bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical Microdiffraction in Lattice Image Analysis
Authors: Gronsky R. , Sinclair R. , Thomas G. 
Published: June 2020

Our applications of lattice imaging to the study of phase transformations in alloys have recently incorporated laser optical techniques to improve microdiffraction capabilities by three orders of magnitude over that attainable in conventional transmission electron microscopy (1). The method is based on optical diffraction from lattice image negatives which have been taken under optimum conditions dictated by computed image simulation. In this paper we present the optical microdiffraction data of two experiments to illustrate the role of this technique in metallurgical analysis.1)Recent observations (2) in Mg3 Cd have revealed the occurrence in thin foils of a structural transition: hexagonal DO19 →orthorhombic B19. In orientations where the Mg3Cd basal plane is parallel to the foil surface, selected area diffraction (S.A.D.) analysis fails to distinguish these phases.
Low-Loss Images in a Stem/Tem Microscope
Authors: Joy David C. , Maher Dennis M. 
Published: June 2020

High-resolution images of the surface topography of solid specimens can be obtained using the low-loss technique of Wells. If the specimen is placed inside a lens of the condenser/objective type, then it has been shown that the lens itself can be used to collect and filter the low-loss electrons. Since the probeforming lenses in TEM instruments fitted with scanning attachments are of this type, low-loss imaging should be possible.High-resolution, low-loss images have been obtained in a JEOL JEM 100B fitted with a scanning attachment and a thermal, fieldemission gun. No modifications were made to the instrument, but a wedge-shaped, specimen holder was made to fit the side-entry, goniometer stage. Thus the specimen is oriented initially at a glancing angle of about 30° to the beam direction. The instrument is set up in the conventional manner for STEM operation with all the lenses, including the projector, excited.
Linear Defects Generated by Inclusion of Hydrogen in Nickel Electrodeposit
Authors: Nakahara S. 
Published: June 2020

During the course of structural characterization of nickel electrodeposit, we have found that there are a large number of linear defects which are different from dislocations. This communication reports a detailed analysis of these defects using transmission electron microscopy.Nickel film was prepared by electrodeposition from a bath containing 0.43 M NiSO4-6H2O and 0.5 M H3BO3. The pH of the bath was adjusted to 1.5. A sheet of annealed OFHC copper was used as the substrate. All the platings were carried out at 30°C.Nickel film plated at a current density of 5 MA/cm2 contained these linear Refects. Figures l(a), (b), and (c) show micrographs of the film taken with g = 200, 220, and 131, respectively. The images of the defects are indicated by four fine arrows in Fig. 1(c). They were not easily discernible with low-order g's such as 111, 200, and 220 (see Figs. 1(a) and (b)).
Fine Structural Evaluation of Bone Cells in Thyroparathyroidectomized Rats Receiving Vitamin
Authors: Weisbrode S. E. , Capen C. C. 
Published: June 2020

Although small amounts of vitamin D are necessary for the hypercalcemic effects of parathyroid hormone, vitamin D in sufficient amounts can induce bone resorption in parathyroidectornized animals. The objective of this investigation was to evaluate the response of bone in mature thyroparathyroidectomized (TXPTX) rats to feeding low calcium diets containing no vitamin D (group 1), normal (group 2) and pharmacologic doses (group 3) of vitamin D for 7 days. These findings were correlated with changes in serum calcium (Ca) and phosphorus (P), urinary hydroxyprol ine:creatinine (HOP:CR) excretion, and bone calcium-dependent adenosinetriphosphatase (Ca-ATPase) quantitation and ultrastructural localization.Pharmacologic doses of vitamin D caused a significant rise in serum Ca (10.22 ± 0.33 mg/100 ml) and urinary HOP:CR (0.31 ± 0.02) and a fall in serum P (12.14 ± 0.65 mg/100 ml) compared to rats in group 1.
Stabilization of Unfixed Tissue with Glycol for the Cytochemical Demonstration of Labile Enzymes
Authors: Slezák Ján , Pease Daniel C. 
Published: June 2020

Ultrastructure generally suffers severely whenever fresh tissue has to be used for cytochemical localizations. Experience with "inert dehydration" with glycol as developed by Pease, indicated that significant morphological stabilization could be achieved without fixation even though considerable water remained in the system. Presumably, also, enzymatic denaturation might be avoided. Therefore, we have tried to explore these advantages in a series of pilot experiments.Succinic dehydrogenase is a chemically labile enzyme which can be demonstrated by a Cu-ferricyanide reaction developed by Kerpel-Fronius and Hajos. Its enzymatic activity proved to be compatible with substantial amounts of glycol. The best compromise between reactivity and the preservation of fine structure was obtained with the following protocol, beginning with placing fresh slabs of rat heart muscle into the standard incubation medium to which 10% glycol had been added.
In vivo Acid Phosphatase Activity of Entamoeba histolytica
Authors: Lushbaugh W. B. , Pence D. B. , Deas J. E. , Miller J. H. 
Published: June 2020

The histochemical localization of phosphohydrolase activity in Entamoeba histolytica in light microscopic studies has been conflicting and inconclusive. Maegraith et al. suggested that the “digestive mucosa” of E. histolytica might be associated with the secretion of enzymes across the cell membrane for extracellular digestion. Eaton et al. have suggested the presence of a surface active lysosome with a trigger mechanism on the basis of EM studies on amebae in tissue culture. The present study involves the demonstration of acid hydrolases in vivo.Caecal ulcerations produced in guinea pigs by the inoculation of polyxenically reared amebae (J-22) were excised, glutaraldehyde fixed, embedded in liquid agar, sectioned at 50 micra and incubated for hydrolase activity.
Electron Microscopy of RNA Released from Chikungunya Virus Varions and DNA of Chlamydia Psittaci
Authors: Higashi N. , Matsumoto A. , Nagatomo Y. 
Published: June 2020

Electron microscopy of Chikungunya virus RNA: The molecular weight of the nucleic acid of animal RNA viruses such as poliovirus(N. Granboulan and M.Girard, 1969), myxovirus(L. Kwok-Kwong and J.T.Seto, 1971), murine leukemia virus(T. Kakefuda and J.P.Bader, 1969) and mouse mammary tumour virus(N.H. Sarker and D.H.Moore, 1970) has been successfully estimated in the electron microscope, applying the protein monolayer method developped by Kleinschmidt and his coworkers(l964). However, there has been no electron microscope studies on the molecular weight of RNA of arboviruses.Highly purified preparation of a BaH strain of Chikungunya virus(CHV), a member of group A arbovirus, was obtained from infected VERO cell cultures by the differential centrifugation involving sedimentation through 25% sucrose solution and density gradient centrifugation by the use of potassium tartrate(l7-27%).
The Effect of Deesterification on the Molecular Organization of Pectin
Authors: Leeper George F. , Dull Gerald G. 
Published: June 2020

Negatively stained preparations of high molecular weight pectic acids contain long elementary fibrils about 30A in diameter. Analogous preparations of high ester pectins contain much shorter elementary fibrils of the same diameter.To investigate the relationship between esterification and elementary fibril length, a 0.1% solution of 86% ester pectin was enzymatically deesterified. The extent of deesterification was monitored during the reaction by titration with NaOH. Samples were removed during deesterification, mixed with an equal volume of 2% PTA (pH 7), and the mixture was applied to film covered grids. Length measurements were made from electron micrographs using an optical micrometer.
The Study of Stalk Rot and Causal Organisms via Scanning Electron Microscopy
Authors: Murphy Judith A. 
Published: June 2020

Cooperative SIU Research Includes: A. J. Pappelis, W. E. Schmid, O. Myers, Jr. (Botany); J. N. Bemiller, C. Hinckley (Chemistry); and J. Murphy (Center for Electron Microscopy).Stalk rot of corn is a disease costing millions of dollars annually. Because of the economic importance of this disease, many studies have been undertaken on the nature of resistance to stalk rot, host-parasite interactions, as well as studies of the various pathogens causing stalk rot.In studying the number of mechanisms for stalk rot resistance, A. J. Pappelis discovered a positive correlation between stalk rot susceptibility to Diplodia maydis and the pattern of natural cell death of parenchyma cells in the stalk and a positive correlation between disease resistance and the presence of living cells in that tissue.
Filaments in Fibroblast in Pulmonary Alveolar Wall
Authors: Hung Kuen-Shan , Hertweck M. Sue , Hardy John D. , Loosli Clayton G. 
Published: June 2020

A small number of fibroblasts (alveolar septal cells, pulmonary interstitial cells, mesenchymal cells) are present in the alveolar areas of the adult lungs. These cells, like fibroblasts elsewhere, may be important in production and maintenance of connective tissue fibers found throughout the lung. Very little attention has been given to these cells in studies of the lungs. Therefore their precise structure and function are not clear. This report demonstrates filaments in the fibroblasts in the alveolar ducts and alveolar walls of the mouse lungs.The lungs were inflated with 2% glutaraldehyde, post-fixed with 1% osmium tetroxide and processed for electron microscopy. The cell body and processes of the alveolar fibroblast are located in the interalveolar septum (Fig. I).
Aberrant Type C Virus Production in a Cell Line Derived from Balb/3T3
Authors: Savage N. , Hackett A. 
Published: June 2020

A cell line, UC1-B, which was derived from Balb/3T3 cells, maintains the same morphological characteristics of the non-transformed parental culture, and shows no evidence of spontaneous virus production. Survey by electron microscopy shows that the cell line consists of spindle-shaped cells with no unusual features and no endogenous virus particles.UC1-B cells respond to Moloney leukemia virus (MLV) infection by a change in morphology and growth pattern which is typical of cells transformed by sarcoma virus. Electron microscopy shows that the cells are now variable in shape (rounded, rhomboid, and spindle), and each cell type has some microvilli. Virtually all (90%) of the cells show virus particles developing at the cell surface and within the cytoplasm. Maturing viruses, typical of the oncogenic viruses, are found along with atypical tubular forms in the same cell.
Replication of Internal Biological Surfaces
Authors: Nowell J. A. , Pangborn J. , Tyler W. S. 
Published: June 2020

Leonardo da Vinci in the 16th century, used injection replica techniques to study internal surfaces of the cerebral ventricles. Developments in replicating media have made it possible for modern morphologists to examine injection replicas of lung and kidney with the scanning electron microscope (SEM). Deeply concave surfaces and interrelationships to tubular structures are difficult to examine with the SEM. Injection replicas convert concavities to convexities and tubes to rods, overcoming these difficulties.Batson's plastic was injected into the renal artery of a horse kidney. Latex was injected into the pulmonary artery and cementex in the trachea of a cat. Following polymerization the tissues were removed by digestion in concentrated HCl. Slices of dog kidney were aldehyde fixed by immersion. Rat lung was aldehyde fixed by perfusion via the trachea at 30 cm H2O. Pieces of tissue 10 x 10 x 2 mm were critical point dried using CO2. Selected areas of replicas and tissues were coated with silver and gold and examined with the SEM.
Selection of Mutants with Disorganized Septation and Transformation to L forms of Nocardia Corynebacterioides Nom Nov and N. asteroides
Authors: Serrano J. A. 
Published: June 2020

Morphology of the cell wall and organization of the cytoplasm of Nocardia corynebacterioides nom nov and Nocardia asteroides ATCC 14597, were examined by electron microscopy after the induction of autolysis using 0.012M ammonium carbonate. Organisms were cultured in casaminic acidbroth modified according to Abrams (1955), medium PPLO (Difco) modified according to Sharp (1954), a modified mixture of electrolytes according to Dienes (1956) and a medium based on amino-acids in proportions of 0.05 mg %. In all of these media we used in an alternate or combined form 1.000 U/ml of penicillin or 100 mg/ml of cycloserine (Sigma). After treatment in ammonium carbonate and culture in the media mentioned above, incubated at 37°C, the growth of the colonies on Agar-peptone and Agar-amino-acid presented a smooth surface and alterations of pigmentation.Cultures in solid or liquid media were observed by phase contrast and with a JEM 7-A electron microscope. The cells were negatively stained with sodium silicotungstate pH 7.6 and fixed in 2% osmium according to Ryter and Kellenberger.
Scanning Electron Microscopy of Fish Scales as an Adjunctive Aid in Speciation
Authors: DeLamater Edward D. , Courtenay Walter R. , Whitaker Cecil 
Published: June 2020

Comparative scanning electron microscopy studies of fish scales of different orders, families, genera and species within genera have demonstrated differences which warrant elaboration. These differences in detail appear to be sufficient to act as “fingerprints”, at least, for family differences. To date, the lateral line scales have been primarily studied. These demonstrate differences in the lateral line canals; the pattern of ridging with or without secondary protuberances along the edges; the pattern of spines or their absence on the anterior border of the scales; the presence or absence of single or multiple holes on the ventral and dorsal sides of the lateral line canal covers. The distances between the ridges in the pattern appear likewise to be important.A statement of fish scale structure and a comparison of family and species differences will be presented.The authors wish to thank Dr. Donald Marzalek and Mr. Wallace Charm of the Marine and Atmospheric Laboratory of the University of Miami and Dr. Sheldon Moll and Dr. Richard Turnage of AMR for their exhaustive help in these preliminary studies.
Variation With Voltage of Probe Current in the Scanning Electron Microscope
Authors: Cosslett V. E. 
Published: June 2020

As the operating voltage Vp of a scanning electron microscope is raised, with an electron source of given emission brightness βE, the current delivered into the probe will increase. The extent of the increase will depend on whether it is the Gaussian probe diameter dG or the total probe diameter dT (determined by the lens aberrations) that is kept constant. It will also depend on whether the probe is limited by spherical aberration alone or also by diffraction.If the Gaussian probe diameter is constant the maximum current imax into a diffraction limited probe is found by setting the diameter of the disc of least confusion due to spherical aberration dS equal to the diameter of the Airy diffraction disc dD.
A Field Emission Scanning Electron Microscope Operating in the Secondary Electron Imaging Mode
Authors: Komoda T. , Saito S. , Kakinuma Y. , Okura A. 
Published: June 2020

The authors have built a surface scanning electron microscope incorporating a field emission electron gun. The gun has a brightness almost three order of magnitude higher than that of the ordinary thermionic electron gun, which is promissing high resolution in the secondary electron imaging mode.Emission current fluctuation, which is one of the most serious problems in field emission guns, depends on the vacuum condition around the field emission tip. In order to provide a good vacuum environment, the gun assembly in this microscope is located in the center of an ion-pump system which is symmetrically laid out relative to the electron optical axis. Two tips are mounted on a turret holder and they are exchangeable from the outside without disturbing the vacuum in the gun chamber. A stable emission current of the order of 10μA is obtainable at the normal vacuum operation better than 5x10-10 Torr.
On the High Voltage Electron Microscopy (1 MeV) of Biological Thick Sections
Authors: Massover William H. 
Published: June 2020

Stereoscopic examination of thick sections of fixed and embedded biological tissues by high voltage electron microscopy has been shown to allow direct visualization of three-dimensional fine structure. The present report will consider the occurrence of some new technical problems in specimen preparation and Image interpretation that are not common during lower voltage studies of thin sections.Thick Sectioning and Tissue Coloration - Epon sections of 0.5 μm or more that are cut with glass knives do not have a uniform thickness as Judged by their interference colors; these colors change with time during their flotation on the knife bath, and again when drying onto the specimen support. Quoted thicknesses thus must be considered only as rough estimates unless measured in specific regions by other methods. Chloroform vapors do not always result in good spreading of thick sections; however, they will spread spontaneously to large degrees after resting on the flotation bath for several minutes. Ribbons of thick sections have been almost impossible to obtain.
An Experimental High Voltage Scanning Electron Microscope
Authors: Strojnik Ales 
Published: June 2020

Crewe and coworkers have shown that by using a field emission source and ultrahigh vacuum a high resolving power is attainable in low voltage transmission scanning microscopes. In the present 0.1 - 1.0 MeV instrument an attempt is being made to combine the advantages of the scanning principle with those of high voltages and in particular to explore the use of the fine high energy, monochromatic electron probe for the scanning of specimens held at or close to atmospheric pressure.The instrument is designed as an electron optical bench with its axis horizontal ( Fig.1 ) in order to provide a high degree of experimental flexibility. The column is elastically suspended. It can be removed from and reconnected to the accelerator within minutes. Horizontal construction allows an easy mechanical alignment of optical components and a speedy addition of new ones. Accessibility of mechanical controls is better than in vertical HV columns.
High Voltage Electron Microscopy for Thick Sections of Biological Materials Combined with Molecular Tracers
Authors: Yamada Eichi , Ishikawa Harunori 
Published: June 2020

One of the advantages of high voltage electron microscopy (HVEM) is the great penetration of electron beam, which permits the examination of thicker sections of resin-embedded biological materials. However, when stained thick sections are examined under the HVEM, all structural details within the whole thickness are brought into focus as superimposed image. Hence, certain structures are not easily observable on such an image, even on the stereo view obtained by specimen tilting technique. To overcome this difficulty, molecular tracers are introduced to the HVEM in an attempt to visualize certain structures selectively.Mouse kidney and cardiac muscle were examined using ruthenium red and peroxidase as molecular tracers. Thick Epon sections ranging from 0.5 to 3 μ were observed in a JOEL JEM-1000 or a Hitachi HU-1000 HVEM, with an accelerating voltage of 1000 KV. Pictures were taken routinely as stereo pairs using a tilting stage device with ±10° or ±8°.
Hetero-Epitaxy of Group Va Metals on Sapphire
Authors: O'Neal J. E. , Bellina J. J. , Rath B. B. 
Published: June 2020

Thin films of the bcc metals vanadium, niobium and tantalum were epitaxially grown on (0001) and sapphire substrates. Prior to deposition, the mechanical polishing damage on the substrates was removed by an in-situ etch. The metal films were deposited by electron-beam evaporation in ultra-high vacuum. The substrates were heated by thermal contact with an electron-bombarded backing plate. The deposition parameters are summarized in Table 1.The films were replicated and examined by electron microscopy and their crystallographic orientation and texture were determined by reflection electron diffraction. Verneuil-grown and Czochralskigrown sapphire substrates of both orientations were employed for each evaporation. The orientation of the metal deposit was not affected by either increasing the density of sub-grain boundaries by about a factor of ten or decreasing the deposition rate by a factor of two. The results on growth epitaxy are summarized in Tables 2 and 3.
(111) Monocrystalline Nickel Films
Authors: Pratt T.E. , Vook R.W. 
Published: June 2020

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.
Contrast in Scanning Images of Thin Crystals
Authors: Kimoto S. , Hashimoto H. , Takashima S. , Stern R. M. , Ichinokawa T. 
Published: June 2020

The most well known application of the scanning microscope to the crystals is known as Coates pattern. The contrast of this image depends on the variation of the incident angle of the beam to the crystal surface. The defect in the crystal surface causes to make contrast in normal scanning image with constant incident angle. The intensity variation of the backscattered electrons in the scanning microscopy was calculated for the defect in the crystals by Clarke and Howie. Clarke also observed the defect using a scanning microscope.This paper reports the observation of lattice defects appears in thin crystals through backscattered, secondary and transmitted electron image. As a backscattered electron detector, a p-n junction detector of 0.9 π solid angle has been prepared for JSM-50A. The gain of the detector itself is 1.2 x 104 at 50 kV and the gain of additional AC amplifier using band width 100 Hz ∼ 10 kHz is 106.
Oxidation of Silicon Carbide
Authors: Donerty J. E. 
Published: June 2020

Most of the available studies of the oxidation of SiC (e.g., [1,2]) find that although the rate of oxidation decreases with time, it does so at a rate somewhat less than would be expected from the normal thickness controlled parabolic rate law. This higher than anticipated rate of oxidation suggests the possibility of small cracks or other such imperfections in the surface which will locally increase the rate of oxidation.In order to explore this phenomenon further, several samples of fully dense SiC were oxidized in air at 1500°C. After oxidation scanning electron micrographs were taken of the surface and, as can be seen in Figure 1 the oxide surface appears to be covered with crater-like or pock-like features. Figures 2a and b, enlarged portions of 1, clearly show these features to be bubbles which apparently are perculating up through the oxide to the surface.