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Background:One challenge surgeons face when using certain suture knot techniques is where the forces concentrate along the central axis of the tissue, making the suture knot prone to failure due to suture pull-through and tissue shredding. New reinforcement techniques have been developed (suture tape augmentation) and are becoming popular to minimize tissue damage. Purpose:To assess biomechanical performance of whipstitch reinforcement techniques (locking stitch method or additional suture material) in human cadaveric semitendinosus tendons (STs). Study Design:Controlled laboratory study. Methods:A total of 42 STs were harvested and divided into 6 groups consisting of a standard whipstitch and varying reinforcement techniques based on stitch pattern (whipstitch [WS], whipstitch through tag [WT], locking whipstitch [WL], or locking whipstitch through tag [WLT]), and products from varying manufacturer samples were preconditioned and then loaded from 50 to 200 N at 1 Hz for 500 cycles, followed by load to failure. Elongation, stiffness, ultimate load, and failure mode were compared across groups. Results:No significant differences were observed between whipstitch groups WS1and WS2. Addition of suture material for reinforcement (WT2) significantly improved biomechanical performance across all metrics compared with WS2. Reinforcement using a new locking whipstitch method (WL) resulted in significant increase in ultimate load compared with WS1. All reinforcement groups (WL, WT1, WT2, and WLT) achieved a similar level of biomechanical performance, with no significant differences across any metric. Addition of a second reinforcement (WLT) did not significantly enhance biomechanics beyond those achieved with a single reinforcement (WL). The failure mode for no-reinforcement groups was tissue pull-through, while reinforcement groups utilizing either material or locking method failed from suture breakage. Conclusion:Whipstitch alone offers limited biomechanical security, but reinforcement with either a locking method or additional suture material significantly enhances biomechanical performance. Clinical Relevance:Reinforcement may help limit tissue damage. The locking whipstitch method offers a promising alternative to reinforce a stitch with relatively less suture material.
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Autonomous scanning probe microscopy investigations over WS2 and Au{111}
Abstract Individual atomic defects in 2D materials impact their macroscopic functionality. Correlating the interplay is challenging, however, intelligent hyperspectral scanning tunneling spectroscopy (STS) mapping provides a feasible solution to this technically difficult and time consuming problem. Here, dense spectroscopic volume is collected autonomously via Gaussian process regression, where convolutional neural networks are used in tandem for spectral identification. Acquired data enable defect segmentation, and a workflow is provided for machine-driven decision making during experimentation with capability for user customization. We provide a means towards autonomous experimentation for the benefit of both enhanced reproducibility and user-accessibility. Hyperspectral investigations on WS2sulfur vacancy sites are explored, which is combined with local density of states confirmation on the Au{111} herringbone reconstruction. Chalcogen vacancies, pristine WS2, Au face-centered cubic, and Au hexagonal close-packed regions are examined and detected by machine learning methods to demonstrate the potential of artificial intelligence for hyperspectral STS mapping.
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- Award ID(s):
- 2011839
- PAR ID:
- 10379960
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- npj Computational Materials
- Volume:
- 8
- Issue:
- 1
- ISSN:
- 2057-3960
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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