Atomic force microscopy of the morphology of the matrix and mineral components of the otolith ofHyperoglyphe antarctica

1995 ◽  
Vol 223 (2) ◽  
pp. 203-214 ◽  
Author(s):  
R. W. Gauldie ◽  
J. Xhie
2012 ◽  
Vol 3 ◽  
pp. 238-248 ◽  
Author(s):  
Joachim Welker ◽  
Esther Illek ◽  
Franz J Giessibl

In frequency-modulation atomic force microscopy the direct observable is the frequency shift of an oscillating cantilever in a force field. This frequency shift is not a direct measure of the actual force, and thus, to obtain the force, deconvolution methods are necessary. Two prominent methods proposed by Sader and Jarvis (Sader–Jarvis method) and Giessibl (matrix method) are investigated with respect to the deconvolution quality. Both methods show a nontrivial dependence of the deconvolution quality on the oscillation amplitude. The matrix method exhibits spikelike features originating from a numerical artifact. By interpolation of the data, the spikelike features can be circumvented. The Sader–Jarvis method has a continuous amplitude dependence showing two minima and one maximum, which is an inherent property of the deconvolution algorithm. The optimal deconvolution depends on the ratio of the amplitude and the characteristic decay length of the force for the Sader–Jarvis method. However, the matrix method generally provides the higher deconvolution quality.


Author(s):  
Wenbiao Jiang ◽  
M. Grant Norton ◽  
David B. Poker

The implantation of materials with noble gas ions is of particular interest in studying some of the fundamental aspects of the ion implantation process and resultant phenomena because the noble gas ions are immiscible with the matrix and therefore chemical effects are unlikely. Electron diffraction studies have clearly demonstrated that noble gas ions implantated into either metals or ceramics may coalesce to form inclusions. These inclusions may be either solid or fluid and their formation often results in swelling of the matrix. This swelling can be readily apparent on the surface of metallic materials. However, in ceramic materials the extent of this swelling, particular at low ion fluences, can be very small and hence only detectable with surface sensitive topographic probes such as atomic force microscopy (AFM).Polished (00l)-oriented MgO single crystals were implanted with xenon ions using an accelerating voltage of 200 keV at a range of fluences. The specimens were then examined with AFM. The AFM results showed that, even at the lowest fluence, there was measurable roughening of the surface. At a fluence of 1 × 1017/cm2 small blisters were observed. These blisters have diameters of 0.5 - 0.8 μm and extend to heights of up to 80 nm.


2017 ◽  
Author(s):  
Olivier Ganier ◽  
Dominik Schnerch ◽  
Philipp Oertle ◽  
Roderick Y. H. Lim ◽  
Marija Plodinec ◽  
...  

AbstractCentrosomes are the main microtubules organizing centers of animal cells. Although centrosome aberrations are common in tumors, their consequences remain subject to debate. Here, we studied the impact of structural centrosome aberrations, induced by deregulated expression of Ninein-like protein (NLP), on epithelial spheres grown in Matrigel matrices. We demonstrate that NLP-induced structural centrosome aberrations trigger the escape (’budding’) of living cells from epithelia. Remarkably, all cells disseminating into the matrix were undergoing mitosis. This invasive behavior reflects a novel mechanism that depends on the acquisition of two distinct properties. First, NLP-induced centrosome aberrations trigger a re-organization of the cytoskeleton, which stabilizes microtubules and weakens E-cadherin junctions during mitosis. Second, atomic force microscopy reveals that cells harboring these centrosome aberrations display increased stiffness. As a consequence, mitotic cells are pushed out of mosaic epithelia, particularly if they lack centrosome aberrations. We conclude that centrosome aberrations can trigger cell dissemination through a novel, non-cell autonomous mechanism, raising the prospect that centrosome aberrations contribute to the dissemination of metastatic cells harboring normal centrosomes.


2003 ◽  
Vol 76 (4) ◽  
pp. 846-859 ◽  
Author(s):  
Natalya Yerina ◽  
Sergei Magonov

Abstract Atomic force microscopy (AFM) and electric force microscopy (EFM) have been applied for compositional mapping of a number of elastomers and related multicomponent materials. Several aspects of optimizing AFM experiments on polymers are discussed. AFM images revealed changes of EPDM morphology caused by crosslinking and by loading with fillers [carbon black (CB) and silica particles] and oil. It was shown that the morphology of isotactic polypropylene (iPP)/EPDM vulcanizates, which were studied with AFM and EFM, depends on the ratio of components, degree of cure and processing conditions. Diffusion of oil from the elastomer component to the matrix is evidenced in the AFM images. Selective distribution of CB in the iPP matrix is responsible for the electric conductivity of the thermoplastic vulcanizate.


2000 ◽  
Vol 10 (1-2) ◽  
pp. 15
Author(s):  
Eugene Sprague ◽  
Julio C. Palmaz ◽  
Cristina Simon ◽  
Aaron Watson

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