Life Sciences Commons^™

Measurement Of Fungicide Smoke Application By Electron Beam Analysis, C. R. Krause, C. C. Powell

Scanning Microscopy

Low volume fungicide smoke particle deposits were studied with scanning electron microscopy and energy dispersive X-ray analysis. Under greenhouse conditions, particles deposited on Rhododendron leaf surfaces and onto inert, carbon planchets adjacent to Rhododendron leaves were characterized by electron beam analysis. Angular particles containing chlorine, identified as vinclozolin deposition, were quantified on a per unit area basis. Leaf samples collected from plants immediately adjacent to the smoke applicator had more particles than leaf samples collected elsewhere. More deposition was measured on leaf surfaces than on inert planchet surfaces. This study increased our knowledge about the effectiveness of using less fungicide …

The Use Of Scanning Electron Microscopy For Investigations Into The Three Dimensional Organisation Of The Interphase Nucleus, T. D. Allen, P. M. O'Connor

Scanning Microscopy

In an attempt to elucidate three dimensional information on the organisation of the nucleus, nuclei have been extracted from ascites tumour cells or tissue culture cells by a variety of biochemical techniques, and prepared for high resolution scanning electron microscopy using an osmium-thiocarbo-hydrazide infiltration procedure which has previously proved successful for analysis of chromosome structure. Nuclei were prefixed with either Methanol-Acetic acid, glutaraldehyde or formaldehyde and then extracted by a variety of detergents with the aim of a 'biochemical dissection' of their outer elements to allow surface visualisation of the nuclear lamina. Continued extraction removed all aspects of the nuclear …

Fine Structure And Organ Culture Of Chick Embryo Dorsal Aorta, C. Ward Kischer, Michael Jaqua

Scanning Microscopy

Embryonic blood vessels have not been grown in organ culture, in a way which might easily submit them to studies of vascular organogenesis. The chick embryo dorsal aorta is easily accessible and relatively simple to explant to culture. Its organ culture may provide a model for wounding and repair of the intima and/or media and provide a model for studies of growth (or maintenance) and differentiation. Fresh dorsal aorta and its organ culture from the chick embryo was characterized morphologically by light microscopy scanning (SEM) and transmission electron microscopy (TEM) from days 4 to 18. Explants were incubated up to …

Observations Of Colloidal Gold Labelled Platelet Microtubules: High Voltage Electron Microscopy And Low Voltage-High Resolution Scanning Electron Microscopy, R. M. Albrecht, J. Prudent, S. R. Simmons, J. Pawley, J. J. Choate

Scanning Microscopy

18 nm colloidal gold-antitubulin and 4 nm colloidal gold-antitubulin were used to label microtubules in adherent, fully spread platelets. Both sizes of marker effectively labelled microtubules in the partially extracted platelets. However only the 4 nm gold penetrated the dense microfilament matrix of the inner filamentous zone so that portions of microtubules within this cytoskeletal zone could be tracked. The gold marker could be visualized well with 1 MeV high voltage transmission EM and with 5 kV or greater secondary imaging or 20 kV backscattered imaging of carbon only coated samples. 1 kV secondary imaging permitted high resolution imaging of …

Quantitative Margin Analysis In The Scanning Electron Microscope., J. F. Roulet, T. Reich, U. Blunck, M. Noack

Scanning Microscopy

Interface between restorative materials and tooth hard substances must be morphologically as perfect as possible to avoid plaque accumulation and subsequent secondary caries or pulpal diseases. Therefore the marginal behavior of restorations is an important parameter to predict their longevity.

Morphologically, the quality of margins is characterized by different well defined criteria. Using a replica technique it is possible to assess the complete marginal circumference of restorations in the SEM. Margins of restorations show a large variety of their morphology. This publication describes a method to quantify the quality of dental restorations.

The restoration margins are traced on the SEM …

Optical Design Considerations In Confocal Scanning Microscopy, T. Wilson

Scanning Microscopy

We review the properties and applications of confocal optical systems. We concentrate on non-fluorescent reflection systems and on applications which make use of the unique optical sectioning property of these instruments to provide three-dimensional images. A crucial design choice concerns the form and size of the detector. We therefore concentrate on the role of the detector size on the strength of the optical sectioning. We find that although the sectioning becomes weaker as the detector sizes where the sectioning remains essentially constant. We also consider the role of lens aberrations which are inevitably present and find, inter alia, that these …

Stimulation Of Collagen Formation In The Intestinal Anastomosis By Low Dose He-Ne Laser, David T. Yew, Winnie W. Y. Li, K. M. Pang, Y. C. Mok, C. Au

Scanning Microscopy

The effect of low dose He-Ne laser on the healing of intestinal anastomosis was studied in the albino rat. A small piece of jejunum was removed from each rat and the ends sutured back with a simple interrupted pattern. In the experimental animal, the anastomosis was Irradiated through an optic fiber with a He-Ne laser (1 mW) for 15 minutes whereas in the control animal, the anastomosis was not irradiated. The differences between the two groups were compared by histology, transmission electron microscopy, scanning electron microscopy and autoradiography 3 and 7 days after operation. The laser treated experimental animals demonstrated …

Complementary Surface Characterization Of Chalcopyrite By Electron Microscopy, Electron Spectroscopy, And Optical Reflectance, P. H. Ruzakowski, P. H. Holloway, G. Remond

Scanning Microscopy

Surface oxidation of polished natural specimens of chalcopyrite (CuFeS₂) at temperature between 23°C and 300°C in air has been characterized by Auger electron and X-ray photoelectron spectroscopies. The reaction products consisted of an outer iron oxide layer and an intermediate copper rich sulfide layer. Several different oxides and sulfides were consistent with the electron spectroscopy data, so specimens were analyzed as a function of time and temperature at selected 20 μm diameter areas with an optical microreflectometer (OMR). Since the optical properties of a compound are unique, a reflectance model with three homogeneous layers was used to calculate …

A New Versatile Holder For The Calibrating Standard Used For Quantitative Analysis In Jeol 840 Sem, Michael Dvorachek

Scanning Microscopy

An improved holder has been designed for a cobalt calibrating standard used in an EDS Link 10,000 system attached to a JEOL 840 SEM. This holder allows the calibration of the EDS software for a wide range of samples differing in size, surface and height. These differences usually cause difficulties during quantitative analyses. The new holder allows the position of the cobalt to be adjusted according to the size and height of the sample.

Ultrastructural And Functional Effects Of Lipopolysaccharide And Interleukin-2 On Human Nk Cells, Yuan-Hsu Kang, Mitchell Carl, Lorrita P. Watson

Scanning Microscopy

Bacterial endotoxin (lipopolysaccharide, LPS) and interleukin-2 (IL-2) are known to stimulate NK cell mediated cytotoxicity against tumor cells. In the present report we sought to correlate the stimulatory effect of LPS and IL-2 on NK cell activity with ultrastructural changes which occurred as a result of such stimulation. Peripheral blood mononuclear cells (PBMC) were purified from healthy donors by a Ficoll-Hypaque density gradient technique. Leu-11a⁺ NK cells were isolated by flow microfluorometry using a monoclonal FITC conjugated anti-Leu-11a antibody and a FACS II cell sorter. The PBMC were incubated, respectively, with E. coli LPS or recombinant IL-2 (IL-2) for …

Crystal Associated Diseases: Role Of Scanning Electron Microscopy In Diagnosis, K. P. H. Pritzker, P. -T. Cheng, M. D. Grynpas, D. P. Holmyard

Scanning Microscopy

As crystals are important etiologic agents for disease, their accurate identification in tissues and body fluids is of utmost importance. This paper surveys the roles of crystals in disease process and outlines current analytical techniques for crystal detection and identification in bone tissues. The value of multiple correlated techniques is demonstrated including scanning electron microscopy, x-ray energy spectroscopy and powder diffraction analysis. The current feasibility of utilizing intermediate voltage scanning transmission analytical electron microscopy to integrate these analytical techniques on the same tissue sample is emphasized.

Clinical Applications Of Electron Microscopy In The Analysis Of Collagenous Biomaterials, Arthur J. Wasserman, Charles J. Doillon, Alvin I. Glasgold, Y. Pedro Kato, David Christiansen, Azam Rizvi, Eric Wong, Jack Goldstein, Frederick H. Silver

Scanning Microscopy

Scanning and transmission electron microscopy are of clinical value in assessing the interaction between biomaterials and ingrowing tissues. Ultrastructural information allows the clinician and biomaterials specialist to determine events occurring during wound healing and the biocompatibility of prosthetic devices. This paper reviews some of the experimental and clinical studies done in our laboratory on the use of natural and reconstituted collagen as replacements for connective tissues. Consideration is given to collagen flakes used for the treatment of dermal ulcers, a collagen fiber prosthesis used for tendon and ligament replacement, the effects of chemical preservatives on cartilage used for replacement of …

Scanning Tunneling Microscopy Methods For Spectroscopic Imaging Of Subsurface Interfaces, L. D. Bell, W. J. Kaiser

Scanning Microscopy

A new method for spatially-resolved, spectroscopic investigation of subsurface interface structure has been developed. The method, Ballistic Electron Emission Microscopy (BEEM), is based on Scanning Tunneling Microscopy (STM) techniques. BEEM combines STM vacuum tunneling with unique ballistic electron spectroscopy capabilities. BEEM enables, for the first time, direct imaging of subsurface interface electronic properties with nanometer spatial resolution. STM topographic images of surface structure and BEEM images of subsurface properties are obtained simultaneously. BEEM capabilities are demonstrated by investigation of important metal-semiconductor interfaces.

Effect Of Fluoride And Cobalt On Forming Enamel: Scanning Electron Microscope And X-Ray Microanalysis Study, S. H. Ashrafi, D. R. Eisenmann, A. E. Zaki, R. Liss

Scanning Microscopy

The forming surfaces of enamel of rat incisors were examined by scanning electron microscope one hour after injection of either 5 mg/100 g body weight of sodium fluoride or 12 mg/100 g body weight of cobalt chloride. The cell debris from the surfaces of the separated incisors was either gently wiped off with soft facial tissues or chemically removed by treating with NaOH, NaOCl or trypsin. Best results to remove cell debris were obtained from 0.25% trypsin treatment.

SEM studies revealed that the surface of the normal secretory enamel was characteristic in appearance with well-developed smooth prism outlines. In fluoride …

Double-Axis Rotary Shadowing For High-Resolution Scanning Electron Microscopy, R. Hermann, J. Pawley, T. Nagatani, M. Müller

Scanning Microscopy

Thin continuous metal coatings and a scanning electron microscope-generated spot size in the range of the visualized particles, are necessary prerequisites if one hopes to extract high-resolution topographic information in the scanning electron microscope. Chemical fixation and dehydration in organic solvents at room temperature lead to severe ultrastructural artifacts which can be avoided by cryofixation and freeze-drying of the specimen. 0.9 to 2.7 nm thick homogeneous layers of chromium and germanium can be deposited onto the surface of cryofixed and freeze-dried specimens at high sub-zero temperatures by electron beam evaporation using "double-axis rotary shadowing". Theoretical calculations of the layer geometry …

Detectors For Quantitative Electron Beam Voltage Measurements, A. R. Dinnis

Scanning Microscopy

Qualitative voltage contrast is produced without difficulty in any SEM. Complete separation of the voltage contrast from other sources of contrast is not a straightforward matter because of the nonlinear relations between the phenomena causing contrast and the video signal.

Quantitative measurements depend on the availability of electron energy analysers which can detect accurately the shift in secondary electron energies due to potentials appearing on integrated circuit tracks, without being affected by transverse fields due to potentials on other conductors or insulators. The principles underlying existing detectors are explained, their effectiveness assessed, and a new form of electron detector is …

Signal Of Backscattered Electrons From Multiple Marks In Dependence On Mark Profile, D. Kaczmarek, Z. Czyżewski

Scanning Microscopy

The backscattered electron signal can be detected using a solid state detector system. Because this signal is affected by the surface topography it is necessary to determine the optimal detection condition for a registration mark detection in the electron-beam lithography and for an automatic topographical surface reconstruction.

The BSE signal from surface marks has been measured using semiconductor detectors with a small collection angle. Calculations of the BSE signal have been carried out by means of a simplified model of electron backscattering. The signal shape depends on some parameters of the mark profile, such as length, height and inclination angle …

Contribution Of Densely Distributed Electron Beam Induced Current Contrasts In Annealed Cz Silicon To Bulk Recombination, M. Kittler, W. Seifert

Scanning Microscopy

The paper presents a detailed analysis of Electron Beam Induced Current (EBIC) diffusion-length and contrast data for samples containing defect accumulations. The formulae given allow one to estimate to which extent the average diffusion length is determined by recombination-active defects showing EBIC contrast.

This analysis may be used to identify essential sources of bulk recombination in annealed silicon. In the light of our results stacking faults are an essential source of bulk recombination in intrinsically gettered p-type Cz silicon.

Mounting Materials For Automated Image Analysis Of Coals Using Backscattered Electron Imaging, W. E. Straszheim, K. A. Younkin, R. T. Greer, R. Markuszewski

Scanning Microscopy

In order to apply SEM-based automated image analysis (AIA) to the characterization of not only minerals in coal but to the coal itself, sample preparation methods need to be developed beyond common practice. A significant consideration is the degree of contrast achievable between the mount media chosen and the coal. Four low-atomic number materials (epoxy, polyethylene, polystyrene and carnauba wax) were compared for their potential as suitable mounting media for coal samples. Epoxy is satisfactory only for characterization of mineral particles since the contrast between epoxy and coal particles is negligible. Polyethylene or polystyrene have marginal application for use as …

The Use Of Backscattered Electron Imaging, X-Ray Microanalysis And X-Ray Microscopy In Demonstrating Physiological Cell Death, I. D. Bowen, N. A. Worrill, C. A. Winters, K. Mullarkey

Scanning Microscopy

The cytochemical localization of enzymatic activity by means of backscattered electron imaging (BEi) is reviewed and the application of BEI to changes in acid phosphatase and ATPase distribution during physiological (programmed) cell death in Heliothis midgut is explored. Programmed cell death entails the release of nascent free acid phosphatase as extracisternal hydrolase. This shift can readily be detected by means of the atomic number contrast imparted by BEI of the lead phosphatase reaction product, thus enabling the distribution of dying cells to be mapped. BEI is particularly useful in this context as it allows the examination of bulk specimens at …

Scanning Electron Microscopic Autoradiography Of Lung, K. E. Lauhala, C. L. Sanders, K. E. Mcdonald

Scanning Microscopy

Scanning electron microscopic (SEM) autoradiography of the lung is being used to determine the distribution of inhaled, alpha particle-emitting, plutonium dioxide particles. SEM autoradiography provides high visual impact views of alpha activity. Particles irradiating the bronchiolar epithelium were detected both on the bronchiolar surface and in peribronchiolar alveoli. The technique is being used to obtain quantitative data on the clearance rates of plutonium particles from bronchi and bronchioles.

The Influence Of Analyser Geometry Effects In Scanning Electron Microscope Voltage Contrast Measurements, Daniel S.H. Chan, Teck Seng Low, Wai Kin Chim, Jacob C. H. Phang

Scanning Microscopy

A computer simulation model used to study specimen dependent and analyser geometry dependent effects is described in this paper. With this model, the influence of the specimen dependent effect on quantitative voltage contrast measurements can be isolated from the analyser geometry dependent effect. Linearization error voltages in quantitative voltage contrast measurements arising from the individual influences of the specimen dependent and analyser geometry dependent effects are presented. The results show that the error component due to very narrow analysers dominate the total linearization error. The same situation arises when the voltage measurement point on the specimen is very near to …

Secondary Ion Mass Spectrometry Studies Of Isotope Effect In Diffusion, U. Södervall, H. Odelius, A. R. E. Lodding

Scanning Microscopy

The mass effect of diffusion is of interest in connection with interactions between defects and impurities and with the mechanisms of atomic displacements in the condensed states. The delineation entails the precise measurement of the isotope ratio as function of tracer concentration, varying within several orders of magnitude along the diffusion profile. The measurement by SIMS (secondary ion mass spectrometry), using stable isotopes, has proved to possess advantages compared to familiar techniques with radiotracers. However, the aims require the utmost counting economy and optimal precision available in SIMS, including the control of the mass fractionation and of some features peculiar …

An Electron Microscopic Study Of Hemopoietic Tissues In The Course Of Lewis Lung Carcinoma, Cheryl Hardy, Yuzhi Wang, Bettye Collier, Mehdi Tavassoli

Scanning Microscopy

Lewis lung carcinoma of C57Bl/6 mice causes a progressive anemia with reticulocytosis and splenomegaly, metastasizes to lungs, liver, and kidneys but does not invade hemopoietic tissues. The cause of this anemia is uncertain. We studied the structure of spleen and bone marrow in these tumor hosts by light and electron microscopy. Splenic congestion of the red pulp with numerous erythropoietic islands and marrow hyperplasia characterized the hemopoietic tissues of these mice, which, when coupled with other hematological parameters suggested a hemolytic condition. However, the erythropoietic response appeared to be in part ineffective as evidenced by phagocytosis of immature as well …

Basis Of The Structure And Development Of Mammalian Enamel As Seen By Scanning Electron Microscopy, A. Boyde, M. Fortelius, K. S. Lester, L. B. Martin

Scanning Microscopy

Mature enamel is the most mineralized of mammalian tissues, contains the least water and therefore does not present problems of shrinkage on preparation for SEM. However, the developing enamel is highly hydrated and presents severe problems in preparation.

The structure of enamel is determined by the activity of its individual formative cells and their group behaviour. The peculiar, unequal secretion of matrix at the distal pole of the ameloblast leads to the presence of characteristically shaped pits in the surface of the formative tissue. Crystals grow in a special relationship to this surface. Sharp changes in orientation of the surface …

Bovine Aorta Endothelial Cell Incubation With Interleukin 2: Morphological Changes Correlate With Enhanced Vascular Permeability, Corazon D. Bucana, Joann Trial, Audrey C. Papp, Kenneth K. Wu

Scanning Microscopy

Interleukin 2 induced alterations in the morphology of bovine aortic endothelial cells in vitro. The changes observed in confluent cultures of bovine aortic endothelial cells included retraction and elongation of eel ls leading to enlarged gaps between cells quantified by image analysis. Purified IL-2 (1 U/ml medium) increased the gaps between endothelial cells 3-4-fold compared with control cultures. The effect was transient, since the cells reverted to their original morphology 6-12 hours after the removal of lL-2. Correlative scanning electron microscopy (SEM) studies using fresh bovine aorta showed a dose-dependent alteration of the endothelial surface by IL-2 characterized by rounding …

Topographic Evolution In The Atomic Scale Growth And Erosion Continuum, G. Carter, I. V. Katardjiev, M. J. Nobes, J. L. Whitton

Scanning Microscopy

This review gives a detailed survey of the range of fascinating surface features which develop under growth or erosion conditions under the combined influence of thermal and more energetic atomic particle fluxes. Collisionally induced atomic ejection and migration, and thermally and radiation induced atom and defect diffusion processes are outlined and their relevance to topographic initiation and evolution explored. A range of experimental observations of surface feature elaboration is discussed from net growth to net erosion conditions and models for their explanation are considered. It is concluded that while much data have been accumulated, much of these have been in …

Quantitative Analysis Of Particulate Burden In Lung Tissue, J. P. Mastin, L. E. Stettler, J. D. Shelburne

Scanning Microscopy

Numerous methods have been used in the preparation and analysis of the particulate matter deposited in human lungs. Preparation techniques include those for particle isolation and for in situ analysis. Analytical techniques include bulk and particle-by-particle analysis. In this paper, a general discussion of many of these methods is presented along with examples of how two specific techniques have been used. In one study, individual particles from the lungs of 75 randomly selected autopsy cases were analyzed using an automated scanning electron microscopy (SEM)/ energy dispersive X-ray microanalysis (EDX) system. An average of 613 million particles, of exogenous origin, per …

Defect Detection And Thickness Mapping Of Passivation Layers On Integrated Circuits Using Energy Dispersive X-Ray Analysis And Image Processing Techniques, Richard G. Sartore

Scanning Microscopy

The relative thickness of passivation layers has been mapped for integrated circuits by utilizing the penetration voltage method, in conjunction with energy dispersive x-ray analysis (EDXA) and a scanning electron microscope (SEM), to detect defects and map film thickness. The thickness mapping technique was evaluated for area coverage and correlated to size of defective areas. The purpose of this study was to determine optimal operational conditions for fast and accurate defect detection on an integrated circuit for failure analysis and non-destructive process evaluation. Image processing was required to enhance the acquired map and to obtain a calibrated image for relative …

Application Of Photovoltage Imaging To Semiconductor Wafer Characterization, Kanji Kinameri, Chusuke Munakata, Noriaki Honma, Hiromichi Shimizu

Scanning Microscopy

A technique for imaging the distribution of ac surface photovoltages induced in a semiconductor wafer by the irradiation with a blue or near-infrared chopped photon beam is applied to non-destructive inspection of faults in Si or GaAs wafers. Faults detected include crystal defects, radiation damage, surface charge-up, striation and junction inhomogeneity. The principles of inspecting for the above mentioned wafer faults are quantitatively presented by numerical analyses of dependence of ac surface photovoltage on wafer electronic characteristics. The minimum detectable changes in minority carrier lifetime, interface trap density, fixed oxide charge density and resistivity for a depleted p-type Si wafer …