How do the right cells get to the right place in lymph nodes? It is known that lymphocytes known as B cells (that originate in the bone marrow) migrate to follicles within the nodes, whereas T cells (that originate in the bone marrow and migrate to the thymus gland) reside in an adjacent region known as the paracortex. By combining confocal, electron, and intravital microscopy, Marc Bajénoff, Jackson Egen, Lily Koo, Jean Pierre Laugier, Frédéric Brau, Nicolas Glaichenhaus, and Ronald Germain have demonstrated a role for the stroma of the node in directing these cells to the appropriate location. The stromal cells that are critical in the B cell follicles are follicular dendritic cells (FDCs) and in the paracortex it's the fibroblastic reticular cells (FRCs).

The Gibeon meteorite is a differentiated iron meteorite that fell in Nambia, Africa in prehistoric times, with fragments spread over an area 70 miles wide and 230 miles long. The Gibeon fall was initially discovered in 1836, and hundreds of thousands of kilograms of fragments have been recovered. These fragments represent the iron core of a meteorite that cooled and crystallized over thousands of years (Norton 2002).

The microstructure of the Gibeon meteorite, which is primarily an iron-nickel alloy, consists of two phases: kamacite, a body-centered cubic material and taenite, a face-centered cubic material that metallurgists would refer to as ferrite and austenite respectively. This material initially crystallizes as taenite, and as the temperature decreases, transforms into kamacite. This meteorite is classified as a Fine Octahedrite (Of) with an average Nickel content of approximately 7.9%

A number of trends in pharmaceutical manufacturing are driving rapid growth in the use of scanning electron microscopes (SEM) for high-resolution imaging and analysis. At the same time, continued development of SEM technology is enhancing system performance while simultaneously reducing usability barriers that have historically limited the acceptance of these techniques in pharmaceutical applications.

Among the most significant industry trends is a concerted effort by governmental regulatory agencies to encourage improvements in pharmaceutical manufacturing processes by applying the same scientific principles and engineering techniques that have lead to successful improvements in other industries, notably automobiles and semiconductors. The exceptionally high requirements for product quality within the pharmaceutical industry have generated a regulatory regime that imposes prohibitively high costs in both time and money to gain approval for process changes, even though the changes result in substantial performance gains.

Most of the specimens for high-resolution electron microscopy have amorphous surface layers due to contamination during observation and/or damaged surface layers during specimen preparation. Moreover, many specimens are radiation sensitive, and a part of the specimen easily becomes amorphous during the observation. These amorphous materials make clear observation of crystal structure difficult. A periodic structure may be extracted by simply using a periodic mask in Fourier space. However, this kind of mask often introduces a periodic feature in addition to the crystal structure. To reduce such artifacts a Wiener filter or an average background subtraction filter has been discussed. However, these filters do not work for non-ideal crystals, such as cylindrical crystals and nano-crystals, where a translational periodicity is limited to the order of nano-meter. In this report we improve these filters by introducing new ways to estimate a contribution from the amorphous materials.

Hydrocarbon (HC) contamination is a persistent problem for users of electron microscopes (EMs), often leading to image distortion and interference with nanoprobing. The Evactron De-Contaminator (D-C) has been available for HC contamination removal in EMs since 1999. The Evactron D-C uses low power radio frequency (RF) generated plasma in order to produce oxygen radicals that clean the EM. The Oxygen Radical Source (ORS) is attached to the EM chamber, and a controlled leak of oxygen containing gas such as room air is passed through the plasma in order to produce oxygen radicals. The oxygen radicals chemically react with the HCs to form volatile oxidation products such as H2O, CO and CO2. These volatile compounds are pumped out of the EM chamber.

The well-known recipe for serial reconstruction in microscopy consists of the following six steps: fix and embed specimen, cut and mount sections for microscopy, image sections, align images in the computer, identify and trace profiles in images, generate three-dimensional (3D) visualizations. The free software program Reconstruct facilitates the final steps of this process for many types of microscopy, including scanning electron or ion beam microscopy applied to material and light microscopy applied to biological samples. We describe here how serial sectioning and transmission electron microscopy (TEM) can be combined with the Reconstruct software to generate large volumes of soft tissue ultrastructure for analysis.

One of the most oft-confronted challenges in materials science, when using scanning electron microscopy, is the limitation of the size of the sample being examined, as well as the analysis application planned. Normally, only small samples in the order of ten to a hundred millimetres in diameter may be investigated. In addition, until now, conventional high-load fatigue testing inside a scanning electron microscope (SEM) seemed impossible. Nevertheless, SEM testing is a very valuable method in the fields of material and biological science as well as in quality control and failure analysis. For many technological interesting applications, conventional scanning electron microscopy is not possible because the specimens that need to be investigated cannot be destroyed for the SEM investigations for one of several reasons. It maybe that the specimen must be kept whole so that it can be returned to a production line or perhaps the specimen is an object of historic and/or artistic interest and value.

This contribution is a continuation of a previously published work in Microscopy Today that described the microscopic analysis of magmatic crystal growth by the example of accessory zircon. Zircon does not only represent a remarkable mineral phase concerning its crystallization out of the magmatic melt, but has also other interesting characteristics, one of which is the rather high physical stability of zircon allowing a determination of the mineral—even in high-grade metamorphic rocks. The changes of zircon from low- to high-grade deformation are very noticable and therefore offer an interesting operating field for electron microscopy. Since crystal microscopy and its specific fascination cannot often be found in a microscopy magazine, it is assumed that the article would awake the interest of the readers.

Specimen preparation techniques for Scanning Electron Microscope (SEM) imaging of condoms as reported by Rosenzweig et al revealed a variety of artifacts. The artifacts were classified as ridging, cracking and melting. The purpose of this article is to introduce a simple specimen preparation technique for condoms to be evaluated via SEM without any surface artifacts. This technique involves the use of two chrome washers to sandwich the condom. The sandwiched condom specimen is then subjected to coating before mounting on an aluminium stub. The execution of this technique requires patience and practice so as not to damage the condom. The method may be applied to any similar polymer material.

The focused ion beam (FIB) is a relatively novel technique to biomedical electron microscopy as it open up new means for the observations and examinations of a wide range of biomedical and biological materials. The focused ion beam, or FIB tool has been utilized mainly in the fields of material sciences and industry. The (FIB) uses high-energy gallium ions to precisely and accurately section or mill samples. Lately FIB method have been used to prepare biological samples such as yeast cells and virus particles. Yeast cells Schwanniomyces occidentalis S. occidentalis were prepared by vacuum sucking them into cellulose tubing, plunge freezing them in liquid nitrogen, followed by chemical fixation in glutaraldehye and postfixed with osmium tetroxide, dehydrated in a series of ascending alcohol concentration up to absolute alcohol, then freeze dried overnight. In the case of SARS virus, the tissue culture containing virus particles was chemically fixed with glutaraldehyde, dehydrated in ascending order of alcohol concentrations and then freeze dried.

Diesel Particulate Filters (DPFs) are designed to capture exhaust particulates from engines. The filter material collects the particulates deep in the substrate (deep-bed filtration) before transitioning to other filtration methods on the surface. The deep-bed filtration has been characterized by modeling studies but little experimental information about the particulate, or soot, penetration in the filter material is available. Traditional evaluation methods do not provide sufficient contrast between the soot and mounting resins.

Due to the difficulty of locating carbon soot in the pores in these filters, ultra-thin section techniques (under 10-micron-thick sections) were used for the characterization of these samples. Under transmitted light, the carbon soot is black because it blocks the light, and the carbon in the resin material is relatively clear.

I was pleased to see the article describing some of the history of the Florida Microscopy Society in a recent issue of Microscopy Today. I have since learned that many regional microscopy societies are busy not only archiving their history but retelling it to the next generation of microscopists. I think this is important. The Southeastern Microscopy Society (SEMS) has had a historian since its early days. I am the current historian and I view my job not just as someone who archives the records but also the one responsible for preserving the human face of our history. This includes telling our story. The Southeastern Microscopy Society's Newsletter, The BEAM (http://www.southeasternmicroscopy.org/beam/beam.html) has a regular history feature, where established microscopists recount interesting experiences in the laboratory, memorable SEMS' meetings, or other aspects of the personal side of science.