A computational model to describe the collagen orientation in statically cultured engineered tissues.
Soares AL, Oomens CW, Baaijens FP.Author information a Department of Biomedical Engineering , Eindhoven University of Technology , Eindhoven , The Netherlands.AbstractCollagen provides cardiovascular tissues with the ability to withstand haemodynamic loads. A similar network is essential to obtain in tissue-engineered (TE) samples of the same nature. Yet, the mechanism of collagen orientation is not fully understood. Typically collagen remodelling is linked to mechanical loading. However, TE constructs also show an oriented collagen network when developed under static culture. Experiments under these conditions also indicate that the tissue gradually compacts due to contractile stresses developed in the α-actin fibres of the cells. Therefore, it is hypothesised that cellular contractile stresses are responsible for collagen orientation. A model describing the cellular α-actin turnover and the stresses developed by them is integrated in a structural constitutive model describing the mechanical behaviour of collagen fibres. Results show that the model can successfully capture the sample compaction, tissue stress generation and its heterogeneous collagen arrangement.
Computer methods in biomechanics and biomedical engineering.Comput Methods Biomech Biomed Engin.2014 Feb;17(3):251-62. doi: 10.1080/10255842.2012.680192. Epub 2012 May 1.
Collagen provides cardiovascular tissues with the ability to withstand haemodynamic loads. A similar network is essential to obtain in tissue-engineered (TE) samples of the same nature. Yet, the mechanism of collagen orientation is not fully understood. Typically collagen remodelling is linked to me
Plate-shaped non-contact ultrasonic transporter using flexural vibration.
Ishii T, Mizuno Y, Koyama D, Nakamura K, Harada K, Uchida Y.Author information Precision and Intelligence Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan. Electronic address: ishii@sonic.pi.titech.ac.jp.AbstractWe developed a plate-shaped non-contact transporter based on ultrasonic vibration, exploiting a phenomenon that a plate can be statically levitated at the place where its gravity and the acoustic radiation force are balanced. In the experiment, four piezoelectric zirconate titanate elements were attached to aluminum plates, on which lattice flexural vibration was excited at 22.3 kHz. The vibrating plates were connected to a loading plate via flexible posts that can minimize the influence of the flexure induced by heavy loads. The distribution of the vibration displacement on the plate was predicted through finite-element analysis to find the appropriate positions of the posts. The maximum levitation height of this transporter was 256 μm with no load. When two vibrating plates were connected to a loading plate, the maximum transportable load was 4.0 kgf.
We developed a plate-shaped non-contact transporter based on ultrasonic vibration, exploiting a phenomenon that a plate can be statically levitated at the place where its gravity and the acoustic radiation force are balanced. In the experiment, four piezoelectric zirconate titanate elements were att
Notochordal cell disappearance and modes of apoptotic cell death in a rat tail static compression-induced disc degeneration model.
Yurube T, Hirata H, Kakutani K, Maeno K, Takada T, Zhang Z, Takayama K, Matsushita T, Kuroda R, Kurosaka M, Nishida K.AbstractINTRODUCTION: The intervertebral disc has a complex structure originating developmentally from both the mesenchyme and notochord. Notochordal cells disappear during adolescence, which is also when human discs begin to show degenerative signs. During degeneration later in life, disc cells decline due to apoptosis. Although many animal models have been developed to simulate human disc degeneration, few studies have explored the long-term changes in cell population and phenotype. Our objective was to elucidate the time-dependent notochordal cell disappearance and apoptotic cell death in a rat tail static compression-induced disc degeneration model.
Arthritis research & therapy.Arthritis Res Ther.2014 Jan 29;16(1):R31. [Epub ahead of print]
INTRODUCTION: The intervertebral disc has a complex structure originating developmentally from both the mesenchyme and notochord. Notochordal cells disappear during adolescence, which is also when human discs begin to show degenerative signs. During degeneration later in life, disc cells decline due
In statics, a structure is statically indeterminate (or hyperstatic) when the static equilibrium equations are insufficient for determining the internal forces and reactions on that structure. Based on Newton's laws of motion, the equilibrium ...
15 Jan 2010 ... How to solve a simple statically indeterminate problem. Statically indeterminate means that you can't solve the problem using statics alone. Extra equation n...