The development of fast cellular pattern transformation algorithms using virtual boundaries

Author(s):  
Josef Pecht
Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1205
Author(s):  
Hai Qiu ◽  
Ying Li ◽  
Tianfu Guo ◽  
Shan Tang ◽  
Zhaoqian Xie ◽  
...  

Structural topology and loading condition have important influences on the mechanical behaviors of porous soft solids. The porous solids are usually set to be under uniaxial tension or compression. Only a few studies have considered the biaxial loads, especially the combined loads of tension and compression. In this study, porous soft solids with oblique and square lattices of circular voids under biaxial loadings were studied through integrated experiments and numerical simulations. For the soft solids with oblique lattices of circular voids, we found a new pattern transformation under biaxial compression, which has alternating elliptic voids with an inclined angle. This kind of pattern transformation is rarely reported under uniaxial compression. Introducing tensile deformation in one direction can hamper this kind of pattern transformation under biaxial loading. For the soft solids with square lattices of voids, the number of voids cannot change their deformation behaviors qualitatively, but quantitatively. In general, our present results demonstrate that void morphology and biaxial loading can be harnessed to tune the pattern transformations of porous soft solids under large deformation. This discovery offers a new avenue for designing the void morphology of soft solids for controlling their deformation patterns under a specific biaxial stress-state.


Development ◽  
1970 ◽  
Vol 23 (2) ◽  
pp. 311-322
Author(s):  
D. R. Garrod ◽  
J. F. Palmer ◽  
L. Wolpert

An electrophysiological investigation of the migrating grex of the slime mould, Dictyostelium discoideum, has been carried out with two aims in view. It was hoped to obtain information which would be relevant to, first, the formation and regulation of cellular pattern in the grex, and secondly, the problem of grex movement. During migration the grex develops a simple, linear cellular pattern. The cells at the front become the so-called ‘prestalk’ cells which will form the stalk of the fruiting body while those at the back become ‘prespore’ cells and form spores at culmination (Raper, 1940; Bonner, 1944; Bonner & Slifkin, 1949). Moreover, this cellular pattern is capable of polarized regulation. Raper (1940) has shown that portions isolated from the front or back of the grex are capable of forming normally proportioned fruiting bodies. A number of workers have suggested that bio-electric potentials may be involved in regulation of linear cellular pattern.


1973 ◽  
Vol 53 (1) ◽  
pp. 315-315
Author(s):  
Frederic L. Wightman

2012 ◽  
Vol 23 (4) ◽  
pp. 322-327 ◽  
Author(s):  
Ruthinéia Diogénes Alves Uchoa Lins ◽  
Pollianna Muniz Alves ◽  
Gustavo Pina Godoy ◽  
Ericka Janine Dantas Silveira ◽  
Lélia Maria Guedes Queiroz ◽  
...  

It was assessed the immunohistochemical profile of CD25+ cells in cases of chronic gingivitis (CG) and chronic periodontitis (CP). Immunohistochemistry was carried out using streptoavidin-biotin complex and anti-CD25 antibody in 17 cases of CG and 25 cases of CP. Sixteen cases (94.1%) of CG were immunopositive. CD25 was focally expressed in 50% of the sample and diffusely expressed in 25%. The stained cells were localized not only beneath the epithelium, but also far from it. In relation to the cellular density quantification of CD25+ cells, score ++ was the most common. Concerning CP, all cases were immunopositive. CD25+ cells were expressed in focal or diffuse pattern either close or far from the epithelium. Diffuse distribution of positive cells throughout the connective tissue was seen in 60% of the cases and 32% showed focal or diffuse cellular pattern. Sixteen cases (64%) received score +++. It was identified that CD25+ cells are present in either a focal or a diffuse pattern in connective tissue. Significant differences in the density of cellular immunostaining between CG and CP were found. The greatest density was observed in CP cases, which suggests that the infiltrate of lymphocytes show a higher degree of cellular activation in periodontitis compared with gingivitis.


Sign in / Sign up

Export Citation Format

Share Document