Micro-grooved Surface Topography Does Not Influence Fretting Corrosion of Tapers in THA

The regulation of cell shape, fibronectin mRNA level, secretion and assembly by substratum surface topography was investigated in early passage human gingival fibroblasts cultured on titanium-coated smooth or V-shaped grooved substrata produced by micromachining. Cells on grooved surfaces were significantly elongated and orientated along the grooves of the substratum, while cell height, measured using confocal scanning laser microscopy, was approximately 1.5-fold greater than that of cells on smooth surfaces. Northern hybridization analysis revealed that on a per cell basis the grooved surface increased the amounts of fibronectin mRNA/cell approximately 3.5-fold at 16 hours, approximately 1.9-fold at 40 hours and approximately 2.2-fold at 90 hours, while the mRNA levels of the house-keeping gene glyceraldehyde-3-phosphate dehydrogenase (GAPD) were constant. The amounts of secreted fibronectin on the grooved surface were increased approximately 2-fold for all time points. The stability of fibronectin mRNA was also altered by substratum surface topography. The half-life of fibronectin mRNA on smooth surfaces was estimated to be approximately 5 hours, but on the grooved surfaces the half-life of fibronectin mRNA showed a two-phase response: a rapid 60% reduction in the first half-life (t1/2 approximately 2 hours) and a 2.4-fold increase in the second half-life (t1/2 approximately 12 hours) relative to that observed on the smooth surface. The GAPD mRNA half-lives were essentially unaffected by the surface topography of the substrata. The grooved surface was also found to alter the amount of fibronectin assembled into the extracellular matrix, producing a approximately 2-fold increase in the cultures at all time points. It thus appears that substratum surface topography alters cell shape and modulates fibronectin at the transcriptional and post-transcriptional levels, as well as the amount of fibronectin assembled into extracellular matrix. Micromachining, which has the ability to precisely control surface topography over a wide range of dimensions and shapes, appears to be a useful technique in investigating the relationship between cell shape and function.

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The Broad Applications of the Scanning Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100062002 ◽

1969 ◽

Vol 27 ◽

pp. 20-21

Author(s):

C. T. Nightingale ◽

S. E. Summers ◽

T. P. Turnbull

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

Light Microscopy ◽

Surface Topography ◽

Great Depth ◽

Resolving Power ◽

Depth Of Field ◽

Pictorial Representations ◽

Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

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Effects of Ion Beam Milling on Surface Topography

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070862 ◽

1973 ◽

Vol 31 ◽

pp. 84-85

Author(s):

P.G. Pawar ◽

P. Duhamel ◽

G.W. Monk

Keyword(s):

Surface Topography ◽

Ion Beam ◽

Solid Material ◽

Beam Current ◽

Atomic Mass ◽

Micro Milling ◽

Ion Milling ◽

Controlled Atmospheres ◽

Milling Operations ◽

Sufficient Energy

A beam of ions of mass greater than a few atomic mass units and with sufficient energy can remove atoms from the surface of a solid material at a useful rate. A system used to achieve this purpose under controlled atmospheres is called an ion miliing machine. An ion milling apparatus presently available as IMMI-III with a IMMIAC was used in this investigation. Unless otherwise stated, all the micro milling operations were done with Ar+ at 6kv using a beam current of 100 μA for each of the two guns, with a specimen tilt of 15° from the horizontal plane.It is fairly well established that ion bombardment of the surface of homogeneous materials can produce surface topography which resembles geological erosional features.

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Low-Loss Images in a Stem/Tem Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010009244x ◽

1976 ◽

Vol 34 ◽

pp. 496-497 ◽

Cited By ~ 1

Author(s):

David C. Joy ◽

Dennis M. Maher

Keyword(s):

High Resolution ◽

Surface Topography ◽

Beam Direction ◽

Low Loss ◽

Specimen Holder ◽

Glancing Angle ◽

High Resolution Images ◽

Set Up ◽

Conventional Manner ◽

Objective Type

High-resolution images of the surface topography of solid specimens can be obtained using the low-loss technique of Wells. If the specimen is placed inside a lens of the condenser/objective type, then it has been shown that the lens itself can be used to collect and filter the low-loss electrons. Since the probeforming lenses in TEM instruments fitted with scanning attachments are of this type, low-loss imaging should be possible.High-resolution, low-loss images have been obtained in a JEOL JEM 100B fitted with a scanning attachment and a thermal, fieldemission gun. No modifications were made to the instrument, but a wedge-shaped, specimen holder was made to fit the side-entry, goniometer stage. Thus the specimen is oriented initially at a glancing angle of about 30° to the beam direction. The instrument is set up in the conventional manner for STEM operation with all the lenses, including the projector, excited.

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A procedure for cross-sectioning materials for TEM analysis without ion milling

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176848 ◽

1990 ◽

Vol 48 (4) ◽

pp. 742-743

Author(s):

J.P. Benedict ◽

Ron Anderson ◽

S. J. Klepeis

Keyword(s):

Surface Topography ◽

Milling Time ◽

Specimen Preparation ◽

Ion Milling ◽

Cleaning Operation ◽

Tem Analysis ◽

Platinum Silicide ◽

Surface Alteration ◽

Polishing Damage ◽

Tools And Methods

Traditional specimen preparation procedures for non-biological samples, especially cross section preparation procedures, involves subjecting the specimen to ion milling for times ranging from minutes to tens of hours. Long ion milling time produces surface alteration, atomic number and rough-surface topography artifacts, and high temperatures. The introduction of new tools and methods in this laboratory improved our ability to mechanically thin specimens to a point where ion milling time was reduced to one to ten minutes. Very short ion milling times meant that ion milling was more of a cleaning operation than a thinning operation. The preferential thinning and the surface topography that still existed in briefly ion milled samples made the study of interfaces between materials such as platinum silicide and silicon difficult. These two problems can be eliminated by completely eliminating the ion milling step and mechanically polishing the sample to TEM transparency with the procedure outlined in this communication. Previous successful efforts leading to mechanically thinned specimens have shown that problems center on tool tilt control, removal of polishing damage, and specimen cleanliness.

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