bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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).
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.
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.
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.
Microstructures and compositions of oxide films formed on CoCrAlY and Y-ion-implanted CoCrAl alloys
Authors: Sprague J. A , Johnston G. R. 
Published: June 2020

Hot stage components in many gas turbine engines require surface coatings to protect them from aggressive atmospheres at elevated temperatures. The most commonly employed protection scheme is to modify the surface composition of the components so that high temperature exposure in an oxidizing atmosphere will produce a dense, slow-growing, and adherent aluminum and/or chromium oxide film. Alloys of the MCrAlX-type, where M = Co, Ni, Fe, or combinations thereof, and X = a highly oxygen-active element such as Y, Hf, or Ce, are widely employed as overlay coatings in these applications. In the present investigation, several microanalytical techniques were applied to examine the mechanisms by which the microstructure and microchemistry of a CoCrAlY coating alloy affects the growth and adherence of protective oxide scales.Two cast alloy compositions were examined: Co-22Cr-llAl, and Co-22Cr-l1A1- 0.5Y (nominal compositions, wt. %). Selected specimens of the CoCrAl alloy were implanted with 2 × 1016 Y+/cm2 or 5 × 1016 Co+/cm2 at 150 keV.
Radiation damage and phase instability in irradiated stainless steel
Authors: Kenik Edward A. , Lee Eal H. 
Published: June 2020

The radiation response of metallic alloys can be strongly dependent on specific solute elements. Void swelling and phase instability of the matrix are two primary concerns in the design of nuclear reactors. A 316 stainless steel, LS1A, with greater than nominal levels of silicon and titanium has been developed which exhibits high resistance to swelling under ion irradiation. The origin of this swelling resistance and the roles of silicon and titanium have been investigated in the current study.Figure 1 illustrates the evolution of the damage structure in LS1A under nickel ion irradiation at 625°C. At low dose [∽1 dpa, Fig. 1(a)], faulted interstitial dislocation loops (43-nm-av diam) are observed. We have previously reported that significant solute silicon segregation (approaching 7.0 at. %) in the vicinity of the loop fault plane occurs at such doses in LS1A. Below 10 dpa, precipitates appear to replace the loops in similar sizes and densities. At 70 dpa [Fig. 1(b)] there is no swelling and the matrix phase instability has produced ∽5% volume fraction precipitate.
Detection of new co phase morphologies in β-III Ti using transmission electron microscopy
Authors: Pande C. S. , Fatemi M. 
Published: June 2020

The to phase transformation in titanium and other alloys has been extensively studied1. This phase has an hep structure with three atoms per cell located at (000), (1/3, 2/3, 1/2) and (2/3, 1/3, 1/2). ‘Isothermal’ ω phase precipitates are oriented in the bec β matrix such that [lll]β ‖ [0001]ω and [110]β ‖ω. In fact four varients of such an ω phase exist oriented in all four [111] directions. Isothermal ω phase has been studied as a displacement controlled growth as distinct from another type of ω phase (as quenched) which is produced by a dif fusionless transformation resulting from a very rapid cooling rate.Using transmission electron microscopy (TEM) and small angle neutron scattering (SANS) we have detected and identified two previously unreported morphologies in β-III Ti (Ti-11.0 Mo-6.0 Zr-4.5 Sn-0.15 O2). Fig. 1 shows a TEM micrograph of a conventional ‘isothermal’ ω precipitate (obtained by annealing β-III Ti 20 hours at 400°C) imaged in bright field with its diffraction pattern showing hep spots as well as the brighter spots of the bec matrix. The long axis of the precipitates is oriented along a [111] direction.
The microstructure of electrodeposited chromium
Authors: Szirmae A. , Fisher R. M. 
Published: June 2020

Electrodeposition of chromium, i.e., chrome plating, is widely used to provide corrosion protection or wear resistance to other materials following fabrication to their finished dimensions and shape. Chrome plate is characterized by hardness as high as 1200 KHN and initially large internal tensile, i.e., contractile, stresses that result in extensive cracking and partial relaxation of the stresses although further electroplating may result in the generation of compressive stresses. These, and other properties of electrodeposited chromium, depend on plating conditions such as current density and bath temperature. Scanning and transmission electron microscopy have been utilized to determine the effects of plating conditions on microstructure.Chromium was electrodeposited on 4340 steel to a thickness of 100 μm, with a conventional chromic acid solution under the following conditions: Sample A, 30 amp/Dm2 at 55°C, resulting in a bright hard (1150 KHN) coating; Sample B, 120 amp/Dm2 at 85°C, resulting in a dull and softer (650 KHN) coating.
The extinction role for forbidden 200 diffraction spots in silicon and spinel
Authors: Ling P. 
Published: June 2020

The conditions for dynamical extinction have been discussed by Cowley, Moodie, Miyake, Takagi, and Fujimoto and by Gjønnes and Moodie. We will extend the analysis used by Gønnes and Moodie for axial glide planes to explain dynamical extinction in crystals with diamond glide planes.Both the diamond glide plane and the four-fold screw axis are present in crystals which have the Fd3m structure, of which silicon, germanium, and spinel are examples. The diamond glide plane is perpendicular to the x-y plane, passing through (0,⅛,0) as shown by the broken line in Fig. 1.
Stage cooling rates and specimen-transfer facilities of the Duke University cryomicroscope
Authors: Lamvik M.K. , Worsham R.E. , Kopf D.A. , Robertson J.D. 
Published: June 2020

A liquid helium cold stage offers unique advantages for biological electron microscopy, including a five-fold reduction in radiation damage, higher ultimate specimen resolution and greater stability for frozen hydrated specimens. Ultra-high vacuum and reduced surface diffusion also reduce specimen contamination to negligible levels. To make efficient use of these advantages in biological studies, however, the microscope must be able to handle a variety of specimens while quickly achieving low temperature.The cryomicroscope that is currently in operation at Duke University (Fig. 1) was originally designed and built at Oak Ridge National Laboratory as a high-resolution electron microscope with a superconducting objective lens. The well-shielded cryostat for the objective lens assures a low specimen temperature. There are two thermal shields surrounding the liquid helium vessel, each cooled by the venting cold helium gas. The inner shield is at its nominal value, 20°K, at the end of the helium transfer when gas is actively venting from the system; later during routine operation, the inner shield temperature is about 30°K.
Instrumentation at the National Center for Electron Microscopy: The atomic resolution microscope
Authors: Gronsky R. , Thomas G. 
Published: June 2020

The Atomic Resolution Microscope (ARM) is one of two unique high voltage electron microscopes at the Lawrence Berkeley Laboratory's National Center for Electron Microscopy (NCEM). This paper reports on the latest results from this new instrument which was manufactured by JEOL, Ltd. to the performance specifications of the NCEM, delivered in January of 1983, and soon to be open to access by the entire microscopy community. Details of its history and development are given in reference 1; its performance specifications are reviewed below.Adopting as a design definition for resolution the first zero crossover of th% phase contrast transfer function at Scherzer defocus, the ARM (Fig. 1) maintains 1.7Å point-to-point resolution over its 400kV to 1000kV operating range. Consequently the microscope can be tuned to a voltage which is below the threshold for knock-on damage in a specimen and used to directly image its contiguous-atom structure. The key to this variable-voltage, high-resolution performance is a top-entry objective stage, which, in addition to ± 40° biaxial tilting, incorporates a height (Z)-control to alter specimen position within the objective lens.