Biomechanical stability of magnesium plate and screw fixation systems in LeFort I osteotomy: a three-dimensional finite element analysis.

Background: Titanium (Ti-6Al-4 V) is used for fixation in LeFort I osteotomy, a procedure for treating midface deformities. This study assessed the biomechanical stabilities of two Mg alloys (WE43 and ZK60) as biodegradable alternatives and compared them against Ti using finite element analyses. The LeFort I osteotomy procedure was simulated, and various plate and screw configurations were tested.

Effect of customized bioactive glass in experimental composites on dentin bond strength after 12 months of aging.

Objectives: This study aimed to investigate the effect of a customized low-sodium bioactive glass (BG) fillers in experimental resin composites on their bond strength to dentin after 12 months of artificial aging. Specifically, it evaluated whether the bond strength was affected by different BG concentrations (0, 10, 20, 40 wt%) and artificial aging durations (1, 6, and 12 months).

Materials And Methods: Experimental composites were prepared with 10, 20, and 40 wt% of a customized low-sodium fluoride-containing BG.

Influence of Number and Strength of Hydrogen Bonds on Fracture Property and Microscopic Mechanisms of Associative Hydrogen-Bonded Polymers via Molecular Dynamics Simulation.

A coarse-grained model combining the acceptor-hydrogen-donor 3-body potential is first developed in this work to explore the fracture property and microscopic mechanisms of associative hydrogen-bonded polymers (AHBPs). Next, a triaxial deformation mode is performed to reveal that the fracture toughness of AHBPs initially improves and then is reduced as the number of active groups increases. By characterizing the stress decomposition, the strong hydrogen bond (HB) network improves the maximum stress but reduces the elongation.

Soft hydrogel-embedded ceramic skeleton mimicking bone structure sacrificial bond concept.

Bone, consisting of calcium phosphate minerals, rigid collagen fibrils, and acidic proteins, exhibits stiff and tough mechanical properties. On a molecular scale, covalent cross-linking in proteins and ionic interactions within proteins and at the protein-mineral boundary contribute to bone's toughness. In addition, hierarchical structures, like the sponge-like arrangement, are also crucial for the energy dissipation system in bone.

Mechanical, water contact angle and fiber thickness data for Insulin-like growth gactor-1 (IGF-1) incorporated in electrospun random DegraPol fibers and IGF-1 impact on tenocyte aspect ratio and gene expression data.

The first set of data refers to Insulin-like Growth Factor-1 (IGF-1) protein incorporation via emulsion electrospinning into a DegraPol random fiber mesh and its characterization. Specifically, the fiber thickness was assessed and compared to pure DegraPol fibers without IGF-1 (control). Furthermore, the mechanical properties of these meshes were assessed and data on ultimate tensile stress, Young's modulus and ultimate fracture strain are presented for ring specimen and rectangular pieces taken from electrospun tubes in the transverse direction as well as rectangular pieces taken in the axial direction of the electrospun tube.

Quantitative Detection Method for Surface Angled Cracks Based on Laser Ultrasonic Full-Field Scanning Data.

Surface angled cracks on critical components in high-speed machinery can lead to fractures under stress and pressure, posing a significant threat to the operational safety of equipment. To detect surface angled cracks on critical components, this paper proposes a "Quantitative Detection Method for Surface Angled Cracks Based on Full-field Scanning Data". By analyzing different ultrasonic signals in the full-field scanning data from laser ultrasonics, the width, angle, and length of surface angled cracks can be determined.

Fatigue Crack Growth Performance of Q370qENH Weathering Bridge Steel and Butt Welds.

Weathering steel possesses good atmospheric corrosion resistance and is increasingly applied in highway and railway bridges. The fatigue performance of the weld joint is an important issue in bridge engineering. This study experimentally investigates the microstructural properties and fracture crack growth behaviors of a Q370qENH bridge weathering steel weld joint.

An Expanded Wing Crack Model for Fracture and Mechanical Behavior of Sandstone Under Triaxial Compression.

A new model is developed to predict the mechanical behavior of brittle sandstone under triaxial compression. The proposed model aims to determine the normalized critical crack length (), through which the failure strength () of sandstone can be estimated based on fracture mechanics applied to secondary cracks emanating from pre-existing flaws, while considering the interaction of neighboring cracks. In this study, the wing crack model developed by Ashby and Hallam (1986) was adopted to account for the total stress intensity at the crack tip () as the summation of the stress intensity due to crack initiation and crack interaction.

Experimental Study on the Size Effect of Compression-Shear Fracture Characteristics of Rock-like Materials Containing Open Cracks.

Understanding fracture mechanics in rock-like materials under compression-shear condition is critical for predicting failure mechanisms in various engineering applications, such as mining and civil infrastructure. This study conducted uniaxial compression tests on cubic gypsum specimens of varying sizes (side lengths of 75 mm, 100 mm, 125 mm, and 150 mm) and crack inclination angles (ranging from 0° to 90°) to assess the size effect on fracture behavior. The effects of specimen size and crack inclination on fracture characteristics, including strength, failure mode, and crack initiation angle, were analyzed based on the maximum tangential stress (MTS) criterion and the generalized maximum tangential stress (GMTS) criterion, with relative critical size (α) and relative openness ().

High Strain Rate Deformation of Heat-Treated AA2519 Alloy.

This study examined the effects of heat treatment on the microstructure and dynamic deformation characteristics of AA2519 aluminum alloy in T4, T6, and T8 tempers under high strain rates of 1000-4000 s. A Split Hopkinson pressure bar (SHPB) was utilized to characterize the mechanical response, and microstructural analysis was performed to examine the material's microstructure. The findings indicated varied deformation across all three temper conditions.

The Influence of Heat Treatment on the Tensile Creep Life of the TC25 Titanium Alloy.

High-temperature titanium alloys are significant materials in the aerospace field, and their service life largely depends on creep aging. However, the creep behavior of the TC25 titanium alloy at high temperatures has not been reported. Here, the creep behavior of TC25 before and after heat treatment at 550 °C under different stresses was investigated.

Welding of S960QL High-Strength Steel by the Manual-Automated MAG Technique-A Study of Mechanical Properties, Residual Stresses and Fracture Mechanisms in the Heat-Affected Zone.

This paper presents results of investigations of a V-type welded joint made of S960QL high-strength steel made using a mixed technique: the root was welded manually and the face automatically. Although high-strength steels have been available on the market for many years, they are still the subject of research due to their increasingly widespread usage. For this reason, detailed investigations of welded joints of S960QL steel were carried out in terms of microstructure, microhardness, impact toughness and residual stresses, in order to expand knowledge in this area.

Pull-Out Progressive Damage and Failure Analysis of Laminated Composite Bolted Joints.

Laminated composite bolted joints are increasingly used in the aerospace field, and their damage and failure behavior has been studied in depth. In view of the complexity and stability requirements of laminated composite bolted structures, accurate prediction of damage evolution and failure behavior is significant to ensure the safety and reliability of the structures. In this paper, a novel asymptotic damage model is developed to predict the damage process and failure behavior of laminated composite bolted joints.

Embedded 3D Printing for Microchannel Fabrication in Epoxy-Based Microfluidic Devices.

Microfluidic devices offer promising solutions for automating various biological and chemical procedures. Epoxy resin, known for its excellent mechanical properties, chemical resistance, and thermal stability, is widely used in high-performance microfluidic devices. However, the poor printability of epoxy has limited its application in 3D printing technologies for fabricating epoxy-based microfluidic devices.

Analysis of Tensile Failure Behavior of Metal Fiber Laminates Under Different Temperature Environments.

The tensile properties of fiber metal laminates were examined at temperatures ranging from 30 °C to 180 °C in this paper through the integration of numerical simulation techniques, experimental measurements, and digital image correlation techniques. The laminates were initially modeled using finite elements, and the failure behavior of porous basalt-fiber-reinforced aluminum alloy plates was numerically simulated. Consequently, metal fiber laminate stress-strain responses were varied by numerous tensile experiments conducted at varying temperatures.

Fish Oil Consumption: Its Effects on Bone and Blood Parameters of the Ovariectomized Rat Model of Osteopenia.

: The beneficial effects of ω-3 fatty acids on the cardiovascular system have been observed in many epidemiological studies; however, their effects on the skeleton and in particular on postmenopausal bone loss appear to vary. The present study's purpose was to investigate the effects of oral fish oil (rich in ω-3 fatty acids) consumption on bone, plasma, and inflammation parameters in the ovariectomized (Ovx) rat model of osteopenia. : Four Groups of ten rats each were separated into Non-Ovx receiving fish oil (2.

Study on the mechanical behavior and rupture characteristics of coal after thermal damage.

High temperature is a critical safety concern that poses challenges to the safe and efficient operation of coal mines. To explore the mechanical behavior and fracture mechanisms of coal exposed to high temperatures, coal samples were subjected to various thermal treatments. After cooling, uniaxial compression tests were performed using an electronic universal testing machine to assess their macroscopic properties.

[Post-Intensive Care Syndrome: functional impairments of critical illness survivors].

With a decrease in mortality of critically ill patients in recent years, intensive care medicine research has shifted its focus on functional impairments of intensive care units (ICU) survivors. ICU survivorship is characterized by long-term impairments of cognition, mental health, and physical health. Since 2012, these impairments have been summarized with the umbrella term Post-Intensive Care Syndrome (PICS).

Acid-Induced in Situ Phase Separation and Percolation for Constructing Bi-Continuous Phase Hydrogel Electrodes With Motion-Insensitive Property.

Conducting polymer hydrogels have gained attention in the bioelectronics field due to their unique combination of biocompatibility and customizable mechanical properties. However, achieving both excellent conductivity and mechanical strength in a hydrogel remains a significant challenge, primarily because of the inherent conflict between the hydrophobic nature of conducting polymers and the hydrophilic characteristics of hydrogels. To address this issue, this work proposes a simple one-step acid-induced approach that not only promotes the gelation of hydrophilic polymers but also facilitates the in situ phase separation of hydrophobic conducting polymers under mild conditions.

Medial Malleolar Stress Fracture Treatment and Return to Activity: A Systematic Review.

Background: Medial malleolar stress fractures (MMSFs) naturally appear to occur primarily in athletes participating in sports requiring prolonged running or repetitive jumping. Nonoperative and operative modalities have been described, yielding a wide range of outcomes and return to activity (RTA) rates.

Hypothesis/purpose: To systematically review the current literature to identify reports of MMSFs to better understand the current state of treatment, outcomes, and RTA rate.

Strained Mechanical and Fracture Analyses of Armchair-Chiral-Zigzag-Based Carbon Nanotubes Using Molecular Dynamics Simulations.

Carbon nanotubes (CNTs) have emerged as one of the most capable and interesting materials in recent decades and have extraordinary mechanical properties (MPs) and resourceful applications in bioengineering and medicine. Equilibrium molecular dynamics simulations have been performed to investigate the structural and MPs of armchair, chiral, and semiconducting and metallic zigzag single-walled CNTs (SWCNTs) under varying temperature (K) and compressive and tensile strains ±γ (%) with reactive bond-order potential. New results elaborate on the buckling and deformation mechanisms of the SWCNTs through deep analyses of density profiles, radial distribution functions, structural visualizations, and stress-strain interactions.

Strength and strain distributions obtained from digital wrist tomosynthesis discriminate patients with and without a history of fragility fracture.

Bone fractures due to osteoporosis are a significant problem. Limited accuracy of standard bone mineral density (BMD) for fracture risk assessment, combined with low adherence to bone health screening precludes identification of those at risk of fracture. Because of the wide availability of digital breast tomosynthesis (DBT) imaging, bone screening using a DBT scanner at the time of breast screening has been proposed.

Evaluating Performance Among National Basketball Association Players After Jones Fractures: A Retrospective Cohort Study.

Background: In professional basketball, Jones fractures are among the most common cause of lower extremity stress injury. Despite its prevalence, there is a paucity of research on the impact of Jones fractures on athletic performance in the National Basketball Association (NBA).

Purpose: To determine the impact of Jones fractures on return to play and performance among NBA players when compared with preinjury values and healthy matched controls.

A Corticotomy-Assisted Extraction for a Rare 3-Part Broken Proximal Femoral Nail: A Case Report.

Introduction: Delayed union, non-union, and unstable fixation can lead to fatigue fractures of orthopedic implants. Breakages typically occur at the fracture site or locking screw insertion, acting as stress concentration foci. This case report highlights a rare instance of a 3-part broken proximal femoral nail (PFN), extracted using a corticotomy-assisted method without knee joint violation.

Finite element analysis of intramedullary nailing and nail-plate combinations for treating unstable proximal tibial metaphyseal fractures.

Background: The anatomy of the proximal tibia presents treatment challenges, and there is currently no widely accepted surgical fixation method for fractures in this region. The aim of this study is to evaluate the efficacy, benefits, and differences between intramedullary nailing (IMN) with a 4-hole Limited Contact Dynamic Compression Plate (LC-DCP) combination and IMN with an 8-hole LC-DCP combination in unstable fractures of the proximal metaphyseal region of the tibia.

Methods: An oblique fracture was created in the metaphyseal region, forming a 30-degree angle in the sagittal plane in three tibial models.