bluuebunny/crossref_metadata_2025_split huggingface dataset:
Murine macrophage activation by cisplatin and carboplatin in culture: An scanning electron microscopic study
Authors: Palma J.P. , Aggarwal S.K. 
Published: June 2020

In order to study the mechanism of action of the drugs cisplatin and carboplatin in the regression of tumors, we investigated the activation and interaction of murine macrophages and S180 ascites cells. Activated macrophages have been shown to selectively and efficiently lyse tumor cells in culture. Cisplatin activated macrophages have been shown to enhance the capacity to recognize and further lyse Dalton's lymphoma cells in vitro. The present study investigates the interaction of cisplatin or carboplatin treated macrophages and S180 cells using scanning electron microscopy.Murine macrophages were isolated from the peritoneal cavity and treated with cisplatin (9ug/ml) or carboplatin (50ug/ml) for 2h at 37C. S180 cells or hepatocytes were co-cultured with the activated macrophages for 10min, 30min, 1h, 2h, 6h, 24h, and 48h. Cells were cultured on coverslips in minimal essential medium with fetal bovine serum supplement. Coverslips were fixed 30min in 1.5% glutaraldehyde in 0.5M phosphate buffer (pH 7.2), dehydrated through a graded series of ethanol for 5min each. Samples were critical point dried, sputter coated with gold for 3min and observed under the JEOL JSM 35CF scanning electron microscope at 15 kV.
Hexachlorobenzene toxicity in the monkey ovary: III. Ultrastructure induced by high (10 mg/kg) dose exposure
Authors: Singh A. , Dykeman A. , Jarrelf J. , Villeneuve D. C. 
Published: June 2020

Hexachlorobenzene (HCB), a persistent and mobile organochlorine pesticide, occurs in environment. HCB has been shown to be present in human follicular fluid. An objective of the present report, which is part of a comprehensive study on reproductive toxicity of HCB, was to determine the cytologic effects of the compound on ovarian follicles in a primate model.Materials and Methods. Eight Cynomolgus monkeys were housed under controlled conditions at Animal facility of Health and Welfare, Ottawa. Animals were orally administered gelatin capsules containing HCB mixed with glucose in daily dosages of 0.0 or 10 mg/kg b.w. for 90 days; the former was the control group. On the menstrual period following completion of dosing, the monkeys underwent an induction cycle of superovulation. At necropsy, one-half of an ovary from each animal was diced into ca. 2- to 3-mm cubed specimens that were fixed by immersion in 2.5% glutaraldehyde in 0.1 M cacodylate buffer (pH 7.3). Subsequent procedures followed to obtain thin sections that were examined in a Hitachi H-7000 electron microscope have been described earlier.
Cytoplasmic hybrids, by fusing fish erythrophores and normal rat kidney cells
Authors: Porter K.R. , Anderson K.L. 
Published: June 2020

When cultured together in the presence of PEG, these cells fuse (M1,M3) and survive in vitro for several days. This offers an opportunity to explore the capacity of one cell type (highly organized structurally) to impose it's structural features on a relatively unorganized cell type (NRK). Also, with two cells differing in several respects, one can ask questions regarding a role of the cell center in the control of pigment aggregation and dispersion, as well as the capacity of one cell type to assemble pigment granules in the cytplasm of another.First, in observations on general architecture .the hybrids have numerous microtubules (M3), but not the organized array of thousands observed in the erythrophores (M2). Furthermore, the microtubules in the hybrid are randomly oriented essentially as they are in the NRK cell (M4). There is a tendency observed in the hybrids for the pigment granules to concentrate among the microtubules and the cistemae of the ER (M3). Thus far, however, we have not succeeded consistently with epinephrine to induce aggregation, or with caffeine, dispersion.
LR White acrylic resin polymerized by microwave energy for immuno-EM ofSaccharomyces cerevisiae: A rapid method
Authors: Giammara B. L. , Rose A. O. , Hanker J. S. 
Published: June 2020

Microwave embedment methods have been developed for epoxy and polyester resins. Because the thick yeast cell wall is known to inhibit penetration by many embedding media, we wished to use an embedding agent exhibiting favorable properties of hydrophilicity and low viscosity. The complex requirement for low temperature and curing using UV irradiation with the polymer Lowicryl, and recent advantages described for yeast using LR White, made the latter polymer a good candidate for our studies.Saccharomyces cerevisiaewas grown at 30°C in selective medium to an OD640= 1.0. A modification of the procedure of Tuinen and Riezman was used to fix the cells. Briefly, the cells were washed three times with Sorenson's buffer, pH 7.3, and fixed as a suspension in 3% paraformaldehyde, 0.25% glutaraldehyde in Sorenson's for 2 hours at room temperature. The cells were again washed three times followed by incubation in 1 % sodium meta-periodate at room temperature for one hour.
Development of a 300kV ultrahigh resolution analytical electron microscope
Authors: Fukushima Kurio , Arai Yoshihiro , Kawasaki Masahiro , Kokubo Yasushi 
Published: June 2020

Intended for atomic-level observation and analysis in the material science field, a 300 kV ultrahigh resolution analytical electron microscope (UHRAEM) has been newly developed on the basis of the JEM-2010, a 200 kV UHRAEM. There are two versions: the UHR version, intended for ultrahigh resolution observation with a point resolution of 0.17 nm and the multi-purpose HT version, featuring specimen tilt angles as large as± 40° , and heating and cooling holders. The external view of the instrument is shown in Fig.1. Some characteristic features of the 300 kV UHRAEM are shown as follows.Electron Gun: An extremely stable and compact 300 kV election gun is constructed with 10-stage accelerating tube. SF6 gas is used for electric insulation.
Three-dimensional morphometry of biological fine structure using HVEM stereo images
Authors: Hama Kiyoshi 
Published: June 2020

There are several approaches of extracting three dimensional (3D) morphometrical information from biological fine structures, computer 3D reconstruction using thin serial sections, stereologica1 analysis of random thin section images, reconstruction from the results obtained by Fourier analysis of continuously tilted images, and so on. We have developed a computer analysis method of HVEM stereo images of thick biological specimens. Each method has advantages and disadvantages and one can choose one or other method according to the nature of samples and/or the nature of the required information.In our method, stereo paired electron micrographs are processed to produce skeletonized images, they are automatically traced, and the z coordinates of the given specimen points are calculated from the parallaxes between the two tilted images and the tilt angle.
Computer-aided image analysis and graphics in biological microscopy at higher voltages
Authors: Carragher B. , Hessler D. F. , Hinshaw J. E. , Martone M. , Milligan R. A. , Young S. J. , Ellisman M. H. 
Published: June 2020

The range of problems accessible to study using high voltage microscopy encompasses structures that span a wide range of dimensions from Angstroms to tens of microns. Structurally oriented cell biologists and neurobiologists examine cells, tissues, organelles and macromolecules in order to gain insight into cellular and molecular physiology by relating structure to function. Comprehension of these structures can be greatly enhanced by the application of computer aided three dimensional reconstruction and analysis techniques.The past decade has seen an explosive growth in the capabilities for the digital acquisition of images. At the same time, the availability of relatively inexpensive graphics workstations and sophisticated image processing and analysis software packages has made graphics and imaging techniques accessible to most research laboratories. However, the complexity of problems studied in the biological sciences has always presented a challenge to the techniques used in the analysis, and methods based on computer graphics are certainly no exception to this rule.
Research thrusts and the BRITE-EURAM project
Authors: Van Dyck D. 
Published: June 2020

The most performant high resolution electron microscopes nowadays achieve a resolution of about 0.2 nm so that the structural details of matter can be visualised at the atomic scale.If a resolution of 0.1 nm could be reached, most of the individual atoms of a structure could be resolved which would make high resolution electron microscopy (HREM) an extremely and unparalleled technique for the study of materials, especially for the characterisation of the structure of defects, new materials, crystalline as well as disordered and amorphous, etc. However, the potential power of the technique is still severely limited by the problem of the interpretation of the images. Thus far, the only way to obtain reliable information is by comparing simultaneously the experimental images with computer calculated images for various structure models. However, this trial and error technique requires a large amount of prior information obtained by other techniques and makes HREM much more dependent and thus much less powerful. For complicated structures such as defects, disordered and amorphous materials, hardly no reliable information can be obtained at present.
Resolution in near-field optical microscopy
Authors: Isaacson M. 
Published: June 2020

It has only been within the last half decade that the concept of super resolution microscopy in the near-field has been vigorously pursued and experimentally demonstrated. However, the idea of optical resolution unhindered by far field diffraction limitations was conceived more than a half century ago by Synge and further elaborated by O'Keefe in the fifties. That die method was possible, however, was only first demonstrated using 3cm wavelength microwaves almost 20 years later.The basic principles of the method of near field scanning optical microscopy (NSOM) have been described before in the literature. Briefly, the idea is as follows: if an optical probe (source or detector) of diameter D is positioned within a distance of approximately D/π from the surface of an object, and the reflected, transmitted or emitted light is detected, then the lateral spatial region from which the information occurs is limited to aregion of approximate size D and not by the wavelength of the illuminated or detected light.
Automatic electron tomography
Authors: Typke D. , Dierksen K. , Baumeister W. 
Published: June 2020

The new generation of microprocessor-controlled electron microscopes in combination with large-area CCD arrays and fast image processing computers enables automatic control of complex imaging procedures. Using a Philips CM 20 CTEM equipped with a Photometries 1Kx1K CCD camera and a TEMDIPS computer, we have set up automatic recording of tilt series for tomographic 3D reconstruction. It is our goal to combine automatic recording with on-line processing of the measured data.Fig. 1 shows a scheme of the experimental set-up. As the goniometer is not incorporated in the microprocessor control of the CM 20, an accurate readout of the tilt angle (resolution 0.01 deg.) and an additional board in the external computer driving the goniometer motor have been installed. The CCD camera is mounted on a pivotable flange; this allows to adjust its orientation with respect to the tilt axis direction in the image. For magnifications higher than 5,000x it is necessary to correct for image displacements caused by the limited mechanical accuracy of the goniometer (ca. +/-1 μm).
Granular bainite or granular ferrite? A preliminary TEM investigation of an HSLA-100 steel
Authors: Varughese R. , Thompson S. W. , Howell P. R. 
Published: June 2020

Ever since Habraken and Economopoulos first employed the term granular bainite to classify certain unconventional transformation products in continuously cooled steels, the term has been widely accepted and used, despite the lack of a clear consensus as to the detailed nature of the transformation products which constitute granular bainite. This paper presents the preliminary results of a TEM investigation of an 0.04 wt% C, copper-containing steel (designated HSLA-100). It is suggested that the term granular ferrite rather than granular bainite is a more accurate description of this multiphase reaction product.Figure 1 is a light micrograph of a sample which had been air-cooled from 900°C to room temperature. The microstructure is typical of that which has been termed granular bainite in the past and appears to consist of equiaxed ferritic grains together with other minor transformation products. In order to examine these structures in more detail, both continuously cooled and isothermally transformed and quenched materials have been examined with TEM. Granular bainite has been found in virtually all samples.
The role of interphase boundary phenomena on mechanical behavior during high-temperature deformation
Authors: Hidalgo-Prada B. 
Published: June 2020

The influence of interphase boundary on the mechanical behavior of a two-phase (α/β) Ni-Modified Ti-6A1-4V alloy during superplastic deformation (SPD), has been investigated in the range of temperature and strain rate where maximum ductility is - attained.Uniaxial tests for constant and differential strain rates were performed over the - range of 5.0 x 10-5 s-1 to 5.0 x 10-3 s-1 and at temperature from 1023 to 1123 K. To optimize the initial microstructure, tensile specimens were static annealed in argon for 1 hour at 815 °C ( SA-1-815).Upon completion of the tests, specimens were quenched in pre-chilled argon to pre—serve the high temperature microstructure for metallographic analysis. The gage portion of the specimen was polished and etched in a solution of 2 ml HF, 3 ml HNO3 and 95 ml H2O. Subsequently, they were subjected to scanning and transmission electron - microscopy (SEM and TEM) examination. A Quantimet Image Analizer was used for determining the phase size, its distribution and volume fractions.
Parallel EELS as a complementary tool in an Analytical TEM study of metal alloys
Authors: Guerra R.E. , Rightor E.G. 
Published: June 2020

The advent of efficient parallel-detection electron energy loss spectrometers (EELS) in analytical transmission electron microscopes (ATEM) promotes rapid elemental characterization of various materials containing light, as well as heavy, elements at high spatial resolution. In the current study, the microstructures of Udimet 520 and HK-25 were investigated to integrate advances in parallel EELS methods with other ATEM techniques.Thin foils of Udimet 520, a nickel based heat-resistant superalloy, were obtained using common ion milling techniques. Precipitates of the HK-25, a heat resistant steel alloy, were obtained by etching (with Marble's reagent) a polished surface, extracting with a replicating Parlodian film, dissolving the film with amyl acetate and dispersing the resulting particles on holey carbon grids. A JEOL 2000FX ATEM fitted with a Gatan Model 666 EELS system was operated at 200 kV for studies of these alloys.
High-resolution REM of the reconstruction of sapphire surfaces
Authors: Liu J. 
Published: June 2020

Sapphire (α-Al2O3) is widely used in industry and research as a high temperature insulator, a substrate for growing thin films and carrier materials in catalysis. It is important to understand the surface properties of the substrate materials for thin film growth and for metal support interactions. Recently RHEED (reflection high energy electron diffraction) and REM (reflection electron microscopy) techniques have been used to characterize surface properties of sapphire annealed in air or in oxygen. The presentpaper reports some results of high resolution REM imaging of lattice fringes of reconstructed sapphire surface.The sample preparation procedure was reported elsewhere. The results presented here were obtained from a sample annealed in pure oxygen at 1650° C for 72 h. The high resolution REM observations were done in a Philips 400T transmission electron microscope operated at 120 kV with a vacuum pressure about 10-7 Torr.
Applications of electron holography to multilayer interfaces
Authors: Weiss J. K. , de Ruijter W. J. , Gajdardziska-Josifovska M. , Smith David J. , Voelkl E. , Lichte H. 
Published: June 2020

Electron holography has received renewed interest recently as a means of resolution enhancement in high resolution phase contrast imaging and as a technique for imaging microscopic magnetic domain structures. Some of the original applications of the technique involved measurement of the absolute mean inner potential in films of known thickness. This approach has now been extended in order to gain information about changes in elemental concentrations at interfaces in multilayer films.The abruptness of interfaces in multilayer films used for X-ray mirrors strongly affects their reflective properties. Previous studies using high resolution phase contrast imaging have shown that this interface diffuseness can be imaged, but typically with low contrast and an unknown contribution from amplitude contrast effects. The differences in mean inner potential between successive layers suggests that the variation of the mean inner potential across the interface should be a good measurement of the change in elemental concentration.
Correcting channeling and diffraction effects in quantitative REELS surface microanalysis
Authors: Wang Z. L. , Bentley J. 
Published: June 2020

Channeling conditions or resonance conditions have to be satisfied in order to enhance image contrast in reflection electron microscopy (REM) and the signal-to-background ratio in reflection electron energy-loss spectroscopy (REELS). The introduction of the channeling and diffraction effects can complicate surface microanalysis (Fig. 1). In REELS, the composition ratio for two elements may be determined by(1)where σ(A,β,Δ) is the single-atom ionization cross-section of element A for collection semi-angle β and energy window Δ; iA is the average local (channeling) current density at A atom sites; NA is the average atomic concentration of A atoms; σeff(A,β,Δ) is defined as an effective ionization cross-section (EICS) of element A; IA(β,Δ) is the integrated core-loss intensity for element A; and KA is introduced to take into account the deviation of the final inelastic electron angular distribution from the Lorentzian function due to dynamical diffraction effects. Equivalent symbols apply to element B.
Nanoanalysis of semi-insulating polycrystalline silicon by high-spatial-resolution electron microscopy
Authors: Catalano M. , Kim M.J. , Carpenter R.W. , Wong J. 
Published: June 2020

Semi-insulating polycrystalline silicon (SIPOS) has been used extensively as a passivating layer in highvoltage power devices and as the wide bandgap material in solar cells. Little information, however, is available on the nano-scale nature of oxygen distribution and its redistribution upon thermal annealing, and the rnicrostructural characteristics of SIPOS thin films. In the present study, the atomic structure of SIPOS layers on Si wafers was characterized by HREM and the oxygen content was quantitatively determined by nanospectroscopy.SIPOS films were chemical vapor deposited on Si {001} wafers from a preset mixture of SiH4 and N2O. Annealing was done in dry N2 at 900°C for 30 min. Cross-sectional TEM specimens were prepared from both as-deposited and annealed materials. HREM was done in an ISI-002B at 200kV. Nanospectroscopy was performed at 100kV in a Philips EM400ST/FEG microscope coupled to a Gatan parallel-detection EELS, with better than 3 nm spatial resolution.
Study of the resistor material of an automotive spark plug by use of the charge-up effect along with elemental mapping in an electron microprobe
Authors: Liu D. R. , Shinozaki S. S. , Park J. S. , Juterbock B. N. 
Published: June 2020

The electric and thermal properties of the resistor material in an automotive spark plug should be stable during its service lifetime. Containing many elements and many phases, this material has a very complex microstructure. Elemental mapping with an electron microprobe can reveal the distribution of all relevant elements throughout the sample. In this work, it is demonstrated that the charge-up effect, which would distort an electron image and, therefore, is normally to be avoided in an electron imaging work, could be used to advantage to reveal conductive and resistive zones in a sample. Its combination with elemental mapping can provide valuable insight into the underlying conductivity mechanism of the resistor.This work was performed in a CAMECA SX-50 microprobe. The spark plug used in the present report was a commercial product taken from the shelf. It was sectioned to expose the cross section of the resistor. The resistor was known not to contain the precious metal Au as checked on the carbon coated sample. The sample was then stripped of carbon coating and re-coated with Au.
A study of the magnetic structure of magnetic force microscope tips using transmission electron microscopy
Authors: McVitie S. , Hartmann U. 
Published: June 2020

Magnetic force microscopy (MFM) has become an important tool in the investigation of the micromagnetic structure of magnetic systems. The interaction of stray magnetic field from a sample with a sharp magnetic tip is measured as the tip is scanned across the surface of the sample. Characterisation of the tip-sample interaction is of paramount importance if the measured signal obtained by MFM is to be put on a quantitative basis. In this paper we describe the preliminary results obtained by studying MFM tips using the Lorentz techniques of transmission electron microscopy.The MFM tips were prepared from 25nm thick Ni wire by an electrolytic etching and polishing technique which produces tips with a sharp apex of radius <100nm. The nature of the tips meant that only the very end of the tips were thin enough to be observed using 200kV electrons in TEM.
Transmission electron microscopy studies of Bi-substituted garnet films
Authors: Labun P.A. , Crazier P.A. , Suzuki T. 
Published: June 2020

Bi-substituted garnet films have attracted much attention as possible materials for high density magneto-optical recording media. Recently a new rapid thermal annealing technique has been developed to produce garnet films with improved microstructural and magnetic properties. We have employed in-situ heating in an analytical electron microscope to characterize the microstructural changes to the morphology and chemistry during thermal annealing of garnet films.Garnet films were produced by an r.f. magnetron sputter deposition method in an Ar atmosphere. The nominal composition of the films was (BiDy)3(FeGa)5O12 with a thickness of ∼ 40 nm. The films were transferred into the hot stage of a Philips 400T transmission electron microscope and heated to a maximum temperature of 720 C. Different rates were used to simulate the effect of heat pulsed annealing.