Objective: To compare the intrinsic stability of an unconstrained resurfacing metacarpophalangeal arthroplasty to that of a normal human cadaveric joint.
Design: Cadaveric joints and metacarpophalangeal prostheses were studied in a mechanical testing machine at different angles and axial loads to determine the stability ratio in eight directions of movement.
Background: An unconstrained resurfacing arthroplasty was designed to replicate the normal anatomy with the exception of the proximal component having a greater arc of curvature on its dorsal aspect.
Methods: Eight fresh-frozen cadaveric joints and five different sizes of the AVANTA metacarpophalangeal prosthesis were studied at 0 degrees, 45 degrees and 90 degrees angles of flexion and at eight different directions of motion with three different axial loads (0, 20, 40 N). A 6-component load cell measured the force needed to sublux the joint. The stability ratio was the measured outcome and is defined as ratio of the force of subluxation to the axial force.
Results And Conclusions: The unconstrained resurfacing arthroplasty has more intrinsic stability than the cadaveric metacarpophalangeal joint in all eight directions tested.
Relevance: A major complication of metacarpophalangeal implants is ulnopalmar subluxation. The AVANTA implant is designed to decrease the risk of ulnopalmar subluxation by having a greater arc of curvature on the dorsal aspect of the proximal component. This study shows that the designed implant has greater stability due to the geometry of the implant compared to that of the anatomical joint.
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http://dx.doi.org/10.1016/s0268-0033(02)00178-x | DOI Listing |
Apoptosis
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Department of Cardiac Surgery, First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan II Rd, Guangzhou, 510080, China.
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January 2025
School of Chemistry, Dalian University of Technology, Dalian 116024 PR China. Electronic address:
The development of electrode materials for aqueous ammonium-ion supercapacitors (NH-SCs) has garnered significant attention in recent years. Poor intrinsic conductivity, sluggish electron transfer and ion diffusion kinetics, as well as structural degradation of vanadium oxides during the electrochemical process, pose significant challenges for their efficient ammonium-ion storage. In this work, to address the above issues, the core-shell VO·nHO@poly(3,4-ethylenedioxithiophene) composite (denoted as VOH@PEDOT) is designed and prepared by a simple agitation method to boost the ammonium-ion storage of VO·nHO (VOH).
View Article and Find Full Text PDFPlants (Basel)
January 2025
Key Laboratory of Mountain Hazards and Earth Surface Processes, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610299, China.
Climate change has led to an increasing frequency of droughts, potentially undermining soil stability. In such a changing environment, the shallow reinforcement effect of plant roots often fails to meet expectations. This study aims to explore whether this is associated with the alteration of plant traits as a response to environmental change.
View Article and Find Full Text PDFSensors (Basel)
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Center for Generic Aerospace Technology, Huanjiang Laboratory, Zhuji 311816, China.
This paper introduces Re-DQN, a deep reinforcement learning-based algorithm for comprehensive coverage path planning in lawn mowing robots. In the fields of smart homes and agricultural automation, lawn mowing robots are rapidly gaining popularity to reduce the demand for manual labor. The algorithm introduces a new exploration mechanism, combined with an intrinsic reward function based on state novelty and a dynamic input structure, effectively enhancing the robot's adaptability and path optimization capabilities in dynamic environments.
View Article and Find Full Text PDFMolecules
January 2025
Department of Chemical Science and Technologies, University of Rome Tor Vergata, 00133 Rome, Italy.
Plastics are widely produced due to their stability and ease of manufacturing, but many of them quickly become a waste, breaking down into microplastics and nanoplastics. While methods for the identification and characterization of plastic particles are well consolidated, the small size of nanoplastics presents challenges for their detection and analysis. Furthermore, due to the difficulty of identifying nanoplastics, analytical studies concerning their effect on cells and a comprehensive spectroscopic characterization are still lacking.
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