bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparison of Grain Size Measurements in Al-Cu Thin Films: Imaging Vs. Diffraction Techniques
Authors: Gignac LM , Murray CE , Rodbell KP , Gribelyuk M
Published: March 2018

Numerous microscopy techniques, based on both imaging and diffraction, exist for the measurement of grain size distributions in polycrystalline thin-film samples. The accuracy of each technique is affected by three major factors: the effective resolution of the instrument relative to the characteristic grain size, the detection of the grain size through the thickness of the film, and the recognition of boundaries between adjacent grains during post-processing. When the instrument resolution is primarily considered, the measurement technique has a practical grain size measurement range, see Fig. 1 for a comparison of ranges for several measurement techniques. In bulk metallurgy grain size analysis, methodology has been developed to represent 3-dimensionai grain structures from measurements taken on 2-dimensional images.
Using a Sony Cyber-Shot Digital Camera for Photomicrography
Authors: Overney Gregor
Published: March 2018

Photomicrography is the combination of photography and compound microscopy. Photographers working with compound microscopes are facing many challenges (for an introduction see [1] and [2]). Digital photography offers great advantages, but also adds additional difficulties. Digital cameras have been used in photomicrography for over a decade now. Today, we have access to many excellent consumer-grade digital cameras that are most suitable for low-cost imaging systems for light microscopy. In this short paper, I summarize my experience with the Sony DSC-S70 digital camera, which comes with a nice, large Zeiss lens. (Most of the ideas presented in this paper are also valid for the DSC-S75 and DSC-S85.)
Confocal Microscopy System Performance: Laser Power Measurements
Authors: Zucker Robert M
Published: March 2018

The reliability of the confocai laser-scanning microscope (CLSM) to obtain intensity measurements and quantify fluorescence data is dependent on using a correctly aligned machine that contains a stable laser power. The laser power test appears to be one of the most useful tests to quickly evaluate if a system is misaligned or functioning sub optimally by recording insufficient laser power readings. The test using a power meter can indicate if the system is aligned properly up to the plane of excitation on the stage, or if the machine has a defective component (i.e. a dying laser, or a defective fiber). In our experience, without sufficient power throughput in the system, the PMT voltages will have to be increased to high values to visualize fluorescence derived from specimens, which will introduce reduced image quality. In addition the cause of the decreased laser power may result in other problems i.e. laser instability, loss of axial resolution, and increased noise.
Digital Imaging in K-12 Biology
Authors: Ekstrom James
Published: March 2018

K-12 instruction in biology has traditionally taken a very descriptive approach. This is in marked contrast to quantitative as well as qualitative way of looking at things in physics and chemistry. This qualitative/descriptive approach even extends into the iaboratory portion of the biological course. One way to introduce a more quantitative approach is in the microscopy portion of the biology curriculum. Because cellular structure is primarily a microscopic province It makes sense to introduce students to the different microscopic tools such as TEM and SEM, as well as the light microscope that are used to investigate cell structure.
Integrating High Resolution Light Microscopy and Real Time Observation of Fluorescent Labels
Authors: Hasling Thomas A
Published: March 2018

Fluorescence microscopy has experienced tremendous growth over the past four decades and has facilitated major advancements in science. The classic fluorescent techniques (which include epifluorescence and confocal) allow researchers to selectively observe labeled structures with great clarity and consistency. Historically, biological scientists have been the most prolific users of fluorescence imaging. However, growing numbers of nano-materials research initiatives are now incorporating quantum dots and other fluorescent labels into their imaging protocols. This is especially true in areas where nano-materials and biological research is overlapping such as drug delivery. This nano-bio convergence, along with other advancements, has generated the need to observe highly dynamic events involving labeled and unlabeled structures in real time.
Surface Rippling & Ion Etch Yields of Diamond Using a Focused Ion Beam: With or Without Enhanced-Chemistry, Aspect Ratio Regulates Ion Etching
Authors: MoberlyChan W J , Felter T E , Wall M A
Published: March 2018

The Focused Ion Beam (FIB) instrument, originally designed for semiconductor circuit modification and repair, has found considerable utility as a tool for specimen preparation in several microscopy disciplines and for micromachining small parts. Essentially, a FIB makes very small and precise cuts into a target sample, which implies well-controlled etch rates and close tolerances of surface finish. However, redeposition can affect etch rate and final surface topographies. This work quantifies this redeposition as it modifies yields for different parameters of etching; models the influence of redeposition as applicable to all ion beam processing; and optimizes FIB processing parameters for enhanced yields.
The NEST Laboratory: The Art of a Multi-User Facility
Authors: Streiker Scott , Smith Rachel
Published: March 2018

Radiolaria are marine protozoa that have thrived in the world's oceans for millions of years. They are particularly unique among marine plankton in that they build silica skeletons, which have allowed them to be preserved in the fossil record. These skeletons are ornate and complex and often demonstrate perfect geometric form and symmetry. The complex and beautiful glass-like structures are visually interesting when examined with electron microscopy. These attributes, coupled with their availability, size, ease of mounting and preparation make them superb specimens for introducing students to the use of electron microscopy (EM).
Butyl-methyl-methacrylate for Immunocytochemistry Through the Light Microscope
Authors: Baskin Tobias I
Published: March 2018

The use of methacrylate monomers for embedding has a venerable history in microscopy. Many formulations have been developed over the years for various purposes, ranging from standard TEM observations to low-temperature embedding. Key parameters include the length of the hydrocarbon chain and the presence and kind of cross linking reagent. In the mixture of butyl and methyl methacrylate (BMM) described here, the monomers are relatively short-chained and there is no cross linker at all. This gives the polymerized material a softness that makes it rather unsuitable for TEM, but on the contrary allows the embedment to be removed after sectioning by a brief incubation in acetone. The latter property is good for immunocytochemistry because loss of the embedment means greater access for the antibody to the antigen. BMM generally preserves structure better than paraffin or glycol-methacrylate, and for this reason is a useful choice for light-level immunocytochemistry, particularly when sub-cellular resolution is desired.
A Protocol for Silver Staining Ion Transport Epithelia of Whole Animals and Excised Organs
Authors: Holliday Charles W
Published: March 2018

Those of us who study the structure and physiological function of ion transport cells in animals or their excised organs (gills, for example) are always interested in “quick and dirty” screening methods to identify ion transport epithelia. Having identified epithelial areas rich in putative “ionocytes”, we are also interested in looking at the mix of non-transport cells and “ionocytes” in the tissue. The so-called “silver staining” method can satisfy both of these desiderata quickly and easily.

Silver staining selectively blackens areas of the organism's body surface which are very permeable to chloride and/or silver ions; such areas are often the sites of ion transport epithelia (Croghan, 1958; Holliday, et al., 1990; Kikuchi & Shirashi, 1997).
The Use of Ultrarapid Freezing and Freeze Substitution to Verify Vitrification and/or Ice Formation in Vascular Tissue
Authors: Lightfoot Fred , Taylor Michael , Brockbank Kelvin GM , Hastings Cindy
Published: March 2018

The expanding field of cryobiology, in particular that of the study of vitrification for long term storage of tissues for transplantation, has demonstrated that ice is damaging to smooth muscle tissue. Consequently conventional methods such as ultrarapid freezing and freeze substitution are becoming routine protocols to determine the quality of cryopreservation. This article introduces the scientific community to the PS-1000 cryofixation unit (Delaware Diamond Knives, Wilmington, DE) which provides both ultrarapid freezing and a means of validation of freeze substitution methods. When any tissue is frozen or vitrif ed for clinical use it is imperative to know the structural and functional integrity of these tissues. Ice formation within the extracellular matrix and dehydration of multi-cellular tissues, using conventional cryopreservation, is the principal reason why these methods frequently prove to be ineffective.
A Commentary On Immunolabeling
Authors: Webster Paul
Published: March 2018

We have witnessed a slow but steady decline in electron microscopy (EM) skills in the biological sciences over the last decade. This decline is illustrated by the continued closures of EM facilities throughout the world. It is, however, difficult to rationalize this decline when the need for these skills is still under a constant demand. Certainly, the introduction of new microscopes has played a part in this. High-resolution confocal light microscopes, two photon imaging and other new technologies are providing impressive amounts of new information on biological systems. Many of these approaches require simple preparation protocols providing information that can be easily interpreted and are thus easily adapted to fast-moving research.

The application of EM techniques is also deceivingly simple. For this reason the field of immunocytochemistry is undergoing an increase in popularity. Laboratories with little or no previous experience in EM are discovering the impressive and convincing results achievable using these high-resolution methods.
Preparing Diatoms for EM
Authors: Strout Greg
Published: March 2018

Diatoms make for beautiful specimens for both transmission and scanning electron microscopy. As well, they are studied by many people, and there is always a need for good diatom preparations for EM.

I find that the diatoms in diatomaceous earth are usually broken, and like to prepare my own from fresh specimens. The materials needed for this are a plankton net, some potassium dichromate, and 30% hydrogen peroxide. Once the diatoms are collected (plankton net tows from shoreline, or wherever), they can be cleaned using the chemicals.
Dissecting Chromosomes, One at a Time!
Authors: Carmichael Stephen W
Published: March 2018

The atomic force microscope (AFM) is proving to be as much a tool as an imaging device. Recently, Stefan Thalhammer, Robert Stark, Stefan Müller, Johannes Wienberg and Wolfgang M. Heckl have added another useful technique to this repertoire. They demonstrated that the AFM can be used to cut out an identified section of DNA and then extract that section for amplification.

They began by flow sorting chromosomes, and then increased the specific amount of the target DNA with a “pre-set” in situ hybridization with chromosome-specific DMA to provide a specimen rich in chromosome 2. To identify the target area, selected chromosomes were examined with the AFM in the non-contact mode using stiff cantilevers.
A Versatile, Cheap, and Easy Self-Made Cell Culture Dish
Authors: Huber Andrea , Brösamle Christian
Published: March 2018

Anybody who has ever worked with cells or tissues in culture knows that the dish in which to grow and look at the specimen can be of crucial importance to the results obtained, With the growing importance of live cell microscopy, be it simple phase contrast or sophisticated multilabel confocal laser scanning microscopy (CLSM), people have been looking for dishes that combine optimal growth conditions with optimal optical properties. As follows, I will describe a solution that has worked for us with a multitude of different cells, tissues and applications. Apart from that, it is cheap and easily self-made.

The bottom of a standard 35 mm plastic ceil culture dish has a hole of ca. 10 mm drilled into it and a coverslip glued to its downside to cover the hole. For a glue we usually use Sylgard, an inert silicone elastomer (Dow Corning) or melted paraffin if we intend to take off the coverslip again.
Handling Creutzfeldt-Jakob Disease Tissues in the Histology Laboratory
Authors: Titford Michael , Bastian Frank O
Published: March 2018

Creutzfeldt-Jakob disease (CJD) resembles two other diseases, kuru (found in New Guinea tribesmen) and scrapie (found in sheep). CJD is a slow progressive dementia of the central nervous system. The transmissible agent of CJD is unusual for several reasons: it has a long incubation period, up to eight years in some cases; it does not provoke an inflammatory reaction within infected tissues; it has never been isolated; it is resistant to routine paraffin processing. Histotechnologists need to be informed of the potential hazards and of the correct handling of tissues infected with this unconventional agent, even though it has low transmissibility. Treatment of CJD tissues with long sterilization at high temperatures or prolonged exposure to bleach has proven effective in deactivating the agent. This article outlines the precautionary procedures used in our laboratory when processing CJD tissues. (J Histolechnol 12:214, 1989).
Grease-Free Cleaning of Parts for Vacuum Systems
Authors: Bigelow Wilbur C
Published: March 2018

There are many reasons for NOT using grease-base polishes for cleaning parts to be inserted into the interior of high vacuum systems, as is so commonly done in electron microscopy laboratories. This matter is discussed in some detail in my book Vacuum Methods in Electron Microscopy. (Portland Press, Ashgate Publishers, 800-535-9544), pp. 69-74.

Basically, one principal reason for cleaning most parts in the first place is to remove hydrocarbon materials from their surfaces, and so it makes no sense at all to use a greasy material to do the job.This is the equivalent of taking a bath in a mud puddle. Then, it becomes necessary to use ‘toxic’ organic solvents to remove the grease-base compounds, which in turn generates expensive and annoying procedures for the use and disposal of the solvents. In addition, the grease and abrasive materials are likely to get embedded in cracks and crevices of the parts on which they are used, and since they often are not readily soluble they may not be completely removed, whereupon they will subsequently act as a persistent source of contamination inside the vacuum system.
Digital Imaging in the Materials Engineering Laboratory
Authors: Clarke Theodore M
Published: March 2018

The recent completion of a company-wide PC network system, supported by network servers intended to rapidly handle large data files from CAD systems, made implementation of digital imaging in the Corporate Materials Engineering laboratory of Case Corporation a wise investment. Laboratory reports in Microsoft Word with linked image files can be rapidly received through any of the networked PC's and are archived in the server system. The changeover from film imaging to digital imaging was very sudden. This change was accelerated by satisfied users, whose work was made easier and more productive, and satisfied customers within Case Corporation.
Putting a Sphere on an Atomic Force Microscope Cantilever Tip
Authors: Zauscher Stefan
Published: March 2018

Atomic Force Microscopes (AFM) can measure the force between a surface and the tip of a cantilever as a junction of separation with great precision. For example, van der Waals type forces and electrostatic repulsive forces can easily be measured in aqueous solutions using an AFM. The complex, pyramidal shape of the typical AFM cantilever is, however, not well suited for quantitative measurements. It is thus desirable to attach particles of known geometry (usually spheres) to the tip of a cantilever.
Reducing Service Contract Costs and Do-lt-Yourself EM Maintenance
Authors: Mills Owen P.
Published: March 2018

Service contract expenses constitute a large proportion of many EM laboratory budgets each year and managers, under constant pressure to reduce costs, no longer look at the expense as sacred. Increasingly, microscopists are faced with finding alternatives to the full service contracts they enjoyed so long. I facilitated a discussion group at the Microscopy & Microanalysis '97 meeting held recently in Cleveland entitled "EM Maintenance: Can you do it yourself?" The audience of 50 represented microscopists from industry, academic and government facilities with a common interest - learning how to sensibly reduce service contract costs. In this article, I will offer my perspective on the subject and relate issues raised by the audience.
Making and Using Aqueous Mounting Media, or Why Buy a Premixed Medium when it's Cheap and Easy to make your own?
Authors: Kiernan John
Published: March 2018

Instructions are given as follows for making five aqueous mounting media: glycerol jelly, buffered glycerol with anti-fade, fructose syrup, Apathy's gum-syrup, and a polyvinylpyrrolidone medium whose composition can be varied to suit the user's needs, For each, hints are given on usage and the preservation of the coverslipped preparations. Media made in the laboratory are cheaper than commercial aqueous mountants, and do not contain any secret ingredients.
Photoshop Distilled: Basic Black and White Image Adjustment for Microscopists
Authors: Carvalho Tina (Weatherby)
Published: March 2018

Ready or not, digital imaging in the microscope lab Is here to stay. While I am one of those fogies who insist that digital images are nowhere near as good as photographic prints, I've also bowed to the inevitable, and am beginning to find ways to assist the clients in our multi-user facility with their digital imaging needs, We can acquire digital images from our FESEM, from our light microscope with a CCD, and from a flatbed scanner. Clients use their images for image analysis, transport to others scientists via the Internet or World Wide Web, for reports, slides, overhead transparencies, and publication, Generally, these images need to be manipulated for use, just as one would manipulate a photographic print to correct any deficiencies in exposure or area of view. Adobe PhotoShop is the software of choice for image adjustment, accounting for more than 80% of the digital image-editing software market.
X-Ray Detectors : A Changing World
Authors: Sareen RA , Nashashbi T
Published: March 2018

The first in a series of articles looking at developments in X-ray detectors and Field effect transistors. In recent years we have seen both Si(Li) and Intrinsic Silicon Detectors with resolutions below 130 eV. These same detectors are capable of measuring the soft X-rays like Be K, B K, C K etc. with good resolution and with peak positions reasonably close to the exact position for these lines. The Carbon peak is the one most affected by the L absorption edges in Silicon and in some circumstances can be shifted as much as 30 eV down in energy. Shifts can also result from the settings of amplifier threshold discriminators and ADC designs. At higher energies (e.g. Mo K) the Si(Li) detector, if not properly drifted can also have a down shift by as much as 200 eV.
The Case for Polarized Light Microscopy
Authors: McCrone Walter C
Published: March 2018

I was one told by a Nobel Laureate in Chemistry that light microscopy was simply a service foundation. By this he meant to class the microscope with computers, gas chromatographs, infrared spectrophotometers, x-ray diffractometers, mass spectrometers, etc. With all due respect to this gentleman and to these other instruments, there is a vital difference between the polarized light microscopes (PLM) and each of these instruments. First, a trained microscopist requires far more training than a qualified operator of, and interpreter of data from these other instruments. Second, there is considerably more basic physical and chemical information observable and measurable with PLM.
Fluorescence Resonance Energy Transfer Microscopy
Authors: Stenz Melanie L , Periasamy Ammasi
Published: March 2018

Fluorescence is a property of certain fluorophores, which allows them to absorb light at one wavelength and emit the light at another, longer wavelength. This fluorescence can be used as a tool to study the interactions of numerous components within a cell. With the use of fluorescent probes, proteins or other cellular matter can be specifically labeled in a fixed or live cell. This allows scientists to closely monitor microscopic cellular functions in order to gain a greater understanding of living biological processes.

Fluorescence Resonance Energy Transfer (FRET) imaging microscopy is an important and reliable tool for studying minute molecular processes in space and time within a single cell. FRET spectroscopy is a better method for studying the structure and localization of proteins in physiological conditions than are X-ray diffraction, nuclear magnetic resonance, and electron microscopy.
Some Things You Might Like to Know About Electron Lenses
Authors: Eades Alwyn
Published: March 2018

The performance of an electron lens depends solely on the size of the space between the pole pieces. This may be a simplification, but not much of one.

In this article, I will describe the operation of electron lenses in general but with specific reference to how they relate to working with SEM long working distances. The theme is related to EBSD performance when long working distances are needed with steeply tilted samples, and where large beam currents are needed to reduce noise in the EBSD pattern.

The lenses in electron microscopes are made of magnetic fields. The field bends the path of the electrons as they travel through it and so focuses them. The magnetic fields are themselves produced by an electric current flowing through a coil of wire. As the current is increased, the field gets stronger and so the lens focuses more strongly - up to a point.
Formaldehyde as a Fixative for Light and Electron Microscopy
Authors: Carson Freida L
Published: March 2018

Since Blum discovered its hardening properties in 1893, formaldehyde has become the most widely used fixative in the world for specimens to be examined by light microscopy. However, since most commercial preparations of formaldehyde contain methanol, a protein precipitant, formaldehyde has been considered an unsatisfactory fixative for tissues to be examined by electron microscopy.In 1973, Carson et a/, described a parallel study comparing the electron microscopic results of fixation with paraformaldehyde vs. formaldehyde. They found that there was no difference in the preservation of ultrastructural morphology provided that the buffer systems were identical. In 1976, McDowell and Trump described a fixative combining commercial formaldehyde and glutaraldehyde (4CF-1G). Both of these fixatives are dual purpose fixatives and preclude the selection of tissue for electron microscopy prior to fixation. They can both be prepared in large quantities and used for routine surgical specimens.
Microscopic analysis of magmatic crystals - Part 2: A SEM study of the stability of accessory zircon under increasing metamorphic conditions
Authors: Sturm Robert
Published: March 2018

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.
The Beginnings of the Southeastern Microscopy Society
Authors: Jerome W Gray (Jay)
Published: March 2018

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.
Exocytosis at the Atomic Level
Authors: Carmichael Stephen W
Published: March 2018

As reviewed in this column on previous occasions, the atomic force microscope (AFM) is steadily making headway as an instrument that can make important contributions to biologic observations. Although the AFM is capable of operating in an aqueous environment, relatively little use has been made of this property to examine cellular structures under conditions that resemble those in vivo. A breakthrough in this regard was recently made by Stefan Schneider, Kumudesh Sritharan, John Geibel, Hans Oberleithner, and Bhanu Jena. of Yale University and the University of Würzburg.
A Trend Towards Computer Aided Microscopy
Authors: Lee Andrew K
Published: March 2018

As the dawn of the next millennium approaches, the light microscope enters its fifth century of use, while the personal computer barely enters its third decade.

When Antony van Leeuwenhoek peered through his self made hand crafted microscope and documented the first observations of bacteria and cells, much of microbiology and cell biology was born. When the personal computer became a tool in modern science, molecular cell biologists were well into the age of human genetic engineering.

While the rise and acceptance into scientific importance of the microscope and the personal computer represent vastly different periods of sophistication in modem science, the combination of these two important scientific tools for computer aided microscopy (CAM) clearly provides bold uncharted potentials and opportunities for medicine, biomedical research, and industry in the future century to come.
Grain Sizing of Anodized Aluminum by Color Image Analysis
Authors: Laroche Sylvain , Forget Clement
Published: March 2018

Grain size characterization in Aluminum alloys can be correlated with thermo-mechanical processing properties. In order to predict the processing characteristics of these alloys under certain combinations of strain, deformation and temperature, the metallographic measure of the grain size can be used. Most of the technigues that have been proposed so far do not provide reliable and reproducible quantitative metallographic measurements of the grain size due to human error. Considering that this manual task is also tedious to perform, a general color image analysis algorithm is proposed to automate the characterization process using an optical microscope with polarized light. This algorithm was tested on several ingots and on rolled aluminum samples. The results show robustness in several conditions, even when the grains can barely be seen by a human operator Other image analysis techniques have been proposed but where judged too slow or too complex, particularly when gathering data over several fields. Time constraints specific to industrial seffings were taken into account when implementing a new algorithm.
Microscope Museum
Authors: Carmichael Stephen W
Published: March 2018

Recently, I had a delightfully pleasant surprise. I was attending a Human Embryology Conference in Washington, D.C., held at the National Museum of Health and Medicine, a Division of the Armed Forces Institute of Pathology. I've heard of the AFIP many times, but I had never been there, didn't even know where it was located. AFIP is located on the campus of Walter Reed Army Medical Center, which is bordered by Georgia Avenue. If you're driving, it's near the Maryland state line. If you're taking the Metro, get off at the Silver Springs stop and take a taxi.
Methods of Maximizing X-ray Detection in SEMs
Authors: Rohde David , Camus Patrick
Published: March 2018

Sample throughput is a significant issue in the microscopy lab. It is possible to improve the efficiency of analysis by changing the way we operate the microscope or upgrading the analytical system. One method to increase the efficiency of the analyst is to automate as many procedures as possible, including acquisitions. However, the most effective way to increase efficiency is to reduce the time that the analyst spends acquiring data. This is fine, but statistical confidence must not be reduced by the use of shorter acquisition times and the quality of the data or shape of the peaks must not be compromised as well (Figure 1, Table 1). To maintain the same level of statistical confidence of a longer analysis, an increase of the x-ray detection rate is needed.
Tungsten Filament Heating Effects
Authors: Beauregard Paul
Published: March 2018

The subject of SEM saturation was discussed on the microscopy list server and off list I was aslied why filaments burn out on the side leg Instead of at the tip. I have degrees in electronics technology and in chemistry as well as being a microscopist. So I investigated this subject and performed some experiments to verify my results.

According to Ohm's Law, one would expect that the highest resistance would be at a sharply bent V’ and that is where the filament would be expected to burn out. However, observations of the phenomenon show this is not where the filament burns out.
ELNES: An Electron Spectroscopic Tool to Study Complex Microstructures
Authors: Bruley John
Published: March 2018

The presence of internal boundaries can significantly influence many important properties of materials, such as fracture toughness, creep, electrical conductivity and magnetic behavior. Interfacial structure, chemical composition and bonding, on a nanometer length scale, are often controlling and sought after factors influencing these properties. An electron spectroscopic technique, known as energy-loss near edge structure (ELNES) analysis, can be utilized to probe compositional and bonding variations with a spatial resolution less than 1 nm and is therefore well suited to this endeavor.

When a fast electron passes through a material in an electron microscope, it collides with the electrons bound to the atoms in that sample. As a result, the fast electron often gives up a small fraction of its kinetic energy to the bound electrons. The laws of quantum mechanics dictate that these so-called inelastic scattering events will only take place if the bound electron can gain enough energy to enter an empty energy level.
Can Dew Help us to Image Insulating Material?
Authors: Carmichael Stephen W
Published: March 2018

In high resolution imaging of biologic structure, atomic lorce microscopy (AFM) has been prevailing over scanning tunneling microscopy (STM). This is primarily because biologic materials do not conduct electricity, and STM requires that electrons flow to or from the surface of the specimen, whereas electron flow is not required for AFM. Microscopists intent on using STM have compensated by coating specimens with a thin coat of metal. However, the presence of metal atoms on the surface degrades the resolution. A new development may make STM more useful to biologists than ever before.
X-Ray Wavelength Spectrometers: Are They Still Needed? ..Or “The More Thing Change, The More They Stay The Same’
Authors: Barbi Nick
Published: March 2018

During the early 1970's there was often heated debate over the quality of analytical performance attainable with Energy Dispersive (ED) systems using solid state detectors. Many scientists, particularly the more practical ones, were convinced that only WDX was reliable; while those with perhaps more imagination were convinced EDX was the future in microanaiysis. At that time, both groups were right.

EDX has seen remarkable improvement since those early days. At that time ED spectrometers were limited to analysis of elements above atomic number 10, and state-of-the-art resolution was improving to about 155 eV at Mn. Overlaps were handled strictly in quantitative analysis routines and even then only by use of simple overlap factors. Wavelength Dispersive (WD) spectrometers, although slow and difficult to operate, were required for light element analysis, to perform analyses when overlaps were present or suspected, and to detect trace elements.
In Praise Of The Hour
Authors: Soeldner Al
Published: March 2018

Years ago electron microscopes usually had an hour meter as a standard part of the instrument Unfortunately hour meters have been eliminated from many modern scapes and are not even readily available as an option from most microscope manufacturers.

An hour meter is a very useful device. Every microscope I've owned or supervised has had an hour meter that was factory installed, added by helpful field service persons, or that I installed myself. Few of us would enthusiastically buy a car without an odometer, why should we want an electron microscope without an hour meter?

If supplying an hour meter on an electron microscope costs too much in production time or money, certainly it would take only minimal effort at the design stage to plan a connection point or plug to operate a clock as an ancillary part of an appropriate circuit.
Through A Cracked Lens: Alternate Views Of Light Microscopy. Part I: Why Does My Microscope Have A Pupil?
Authors: Lund Mark W
Published: March 2018

Let's face it, optics is a fascinating field, but it can bore you to death. My purpose in writing these articles is to show that there are simple, intuitive ways to look at microscopes that can illuminate rather than bore. I have been an optical engineer for many years and have observed many unique ways of looking at optical instruments. I hope that I can share my enthusiasm and insight for light and its manipulation and give some insights that microscopisis may have missed. The microscope is particularly interesting because the glass lenses often do more than one job at the same time. Most of the principles of optical microscopy are directly transferable to electron microscopy, and I will point out specific cases as I go along.
Replicating The Unreplicatable
Authors: Garber Charles A
Published: March 2018

When doing replication, it is very important that all traces of the sample be removed from the replica. Adhering sample material introduces artifacts into the image and may, in extreme cases, make the replica so thick that the TEM beam cannot “see” through it. This may be a problem for both “ordinary” Pt/C replicas and freeze fracture situations. For organic samples, including both biological materials and polymers. For example, polymer latex particle fragments have a particular tendency to stick to the replica in freeze fracture preparations. Some freeze fracture samples will “wet” the replica surface if the replica is stripped by melting the substrate.
Automated Particle Analysis by Microscopy, A Primer
Authors: Vander Wood Tim B
Published: March 2018

Questions about samples consisting entirely of a collection of microparticles come from people involved in a wide variety of industries dealing with powders, from Pharmaceuticals to industrial minerals, powdered coatings to industrial hygiene concerns. The questions often asked are morphological. How big? How long? How wide?, and often pose a special problem for the microscopist. The time and tedium associated with answering these questions for a significant subset of the sample particles without an automated system causes the cost to skyrocket and sends the requester off to the light scatterers who at least give cheap answers, never mind that nobody knows what they really mean (What is the average size of a particle with an aspect ratio of 5? And did you calibrate your scattering system for my particles in my dispersant or are you still using latex spheres in water?). A common additional question is “How many are quartz, or titania, or organic, or….?” The inherent advantages of microscopy—the ability to determine detailed morphology in two dimensions (and maybe three), and to discriminate different particle types in a mixture—were usually overwhelmed by the cost and time involved.
Training Trends and their Implications for Microscopy
Authors: Murphy Judy A
Published: March 2018

Microscopy training has always been labor intensive. As the need grew for electron microscopists so did the need for methods of training to maintain quality while increasing the quantity of people trained. Various trends in scientific research needs, development of various types of microscopies, environmental concerns and increasing computer sophistication brought about significant changes in microscopy training and service facilities.

In the 1960's TEM research flourished. Many single user facilities appeared with scopes provided by grant funds, especially in biology. There was a great need for people trained in EM. In the mid 1960's, commercial SEMs became available, and SEM research flourished.
Maya Blue Paint
Authors: Carmichael Stephen W
Published: March 2018

It has been noted by many people who have had the privilege of exploring Mayan ruins that there is a stunning blue color that has been preserved amazing well for centuries. Considering the tropical jungle is quite a hostile environment, the tenacity of this “paint” is remarkable. It had been suggested that this “paint” was made by mixing indigo dye with clay, but this did not explain its special characteristics. Recent work by Miguel José-Yacamán at the National University of Mexico and colleagues has revealed what is special about this material, which is called Maya blue paint. They collected specimens in Mexico at archeologic sites known as Jaina Island and Palenque.
Cell-Free Secretion
Authors: Carmichael Stephen W
Published: March 2018

Regulated secretion occurs when the ceil detects a signal, vesicles containing the secretory product fuse with the plasma membrane of the cell, and the contents are released into the extracellular space. This mechanism is called exocytosis. Many laboratories around the world have studied exocytosis for the past couple of decades, and we know a lot about the many steps that are involved. The cytoskeleton appears to play a role in allowing vesicles to approach the plasma membrane, and many other proteins are in the cascade between reception of the signal and the release of the secretory products.
Atomic Resolution with the Atomic Force Microscope
Authors: Carmichael Stephen W
Published: March 2018

For biologic studies, atomic force microscopy (AFM) has been prevailing over scanning tunneling microscopy (STM) because it has the capability of imaging non-conducting biologic specimens. However, STM generally gives better resolution than AFM, and we're talking about resolution on the atomic scale. In a recent article, Franz Giessibl (Atomic resolution of the silicon (111)- (7X7) surface by atomic force microscopy, Science 267:68-71, 1995) has demonstrated that atoms can be imaged by AFM.
Fundamental Parameters For Microanalysis
Authors: Joy David C
Published: March 2018

In order to perform quantitative X-ray microanalysis many parameters, representing the various stages of X-ray generation and transport through the specimen at the chosen experimental conditions, must be known for all of the elements that might be encountered. Although ideally quantification is done by reference to standards so that only the functional variation of these parameters is required, in current practice it is increasingly necessary to work in situations where standardization is impossible and consequently where absolute magnitudes must be known. The quality and quantity of data that is now available varies widely.
Simultaneous Specimen & Stage Cleaning for Analytical Electron Microscopy
Authors: Henriks David
Published: March 2018

An innovative technique has been developed which allows simultaneous cleaning of a sample and a specimen stage which minimizes and, in some cases eliminates, contamination of inorganic specimens analyzed via SEM.TEM, STEM and AEM.

The technology involves subjecting the specimen and the specimen stage to a reactive plasma gas which efficiently removes a wide range of contaminants from critical surfaces. The procedure may be carried out prior to inserting the specimen and specimen stage into the EM via an externally produced accessory unit and can be extended for use on all types of electron microscopes where the sample and stage are loaded external to the instrument. Such an instrument was produced and implemented first by Dr. Nestor Zaluzec at Argonne National Laboratory. His system modified a commercially available pfasma etching system which included adapting it to accept a side entry holder.
Is the TEM Obsolete?
Authors: Williams D B
Published: March 2018

In 1968, as an undergraduate, I was first taught how to operate a Philips EM300 TEM that, at the time, was a state-of-the-art 100 keV TEM for materials studies. Last year, I spent time evaluating current state-of-the-art microscopes, f.e., intermediate-voltage, field-emission gun TEMs, from all the major manufacturers. In watching the operators running these latest microscopes, I was struck by the similarity between many of their actions and the same steps that I had learned, so laboriously, 30 years previously.
A Tell-Tale Heartwood
Authors: Kellar Eric C
Published: March 2018

In Medieval Europe, manuscripts and formulas on the preparation of colors and dyes used by chemists and artists contained many references to natural plant extracts, The yellow stigmas of aromatic saffron (Crocus sativus) were crushed and used both as a medicine and colorant as far back as the ninth century BCE. In 1437 CE, a manual was written by Cennini, II Libro del Arte, a collection of recipes on the preparation of tempera and block-printing inks from saffron and brazilwood (Caesalpinia echinata), Finely divided brazil wood was prepared by scraping sticks with a knife.
The Influence of TEM Education on TEM Development
Authors: Williams D B
Published: March 2018

Learning how to operate the microscope has dominated the TEMteaching process in a way that is perhaps unparalleled by any other common scientific instrument. The TEM column is so complex that the arcane aspects of its manual manipulation become the main points to be learned by the student, rather than the use of the instrument to solve materials problems. In other words, command of the instrument often becomes an end in itself. Such an approach would preach that it is better to be able to produce a striking CDF image that is well aligned and focused than it is to be able to interpret that image in terms of the materials processing responsible for the microstructure!
Preparation of Milk Products for SEM Examination
Authors: Walsh Rosemary
Published: March 2018

This laboratory has compared several techniques in our effort to produce artifact-free SEM images in order to compare the effect of different stabilizers on microstructure of soft serve frozen yogurt and stirred yogurt. Such samples are a porous matrix of casein micelles fused to form chains which immobilize the liquid phase. Two sample preparation protocols were used: cryo-SEM for the product sampled at lower temperature, and encapsulation of those semi-liquid or soft-set yogurts within an agar gel tube or in drilled aluminum stubs / molds coated with low melting point 3% agar.
Mating Cameras To Microscopes
Authors: Hinsch Jan
Published: March 2018

The compound microscope forms images in two stages. The objective (first stage) projects a real image of the specimen into the intermediate image plane (IIP) of the microscope at a ratio of magnification (M). The resolution in the IIP is typically between 40 and 100 line pairs permillimeter (Ip/mm). Since the resolution of the human eye is of the order of 5 Ip/mm, additional virtual magnification (V) by the eyepiece (second stage) is necessary to match the resolution of the eye to that of the microscope. The total microscope magnification (VTOTAL) is the product of W x V. The designation VTOTAL is used because the eye views a virtual image in the microscope.
Cover Glass Perspectives
Authors: Gill Gary W
Published: March 2018

Cover glasses, and by extension mounting media, are the cfe facto front lens of every microscope objective. Those who coverslip are, in effect, completing the assembly of a microscope objective with every cover glass they apply. So while coversliping is a tedious process, its visibly appreciable contribution should not be minimized.

There are optical reasons on which coverslipping do's and don'ts are based. It is optically and physically impossible for alternatives such as liquid substitutes and plastic film to duplicate the specifications and performance of glass cover glasses. Such substitutes are used, however, perhaps because there is so little related useful technical information available to discourage such use.
More Fun With Photoshop
Authors: Weatherby Tina
Published: March 2018

As humans, we are very sight oriented. As microscopists, we usually acquire data that is in the form of images. Since micrographs, or pictures, are what we deal with, we tend to become involved with the presentation of the data and its visual impact. When making a figure plate for publication, do you often find yourself moving images around, adjusting sizes, tonal gradations, and positions to achieve a more visually pleasing arrangement? Microscopy must be the most artistic of the sciences. We might like to have fun with our images, as well.

Images formed by electrons are collected on media that sees only if the electrons were there or not. Traditional electron micrographs are black and white images; photons are needed for the colors that we can detect.
Sizing of Liposomes by TEM
Authors: Gantz Donald
Published: March 2018

We are using negative stain or a combination of osmium tetroxide fixation and negative stain to monitor the size homogeneity of lipid vesicle/liposome populations prepared by such techniques as sonication, extrusion, and gel filtration chromatography. Small sonicated vesicles up to about 50 nm in diameter seem sufficiently well preserved in negative stain for adequate size determination, although some flattening upon adherence probably does occur. Larger vesicles such as 100 nm extruded liposomes which contain a large aqueous core are likely to be flattened significantly in negative stain and may be partially stabilized with an osmium tetroxide fixation. The effectiveness of this fixation will in large part depend upon the degree of saturation of the lecithin species.