Digital Commons Network^™

Scanning Electron Microscopy, X-Ray Microanalysis And Immunohistochemistry On Worn Soft Contact Lenses, Piera Versura, M. C. Maltarello, Godfried M. Roomans, R. Caramazza, R. Laschi

Scanning Microscopy

The deposits accumulated on the surfaces of soft contact lenses are a cause of problems for the wearer of these lenses, as the deposits are never completely removed by the available washing solutions. Therefore it appears of interest to investigate the composition of these deposits.

In this paper we review the major findings in the literature and, in addition, present our personal experience.

We have studied new, continuously and daily worn soft contact lenses by scanning electron microscopy (SEM), X-ray microanalysis and immunohistochemistry. We have carefully evaluated preparative methods, and we can conclude that SEM and X-ray microanalysis are best …

Adult Phyllostomid (Bat) Enamel By Scanning Electron Microscopy - With A Note On Dermopteran Enamel, K. S. Lester, S. J. Hand, F. Vincent

Scanning Microscopy

This study assesses the enamel of five phyllostomids of differing feeding habits; only one example of the microchiropteran super-family Phyllostomoidae having previously been studied by SEM. A dermopteran was also examined to ascertain whether the enamel might reveal insectivore, chiropteran or primate characteristics.

The five phyllostomids were found to display the additional crystallite discontinuity feature (minor boundary plane or seam) which is a major characteristic of all the bats we have so far examined with the exception of two megachiropterans. The enamel of the four fruit and nectar feeders (Phyllostomus, Carollia, Glossophaga and Artibeus) is essentially similar and different to …

Cleaning Procedures For Small Dental Instruments Prior To Sterilization, K. S. Lester, P. Mitchell

Scanning Microscopy

Observations were made in an institutional setting on the quality of cleaning of dental burs. Assessments were made by scanning electron microscopy of surface contamination and change to the surface quality of burs before and after use, and as a result of different cleaning procedures.

The most significant finding was the corrosive action on carbon steel burs of a phosphoric acid based cleaning solution in routine use at the time. We show by comparison the effectiveness and non-corrosive nature of an alternative detergent based on sulfamic acid, and propose a suitable cleaning routine.

Two other findings are presented: new burs …

The Emission Microscope: A Valuable Tool For Investigating The Fundamentals Of The Scanning Electron Microscope, Franz Hasselbach

Scanning Microscopy

In scanning microscopy in transmission (STEM) and reflection (SEM) the spreading of the spatial distributions of the forward-and backscattered electrons, respectively, deteriorates contrast and resolution. We therefore investigate this spreading by measuring quantitatively the corresponding distributions of secondaries released by these reemerging electrons. In order to carry out this experiment we visualize these distributions by using the surface of the specimen as the source of an emission microscope.

The spreading of transmitted beams of 19.5 keV in thin films of Al and Ge 0 .2-2 μm in thickness is reported here as well as the spatial distributions of secondaries released …

Electron Energy Loss Spectroscopic Imaging In Biology, G. T. Simon, Y. M. Heng

Scanning Microscopy

One of the goals in biology is to relate the ultrastructure with the movement of elements to under stand better physiological and pathophysiological mechanisms. Electron energy loss spectroscopy (EELS) imaging, which was developed in the last decade, appears to be an ideal technique to make such correlation.

EELS takes advantage of the energy distribution of transmitted electrons which interacted with the specimen. All these electrons are collected and can be displayed as an energy loss spectrum for analytical purposes. Images can be produced from selected regions from the energy distribution allowing the mapping of specific elements. The main advantage of …

An Overview Of Platelet Structural Physiology, J. G. White

Scanning Microscopy

Marion Barnhart and her colleagues used light, phase contrast and scanning electron microscopy to provide a clear picture of platelet surface changes developing in response to aggregating agents. This review, in honor of Marion and her work, has sought to expand the horizon provided through study of surface alterations by peeling back the membrane of the platelet to reveal the dynamic world within. A cytoskeleton consisting of a circumferential microtubule and submembrane actin filaments supports the discoid shape of the resting cell. Following exposure to aggregating agents in suspension, to foreign surfaces or denuded blood vessels and to fibrin strands …

Age Dependent Dehydration Of Postmitotic Cells As Measured By X-Ray Microanalysis Of Bulk Specimens, György Lustyik, Imre Zs.-Nagy

Scanning Microscopy

In this paper we give a brief outline of our bulk specimen technique developed to measure intracellular water concentration in frozen-hydrated biological specimens by means of energy dispersive X-ray microanalysis. Fractured surface of the deep-frozen tissue samples is analyzed in an electron microscope (a specimen area of 15x11.5 𝝁m is scanned) using 20 kV accelerating voltage and 1-5 pA effective beam current (measured in the specimen). Strong electric charging, which is the main problem associated with the low temperature X-ray microanalysis of frozen-hydrated specimens, is reduced by choosing optimum temperature range for the measurements (170-185 K) and by etching a …

Scanning Electron Microscopy Of Oral Mucosa In Vivo And In Vitro: A Review, Kristina Arvidson, Roland C. Grafström, Anders Pemer

Scanning Microscopy

The oral mucosa is classified by function into lining, masticatory and specialized oral mucosa, with regional structural adaptation. In this review, the surface structures of the human oral mucosa have been studied in the scanning electron microscope (SEM). Regional variations in regard to keratinization, cell arrangements and microplications with related specific structures observed in SEM are described and correlated with the appearance of similar areas observed in the light microscope. Furthermore, human oral tissue and cell cultures have also been studied. These systems offer usable and complementary models for performing similar studies in vitro under controlled experimental conditions. We now …

Tandem Scanning Reflected Light Microscopy: Applications In Clinical Dental Research, Timothy F. Watson, Alan Boyde

Scanning Microscopy

The Tandem Scanning Reflected Light Microscope (TSRLM) enables the investigation of microscopic structures both at and deep to the surface of intact objects. The present paper reviews studies undertaken to determine whether the TSRLM would be usable and useful in the investigation of natural and restorative dental materials in vitro and in vivo.

It was found that the TSRLM could be used to study normal and diseased dental tissues and the new materials which are used to replace lost substance. More importantly, it could be used to characterize the interface between tooth and optically translucent materials in bulk samples, giving …

Cell Rearrangement And Directional Migration In Pronephric Duct Development, T. J. Poole

Scanning Microscopy

The morphology of the directed migration of the pronephric duct rudiment of three vertebrates, the salamander, chick and sturgeon, has been examined by scanning electron microscopy. Of particular interest in this paper are the morphology of the duct tip, the role of cell rearrangement, and the relation of duct extension to somite segmentation. The duct rudiments of all three species have motile cell processes (lamellipodia and filopodia) largely confined to their posterior tips. The salamander and sturgeon embryos extend their duct rudiments by extensive cell rearrangements. A short, wide rudiment is elongated to form a long, thin one. The chick …

Developmental Angiogenesis: Quail Embryonic Vasculature, T. J. Poole, J. D. Coffin

Scanning Microscopy

We have examined the segregation and early morphogenesis of the embryonic vasculature by using a monoclonal antibody for immunofluorescence and by scanning electron microscopy. This antibody labels the presumptive endothelial eel ls (PECs) as they segregate from mesoderm. Similar embryos prepared for SEM revealed finer details of how these segregated cells interact to form the rudiments of the major blood vessels. Here we concentrate on the development of the dorsal aortae and the posterior cardinal veins. The dorsal aortae form from single PECs which segregate from the lateral mesoderm and aggregate into a loose cord ventral to the somites. These …

Ex Vivo Platelet Deposition On Fibronectin-Preadsorbed Surfaces, William E. Collins, Deane F. Mosher, Anil R. Diwan, Kedar D. Murthy, Scott R. Simmons, Ralph M. Albrecht, Stuart L. Cooper

Scanning Microscopy

Temporal platelet deposition profiles of canine plasma fibronectin (CPFN) adsorbed to different polymers ex vivo and the in vitro characteristics of CPFN adsorption were studied in an attempt to correlate the two. The maximum platelet deposition (𝚪_plt^max) obtained at a protein preadsorption time of 30 min was greater than that obtained using an adsorption time of 120 min for all surfaces studied. At 30 min of preadsorption, 𝚪_plt^max was 520, 560 and 1230 platelets/1000 μm² on Biomer, polyethylene (PE) and oxidized PE (OXPE), respectively. In contrast, the platelet deposition at 120 min. of fibronectin …

Scanning Electron Microscopy - Electron Beam Induced Current And Deep Level Transient Spectroscopy Studies Of Gaas(In) Layers Grown By Molecular Beam Epitaxy, Y. J. Huang, Dimitris E. Ioannou, A. Iliadis

Scanning Microscopy

Electrically active defects in indium-doped (0.6%) GaAs layers grown by Molecular Beam Epitaxy (MBE) on Si-doped (≈1x10¹⁸ cm^-3) GaAs substrates have been studied by the combination of two techniques: Scanning Electron Microscope - Electron Beam Induced Current (SEM-EBIC) technique, and Deep Level Transient Spectroscopy (DLTS). The epilayers studied were three microns thick. No electrically active defects were revealed by the EBIC micrographs in the top one micron of the epilayers, whereas a large number of non-propagating misfit dislocations were observed at the epilayer/substrate interface. DLTS measurements made in the dislocation free top region of the epilayer showed …

Preliminary Observations On The Effects In Vivo And In Vitro Of Low Dose Laser On The Epithelia Of The Bladder, Trachea And Tongue Of The Mouse, Y. C. Mok, K. M. Pang, C. Y. W. Au, D. T. Yew

Scanning Microscopy

The effects of low dose CW laser were studied by in vivo and in vitro systems. The experimental tissues that were used included bladders, tracheas and tongues as experimental tissues. Buddings (round surface projections) from the transitional epithelium of bladder were frequently observed 3 days after laser treatment in both in vivo and in vitro systems. The trachea and tongue were less affected. In both the in vivo and in vitro systems, some epithelial cells of the trachea showed decreased microvilli and cilia 3 days after treatment whereas the epithelial cells of the tongue revealed no response to laser treatment …

The Root Surface: An Illustrated Review Of Some Scanning Electron Microscope Studies, Sheila J. Jones

Scanning Microscopy

This review paper highlights how the advent of a new type of surface microscopy in the late 1960s, scanning electron microscopy (SEM), was responsible for a fresh appraisal of the structure of the root surface. Details of the formation, resorption and repair of cementum, all surface phenomena, and the varied relationships and mineralization patterns of the two sets of fibres within cementum - the hall mark of the tissue - could be seen in a way and at a range of magnifications hitherto impossible. The major interpretational advances were made rapidly using secondary electron imaging of anorganic normal, exposed, carious …

Tandem Scanning Reflected Light Microscopy Of Primate Enamel, Alan Boyde, Lawrence Martin

Scanning Microscopy

Studies of the cross sectional packing arrangements of primate enamel prisms have been used in a number of recent studies in attempts to determine their taxonomic utility. Credibility of the results has been greatly influenced by the methods employed to examine enamel prism packing patterns and also by the limited sampling. We report here the use of a technique for the non destructive examination, in depth, of enamel prism packing patterns in modern and fossil primate teeth which has considerable advantages over any others so far used, and the preliminary results of a survey of enamel structural diversity in the …

Scanning Microscopic Observations On Dental Caries, Sheila J. Jones, Alan Boyde

Scanning Microscopy

This paper presents findings made using special techniques of imaging and/or of specimen preparation to investigate the changes in tooth structure which occur in caries. We have studied both coronal and root caries in enamel, dentine and cementum using scanning electron and confocal scanning optical microscopy.

In preparation for backscattered electron (BSE) imaging in the SEM, teeth were stored in 70% ethanol until further dehydration in ethanol and embedding in polymethylmethacrylate (PMMA). Longitudinally cut surfaces were diamond polished and coated with carbon or silver before BSE imaging. Important changes in the distribution of densities in both enamel and dentine occurred …

The Influence Of Metal Substrates On The Electronic States Of Metal Overlayers, P. A. Dowben, M. Onellion, Y. J. Kime

Scanning Microscopy

The aim of this paper is to provide an introduction to the electronic structure of very thin film (one to ten monolayers) overlayers using examples from studies of Hg overlayers on Ag(100) and Fe thin film overlayers. Interracial states as a result of the interaction of the substrate and overlayer, as well as the new electronic states of the overlayer caused by a new crystallographic structure can modify the overlayer metal electronic structure. Additional changes in the overlayer electronic structure arise from the reduced dimensionality (2 dimensionality as opposed to 3 dimensionality) of the thin film. We discuss the photoemission …

Image Analysis And X-Ray Microanalysis In Cytochemistry, W. C. De Bruijn, H. K. Koerten, M. I. Cleton-Soeteman, C. J. G. Blok-Van Hoek

Scanning Microscopy

When cytochemical reaction products are homogeneously distributed within an organelle, point analyses suffice for the quantitative approach. However, quantitative analysis becomes tedious, when the elements in the reaction product are inhomogeneously distributed. Problems arise when elements from two reaction products have to be related to each other, or to endogenous cytological products (ferritin, haemosiderin, calcium, electron dense markers), either topographically or in concentration. When analyzing inhomogeneous/heteromorphical reaction product-containing organelles special attention has to be paid to measure and relate both volume and concentration. In this paper a relative simple structure (eosinophil granules) is chosen to demonstrate that the acquisition of …

A Scanning Electron Microscopy Study Of Approximal Premolar Surfaces From Fifteen Year Old Children Living In A Fluoridated Community, Lisbeth Holmen

Scanning Microscopy

The aim of the present study was to examine approximal enamel surfaces in the scanning electron microscope (SEM). Thirty premolars developed and erupted in an 'optimally' fluoridated (1 ppm) community had clinical indications of dental fluorosis and early signs of dental caries corresponding to the approximal contact area. The SEM-examination disclosed a spectrum of posteruptive changes ranging from isolated surface fractures to carious dissolution, abrasion and calcified microbial deposits. Conclusively, we found that teeth developed and erupted in areas with fluoridated water undergo similar posteruptive alterations due to prevailing environmental conditions as reported in teeth from low fluoride areas.

Scanning Electron Microscopy Of The Human Thyroid Gland And Its Disorders, Jahn M. Nesland, Manuel Sobrinho-Simoes, Jan Vincents Johannessen

Scanning Microscopy

The characteristic scanning electron microscopic features of the normal thyroid gland, benign thyroid lesions such as nodular (adenomatous) and colloid goitre, adenomas and thyroiditis, and malignant tumors such as papillary carcinoma, follicular carcinoma, anaplastic carcinoma and medullary carcinoma are described.

One or more cilia are present in the center of the follicular surface of almost every epithelial cell in the normal thyroid gland as well as in most goitres. Their number is reduced in adenomas and differentiated carcinomas. Medullary carcinomas and anaplastic carcinomas usually lack cilia.

Variation in distribution and appearance of microvilli seems to be related to functional differences …

An Electron Beam Tester With Dispersive Secondary Electron Energy Analyser, P. Kruit, L. Dubbeldam

Scanning Microscopy

The design principles of a new, experimental e-beam tester are described. Using the magnetic field of an immersion objective lens the secondary electrons are guided to an energy analyser between the condenser lenses and the objective lens. The latter can now have a short working distance and small aberrations. The electron energies are analysed by a combination trochoidal motion - retarding field analyser, which enables detection of the faster secondary electrons on one detector and detection of the slower secondary electrons on a second detector. The benefit of this set up is a possibility for voltage contrast isolation, normalization with …

Signal-To-Noise Ratio Improvement In Electron Beam Testing By Using A Dispersive Analyser, L. Dubbeldam, P. Kruit

Scanning Microscopy

In conventional e-beam testers the potential of a device under test is measured by collecting the secondary electrons (SE's) faster than a certain limit, while the slower SE's are rejected. We have built an e-beam tester in which the slower SE's are also collected. In this paper we will show that this can decrease the minimum measurable voltage substantially. An additional advantage of a double channel analyser is the possible reduction of the influence of fluctuations in the primary beam and in the secondary emission coefficient.

Storage Of Sperm In The Reptilian Oviduct, Daniel H. Gist, Jeffrey M. Jones

Scanning Microscopy

Female reptiles have the ability to store sperm within their reproductive tracts for extended periods of time. Sites of sperm storage in lizards and snakes include both the anterior vagina and the infundibulum. Vaginal receptacles are found in between longitudinal folds (snakes) and in tubules formed by invaginations of the epithelium (lizards). Infundibular receptacles are alveolar or tubular in structure and are formed from invaginations into the lamina propria of the oviduct wall. In turtles, sperm are stored in the posterior portion of the tuba, in tubular albumen-secreting glands. Sperm may be embedded within the cells of the receptacles, but …

The Role Of The Cytoskeleton In Endothelial Repair, Avrum I. Gotlieb, Michael K. K. Wong, Patricia Boden, Alan Choo Fone

Scanning Microscopy

The injured endothelium undergoes rapid repair of areas of cell desquamation in order to maintain the structural integrity of the endothelial surface. Endothelial repair involves a series of processes which include endothelial cell spreading, translocation, and proliferation. These processes are well defined events which occur sequentially in time. Spreading and translocation are mediated by the cell cytoskeleton - F-actin microfilaments and microtubules and associated centrosomes. The regulation of these processes is complex and is likely due to soluble factors present at the site of injury which are released from activated endothelial cells, platelets, the subendothelial substratum, activated serum factors, and …

Scanning Electron Microscopy Of Burnt Electric Wires, R. P. Singh

Scanning Microscopy

Aluminium and copper wires were burnt by electric short circuit and by outside flame. These wires have been studied under scanning electron microscope with a view to distinguish them in fire cases. It was observed that there were extensive grains on the cylindrical surfaces near the ends of copper wires burnt by electric short circuit. The grainy structures were continuously decreasing with distance from the ends and vanished. Aluminium wires had bucklings starting from the ends and decreasing on subsequent portions. These features were found to have a potential advantage to identify the ends specially those which did not have …

Ureteroscopic And Scanning Electron Microscopical Findings In Ureteral Anastomoses After Segment Resection, Johannes B. Pohl, Ulrike B. Meyer-Jürgens, Dietrich B. Leusmann

Scanning Microscopy

In an experimental study on 8 canine ureters, end-to-end anastomoses were performed after segmental resection between 9 and 13 cm, using two different surgical techniques. After 3 months of observation the three-dimensional structure of the anastomosis and the surrounding areas was investigated by ureteroscopy and scanning electron microscopy. 3 types could be differentiated by the morphologic features of the ureteral lumen: normal width, segmental stricture, and circumferential stricture. The results offer a plausible explanation for the occasional discrepancy between histologic findings of relatively normal lumen width, and functional disorders apparently reflecting ureteral stenosis. They further support that excellent functional and …

Industrial Problem Solving With Microbeam Analysis, Klara Kiss

Scanning Microscopy

The objective of this paper is to provide an overview of the microbeam analytical techniques and to help select the appropriate one to solve complex problems often arising in today's high - tech industries. case histories are given to show how renowned analytical service laboratories and microbeam experts formulated their strategies to approach a real life problem, what type of conclusions were deduced from the data and, finally, how the problem was solved.

The Vascularization Of The Vertebral Column Of Rats, M. A. Konerding, M. Blank

Scanning Microscopy

The intrinsic and extrinsic blood supplies of the vertebral column of rats have been examined by corrosion cast with Mercox CL2B(R). The close functional and topographic relationship of vessels to supplied structures were exposed by fractionated maceration of the soft tissues. The segmental arteries diverge into an anterior, median and posterior group with various anastomoses between their branches. Vertebral bodies and intervertebral discs are preferably supplied by branches of the anterior and median section. The vessels reaching the vertebral body from the dorsal side diverge in a treelike branching mode into the direction of the vertebral endplate. The venous drainage …

Tooth Enamel Structure In The Koala, Phascolarctos Cinereus: - Some Functional Interpretations, William G. Young, Maria Mcgowan, Terrence J. Daley

Scanning Microscopy

The purpose of this study is to determine whether the structural organization of Pattern 2 marsupial enamel in the Koala is disposed to resist wear on the sectorial crests of the molar teeth. The orientation of wear on the crests is uniformly delineated by parallel scratches on their polished surfaces. Twin blades, a leading and a trailing edge of enamel are formed on each crest by wear into dentine on which the differential wear at enamel to dentine interfaces indicates that the direction of wear is labial to lingual.

96 leading and trailing edges from 12 koala molars were examined …