This symposium, and the special issue of Microscopy & Microanalysis that Barry Carter and Uli Dahmen have put together, provides us with a glimpse of a career that has not only spanned the development of electron microscopy of materials but also helped to drive it. Over the last 40 years Gareth has guided more than a hundred graduate students and over forty post-doctoral fellows, building a foundation for the application of transmission electron microscopy in the United States including the creation of the National Center for Electron Microscopy. It is with great pleasure that we celebrate his 70th birthday, gratified that he is still going strong and marveling at how he does it.

Through recent years, off-axis electron holography has helped us to understand and to overcome some experimental restrictions in transmission electron microscopy. With development of powerful electron microscopes, slow-scan CCD cameras, and computers, holography is not an academic technique anymore used by specialized laboratories. Holography has proven its wide range of applications in solving real-world problems in materials science and biology. At medium resolution, that is, on nanometer scale, holography allows access to large area phase contrast produced by magnetic fields and electric potentials. In the high-resolution domain, holography unveils its power by unscrambling amplitude and phase of the electron wave, resulting in an improved lateral resolution up to the information limit. Holography is a thoroughly quantitative method, and, in combination with the perfect zero-loss filtering inherent to this method, the interpretation of the reconstructed data is strongly simplified. After outlining the basics of holography, in this tutorial we focus on development of a step-by-step procedure for recording and reconstruction of holograms. At the end, some recent applications are discussed.

Foam cells in the atherosclerotic lesion have substantial cholesterol stores within large, swollen lysosomes. This feature is mimicked by incubating THP-1 macrophages with mildly oxidized low density lipoprotein (LDL). Incubation of THP-1 cells with acetylated LDL produces cytoplasmic cholesteryl ester accumulation rather than lysosomal storage. The differences could be due to differences in uptake and delivery of lipoprotein to lysosomes or to lysosomal and post-lysosomal processing events. We compared uptake and lysosomal trafficking of acetylated and oxidized LDL using colloidal gold-labeled lipoproteins. Labeling did not alter cellular cholesterol accumulation. We found that uptake and delivery to lysosomes are not different for acetylated and oxidized LDL. In fact, both oxidized and acetylated LDL can be delivered to the same lysosomes. Sequential incubation with oxidized LDL followed by acetylated LDL showed that the lipid-engorged lysosomes are long-lived structures, continuously accepting newly ingested lipoprotein. Comparison of acetylated and oxidized LDL in mouse peritoneal macrophages, a cell which does not accumulate substantial lysosomal lipid, also revealed no differences in uptake. This indicates that in THP-1 cells, the differences in metabolism of oxidized and acetylated LDL are due to cell-specific lysosomal or post-lysosomal events not present in B6C3F1 mouse macrophages.

Olfaction is an important and primitive sense. As its importance has changed with evolution, anatomic adjustments have occurred in its structure and vasculature. Primates are a family of vertebrates that have had to develop their visual system to adapt to the arboreal environment and have evolved from a macrosmatic to a microsmatic species as the optic system has enlarged. This has resulted in anatomic changes of a small but critical area at the base of the brain. This paper describes the three-dimensional vascular anatomy of the olfactory organ of the Japanese monkey (Macaca fuscata fuscata). This is best understood by dividing the organ into three parts: the olfactory tract, olfactory bulb, and olfactory nerves in the nasal mucosa. The bulb can be partitioned into an outer or cortical part and inner or medullary part. The vasculature and tissue were examined grossly and with light microscopy and scanning electron microscopy of vascular corrosion casts. The olfactory tract and bulb were supplied by an arteriole from the anterior cerebral artery on each side. The tract was supplied by capillaries running spirally with a coarse network. At the olfactory bulb, the arteriole ramified into the intracortical and medullary branches that formed capillary networks. The bulbar intracortical capillaries were divided into two layers with different densities and vascular patterns. The capillaries of the superficial layer had a ladder-like pattern. The branches that ran into the medulla of the olfactory bulb were more widely spaced. Twigs from the posterior ethmoidal artery ran along the nerve fiber and formed intra- and extrafascicular networks. Each region of the olfactory organ had characteristic three-dimensional vascular patterns that were related to their cellular architecture.

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Beginning with this issue Microscopy and Microanalysis will be published by the Cambridge University Press in New York. The high-quality production standards established by our former publisher, Springer-Verlag, will be maintained and improved over the coming years. Major changes you may notice are the increased number of pages for scientific articles and the decreased cost of subscriptions for institutional libraries and for members of affiliated societies. An indication of the quality and reputation of the journal is shown by our favorable Impact Factor ranking from the Institute for Scientific Information (ISI). In 1999, ISI ranked Microscopy and Microanalysis the number four microscopy journal in the world. The journal is affiliated with eleven microscopy and microanalysis societies around the world making it truly an international communications vehicle. In fact, Microscopy and Microanalysis has the largest paid circulation of any microscopy journal in the world. On behalf of the Editors and the Editorial Board, I thank the authors, reviewers, advertisers, and readers for supporting this journal during its formative years. I look forward to your continuing support.

Programmed cell death or apoptosis occurs in many tissues during normal development and in the normal homeostasis of adult tissues. Apoptosis also plays a significant role in abnormal development and disease. Increased interest in apoptosis and cell death in general has resulted in the development of new techniques and the revival of old ones. Each assay has its advantages and disadvantages that can render it appropriate and useful for one application, but inappropriate or difficult to use in another. Understanding the strengths and limitations of the assays would allow investigators to select the best methods for their needs.

Microscopy and Microanalysis 2002 hosted by the Microscopy Society of America (MSA), the Microbeam Analysis Society (MAS), the Microscopical Society of Canada (MSC)/Societe de Microscopie du Canada (SMC), and the International Metallographic Society (IMS) will provide comprehensive Symposia, Tutorials, and Special Sessions covering all aspects of microscopy. Events will begin on Friday, August 2nd with a two-day Pre-meeting Congress chaired by Raynald Gauvin of McGill University entitled “Characterization of non-Conductive or Charging Materials by Microbeam Analysis.” This Pre-meeting Congress will be at McGill University, Montreal, Canada. On Sunday, August 4th, there will be several Short Courses on a variety of topics for those active in teaching, research, and industrial applications involving microscopy and microanalysis. Formal meeting sessions will begin on Monday, August 5th, and will consist of a blend of different presentation formats including Symposia, Tutorials, and Poster sessions that will offer the latest information on cutting-edge discoveries and also provide the opportunity to learn new techniques and procedures. The unique opportunity for “hands-on” learning with state-of-the-art instrumentation will be provided by the integration of the program with the commercial exhibits.

This issue is dedicated to Professor Sir John Meurig Thomas for his renowned contributions to electron microscopy in the chemical sciences. It is a collection of peer-reviewed leading articles in electron microscopy, based on the presentations at the Microscopy and Microanalysis (M&M) 2000 symposium, which was held to honor Professor Thomas's exceptional scientific leadership and wide-ranging fundamental contributions in the chemical applications of electron microscopy.

Alloy design has been a lifelong interest of Gareth Thomas, and modern design algorithms include atomistic parameters which are obtainable from new electron microscope techniques such as ALCHEMI. In this paper, we discuss the relevance of ALCHEMI site occupancy measurements to intermetallic alloys, and summarize prior work. The results are found to lie in regions of a site-occupancy diagram (SOC) relating ordering energies to occupancy, as predicted by the Bragg–Williams theory of short-range order. These predictions also explain previous inconsistencies in the ALCHEMI measurements. A diffraction camera and X-ray detector system of novel design is proposed for dedicated ALCHEMI analysis for substitutional and interstitial dopant site-occupancy measurement, and details of the design given. Using this novel hardware design, the data-collection times for two-dimensional ALCHEMI patterns should be reduced by an order of magnitude or more, and the full data collection process automated. The resulting occupancy information can provide essential input parameters for atomistic alloy design algorithms, and can provide entirely new information on interstitial occupancies in minerals, ceramics, semiconductors, and alloys.

This work concerns the use of parallel electron energy loss spectroscopy (PEELS) to investigate the detection, distribution, and quantification of carbon in various steel microstructures generated by rapid cooling rates or by isothermal transformation. The feasibility of detecting C in steels containing very small amounts of carbon was first examined by calculating the minimum detectable mass fraction for a variety of binary Fe-C alloy specimen thicknesses and microscope conditions. These theoretical studies indicated that the detection of carbon in steel microconstituents containing about 0.01 wt.% (or even less) was easily possible with an analytical transmission electron microscope equipped with a LaB6 emitter and a PEEL spectrometer. These theoretical calculations seemed to be reasonable, as it proved possible to make a quantitative PEELS study of the partitioning between the microconstituents ferrite, retained austenite, and martensite found in an ultralow carbon (0.03 wt.%) steel weld metal provided care was taken to avoid hydrocarbon contamination. Studies of both carbon and molybdenum segregation to ferrite/martensite interfaces in an isothermally transformed Fe-C-Mo alloy were also carried out in order to investigate the nature of the “solute drag” effect in this alloy system.

Laser capture microdissection uses a microscope to identify specific cells for microdissection and then a laser-sensitive plastic to capture and remove the cells from their substrate. This efficient capture method was originally developed to capture cells for genetic analysis. However, it has also been used to capture cells for proteonomic analysis. In this article, we extend the uses of laser-capture microdissection by reporting a method for preparing captured cells for ultrastructural analysis by transmission electron microscopy. Cells prepared by our methodology show good fine structure preservation and are easily sectioned by standard ultramicrotomy.

Apicomplexan parasites employ complex and unconventional mechanisms for cell locomotion, host cell invasion, and cell division that are only poorly understood. While immunofluorescence and conventional transmission electron microscopy have been used to answer questions about the localization of some cytoskeletal proteins and cell organelles, many questions remain unanswered, partly because new methods are needed to study the complex interactions of cytoskeletal proteins and organelles that play a role in cell locomotion, host cell invasion, and cell division. The choice of fixation and preparation methods has proven critical for the analysis of cytoskeletal proteins because of the rapid turnover of actin filaments and the dense spatial organization of the cytoskeleton and its association with the complex membrane system. Here we introduce new methods to study structural aspects of cytoskeletal motility, host cell invasion, and cell division of Toxoplasma gondii, a most suitable laboratory model that is representative of apicomplexan parasites. The novel approach in our experiments is the use of high resolution low voltage field emission scanning electron microscopy (LVFESEM) combined with two new specimen preparation techniques. The first method uses LVFESEM after membrane extraction and stabilization of the cytoskeleton. This method allows viewing of actin filaments which had not been possible with any other method available so far. The second approach of imaging the parasite's ultrastructure and interactions with host cells uses semithick sections (200 nm) that are resin de-embedded (Ris and Malecki, 1993) and imaged with LVFESEM. This method allows analysis of structural detail in the parasite before and after host cell invasion and interactions with the membrane of the parasitophorous vacuole as well as parasite cell division.

Through recent years, off-axis electron holography has helped us to understand and to overcome some experimental restrictions in transmission electron microscopy. With development of powerful electron microscopes, slow-scan CCD cameras, and computers, holography is not an academic technique anymore used by specialized laboratories. Holography has proven its wide range of applications in solving real-world problems in materials science and biology. At medium resolution, that is, on nanometer scale, holography allows access to large area phase contrast produced by magnetic fields and electric potentials. In the high-resolution domain, holography unveils its power by unscrambling amplitude and phase of the electron wave, resulting in an improved lateral resolution up to the information limit. Holography is a thoroughly quantitative method, and, in combination with the perfect zero-loss filtering inherent to this method, the interpretation of the reconstructed data is strongly simplified. After outlining the basics of holography, in this tutorial we focus on development of a step-by-step procedure for recording and reconstruction of holograms. At the end, some recent applications are discussed.

α-Si3N4 nanorods with 20–80 nm width were synthesized by carbothermal reduction of SiO with amorphous activated carbon (AAC) as a reductant. Microstructural characterization of the synthesized nanorods was carried out by high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray analysis. Many Si3N4 nanorods were found to be twisted. Each twisted nanorod contained several straight Si3N4 parts. The straight parts had the rod axes orientated along the 〈1010〉 direction, which is the closest packing direction of α-Si3N4. There were two kinds of joints between the two adjacent straight Si3N4 parts. Formation mechanism of the Si3N4 nanorods is discussed.

Fe, Co, and Ni magnetic nanoparticles have been characterized using energy-selected imaging in a high-resolution transmission electron microscope. The samples comprised Fe/FeOx and Co/CoOx nanoparticles synthesized by inert gas evaporation and a Ni/C nano-composite prepared by a sonochemical method. All of the particles examined were found to be between 5 and 30 nm in size, with the Fe and Co crystals coated in 5–10 nm of metal oxide layer and the Ni metallic crystallites embedded in an amorphous carbon spherical matrix.

Topic: Characterization of Non-Conductive or Charging Materials by Microbeam Analysis

The goal of this topical conference is to present the state of the art for materials characterization of non-conductive or charging materials using microbeam analysis. Examples of charging materials include polymeric materials, ceramic materials, and photoresist materials in the microelectronic industry. Also, the characterization of biological specimens will be covered because they are prone to problems related to charging. These materials are of great technological importance and their characterization is still a great challenge because they charge when analyzed with an electron beam. The techniques of microbeam analysis that will be considered are: X-ray Microanalysis in the Electron Microprobe, Low Voltage Scanning Electron Microscopy, Environmental Scanning Electron Microscopy, Analytical Electron Microscopy with Field Emission Transmission Electron Microscopy, and Focused Ion Beam Milling for specimen preparation. World experts will present papers on these topics. Papers from this topical conference will be published in a special issue of Microscopy & Microanalysis.

The study of the gaussian parameter ω—the approximate width of a peak at half height—of the intensity curves obtained by means of the Unidirectional Laser Oblique Illumination technique employed in the optical microscopy of materials permits introduction of the concept of variation of a surface pattern at different magnifications. This concept establishes how the surface pattern or topography varies among different areas when different magnifications are used. Diffraction gratings and metallic surfaces which have been subjected to different metallographic procedures are analyzed, using objectives of 8×, 16×, and 32×.