As a composite material, cortical bone accumulates fatigue microdamage through the repetitive loading of everyday activity (e.g. walking). The accumulation of fatigue microdamage is thought to contribute to the occurrence of fragility fractures in older people. Therefore it is beneficial to understand the relationship between microcrack accumulation and the fracture resistance of cortical bone. Twenty longitudinally orientated compact tension fracture specimens were machined from a single bovine femur, ten specimens were assigned to both the control and fatigue damaged groups. The damaged group underwent a fatigue loading protocol to induce microdamage which was assessed via fluorescent microscopy. Following fatigue loading, non-linear fracture resistance tests were undertaken on both the control and damaged groups using the J-integral method. The interaction of the crack path with the fatigue induced damage and inherent toughening mechanisms were then observed using fluorescent microscopy. The results of this study show that fatigue induced damage reduces the initiation toughness of cortical bone and the growth toughness within the damage zone by three distinct mechanisms of fatigue-fracture interaction. Further analysis of the J-integral fracture resistance showed both the elastic and plastic component were reduced in the damaged group. For the elastic component this was attributed to a decreased number of ligament bridges in the crack wake while for the plastic component this was attributed to the presence of pre-existing fatigue microcracks preventing energy absorption by the formation of new microcracks.
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http://dx.doi.org/10.1007/s10856-014-5213-5 | DOI Listing |
J Endod
January 2025
Department of Endodontics, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, Shandong province, China. Electronic address:
Introduction: Traditional access cavity preparation involves removing the roof of the pulp chamber and smoothing the dentin bulges at the root canal orifice, thereby creating straight-line access. However, this may damage more healthy dental tissue and reduce the tooth's fracture resistance. This case series presents a novel minimally invasive endodontic protocol for one maxillary canine and four mandibular premolars, which required root canal therapy due to labial/buccal cervical decay that caused pulpitis or periapical periodontitis.
View Article and Find Full Text PDF3D Print Med
January 2025
AO Innovation Translation Center (AO ITC), AO Foundation, Davos, Switzerland.
Background: The emergence of 3D printing has revolutionized medical training and preoperative planning. However, existing models have limitations, prompting the development of newly designed flexible 3D-printed bone fracture models.
Methods: The designed flexible 3D-printed bone fracture models were evaluated by 133 trauma surgeons with different levels of experience for perceived value as educational tool or as preoperative planning tool.
Objective: This study aims to utilize bioinformatics and network pharmacology to identify the active components of Bushen Tiansui decoction (BSTSD) and elucidate its molecular mechanisms and targets in promoting delayed fracture healing.
Materials And Methods: Using various databases and tools, we identified 155 active compounds within BSTSD's herbal components. Key compounds such as eriodictyol and β-sitosterol were noted for their significant anti-inflammatory, antioxidant, and immunomodulatory effects, which are crucial for promoting fracture healing.
Nanotechnology
January 2025
Anhui Agricultural University, Hefei, 230036, P. R. China, Hefei, 230036, CHINA.
Strain sensing fabrics are able to sense the deformation of the outside world, bringing more accurate and real-time monitoring and feedback to users. However, due to the lack of clear sensing mechanism for high sensitivity and high linearity carbon matrix composites, the preparation of high performance strain sensing fabric weaving is still a major challenge. Here, an elastic polyurethane(PU)-based conductive fabric(GCPU) with high sensitivity, high linearity and good hydrophobicity is prepared by a novel synergistic conductive network strategy.
View Article and Find Full Text PDFPLoS One
January 2025
GuiZhou Institute of Subtropical Crops, Guizhou Academy of Agricultural Sciences, Guiyang, China.
Background: Fracture disrupts the integrity and continuity of the bone, leading to symptoms such as pain, tenderness, swelling, and bruising. Rhizoma Musae is a medicinal material frequently utilized in the Miao ethnic region of Guizhou Province, China. However, its specific mechanism of action in treating fractures remains unknown.
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