Scholarly Work - Mechanical & Industrial Engineering

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    Graphene quantum dots/cellulose nanocrystal inclusion complex for enhancing the physical and thermal properties of HDPE polymer matrix
    (Elsevier BV, 2024-06) Bajwa, Dilpreet S.; Chanda, Saptaparni; Ryan, Cecily; Bajwa, Sreekala G.; Stark, Nicole; Matteson, Kirsten
    Cellulose nanocrystals (CNC) are desirable material due to universal accessibility, and superior mechanical properties. A major challenge is non-uniform dispersion of CNC in the hydrophobic matrices due to their tendency to agglomerate. A novel technique was evaluated to prepare a hybrid system of cellulose nanocrystal (CNC)/graphene quantum dots (GQD). Hybrid system of CNC/GQD was added to high density poly (ethylene) (HDPE) to manufacture composites. The CNC/GQD inclusion complex properties were evaluated using Zeta potential measurement, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis. The composite properties were analysed using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and tensile testing and analysis of electrical impedance spectra. Raman spectroscopy, XPS and XRD confirmed the interaction of CNC and GQD. The SEM micrographs of the cross-sections of GQD induced composites showed a uniform honeycomb like morphology and no sign of agglomeration. GQD incorporated composites exhibited better thermal stability and higher elastic modulus than neat HDPE. The composites showed a purely capacitive response for an AC electrical system measured over 4 Hz to 1 MHz. The results indicate significantly improved dispersion of CNC in the polymer matrix, compared to unmodified CNCs.
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    Biotrapping Ureolytic Bacteria on Sand to Improve the Efficiency of Biocementation
    (American Chemical Society, 2024-01) Ugur, Gizem Elif; Rux, Kylee; Boone, John Connor; Seaman, Rachel; Avci, Recep; Gerlach, Robin; Phillips, Adrienne; Heveran, Chelsea
    Microbially induced calcium carbonate precipitation (MICP) has emerged as a novel technology with the potential to produce building materials through lower-temperature processes. The formation of calcium carbonate bridges in MICP allows the biocementation of aggregate particles to produce biobricks. Current approaches require several pulses of microbes and mineralization media to increase the quantity of calcium carbonate minerals and improve the strength of the material, thus leading to a reduction in sustainability. One potential technique to improve the efficiency of strength development involves trapping the bacteria on the aggregate surfaces using silane coupling agents such as positively charged 3-aminopropyl-methyl-diethoxysilane (APMDES). This treatment traps bacteria on sand through electrostatic interactions that attract negatively charged walls of bacteria to positively charged amine groups. The APMDES treatment promoted an abundant and immediate association of bacteria with sand, increasing the spatial density of ureolytic microbes on sand and promoting efficient initial calcium carbonate precipitation. Though microbial viability was compromised by treatment, urea hydrolysis was minimally affected. Strength was gained much more rapidly for the APMDES-treated sand than for the untreated sand. Three injections of bacteria and biomineralization media using APMDES-treated sand led to the same strength gain as seven injections using untreated sand. The higher strength with APMDES treatment was not explained by increased calcium carbonate accrual in the structure and may be influenced by additional factors such as differences in the microstructure of calcium carbonate bridges between sand particles. Overall, incorporating pretreatment methods, such as amine silane coupling agents, opens a new avenue in biomineralization research by producing materials with an improved efficiency and sustainability.
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    Make engineered living materials carry their weight
    (Elsevier BV, 2023-11) Heveran, Chelsea M.; Hernandez, Christopher J.
    Engineered living materials (ELMs) are a new class of materials synthesized and/or populated by living organisms. ELMs have the potential to reduce energy costs in manufacturing and provide desirable material functionalities including self-healing and sensing. To substantially reduce carbon emissions, ELMs must be able to replace rigid materials. However, naturally occurring materials synthesized by cells are not sufficiently stiff to replace rigid engineering materials. Furthermore, the cellular viability in the stiffest ELMs is not yet adequate for achieving their sustainability potential. The need for rigid ELMs will require new approaches to enhance cell viability and/or combine living cells with rigid scaffolds. Among naturally occurring materials, bone is a rare example of a rigid material that is synthesized and functionalized by cells that maintain impressive viability. Bone is expected to provide lessons for surmounting challenges in achieving the requisite viability and mechanical properties required for ELMs to serve common load-bearing purposes.
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    A pilot study comparing prosthetic to sound limb gait mechanics during a turning task in people with transtibial amputation
    (Elsevier BV, 2023-10) Clemens, Sheila; Pew, Corey
    Background. Observational gait analysis is frequently used by clinicians to subjectively assess straight walking but is not often used to examine turning. Interlimb comparisons of phase- specific turning biomechanics in people with unilateral lower limb amputation has not previously been documented. Methods. A retrospective examination of gait kinematics and kinetics from five participants with unilateral transtibial amputation was performed. Data were collected during 90° step and spin turns capturing three distinct turning steps. Gait metrics of interest included: total turn time, stance time, peak knee flexion angle during Pre-Swing and Initial Swing gait phases, peak hip flexion and extension, ground reaction impulse, and whole body angular momentum. Statistical comparisons were made based on turn type between sound and prosthetic limbs. Findings. During the three turn steps (approach, apex, depart), participants spent significantly more time (P < 0.01) on their sound limb compared to their prosthetic limb regardless of turn type. Additionally, the prosthetic limb hip and knee exhibited more flexion (P < 0.05) during the apex step of turns, and whole body angular momentum was higher when the sound limb was used during the apex step of a turn (P < 0.05). Interpretation. This descriptive study offers the first phase-specific quantification of turning biomechanics in people with lower limb amputation. Results indicate that people with unilateral transtibial amputation spend more time on and experience higher impulses through their sound compared to their prosthetic limb during 90° turns, and that the prosthetic limb is performing differently than the sound limb, potentially increasing risks of injury or falls.
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    Three Decades of Advancements in Osteoarthritis Research: Insights from Transcriptomic, Proteomic, and Metabolomic Studies
    (Elsevier BV, 2023-12) Farooq Rai, Muhammad; Collins, Kelsey H.; Lang, Annemarie; Maerz, Tristan; Geurts, Jeroen; Ruiz-Romero, Cristina; June, Ronald K.; Ramos, Yolande; Rice, Sarah J.; Ali, Shabana Amanda; Pastrello, Chiara; Jurisica, Igor; Appleton, C. Thomas; Rockel, Jason S.; Kapoor, Mohit
    Objective. Osteoarthritis (OA) is a complex disease involving contributions from both local joint tissues and systemic sources. Patient characteristics, encompassing sociodemographic and clinical variables, are intricately linked with OA rendering its understanding challenging. Technological advancements have allowed for a comprehensive analysis of transcripts, proteomes and metabolomes in OA tissues/fluids through omic analyses. The objective of this review is to highlight the advancements achieved by omic studies in enhancing our understanding of OA pathogenesis over the last three decades. Design. We conducted an extensive literature search focusing on transcriptomics, proteomics and metabolomics within the context of OA. Specifically, we explore how these technologies have identified individual transcripts, proteins, and metabolites, as well as distinctive endotype signatures from various body tissues or fluids of OA patients, including insights at the single-cell level, to advance our understanding of this highly complex disease. Results. Omic studies reveal the description of numerous individual molecules and molecular patterns within OA-associated tissues and fluids. This includes the identification of specific cell (sub)types and associated pathways that contribute to disease mechanisms. However, there remains a necessity to further advance these technologies to delineate the spatial organization of cellular subtypes and molecular patterns within OA-afflicted tissues. Conclusions. Leveraging a multi-omics approach that integrates datasets from diverse molecular detection technologies, combined with patients’ clinical and sociodemographic features, and molecular and regulatory networks, holds promise for identifying unique patient endophenotypes. This holistic approach can illuminate the heterogeneity among OA patients and, in turn, facilitate the development of tailored therapeutic interventions.
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    Nano Boron Oxide and Zinc Oxide Doped Lignin Containing Cellulose Nanocrystals Improve the Thermal, Mechanical and Flammability Properties of High-Density Poly(ethylene)
    (MDPI, 2023-12) Bajwa, Dilpreet S.; Holt, Greg; Stark, Nicole; Bajwa, Sreekala G.; Chanda, Saptaparni; Quadir, Mohiuddin
    The widely used high-density polyethylene (HDPE) polymer has inadequate mechanical and thermal properties for structural applications. To overcome this challenge, nano zinc oxide (ZnO) and nano boron oxide (B2O3) doped lignin-containing cellulose nanocrystals (L-CNC) were blended in the polymer matrix. The working hypothesis is that lignin will prevent CNC aggregation, and metal oxides will reduce the flammability of polymers by modifying their degradation pathways. This research prepared and incorporated safe, effective, and eco-friendly hybrid systems of nano ZnO/L-CNC and nano B2O3/L-CNC into the HDPE matrix to improve their physio-mechanical and fire-retardant properties. The composites were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, thermo-gravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, horizontal burning test, and microcalorimetry test. The results demonstrated a substantial increase in mechanical properties and a reduction in flammability. The scanning electron microscope (SEM) images showed some agglomeration and irregular distribution of the inorganic oxides.
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    Classroom aerosol dispersion modeling: experimental assessment of a low-cost flow simulation tool
    (Royal Society of Chemistry, 2023-01) Dacunto, P.; Nam, S.; Hirn, M.; Rodriguez, A.; Owkes, M.; Benson, M.
    The purpose of this study was to assess the utility of a low-cost flow simulation tool for an indoor air modeling application by comparing its outputs with the results of a physical experiment, as well as those from a more advanced computational fluid dynamics (CFD) software package. Five aerosol dispersion tests were performed in two different classrooms by releasing a CO2 tracer gas from six student locations. Resultant steady-state concentrations were monitored at 13 locations around the periphery of the room. Subsequently, the experiments were modeled using both a low-cost tool (SolidWorks Flow Simulation) and a more sophisticated tool (STAR-CCM+). Models were evaluated based on their ability to predict the experimentally measured concentrations at the 13 monitoring locations by calculating four performance parameters commonly used in the evaluation of dispersion models: fractional mean bias (FB), normalized mean-square error (NMSE), fraction of predicted value within a factor of two (FAC2), and normalized absolute difference (NAD). The more sophisticated model performed better in 15 of the 20 possible cases (five tests at four parameters each), with parameters meeting acceptance criteria in 19 of 20 cases. However, the lower-cost tool was only slightly worse, with parameters meeting acceptance criteria in 18 of 20 cases, and it performed better than the other tool in 3 of 20 cases. Because it provides useful results at a fraction of the monetary and training cost and is already widely accessible to many institutions, such a tool may be worthwhile for many indoor aerosol dispersion applications, especially for students or researchers just beginning CFD modeling.
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    System efficiency of packed bed TES with radial flow vs. axial flow – Influence of aspect ratio
    (Elsevier BV, 2023-11) Skuntz, Matthew E.; Elander, Rachel; Azawii, Mohammad Al; Bueno, Pablo; Anderson, Ryan
    This paper compares the net system efficiency, including thermal efficiency and pressure drop effects, of radial versus axial flow packed beds for thermal energy storage. The traditional packed bed system is a cylindrical geometry where fluid flows axially from one end to another. However, issues of thermal stratification and high-pressure drop have led to recent studies on radial flow systems. One potential benefit is the reduced pressure drop in a radial flow system. This paper compares the performance of radial flow and axial flow systems at a range of aspect ratios (AR = H/Dbed) from 0.21 to 1.92 using a numerical model where the storage volume is held constant in all cases. When the radial flow bed is at a low aspect ratio (short/wide), the thermal front is improved but the pressure drop is high. At a high aspect ratio, the velocity is reduced in radial flow, leading to decreased pressure drop but an increased spreads in the thermal front that lowers thermal efficiency. The opposite trends are noted in axial flow. Thermal efficiencies of 83–91 % were noted for radial flow, while they ranged from 85 to 94 % in axial flow. Net efficiencies including pressure drop ranged from 74 to 82 % for radial flow and 80–87 % for axial flow. In both systems, a peak net efficiency was noted between the highest and lowest aspect ratio. While some aspect ratios with radial flow outperform axial flow from a net efficiency perspective, the results show that the highest net efficiency from axial flow is higher than that from radial flow. Overall, this paper highlights the importance of innovative TES designs and their potential to improve energy efficiency.
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    Germ‐Free C57BL/6 Mice Have Increased Bone Mass and Altered Matrix Properties but Not Decreased Bone Fracture Resistance
    (Wiley, 2023-08) Vahidi, Ghazal; Moody, Maya; Welhave, Hope D.; Davidson, Leah; Rezaee, Taraneh; Behzad, Ramina; Karim, Lamya; Roggenbeck, Barbara A.; Walk, Seth T.; Martin, Stephen A.; June, Ronald K.; Heveran, Chelsea M.
    The gut microbiome impacts bone mass, which implies a disruption to bone homeostasis. However, it is not yet clear how the gut microbiome affects the regulation of bone mass and bone quality. We hypothesized that germ-free (GF) mice have increased bone mass and decreased bone toughness compared with conventionally housed mice. We tested this hypothesis using adult (20- to 21-week-old) C57BL/6J GF and conventionally raised female and male mice (n = 6–10/group). Trabecular microarchitecture and cortical geometry were measured from micro–CT of the femur distal metaphysis and cortical midshaft. Whole-femur strength and estimated material properties were measured using three-point bending and notched fracture toughness. Bone matrix properties were measured for the cortical femur by quantitative back-scattered electron imaging and nanoindentation, and, for the humerus, by Raman spectroscopy and fluorescent advanced glycation end product (fAGE) assay. Shifts in cortical tissue metabolism were measured from the contralateral humerus. GF mice had reduced bone resorption, increased trabecular bone microarchitecture, increased tissue strength and decreased whole-bone strength that was not explained by differences in bone size, increased tissue mineralization and fAGEs, and altered collagen structure that did not decrease fracture toughness. We observed several sex differences in GF mice, most notably for bone tissue metabolism. Male GF mice had a greater signature of amino acid metabolism, and female GF mice had a greater signature of lipid metabolism, exceeding the metabolic sex differences of the conventional mice. Together, these data demonstrate that the GF state in C57BL/6J mice alters bone mass and matrix properties but does not decrease bone fracture resistance. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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    Biofilm.jl: A fast solver for one-dimensional biofilm chemistry and ecology
    (Elsevier BV, 2023-12) Owkes, Mark; Coblentz, Kai; Eriksson, Austen; Kammerzell, Takumi; Stewart, Philip S.
    Biofilms are communities of microorganisms that grow on virtually all surfaces with sufficient nutrients including aquatic and industrial water systems and medical devices. Biofilms are complex, structured communities where the interplay of growth, metabolism, and competition between species interact with physical processes of diffusion, convection, attachment, and detachment. This work describes a model of a one-dimensional biofilm in a stirred tank reactor that incorporates these complexities. The model is implemented in the modern Julia programming language providing an efficient tool for studying a large variety of biofilms and the intricate communities the microorganisms create. Details of the new software, known as Biofilm.jl, including the mathematical model and organization and execution of the code, are provided. Examples of biofilms modeled using Biofilm.jl are presented such as a single heterotroph, sulfide-oxidizing bacteria (SOB) and sulfate-reducing bacteria (SRB), and a phototroph. Postprocessing tools are described that allow a Biofilm.jl user to make plots and extract specific values from the solution and explore the simulated biofilm results.
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    High-fidelity simulations of a rotary bell atomizer with electrohydrodynamic effects
    (Elsevier BV, 2023-11) Krisshna, Venkata; Liu, Wanjiao; Owkes, Mark
    Electrostatic rotary bell atomizers are extensively used as paint applicators in the automobile industry. Paint undergoes atomization after exiting the edge of a high-speed rotating bell. In most setups, the paint is electrically charged and a background electric field is applied between the nozzle and the target surface to increase the transfer efficiency (TE). The atomization process directly determines the droplet size and droplet charge distributions which subsequently control TE and surface finish quality. Optimal spray parameters used in industry are often obtained from expensive trial-and-error methods. In this work, three-dimensional near-bell atomization is computationally simulated using a high-fidelity volume-of-fluid transport scheme that includes electrohydrodynamic (EHD) effects. We find that electrifying the setup results in the production of smaller droplets. Additionally, the electric field has a minor effect on primary atomization but a negligible effect on the size and stability of atomized droplets after secondary breakup. This cost-effective method of simulating EHD-assisted atomization allows for the understanding of the effect of the electric field and the extraction of droplet charge characteristics which is otherwise challenging to obtain experimentally.
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    Validation of a Low-Cost Portable Device for Inducing Noninvasive Anterior Cruciate Ligament Injury in Mice
    (ASME International, 2023-08) Jbeily, Elias H.; Lin, Yu-Yang; Elmankabadi, Seif B.; Osipov, Benjamin; June, Ron K.; Christiansen, Blaine A.
    Noninvasive compression-induced anterior cruciate ligament rupture (ACL-R) is an easy and reproducible model for studying post-traumatic osteoarthritis (PTOA) in mice. However, equipment typically used for ACL-R is expensive, immobile, and not available to all researchers. In this study, we compared PTOA progression in mice injured with a low-cost custom ACL-rupture device (CARD) to mice injured with a standard system (ElectroForce 3200). We quantified anterior–posterior (AP) joint laxity immediately following injury, epiphyseal trabecular bone microstructure, and osteophyte volume at 2 and 6 weeks post injury using micro-computed tomography, and osteoarthritis progression and synovitis at 2 and 6 weeks post injury using whole-joint histology. We observed no significant differences in outcomes in mice injured with the CARD system compared to mice injured with the Electroforce (ELF) system. However, AP joint laxity data and week 2 micro-CT and histology outcomes suggested that injuries may have been slightly more severe and PTOA progressed slightly faster in mice injured with the CARD system compared to the ELF system. Altogether, these data confirm that ACL-R can be successfully and reproducibly performed with the CARD system and that osteoarthritis (OA) progression is mostly comparable to that of mice injured with the ELF system, though potentially slightly faster. The CARD system is low cost and portable, and we are making the plans and instructions freely available to all interested investigators in the hopes that they will find this system useful for their studies of OA in mice.
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    Design of Experiment to Determine the Effect of the Geometric Variables on Tensile Properties of Carbon Fiber Reinforced Polymer Composites
    (MDPI AG, 2023-05) Janicki, Joseph C.; Egloff, Matthew C.; Bajwa, Dilpreet S.; Amendola, Roberta; Ryan, Cecily A.; Cairns, Douglas S.
    Carbon fiber reinforced polymers (CFRPs) are increasingly used in the aerospace industry because of their robust mechanical properties and strength to weight ratio. A significant drawback of CFRPs is their resistance to formability when drawing continuous CFRPs into complex shapes as it tends to bridge, resulting in various defects in the final product. However, CFRP made from Stretch Broken Carbon Fiber (SBCF) aims to solve this issue by demonstrating superior formability compared to conventional continuous CFRPs. To study and validate the performance of SBCF, a statistical design of the experiment was conducted using three different types of CFRPs in tow/tape form. Hexcel (Stamford, CT, USA) IM7-G continuous carbon fiber impregnated with Huntsman (The Woodlands, TX, USA) RDM 2019-053 resin system, Hexcel SBCF impregnated with RDM2019-053 resin, and Montana State University manufactured SBCF impregnated with Huntsman RDM 2019-053 resin were tested in a multitude of forming trials and the data were analyzed using a statistical model to evaluate the forming behavior of each fiber type. The results show that for continuous fiber CFRP tows forming, Fmax and Δmax do not show statistical significance based on temperature fluctuations; however, in SBCF CFRP tows forming, Fmax and Δmax is dominated by the temperature and geometry has a low statistical influence on the Fmax. The lower dependence on tool geometry at higher temperatures indicates possibly superior formability of MSU SBCF. Overall findings from this research help define practical testing methods to compare different CFRPs and provide a repeatable approach to creating a statistical model for measuring results from the formability trials.
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    Osteocyte Remodeling of the Lacunar-Canalicular System: What’s in a Name?
    (Springer Science and Business Media LLC, 2022-12) Heveran, C. M.; Boerckel, J.D.
    Purpose of Review. Osteocytes directly modify the bone surrounding the expansive lacunar-canalicular system (LCS) through both resorption and deposition. The existence of this phenomenon is now widely accepted, but is referred to as “osteocyte osteolysis,” “LCS remodeling,” and “perilacunar remodeling,” among other names. The uncertainty in naming this physiological process reflects the many persistent questions about why and how osteocytes interact with local bone matrix. The goal of this review is to examine the purpose and nature of LCS remodeling and its impacts on multiscale bone quality. Recent Findings. While LCS remodeling is clearly important for systemic calcium mobilization, this process may have additional potential drivers and may impact the ability of bone to resist fracture. There is abundant evidence that the osteocyte can resorb and replace bone mineral and does so outside of extreme challenges to mineral homeostasis. The impacts of the osteocyte on organic matrix are less certain, especially regarding whether osteocytes produce osteoid. Though multiple lines of evidence point towards osteocyte production of organic matrix, definitive work is needed. Recent high-resolution imaging studies demonstrate that LCS remodeling influences local material properties. The role of LCS remodeling in the maintenance and deterioration of bone matrix quality in aging and disease are active areas of research. Summary. In this review, we highlight current progress in understanding why and how the osteocyte removes and replaces bone tissue and the consequences of these activities to bone quality. We posit that answering these questions is essential for evaluating whether, how, when, and why LCS remodeling may be manipulated for therapeutic benefit in managing bone fragility.
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    Development of a Novel Perturbation Platform System for Balance Response Testing and Rehabilitation Interventions
    (ASME International, 2023-04) Pew, Corey A.; Sadeh, Soroosh; Hsiao, Hao-Yuan; Neptune, Richard R.
    Balance perturbations are often used to gain insight into reactive control strategies used to prevent falls. We developed a perturbation platform system (PPS) that can induce perturbations in both vertical and angled directions. The PPS was evaluated using human subject testing to verify its function and performance. The final system consisted of two box platforms that can individually perform vertical and angled surface perturbations. Following a perturbation, the system can automatically reset for the next iteration under the weight of the standing participant. The PPS achieves a peak downward acceleration of 4.4 m/s2 during drop events that simulate sudden surface changes. The experimental testing revealed that the perturbation induced a peak limb loading of 280 ± 38% of body weight (BW) during vertical drops and that participants' center of mass displacements were consistent with previous balance studies evaluating vertical perturbations. The system can be used in a laboratory or clinical setting to better understand balance response and control mechanisms and assist in rehabilitation training to improve balance control and help mitigate the incidence of falls.
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    Osteocyte Remodeling of the Lacunar-Canalicular System: What’s in a Name?
    (Springer Science and Business Media LLC, 2022-12) Heveran, C. M.; Boerckel, J. D.
    Purpose of Review. Osteocytes directly modify the bone surrounding the expansive lacunar-canalicular system (LCS) through both resorption and deposition. The existence of this phenomenon is now widely accepted, but is referred to as “osteocyte osteolysis,” “LCS remodeling,” and “perilacunar remodeling,” among other names. The uncertainty in naming this physiological process reflects the many persistent questions about why and how osteocytes interact with local bone matrix. The goal of this review is to examine the purpose and nature of LCS remodeling and its impacts on multiscale bone quality. Recent Findings. While LCS remodeling is clearly important for systemic calcium mobilization, this process may have additional potential drivers and may impact the ability of bone to resist fracture. There is abundant evidence that the osteocyte can resorb and replace bone mineral and does so outside of extreme challenges to mineral homeostasis. The impacts of the osteocyte on organic matrix are less certain, especially regarding whether osteocytes produce osteoid. Though multiple lines of evidence point towards osteocyte production of organic matrix, definitive work is needed. Recent high-resolution imaging studies demonstrate that LCS remodeling influences local material properties. The role of LCS remodeling in the maintenance and deterioration of bone matrix quality in aging and disease are active areas of research. Summary. In this review, we highlight current progress in understanding why and how the osteocyte removes and replaces bone tissue and the consequences of these activities to bone quality. We posit that answering these questions is essential for evaluating whether, how, when, and why LCS remodeling may be manipulated for therapeutic benefit in managing bone fragility.
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    Subchondral bone structure and synovial fluid metabolism are altered in injured and contralateral limbs 7 days after non-invasive joint injury in skeletally-mature C57BL/6 mice
    (Elsevier BV, 2022-12) Hislop, B. D.; Devine, C.; June, R. K.; Heveran, Chelsea M.
    Objective. Post-traumatic osteoarthritis (PTOA) commonly develops after ACL injury, but early changes to the joint soon after injury are insufficiently understood. The objectives of this study were (1) evaluate the response of subchondral bone tissue modulus to joint injury and (2) identify which bone structural, material, and metabolic outcomes are local (i.e., injured joint only) or systemic (i.e., injured and contralateral-to-injured). Design. Female C57Bl∖6N mice (19 weeks at injury) underwent tibial compression overload to simulate ACL injury (n = 8) or a small pre-load (n = 8). Synovial fluid was harvested at euthanasia 7 days later for metabolomic profiling. Bone outcomes included epiphyseal and SCB microarchitecture, SCB nanoindentation modulus, SCB formation rate, and osteoclast number density. Results. Injury decreased epiphyseal bone volume fraction ([-5.29, −1.38%], P = 0.0016) and decreased SCB thickness for injured vs sham-injured limbs ([2.2, 31.4 μm], P = 0.017)). Epiphyseal bone loss commonly occurred for contralateral-to-injured limbs. There was not sufficient evidence to conclude that SCB modulus changes with injury. Metabolomic analyses revealed dysregulated synovial fluid metabolism with joint injury but that many metabolic pathways are shared between injured and contralateral-to-injured limbs.Conclusion. This study demonstrates rapid changes to bone structure and synovial fluid metabolism after injury with the potential for influencing the progression to PTOA. These changes are often evidenced in the contralateral-to-injured limb, indicating that systemic musculoskeletal responses to joint injury should not be overlooked.
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    Evaluation of the bonding properties between low-value plastic fibers treated with microbially-induced calcium carbonate precipitation and cement mortar
    (Elsevier BV, 2022-11) Espinal, Michael; Kane, Seth; Ryan, Cecily; Phillips, Adrienne J.; Heveran, Chelsea
    Plastic fiber reinforced cementitious materials offer the potential to increase the reusability of plastic waste and create lower-CO2 cementitious composites. However, the bonding properties of many plastic types with ordinary Portland cement (OPC) are largely unknown. This work employs single fiber pullout (SFPO) tests to quantify the interfacial bonding properties of polyvinyl chloride, low-density polyethylene, polypropylene, polystyrene, and acrylonitrile butadiene styrene embedded in OPC mortar. The interfacial bonding properties were compared for fibers either treated with microbially-induced calcium carbonate precipitation (MICP) or left untreated. SFPO tests revealed that plastic type had a large influence over bonding properties. Specifically, the fiber surface energy, as estimated from water contact angle measurements, was found to be the driving factor of bond strength. ABS had the highest surface energy and demonstrated the strongest bonding out of all plastic types studied. However, MICP treatment of fibers did not increase the interfacial bond strength for any of the plastics studied. The thick and inconsistent coverage of biomineral over the fiber surface from MICP is likely attributed to preventing an increase in bond strength. These results contribute to the design and application of plastic-reinforced mortars by comparing bonding properties for a range of typically low-value, unrecycled plastic types.
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    Rural implementation of the perioperative surgical home: A case-control study
    (Baishideng Publishing Group Inc., 2023-03) Sridhar, Srinivasan; Mouat-Hunter, Amy; McCrory, Bernadette
    BACKGROUND. Perioperative surgical home (PSH) is a novel patient-centric surgical system developed by American Society of Anesthesiologist to improve outcomes and patient satisfaction. PSH has proven success in large urban health centers by reducing surgery cancellation, operating room time, length of stay (LOS), and readmission rates. Yet, only limited studies have assessed the impact of PSH on surgical outcomes in rural areas. AIM. To evaluate the newly implemented PSH system at a community hospital by comparing the surgical outcomes using a longitudinal case-control study. METHODS. The research study was conducted at an 83-bed, licensed level-III trauma rural community hospital. A total of 3096 TJR procedures were collected retrospectively between January 2016 and December 2021 and were categorized as PSH and non-PSH cohorts (n = 2305). To evaluate the importance of PSH in the rural surgical system, a case-control study was performed to compare TJR surgical outcomes (LOS, discharge disposition, and 90-d readmission) of the PSH cohort against two control cohorts [Control-1 PSH (C1-PSH) (n = 1413) and Control-2 PSH (C2-PSH) (n = 892)]. Statistical tests including Chi-square test or Fischer’s exact test were performed for categorical variables and Mann-Whitney test or Student’s t-test were performed for continuous variables. The general linear models (Poisson regression and binomial logistic regression) were performed to fit adjusted models. RESULTS. The LOS was significantly shorter in PSH cohort compared to two control cohorts (median PSH = 34 h, C1-PSH = 53 h, C2-PSH = 35 h) (P value < 0.05). Similarly, the PSH cohort had lower percentages of discharges to other facilities (PSH = 3.5%, C1-PSH = 15.5%, C2-PSH = 6.7%) (P value < 0.05). There was no statistical difference observed in 90-d readmission between control and PSH cohorts. However, the PSH implementation reduced the 90-d readmission percentage (PSH = 4.7%, C1-PSH = 6.1%, C2-PSH = 3.6%) lower than the national average 30-d readmission percentage which is 5.5%. The PSH system was effectively established at the rural community hospital with the help of team-based coordinated multi-disciplinary clinicians or physician co-management. The elements of PSH including preoperative assessment, patient education and optimization, and longitudinal digital engagement were vital for improving the TJR surgical outcomes at the community hospital. CONCLUSION. Implementation of the PSH system in a rural community hospital reduced LOS, increased direct-to-home discharge, and reduced 90-d readmission percentages.
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    Hydraulic bulge testing to compare formability of continuous and stretch broken carbon fiber reinforced polymer composites
    (Springer Science and Business Media LLC, 2023-02) Shchemelinin, Yoni; Nelson, Jared W.; Ryan, Cecily; Bajwa, Dilpreet S.; Cairns, Doug; Amendola, Roberta
    The use of carbon fiber reinforced polymer composites has increased with the increased need for high-strength, low-density materials, particularly in the aerospace industry. Stretch broken carbon fiber (SBCF) is a form of carbon fiber created by statistically distributed breakage of aligned fibers in a tow at inherent flaw points, resulting in a material constituted of collimated short fibers with an average length larger than chopped fibers. While continuous carbon fiber composites have desirable material properties, the limited ability to form in complex geometries prevents their wide adoption. SBCF composites exhibit pseudo-plastic deformation that can potentially enable the use of traditional metal forming techniques like stamping and press forming, widely used for mass production applications. To investigate the formability of carbon fiber reinforced polymer composites prepared with either continuous or stretch broken Hexcel IM-7 12 K fibers and impregnated with Huntsman RDM 2019–053 resin, hydraulic bulge testing was performed at atmospheric pressure and elevated temperature to explore the strain behavior under biaxial stress conditions for the material system. Results based on deformation of surface patterning, bulge apex displacement and measurement of the bulge internal surface and volume, support the enhanced formability of the SBCF material when compared to its continuous counterpart. The SBCF enhanced formability is characterized by an axisymmetric stress response and a failure mechanism similar to the one observed for sheet metal
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