They're right at your fingertips, but how often do you consider the microscopic anatomy of your fingernails? How is their form fitted to function? Primates, including humans, use fingernails to maintain the anatomic integrity at the distal end of our phalanges, which often serves as the leading edge of our physical sensory apparatus. The nails serve as a stiff backing to the soft pads of our fingers, helping to improve the grip and sensitivity by allowing the pad to “push back” on the object we are touching. Nails also serve specific functions in maneuvering within cracks, scratching, and fighting.

The gross structure of nails helps to resist upward bending forces that are encountered in these functions. The convex curvature contributes, just like a curved piece of paper has more stiffness than a flat sheet. The composition of nails is also suitable. As with the outer layer of skin, and the structure of hair, nails are also composed of keratin.

I am a botanist, with an expertise in plant anatomy, specifically wood anatomy. In my capacity of mkroscopist for the Smithsonian Institution, I help answer research questions developed by curators, conservators, anthropologists and archaeologists. I am typically presented with a variety of materials that range from large, entire objects from museums to small, deteriorated, fragmentary samples from archaeological digs. Many of the requests center around the questions “What is it?” and “Where did it come from?” The answers to these questions help determine the traditional materials used by a culture and the distribution of these objects through trade and cultural exchange. Of the numerous requests that I receive, one or two each year tend to stand out as captivating examples of applied optical microscopy. The one that I would like to present in this article (along with my intern for the project - Alvaro Galvis) is the early Catholic statues (santos) from Chihuahua, Mexico and southern California.

The high cost of Photoshop and its increasing complexity with each new version can leave the user longing for a version that is a fraction of the price, but still contains the basic features. That longing may be met with Adobe's Photoshop Elements.

Certainly its price is attractive at $99.00 on some websites and about $50.00 on others (including sites for those in Education), For the shopper who wishes to do a little extra research, a web search may reveal that Elements is included with a scanner or ink jet printer at well under $99.00, making the purchase a 2-for-1.

Elements is a pared down version of Photoshop, but it is still a viable solution for almost all image processing needs. Simply because it is pared down, it becomes very attractive for occasional users who do not desire to re-learn the full version of Photoshop, let alone yet another upgrade and yet more frustrating minutea to discover.

Energy-Dispersive X-Ray Spectroscopy (ED-XRS or EDS) is a powerful and easy-to-use technique for the elemental analysis of a wide variety of materials. Most commonly, this technique is called X-Ray Fluorescence (XRF), which classically uses x-ray photon sources to excite the sample. A Scanning Electron Microscope (SEM), of course, uses electrons as the excitation source for microbeam x-ray spectroscopy together with sample imaging using characteristic x-rays and/or secondary electrons. These two XRS techniques are used independently, although often the same sample is analysed by both, to provide complementary information.

The advantages of both techniques have been reviewed several times [e.g. 1,2], SEM-EDS being more suited to imaging and microbeam quantitative compositional analysis and maps, and XRF more suited to accurate quantitative analysis, especially for trace elements, while analyzing a much larger area.

Many dynamic processes do not occur in nature, science or industry in a typical TEM high (and sometimes not so high) vacuum environment. Dynamic in-situ data related to the real world need to be obtained under Controlled conditions of gas/vapor/liquid environment and temperature. In the ETEM (Environmental Transmission Electron Microscope), the specimen - but nothing much else - is shared between the chemical reactor on the horizontal axis and the vertical microscope column (Fig.1). The original Philips CM30 column is highly modified with pressure limiting apertures around the beam and multiple stages of differential pumping (Fig.2).

Delamination is defined as separation into constituent thin layers (lamellae). Glass delamination, which can have several causes, could then be defined as a separation of surface glass, as from a vial, into thin layers resulting in a flaky appearance. Pitting could be related to, or even be the initial stages of glass delamination; data will be provided that supports a relationship. The presence of glass delamination is a serious concern to the pharmaceutical industry, not only because suspended glass flakes in any pharmaceutical product poses an obvious health hazard, but because of regulatory quality control standards, and medical profession requirements.

There are, of course, many ways of addressing the problem of glass delamination in pharmaceutical vials, including looking into the relationship of chemical nature of vial contents to degree of delamination and conditions of vial manufacture. Specialized lighting and imaging methods are other research approaches.

Chromatic aberrations are defects in an imaging system caused by the fact that different wavelengths or colors of light are refracted by different amounts. There are two types of chromatic aberration: longitudinal and lateral. Longitudinal Chromatic Aberration arises when a lens fails to focus various colors sharply in the same plane. If white light is used, the resulting image will be unsharp due to the different focal points of its component colors. Some colors will be in focus (and therefore sharp) and other colors will be out of focus. Lateral Chromatic Aberration results in a lateral shift of the different color components of an image as a single lens with a fixed refractive index will disperse each color by different amounts. This results in color stripes at slightly different magnifications, much like a rainbow, around hard edges and a general softening or decrease in resolution in all areas.

Renishaw's structural and chemical analyser (SCA) provides new analytical techniques for scanning electron microscopes (SEM). For many years energy dispersive X-ray analysis (EDS) has been the default in-SEM analytical technique, and whilst it can provide fast and accurate data from any samples, it can only provide elemental information about the sample being analysed. For materials applications, assumptions about stoichiometry may enable accurate characterisation, but in most Instances “chemistry by guesswork” does not provide an acceptable solution. Furthermore, EDS is rather insensitive to light elements - atomic number 11 (sodium) and below, which severely limits its applicability to organic chemistry and life sciences.

At the Microscopy and Microanalysis 2003 meeting, a member of the audience in one talk sharply criticized a speaker of a talk for his use of a Savitsky-Golay (S-G) digital filter for smoothing Electron Energy Loss Spectroscopy (EELS) data. The statement was made that the digital filter would decrease the resolution of the peak, i.e. widen the width, and that all digital filters do that, including the Top Hat filter. In support of this statement, he said to consider what would happen if the filter were applied to a Dirac delta function. I knew that his argument was not correct, but I didn't think of the reason until later. This interchange was on my mind because I was familiar with both of these filters due to implementing both the Top Hat and the Savitsky-Golay filters into my “Beerware” program, EELS-PLOT.

Scanned Probe Microscopy (SPM) techniques are attractive because they provide easily acquired micrographs that map specimen properties with nanometer scale resolution. SPM micrographs can be collected without the use of high vacuum (as opposed to many electron microscopies). Moreover, SPM methods allow in-situ imaging of specimens in a variety of environments, including under liquids and at higher temperatures. However, from a metrology perspective, the great promise of SPM must be balanced by the fact that SPM techniques generally provide qualitative data unless supplementary actions are taken. That is, quantification of SPM image contrast is difficult since it depends highly upon probe characteristics, probe/ sample interactions (both of which can be difficult Eo gauge), and instrument calibration.

Traditionally, focused ion beam (FIB) microscopy systems have been used as instruments to repair integrated circuits, isolate defects or prepare mateiials for characterization with other techniques. Recently however, FIB microscopy has been used extensively as a standalone characterization technique. Typically, FIB microscopy can be used to probe site specific areas of a sample through secondary electron and ion imaging, energy dispersive x-ray analysis (EDX), or secondary ion mass spectroscopy (SIMS). These analyses will often combine two-dimensional elemental mapping or sputter depth profiles with imaging to investigate spatial variations of chemical and imaging signals. Inherently, these investigations are confined to two dimensions but often, complex materials problems are more easily understood if chemical and geometric information can be collected.

Biowarfare was first documented in the eighteenth century during the French and Indian War when the British distributed smallpox-contaminated blankets to the American Indians. Smallpox is considered a likely agent even today because the USSR was known to have produced and stockpiled large amounts of the virus even after signing the 1972 treaty prohibiting such production. Because of the large number of workers involved and the poor economy, the security of these stockpiles is unclear [1, txtwriler.com/Backgrounders/Bioterrorism/bioterrar4.html]. Since the terrorist attacks in the United States in 2001, world attention has been drawn to terrorism and potential release of dangerous biological organisms. Considerable efforts are being made to establish methods for rapidly recognizing these agents. Numerous electron microscopy (EM) laboratories have been approached to join rapid response teams for the detection of viral agents. However, several issues should be carefully considered before an EM laboratory agrees to participate in surveillance.