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Analysis Of Early Hard Tissue Formation In Dentine By Energy Dispersive X-Ray Microanalysis And Energy-Filtering Transmission Electron Microscopy, Hans-Peter Wiesmann, Ulrich Plate, Hans-Jürgen Höhling, Rudolf H. Barckhaus, Karl Zierold

Scanning Microscopy

Thin cryosections and sections of embedded tissue were prepared from dentine of cryofixed rat incisors. Energy dispersive X-ray microanalysis (EDX) and electron energy-loss spectroscopy (EELS) have been applied to study the calcium and phosphorus distribution in predentine of these incisors. A small enrichment of calcium and phosphorus was found in the predentine zone near the dentine border.

Element distributions were correlated with analyses of the early crystal formation in dentine. These investigations were carried out by parallel applications of electron spectroscopic diffraction (ESD) and electron spectroscopic imaging (ESI) using zero-loss filtering. It was found that the earliest crystal formations already …

Microvascular System Of The Human Fetal Inner Ear: A Scanning Electron Microscopic Study Of Corrosion Casts, A. J. Miodoński, J. Gorczyca, M. Nowogrodzka-Zagórska, J. A. Litwin, J. Składzień

Scanning Microscopy

The vascular system of the inner ear was investigated in 18-21 weeks old human fetuses, using the corrosion cast technique in scanning electron microscopy. At that developmental stage, vascularization of the cochlea and semicircular canals shows a pattern very similar to that described for adults. The most important differences which can be regarded as fetal features include: (1) denser limbus vessels, (2) the marginal vessels of the spiral lamina appearing as irregular network which shows a less clear arcade-like arrangement, (3) some radiating arterioles of the spiral lamina and marginal vessels possessing connections with the vascular system of the external …

Degeneration And Reorganization Of Vestibular Epithelia After Local Aminoglycoside Application In The Mammalian Inner Ear, J. Dupont, A. Guilhaume, J. -M. Aran

Scanning Microscopy

The development of degeneration of vestibular end organs and their possible reorganization have been observed over a 2 year period after local application of sisomicin in the inner ear using scanning electron microscopy (SEM). Degeneration of stereocilia took place as early as 5 days after the treatment in the utricule, the saccule and the cristae. At 10 days, almost the entire surface of these sensory epithelia presented a smooth aspect without specific structure. However, after 15 days, an epithelial reorganization developed with clear limits between cells. At 25 days, systematic kinociliary structures were observed at the apical surface of the …

Improved Tissue Corrosion Of Vascular Casts: A Quantitative Filtration Method Used To Compare Tissue Corrosion In Various Concentrations Of Sodium And Potassium Hydroxide, Paul A. Sims, Ralph M. Albrecht

Scanning Microscopy

In this study, we compare weights of filter retained material (11 μm particle retention) after solubilization and filtration of unfixed, un-perfused tissue (fat, liver and trachea) in sodium and potassium hydroxide (1% , 5%, 10% and 20% weight/volume, w/v) at 8, 24 and 48 hour time points at 45°C. Three detergents [1% Triton-X-100 (volume/volume, v/v), 1% 7X (v/v), 1% Terg-A-Zyme (w/v)] used in combination with hydroxide were evaluated for use in solubilizing fat. Additionally, vascular casts from mouse kidneys were corroded to test the practical effectiveness of corroding solutions on resin infused tissue.

Five percent KOH for eight hours proved …

Microsporum Canis Scalp Ringworm: Its Primary Or Secondary Ectothrix Character, Hester F. Vismer

Scanning Microscopy

This study supports the view that, in cases of tinea capitis due to a Microsporum canis infection, ectothrix arthroconidium formation is extrapilary and arises from intrapilary hyphae. The hyphae of M. canis perforate and digest the hair cuticle to alter its appearance from a normally identifiable structure of imbricated cells with a distal free border, to a grossly altered and pathological layer. Conidium production mainly takes place outside the hair shaft and forms thick clusters between the cuticular tiles. Finally, a shaft of conidia is formed around the hair. The cuticular covering of such a conidium sheath belongs to the …

The Sociology Of Plants, Julie L. Welch Stuehser

Undergraduate Honors Capstone Projects

The purpose of this research is to assess the link between plants, people, and performance. Several studies have suggested that plants in a social environment will change the behavior of the people in their vicinity (Relf, 1990, 1992; Bryant, 1992).

Urinary Calculi: Review Of Classification Methods And Correlations With Etiology, M. Daudon, C. A. Bader, P. Jungers, O. Beaugendre, M. P. Hoarau

Scanning Microscopy

Current physical and chemical methods available for urinary stones analysis are critically reviewed. No one method is sufficient to provide all the clinically useful information on the structure and composition of the stones. We show that a combination of refined morphological and structural examination of stone with optical microscopy, complemented by compositional analysis using infrared spectroscopy of the core, cross-section and surface of calculi, provides a precise and reliable method for identifying the structure and crystalline composition, and permits quantification of stone components while being highly cost effective. Using such morphoconstitutional studies leads to a classification of urinary stones in …

Calculation Of A Topographic Contrast In The Scanning Electron Microscope, M. Kotera, T. Fujiwara, S. Yamaguchi, H. Suga

Scanning Microscopy

A direct simulation of electron scattering in solids is developed. Using this simulation, a topographic contrast found in the scanning electron microscope is quantitatively discussed. The surface topography studied here is a rectangular rod pattern and a rectangular groove pattern at an infinite horizontal plane surface of Al. We quantify characteristics of the secondary electron image and of the backscattered electron image at the topography. The intensity profile at the bottom surface of the groove pattern is roughly approximated by an analytical model.

Surface Morphology And Strain Relief In Surfactant Mediated Growth Of Germanium On Silicon (111), M. Horn-Von Hoegen, M. Pook, A. Al Falou, B. H. Müller, M. Henzler

Scanning Microscopy

The growth of Ge on Si is strongly modified by adsorbates called surfactants. The relevance of the stress on surface morphology and the growth mode of Ge on Si(111) is presented in a detailed in situ study by high resolution low energy electron diffraction (LEED) during the deposition. The change from islanding to layer-by-layer growth mode is seen in the oscillatory intensity behaviour of the 00-spot. As a strain relief mechanism, the Ge-film forms a microscopic rough surface of small triangular and defect-free pyramids in the pseudomorphic growth regime up to 8 monolayers. As soon as the pyramids are …

Human Chromosomes: Evaluation Of Processing Techniques For Scanning Electron Microscopy, O. H. Sanchez-Sweatman, E. P. De Harven, I. D. Dubé

Scanning Microscopy

Methods for scanning electron microscopy (SEM) of chromosomes have been developed in the last two decades. Technical limitations in the study of human chromosomes, however, have hindered the routine use of SEM in clinical and experimental human cytogenetics. We compared different methodologies, including metal impregnation, air drying and specimen coating. SEM preparation of human chromosomes in which osmium impregnation is mediated by tannic acid, yielded more reproducible results when compared with osmium impregnation protocols previously described. The level of osmium impregnation was systematically evaluated by imaging chromosomes in the backscattering mode. Critical point drying and a light gold-palladium coating were …

Keynote Paper: The Scanning Electron Microscope (Sem) Supplemented By The Polarized Light Microscope (Plm), And Vice Versa, Walter C. Mccrone

Scanning Microscopy

The scanning electron microscope (SEM) yields excellent topographic and other shape information and, when fitted with an energy dispersive system (EDS), elemental composition. The polarized light microscope (PLM) on the other hand, delivers information on the internal properties of small particles, fibers, and films. By determining optical properties as well as shape, PLM determines molecular, rather than elemental, composition. Both SEM and PLM have impressive records for problem solving in the research and development world and each is usually applied without aid from the other. Examples are given of important problems that have been solved by supplementary PLM with SEM …

The Vascularization Of The Kidney Of The Eel (Anguilla Anguilla - Osteichthyes) In The Freshwater Habitat, Hans Ditrich, Heinz Splechtna

Scanning Microscopy

The renal vascular system of eels (Anguilla anguilla L.) in freshwater has been investigated using light-, transmission electron-, and scanning electron microscopy of vascular corrosion casts and critical-point dried specimens. The morphology of the kidney exhibits a highly evolved, unpaired, spindle-shaped form. The renal tissue extends partially into a recessus dorso-caudal to the anus. Renal glomeruli are comparatively large (100.8 μm +/-17 standard deviation) and well vascularized. They are arranged in grape-like clusters around the intrarenal arteries. Closely neighbouring glomeruli can be surrounded by incompletely separated Bowman's capsules sharing the same renal tubule. The peritubular capillary plexus is …

Identification Of Ion Transport Compartments In Turtle Urinary Bladder, P. Fraunberger, A. Dörge, P. Buchinger, F. X. Beck, K. Thurau

Scanning Microscopy

To identify the turtle urinary bladder cells involved in Na and Cl absorption and Hand HCO₃ secretion cellular electrolyte concentrations and uptake of Br and Solutrast were determined using electron microprobe analysis. Whereas inhibition of transepithelial Na transport by ouabain (reversion of short circuit current) led to a pronounced K-Na exchange in granular, and most of the basal cells, surface CA-cells and some basal cells were ouabain insensitive. Surface CA-cells could be divided into a large Cl-rich and a small Cl-poor population. Since the ouabain-induced K-Na exchange could be completely prevented by blocking passive luminal Na entry by amiloride, …

Preparation Of Dinosaur Fossils For Scanning Electron Microscopic Evaluation Of Bone Histology, C. Barreto, R. M. Albrecht

Scanning Microscopy

The quality of preservation is a major determinant of the amount and kind of information to be derived from a paleontological specimen. Various fossilization regimes may produce specimens that contain biological information on a microscopic level. Light microscopic inspection of adolescent fossil dinosaur bones from the Two Medicine Formation (northwestern Montana) revealed that precise preservation of tissue may occur at a cellular level. In the following report, we test and compare techniques of specimen preparation for examination by scanning electron microscopy and illustrate an example of faithful preservation of dinosaur bone histology.

Evaluation Of The Surface Roughness Of Cystine Stones Using A Visible Laser Diode Scattering Approach, R. Thibert, B. Dubuc, M. Dofour, R. Tawashi

Scanning Microscopy

To understand the processes of fragmentation and the chemical reactivity of solids, proper characterization of surface topography is crucial. This paper describes a non-destructive technique of quantifying the surface roughness of cystine renal stones, using visible laser diode scattering and fractal geometry. Fragments of cystine stones were mounted on microscope slides and coated by a carbon-sputtering apparatus. The slides were placed under a dynamic active-vision system, using a visible laser diode to measure three-dimensional surface coordinates. The data obtained were analyzed by fractal geometry. Surface fractal dimensions were determined by the variation method. The results showed that the surface of …

Scanning Electron Microscopy Of Vascular Smooth Muscle Cells From Spontaneously Hypertensive Rats, William J. Krizmanich, Robert M. K. W. Lee

Scanning Microscopy

The fine structure of vascular smooth muscle cells from large mesenteric arteries of adult (28 weeks) spontaneously hypertensive rats and Wistar-Kyoto rats was studied using scanning electron microscopy (SEM). The effect of the digestion method for SEM on tissue size and smooth muscle cell size was also studied using morphometric analysis. A significant reduction in cell size (42-43%) was present after critical point drying, based on the reduction in volume to surface ratio of smooth muscle cells. However, percent change of volume density and volume to surface ratio of smooth muscle cells after digestion and after critical point drying, was …

Reversible And Irreversible Effects Of Temperature On Amelogenesis Of Hamster Tooth Germs In Vitro, J. H. M. Wöltgens, D. M. Lyaruu, Th. J. M. Bervoets, A. L. J. J. Bronckers

Scanning Microscopy

Hamster first hamster molar tooth germs in early secretory stage of amelogenesis were cultured for one day in vitro at 6°C, 22°C, 37°C or 45°C in the presence of ³H-proline, ⁴⁵Ca and ³²P-orthophosphate. Other explants were cultured without these labels and after culture examined by histology. The highest temperature tested was lethal to the explants, decreased total dry weight and rapidly increased total uptake of the radio-labelled mineral ions, probably merely due to physicochemical modification of the existing preculture minerals. Optimal synthesis and secretion of amelogenins were measured at physiological temperature (37°C). Effects of exposure to both …

Electron Acoustic Signal Of Metallic Layers Over A Semiconductor Substrate, J. F. Bresse

Scanning Microscopy

Calculations have been made for the electron acoustic signal in the case of one and two metallic layers deposited over a semiconductor substrate. The temperature distribution as function of the depth has been determined by taking into account the power absorbed in the metallic layers and the substrate. We have considered strain-free and constrained layers. Experimental results have been obtained for a single metallic layer (Au, W, Pd, Mo, Mn, Ti) deposited over GaAs and for Au-Ti contacts. Comparison between experiments and calculations allows us to determine whether the layers are constrained or not.

Problem Analysis For The Vegetation Diversity Project, David A. Pyke, Michael M. Borman, U.S. Department Of The Interior, Bureau Of Land Management

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

Management of the majority of public rangeland in the Great Basin and Columbia-Snake River Plateau falls under the authority of the Bureau of Land Management. The flora of this land ranges from highly diverse native plant communities to deteriorated lands dominated by exotic annuals. Approximately nine percent of the BLM’s 78 million acres of public land in this region is degraded to such a degree that changes in land management alone will not result in significant improvement. The BLM intends to restore native plant communities on these deteriorated lands, but current revegetation techniques used to establish introduced perennial grasses are …

A Scanning Tunneling Microscopy Study Of Vanadium Oxide, Takanori Oshio, Yoshiyuki Sakai, Tohru Moriya, Shaw Ehara

Scanning Microscopy

Atomic resolution images of the (010) surface of a divanadiun pentoxide (V₂O₅) single crystal were successfully obtained by the use of a scanning tunneling microscope (STM).

The images of the filled states at sample bias voltage, Vs = -2 V and the empty states at Vs = +2 V correspond to oxygen and vanadium ions, respectively.

As for the vanadium ion sites, an additional peak of the electronic states at the conduction band edge due to the defects of vanadyl oxygen ions was found in the normalized conductance spectrum through the tunneling spectroscopy (TS) measurement.

Fungiform Papillae Of The Pig And The Wild Boar Analyzed By Scanning Electron Microscopy, C. A. Chamorro, P. De Paz, J. G. Fernández, L. Anel

Scanning Microscopy

Fungiform papillae of wild boar and pig were studied by scanning electron microscopy (SEM). Four regions were defined on the tongue: rostral, medial and caudal thirds and lateral sides. Morphologically the fungiform papillae correspond with their denomination. Rostral and lateral tongue regions presented the largest average number of fungiform papillae. Taste pores opened onto the upper surface of the papillae and were easily identifiable by SEM. The total number of fungiform taste pores from both animals was the highest reported in the literature. The lateral papillae of wild boar and pig contained the largest average number of pores per papilla. …

Morphology Studies Of Iron-Manganese Thin Films, G. Mathew, K. -W. Ng, A. R. Sethuraman, J. M. Stencel

Scanning Microscopy

Fe-based catalysts are known to be effective for Fischer-Tropsch synthesis from coal but are sensitive to sulfur poisoning. Addition of manganese to these catalysts has been proposed in an effort to combat this catalyst deactivation. To investigate the fundamental physical aspects of Mn incorporation into Fe, different compositions of model thin films of Fe-Mn, ranging from 100% Fe to 100% Mn were studied for the very first time, using scanning tunneling microscopy (STM), atomic force microscopy (AFM) and scanning electron microscopy. Our preliminary results indicate that the grain size of iron varied from 50 nm to 150 nm using the …

Scanning Electron Microscopy Of Muscle Myofibrils After High Pressure Freezing And Freeze-Substitution-Staining, M. Malecki, M. L. Greaser

Scanning Microscopy

A novel approach to study the three dimensional ultrastructure of organelles and cells by means of scanning electron microscopy is described. Muscle myofibrils have been used in the development of the techniques since their structure is well characterized using conventional electron microscopic methods. Myofibrils in rigor buffer (with no cryo-protectants or pressure sealants) were frozen at high pressure (2300 bar) within specially designed chambers. The frozen specimens were then freeze-substituted-stained with methanol containing tungsten and iron salts and finally critical point dried. These methods allowed scanning electron microscopic observations of the organization of individual filaments within whole myofibrils over several …

Application Of Scanning Electron Microscopy And X-Ray Analysis To Urinary Tract Cancer In Animals And Humans, Martin Cano, Toru Suzuki, Samuel M. Cohen

Scanning Microscopy

Scanning electron microscopy (SEM) has proven useful in various aspects of urinary bladder carcinogenesis research and these are reviewed as they pertain to our research involving sodium saccharin in the rat. Sodium saccharin-carcinogenesis in rats requires administration at high doses beginning at birth or earlier. Administration beginning at ages of 5 weeks or later results in much lower incidences of bladder tumors. Methods were developed for examining the rat fetal and neonatal bladder to further evaluate effects at these critical ages. Several significant differences were found by SEM between the fetal bladder compared to the-adult. The typical polygonal superficial cells …

Quantitative Scanning Electron Acoustic Microscopy Of Silicon, M. Domnik, L. J. Balk

Scanning Microscopy

So far results of scanning electron acoustic microscopy (SEAM) have retained a widely qualitative meaning only due to the enormous uncertainty in understanding sound generation and contrast mechanisms in SEAM micrographs. In this work, a detailed treatment of these mechanisms has been undertaken for silicon resulting in precise knowledge of the signal generation processes and a well understood interpretation of the contrast mechanisms involved in imaging thermo-mechanical and electronic features.

Scanning Electron Microscopy Of Styrene-Methylethylketone Casts Of The Airway And The Arterial System Of The Lung, Teruyuki Hojo

Scanning Microscopy

The method of making casts of airways and the pulmonary arterial system using a styrene polymer resin is described. A human and a dog were used as models. The viscosity of this resin ranges between 40 and 60 dPa/s at 24°C. The elastic rubber tube used for resin injection allows a constant perfusion pressure, i.e., 44 mm Hg and 110 mm Hg for airway and vascular filling, respectively. The casts obtained using this method are suitable both for macro- and microscopic analysis. Shrinkage during polymerization is minimal. Moreover, a preceding lavage is not necessary. Scanning electron microscopy (SEM) of cast …

Electron Probe Micro-Analysis Of Human Dental Pulp Stones, O. Le May, J. C. Kaqueler

Scanning Microscopy

The mineral composition of ten human dental pulp stones presenting various morphological aspects has been studied by electron probe micro-analysis. The denticles were composed of two major chemical elements Ca and P with mean concentrations 32.12% and 14.69% respectively giving a Ca/P weight ratio of 2.19 which is very close to the weight ratio of pure stoichiometric hydroxyapatite (2.15). The concentration of some other elements was much lower (0.88% for F ; 0.75% for Na ; 0.51% for Mg). The other analysed constituents (K, Cl, Mn, Zn, Fe) were present at trace concentrations. The mineral composition of sound human dentine …

Letter To The Editor By M.B. Engel And H.R. Catchpole Relating To: "Can We See Living Structures In The Cell" [By G.N. Ling, Scanning Microscopy Vol. 6, P. 405-450 (1992)] And Reply By G.N. Ling, M. B. Engel, H. R. Catchpole

Scanning Microscopy

Dear Editor,

As workers in the field of ionic equilibrium in extracellular matrices and cells, and as contributors to this Journal of papers supporting an alternative explanation to that represented by the dominant schools of active transport (ionic pumps), we are surprised by the statement of Ling (1992, p. 449) which appears to limit published criticism of those schools to himself and A.S. Troshin. By an odd coincidence, our abstract (Catchpole et al., 1951) on the distribution of potassium and sodium through selective action of the cations with ground substance and water appeared simultaneously with that of Ling (1951): "Tentative …

Role Of Adhesion Molecules In The Mechanism Of Non-Mhc (Major Histocompatibility Complex) Restricted Cell-Mediated Cytotoxicity, Walter Malorni, Francesca Iosi, Daniela Zarcone, Carlo Enrico Grossi, Giuseppe Arancia

Scanning Microscopy

Adhesion molecules involved in the interaction between immune system effector cells and tumor targets are surface molecules which contribute to the formation of cell-to-cell contacts and belong to the integrin family. In this paper, the role played by the adhesion molecules in the process of cell-mediated cytotoxicity is reviewed. Furthermore, the contact area between effector and target cells has been analyzed by scanning electron microscopy. This region, termed "closed chamber", seems to contribute to killing efficiency by creating an intimate contact region in which cytotoxic factors can easily induce lethal hit in target cell. Thus, the extension of the closed …

Radiation-Induced Neoplastic Transformation Of Human Cells, J. S. Rhim, P. Thraves, A. Dritschilo, M. R. Kuettel, M. -S. Lee

Scanning Microscopy

Ionizing radiation can induce cancers in humans and animals and can cause in vitro neoplastic transformation of various rodent cell systems. However, numerous attempts to achieve neoplastic transformation of human cells by radiation have generally proven unsuccessful. Neoplastic transformation of immortalized human epidermal keratinocytes by X-ray irradiation has recently been reported. The carcinogenic effect of radiation on cultured human cells will be briefly reviewed. The current state-of-the-art in radiation-induced transformation of human cells in culture is presented. This will provide insight into the molecular and cellular mechanisms in the conversion of normal cells to a neoplastic state of growth.