bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deposition and anneal behavior of Al-1.5%Cu films: TEM characterization
Authors: David Theodore N. , Dreyer Mike , Varker Charles 
Published: June 2020

Al-1.5%Cu materials are of interest for interconnect-metallization in semiconductor integrated-circuits. It is known from the literature that the mean-time-to-failure (MTF) due to electromigration of the Al-1.5%Cu interconnects depends on the microstructure of the materials. A correlation is seen for instance between grain-size distributions in the material and the MTF. Uniform large-grained distributions improve lifetime. The present study evaluated the microstructure of Al-1.5%Cu films deposited and annealed under different conditions.Al-1.5%Cu films had been deposited at 25°C and at 300°C; the layers had then been annealed at 300°C for 17 hours, prior to TEM investigation. Plan-view TEM specimens were prepared in the 100 substrategeometry, and cross-section TEM specimens were prepared in the 110 substrate-geometry. These were then analyzed using bright-field and dark-field TEM imaging techniques. A JEOL JEM 200CX transmission electron microscope was used for the investigation, operating at 200 kV.
On the Phase Transformation between the Quasicrystalline to Crystalline Phases in Alloys of Al-Cu-Fe-Co
Authors: Pérez R. , Juárez-Islas J.A. , Martínez L. , Campillo B. , Albarrán J.L. 
Published: June 2020

We report in this investigation preliminary results on the phase transformations between the quasicrystalline phases in quaternary alloys of Al-Cu-Fe-Co to crystalline structures. In these alloys obtained by normal casting methods under inert atmospheres both quasicrystalline phases; icosahedral and decagonal are found to coexist. By means of annealing, transformation of the quasicrystalline phases to crystalline structures are induced.Although not quite clear from diffraction patterns along the five-fold and threefold axis, experimental evidence on this crystallization process is clearly obtained along the two-fold axis. The diffraction patterns obtained from the annealed specimens show sign of different degrees of crystallization for different quasicrystalline grains.
Image-Recording Systems for Photons and Charged Particles
Authors: Timothy J. Gethyn 
Published: June 2020

Image-recording systems for photons and charged particles are under intensive development at this time to meet the needs of space astrophysics and space plasma physics missions. Many of these image-recording systems are also finding applications in a number of other disciplines.A number of different technologies for photon imaging have made major progress in the past five years. First, the development of T-grain emulsions has significantly improved the resolution and dynamic range of photographic emulsions and greatly improved their sensitivity at extreme-ultraviolet and soft x-ray wavelengths.
Multiple-inelastic phonon, single electron, and valence excitations in high-energy electron scattering
Authors: Wang Z. L. 
Published: June 2020

In this paper, inelastic scattering theory, as described in Reference 1, is applied to multiple-elastic and -inelastic electron scattering in crystals. Under the small angle approximation, the inelastically scattered wave Ψnof energy En=E-enafter exciting the nthcrystal excited state can be taken as a position modification to the elastically scattered wave,(1)where Ψn0(r) is the elastic wave of wave vector knand satisfies the elastic scattering Schrödinger equation,(2)and V = H'nnis the crystal potential;. Under the small angle and forward scattering approximations(3)
Phase transitions of a comb-shaped side-chain polyester: An electron diffraction study
Authors: Li L. S. , Stupp S. I. 
Published: June 2020

In order to reveal the phase transition sequence of aromatic polyesters and to characterize each phase appearing during heating, a comb-shaped side-chain polyester has been studied using electron diffraction techniques at room and higher temperatures. The chemical structure of the polyester is shown below,Fig. 1 is an electron diffraction pattern of two layers of the polymer, showing a chiral smectic E phase at room temperature. In this phase each layer consists of three orthorhombic lattices with orientations related to each other by rotations of ±60° as in a smectic E phase. However, there is an additional rotation of 5.9° between orthorhombic lattices in adjacent layers. When this polymer was heated to 67°C the electron diffraction pattern changed dramatically (Fig. 2). There are six strong reflections arrayed at equal angles, and the whole pattern shows a hexagonal reciprocal lattice plane. This indicates that the structure of the polymer is no longer that of a chiral smectic E phase, but a new phase, which is similar to the phase of p-hydroxybenzoate/m-hydroxybenzoate copolymer(95/5) at 350°C.
Cryomicroscopy of multiphase latices
Authors: Shaffer O. L. , El-Aasser M.S. , Zhao C. L. , Winnik M. A. , Shivers R. R. 
Published: June 2020

Transmission electron microscopy is an important approach to the characterization of the morphology of multiphase latices. Various sample preparation techniques have been applied to multiphase latices such as OsO4, RuO4 and CsOH stains to distinguish the polymer phases or domains. Radiation damage by an electron beam of latices imbedded in ice has also been used as a technique to study particle morphology. Further studies have been developed in the use of freeze-fracture and the effect of differential radiation damage at liquid nitrogen temperatures of the latex particles embedded in ice and not embedded.Two different series of two-stage latices were prepared with (1) a poly(methyl methacrylate) (PMMA) seed and poly(styrene) (PS) second stage; (2) a PS seed and PMMA second stage. Both series have varying amounts of second-stage monomer which was added to the seed latex semicontinuously. A drop of diluted latex was placed on a 200-mesh Formvar-carbon coated copper grid.
Imaging CPE/PVC phase morphology using a transmission detector in the SEM
Authors: Barnes C. G. , Rightor E. G. 
Published: June 2020

Characterization of the phase morphology of chlorinated polyethylene (CPE) modified poly (vinyl chloride) (PVC) blends is crucial in understanding the physical properties. Scanning transmission electron microscopy (STEM) can successfully reveal the phase morphology in unstained specimens of these materials, resulting in a significant decrease in analysis time -and elimination of staining techniques required for convention TEM. The advantages of STEM for such materials arise from the smaller electron dose, minimal irradiation of adjacent specimen regions, and electronic signal enhancement capabilities.We have combined these advantages and the availability of an SEM by utilizing a transmission detector to perform SEM based STEM. Development of this technique has focussed on image quality, contrast, resolution, and minimization of specimen irradiation damage. The experiments were performed in a Cambridge S200 SEM @30 KeV using a commercial solid state transmission detector (K. E. Developments Ltd.), which is mounted beneath the electron transparent specimen.
TEM observations of electromagnetically characterized YBa2Cu3O7-x grain boundaries in flux-grown bicrystals
Authors: Babcock S.E. , Zhang N. 
Published: June 2020

The original thin-film bicrystal studies strongly indicated that all high-angle grain boundaries in YBa2Cu3O7-x are intrinsically weak-linked and exhibit Josephson junction characteristics. More recent investigations of individual grain boundaries in both bulk-scale bicrystals and textured thin films have shown that the Jct properties of high-angle grain boundaries can vary in important ways. Specifically, high-angle grain boundaries with Jct behavior characteristic of a flux pinning mechanism have been discovered. These results are encouraging from the view point of large-scale applications. However, further engineering of polycrystalline materials can first be conducted in a deliberate way when the microstructural origin of the observed behaviors is understood in detail.In these studies, light and transmission electron microscopy techniques are used to investigate the microstructure of the very same bulk bicrystalline samples whose electromagnetic properties have been characterized. The three-dimensional macroscopic features of the grain boundary are deduced from light microscopy observations as the entire bicrystal is mechanically ground and polished to approximately 20 microns in thickness.
Observations of strong pinning centers in Y-Ba-Cu-O
Authors: Zhang J. P. , Li D. J. , Marks L. D. , Lin C. H. , Eades J. A. 
Published: June 2020

Using additional Y (or Cu) nitrate we had been successful in production of Y-enriched 123 (YBa2Cu3O7-x) as well as Cu-enriched ones. The magnetic Jc at 77K is 106 (B=0) and 105 (B=1 Tesla). A critical issue is the understanding flux pinning in terms of defects in microstructure.Precipitates were observed inside of the 123 crystal as shown in Fig. 1. These precipitated slabs are usually 3 - 10 nm long along c axis of 123 and 101 - 102 nm in the a-b plane, similar to that reported in CVD films. An interesting point is the precipitates found in both Yenriched and Cu-enriched samples have similar size and morphology. It is reasonable to assume those precipitates are the strong pinning centers for the size effect as known in type II superconductors. In the 123 compound the coherent length is about 2∼3 angstrom in the c direction and 16∼30 angstrom in the a-b plane.
High Voltage Electron Microscopy of Cultured Muscle Cells
Authors: Shay Jerry W. 
Published: June 2020

It is known from earlier observations that the in vitro rat L6 muscle cell line exhibits many of the features characteristic of in vivo muscle differentiation. The appearance of multinucleated cells, the development of highly organized contractile proteins and the phenomenon of muscle contraction are all easily recognizable features unique to muscular tissue. The L6 myoblasts fuse in a rather homogeneous and synchronous fashion to form myotubes and offer an excellent in vitro system to study the general mechanisms of muscle differentiation.The availability of the high voltage electron microscope (H.V.E.M.) in recent years for biological research has brought about a new interest in the three dimensional organization of components within whole cells, and the present study on L6 cells was undertaken, using the Jeol-1000 facility, at the University of Colorado in Boulder.
Differences in Ultracytochemical Localization of Na-K Dependent Atpase in the Rat Choroid Plexus and Ependyma
Authors: Saburo Nakamura , Donald A. Davis , Thomas H. Milhorat 
Published: June 2020

The ventricular ependyma shares a common embryological origin with the choroid plexus (1). These epithelia have many structural and ultrastructural similarities, and both have been considered probable sites of cerebrospinal fluid (CSF) secretion (2,3). The purpose of the present study is to investigate the localization of Na-K dependent (transport) ATPase in rat ventricular ependyma and to compare these findings with the results of previous studies on the choroid plexus.Adult male Wistar rats were perfused through the heart with 3% depolymerized paraformaldehyde in 0.1M cacodylate buffer (pH 7.3). The brain was rapidly removed and samples of cerebral ependyma with adjacent white matter and choroid plexus were excised and placed in a vial where prefixation continued for 30 minutes at room temperature.
Application of Gaboul Method to the Ultracytochemical Study of Mouse Blood-Brain Barrier
Authors: Castejón Orlando J. , Castejón Haydée V. 
Published: June 2020

The cationic dye Alcian blue has been used to demonstrate protein-polysaccharide com plexes at the level of nerve tissue (1,2). The results obtained in the capillary wall when this dye was applied to mouse brain and examined in the electron microscope are the object of the present report.The central nervous system of normal adult mice was fixed either by vascular perfusion or by immersion with 4% glutaraldehyde-0.1M sodium cacodylate-0.1 M sucrose at pH 6.8 followed by the same procedure using the same fixative but with the addition of 0.5% Alcian blue. After fixation, tissue was immersed in 1% OsO4-0.1M phosphate buffer pH 7.2, dehydrated by graded ethanol and embedded in Araldite. Ultrathin sections were doubly stained with uranyl acetate and lead citrate. The complete procedure has been denominated GABOUL method (3).The submicroscopic study of cerebral and cerebellar capillaries showed the presence of a thin line of GABOUL positive material attached to the outer layer of the asymmetric luminal membrane of endothelial cells (endocapillary layer) (Fig. 1).
The Ultrastructure of the Gerbil Pineal Gland Under Normal and Experimental Conditions
Authors: Welsh M.L. , Reiter R.J. 
Published: June 2020

Multilayered concretions (corpora arenacea), which have been found in the pineal gland of numerous species, may be indicative of the intensity of the secretory processes of the pineal gland. Concretions in the pineal gland of the gerbil (Meriones unguiculatus) occur by the age of 2 months and are a consistent feature in the adult animal. We feel the gerbil pineal provides a good system for examining pineal calcification under controlled conditions.The ultrastructure of the pineal gland of the gerbil was examined in 1 to 18 month old gerbils which had been maintained in a controlled light environment (LD 14:10). Other gerbils used for this study had been maintained either in constant light environment, had been superior cervical ganglionectomized, or had been blinded by bilateral optic enucleation.
Ultrastructural Study of Human Testicular Biopsies in Infertility
Authors: Siew Shirley , Troen Philip , Nankin Howard R. 
Published: June 2020

Testicular biopsies were obtained from six young male subjects (age range 24-33) who complained of infertility and who had clinical evidence of oligospermia. This was confirmed on histological examination which showed a broad spectrum from profound hypospermatogenesis to relatively normal appearing germinal epithelium. Thickening of the tubular walls was noted in half of the cases and slight peritubular fibrosis in one. The Leydig cells were reported as normal or unremarkable.Transmission electron microscopy showed that the thickening of the supporting tissue of the germinal epithelium was caused more by an increase in the thickness of the layers of the lamina propria than of the tubular wall itself. The changes in the basement membrane of the tubular wall consisted mostly of a greater degree of infolding into the tubule and some reduplication which gave rise to a multilayered appearance.
Quantitative Freeze Fracture Studies of Gap Junctions in Somatic Cell Hybrids, Their Parents, and Revertants
Authors: Larsen W. J. , Azarnia R. , Loewenstein W. R. 
Published: June 2020

Although the physiological significance of the gap junction remains unspecified, these membrane specializations are now recognized as common to almost all normal cells (excluding adult striated muscle and some nerve cells) and are found in organisms ranging from the coelenterates to man. Since it appears likely that these structures mediate the cell-to-cell movement of ions and small dye molecules in some electrical tissues, we undertook this study with the objective of determining whether gap junctions in inexcitable tissues also mediate cell-to-cell coupling.To test this hypothesis, a coupling, human Lesh-Nyhan (LN) cell was fused with a non-coupling, mouse cl-1D cell, and the hybrids, revertants, and parental cells were analysed for coupling with respect both to ions and fluorescein and for membrane junctions with the freeze fracture technique.
The Virus in Oral Condyloma Acuminatum
Authors: Gysland W. B. , Reimann B. E. F. , Shaffer E. L. 
Published: June 2020

Condyloma acuminatum, a wart type which usually occurs in the anogenital areas of humans, has occasionally been reported to occur in the oral cavity.Papilloma virus particles have been demonstrated in lesions of anogenital location. This report is concerned with the findings of similar virus particles in abundance in oral condylomata.Specimens were excised from the palate of the patient, fixed in glutaraldehyde and osmium tetroxide and post-contrasted with uranyl acetate and lead citrate.In 4 out of 5 sites, with a parakeratotic surface appearance, intranuclear viral particles were found. The virus particles are circular (23%) to slightly oval in shape with a mean diameter of 46.8 x 49.3 nm (minimum diameter 45 nm, maximum diameter 52 nm).
Ultrastructural Changes in the Mammary Epithelial Cell Population During Neoplastic Development Induced by A Chemical Carcinogen.
Authors: Russo J. , Isenberg W. , Ireland M. , Russo I.H. 
Published: June 2020

The induction of rat mammary carcinoma by the chemical carcinogen DMBA is used as a model for the study of the human disease (1). We previously described the histochemical changes that occur in the mammary gland of DMBA treated animals before the earliest manifested histological change, the intraductal proliferation (IDP), was observed (2). In the present work, we demonstrate that a change in the stable cell population found in the resting mammary gland occurs after carcinogen administration.Fifty-five day old Sprague-Dawley virgin female rats were inoculated intragastrically with 20mg of 7,12-dimethylbenz(a)anthracene (DMBA) in 1ml sesame oil. Non-inoculated, age-matched females were used as controls. Mammary glands from control and inoculated rats were removed weekly from the time of inoculation until 60 days post-inoculation. For electron microscopy, the glands were immersed in Karnovsky's fixative, post-fixed in 1% OsO4, dehydrated, and embedded in an Epon-Araldite mixture. Thick (lμ) sections were stained with 1% toluidine blue and were used for selecting areas for ultrastructural study.
Morphometric Analysis of the Hepatocytes from Fish Exposed to Arsenic
Authors: Sorensen Elsie M. B. 
Published: June 2020

The detoxification capacity of the liver is well documented for a variety of substances including ethanol, organic pesticides, drugs, and metals. The piscean liver, although less enzymatically active than the mammalian counterpart (1), contains endoplasmic reticulum with an impressive repertoire of oxidizing, reducing, and conjugating abilities (2). Histopathologic changes are kncwn to occur in fish hepatocytes following in vivo exposure to arsenic (3); however, ultrastructural changes have not been reported. This study involved the morphometric analysis of intracellular changes in fish parynchymal hepatocytes and correlation with arsenic concentration in the liver.Green sunfish (Lepomis cyanellus, R.) were exposed to 0, 30, or 60 ppm arsenic (as sodium arsenate) at 20°C for 1, 2, or 3 week intervals before removal of livers for quantification of the arsenic burden (using neutron activation analysis) and morphometric analysis of ultrastructural alterations. Livers were cut into 1 mm cubes for fixation, dehydration, and embedding.
Stem/Edx Analysis of A Bone-Bioglass Interface
Authors: Hren J. J. , Johnson P. F. , Bates S. R. , Hench L. L. 
Published: June 2020

Previous studies have established that a special glass (45 w/o SiO2, 24.5 w/o CaO, 24.5 w/o Na20, 6.0 w/o P2O5), can form a bond with living bone (1) In-vitro studies suggest that an amorphous gel composed of Si02, CaO, and P2O5serves as a transition layer between the bioglass and the bone. The present study sought to measure the in-vivo composition of this layer using a Phillips EM 301 with a specially designed specimen holder, and an Ortec EDX and detector (2).A sample (5 x 1 x 4 mm), was implanted in a rat tibia for 3 weeks, blocks obtained, and fixed in gluteraldehyde*. Sections were cut much thicker than normal, resulting in a loss of histological detail, but a higher X-ray production. No OsO4or heavy staining metal was used.
The Structure of the Aleutian Disease Antigen
Authors: Sarkar N.H. , Notani G.W. , Kenyon A.J. 
Published: June 2020

Aleutian disease of mink is transmissible by cell free extracts of affected mink tissues. Two antigenic components (Ag-1 and Ag-2) have been isolated from infected mink tissues by Kenyon and his associates. The relationships of the two antigens with the structural components of the Aleutian disease virus (ADV) have not yet been established; furthermore the details of the virus structure is lacking.We have prepared antigens from liver extracts of mink infected with Connecticut as well as Canadian strain of ADV. One of the antigen prepared from Connecticut strain of ADV contained primarily ring structures (13 nm in diameter) and few particules having icosahedral symmetry (27 nm in average diameter).
An Ultrastructural Study of Chronic Pyelonephritis in Macaca Arctoides
Authors: Smith T.W. , Roberts J.A. , Martin B.J. 
Published: June 2020

Chronic pyelonephritis is one of the most common diseases of the kidney and accounts for a sizeable number of cases of renal insufficiency in man, however its pathogenesis requires further elucidation. Transmission electron microscopy may serve as a uniquely effective means of observing details of the nature of this disease. The present paper describes preliminary results of an ultrastructural study of chronic pyelonephritis in Macaca arctoides (stumptail monkey).The infection was induced in these experiments in a retrograde fashion by means of a unilateral catheterization of the left ureter whereby an innoculum of 10 cc of broth containing approximately 2 billion E. coli per cc and radio-opaque dye were injected under pressure (mimicing vesico-ureteric reflux).
Lead Staining by Ion Implantation
Authors: Dobbs B. C. 
Published: June 2020

Ion implantation has been effectively used as a stain for biological specimens prepared for electron microscope examination (1,2). We have used this method of staining on critical point dried T4 bacteriophage. The lead ions proved to be a non-specific stain. However, these ions are also highly susceptible to radiation damage (3,4). With precautions, the specimens may be tilted to the implanting beam so that the implanted ions provide an ultrafine uniform shadowing for the specimen. Also, tilting effectively increases the thickness of the support film.400 mesh copper grids were covered with a 120Å formvar film, then carbonized with 50Å of carbon to provide the specimen support. The bacteriophage were then critical point dried (5) by first replacing the specimen water with ethanol, the ethanol by Freon 113 and the Freon 113 by Freon 13 which was then dried in a high pressure container.
Wafer Embedment to Facilitate Light Microscope Selection of Specimens for Ultrathin Sectioning
Authors: Romanovicz Dwight K. , Hanker Jacob S. 
Published: June 2020

An unfortunate consequence of the high magnification achieved in electron microscopy is the inability to scan large areas of tissue or locate structures which are small and of infrequent occurrence. The standard procedure is to section repeatedly, hoping that an area of interest will be encountered. However, this time-consuming practice can be avoided by the use of a special embedding platform which permits the embedment of tissue for examination by light microscopy prior to sectioning.Aldehyde-fixed tissues are cut into 10μm sections with a Vibratome or into 20-30μm sections with a Sorvall TC-2 tissue sectioner. At this point optimal sections may be selected on the basis of a particular morphological feature, for which a light methylene blue or Alcian blue stain may be employed; or selection may be based upon activity of a cytochemical enzyme stain, particularly one which involves 3,3'-diaminobenzidine (DAB).