Life Sciences Commons^™

X-Ray Microanalysis In Cryosections Of Natively Frozen Paramecium Caudatum With Regard To Ion Distribution In Ciliates, M. Schmitz, R. Meyer, K. Zierold

Scanning Electron Microscopy

Cells of Paramecium caudatum were shock-frozen without pretreatment for cryoultramicrotomy and freeze-dried for subsequent X-ray microanalysis. Na, Mg, P, S, Cl, K, and Ca were detected in different amounts in several subcellular compartments. In particular, calcium was localized below the cell surface (pellicle). Trichocysts were found to contain significant amounts of Na in their base but not in the tip. Na, Mg, P, S, Cl, K, Ca were found in electron dense deposits within the lumen of the contractile vacuole. A small K concentration was found in the cytoplasm and in the mitochondria. X-ray microanalysis of the element distribution in …

Scanning Electron Microscopy In Retinal Research, Bessie Borwein

Scanning Electron Microscopy

The literature on scanning electron microscopy (SEM) pertaining to the retina has been surveyed and described.

The first two papers on SEM and retina appeared in 1969. Most of the earlier studies concentrated on descriptions [by SEM alone, or with light microscopy (LM) and transmission electron microscopy (TEM)] of the appearance of various retinae and retinal cells [fish, newt, primates, rodents and rabbits, bullfrog]; or embryology of the chick retina. Two papers dealt with retinal disease. In all there were 25 papers in SEM/retinal research before and in 1974. Since 1975 there have been 111 papers which have used SEM …

A Rapid Technique For Counting Cracks In Rocks, W. B. Durham, J. M. Beiriger, H. C. Weed

Scanning Electron Microscopy

Using a scanning electron microscope (SEM) and an image analyzer, we have developed a technique for counting and measuring cracks in rocks which is more efficient than traditional techniques in which an operator performs all image analysis functions. The key aspect of the technique is that black-on-white tracings of fresh cracks, which can be made rather rapidly by an operator, are measured and digitized by an image analyzer. The most time-consuming step in the process has now become the generation of SEM micrographs and pertinent chemical (mineralogical) information, not the quantification of crack structure. The technique has been applied to …

Surface Roughness Contribution To The Auger Electron Emission, D. Wehbi, C. Roques-Carmes

Scanning Electron Microscopy

Scanning Auger Microscopy (SAM) experiments have shown that z height and θ slope relative to the analysed spot are parameters that contribute to the measured Auger intensity I(z, θ). For greater analysed areas specific to Auger Electron Spectroscopy (AES), the knowledge of height and slope statistical distributions P(z) and P(θ) is required. These functions have been determined by means of profilometric data. The spatial resolution of the used tactile profilometer is similar to that which characterizes AES. A mathematical relationship I { P(z), P(θ) } has been set up for Si samples whose roughness is well defined. On the other …

Sputtered Thermal Ion Mass Spectrometry As A New Quantitative Method For In-Depth Analysis, G. Blaise

Scanning Electron Microscopy

The Sputtered Thermal Ion Mass Spectrometry method (STIMS) consists of collecting a part of the matter sputtered from a solid by ion bombardment into a heated cell where it is reduced into atoms. A thermal ionization process or an electron impact process taking place in the cell yields ions which are extracted and mass analyzed. The composition of the solid is determined from ion intensities after calibration of ionization coefficients. It has been demonstrated that the method has an absolute quantitative character. Applications to elemental quantitative analysis (identification of new compounds in diffusion couples, dust particle analysis) and in-depth analysis …

Wave-Length Dispersive Microprobe Analysis Of Coated Samples Of Bulk Tissues, C. Ward Kischer, Thomas M. Teska

Scanning Electron Microscopy

Hypertrophic scars contain highly pleomorphic cells, including many from the erythrocytic series which have been extravasated. The conventional visual mode of SEM cannot distinguish the cell types with certainty except in the case of typical biconcave disc-shaped erythrocytes. Microprobe elemental analysis might be used to differentiate one type from another on the basis of iron and possibly phosphorus (for nucleated cells). Using coated specimens (gold or gold-palladium) precludes simultaneous visual mode SEM with EDX because of energy line interference with phosphorus and other elements. However, wave-length dispersive analysis offers minimal or no interference, and a coated specimen offers the use …

Progress In Element Analysis On A High-Voltage Electron Microscope, W. F. Tivol, D. Barnard, T. Guha

Scanning Electron Microscopy

X-Ray microprobe (XMA) and electron energy-loss (EELS) spectrometers have been installed on the high-voltage electron microscope (HVEM). The probe size has been measured and background reduction is in progress for XMA and EELS as are improvements in electron optics for EELS and sensitivity measurements.

XMA is currently useful for qualitative analysis and has been used by several investigators from our laboratory and outside laboratories. However, EELS background levels are still too high for meaningful results to be obtained. Standards suitable for biological specimens are being measured, and a library for quantitative analysis is being compiled.

Oxidation Of Aluminum Studied By Ion Scattering Spectroscopy (I.S.S) In A Scanning Auger Microscope, M. Gautier, J. P. Duraud, J. P. Vigouroux, C. Le Gressus, R. Shimizu

Scanning Electron Microscopy

The set up of an ion gun, producing a focused beam in the analysis chamber of a Scanning Auger Microscope permits ion scattering experiments: surface studies performed by electron spectroscopies can then be enlarged by Ion Scattering Spectroscopy (I.S.S.) to get additional information.

I.S.S. appears to be very sensitive to the cleanliness of the surface: comparison between Electron Energy Loss Spectroscopy (E.E.L.S.) and I.S.S. studies on clean samples show that I.S.S. can still detect oxygen even when it is not detectable by E.E.L.S.

Preliminary results on oxidation of Al (111) and Al (100) give oxidation curves in good agreement with …

Cross-Sectional Analysis Of Silicon Metal Oxide Semiconductor Devices Using The Scanning Electron Microscope, Daniel S. Koellen, David I. Saxon, Kenneth E. Wendel

Scanning Electron Microscopy

A technique has been developed which enables one to cross-section specific devices or features for examination with the scanning electron microscope (SEM). This method is used for investigation of all facets of microelectronic circuit manufacture from research and development to failure analysis of the finished product.

Selective etching is used to provide contrast to each processed layer. Etch type and sequence, used for delineation, are important to understand since they may add artifacts to the cross-section, leading to erroneous analysis conclusions. The etchant and etch conditions used will be dictated by the information needed from a particular sample.

Etching systems …

Digital Processing Of Electron Energy Loss Spectra And Images, R. D. Leapman, K. E. Gorlen, C. R. Swyt

Scanning Electron Microscopy

Processing in electron energy loss spectroscopy involves both data acquisition and analysis. The interface of an analytical electron microscope to a laboratory computer with a satellite microcomputer dedicated to data acquisition results in a system with a high degree of flexibility. In spectrum acquisition, channels may be selected around specific core edges, or dwell times may be varied continuously as a function of energy loss to reduce the dynamic range of the signal. Data transfer to the host computer allows further analysis such as the removal of plural scattering by spectral deconvolution. Elemental maps and line-scans can be recorded with …

Intracellular Localization Of Heavy Metals In Yeast By X-Ray Microanalysis, Ljerka Kunst, Godfried M. Roomans

Scanning Electron Microscopy

The intracellular localization of heavy metals in yeast cells was studied by means of energy-dispersive X-ray microanalysis. The yeast, Saccharomyces cerevisiae, was pretreated with phosphate and then loaded with different metal ions, by suspending the cells in salt solutions (Ni, Zn, Cd, Pb, Al and Cr). For the analysis, the cells were embedded in gelatin, rapidly frozen, and thin cryosections were cut on a dry knife.

A considerable uptake of divalent cations by the yeast cells was found to occur. The cations were bound to the polyphosphate granules localized in or close to the cell vacuoles. Immediately after phosphate …

Alterations Of The Intracellular Water And Ion Concentrations In Brain And Liver Cells During Aging As Revealed By Energy Dispersive X-Ray Microanalysis Of Bulk Specimens, Gy. Lustyik, I. Zs.-Nagy

Scanning Electron Microscopy

Age dependence of the intracellular concentrations of monovalent ions (Na+, K+ and Cl-) was examined in 1, 11 and 25-month-old rat brain and liver cells by using energy dispersive X-ray microanalysis. The in vivo concentrations of Na+, K+ and Cl- ions were calculated from two different measurements: The elemental concentrations were measured in freeze-dried tissue pieces, and the intracellular water content was determined by means of a recently developed X-ray microanalytic method, using frozen-hydrated and fractured bulk specimens as well as subsequent freeze-drying.

All the single monovalent ion concentrations and consequently, also the total monovalent ion content showed statistically significant …

Study By Scanning Electron Microscopy And Electron Spectroscopy Of The Cascade Of Electron Multiplication In An Insulator Submitted To An Electric Field, J. P. Vigouroux, J. P. Duraud, C. Le Gressus, G. Petite, P. Agostini, C. Boiziau

Scanning Electron Microscopy

An original method for revealing the dielectric heterogeneities on an insulating surface has been developed on creation of an electron multiplication cascade inside the insulator placed in an electric field. The steps of the physical process are: (i) excitation of electrons into the conduction band, (ii) electric field acceleration of the conduction electrons, (iii) ionization of the valence levels, (iv) creation of many more new defects in the vicinity of dielectric heterogeneities, (v) charge localization on defects and appearance of a local residual potential. The potential map is observable by scanning electron microscopy after propagation of the ionizing cascade, but …

High Accuracy And Automatic Measurement Of The Pattern Linewidth On Very Large Scale Integrated Circuits, H. Yamaji, M. Miyoshi, M. Kano, K. Okumura

Scanning Electron Microscopy

High accuracy measurement of pattern linewidth is particularly important in Very Large Scale Integrated Circuits (VLSI) manufacturing.

The measurement of pattern linewidth has been done by optical methods. However, the optical methods have several problems: as the measured value depends on slope angle at pattern edge, thickness and optical property of film and also substrate, there exists a large difference in size (0.3 μm) between the defined edge and the true edge in case of photoresist linewidth measurements. Especially, the optical methods have severe problems to measure bottom of pattern edge and are unsuitable to measure pattern linewidth in VLSI's …

A Wien Filter Energy Loss Spectrometer For The Dedicated Scanning Transmission Electron Microscope, P. E. Batson

Scanning Electron Microscopy

A Wien filter electron spectrometer has been added to a VG Microscopes, Ltd. HB501 STEM to improve the energy resolution and accuracy of energy loss analysis combined with a high spatial resolution. An energy resolution of 130meV is obtained with a 2mR collection angle at the specimen. The 0.28eV wide field emission energy profile therefore dominates the energy resolution for the device. The energy axis is automatically calibrated by the electrostatic method of scanning, yielding an accuracy and stability of 30meV. A preliminary energy resolution of 0.5eV is demonstrated for 20mR full collection angles at the specimen. Results of experiments …

Scanning Electron Microscopy Of The Lateral Ventricle Of The Pigeon Brain, P. Mestres, K. Rascher, J. D. Delius

Scanning Electron Microscopy

Adult pigeons of both sexes were used for this study. Depending upon the distribution of various surface profiles, for example cilia, microvilli and blebs, ependymal areas with differing surface patterns were distinguished in the lateral ventricle. The topographical locations of these areas with respect to the underlying forebrain nuclei were determined in accord with the atlas of Karten and Hodos (1967). The medial surface (A) of the ventricle was much more densely ciliated than the lateral surface (B). There did not appear to be any correlation between a given surface pattern and a specific type of underlying nervous tissue. Comparison …

Characterization Of Carbonaceous Materials By Correlated Electron And Optical Microscopy And Raman Microspectroscopy, C. Beny-Bassez, J. N. Rouzaud

Scanning Electron Microscopy

Carbonaceous materials differ according to their chemical composition (types of heteroatoms), their structure and their microtexture. So, it is interesting to find methods for characterizing them. We choose to correlate data from Raman microspectroscopy, optical microscopy and transmission electron microscopy. First, we use both graphitizable or non-graphitizable reference carbon series of simple chemical composition in order to follow the structural transformation of the carbonaceous materials according to the evolution of these data throughout heat-treatment of these samples. Then, the coals of different ranks are studied.

The Raman results are correlated with those from electron microscopy, particularly by plotting, for the …

Advances In Non-Contact Thermal-Wave Imaging With Infrared Detection, F. H. Dacol, H. Ermert, R. L. Melcher

Scanning Electron Microscopy

We are making further advances in non-destructive and non-contact thermal imaging with infrared detection. We employ a chopped and scanned electron beam as heat source, a cooled HgCdTe infrared detector as temperature sensor, and digital processing of the measured temperature pattern for display and storage. The results give a convincing, high contrast image of subsurface structures.

Scanning Electron Microscopy Methodology For Study Of The Pathophysiology Of Calcification In Bioprosthetic Heart Valves, Alan C. Nelson, Frederick J. Schoen, Robert J. Levy

Scanning Electron Microscopy

Scanning electron microscope (SEM) morphologic analysis combined with energy dispersive characteristic X-ray (EDX) microprobe analysis provides insight into the mechanisms associated with disease-related crystal formation in biological materials. SEM and EDX were employed in analyzing specimens which were embedded in standard fashion in glycolmethacrylate (JB-4). The specimen surfaces under electron microscope investigation resulted from microtomy used in the preparation of reference light microscope histological sections; thus histology served as a direct reference for the SEM and EDX analyses.

The particular application of these methods was in the study of bioprosthetic heart valve calcification, largely responsible for clinical failure of these …

Detection System For Scanning Electron Microscope, J. Hejna, Z. Radzimski, A. Buczkowski

Scanning Electron Microscopy

The kind of information and the quality of the backscattered electron (BSE) images depend upon numerous features of the detector. Therefore, various types of detectors should be used simultaneously to obtain as much of information as possible. The detection system presented here contains a large area semiconductor detector and a BSE to secondary electrons (SE) converter system. These two different kinds of detectors give different BSE images. After subtracting the signal of a semiconductor detector from that of a converter system, an image with good topography and reduced material contrast can be achieved.

Ultrasonic Microdissection Of Rat Cerebellum For Scanning Electron Microscopy, C. E. Arnett Iii, F. N. Low

Scanning Electron Microscopy

The cerebelli of rats were initially fixed with aldehydes (modified Karnovsky's fixative; 503 mOsM/L) by cardiac perfusion. Blocks of tissue were razor-cut, usually longitudinal to folia, and immersed in the same fluid for 2-4 hours. Three separate methods of treatment followed: (1) immersion in 1% aqueous boric acid, or (2) in 2% phosphate buffered OsO₄ followed by boric acid or (3) in an 8/2 mixture of boric acid and OsO₄. After 18-48 hours immersion the blocks were dehydrated in ascending grades of acetone. They were then exposed to ultrasound in 100% acetone at frequencies of 80 kHz …

Use Of Scanning Electron Microscopy To Study Structural-Functional Relationships In Normal And Diseased Platelets, J. C. Mattson

Scanning Electron Microscopy

This paper reviews the contribution of scanning electron microscopy (SEM) to our understanding of platelet physiology and pathology. Observations of platelet shape changes which accompany activation and the ability to visualize and analyze platelet aggregation and adhesion in three dimensions make this experimental medium an important tool in the evaluation of healthy and diseased platelets. While SEM adds a valuable third dimension to the study of morphology and ultrastructure, its greatest contribution is realized when studies are correlated directly with light and/or transmission electron microscopic observations and with studies of functional capacity.

Some Considerations Of The Ultimate Spatial Resolution Achievable In Scanning Transmission Electron Microscopy, Anthony J. Garratt-Reed

Scanning Electron Microscopy

The fundamental limitations on spatial resolution of X-ray microanalysis in the scanning transmission electron microscope are set by the interrelationships between the gun brightness, operating voltage, probe convergence angle, size and current, specimen thickness, beam broadening, the probability of characteristic and Bremsstrahlung X-ray production and the statistics of the X-ray spectrum. Manipulation of expressions describing these interrelationships leads to equations predicting the optimum probe size and specimen thickness for the best achievable spatial resolution (defined as the diameter of a cylinder containing 90% of the X-ray production) in microscopes fitted with different electron sources and operating at different voltages in …

Morphological Study Of The Anodic-Oxide And Hydrated-Oxide Films On Pure Aluminium, S. M. El-Mashri

Scanning Electron Microscopy

A high resolution scanning transmission electron microscope (STEM), operated in the SEM mode, has been used to examine the morphology of the oxide anodically formed on a surface of pure aluminium, using different electrolyte solutions (tartaric, oxalic, boric, phosphoric and chromic acids). The microstructural changes of these films following their hydration in hot water showed degradation of the oxide and conversion to an oxy-hydroxide phase (pseudo-boehmite). These observations are in agreement with previous EXAFS measurements of the Al-O bondlength which indicated the formation of crystalline boehmite (AlOOH). Observation of the oxide and oxy-hydroxide derived from anodisation in phosphoric acid electrolyte …

Recent Advances In Laser Microprobe Mass Analysis (Lamma) Of Inner Ear Tissue, A. Meyer Zum Gottesberge-Orsulakova, R. Kaufmann

Scanning Electron Microscopy

Maintenance of ionic gradients within the various fluids compartments of the inner ear requires transport active cellular systems at different locations. LAMMA analysis is ideally suited for detection of ions in microquantity on cellular levels overcoming many technical difficulties. The present paper summarizes the results of microprobe analysis obtained with laser induced mass spectrometry (LAMMA) supplemented by X-ray microprobe analysis of epithelial cell layers adjacent to the endolymphatic space (a) in the cochlear duct, (b) in the vestibular organ and (c) in the endolymphatic sac. The possible role of inner ear as well as ocular melanin in the mechanisms of …

The Ependyma Of The Cat Central Canal, With Particular Reference To Its Mitochondria-Containing Bulbs, K. Rascher, K. H. Booz, A. C. Nacimiento, E. Donauer

Scanning Electron Microscopy

The ultrastructure of the ependyma in the central canal of adult cats was examined in both the scanning and the transmission electron microscopes (SEM and TEM).

The same morphological details were seen in the ependyma of the central canal as have so frequently been described in the ependyma of the brain ventricular system, for example bundles of cilia, single cilia, microvilli and occasional small cytoplasmic protrusions. The supraependymal cells and supraependymal nerve fibers found in the central canal also resembled those seen in the ventricular system.

The most striking feature of the canal ependyma were the large, spherical bodies containing …

Microcharacterization Of Fluid Inclusions In Minerals By Raman Microprobe, J. C. Touray, C. Beny-Bassez, J. Dubessy, N. Guilhaumou

Scanning Electron Microscopy

Fluids trapped in inclusions in minerals are micro-amounts of ore-forming media composed of water, dissolved salts, gases and sometimes liquefied gases, liquid, hydrocarbons and solids. The aim of this paper is to summarize the contribution of the Raman scattering microspectrometry to the knowledge of fluid inclusions. After a review of the composition of fluid inclusions and a short presentation of microthermometrical investigations, a description of the Raman microprobe is given. Applications are reviewed; identification of ionic species dissolved in aqueous phase, characterization of gases of C-O-H-N-S system, identification of solids and non aqueous liquids. The complementary characteristics of Raman microanalysis …

Scanning And Transmission Electron Microscopic Studies On The Oviducts Of Pekin Ducks Fed Methyl Mercury Containing Diets, A. Balachandran, M. K. Bhatnagar, H. D. Geissinger

Scanning Electron Microscopy

This study was undertaken to examine the effects of varying levels of methyl mercury (MeHg) on the ultrastructure of the surface epithelium of the oviduct of ducks. Accordingly, Pekin ducks were maintained on feed containing varying doses of (0.0; 0.5; 5.0; 15.0 ppm) of MeHg (Group I - control to IV) for 12 weeks and sacrificed. Tissue from the magnum and the shell gland regions of the oviduct was processed for scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the primary and secondary folds of these regions of the oviducts of the control and 0.5 …

Calcium Oxalate Crystal Production In Two Members Of The Mucorales, M. D. Powell, H. J. Arnott

Scanning Electron Microscopy

Calcium oxalate crystals are found in association with the sporangia of Mucor hiemalis and Rhizopus oryzae. Crystals observed in each species vary in morphology from simple crystals consisting of single spines in M. hiemalis to complex crystals with twin spines, sometimes three-parted, on a common base in R. oryzae. The early development of the crystals is similar in both species with a layer of the cell wall covering in the initial crystals. The spines of M. hiemalis rapidly emerge while the crystals of R. oryzae appear to remain covered with a layer of outer wall material. The crystals …

Parameters Of Growth In The Embryonic And Neonatal Chick Basilar Papilla, Douglas A. Cotanche, Kathleen K. Sulik

Scanning Electron Microscopy

The growth of the basilar papilla in the chick cochlear duct was studied utilizing light, scanning, and transmission electron microscopy. The ages of the cochleae investigated ranged from embryonic day 6 to post-hatching day 7. The changes in the length and width of the basilar papilla as well as the establishment of its spatula-like shape were correlated with the maturation of the hair cells' apical surfaces and the changes in the cellular organization of the sensory epithelium. The histological reorganization of the distal hair cell nuclei was concomitant with the broadening of the distal region of the basilar papilla and …