A biomechanical study of an interspinous stabilization spinal implant (Coflex) was carried out using eight human lumbar L4/L5 motion segments. Each motion segment was tested in compression, then flexion/extension, then lateral bending, and then axial rotation at five conditions: 1) intact; 2) partial destabilization (by cutting the supraspinous and interspinous ligaments, the ligamentum flavum, the facet capsules, and 50% of the inferior bony facet bilaterally); 3) stabilization with the Coflex device; 4) complete destabilization with total laminectomy; and 5) stabilization with pedicle screws and rods. The most important result is that the motion segment after destabilization and insertion of the Coflex device does not allow significantly more or less motion than the intact specimen in either flexion/extension or axial rotation. Thus the Coflex offers nonrigid fixation and can return a partially destabilized specimen back to the intact condition in terms of motion in flexion/extension and axial rotation.
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Reprod Toxicol
January 2025
NEXTREAT Laboratories, Hajmáskér, Hungary.
One of the main endpoints for the evaluation of Developmental and Reproductive Toxicology (DART) studies is the determination of potential effects of a test substance on the skeleton during foetal development. In the course of a DART study according to the OECD 414 guideline, 400 to 500 gestational day 20-old (GD20), alizarin red and alcian blue-stained (ARAB) rat foetuses have to be assessed by a teratology expert, which is a time consuming and sub-optimally documented process. We have developed a method which allows for a standardised, comprehensive, quick and easy to perform, head-to-toe digital documentation of ARAB-stained GD20 rat foetuses.
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January 2025
Musculoskeletal Biomechanics Research Lab, Department of Mechanical Engineering, McGill University, 845 Sherbrooke St. W (163), Montréal, QC, H3A 0C3, Canada.
Background: There exists a need for validated lumbar spine models in spine biomechanics research. Although cadaveric testing is the current gold standard for spinal implant development, it poses significant issues related to reliability and repeatability due to the wide variability in cadaveric physiologies. Moreover, there are increasing ethical concerns with human dissection practices.
View Article and Find Full Text PDFKnee Surg Sports Traumatol Arthrosc
January 2025
Clinical Research Department, Sydney Knee Specialists, Kogarah, New South Wales, Australia.
Purpose: In functionally aligned (FA) total knee arthroplasty (TKA), femoral component rotation (FCR) is personalised to optimise flexion gap balance. As axial malalignment has been attributed to patellofemoral complications, this study assessed FA FCR in relation to the surgical transepicondylar axis (TEA) and early implant survivorship.
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Sci Rep
January 2025
College of Civil Engineering and Communication, North China University of Water Resources and Electric Power, Zhengzhou, 450045, China.
Acid rain can significantly undermine the structural integrity and seismic resilience of concrete structures, posing substantial risks of catastrophic failures and jeopardizing safety. However, studies on the seismic behavior of reinforced concrete (RC) columns affected by acid rain corrosion remain nascent. Therefore, this study explored the impact of acid-rain corrosion extent and axial compression ratio on the seismic behavior of RC columns that experienced flexural failure using an artificial rapid corrosion method and pseudo-static test in sequence.
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January 2025
US Department of Agriculture, Agriculture Research Service, Hydrology and Remote Sensing Laboratory, Beltsville, MD, United States of America.
Metolachlor is the most heavily used member of acetanilide herbicides, which are noted for forming highly soluble metabolites in root zone soils soon after field application. The two primary metabolites of metolachlor, metolachlor ethane sulfonic acid (MESA) and metolachlor oxanilic acid (MOXA), retain the same chiral chemistry as their source and are important tracers of nitrate loading from agricultural cropland. New analytical methods for separating the isomers of MESA and MOXA, enable studies assessing changes in the abundance of atropisomer pairs of the carbon chiral enantiomers in environmental samples.
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