bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copper Localization in Cirrhotic Rat Liver by Scanning Electron Microscopy
Authors: Russ J. C. , McNatt E. 
Published: June 2020

In order to study the retention of copper in cirrhotic liver, rats were made cirrhotic by carbon tetrachloride inhalation twice weekly for three months and fed 0.2% copper acetate ad libidum in drinking water for one month. The liver tissue was fixed in osmium, sectioned approximately 2000 Å thick, and stained with lead citrate. The section was examined in a scanning electron microscope (JEOLCO JSM-2) in the transmission electron mode.Figure 1 shows a typical area that includes a red blood cell in a sinusoid, a disse, and a portion of the cytoplasm of a hepatocyte which contains several mitochondria, peribiliary dense bodies, glycogen granules, and endoplasmic reticulum.
Lattice Defects in the Li2 Superlattice
Authors: Kear B. H. 
Published: June 2020

At the AB3 composition, four families of phases exist that can be classified according to various stacking schemes of identical close-packed octahedral planes. These are listed in Table I. The noteworthy feature of all four stacking variants is that each A atom is surrounded by 12 nearest neighbor B atoms.1. Stacking FaultsStacking faults in the fee (Li2) superlattice are of three basic types - superlattice intrinsic (or extrinsic) faults, antiphase boundary faults, and complex faults.
An Ultrahigh-Vacuum Specimen Chamber for In-Situ Electron Microscopy of Vapor Deposition Processes
Authors: Moorhead R. Dale , Poppa Helmut 
Published: June 2020

The electron microscope has often been used in the past to study in-situ the details of thin film nucleation and growth processes. However, a lack of adequate control of important experimental deposition parameters, such as substrate cleanliness, residual gas pressure and composition, and super-saturation ratio, has limited the usefulness of the technique and in most cases prevented the acquisition of reliable quantitative results.Accordingly, a new specimen chamber for use on a RCA EMU-4 instrument was built that regularly reaches base pressures of 3x10-10 torr, maintains pressures of less than 5x10-9 torr during the vapor deposition phase, and affords accurate control of the other deposition parameters.
Aldehyde Fixation and Fine Structural Localization of Alkaline Phosphatase Activity in Intestinal Epithelial Cells
Authors: Makita T. , Sandborn E.B. 
Published: June 2020

A high level of enzymatic activity can be retained in tissues which have been fixed for very brief periods of time (5 to 10 minutes) by perfusion in aldehyde-DMSO solutions. Following the combination of short fixation time and the lead citrate method for alkaline phosphatase, membranes in the normal rat duodenum were studied.Tissues fixed in glutaraldehyde (4%), paraformaldehyde (4%), and a mixture of the two fixatives all containing 5% DMSO and 5% sucrose in a 0.1M cacodylate buffer were compared.
Electron Microscopy of Clam Myocardium Under Normal and Experimental Conditions
Authors: Sitzenstock Nan E. , Baxter William D. 
Published: June 2020

The effect of 2,4-dinitronhenol (DNP) on the fine structure of the myocardium of several vertebrates has been reported by DiDio. We have studied the effects of DNP and lowered oxygen tension on the myocardium of a fresh water clam, an invertebrate.The clam, Amblema plicata (Say, 1817), was used in this investigation. All specimens were maintained in stream water saturated with oxygen unless otherwise noted. Control and experimental animals were opened and the still-beating heart fixed in cold, buffered 1.2% osmium tetroxide. Small blocks of ventricle were dehydrated through an ethanol series, equilibrated in propylene oxide, and embedded in Araldite.
Cytoplasmic Tubules in Cells Infected with Laryngotracheitis Virus
Authors: Watrach A. M. 
Published: June 2020

During a study of the development of infectious laryngotracheitis (LT) virus in tissue culture cells, unusual tubular formations were found in the cytoplasm of a small proportion of the affected cells. It is the purpose of this report to describe the morphologic characteristics of the tubules and to discuss their possible association with the development of virus.The source and maintenance of the strain of LT virus have been described. Prior to this study, the virus was passed several times in chicken embryo kidney (CEK) tissue culture cells.
A Superconducting Microscope
Authors: Worsham R. E. , Mann J. E. , Richardson E. G. 
Published: June 2020

This superconducting microscope, Figure 1, was first operated in May, 1970. The column, which started life as a Siemens Elmiskop I, was modified by removing the objective and intermediate lenses, the specimen chamber, and the complete vacuum system. The large cryostat contains the objective lens and stage. They are attached to the bottom of the 7-liter helium vessel and are surrounded by two vapor-cooled radiation shields.In the initial operational period 5-mm and 2-mm focal length objective lens pole pieces were used giving magnification up to 45000X. Without a stigmator and precision ground pole pieces, a resolution of about 50-100Å was achieved. The boil-off rate of the liquid helium was reduced to 0.2-0.3ℓ/hour after elimination of thermal oscillations in the cryostat. The calculated boil-off was 0.2ℓ/hour. No effect caused by mechanical or electrical instability was found. Both 4.2°K and 1.7-1.9°K operation were routine. Flux pump excitation and control of the lens were quite smooth, simple, and, apparently highly stable. Alignment of the objective lens proved quite awkward, however, with the long-thin epoxy glass posts used for supporting the lens.
A Method of Extending Electron Microscope Filament Life
Authors: Thomas G. F. 
Published: June 2020

One of the problems of electron microscopy is the short life of the electron source, or filament. Exchanging filaments frequently requires realignment and recalibration procedures which are time-consuming.We have developed a simple “tempering” procedure which more than doubled the filament life in our instrument, an RCA EMU-3G electron microscope.Early in the use of our microscope, we noted that during the initial phase of emission of a new filament, a physical dislocation of the filament from its original point of alignment occurred. We also noted that oxidized surface material on the filament decomposed and emitted as contaminants into the gun area. It was felt that if a preliminary heating under well-controlled conditions (gradual increase of electron flow in a clean atmosphere as in a vacuum evaporator) was applied to a filament, there would be a pre-functional reorientation of valence electrons.
Combined Scanning—Transmission and Electron Probe Analysis of the Mammalian Small Intestine
Authors: Tousimis A. J. 
Published: June 2020

The fine structure of the epithelium lining of the small intestine has been extensively studied by transmission electron microscopy of ultrathin sections during the past two decades.Chemical identification of cellular components, visualized by this method, have been limited primarily to the physicochemical identification of isolated fractions. Biochemical reactions carried out on these components are utilized for the indirect localization of macromolecular species such as proteins, carbohydrates, lipids, nucleic acids, nucleoproteins and other. Similarly, ionic species-electrolytes, nucleic acids and other molecular species transported or utilized by and for cellular activity have been “localized” by indirect methods only.Early electron probe microanalyses of biological tissues have been applied in the localization and measurement of structural components of the cell, mineral or inclusion and biological calcification studies. Measurement of organic molecules in situ is possible only on tissue sections that have been specifically reacted with chemicals that can be elementally differentiated from other cellular structures.
Dynamic Observation of Dislocation Movements at Elevated Temperatures Using a Heating and Straining Stage
Authors: Ishida Y. , Moritoh F. 
Published: June 2020

Dynamic observation of dislocation movements is a direct means of examining proposed deformation mechanisms. Room temperature deformations have been observed dynamically by various authors, but at elevated temperatures no observation has been reported. Various dislocation theories have been proposed on the creep mechanism of metals at elevated temperatures. They disagree to each other even in the basic eharacteristics of the dislocation movements. The dislocation may move either individually or as a group. The motion may be either smooth or intermittent. The dynamic observation is suitable to resolve those basic conflicts.A heating-straining goniometer stage (Fig. 1) was developed for the experiment. It was mounted in a Hitachi 200KV electron microscope. The foil is pasted between A areas and heated indirectly by a furnace B through a stainless steel tube C. A rapid drying paste Aron α was used in the present experiment. The tube C surrounds the top of the specimen holder.
The Operative Glide Systems in β-NiAl During High Temperature Deformations
Authors: Rowe G. M. , Ingram J. , Strutt P. R. 
Published: June 2020

The mechanical properties of β-NiAl, and its operative glide systems have been of interest in recent years (1-4). Strutt, Dodd, & Rowe summarize some of the main findings in a continuation of this work.The operative glide systems in β-NiAl single crystals were obtained by combined surface slip line observations with the scanning electron microscope, and dislocation diffraction contrast studies using transmission electron microscopy. A method was developed to obtain simulated pictures of dislocations using the two-beam dynamical equations, and considering the effect of elastic anisotropy. The method gave results that are in perfect agreement with those obtained by Head. Since the electron beam was not assumed to be normal to the foil surface the method is more general than that described by Head. However, it is important to note that with the degree of elastic anisotropy in β-NiAl (AF = 3.28) the Burgers vectors of dislocations can be determined with certainty without this procedure providing that a sufficient number of two-beam conditions are employed. This was accomplished with the Philips 300 microscope using the 360° rotation with ±45° tilt goniometer stage.
Electron Metallography of Structures in Crystal Boundaries of Tungsten Wire
Authors: Tufts Charles F. 
Published: June 2020

Tungsten lamp wires (0.010 inch diameter) doped with compounds of Al, K and Si to control grain growth at elevated temperatures were studied in “as drawn” and “furnace-annealed” conditions using replication electron microscopy (REM) and transmission electron diffraction contrast microscopy (TEDCM) assisted by selected area electron diffraction (SAED). In addition, thin sections of wire were heated in the goniometer stage of the Philips EM300 electron microscope using a holder that heated the specimen over a temperature range of 20°–1000°C. Rate of increase for specimen temperature was approximately 100°C per minute. Data were obtained by TEDCM and SAED. Purpose of the work was to relate particulate material found in “as drawn” wire to porosity and inclusions distinguishable after elevated-temperature treatment.Furnace annealing was in vacuum (10-6 torr) at 700°C (30 minutes) or 1500°C (10 minutes or one hour). REM with two-stage Parlodion-carbon replicas was used to observe longitudinal and cross-sectional views of etched specimens.
Recent Studies of the Fine Structure of Carbon Blacks
Authors: Marsh Peter A. , Mullens Troy J. , Price L. D. 
Published: June 2020

The paracrystalline nature of the fine structure of carbon blacks was first shown in high resolution phase contrast micrographs by Hess and Ban. These authors described the continuous network of distorted graphite layers within the carbon particles. Measurements of the spacings between these layers has been the subject of our recent work.The results show that the interplanar spacings have a distribution of sizes in all carbon blacks; for example, the variation in interplanar spacings in furnace blacks ranged from approximately 345 pm (picometers) to 450 pm. In addition, the spacing distribution is independent of both the size of the carbon particles or the degree of interparticle fusion.Carbon blacks made by the Oil Furnace Process and the Channel Process have the same fine structure, and the distribution of their spacings follows a log-normal distribution pattern. The average spacing for these carbons is 386 ±6 pm. The value obtained by X-ray diffraction methods, approximately 355 pm, is lower because the data is restricted solely to parallel planes.
Use of Digital Voltmeter for Selected Area Diffraction Calibration
Authors: Grieger G. R. 
Published: June 2020

In the interpretation of selected area electron diffraction patterns, the crystal interplanar spacing value d is generally obtained from the formula(1)where D is the measured diameter of the diffraction photograph and F is an instrument factor. The value of F is defined as(2)where λ is the deBroglie wavelength of the high voltage electron and Le is the effective length of the diffraction camera. The error is d then is(3)The error in λ for most modern instruments is quite small, 0.01% or less. The diameter of the ring D can, in general, be read to 0.1 mm which for most patterns is about 0.1%-0.2%. The major source of error in disdue to error in F in general and Le in particular.
The Structures of Adherent and Nonadherent Al2O3 Scales on Fe-25Cr-4Al Alloys
Authors: Tien J. K. , Pettit F. S. 
Published: June 2020

It is well documented that the adherence of protective oxide scales to alloy substrates is significantly improved by small alloy additions of such less-common elements as yttrium. This important effect is little understood, however. The lack of structural data is believed to be the major reason for this lack of understanding. Accordingly, we are determining the oxide scale and substrate morphologies of model oxidation resistant alloys. In what follows, we present and discuss the structural details of the nonadherent Al2O3 scale on Fe-25Cr-4Al (wt pct) and the adherent Al2O3 scale on the same alloy with about 0.1 wt pet yttrium or scandium.The Al2O3 scales are developed by oxidizing these alloys in air at 1200°C. Upon cooling, the nonadherent scale spalls-off as a result of thermal stresses and is immediately ready for examination. The adherent oxide scales had to be extracted by the preferential dissolution of the alloy substrates in a bromine-methanol solution, which does not in any way affect the structure of Al2O3. The scales are then examined by scanning and replication electron microscopy. Figures 1, 2 and 3 are the top (gas surface), side and bottom views of these Al2O3 scales, respectively.
Thoria Particle Growth in Ni-2%ThO2by a Sintering Mechanism
Authors: Kimmel E. R. , Scheithauer W. 
Published: June 2020

Good high-temperature mechanical properties exhibited by oxide-dispersion-strengthened metals are strongly dependent on the presence of a cold worked microstructure which is thermally stabilized by fine oxide particles uniformly distributed in the metal matrix. Microstructural features of this nature are produced by subjecting the material to thermal mechanical processing. Such processing has a two-fold purpose—to improve the spatial distribution and to control the size of the dispersion.The typical state of the dispersion in the hot consolidated P-M plate can best be described as one of fine particles which tend to be highly agglomerated, i.e. a poor spatial distribution. By properly controlling deformation and annealing conditions during thermal mechanical processing of plate to sheet, one can greatly improve the spatial distribution and control the size of the oxide particles. If agglomerates consist of fine particles only in close physical arrangement, deformation will disperse them and thus improve the total spatial distribution.
An Electron Microscopic Study of an Avian Reovirus that Causes Arthritis
Authors: Walker E, R. , Olson N. O. , Friedman M. H. 
Published: June 2020

An unidentified virus, responsible for an arthritic-like condition in chickens was studied by electron microscopy and other methods of viral investigation. It was characterized in chorio-allantoic membrane (CAM) lesions of embryonating chicken eggs and in tissue culture as to: 1) particle size; 2) structure; 3) mode of replication in the cell; and 4) nucleic acid type.The inoculated virus, coated and uncoated, is first seen in lysosomal-like inclusions near the nucleus; the virions appear to be uncoated in these electron dense inclusions (Figure 1), Although transfer of the viral genome from these inclusions is not observable, replicating virus and mature virus crystals are seen in the cytoplasm subsequent to the uncoating of the virions.The crystals are formed in association with a mass of fibrils 50 to 80 angstroms in diameter and a ribosome-studded structure that appears to be granular endoplasmic reticulum adapted to virus replication (Figure 2). The mature virion (Figure 3) is an icosahedral particle approximately 75 millimicrons in diameter. The inner core is 45 millimicrons, the outer coat 15 millimicrons, and the virion has no envelope.
The Reaction of Brain Structures with OsO4-Zinc-Iodide Stain
Authors: Niklowitz Werner J. 
Published: June 2020

After intoxication of rabbits with certain substances such as convulsant agents (3-acetylpyridine), centrally acting drugs (reserpine), or toxic metal compounds (tetraethyl lead) a significant observation by phase microscope is the loss of contrast of the hippocampal mossy fiber layer. It has been suggested that this alteration, as well as changes seen with the electron microscope in the hippocampal mossy fiber boutons, may be related to a loss of neurotransmitters. The purpose of these experiments was to apply the OsO4-zinc-iodide staining technique to the study of these structural changes since it has been suggested that OsO4-zinc-iodide stain reacts with neurotransmitters (acetylcholine, catecholamines).Domestic New Zealand rabbits (2.5 to 3 kg) were used. Hippocampal tissue was removed from normal and experimental animals treated with 3-acetylpyridine (antimetabolite of nicotinamide), reserpine (anti- hypertensive/tranquilizer), or iproniazid (antidepressant/monamine oxidase inhibitor). After fixation in glutaraldehyde hippocampal tissue was treated with OsO4-zinc-iodide stain and further processed for phase and electron microscope studies.
Ultrastructurc of Subcutaneous Adipose Tissue in Human Neonates
Authors: Alzamora D. , Pardo V. , Monkus E. , Novak M. 
Published: June 2020

In vitro studies on the metabolic characteristics of white subcutaneous adipose tissue obtained from human newborns have shown metabolic differences with those in adults. There is an increase in oxygen consumption, CO2 production from labeled glucose, and increased incorporation of palmitic acid into triglycerides. Glycogen content was high in 2 to 4 hours old neonates.In order to compare the structure of neonate and adult fat, needle biopsies of gluteal subcutaneous adipose tissue were performed in 15 newborns ranging in age from 2 hours to 5 days, and in 4 adults. Tissue fragments and fat cells isolated by collagenase digestion were fixed in 4% osmium tetroxide and 3.5% glutaraldehyde followed by osmium tetroxide in phosphate buffer and embedded in Epon 812.
Alterations of Gap Junctions in a Human Breast Carcinoma
Authors: Dermer Gerald B. , Kern William H. 
Published: June 2020

The cells of solid tumors lack adhesiveness and many cancerous cell types lack intercellular communication. These functional derangements of cell-to-cell interactions in tumor cells may have a structural basis in recent observations that showed a lack or reduction in tight and gap junctions (nexus junctions) in several solid tumors. In an attempt to confirm these findings, gap junctions between human breast carcinoma cells were analyzed and compared to normal breast epithelium by using lanthanum hydroxide as a tracer of intercellular spaces.Portions of a biopsy from normal breast and a tumor bearing area of a resected breast obtained at the time of surgery were prefixed for 3 hours in a 2.0% glutaraldehyde solution in 0.2M cacodylate buffer containing 1.0% lanthanum nitrate brought to a pH of 7.7 with 0.1N NaOH. The pieces were washed for an additional 24 hours in 0.2M cacodylate buffer containing 1.0% lanthanum nitrate (pH 7.7), postfixed for 1 hour in 1.0% cacodylate buffered OsO4 also containing 1.0% lanthanum nitrate, dehydrated rapidly in graded acetones and embedded in vestopal W.
A Protozoan Model for Golgi-Associated Calcification
Authors: Williams D. C. , Outka D. E. 
Published: June 2020

Many studies have shown that the Golgi apparatus is involved in a variety of synthetic activities, and probably no Golgi product is more elaborate than the scales produced by various kinds of phytoflagellates. The formation of calcified scales (coccoliths, Fig. 1,2) of the coccolithophorid phytoflagellates provides a particularly interesting model system for the study of biological mineralization, and the sequential formation of Golgi products.The coccoliths of Hymenomonas carterae consist of a scale-like base (Fig. 2 and 4, b) with a highly structured calcified (CaCO3) rim composed of two distinct elements which alternate about the base periphery (Fig. 1 and 3, A, B). Each element is enveloped by a sheath-like organic matrix (Fig. 3; Fig. 4, m).
Development of a Multilaminate Core in Microbodies of Euglena gracilis Var. Bacillaris (SM-LI)
Authors: Hanzely L. , Graves L. B. , Molsen D. 
Published: June 2020

Ultrastructural surveys have established the microbody as an ubiquitous organelle among the eukaryotes. Examination of Euglena cells, grown on acetate and ethanol and fixed simultaneously with glutaraldehyde-osmium tetroxide, revealed the presence of microbodies morphologically similar to those of other organisms. Moreover, it was shown that these organelles of Euglena possess a multilaminate core or nucleoid apparently not present in other microbodies. The present report concerns these cores and deals specifically with their development.Microbodies are recognized as organelles bounded by a single membrane, measuring about 0.4 to 0.8 µ in diameter and possessing an electron-dense granular matrix which is distributed evenly throughout the entire organelle (Fig. 1). Often these organelles also show a close association with a single cisterna of the endoplasmic reticulum (Figs. 1, 4, arrows).
Intake of Ferritin byArmillaria melleaHyphae
Authors: Bal Arya K. , Singh Pritam 
Published: June 2020

Our earlier study on the fine structure of young hyphae ofArmillaria mellearevealed the presence of numerous invaginations of the plasma-membrane - the so called lomasomes. Functions of these plasma-membrane modifications still remain ambiguous although suggestions have been made as to their involvement in nutrient absorption. With a view to clarifying this functional aspect, ferritin was employed as a marker to trace its path of intake into the hyphal cells.The fungus was isolated from mycelial fans present under the bark of infected roots ofPicea glauca(Moench). Voss and maintained on 2% Malt agar. Periferal hyphae from 19 days old culture ofA. melleawere exposed to 0.1 ml of a 0.5% aqueous ferritin (Pentax, Inc. 104 ug/ml) solution. The solution was injected into the agar containing the peripheral hyphae. Samples of hyphae were fixed 1-5 seconds after exposure and at 30 minutes, 3 hours, 10 hours, and 24 hours. Fixation, embedding and staining was followed according to the method described by Bal and Singh.