bluuebunny/crossref_metadata_2025 huggingface dataset:
Image Analyzer for Electron Microscope
Authors: Hirano Y. , Suzuki K. , Fujisawa M.
Published: June 2020

We have recentry developed a unique image analyzer system which combines a scanning electron microscope or a transmission electron microscope with a scanning attachment, and a minicomputer having a 4k-memory. In this system, all measurements and data processings are carried out by computer programs. So, the hardware required for the system consists only of a discriminator, a clock generator, a sampling gate and a computer interface, as shown in Fig.1. Any modification of its function or addition of new functions is performed by software only.
Specimen Observation at Large Tilt Angles with a Top-Entry Goniometer Stage
Authors: Fotino Mircea
Published: June 2020

In one of the most resourceful applications of million-volt electron microscopy to biological problems, whole cells cultured directly on grids under controlled conditions and maintained unperturbed in vacuo through critical-point drying are viewed stereoscopically for morphological studies.

Great advantage would thus be drawn in this regard from high tilting flexibility that would allow specimen observation under larger tilting angles yielding side stereo views, as it were, in addition to the more routine top views.
Patterns of Interaction Between Cytoskeletal Elements of Cultured Cells: Modification by Cytochalasin D and A Tumor Promotor
Authors: Schliwa Manfred
Published: June 2020

Immunofluorescence and electron microscopy have identified three major filament types in a wide variety of cultured cells: microtubules, intermediate filaments, and microfilaments (F-actin). The complex of these filaments and their associated proteins is now commonly referred to as the cytoskeleton and is generally believed to form the structural basis for such cellular activities as cell movement, intracellular transport, and cell shape changes.
Cytoskeletal 3-Dimensional Organization During Platelet Adhesion and Release
Authors: Lewis J.C. , White M.S. , Prater T. , Hartle F.A. , Campbell G. , Wray G.
Published: June 2020

Blood platelet activation is integral to primary hemostasis. Prior to activation the cytoplasm of platelets is amorphous and contains storage granules, membranes and a band of microtubules. Upon activation following vascular injury, reorganization of the platelet cytoplasm occurs leading to granule release. These studies report the use of 120 KV and HVEM (1000 KV) to describe the 3-D cytoskeletal changes accompanying platelet adhesion and release.
Diverse Effect of Microtuble Poisons to Alkaline Phosphatase Activity in Duodenum, Kidney, Liver and Serum of RAT and Mouse: A Histochemical Study
Authors: Makita T. , Sugiura K. , Hatsuoka M.
Published: June 2020

A single injection of colchicine(l-3mg/kg) has been reported to cause a remarkable induction of hepatic alkaline phosphatase(ALP ase) in rats.As an extension work of ALPase and calcium in duodenum we compared the degree of ALPase induction with colchicine and vinblastine in duodenum,kidney,liver and serum of rats and mice.

Male Wister rats(B.W. 120-160g) and ICR mice(33-35g) were intravenously injected either colchicine(3mg/kg) or vinblastine(lmg/kg) after 5-6hr,10-12hr,or 20-22hr of the injection. ALPase was measured by Bessey-Lowry method using paranitrophenol phosphate as substrate. For electron microscopic histochemistry,tissue blocks were fixed in 2%glutaraldehyde for lhr and cut with Vibratome to be incubated in Mayahara's medium for 20min at 37°C.
Cell Reactivity Pattern of the Guinea Pig Cecal Mucosa Evidenced by the ZIO Technique
Authors: Mora-Galindo Juan , Arauz-Contreras Jorge
Published: June 2020

The zinc iodide-osmium tetroxide (ZIO) technique is presently employed to study both, neural and non neural tissues. Precipitates depends on cell types and possibly cell metabol ism as well.

Guinea pig cecal mucosa, already known to be composed of epithelium with cells at different maturation stages and lamina propria which i s formed by morphologically and functionally heterogeneous cell population, was studied to determine the pat tern of ZIO impregnation. For this, adult Guinea pg cecal mucosa was fixed with buffered 1.2 5% g 1 utara 1 dehyde before incubation with ZIO for 16 hours, a t 4°C in the dark. Further steps involved a quick sample dehydration in graded ethanols, embedding in Epon 812 and sectioning to observe the unstained material under a phase contrast light microscope (LM) and a transmission electron microscope (TEM).
Induction of Ultrastructural Alterations by Aromatic Hydrocarbons
Authors: Norton W.N. , Livingston M. , Mattie D.
Published: June 2020

Petroleum-derived aviation fuel consists of a variety of aromatic compounds including toluene, benzene, xylene and naphthalene. Investigators have determined that the rate of aromatic hydrocarbon accumulation in aquatic organisms is highly species specific. Toluene is capable of concentrating in a variety of organs once uptake has occurred. Additional compounds such as benzene, xylene and naphthalene have been studied as to their relative toxicities to aquatic organisms. There is a paucity of information regarding histopathological and physiological responses of aquatic vertebrates to the aromatic hydrocarbons mentioned above.
Three Dimensional Reconstruction of Map-Free Tubulin Sheets
Authors: Ceskaa T.A. , McEwena B. , Edelsteina S.J.
Published: June 2020

The three-dimensional structure of zinc-induced tubulin sheets freed from microtubule associated proteins (MAPs) has been reconstructed from a series of electron micrographs of negatively stained specimens at various tilt angles. Digitized images of these sheets were analyzed by computer using a combination of real space correlation techniques and Fourier analysis to obtain a three-dimensional representation of the structure.
Mesenchyme-Induced Alteration of Urothelial Differentiation
Authors: Cunha G. R. , Shannon J. M. , Fujii H.
Published: June 2020

Epithelial development is known to be dependent upon inductive influences from mesenchymal cells. Recent studies on embryonic epithelial development indicate that mesenchymal cells control epithelial growth, morphogenesis, cytodifferentiation, and ultimately functional (biochemical) expression. During this process it is thought that the developmental options of epithelium are progressively restricted until eventually epithelial differentiation is irreversibly determined. An exception to this general rule is now reported for adult urinary bladder epithelium (BLE).
An Sem and X-Ray Evaluation of Crystals in the Leaves of Rosa
Authors: Arnott H. J. , Kelly M. L. , Webb M. A.
Published: June 2020

The common occurrence of calcium oxalate in plant tissues belies our level of understanding of these objects; broad distribution has not yet brought a comprehensive understanding of their development and function (see reviews 1 and 2). Using isolation techniques developed previously, we have examined the crystals present in the small and medium leaflets of Rosa multiflora Thumb. With powder x-ray diffraction we have identified the crystals as whewellite (calcium oxalate monohydrate). All of the major peaks present in the ASTM standard are also found in our diffractograms, however the intensity of the peaks varies from the standards. Examination of cleared leaves shows the crystals are broadly distributed through the leaflet lamina but tend to be more concentrated along veins (Fig. 1).
Calcium Oxalate Dihydrate-Monohydrate Association in Grape (Vitis Vinifera) Endosperm
Authors: Webb Mary Alice , Arnott Howard J.
Published: June 2020

Calcium oxalate occurs in two forms, monohydrate (whewellite) and dihydrate (weddelite). Both forms occur intracellularly in plants, typically within vacuoles. In particular plant species a given tissue usually has crystals with specific and characteristic morphology. The occurrence of calcium oxalate monohydrate and dihydrate together in the same cell is thought to be extremely rare and has been reported only in Allium and Begonia. In vitro the dihydrate is unstable under certain conditions and may dissolve and reprecipitate as the monohydrate. In this paper we report observations of crystals isolated from grape (Vitis vinifera) endosperm. Using optical methods both calcium oxalate monohydrate and dihydrate, as well as dihydratemonohydrate associations, have been identified.
Interference Reflection Microscopy
Authors: Izzard Colin S.
Published: June 2020

Information on the contacts formed between cells and their substrates is essential to the study of cellular adhesion and motility. The potential to obtain this information on living cells was realized in 1964 when Curtis introduced the method of interference reflection microscopy (IRM). The method is applicable to a wide variety of cells provided contact is made with an optically transparent planar substrate such as glass. The cell is illuminated through the substrate via an oil-immersion objective using epior incident light optics. The image results from the interference of wavefronts reflected from the refractive index boundaries which define the gap between the cell and substrate. However, the images obtained by Curtis with chick heart fibroblasts were complex, comparable to that in Fig. 1. This resulted from the use of a low illuminating numerical aperture (INA) designed to provide near normal incidence on the specimen and simplify calculation of cell-substrate separation distance from irradiance measurements.
XRF and PIXE Analysis of light and Dark Adapted Ocular Tissue
Authors: Panessa B. J. , Kraner H. W. , Warren J. B. , Jones K. W.
Published: June 2020

During photoexcitation the retina requires specific electrolytes and trace metals for optimal function (Na, Mg, Cl, K, Ca, S, P, Cu and Zn). According to Hagins (1981), photoexcitation and generation of a nerve impulse involves the movement of Ca from the rhodopsin-ladened membranes of the rod outer segment (ROS) to the plasmalemma, which in turn decreases the in-flow of Na into the photoreceptor, resulting in hyperpolarization. In toad isolated retinas, the presence of Ba has been found to increase the amplitude and prolong the delay of the light response (Brown and Flaming, 1978). Trace metals such as Cu, Zn and Se are essential for the activity of the metalloenzymes of the retina and retina pigment epithelium (RPE) (i.e. carbonic anhydrase, retinol dehydrogenase, tyrosinase, glutathione peroxidase, superoxide dismutase...). Therefore the content and fluctuations of these elements in the retina and choroid are of fundamental importance for the maintenance of vision. This paper presents elemental data from light and dark adapted frog ocular tissues examined by electron beam induced x-ray microanalysis, x-ray fluorescence spectrometry (XRF) and proton induced x-ray emission spectrometry (PIXE).
Unusual Astrocytic Junctions Induced by Nickel wire Implant in Rat Brain
Authors: Kress Yvonne , Gaskin Felicia , Horoupian Dikran S.
Published: June 2020

In our studies on metal toxicity we found that nickel wire implants into the central nervous system of rats caused specific changes. After a period of six to nine weeks of implant, a concentric zone of protein-rich fluids containing cellular and nickel debris surrounded the nickel wire. Marked reactive fibrillary astrocytosis appeared in the neuropil adjacent to this zone and the perivascular and intercellular spaces were distended by large pools of extracellular proteinaceous fluids. Many astrocytic processes contained Rosenthal fiber-like profiles which were closely associated with glial filaments. Frequently unusual desmosoroe-like junctional complexes were seen between interdigitating glial processes.
Synapse Formation in Familial Retinoblastoma, Electron Microscopy Study of Three Siblings Including Fraternal Twins
Authors: Sun C.N.
Published: June 2020

In the past century, investigations dealing with retinoblastoma have been done at the light microscopic level. Due to the lack of histological criteria, confusion has been created in the subjective interpretation of the areas of special differentiation. These areas, as revealed by electron microscopy, present certain specific organelles resembling photoreceptor and synaptic elements. This synapse formation in retinoblastoma is considered an important discovery in revealing the nature of the tumor.
Sebaceous Basal Cell Carcinoma - An Ultrastructural Study
Authors: Andrews Annette M. , Blackwell Boon-Nam , Hoage Terrell R. , Kadiubar Fred F.
Published: June 2020

Basal cell carcinoma with sebaceous gland differentiation has been described in mice and humans but spontaneous skin tumors of this type are uncommon in the rat.

The tumor specimen was taken from a 26 month old male Wistar rat. Electron microscopy specimens were fixed by immersion in cacodylatebuffered 4% glutaraldehyde, post-fixed in 1% osmium tetroxide, dehydrated, cleared and embedded by standard procedures. Semi-thin (μm) sections were stained with ethanolic uranyl acetate followed by lead citrate, then examined on a Philips EM201 electron microscope.
Ultrastructure of NPC/HK1 cells heterotransplanted in athymic nude mice
Authors: Chew E.C. , Li C.L. , Huang D.P. , Ho H.C. , Mak L.S. , Lui M.
Published: June 2020

An epithelial cell line, NPC/HK1, has recently been established from a biopsy specimen of a recurrent tumour of the nasopharynx which was histologically diagnosed as a moderately to well differentiated squamous cell carcinoma. A definite decrease in the amount of tonofilaments and desmosomes in the NPC/HK1 cells during the cell line establishment was observed. The present communication reports on the fine structures of the NPC/HK1 cells heterotraneplanted in athymic nude mice.
Concanavalin a (Con A) Binding Sites in Bronchial Epithelium of Hamster
Authors: Sato T. , Trump B.F.
Published: June 2020

The surface of a wide variety of cell types is covered with membrane-associated glycoproteins whose role remains to be determined. Lectins have a remarkable specificity for binding to certain carbohydrates. Con A binds specifically to α-methyl-D-glucopyranoside, α-methl-D-mannopyrannoside, and β-methl-D-fructofuranoside groups on cellular membranes. In this study. Con A binding sites within bronchial epithelium of hamsters were studied.
Changes Occur in Plasma Membrane Turnover when K562 Leukemia Cells are Induced to Differentiate
Authors: Marshall L. M.
Published: June 2020

A human erythroleukemic cell line, metabolically blocked in a late stage of erythropoiesis, becomes capable of differentiation along the normal pathway when grown in the presence of hemin. This process is characterized by hemoglobin synthesis followed by rearrangement of the plasma membrane proteins and culminates in asymmetrical cytokinesis in the absence of nuclear division. A reticulocyte-like cell buds from the nucleus-containing parent cell after erythrocyte specific membrane proteins have been sequestered into its membrane. In this process the parent cell faces two obstacles. First, to organize its erythrocyte specific proteins at one pole of the cell for inclusion in the reticulocyte; second, to reduce or abolish membrane protein turnover since hemoglobin is virtually the only protein being synthesized at this stage. A means of achieving redistribution and cessation of turnover could involve movement of membrane proteins by a directional lipid flow. Generation of a lipid flow towards one pole and accumulation of erythrocyte-specific membrane proteins could be achieved by clathrin coated pits which are implicated in membrane endocytosis, intracellular transport and turnover. In non-differentiating cells, membrane proteins are turned over and are random in surface distribution. If, however, the erythrocyte specific proteins in differentiating cells were excluded from endocytosing coated pits, not only would their turnover cease, but they would also tend to drift towards and collect at the site of endocytosis. This hypothesis requires that different protein species are endocytosed by the coated vesicles in non-differentiating than by differentiating cells.
Subcellular Localization of Amylose Precipitating Factor in Neurospora
Authors: Varkey Jacob P. , Nadakavukaren Mathew J. , McCracken Derek A.
Published: June 2020

Amylose precipitating factor (APF) is a lipoprotein first found associated with starch in some fungi. Since then, APF has been reported from many organisms. The ability of the lipoprotein to bind to short chain amylose molecules and precipitate them is used as a distinguishing characteristic. Starch produced by certain fungi consists of short chain amylose molecules. Even though these fungi have the enzymes needed for the formation of large amylose molecules as in higher plants, the reason for the formation of short chain amylose is not known. Since APF is associated with short chain amylose molecules, we were interested in studying the effect of APF on the fungal starch biosynthesis. In this paper we describe the localization of APF in the fungal hyphae.
Ultrastructural Changes of the Symbiotic Chlorella-Like Alga Isolated from Hydra Viridis
Authors: Lee K.W. , Meints R.H. , Kuczmarski D. , Van Etten J.L.
Published: June 2020

The physiological, biochemical, and ultrastructural aspects of the symbiotic relationship between the Chlorella-like algae and the hydra have been intensively investigated. Reciprocal cross-transfer of the Chlorellalike algae between different strains of green hydra provide a system for the study of cell recognition. However, our attempts to culture the algae free of the host hydra of the Florida strain, Hydra viridis, have been consistently unsuccessful. We were, therefore, prompted to examine the isolated algae at the ultrastructural level on a time course.
Tem Identification of Persistent Cocci in Treated Infective Endocarditis
Authors: M.D. Shirley Siew
Published: June 2020

Transmission electron microscopy (TEM) demonstrated the presence of causative organisms in a surgically resected mitral valve from a 22 year old male who had received vigorous antibiotic therapy for Staphyloccocus aureus septicemia and infective endocarditis. The portal of infection had apparently been a small blister on the lateral side of the left ankle which had developed after he had played hockey. Cultures of the blister were positive for Staph, aureus and Keflex therapy was begun. But, it was discontinued by the patient, once there was healing of the lesion. However, the following week he was admitted to the hospital with obvious sepsis. Three blood cultures were positive for Staph, aureus and he was placed on Cefoxitin. Subsequently, this was switched to Nafcillin and Tobramycin. The latter was discontinued when he developed impairment of hearing. The patient manifested the symptoms and signs of moderate to severe mitral regurgitation. Blood cultures were negative and a mitral valve resection was done six weeks after the onset of the sepsis.
Isolation of Asbestos from Lung Tissue and Sputum
Authors: Williams M. G. , Corn C. , Dodson R. F. , Hurst G. A.
Published: June 2020

During this century, interest in the particulate content of the organs and body fluids of those individuals affected by pneumoconiosis, cancer, or other diseases of unknown etiology developed and concern was further prompted with the increasing realization that various foreign particles were associated with or caused disease. Concurrently particularly in the past two decades, a number of methods were devised for isolating particulates from tissue. These methods were recently reviewed by Vallyathan et al. who concluded sodium hypochlorite digestion was both simple and superior to other digestion procedures.
Peliosis in Spontaneous Adenomas of the Rat Pituitary. An Electron Microscopic Study
Authors: Ilse G. , Kovacs K. , Beri J. , Zak F.
Published: June 2020

Lakes of blood are frequently observed in spontaneous prolactin cell adenomas of the rat pituitary. The lesions resemble peliosis, a disorder found mainly in the liver but also in the adrenal cortex. In order to reconstruct the events involved in the formation of these blood lakes, 25 spontaneous prolactin cell adenomas and 1 non-prolactin cell adenoma were harvested from adult female Long-Evans and Sprague-Dawley rats and investigated by electron microscopy.
Electron Microscopy in Diagnostic Virology: A Five Year Study of the Etiologic Agents of Acute Non-Bacterial Gastroenteritis
Authors: Payne C.M. , Ray C.G. , Borduin V.F. , Minnich L.L.
Published: June 2020

A total of 472 stool specimens from patients with gastroenteritis were examined by electron microscopy after negative staining with 2% phosphotungstic acid (pH 6.5). Forty-two percent of the specimens submitted over a five year period were determined to be positive for virus belonging to one or more of seven morphologically distinct viral groups. Seventy percent of the positive stool specimens contained coronavirus-like particles (CVLP). These viruses are pleomorphic enveloped particles containing a flexible fringe (Fig. 1) 13-18 nm in length with a bulbous shape at the distal end of individual filaments making up the fringe (Fig. 2). CVLP have recently been associated with clinical gastrointestinal syndromes including necrotizing enterocolitis which affects predominately neonates. In some preparations the fringe is not clearly visible in negatively-stained preparations unless a very thin film of stool covers the formvar carbon-coated grids. In other preparations a single drop of stool is allowed to dry completely on a grid which has been placed in a microtiter well containing 1% agar.
Epoxy Slide Embedment for LM, TEM, STEM and HVEM Cytochemistry
Authors: Giammara B. L. , Hanker J. S.
Published: June 2020

The selection of cytochemical and immunocytochemical specimens for semi thin sectioning for STEM or HVEM and ultrathin sectioning for TEM is enhanced by the ability to survey cytochemically stained specimens by light microscopy (LM). Procedures previously reported for this purpose, generally involve embedding the specimen between Teflon coated coverslips. The release of the embedded Specimen from the coverslip is sometimes difficult. Addition ally, the small specimen must be attached to a glass microscope slide for LM viewing. Reported here is a newly devised one-step casting procedure that provides for the embedment of stained cells or tissue sections in the form of an epoxy microscope slide that circumvents these problems.
Validation of George and Robinson SE-I Signal Theorem. Implications for Ultrahigh Resolution Sem on Bulk Untilted Specimens
Authors: Peters Klaus-Ruediger
Published: June 2020

In scanning electron microscopy on bulk untilted specimens topographic resolution in conventional “secondary electron imaging” (SEI) mode is very low; only in the order of several beam diameters. Extensive electron scattering within the specimen was thought to limit resolution since secondary electrons (SE) are collected irrespectively of their origin.
Pulsed Ion Beam Annealing of Metal and Silicide Thin Films on Silicon
Authors: Chen L.J. , Hung L.S. , Mayer J.W.
Published: June 2020

Metal silicides have found increasing use in microelectronic industry as contact materials. Energy beam annealing offers controlled energy deposition in the near surface region so that silicide growth is achieved without heating the entire layer. When pulsed laser and electron at high power density were applied to metal-semiconductor systems, cellular structures have been formed with silicon columns surrounded by silicide walls as a result of the formation of the molten layer of metal and silicon followed by segregation due to constitutional supercooling as the melt front moves toward the surface. A wealth of microstructures were observed in pulsed ion beam annealed nickel thin films on silicon. An interface melting mechanism was invoked to explain the results. In this paper, we report further data on the subject.
A Tem Study of Low Temperature Shock Induced α'-Martensite in 304 Stainless Steel
Authors: Staudhammer K. P. , Murr L. E.
Published: June 2020

A number of investigations have established that α'- martensite will form in shock-loaded 304 stainless steel at ambient temperature. The α'- martensite resulting from shock events above -195°C form at twin-fault or shear band intersections producing strain-induced α'- martensite morphologies. How ever, very little experimental work has been done at low tempertures (down to -268°C). In this present study we demonstrate that shock-loaded 304 stainless steel transforms by different mechanism at very low temperature. That is to say a “stress-assisted” nucleation, or different types of strain-induced mechanism.
Microstructure of Oxide Films on Sic
Authors: Mieskowski D. M. , Mitchell T. E. , Heuer A. H.
Published: June 2020

SiC is a ceramic which is used for abrasives and heating elements and has potential high temperature structural applications. Between 1200-1400° C, and at sufficiently high oxygen partial pressures, SiC develops a protective SiO2 film. The film produced at short oxidation times (less than 5 hrs.) is mostly amorphous SiO2 but becomes increasingly crystalline as oxidation continues. The crystalline phase is cristobalite which nucleates and grows as disc-shaped "spherulites". The present paper describes a microstructural investigation of the SiO2 film.
The Application of Electron Diffraction in the Study of Biocrystals
Authors: Lee DoSuk D.
Published: June 2020

The transmission electron microscope (TEM) is employed in a wide range of interdisciplinary studies related to the ultrastructure of the synthetic and naturally occurring calcified crystals. However, the use of electron diffraction in studying the orientation, atomic configuration and defects of these crystals has been given little attention. This paper will examine the potential applications of electron diffraction in the study of these biominerals.
Radiation Damage Related to Fusion Reactors Materials
Authors: Brimhall J. L.
Published: June 2020

Transmission electron microscopy has long been used to study the microstructual evolution in materials as a result of radiation damage. The radiation environment in a fusion reactor is unlike that in well-studied fission reactors, therefore unique microstructures in fusion reactor materials may occur. The fusion reactor energy spectra will be strongly peaked at 14 MeV, whereas typical fission neutron energy spectra are peaked in the range 0.5 to 1.0 MeV We need to know how this higher energy neutron spectra in a fusion reactor will perturb the radiation damage states normally observed in fission reactor irradiations.
Corrosion of Copper and Brass: Non-Stoichiometric Mixed-Valence Oxides
Authors: Gibbon Donald L.
Published: June 2020

During the course of studies of the corrosive effects of specific dissolved ions on copper and brass, persistent indications were found that the initial corrosion products did not conform to the simple cuprous and cupric oxides. Visual examination showed corrosion to be highly inhomogeneous, ranging from red to black or blue-black, with the red product commonly in sweeping, feather- like patches or spots. Reflection electron diffraction patterns did not show a simple correspondence: black = CuO and red = CU2O. Many black samples gave diffraction patterns for the red copper oxide, CU2O, although some had CuO patterns. Many of the CU2O patterns contained extra peaks, and preferred orientation was especially common in the brass samples (Figures 1 and 2, Table 1).
High Resolution Study of Polytypism: Application to SiC and Au3 Mn
Authors: Tendeloo G. Van , Landuyt J. Van , Amelinckx S.
Published: June 2020

Polytypism has been studied for a number of years and a wide variety of stacking sequences has been detected and analysed. SiC is the prototype material in this respect; see e.g. Electron microscopy under high resolution conditions when combined with x-ray measurements is a very powerful technique to elucidate the correct stacking sequence or to study polytype transformations and deviations from the ideal stacking sequence.
Cathodoluminescence of Catalyst Crystallites
Authors: Boyes E.D. , Gai P.L. , Darby D.B. , Warwick C.
Published: June 2020

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.
“Further Ultrastructure Observations of the Salamander Heart Maintained in Vitro”
Authors: Millhouse Edward W.
Published: June 2020

Three years ago an initial report from our laboratory demonstrated the morphological changes observed in whole larval salamander (Taricha torosa) hearts maintained in culture for six months. Since then we have examined whole hearts that have been cultured from one to four months. During the culture period all hearts continued and maintained a particular beat with fluctuations in pulsation rates indicating a 24-hour periodicity.

This report will deal with the ultrastructure observations of control hearts and one, two, three, and six month cultured hearts. All tissues were fixed initially from 4 to 6 hours at 4°C in 4%, redistilled glutaraldehyde buffered with cacodylate to a pH 7.4. Then the atrium was dissected free and the ventricle cut in half and, using fresh fixative, the fixation was continued for 10 hours. The tissues were washed in cacodylate buffer and stored in the cacodylate buffer containing 7% sucrose for 12 to 24 hours. These tissues were washed in buffer and post-fixed in 2% OsO4 buffered with cacodylate to pH 7.4 for two hours at 4°C. Then the tissues were dehydrated in graded ethanols, embedded in Epon 812, and sectioned on a Porter-Blum ultramicrotome. Sections were stained for 30 minutes in saturated aqueous uranyl acetate and for 15 minutes in lead citrate and viewed in an RCA EMU-3H.
Structural Features of the Bluetongue Virus of Sheep (BT - 8 Strain)
Authors: Ritchie A. E. , Bowne J. G.
Published: June 2020

The morphology of the BT-Cy strain of Bluetongue virus has been described previously by Studdert, et al. (Virology 29: 509 (1966). Characteristic particles that they observed in negative stain exhibited reovirus symmetry and had diameters averaging about 53 my.

We have examined primary lamb kidney cell cultured virus of the common BT-8 strain utilizing both thin-sectioning and negative staining methods. Our results suggest that the architectural design of Bluetongue virus, although based upon reovirus-like symmetries, is more complex than previously suspected. Some forms of BT appear to be morphologically similar to the agent of African Swine Fever described recently by Breese and DeBoer (Virology 28: 420 (1966).
A Micrurgical Method for Preparation of Chromosomes for Electron Microscopy
Authors: Hoskins Godfrey C.
Published: June 2020

Mammalian cells on coverslips in vitro are used during logarithmic growth phase to obtain many cells in mitosis without the use of mitotic inhibitors.

Two short lengths of glass tubing attached by beeswax to a standard microscope slide provide support for the coverslip. The coverslip is placed cell side down to form a chamber with open ends for admission of microneedles and for changing the fluid environment of the cells. This open ended chamber is then filled with a physiologic salt solution such as Hanks or a growth medium such as Eagles.

Microneedles governed by deFonbrune micromanipulators are admitted through the open ends of the chamber. A cell in metaphase is located, picked up by microneedle, and carried to a clear area on the coverslip (Fig. 1). The second microneedle may hold the cell while the first is moved sidewise to create an incision in the cell membrane through which the mitotic apparatus may egress.
An Investigation of the Effects of Massive Doses of Cyclamate NA on the Ultrastructure of Monkey Liver
Authors: Richter W. R. , Stein R. J. , Rdzok E. J. , Moize S. M.
Published: June 2020

Previous histologic investigations of animals fed large amounts of cyclamates have not indicated injury to the liver. However, the electron microscope is much more sensitive in detecting injury because of its ability to visualize early subcellular changes. This instrument is becoming more and more valuable in toxicity studies and drug safety evaluation. Because there is some concern over possible liver damage resulting from the current widespread use of cyclamates we decided to further investigate the effects of massive doses of cyclamate on the liver of monkeys at the ultrastructural level. Previous work on liver ultrastructure in street dogs indicated the need to establish a baseline for each species and, therefore, we studied the liver tissue of eleven normal Rhesus monkeys before beginning experimental work on cyclamate. There was enough baseline variation in liver ultrastructure of the monkeys to require pre-experimental biopsies as control tissue for proper evaluation of drug safety studies.
Effects of Hypophysectomy on the Fine Structure of Rat Liver Cells
Authors: Cardell Robert R.
Published: June 2020

Hypophysectomy of the rat renders this animal deficient in the hormones of the anterior pituitary gland, thus causing many primary and secondary hormonal effects on basic liver functions. Biochemical studies of these alterations in the rat liver cell are quite extensive; however, relatively few morphological observations on such cells have been recorded. Because the available biochemical information was derived mostly from disrupted and fractionated liver cells, it seemed desirable to examine the problem with the techniques of electron microscopy in order to see what changes are apparent in the intact liver cell after hypophysectomy. Accordingly, liver cells from rats which had been hypophysectomized 5-120 days before sacrifice were studied. Sham-operated rats served as controls and both hypophysectomized and control rats were fasted 15 hours before sacrifice.
Electron Microscopy of Liver in a Case of Neonatal Leukemia
Authors: Monroe J. H. , Chandra S.
Published: June 2020

Histologic changes in the liver observed in cases of leukemia, particularly regarding the infiltration of leukocytes into the organ, have been recently reviewed. The present paper attempts to examine some of these changes on the fine-structural level.

An autopsy sample of liver from a seven week old female infant with acute lymphoblastic leukemia was obtained six hours after death and immediately transferred into 2% glutaraldehyde in phosphate buffer. The tissue was processed for electron microscopy by standard procedures.

A light microscope examination of the liver showed infiltration of lymphocytes in the portal radicles and the sinusoids. Parenchymal cells (P) adjoining the areas of extreme leukocytic infiltration (L) revealed the presence of dense granules which have not been previously described. A low power electron micrograph of such an area is shown in Fig. 1 where the disorganization of the parenchyma is clearly noticed.
Type II Glycogenosis: Mobilization of Lysosomal Glycogen
Authors: Hug George , Schubert William K.
Published: June 2020

Type II glycogenosis (generalized glycogen storage disease) is a fatal disease of infants characterized by increased concentration of tissue glycogen and deficiency of lysosomal acid α-1,4-glucosidase activity (acid glucosidase). In a three month old negro girl with the clinical features of the disease, the diagnosis was confirmed by needle biopsy of liver, muscle and brain. Glycogen concentration was 7.8% in liver (normal 2.5% - 6.5%), 7.8% in muscle (normal up to 1.5%), and 0.18% in brain (normal up to 0.08%). Acid glucosidase activity was deficient in all tissues. Electron photomicrographs showed the characteristic abnormal lysosomes packed with glycogen in the liver and brain, but relatively few lysosomes in the muscle despite the presence of large amounts of glycogen. Notable was the abundance of abnormal lysosomes in all hepatic sections. An extract of the fungus Aspergillus niger was prepared with a protein concentration of 25 mgm/cc and a specific activity for acid glucosidase of 22 μM of glucose liberated from glycogen/mgm of protein/minute.
Proliferation of the Z Band and Disc in a Specialized Region of the Heart
Authors: Challice C. E. , DeFelice L. J.
Published: June 2020

The variation of morphology of cells of the specialized system of the rabbit heart have been studied and a pattern of cellular ultrastructure is becoming established. The present paper relates to an observation consistently obtained in cells of the atrium which border the collagenous join between the atrial and ventricular septums. This tissue is classified by cellular electrophysiologists as N or NH and is, consequently, a part of the functional atrioventricular node, that is, it represents an area in which a delay in the propagation of the transmembrane potential is known to occur. The cells of this region are found to have poorly developed myofibrils and show a marked proliferation of the Z band. On occasion the proliferation can extend the length of a sarcomere (Figs. 1,2) and also make contact, in a variety of ways, between the Z band, the disc, the desmosomes and a peripheral accumulation of a Z-like material (Figs. 1-4).
High Ampere-Turn Density Coils for the Reduction of Magnetic Lens Size
Authors: Lund N.C.
Published: June 2020

In Electron Microscope design it is often of considerable practical advantage to keep the amount of iron used in the column at the optically necessary minimum. To achieve this, lens dimensions must be kept relatively small with concomitant high ampere-turn density. In the design of the 500,000-volt column for the University of Virginia, ampere-turn densities in the order of 2500 to 3000 NI/in2 were made possible by the incorporation of high-efficiency cooling techniques in the coil design.

A system was devised which would envelop the windings with a water-cooling jacket of minimum thickness in such a manner as to serve also as the sole structure or support for the windings. The combining of cooling and support functions into a single thin-walled structure allows maximum window area to be utilized for windings, within the confines of established iron circuitry dimensions.
A 1 mev Electron Microscope Facility
Authors: Fisher R. M. , Lally J. S.
Published: June 2020

The resolution and transmissive power of the transmission electron microscope improve markedly with increasing accelerating voltage. In order to realize the advantages of high voltage microscopy in U. S. Steel's metallurgical research program, the Board of Directors, in December 1965, approved the construction of a 1 mev electron microscope at the Fundamental Research Laboratory. All three phases of the microscope facility, i.e. 1 mev accelerator, electron optical column and special building, have progressed rapidly since that time and the present projection is that the instrument will go into operation in early summer of 1967.

The microscospe uses an open Cockcroft-Walton accelerator manufactured by Haefely Ltd. as the electron source and scaled-up conventional magnetic lenses in the optics. The column, manufactured by RCA, has a number of unique features including a 6th lens used as a projector to enlarge a selected area diffraction pattern and to give a wider range of magnifications at the highest voltages.
Application of the Election Microscope to the Study of Polytetrafluoroethylene
Razor-Blade Coatings
Authors: Symons N. K. J.
Published: June 2020

Applying a polytetrafluoroethylene (PTFE) coating to the edges of razor blades leads to a marked increase in shaving comfort, due to a reduction in the flank frictional adhesion forces encountered by the blade and consequent decreased drag on the beard hairs during cutting. The electron microscope has provided valuable information concerning the nature of this blade coating and its behaviour during the shaving process.

In the coating operation, the blade edges are sprayed with an aqueous dispersion of PTFE, and the blades then heated to about 400 C. to melt the dispersion polymer particles, which coalesce to form a coherent coating; the ability to withstand this temperature without undue loss of mechanical properties is one of the advantages of the stainless steel blades used. Replication shows the coating to consist of very small crystals in apparently random orientation.
Substrate-Overgrowth Interaction During the Epitaxial Growth of Niobium on Magnesium Oxide
Authors: Olsen K. H. , Hutchinson T. E.
Published: June 2020

Epitaxial growth studies of niobium on cleaved magnesium oxide have shown that chemical interaction between substrate and condensate is a controlling parameter in the resultant film structure. High purity niobium (99.93%) was vacuum vapor deposited by electron beam melting onto heated single crystals of magnesium oxide. The resultant film structures were examined by transmission electron microscopy and electron diffraction.

Examination of films grown under the conditions indicated in Fig. 1 has yielded the following generalized conclusions: a) all composite films contain an initial fcc layer (<100 Å) having a lattice parameter of 4.38 At 0.02 and an orientation and direction of (001)fcc//(001)MgO and [010]fcc// [010]MgO respectively.
Lorentz Miscroscopy of Thick Ni-Fe Films
Authors: Lo D. S. , Olson A. L. , Simon W. J. , Torok E. J.
Published: June 2020

The importance of Lorentz microscopy in carrying out investigations of the magnetic microstructure of Ni-Fe films is attested to by the extensive amount of literature on the subject. As the electron beam passes through the magnetic film, it is acted upon by the Lorentz force, , where e and are the electron charge and velocity and is the local magnetization component perpendicular to the electron beam. Most Lorentz microscopy has been reported for films less than 1200 Å thick. In this paper, techniques are reported which have made Lorentz microscopy possible in films 2000 Å thick. Some of the interesting results are also briefly reported.

The work reported herein was done with an Hitachi HU 10 at the maximum available potential of 100 KV. Modifications in the stage were made so that the sample films could be placed from 15 to 35 mm above the objective lens. With the sample in this position, the objective lens current necessary for focus was 26 ma instead of the usual 135 ma. In an effort to increase the beam current, the filament was adjusted so that the tip of the filament was placed even with the bottom of the grid cap hole.
Cut Surface Damage to Metals from Diamond Knife Ultramicrotomy
Authors: Hugo J. A. , Phillips V. A.
Published: June 2020

Recent work in our laboratory has shown that cut surfaces which are perfect when viewed in the light microscope may be prepared by ultramicrotomy using a diamond knife. Alloys successfully examined include Pb-Sn, Sn-Bi, Al-Mg, Cu-Al, and Cu-Co. After a normal etch, a Sn-5% Bi alloy showed no damage by replication electron microscopy over extensive areas. Although the cut surface may be flat, the question of whether or not there is an internally damaged layer remains unanswered. This is particularly pertinent to the use of ultramicrotomed slices for transmission electron microscopy, since damage left on the cut surface would be incorporated in the next slice cut, furthermore, if the damage layer were deep there could be a cumulative effect, so that damage from two or more previous cuts could be incorporated in a slice, in addition to that resulting from the shear during cutting.
Clean Electron Microscope Substrate Films Used for Micrometeorite Collection and Study
Authors: Davies D. M. , Kemner R. , Fullam E. F.
Published: June 2020

All serious electron microscopists at one time or another have been concerned with the cleanliness and freedom from artifacts of thin film specimen support substrates. This is particularly important where there are relatively few particles of a sample to be found for study, as in the case of micrometeorite collections. For the deposition of such celestial garbage through the use of balloons, rockets, and aircraft, the thin film substrates must have not only all the attributes necessary for use in the electron microscope, but also be able to withstand rather wide temperature variations at high altitude, vibration and shock inherent in the collection vehicle's operation and occasionally an unscheduled violent landing.

Nitrocellulose has been selected as a film forming material that meets these requirements yet lends itself to a relatively simple clean-up procedure to remove particulate contaminants. A 1% nitrocellulose solution is prepared by dissolving “Parlodion” in redistilled amyl acetate from which all moisture has been removed.
Applications & Comparison of Solid State Non-Dispersive & Dispersive X-Ray Analysis on a High Resolution Scanning Electron Microscope
Authors: Ruscica R. , Wolf R. , Evins D.
Published: June 2020

A logical extension of applications of the Scanning Electron Microscope is the area of x-ray analysis. The instrument utilized is the Materials Analysis Company Model 700 High Resolution Scanning Electron Microscope equipped with a fully focusing dispersive spectrometer and a Solid-State nondispersive spectrometer. The instrument can be equipped with both accessories so that simultaneous analysis with both systems is possible.
Scanning Microscopy of Thin Biological Specimens
Authors: Crewe A. V. , Wall J.
Published: June 2020

We have recently improved our scanning electron microscope to a level that point resolution of 5 Å or so is possible. The electron current in the focused spot is about 10-10amps so that good pictures can be obtained with a 10 sec exposure and the highest quality pictures can be obtained in 100 sec.

The resolving power of this microscope is now comparable to that in a conventional transmission microscope for thin biological specimens and it is therefore of value to compare micrographs taken on the two types of instrument.
Ciliary Patterns in the Nasal Mucosa
Authors: Graziadei P. P. C.
Published: June 2020

Ciliary structures are closely associated to two main functions: movement and sensory perception. In olfactory receptors they are postulated as essential specific devices in the mechanism of olfactory transduction. If the postulate is correct, all olfactory receptors should be provided with cilia. The comparative anatomy provides a suitable test for this hypothesis. It is well known that vomero-nasal receptors respond to odors with modalities similar to the olfactory receptors proper. In several species of turtles the vomeronasal epithelium is fully exposed in the nasal cavity so that a surface study with the scanning electron microscope can demonstrate in one single preparation the texture and surface pattern of respiratory, olfactory and vomero-nasal areas.
Lattice Defects in Ceramics
Authors: Heuer A. H.
Published: June 2020

Because of the difficulties associated with preparing electron-transparent foils of bulk ceramics, our knowledge of lattice defects derived from electron microscopy - including point, line, and planar defects - is limited to a few materials. Of these, alumina is one of the more interesting; it is strong, light, refractory, chemically inert (and hence difficult to thin by ordinary chemical polishing procedures), anisotropic, exhibits some ductility at high temperatures, and is one of the most widely used ceramics for advanced structural applications.