Arrayed three-dimensional structures designed to induce and maintain a cell pattern by a topographical effect on cell behavior

2015 ◽  
Vol 49 ◽  
pp. 256-261 ◽  
Author(s):  
Takao Saito ◽  
Kay Teraoka ◽  
Kazuyoshi Ota
2021 ◽  
Vol 22 (9) ◽  
pp. 4715
Author(s):  
Guanning Wei ◽  
Hongmei Sun ◽  
Haijun Wei ◽  
Tao Qin ◽  
Yifeng Yang ◽  
...  

The hair follicle dermal papilla is critical for hair generation and de novo regeneration. When cultured in vitro, dermal papilla cells from different species demonstrate two distinguishable growth patterns under the conventional culture condition: a self-aggregative three dimensional spheroidal (3D) cell pattern and a two dimensional (2D) monolayer cell pattern, correlating with different hair inducing properties. Whether the loss of self-aggregative behavior relates to species-specific differences or the improper culture condition remains unclear. Can the fixed 2D patterned dermal papilla cells recover the self-aggregative behavior and 3D pattern also remains undetected. Here, we successfully constructed the two growth patterns using sika deer (Cervus nippon) dermal papilla cells and proved it was the culture condition that determined the dermal papilla growth pattern. The two growth patterns could transit mutually as the culture condition was exchanged. The fixed 2D patterned sika deer dermal papilla cells could recover the self-aggregative behavior and transit back to 3D pattern, accompanied by the restoration of hair inducing capability when the culture condition was changed. In addition, the global gene expressions during the transition from 2D pattern to 3D pattern were compared to detect the potential regulating genes and pathways involved in the recovery of 3D pattern and hair inducing capability.


2021 ◽  
Vol 4 (2) ◽  
pp. 1319-1329
Author(s):  
Minami Yoshida ◽  
Paul R. Turner ◽  
M. Azam Ali ◽  
Jaydee D. Cabral

Author(s):  
W. T. Tiow ◽  
M. Zangeneh

The development and application of a three-dimensional inverse methodology is presented for the design of turbomachinery blades. The method is based on the mass-averaged swirl, rV~θ distribution and computes the necessary blade changes directly from the discrepancies between the target and initial distributions. The flow solution and blade modification converge simultaneously giving the final blade geometry and the corresponding steady state flow solution. The flow analysis is performed using a cell-vertex finite volume time-marching algorithm employing the multistage Runge-Kutta integrator in conjunction with accelerating techniques (local time stepping and grid sequencing). To account for viscous effects, dissipative forces are included in the Euler solver using the log-law and mixing length models. The design method can be used with any existing solver solving the same flow equations without any modifications to the blade surface wall boundary condition. Validation of the method has been carried out using a transonic annular turbine nozzle and NASA rotor 67. Finally, the method is demonstrated on the re-design of the blades.


Author(s):  
Cengiz Yeker ◽  
Ibrahim Zeid

Abstract A fully automatic three-dimensional mesh generation method is developed by modifying the well-known ray casting technique. The method is capable of meshing objects modeled using the CSG representation scheme. The input to the method consists of solid geometry information, and mesh attributes such as element size. The method starts by casting rays in 3D space to classify the empty and full parts of the solid. This information is then used to create a cell structure that closely models the solid object. The next step is to further process the cell structure to make it more succinct, so that the cells close to the boundary of the solid object can model the topology with enough fidelity. Moreover, neighborhood relations between cells in the structure are developed and implemented. These relations help produce better conforming meshes. Each cell in the cell structure is identified with respect to a set of pre-defined types of cells. After the identification process, a normalization process is developed and applied to the cell structure in order to ensure that the finite elements generated from each cell conform to each other and to other elements produced from neighboring cells. The last step is to mesh each cell in the structure with valid finite elements.


2021 ◽  
Vol 220 (11) ◽  
Author(s):  
Sourabh Bhide ◽  
Denisa Gombalova ◽  
Gregor Mönke ◽  
Johannes Stegmaier ◽  
Valentyna Zinchenko ◽  
...  

The intrinsic genetic program of a cell is not sufficient to explain all of the cell’s activities. External mechanical stimuli are increasingly recognized as determinants of cell behavior. In the epithelial folding event that constitutes the beginning of gastrulation in Drosophila, the genetic program of the future mesoderm leads to the establishment of a contractile actomyosin network that triggers apical constriction of cells and thereby tissue folding. However, some cells do not constrict but instead stretch, even though they share the same genetic program as their constricting neighbors. We show here that tissue-wide interactions force these cells to expand even when an otherwise sufficient amount of apical, active actomyosin is present. Models based on contractile forces and linear stress–strain responses do not reproduce experimental observations, but simulations in which cells behave as ductile materials with nonlinear mechanical properties do. Our models show that this behavior is a general emergent property of actomyosin networks in a supracellular context, in accordance with our experimental observations of actin reorganization within stretching cells.


1971 ◽  
Vol 49 (3) ◽  
pp. 468-476 ◽  
Author(s):  
Lilian Y. Y. Chan ◽  
F. W. B. Einstein

The crystal structure of potassium hydrogen di-iodate (bi-iodate) KIO3.HIO3 was determined from three dimensional X-ray data collected by counter methods. The structure was refined by full-matrix least-squares techniques to a conventional R factor of 5.0 % for the 1392 observed reflexions. The salt crystallizes in the monoclinic space group P21/c with eight formula units in a cell of dimension a = 7.028(1) Å, b = 8.203(1) Å, c = 21.841(3) Å, β = 98.03(1)°.The iodate units are all basically pyramidal; weak interionic I—O contacts complete a very distorted octahedral environment around three iodine atoms. There is a capped octahedral (7-coordinate) environment around the remaining iodine atom. The I—O bonds are in the range 1.75–1.82 Å and the I—OH bonds are 1.91 and 1.95 Å, variations in length can be correlated with differences in the degree of involvement in (a) hydrogen bonding and (b) interaction with adjacent iodine atoms.


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