The effects of surface topography of nanostructure arrays on cell adhesion

2018 ◽  
Vol 20 (35) ◽  
pp. 22946-22951 ◽  
Author(s):  
Jing Zhou ◽  
Xiaowei Zhang ◽  
Jizheng Sun ◽  
Zechun Dang ◽  
Jinqi Li ◽  
...  

The effects of geometry and surface density distribution of nanopillars on cell adhesion studied by a quantitative thermodynamic model showed that high (low) surface distribution density and large (small) radius result in the “Top” (“Bottom”) mode.

Nanoscale ◽  
2020 ◽  
Author(s):  
Feifei ZHANG ◽  
Jérôme Plain ◽  
Davy Gerard ◽  
Jérôme Martin

The surface topography is known to play an important role on the near- and far- field optical properties of metallic nanoparticles. In particular, aluminum (Al) nanoparticles are commonly fabricated through...


Polymers ◽  
2015 ◽  
Vol 7 (11) ◽  
pp. 2371-2388 ◽  
Author(s):  
Andres Diaz Lantada ◽  
Hernán Alarcón Iniesta ◽  
Josefa García-Ruíz

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Zhanwu Lei ◽  
Wenbin Cai ◽  
Yifei Rao ◽  
Kuan Wang ◽  
Yuyuan Jiang ◽  
...  

AbstractSingle-atom catalysts (SACs) have attracted tremendous research interests in various energy-related fields because of their high activity, selectivity and 100% atom utilization. However, it is still a challenge to enhance the intrinsic and specific activity of SACs. Herein, we present an approach to fabricate a high surface distribution density of iridium (Ir) SAC on nickel-iron sulfide nanosheet arrays substrate (Ir1/NFS), which delivers a high water oxidation activity. The Ir1/NFS catalyst offers a low overpotential of ~170 mV at a current density of 10 mA cm−2 and a high turnover frequency of 9.85 s−1 at an overpotential of 300 mV in 1.0 M KOH solution. At the same time, the Ir1/NFS catalyst exhibits a high stability performance, reaching a lifespan up to 350 hours at a current density of 100 mA cm−2. First-principles calculations reveal that the electronic structures of Ir atoms are significantly regulated by the sulfide substrate, endowing an energetically favorable reaction pathway. This work represents a promising strategy to fabricate high surface distribution density single-atom catalysts with high activity and durability for electrochemical water splitting.


2005 ◽  
Vol 627 (2) ◽  
pp. L153-L155 ◽  
Author(s):  
Sanford S. Davis

1993 ◽  
Vol 104 (2) ◽  
pp. 275-288
Author(s):  
D. Hanein ◽  
H. Sabanay ◽  
L. Addadi ◽  
B. Geiger

In this study we have characterized the mode of cell adhesion to calcite and calcium (R,R)-tartrate tetrahydrate crystals. The use of crystals as adhesion substrata was motivated by their well-established chemical nature and structurally defined surfaces. We show that calcite binds A6 Xenopus laevis epithelial cells rapidly and efficiently, most likely via surface-adsorbed proteins. Surface topology had only a limited effect on the adhesive interactions. Calcium (R,R)-tartrate tetrahydrate crystals exhibits two chemically equivalent, yet structurally distinct faces that differ mainly in the surface distribution of their lattice water molecules and charges. However, despite the gross similarity between the two faces striking differences were noted in their adhesive behavior. One of the faces was highly adhesive for cells, leading to protein-independent attachment and spreading followed by cell death. In contrast, cell adhesion to the other surface of tartrate was slow (> 24 h) and apparently mediated by RGD-containing protein(s). It was further shown that the latter face of tartrate crystals could be “conditioned” by long (24 h) incubation with serum-containing medium, after which it becomes highly adhesive. The results presented here indicate that crystal surfaces may serve as excellent, structurally defined, substrata for cell adhesion, that cell binding may occur directly or via RGD-containing proteins and that cell adhesion may be dramatically modulated by variations in surface structure. The implications of the results to the mechanism of cell-substratum adhesion are discussed.


2020 ◽  
Vol 495 (4) ◽  
pp. 3722-3726
Author(s):  
Ilia Kalashnikov

ABSTRACT This paper presents a new method of calculating dark matter density profiles for superthin axial symmetric galaxies without a bulge. This method is based on a simple physical model, which includes an infinitely thin galactic disc immersed in a spherically symmetric halo of dark matter. To obtain the desired distribution density, it suffices to know a distribution of visible matter surface density in a galaxy and a dependence of angular velocity on the radius. As a byproduct, the well-known expression, which reproduces surface density of a superthin galaxy expressed through a rotation law, was obtained.


2019 ◽  
Vol 629 ◽  
pp. A106 ◽  
Author(s):  
Sota Arakawa ◽  
Yuhito Shibaike

Jupiter has four large regular satellites called the Galilean satellites: Io, Europa, Ganymede, and Callisto. The inner three of the Galilean satellites orbit in a 4:2:1 mean motion resonance; therefore their orbital configuration may originate from the stopping of the migration of Io near the bump in the surface density distribution and following resonant trapping of Europa and Ganymede. The formation mechanism of the bump near the orbit of the innermost satellite, Io, is not yet understood, however. Here, we show that photophoresis in the circumjovian disk could be the cause of the bump using analytic calculations of steady-state accretion disks. We propose that photophoresis in the circumjovian disk could stop the inward migration of dust particles near the orbit of Io. The resulting dust-depleted inner region would have a higher ionization fraction, and thus admit increased magnetorotational-instability-driven accretion stress in comparison to the outer region. The increase of the accretion stress at the photophoretic dust barrier would form a bump in the surface density distribution, halting the migration of Io.


1998 ◽  
Vol 184 ◽  
pp. 123-124
Author(s):  
D. Minniti ◽  
C. Alcock ◽  
D. Alves ◽  
K. Cook ◽  
S. Marshall ◽  
...  

We have analyzed a sample of 1150 type ab, and 550 type c RR Lyrae stars found in 24 of 94 bulge fields of the MACHO database. These fields cover a range in Galactocentric distances from 0.3 to 1.6 kpc. In combination with the data on the outer bulge fields of Alard (1997) and Wesselink (1987), here we present the surface density distribution of bulge RR Lyrae between 0.3 and 3 kpc.


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