bluuebunny/crossref_metadata_2025 huggingface dataset:
High Voltage (800 Kv) Electron Petrography of Unequilibrated Stony Meteorites — Allende and Parnallee
Authors: Green H. W. , Radcliffe S. V. , Heuer A. H.
Published: June 2020

Electron petrography (transmission study of thin foils of rock prepared from bulk material) has been performed on specimens of the Pueblito de Allende Carbonaceous Chondrite (Type III of Wiik) and on the Parnallee unequi1ibrated ordinary chondrite (Type LL3 of Van Schmus and Wood). Specimens ∼30 μm. thick were prepared by grinding; then further thinned by a low-angle ion-bombardment process until electron-transparency was attained. Polarizing optical petrography in both transmission and reflection was performed at various stages in the thinning process. No damage due to the thinning method was observed in any phases examined, nor was any damage noted due to the high voltage electron beam.
Ion Etching Studies with Varied Materials
Authors: Thompson George R.
Published: June 2020

With the evolution of ion thinning in the latter 50's and its acceptance and application by the microscopist in the last few years, attention has been focused on the ability to prepare specimens from a polycrystalline or multiphase materials for transmission electron microscopy. Subsequent to the initial and significant results with alumina, work has been undertaken to show the versatility of this technique with a wide variety of materials. It is the purpose of this paper to describe the numerous types of ion etched specimens which have been successfully analyzed. Experience involving hundreds of specimens prepared with an Ion Micro Milling Instrument, often called IMMI.

The electronic industry has found uses for this type of,equipment with semiconductor materials such as silicon, germanium, gallium arsenide, gallium phosphate, barium titinate, and niobium tin. The most work to date has been done with silicon. Fig. 2 shows a recent photomicrograph of GaAs where lattice planes are visible throughout the matrix. Extensive research has been undertaken with ceramic materials including aluminum oxide, zerconia, and magnesium oxide.
Stability Of Precipitates In Thin Metal Films
Authors: Kinsman K. R.
Published: June 2020

The prime function of transmission electron microscopy in the study of solid state precipitation phenomena is detailed structural characterization of the precipitate and matrix. It is fundamental that the investigator be aware of the possible structural anomalies associated with the technique. An illustration is the response to electrochemical thinning of iron-rich precipitates produced during isothermal reaction of a Cu-2.56%Fe alloy. Although the fcc(austenite) → bcc(martensite) transformation occurs at about 400°C in a bulk alloy of precipitate composition, precipitates in the copper matrix are constrained in their fee state to below 77°K, so long as the specimen remains plastically undeformed. Here it is shown that such precipitates can be induced to transform in carefully handled undeformed foils simply through reduction of the constraints offered by the surrounding matrix (Fig.1).
Dislocations, Ordering and Antiferromagnetic Domains in MnO
Authors: Barber D. J. , Evans R. G.
Published: June 2020

Manganese (II) oxide, MnO, in common with CoO, NiO and FeO, possesses the NaCl structure and shows antiferromagnetism below its Neel point, Tn∼ 122 K. However, the defect chemistry of the four oxides is different and the magnetic structures are not identical. The non-stoichiometry in MnO2 small (∼2%) and below the Tn the spins lie in (111) planes. Previous work reported observations of magnetic features in CoO and NiO. The aim of our work was to find explanations for certain resonance results on antiferromagnetic MnO.

Foils of single crystal MnO were prepared from shaped discs by dissolution in a mixture of HCl and HNO3. Optical microscopy revealed that the etch-pitted foils contained cruciform-shaped precipitates, often thick and proud of the surface but red-colored when optically transparent (MnO is green). Electron diffraction and probe microanalysis indicated that the precipitates were Mn2O3, in contrast with recent findings of Co3O4 in CoO.
Direct Observation of Cu-Hexadecachlorophthalocyanine Molecules in Epitaxial Films
Authors: Uyeda N. , Kobayashi T. , Suito E. , Harada Y. , Watanabe M.
Published: June 2020

From a practical point of view concerning the image resolution of organic molecules, it is obvious that they must be suitably oriented to the optical axis without any thermal motions even when planar molecules of polycyclic compounds are chosen as favorable spesimens. Using thin crystalline films of such compounds seems promising since the epitaxial growth is known to cause satisfactory molecular orientations. In the present work, Cu-hexadecachlorophthalocyanine was used as the specimen instead of the ordinary cyclic compounds as they were found less resistant of radiation damage than expected. As the effect of the halogenation of the maginal CH-bonds which are considerd most responsible for the damage, this compound is almost 30 times more stable than the original one even in an electron beam as intense as 1.5×10−2 Amp./cm2.
Interference Experiments with a Field Emission Source
Authors: Crewe A. V. , Saxon J.
Published: June 2020

Field emission from a tungsten tip provides a source with very high brightness and high partial coherence. An electron gun of low spherical aberration is used to focus the electrons from the tip to a small spot about 100 Å in diameter. Since the voltages applied to the tip and gun are stable to better than 5 ppm, the temporal coherence is limited by the energy spread of the source, about 200 mv.

Using the focused spot a few centimeters below the gun as an effective source, a metalized quartz fiber about 2 μ in diameter is positioned a few centimeters below the source, as shown in Fig. 1. Two cylindrica11y symmetric magnetic lenses are used to magnify the resulting Fresnel diffraction pattern. The image is produced on a fluorescent coating deposited on the vacuum side of a fiber optic window. The image is recorded directly on film placed against the window outside the vacuum system.
A Comparison of Scanning and Fixed Beam High Voltage Electron Microscopy
Authors: Cowley J. M.
Published: June 2020

Since the theoretical advantage of high voltage microscopy in terms of improved resolution has not yet been achieved, the justification for the building of high voltage microscopes has been mainly the possibility of studying thicker specimens plus the observation of some radiation damage and some relativistic n-beam dynamical diffraction effects. For most of these purposes the scanning mode of transmission electron microscopy has clear advantages.

As in the case of the fixed beam instrument (FBI), the limitation on resolution of the scanning transmission electron microscope (STEM) for ideal thin specimens is determined largely by instabilities of the high voltage supply and lens currents and by mechanical instabilities. In this respect the STEM suffers from the disadvantage that the point-by-point recording of the image involves a greater recording time and hence greater sensitivity to long term instabilities.
Fasciaton of Pectate Elementary Fibrils
Authors: Leeper George F.
Published: June 2020

Polysaccharide elementary fibrils are usually fasciated into microfibrils of from one hundred to a few hundred Angstroms wide. Cellulose microfibrils when subjected to acid treatment dissociate into component elementary fibrils. For pectic acid it was observed that variations in pH could cause a change in the fasciation of the elementary fibrils.

Solutions of purified pectic acid and sodium phosphotungtate were adjusted to various pH levels with NaOH or HCl and diluted to give a final concentration of 0.5 and 1% for the polysaccharide and negative stains respectively. Micrographs were made of the samples after drying on a carbon film covered grid. The average number of elementary fibrils was determined by counting the number of elementary fibrils in each fascicle intersected by lines drawn across the micrograph.
Structure of Grain Boundaries in Metals and Alloys: Direct Observations in the TEM
Authors: Murr L. E.
Published: June 2020

Many models of grain boundaries in metals and alloys have been developed in attempts to interpret their properties and observed structures. Because of the complexity of grain boundary structure, it is generally possible to apply any of the proposed models in any material, and to describe grain boundaries as possessing dislocation structures, ledges, protrusions, island structures, facets, coincidence regions which exhibit good atomic fit and establish a kind of superlattice array, and combinations of these structural features.

The dislocation nature of small angle grain boundaries is well known, consisting of tilt or twist arrays or combinations of edge or screw dislocations.
Field-Ion Microscopy of BCC Metals: A Study of Image Differences and Topographical Variations
Authors: Inal O. T. , Murr L. E.
Published: June 2020

When sharp metal filaments of W, Fe, Nb or Ta are observed in the field-ion microscope (FIM), their appearance is differentiated primarily by variations in regional brightness. This regional brightness, particularly prominent at liquid nitrogen temperature has been attributed in the main to chemical specificity which manifests itself in a paricular array of surface-atom electron-orbital configurations.

Recently, anomalous image brightness and streaks in both fcc and bee materials observed in the FIM have been shown to be the result of surface asperities and related topographic features which arise by the unsystematic etching of the emission-tip end forms.
A Fabric Study of Clay Floccules
Authors: Naymik T. G.
Published: June 2020

Authigenic clays have been favored in SEM clay studies due to their large crystallite size, well developed individuals and open texture. Detrital clay material which is less stable under the electron beam, shows poor crvstal morphology and in general, smaller particle size is more difficult to observe.

Specimen preparation is extremely important for viewing detrital clays. The main difficulty in photographing clays lies in the edge brightening effect inherent in clay platelets. Edge brightening arises from charging due to water migration from between clav platelets to the edges and from high atomic number coating material (gold) which tends to concentrate at the edges.
S.E.M. Observations of Quartz in Cherts: Etched vs. Unetched Surfaces
Authors: Jendrzejewski John P. , Knauth L. Paul
Published: June 2020

Cherts, rocks composed essentially of microcrystalline quartz, display a wide variety of crystal forms. Fractured and polished surfaces of a bedded and a nodular chert were examined with the S.E.M. before and after being etched in various solutions (HF, KOH, NaOH). The bedded chert is a member of the Arkansas Novaculite containing pyrite, organic matter, and silicified organic spherical bodies (possibly spores) 100-500 microns in diameter. The chert nodule is from a Cretaceous carbonate, and displays a white patina which is interpreted as a weathering rind.

Unetched surfaces generally do not display crystal morphologies as well as etched surfaces. However, crystal forms were observed on unetched surfaces where the fracture exposed cavities within the rock.
Observation of Point Defects in Niobium Oxides by High Resolution E.M.
Authors: Iijima S.
Published: June 2020

Under highly controlled imaging condition, some structural information haso been obtained from some transition metal oxides at a resolution of about 3Å and also an unknown structure has been derived in some cases from the high resolution microscope images. Those images have been interpreted to some extent by using a weak phase object approximation. The fact that faulted regions can be imaged as well as ordered regions suggests that a dynamical scattering of electron can be treated by a column approximation. where effects of all diffracted beams are confined within a column of about 3-5Å diameter through the crystal. It can therefore be expected that point defects within lines of atoms along the incident beam direction will be imaged at this resolution.
Electron Microscopy and X-Ray Microanalysis in Forensic Science
Authors: Johnson James W. , Brown John L.
Published: June 2020

Forensic science has been described as an application of all disciplines of science in matters of jurisprudence. As society and technology advance, more sophisticated analytical techniques must be applied to the investigation of crime and the determination of fault in civil suits. The legal investigator must work constantly to keep abreast of new methods and their proper application.

The examination of physical evidence has been the most important means of determining the facts of a given case. Personal inspection of evidence with the unaided eye and optical microscope have long been used and have become accepted in court room testimony.
Microanalysis of Particulate Materials
Authors: Ferrell R. E. , Paulson G. G.
Published: June 2020

The scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis system is probably the best combination instrument for the micro- analysis of particulate material. The versatility of image forming capabilities with the SEM and the rapid chemical determination which are possible with the EDX are the most notable advantages. The purpose of this paper is to illustrate some of the qualitative and quantitative techniques of the system and their applicability to the analysis of particulate materials. An AMR 1000 scanning electron microscope and an Ortec X-ray microanalysis system were employ d to generate the results discussed below.
A Technique For The Rapid Determination of the Contrast Transfer Characteristics of an Electron Microscope
Authors: Krakow William , Downing Kenneth H. , Siegel Benjamin M.
Published: June 2020

A focal series of a thin carbon film in bright-field phase contrast has been used by Thon to obtain a family of curves that represent the contrast transfer characteristics of a particular objective lens as a function of the defocus value. The thin carbon film is assumed to be a weak phase object, and the light optical diffractogram gives the Fourier transform of each micrograph from which the relative contrast at each spatial frequency can be obtained for the corresponding amount of defocus.

We have obtained the equivalent information from a single electron micrograph of a thin carbon film specimen tilted at a large angle (65°), see Fig. 1.
Dispersion of Solid State Excitations
Authors: Chen C. H. , Silcox J. , Vincent R.
Published: June 2020

The addition of an electron spectrometer to an electron microscope extends the
capabilities not only of the microscope but also of the electron spectrometer. Operation of the electron microscope in the high angular resolution, small angle scattering mode (see, for example, Wade and Silcox) extends the angular scattering range of the electron spectrometer into an interesting small angle region (<10−4 radians) hitherto inaccessible. The dispersion of many solid state excitations in the energy range leV to 20eV is strongly affected by the light line w = ck where the energy loss ΔE = ђw and the momentum transfer is ђk. These effects can be observed directly by the electron microscope/spectrometer combination at scattering angles <10-4 radians.
Generalizing The Field Emission Illumination System
Authors: Veneklasen Lee H.
Published: June 2020

In comparison with conventional systems, field emission systems represent a larger fraction of the total cost and effort for new instrumentation. This is primarily due to factors common to F.E. rather than to requirements specific to the application. There may be advantage in a generalized modular system simultaneously suitable for high current microprobes (MP), high resolution scanning transmission microscopy (STEM), and conventional transmission microscopy (CEM). Optimization of the F.E. optics for each application can suggest a single generalized system exploiting F.E. in these three modes of operation.
Field Emission SEM Equipped With Noise Compensator
Authors: Saito S. , Todokoro H. , Nomura S. , Komoda T.
Published: June 2020

Field emission scanning electron microscope (FESEM) features extremely high resolution images, and offers many valuable information. But, for a specimen which gives low contrast images, lateral stripes appear in images. These stripes are resulted from signal fluctuations caused by probe current noises. In order to obtain good images without stripes, the fluctuations should be less than 1%, especially for low contrast images. For this purpose, the authors realized a noise compensator, and applied this to the FESEM.

Fig. 1 shows an outline of FESEM equipped with a noise compensator. Two apertures are provided gust under the field emission gun.
Identification of Airborne Asbestos by Selected Area Electron Diffraction
Authors: Smith Glenn R. , Stone Glen A. , Stanley Ronald L. , Carpenter Leslie M. , Seshan Krishna , Mueller Peter K.
Published: June 2020

In the Air and Industrial Hygiene Laboratory's development of a method for characterization of the asbestos distribution in ambient air, positive identification of the asbestos fiber type is essential because the different types of asbestos have varying degrees of carcinogenicity and toxicity. However, chrysotile is the only asbestos mineral which currently can be positively identified when its fibers are less than 1 in size. Samples of ambient air in California cities show the presence of chrysotile fibers less than 1 in diameter In addition, we find unidentified smaller fibers of the asbestos types in concentrations of about 1 million per cubic meter.
Cytomembrane Preservation in Tissue Dehydrated Only With Glutaraldehyde and Epon 812 Resin
Authors: Pease Daniel C.
Published: June 2020

A previous study demonstrated that tissue could be successfully infiltrated with 50% glutaraldehyde, and then subsequently polymerized with urea to create an embedment which retained cytomembrane lipids in sectioned material. As a result, the 180-190 Å periodicity characteristic of fresh, mammalian myelin was preserved in sections, as was a brilliant birefringence, and the capacity to bind OsO4 vapor in the hydrophobic bilayers. An associated (unpublished) study, carried out in co-operation with Drs. C.K. Akers and D.F. Parsons, demonstrated that the high concentration of glutaraldehyde (and urea) did not significantly alter the X-ray diffraction pattern of aldehyde-fixed, myelin. Thus, by itself, 50% glutaraldehyde has little effect upon cytomembrane systems and can be used with confidence for the first stages of dehydration.
Elaboration of Collagen Precursors By Osteoblasts in Rat Alveolar Bone As Visualized By Electron Microscope Radioautography
Authors: Weinstock Melvyn
Published: June 2020

Recent studies, reviewed by Grant and Prockop, have provided evidence for an intracellular form of collagen referred to as "procollagen". This molecule is similar to the rod-like tropocollagen molecule except for the presence of a 13nm terminal piece. The conversion of procollagen to tropocollagen by cleavage of the terminal piece is believed to take place extracellularly. Fine structural studies on odontoblasts, the cells which secrete the collagen of dentin matrix, indicate that filamentous structures, interpreted as procollagen, are condensed into secretory granules in the Golgi apparatus, transported to their sites of secretion in the odontoblast process and released to the cell surface by exocytosis. To determine whether similar events occur in osteoblasts, the elaboration of collagen by these cells was investigated using radioautography and electron microscopy.
Ultrastructural Evaluation of the Effects of Vitamin D and Parathyroid Hormone On Bone of Thyroparathyroidectomized Rats
Authors: Weisbrode S. E. , Capen C. C.
Published: June 2020

To evaluate the effects of vitamin D (VD) and parathyroid hormone (PTH) individually and in combination on bone, adult male thyroparathyroidectomized (TXPTX) ruts fed a low calcium diet (0.05% CA) were administered 7,500 I.U. VD/day (group 1), 50 USP units PTH/day (group 2), 7,500 I.U. VD and 50 USP units PTH/day (group 3), or placebo (group 4). All animals were supplemented daily with 10 g sodium levothyroxine for the 7 day experimental period. Undemineral ized tibial bone was evaluated electron microscopically and these findings were correlated with changes in terminal serum calcium (CA), serum phosphorus (P) and urinary total hydroxyproline excretion, expressed as a ratio to creatinine (HOP/CR).
Electron Microscopic Observations of a Human Brain Abscess
Authors: Sekhon Sant S.
Published: June 2020

A brain biopsy taken from an abscess located in the left temporal region of a 55-year-old caucasian male provided the basis for the present observations. The patient had a history of viral encephalitis, and a chronic brain syndrome secondary to this. He also had a positive history of grand mal seizuies probably from the viral encephalitis. The main objectives of this study were to demonstrate if possible the presence of viral particles in nerve cells and to observe and describe ultrastructural alterations and other morphological expressions of cell injury.

Brain tissue from the abscess area was fixed in 2.5% cacodylate-buffered glutaraldehyde-formaldehyde mixture and post-fixed in 1% cacodylate-buffered osmium tetroxide, dehydrated and embedded in Araldite. The sections were stained with a combination of uranyl acetate and lead citrate and examined under RCA EMU 3E electron microscope.
Preparation of Helminths For Scanning Electron Microscopy
Authors: Weise Robert W.
Published: June 2020

The role that scanning electron microscopy (SEM) is playing in descriptive helminthology is becoming more apparent in the literature. However, the majority of papers on the SEM of helminths have used conventional or modified light microscope techniques of fixation and dehydration, and not established SEM techniques in which freeze- and critical point-drying are routinely used. The present investigation was undertaken to examine the applicability of modified scanning and transmission electron microscope techniques for the preparation of certain helminths for SEM.

Method I.– Live animal-parasitic nematodes were fixed in 6% phosphate buffered glutaraldehyde for 24 hr at room temperature.
Application of Improved Voltage Compensation in the SEM to Imaging of Organic Materials
Authors: Killingworth P.J. , Warren M.
Published: June 2020

Ultimate resolution in the scanning electron microscope is determined not only by the diameter of the incident electron beam, but by interaction of that beam with the specimen material. Generally, while minimum beam diameter diminishes with increasing voltage, due to the reduced effect of aberration component and magnetic interference, the excited volume within the sample increases with electron energy. Thus, for any given material and imaging signal, there is an optimum volt age to achieve best resolution.

In the case of organic materials, which are in general of low density and electric ally non-conducting; and may in addition be susceptible to radiation and heat damage, the selection of correct operating parameters is extremely critical and is achiev ed by interative adjustment.
Properties of Isolated Mitochondria of Agaricus Bisporus: Their Relationship to Dormancy and the Germination of Spores
Authors: McCarty K. S. , Weave R. F. , Kemper L. , Vogel F. S.
Published: June 2020

During the prodromal stages of sporulation in the Basidiomycete, Agaricus bisporus, mitochondria accumulate in the basidial cells, zygotes, in the gill tissues prior to entry of these mitochondria, together with two haploid nuclei and cytoplasmic ribosomes, into the exospores. The mitochondria contain prominent loci of DNA [Fig. 1]. A modified Kleinschmidt spread technique1 has been used to evaluate the DNA strands from purified whole mitochondria released by osmotic shock, mitochondrial DNA purified on CsCl gradients [density = 1.698 gms/cc], and DNA purified on ethidium bromide CsCl gradients. The DNA appeared as linear strands up to 25 u in length and circular forms 2.2-5.2 u in circumference. In specimens prepared by osmotic shock, many strands of DNA are apparently attached to membrane fragments [Fig. 2]. When mitochondria were ruptured in hypotonic sucrose and then fixed in glutaraldehyde, the ribosomes were released for electron microscopic examination.
Radiation Damage in Biological Materials
Authors: Parsons Donald F.
Published: June 2020

The importance of inelastic scattering in biological electron microscopy has been under-rated with respect to structural damage produced by the electron beam. Recently, semi-quantitative estimates of the beam damage associated with obtaining the micrograph indicate that the sturctural damage is severe. An improved theoretical description of inelastic scattering shows that the total inelastic scattering from carbonaceous material exceeds the elastic scatter by acout 3:1. This ratio is unaffected by acceleration voltage and no reduction in beam damage is expected from the use of high voltage (1Mev) for biological electron microscopy. The new calculations show also that over the wide angle scatter region (4Å to 1Å) the inelastic scatter is of approximately equal magnitude to the elastic scatter intensity. Hence, apertures, phase plates and collectors placed in this angular region intercept as much inelastic as elastic scatter.
Inheritance of Intracellular Bacteroids in Periplaneta Americana
Authors: Daniel R. S.
Published: June 2020

Blockmann was the first to assume that intracellular symbiotic bacteroids of blattids are transmitted to progeny through the ovaries of the parent. Subsequent literature has generally supported the transovariole transmission theory, but whether bacteroids infect differentiated oocytes or ovarian anlage has not been determined. This paper presents electron microscopic data relevant to the question of bacteroid inheritance.

Ovaries of P. americana were fixed in cacodylate buffered glutaraldehyde and osmium then block-stained in uranyl acetate. Sections were stained with uranyl acetate and lead citrate. Serial sections (Fig 1 insert) of germaria (Zone II) reveal that bacteroids are absent in formative follicle cells (Fig 1), oogonia (Fig 2) and intercellular spaces of germinal tissue in adults and nymphs.
Monoamine Oxidase (MAO) Demonstrated Ultrastructurally via Nonosmiophilic Tetrazolium Salt Reduction to Osmiophilic Formazan
Authors: Shannon W. Allen , Wasserkrug Hannah L. , Seligman Arnold M.
Published: June 2020

Recently, Seligman and his co-workers have synthesized and introduced a nonosmiophilic tetrazolium salt, 2-(2'-benzothiazolyl-5-styryl-3-(4'-phthalhydrazidy]) tetrazolium chloride (BSPT), for the investigation of succinic dehydrogenase. BSPT satisfies the requirement for a nonosmiophilic tetrazolium salt which is reduced to an osmiophilic formazan poorly soluble in lipid.

In this investigation, BSPT was used with tryptamine in a modification of the method developed by Glenner et al. and modified by Boadle and Bloom for ultrastructural studies, to make feasible the ultrastructural demonstration of MAO. Myocardial, renal, and hepatic tissues were incubated fresh or briefly fixed, with tryptamine as the substrate at pH 7.4.
Effects of Cis-Dichloro-Diammine-Platinum(II) on the Fine Structure of the Mammalian Cells in vitro
Authors: Aggarwal S. K. , Sodhi A.
Published: June 2020

Cis-dichloro-diammine-platinum(II) has been shown to be a potent antitonor agent effective against a number of animal tumors. A possible mechanism of its action through an enhanced antigenicity or the enhanced cellular immune system has already been proposed. Present studies outline the direct cytotoxic effects of Cis-Pt(II)(NH3)2Cl2 on Sarcoma-180 ascites cells, Human lymphoma cells and Human AV3 cells in absence of the hostdefense mechanisms.

Majority of Sarcoma-180 ascites cell population consists of lightly staining cells with a few dark cells, macrophages and polymorphic leukocytes. The cellular organelles are randomly distributed in the cytoplasm (Fig. 1). The large rounded or oval mitochondria have dense matrix and the cisternae of the RER are usually 600-1000 Å wide. 60-70 Å thick microfilaments are present through out the cell and often concentrate in the perinuclear region associating with the outer nuclear membrane.
Effects of Metabolic Inhibitors on Responses of Interstitial Cells to LH
Authors: Carithers J. R.
Published: June 2020

Ovarian interstitial cells from hypophysectomized rats treated with luteinizing hormone (LH) have undergone pronounced proliferation of cytoplasmic membranes 12 hours after initiation of treatment, while nuclear morphology does not yet appear altered. However, nuclear response is maximal after 24 hours, while cytoplasmic changes continue for at least 2 more days. A lag in nuclear response compared to cytoplasmic membranogenesis after LH has also been observed during luteinization in the sow. These findings are consistent with a suggestion that LH has a primarily cytoplasmic locus of action, based on evidence that actinomycin D can decrease RNA formation to 1/10 of control values without inhibiting LH-induced stimulation of steroidogenesis in vitro. Puromycin, an inhibitor of protein synthesis, does block steroid ogenic effects of LH, but does not prevent some other metabolic effects.
Hormone-Induced Crystalline Inclusions in Uterine Epithelium
Authors: Hoffman L. H. , Davies J.
Published: June 2020

Epithelial cells lining the rabbit uterus undergo dramatic changes in response to alterations in circulating levels of estrogen and progestins. We have observed the appearance of two structures in the uterine epithelium of rabbits under the influence of progestins, namely cytoplasmic crystalline bodies and intramitochondrial lamellae. Such structures are not present in estrous uterine tissue.

The crystalline bodies have been observed in the cytoplasm of glandular epithelial cells beginning on Day 4 of pseudopregnancy. They appear to increase in numbers during pseudopregnancy (through Day 16) and have disappeared by Day 21. The crystals are rod-shaped (0.25 × 4-5μ) with their long axes most frequently at right angles to the basal lamina (Fig. 1).
Periplasmic Localization of Mesosomes of Bacillus Licheniformis (749/C) in Thin Sections
Authors: Ghosh B. K. , Marathe G. V. , Hess N. , Ghosh A.
Published: June 2020

It has been shown earlier in negatively-stained and freeze-etched cells that mesosomes are located in the periplasm of this organism. We are now presenting results from thin section study to confirm these observations.

Log-phase washed cells were prefixed in a mixture of 1. 5% paraformaldehyde and 1% glutaraldehyde. Further these cells were fixed in osmium tetroxide as previously described and embedded in DER resin. Glancing thin sections were frequently obtained from such preparations. Comparison of Figs. 1 and 2 clearly show that a longitudinal glancing section through the cell wall and periplasm has been obtained (white-faced arrows of Fig. 1 indicate plane of section for Fig. 2).
The Immuno-Electron Microscopic Localization of the Mo-Fe Protein Component of Nitrogenase in Cells of Azotobacter Vinelandii
Authors: Stasny J. T. , Burns R. C. , Hardy R. W. F.
Published: June 2020

Structure-functlon studies of biological N2-fixation have correlated the presence of the enzyme nitrogenase with increased numbers of intracytoplasmic membranes in Azotobacter. However no direct evidence has been provided for the internal cellular localization of any nitrogenase. Recent advances concerned with the crystallizatiorTand the electron microscopic characterization of the Mo-Fe protein component of Azotobacter nitrogenase, prompted the use of this purified protein to obtain antibodies (Ab) to be conjugated to electron dense markers for the intracellular localization of the protein by electron microscopy. The present study describes the use of ferritin conjugated to goat antitMo-Fe protein immunoglobulin (IgG) and the observations following its topical application to thin sections of N2-grown Azotobacter.
Nucleocapsid “Core” Particles of Hepatitis B Virus from the Liver of an Experimentally Infected Chimpanzee
Authors: Jackson Daniel R. , McGrath Philip P. , Barker Lewellys F.
Published: June 2020

Forty to 4-2 nm “Dane” particles in the serum of individuals with viral hepatitis, type B, have been postulated to be the infectious units of this disease. The outer coat material of these particles, composed of hepatitis B antigen (HBAg), is synthesized in great excess in the cytoplasm of hepatocytes infected with hepatitis B virus (HBV) and released into the serum as pleomorphic particles, predominantly 20 nm spherical forms and filaments. Twenty-five to 27 nm virus-like particles in the nuclei of infected cells are thought to comprise the nucleocapsid cores of the “Dane” particles. The HBAg coat and the cores of the “Dane” particles were shown by Almeida et al. to possess distinct antigenic determinants by immune electron microscopy. bimunofluorescent staining of infected chimpanzee liver cells revealed differential staining of cytoplasm by antiserum against HBAg (coat)and of nuclei by antiserum against the cores, supporting Almeida's immune electron microscopic findings.
Morphogenesis of a New Human Herpes-Type Virus Isolate (Sasha Virus)
Authors: Zeigel R. F. , Munyon W.
Published: June 2020

In continuing studies on the role of viruses in biochemical transformation, Dr. Munyon has succeeded in isolating a highly infectious human herpes virus. Fluids of buccal pustular lesions from Sasha Munyon (10 mo. old) uiere introduced into monolayer sheets of human embryonic lung (HEL) cell cultures propagated in Eagles’ medium containing 5% calf serum. After 18 hours the cells exhibited a dramatic C.P.E. (intranuclear vacuoles, peripheral patching of chromatin, intracytoplasmic inclusions). Control HEL cells failed to reflect similar changes. Infected and control HEL cells were scraped from plastic flasks at 18 hrs. of incubation and centrifuged at 1200 × g for 15 min. Resultant cell packs uiere fixed in Dalton's chrome osmium, and post-fixed in aqueous uranyl acetate. Figure 1 illustrates typical hexagonal herpes-type nucleocapsids within the intranuclear virogenic regions. The nucleocapsids are approximately 100 nm in diameter. Nuclear membrane “translocation” (budding) uias observed.
A Correlated Scanning And Transmission Electron Microscopy Study of Pulmonary Airway Morphology in the Rhesus Monkey
Authors: Castleman W. L. , Dungworth D. L.
Published: June 2020

Previous research has indicated that there are important differences in the structure of pulmonary airways among various species of mammals and that these structural differences must be taken into consideration when animal models are being used in experimental studies of pulmonary disease. An investigation is being undertaken in this laboratory to characterize airway structure in several species of nonhuman primates and compare that structure with airway structure that has been described in man. The following is a report on studies of lungs from rhesus monkeys.

Lungs from adult rhesus monkeys were, fixed via the airways with cacodylatebuffered glutaraldehyde-formaldehyde. Various levels of bronchi and bronchioles were bisected with razor blades. One half of the bisected airway was prepared for scanning electron microscopy by dehydration, critical point drying from CO2, and conductive coating with silver and gold.
Two Distinct Types of Microfilaments in the Cytoplasm of Human Adenohypophysial Cells
Authors: Horvath E. , Kovacs K. , Stratmann I. E. , Ezrin C.
Published: June 2020

Surgically removed human pituitary glands as well as pituitary tumors fixed in glutaraldehyde, postfixed in osmium tetroxide, embedded in epon resin, stained with uranyl acetate and lead citrate have been investigated by electron microscopy in order to correlate ultrastructure with functional activity. In the course of this study two distinct types of microfilaments have been identified in the cytoplasm of adenohypophysiocytes.

Type I microfilaments (Fig. 1) were found in the cytoplasm of anterior lobe cells of five female subjects with disseminated mammary cancer and two patients with severe diabetes mellitus. The breast cancer patients were treated pre-operatively for various periods of time with different doses of oxysteroids. The microfilaments had an average diameter of JO A, formed parallel bundles, were scattered irregularly in the cytoplasm and were frequently located in the perikaryon. They were not membrane-bound and failed to show any periodicity.
Electron Microscopic Autoradiography of Rabbit Thyroid Gland Following Calcitonin
Authors: Lupulescu A. P. , Stebner F. C.
Published: June 2020

In a previous paper we observed that long-term administration of salmon calcitonin (SCT) exerts a goitrogenic effect on rabbit thyroid glands. In order to explain if this is a direct effect on thyroid follicular cells or mediated through other factors, we studied the cellular and intracellular radioiodine (125I) distribution by using high resolution autoradiography.

For electron microscopic autoradiography, five adult rabbits were injected i.m. three times weekly with salmon calcitonin (Armour Pharmaceutical Company), total dose of 800 MRCU (Medical Research Council Units) per rabbit. Another three rabbits served as controls. Both calcitonin-treated and control rabbits received 500 μc radioiodine (125I) intraperitoneally (each rabbit) and thyroid lobes were removed 1½ hours after isotope and calcitonin administration.
Fine Structural Evaluation of Parathyroid Glands From Cows Fed Low and High Calcium Diets
Authors: Capen C. C. , Black H. E. , Arnaud C. D.
Published: June 2020

The calcium (CA) content of the prepartal diet has been shown to significantly influence the development of profound hypocalcemia with paresis in dairy cows near parturition. The mechanisms by which these provocative and preventative diets influence endocrine function and skeletal metabolism are uncertain. The objective of this investigation was to evaluate the effects of feeding high and low CA diets on the ultrastructure and function of parathyroid chief cells in adult cows.

The effects of feeding a low CA diet (4.9 gm/day for 30 days) was investigated in 3 non-1actating Jersey cows. The serum CA decreased from 10.7 to 8.8 mg/100 ml after 30 days.
Localization of Alkaline Phosphatase in Marrow Cells
Authors: Geddes Anne D. , Kirchen Mary E. , Marshall G. June
Published: June 2020

Leukocyte alkaline phosphatase(LAP) is potentially a significant marker for following the maturation sequence of normal and abnormal neutrophils. This enzyme can be localized in the rough endoplasmic reticulum (rer) and in the Golgi complex of immature neutrophils but it has been very difficult to demonstrate LAP activity in the granules of mature neutrophils. This observation presents a dilemma since LAP is present in higher concentrations in mature as opposed to immature neutrophils as demonstrated by biochemical and light microscopy methods.

In an attempt to solve this problem, variations on the routine methods for demonstrating LAP activity were explored. Acetone, formaldehyde, methanol and gluteraldehyde were used as fixatives.
A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin
Authors: Mizuhira V. , Futaesaku Y.
Published: June 2020

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.
Low-loss electron image in the sem
Authors: Wells Oliver C.
Published: June 2020

The idea of filtering the backscattered electrons (BSE) in the scanning electron microscope (SEM) in order to improve the spatial resolution was suggested by McMullan (1953a) as follows: “...the beam from the specimen could be restricted to the electrons which have lost only small amounts of energy and which have therefore travelled only short distances through the specimen.” BSE which have lost less than about 1% of the primary energy can be called “low-loss electrons” or LLE (Wells 1971). As compared with LLE, the reflected electron peak contains electrons that have lost essentially no energy (Seiler 1983).

Data on BSE and LLE from solid targets was given by Kanter (1957) and by Wolf, Coane and Everhart (1970). The wide-angle scintillator detector for BSE (in which the scintillator subtends a large solid angle at the specimen) was investigated by Smith (1956) and by Everhart (1958). The importance of the takeoff angle with this detector was shown experimentally by Wells (1957 and 1970).
Imaging ion microscopy
Authors: Morrison G. H. , Moran M. G.
Published: June 2020

Ion induced sputtering of materials can be used to generate images which contain morphological and chemical information. This method of image generation has several key advantages over other techniques. All elements can be detected and imaged. Discrimination among the various isotopes of the elements is possible with sufficiently high mass resolution. Analytical sensitivity is high for many elements, especially those of biological importance such as Na, K, Mg, Ca. The extension of these principles to imaging of molecular ion species is straightforward. Since the sputtering of the sample surface causes erosion, the distribution of elements as a function of depth can be investigated. Depth profiling, in conjunction with imaging is a powerful technique for solving problems of multielement microcharacterization of materials. This technique, which the authors have dubbed Image Depth Profiling, (IDP) also forms the basis for three dimensional reconstruction of elemental distributions within microvolumes of materials.

In imaging ion microscopy, the image is acquired in a manner reminiscent of light microscopy. The analogy is depicted in figure 1. An energy homogeneous beam of primary ions irradiates the sample surface and sputtered secondary ions are focused directly on a microchannel ion to electron conversion plate. The primary ions are analogous to the illuminating photons of light microscopy and the secondary ions are analogous to the transmitted or reflected photons.
Spinel/oxide interfaces formed by internal solid-state reactions
Authors: Ostyn K. M. , Schmalzried H. , Carter C. B.
Published: June 2020

The usual method of forming the spinel AB2O4 by a solid-state reaction is to bring two oxides, AO and B2O3, into contact with one another at elevated temperatures, where diffusion is fast. The spinel then grows into both parent oxides; the kinetics of this solid-state reaction are well understood. Spinel can also be formed by exsoluting it as a second-phase in an oxide matrix. The two distinct internal reaction systems which have been used in this study are internal reduction and internal oxidation. Starting with an (Al-xBx)2O3 (x<1) solid solution, where one of the cations (B) can exist in at least two different valence states, it is possible to form spinel particles in an almost pure A2O3 matrix by internal reduction. Similarly, an (Al-xBX)O solid solution can be internally oxidized to form spinel in an almost pure AO matrix.
Cutting of 20 Å holes and lines in metal-β-aluminas
Authors: Mochel M.E. , Humphreys C. J. , Mochel J. M. , Eades J. A.
Published: June 2020

Holes 20 Å in diameter and fine lines 20 Å wide can be cut in the metal-β-aluminas using the 10 Å electron beam of the Vacuum Generators, HB5 scanning transmission electron microscope. The minimum current density required for cutting was 103 amp/cm2. Electron energies of 40,60,80,100 keV were used.

This technique has higher resolution than current lithography methods and is direct, requiring no chemical development. The width of isolated lines made on solid substrates is currently about .1μm (Ahmed and McMahon, 1981) and .03μm (Jackel et al., 1980). M. Isaacson and A. Murry have carried out electron beam writing on NaCl crystals supported on a carbon film on the scale we report here.

In our case uniform 20Å holes and lines can be cut through self-supporting 1000A thick slabs of sodium-β-alumina to provide very high electron contrast. Once cut, the β-aluminas are stable and will tolerate exposure to air without degradation of the electron cut patterns. They may be used directly as masks (eg. for ion implantation). We believe they could be cut on the substrate with no damage to the underlying material.
Degradation mechanisms of Cu2-xS/CdS solar cells as revealed by high-resolution electron microscopy
Authors: Sands T.
Published: June 2020

A major factor preventing the production of inexpensive and efficient p-Cu2S/n-CdS thin film solar cells is the inherent sensitivity of the electronic and optical properties of the copper sulfide layer to small changes in composition. This layer can act as an efficient absorber-emitter only if the predominant phase is low chalcocite (CU2S). A small amount of copper loss due to non-optimum formation conditions, in-service oxidation, or electromigration under load result in the formation of djurleite (Cu1.97S) and a corresponding reduction in cell efficiency. The structures of both low chalcocite and djurleite are based on an hep sulfur network. However, further copper loss encourages the nucleation and growth of low digenite (Cu1.82S), a metastable phase based on an fee sulfur network.

This study addresses the problem of determining the dominant factors influencing these degradation transformations so that methods to produce more stable layers or device configurations can be systematically developed.
ESCA for microelectronic applications
Authors: Moulder J. F. , Burkstrand J. M. , Wagner C. D.
Published: June 2020

As the dimensions of microelectronic devices continue to shrink, the use of surface sensitive analysis techniques to characterize thin film structures continues to grow. These techniques including: ESCA or XPS (X-ray photoelectron spectroscopy), AES (Auger electron spectroscopy), SIMS (secondary ion mass spectroscopy) and ISS (ion scattering spectroscopy) are now routinely being used to study a wide variety of material and process related problems.ESCA, which has become a standard analytical tool in the chemical industry, has not been utilized in the microelectronic industry to the extent that AES and SIMS have, even though it has the potential to provide more chemical state and structural information than other surface analysis techniques.

ESCA like the other surface analysis techniques analyzes the outermost atomic layers of a solid surface (typically 5 to 50 Å in depth). A low energy X-ray source (Mg 1253.6 eV or Al 1486.7 eV) is used to bombard the sample causing electrons to be ejected from it. These photo-electrons are collected and analyzed to determine their kinetic energy.
Lattice parameter measurement in retained austenite by CBED
Authors: Sarikaya Mehmet , Steeds John W. , Thomas Gareth
Published: June 2020

The thin film (50-400 Å) retained austenite (ret-γ) (fig.1.a-b) has been identified at the lath boundaries of dislocated martensitic medium carbon (C) low alloy experimental steels, which were designed for structural applications. The existance of this parent γ-phase at the ambient temperatures has been attributed to several stabilization mechanisms in which the intersititial C has important effects, especially when it partitions into ret-γduring the course of the austenite to martensite transformation. Hence, the measurement of any C enrichment in γ has prime importence in understanding the exact nature of the stabilisation. However, any quantitative measurement on the amount of C in such restricted conditions requires a method with high chemical and spatial resolutions. In the present work convergent beam electron diffraction method, which has been shown to give highly accurate results, has been utilized succesfully.