bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectral Simulation With Nist-Nih Desktop Spectrum Analyzer (Dtsa): A Critical Tool for Estimating Limits of Detection
Authors: Newbury Dale E 
Published: July 2020

Abstract
X-ray microanalysis often must estimate limits of detection for specific specimen compositions to optimize analytical strategy and to adequately describe results. Several approaches are available which make use of experimentally measured spectra to obtain peak and local background intensities. One of the oldest and simplest involves the use of pure element spectra. However, such an estimate procedure does not take into account the matrix effects, particularly absorption, which can be quite important in defining limits of detection in a particular multi-element composition. If a microhomogeneous standard is available with the appropriate matrix that also contains the other constituent(s) of interest at a known level, ideally at a minor constituent level (0.01 to 0.1 mass fraction), then the limit of detection, CDL, can be estimated through the use of the expression:
Mouse Sperm Association During Epididymal Transit
Authors: Monclus M , Burgos M H , Fornés MW 
Published: July 2020

Abstract
Head-to-head sperm association was described in some species as a normal phenomenon during epididyma transit (Phillips and Bedford, 1987). Recently, a new sperm head association (SHA) was characterized in the rat (Fornés & Burgos 1990; 1994).
At this moment, the study of SHA was extended to mouse sperm. SHA is a type of cell-cell interaction clearly observed when an a drop of epididymal fluid, obtained by a puncture of epididymal duct, is placed in a culture medium (HMB media: Modified Ringers medium).
This preparation can be observed under contrast phase microscope (optiphot-2, Nikkon) with or without fixative (2% paraformaldehyde and 2% glutaraldehyde in 0.01 M PBS buffer, pH 7,2). The mass of spermatozoa begin to move but not as a single sperm. They move as a clump of sperm and without fixative the sperm motility alone disaggregate the SHA.
Development of Ion Channel Analysor Employing Pores of Subunit C of ATP Synthase
Authors: McGeoch J E M 
Published: July 2020

Abstract
Many pathological states are related to aberrant functioning of ion channels. Cures for these conditions involve the design of chemicals that will interact with the ion channels or a channel regulator to return their function to the normal level. A notable example of a pathological state associated with ion channel malfunction is the abnormal conductance of inward rectifying potassium channels associated with irregular heart beat. The development of drugs targeting ion channels requires efficient screening of thousands of potential channel ligands. Classically the function of ion channels are assayed by patch clamping which is a fairly elaborate technique and not efficient from the point of screening thousands of ligands. Here is described the development of a compact sensor device where an ion channel is made to function in a lipid bilayer in 50nm holes in silicon or polymer hardware.
Key Elements of Biomedical Polymer-based Opto Electro Mechanical Systems for a New Generation of Microscope and Microanalysis Biochips
Authors: Lee Luke P 
Published: July 2020

Abstract
In this talk, the development of key elements for BioPOEMS (Biomedical Polymer-based Opto Electro Mechanical Systems) will be discussed as a new generation of microscopic and microanalysis biochips. Current BioMEMS (Biomedical Microelectromechanical Systems) technology is in its infancy stage. Just as silicon-based microelectronics technology went through many stages since the late ‘60's, BioMEMS technology will have to overcome many obstacles before becoming a mature industry. The IC industry was made possible by the development of fabrication processes, integration technologies, and design tools. Similarly, the field of BioMEMS must prepare new components with biomaterials and tools for the development of new microsystems, enabling the combination of biological sensors and actuators with the rapidly growing capabilities of bioinformatics.
Polymers are not only used in macroscopic systems, but are now increasingly finding use in the microscopic realm such as microfluidic devices. Among the many different classes of polymers, it is the fluoropolymers that provide the most unique material characteristics.
Bioactive Ceramic And Model Surfaces Adsorb Ligands and Factors That Stimulate Cellular Function
Authors: Composto Russell J , Ducheyne Paul , Effah Kaufman Elsie 
Published: July 2020

Abstract
Microscopy and microanalysis techniques have played an important role in our understanding of how biomaterials interact with their environment. In first part of this study, we will focus on the behavior of bioactive glass, whereas in the second a model surface will be investigated. Upon implantation bioactive glass undergoes a series of reactions that leads to the formation of a calcium phosphate-rich layer. Most in vitro studies of the changes that occur on the surface of bioactive glass have employed the use of buffer solutions with compositions reflecting the ionic composition of interstitial fluid. Although these studies have documented the physical and chemical changes associated with bioactive glass immersed in aqueous media, they do not reveal the effect of serum proteins and cells which are present at the implantation site. In the present study, we document, using atomic force microscopy (AFM) and Rutherford backscattering spectrometry (RBS), significant differences in reaction layer composition, thickness, morphology and kinetics of formation arising from the presence of serum proteins.
Protein Characterization by Low-Angle, Rotary-Replication Electron Microscopy
Authors: Samuelsson S 
Published: July 2020

Abstract
There are several established strategies for visualizing proteins by transmission electron microscopy (TEM). These include negative staining, cryo-TEM, glycerol-spray/rotary-replication, mica-flake/freeze-fracture. Of these, low-angle, rotary-replication of proteins dried out of glycerol has proven to be a reliable and accurate method for studying surface topologies of macromolecular assemblies and particles. We have characterized many proteins, both chimeras and wild type; methods, caveats and the surface structure of a couple examples are described here.
The technique of using heavy metals to cast replicas of proteins and particles has been around for decades (metal replication of proteins was first described in 1956) and continues to provide an excellent method for evaluating protein topology. The success of this method is based on the physical properties of protein in contact with freshly cleaved mica, glycerol and atomic platinum. Mica is easily split and atomically flat making it an excellent substrate.
High-Resolution Three-Dimensional Microscopy System
Authors: Kerschmann Russell 
Published: July 2020

Abstract
The demand for new methods of three-dimensional imaging of biological systems grown significantly over the past decades. Systems for volumetric analysis of macroscopic structures have been addressed through the introduction of modem CT/MRI systems; and on the cellular level, confocal microscopy has evolved into a powerful research tool for the examination of both biological tissues and manufactured goods. However, there persists a need for the visualization and analysis of types of material in the cubic millimeter size range, a class of materials which has not been adequately addressed by either radiological or optical sectioning techniques. These materials include research and clinical biological tissue samples, as well as many types of manufactured materials such as textiles and paper.
The main method currently in use for the examination of such materials is standard histopathology. Whether one is concerned with the diagnosis of a human tumor or the arrangement of cells in the leaf of a plant,
Ultrasound Biomicroscopy of Cancer Therapy Effects: Correlation between Light and Electron Microscopy, and a New Non-Invasive Ultrasound Imaging Method for Detecting Apoptosis
Authors: Czarnota GJ , Kolios MC , Heng YM , Devaraj K , Tam C , Tan L , Ottensmeyer FP , Hunt JW , Sherar MD 
Published: July 2020

Abstract
We have discovered that high-frequency ultrasound imaging, or ultrasound biomicroscopy, can be used to detect apoptosis in a number of experimental systems. We have shown that such detection with 30-40 MHz ultrasound is possible using cells in an in vitro system (AML-3 leukemia cells) made to undergo apoptosis in response to treatment with a variety of cancer killing chemotherapeutic drugs. We have shown that ultrasound biomicroscopy can also detect programmed cell death in tissues made to undergo apoptosis in response to photodynamic therapy, currently an experimental cancer treating regimen. Lastly, we have shown that this ultrasound imaging approach works in vivo, using living animals where apoptosis has been induced similarly using photodynamic therapy. Specifically, apoptotic cells and regions of apoptosis in tissues exhibit up to a 36-fold increase in ultrasound backscatter intensity permitting this type of cell death to be readily discriminated from surrounding viable tissue.
The Optimum CS Condition for High-Resolution Transmission Electron Microscopy
Authors: O'Keefe Michael A 
Published: July 2020

Abstract
High-resolution electron microscopists are familiar with the concept of an “optimum defocus” for obtaining highresolution transmission electron microscope images. Scherzer recognized that it is possible to balance the phase changes imposed by the spherical aberration of the TEM objective lens by adjustments to lens defocus. Selection of this focus condition maximizes the same-phase transfer of structural information carried by electrons scattered from the specimen. The upper limit of spatial frequencies transferred with the same phase change determines the resolution of the microscope. The resolution and “optimum defocus” depend only on the electron wavelength of the microscope and the spherical aberration coefficient, CS, of its objective lens. Reduction of Cs is the major route to improved resolution.
With the advent of electron-optical systems able to generate negative spherical aberration (usually called “Cs correctors“), it has now become feasible to zero-out objective lens Cs in the high-resolution transmission electron microscope.
Creep Mechanism Determination on Dispersed Phase Amalgams using High Resolution Electron Microscopy (HRTEM) Observation
Authors: Amado Quintero H , Ramon A Caballero A , G. O Hilders 
Published: July 2020

Abstract
Creep mechanism determination on dental amalgams has been a subject of interest in recent research works. Most of these studies conclude that the creep behavior can be explained by the well-known expression: ɛ = A σnexp (-Q/RT). Reported values for n (potential coefficient of stress) are in the order of 3 for phase dispersed dental amalgams and 2 for conventional amalgams. It suggests a grain sliding creep mechanism for conventional amalgams and a climb dislocation mechanism for creep in phase dispersed amalgams due to interactions with the dispersed CuxSny particles typical of this kind of amalgam(l). For both cases, the creep process occurs inside the γ (Ag2Hg3) phase matrix of low melting point (310 °K) which is slightly higher than typical mouth temperatures of about 400 °K (37 °C). In this work some microestructural evidences are obtained to support the behavior described above by using High Resolution Transmission Electron Microscopy (HRTEM).
HREM Analysis of ∑3 ﹛112﹜ Tilt Grain Boundaries in Au Bicrystals Observed in &lt; 111 &gt; Projection
Authors: Hetherington CJD , Dahmen U 
Published: July 2020

Abstract
Grain boundaries in fee metals with low stacking fault energy are known to undergo extended relaxations that can at times lead to a thin layer of a different structure. In Cu, for example, it has been found that ∑3﹛ 112﹜ boundaries relax into a 9R phase [1]. In this work, we have used high resolution electron microscopy to investigate the atomic structure of ∑3 grain boundaries in mazed bicrystal films of Au. Using ﹛111﹜ Ge surfaces as a template, Au bicrystals can be grown in two orientation variants, related to each other by a 60° rotation about the surface normal. As described previously, such films have a strong tendency to facet onto the coherent twin plane parallel to the substrate [2], also known as “double positioning” [3]. If films are made very thin, the likelihood for such in-plane boundaries to lie in the foil decreases, and it becomes possible to observe the atomic structure of edge-on interfaces along &lt;111&gt;.
A TEM Study of Cr Based Contacts to (0001) 6H-SiC
Authors: Liu R-J , Kim M J , Carpenter R W , Porter L M , Scheunemann L P , Davis R F 
Published: July 2020

Abstract
6H-SiC is a wide band-gap semiconductor. In recent years, a variety of high-power, -temperature, -speed and optoelectronic devices have been produced in SiC films. The search for metals which can form thermally stable, uniform ohmic contacts with SiC with low resistivity is still ongoing. In this study, Cr and CrBx (1&lt;x&lt;2) films were deposited by electron beam evaporation onto p-type, vicinal Si-terminated (0001) 6H-SiC surface. Both contacts exhibited rectifying behavior in the as-deposited condition. Ohmic-like behavior was observed for Cr/SiC system after annealing at 1000 °C for 240 seconds in a rapid thermal anneal furnace in an Ar atmosphere. It was also reported that ohmic behavior was observed for CrB2 /SiC system after annealing at 1100 °C for 2 minutes at a pressure of 5x10“7 Torr.2 The microstructure and chemistry of these two contact systems in both as-deposited and annealed conditions were investigated by transmission electron microscopy (TEM).
Lateral Epitaxial Overgrowth of GaSb on GaAs and GaSb Substrates
Authors: Inoki C K , Harris D L , Kuan T S , Yi S S , Hansen D M , Kuech T F 
Published: July 2020

Abstract
Lateral epitaxial overgrowth (LEO) technique has recently been used to improve the quality of semiconductor layers grown on a substrate. Previous studies with GaN grown on sapphire showed a significant reduction in dislocation density in LEO layers. The LEO technique uses a thin mask layer to achieve selective epitaxy, allowing vertical and lateral growth through patterned windows. Reduced defect density is expected in laterally grown materials, since no lattice mismatch is involved. In practice, however, the thermal and mismatch stresses often cause dislocations to propagate laterally during LEO, and excessive dislocation activities induced by the stresses also tilt the LEO regions. GaSb-based semiconductors, which are of interest for infrared optoelectronic device applications, have much larger (∼8%) lattice constants than the commonly used GaAs substrate. The LEO technique is therefore of particular interest for its potential to significantly reduce the defect density in GaSb films grown on GaAs substrates.
A Copper Leadframe Oxidation Investigation by Electron Energy-Loss Spectroscopy
Authors: Rucki A , Lee C 
Published: July 2020

Abstract
Copper alloys are widely used as a leadframe (chip carrier) material in plastic packaged semiconductor devices. The oxidation of Cu leadframes during the assembly process can result in poor adhesion between the moulding compound and the die-pad. This often leads to interfacial delamination and contributes to popcorn cracking during the component-board attachment process. The main cause of poor adhesion has been attributed to the weak Cu oxide(s) layer on the leadframe surface. Studies have shown that the moulding compound/leadframe adhesion decreases with increasing oxide thickness.
The aim of this investigation is to give a detailed analysis of the phase formation of a CuNiSi alloy during oxidation and to identify the locus of failure for the interfacial delamination. The Cu leadframes were oxidized in an air oven at 240° C for up to 200 min exposures before encapsulation. A scanning acoustic microscope was used to locate delamination regions along the moulding compound/leadframe interface.
Interfacial Structure and Defects in GaN/AlGaN Heterojunction Epitaxially Grown on LiGa02 Substrate by Molecular Beam Epitaxy
Authors: Dai Z R , Kang Sangbeom , Doolittle W Alan , Wang Z L , Brown April S 
Published: July 2020

Abstract
The performance of III-Nitride based Light Emitting Diodes (LEDs), LASERs, GaN/AlGaN MODFETs (Modulation-doped Field Effect Transistors) and HEMTs (High Electron Mobility Transistors) have been improved dramatically over the past few years [1,2], despite the relatively poor material quality of GaN, as compared to GaAs, for example. The intrinsic properties of the materials system make it extremely well suited to both optoelectronic and microwave power transistor applications. Typically, GaN is grown on substrates such as GaAs, Al2O3 (sapphire) or SiC with large lattice mismatch. This has usually resulted in an extremely high defect density in the GaN layer. The growth of GaN on lithium gallate LiGaO2 (LGO) affords many advantages compared to all other available substrates. LGO offers the smallest average lattice mismatch of any available substrate for the Ill-nitrides. This facilitates the growth of high quality GaN directly on Lithium Gallate without the need for a defective buffer to decouple the strain associated with the large lattice mismatch of other substrates [3].
SIO2-Supported Metallocene Catalysts for Propene Polymerization: Electron Microscopic Studies and Tomographical Reconstructions of Polymer Growth
Authors: Steinmetz B , Weimann B , Fink G , Tesche B 
Published: July 2020

Abstract
Summary:
The polypropylene growth process on silica supported metallocene catalysts was examined by electron microscopy and kinetic investigations. It was possible to identify different polymerization stages with different characteristic kinetic data in the slurry phase which led to the development of a refined polymer growth model [1-2]. Tomographical reconstruction of shortly polymerized catalyst particles obtained by electron micrographs of serial microtome sections turned out to be a useful tool to achieve a better understanding of the heterogeneous polymerization process and the influence of the support structure on polymer growth.
1. Introduction
Single-site metallocene catalysts produce extremely uniform polymers with molecular weight distributions (MWD) of 2 or less and very narrow compositional distributions in comparison to conventional Ziegler-catalysts. For industrial gas phase or bulk polymerization in existing plants (drop-in-technology) it is necessary to fix the catalytically active components on a heterogeneous support.
Investigation of Polymerized Phospholipid Monolayer Thin Film Structures by Energy- Filtered Transmission Electron Diffraction
Authors: Stevens M , Longo ML , Spence J 
Published: July 2020

Abstract
The photopolymerizable, conductive, and chromatic behavior of diacetylene containing films has lead to a number of investigations into possible applications. For example, when diacetylene films were investigated as photoresists it was demonstrated that 50 nm resolution could be achieved by electron lithography. Polymerized diacetylene layers display enviromentally dependent chromatic transitions and thus have been studied for sensor applications. Single crystals of polymerized diacetylene films belong to a class of one-dimensional semiconductors. Thus, conductive materials have been constructed using extended multilayers and monolayer of such polymers. For example, the conductive and self-supportive nature of films containing polymerized diacetylene makes them ideal for imaging large embedded molecules. The purpose of this article is to report the details of preparation of ultrathin Langmuir-Blodgett deposited phospholipid films containing polymerized diacetylene groups and analysis of the energy filtered electron diffraction spot intensities. This work shows promise that useful structural information of such systems can be obtained by TEM where owing to their finite grain size and radiation sensitivity,
Experimental Method to Measure the Detective Quantum Efficiency of a Charge-Coupled Device Camera for Electron Microscopy.
Authors: Favia P , Cooper S , Mooney P E 
Published: July 2020

Abstract
The Detective Quantum Efficiency (DQE) is one of the best parameters to characterize the performance of a charge-coupled device (CCD) camera when electron dose is an issue. This can be when there are beam source brightness limitations as in high-resolution applications or when specimen dose must be limited. For single parameter detectors such as a backscatter detector in a SEM, the DQE is defined as the square of the signal-to noise ratio (SNR) at the output divided by the square of the signal-to-noise ratio at the input:

where S, N, and n are respectively the signal, the noise and the electron dose. This definition is not valid to describe the performance of a multi-component device as an imaging detector. In fact a CCD camera is composed of many elements or pixels.
Image Management for a Multi-Instrument, Multi-Platform Teaching Facility and Implications for Outreach Programs
Authors: Murphy Judy A 
Published: July 2020

Abstract
In the digital age, the management of images can be very time consuming when there are several digital image acquisition systems involved. For simplicity in this article, databases have been categorized as active or passive. Active databases are those where the categorization of the image is done during the image acquisition. Passive databases by this definition use saved images that are then categorized after image acquisition. The databases can be further separated based on whether they are multi-platform where they usually use a browser of some sort or Java script, or are specific to a certain platform such that no browser is involved. Some databases allow user defined fields, and some do not. Many of the image database software packages were made for categorizing images after they were collected i.e. passive, and developed for photography, catalogues, newspapers, etc. which do not necessarily cater to the needs in microscopy.
“Microscopic Explorations“: One Kit Many uses.
Authors: McKernan Stuart 
Published: July 2020

Abstract
Since 1996 the Minnesota Microscopy Society (MMS) has had several different opportunities to use the “Microscopic Explorations” [1] handbook that has been developed by MSA in collaboration with the Lawrence Hall of Science [2] as part of their Great Explorations in Math and Science (GEMS) series. Initially we used a beta-test version of the manual and worked with several different schools in the St. Paul's school district. Since then we have broadened the range of our outreach, and have interacted with different school districts, as well as local museums and other youth and community organizations - including church youth groups, scout groups and local governments. One of the strengths of the manual is that it can be used in many ways, and is adaptable to the particular learning situation available. These opportunities can span the range from essentially uncontrolled interactibns with the general public, with its large age range and ability spectrum, to the very carefully structured setting of an ongoing, single-age class program.