Open Access. Powered by Scholars. Published by Universities.®
Biomedical Engineering and Bioengineering Commons™
Open Access. Powered by Scholars. Published by Universities.®
University of Nebraska - Lincoln
Department of Mechanical and Materials Engineering: Faculty Publications
- Discipline
-
- Mechanical Engineering (6)
- Medicine and Health Sciences (6)
- Other Biomedical Engineering and Bioengineering (5)
- Biomedical Devices and Instrumentation (4)
- Engineering Science and Materials (4)
-
- Biomechanics and Biotransport (3)
- Cardiology (3)
- Mechanics of Materials (3)
- Medical Specialties (3)
- Nanoscience and Nanotechnology (3)
- Other Engineering Science and Materials (3)
- Other Mechanical Engineering (3)
- Analytical, Diagnostic and Therapeutic Techniques and Equipment (2)
- Biology and Biomimetic Materials (2)
- Circulatory and Respiratory Physiology (2)
- Materials Science and Engineering (2)
- Medical Sciences (2)
- Acoustics, Dynamics, and Controls (1)
- Anatomy (1)
- Biochemistry, Biophysics, and Structural Biology (1)
- Biological Engineering (1)
- Biomechanical Engineering (1)
- Biotechnology (1)
- Cardiovascular System (1)
- Dental Materials (1)
- Dentistry (1)
- Dynamics and Dynamical Systems (1)
- Equipment and Supplies (1)
- Keyword
-
- Artery (2)
- Blast wave (2)
- Finite element modeling (2)
- Hypertension (2)
- Mechanical stimuli (2)
-
- Remodeling (2)
- Tissue mechanics (2)
- Wall stress (2)
- Aneurysm (1)
- Aorta (1)
- Atherosclerosis (1)
- Balloon-expandable stent (1)
- Blast (1)
- Cell contraction (1)
- Crimping (1)
- Dental nanocomposites (1)
- Ear canal (1)
- Eigenstrain (1)
- Finite element analysis (1)
- Fluid-structure interactions (1)
- Gene deconvolution (1)
- Interface (1)
- Interface/interphase (1)
- Interphase (1)
- Layered structures (1)
- Material mismatch (1)
- Matrix metalloproteinase (1)
- Mechanical properties (1)
- Mechanobiology (1)
- Mechanosensing (1)
Articles 1 - 13 of 13
Full-Text Articles in Biomedical Engineering and Bioengineering
Eigenstrain As A Mechanical Set-Point Of Cells, Shengmao Lin, Marsha C. Lampi, Cynthia A. Reinhart-King, Gary C.P. Tsui, Jian Wang, Carl A. Nelson, Linxia Gu
Eigenstrain As A Mechanical Set-Point Of Cells, Shengmao Lin, Marsha C. Lampi, Cynthia A. Reinhart-King, Gary C.P. Tsui, Jian Wang, Carl A. Nelson, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
Cell contraction regulates how cells sense their mechanical environment. We sought to identify the set-point of cell contraction, also referred to as tensional homeostasis. In this work, bovine aortic endothelial cells (BAECs), cultured on substrates with different stiffness, were characterized using traction force microscopy (TFM). Numerical models were developed to provide insights into the mechanics of cell–substrate interactions. Cell contraction was modeled as eigenstrain which could induce isometric cell contraction without external forces. The predicted traction stresses matched well with TFM measurements. Furthermore, our numerical model provided cell stress and displacement maps for inspecting the fundamental regulating mechanism of cell …
Expanded 3d Nanofiber Scaffolds: Cell Penetration, Neovascularization, And Host Response, Jiang Jiang, Zhuoran Li, Hongjun Wang, Yue Wang, Mark A. Carlson, Matthew J. Teusink, Matthew R. Macewan, Linxia Gu, Jingwei Xie
Expanded 3d Nanofiber Scaffolds: Cell Penetration, Neovascularization, And Host Response, Jiang Jiang, Zhuoran Li, Hongjun Wang, Yue Wang, Mark A. Carlson, Matthew J. Teusink, Matthew R. Macewan, Linxia Gu, Jingwei Xie
Department of Mechanical and Materials Engineering: Faculty Publications
Herein, a robust method to fabricate expanded nanofiber scaffolds with controlled size and thickness using a customized mold during the modified gas-foaming process is reported. The expansion of nanofiber membranes is also simulated using a computational fluid model. Expanded nanofiber scaffolds implanted subcutaneously in rats show cellular infiltration, whereas non-expanded scaffolds only have surface cellular attachment. Compared to unexpanded nanofiber scaffolds, more CD68+ and CD163+ cells are observed within expanded scaffolds at all tested time points post-implantation. More CCR7+ cells appear within expanded scaffolds at week 8 post-implantation. In addition, new blood vessels are present within the expanded scaffolds at …
Background Differences In Baseline And Stimulated Mmp Levels Influence Abdominal Aortic Aneurysm Susceptibility, Matthew A. Dale, Melissa K. Suh, Shijia Zhao, Trevor Meisinger, Linxia Gu, Vicki J. Swier, Devendra K. Agrawal, Timothy Greiner, Jeffrey S. Carson, B. Timothy Baxter, Wanfen Xiong
Background Differences In Baseline And Stimulated Mmp Levels Influence Abdominal Aortic Aneurysm Susceptibility, Matthew A. Dale, Melissa K. Suh, Shijia Zhao, Trevor Meisinger, Linxia Gu, Vicki J. Swier, Devendra K. Agrawal, Timothy Greiner, Jeffrey S. Carson, B. Timothy Baxter, Wanfen Xiong
Department of Mechanical and Materials Engineering: Faculty Publications
Objective: Evidence has demonstrated profound influence of genetic background on cardiovascular phenotypes. Murine models in Marfan syndrome (MFS) have shown that genetic background-related variations affect thoracic aortic aneurysm formation, rupture, and lifespan of mice. MFS mice with C57Bl/6 genetic background are less susceptible to aneurysm formation compared to the 129/SvEv genetic background. In this study, we hypothesize that susceptibility to abdominal aortic aneurysm (AAA) will be increased in 129/SvEv mice versus C57Bl/6 mice. We tested this hypothesis by assessing differences in aneurysm size, tissue properties, immune response, and MMP expression.
Methods: Mice of C57Bl/6 or 129/SvEv background underwent AAA induction …
Characterization Of Closed Head Impact Injury In Rat, Yi Hua, Praveen Akula, Matthew Kelso, Linxia Gu
Characterization Of Closed Head Impact Injury In Rat, Yi Hua, Praveen Akula, Matthew Kelso, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
The closed head impact (CHI) rat models are commonly used for studying the traumatic brain injury. The impact parameters vary considerably among different laboratories, making the comparison of research findings difficult. In this work, numerical CHI experiments were conducted to investigate the sensitivities of intracranial responses to various impact parameters (e.g., impact depth, velocity, and position; impactor diameter, material, and shape). A three-dimensional finite element rat head model with anatomical details was subjected to impact loadings. Results revealed that impact depth and impactor shape were the two leading factors affecting intracranial responses.The influence of impactor diameter was region-specific and an …
Blast-Induced Mild Traumatic Brain Injury Through Ear Canal: A Finite Element Study, Praveen Akula, Yi Hua, Linxia Gu
Blast-Induced Mild Traumatic Brain Injury Through Ear Canal: A Finite Element Study, Praveen Akula, Yi Hua, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
Purpose The role of ear canal in transmitting blast waves to the brain is not clear. The goal of this work is to characterize the influence of ear canal on blast-induced mild traumatic brain injury through a computational approach.
Methods A three-dimensional human head model with single-side ear canal details was reconstructed from computed tomography images. The ear canal was positioned either facing the incident blast wave or facing away from the blast wave.
Results The blast wave-head interaction has demonstrated that the overpressure within the ear canal was substantially amplified when the ear directly faced the blast wave. When …
Implementation And Validation Of Aortic Remodeling In Hypertensive Rats, Shijia Zhao, Linxia Gu
Implementation And Validation Of Aortic Remodeling In Hypertensive Rats, Shijia Zhao, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
A computational framework was implemented and validated to better understand the hypertensive artery remodeling in both geometric dimensions and material properties. Integrating the stress-modulated remodeling equations into commercial finite element codes allows a better control and visualization of local mechanical parameters. Both arterial thickening and stiffening effects were captured and visualized. An adaptive material remodeling strategy combined with the element birth and death techniques for the geometrical growth were implemented. The numerically predicted remodeling results in terms of the wall thickness, inner diameter, and the ratio of elastin to collagen content of the artery were compared with and fine-tuned by …
Implementation And Validation Of Aortic Remodeling In Hypertensive Rats, Shijia Zhao, Linxia Gu
Implementation And Validation Of Aortic Remodeling In Hypertensive Rats, Shijia Zhao, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
A computational framework was implemented and validated to better understand the hypertensive artery remodeling in both geometric dimensions and material properties. Integrating the stress-modulated remodeling equations into commercial finite element codes allows a better control and visualization of local mechanical parameters. Both arterial thickening and stiffening effects were captured and visualized. An adaptive material remodeling strategy combined with the element birth and death techniques for the geometrical growth were implemented. The numerically predicted remodeling results in terms of the wall thickness, inner diameter, and the ratio of elastin to collagen content of the artery were compared with and fine-tuned by …
Experimental And Numerical Investigation Of The Mechanism Of Blast Wave Transmission Through A Surrogate Head, Yi Hua, Praveen Akula, Linxia Gu, Jeff Berg, Carl A. Nelson
Experimental And Numerical Investigation Of The Mechanism Of Blast Wave Transmission Through A Surrogate Head, Yi Hua, Praveen Akula, Linxia Gu, Jeff Berg, Carl A. Nelson
Department of Mechanical and Materials Engineering: Faculty Publications
This work is to develop an experiment-validated numerical model to elucidate the wave transmission mechanisms through a surrogate head under blast loading. Repeated shock tube tests were conducted on a surrogate head, i.e., water-filled polycarbonate shell. Surface strain on the skull simulant and pressure inside the brain simulant were recorded at multiple locations. A numerical model was developed to capture the shock wave propagation within the shock tube and the fluid-structure interaction between the shock wave and the surrogate head. The obtained numerical results were compared with the experimental measurements. The experiment-validated numerical model was then used to further understand …
Systems Biology Of The Functional And Dysfunctional Endothelium, Jennifer Frueh, Nataly Maimari, Takayuki Homma, Sandra M. Bovens, Ryan M. Pedrigi, Leila Towhidi, Rob Krams
Systems Biology Of The Functional And Dysfunctional Endothelium, Jennifer Frueh, Nataly Maimari, Takayuki Homma, Sandra M. Bovens, Ryan M. Pedrigi, Leila Towhidi, Rob Krams
Department of Mechanical and Materials Engineering: Faculty Publications
This review provides an overview of the effect of blood flow on endothelial cell (EC) signalling pathways, applying microarray technologies to cultured cells, and in vivo studies of normal and atherosclerotic animals. It is found that in cultured ECs, 5–10% of genes are up- or down-regulated in response to fluid flow, whereas only 3–6% of genes are regulated by varying levels of fluid flow. Of all genes, 90%are regulated by the steady part of fluid flow and 10% by pulsatile components. The associated gene profiles show high variability from experiment to experiment depending on experimental conditions, and importantly, the bioinformatical …
Micromechanical Analysis Of Nanoparticle-Reinforced Dental Composites, Yi Hua, Linxia Gu, Hidehiko Watanabe
Micromechanical Analysis Of Nanoparticle-Reinforced Dental Composites, Yi Hua, Linxia Gu, Hidehiko Watanabe
Department of Mechanical and Materials Engineering: Faculty Publications
The mechanical behavior of TiO2 nanoparticle-reinforced resin-based dental composites was characterized in this work using a three-dimensional nanoscale representative volume element. The impacts of nanoparticle volume fraction, aspect ratio, stiffness, and interphase zone between the resin matrix and nanoparticle on the bulk properties of the composite were characterized. Results clearly demonstrated the mechanical advantage of nanocomposites in comparison to microfiber-reinforced composites. The bulk response of the nanocomposite could be further enhanced with the increased nanoparticle volume fraction, or aspect ratio, while the influence of nanoparticle stiffness was minimal. The effective Young’s modulus and yield strength of the composite was …
On The Importance Of Modeling Stent Procedure For Predicting Arterial Mechanics, Shijia Zhao, Linxia Gu, Stacey R. Froemming
On The Importance Of Modeling Stent Procedure For Predicting Arterial Mechanics, Shijia Zhao, Linxia Gu, Stacey R. Froemming
Department of Mechanical and Materials Engineering: Faculty Publications
The stent-artery interactions have been increasingly studied using the finite element method for better understanding of the biomechanical environment changes on the artery and its implications. However, the deployment of balloon-expandable stents was generally simplified without considering the balloon-stent interactions, the initial crimping process of the stent, its overexpansion routinely used in the clinical practice, or its recoil process. In this work, the stenting procedure was mimicked by incorporating all the above-mentioned simplifications. The impact of various simplifications on the stent-induced arterial stresses was systematically investigated. The plastic strain history of stent and its resulted geometrical variations, as well as …
The Influence Of Heterogeneous Meninges On The Brain Mechanics Under Primary Blast Loading, Linxia Gu, Mehdi S. Chafi, Shailesh Ganpule, Namas Chandra
The Influence Of Heterogeneous Meninges On The Brain Mechanics Under Primary Blast Loading, Linxia Gu, Mehdi S. Chafi, Shailesh Ganpule, Namas Chandra
Department of Mechanical and Materials Engineering: Faculty Publications
In the modeling of brain mechanics subjected to primary blast waves, there is currently no consensus on how many biological components to be used in the brain–meninges–skull complex, and what type of constitutive models to be adopted. The objective of this study is to determine the role of layered meninges in damping the dynamic response of the brain under primary blast loadings. A composite structures composed of eight solid relevant layers (including the pia, cerebrospinal fluid (CSF), dura maters) with different mechanical properties are constructed to mimic the heterogeneous human head. A hyper-viscoelastic material model is developed to better represent …
Numerical And Experimental Investigation Of Vascular Suture Closure, Linxia Gu, Ananth Ram Mahanth Kasavajhala, Haili Lang, James M. Hammel
Numerical And Experimental Investigation Of Vascular Suture Closure, Linxia Gu, Ananth Ram Mahanth Kasavajhala, Haili Lang, James M. Hammel
Department of Mechanical and Materials Engineering: Faculty Publications
Purpose — In order to optimize the performance of the suture for tissue closure, it is essential to develop strategies for devising new and improved techniques that can visualize and compare various suturing techniques. This paper describes an experimental and numerical investigation on the performance of sutured tissue.
Methods — In the experiments, two pieces of glutaraldehyde cross-linked bovine pericardium were sutured together through simple running suture and tensioned to study the performance of the sutured tissue. During testing, the tension load and the total displacement of the specimen were recorded. The strain field of the specimen was simultaneously captured …