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Introduction: Ballistic fractures of the humerus secondary to gunshot wounds are increasingly common injuries that pose challenges for orthopedic surgeons. The primary purpose of this study was to examine the rates of neurovascular injury, compartment syndrome, and infection of ballistic humerus fractures relative to blunt, non-penetrating fractures. Methods: A consecutive cohort of 135 patients with ballistic humerus fractures and 167 patients with blunt humerus fractures treated at a level 1 trauma center were identified. A review of patient medical records and radiographic studies was performed to obtain demographic information, injury mechanism, fracture location, choice of treatment, and complications. Statistical analysis was performed using independent sample t -tests, chi-square tests, and odds ratios (p < 0.05 significance). Results: Compared with blunt fractures, patients in the ballistic fracture cohort were younger, male, African American, test positive for illicit drug use, and sustain proximal fractures. Ballistic fractures had significantly lower Injury Severity Scores and New Injury Severity Scores. Ballistic fractures were three times as likely to present with neurovascular injury than blunt fractures (OR: 2.927, p < 0.001). The overall rate of spontaneous recovery of significant motor function for ballistic fractures with neurologic injury was 55%. There were no statistically significant differences in rates of vascular injury, compartment syndrome, infection, non-union, or the need for soft tissue reconstruction. Conclusion: Compared with blunt humeral fractures, ballistic fractures appear to have a significantly higher rate of neurologic injury but no increased risk for compartment syndrome or infection. Surgical treatment of ballistic humeral injuries was not associated with increased neurological recovery compared to non-operatively managed fractures. [ABSTRACT FROM AUTHOR]

Fullerenes, as single crystals, present exceptional mechanical and physical properties due to their hollow spherical molecular structure consisting of carbon atoms connected by covalent bonds. The idea of linking these allotropes of carbon to create monolayer networks has now been accomplished experimentally. The question that remains to be answered is if these synthesized single‐layered nanosheets of fullerene present comparable properties with graphene monolayers. To answer this important question and to estimate the full tensile stress–strain behavior of quasi‐tetragonal as well as quasi‐hexagonal configurations of C60 planar networks, several Molecular Dynamics simulations are performed in this work by using a new REAXFF and the AIREBO‐M potential. Various mechanical properties, such as Young's modulus, Poisson's ratio, ultimate tensile strength, ultimate tensile strain, and fracture energy at failure of C60 monolayers of several sizes, are computed and compared with the results reported in the literature. Furthermore, a comprehensive discussion is made regarding the significant influence of the adopted potential on the numerical predictions of the elastic mechanical and fracture behavior of the fullerene nanosheets. [ABSTRACT FROM AUTHOR]

ABSTRACT Plasticity and fracture problems have always been hot topics in numerical methods. In this work, a universal implementation procedure for the elasto‐plastic constitutive model is developed in the four‐dimensional lattice spring model (4D‐LSM), in which the Jaumann stress rate is incorporated to exclude the influence of the rigid rotation in the particle stress, expanding the ability of 4D‐LSM to deal with large elastic deformation problems by its own to large plastic deformation problems. As an example, the Zienkiewicz–Pande (ZP) constitutive model is implemented. Several numerical examples are carried out to check the performance of the implemented model. Through a comparison with analytical solutions, available experimental data, and other numerical results, the stability of the developed plastic framework and the correctness of the stress calculation scheme are verified. Meanwhile, numerical results show that the developed code is capable of solving elasto‐plastic large deformation problems. With the advantage of 4D‐LSM in handling fracture problems, the ability of the embedded model to solve plastic fracture problems is verified with a simple maximum deformation failure criterion. [ABSTRACT FROM AUTHOR]

Background: Two intra‐coronal preparation designs with varying extensions of cuspal coverage can perform differently regarding their fracture resistance against introral forces. Methods: Two materials (IPS e‐max CAD [EX], VITA ENAMIC [EN]), and two different preparation designs (EX‐D1), (EX‐D2), (EN‐D1), and (EN‐D2) were investigated to compare their fracture resistance. A total of 40 (n = 40) caries free human mandibular molars were used. All the prepared samples were scanned using CEREC Omnicam scanner and the preparations were checked by the software for any sharpness and undercuts before restoration designing and fabrication. All restorations were milled using Cerec MCXL 4.4 milling machine. Duo‐Link resin cement was used for cementation. After thermocycling and chewing simulation, all samples were loaded in the Universal testing machine in order to evaluate fracture resistance of all samples. Results: Fracture resistance testing revealed that e‐max CAD (2134 N) showed statistically significantly higher mean fracture resistance values than Vita Enamic (1728 N). On the other hand, there was no statistically significant difference between mean fracture resistances between the two tested designs. Conclusions: Within the confines of this investigation, it can be said that although preparation design had no appreciable impact on fracture resistance, the CAD/CAM ceramic material utilized did. Clinical Significance: When restoring compound cavitties indirectly; a conservative defect oriented approach should be used. Glass Ceramic are prefered as restorative material. [ABSTRACT FROM AUTHOR]

Osteoporotic fracture is a prevalent noncommunicable disease globally, causing significant mortality, morbidity, and disability. As the population ages, the healthcare and economic burden of osteoporotic fracture is expected to increase further. Due to its multifactorial features, the development of osteoporotic fracture involves a complex interplay of multiple risk factors, including genetic, environmental, and lifestyle factors. Helicobacter pylori, which infects approximately 43% of the world's population, has been associated with increased fracture risk due to hypochlorhydria from atrophic gastritis and systemic inflammation from elevated pro‐inflammatory cytokines. However, the potential impact of H. pylori infection and eradication on fracture risk remains contentious among various studies due to the study design and inadequate adjustment of confounding factors including baseline gastritis phenotype. In this review, we provided a comprehensive evaluation of the current evidence focusing on the underlying mechanisms and clinical evidence of the association between H. pylori infection and osteoporotic fracture. We also discussed the potential benefits of H. pylori eradication on fracture risk. [ABSTRACT FROM AUTHOR]

ABSTRACT This study investigates the fracture behavior of brittle solids with combined defects by prefabricating internal cracks in glass materials using three‐dimensional internal laser‐engraved crack (3D‐ILC) technology. The results of physical and numerical experiments indicate that under biaxial compression, cracks first appear on the surface of the cavity, followed by the propagation of the prefabricated cracks. During propagation, these two cracks attract each other, ultimately leading to crack coalescence. As the geometric distribution of the combined defects changes, the propagation direction of the prefabricated cracks deflects to varying degrees as is to be expected. The failure process of the specimens with combined defects was a mixed‐mode I–II–III fracture. This research provides experimental and theoretical references for the study of crack propagation in rock materials containing combined defects. [ABSTRACT FROM AUTHOR]

ABSTRACT Background Objective Methods Results Conclusion Condylar fractures (CFs) are a common type of maxillofacial trauma, especially in adolescents. Conservative treatment of CF avoids the possible complications of surgical intervention, but prolongs the patient's suffering because of the requirement for extended intermaxillary fixation. Therefore, the development of a new strategy to accelerate the rate of fracture healing to shorten the period of conservative treatment is of great clinical importance.To investigate the potential of deferoxamine (DFO) in promoting the healing process of CF in adolescent mice.Thirty‐two 4‐week‐old male C57BL/6J mice were randomly assigned to four groups: vehicle + sham group, vehicle + CF group, DFO + sham group and DFO + CF group. After constructing the mandibular CF model, mandibular tissue samples were collected respectively at 1, 2 and 4 weeks postoperatively. Radiographic and histomorphometric analyses were employed to assess bone tissue healing and vascular formation.Deferoxamine was observed to promote the early bone healing of fracture, both radiologically and histomorphometrically. Furthermore, this enhancement of condylar neck fracture healing was attributed to the upregulation of the hypoxia‐inducible factor‐1α (HIF‐1α) signalling pathway while facilitating the formation of type H vessels. In addition, DFO did not produce significant effects on the condylar neck between vehicle + sham and DFO + sham group.The application of the HIF‐1α inducer DFO can enhance type H vessels expansion thereby accelerating condylar neck fracture healing. [ABSTRACT FROM AUTHOR]

This paper presents a numerical investigation into the effects of pre-induced cracks on polycrystalline diamond compact (PDC) rock drilling processes under varying pressure conditions. A 3-D finite element model was created using a linear Drucker–Prager yield criterion in conjunction with a damage criterion to model element erosion. The model used a single PDC linear cutting configuration to highlight the differences between uncracked and cracked rock cutting in terms of cutting forces and cutting mechanism. The objective is to address the change in the effectiveness of pre-induced cracks under high-pressure conditions, similar to those in actual deep-drilling operations. The results show that the pre-induced cracks reduce the cutting force under the tested pressure range (0–100 MPa). The overall effectiveness decreases as the confining pressure increases because the pressure compacts the rock, restricting fracturing ahead of the cutter surface. Additionally, the rock cutting mechanism changes from a continuous removal of material at the atmosphere to a more intermittent form at higher pressures. Highlights: Finite element simulations reveal the impact of confining pressure and pre-existing cracks on single cutter rock cutting dynamics Calibration of granite rock behavior utilizing a pressure dependent Linear Drucker–Prager Yield criteria Integration of pre-existing cracks in the simulation through a node-separation algorithm Analysis of the interaction between confining pressure and pre-existing cracks on rock cutting efficiency Simulation results showed changes in cutting mechanisms and force responses due to varying confining pressures and crack presence [ABSTRACT FROM AUTHOR]

High-temperature oxidation and uniaxial tensile tests were conducted on cylinder head cast iron material to investigate oxidation kinetics, surface and cross-section oxidation features, oxidation growth behaviour, and the influence of oxidation on fracture through characterisation analysis of microstructure. The results indicate that the oxidation kinetics approximately follow the parabolic rate law above 570℃ but exhibit poor consistency at 500℃. A multi-layered oxide structure forms with unique morphological characteristics in a cross-sectional direction. Based on the spatial distribution of graphite, two oxidation mechanisms were identified in both the matrix and graphite phases. Uniaxial tensile tests reveal that the mechanical and fracture properties of the material are significantly affected by the oxidation temperature. [ABSTRACT FROM AUTHOR]

Summary: Long-term glucocorticoids (GCs) treatment is associated with osteoporosis and fractures. We investigated whether low-dose GC treatment also increased the risk of osteoporotic fractures, and the results showed that even low-dose GC treatment increased the risk of osteoporotic fractures, especially spine fractures. Purpose: The effect of low-dose glucocorticoid (GC) therapy on the fracture risk in postmenopausal women with low bone mass was investigated. Methods: 119,790 66-year-old postmenopausal women with low bone mass based on bone mineral density (BMD) results were included. GC group consisted of patients who had been prescribed oral GCs within 6 months of BMD testing. In GC group, GCs dosage was calculated by a defined daily dose (DDD), and divided into five groups according to GC usage (Group 1[G1]; < 11.25 DDDs, G2; ≥ 11.25, < 22.5 DDDs, G3; ≥ 22.5, < 45 DDDs, G4; ≥ 45, < 90 DDDs, G5; ≥ 90 DDDs). The risk of major osteoporotic fractures (MOF) and non-MOF was analyzed and compared with that of the control group during the 1-year follow-up. Results: The risk of total fracture was higher in G3–G5 than in the control group (G3, hazard ratio (HR) 1.25, 95% confidence interval [CI] 1.07–1.46; G4, 1.37 [1.13–1.66]; G5 1.45 [1.08–1.94]). The risk of MOF was higher in all groups except G2 than in the control group (G1, 1.23 [1.05–1.45]; G3, 1.37 [1.11–1.68]; G4, 1.41 [1.09–1.83]; G5, 1.66 [1.14–2.42]). The risk of spine fracture was significantly higher in all GC groups except G2 than in the control group. The risk of non-MOF was higher only in G4 than in the control group (G4, 1.48 [1.13–1.94]). Conclusion: Low-dose GC therapy can increase the risk of osteoporotic fractures, particularly spine fractures, in postmenopausal women with low bone mass. [ABSTRACT FROM AUTHOR]

Patients with myasthenia gravis (MG), because of their muscle weakness and exposure to corticosteroids treatment, are generally considered to be at increased risk for osteoporosis or fracture. However, clinical evidence of this issue is lacking. In this review, we systematically searched databases, including Cochrane Library, PubMed, Embase, and Airiti library from inception to the end of November 2023 for cohort studies that compared participants with MG and participants without MG for incidence of osteoporosis or fracture. We used the Newcastle–Ottawa Scale for quality assessment. In total, we included 3 studies with 34,865 participants. The pooled meta-analysis using the random effect model demonstrated no significant difference in risk of fracture in the MG group (odds ratio = 1.52; 95% confidence interval = 0.74 to 3.12; I2 = 93%; between-study variance [τ2] = 0.32) compared with that for the non-MG group. Due to limited studies, we could not perform a quantitative analysis for risk of osteoporosis. In conclusion, we found no robust evidence to support the proposition that patients with MG are at higher risk for fracture than general comparators. The explanations and underlying mechanisms of this finding remain unclear, we therefore conclude that additional studies are warranted. [ABSTRACT FROM AUTHOR]

The mechanical properties of fiber metal laminates (FML) are influenced by several various factors. Interface adhesion plays a particularly crucial role in interlaminar strength. Enhancing the interlaminar strength of carbon fiber reinforced aluminum laminate (CARALL) composites present a persistent challenge due to inherent weaknesses between metal and composite elements. Therefore, this study focuses on improving the interlaminar performance of CARALL composites by introducing cellulose paper interlayer at the metal/composite interface. The cellulose paper interlayer offers the advantage of being cost-effective and sustainable. Cellulose paper-interleaved CARALL composites were fabricated by vacuum bagging method and exhibited noteworthy improvements in mechanical properties. Comparative analysis with pristine samples revealed substantial enhancements, including a 15% increase in tensile strength, a remarkable 42% improvement in flexural strength, and a significant enhancement in mode-I fracture toughness by 65%. Furthermore, the cellulose paper interleaving played a crucial role in stabilizing fracture formation at the fiber-matrix interface, with mode II fracture toughness witnessing a 3% increase. Visual examination revealed the underlying toughening processes occurring in the interfacial area. This innovative approach of interleaving laminated composites with cellulose paper emerges as a sustainable and effective strategy, demonstrating the potential to fortify and toughen the interlaminar zones of CARALL composites. [ABSTRACT FROM AUTHOR]

Purpose: Total Elbow Arthroplasty (TEA) was first developed to treat severe rheumatoid arthritis, but its uses have grown to encompass end-stage osteoarthritis, post-traumatic arthritis, and distal humeral fractures. This study analyzes indications changes, long-term survival, complications, and post-operative functional results of the Coonrad-Morrey prostheses, enhancing the existing literature on this technique and substantial case history. Methods: We included 122 arthroplasties in 117 patients, 28 males and 89 females (mean age of 67 years) treated in our hospital between 2002 and 2016. Minimum follow-up was four years. We collect functional parameters of 48 patients (51 elbows), due to death of patients due to old age and loss at follow-up. Results: Survival rate at five years was 90%, 85% at 10 years and 83% at 15 years. The overall medium Mayo elbow score was 79.7 ± 18.3 with the highest result in osteoarthritis patients (p < 0.005); QuickDASH score was 33.1 ± 25.5 with the worse result in rheumatoid group. Average post-operative arc of motion (ROM) was 95°±27°. There were complications in 46 out of 122 cases (37.7%) and revision surgeries were performed in 12 of them (9.8%): seven aseptic loosening, four late septic loosening, one bushing wear. In 27 instances (22.1%) was reported ulnar nerve involvement. Conclusion: Coonrad-Morrey prosthesis has shown satisfactory clinical results in the treatment of a wide range of pathologies. The long-term implant survivorship was satisfactory, yet the occurrence of failures and complications cannot be overlooked, above all the ulnar nerve paresthesia. There was a good recovery in quality of life, pain-free with limited residual limb disability. [ABSTRACT FROM AUTHOR]

Purpose: The authors experienced several cases of extra-articular calcaneal fracture accompanied by joint depression involving the entire posterior facet without joint involvement. This type of fracture and its characteristics and treatment outcomes have not been previously reported. The study was performed to analyze the characteristics of extra-articular calcaneal fractures of the joint depression type and their postoperative clinical and radiographic results and complications. Methods: Between February 2013 and March 2021, 23 extra-articular calcaneal fractures of the joint depression type were consecutively treated by a single surgeon. Relationships between fracture characteristics and patient demographics were assessed. Clinical results were quantified using visual analog scale, American Orthopaedic Foot and Ankle Society ankle-hindfoot scale, and Foot Function Index, radiographic results were evaluated using Böhler's angles, and calcaneal widths were determined using calcaneal axial and lateral radiographs obtained preoperatively and at last follow-up. Results: Twenty (87%) of the 23 cases occurred in women, and the mean age of all patients was 65.8 years (43–90). The three men were older than 65. Five (21.7%) patients had osteopenia, and 12 (52.2%) had osteoporosis. Bone mineral density testing could not be performed in the other six patients. Clinical and radiographic results were significantly improved after surgery. Conclusion: Extra-articular calcaneal fractures of the joint depression type are much more common in women and occur at an older age than calcaneal fractures commonly occur. These fractures are also more common in patients with a low bone mineral density. Level of evidence: Level IV. Case series. [ABSTRACT FROM AUTHOR]

This article discusses a numerical study on the influence of the parameters of the statistical distribution of the ultimate strength of structural elements on the fracture processes of deformable bodies. The study uses computational methods to analyze the deformation and fracture processes of solids. The results show that the distribution and dispersion of the strength properties significantly affect the behavior and load-bearing capacity of the body. The study also highlights the importance of considering the inhomogeneity of mechanical properties in the modeling of fracture processes. The text also references two research papers and an experimental study related to stochastic response analysis and the behavior of concrete structures, which may be useful for library patrons researching related topics. [Extracted from the article]

This document is a list of references to research papers and articles that focus on machining processes, specifically the machining of superalloy Inconel 718. The papers cover a range of topics including tool wear reduction, surface integrity evaluation, optimization techniques, and prediction models using artificial intelligence and machine learning. The research explores different lubrication techniques, nanofluid additives, and cutting parameters to improve the machinability of Inconel 718. The papers utilize various methodologies such as neural networks, fuzzy logic, response surface methodology, and genetic algorithms to optimize machining parameters and predict tool wear, surface roughness, and material removal rate. [Extracted from the article]

Traumatic subaxial cervical spine fractures are a significant public health concern due to their association with spinal cord injuries (SCI). Despite being mostly caused by low-energy trauma, these fractures significantly contribute to morbidity and mortality. Currently, research regarding early mortality based on the choice of treatment following these fractures is limited. Identifying predictors of early mortality may aid in postoperative patient monitoring and improve outcomes. This study aimed to identify predictors of 30-days, 90-days, and 1-year mortality in adults treated for subaxial fractures. A retrospective review of the nationwide Swedish Fracture Register (SFR). All adult patients in the SFR who underwent treatment for a subaxial cervical fracture (n = 1,963). Analyzed variables included age, sex, injury mechanism, neurological function, fracture characteristics, and treatment type. The primary endpoints were 30-days, 90-days, and 1-year mortality. About 1,963 patients in the SFR, treated for subaxial cervical fractures between 2013 and 2021, were analyzed. Surgical procedures included anterior, posterior, or anteroposterior approaches. Nonsurgical treatment included collar treatment or medical examinations without intervention. Stepwise regression and Cox regression analysis were used to determine predictors. Model performance was tested using the area under the receiver operating characteristic curve (AUC). A total of 620 patients underwent surgery and 1,343 received nonsurgical treatment. Surgical cases had primarily translation fractures, with 323 (52%) displaying no neurological deficits. Mortality rates at 30 days, 90 days, and 1 year were 22/620 (3.5%), 35/620 (5.6%), and 53/620 (8.5%), respectively. Age and SCI were predictors of mortality. Nonsurgically treated patients mostly had compression fracture, with 1,214 (90%) experiencing no neurological deficits. Mortality rates at 30 days, 90 days, and 1 year were 41/1,343 (3.1%), 71/1,343 (5.3%), and 118/1,343 (8.7%). Age, male sex, SCI and fractures occurring at the C3 or C6 levels were predictors of mortality. An intact neurological function was a positive predictor of survival among nonsurgically treated patients (AUC >0.78). Age and SCI emerged as significant predictors of early mortality in both surgically and nonsurgically treated patients. An intact neurological function served as a protective factor against early mortality in nonsurgically treated patients. Fractures at C3 or C6 vertebrae may impact mortality. [ABSTRACT FROM AUTHOR]

Contact damage of glass is one of the most crucial issues for glass products. To develop strong and tough glass products and to compare damage resistance among glass compositions, a simple method for evaluating the mechanical response of glass during contact is required not only for glass mechanists but also for glass customers and suppliers. Although it is well known that the quasi‐static Vickers indentation test is one of the simplest and most useful methods to evaluate hardness and brittleness in glass, the indentation response of glass under the indenter at higher impact velocities remains to be quantitively understood because of the difficulty of measurement and limited experimental works. In this study, therefore, the dynamic indentation behavior of soda‐lime glass is evaluated by using a lab‐made free‐drop indentation set‐up with the coils for detecting electromotive forces (EMFs). The cono‐spherical indenter made of tungsten carbide attached with a neodymium magnet was employed to generate the EMFs when the indenter passed through the coils located near the glass sample. The impact load versus indentation depth curve during the impact within a few tens of microseconds was successfully obtained both for an elastic contact and for an inelastic contact. Under an elastic condition, where no residual indent nor any cracks were left on the glass surface after the test, it is confirmed that there is almost no hysteresis in the impact load versus indentation depth curve and that the curve can be reproduced by the Hertzian analytical solution. Under an inelastic condition, on the other hand, it is found that the hysteresis in the impact load versus indentation depth curve stems from inelastic phenomena, such as plastic deformation (shear flow and/or permanent densification) and cracking. These results suggest that the dynamic indentation technique based on electromagnetic induction phenomena is a useful and effective tool for evaluating the mechanical responses of glasses during the impact. [ABSTRACT FROM AUTHOR]

In this work, the relationship was considered between the structure and cyclic loading resistance of a layered composite consisting of PEI (PEEK) plate/PEI (PEEK) film/PEI-impregnated carbon-fiber fabric prepreg/PEI (PEEK) film/PEI (PEEK) plate by analyzing the time variation in the parameters of mechanical hysteresis loops calculated using digital image correlation. It was shown that the polyetherimide-based layered composite has low fatigue life under cyclic loading (0.8 of the yield strength), resulting from incompatible deformation between the PEI plates and the prepreg due to a layer interface formed by low-melting TecaPEI film. In the PEEK layered composite, the layer interface was formed by neat PEEK energy director and therefore had a little amount of defects, due to which the load was well transferred from the PEEK plates to the middle reinforcement layer. As a result, the fatigue life at a load level of 0.8 of the yield strength corresponded to high-cycle fatigue (more than 86000 cycles). [ABSTRACT FROM AUTHOR]

TEM studies were performed to examine the effect of holding of dispersion-strengthened heat-resistant reduced activation 12% chromium ferritic-martensitic steel EK-181 in static liquid lead for 3000 h at 600°C on the steel microstructure in comparison with the steel after conventional heat treatment by quenching and tempering at 720°C. It was found that the steel microstructure has good thermal stability under the specified experimental conditions. Microstructural deformation of EK-181 steel was studied in the neck region of tensile specimens tested at the temperatures 20, 680, 700, and 720°C with and without holding in liquid lead, and their fracture mechanisms were investigated. As a result of plastic deformation during tensile testing at room temperature, martensite plates and laths near the fracture surface are distorted and fragmented with the formation of new low-angle boundaries, and the dislocation density increases. At the deformation temperatures 680–720°C, nearly equiaxed ferrite grains are formed, the density and size of second-phase particles (M23C6 and MX) increases due to dynamic strain aging, and the dislocation density decreases locally. As the test temperature rises, the degree of martensite tempering increases. At T ≥ 700°C, some dynamic polygonization and dynamic recrystallization are observed. At elevated tension temperatures, ferrite coarsening is more significant in the specimens held in lead as compared to the conventionally treated material. The plastic deformation and fracture behavior of the steel are largely determined by the test temperature, rather than by the treatment mode. [ABSTRACT FROM AUTHOR]

The paper briefly reviews the achievements of ISPMS SB RAS in the development of numerical computation methods and models for modeling the mechanical behavior of materials with hierarchical structure in the range of scales from nano to macro. The main stages in the development of several key areas are considered: atomistic modeling at the nanoscale level, continuum numerical methods, and particle method for studying the effect of structure on the behavior and properties of materials at larger spatial and temporal scales. The application of the multiscale approach to the structural modeling and design of metallic and ceramic materials is discussed. Prospects are outlined for transitioning to complete digital twins that link the structure formation process of the material with its final structure, mechanical properties, and mechanical behavior. [ABSTRACT FROM AUTHOR]

Background: Charcot neuroosteoarthropathy (CNO) is characterized with increased osteoclastic activity that can be curbed with antiresorptive agents. Chronic kidney disease (CKD) precludes bisphosphonates but anti–receptor activator of nuclear factor-B ligand (anti-RANKL) antibody, denosumab, can be contemplated in CKD. We investigated denosumab for active CNO of foot in CKD for CNO remission. Methods: During the study period, 446 persons of diabetes with unilateral, active CNO of foot and CKD were identified and 78 were finally enrolled. Patients received either 60 mg denosumab (single-dose, subcutaneous) along with standard of care (SoC) as total contact cast (TCC) (group A; n = 26) or SoC (group B; n = 52) only. Patients were followed every 4 weeks until CNO remission and subsequently every 8 weeks until 48 weeks following remission. Remission was defined as temperature difference <2 °C between 2 feet confirmed twice (4 weeks apart) with clinical resolution of signs of inflammation. The primary outcome studied was proportion of patients achieving remission within 48 weeks and the time to remission. Results: Median age was 56.5 (48.8-65) and 57 (48.5-61.2) years, P =.57; duration of diabetes 16 (10-25.3) and 14.9 (10-19) years, P =.151; and estimated glomerular filtration rate 44.8 (21.1-65.6) and 45.7 (32.9-55.7) mL/min/1.73 m2, P =.771, in group A and B, respectively. Median temperature difference at presentation between the affected and opposite foot was 3.4 °C (2.7-6.9) and 3.2 °C (2.2-4.0), P =.119, respectively. All patients achieved remission in group A (100%) compared with 42 (80.8%) in group B (P =.006) (hazard ratio 0.52, 95% CI: 0.32-0.87; P =.012). The median time to remission was similar in the 2 groups (15 [11-25] and 17.5 [14-31.5] weeks, P =.229, respectively). 25-Hydroxyvitamin D3 >14 ng/mL was significantly associated (OR 9.5, 95% CI 1.04-87.5, P =.045) with remission. Conclusion: Anti-RANKL antibody added to SoC (TCC) induces remission of active foot CNO in greater proportions of patients with diabetes and CKD. [ABSTRACT FROM AUTHOR]

Iliofemoral venous obstructive disease can result in significant, potentially debilitating symptoms that can negatively affect quality of life. Unlike arterial disease, patients with deep venous disease have a significantly lower median age, therefore the need for long term stent patency becomes a matter of decades rather than years. Furthermore, iliofemoral lesions frequently require stent placement across the inguinal ligament. Such stents are subject to dynamic stress from leg movement and associated concerns for device fatigue, resulting in stent fracture. The aim of this study was to describe an in vitro 50 year stent fatigue test method designed to assess durability against dynamic stress induced device fracture. Through literature review, cadaver studies, and computer modelling, the most challenging loading was confirmed to be hip flexion across the inguinal ligament. This occurs when the patient adjusts between a seated and standing position. Sit to stand hip flexion at the inguinal ligament was effectively simulated on the bench in this in vitro experimental study. When tested under challenge parameters, hip flexion was reliably found to cause fractures in non-venous nitinol stents. However, a dedicated self expanding nitinol venous stent, engineered for improved durability, underwent up to 50 years of simulated loading on the bench with 15% (3/20) of stents experiencing fractures at 50 years, compared with fractures in 35% (14/40) of non-venous stents tested to 1.4 years; no statistical testing was performed as durations do not match and the objective was to demonstrate the test method. The presented fatigue test method is a suitable approach for evaluating the durability of stents intended for venous use. Venous stents demonstrated superior fatigue resistance compared with non-venous stents via in vitro hip flexion testing. [ABSTRACT FROM AUTHOR]

Metacarpal fractures produce significant hand disability, and non-operative management of these fractures can produce satisfactory functional outcomes with few complications. However, most studies assessing non-operative outcomes of metacarpal fractures revolves around metacarpals I and V, which possess different anatomy. Therefore, further investigation into outcomes after non-operative treatment of metacarpals II-IV is required to inform management decisions and allow modification of the rehabilitation protocols to specific fracture patterns. All records for 76 non-operative patients presenting with fractures of metacarpals II-IV to our tertiary centre in the year 2019 were retrospectively reviewed. Patients were treated with thermoplastic splinting or fibreglass casting with a rehabilitative exercise programme. Range of motion (ROM) of the Metacarpophalangeal (MCPJ), Proximal Interphalangeal (PIPJ), and Distal Interphalangeal joints (DIPJ), return to work time, and complications were assessed at 12 weeks post-treatment. Mean return to work time was 5.4 weeks, and patients did not report any serious adverse events; the main complication reported was tenderness on palpation (20%). The MCPJ exhibited the poorest ROM (9° flexion reduction relative to the healthy hand). Metacarpal II fractures were associated with significantly worse MCPJ flexion than metacarpal III (p = 0.022) and metacarpal IV (p = 0.049) fractures. Fractures of the metacarpal base were associated with superior MCPJ flexion (p = 0.004) but longer return to work time (p = 0.042) than head fractures. Spiral fractures were associated with shorter return to work time (p = 0.043) and superior ROM results (p = 0.041). In conclusion, outcomes of the non-operative treatment of metacarpal II-IV fractures are highly dependent on the location and pattern of the fracture, and this should be considered during clinical decision making. [ABSTRACT FROM AUTHOR]

The effect of triaxiality on the evolution of damage in Al-2024 aluminum cylindrical specimens is studied in this work. Uncoupled and coupled damage models, all of them explicitly dependent on triaxiality, are assessed and compared. These models are characterized by tensile tests on cylindrical specimens without notches, to obtain the material parameters for each model. The capability of each model to predict fracture when different positive triaxial conditions evolve is then evaluated through tensile tests on notched cylindrical specimens. In particular, the damage index, evaluated at the fracture strain level, is compared with the experimental results validating the models. Moreover, the triaxiality evolution in the different specimens is studied in order to assess its effect on damage, demonstrating that the fracture strain decreases at greater triaxiality values. Observations through scanning electron microscopy confirm this pattern; i.e., an increase in triaxiality reveals a shift in the fracture mechanism from a more ductile condition in the original specimens to a more brittle one as the notch radius decreases. In addition, bilinear damage evolution is proposed to describe the physical behavior of the material when the Lemaitre coupled model is considered. In such a case, special attention must be devoted to the material characterization since coupling between hardening material parameters and damage affects the results. [ABSTRACT FROM AUTHOR]

Background: Minimally invasive plate osteosynthesis (MIPO) for clavicular shaft fracture yields favorable functional outcomes and results in less surgery-related soft tissue injury than other techniques. Anterior chest and shoulder skin numbness, a common complication after open reduction and plate fixation, is related to injury to the supraclavicular nerves. We propose MIPO combined with a mini-open approach without fluoroscopy for nerve preservation to minimize the risk of postoperative numbness compared with traditional open plating without nerve preservation. Methods: A total of 59 patients were retrospectively identified, with a follow-up period of 6 months. Thirty-two patients underwent MIPO with mini-open and nerve preservation technique (MIPO group), and 27 patients underwent traditional open plating without nerve preservation (open group). Constant–Murley shoulder outcome score, operation time, wound length, skin numbness, and number of implant removals were compared between the groups. Results: The MIPO group had significantly lower rates of anterior chest and shoulder skin numbness than the open group (MIPO: 12.5% vs. open: 55.6%; p < 0.001). Operation time was significantly longer in the MIPO group than in the open group (MIPO: 109.38 ± 18.83 vs. open: 81.48 ± 18.85; p < 0.001). Wound length was significantly shorter in the MIPO group than in the open group (MIPO: 4.73 ± 0.79 vs. open: 9.76 ± 1.64; p < 0.001). Both groups had similarly excellent Constant–Murley shoulder scores. There were significantly fewer implant removals in the MIPO group than in the open group (MIPO: 6.3% vs. open: 25.9%; p = 0.036). Neither group experienced any infection, implant failure, or nonunion. Conclusions: Our technique combining MIPO with the mini-open approach and supraclavicular nerve preservation yields a lower incidence of skin numbness than traditional open plating without nerve preservation. [ABSTRACT FROM AUTHOR]

Background and Objectives: Motor vehicle accidents (MVAs) are the leading cause of disability, particularly among young adults in Saudi Arabia. Persistent disabilities account for around 7% of all injuries attributed to MVAs in Saudi Arabia in the last twenty years. Limited studies on musculoskeletal disabilities following MVAs have been carried out in Saudi Arabia. This study aims to explore the epidemiology and prevalence of musculoskeletal disabilities in motor vehicle accident (MVA) patients in the Aljouf region, Saudi Arabia. Materials and Methods: This retrospective cross-sectional study evaluated all MVA victims treated in the Aljouf region, Saudi Arabia, from January 2020 to December 2022. A total of 3252 medical records were collected, with 731, 1197, and 1324 musculoskeletal injury cases per year, of which 88, 168, and 153 records from 2020, 2021, and 2022 were analysed, respectively. Results: The study found that patients aged 25–34 and 35–44 years were the most likely to experience disability following MVAs. The difference between age groups during a single year was statistically significant (p < 0.001). Most patients were male (89.8%, 82.7%, and 79.7%) during 2020, 2021, and 2022, respectively. The majority of injuries involved the upper extremities (38.6%, 36.9%, and 40.5%), followed by lower extremities (36.4%, 35.7%, and 34.6%), head and neck (21.6%, 26.2%, and 34.6%), thoracic region (20.5%, 24.4%, and 17%), and finally lumbosacral spine (6.8%, 5.4%, and 6.5%) during 2020, 2021, and 2022, respectively, with a significant difference for each year (p < 0.001). The study found a link between the likelihood of developing high disability grades and injury severity scores. The patients with very severe ISS ≥ 25 (OR: ∞ CI 95%: 39.81–∞; p < 0.001), severe ISS = 16–24 (OR: ∞ CI 95%: 20.90–∞; p < 0.001), and moderate ISS = 9–15 (OR: ∞ CI 95%: 1.2–∞; p = 0.02) were at greater risk of developing high grades of disability. Conclusions: This study highlighted the musculoskeletal disabilities in the Aljouf region following MVAs. Severe musculoskeletal disabilities were rare, but fractures were the most common following MVAs. More efforts should be directed towards education on early transportation and transfer to the nearest medical centres, seeking assistance immediately after MVAs for patient safety, and disability prevention. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Antiretroviral therapy roll-out has dramatically reduced HIV-related mortality; more women are living to reach menopause. Menopausal estrogen loss causes bone loss, as does HIV and some of its treatments. However, data describing HIV's impact on osteoporosis prevalence and fracture risk are scarce in southern Africa. A cross-sectional study of women aged 40-60 years (49% women with HIV [WLH]) was conducted in Harare, Zimbabwe. Menopause, fracture, and HIV history were collected, and anthropometry and BMD (by DXA) measured, and FRAX 10-year fracture probabilities quantified. The FRAX probability of a major osteoporotic fracture (MOF) included HIV as a risk factor for secondary osteoporosis. Linear and Poisson regression determined the relationships between clinical risk factors and both femoral neck (FN) BMD and the 10-year FRAX probability of MOF respectively. The 393 participants had a mean (SD) age of 49.6 (5.8) years and mean (SD) BMI of 29.1 (6.0) kg/m2. 95% of WLH were antiretroviral therapy (ART) established (85% tenofovir disoproxil fumarate) and 81% had a viral load <50 copies/mL. A BMD T-score ≤ –2.5 was more common in WLH than those without, at both FN and lumbar spine (LS) (FN, 22 [11.4%] vs 5 [2.5%]; LS, 40 [20.8%] vs 9 [4.5%], respectively). Prior fracture was more prevalent in WLH: any fracture type (27 [14%] vs 14 [7%]); MOF (14 [7.3%] vs 5 [2.5%]). WLH had a higher 10-year MOF probability (median, 1.2%; IQR, 0.9-1.8) compared with those without HIV (1.0%; IQR, 0.9-1.5) (p <.001), although probabilities were low. Older age, low weight, and HIV infection were strongly associated with lower FN BMD. Higher probability of MOF was associated with older age, HIV infection, parental hip fracture and prior fracture, although adjustment attenuated the association with HIV. No woman reported anti-osteoporosis medication use. While osteoporosis and previous fractures were common and untreated in this relatively young population, particularly in WLH, the FRAX-predicted 10-year MOF risk was low. Clinical risk factors considered in fracture risk prediction tools in Zimbabwe may need contextual modification. Lay Summary: Improved access to treatment for HIV now means women with HIV are able to live well into older adulthood; however, this puts them at risk of age-related diseases, such as osteoporosis. HIV and some of its treatments are known to cause bone loss, as does menopause, but studies on osteoporosis and fracture risk are scarce in southern Africa, where most people with HIV live. In this study in Zimbabwe, we found women with HIV were more likely to have osteoporosis and to have had a fracture, and a higher risk of having a major osteoporotic fracture over the next 10 years, compared with women without HIV (calculated using FRAX, a fracture risk prediction tool), although the risk was surprisingly low. Older age, being underweight, and having HIV were strongly related to lower bone density at hip (an important site for fractures). Higher risk of future fracture was associated with older age, previous fracture, having HIV, and having a parent who had a hip fracture. Despite these findings, no woman had ever been offered any anti-osteoporosis medication. Our findings suggest that osteoporosis is underrecognized and undertreated in Zimbabwe, where clinical fracture risk prediction tools need to be modified for the specific context. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Metacarpal fractures are common and account for over 30% of all hand fractures. Previous literature has shown similar outcomes between operative and nonoperative management of metacarpal shaft fractures. There is little information regarding the natural history of conservatively managed metacarpal shaft fractures and changes in management based on follow-up radiographs. Methods: A retrospective chart review was performed on all patients who presented to a single institution with an extraarticular metacarpal shaft or base fracture between 2015 and 2019. Results: Thirty-one patients with 37 metacarpal fractures were included for review: average age 41 years, male 48%, right hand dominant 91%, and average follow-up duration 7.3 weeks. At follow-up, a change of 2.4° in angulation (P =.0005) and a change in shortening of 0.1 mm (P =.0386) were noted over the 6-week time interval. No fractures had malrotation at presentation, and none developed malrotation during the follow-up period. Conclusions: Recent systematic reviews and meta-analysis have suggested that metacarpal fractures treated nonoperatively had similar outcomes to surgical fixation at 12 months of follow-up. We found that extraarticular metacarpal shaft fractures that do not meet operative indications at the initial visit should be expected to heal reliably with minimal change in angulation and shortening over time. The transition to removable brace or no brace at the 2-week follow-up is likely sufficient, and additional follow-up is not necessary and will reduce cost. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Fractures of the hook of the hamate are traditionally thought to be caused by direct trauma. A review of the anatomy and function of the hamate hook suggests that fracture is more likely as a result of a fatigue response that develops in the hook from repetitive load applied by the adjacent deep flexor tendons. Additional vascular compromise, from direct pressure of the tendons on critical local vessels, reduces blood flow leading to both mechanical and vascular effects that create pathological osseous change and weakening. These changes are likely to predispose to stress fracture and nonunion in repetitive gripping activities and are consistent with radiological findings. [ABSTRACT FROM AUTHOR]

Background Relationship of caffeine intake and consumption of caffeinated beverages, such as tea and coffee, with bone health remains controversial. This study aimed to evaluate whether genetically determined caffeine intake from tea or coffee has causal effects on overall total body bone mineral density (TB-BMD) and fracture. We also assessed the association with TB-BMD in five age strata. Methods Using two-sample Mendelian randomization approach, summary statistics were retrieved from genome-wide association studies (GWAS)/GWAS meta-analyses of caffeine intake from tea (n  = 395 866)/coffee (n  = 373 522), TB-BMD (n  = 66 628), and fracture (n  = 426 795). Inverse variance weighted method was adopted as the main univariable analysis. Multivariable analysis was conducted to evaluate whether the causal effect is independent. Results In univariable analysis, genetically determined caffeine intake from tea had positive association with overall TB-BMD (per SD increase in genetically determined caffeine intake, beta of TB-BMD [in SD]: 0.166; 95% confidence interval (CI): 0.006–0.326) and inverse association with fracture (OR = 0.79; 95% CI: 0.654–0.954). Genetically determined caffeine intake from coffee was also positively associated with overall TB-BMD (beta = 0.231; 95% CI: 0.093–0.369). The association remained significant after adjustment for smoking in multivariable analysis. Genetically determined caffeine intake from tea or coffee was both positively associated with TB-BMD in the age strata of 45–60 years, but we lacked evidence of association in other strata. Conclusions Genetically, caffeine intake from tea or coffee may be beneficial to bone health. Due to the ascertainment method of caffeine intake from tea, our study also implied genetically higher tea consumption may improve TB-BMD and lower fracture risk. What is already known on this topic Published studies demonstrated controversial findings on the relationship of caffeine intake and consumption of caffeinated beverages, such as tea and coffee, with bone health. What this study adds This two-sample Mendelian randomization study demonstrated that genetically determined caffeine intake from tea or tea consumption was causally associated with improved overall TB-BMD and reduced fracture risk. Genetically determined caffeine intake from coffee was also positively associated with overall TB-BMD. How this study might affect research, practice or policy Caffeine and other active ingredients in tea may improve bone health. Tea may be included in the diet as a strategy to improve BMD and prevent osteoporosis-associated fracture. [ABSTRACT FROM AUTHOR]

Interlocking metasurfaces (ILMs) are arrays of autogenous latching unit cells patterned across a surface. These create structural joints similar to bioinspired suture joints but patterned over a 2D surface rather than a 1D seam. This enables ILMs to be an alternative to conventional joining technologies such as bolts, welds, and adhesives. However, compared to conventional joining methods, relatively little is known of the engineering considerations for designing structural ILMs. Herein, the interfacial toughness of an archetypal ILM is examined for the first time. Under the conditions studied here, the ILM is substantially tougher than the material from which it is made, in this case, exhibiting up to a 50% increase in interfacial crack initiation energy over the solid base material, a photocured 3D‐printed polymer. Through experimental tests using in‐situ digital image correlation along with complementary computational analyses, the mechanism of toughening in the ILM structure and the origins of toughness anisotropy are revealed. The increase in toughness is associated with cross‐cell interactions, that is, load‐sharing across unit cells, which give rise to a finite process zone length with different effective material properties. In this way, ILM toughening is analogous to crack blunting in ductile materials or fiber bridging in composites; yet here, the ILM is composed of a single‐phase base material and so the architected toughening is geometric in nature and hence amenable to future topological optimization. [ABSTRACT FROM AUTHOR]

Context Parathyroidectomy (PTX) is recommended for curing primary hyperparathyroidism (PHPT), although uncertainty remains regarding the extent of fracture risk reduction following surgery. Objective This work aimed to compare fracture risk and bone mineral density (BMD) changes in patients with PHPT undergoing PTX vs observation (OBS). Methods We systematically searched PubMed, Embase, and the Cochrane Library until September 2022, including randomized controlled trials (RCTs) and cohort studies, and reviewed citations from previous reviews. Among 1260 initial records, 48 eligible articles from 35 studies (5 RCTs; 30 cohorts) included PHPT patients receiving PTX or OBS interventions with reported fracture events at any site, including the hip, spine, or forearm, and/or BMD changes at each location. Data extraction followed Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines by 2 independent reviewers. Results In 238 188 PHPT patients (PTX: 73 778 vs OBS: 164 410), PTX significantly reduced fractures at any site (relative risk [RR], 0.80; 95% CI, 0.74-0.86) compared to OBS. In 237 217 patients (PTX: 73 458 vs OBS: 163 759), the risk of hip fractures decreased (RR, 0.63; 95% CI, 0.52-0.76). No reduction in forearm and vertebral fractures was observed in 3574 and 3795 patients, respectively. The annual percentage BMD changes from baseline were higher in the PTX group: femoral neck, 1.91% (95% CI, 1.14-2.68); hip, 1.75% (95% CI, 0.58-2.92); radius, 1.75% (95% CI, 0.31-3.18); spine, 2.13% (95% CI, 1.16-3.10). Conclusion PTX significantly reduced overall and hip fracture risks in PHPT patients. Despite minimal BMD increase, the substantial decrease in fracture risk suggests additional benefits of PTX beyond mineral content enhancement. [ABSTRACT FROM AUTHOR]

Background: This study aims to assess the lifetime cost-effectiveness of a multi-component adherence intervention (MCAI), including a patient decision aid and motivational interviewing, compared to usual care in patients with a recent fracture attending fracture liaison services (FLS) and eligible for anti-osteoporosis medication (AOM). Research design and methods: Data on AOM initiation and one-year persistence were collected from a quasi-experimental study conducted between 2019 and 2023 in two Dutch FLS centers. An individual level, state-transition Markov model was used to simulate lifetime costs and quality-adjusted life years (QALYs) with a societal perspective of MCAI vs usual care. One-way and probabilistic sensitivity analyses were conducted including variation in additional FLS and MCAI costs (no MCAI cost in baseline). Results: MCAI was associated with gain in QALYs (0.0012) and reduction in costs (-€16) and is therefore dominant. At the Dutch willingness-to-pay threshold of €50,000/QALY, MCAI remained cost-effective when increasing costs of the FLS visit or the yearly maintenance cost for MCAI up to +€60. Probabilistic sensitivity analysis demonstrated MCAI to be dominant in 54% of the simulations and cost-effective in 87% with a threshold of €50,000/QALY. Conclusions: A MCAI implemented in FLS centers may lead to cost-effective allocation of resources in FLS care, depending on extra costs. [ABSTRACT FROM AUTHOR]

The tooth fracture failure modes in the spur gear tooth root are mainly influenced by the magnitude and positions of bending fatigue load along the gear face width. Numerous studies in the literature used 3D finite element (FE) models to analyze crack propagation, but they did not take into account the effect of the load distribution ratio (LDR) throughout the gear face width, either in a moving load model or a uniform load model. In this study, an effort is made to investigate the impact of LDR and Load Sharing Ratio (LSR) in the modeling of moving loads for various loading positions and measure the actual crack propagation behavior of a spur gear with a root fracture using the 3D FE technique. Further, the influences of FE spur gear models on the variation of Actual Load Distribution with the effect of LSR, Stress Intensity Factors (SIFs), and crack propagation paths are also studied. A 3D FE crack propagation modeling procedure is validated with the experimental results of the SAEJ1619 fatigue test procedure. The experimental investigation using standard SAEJ1619 fatigue test procedure shows that the symmetric crack propagation failure at the crack front of the spur gear tooth was observed for a given uniform bending fatigue load. The results show that the mode I SIFs (KI) and mode II SIFs (KII) are dominant at the crack opening displacement for the positions of moving load between the Highest Point of Single Tooth Contact (HPSTC) and Highest Point of Tooth Contact (HPTC) lines. But, the KII is highly influenced by KI for further crack growth when the load is moved to the HPSTC line than the HPTC line. This study provides the guidelines to predict the actual crack propagation path failure behavior for various positions of moving load for various gear drive systems with root crack. [ABSTRACT FROM AUTHOR]

Recent works have shown that in contrast to classical linear elastic fracture mechanics, endowing crack fronts in a brittle Green-elastic solid with Steigmann-Ogden surface elasticity yields a model that predicts bounded stresses and strains at the crack tips for plane-strain problems. However, singularities persist for anti-plane shear (mode-III fracture) under far-field loading, even when Steigmann-Ogden surface elasticity is incorporated. This work is motivated by obtaining a model of brittle fracture capable of predicting bounded stresses and strains for all modes of loading. We formulate an exact general theory of a three-dimensional solid containing a boundary surface with strain-gradient surface elasticity. For planar reference surfaces parameterized by flat coordinates, the form of surface elasticity reduces to that introduced by Hilgers and Pipkin, and when the surface energy is independent of the surface covariant derivative of the stretching, the theory reduces to that of Steigmann and Ogden. We discuss material symmetry using Murdoch and Cohen's extension of Noll's theory. We present a model small-strain surface energy that incorporates resistance to geodesic distortion, satisfies strong ellipticity, and requires the same material constants found in the Steigmann-Ogden theory. Finally, we derive and apply the linearized theory to mode-III fracture in an infinite plate under far-field loading. We prove that there always exists a unique classical solution to the governing integro-differential equation, and in contrast to using Steigmann-Ogden surface elasticity, our model is consistent with the linearization assumption in predicting finite stresses and strains at the crack tips. [ABSTRACT FROM AUTHOR]

Despite being invented several decades ago, fiber metal laminates (FMLs) still encounter challenges in large-scale manufacturing, especially in forming small and complex-shaped components. These challenges arise from the limited strain rate of the fiber layers compared to the metallic layers. Consequently, conventional approaches to form FML parts are often inadequate. To produce parts free of defects such as fractures and wrinkles, this study investigates the effects of Thermo-stamping (TH-S), in addition to fiber orientation, on the forming behavior of FMLs, employing two different aluminum layer thicknesses. A comprehensive approach combining finite element simulations and experimental analyses was employed. The study investigated thinning of aluminum alloy layers, stress distributions across different layers, and the influence of fiber orientation. The FML blanks are made of a middle woven glass fiber prepreg with a thickness of 0.2 mm, using a thermosetting epoxy system, and Al 2024-T3 alloy sheets with varying thicknesses of 0.3 mm and 0.5 mm. Material behavior was evaluated using Abaqus software, applying the Johnson-Cook criterion for damage initiation in ductile metals and Hashin's theory for damage initiation in fiber-reinforced composites. These simulations were then compared with experimental results. The findings highlight the potential of the TH-S process to enhance the forming performance of FMLs, particularly evident in the case of the 0°/45° middle layer fiber, which exhibits a higher forming depth and a more uniform thickness distribution. Additionally, a greater flexibility of the glass fiber under the 0°/45° layup compared to the 0/90 layup was detected. This flexibility provides the aluminum layers with more freedom of deformation in the plastic domain. These advancements hold promise for widespread industrial applications of FMLs. [ABSTRACT FROM AUTHOR]

In this study, the effects of surface roughness and Reynolds number (Re) on fluid flow and solute transport are investigated based on a double rough-walled fracture model that precisely represents the natural geometries of rock fractures. The double rough-walled fracture model is composed of two three-dimensional(3D) self-affine fracture surfaces generated using the improved successive random additions (SRA). Simulation of fluid flow and solute transport through the models were conducted by directly solving the Navier-Stokes equation and advection-diffusion equation (ADE), respectively. The results indicate that as the Re increases from 0.1 to 200, the flow regime changes from linear flow to nonlinear flow accompanied with the tortuous streamlines and significant eddies. Those eddies lead to the temporary stagnant zones that delay the solute migration. The increment of Re enhances the transport heterogeneity with the transport mode changing from the diffusion-dominated to the advection-dominated behavior, which is more significant in the fracture with a larger joint roughness coefficient (JRC). All breakthrough curves (BTCs) of rough-walled fractures exhibited typical non-Fickian transport characteristics with "early arrival" and "long tailing" of BTCs. Increasing the JRC and/or Re will enhances the non-Fickian transport characteristics. The ADE model is able to accurately fit the numerical BTCs and residence time distributions (RTDs) at a low Re, but fails to capture the non-Fickian transport characteristics at a large Re. In contrast, the continuous time random walk (CTRW) model provides a better fit to the numerical simulation results over the whole range of Re. Whereas, the fitting error gradually increases with increasing Re. [ABSTRACT FROM AUTHOR]

ABSTRACT Landfills emissions, ranking as the third‐largest anthropogenic source of methane in the atmosphere, pose environmental challenges and threaten public health. The pivotal role of clay as a mitigating agent for methane emission within landfill cover systems cannot be overstated; however, our understanding of methane escape from fractured clay remains limited. This study aims to address the existing gaps by proposing a robust analytical model of methane transport in both fractures and clay matrix. Our investigation also includes a dimensionless analysis to govern the relative significance of diffusion and advection in methane emission from fractured clay, systematically reviewing factors such as the degree of water saturation (Sr) and fracture width. The methane concentration profiles in cracked clay demonstrated escalating sensitivity to Péclet (Pe) numbers, especially when advection dominates transport. Our findings also highlight the prevalence of preferential methane flow with increasing Sr in the clay matrix. The flux of methane emission from fractures at Sr = 0.8 was 130 times greater than that from intact clay. However, the study necessitates considering methane emission from clay matrix, particularly in dry clay conditions (Sr = 0.2 and 0.4). The accumulated methane emission flux from intact clay, more than that emitted from fractures by about 2.5 times at Sr = 0.2, was 1.3 × 10−5 g/m/s. The findings significantly advance the understanding of gas transport in fractured geomaterials, revealing the effect of water saturation and crack width on methane emissions from fractures. Overall, the outcomes emphasize the inclusion importance of methane emission from cracked clay in the design of gas barriers. [ABSTRACT FROM AUTHOR]

This work investigates the hydrogen embrittlement (HE) behavior of Nickel-201 alloy using experimental and numerical approaches. In experimentation, the effect of electrochemical hydrogen charging on the deformation behavior of tensile oligocrystals is investigated at different strain rates. Irrespective of the strain rate levels, all the hydrogen-charged tensile oligocrystals exhibited intergranular (IG) fracture exclusively along the random high-angle grain boundaries (RHAGBs). At the same time, no crack was observed along the coincident site lattice (CSL) Σ 3 type grain boundaries. The absence of an interconnected grain boundary network, lower stress levels, and insensitivity of H-induced IG fracture to the strain rate levels of investigated FCC oligocrystals (with low lattice hydrogen diffusion coefficient) established the insignificance of dynamic H-redistribution toward HE. In numerical simulations, a crystal plasticity-phase field fracture finite element model simulates the macroscopic tensile response and corresponding microscopic fracture evolution behavior for hydrogen-free and hydrogen-charged tensile oligocrystals. The experimental results corroborated by numerical simulations, validate that the reduction in fracture energy of RHAGBs, induced by hydrogen segregation through thermodynamic equilibrium during hydrogen charging prior to deformation, is the dominating factor governing HE. • Hydrogen embrittlement (HE) of Ni- oligocrystals at various strain rate is investigated. • Experimental results are corroborated by crystal plasticity-phase field fracture simulations. • H-induced intergranular fracture initiated and propagated along the RHAGBs only. • H-segregation by thermodynamic equilibrium established prior to deformation governs the HE. [ABSTRACT FROM AUTHOR]

Quasi‐2D Ruddlesden–Popper perovskite (RPP) have surfaced as a promising candidate for light emitting diodes (LEDs) due to its outstanding optoelectronic properties. However, a reliable approach for patterning RPPs remains elusive due to the use of polar solvents in lithographic processes, which can damage the RPP. Here, a reliable and damage‐free dry micropatterning method of RPPs is reported, which also offers a cost/time advantage compared to conventional patterning methods. The sharp edges of high aspect ratio silicon micropillars are used to cut RPPs to a pre‐defined shape and then the cut RPPs are delaminated to obtain a patterned array of RPPs. The resultant patterned array exhibits no sign of degradation or discernable difference between adjacent pixels, achieving a ≈100% yield. The obtained array is utilized to fabricate a pixelated LED where a sharp electroluminescence (EL) spectrum peaking at 410 nm with full‐width‐at‐half‐maximum (FWHM) of 10 nm is observed. The pixelated devices demonstrate the potential to suppress EQE drops as the pixel size decreases, attributed to both the damage‐free micropatterning process and the defect tolerance of RPPs. Moreover, further improvements of the patterning method are demonstrated to avoid parasitic emission and suggest a promising strategy to fabricate pixel‐accessible micro‐LEDs. [ABSTRACT FROM AUTHOR]

Objective: Osteoporosis and falls are major risk factors for osteoporotic fractures, with significant detriment to patients' quality of life. We aimed to describe healthcare provider (HCP) perspectives and experiences in the diagnosis, management and prevention of osteoporosis, falls and fractures obtained through primary qualitative research. Methods: Thematic synthesis was performed on articles identified through a search of electronic databases (MEDLINE, Embase, PsychINFO and CINAHL), which were searched from inception to May 2023. Results: Twenty-seven studies including 1662 HCPs, including general practitioners (GPs), physicians, surgeons, physiotherapists (PTs), occupational therapists (OTs), pharmacists and nurses, were included, with identification of six themes: overshadowed as a disease entity, uncertainty in decision making, frustration with interdisciplinary and systemic tension, avoiding medical paternalism, desire for improved care and embracing the responsibility. Conclusion: Osteoporotic fracture and fall prevention in routine clinical care is hampered by inadequate priority and lack of perceived connection with morbidity and mortality, deficits in interdisciplinary collaboration, lack of clinical confidence and health resourcing. However, HCPs acknowledge their role in promoting healthy ageing, thus providing support through appropriate continuing education, resourcing and public health campaigns that are significant future directions, which may improve osteoporotic fracture prevention. [ABSTRACT FROM AUTHOR]

The shear fatigue performance and fracture behavior of microscale ball grid array (BGA) structure Cu/Sn-3.0Ag-0.5Cu/Cu solder joints with different heights (500 μm, 300 μm, and 100 μm) with increasing current density (from 6.0 × 10³ to 1.1 × 104 A/cm²) were investigated systematically. The results reveal that the fatigue life of solder joints decreases with increasing current density, while increasing with decreasing the height of solder joints. The location of fatigue fracture shifts from solder matrix to the interface between solder and intermetallic compound (IMC) layer for those with heights of 500 μm and 300 μm with increasing current density, in which the interfacial fracture is triggered by current crowding at the groove of the IMC layer and driven by mismatch strain at the solder/IMC layer interface; while, the fatigue fracture all occurs in the solder matrix for solder joints with a height of 100 μm. Moreover, the fracture in solder matrix of solder joints with heights of 500 μm and 300 μm exhibits an arc-shape fracture path, while a linear path for those with a height of 100 μm. These fracture paths are consistent with the concentration distribution region of plastic strain energy in solder joints. [ABSTRACT FROM AUTHOR]

The mechanical behaviour of polymer adhesives is influenced by the environmental conditions leading to ageing and affecting the integrity of the material. The polymer adhesives have hygroscopic behaviour and tend to absorb moisture from the environment, causing the material to swell without applying external load. The focus of the work is to investigate the viscoelastic material behaviour under ageing conditions. The constitutive equations and the governing equations to numerically investigate the fracture in swollen viscoelastic material are discussed to describe the numerical implementation. Phase-field damage modelling has been used in numerical studies of ductile and brittle materials for a long time. The finite-strain phase-field damage model is used to investigate the fracture behaviour in aged viscoelastic polymer adhesives. The finite-strain viscoelastic model is formulated based on the continuum rheological model by combining spring and Maxwell elements in parallel. Commercially available post-cured crosslinked polyurethane adhesives are used in the current investigation. Post-cured samples of crosslinked polyurethane adhesives are prepared for different humidity conditions under isothermal conditions. These aged samples are used to perform tensile and tear tests and the test data are used to identify the material parameters from the curve fitting process. The experiment and simulation are compared to relate the findings and are the first step forward to improve the method to model crosslinked polymers. [ABSTRACT FROM AUTHOR]

BackgroundPurposeMethodsResultsConclusionOccult scaphoid fractures are difficult to diagnose radiographically. Evidence regarding prevalence and diagnostic accuracy of clinical tests is growing; however, gaps in knowledge remain and further research is needed.This study aimed to determine the prevalence of occult scaphoid fractures and other hand/wrist fractures, plus any clinical/demographic findings diagnostic of scaphoid fractures.Prognostic prospective cohort study. Patients referred with diagnosis of occult scaphoid fractures, non-diagnostic radiographs, and one or more positive provocative test for scaphoid fractures were included. Clinical data were compared to reduce sequence magnetic resonance imaging. Univariate logistic regression was used to determine significance. Multivariable logistic regression was used to determine the effect size of these variables.Of 197 included participants, 43(22%) had a scaphoid fracture and 59(30%) had an occult fracture other than scaphoid. Average age of patients with confirmed occult scaphoid fractures was 22 years old. Distal pole fractures were the most common scaphoid fracture (n = 28/65.1%, average age 16.9 years). Three clinical tests (pain with ulnar-deviation, anatomical snuffbox swelling and pain-free grip) plus two demographics (age <23 and male) resulted in accuracy of 81.7%, positive predictive value of 73.3%, and negative predictive value of 82.4% in diagnosing scaphoid fractures.This study confirms a high prevalence of occult fractures in our population. Patients demonstrating the relevant demographics and positive clinical tests may be appropriate to treat as scaphoid fractures without advanced imaging. Most patients will present with differing clinical findings and/or demographics, and routine use of magnetic resonance imaging is recommended. [ABSTRACT FROM AUTHOR]

The microstructure and fracture mechanism of a 950 MPa grade heavy steel plate for hydro-power were studied using various microscopy techniques such as optical microscopy, scanning electron microscopy, transmission electron microscopy, and electron backscattering diffraction. The investigation was carried out on the surface (0 T), 1/4 thickness (1/4 T), and center (1/2 T) of the plate. The results revealed that the microstructure at 0 T was tempered lath martensite while at 1/4 T, it was mainly tempered lath bainite. The low-temperature impact toughness at 1/2 T decreases significantly compared to that at 0 T and 1/4 T due to the microstructure being composed of tempered lath bainite and tempered granular bainite. The coarser carbide resulting from a low cooling rate at 1/2 T is considered to be the initiation source of micro-cracks, consequently reducing the material's impact toughness. According to the study, the high-angle grain boundary line density is more pronounced at 0 T and 1/4 T. This characteristic can effectively hinder crack propagation, promote crack deflection, increase energy consumption, and ultimately improve low-temperature impact toughness. [ABSTRACT FROM AUTHOR]

The success of foam-induced flow diversion in fractured carbonates hinges on proper injection strategies, requiring an in-depth understanding of the factors responsible for stimulating fracture–matrix interactions. In this study, we present a novel investigation of the interactions between the fracture and the matrix influenced by the mobility control effect during CH4-foam injections. These interactions were probed at the pore scale using a three-phase flow system integrated with a high-resolution micro-CT scanner. In situ phase saturations were monitored and quantified to interpret the resulting fluid transport at various injection parameters. At the initial stage of foam injection, the surfactant solution was able to invade the matrix leading to water/oil displacement events, however, impeding gas penetration. Increasing total injection velocity produced higher in situ foam quality in the fracture than the injected quality, where significant fraction of the surfactant solution from the foam was primarily diverted into the matrix. A pronounced increase in the average gas saturation within the matrix was only observed at the highest injection velocity. The pore-scale evidence showed the occurrence of combined displacement processes (water/oil, gas/oil, gas/oil/water) in the matrix, attributed to the established mobility control in the fracture, which contributed to the diversion of surfactant solution and gas to the matrix. Lastly, the injection–soaking–production technique effectively mobilized the residual oil after a long injection process of CH4-foam. At this stage, the surfactant solution was no longer playing a role as the primary invading fluid; rather, it was the diverted gas that led to the increase in the matrix-oil production. [ABSTRACT FROM AUTHOR]