Digital Commons Network^™

Detectors For Fluorescence Microscopy, Kenneth R. Spring

Scanning Microscopy

The low light levels originating from living cells viewed in the fluorescence microscope place significant limitations on the spatial and temporal resolution which can be achieved . The development of intensified video cameras has enabled the detection , visualization and measurement of these low level signals . The performance characteristics of popular intensified video cameras are compared and guidelines are given for the selection of the appropriate detector for various experimental requirements. Intensified or cooled CCD cameras appear to be the most suitable device for quantitative imaging at low light levels in fluorescence microscopy.

Lung Particulate Burdens Of Subjects From The Cincinnati, Ohio Urban Area, L. E. Stettler, S. F. Platek, R. D. Riley, J. P. Mastin, S. D. Simon

Scanning Microscopy

Because of the relatively small data base existing for lung particulate burdens of subjects with no overt pneumoconioses, the total exogenous lung particulate concentrations of 91 subjects from the Cincinnati, Ohio urban area were determined using an automated scanning electron microscope-energy dispersive x-ray analysis-image analysis system. Four of these subjects were foundry workers and had the highest exogenous particle concentrations seen in the 91 lungs, ranging from 1860 to 2990 x 10⁶ particles per gram of dry lung (ppg). The average exogenous particle concentration for the remaining 87 subjects was 476 ± 380 x 10⁶ ppg with a …

X-Ray Microanalytical Studies Of Freshwater Biota: Changes In The Elemental Composition Of Anabaena Spiroides During Blooms Of 1988 And 1989, S. Clay, D. C. Sigee, E. Bellinger

Scanning Microscopy

Samples of Anabaena spiroides were collected from a eutrophic freshwater lake (Rostherne Mere, Cheshire) during the bloom periods of 1988 and 1989, and analysed by SEM electron probe X-ray microanalysis. Vegetative cells, akinetes and heterocysts consistently had clear peaks of Mg, Si, P, S, Cl, Kand Ca.

In comparison to vegetative cells, akinetes had generally higher elemental mass fractions (particularly K and P) while heterocysts had significantly lower levels of Mg, P, and Ca.

For both years, elemental mass fractions in vegetative cells showed significant changes during the course of the bloom, but these were not consistent from one year …

A Straightforward Scanning Electron Microscopy Technique For Examining Non-Metal Coated Dental Hard Tissues, S. M. Mccormack, F. J. Tormo, J. D. B. Featherstone

Scanning Microscopy

Modifications to the standard operating settings for accelerating voltage , condenser lens current, scan rate, working distance and tilt on the conventional scanning electron microscope (SEM) enabled non-metal coated dental hard tissues and synthetic apatite pellets to be viewed free of charging effects . Well -resolved images at magnifications as high as 35,000x were achieved using accelerating voltages less than 5 kV . The methodology detailed here allowed for serial SEM examination of the same sample at various points during an experimental procedure , and may be applied to other sample types. The procedure is non-destructive to the sample and …

Microcirculatory Pathways And Blood Flow In Spleen: New Insights From Washout Kinetics, Corrosion Casts, And Quantitative Intravital Videomicroscopy, A. C. Groom, E. E. Schmidt, I. C. Macdonald

Scanning Microscopy

The dynamics of splenic microcirculatory blood flow and the role of the spleen with respect to red blood cells (RBCs) have been elucidated by means of several different experimental approaches. First, the organ was treated as a 'black box' and input/output relationships were studied, such as the kinetics of RBC and plasma washout during Ringer perfusion. Second, micro-corrosion casts were prepared from minimal amounts of injected material, such that 'fast' pathways for flow were selectively identified. Third, high-resolution video-microscopy was carried out in rat and mouse spleens transilluminated in vivo, with subsequent quantitative analysis of the data. New insights were …

Microprobe Analyses Of The Potassium-Calcium Distribution Relationship In Predentine, H. J. Höhling, H. Mishima, Y. Kozawa, T. Daimon, R. H. Barckhaus, K. -D. Richter

Scanning Microscopy

Apex regions of continuously growing incisors of Wistar rats were quickly dissected, shock-frozen in liquid nitrogen-cooled propane, freeze-dried at -80 °C and infiltrated with Spurr's resin . 400nm thick dry sections were cut with a diamond knife on an ultramicrotome . Relatively flat sections were transferred with an eye lash onto collodium coated aluminum grids. They were flattened with a glass stick and by placing another collodi um coated aluminum grid just on top of the first one, exerting a uniform pressure . After carbon coating the sections were observed using the backscattered and secondary electron signals in a scanning …

The Hall Method In The Quantitative X-Ray Microanalysis Of Biological Specimens: A Review, Godfried M. Roomans

Scanning Microscopy

In the two decades since its inception by T.A. Hall, the continuum theory of quantification has become the general method for quantitative analysis of biological specimens. Although the method was originally developed for thin specimens, its use has been extended to thicker specimens, and it has also been used in quantitative determinations of local water content. The single most important difficulty in the application of the "Hall method" is the accurate calculation of the extraneous continuum, i.e., the continuum due to non-specimen sources. The different variations in methods for quantitative analysis of local water content are critically compared and a …

Scanning Electron Microscopic Analysis Of Mineral Fiber Content Of Lung Tissue In The Evaluation Of Diffuse Pulmonary Fibrosis, Victor L. Roggli

Scanning Microscopy

The mineral fiber content of lung parenchyma in 24 cases of diffuse pulmonary fibrosis of unknown cause was determined by scanning electron microscopy and compared with that of 36 autopsy cases of histologically confirmed asbestosis and 20 autopsy cases of patients with normal lungs . Fibers were isolated from the lung using a hypochlorite digestion technique and collected on the surface of a polycarbonate filter. In addition, the types of fibers present (asbestos vs. other mineral fibers) were determined by energy dispersive x - ray analysis (EDXA). When the histologic grade of fibrosis in the cases of asbestosis was compared …

The Observation Of The Displacement Of Emulsifiers By Confocal Scanning Laser Microscopy, I. Heertje, J. Nederlof, H.A.C.M. Hendrickx, E. H. Lucassen-Reynders

Food Structure

The stability of food emulsions is an important aspect of the processing and the shelf life of many food systems. In order to control the stability, knowledge of the competitive adsorption of different emulsifiers is required. Current methods to study the displacement of emulsifiers from interfaces are rather laborious. A new method has been developed which is based on the observation of a planar interface between oil and water by fluorescent Confocal Scanning Laser Microscopy (CSLM). The displacement of fluorescein isothio-cyanate- labeled sodium caseinate by monoacylglycerols and proteins has been studied. Quantitative information on the competitive adsorption as a function …

High Energy Proton Induced X-Ray Emission And Its Applications, J. S. C. Mckee, G. R. Smith, A. A. Mirzai, M. S. Mathur, N. M. Halden, C. Pinsky, R. Bose

Scanning Microscopy

High energy protons of energies between 30 and 60 MeV are particularly valuable in particle induced X-ray analysis of elements in the rare earth region and above. Transmission samples of thickness up to 100 μm can be used, and damage to both biological and mineral samples is minimal. Detection limits are estimated, and the use of Fourier transformation techniques in the analysis of data is discussed in some detail. The quality of the raw data from mineralogical and biological experiments is such as to permit immediate identification of all elements above Germanium present at the part per million level or …

Digital Correlation Of Ion And Optical Microscopic Images: Application To The Study Of Thyroglobulin Chemical Modification, J. C. Olivo, E. Kahn, S. Halpern, P. Fragu

Scanning Microscopy

A method has been developed in order to digitally correlate ion and optical microscopic images of the same sample areas. Serial cross-sections of human thyroid tissue were analyzed by secondary ion mass microscopy and by light microscopy. The resulting chemical and immunochemical map images were superimposed and correlated by means of a two-pass registration algorithm which allows to correct for geometrical distortions introduced by the ion microscope. Results are presented for the study of thyroglobulin chemical modification in pathological thyroid tissue that demonstrates heterogeneous molecular activity.

Utah Science Vol. 51 No. 3, Fall 1990

Utah Science

96 Shouting from the Rooftop and Lo king under the Table

100 Food Fear That Fizzled

104 When You and Microbes Share the Same Food: How to Prevent Foodborne Illnesses

106 Bacteria 1, Director 0

109 Research in Brief

113 “Natural Isn’t Necessarily Nontoxic

116 Clarifying the Risk of Pesticide Residues

119 Taking Step for Safe Food

120 Home Canning: Do it Safely

121 Tip for Handling Meat and Poultry

124 Food Substitute Pose Nutritional Concerns

125 National Research Council Dietary and Health Recommendations

127 Tests Guarantee Milk’S Safety

128 No Compromises when Safety is Involved

Direct Observations Of Surface Diffusion, Gert Ehrlich

Scanning Microscopy

The field ion microscope, with its ability to depict individual metal atoms on crystals, has made it possible to measure diffusivities of individual atoms. After a brief sketch of the technical problems in such quantitative studies of surface diffusion, data on the effects of different surface structures upon the diffusion characteristics of individual a toms are presented for both bee and fee metals. Through the use of the field ion microscope the mechanisms of atomic motion have for the first time become accessible to direct examination; recent studies are presented which indicate that the traditional view of surface diffusion as …

Classification Of The Apidae (Hymenoptera), Charles D. Michener

Mi

No abstract provided.

Characteristics Of Granulation Tissue Which Promote Hypertrophic Scarring, C. Ward Kischer, Jana Pindur, Peggy Krasovitch, Eric Kischer

Scanning Microscopy

Hyper trophic scars and keloids are characterized by nodules of collagen that originate in granulation tissue arising from full thickness or deep 2° injuries to the skin. Fifty-six granulation tissues of varying ages post-injury were examined morphologically for evidences of how the nodules and, thus, the scar form. New microvessels grow in ascension towards the free surface in a milieu of inflammatory cells and fibroblasts. Collagen deposition increases with time from the base of the wound to the free surface and begins to concentrate between lateral branching of the new microvessels. Computer derived serial reconstructions of hypertrophic scar nodules indicate …

Scanning Electron Microscopy Of The Celloidin-Embedded Inner Ear Sections, Kunihiro Mizuta, Tomoyuki Hoshino, Hirofumi Morita

Scanning Microscopy

The nerve fibers running inside the organ of Corti were studied in cats by scanning electron microscopy (SEM). The fixed temporal bones were decalcified and embedded in celloidin according to the conventional method. Thick serial sections (100-150 μm) were cut parallel to the basilar membrane. After removing the celloidin, the sections were freeze-dried in t-butyl alcohol. Though some outer hair cells had been deformed, the nerve fibers were well preserved for analysis.

Some new findings were observed in the present SEM study. The tunnel spiral bundle in a kitten took an atypical course on the floor of Corti's tunnel apart …

Fine Structure Of The Inner Enamel In Human Permanent Teeth, T. Kodaka, M. Kuroiwa, M. Abe

Scanning Microscopy

Using SEM after EDTA etching, the mid-coronal inner enamel of human permanent teeth was classified into three regions of the 1st, 2nd, and 3rd zones. The 1st zone showing a highly negative birefringence was the innermost 10 - 15 μm enamel. This zone consisted of arcade and circular initial prisms, and the succeeding arcade prisms only. These initial prisms arising perpendicularly to the dentine surface resembled pseudoprisms because these prisms showed a somewhat centripetal arrangement of crystal lites and indistinct prism boundaries. The succeeding prisms were frequently bent following a faint slit within the prism. The 2nd zone adjacent to …

Scanning Electron Microscopy Of Vascular Corrosion Casts - Technique And Applications: Updated Review, A. Lametschwandtner, U. Lametschwandtner, T. Weiger

Scanning Microscopy

The present paper states very briefly the main steps leading to the technique of scanning electron microscopy (SEM) of vascular corrosion casts. From the terms presently used (injection method, microcorrosion cast, injection replica, vascular corrosion cast, vascular cast) the use of "vascular corrosion cast" for lymphatic and blood vessels is recommended. Specification and pretreatment (kind, volume, dosage of anticoagulants, vasoactive substances and spasmolytica used) of the animals examined are referenced as they are available from the literature. The recommendation is given to pay more attention to these parameters than done so far. The steps necessary for producing reasonable and suitable …

Proceedings From The 27th Annual Marschall Italian Cheese Seminar, Various Authors

Cheese Industry Conference

No abstract provided.

Backscattered Electron Imaging And Windowless Energy Dispersive X-Ray Microanalysis: A New Technique For Gallstone Analysis, H. S. Kaufman, K. D. Lillemoe, T. H. Magnuson, P. Frasca, H. A. Pitt

Scanning Microscopy

Scanning electron microscopy with or without conventional energy dispersive x-ray microanalysis is currently used to identify gallstone microstructure and inorganic composition. Organic calcium salts are among many biliary constituents thought to have a role in gallstone nidation and growth. However, current analytical techniques which identify these salts are destructive and compromise gallstone microstructural data. We have developed a new technique for gallstone analysis which provides simultaneous structural and compositional identification of calcium salts within gallstones. Backscattered electron imaging is used to localize calcium within cholesterol at minimum concentrations of 0.01%. Windowless energy dispersive x-ray microanalysis produces elemental spectra of gallstone …

Ultrastructural Investigations Of The Bone And Fibrous Connective Tissue Interface With Endosteal Dental Implants, David E. Steflik, Ralph V. Mckinney, Allen L. Sisk, David L. Koth, Baldev B. Singh, Gregory R. Parr

Scanning Microscopy

The interface between the tissues of the oral cavity and ceramic and titanium cylindrical endosteal dental implants was investigated with correlated light microscopy, transmission electron microscopy and scanning electron microscopy. This study suggested that mandibular bone can directly interface and form an intimate association with one-stage endosteal dental implants. This potential attachment matrix is composed of a composite of calcified bone, and an osteoid unmineralized matrix in association with an apparent osteogenic connective tissue. Further, results from this study suggested that at a level inferior to the junctional epithelium, and superior to the level of crestal bone, fibrous connective tissue …

Scanning Electron Microscopic Studies Of The Oral Tissue Responses To Dental Implants, David E. Steflik, Ralph V. Mckinney, Allen L. Sisk, Gregory R. Parr, David L. Koth

Scanning Microscopy

Scanning electron microscopy ( SEM) and its associated technologies have proven invaluable in elucidating the interfacial oral tissue responses to dental implants. Since the dental implant must extend from the mandibular or maxillary jaw, through the oral mucosa, and into the oral cavity, these tissue responses include epithelium, connective tissue and bone. The continual occlusal forces acting upon these tissues reinforce the dynamic character of these tissue responses. Immediately upon implantation, a healing phase begins as a response to the implanted biomaterial. Following this immediate response a longer healing phase occurs, beginning approximately 1 week after implantation, resulting in the …

Scanning Electron Microscopic Quantitative Study Of Changes With Age In Closing Pattern Of Openings Of Dentinal Tubules On Worn Occlusal Surfaces Of Japanese Permanent Mandibular Incisors, Teruyuki Hojo

Scanning Microscopy

Age-related changes in the closing of dentinal tubules of Japanese permanent mandibular incisors were surveyed using a non-destructive replication technique suitable for SEM analysis at the magnifications of up to X3,000. The areas of openings of dentinal tubules on occlusal surfaces decreased significantly between a 20-39-year age group and a 40+ age group, but the number of the openings tended to decrease. Heavy toothwear on occlusal surfaces of these Japanese permanent incisors was evident even at 27 years of age. A subject or 30 years of age showed surprisingly small number of the opening of dentinal tubules on occlusal surface. …

Kidney Structure Investigations Using Scanning Electron Microscopy Of Corrosion Casts - A State Of The Art Review, H. Ditrich, H. Splechtna

Scanning Microscopy

The corrosion casting technique using acrylic resins in the scanning electron microscope (SEM), was originally developed to investigate renal microvascular structure and is now also successfully used in studies on various other organs. However, in the last two decades nearly 100 papers have been published on the renal vascular anatomy of various taxa of vertebrates or on pathomorphological structures of kidneys, using this technique. Analyzing these works, trends and developments in this field can be summed up as follows: The majority of studies are anatomical works on the vascular system of kidneys from all vertebrate classes. In addition, experimental pathological …

Equations Of Charge Distribution In The Environmental Scanning Electron Microscope (Esem), G. D. Danilatos

Scanning Microscopy

In the environmental scanning electron microscope (ESEM), the electron beam together with various signals emanating from the beam-specimen interaction ionize the gaseous medium in the specimen chamber. A detailed derivation of equations describing the charge density and current flow in the system is presented. It is shown that the various causes of ionization operate over distinct regions, which can be separated out by suitable electrode configuration. The electron probe retains a fraction of electrons with the original charge distribution; this is surrounded by a widespread electron skirt, which, in turn, is surrounded by charge created by the secondary electrons, beyond …

Field Command Of A Tactical Satellite System, Ron Turner, Stephen Hopkins

Small Satellite Conference

One way to ensure tactical satellite systems remain fully responsive to a field commander's needs would be to place all command and control aspects of the system under direct field control. This paper presents the results of a study to evaluate the feasibility of field command of a notional tactical imaging satellite system. The study indicates that such a system is feasible. A satellite constellation can be designed to provide the field commander with significant, timely, tactical data. The hardware is available, or will be within the near term, that enables field command and control facilities manned by a team …

Cryo-Preparation And Planar Magnetron Sputtering For Low Temperature Scanning Electron Microscopy, T. Müller, P. Walther, C. Scheidegger, R. Reichelt, S. Müller, R. Guggenheim

Scanning Microscopy

Cryo-preparation is a reliable technique for the structural investigation of food products in low temperature scanning electron microscopy (SEM). Artifacts, such as, the segregation of water/non-water ingredients, occur during the freezing process by the crystallization of ice; they can be helpful for correct interpretation of visualized details, e.g., the detection of water containing compartments. The size of the segregation structures depends on water concentration and specimen thickness. The condensation of water vapor (ice contamination) is influenced by the specimen temperature and the partial pressure of the water inside the vacuum system. Furthermore, the evaporation (sublimation, etching) of specimen water can …

Gelatin Of Myosin Filament Under High Hydrostatic Pressure, Katsuhiro Yamamoto, Takeo Miura, Tsutomu Yasui

Food Structure

Gelation of myosin filaments under high hydrostatic pressure was investigated. At room temperature myosin filaments in 0.1 M KCl and 20 mM phosphate, pH 6.0, formed gels at 280 MPa and a protein concentration above 2 mg/ml or at 210 MPa and 3 mg/ml. However, no pressure-induced gelation was observed at 140 MPa. The gel strengths of pressure-induced gels were almost proportional to the protein concentration and they were comparable to those of heat-induced gels. The association of myosin filaments and the structural disturbance seemed to coincide with the formation of the gel. The microstructure of the pressure-induced myosin gel …

Scanning Tunneling Microscopy And Spectroscopy Of Plasmid Dna, D. P. Allison, J. R. Thompson, K. Bruce Jacobson, R. J. Warmack, T. L. Ferrell

Scanning Microscopy

We present scanning tunneling microscope (STM) images of uncoated deoxyribonucleic acid (DNA) electrochemically mounted on highly-oriented pyrolytic graphite (HOPG) and imaged in air. Images of linear abnormalities inherent to HOPG surfaces that can be confused with DNA are also presented. Scanning tunneling spectroscopic (STS) images generated by superimposing a small, high frequency ac bias onto the de tunnel bias and recording the ac current signal were taken simultaneously with the topographic images. These spectroscopic images reveal contrast due to local conductivity variations and can be used to differentiate DNA molecules from graphite artifacts.

The Morphology Of Synovial Lining Of Various Structures In Several Species As Observed With Scanning Electron Microscopy, Peter J. Steinberg, Kees C. Hodde

Scanning Microscopy

Data concerning surface morphology of synovial lining of tendons, tendon sheaths, cruciate ligaments, infra-patellar fat pads and peripatellar synovial ridges in various species (rat, rabbit, dwarf goat, sheep, pig, dog, human) are reported on. Supportive studies with transmission electron microscopy (TEM) and light microscopy were performed.

Three principal morphological appearances of the synovium are evident. On structures with a dense fibrous architecture like tendons, tendon sheaths and cruciate ligaments the intimal cells and processes are mostly slender and may tend to orientation in the length-axis of the structure. On the peri- and infrapatellar adipose tissues two principal 'extremes' are seen: …