Multiaxial testing of the small intestinal wall is critical for understanding its biomechanical properties and defining material models, but limited data and material models are available. The aim of the present study was to develop a microstructure-based material model for the small intestine and test whether there was a significant variation in the passive biomechanical properties along the length of the organ. Rat tissue was cut into eight segments that underwent inflation/extension testing, and their nonlinearly hyper-elastic and anisotropic response was characterized by a fiber-reinforced model. Extensive parametric analysis showed a non-significant contribution to the model of the isotropic matrix and circumferential-fiber family, leading also to severe over-parameterization. Such issues were not apparent with the reduced neo-Hookean and (axial and diagonal)-fiber family model, that provided equally accurate fitting results. Absence from the model of either the axial or diagonal-fiber families led to ill representations of the force- and pressure-diameter data, respectively. The primary direction of anisotropy, designated by the estimated orientation angle of diagonal-fiber families, was about 35° to the axial direction, corroborating prior microscopic observations of submucosal collagen-fiber orientation. The estimated model parameters varied across and within the duodenum, jejunum, and ileum, corroborating histologically assessed segmental differences in layer thicknesses.
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http://dx.doi.org/10.3390/bioengineering8030032 | DOI Listing |
PLoS One
January 2025
School of Ophthalmology and Optometry, Wenzhou Medical University, Zhejiang, P. R. China.
Purpose: To evaluate the corneal biomechanical properties of phacoemulsification in the treatment of cataract patients.
Methods: Pertinent studies were searched in PubMed, EMBASE, Web of Science and clinicaltrials.gov.
PLoS One
January 2025
Faculty of Education and Arts, Sohar University, Sohar, Oman.
Conjugate Gradient (CG) methods are widely used for solving large-scale nonlinear systems of equations arising in various real-life applications due to their efficiency in employing vector operations. However, the global convergence analysis of CG methods remains a significant challenge. In response, this study proposes scaled versions of CG parameters based on the renowned Barzilai-Borwein approach for solving convex-constrained monotone nonlinear equations.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Sports Medicine of the Second Affiliated Hospital, and Liangzhu Laboratory, Zhejiang University School of Medicine, Hangzhou 311113, China.
Joining heterogeneous materials in engineered structures remains a significant challenge due to stress concentration at interfaces, which often leads to unexpected failures. Investigating the complex, multiscale-graded structures found in animal tissue provides valuable insights that can help address this challenge. The human meniscus root-bone interface is an exemplary model, renowned for its exceptional fatigue resistance, toughness, and interfacial adhesion properties throughout its lifespan.
View Article and Find Full Text PDFJ Biomed Mater Res B Appl Biomater
February 2025
McGowan Institute for Regenerative Medicine, Pittsburgh, Pennsylvania, USA.
Cardiovascular diseases (CVDs) were responsible for approximately 19 million deaths in 2020, marking an increase of 18.7% since 2010. Biological decellularized patches are common therapeutic solutions for CVD such as cardiac and valve defects.
View Article and Find Full Text PDFGels
January 2025
Department of Epidemiology, University of Medicine and Pharmacy of Craiova, 2 Petru Rares Str., 200349 Craiova, Romania.
Carpal Tunnel Syndrome (CTS) is a prevalent neuropathic disorder caused by chronic compression of the median nerve, leading to sensory and motor impairments. Conventional treatments, such as corticosteroid injections, wrist splinting, and surgical decompression, often fail to provide adequate outcomes for chronic or recurrent cases, emphasizing the need for innovative therapies. Hydrogels, highly biocompatible three-dimensional biomaterials with customizable properties, hold significant potential for CTS management.
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