Microscopy and Microanalysis, the sister publication of this magazine, is currently the #1 microscopy journal in the world, according to the Thomson-Reuters-ISI organization that ranks scientific journals on the basis of Impact Factor. This ranking is based on our Impact Factor of 2.992 for the year 2008 (the most recent data available). This is the culmination of a long climb from the journal's beginning in 1995.

All cells have the ability to synthesize and secrete proteins. Although many details of this process are well-known, Martin Kampmann and Günter Blobel recently highlighted two “landmark papers” that used cryo-electron microscopy (cryoEM) to obtain information at subnanometer resolution, which provided direct visualization of nascent polypeptide chains in the tunnel with ribosomes . It is known that the signal peptide (the first few amino acids on the amino terminal that do not become part of the final polypeptide) emerges from a ribosome and engages the signal recognition particle (SRP) in the cytoplasm, and this complex is directed to the SRP receptor on the endoplasmic reticulum (ER). The SRP is released, the signal peptide enters the protein-conducting channel (PCC), and the nascent polypeptide chain (that will become the protein) enters the lumen of the ER.

In this paper, a new way for visualization of unstained transparent specimens is described, which is based on bright-field imaging and promises an improved resolution and contrast. The final results can be compared with conventional phase contrast images, and the new method may lead to superior results in most specimens.

Feldspar is the name for a mineral group consisting of nearly 20 triclinic or monoclinic mineral species, of which only nine are well documented and widely distributed in the Earth's crust. Single members of the feldspar group belong to the so-called framework—or tectosilicates, where SiO4- and AlO4-tetrahedra share all their oxygen ions, resulting in an infinite three-dimensional network . Feldspar crystals include the major elements K, Na, Ca, Al, as well as Si and thus may be attributed to one of the following three endmembers: potassium-feldspar (K-feldspar) KAlSi3O8, albite NaAlSi3O8, or anorthite CaAl2Si2O8 (Table 1). Solid solutions occur between K-feldspar and albite, forming what is commonly known as alkali feldspar, and between albite and anorthite, forming plagioclase. The alkali feldspar group consists of orthoclase, microcline, sanidine, and anorthoclase, whereas the plagioclase group includes albite, oligoclase, andesine, labradorite, bytownite, and anorthite .

Steve Chapman's “An Old Man's Saga” in the May 2009 issue of Microscopy Today about the various methods he has used for determining when saturation is achieved in the common self-biased electron gun prompts me to share with Microscopy Today's readers my experience in lecturing to my students about the characteristics of this remarkable device.

Element-selective imaging and analysis at atomic resolution have become possible by the recent advancements in TEM and STEM. However, the spatial resolution in images of soft materials can be limited by electron beam damage and/or contamination. This contamination is a carbonaceous layer deposited on the specimen surface as a result of electron bombardment. Beam-induced specimen contamination is caused by polymerization of hydrocarbons that are present in a TEM specimen chamber. The electron beam reacts with stray hydrocarbons in the beam's path to create hydrocarbon ions, which then condense and form carbon-rich polymerized film on the area being irradiated. Figure 1a shows contamination spots created on a carbon thin foil by illuminating a beam with an intensity of 5.6 × 104 el/nm·s at an accelerating voltage of 200 kV. The thickness of the contamination spots can be estimated by electron energy-loss spectroscopy (EELS). With increase in the irradiation period, the intensity of the zero-loss peak decreases, but the overall intensities in the energy-loss regions of the spectrum increase (Figure 1b). The thickness (D) can be estimated using the equation, D = Λ·ln(It/I0), where Λ is the total mean free path for inelastic scattering, and It and I0 are the integral intensities of the overall spectrum and the zero-loss peak, respectively. Using this equation, the thickness of the contamination was found to be about 600 nm with a 10-minute irradiation.

The infiltration of porous and particulate materials for metallographic examination with low-melting alloys was first described by Rose and DeRoos . The use of Wood's metal to fill porosity in sandstone was reported by Craze , by Dullien , and by Yadev et al. . Changes in pore structure and phase dispersions in iron ore pellets after simulated blast furnace reduction were reported by Shultz et al. , wherein liquid Bi-Sn impregnation was used to prepare cross sections of deformed and reduced pellets for backscatter electron imaging. Steele and Engelalso applied the technique to examine the microstructure in commercial boron nitride (BN). In that study porosity formed by leaching the B2O3 phase was filled with liquid metal to allow argon-ion etching to expose the BN microstructure. The characterization of cracks and porosity in cement-based materials after filling with Wood's metal has been reported by Nemati et al. . Cracks developed during compression testing of marble were studied by in-situ metal impregnation in Chang et al. .

In the last decade, microscopy has been successfully employed by a number of research groups as a means of instilling enthusiasm for science and technology into students of all ages, especially school children . Remote microscopy (or telemicroscopy) and virtual microscopy (in the form of software simulators) continue to play important roles in these efforts and also in the teaching and training of new microscopists . Such work and associated electronic teaching resourceshave become prominent features of conferences such as Microscopy & Microanalysis.

Giovanni Amici was an Italian microscopist, astronomer, optical instrument designer, and botanist who is best known as the achromatic lens inventor. He also designed reflecting telescopes and introduced a lens for the inspection of an objective's rear focal plane, termed the Amici-Bertrand lens. Aditionally, in 1850 he invented the water immersion lens.

If you wish to look inside an arbitrary piece of material and you own a light microscope (LM) or scanning electron microscope (SEM), there are probably three ways that you may accomplish your aim: (a) embed the material in epoxy, then grind and polish it flat; (b) embed the material and use a microtome to obtain cross sections; or (c) CRACK IT. In this short article, it is the last option that will be discussed. The last method is the simplest and quickest of the textbook sample preparation methods for SEM .

Selected postings from the Microscopy Listserver from February 1, 2010 to April 1, 2010. Complete listings and subscription information can be obtained at http://http://www.microscopy.com. Postings may have been edited to conserve space or for clarity.

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