Repair Model Research Articles

A Composite Foam of Dermal Matrix-Demineralized Bone Matrix for Enhanced Bone Regeneration.

Allogenic demineralized bone matrix (DBM) is widely used for bone repair and regeneration due to its osteoinductivity and osteoconductivity. The present study utilized acellular dermis microfibers to improve the DBM's clinical handling properties and to enhance bone regeneration. Donated human cadaver skin was de-epidermized and decellularized to be acellular dermal matrix (ADM), which was further processed into microfibers. Donated human bone was micronized and partially demineralized (∼30% calcium removal) for optimal bone regeneration. A flexible ADM/DBM composite foam was fabricated with ADM microfibers and DBM particles. Structural analysis found that the ADM/DBM composite foam had proper porosity with interconnected micropores and rapid wettability, and good stability upon cyclic compressions, whereas cytotoxicity test, in vitro collagenase degradation, and rat subcutaneous implantation showed good biocompatibility and biodegradability. The composite foam, used for in vitro coculture, significantly increased the alkaline phosphatase activity of C2C12 cells and upregulated the expression of osteogenesis-related genes of human umbilical cord mesenchymal stem cells. Using the rat Φ8 mm calvarium defect repair model, the ADM/DBM composite foam demonstrated superior osteogenicity by rapidly inducing new bone formation and achieving complete closure of the bone defects, as compared with the commercially available bone graft for skull repair (SkuHeal). Therefore, the ADM/DBM composite foam holds promise as a superior DBM-based product for repairing critical bone defects.

Evaluation of Dexamethasone-Eluting Cell-Seeded Constructs in a Preclinical Canine Model of Cartilage Repair.

In this 12-month long, preclinical large animal study using a canine model, we report that engineered osteochondral grafts (comprised of allogeneic chondrocyte-seeded hydrogels with the capacity for sustained release of the corticosteroid dexamethasone [DEX], cultured to functional mechanical properties, and incorporated over porous titanium bases), can successfully repair damaged cartilage. DEX release from within engineered cartilage was hypothesized to improve initial cartilage repair by modulating the local inflammatory environment, which was also associated with suppressed degenerative changes exhibited by menisci and synovium. We note that not all histological and clinical outcomes at an intermediary time point of three months paralleled 12-month outcomes, which emphasizes the importance of invivo studies in valid preclinical models that incorporate clinically relevant follow-up durations. Together, our study demonstrates that engineered cartilage fabricated under the conditions reported herein can repair full-thickness cartilage defects and promote synovial joint health and function.

Optimal Suturing Techniques in Patch-Bridging Reconstruction for Massive Rotator Cuff Tears: A Finite Element Analysis

PurposeTo use a finite element method to construct a patch-bridge repair model for MRCTs and investigate the effects of different suture methods and knot numbers on postoperative biomechanics. MethodsA finite element model based on intact glenohumeral joint data was used for a biomechanical study. A full-thickness defect and retraction model of the supraspinatus tendon simulated MRCTs. Patch, suture, and anchor models were constructed, and the Marlow method was used to assign the material properties. Three suturing models were established: 1-knot simple, 1-knot mattress, and 2-knot mattress. The ultimate failure load, failure mode, stress distribution of each structure, and other biomechanical results of the different models were calculated and compared. ResultsThe ultimate failure load of the 1-knot mattress suture (71.3 N) was 5.6% greater than that of the 1-knot simple suture (67.5 N), while that (81.5 N) of the 2-knot mattress was 14.3% greater than that of the 1-knot mattress. The stress distribution on the patch and supraspinatus tendon was concentrated on suture perforation. Failure of the bridging reconstruction mainly occurred at the suture perforation of the patch, and the damage forms included cutting-through and isthmus pull-out. ConclusionA finite element model for the patch-bridging reconstruction of MRCTs was established, and patch-bridging restored the mechanical integrity of the rotator cuff. The 2-knot mattress suture was optimal for patch-bridging reconstruction of MRCTs.

A Potent, Selective, Small-Molecule Inhibitor of DHX9 Abrogates Proliferation of Microsatellite Instable Cancers with Deficient Mismatch Repair.

DHX9 is a multifunctional DExH-box RNA helicase with important roles in the regulation of transcription, translation, and maintenance of genome stability. Elevated expression of DHX9 is evident in multiple cancer types, including colorectal cancer (CRC). Microsatellite instable-high (MSI-H) tumors with deficient mismatch repair (dMMR) display a strong dependence on DHX9, making this helicase an attractive target for oncology drug discovery. In this report, we show that DHX9 knockdown increased RNA/DNA secondary structures and replication stress, resulting in cell cycle arrest and the onset of apoptosis in cancer cells with MSI-H/dMMR. ATX968 was identified as a potent and selective inhibitor of DHX9 helicase activity. Chemical inhibition of DHX9 enzymatic activity elicited similar selective effects on cell proliferation as seen with genetic knockdown. In addition, ATX968 induced robust and durable responses in an MSI-H/dMMR xenograft model but not in a microsatellite stable (MSS)/proficient mismatch repair (pMMR) model. These preclinical data validate DHX9 as a target for the treatment of patients with MSI-H/dMMR. Additionally, this potent and selective inhibitor of DHX9 provides a valuable tool with which to further explore the effects of inhibition of DHX9 enzymatic activity on the proliferation of cancer cells in vitro and in vivo.

Preparation and characterization of Pistacia atlantica oleo-gum-resin-loaded electrospun nanofibers and evaluating its wound healing activity in two rat models of skin scar and burn wound.

A growing body of research is dedicated to developing new therapeutic agents for wound healing with fewer adverse effects. One of the proceedings being taken today in wound healing research is to identify promising biological materials that not only heal wounds but also vanish scarring. The effectiveness of nanofibers like polyvinyl alcohol (PVA), in improving wound healing can be related to their unique properties. Pistacia atlantica Desf. subsp. kurdica (Zohary) Rech. f. (PAK) [Anacardiaceae], also known as "Baneh" in traditional Iranian medicine, is one of the most effective herbal remedies for the treatment of different diseases like skin injuries due to its numerous pharmacological and biological properties, including anti-inflammatory, antioxidant, and anti-bacterial effects. Our study aimed to evaluate the wound-healing activity of nanofibers containing PVA/PAK oleo-gum-resin in two rat models of burn and excision wound repair. PVA/PKA nanofibers were prepared using the electrospinning method. Scanning electron microscope (SEM) images and mechanical properties of nanofibers were explored. Diffusion and releasing experiments of nanofibers were performed by the UV visible method at different time intervals and up to 72h. The animal models were induced by excision and burn in Wistar rat's skin and the wound surface area was measured during the experiment for 10 and 21days, respectively. On the last day, the wound tissue was removed for histological studies, and serum oxidative factors were measured to evaluate the antioxidant properties of the PVA/PKA. Data analysis was performed using ImageJ, Expert Design, and statistical analysis methods. PVA/PKA nanofibers were electrospun at different voltages (15, 18, and 20kV). The most suitable fibers were obtained when the nozzle was positioned 15cm away from the collector, with a working voltage of 15kV, and an injection rate of 0.5mm per hour, using the 30:70 w/v PKA gum. In the SEM images, it was found that the surface tension of the polymer solution decreased by adding the gum and yield thinner and longer fibers at a voltage of 15kV with an average diameter of 96 ± 24nm. The mechanical properties of PVA/PKA nanofibers showed that the presence of gum increased the tensile strength and decreased the tensile strength of the fibers simultaneously. In vivo results showed that PVA/PKA nanofibers led to a significant reduction in wound size and tissue damage (regeneration of the epidermal layer, higher density of dermal collagen fibers, and lower presence of inflammatory cells) compared to the positive (phenytoin and silver sulfadiazine) and negative control (untreated) groups. Wound contraction was higher in rats treated with PVA/PKA nanofibers. Additionally, antioxidative serum levels of catalase and glutathione were higher in the PVA/PKA nanofiber groups even in comparison to positive control groups. Pistacia atlantica oleo-gum-resin-loaded electrospun nanofibers potentially improve excision and burn models of skin scars in rats through antioxidative and tissue regeneration mechanisms.

The Rochester Model for Spinal CSF Leak Repair Simulation and Scoring.

Iatrogenic spinal durotomies occur at a rate of 1% to 17%. Surgical simulation for durotomy repair is needed to provide affordable, accessible, and validated practice. This study sought to design and validate a simple 3-dimensional printed model for spinal cerebrospinal fluid (CSF) leak repair and to introduce the Rochester original objective structured assessment of technical skills (OSATS) CSF leak (ROCL) repair criteria for assessment. A spinal model was designed to mimic a lumbar laminectomy with the L3-5 lamina removed and 3-dimensional printed using Vero polymers. The model was paired with a porcine collagen "dura" that was pressurized using IV saline and overlayed with gel-molded fascial, muscle, and skin layers with an opening. Participants were provided a training model with a 1.5-cm midline durotomy, surgical microinstrument set, microscope, and 6-0 prolene suture. The 25-point ROCL repair criteria were adapted from the original OSATS principles to assess proficiency in surgical repair by 2 blinded neurosurgeons not participating in the trials. Postsimulation survey data regarding model realism were collected. Six residents and 4 attendings participated. Median operative time in minutes was 13 minutes among residents and 7 minutes among attendings. Moreover, the ROCL score was a median of 19/25 for attendings and 15/25 for residents. The suture angle was statistically more consistent among senior residents and attendings compared with junior residents. Participants agreed that the model was realistic (median 4/5), useful for improving the operative technique (median 5/5), and would increase comfort in spinal CSF leak repair procedures (median 5/5). Each reusable model had a cost of $19.99 if printed with polylactic acid and each replacement dura cost <3¢. This study presents an affordable, realistic, and educational spinal CSF leak repair model and introduces ROCL for assessment.

Electrohydrodynamic-Printed Dual-Triphase Microfibrous Scaffolds Reshaping the Lipidomic Profile for Enthesis Healing in a Rat Rotator Cuff Repair Model.

Rotator cuff injuries often result in chronic pain and functional limitations due to retears and scar formation at the enthesis. This study assess the efficacy of electrohydrodynamic-printed microfibrous dual-triphase scaffolds (DTSs), designed to optimize enthesis repair. These scaffolds, composed of polycaprolactone enhanced with nanohydroxyapatite, nano-magnesium-oxide, and kartogenin demonstrate significant biological advantages. In vitro, the scaffolds support over 95% stem cell viability and promote enhanced expression of critical markers such as tenomodulin (TNMD), sex-determining region Y-Box transcription factor 9 (SOX-9), and runt-related transcription factor 2 (RUNX-2). Enhanced expressions of tendon markers tenomodulinand scleraxis (SCX) are noted, alongside significant upregulation of chondrocyte and osteoblast markers. In vivo, these scaffolds significantly improve the biomechanical properties of the repaired enthesis, with a maximum failure load of 27.0 ±4.2 N and ultimate stress of 5.5 ±1.0MPa at 6 weeks postimplantation. Lipidomic analysis indicates substantial regulation of phospholipids such as phosphatidylcholine and phosphatidylserine, highlighting the scaffold's capacity to modulate biochemical pathways critical for tissue repair and regeneration. This study underscores the potential of DTS to improve clinical outcomes in rotator cuff injury treatment by enhancing cellular differentiation, biomechanical properties, and biochemical environment, setting a foundation for personalized treatment strategies in tendon-bone repair.

Optimizing the Electrical Microenvironment Provided by 3D Micropillar Topography on a Piezoelectric BaTiO3 Substrate to Enhance Osseointegration.

The electrical properties of bone implant scaffolds are a pivotal factor in regulating cellular behavior and promoting osteogenesis. The previous study shows that built-in electric fields established between electropositive nanofilms and electronegative bone defect walls are beneficial for promoting bone defect healing. Considering that the physiological electrical microenvironment is spatially distributed in 3D, it is imperative to establish a 3D spatial charged microenvironment on bone scaffolds to optimize the efficacy of osseointegration. Nevertheless, this still poses a formidable challenge. Here, a bone repair strategy that utilizes micro-scale 3D topography is developed on a piezoelectric BaTiO3 (BTO) substrate to provide 3D spatial electrical stimulation. The BTO micropillar arrays, especially with a height of 50 µm and positive-charge distribution (50 µm positive), promote the spreading, cytoskeletal reorganization, focal adhesion maturation, and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). They enhanced the clustering of mechanosensing integrin α5 in BMSCs. The biomimetic 3D spatial electrical microenvironment accelerated bone repair and osseointegration in a rat femoral diaphysis defect repair model. The study thus reveals that implants with a 3D spatial electrical microenvironment can significantly enhance osseointegration, thereby providing a new strategy to optimize the performance of electroactive biomaterials for tissue regenerative therapies.

GaussianObject: High-Quality 3D Object Reconstruction from Four Views with Gaussian Splatting

Reconstructing and rendering 3D objects from highly sparse views is of critical importance for promoting applications of 3D vision techniques and improving user experience. However, images from sparse views only contain very limited 3D information, leading to two significant challenges: 1) Difficulty in building multi-view consistency as images for matching are too few; 2) Partially omitted or highly compressed object information as view coverage is insufficient. To tackle these challenges, we propose GaussianObject, a framework to represent and render the 3D object with Gaussian splatting that achieves high rendering quality with only 4 input images. We first introduce techniques of visual hull and floater elimination, which explicitly inject structure priors into the initial optimization process to help build multi-view consistency, yielding a coarse 3D Gaussian representation. Then we construct a Gaussian repair model based on diffusion models to supplement the omitted object information, where Gaussians are further refined. We design a self-generating strategy to obtain image pairs for training the repair model. We further design a COLMAP-free variant, where pre-given accurate camera poses are not required, which achieves competitive quality and facilitates wider applications. GaussianObject is evaluated on several challenging datasets, including MipNeRF360, OmniObject3D, OpenIllumination, and our-collected unposed images, achieving superior performance from only four views and significantly outperforming previous SOTA methods.

Optimal replacement policy for repairable products with multi-attempt minimal repair under the free-repair warranty

ABSTRACT This paper investigates the effects of unsuccessful repairs on the optimal periodic replacement policy for a repairable product with multiple attempts of minimal repair under the free-repair warranty. The motivation for this study is based on the novel notion of ‘multi-attempt minimal repair’, first introduced by Cha and Finkelstein (2024a, 2024b), in which they highlighted various practical reasons and examples to illustrate that minimal repair attempts may sometimes fail and need to be repeated until success is achieved. Their repair model and useful properties served as the motivation for this study. For both the warranted and non-warranted products, cost models are developed from the user’s perspective, and the corresponding optimal replacement policies are derived to minimize the long-run expected cost rates. By comparing these optimal policies, we show that the optimal planned time for preventive replacement should be adjusted toward the end of the warranty period, and the effects of unsuccessful minimal repair produce different degrees of impact, respectively, on the warranted and non-warranted product. Finally, detailed numerical examples and computation results illustrate our findings, and some insightful observations about practical and managerial implications are concluded.

Early exercise disrupts a pro-repair extracellular matrix program during zebrafish fin regeneration.

Controlled exercise promotes healing and recovery from severe skeletal injuries. However, properly timed interventions are essential to promote recovery and prevent further damage. We use zebrafish caudal fin regeneration to mechanistically study exercise impacts on a naturally robust and experimentally accessible model of tissue repair. We link detrimental early exercise effects during fin regeneration to impaired ECM synthesis, mechanotransduction, and cell proliferation. These insights could explain the value of delaying the onset of physical therapy and suggest pursuing therapies that maintain ECM integrity for regenerative rehabilitation.

3D-Printed Bioceramic Scaffolds Reinforced by the In Situ Oriented Growth of Grains for Supercritical Bone Defect Reconstruction.

Porous calcium phosphate ceramics have attracted widespread attention owing to their excellent bioactivity. However, their poor mechanical properties severely limit their clinical applications. Significantly improving the mechanical strength of porous CaP ceramics while maintaining their bioactivity remains a major challenge. To address this issue, calcium sulfate is used to regulate the directional growth of hydroxyapatite grains during ceramic sintering. The in situ oriented grains can not only alleviate the stress concentration but also strengthen the bonding force between the ceramic grain boundaries. Calcium sulfate improves the release of active calcium ions from calcium phosphate ceramics, further enhancing their bioactivity and osteoinductivity in vivo. Transcriptome and proteome sequencing reveals that the in situ whisker-reinforced ceramics increase the expression of proteins related to calcium ion binding and promote the expression of osteogenesis-related proteins. In the supercritical bone defect repair model, repair of the defect is achieved within 3 months, with mechanical recovery reaching more than 70% of the autologous bone.

Design and evaluation of a novel variable-length stepped scarf repair technique using a cohesive damage model

The advantages of Carbon Fibre Reinforced Polymers (CFRPs) are well established, but repairing CFRP components remains difficult and costly, posing challenges for industries like aerospace. This paper explores the design, modelling, inspection, and testing of a Variable Length Stepped Scarf (VLSS) repair scheme for highly loaded composite structures. A fully nonlinear 2D Finite Element Model (FEM) is used to design the VLSS repair, predict failure loads and modes, and model adhesive cohesion and delamination. The model incorporates a validated progressive damage model, general contact, and both force and geometric nonlinearities. Two manufacturing techniques involving hard repair patches and glass beads to maintain a constant bond line are employed. A 3D FEM validated against repaired composite coupons under uniaxial tension shows excellent agreement with experimental data. The static strength repair efficiency is approximately 80 % of a pristine sample, with failure displacements at 87 %, and Hooke's stiffness at 102 % of pristine laminates. Cohesive failure at adhesive overlap edges is identified as the cause of stiffness degradation, confirming experimental observations. This study contributes to both composite repair modelling and repair design optimisation.

Robert Rosen’s Relational Biology Theory and His Emphasis on Non-Algorithmic Approaches to Living Systems

This paper examines the use of algorithms and non-algorithmic models in mathematics and science, especially in biology, during the past century by summarizing the gradual development of a conceptual rationale for non-algorithmic models in biology. First, beginning a century ago, mathematicians found it impossible to constrain mathematics in an algorithmic straitjacket via öö’s Incompleteness Theorems, so how would it be possible in biology? By the 1930s, biology was resolutely imitating classical physics, with biologists enforcing a reductionist agenda to expunge function, purpose, teleology, and vitalism from biology. Interestingly, physicists and mathematicians often understood better than biologists that mathematical representations of living systems required different approaches than those of dead matter. Nicolas Rashevsky, the Father of Mathematical Biology, and Robert Rosen, his student, pointed out that the complex systems of life cannot be reduced to machines or mechanisms as per the Newtonian paradigm. Robert Rosen concluded that living systems are not amenable to algorithmic models that are primarily syntactical. Life requires semantics for its description. Rashevsky and Rosen pioneered Relational Biology, initially using Graph Theory to model living systems. Later, Rosen created a metabolic–repair model (M, R)-system using Category Theory to encode the basic entailments of life itself. Although reductionism still dominates in current biology, several subsequent authors have built upon the Rashevsky–Rosen intellectual foundation and have explained, extended, and explored its ramifications. Algorithmic formulations have become increasingly inadequate for investigating and modeling living systems. Biology is shifting from a science of simple systems to complex ones. This transition will only be successful once mathematics fully depicts what it means to be alive. This paper is a call to mathematicians from biologists asking for help in doing this.

Inflammation-Responsive Functional Core-Shell Micro-Hydrogels Promote Rotator Cuff Tendon-To-Bone Healing by Recruiting MSCs and Immuno-Modulating Macrophages in Rats.

Rotator cuff injuries often necessitate surgical intervention, but the outcomes are often unsatisfactory. The underlying reasons can be attributed to multiple factors, with the intricate inflammatory activities and insufficient presence of stem cells being particularly significant. In this study, an innovative inflammation-responsive core-shell micro-hydrogel is designed for independent release of SDF-1 and IL-4 within a single delivery system to promote tendon-to-bone healing by recruiting MSCs and modulating M2 macrophages polarization. First, a MMP-2 responsive hydrogel loaded with IL-4 (GelMA-MMP/IL-4) is synthesized by cross-linking gelatin methacrylate (GelMA) with MMP-2 substrate peptide. Then, the resulting core particles are coated with a shell of chitosan /SDF-1/hyaluronic acid (CS/HA/SDF-1) using the layer-by-layer electrostatic deposition method to form a core-shell micro-hydrogel composite. The core-shell micro-hydrogel shows sustained release of SDF-1 and MMP-2-responsive release of IL-4 associated in situ MSCs homing and smart inflammation regulation by promoting M2 macrophages polarization. Additionally, by injecting these micro-hydrogels into a rat rotator cuff tear and repair model, notable improvements of fibrocartilage layer are observed between tendon and bone. Notably, this study presents a new and potentially powerful environment-responsive drug delivery strategy that offers valuable insights for regulating the intricate micro-environment associated with tissue regeneration.

Nanodosimetric study of the γ-ray damage repair model based on the germ cell of Caenorhabditis elegans

Monte Carlo calculations are extensively used in the fields of nanodosimetry and DNA damage research. Presently, the focus of DNA repair simulation studies is predominantly on the temporal aspects of the repair process, the impact of radiation dose on DNA repair requires further investigation. Caenorhabditis elegans (C.elegans) is one of the important model organisms in radiation biology research, and its germ cells are closely related to the DNA damage. Using the Hilbert curve, the DNA germ cell of C. elegans was constructed, and the double-strand breaks (DSB) yields quantified by Geant4-DNA. After comparing the simulation results of total DNA damage and cluster damage with biological data, it was found that the simulation results of cluster damage are close to the biological data. The number of DSBs induced by 137Cs radiation was further compared with experimental data at different doses and proposed a damage repair model for the number of DSBs in the germ cell of C.elegans that is related to the dose.The repair fitting was conducted for both total DSB damages and DSB cluster damages. After the application of the repair model fitting for the two types of DNA damage mentioned above, the results matched well with the corresponding biological experimental data (R2 > 0.950).

Monte Carlo damage models of different complexity levels predict similar trends in radiation induced DNA damage

Ion therapies have an increased relative biological effectiveness (RBE) compared to X-rays, but this remains poorly quantified across different radiation qualities. Mechanistic models that simulate DNA damage and repair after irradiation could be used to help better quantify RBE. However, there is large variation in model design with the simulation detail and number of parameters required to accurately predict key biological endpoints remaining unclear. This work investigated damage models with varying detail to determine how different model features impact the predicted DNA damage.&#xD;&#xD;Methods: Damage models of reducing detail were designed in TOPAS-nBio and Medras investigating the inclusion of chemistry, realistic nuclear geometries, single strand break damage, and track structure. The nucleus models were irradiated with 1 Gy of protons across a range of linear energy transfers (LETs). Damage parameters in the models with reduced levels of simulation detail were fit to proton double strand break (DSB) yield predicted by the most detailed model. Irradiation of the optimised models with a range of radiation qualities was then simulated, before undergoing repair in the Medras biological response model.&#xD;&#xD;Results: Simplified damage models optimised to proton exposures predicted similar trends in DNA damage across radiation qualities. On average across radiation qualities, the simplified models experienced an 8% variation in double strand break (DSB) yield but a larger 28% variation in chromosome aberrations. Aberration differences became more prominent at higher LETs, with model features having an increasing impact on the distribution and therefore misrepair of DSBs. However, overall trends remained similar with better agreement likely achievable through repair model optimisation. &#xD;&#xD;Conclusion: Several model simplifications could be made without compromising key damage yield predictions, although changes in damage complexity and distribution were observed. This suggests simpler, more efficient models may be sufficient for initial radiation damage comparisons, if validated against experimental data.&#xD.

A biomechanical investigation comparing a novel bone cement bridging screw system with conventional treatment methods for Kummell’s disease

Based on the characteristics of Kummell’s disease (KD) and related anatomical structures of the thoracolumbar spine, a novel bone cement screw system has been designed to effectively avoid the cement loosening and displacement. This experiment aimed to assess the biological effects of the novel bone cement screw system in KD on fresh cadaveric thoracolumbar spine specimens, thereby discussing its potential application value and providing a foundation for clinical implementation. This study employed a total of 50 fresh female adult cadaver specimens. Each specimen underwent extraction of the T12 to L2 segment followed by the creation of an artificial KD model at the L1 segment and subsequent establishment of five distinct types of bone cement repair models. Model A represents the percutaneous vertebroplasty (PVP) model, Model B combines PVP with unilateral percutaneous pediculoplasty (PPP), Model C combines PVP with bilateral PPP, Model D introduces the novel bone cement screw combined with unilateral PVP, and Model E combines the novel screw with bilateral PVP, each group consists of 10 specimens. Subsequently, the six-axis spine robot was employed to execute cement three-dimensional biomechanical strength tests in six directions, including anterior flexion and posterior extension, left and right lateral bending, as well as left and right rotation. The novel bone cement screw, whether used unilaterally or bilaterally in combination with the PVP model, exhibits significantly reduced bone cement mobility and superior biomechanical stability during anterior flexion, posterior extension, left lateral bending, and right lateral bending (P<0.05).No significant differences were observed among the five models under both left and right rotation (P > 0.05).When comparing the novel bone cement screw combined with PVP unilaterally and bilaterally, no statistically significant difference was observed in the stability of bone cement across all six directions of motion (P>0.05). To conclude, this novel bone cement bridging screw system exhibits superior biomechanical stability compared to commonly used treatments. Furthermore, both unilateral and bilateral implementations of the novel bone cement screw system yield without significant differences observed. These findings present a reliable and innovative approach for clinical management of KD.

Systematic Analysis of Image Restoration Methods Based on Deep Learning

In today's digital age, people often use images to convey information. However, during the process of sending images, they can become damaged for various reasons, causing the images to lose their original meaning. In such cases, image repair is necessary to restore the damaged areas to their original, undamaged appearance. Traditional image repair methods often struggle to produce effective results for highly damaged images. However, image repair using deep learning techniques can address these challenges effectively. This paper will detail the impact of image repair on Convolutional Neural Networks (CNN), Recurrent Neural Networks (RNN), Long Short-Term Memory networks (LSTM), Convolutional Recurrent Neural Networks (CRNN), and other models, as well as the advantages and disadvantages of each approach. From the data, it is evident that combining multiple models for image repair is the most effective method. This approach reduces the consumption of hardware resources and time required for image repair, thereby improving the overall efficiency of the process.

Crack monitoring and repair model of SMA composite material based on strain transfer

In the process of using composite materials, crack damage is unavoidable. These cracks may cause a decrease in the structural performance of the material and may even pose a threat to the safety of the entire structure. In this paper, the shape memory alloy (SMA) is embedded into the composite material, and the strain transfer effect of the interface layer is considered. The crack monitoring and repair model of SMA composite material based on strain transfer are established using SMA resistance-sensing characteristics and SMA constitutive model. Based on this monitoring and repair model, the crack monitoring behavior of SMA under different initial states and temperature conditions is discussed, and the crack repair behavior of SMA under specific initial states and temperature conditions is also discussed. The research results show that the change in SMA resistance and the strain of the composite material crack are linearly segmented, and as the temperature increases, the composite material crack is gradually repaired. This study can provide theoretical guidance for the further engineering application of SMA composite material crack monitoring and repair theory.