bluuebunny/crossref_metadata_2025 huggingface dataset:
The Histology and Ultrastructure of Cat Abdominal Paraganglia After Fixation and Localization with Glutaraldehyde/Potassium Dichromate
Authors: Mascorro Joe A. , Yates Robert D.
Published: June 2020

Potassium dichromate is the compound used for the classical chromaffin reaction diagnostic of adrenal medullary cells. We recently described a technique which utilizes this catecholamine oxidizing agent for the purpose of tracing extra-adrenal chromaffin tissue (paraganglia) which is similar morphologically to that of the adrenal medulla. The action of potassium dichromate resulted in the cat paraganglia becoming brown due to the dichromate-catecholamine interaction. The organs were then easily visible as slender elongated structures extending along the abdominal aorta.
Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM
Authors: Revel J. P.
Published: June 2020

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.
Calculations of Ionization Cross Sections of Small Molecules
Authors: Parikh Mihir
Published: June 2020

Inelastic scattering of an incident electron in an EM can cause the physical disintegration of the specimen. Of all inelastic collisions, an ionizing collision generally leads to molecular dissociation (except maybe in the case of aromatic molecules). Here we outline a method developed to estimate the ionization cross sections of small molecules.
Interference Experiments with a Field Emission Electron Miscroscope
Authors: Munch J. , Zeitler E.
Published: June 2020

We have modified a Hitachi HU 12 electron microscope by replacing the thermionic electron gun with a field emission gun. The design principles of this gun are substantially the same as those used in the scanning microscopes developed at the University of Chicago by A. V. Crewe and his collaborators. To accommodate the field emission gun in the conventional column two differentially pumped stages were employed, assuring a vacuum of better than 2 x 10−10Torr in the tip region.
Holographic Image Deconvolution in High Resolution Electron Microscopy
Authors: Stroke G.W. , Halioua M. , Thon F. , Willasch D.
Published: June 2020

The phase contrast transfer function (CTF) for imaging of weak phase objects in high resolution electron microscopy is well known. It is an oscillating function, generating transfer intervalls with positive and negative contrast. Due to the influence of chromatic aberration and partial coherence its amplitude decreases at higher spatial frequencies. Several attempts have been made to improve the CTF by a posteriori optical filtering, e.g. zonal filtering or the use of Tsujiuchi-type phase filters. The method of holographic deconvolution, as proposed by Stroke and Halioua, employs phase and amplitude filters in such a way that the CTF approaches nearly a constant value.
Application of Modified Bloch Waves to Image Analysis of Extended Linear Defects
Authors: Nakahara S. , Maher D. M.
Published: June 2020

Since Head first demonstrated the advantages of computer displayed theoretical intensities from defective crystals, computer display techniques have become important in image analysis. However the computational methods employed resort largely to numerical integration of the dynamical equations of electron diffraction. As a consequence, the interpretation of the results in terms of the defect displacement field and diffracting variables is difficult to follow in detail. In contrast to this type of computational approach which is based on a plane-wave expansion of the excited waves within the crystal (i.e. Darwin representation ), Wilkens assumed scattering of modified Bloch waves by an imperfect crystal. For localized defects, the wave amplitudes can be described analytically and this formulation has been used successfully to predict the black-white symmetry of images arising from small dislocation loops.
Unique Features of a High Resolution Scanning Transmission Electron Microscope
Authors: Wiggins J. W. , Beer M. , Woodruff D. C. , Zubin J. A.
Published: June 2020

A high resolution scanning transmission electron microscope has been constructed and is operating. The initial task of this instrument is to attempt the sequencing of DNA by heavy-atom specific staining. It is also suitable for many other biological investigations requiring high resolution, low contamination and minimum radiation damage.

The basic optical parameters are: 20 to 100 KV acceleration potential, objective lens focal length of 1.0 mm. with Cs = 0.7 mm., and two additional lenses designated as condensor and diffraction lenses. The purpose of the condensor lens is to provide a parallel beam incident to the objective, and the diffraction lens produces an image of the back focal plane of the objective in the plane of an annular detector.
Sample Preparation and Trace Element Analysis of the Shell Layers of a Recent Oyster Crassostrea virginica
Authors: Hastings S. C.
Published: June 2020

This study was conducted in order to determine the best method of sample preparation for microprobe analysis of the trace element content of the Recent oyster Crassostrea vlrglnlca. Ordinarily, a flat and polished surface provides the best results in X-ray techniques. However, examination of individual shell layers requires a method that allows visual recognition of the shell structure while still providing the flattest surface possible for micro-probe analysis. If, in response to its environment, the oyster incorporates trace elements into its shell as the dally growth layers are secreted, analysis of the individual shell layers will provide a record of environmental and temporal variations in the trace element composition of the surrounding waters.
Scanning Electron Microscope Studies on the Morphology of Zeolites Occurring in Bentonites
Authors: Jehn Paul J. , Güven Necip , Bailey J. Franklin
Published: June 2020

Zeolites occur as major constituents in several bentonite samples from Japan and Argentina. They are believed to be formed by devitrification of volcanic material. X-ray diffraction data indicate that the major zeolite phases in these samples are heulandite Ca(Al2Si7O18)·6H2O, clinoptilolite Na2(Al2Si7O18)6H2O, mordenite (Na2K2Ca) (Al2Si10O24)·7H2O, analcite Na(AlSi2O6)·H2O and possibly epistilbite Ca(Al2Si6O16)·5H2O.
Biogenic Opal Dissolution: SEM Observations of Gulf of Mexico Bottom Sediments
Authors: Jendrzejewski John P.
Published: June 2020

Siliceous biogenic remains from Gulf of Mexico bottom sediments illustrate numerous states of preservation when viewed with the scanning electron microscope (SEM). This report is a preliminary investigation of biogenic opal preservation from bottom sediment samples exclusive of the continental shelf regions from the Gulf basin. The open Gulf of Mexico is an area of low primary productivity with surface waters characterized by low silicate values generally less than 1 to 12 μg-at./l. These low values are reflected by the relatively low abundance of siliceous plankton living in the surface waters of the open Gulf. The low siliceous productivity along with the high terrigenous influx of sediment into the Gulf tends to favor dissolution of biogenic opal in the sediments.
Application of TEM to Deformation, Wear, and Fracture of Ceramics
Authors: Hockey B. J.
Published: June 2020

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.

The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.
Precipitates as Internal Markers for High Temperature Deformation Studies
Authors: Nuttall K.
Published: June 2020

A problem in the study of high temperature deformation mechanisms such as grain boundary sliding or diffusion creep is to obtain good metallographic evidence to demonstrate the probable occurrence of such processes. The difficulty arises because marked changes in microstructure such as those commonly observed after dislocation creep, e.g. grain elongation, sub-grain formation, changes in dislocation distribution, are not usually associated with sliding and diffusion creep so that microstructural comparisons before and after deformation are not too informative. Surface markers are frequently used as an indication of relative grain sliding and rotation, but there are separate difficulties in relating these observations to bulk behaviour.
Observation of Extrinsic Faults in a Non-Stoichiometric Heusler Structure Alloy
Authors: Tzeng W. S. , Strutt P. R.
Published: June 2020

Previously, stacking faults have been observed in ordered nickel-base alloys with a b.c.c. type structure (1,2). Ball (1) found an unusual fault in non-stoichiometric Al-rich NiAl, and proposed it was produced by a double layer of vacancies. The present study now reveals a new type of extrinsic fault in heat treated Al-rich non-stoichiometric Ni2AlTi. This alloy has the atomic composition 50% Ni, 30% Al, and 20% Ti. It is relevant to mention that diffuse contrast faults of the type previously described (2) occur in as-cast material prior to heat treatment. In general these faults were non-crystallographic, and had a convoluted appearance. However, after heat treatment at 1000°C for 48 hrs. in vacuo (∼10-7torr) a new type of fault was observed.
Preparation of Thin Cadmium Telluride Samples for Electron Microscope Studies
Authors: Magee T. J. , Peng J. , Bean J.
Published: June 2020

Cadmium telluride has become increasingly important in a number of technological applications, particularly in the area of laser-optical components and solid state devices, Microstructural characterizations of the material have in the past been somewhat limited because of the lack of suitable sample preparation and thinning techniques. Utilizing a modified jet thinning apparatus and a potassium dichromate-sulfuric acid thinning solution, a procedure has now been developed for obtaining thin contamination-free samples for TEM examination.
On Some Testing Specimens for High Resolution SEM
Authors: Lin P. S. D.
Published: June 2020

In assessing the resolving power of a high resolution scanning electron microscope using field emission tip (Hitachi HFS-2), two types of specimens were found to be of value.

Fig. 1a, 1b are two successive exposures of some bright spots found on some thin carbon films. These carbon films were originally prepared for work in a high resolution scanning transmission electron microscope. Spots similar in size and distribution have been detected on micrographs taken in that microscope (Fig. 2).
A Comparative Study of Fractographic Replicas
Authors: Anderson Loren , Pizzo Pat , Haydon Glen
Published: June 2020

Transmission electron microscopy of replicas has long been used to study the fracture surfaces of components which fail in service. Recently, the scanning electron microscope (SEM) has gained popularity because it allows direct examination of the fracture surface. However, the somewhat lower resolution of the SEM coupled with a restriction on the sample size has served to limit the use of this instrument in investigating in-service failures. It is the intent of this paper to show that scanning electron microscopic examination of conventional negative replicas can be a convenient and reliable technique for determining mode of failure.
The Distribution of Water in the Cytoplasm
Authors: Porter K.R. , Boggs D.P. , Anderson K.L.
Published: June 2020

It has become apparent in recent years that the cytoplasmic matrix (cytomatrix) is structured. If the evidence available for this is correctly interpreted, we should put aside the concept that the majority of the enzymes which catalyze metabolic reactions are in solution in a soluble phase of the cytoplasm, also called the cytosol. This evidence, derived in large part from high voltage micrographs of whole cultured cells, says that the cytomatrix is a three-dimensional mesliwork of fine strands measuring 5-20 nm in diameter and 50-200 nm in length. By its existence, the microtrabecular lattice transforms the cytosol into a two-phase system, one protein-rich and the other water-rich. It is the purpose of this paper to report a few observations on the latter of these two, i.e. the water-rich phase.
Subcellular Localization of the Hepatic Asialoglycoprotein Receptor by Immunoelectron Microscopy
Authors: Lodish H.F. , Geuze H.J. , Slot J.W. , Strous G.J.A.M. , Louvard D. , Schwartz A.L.
Published: June 2020

The hepatic receptor for asialoglycoproteins provides an excellent system with which to study the subcellular localization and function of an intrinsic membrane glycoprotein. This receptor, specific for galactoseterminal glycoproteins, mediates the rapid and specific binding and subsequent internalization of glycoprotein ligands. The receptor is abundant; there are approximately 500,000 high affinity ligand binding sites per rat hepatocyte cell surface. The receptor has been isolated from rat liver by affinity chromatography. Using a monoclonal antibody, we showed that the surface receptor consists of two non-identical subunits which contain the same or closely related polypeptide chains. Morphologic studies, primarily by A. Hubbard and collaborators, have evaluated the fate of the asialoglycoprotein ligand once bound by the hepatocyte. They demonstrated, both in the rat and in perfused rat liver, a rapid association of labeled ligand with the plasma membrane of the parenchymal cell. This was followed by accumulation of ligand within the lysosomes and Golgi region. We have taken an immunocytochemical electron microscopic approach to examine the distribution and localization of the asialoglycoprotein receptor both in normal rat liver, and in liver cells exposed to asialoglycoprotein ligand.
Aminotriazole-Insensitive Catalase Activity in Rabbit Peritoneal Exudate Monocytes
Authors: Zellmer D.M. , Shannon W.A.
Published: June 2020

Peroxidase activity has been identified in the monocyte of several species, but could not be demonstrated in the rabbit monocyte except in the rough endoplasmic reticulum (RER) and digestive vacuoles of "resident" macrophages. Aminotriazole-sensitive catalase activity has been demonstrated in the RER of guinea pig monocytes, but has not been demonstrated in their granules or in the rabbit monocyte. Recently, we attempted to localize catalase activity in the monocyte and to cytochemically differentiate between catalase and myeloperoxidase (MPO) reactivity.
A One Step Indigogenic Ultrastructural Method for Na+-K+ATPase
Authors: Tsou K. C. , Suganuma T.
Published: June 2020

The use of 5-nitroindoxyl phosphate (NIP) as an indigogenic substrate for Na+-K+-ATPase had been reported, further investigation was necessary to simplify this procedure to a one step method. This paper reports the use of lead citrate as atraping agent in this method, and a comparison with the well-known p-nitrophenyl phosphate (NPP) method.
Temperature Dependence of the Critical Electron Dose for Fatty Acid Monolayers
Authors: Downing Kenneth H. , Glaeser Robert M.
Published: June 2020

The structural damage of molecules irradiated by electrons is generally considered to occur in two steps. The direct result of inelastic scattering events is the disruption of covalent bonds. Following changes in bond structure, movement of the constituent atoms produces permanent distortions of the molecules. Since at least the second step should show a strong temperature dependence, it was to be expected that cooling a specimen should extend its lifetime in the electron beam. This result has been found in a large number of experiments, but the degree to which cooling the specimen enhances its resistance to radiation damage has been found to vary widely with specimen types.
Structural Investigations of the Pore-Forming OMPC Protein from E. Coli
Authors: Grano David A. , Chang Chung-Fu , Glaeser Robert M.
Published: June 2020

OmpC protein is one of the major pore-forming proteins found in the outer membrane of E. coli. It bears a close similarity to ompF protein, the “matrix protein” of Rosenbusch. The relative abundances of ompC and ompF protein are influenced by nutritional and osmotic factors. Their amino acid compositions are very close and they appear to act as functionally similar but not equivalent passive diffusion pores. A trimeric protein seems responsible for the formation of pores.
Actin Structure and Function Studied by Electron Microscopy and Image Processing
Authors: Aebi U. , Fowler W.E. , Smith P.R.
Published: June 2020

During the past few years analog and digital image processing techniques have become indispensable tools for the study of protein structure by electron microscopy [for reviews see e.g. 1,2,3]. The two most frequently used among these techniques are ‘image enhancement’ and ‘structure reconstruction'. Image enhancement techniques are used to objectively extract the reproducible structural features contained in noisy images recorded from the specimen under investigation, by combining their redundant information by means of ‘real space averaging’ or ‘Fourier space filtering'. The prerequisite for the ultimate success of these techniques is the ability to properly align the images relative to each other. The purpose of structure reconstruction techniques is to determine the three-dimensional structure of proteins by combining a set of sufficiently independent two-dimensional projection images recorded from the object under study - hence three-dimensional reconstruction techniques. This step becomes necessary, because biological specimens are generally translucent to the electron illumination, and therefore micrographs recorded from them in transmission mode represent projection images of the inherently threedimensional specimen that superimpose structural features from different depth within it.
Mass Measurements of Lobster Muscle Thick Filaments by Scanning Transmission Electron Microscopy
Authors: Freeman R. , Hofmann W. , Berriman J.
Published: June 2020

The structure of muscle thick filaments has been elucidated by a combination of electron microscopic and X-ray diffraction methods. Although X-ray diffraction provides much detailed information about the structure of the filaments, a long-standing problem is the number of myosin molecules per repeating unit along the filament. Direct measurements using STEM have recently established that in vertebrate skeletal muscle and insect flight muscle there are respectively 3 and 4 myosin molecules in each 145Å. period along the filament.
Microtubules and Intermediate Filaments in Human Neutrophils
Authors: Parysek L. M.
Published: June 2020

The polymorphonuclear leukocyte (PMN) or neutrophil is capable of persistent directional locomotion, a process known as chemotaxis. Actin filaments found in the neutrophil cortex are thought to be essential for pseudopod formation and subsequent cell locomotion. Other cytoskeletal elements such as microtubules and intermediate filaments have been observed in chemotaxing human neutrophils. The purpose of this work is to examine these cytoskeletal elements in neutrophils in a non-activated state by morphologic and biochemical means.
Stereo-Triplet Analysis of Thick Sections and Whole Mounts of Latex-Labelled Allogromia (Protozoa, Foraminifera)
Authors: McGee-Russell S.M. , Bowser S.S. , Rupp G.
Published: June 2020

We recommend a standard usage for stereo-triplet analysis and presentation of depth information in electron micrographs. In both CTEM and HVEM stereotriplet analysis significantly improves interpretation of structural detail in whole mounts and thick sections. Micrographs are made at 0°, +6°, and -6°, and mounted from left to right in that order (Figs. If, 2). The left pair (0°, +6°) will give a cameo image (substrate down) and the right pair (same +6°, -6°) an intaglio image (substrate up) with a suitable whole mount. Rapid interchange (flip-flop) between the two images (slight shift of stereoscope) and the consequent rapid mental comparison of the two images results in greatly improved interpretation of difficult images such as membrane-filament associations, and ultra-microspike activity of reticulopods. In this arrangement a stereo-triplet contains significantly more information than a stereo-pair. The cameo/intaglio reversal may be obtained from a stereo-pair printed +6°,-6°,+6° from L to R, (Fig. 3), but contains fewer cues.
The Ultrastructure of Cellular Ontogeny in Leaf Cavity Trichomes of Azolla Caroliniana Willd
Authors: Calvert H.E. , Pence M.K. , Peters G.A.
Published: June 2020

A cyanobacterium, Anabaena azollae, lives symbiotically with the water-fern Azolla. It occupies cavities formed in the AzoIIa leaves and can provide the association with its total N requirement by fixing N2. Multicellular trichomes, present on the walls of the cavities, are intimately associated with the microsymbiont. The discovery of transfer cell ultrastructure in some of these trichomes has led to suggestions that they may be involved in metabolic exchange between the partners. To gain insight into their role in the symbiosis, the ontogeny of the cavity trichomes has been examined in detail and its stages correlated with microsymbiont development and N2 fixation activity.
Control of Vacuole Formation in the Parotid Gland
Authors: Leslie B. A. , Putney J. W.
Published: June 2020

In the salivary glands, neurotransmitters regulate the secretion of proteins and water. In the rat parotid glands these processes are primarily controlled by distinct membrane receptors; the secretion of protein by β-adrenergic receptors, and the secretion of water by α-adrenergic or cholinergic receptorsl. Morphological studies have shown that the secretion of protein occurs by exocytosis. When receptors involved with augmentation of water secretion are activated, there is a concomitant formation of watery vacuoles in the acinar cells. Calcium ions are known to be necessary for this process. Beyond this, the mechanism of formation of vacuoles, and their function in the process of secretion, are not understood. A detailed examination of the ultrastructural consequences of activating the cholinergic system of the rat parotid gland with carbachol is the focus of this study.
The Abscence of Direct Permeability Pathways in Continuous Capillaries and the Internal Nature of Endothelial Vesicles
Authors: Wagner Roger C. , Robinson Candy S.
Published: June 2020

The paired rete mirabile (red bodies) of the eel swim bladder consist of counterparallel venous and arterial capillary segments which function in countercurrent exchange of gases. The arterial capillaries are thick-walled and continuous and the venous capillary walls have thin, fenestrated endothelium. This permits one type of capillary to serve as a control for the other in differential permability studies. The capillaries are unbranched and of similar length which allows for the perfusion of each of them at the same flow rate and under the same hydrostatic and osmotic pressure.
Video-Enhanced Microscopy--Better Visibility of Plant Cell Structures
Authors: Allen N.S. , Allen R.D.
Published: June 2020

Various methods of video-enhanced microscopy combine TV cameras with light microscopes creating images with improved resolution, contrast and visibility of fine detail, which can be recorded rapidly and relatively inexpensively. The AVEC (Allen Video-enhanced Contrast) method avoids polarizing rectifiers, since the microscope is operated at retardations of λ/9- λ/4, where no anomaly is seen in the Airy diffraction pattern. The iris diaphram is opened fully to match the numerical aperture of the condenser to that of the objective. Under these conditions, no image can be realized either by eye or photographically. Yet the image becomes visible using the Hamamatsu C-1000-01 binary camera, if the camera control unit is equipped with variable gain control and an offset knob (which sets a clamp voltage of a D.C. restoration circuit). The theoretical basis for these improvements has been described.
Characteristics of Irreversibly Constricted Cerebral Blood Vessels
Authors: Liszczak T.M. , Varsos V.G. , Black P.Mcl. , Heros R.C. , Zervas N.T.
Published: June 2020

Cerebral vasospasm is a biphasic event resulting in most cases in an irreversibly constricted cerebral blood vessel. The major initiator of vasoconstriction is subarachnoid hemorrhage (SAH) or trauma. Several animal models have been developed but none approximates the pathological sequellae seen in man after SAH. We have refined a dog SAH model which possesses many of the physiological and ultrastructural features seen in man after SAH induced vasospasm and report some clinically relevant findings.
Fine Structural Changes in the Renal Tubules and the Blood Pressure in Rats after Cisplatin Treatment
Authors: Aggarwal S. K.
Published: June 2020

Cisplatin [cis-dichlorodiammineplatinum (II)], a broad spectrum antitumor agent is now available for the treatment of ovarian and testicular tumors. However, it is not free from its toxic side effects, like neuroand nephrotoxicity, intestinal toxicity and toxicity to the hematopoetic organs. Further, it induces gastric distension, gastric ulcers and causes resorption or abortion of the embryos depending upon the time of its administration during pregnancy. In spite of its severe toxicity, cisplatin is still a potent drug in the armamentarium of cancer chemotherapeutics.
An Established Epithelial Cell Line (NPC/HK1) from a Nasopharyngeal Carcinoma - I. A Tem Study
Authors: Li C.L. , Chew E.C. , Huang D.P. , Ho H.C. , Lui M. , Mak L.S.
Published: June 2020

An epithelial cell line, NPC/HK1, has recently been successfully established from a moderately to well differentiated squamous carcinoma of the nasopharynx. This communication reports on the fine structures observed in the carcinoma cells of the original tumour biopsy and those of the NPC/HK1 cells from different culture generations derived from it.
An Established Epithelial Cell Line (NPC/HK1) from a Nasopharyngeal Carcinoma - II. A Sem Study
Authors: C.L. Li , E.C. Chew , D.P. Huang , H.C. Ho , L.S. Mak , M. Lui
Published: June 2020

An epithelial cell line, NPC/HK1, has recently been successfully established from a nasopharyngeal carcinoma of the moderately to well differentiated squamous type. The present communication reports on the surface morphology of the NPC/HK1 cells in culture.
The Diagnosis of Viral Disease by Electron Microscopy
Authors: McCombs William B. , McCoy Cameron E.
Published: June 2020

Recent years have brought a reversal in the attitude of the medical profession toward the diagnosis of viral infections. Identification of bacterial pathogens was formerly thought to be faster than identification of viral pathogens. Viral identification was dismissed as being of academic interest or for confirming the presence of an epidemic, because the patient would recover or die before this could be accomplished. In the past 10 years, the goal of virologists has been to present the clinician with a viral identification in a matter of hours. This fast diagnosis has the potential for shortening the patient's hospital stay and preventing the administering of toxic and/or expensive antibiotics of no benefit to the patient.
On Future Directions in Pathology
Authors: Trump Benjamin F. , Berezesky Irene K. , Jones Raymond T.
Published: June 2020

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.
Methionine-Specific Staining of Collagen
Authors: Kuhn E.M. , Marenus K.D. , Beer M.
Published: June 2020

Fibers composed of different types of collagen cannot be differentiated by conventional electron microscopic stains. We are developing staining procedures aimed at identifying collagen fibers of different types.

Pt(Gly-L-Met)Cl binds specifically to sulfur-containing amino acids. Different collagens have methionine (met) residues at somewhat different positions. A good correspondence has been reported between known met positions and Pt(GLM) bands in rat Type I SLS (collagen aggregates in which molecules lie adjacent to each other in exact register). We have confirmed this relationship in Type III collagen SLS (Fig. 1).
FMDV-RNA Polymerase - The Localization of an Enzyme and its Product by EM Immunocytochemistry and Autoradiometric Analysis
Authors: Polatnick J. , Wool S. H.
Published: June 2020

Foot-and-mouth disease virus infected bovine kidney cell cultures were treated at intervals from 1-4 hours post-infection with 1% saponin and.05% glutaraldehyde for 30 min. The cells were then treated with guinea pig anti-polymerase sera for 60 min followed by ferritin-tagged rabbit antiguinea pig sera or Protein-A peroxidase. Diaminobenzidine in 0.01% H2O2 served as the peroxidase substrate. Cells were then post-fixed in 2% OSO4 and embedded through alcchols into Epon. in sane cases, cell fractions were also treated.
A Chlamydial-Like Organism Isolated from Insects in Insect Mass Rearing Facilities
Authors: Adams J. R. , Beegle C. C. , Tompkins G. J.
Published: June 2020

In examinations of larvae of cabbage looper, Trichoplusia ni, and cotton bollworm, Heliothis virescens, collected in an outbreak of disease in the Brownsville insect mass rearing facilities, one of the pathogens isolated was a chlamydial-like organism (CLO). This organism is infectious per os. Infected larvae are stunted, develop a tan coloration and finally become brown cadavers. One day old larvae inoculated with CLO became severely stunted and failed to reach pupation.
Cell Surface Properties of a Suctorian Ciliate
Authors: Sundermann Christine A.
Published: June 2020

Discophrya collini, a suctorian ciliate, subsists on live prey (i.e. Tetrahymena) which is captured and ingested through tentacles. The tentacles are characterized by a swelling or knob at the distal ends which contain extrusive organelles termed haptocysts that assist in prey capture and/or attachment. Prey selection is rather specific, only certain ciliated species are recognized as food. Other ciliates, flagellates, and Discophrya's own ciliated larvae for instance, can make contact with tentacles and remain unharmed. This study was undertaken to investigate and compare Discophrya's surface topography associated with the following: a) cell body, b) tentacle shaft, and c) tentacle knob. Cell surface properties have been characterized in numerous animal cell types but discovery of marked variation in different regions of a particular cell has been infrequent.
Quantification of Silica Uptake by Alveolar Macrophages - An Emperical Scanning Electron Microprobe Method
Authors: Damiano V. V. , Daniele R. P. , Tucker H. T. , Dauber J. H.
Published: June 2020

An important example of intracellular particles is encountered in silicosis where alveolar macrophages ingest inspired silica particles. The quantitation of the silica uptake by these cells may be a potentially useful method for monitoring silica exposure. Accurate quantitative analysis of ingested silica by phagocytic cells is difficult because the particles are frequently small, irregularly shaped and cannot be visualized within the cells. Semiquantitative methods which make use of particles of known size, shape and composition as calibration standards may be the most direct and simplest approach to undertake. The present paper describes an empirical method in which glass microspheres were used as a model to show how the ratio of the silicon Kα peak X-ray intensity from the microspheres to that of a bulk sample of the same composition correlated to the mass of the microsphere contained within the cell. Irregular shaped silica particles were also analyzed and a calibration curve was generated from these data.
The Influence of Inflation Level on the Ultrastructure of Pleura
Authors: O'Sullivan Michael F. , Corn Carolyn , Dodson Ronald F. , Hurst George A.
Published: June 2020

The pleura is a membranous coating which lines the pleural cavity. An extension of this lining forms a closely apposed continuous sheath from the apex to the base of the lungs and constitutes the visceral pleura.

While certain pathological changes such as thickening, rare-asbestos related tumors (mesotheliomas), and other pathomorphological features are recognized with regard to pleural response, a comparison of pleura from inflated and deflated lungs has not been described. These features must be established if the true early pathological responses are to be differentiated from artificially induced changes.
Frozen-Hydrated Lung Preparation for Low Temperature Scanning Electron Microscopy
Authors: Hook Gregory , Bastacky Jacob , Hayes Thomas , Conhaim Robert , Staub Norman
Published: June 2020

Conventional lung preparatory methods for electron microscopy utilizing chemical fixation, dehydration, embedding and/or drying have been critical for understanding alveolar structure. However, these procedures cause the removal of all fluids, alteration of dimensions, and distortion of sp. tial relationships and therefore limit the information that can be obtained. Freeze fracture replica techniques, on the other hand, have provided information on frozen hydrated alveolar structures, but replica procedures require removal of all tissue and cannot preserve the convoluted topography of entire inflated alveoli. Described here is an alternative lung preservation method for use in freeze-fracture, low temperature scanning electron microscopy (SEM) which preserves alveoli in the frozen-hydrated state and permits direct observation of entire inflated alveoli.
Energy Loss Imaging in Biology
Authors: Shuman H. , Somlyo A.V. , Somlyo A.P. , Frey T. , Safer D.
Published: June 2020

It has been recognized for sometime that electron energy loss spectroscopy (EELS) is potentially the most sensitive method of measuring elemental composition in the electron microscope. Magnetic sector spectrometers currently in use collect most of the inelastically scattered electrons, while the cross sections for ionization of the L2 3 levels of the biologically important elements are large. The energies of the theoretically predicted L2 3 absorption edge maxima and their corresponding differential cross section for lOmrad collection and 80keV incident electrons are shown in Table I. The characteristic energy loss electron count rate expected from one atom with lOeV spectrometer slit width and lOOA/cm2 (the maximum available from a tungsten hairpin) electron flux at the specimen, indicates that the minimum detectable mass sensitivity of EELS will be high. An experimentally determined count rate and cross section for the Fe M2, 3 edge was determined from the ferritin images shown in Fig. 1.
Atomic Structure at Single-Crystal Metal-Semiconductor Interfaces and Misfit Dislocations
Authors: Gibson J.M.
Published: June 2020

However you look at it, you cannot ignore the migration of solid-state physicists from the bulk to surfaces and interfaces. This intellectual “boundary-segregation” is partly a testimony to the success of solid-state physics in relating the properties of matter to atomic and electronic structure. There is nevertheless a more altruistic reason: the physical importance of surfaces and interfaces far exceeds the relative weight of the number of atoms at or near them. It hardly needs saying that a world without interfaces would be a pretty monotonous place.
The Thickness Dependence of Energy Loss Spectra
Authors: Sarikaya M. , Rez P.
Published: June 2020

One factor limiting energy loss analysis is the effect of multiple scattering on core loss edge shapes. Multiple scattering distorts fine structures, leads to incorrect quantitative analyses and even affects analysis of extended fine structure (EXELFS). Two procedures for extracting the single scattering spectrum from a spectrum showing the effects of multiple scattering have been proposed. Johnson and Spence derive the single scattering profile by taking the logarithm of the fourier transformed spectrum. If all scattering angles are accepted by the spectrometer this is an exact procedure. Leapman and Swyt have had some success assuming that multiple scattering imposes low loss structure on the high loss part of the spectrum. It is of interest to know how stable these procedures are with thickness and whether the logarithmic deconvolution can be used in thicker specimens than the method described by Leapman and Swyt.
Eels Under Standing Wave Conditions
Authors: Krivanek O.L. , TaftØ J.
Published: June 2020

It is well known that a standing electron wavefield can be set up in a crystal such that its intensity peaks at the atomic sites or between the sites or in the case of more complex crystal, at one or another type of a site. The effect is usually referred to as channelling but this term is not entirely appropriate; by analogy with the more established particle channelling, electrons would have to be described as channelling either through the channels or through the channel walls, depending on the diffraction conditions.
Alternative Background Fitting for Electron Energy Loss Spectra
Authors: Bentley J. , Lehman G. L. , Sklad P. S.
Published: June 2020

Microanalysis using inner shell ionization edges in electron energy loss spectra obtained in an analytical electron microscope is now well established. In order to assess true edge profiles and obtain integrated intensities of the inner shell ionization edges of interest, it is first necessary to subtract the background. The background arises from the tails of preceding ionization edges, multiple plasmon excitations and valence electron excitations.
Application of QUantitative Eels to Analysis of the Titanium Carbide Phase in Austenitic Stainless Steels
Authors: Maziasz P. J. , Zaluzec N. J.
Published: June 2020

The intent of this work is to study the light element (C,N,O) contents, particularly C, of individual particles of the titanium MC carbide phase. Analytical electron microscopy (AEM) studies can employ either electron energy loss spectroscopy (EELS) or x-ray energy dispersive spectroscopy (XEDS) with ultra-thin window detectors to detect these elements, but we will show that because MC contains substantial Mo and C, the former method is best. The alloy studied is, in wt %, a 14 Cr/16 Ni/0.25 Ti modification of normal type 316 austenitic stainless steel. This alloy is the first generation Prime Candidate Alloy (PCA) of its alloy class for the Alloy Development for Irradiation Performance (ADIP) task of the Magnetic Fusion Energy (MFE) program, and the microstructure studied was designed for scoping the resistance of this material to fusion irradiation. The key to this application is stability of the MC phase, and composition is very important to stability. However, such studies cannot be undertaken without the advanced techniques and equipment development of EELS and we will focus on the interfacing of the latter with the metallurgical system studied.
Analytical Electron Microscopy Applied to the Study of the Solid State Reaction Between Si-Base Ceramics and Ni-Base Superalloys
Authors: Hall E. L. , Kouh Y. M.
Published: June 2020

There is at present great interest in the use of silicon-base structural ceramics as components in hot machinery such as gas turbines, where the ceramic will be in intimate contact with metal parts under conditions where chemical reactions may occur which will severely degrade the properties of both the metal and ceramic. The present investigation was initiated to systematically study the kinetics and reaction products of the interaction between siliconbase ceramics and nickel-base superalloys. This paper reports the results of the reaction of SiC with a metal consisting of 75.8 w/o Ni, 19.2 w/o Cr, and 5.0 w/o A1 at 1100° C for 100 hours. This metal composition was chosen to model the behavior of a superalloy without introducing complexities caused by additional alloying elements.
Microstructures of Oxidized Si3N4-8%Y2O3
Authors: Kuroda K. , Liu H. C. , Heuer A. H. , Mitchell T. E.
Published: June 2020

Introduction. There is considerable interest in the effect of oxidation on the microstructure of yttria-doped silicon nitride, since some compositions are unstable at low temperatures (=1000°C) despite their apparent stability at 1400°C (1). The material used in this study was the same commercial hotpressed Si3N4-8%Y2O3 (NCX-34) as one investigated previously, which had exhibited only passive oxidation during heating in air from 600° to 1400°C. Some thin (=100μm) specimens were oxidized at 800°, 1000° and 1450°C in ambient air and then ion-thinned from one side; others were ion-milled and oxidized. Specimens were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) along with energy dispersive x-ray (EDX) analysis.
Microstructural Damage Evolution in "Triple-Beam" Ion-Irradiated Fe-10% Cr*
Authors: Horton L. L. , Bentley J.
Published: June 2020

The evolution of the damage microstructures which result from fusion environment irradiation of Fe— 10% Cr has been characterized with transmission electron microscopy (TEM). Disk specimens (3 mm diameter) were bombarded at 850 K in the ORNL dual Van de Graaff accelerator system with a “triple beam” of He+, D+, and 4 MeV Fe++ to fluences of 0.3, 1, 3, 10, 30 and 100 dpa with 10 at. ppm He/dpa and 41 at. ppm D/dpa. The specimens were prepared for TEM using standard electrolytic “sectioning” and “back-thinning” techniques with a sectioning depth of 0.9 μm. TEM examination was performed at 120 kV in a JEM 120C equipped with a special objective lens pole-piece (AMG) for the observation of magnetic materials.
The Temperature Dependence of Void Formation in Glass
Authors: DeNatale J. F.
Published: June 2020

The stability of glasses under irradiation are important to the evaluation of their properties in such diverse applications as nuclear and waste storage and optical wave guides and it is apparent that in the study of these materials by electron microscopy they must often be regarded as being "beam sensitive".
Variations in Grain Boundary Segregation for Al-8 Mg
Authors: Malis T. , Chaturvedi M. C.
Published: June 2020

Ottawa, Ontario, Canada. KlA 0G1 Winnipeg, Manitoba, Canada. R3T 2N2 Energy dispersive X-ray analysis (EDS) has been used in conjunction with STEM microscopy to characterize interfacial segregation. Segregation via solute-vacancy pair migration to grain boundaries has been proposed to influence the hydrogen embrittlement, or stress corrosion cracking, of Al-Zn-Mg alloys. In addition, it has been seen that substantial variations exist in the distribution of boundary precipitates in such alloys. Thus, there is a need for more rigorous characterization of boundary segregation than the normal approach of obtaining elemental profiles across boundaries. Accordingly, specimens of A1 8-wt% Mg were water-quenched from 350°C, aged at room temperature, and EDS profiles were obtained along suitable boundaries from thin foils of both conditions. The traces were in the form of 10-15 point analyses (nominal beam diameter of 20 nm) spaced at 100 nm intervals along the boundary.
Electron Microscopy of Bimetallic Catalysts under Controlled Atmosphere
Authors: Baker R. T. K. , Sherwood R. D. , Dumesic J. A.
Published: June 2020

Over recent years there has been considerable interest in the behavior of supported bimetallic systems. They exhibit unusual product selectivity patterns and have a high tolerance toward carbon deposition, features which make them very attractive as catalysts for a variety of hydrocarbon conversion processes. One of the most intriguing problems related to bimetallic catalysts is the question of what is the composition of the surface during exposure to a reactant gas. A number of workers have attempted to solve this issue by the use of sophisticated surface chemical tools, however, many of these approaches suffer from a common limitation, namely, that specimens can only be examined in a post-reaction state and under high vacuum conditions. These drawbacks are readily overcome by controlled atmosphere electron microscopy (CAEM), where it is possible to continuously observe the appearance of a specimen while it is undergoing reaction.
On the Lubrication Mechanism of SbSbS4
Authors: Harris J. S. , Ives L.K. , Peterson M. B.
Published: June 2020

Recent investigations have shown that SbSbS4 is a promising solid lubricant. It exhibits outstanding extreme pressure (EP) performance, and good antiwear behavior under laboratory test conditions. An investigation was undertaken to identify the mechanism by which SbSbS4 functioned when used as a lubricant in the dry powder form and as an additive to oils and greases. Friction and wear behavior of SbSbS^ was investigated using several different wear tests carried out in air at temperatures ranging from 20°C to 500°C.
Defect Structure of Fe1-x0
Authors: Lebreton C. , Hobbs L. W.
Published: June 2020

Short-range and long-range ordering of defects in wüstite (Fe1-xO) have been studied using electron diffraction and high-resolution structure imaging in TEM. Single crystals of high purity were grown by a floating zone technique, sectioned and equilibrated in CO/CO2 atmospheres between 1175 K and 1625 K to obtain a series of compositions across the wüstite phase field from Fe0.9 5O (Fe/FeO phase boundary) to Fe0.8 7O (Fe/Fe3O4, phase boundary). Equilibrated specimens were quenched, in some cases subsequently annealed between 475 K and 575 K, and reduced to electron transparency by mechanical polishing and ion-beam thinning.
Observation of a Central Subunit in Annelid Extracellular Hemoglobins using the Stem Digital Image Processing Techniques
Authors: Ohtsuki M. , Crewe A. V.
Published: June 2020

Extracellular hemoglobins of annelids consist of 12 subunits with appearance of superposed hexagons. So far, electron microscopy using negative staining techniques indicated that only the hemoglobins of Nephtys and Oenone contain an additional central subunit.
Ion Beam Induced Phase Transitions in Nickel and Cobalt thin Films on Silicon
Authors: Chen L.J. , Chang T.T. , Hou C.Y. , Mayer J.W.
Published: June 2020

Ion implantation metallurgy has received increasing attention because of its important applications in the modification of surface composition and structure of materials. Relatively low dose ion beam material modification can be achieved by ion-beam induced atomic mixing between thin film and its substrate. Ion beam mixing of metal thin films on silicon is by far the most widely studied system for its potential applications in VLSI technology. In this paper, we report the results of ion beam induced phase transitions in nickel and cobalt thin films on silicon.