Life Sciences Commons^™

The Identification And Characterization Of Metal Wrappings In Historic Textiles Using Microscopy And Energy Dispersive X-Ray Spectrometry: Problems Associated With Identification And Characterization, N. Indictor, R. J. Koestler

Scanning Electron Microscopy

Scanning electron microscopy-energy dispersive x-ray spectrometry (SEM-EDS) has been employed for the description of metal wrapped yarns. Although considerable detail is obtainable as microphotographs, and elemental analysis is obtained with ease, caution should be exercised in interpreting results. Several unravelled samples should be examined; light microscopy should be employed prior to SEM-EDS analysis. Examination of eight specimens (six from the textile collection of the Metropolitan Museum of Art, New York; two from private collections) is described. The samples were Chinese (5), German (1), Spanish (1), Turkish (1). Difficulties encountered in describing this set of samples are enumerated.

Weighted Silks Observed Using Energy Dispersive X-Ray Spectrometry, M. Ballard, R. J. Koestler, N. Indictor

Scanning Electron Microscopy

A group of modern silk fabrics was treated with various weighting agents as standards. These standards were observed using energy dispersive x-ray spectrometry. The standards were compared to untreated samples and to museum specimens of weighted silks. In all prepared specimens the elements expected from treatment were observed; weighting treatments could be distinguished. The analytical procedures are discussed and compared to recent work on mordant analysis using the same techniques.

Elemental And Ultrastructural Characteristics Of The Egg Capsules Of Nautilus Pompilius, R. J. Koestler, E. D. Santoro, G. Dingerkus

Scanning Electron Microscopy

Six pearly nautili (Nautilus pompilius) raised in captivity produced nonviable egg capsules which were examined using scanning electron microscopy ( SE M) and energy dispersive x-ray spectrometry (EDS). Macro and microscopic observations revealed two distinct and separate walls encircling the yolk sac. Both walls exhibited a porous appearance in cross-section. Protein analysis demonstrated the proteinaceous nature of nidimental gland secretions and egg capsule walls.

EDS analysis of each wall shows the elemental composition to be identical in both, with each wall containing similar proportions of S, CI, Mg, Na, K, and trace amounts of Ca. X-ray mapping of Na and …

Urolithiasis In A Patient Ingesting Pure Silica: A Scanning Electron Microscopy Study, D. B. Leusmann, J. Pohl, G. Kleinhans

Scanning Electron Microscopy

A patient who repeatedly produced urinary calculi, had consumed about 3g of cristobalite (SiO₂) per day for many years. Investigations using scanning electron microscopy revealed minute particles containing silicon in the core of the stone as well as in urine sediment. A mechanism similar to that proposed for the effect of silicon-containing drugs against gastric ulcer, may play a role in this formation of silicon-containing urinary stones.

Microtextures Of Laterites And Bauxites Capping Deccan Trap Basalts In Western India, D. V. Chitale, N. Güven

Scanning Electron Microscopy

Thirty-five samples of laterites and bauxites representing both the high-level (elevation > 1000 m) and low-level (elevation < 100 m) deposits in western India have been examined by scanning electron microscopy. Megascopically, laterites exhibit vesicular, spongy and pisolitic textures, whereas bauxites display pisolitic, massive and nodular textures. Laterites, as well as bauxites are commonly characterized by framework microtexture produced by a three dimensional arrangement of crystallites. Locally, the luterites and bauxites exhibit crystalline-webby microtexture formed by a web-like arrangement of stacks of lamellar crystals. The individual crystals in the matrix of laterites and bauxites display anhedral forms and they range in size from about 0.5 μm to 20 μm. Crystals larger than 20 μm in size generally occur as linings of the vugs, in channels and veins, and they are usually euhedral. Pisolites and nodules in laterites and bauxites are composed of material generally finer than the material in the matrix around them. Platy morphology is most common for the minerals in laterites and bauxites. Gibbsite occurs in various forms ranging from prismatic, stubby slab-like to lath-shaped crystals.

Both high-level and low-level deposits of laterites are characterized by similar textures. The variations in textures of bauxites are also found to be independent of the elevation of the deposits.

Quantitative Vascular Casting Of The Post-Ischemic Hydronephrotic Kidney, Vincent H. Gattone Ii, Robert D. Sale

Scanning Electron Microscopy

The renal microvasculature (afferent arteriole) and glomeruli were examined and quantitated by two methods in the post-ischemic hydronephrotic (PIH) kidney. The methods used were: 1) an in vivo examination and 2) controlled perfusion-fixation, quantitative vascular casting examined by scanning electron microscopy. The second method was also applied to the vasculature of the contralateral, functional kidney. The goals of the study were to: 1) validate the quantitative vascular casting method by comparing PIH renal microvascular data from the casting method with in vivo values and 2) determine the extent of microvascular dimensional difference of the PIH kidney from its contralateral functional …

Embryonic Development Of The Chicken External Cloaca And Phallus, M. R. Bakst

Scanning Electron Microscopy

The use of the scanning electron microscope has provided new detailed information about the embryonic development of the chicken external cloaca and phallus and has consequently clarified the origin of the differences between the anatomy of the chicken and turkey phallus. At Day 6 (of incubation), the genital (g.) tubercle is formed in the ventral aspect of the embryo between the caudal fold of the amnion and the tail bud. On the ventral surface of the tail bud are paired g. swellings which flank the g. tubercle. Originating at the midline between the g. swellings is the g. crest which …

Lack Of Regional Surface Differences In Mouse Bladder Urothelium: A Scanning Electron Microscopic Study, Kari Feren, Jon B. Reitan

Scanning Electron Microscopy

The surface structures of mouse urinary bladder epithelium, the urothelium, were examined in SEM. The entire surface area of both a moderately and a well stretched bladder were studied. No regional differences were found in either case. The moderately stretched bladder showed deep folds, while the well stretched bladder had only small folds giving the bladder an accordion-like appearance. In both bladders the typical surface structures were microridges arranged in a honeycomb-like pattern. The present study indicates that focal or regional differences found in bladders treated with chemicals or exposed to radiation are a result of the treatment itself, and …

Histochemistry Of Colloidal Iron Stained Crystal Associated Material In Urinary Stones And Experimentally Induced Intrarenal Deposits In Rats, Saeed R. Khan, Raymond L. Hackett

Scanning Electron Microscopy

Organic material associated with the calcium oxalate crystals in urinary stones and experimentally induced nephrolithiasis was stained with colloidal iron and analysed by energy dispersive x-ray microanalysis using standard techniques. Iron was positively identified in the stained specimens indicating that some of the organic material is an acidic mucosubstance. The results also indicate that some of the organic material of urinary stones may originate in the kidneys.

Scanning Electron Microscopy Of The Irradiated Mouse Bladder Urothelium, Jon B. Reitan, Kari Feren

Scanning Electron Microscopy

The luminal surface of mouse bladder urothelium was studied by scanning microscopy 1 year after irradiation with 0, 10 and 20 Gy respectively. The controls that were anaesthetized only displayed surface characteristics indistinguishable from normal urothelium.

Irradiation with 10 Gy did not result in marked overall changes in the scanning electron microscopic features of the luminal aspect, but in some areas alterations comparable to the alterations after 20 Gy were observed. After irradiation with 20 Gy focal hyperplastic areas, superficial early ulceration and dedifferentiation of cover cells were seen. The dedifferentiation to featureless cells is probably not associated with increased …

Immunoarchitecture Of The Regenerating Rat Spleen: Effects Of Partial Splenectomy And Heterotopic Autotransplantation, Michael C. Dugan, Thomas M. Grogan, Marlys H. Witte, Catherine Rangel, Lynne Richter, Charles L. Witte, David B. Van Wyck

Scanning Electron Microscopy

To investigate the microstructure of in situ (eutopic) and autotransplanted (ectopic) splenic remnants, adult Sprague-Dawley rats were studied 60 days after 1) subtotal (~80%) splenectomy, 2) total splenectomy followed by single or multiple remnant intraperitoneal autotransplantation, or 3) sham operation. Total nucleated cell counts were determined in excised splenic remnants, and immunohistochemical staining using monoclonal antibodies to rat B-and T-cell antigens was performed in serial tissue sections.

Immunoarchitecture of eutopic remnants was indistinguishable from that of intact spleens and total nucleated cell counts remained proportional to weight. In contrast, ectopic remnants showed sparsity and abnormal mixing of B and T …

Use Of Electron Back Scatter Diffraction Patterns For Determination Of Crystal Symmetry Elements, D. J. Dingley, Karim Baba-Kishi

Scanning Electron Microscopy

The application of electron back scatter diffraction in the scanning electron microscope has been extended to the determination of crystal symmetry elements, point group and space group. The wide angular range of the patterns makes this a relatively simple task compared with equivalent analysis using electron channelling patterns, convergent beam patterns or standard x-ray methods, though the complexity of the analysis does not permit an unthinking approach. To establish the best procedure specimens from the seven crystal systems were investigated and results from the examination of the metal tin (tetragonal), and minerals zircon (ZrSiO₄, tetragonal) and calcite (CaCO …

Preparation Methods For Quantitative Electron Probe X-Ray Microanalysis Of Rat Exocrine Pancreas: A Review, N. Roos, T. Barnard

Scanning Electron Microscopy

Pancreatic acinar cells are thought to secrete a fluid containing digestive enzymes and electrolytes and use e,g, calcium as a second messenger upon stimulation, Together with their pronounced morphological polarity, they provide a model system to study the effect of different preparation methods for quantitative biological electron probe X-ray microanalysis (EPXMA) of ultrathin sections, Several preparation methods i,e,, freeze-drying and plastic-embedding, freeze-substitution (2 days) and freeze-drying of ultrathin cryosections have been applied to examine the retention of sodium, magnesium, phosphorus, sulfur, (chlorine), potassium and calcium in subcellular compartments (basal cytoplasm, apical cytoplasm, mitochondria and zymogen granules), In freeze-substituted samples the …

The Study Of Biominerals By High Resolution Transmission Electron Microscopy, Stephen Mann

Scanning Electron Microscopy

This paper presents an overview of the study of the ultrastructure of biogenic inorganic solids (biominerals) using high resolution transmission electron microscopy (HRTEM). A range of biominerals have been studied including iron oxides, calcium phosphates, calcium carbonates and silica. The studies have revealed information concerning the structural complexity of these materials and have identified crystallographic order and disorder at the nanometre level. In addition, the results have aided the elucidation of the mechanisms of nucleation and growth of biogenic minerals.

Corrosion Cast Technique Applied In Lymphatic Pathways, A. Castenholz

Scanning Electron Microscopy

The paper deals with methods and results of the microcorrosion cast technique in lymph angiology. For the representation of the special organization of the lymph vascular system including the initial vascular structures, intranodal pathways, bigger collectors, and lymph trunks, the application of various injection techniques is necessary. The interstitial injection of Mercox proves to be suitable to show the initial lymphatics and prelymphatic spaces. Similarly, the intranodal injection makes visible the system of the lymph sinuses and the spaces of the reticular tissue in this organ. Casts of bigger collecting vessels, lymph trunks, and thoracic duct can be obtained by …

The Determination Of Wet Weight Concentrations Of Elements In Freeze-Dried Cryosections From Biological Cells, Karl Zierold

Scanning Electron Microscopy

Energy dispersive X-ray microanalysis in STEM (scanning transmission electron microscope) of freeze-dried cryosections from biological cells provides information on the subcellular element distribution in terms of dry weight concentration. The local dry weight content in the range of 5-50%, respectively the local water content within 50 to 95%, in different subcellular compartments can be determined by measuring the darkfield intensity by means of an annular detector in STEM. Calibration is done by measuring the darkfield intensity of similarly prepared cryosections from dextran-water-solutions in varying concentration. Thus, by combining the X-ray microanalytical data evaluated by the continuum method with the STEM …

Functional Aspects Of Renal Glomeruli Based On Scanning Electron Microscopy Of Corrosion Casts, With Special Emphasis On Reptiles And Birds, H. Ditrich, H. Splechtna

Scanning Electron Microscopy

The glomerular complexity of several species of birds and reptiles is investigated in this study by scanning electron microscopy of vascular corrosion casts. Comparing these results with those of a freshwater teleost and a mammalian species, a trend towards small, simple glomeruli of the avian type, beginning with large, well vascularized glomeruli resembling the type found in fish, can be observed in reptiles.

A close correlation between glomerular size and habitat can be established comparing related species having a similar physiological mode of renal function.

Entirely different from this sauropsidian evolutionary line of development is the highly complex, large differentiation …

Computer Simulation And Experimental Performance Data For An Electron Spectrometer For Electron Beam Testing Of Integrated Circuits, D. Deutges, S. Görlich, E. Kubalek

Scanning Electron Microscopy

Electron beam testing using voltage contrast in the scanning electron microscope has been established as a useful tool for nondestructive and nonloading functional testing and failure analysis of integrated circuits (IC). The accuracy of quantitative voltage measurements within the IC with the electron beam probe is determined by the performance of the secondary electron (SE) spectrometer used.

For simulating the performance of SE-spectrometers a program-package has been developed by aid of which the voltage-and field-distributions within the spectrometers can be evaluated using a finite element method. Thus it is possible to trace electron trajectories throughout the spectrometer. By considering a …

Technical Parameters Of Plastics (Mercox Cl-2b And Various Methylmethacrylates) Used In Scanning Electron Microscopy Of Vascular Corrosion Casts, T. Weiger, A. Lametschwandtner, P. Stockmayer

Scanning Electron Microscopy

The most frequently used resins for vascular corrosion casting Mercox Cl-2B, Mercox Cl-2B diluted with methylmethacrylate (MMA) monomer and various self prepared MMA and hydroxyproyl-methacrylate mixtures were tested with regard to their thermostability, shrinkage, viscosity and replication quality. It was found that tempering of the plastics improves their thermostability with the exception of Mercox Cl-2B and that shrinkage depends on the amount of monomers a resin contains. In detail; Mercox Cl-2B has the lowest shrinkage (8.018%) whereas a hydroxypropyl-methacrylate mixture possessed the highest (20.408%). But, on the other hand, viscosity decreases with the quantity of monomers. All resins tested were …

Scanning Electron Microscopic Studies On Microvascular Architecture Of Human Coronary Vessels By Corrosion Casts: Normal And Focal Necrosis, T. Ono, Y. Shimohara, K. Okada, S. Irino

Scanning Electron Microscopy

Microvascular architecture of the normal human heart and myocardial focal necrosis were studied by scanning electron microscopy of corrosion casts. Casts macroscopically identical in form to the left ventricular posterior wall were prepared.

The following results were obtained in the normal human heart. (I) Most of the arterioles communicated with capillary plexuses smoothly and straight forwardly in the left ventricular posterior free wall. (2) Arterioles which branched from the arteries ran in various directions and continued into capillaries either at right angles or obliquely in the trabeculae carneae. (3) capillaries running parallel with the cardiac muscle fibers ran in different …

Physical Basis For Spectrometer Calibration, M. Gautier, J. P. Duraud, J. P. Vigouroux, C. Le Gressus

Scanning Electron Microscopy

Progress in quantitative surface analysis is hampered by the lack of experimental procedure including spectrometer calibration, sample preparation, and general experimental setting-up. Two methods for spectrometer alignment are compared: the linearization method and the elastic peak test. Experimental spectra are presented, which can be considered as stringent reference data to check the instrument response and the analyser transmission at low energies.

Intensity Of Valence Auger Transitions (L23vv) Of Al And Si In Metal, Oxide And Nitride, M. Gautier, C. Quennisset, J. P. Duraud, J. P. Vigouroux, C. Le Gressus

Scanning Electron Microscopy

L₂₃VV Auger transition has been studied in Si, SiO₂, Al, AlN, Al₂O₃ by electron spectroscopy excited either by electron beam or X Rays. A strong difference is observed in intensity between pure solid and oxide or nitride under electron bombardment. Auger intensity is very sensitive to changes in the backscattering coefficient or inelastic mean free path. However transient local trapping of electrons seems to be responsible for the large change observed.

A Summary Of Ion Beam Etching Of Biological Material With Special Reference To The Saddle Field Source, D. Claugher

Scanning Electron Microscopy

A brief review of etching of biological materials using radio frequency, ion beam and electrostatic focused sources. Results of experiments using fast atom sources to dissect pollen, diatoms, protozoa and small arthropods, indicate that they produce a much smoother result which enables investigations to be carried out at high magnifications with the SEM.

Principles Of X-Ray Spectroscopy, Edwin R. Levin

Scanning Electron Microscopy

X-ray spectroscopy has become an essential tool for obtaining local chemical constituent data, particularly for identifying features observed in imaging systems. This tutorial paper is intended to introduce the basic ideas of X-ray spectroscopy, especially to the newcomer to scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The primary focus is on energy-dispersive analysis (EDS); however, the close parallels with wavelength-dispersive analysis (WDS) are shown. Topics include electron beam-specimen interactions, X-ray generation and detection, spectral analysis, approaches to quantitation, and limits of detection and resolution.

Theory For Calcium-Phosphate Crystal Formation In Tissue From Scanning Electron Microscope Data, Alan C. Nelson

Scanning Electron Microscopy

Scanning electron microscope (SEM) morphological analysis combined with energy dispersive characteristic x-ray analysis provides insight into the mechanism of biological mineralization. A time series of tissue micrographs and mineralization measurements can permit the determination of the mineralization kinetic behavior and is the basis upon which a computer model has been devised. The computer model is constructed from fundamental principles of crystal nucleation and precipitation theory. Various general forms of the model are tested against the laboratory data for goodness-of-fit using the least squares method, and two models are found to be acceptable. Both of the acceptable models involve inhibition of …

Mineral Recognition And Liberation Degree Measurements In Industrial Ore Processing, G. Bonifazi, P. Massacci

Scanning Electron Microscopy

This study aims at identifying calculation procedures and representation methods for identifying the mineral species present in a rock. The goal of the study is to identify: the characteristic spectrum for each mineral species identified in the ore; the main shape of the individual species; the preferential arrangement of the individual mineral species; the grain-size distribution of the individual mineral species and of the grains resulting from comminution processes; the degree of liberation for each mineral; and the degree of liberation of the comminution products obtained from the ores.

Surface Studies Of Duodenal Lesions Induced By Thoracic Irradiation, K. E. Carr, S. Ellis, A. Michalowski

Scanning Electron Microscopy

Acute duodenal ulcers are produced in mice as a remote ("abscopal") effect of irradiation to the lower mediastinum. Such lesions have been examined with scanning electron microscopy at 5, 8 and 28 days after irradiation with 18 Gy of X-rays. All the ulcers occur within the first 1 cm long segment of the duodenum which is endowed with Brunner's glands. The single lesions vary in size, shape and position. The damaged area often includes much of the duodenal circumference and is distinguished by conical or rudimentary villi, or even by the complete absence of villi. In contrast, around the periphery …

Pollen Wall Structure, A New Interpretation, D. Claugher

Scanning Electron Microscopy

A new preparative procedure using potassium permanganate has enabled previously undescribed structures on the surface and in the walls of pollen grains to be visualised. The results in some respects lend support to predictions that have been made on the ultrastructure of walls which have not been imaged clearly by any presently available technique. The findings may necessitate a reappraisal of current concepts regarding pollen wall structure.

Cell Ultrastructure In Disease, R. Laschi, E. Govoni

Scanning Electron Microscopy

The doctor of today must adopt the 'cellular way of thinking' in the evaluation of diseases. This ultrastructural outlook provides him with much indispensable information that also serves a practical purpose. A diseased cell organelle is at the basis of every clinical sign and any attempt of therapy must be aimed at that specific point of lesion. We intend, in the light of a long experience, to propose to clinicians a new way of thinking in which a precise correlation between symptoms and sub-microscopic changes of the cell is considered. Many different examples amply justify this proposal. Electron microscopy can …

Exocytosis From Large Dense Cored Vesicles As A Mechanism For Neuropeptide Release In The Peripheral And Central Nervous System, Asa Thureson-Klein, Richard L. Klein, Pei-Chun Zhu

Scanning Electron Microscopy

Nerve terminals often contain morphological-distinct populations of large (75-110 nm) and small (45-55 nm) vesicles. The small vesicles are speculated to account for release of transmitter quanta as they accumulate at presynaptic membranes. Large vesicles can co-store neuropeptides and classical transmitters but their function in neurotransmission has been disputed because they do not appear to accumulate at chemical synapses. However, there is now evidence that the large vesicles play a role in neuro-transmission or its modulation even though they may not be eminently involved in synaptic release. Thus, exocytosis occurs along the synapse-lacking membranes of peripheral noradrenergic varicosities. Large vesicles …