While mechanical stimulation of monodisperse cells can increase cytokine production, the influence of mechanical loading on MSC spheroids is unknown. Here, we evaluated the effect of controlled, uniaxial cyclic compression on the secretion of immunomodulatory cytokines by human MSC spheroids and tested the influence of load-induced gene expression on MSC mechanoresponsiveness. We exposed MSC spheroids, entrapped in alginate hydrogels, to three cyclic compressive regimes with varying stress (L) magnitudes (i.e., 5 and 10 kPa) and hold (H) durations (i.e., 30 and 250 s) L5H30, L10H30, and L10H250. We observed changes in cytokine and chemokine expression dependent on the loading regime, where higher stress regimes tended to result in more exaggerated changes. However, only MSC spheroids exposed to L10H30 induced human THP-1 macrophage polarization toward an M2 phenotype compared to static conditions. Static and L10H30 loading facilitated a strong, interlinked F-actin arrangement, while L5H30 and L10H250 disrupted the structure of actin filaments. This was further examined when the actin cytoskeleton was disrupted via Y-27632. We observed downregulation of YAP-related genes, and the levels of secreted inflammatory cytokines were globally decreased. These findings emphasize the essential role of mechanosignaling in mediating the immunomodulatory potential of MSC spheroids.

The ~5 Myr PDS 70 is the only known system with protoplanets residing in the cavity of the circumstellar disk from which they formed, ideal for studying exoplanet formation and evolution within its natal environment. Here, we report the first spin constraint and C/O measurement of PDS 70b from Keck/KPIC high-resolution spectroscopy. We detected CO (3.8 σ ) and H _2 O (3.5 σ ) molecules in the PDS 70b atmosphere via cross correlation, with a combined CO and H _2 O template detection significance of 4.2 σ . Our forward-model fits, using BT-Settl model grids, provide an upper limit for the spin rate of PDS 70b (

Vortex fiber nulling (VFN) is a technique for detecting and characterizing faint companions at small separations from their host star. A near-infrared (∼2.3 μ m) VFN demonstrator mode was deployed on the Keck Planet Imager and Characterizer (KPIC) instrument at the Keck Observatory and presented earlier. In this Letter, we present the first VFN companion detections. Three targets, HIP 21543 Ab, HIP 94666 Ab, and HIP 50319 B, were detected with host–companion flux ratios between 70 and 430 at and within one diffraction beamwidth ( λ / D ). We complement the spectra from KPIC VFN with flux ratio and position measurements from the CHARA Array to validate the VFN results and provide a more complete characterization of the targets. This Letter reports the first direct detection of these three M dwarf companions, yielding their first spectra and flux ratios. Our observations provide measurements of bulk properties such as effective temperatures, radial velocities, and $v\sin i$ , and verify the accuracy of the published orbits. These detections corroborate earlier predictions of the KPIC VFN performance, demonstrating that the instrument mode is ready for science observations.

Traumatic brain injury (TBI) is one of the most prevalent causes of morbidity in the United States and is associated with numerous chronic sequelae long after the point of injury. One of the most common long-term complaints in patients with TBI is sleep dysfunction. It is reported that alterations in melatonin follow TBI and may be linked with various sleep and circadian disorders directly (via cellular signaling) or indirectly (via free radicals and inflammatory signaling). Work over the past two decades has contributed to our understanding of the role of melatonin as a sleep regulator and neuroprotective anti-inflammatory agent. Although there is increasing interest in the treatment of insomnia following TBI, a lack of standardization and rigor in melatonin research has left behind a trail of non-generalizable data and ambiguous treatment recommendations. This narrative review describes the underlying biochemical properties of melatonin as they are relevant to TBI. We also discuss potential benefits and a path forward regarding the therapeutic management of TBI with melatonin treatment, including its role as a neuroprotectant, a somnogen, and a modulator of the circadian rhythm.

This paper introduces a mixed finite-element shallow-water model on the sphere. The mixed finite-element approach is used as it has been shown to be both accurate and highly scalable for parallel architecture. Key features of the model are an iterated semi-implicit time-stepping scheme, a finite-volume transport scheme, and the cubed sphere grid. The model is tested on a number of standard spherical shallow-water test cases. Results show that the model produces similar results to other shallow-water models in the literature.

Significant progress has been made in designing bone materials capable of directing endogenous cells to promote vascularized bone regeneration. However, current strategies lack regulation of the specific endogenous cell populations for vascularized bone regeneration, thus leading to adverse tissue formation and decreased regenerative efficiency. Here, we engineered a biomaterial to regulate endogenous cell adhesion and promote vascularized bone regeneration. The biomaterial works by presenting two synthetic ligands, LLP2A and LXW7, explicitly targeting integrins α4β1 and αvβ3, respectively, expressed on the surfaces of the cells related to bone formation and vascularization, such as mesenchymal stem cells (MSCs), osteoblasts, endothelial progenitor cells (EPCs), and endothelial cells (ECs). In vitro, the LLP2A/LXW7 modified biomaterial improved the adhesion of MSCs, osteoblasts, EPCs, and ECs via integrin α4β1 and αvβ3, respectively. In an adult rat calvarial bone defect model, the LLP2A/LXW7 modified biomaterial enhanced bone formation and vascularization by synergistically regulating endogenous cells with osteogenic and angiogenic potentials, such as DLX5+ cells, osteocalcin+ cells, CD34+/CD45- cells and CD31+ cells. In a fetal sheep spinal bone defect model, the LLP2A/LXW7 modified biomaterial augmented bone formation and vascularization without any adverse effects. This innovative biomaterial offers an off-the-shelf, easy-to-use, and biologically safe product suitable for vascularized bone regeneration in both fetal and adult disease environments.

IntroductionThe relation between traumatic brain injury (TBI), its acute and chronic symptoms, and the potential for remote neurodegenerative disease is a priority for military research. Structural and functional connectivity (FC) of the basal ganglia, involved in motor tasks such as walking, are altered in some samples of Service Members and Veterans with TBI, but any behavioral implications are unclear and could further depend on the context in which the TBI occurred.MethodsIn this study, FC from caudate and pallidum seeds was measured in Service Members and Veterans with a history of mild TBI that occurred during combat deployment, Service Members and Veterans whose mild TBI occurred outside of deployment, and Service Members and Veterans who had no lifetime history of TBI.ResultsFC patterns differed for the two contextual types of mild TBI. Service Members and Veterans with deployment-related mild TBI demonstrated increased FC between the right caudate and lateral occipital regions relative to both the non-deployment mild TBI and TBI-negative groups. When evaluating the association between FC from the caudate and gait, the non-deployment mild TBI group showed a significant positive relationship between walking time and FC with the frontal pole, implicated in navigational planning, whereas the deployment-related mild TBI group trended towards a greater negative association between walking time and FC within the occipital lobes, associated with visuo-spatial processing during navigation.DiscussionThese findings have implications for elucidating subtle motor disruption in Service Members and Veterans with deployment-related mild TBI. Possible implications for future walking performance are discussed.

Background: The traditional lateral extensile approach to the calcaneus allows for excellent visualization but is associated with high wound complication rates. The sinus tarsi approach has been shown to produce similar radiographic outcomes with much lower rates of wound complications. The purpose of this study is to prospectively determine clinical and radiographic outcomes in calcaneus fractures treated with a sinus tarsi approach. Methods: Twenty-nine patients with 30 calcaneus fractures underwent operative fixation through a sinus tarsi approach and were prospectively evaluated. Routine pre- and postoperative radiographs were obtained, in addition to computed tomography (CT) scans at 6 weeks and 12 months after surgery. Patient-reported outcomes including American Orthopaedic Foot & Ankle Society (AOFAS) score, visual analog scale (VAS) pain score, Veterans Rand 12-Item Health Survey (VR-12), and Foot Functional Index (FFI) were recorded. Patients were followed for a minimum of 1 year postoperation. Results: Twenty-one patients with 22 calcaneus fractures completed 1 year of follow-up. At 12 months postoperation, 20 of 22 patients (91%) had 0 to 2 mm of fracture displacement at the posterior facet on CT scans whereas 2 of 22 patients had 2 to 4 mm of fracture displacement. There was no significant change in posterior facet fracture displacement comparing 6-week and 12-month postoperative CT scans ( P > .99). Mean postoperative Bohler angle was 26.1 degrees compared to 13.2 degrees preoperatively. All patients had complete union of fracture site. There were no major wound complications. Four of 22 patients (18.2%) had minor wound complications. AOFAS, FFI, and VAS pain scores improved postoperatively but were not found to correlate with Bohler angle or critical angle of Gissane. Conclusion: We found that in select patients excellent anatomic alignment and good clinical outcomes with low wound complication rates can be achieved when fixing calcaneus fractures through the sinus tarsi approach. Level of Evidence: Level II, prospective cohort study.

Chronic nonhealing wounds are debilitating and diminish one's quality of life, necessitating the development of improved strategies for effective treatment. Biomaterial- and cell-based therapies offer an alternative treatment compared to conventional wound care for regenerating damaged tissues. Cell-based approaches frequently utilize endothelial cells (ECs) to promote vascularization and mesenchymal stromal cells (MSCs) for their potent secretome that promotes host cell recruitment. Spheroids have improved therapeutic potential over monodisperse cells, while degradable scaffolds can influence cellular processes conducive to long-term tissue regeneration. However, the role of biomaterial degradation on the therapeutic potential of heterotypic EC-MSC spheroids for wound healing is largely unknown. We formed poly(ethylene) glycol (PEG) hydrogels with varying ratios of matrix metalloproteinase (MMP)-degradable and non-degradable crosslinkers to develop three distinct constructs – fully degradable, partially degradable, and non-degradable – and interrogate the influence of degradation rate on engineered cell carriers for wound healing. We found that the vulnerability to degradation was critical for cellular proliferation, while inhibition of degradation impaired spheroid metabolic activity. Higher concentrations of degradable crosslinker promoted robust cell spreading, outgrowth, and secretion of proangiogenic cytokines (i.e., VEGF, HGF) that are critical in wound healing. The degree of degradation dictated the unique secretory profile of spheroids. When applied to a clinically relevant full-thickness ex vivo skin model, degradable spheroid-loaded hydrogels restored stratification of the epidermal layer, confirming the efficacy of scaffolds to promote wound healing. These results highlight the importance of matrix remodeling and its essential role in the therapeutic potential of heterotypic spheroids.

Abstract Background Subconcussive blast exposure during military training has been the subject of both anecdotal concerns and reports in the medical literature, but prior studies have often been small and have used inconsistent methods. Methods This paper presents the methodology employed in INVestigating traIning assoCiated blasT pAthology (INVICTA) to assess a wide range of aspects of brain function, including immediate and delayed recall, gait and balance, audiologic and oculomotor function, cerebral blood flow, brain electrical activity and neuroimaging and blood biomarkers. Results A number of the methods employed in INVICTA are relatively easy to reproducibly utilize, and can be completed efficiently, while other measures require greater technical expertise, take longer to complete, or may have logistical challenges. Conclusions This presentation of methods used to assess the impact of blast exposure on the brain is intended to facilitate greater uniformity of data collection in this setting, which would enable comparison between different types of blast exposure and environmental circumstances, as well as to facilitate meta-analyses and syntheses across studies.

Abstract Cell therapies offer a tailorable, personalized treatment for use in tissue engineering to address defects arising from trauma, inefficient wound repair, or congenital malformation. However, most cell therapies have achieved limited success to date. Typically injected in solution as monodispersed cells, transplanted cells exhibit rapid cell death or insufficient retention at the site, thereby limiting their intended effects to only a few days. Spheroids, which are dense, three-dimensional (3D) aggregates of cells, enhance the beneficial effects of cell therapies by increasing and prolonging cell–cell and cell–matrix signaling. The use of spheroids is currently under investigation for many cell types. Among cells under evaluation, spheroids formed of mesenchymal stromal cells (MSCs) are particularly promising. MSC spheroids not only exhibit increased cell survival and retained differentiation, but they also secrete a potent secretome that promotes angiogenesis, reduces inflammation, and attracts endogenous host cells to promote tissue regeneration and repair. However, the clinical translation of spheroids has lagged behind promising preclinical outcomes due to hurdles in their formation, instruction, and use that have yet to be overcome. This review will describe the current state of preclinical spheroid research and highlight two key examples of spheroid use in clinically relevant disease modeling. It will highlight techniques used to instruct the phenotype and function of spheroids, describe current limitations to their use, and offer suggestions for the effective translation of cell spheroids for therapeutic treatments.

Spheroids are three-dimensional cell aggregates that mimic fundamental aspects of the native tissue microenvironment better than single cells, making them a promising platform for the study of tissue development and therapeutics. Spheroids have been investigated for decades as models in cancer research, yet we have only just scratched the surface of their potential clinical utility in cell-based therapies. Like many cells, spheroids commonly exhibit a loss of key attributes upon implantation, motivating the need for strategies to regulate their function in situ. Biomaterials offer numerous opportunities to preserve spheroid function and guide spheroid behavior by tailoring the local microenvironment.

Abstract Regulatory guidelines for tissue engineered products require stringent characterization during production and necessitate the development of novel, non-destructive methods to quantify key functional parameters for clinical translation. Traditional assessments of engineered tissues are destructive, expensive, and time consuming. Here, we introduce a non-destructive, inexpensive, and rapid sampling and analysis system that can continuously monitor the mechanical, biochemical, and structural properties of a single sample over extended periods of time. The label-free system combines the imaging modalities of fluorescent lifetime imaging and ultrasound backscatter microscopy through a fiber-based interface for sterile monitoring of tissue quality. We tested the multimodal system using tissue engineered articular cartilage as an experimental model. We identified strong correlations between optical and destructive testing. Combining FLIm and UBM results, we created a novel statistical model of tissue homogeneity that can be applied to tissue engineered constructs prior to implantation. Continuous monitoring of engineered tissues with this non-destructive system has the potential for in-process monitoring of tissue engineered products, reducing costs and improving quality controls in research, manufacturing, and clinical applications.

We present high-resolution K -band emission spectra of the quintessential hot Jupiter HD 189733 b from the Keck Planet Imager and Characterizer. Using a Bayesian retrieval framework, we fit the dayside pressure–temperature profile, orbital kinematics, mass-mixing ratios of H _2 O, CO, CH _4 , NH _3 , HCN, and H _2 S, and the ^13 CO/ ^12 CO ratio. We measure mass fractions of ${\mathrm{logH}}_{2}{\rm{O}}=-{2.0}_{-0.4}^{+0.4}$ and $\mathrm{logCO}=-{2.2}_{-0.5}^{+0.5}$ , and place upper limits on the remaining species. Notably, we find logCH _4 < −4.5 at 99% confidence, despite its anticipated presence at the equilibrium temperature of HD 189733 b assuming local thermal equilibrium. We make a tentative (∼3 σ ) detection of ^13 CO, and the retrieved posteriors suggest a ^12 C/ ^13 C ratio similar to or substantially less than the local interstellar value. The possible ^13 C enrichment would be consistent with accretion of fractionated material in ices or in the protoplanetary disk midplane. The retrieved abundances correspond to a substantially substellar atmospheric C/O = 0.3 ± 0.1, while the carbon and oxygen abundances are stellar to slightly superstellar, consistent with core-accretion models which predict an inverse correlation between C/O and metallicity. The specific combination of low C/O and high metallicity suggests significant accretion of solid material may have occurred late in the formation process of HD 189733 b.

M dwarfs are common host stars to exoplanets but often lack atmospheric abundance measurements. Late-M dwarfs are also good analogs to the youngest substellar companions, which share similar T _eff ∼ 2300–2800 K. We present atmospheric analyses for the M7.5 companion HIP 55507 B and its K6V primary star with Keck/KPIC high-resolution ( R ∼ 35,000) K -band spectroscopy. First, by including KPIC relative radial velocities between the primary and secondary in the orbit fit, we improve the dynamical mass precision by 60% and find ${M}_{B}={88.0}_{-3.2}^{+3.4}\,{M}_{\mathrm{Jup}}$ , putting HIP 55507 B above the stellar–substellar boundary. We also find that HIP 55507 B orbits its K6V primary star with $a={38}_{-3}^{+4}$ au and e = 0.40 ± 0.04. From atmospheric retrievals of HIP 55507 B, we measure [C/H] = 0.24 ± 0.13, [O/H] = 0.15 ± 0.13, and C/O = 0.67 ± 0.04. Moreover, we strongly detect ^13 CO (7.8 σ significance) and tentatively detect ${{\rm{H}}}_{2}^{18}{\rm{O}}$ (3.7 σ significance) in the companion’s atmosphere and measure ${}^{12}\mathrm{CO}{/}^{13}\mathrm{CO}={98}_{-22}^{+28}$ and ${{\rm{H}}}_{2}^{16}{\rm{O}}/{{\rm{H}}}_{2}^{18}{\rm{O}}={240}_{-80}^{+145}$ after accounting for systematic errors. From a simplified retrieval analysis of HIP 55507 A, we measure ${}^{12}\mathrm{CO}{/}^{13}\mathrm{CO}={79}_{-16}^{+21}$ and ${{\rm{C}}}^{16}{\rm{O}}/{{\rm{C}}}^{18}{\rm{O}}={288}_{-70}^{+125}$ for the primary star. These results demonstrate that HIP 55507 A and B have consistent ^12 C/ ^13 C and ^16 O/ ^18 O to the

We present the first on-sky segmented primary mirror closed-loop piston control using a Zernike wavefront sensor (ZWFS) installed on the Keck II telescope. Segment cophasing errors are a primary contributor to contrast limits on Keck and will be necessary to correct for the next generation of space missions and ground-based extremely large telescopes, which will all have segmented primary mirrors. The goal of the ZWFS installed on Keck is to monitor and correct primary mirror cophasing errors in parallel with science observations. The ZWFS is ideal for measuring phase discontinuities such as segment cophasing errors and is one of the most sensitive WFSs, but has limited dynamic range. The vector-ZWFS at Keck works on the adaptive-optics-corrected wavefront and consists of a metasurface focal plane mask that imposes two different phase shifts on the core of the point-spread function to two orthogonal light polarizations, producing two pupil images. This design extends the dynamic range compared with the scalar ZWFS. The primary mirror segment pistons were controlled in closed loop using the ZWFS, improving the Strehl ratio on the NIRC2 science camera by up to 10 percentage points. We analyze the performance of the closed-loop tests, the impact on NIRC2 science data, and discuss the ZWFS measurements.

Using Keck Planet Imager and Characterizer high-resolution ( R ∼ 35,000) spectroscopy from 2.29 to 2.49 μ m, we present uniform atmospheric retrievals for eight young substellar companions with masses of ∼10–30 M _Jup , orbital separations spanning ∼50–360 au, and T _eff between ∼1500 and 2600 K. We find that all companions have solar C/O ratios and metallicities to within the 1 σ –2 σ level, with the measurements clustered around solar composition. Stars in the same stellar associations as our systems have near-solar abundances, so these results indicate that this population of companions is consistent with formation via direct gravitational collapse. Alternatively, core accretion outside the CO snowline would be compatible with our measurements, though the high mass ratios of most systems would require rapid core assembly and gas accretion in massive disks. On a population level, our findings can be contrasted with abundance measurements for directly imaged planets with m < 10 M _Jup , which show tentative atmospheric metal enrichment compared to their host stars. In addition, the atmospheric compositions of our sample of companions are distinct from those of hot Jupiters, which most likely form via core accretion. For two companions with T _eff ∼ 1700–2000 K ( κ And b and GSC 6214–210 b), our best-fit models prefer a nongray cloud model with >3 σ significance. The cloudy models yield 2 σ −3 σ lower T _eff for these companions, though the C/O and [C/H] still agree between cloudy and clear models at the 1 σ level. Finally, we constrain ^12 CO/ ^13 CO for three companions with the highest signal-to-noise ratio data (GQ Lup b, HIP 79098b, and DH Tau b) and report $v\sin i$ and radial velocities for all companions.

The 1RXS J034231.8+121622 system consists of an M dwarf primary and a directly imaged low-mass stellar companion. We use high-resolution spectroscopic data from Keck/KPIC to estimate the objects' atmospheric parameters and radial velocities (RVs). Using PHOENIX stellar models, we find that the primary has a temperature of 3460 ± 50 K and a metallicity of 0.16 ± 0.04, while the secondary has a temperature of 2510 ± 50 K and a metallicity of ${0.13}_{-0.11}^{+0.12}$ . Recent work suggests this system is associated with the Hyades, giving it an older age than previous estimates. Both metallicities agree with current Hyades [Fe/H] measurements (0.11–0.21). Using stellar evolutionary models, we obtain significantly higher masses for the objects, 0.30 ± 0.15 M _⊙ and 0.08 ± 0.01 M _⊙ (84 ± 11 M _Jup ), respectively. Using the RVs and a new astrometry point from Keck/NIRC2, we find that the system is likely an edge-on, moderately eccentric ( ${0.41}_{-0.08}^{+0.27}$ ) configuration. We also estimate the C/O ratio of both objects using custom grid models, obtaining 0.42 ± 0.10 (primary) and 0.55 ± 0.10 (companion). From these results, we confirm that this system most likely went through a binary star formation process in the Hyades. The significant changes in this system's parameters since its discovery highlight the importance of high-resolution spectroscopy for both orbital and atmospheric characterization of directly imaged companions.

We present the projected rotational velocity and molecular abundances for HD 33632 Ab obtained via Keck Planet Imager and Characterizer (KPIC) high-resolution spectroscopy. HD 33632 Ab is a nearby benchmark brown dwarf companion at a separation of ∼20 au that straddles the L–T transition. Using a forward-modeling framework with on-axis host star spectra, which provides self-consistent substellar atmospheric and retrieval models for HD 33632 Ab, we derive a projected rotational velocity of 53 ± 3 km s ^−1 and carbon monoxide and water mass fractions of logCO = −2.3 ± 0.3 and logH _2 O = −2.7 ± 0.2, respectively. The inferred carbon-to-oxygen ratio (C/O = 0.58 ± 0.14), molecular abundances, and metallicity ([C/H] = 0.0 ± 0.2 dex) of HD 33632 Ab are consistent with its host star. Although detectable methane opacities are expected in L–T transition objects, we did not recover methane in our KPIC spectra, partly due to the high v sin i and to disequilibrium chemistry at the pressures to which we are sensitive. We parameterize the spin as the ratio of rotation to the breakup velocity, and compare HD 33632 Ab to a compilation of >200 very low-mass objects ( M ≲ 0.1 M _⊙ ) that have spin measurements in the literature. There appears to be no clear trend for the isolated low-mass field objects versus mass, but a tentative trend is identified for low-mass companions and directly imaged exoplanets, similar to previous findings. A larger sample of close-in gas giant exoplanets and brown dwarfs will critically examine our understanding of their formation and evolution through rotation and chemical abundance measurements.

Young, self-luminous super-Jovian companions discovered by direct imaging provide a challenging test for planet formation and evolution theories. By spectroscopically characterizing the atmospheric compositions of these super-Jupiters, we can constrain their formation histories. Here we present studies of the recently discovered HIP 99770 b, a 16 M _Jup high-contrast companion on a 17 au orbit, using the fiber-fed high-resolution spectrograph KPIC ( ${ \mathcal R }$ ∼ 35,000) on the Keck II telescope. Our K -band observations led to detections of H _2 O and CO in the atmosphere of HIP 99770 b. We carried out free retrieval analyses using petitRADTRANS to measure its chemical abundances, including the metallicity and C/O ratio, projected rotation velocity ( $v\sin i$ ), and radial velocity (RV). We found that the companion’s atmosphere has C/O $=\,{0.55}_{-0.04}^{+0.06}$ and [M/H] $=\,{0.26}_{-0.23}^{+0.24}$ (1 σ confidence intervals), values consistent with those of the Sun and with a companion formation via gravitational instability or core accretion. The projected rotation velocity $v\sin (i)\lt 7.8$ km s ^−1 is small relative to other directly imaged companions with similar masses and ages. This may imply a nearly pole-on orientation or effective magnetic braking by a circumplanetary disk. In addition, we added the companion-to-primary relative RV measurement to the orbital fitting and obtained updated constraints on orbital parameters. Detailed characterization of super-Jovian companions within 20 au like HIP 99770 b is critical for understanding the formation histories of this population.

We used the Keck Planet Imager and Characterizer to obtain high-resolution ( R ∼ 35,000) K -band spectra of κ Andromedae b, a planetary-mass companion orbiting the B9V star, κ Andromedae A. We characterized its spin, radial velocity, and bulk atmospheric parameters through use of a forward-modeling framework to jointly fit planetary spectra and residual starlight speckles, obtaining likelihood-based posterior probabilities. We also detected H _2 O and CO in its atmosphere via cross correlation. We measured a $v\sin (i)$ value for κ Andromedae b of 38.42 ± 0.05 km s ^−1 , allowing us to extend our understanding of the population of close-in bound companions at higher rotation rates. This rotation rate is one of the highest spins relative to breakup velocity measured to date, at close to 50% of breakup velocity. We identify a radial velocity $-{17.35}_{-0.09}^{+0.05}$ km s ^−1 , which we use with existing astrometry and radial velocity measurements to update the orbital fit. We also measure an effective temperature of 1700 ± 100 K and a $\mathrm{log}(g)$ of 4.7 ± 0.5 cgs dex.

GQ Lup B is one of the few substellar companions with a detected cicumplanetary disk (CPD). Observations of the CPD suggest the presence of a cavity, possibly formed by an exosatellite. Using the Keck Planet Imager and Characterizer (KPIC), a high-contrast imaging suite that feeds a high-resolution spectrograph (1.9–2.5 µ m, R ∼35,000), we present the first dedicated radial velocity (RV) observations around a high-contrast, directly imaged substellar companion, GQ Lup B, to search for exosatellites. Over 11 epochs, we find a best and median RV error of 400–1000 m s ^−1 , most likely limited by systematic fringing in the spectra due to transmissive optics within KPIC. With this RV precision, KPIC is sensitive to exomoons 0.6%–2.8% the mass of GQ Lup B (∼30 M _Jup ) at separations between the Roche limit and 65 R _Jup , or the extent of the cavity inferred within the CPD detected around GQ Lup B. Using simulations of HISPEC, a high resolution infrared spectrograph planned to debut at W.M. Keck Observatory in 2026, we estimate future exomoon sensitivity to increase by over an order of magnitude, providing sensitivity to less massive satellites potentially formed within the CPD itself. Additionally, we run simulations to estimate the amount of material that different masses of satellites could clear in a CPD to create the observed cavity. We find satellite-to-planet mass ratios of q > 2 × 10 ^−4 can create observable cavities and report a maximum cavity size of ∼51 R _Jup carved from a satellite.

Category: Trauma; Midfoot/Forefoot Introduction/ Purpose: Primary arthrodesis of Lisfranc and midfoot fracture-dislocations is a reliable treatment option, yet concerns remain about nonunion and dorsiflexion malunion. The use of a new generation of nitinol staples has proliferated in midfoot arthrodesis. The purpose of this study is to examine the use of nitinol staples in primary arthrodesis of acute Lisfranc fracture-dislocations, comparing outcomes to traditional plate and screw fixation. The primary hypothesis is that nonunion rates are lower with constructs that include nitinol staples than those with plates and screws alone. Secondary hypotheses are: 1. Total operative and tourniquet time are shorter using nitinol staples. 2. Reoperation rates are lower using nitinol staples. 3. Dorsiflexion malunion rates are lower using nitinol staples. 4. Functional outcome scores will indicate comparable post-arthrodesis disability. Methods: Midfoot fracture-dislocations treated with primary arthrodesis by seven foot and ankle orthopaedic surgeons at a tertiary referral center from 1/1/2012 to 8/1/2021 were reviewed. Patients with open fractures, fractures managed with external fixation, Charcot arthropathy, neuropathy, previous midfoot surgery, or concomitant hindfoot/ankle fractures were excluded. Of 160 eligible patients, 121 patients met the required 4-month minimum radiographic follow-up. Preoperative records were reviewed, evaluating for associated metatarsal and cuneiform fractures, operative and tourniquet time, joints included, and fixation construct. Outcomes were analyzed at both patient and individual joint levels. Patients (121 total) and individual joints (305 total) were categorized as either staples alone (45 patients, 154 joints), staples plus plates and screws (hybrid) (45 patients, 40 joints), or plates and screws alone (31 patients, 111 joints). Postoperative radiographs were analyzed for union and malunion at each joint fused. Medical records were reviewed for postoperative complications. FAAM, VR-12, and NPRS were collected. Results: When assessed at the individual joint level, the nonunion rate was higher (8.1%, 9/111) among joints fixed with plate and screw constructs than with hybrid (2.5%, 1/40) or staple only constructs (1.3%, 2/154) (P = 0.017). Of the 12 nonunions in the study, 6 had either a metatarsal or cuneiform fracture. Median OR and tourniquet time were both shorter for hybrid (92 & 83 minutes) and staple only (67 & 63 minutes) constructs compared to plate and screw only fixation (106 & 95 minutes) (P = 0.0003 & < 0.0001). There were 15 (12.4%) reoperations including 10 hardware removals, 3 nonunion revisions, and 1 malunion revision. There was no difference in reoperation, malunion (14 total, 11.6%), or patient reported outcome measure between fixation types. Conclusion: Nitinol staples are effective in achieving bony fusion when used alone or in combination with plates and screws. Their use should be considered for primary arthrodesis of Lisfranc and midfoot fracture-dislocations due to lower rates of nonunion and shorter tourniquet and operative time compared to traditional plate and screw fixation. Further studies are needed to determine if staples decrease the risk for dorsiflexion malunion and improve patient reported outcomes.

Recombinant growth factors are used in tissue engineering to stimulate cell proliferation, migration, and differentiation. Conventional methods of growth factor delivery for therapeutic applications employ large amounts of these bioactive cues. Effective, localized growth factor release is essential to reduce the required dose and potential deleterious effects. The endogenous extracellular matrix (ECM) sequesters native growth factors through its negatively charged sulfated glycosaminoglycans. Mesenchymal stromal cells secrete an instructive extracellular matrix that can be tuned by varying culture and decellularization methods. In this study, mesenchymal stromal cell-secreted extracellular matrix was modified using λ-carrageenan as a macromolecular crowding (MMC) agent and decellularized with DNase as an alternative to previous decellularized extracellular matrices (dECM) to improve growth factor retention. Macromolecular crowding decellularized extracellular matrix contained 7.7-fold more sulfated glycosaminoglycans and 11.7-fold more total protein than decellularized extracellular matrix, with no significant difference in residual DNA. Endogenous BMP-2 was retained in macromolecular crowding decellularized extracellular matrix, whereas BMP-2 was not detected in other extracellular matrices. When implanted in a murine muscle pouch, we observed increased mineralized tissue formation with BMP-2-adsorbed macromolecular crowding decellularized extracellular matrix in vivo compared to conventional decellularized extracellular matrix. This study demonstrates the importance of decellularization method to retain endogenous sulfated glycosaminoglycans in decellularized extracellular matrix and highlights the utility of macromolecular crowding to upregulate sulfated glycosaminoglycan content. This platform has the potential to aid in the delivery of lower doses of BMP-2 or other heparin-binding growth factors in a tunable manner.

Category: Trauma; Midfoot/Forefoot Introduction/Purpose: Primary arthrodesis of Lisfranc and midfoot fracture-dislocations is a reliable treatment option, yet concerns remain about nonunion and dorsiflexion malunion. The use of a new generation of nitinol staples has proliferated in midfoot arthrodesis. The purpose of this study is to examine the use of nitinol staples in primary arthrodesis of acute Lisfranc fracture-dislocations, comparing outcomes to traditional plate and screw fixation. The primary hypothesis is that nonunion rates are lower with constructs that include nitinol staples than those with plates and screws alone. Secondary hypotheses are: 1. Total operative and tourniquet time are shorter using nitinol staples. 2. Reoperation rates are lower using nitinol staples. 3. Dorsiflexion malunion rates are lower using nitinol staples. 4. Functional outcome scores will indicate comparable post-arthrodesis disability. Methods: Midfoot fracture-dislocations treated with primary arthrodesis by seven foot and ankle orthopaedic surgeons at a tertiary referral center from 1/1/2012 to 8/1/2021 were reviewed. Patients with open fractures, fractures managed with external fixation, Charcot arthropathy, neuropathy, previous midfoot surgery, or concomitant hindfoot/ankle fractures were excluded. Of the 160 eligible patients, 121 met the required 4-month minimum radiographic follow-up. Preoperative imaging and operative records were reviewed, evaluating for associated metatarsal and cuneiform fractures, operative and tourniquet time, joints included, and fixation construct. Patients and individual joints (303 total) were categorized as either staples alone (47 patients), staples plus plates and screws (hybrid) (47), or plates and screws alone (35). Postoperative radiographs at last follow-up were then analyzed for union and malunion at each joint fused. CT scans were used, when available (41 patients), to assess for union. Medical records were reviewed for postoperative complications. FAAM, VR-12, and NPRS were collected. Results: When assessed at the individual joint level, the nonunion rate was higher (8%, 9/101) among joints fixed with plate and screw constructs than with hybrid (2.4%, 1/41) or staple only constructs (1.3%, 2/152) (P = 0.015). Of the 12 nonunions in the study, 6 had either a metatarsal or cuneiform fracture. Median OR and tourniquet time were both shorter for hybrid (92 & 83 minutes) and staple only (67 & 63 minutes) constructs than plate and screw only fixation (107 & 96 minutes) (P = 0.0002 & 0.0009). There were 17 (14%) reoperations including 10 hardware removals, 3 nonunion revisions, and 1 malunion revision. There was no difference in reoperation, malunion (14 total, 12%), or patient reported outcome measure between fixation types. Conclusion: Nitinol staples are effective in achieving bony fusion when used alone or in combination with plates and screws. With lower rates of nonunion and shorter tourniquet and operative time compared to traditional plate and screw fixation, their use should be considered for primary arthrodesis of Lisfranc and midfoot fracture-dislocations. Further studies are needed to determine if staples decrease the risk for dorsiflexion malunion and improve patient reported outcomes.

Therapeutic approaches for musculoskeletal tissue regeneration commonly employ growth factors (GFs) to influence neighboring cells and promote migration, proliferation, or differentiation. Despite promising results in preclinical models, the use of inductive biomacromolecules has achieved limited success in translation to the clinic. The field has yet to sufficiently overcome substantial hurdles such as poor spatiotemporal control and supraphysiological dosages, which commonly result in detrimental side effects. Physiological presentation and retention of biomacromolecules is regulated by the extracellular matrix (ECM), which acts as a reservoir for GFs via electrostatic interactions. Advances in the manipulation of extracellular proteins, decellularized tissues, and synthetic ECM-mimetic applications across a range of biomaterials have increased the ability to direct the presentation of GFs. Successful application of biomaterial technologies utilizing ECM mimetics increases tissue regeneration without the reliance on supraphysiological doses of inductive biomacromolecules. This review describes recent strategies to manage GF presentation using ECM-mimetic substrates for the regeneration of bone, cartilage, and muscle.

In the study of microbial life, microscopy plays a unique role due to its ability to detect ordered structure, motility, and fluorescence signals. As such it has also recently gained attention in the context of searching for extant life on distant Solar System bodies bearing liquid water. In this paper we introduce a multi-modal volumetric microscopy system for potential future spaceflight missions that combines digital holographic microscopy (DHM) and volume fluorescence imager (VFI), which are volumetric imaging methods that provide high-resolution, high-throughput examination of liquid samples. DHM provides information on the absorption, morphology, and motility of imaged objects without requiring the use of contrast agents. On the other hand, VFI based on light field microscopy focuses on the fluorescence signals from the sample to observe specific structures dyed with targeted contrast agents or providing unique autofluorescence signals. We also present an autonomous sample handling and data acquisition system to allow for an autonomous mission to distant planets or moons, or for autonomous use in bodies of water on Earth. The full system, named ELVIS, or Extant Life Volumetric Imaging System, is capable of autonomously surveying a liquid sample to extract morphology, motility, and fluorescence signals of extant microbial life.

AimTo evaluate the mechanosensitivity of muscle satellite cells (MuSCs) and fibro-adipogenic progenitors (FAPs) in cerebral palsy (CP) and the efficacy of the drug verteporfin in restoring cells' regenerative capacity.MethodMuscle biopsies were collected from six children with CP and six typically developing children. MuSCs and FAPs were isolated and plated on collagen-coated polyacrylamide gels at stiffnesses of 0.2 kPa, 8 kPa, and 25 kPa. Cells were treated with verteporfin to block mechanosensing or with dimethyl sulfoxide as a negative control. MuSC differentiation and FAP activation into myofibroblasts were measured using immunofluorescence staining.ResultsSurprisingly, MuSC differentiation was not affected by stiffness; however, stiff substrates resulted in large myonuclear clustering. Across all stiffnesses, MuSCs from children with CP had less differentiation than those of their typically developing counterparts. FAP activation into myofibroblasts was significantly higher in children with CP than their typically developing peers, but was not affected by stiffness. Verteporfin did not affect differentiation or activation in either cell population, but slightly decreased myonuclear clustering on stiff substrates.InterpretationCells from children with CP were less regenerative and more fibrotic compared to those of their typically developing counterparts, with MuSCs being sensitive to increases in stiffness. Therefore, the mechanosensitivity of MuSCs and FAPs may represent a new target to improve differentiation and activation in CP muscle.

Abstract The extraction of the strange quark parton distribution function (PDF) poses a long-standing puzzle. Measurements from neutrino-nucleus deep inelastic scattering (DIS) experiments suggest the strange quark is suppressed compared to the light sea quarks, while recent studies of $$W^\pm /Z$$ W ± / Z boson production at the LHC imply a larger strange component at small x values. As the parton flavor determination in the proton depends on nuclear corrections, e.g. from heavy-target DIS, LHC heavy ion measurements can provide a distinct perspective to help clarify this situation. In this investigation we extend the nCTEQ15 nPDFs to study the impact of the LHC proton-lead $$W^\pm /Z$$ W ± / Z production data on both the flavor differentiation and nuclear corrections. This complementary data set provides new insights on both the LHC $$W^\pm /Z$$ W ± / Z proton analyses and the neutrino-nucleus DIS data. We identify these new nPDFs as nCTEQ15WZ. Our calculations are performed using a new implementation of the nCTEQ code (nCTEQ++) based on C++ which enables us to easily interface to external programs such as HOPPET, APPLgrid and MCFM. Our results indicate that, as suggested by the proton data, the small x nuclear strange sea appears larger than previously expected, even when the normalization of the $$W^{\pm }/Z$$ W ± / Z data is accommodated in the fit. Extending the nCTEQ15 analysis to include LHC $$W^\pm /Z$$ W ± / Z data represents an important step as we advance toward the next generation of nPDFs.

Category: Ankle; Basic Sciences/Biologics; Trauma Introduction/Purpose: The PUMA System (Panther Orthopedics, Sunnyvale, CA) is an FDA cleared. superelastic, nitinol based fixation device for the ankle syndesmosis which provides stabilization without over-compression or loosening due to creep from cyclic loading. Objective The objective of this study was to test resistance to lengthening (creep) of the PUMA System in cyclic fatigue testing. Methods: Five PUMA System devices, each having a nitinol Body consisting of six layers, were cycle-tested between 20/40 pounds per cubic foot (lb/ft 3 ) polyurethane foam Bone Blocks (Figure 1).[1] The PUMA System devices were set up with an initial device Active Length of approximately 66 millimeters (mm) between their polyether ether ketone (PEEK) Anchor buttons. All devices were tightened to a minimum of 11.1 Newtons (2.5 pounds force) and cycled at 5 cycles per second (5 Hz) for 4500 cycles to 2.4 mm displacement. Device Active Length was recorded pre- and post-testing. Devices were visually inspected for any break in the 30 nitinol layers. [1] ASTM F1839: Standard Specification for Rigid Polyurethane Foam for Use as a Standard Material for Testing Orthopedic Devices and Instruments. Results: None of the 30 layers incorporated in the 5 PUMA System TM device Bodies failed due to cyclic fatigue. Also, there was little-to-no difference between pre- and post-testing Active Length ( Figure 2 ). More specifically an average increase of only 0.2% in length with a with a Standard Deviation of 0.16% evidences no significant creep (Table 1). Conclusion: The PUMA System TM allows for ankle syndesmosis repair with an implant that experiences no significant creep as demonstrated in cyclic-fatigue testing under challenging displacement cycle testing.

Category: Ankle; Trauma Introduction/Purpose: Syndesmosis injuries are increasingly common. Available fixation options are not yet optimal. The PUMA System (Panther Orthopedics, Sunnyvale, CA) is an FDA-cleared superelastic, nitinol-based fixation device for the ankle syndesmosis which provides stabilization without over-compression or loosening during cyclical loading. The spring-like design of the PUMA System allows physiological micro-motion while maintaining continuous compression and resisting syndesmosis widening, without material creep. The objective of this prospective study is to assess the effectiveness and complication rate of the PUMA device for treatment of fracture-associated syndesmosis injuries. Methods: We prospectively collected radiographic and clinical data on 32 consecutive patients treated for fracture-associated syndesmotic disruption with the PUMA System TM at 8 centers. Primary outcome measures included adverse event rates, radiographic evaluations for syndesmosis integrity and implant failure, and rates of revision surgery. Results: All 32 patients had successful repair of their ankle syndesmosis (Figure 1). The mean age of patients at time of operation was 42 years (range 16- 68). There were 13 females (13/32, 40.6%) and 19 (19/32, 59.4%) males. Postoperative radiographic evaluations confirmed satisfactory syndesmosis healing with maintained reduction in the ankle mortise in 33/33 (100%) ankles. There was no evidence of lysis, device migration or syndesmotic or medial clear space widening. There were no infections or soft tissue complications. All fractures healed. No devices required removal and there were no revision surgeries. Conclusion: The PUMA System TM provides physiologic stabilization of the syndesmosis due to the design features that allow for continuous compression without creep. We found no device-related complications nor construct failures in our series. The superelastic implant design allows physiologic motion at the syndesmosis but does not creep or stretch following displacement. This flexibility obviates the need for routine removal. The implant's low-profile buttons without suture and knot tying requirements eliminate the concern for subcutaneous knot irritation and slippage. Additional biomechanical and clinical outcomes study of this device may further optimize rehabilitation protocols for patients treated for syndesmotic injury.

Category: Ankle; Ankle Arthritis Introduction/Purpose: In total ankle arthroplasty (TAA), the implant can be inserted with or without cement. The United States Food and Drug Administration (FDA) requires cement fixation on most TAAs, whereas cementless TAA can be performed in other countries. The laterally placed trabecular metal ankle replacement is inserted using a jig and a fibular osteotomy. The tibia and talus are reamed to match the curved contour of the replacement. Two rails on the tibial and talar component are used to transfix the cementless component onto bone. FDA licensing requires a bead of cement applied on the fixation rails to assist in early component fixation. The purpose of this study was to compare early and three-year results of TAA with and without rail cement performed in six countries. Methods: One hundred and twenty-one patients were prospectively enrolled (from 2014 to 2016) across 11 centers in six countries. Patients were assigned cement or no cement based on the surgeon's practice. EQ5D, AOS, and AOFAS scores were obtained preoperatively, six weeks and six months postoperatively, and yearly thereafter. Secondary endpoints were revision of metal components for infection or loosening. Statistical significance was tested by the Wilcoxon Signed Rank Test and set at p=0.05.Sixty ankles had cement; 61 ankles were press fit. Cement augmentation patients were heavier and older. Cement cases had longer surgical times (173 minutes, 95% CI 162.8 to 183.2, versus 150 minutes, 95% CI 139.9 to 158.4). The sites using cement fixation varied. Of 121 cases, 117 were followed at one year, 96 at two years, and 84 at three years. Three patients underwent revision and five withdrew (one died, two lost to follow-up, and two requested discontinuation). Results: The EQ5D scores demonstrated better outcomes for the press fit component without cement at six weeks (p

Background: Elevations of inflammatory cytokine levels occur immediately after mild traumatic brain injury (mTBI) and can persist for years. These elevations have been associated with neuropsychological outcomes, including depression and PTSD symptoms. Sleep disorders, another common sequelae of mTBI, are independently associated with inflammation in otherwise healthy individuals. However, whether sleep and inflammation are linked in chronic mTBI has not been reported.Methods: A retrospective cross-sectional cohort of warfighters was used to investigate the hypothesis that inflammation may be linked to sleep quality in chronic mTBI. Clinical history, peripheral blood samples, and sleep quality scores were collected from 182 warfighters (n = 138 mTBI; n = 44 controls) during enrollment in the Chronic Effects of Neurotrauma Consortium study. Biomarkers of inflammation (IL-6, IL-10, TNFα cytokines) from plasma and plasma-derived extracellular vesicles (EVs) were quantified using single molecule array. Relationships between sleep quality and cytokine levels were assessed, controlling for age, sex, and BMI. Using clinical cutoff scores for sleep quality, mTBI patients were then divided into “good” and “poor” sleepers and cytokine levels compared between groups.Results: In mTBI participants, sleep quality was significantly associated with EV levels of IL-10 [ß (SE) = 0.11 (0.04), p = 0.01] and TNFα [ß (SE) = 0.07 (0.03), p < 0.01]. When divided according to “good” versus “poor” sleepers, those reporting poor sleep had significantly elevated EV IL-10 compared to those reporting good sleep [ß (SE) = 0.12 (0.04), p < 0.01]. Plasma-derived associations were not significant. No associations were found between sleep quality and cytokine levels in controls.Conclusion: These results suggest a significant relationship between sleep quality and chronic inflammation in mTBI patients. Clinically, mTBI patients with a high likelihood of sleep disorders demonstrate elevated levels of inflammatory cytokines. Signal from EVs, though smaller in magnitude, may have stronger clinical associations than from plasma. Sleep-focused interventions may also serve to regulate chronic inflammatory processes in these patients. Larger prospective studies are needed to investigate the mechanisms and therapeutic implications of the likely bi-directional relationship between sleep and inflammation following mTBI.

Category: Bunion; Midfoot/Forefoot; Other Introduction/Purpose: Hallux rigidus is the most common degenerative arthropathy of the foot. Primary hallux metatarsophalangeal (MTP) joint arthrodesis is the most common surgical treatment for end-stage hallux rigidus and can also be utilized for correction of hallux valgus. Though satisfaction rates following hallux MTP joint arthrodesis are very favorable, nonunion rates have been reported as high as 12%. Many surgeons use orthobiologics and/or autograft to augment arthrodeses about the foot and ankle in an effort to increase union rates. The purpose of this study is to retrospectively compare union rates of hallux MTP joint arthrodesis with and without calcaneus autograft. Methods: A query of our institution’s administrative database was performed to identify patients who underwent a primary hallux MTP joint arthrodesis between February 2016 and February 2019. We compared patients who underwent arthrodesis with and without calcaneus autograft. Surgeon preference dictated use of autograft, as some in our group routinely use graft while others do not. Patients 18 years and older who underwent a primary hallux MTP arthrodesis were included. Patients were excluded if they had radiographic evidence of significant bone loss or if allograft or biologic therapies were used. Patient charts and final radiographs were reviewed. The primary outcome was successful union of the hallux MTP joint arthrodesis. Secondary outcomes included preoperative diagnosis, type of surgical fixation and surgical complications. Data was compared using a student T-test. Results: There were 336 feet included in the final analysis, and 140 underwent hallux MTP arthrodesis with calcaneus autograft. Mean follow-up time was 14.8 weeks. Among all patients, 89.9% had a successful union. There was no difference in union rates between those who underwent arthrodesis with calcaneus autograft (87.9%) compared to without autograft (91.4%; p = 0.302). Hallux valgus was the preoperative diagnosis in 52.7% of cases followed by hallux rigidus (39.9%). The most common fixation method was a lag screw with a dorsal plate (80.5%). Painful hardware was the next most common complication (8.6%), and smoking and diagnosis of diabetes demonstrated no effect on union rates. In the autograft group, there were no complications related to the calcaneus autograft donor site. Conclusion: As orthobiologics and local bone autograft gain popularity in foot and ankle surgery, it is important to report clinical outcomes and establish evidence-based guidelines for use. In this relatively large retrospective comparison, the use of calcaneal graft was noted to be safe (no complications from graft site). However, there was no difference in union rate when comparing hallux MTP arthrodesis with and without calcaneus autograft.