Life Sciences Commons^™

Overview Of Physical Studies Of Bulk Water In Biopolymers, Wm. Negendank

Scanning Microscopy

The Symposium of which this paper is a part, "The State Of Water In The Cell", examines evidence which indicates that the bulk water of the cell has physical properties that are different from those of free water in a dilute aqueous solution. The heterogeneity of environments of water within cells makes direct application of physical studies difficult. However, the major physiologic effect of an ordered state of bulk cell water is solute exclusion, and this is also demonstrated by simple polymer solutions. Such systems have provided an opportunity to show that such water has motional correlation times within an …

Fibroblast And Epidermal Cell-Type I Collagen Interactions: Cell Culture And Human Studies, Charles J. Doillon, Frederick H. Silver, Robert M. Olson, Chandrakala Y. Kamath, Richard A. Berg

Scanning Microscopy

Fibroblast and epidermal cell-type I collagen sponge interactions were studied in cell culture as well as in humans. In cell culture, fibroblasts were observed to migrate and proliferate throughout a type I collagen sponge containing either hyaluronic acid (HA) or fibronectin (FN). Fibroblasts accumulated in the center of the pores in sponges containing HA and appeared to surround themselves with newly synthesized extracellular matrix. In sponges containing FN, fibroblasts attached to and elongated along the collagen fibers of the sponge. In the absence of FN or HA protein synthesis of fibroblasts appeared to be inhibited by the presence of the …

The Role Of Scanning Electron Microscopy In Periodontal Research, A. Carrassi, S. Abati, G. Santarelli

Scanning Microscopy

During recent years a great amount of research has led to a better understanding of the etiology, pathogenesis and pattern of progression of periodontal diseases. Scanning electron microscopy (SEM) has contributed to this improvement, mainly with respect to histology of periodontal tissues, the description of the morphology and distribution of bacteria on the exposed root surface, analysis of the host-parasite interactions on the gingival pocket wall, and morphological evaluation of root treatment. This review deals with all these topics. Unusual types of SEM research are also described and discussed. Uncommon sample preparation techniques for SEM in periodontal research are described. …

The Cell Water Problem Posed By Electron Microscopic Studies Of Ion Binding In Muscle, L. Edelmann

Scanning Microscopy

The question whether cell K⁺ is free or bound in the striated frog muscle has been investigated during the last 10 years by different cryomethods and electron microscopy. The results support the view that most of cellular ions are osmotically inactive and that therefore the observed cell water activity must be explained by a model which assumes a specific cell water structure. According to the association-induction hypothesis, cell water is influenced by macromolecules and has low solubilities for Na⁺ and other solutes which therefore are partly excluded from cellular water. Autoradiography of frozen hydrated Na⁺ loaded muscles …

Microvascular Casting Of The Lung: Vascular Lavage, Dean E. Schraufnagel, Aloisia Schmid

Scanning Microscopy

Corrosion casting is an important tool for the study of microvascular structure, but unlike tissue preparation for light and electron microscopy, few controlled studies of the methods for preparation of microvascular casts for scanning electron microscopy have been reported. Most vascular casting begins with rinsing cells from the lumen of the blood vessels, but the necessity of this has not been shown. Because of a report of successful casting without rinsing and light microscopic evidence of edema with complete rinsing prior to casting, this preparation procedure was examined. Casts of lung vasculature that were thoroughly rinsed were compared to those …

A Review Of Methodology And Quantification In Dental Microwear Analysis, K. D. Gordon

Scanning Microscopy

Dental microwear analysis is a method of inferring oral events (primarily food processing and aspects of masticatory biomechanics) from microscopic abrasion patterns retained on the enamel surfaces of teeth. Although some qualitative pattern differences may be easily distinguishable, most of the significant results produced thus far have derived from quantified studies of SEM images of occlusal enamel. It often goes unnoticed by readers of microwear reports who are not themselves specialists that microwear analysis is essentially a statistical method, not a visual one. In this review of current techniques and methods, several problems in current approaches are detailed. It is …

Industrial Applications Of Auger Surface Analysis, R. E. Chase, G. S. Cole

Scanning Microscopy

Scanning Auger microscopy is distinguished by its unique combination of surface selectivity, high spatial resolution, ease of identifying elements and quantifying composition, and ability to distinguish between chemical states. This paper describes several applications of scanning Auger microscopy, emphasizing the range of industrial research activities:

1. Electronic Materials. Contamination in an integrated circuit processing facility was identified and procedures for its removal determined. Causes for the delamination of printed circuit board foils were identified. Superlattice films were characterized and the deposition process evaluated.

2. Tribology. Analysis of surfaces in lubricated sliding contact revealed the effects of con tact kinematics and …

A Review Of Dental Microwear And Diet In Modern Mammals, Mark F. Teaford

Scanning Microscopy

Recent work has shown that microscopic wear patterns on teeth may yield insights into variations in diet and tooth use in modern and prehistoric mammals. This paper presents a review of dental microwear and diet in modern mammals, plus a discussion of topics for further research. To date, incisor and molar microwear have been examined, although there are far fewer studies of the former. Facilitated by the use of high-resolution casts and scanning electron microscopy, analyses have ranged from: qualitative to quantitative, low magnification to high magnification, and experimental studies to comparative studies of museum collections. Results are encouraging and …

Microanalytical And Micromorphological Investigations Of High Temperature Materials With And Without Protective Coatings, Volker Thien, W. Voss

Scanning Microscopy

The phenomenon "High Temperature Corrosion" (HTC) is described; three different types (pure oxidation, high temperature hot corrosion, low temperature hot corrosion) are defined. HTC is demonstrated taking gas turbine blades as an example. The results of laboratory HTC tests under defined conditions were compared with those of long time engine experience; the agreement is very satisfactory.

Metallurgical investigations with scanning electron microscopy and EDX-/WDX-analytical techniques gave explanations for the behaviour of protective coatings . The corrosion mechanism of a NiCrAlY-plasma spray coating is explained as consequence of Cr- and Al-oxidation. A special analytical technique - the "integral layer profile analysis" …

Preparation Of Biological Samples For Transmission X-Ray Microanalysis: A Review Of Alternative Procedures To The Use Of Sectioned Material, D. C. Sigee

Scanning Microscopy

Although transmission X-ray microanalysis of biological material has traditionally been carried out mainly on sectioned preparations, a number of alternative procedures exist. These are considered under three major headings - whole cell preparations, analysis of cell homogenates and biological fluids, and applications of the technique to microsamples of purified biochemicals. These three aspects provide a continuous range of investigative level - from the cellular to the molecular.

The use of X-ray microanalysis with whole cell preparations is considered in reference to eukaryote (animal) cells and prokaryotes - where it has particular potential in environmental studies on bacteria. In the case …

Influence Of Phosphorus And Sulphur Segregation On Stress Relief Cracking, H. Horn, T. Pintat, V. Schlett, H. Weiss

Scanning Microscopy

Three commercial weldable fine grained structural steels and four experimental melts with lowered contents of trace elements were subjected to a welding simulation treatment followed by stress relaxation (SR) tests. After testing times of up to 8 hours the samples were removed from the testing rig, broken in the fracture stage of an Auger instrument, and the fracture surface was examined in situ for segregation of elements. SEM investigations of the fracture surfaces and light microscope served to characterize fracture mode and microstructure.

The microfractural appearance of the grain boundaries exposed by the impact loading in the Auger instrument and …

Processing Of Scanning Electron Microscope Images On Basis Of Fast Fourier-Transformation, A. Yu. Sasov, A. A. Shanyavsky

Scanning Microscopy

The solar cell as a combined substrate and detector was used for automated SEM-image analysis. It was noted that an image processing system was created and its operational features are shown in some typical applications. The step size of the fatigue striations was found. The obtained value of the step corresponds to the formula with an accuracy of about 1 per cent. Quantum-mechanical constant of material fracture for aluminum alloys was found to be 𝛥 = 0.22. Two-dimensional periodic analysis was applied to fracture surfaces and a microchannel plate. The integral characteristics of microstructure was determined quantitatively.

Quantitative Morphology Of Synaptic Plasticity In The Aging Brain, Carlo Bertoni-Freddari, William Meier-Ruge, Jurg Ulrich

Scanning Microscopy

Quantitation of synaptic ultrastructural changes is of great importance in neurobiology, since merely qualitative alterations, if not extreme, are not readily detectable. In the present paper we discuss our previous and present findings on the number (numerical density: Nv), size (average length of the synaptic profiles: L) and surface contact area (surface density: Sv) of the synaptic junctions in aging rodent and human brains. We found that number and size of the synapses are in a close inverse relationship so as to maintain the total surface contact area among the nerve cells constant. These three parameters are closely related to …

Transit Time Effect On Voltage Contrast In The Stroboscopic Scanning Electron Microscope, K. Nakamae, H. Fujioka, K. Ura

Scanning Microscopy

Voltage contrast varies if the specimen voltage changes within the secondary electron transit time through the specimen electric field. This effect would affect the time resolution in stroboscopic scanning electron microscopy. The method to calculate the transit time effect that was described in a previous paper is reviewed. The calculated results agreed well with the experiment in which a specially designed specimen is used to estimate the applied voltage as exactly as possible.

Microcorrosion Casting In Normal And Pathological Biliary Tree Morphology, E. Gaudio, L. Pannarale, F. Carpino, G. Marinozzi

Scanning Microscopy

The organization of the intrahepatic biliary tree was studied in three dimensions by scanning electron microscopic (SEM) corrosion casts, in normal and cholestatic rat liver.

In the normal liver the observation revealed the features of the biliary passages from the bile canaliculi to the canaliculo-ductular junction, to the ductules and the bile ducts, confirming previous SEM observations.

In cholestatic liver, the modifications and the proliferation of bile ductules appear clearly.

Resin flow from canalicular to sinusoidal network was never observed.

The method was found to be very useful in the evaluation of the architecture of the intrahepatic biliary tree, under …

Extraneous Background-Correction Program For Matrix Bound Multiple Point X-Ray Microanalysis, W. C. De Bruijn, M. P. C. Van Miert

Scanning Microscopy

A program is described that allows online determination of extraneous background in multiple point X-ray microanalytical matrices. The program is based upon the calculations of the extraneous background for the film (when present), the standard and the unknown by (100 sec.) point analysis. The program searches for a peak-free part of the spectrum in which the calculated value for the extraneous background is about equal to the value in this region of the spectrum (=b_e). Online the contents of this b_e-region is subtracted from an unmanipulated continuum region in the vicinity of the element present in …

Effects Of Cytochalasin B And Colchicine On The Morphology Of Sw-13 Human Adrenal Cortical Tumor Cells In Culture, S. A. Murray, H. N. Tung

Scanning Microscopy

Human adrenal cortical tumor cells (SW-13) grow into a typical epithelial cell monolayer when seeded onto culture dishes. The cells of the SW-13 population monolayer appear flattened with few conspicuous surface features. The cells are attached to one another at their lateral borders and are arranged in a cobblestone-like manner. Following Triton X-100 extraction, the distribution of the cytoskeletal elements was observed with scanning electron microscopic techniques to correspond to the shape of the non-extracted cell. Changes in the distribution and morphology of projections on the cell surface as well as changes in cell shape were revealed after treatment of …

Contrasting Views On The Organization Of Cytoplasm, J. S. Clegg

Scanning Microscopy

The widely held conception of cytoplasm as a concentrated solution of dissolved proteins and other macromolecules, metabolites and inorganic ions, within which the various organelles and other formed elements are suspended appears to be a gross over-simplification. Evidence to be reviewed briefly here, from a wide variety of experiments and cell types, indicates that a much more extensive organization exists, in animal cell cytoplasm at least. Results from experiments on dextran sulfate permeabilized L-929 cells will be presented which support that organized paradigm. It seems likely that this intracellular architecture also exerts a strong influence on the water in the …

Presence Of Calcium Oxalate Crystals In The Mammalian Thyroid Gland, Raymond L. Hackett, Saeed R. Khan

Scanning Microscopy

Birefringent crystals of calcium oxalate have been previously identified in the colloid of human thyroid glands. We found such crystals in 19/20 adult thyroids at autopsy, in 4/ 20 infants at autopsy, and, using frozen sections, in 19/20 thyroids partially or totally removed at surgery. These crystals were soluble in hydrochloric acid, insoluble in acetic acid, and contained only calcium by energy dispersive X-ray microanalysis, confirming their calcium oxalate character. Similar crystals were found in equine and ovine thyroids.

Tip-Techniques For Microcharacterization Of Materials, Y. Martin, C. C. Williams, H. K. Wickramasinghe

Scanning Microscopy

The invention of the Scanning Tunneling Microscope has stimulated the development of new techniques for microcharacterization of materials, which are based on the use of a very fine tip. Two of these techniques have emerged about one year ago, the Thermal Profiler and the Atomic Force Microscope. Both techniques have recently demonstrated the capability to profile and image conductors and insulators. The resolution attained varies from approximately 50 nm by the Thermal Profiler to a few nanometers with the Atomic Force Microscope, therefore competing with the resolution obtained with electron beam microscopy. We shall describe the principle of these techniques, …

Arterial Elastin As Seen With Scanning Electron Microscopy: A Review, Margot R. Roach, S. H. Song

Scanning Microscopy

All large arteries contain elastin, collagen, and muscle which can be seen with light microscopy and transmission electron microscopy. Elastin forms an internal elastic lamina (IEL) in all arteries, but also forms multiple fenestrated sheets in the media of the aorta and other large arteries. The fenestrations in the media are larger than those in the IEL. The adventitial elastin is more fibrous and often contains tubular elastin surrounding vasa vasorum when prepared by removing all non-elastin by placing the aorta in 0.1 N NaOH at 70-75°C for five hours. The fenestrations are larger near branches and in an experimentally …

Interferon-Induced Surface Alterations In Hairy Cells. A Review, Haim Gamliel, Dorit Gurfel, Shi-Hua Wu, Harvey M. Golomb

Scanning Microscopy

Hairy cells (HCs), derived from the peripheral blood and spleen of hairy cell leukemia (HCL) patients, constantly displayed both ruffles and microvilli. HCs which were kept in culture for up to three days exhibited extremely polarized and active surfaces with elongated microvilli and exaggerated "spiked" ruffles. Cells derived from 11 cases of HCL were treated with alpha-interferon (IFN) in-vitro and examined by immuno -scanning electron microscopy (immuno-SEM). In 8 cases, up to one-third of the IFN-treated hairy cells displayed deformed surfaces with "bubbling" membrane and markedly villous bud-like formations. Monoclonal antibodies (MoAb), used in conjunction with immuno-qold labeling, facilitated better …

Enhanced Floral Analysis By Low Temperature Scanning Electron Microscopy, Brenda Brookes, Ernest Small

Scanning Microscopy

Traditional methods of preparation of botanical specimens for scanning electron microscopy (SEM) have proven to induce artifacts in some specimens which often reduce quality of resulting images, and are highly misleading for taxonomic purposes. The advantages of low temperature SEM are illustrated by an investigation of freshly collected flowers, using a cryo-system interfaced to an SEM. This method overcame the deficiencies of traditional procedures to produce exceptional images of floral surfaces in their natural state. Depending on the nature of the material under investigation, the method my be indispensable (e.g., for accurate details of petal surfaces), preferable (e.g., glandular hairs …

Myocyte Swelling And Plasmalemmal Integrity During Early Experimental Myocardial Ischemia In Vivo, Martin D. Sage, Robert B. Jennings

Scanning Microscopy

Using scanning and transmission electron microscopy, the structure of myocytes early in the phase of irreversible injury induced by 40 minutes of severe regional ischemia has been investigated, paying particular attention to the effects of cell swelling on the SEM appearance of the myocytes. Swollen myocytes showed an increased space beneath the plasmalemma and between organelles. True subsarcolemmal blebs were not seen and the attachment complexes between the Z-band and the underlying myofibrils remained intact. The proportion of the PS face of the plasmalemma which appeared "en face" (0.70%, SD:1.22 vs 5.0196, SD:3.72) in freeze-fracture faces of ischemic tissue was …

The Effect Of Fatigue On Essential Element Distribution In The Rabbit Masseter, M. B. Engel, J. K. Bressman

Scanning Microscopy

The rabbit masseter is composed of mainly fast fatiguable type IIB fibers which give a positive mATPase reaction at pH 9.3. To study the effect of fatigue on the distribution of some crucial elements, the masseter was stimulated electrically for 45 minutes. The contralateral muscle served as a control. Control and experimental tissues were rapidly excised, and frozen in isopentane cooled to -150°C in liquid nitrogen. Sections were cut in a cryostat and prepared by freeze-drying. Water content of fatigued muscle was significantly higher than controls: 79.3% versus 77.3%. The fatigued state was verified by glycogen depletion viewed in PAS-stained …

Materials Analysis By Mass Spectrometry Of Sputtered Neutrals, Hans Oechsner

Scanning Microscopy

Mass spectrometric detection of neutral surface particles released by ion bombardment has become an important method for surface and depth profile analysis. Its fundamental difference to secondary ion mass spectrometry SIMS is the separation of the formation of the analyzed particles and their ionization. Hence, matrix and selectivity effects influencing SIMS signals in a mostly unknown manner via the ionization process in secondary ion emission are avoided in general.

The different techniques being presently employed for the necessary postionization of the sputtered neutrals are reviewed and discussed with respect to their potentialities. Secondary Neutral Mass Spectrometry (SNMS) using efficient postionization …

3-Dimensional Imaging Of Biological Structures By High Resolution Confocal Scanning Laser Microscopy, G. J. Brakenhoff, H. T. M. Van Der Voort, E. A. Van Spronsen, N. Nanninga

Scanning Microscopy

Imaging in confocal microscopy is characterized by the ability to make a selective image of just one plane inside a specimen, virtually unaffected -within certain limits-by the out-of-focus regions above and below it. This property, called optical sectioning, is accompanied by improved imaging transverse to the optical axis. We have coupled a confocal microscope to a computer system, making the combination of both an excellent instrument for mapping the 3-dimensional structure of extended specimens into a computer memory/data array. We measured that the volume element contributing to each data point has, under typical fluorescence conditions, a size of 0.2 x …

Junction Electron-Beam-Induced Current Techniques For The Analysis Of Photovoltaic Devices, R. J. Matson

Scanning Microscopy

A number of useful electron-beam-induced current (EBIC) techniques have evolved through the study of junction behavior in photovoltaic (PV) devices in cross section as a function of light and voltage bias, temperature, and electron beam scanning parameters. The necessary hardware modifications, the techniques themselves, and their applications are presented. In the case of PV devices, light and/or voltage biasing the entire device while electron probing it in cross section permits the observation of the distribution of the narrowing or extension of the space-charge region. Monitoring the junction behavior as a function of temperature has at least two applications. In situ …

Ion And Water Retention By Permeabilized Cells, Carlton F. Hazlewood, Miklos Kellermayer

Scanning Microscopy

Nonionic detergents, Triton X-100 and Brij 58, removed, within 2-5 minutes, lipid membrane of suspended thymus lymphocytes and monolayer H-50 cells grown in culture. Studies of hydration, ionic asymmetry, and ionic and protein release kinetics were conducted on these membraneless cellular preparations. The hydration of nuclei isolated by Triton X-100 procedures appears to be influenced strongly by the monovalent ionic concentration of the buffer bathing the organelles. The putative monovalent ionic concentration of the cellular aqueous phase (i.e., 150 meq/L) caused nuclei to swell and coalesce. Monovalent ionic concentrations of 30 meq/L or less caused minimal changes in volume and …

The Correction For Extraneous Background In Quantitative X-Ray Microanalysis Of Biological Thin Sections: Some Practical Aspects, Godfried M. Roomans

Scanning Microscopy

The correction for extraneous continuum is of great importance in the quantitative analysis of thin sections of biological tissue. Although a theoretical model for this correction is available, its application in practice meets with problems. In this paper, a model system, consisting of sections of homogeneous plastic on copper mesh grids was used to identify sources of inaccuracies in the quantitative procedures. An unmodified electron microscope was operated under standard analytical conditions. It appeared that geometrical factors connected with the position of the analysis relative to the grid bars were of prime importance. The correction for the contribution of the …