Digital Commons Network^™

Scanning Electron Microscopy Of Lung Following Alpha Irradiation, C. L. Sanders, K. E. Lauhala, K. E. Mcdonald

Scanning Microscopy

Pulmonary aggregation of inhaled ²³⁹PuO₂ particles leads to a cellular evolution of focal inflammation, fibrosis, epithelial dysplasia and lung tumor formation. Female Wistar rats were exposed to an aerosol of high-fired ²³⁹PuO₂ (initial lung burden, 3.9 kBq) and the lungs examined at intervals from 1 day to 700 days after exposure by light and scanning electron microscopy and autoradiography. Peribronchiolar Pu particle aggregation increased with time, resulting in well-defined focal inflammatory lesions after 120 days and fibrotic lesions after 180 days. A generalized hypertrophy and hyperplasia of nonciliated bronchiolar cells was seen at 15 days and …

Biuret Staining And X-Ray Microanalysis For Locating Grafted Poly(Methyl Acrylate) On Wool Fibers, R. R. Bresee, P. A. Annis

Scanning Microscopy

Biuret reagent was used to stain wool fibers with copper so the location of a small amount of poly(methyl acrylate) grafted onto the fibers could be determined by energy dispersive x-ray microanalysis of copper. The grafted polymer was determined to be located in regions of the fibers where cuticle had been previously damaged. The amount of grafted polymer present was too small for secondary electron imaging to be useful for locating the polymer grafts.

Dendritic Oxide Growth On The Surface Of Liquid Gallium, Y. L. Wang, A. Raval, R. Levi-Setti

Scanning Microscopy

We have studied the oxidation of a liquid gallium surface with a high spatial resolution scanning ion microprobe. A 40 keV focused gallium ion beam, extracted from a liquid metal ion source, was employed, first, to sputter clean a 40 x 40 μm² area on a drop of liquid gallium, in a ultra high vacuum (UHV) specimen chamber. It was then used to monitor the oxide growth by secondary ion mass spectrometry imaging microanalysis while the chamber was gradually back-filled with oxygen. In the initial stages, gallium oxide grew in a dendritic pattern from the edge of the cleaned …

Surface And Grain Boundary Analysis Of High Temperature Superconductors, F. J. Himpsel, A. G. Schrott

Scanning Microscopy

The purpose of this paper is to survey the methods that are available for probing surfaces and grain boundaries of high temperature superconductors. Various surface-sensitive spectroscopies are applied to the analysis of YBa₂Cu₃O_7-x and Bi₂Sr₂CaCu₂O_8+x including photoelectron spectroscopy, spatially-resolved electron energy loss spectroscopy, and scanning electron microscopy (SEM). One of the major sources of contamination at surfaces and grain boundaries is found to be BaCO₃. The cleavage surface of single crystal Bi₂Sr₂CaCu₂O_8+x is inert and can be used to …

A Calculation Method Of X-Ray Emitted Intensity In Multi-Layer Films By Monte Carlo Simulation, Yen-Cai Ho, Jia-Guang Chen, Xin-Lei Wang

Scanning Microscopy

A calculation method of X-ray emitted intensity in multi-layer films is proposed in this paper. The method is based on the work developed by us: (1) a simplified physical model of electron scattering and Monte Carlo evaluations in a single medium and in multi-layer media and (2) the theories and the formulae for excitation, absorption and fluorescence of characteristic X-rays. The intensity ratio of X-rays for the known thickness films, Au/Cu/Si and Cr/Ni/Si, were calculated at 20, 25 and 30 keV. Calculated results are compared with experimental values of electron microprobe analysis for the multi-layer film specimens, and the correspondence …

An Analysis Of The Water Situation In The United States: 1989-2040, Richard W. Guldin, Usda Forest Service

All U.S. Government Documents (Utah Regional Depository)

Several Federal agencies have historically had responsibilities for conducting assessments of the Nation's water resources. The U.S. Geological Survey (USGS), U.S. Army Corps of Engineers, U.S. Department of Agriculture's Soil Conservation Service (SCS), and U.S. Environmental Protection Agency (EPA) and its predecessor agencies, among others, have conducted studies assessing the current situation and future prospects for water in particular regions of the country. Responsibility for national water assessments was assigned to the U.S. Water Resources Council (WRC) by the Water Resources Planning Act of 1965. With the demise of the WRC in 1981, several member agencies have attempted to take …

Application Of Bmp For Prevention Of Ground-Water Contamination, Majid Ehteshami, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

The use of pesticides is an integral part of today's agriculture. In many cases, pesticides safeguard crops from severe pest infestation, or increase yield by suppressing competing weed growth. Pesticides often make the difference between profits and losses in farming operations. However, pesticides, even in extremely low concentrations, can pose a risk to human health and to the environment. Applied to plant or soil surfaces, or injected into the soil, pesticides may leach to the ground water or may be washed off with surface water. Pesticide contaminated surface water can reach ground water, or contaminated ground water can reach the …

The Dark Side Of Bright Metal Coatings, L. Bartosiewicz, C. J. Kelly

Scanning Microscopy

The surface quality of light reflective metal films on polymer substrates were experimentally examined and evaluated. The study included light optical hotstage microscopy of in-situ samples and scanning electron microscopy. Conditions for producing aluminum metal films with desirable light reflecting properties are relatively demanding. The film formation is a complex series of events which include nucleation, coalescence and crystal growth.

Surface flaws, debris or other imperfections are readily visualized with the aid of the optical or the electron microscope. Although complex methods have been developed for the examination of small surface areas with fine-featured metallic films, there was little incentive …

Endothelial Injury In Human Atherosclerosis, G. Pasquinelli, A. Cavazza, P. Preda, A. Stella, B. I. Cifiello, M. Gargiulo, M. D'Addato, R. Laschi

Scanning Microscopy

A light and electron microscopic investigation (scanning and transmission electron microscopy) was performed on 51 human atherosclerotic carotid lesions. The purpose of this study was to establish whether features of endothelial injury such as those described in animals occur in man and whether these features can be related to specific stages of human atherosclerosis.

Irrespective of their histological appearance the atherosclerotic lesions were covered with endothelium which showed non-specific changes in cell shape and size. However, all complicated lesions appeared denuded. Moreover, a peculiar interaction of endothelium with monocytes and lymphocytes as well as blood components (e.g., fibrin and lipoproteins) …

A Contribution To The Scanning Electron Microscope Based Microcharacterization Of Semi-Insulating Gallium Arsenide Substrates, D. Köhler, G. Koschek, E. Kubalek

Scanning Microscopy

The macroscopic behaviour of semiconducting materials is determined by the distribution of microscopic defects like dislocations, impurities and intrinsic defects. Therefore, microanalytical methods are necessary to control the influence of technological process parameters on the materials properties. In the case of GaAs substrates, measurements of the cathodoluminescence (CL) and the electron beam induced voltage (EBIV) as well as the new charging technique seem to be promising methods to perform this task. CL-micrographs of as-grown GaAs substrates show bright cellular structures, which correspond to dislocation networks. Comparative investigations by use of the new charging contrast technique indicate an increased conductivity in …

Effects Of Extracellular Matrix On Cytoskeletal And Myofibrillar Organization In Vitro, Lula L. Hilenski, Louis Terracio, Roger Sawyer, Thomas K. Borg

Scanning Microscopy

The distribution and three-dimensional relationship of myofibrillar and cytoskeletal components during myofibrillogenesis were examined in preparations of neonatal rat cardiac myocytes processed in parallel for scanning electron microscopy (SEM), intermediate voltage transmission electron microscopy (IVEM) and immunofluorescence (IF). Of the various methods used for processing, optimal results were achieved by pre-extraction with Triton X-100 in an actin-stabilizing buffer. This procedure effectively removed the surface membrane, as viewed by SEM images, while preserving myofibrillar and cytoskeletal structure, as evidenced by IF for actin, 𝝰-actinin and vinculin. Cytoskeletons in SEM images consisted of a cortex of anastomosing filaments through which ran parallel …

Energy Dispersive X-Ray Microanalysis, Neutron Activation Analysis And Atomic Absorption Spectrometry - Comparison Using Biological Specimens, Romuald Wróblewski, Joanna Wroblewski, Helena Lundström, Lars Edström, Eva Jansson

Scanning Microscopy

X-ray microanalysis, neutron activation analysis and atomic absorption spectrometry were performed on normal and injured skeletal muscle. X-ray microanalysis of tenotomized rat soleus muscle showed significantly elevated levels of sodium and chlorine and lower potassium compared with normal muscle. Similar ion shifts could be demonstrated by neutron activation analysis and atomic absorption spectrometry. The concentrations of sodium and chlorine obtained by these techniques were somewhat higher and that of potassium lower than the values obtained by X-ray microanalysis. This can probably be attributed to the fact that in atomic absorption spectrometry and in neutron activation analysis the entire muscle biopsy …

Correlated Microscopic Observations Of Arterial Responses To Intravascular Stenting, K. A. Robinson, G. Roubin, S. King, R. Siegel, G. Rodgers, R. P. Apkarian

Scanning Microscopy

Percutaneous catheter implantation of intravascular stent prostheses has emerged as a novel clinical adjunct to balloon angioplasty in the treatment of obstructive atherosclerotic vascular disease. We have examined the cellular and subcellular responses to stenting in the coronary arteries of the dog and pig (both normal and atherosclerotic), and in the iliac arteries and aorta of the atherosclerotic rabbit, using scanning electron, transmission electron, and light microscopies. Stenting in these models resulted in a thrombotic reaction ranging from mild to severe, depending on species and antithrombotic therapy. Subsequent organization of thrombotic material with hyperplasia of smooth muscle and inflammatory cells, …

A Review On The Use Of Bulk Specimen X-Ray Microanalysis In Cancer Research, I. Zs.-Nagy

Scanning Microscopy

The freeze-fracture, freeze-drying ( FFFD) method of biological bulk specimen preparation combined with quantitative X-ray microanalysis is suitable for the measurement of intracellular concentrations of biologically relevant elements in human biopsy or experimental animal materials. Especially useful information can be obtained regarding the intracellular Na⁺/K⁺ ratios being independent of the actual (and unknown) water content of the cytoplasm. The sustained increase of this ratio indicates a sustained depolarization of the cell membrane. These data are of importance from the point of view of the membrane hypothesis of mitogenesis (MHM). It has been revealed that the distribution histograms …

The Chorioallantoic Capillary Plexus Of The Chicken Egg: A Microvascular Corrosion Casting Study, G. J. Burton, M. E. Palmer

Scanning Microscopy

The chorioallantoic membrane of the avian egg serves as the principal organ of respiratory gaseous exchange for the embryo until close to hatching. It lies closely apposed to the inner shell membrane and contains an extremely dense capillary plexus supplied by the allantoic blood vessels. This study applied the microvascular corrosion casting technique to investigate the three-dimensional arrangement of the plexus at various stages of incubation. Casts were produced between days 6 and 14 of incubation, and their appearances were compared with those obtained from traditionally sectioned material and from freeze-cleaved specimens.

By day 6 the capillary network was remarkably …

Application Of The Pyroantimonate Method And Electron Probe Microanalysis To The Study Of Glycogen Metabolism In Liver, Pascale Mentré, Sylvain Halpern

Scanning Microscopy

Glycogen distribution in the liver of mouse under different metabolic conditions was studied by the pyroantimonate (PA) method combined with semi-quantitative electron probe microanalysis (EPMA). In the liver of animals subjected to a sugar-rich diet, glycogen granules were abundant and electron transparent. In fasted animals, they were less numerous and stained by PA, which indicates the presence of a complexed cation. This cation was identified as calcium by EPMA. In both cases, adjacent cytoplasmic areas contained "masked" calcium not revealed by PA but detected by EPMA, which is characteristic of a neutral complexed form; but in the case of the …

Bioremediation Of Contaminated Surface Soils, J. L. Sims, R. C. Sims, J. E. Matthews

Reports

Biological remediation of soils contaminated with organic chemicals is an alternative treatment technology that can often meet the goal of achieving a permanent clean-up remedy at hazardous waste sites, as encouraged by the U.S. Environmental Protection Agency (U.S. EPA) for implementation of The Superfund Amendments and Authorization Act (SARA) of 1986. Bioremediation is consistent with the philosophical thrust of SARA, for it involves the use of naturally occurring microorganisms to degrade and/or detoxify hazardous constituents in the soil at a contaminated slip to protect public health and the environment.Bioremediation of contaminated soils, including applications and limitations, has been addressed.

X-Ray Microanalysis Of Hamster Tracheal Epithelium, A. J. Spencer, G. M. Roomans

Scanning Microscopy

Studies of ion transport across respiratory epithelia are of great interest if we are to understand the pathophysiology of diseases such as cystic fibrosis in which ion transport is abnormal. Concentrations of elements were determined in various subcellular regions of normal or isoproterenol-treated hamster tracheal epithelium, using X-ray microanalysis of freeze-dried cryosections. Samples of trachea were taken from animals under anesthesia and either frozen in situ or dissected and plunge frozen. Concentrations of Mg, P, S, Cl, K and Ca were higher in cytoplasm and nuclei of control epithelial cells in dissected samples than in cryoneedle samples. Following treatment with …

Scanning Tunneling Microscopy Of Proteins On Graphite Surfaces, L. Feng, J. D. Andrade, C. Z. Hu

Scanning Microscopy

We applied scanning tunneling microscopy (STM) to the observation of amino acids and proteins deposited and/or adsorbed on highly oriented pyrolytic graphite (HOPG).

Although many questions remain, it is demonstrated that relatively high resolution images of uncoated proteins can often be obtained in air. We present images of five amino acids (glycine, leucine, lysine, methionine and tryptophan) and three proteins (lysozyme, albumin and fibrinogen) under various conditions of deposition and adsorption. We discuss the role of affinity of the amino acids and proteins to the substrate, their adsorbed states and distribution, and STM tip-induced deformation and/or destruction.

STM studies of …

Quantitative Electron Probe X-Ray Microanalysis In Biology, T. A. Hall

Scanning Microscopy

This review summarizes existing formalisms for the quantitative analysis of biological specimens, and considers the analysis of bulk specimens, micro-droplets, homogenates, and thin or ultrathin sections, respectively. For (ultra)thin sections, one may use elemental ratios for semi-quantitative analysis, measure elemental concentrations as mmol/volume using peripheral standards, or as mmol/kg using the continuum method. Often it is physiologically more relevant to know the concentration of ions as mmol/kg water. This can be achieved by analysing the specimen first in the frozen-hydrated state and then again after freeze-drying, or by using a peripheral standard. Attention has to be given to the selection …

Polarized Membrane Domains Of Fibroblasts, Z. Somosy, Tamara Kubasova, G. J. Köteles

Scanning Microscopy

Data on the heterogeneous distribution of various membrane domains on the surface of fibroblasts are reviewed. Polarized localization of negative charges is demonstrated and new results on the development and maintenance of polarity in primary human fibroblasts are presented. Cell membrane heterogeneity in fibroblasts and in other cells is compared. Our results indicate that the regional localization of membrane domains of fibroblasts, and their dependence on cell movement and cell contacts is in several aspects similar to that described for epithelial cells.

Effect Of Duct Obstruction On Structure, Elemental Composition, And Function Of Rat Submandibular Glands, Samuel Sagström, Gun-Britt Sagulin, Godfried M. Roomans

Scanning Microscopy

Obstruction of salivary glands occurs in association with a number of pathological conditions. It has been suggested that the major changes found in the salivary glands of patients with cystic fibrosis are due to obstruction of the excretory duct by viscous mucus. In the present study, the effect of excretory duct obstruction on structure, elemental composition and function of rat submandibular gland was investigated. Obstruction was effected by infusion of a fast-hardening protein emulsion in the main excretory duct. After 1 week, and more pronounced after 2 weeks of obstruction the number of granular duct cells had decreased in the …

Element Concentrations In The Intestinal Mucosa Of The Mouse As Measured By X-Ray Microanalysis, Thomas Von Zglinicki, Godfried M. Roomans

Scanning Microscopy

Subcellular ion distribution in villus, crypt, Paneth and smooth muscle cells of the mouse small intestine under resting conditions was investigated by X-ray microanalysis of ultrathin cryosections. In addition, the mass distribution was estimated by measuring the optical transmission of the compartments in transmission electron micrographs.

Each cell type is characterized by a special composition in terms of the major monovalent ions Na, K, and Cl. In particular, among crypt epithelial cells, those cells containing small secretion granula (termed crypt A cells) also display cytoplasmic ion concentrations significantly different from crypt epithelial cells lacking secretion granula (crypt B cells). Monovalent …

1989 Annual Report And Planning Meeting, Various Authors

Annual Reports

No abstract provided.

Processing Of Particle Induced X-Ray Emission (Pixe) Spectra Contrasted With Electron Probe Microanalysis, J. L. Campbell

Scanning Microscopy

PIXE (proton-induced X-ray emission) analysis and EPMA (electron probe microanalysis) give rise to similar energy-dispersive X-ray spectra, and so the processing of these spectra has common elements. Consequently approaches developed for EPMA may be of use in PIXE, one example being methodology for removing the continuous background. However various special aspects of PIXE result in a somewhat more complex problem. The range of X-ray energies of interest is wider and K X-rays of medium atomic number elements tend to be used where EPMA would rely upon their L X-rays; since the projectile penetration is much greater, matrix corrections are larger; …

The Opisthonephric Blood Vascular System Of The Chicken Embryo As Studied By Scanning Electron Microscopy Of Microvascular Corrosion Casts And Critical Point Dried Preparations, H. Ditrich, H. Splechtna

Scanning Microscopy

Microvascular corrosion casts of chicken embryos between four and 19 days after fertilization have been prepared. The developing kidney was investigated with scanning electron microscopy (SEM). The injection technique and resin composition were modified in order to facilitate the complete replication of native blood vascular systems of specimens as small as 15 mm body length. The development of the opisthonephros was followed from near the beginning of its function until a vascular development comparable to the adult situation was reached. Critical point dried glomeruli show the differentiation of the glomerular visceral epithelium (podocytes) from initially epithelioid to highly branched forms. …

Inspection Of Single-Point Diamond Turning Tools At Low Accelerating Voltage In A Scanning Electron Microscope, Michael T. Postek, Christopher J. Evans

Scanning Microscopy

Single crystal diamond tools used in the machining process have been inspected in both the optical microscope and scanning electron microscope. Attention was focused on surface characteristics related to the specific polishing process and its relationship to cutting-edge structure. The need for tool inspection is discussed as well as the drawbacks with the inspection techniques presently used. Low accelerating voltage ( < 2.5 keV) inspection of uncoated diamond tools for machining is shown to be a viable method for the determination of polishing flaws that grossly reflect in the surface quality of the finished part.

The Effects Of Retinoic Acid And Butyric Acid On In Vitro Migration By Murine B16a Cells: A Quantitative Scanning Electron Microscopic Study, T. W. Mcgarvey, B. Persky

Scanning Microscopy

Retinoic acid (RA) and butyric acid (BA) were investigated for their effect on in vitro migration of highly metastatic murine B16a melanoma cells. These potential antitumor agents are known to alter the cytoskeleton. Our initial studies determined the 72 h cytostatic /cytotoxic concentration of RA (1 X 10^-6 M / > 1 X 10^-5M) and BA (1.5 mM) / > 2.0 mM). Cytostasis by RA and BA was confirmed by autoradiography and radioisotope incorporation. For migration assays, cells were plated on 3 and 5 μm diameter pore polycarbonate membranes. Complete media was added containing RA or BA at time …

The Lectin-Gold Technique: An Overview Of Applications To Pathological Problems, P. Versura, M. C. Maltarello, F. Bonvicini, R. Laschi

Scanning Microscopy

Lectins are proteins, mainly of vegetal origin, which recognize glycosidic residues with high specificity; for this property they have been used for many studies of molecular biology. The colloidal gold represents at present the most popular electron dense marker employed in immunocytochemistry, since it offers intrinsic and unique characteristics which are superior to those displayed by the other markers.

The cytochemical method which utilizes the gold-labelled lectins takes advantages from both the two systems, in order to optimize the localization of the glycoconjugates.

The present paper reviews both the technical aspects of the preparation of the lectin-gold complex and its …

Recent Uses Of Electron Microscopy In The Study Of Physico-Chemical Processes Affecting The Reactivity Of Synthetic And Biological Apatites, J. D. B. Featherstone, D. G. A. Nelson

Scanning Microscopy

Studies which used scanning electron microscopy (SEM) to investigate subsurface demineralization of dental enamel have recently been well reviewed. The purpose of the present paper was to review several studies, carried out in our laboratories, which have used electron microscopy to examine physicochemical properties of synthetic and biological apatites, to relate these results to previous studies, and to present new data.

Aspects of the ultrastructure of hydroxyapatite and carbonated-apatites have been observed by high resolution transmission electron microscopy, and related to shape and growth of these crystals.

Surface morphologies of discs prepared from precipitated carbonated-apatites and from ceramic carbonated-apatites were …