bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of a 20-Minute Exposure of Colloidal Silver on the Membrane of Human Peripheral Blood Lymphocytes and Raji Cells
Authors: Garvin K R , Hintze C J , Bowden R D , Johnson D A , Tidwell J E , Standing M D , Murray B K , O'Neill KL 
Published: July 2020

Abstract
Apoptosis (programmed cell death) is an important form of physiological cell death displayed under divergent conditions by an enormous variety of tissues. Apoptosis can be characterized by cell shrinkage, membrane blebbing, and DNA fragmentation (1). Data from recent reports have suggested that many types of cancer are accompanied by the loss of apoptotic ability (2). Many manufacturers have hailed colloidal silver as an effective treatment of many diseases including cancer (3). The FDA has recently finalized a rule stating that drug products containing colloidal silver or silver salts are not recognized as safe and effective. They conclude that product labels claiming that scientific evidence suggests otherwise are incorrect (4). In this study we undertook to examine the effects of colloidal silver on both Raji cells, a B lymphocyte lymphoma, (ATCC # CCL-86) and normal, peripheral blood lymphocytes (PBL). We noted a decrease in viability of 90% in both Raji cells and lymphocytes after exposure to colloidal silver.
Structural Details as Clues to Understanding Nacre Formation
Authors: Yao N , Markiewicz D J , Aksay I A 
Published: July 2020

Abstract
Mollusk nacre, the opalescent lining of shells such as abalone, has a fracture toughness about 3000 times greater than that of aragonite (CaCO3), the mineral of which it is almost entirely composed. Since it owes its fracture strength and toughness to its composite organic/inorganic microstructure, details of nacre formation provide clues for materials scientists hoping to mimic nacre's microstructure in fracture-resistant synthetic materials. TEM and SEM provide detailed structural information, which contributes to the understanding of nacre.
An abalone shell was fractured to expose the stacked-plate morphology for imaging in a Philips XL30 FEG-SEM. Also, an ion-milled, cross sectional sample was prepared for imaging in a Philips CM200 FEG-TEM. While SEM shows tablets of aragonite with a highly uniform thickness of 0.5 μm, stacked in interdigitated columns (Fig. 1), cross-sectional TEM reveals organic layers, ∼10 nm thick, which separate the aragonite lamella (Fig. 2), consistent with previous studies.
Low-Loss EELS Spectral Fingerprints of Lipids and Protein
Authors: Aitouchen A , Shi S , Libera M , Misra M 
Published: July 2020

Abstract
Because of their amphiphilic nature, lipids tend to self-assemble into membranes and other topologically complex structures that can serve a number of functions in both natural and synthetic environments. The structure of lipid assemblies often varies on length scales of 2-100 nm, and morphological studies of such structures often require electron-optical methods. Image contrast in an electron microscope is usually generated by large defocus for unstained samples or by positive/negative staining methodologies. We currently are developing alternate approaches to generate image contrast based on spatially resolved Electron Energy Loss Spectroscopy (EELS) [1]. This has allowed us to distinguish between different lipid species as well as between lipids and protein. Low-loss spectra taken from cholesterol, ceramide and protein (BSA) show that these materials have characteristic spectroscopic fingerprints due to both π and σ valence-electron excitations that are sufficiently different to distinguish between them.
Quantitative Analysis of Metal Sequestering in Different Cell Components of Gloeocapsa alpicola in the Overplus Phase
Authors: Goldberg JJ , Jensen TE 
Published: July 2020

Abstract
The elemental composition of polyphosphate bodies (PPB's) and other components of the cell have previously been determined by using energy dispersive X-ray spectrometers(EDX). In this present study we perform a quantitative analysis of normally grown cells and cells that were grown in the overplus phenomenon.
Cells of Gloeocapsa alpicola were grown in modified Fitzgerald's media and harvested after a logarithmic growth phase of 14 days. The overplus cells were grown, as has been previously described. The cells were exposed to 20ppm of Al, Cd, Cu, Mn, Ni, Pb, and Zn, as well as a control, for one hour. The cells were then air dried on formvar coated grids or fixed and embedded in EPON according to Luft's procedure.
For Xn-ay analysis cells were first located using the TEM mode, and then the microscope was switched to the STEM mode. Analyses of cell components were carried out using the spot mode (75Kv).
Gene Expression Profiling Following Instillation of Diesel Exhaust Particles in Rat Lung: A First Study
Authors: Reynolds Lucy , BéruBé Kelly , Jones Timothy , Richards Roy 
Published: July 2020

Abstract
Epidemiological studies conducted first in the USA and later in the UK, suggest that a relationship exists between increased cardio-respiratory hospital admissions, morbidity and mortality rates and increases in PM10 concentrations. In urban environments, ultrafine diesel exhaust particles (DEP), accounts for 20-80 % by mass of the airborne PM10 arising from vehicular activities. In previous work, we used well characterised DEP as a surrogate for PM10 and examined its bioreactivity in vivo by assessing lung permeability, inflammation and epithelial cell markers in lavage fluid. Delivery of a single instillate of l mg DEP into the rat lung was not found to cause progressive damage but did produce a transient change in lung permeability. In the experiment described here, we instilled two different doses (control [NaCl], 0.25 and 1.25 mg) of DEP into the rat lung and assessed the responses using the methods described above with the addition of a new technique known as gene expression profiling.
On the Peak to Background Ratio of X-Rays emitted from Rough Surfaces
Authors: Gauvin Raynald , Lifshin Eric 
Published: July 2020

Abstract
The classical schemes to convert the x-ray intensity into concentration, using the ZAF or the ϕ (ρz ) methods, are valid for specimens having homogeneous composition and flat surfaces. Quantitative schemes have also been developed for x-ray microanalysis of multi-layered specimens. More recently, a quantitative method has been proposed for the microanalysis of spherical inclusions embedded in a matrix as well as Monte Carlo simulations of x-ray emission from porous materials.
For the case of specimens having a non-planar surface, a quantitative method based on the peak to background ratio, using photons of the same energy, has been proposed1. However, this method has some pitfalls. First, this method is based on the assumption that the peak to background ratio is independent of the specimen roughness which is not strictly correct because the ionization cross sections and the bremstrallung cross sections are not the same. Therefore, the shapes of the ϕ (p z ) curves are not the same for characteristic and continuum photon of the same energy resulting in different absorption corrections. The result is that the peak to background ratio will vary with beam position on a rough surface.
Electron microprobe analysis under conditions of non-normal Electron beam incidence
Authors: Lifshin E , Gauvin R 
Published: July 2020

Abstract
From its inception, electron microprobe analysis was almost exclusively done under conditions of normal electron probe incidence. The radial symmetry of this geometry greatly simplified the development of quantitative equations, and these equations where further refined based on large amounts of data also collected at normal incidence. However, as x-ray detection systems where added to scanning electron microscopes (SEMs), samples were often viewed under conditions of non-normal incidence and attempts were made to modify the various correction procedures to give acceptable quantitative results. Little justification for these methods has ever been published and so the current study was undertaken to compare theoretically calculated x-ray emission from a well characterized sample, in this case NiAl (.685 wt. % Ni,.315 wt. %A1) with experimentally measured results collected as a function of tilt angle. The theoretical calculation where done using a Monte Carlo (MC) program developed by Gauvin and Lifshin.
Improving the Analtical Accuracy in the Analysis of Particles by Employing Low Voltage Analysis:
Authors: Small JA , Armstrong JT 
Published: July 2020

Abstract
The energy of the electron beam, in conventional electron probe microanalysis, is generally in the range of 15-25 keV which provides the necessary overvoltage to excite efficiently the K and L x-ray lines for elements with atomic numbers in the range of about 5-83. One of the primary microanalytical methods for obtaining compositional information on particles is X-ray analysis in the electron probe and these same voltage criteria have been applied to the procedures developed for this purpose. The main difference in analytical procedures for bulk samples and particles is that corrections have to be applied to the particle k-ratios or calculated compositions to compensate for: 1) the penetration or scattering of electrons out of the particle volume and 2) variations in the absorption due to particle geometry of x-rays less than about 3 keV. In general, particle corrections improve the accuracy and reduce the relative uncertainty estimates from several tens of percent for uncorrected data to about 10% for corrected data.
A New Parametrization of Mott Scattering Cross Section for Monte Carlo Simulation
Authors: Demers Hendrix , Gauvin Raynald 
Published: July 2020

Abstract
In the recent years the Monte-Carlo simulation has been used successfully to exploit and understand fully the capabilities of electron microscopes. In this paper, we propose a new parametrization of Mott scattering cross-section for the calculation of the total cross-section as well as the polar angle of collision. This parametrization gives better results than Rutherford cross-section for Monte Carlo simulation at low beam energy without the numerous data files needed to use the exact Mott cross-section.
The calculation of elastic scattering cross-section can be performed with the Rutherford equation using the screening parameter, δ, the energy of the incident electron, and the electron wavelength, differential cross-section is given by:
Development of a Spectral Database for Testing Quantitative Electron Probe Microanalysis of Rough, Bulk Samples
Authors: Newbury Dale E 
Published: July 2020

Abstract
The vast majority of applications of electron probe x-ray microanalysis takes place on specimens which deviate significantly from the ideal configuration. Classic quantitative x-ray microanalysis makes the tacit assumption that the only reason the unknown differs in emitted x-ray intensity from standards is that there is a difference in composition between them. While this seems trivial, it forces the analyst to eliminate a major non-compositional source of possible intensity differences, namely the geometric effects associated with surface roughness. An important early paper by Yakowitz demonstrated that deviations from an ideal flat surface due to surface topography could seriously degrade the accuracy of analysis. Yakowitz interrupted the grinding and polishing procedure on pure elements and alloys at various stages and measured the variance in the x-ray intensity as the probe was scanned across the surface as compared to the predicted distribution based on counting statistics.
Tackling the Complexities of Analyzing Phases in Metallurgical SLAGS
Authors: Livi KJT , Farthing DJ , Veblen LA , Wing BA 
Published: July 2020

Abstract
In many areas of the world slags pose potential environmental threats to their surroundings. Heavy metals, toxic and radioactive elements contained in some slags may leach into drinking water and contaminate agricultural areas. Leaching experiments can estimate short-term alteration rates, but such tests cannot reproduce long-term weathering processes. Such studies are particularly important in the case of U- and Th-bearing slags which may remain hazardous for 103 104 years. These radioactive slags are of concern to decisions regarding the termination of a nuclear materials license and the subsequent allowances for unrestricted public use of the smelting sites and slag piles. To thoroughly evaluate leaching from slags, one must understand the distribution of elements among the slag phases and the stability of each phase. Questions regarding the distribution of elements among multiple phases are best answered by detailed electron microprobe (EMP) studies.
Slags are often mineralogically and compositionally complex, and may have complicated exposure histories.
EBSD in FESEM and LVSEM
Authors: Camus Patrick 
Published: July 2020

Abstract
Background
Electron backscattered diffraction (EBSD) is a very powerful analysis technique to understand the crystallography of a sample in the SEM. Typically, a high beam current is needed to obtain good results because of inefficient collection of the patterns. In W-filament SEM's, the high beam current necessitates a large spot size and requisite low image resolution. The large beam current can also be a source of problems for insulating samples or sample mounts by causing charging and the resulting image drift.
To reduce the spot size with adequate beam currents for imaging, field-emission (FE) guns are used. For most FESEM's, the beam current is markedly reduced from that produced by W-filament instruments. Even though the image resolution is better, the EBSD performance tends to suffer at low beam currents for standard hardware configurations. To regain the performance of a comparable W-filament system, the EBSD hardware should be changed for the low beam current operation. This paper will address the hardware considerations for low beam current applications.
Reduced Unit Cell Determination From Unindexed EBSD Patterns
Authors: Michael J R , Goehner R P 
Published: July 2020

Abstract
Electron backscatter diffraction (EBSD) is a technique that can provide identification of unknown crystalline phases while exploiting the excellent imaging capabilities of the scanning electron microscope (SEM). Phase identification using EBSD has now progressed to the point that it is commercially available. Phase identification in the SEM requires high quality EBSD patterns that can only be collected using either film or charge coupled device (CCD)-based cameras. High quality EBSD patterns obtained in this manner show many diffraction features that are useful in the determination of the unit cell of the sample.’ This paper will discuss the features in the EBSD patterns and the procedure used to determine the reduced unit cell of the sample.
One of the major advantages of EBSD over electron diffraction in the transmission electron microscope is the remarkable field of view that is routinely attained. The large angular view of the diffraction pattern permits many zone axes and their associated symmetries to be viewed in a single pattern or at most a few patterns.
Spatial Distribution of Crystallographic Orientational Variants in Yag-Al2O3 Directionally Solidified Eutectic Composite
Authors: Frazer Colleen S , Dickey Elizabth C 
Published: July 2020

Abstract
YAG-A12O3 directionally solidified eutectic composites show great promise in applications requiring high temperature strength and creep resistance.’ The orientation relationships between YAG and Al2O3 have been established within the composite by use of SEM Electron Backscatter Diffraction (EBSD) and x-ray diffraction (XRD). The orientation relationships of were determined. Two related variants of A12O3 were discovered in the sample. EBSD was employed to determine the spatial distribution of the variants within the sample.
The microstructure of the eutectic composite, shown in Figure 1, reflects a “chinese script” pattern, neither lamellar nor fibrous. The directionally solidified eutectic fibers, approximately 2.5 mm in diameter, were cut into disks normal to the fiber axis by a diamond saw and polished by with diamond-imbedded paper to reduce chances of phase-preferential wear. Samples used for EBSD were ion milled for 30 minutes at low power and incident angle to improve the patterns.
Identification of cu6sn5 and cu10sn3 Phases in Admixed Dispersal Phase Dental Amalgam by High Resolution Trasmission Electron Microscopy Combined with Convergent Beam Electron Diffraction.
Authors: Ramon Caballero , Amado Quintero , Oswaldo Hilders 
Published: July 2020

Abstract
Creep process in dental amalgams has been a subject of study. The performance of dental amalgams depends on the creep resistance of different products offered in the market. Creep process occurs at mouth temperatures which are slightly lower than Gamma 1 matrix phase (Ag2Hg3) melting point (310°K). One successful attempt to improve the creep resistance has been the addition of a dispersed phase (particles of eutectic Ag-Cu phase) in conventional amalgams. By this method, a new phase (η- Cu6Sn5) has been produced which inhibits the detrimental gamma 2 (Sn8Hg) formation. It has been proposed that the presence of finely distributed particles of η-Cu6Sn5 in the matrix lowers the creep rate. This behavior has been attributed to the pinning effect of these fine particles on the dislocations produced during the creep process (1). The presence of η-Cu6Sn5 phase finely dispersed in the matrix has been explained by the initial formation of reaction rings around the eutectic Ag-Cu spherical particles.
Apoptosis During the Knee Joint Development of Mouse
Authors: Hwang D H , Lim H S , Kim Y W 
Published: July 2020

Abstract
Apoptosis has been known as a significant element in the process of embryonic morphogenesis (1). Many studies on the role of apoptosis during development have been done using several organ systems, such as limb bud (2), nervous system(3), and inner ear (4). Recently, cell death with many morphological characteristics of apoptosis was reported in the developmental study of chick knee joint (5). This study was designed to observe the appearance of apoptotic cells during the joint cavity formation of mouse knee joint by transmission electron microscopy and TUNEL staining. The fetus were collected from l5thday(15D) to 19th day(l 9D) of pregnancy.
We observed many blood vessels and mesenchymal cells at 15D between the cartilages of femur and tibia. Mesenchymal cells had condensed heterochromatin and dilated rough endoplasmic reticulum (rER). At 16D, the joint clefts were first formed. Apoptotic cells, with characteristic nuclear fragmentation and condensation, appeared between the joint cleft and the capillaries.
Antioxidants Stimulate Germinal Vesicle Breakdown, But Inhibit Chromosome Formation And Spindle Assembly In Porcine Oocytes
Authors: Bailey GW , McKernan S , Price RL , Walck SD , Charest P-M , Gauvin R , Sun Qing-Yuan , Prather Randall S , Schatten Heide 
Published: July 2020

Abstract
Mammalian oocytes are arrested at the diplotene stage of the first meiotic division. Release of oocytes from their follicles induces meiotic resumption characterized by germinal vesicle breakdown (GVBD), followed by the chromosome formation and metaphase I spindle organization and finally the extrusion the first polar body. Recently it was shown that cellpermeant antioxidants significantly inhibit spontaneous resumption of meiosis in mouse oocytes, which may indicate a role of oxygen radicals in oocyte maturation. The regulation of mouse oocyte meiosis resumption is different from that of large domestic animals in that GVBD is independent of Ca2+ and protein synthesis. The present study investigated the influence of two cell-permeant antioxidants, 2(3)-ter-butyl-4-hydroxyanisole (BHA) and nordihydroguaiaretic acid (NDGA), on porcine oocyte meiosis resumption, chromatin behavior and spindle assembly. Our findings revealed a different role of antioxidants in porcine oocyte meiosis resumption than in mouse oocyte maturation.
Cortical Granule Exocytosis and Fertilization Coat Elevation is Reduced in Aging Sea Urchin Eggs
Authors: Bailey GW , McKernan S , Price RL , Walck SD , Charest P-M , Gauvin R , Chakrabarti Amitabha , Schatten Heide 
Published: July 2020

Abstract
Cortical granules are specialized Golgi-derived membrane-bound secretory granules that are located beneath the plasma membrane in unfertilized sea urchin eggs. Upon fertilization cortical granules discharge in a reaction induced by calcium and release their contents between the plasma membrane and a thin vitelline layer that lines the plasma membrane. Microvilli at the plasma membrane elongate incorporting cortical granule membranes during elongation. The vitelline layer elevates and becomes the egg's fertilization coat that hardens and serves as physical block to polyspermy. While we do not understand the precise mechanisms that participate in cortical granule discharge it is believed that actin plays a role in this process. Because actin and calcium metabolism is affected in aging cells we investigated if cortical granule secretion is affected in aging sea urchin eggs.
Lytechinus pictus eggs were obtained by intracoelomic injection of 0.5M KCI to release the eggs into sea water at 23°C.
Toward Measuring In-Vitro Single Molecule Force Fields Using a Scanning Force Microscope
Authors: Eppell S J , Todd B A , Zypman F R 
Published: July 2020

Abstract
The interaction of surfaces with their surroundings can be described as arising from force fields generated by molecules at the surface of interest. This statement is true for electrostatic interactions of proteins on cell membranes as well as steric interactions of macromolecules on polymer surfaces. To better understand these systems and ultimately to design superior materials, it is necessary to make direct measurements of these near-surface molecular scale force fields. Scanning force microscopy (SFM) holds some promise in the endeavor to make surface force measurements in a full three dimensional submolecularly resolved space. In-vitro measurements present a problem in that the force fields tend to be very short ranged. This necessitates placing the SFM probe very near the surface in order to measure the fields. The ubiquitous van der Waals attraction tends to induce an instability in the SFM instrument under these conditions leading to a non-equilibrium state. We have carefully examined this state of affairs and found that it is essential to use a substantially more sophisticated method to analyze SFM data than is commonly performed.
Dynamic Debonding Force Measurements of Ligand (RGD)-Platelet Receptor (GP Ilb/IIIa) System under Physiological Conditions
Authors: Lee ImShik , Marchant Roger E 
Published: July 2020

Abstract
ABSTRACT
Binding formation between a peptide sequence (GSSSGRGDSPA) which contains the cell adhesion sequence –RGD-found in fibrinogen, vWF, fibrinonectin, and vitronectin and human platelet intergrin GP Ilb/IIIa plays an important role in thrombus formation. Using atomic force microscopy (AFM), we visualized the detailed structures of membrane and submembrane of the cell, and measured the interaction forces between a peptide modified cantilever probe tip and platelet surface from pN to nN levels under physiological buffer. Direct measurements of the debonding force for the RGD ligand - GP Ilb/IIIa system are presented. To eliminate the possible measurement of the hgand-receptor pair, or of the ligand and AFM tip, following desorption of the ligand; the cantilever tip surface was modified with covalent coupling chemistry rather than physical absorption. Our results showed that the single molecular rupturing force was 93.3 ± 10.41 pN with considerable chain extension in the receptor. The rupturing forces showed a logarithmic dependence of the rate of loading