Polyvinyl alcohol hydrogels are biocompatible and can be used as synthetic articular cartilage. Their mechanical characteristics can be tailored by various techniques such as annealing or blending with other hydrophilic polymers. In this study, we quantified the coefficient of friction of various candidate polyvinyl alcohol hydrogels against cobalt-chrome alloy or swine cartilage using a new rheometer-based method. We investigated the coefficient of friction of polyvinyl alcohol-only hydrogels and blends with polyethylene glycol, polyacrylic acid, and polyacrylamide against swine cartilage and polished cobalt-chrome surfaces. The addition of the functional groups to polyvinyl alcohol, such as acrylamide (semi-interpenetrating network) and acrylic acid (blend), significantly reduced the coefficient of friction. The coefficient of friction of the polyvinyl alcohol-only hydrogel was measured as 0.4 ± 0.03 against cobalt-chrome alloy, and 0.09 ± 0.004 against cartilage, while those measurements for the polyvinyl alcohol-polyacrylic acid blends and polyvinyl alcohol-polyacrylamide semi-interpenetrating network were 0.07 ± 0.01 and 0.1 ± 0.003 against cobalt-chrome alloy, and 0.03 ± 0.001 and 0.02 ± 0.001 against cartilage, respectively. There was no significant or minimal difference in the coefficient of friction between samples from different regions of the knee, or animals, or when the cartilage samples were frozen for 1 day or 2 days before testing. However, changing lubricant from deionized water to ionic media, for example, saline or simulated body fluid, increased the coefficient of friction significantly.
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Sci Rep
January 2025
College of Engineering, Ocean University of China, Qingdao, 266404, China.
Although deterministic analysis can provide initial insights into slope stability, there is no way to reflect the true distribution of soil properties within a slope. To further investigate the effects of the spatial variability of soil properties on the stability and failure mechanism of slope under different foundation types, this study develops a framework combining simple limit equilibrium method (LEM), Monte Carlo Simulation (MCS), and random field to incorporate these factors into slope probabilistic stability analysis. The slope models of two typical foundations (e.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 101408 China. Electronic address:
The exploration of pure organic ultra-long room temperature phosphorescence (RTP) materials has emerged as a research hotspot in recent years. Herein, a simple strategy for fabricating long-afterglow polymer aerogels with three-dimensional ordered structures and environmental monitoring capabilities is proposed. Based on the non-covalent interactions between pectin (PC) and melamine formaldehyde (MF), a composite aerogel (PCMF@phenanthrene) (PCMF@PA) doped with phosphorescent organic small molecules was constructed.
View Article and Find Full Text PDFEnviron Technol
January 2025
School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan, People's Republic of China.
This study introduces a novel landfill cover material, employing lake sediment as a substrate, stabilised with fly ash, slag, desulfurisation gypsum and construction waste. The mechanical properties, including shear strength parameters, unconfined compressive strength, hydraulic conductivity, volumetric shrinkage, and water content, of the solidified sludge were evaluated. The microscopic mechanism of the solidified sludge were investigated through XRD, FTIR, and SEM-EDS techniques.
View Article and Find Full Text PDFCureus
December 2024
Department of Health Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, JPN.
Purpose The infrapatellar fat pad (IFP) has the lowest pain threshold among all knee joint components and causes anterior knee pain after knee arthroplasty. It has been reported that selective muscle atrophy of the vastus medialis (VM) and fibrosis of the IFP may develop following knee joint surgery. Ultrasound enables visualization of IFP deformation (A1) from within the joint to the proximal area in response to muscle contraction, and this may be helpful in developing preventive and therapeutic strategies for IFP fibrosis.
View Article and Find Full Text PDFAnn Biomed Eng
January 2025
School of Mechanical Engineering, Purdue University, West Lafayette, IN, 47907, USA.
Purpose: To evaluate the mechanical wear of cartilage with different types of degradation.
Methods: Bovine osteochondral explants were treated with interleukin-1β (IL-1β) to mimic inflammatory conditions, with chondroitinase ABC (ChABC) to specifically remove glycosaminoglycans (GAGs), or with collagenase to degrade the collagen network during 5 days of culture. Viscoelastic properties of cartilage were characterized via indentation.
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