Flexural Rigidity of a Single Microtubule

Takasone, Toru; Juodkazis, Saulius; Kawagishi, Yuji; Yamaguchi, A.; Matsuo, Shigeki; Sakakibara, Hitoshi; Nakayama, Haruo; Misawa, Hiroaki

doi:10.1143/jjap.41.3015

Cited by 70 publications

(70 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Typical setup to perform all-optical switching experiments by laser trapped droplets of liquid crystals (LCs) is shown in Figure 29. 141,143,148,149 A combined angular tuning of =2 and =4 plates allows precise control of the polarization of the laser beam at the focus (the polarization is analyzed by a Nikol prism at point A before the objective lens). The laser trapping force is calibrated by measuring the speed at which the laser trapped micro-sphere of radius, r, is released in liquid of known viscosity, , using Stokes' law.…”

Section: Laser Tweezers Acting On Birefringent Particlesmentioning

confidence: 99%

Three-Dimensional Micro- and Nano-Structuring of Materials by Tightly Focused Laser Radiation

Juodkazis¹,

Mizeikis²,

Matsuo³

et al. 2008

Bulletin of the Chemical Society of Japan

Self Cite

View full text Add to dashboard Cite

Three-dimensional laser microfabrication blends microscopy, optical nonlinear phenomena, photomodification, laser trapping, and creates novel possibilities for fabrication of micro-and nano-structures in a wide range of materials. This work reviews various implementations of laser photo-structuring and micromanipulation applied to photo-modification of various materials: glasses, crystals, polymers, gels, and liquid crystals.

show abstract

Section: Laser Tweezers Acting On Birefringent Particlesmentioning

confidence: 99%

Three-Dimensional Micro- and Nano-Structuring of Materials by Tightly Focused Laser Radiation

Juodkazis¹,

Mizeikis²,

Matsuo³

et al. 2008

Bulletin of the Chemical Society of Japan

Self Cite

View full text Add to dashboard Cite

show abstract

“…Experimental measurements suggest that the EI of microtubules is height dependent, such that shorter microtubules have lower values of EI (Kurachi et al, 1995;Takasone et al, 2002;Pampaloni et al, 2006), but this height dependence is not expected for an isotropic Euler-Bernoulli beam, demonstrating that the MT is not accurately modeled as such. Indeed, atomic force microscopy shows that MTs are highly anisotropic because the longitudinal bond strength between tubulin dimers along the protofilaments is greater than the lateral bond strength between protofilaments (Kis et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Biomechanics of hair cell kinocilia: experimental measurement of kinocilium shaft stiffness and base rotational stiffness with Euler–Bernoulli and Timoshenko beam analysis

Spoon

Grant

2011

Journal of Experimental Biology

View full text Add to dashboard Cite

the OL movement is transmitted to the mechanotransducing part of the hair bundle. Previous computational studies have shown that the tall and compliant kinocilia of extrastriolar bundles increase the hair cells' operating range (range of deflections over which vestibular sensory cell can encode) to several microns compared with that of striolar bundles, which is ~0.1m (Nam et al., 2005). Knowing the mechanical properties of the kinocilium will further our understanding of how these hair cells operate.Kinocilia are composed of a microtubular core, a 9+2 axoneme, composed of nine peripheral doublet microtubules encircling two central single tubules. This configuration is common to motile cilia and eukaryotic flagella (Fig.1A) but, despite their common structure, kinocilia are thought to be non-motile, unlike flagella, as they lack the inner arms of the motor protein dynein, which are essential for motility (Kikuchi et al., 1989). A limited number of spontaneous flagella-like oscillations have been observed in ampullary kinocilia but were limited in number and suggested to result from tissue Accepted 23 November 2010 SUMMARY Vestibular hair cell bundles in the inner ear contain a single kinocilium composed of a 9+2 microtubule structure. Kinocilia play a crucial role in transmitting movement of the overlying mass, otoconial membrane or cupula to the mechanotransducing portion of the hair cell bundle. Little is known regarding the mechanical deformation properties of the kinocilium. Using a force-deflection technique, we measured two important mechanical properties of kinocilia in the utricle of a turtle, Trachemys (Pseudemys) scripta elegans. First, we measured the stiffness of kinocilia with different heights. These kinocilia were assumed to be homogenous cylindrical rods and were modeled as both isotropic Euler-Bernoulli beams and transversely isotropic Timoshenko beams. Two mechanical properties of the kinocilia were derived from the beam analysis: flexural rigidity (EI) and shear rigidity (kGA). The Timoshenko model produced a better fit to the experimental data, predicting EI10,400pNm 2 and kGA247pN. Assuming a homogenous rod, the shear modulus (G1.9kPa) was four orders of magnitude less than Young's modulus (E14.1MPa), indicating that significant shear deformation occurs within deflected kinocilia. When analyzed as an Euler-Bernoulli beam, which neglects translational shear, EI increased linearly with kinocilium height, giving underestimates of EI for shorter kinocilia. Second, we measured the rotational stiffness of the kinocilium insertion () into the hair cell's apical surface. Following BAPTA treatment to break the kinocilial links, the kinocilia remained upright, and  was measured as 177±47pNmrad -1 . The mechanical parameters we quantified are important for understanding how forces arising from head movement are transduced and encoded by hair cells.

show abstract

“…However, a large variation of Young's modulus E was obtained and reported in the open literature. For example, Takasone et al (2002) gave E = 0.1 GPa by using a laser trapping technique and darkfield microscopy, while by using a nondestructive method Wagner et al (1999) gave E = 2.55 GPa, which is found to be about 25 times as large as that of Takasone et al (2002). It has been reported that the material properties of MTs are anisotropic and temperature-dependent (Kis et al 2002;Tuszynski et al 2005;Pampaloni et al 2006).…”

Section: Numerical Results and Discussionmentioning

confidence: 97%

Nonlocal shear deformable shell model for postbuckling of axially compressed microtubules embedded in an elastic medium

Shen

2009

Biomech Model Mechanobiol

View full text Add to dashboard Cite

Buckling and postbuckling analysis is presented for axially compressed microtubules (MTs) embedded in an elastic matrix of cytoplasm. The microtubule is modeled as a nonlocal shear deformable cylindrical shell which contains small scale effects. The surrounding elastic medium is modeled as a Pasternak foundation. The governing equations are based on higher order shear deformation shell theory with a von Kármán-Donnell-type of kinematic nonlinearity and include the extension-twist and flexural-twist couplings. The thermal effects are also included and the material properties are assumed to be temperature-dependent. The small scale parameter e (0) a is estimated by matching the buckling load from their vibrational behavior of MTs with the numerical results obtained from the nonlocal shear deformable shell model. The numerical results show that buckling load and postbuckling behavior of MTs are very sensitive to the small scale parameter e (0) a. The results reveal that the MTs under axial compressive loading condition have an unstable postbuckling path, and the lateral constraint has a significant effect on the postbuckling response of a microtubule when the foundation stiffness is sufficiently large.

show abstract

Flexural Rigidity of a Single Microtubule

Cited by 70 publications

References 16 publications

Three-Dimensional Micro- and Nano-Structuring of Materials by Tightly Focused Laser Radiation

Three-Dimensional Micro- and Nano-Structuring of Materials by Tightly Focused Laser Radiation

Biomechanics of hair cell kinocilia: experimental measurement of kinocilium shaft stiffness and base rotational stiffness with Euler–Bernoulli and Timoshenko beam analysis

Nonlocal shear deformable shell model for postbuckling of axially compressed microtubules embedded in an elastic medium

Contact Info

Product

Resources

About