bluuebunny/crossref_metadata_2025_split huggingface dataset:
Imaging Cell Surface Macromolecular Distribution by Mapping Intermolecular Interactions with an Atomic Force Microscope
Authors: Bhatia R , Lin H , Quist A , Primbs G , Desai N , Lai R 
Published: July 2020

Abstract
An atomic force microscope (AFM) can image real-time intermolecular interactions between complementary macromolecules, such as receptor-ligand and antigen-antibody with nanometer resolution in hydrated state. Recent developments in AFM imaging allow mapping of such interaction forces over a large surface area such that local as well as global distribution of complementary biomolecules could be ascertained simultaneously. Using the force-volume maps and AFM probe conjugated with antibody, we have mapped the reorganization of specific receptors on the cell surface as well as the resultant changes in cellular micromechanical properties, such as elasticity and cytoskeletal reorganization of the cell (Figure 1).
In present study, we have mapped vascular endothelial growth factor receptor (VEGF-R) in the plasma membrane of cultured endothelial cells using anti-VEGFR - antibody conjugated to AFM probe. VEGF induced changes in cytoskeleton reorganization in endothelial cells were observed by real-time AFM imaging.
Microscopic Analysis of Porous Biodegradable Scaffolds for Tissue Engineering
Authors: Buevich F , Pulapura S , Kohn J 
Published: July 2020

Abstract
Introduction: There is considerable interest in the use of three-dimensional porous scaffolds for tissue regeneration. The presence of an interconnected framework of pores with large surface area facilitates the formation of extracellular matrix and permits cellular ingrowth into implanted structures. For scaffolds to be useful for tissue regeneration, they must maintain good dimensional stability during the lifetime of the implant. While the initial scaffold architecture is often well characterized, a systematic study of the influence of incubation on the scaffold architecture is critical to ensure that the scaffolds retain their interconnected network of pores during their useful lifetime. Herein, we report on the evaluation of the architecture of polyarylate scaffolds and their stability under in vitro conditions using scanning electron microscopy (SEM).
The polymers used in this study were selected from a library of degradable polyarylates. This library is the first reported combinatorial library of biodegradable condensation polymers.
Non-invasive video imaging for interrogating pharmaceutical crystallization processes
Authors: Wilkinson M J , Jennings K H , Hardy M 
Published: July 2020

Abstract
Crystallization is fundamental to much drug manufacture. Consequently a great deal of attention is focused on trying to attain a reproducible, robust process with predictable outcomes.
Crystallization may be interrogated by various means including laser light scattering, infra-red spectroscopy, calorimetery, x-ray diffraction, solid state NMR analysis and optical and electron microscopy. Although laser backscattering is applicable to real time, in-situ studies it detects chord length and hence it is most accurate when all particles are spherical. This is clearly is not so with drug crystals. Crystal analysis by microscopy is usually conducted on samples removed from the reactor. While this approach has value it may lead to post-sampling changes and is not capable of fully characterising the real time dynamics of particle morphology. In-situ epifluorescence microscopy of cells within a bioreactor has been reported. However, this required insertion of a quartz window into the reactor wall which limited the observation position to one fixed location, which would be less appropriate for batch crystallization reactors.
The Role of Microscopy in Preclinical Safety Assessment
Authors: Dovey-Hartman Barbara J 
Published: July 2020

Abstract
Microscopy plays a vital role in assessing the safety of New Chemical Entities (NCE) in the pre-clinical phase of drug development. Light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are used at the Schering-Plough Research Institute (SPRI) for evaluation of NCE. To support regulatory submissions, NCE are routinely tested in rodents in short-term studies such as one-month toxicity studies, and in longterm studies such as oncogenicity studies that may last 24 months. At the completion of a study, the animals are necropsied and the required tissues collected and stored in fixative. The tissues for LM are processed to slides and stained with Hematoxylin and Eosin (H&E). The information derived from the examination of these tissues by LM becomes an essential part of the pathology report. The LM examination of these tissues usually yields the information needed to either progress a NCE or otherwise deter or halt development.
“In-Situ” TEM Studies and “Real-Time” Digital Imaging
Authors: Alani R , Pan M 
Published: July 2020

Abstract
“In-situ” TEM studies is currently going through resurgence for materials microcharacterization. One important aspect of these studies has always been the image recording process. Traditionally, the following analog image recording techniques have been used: i) “static” images taken by photographic films and ii) viewing the images with a TV camera and recording them onto a videotape [1]. On the other hand, with the advent of CCD cameras and its rapid evolution for digital “static” imaging in TEM [2-3], “real-time” digital imaging for “in-situ” experimentation has been in high demand. In this work, we report the utilization of a new CCD camera for both “real-time” and “static” image acquisitions. The performance of the camera is shown for heating/cooling “in-situ” TEM experiments performed on an aluminum alloy using a double tilt hot stage.
We have utilized a newly designed CCD camera that addresses imaging needs for “in-situ” applications.
New Frame-Transfer Wide-Angle Slow-Scan CCD Camera Allows Recording of Distortion-Free Images for Digital Montages
Authors: Hiller SA , Probst W , Seybold V , Zellmann E , Kabius B , Trondle A 
Published: July 2020

Abstract
Modern SSCs combine low noise with high sensitivity and provide digital images with high dynamic and excellent linearity. Since these images are immediately available in a PC, SSCs have become a non-dispensable tool for on-line image processing and software driven automated TEM tuning [1]. Many experiments performed nowadays in the area of high resolution, low dose, holographic reconstruction, and EFTEM [2] would not be possible without the digital input coming from SSCs.
Despite their excellent characteristics SSCs provide a restricted number of individual image points in respect to film. This turned out to be the most prominent disadvantage of SSCs especially for applications where highly resolved large specimen areas need to be captured. Tab. 1 shows a typical example for a biological application where an image detail of 4 nm (plasma membrane) needs to be resolved. Depending on the film material used, this resolution is matched more or less by a TEM magnification of ∼8,000x.
Position Normalization as a Tool to Extract Compositional and Microstructural Profiles from Backscatter and Secondary Electron Images
Authors: Lee P J , Larbalestier D C 
Published: July 2020

Abstract
Position normalization is a method of manipulating data from any image source so that the effective information to noise ratio is dramatically increased. In this paper we present two very different examples of the application of position normalization used in the study of high current density superconductors. In the first example we use FESEM fractography to analyze grain boundary density and grain shape in micron-diameter filaments and then normalize the data obtained from individual grains to their positions with respect to the filament-matrix interface. In this way we extract the change of grain structure with position in apparently inhomogeneous microstructure. In the second example we analyze the backscattered electron intensity, BEI, from the cross-section of a superconductor filament with respect to its proximity to phase boundaries. In this way we extract small trends in the mean atomic number with a spatial resolution of better than 100 nm.
Effective Extinction Distances in Zone Axis Silicon
Authors: Yu Z , Vanfleet R R , Silcox J 
Published: July 2020

Abstract
Many scientific questions encountered in electron microscopy require quantitative deductions from the observations. Comparisons of experimental observations with simulations are however, still relatively rare since measurements of intensity are normally difficult. In this paper we discuss the use of experimental observations of the effective extinction distances for zone axis silicon using a convergent beam STEM mode for comparison with a number of simulations. On the experimental side, the measurements were made with a STEM that provides accurate intensity measurements directly with a digital image recording system. Two theoretical schemes widely used in electron microscopy simulations, multislice simulation and Bloch-wave calculation, were employed for the simulations. In each case, both a TEM case and a STEM case were calculated for comparison.
The multislice simulations were carried out using codes available from Kirkland. For the TEM case with plane waves at normal incidence on the sample surface, the unscattered (0,0) exit beam gives the Bright Field (BF) intensity.
In-Line Holography and Phase Amplification for Quantitative Phasecoherent Foucault Imaging
Authors: Volkov VV , Zhu Y 
Published: July 2020

Abstract
For magnetic flux mapping in magnetic materials it is important to use a simple, reliable and quantitative method operating with resolution down to few nanometers scale. The traditional off-axes electron holography can reach, in principle, such a resolution. However, the time-consuming phase reconstruction procedure limits its applications to real-time dynamic studies of magnetic domains behavior under varied external field. A novel recently developed in-line holographic approach, based on magnetic interferograms generated by phase-coherent Foucault (PCF)-imaging, complies with most of these demands and is suitable for dynamic studies of domain structure. For instance, it was successfully applied for induction mapping of closure domains in soft Fe-films [1]. It was found, however, that the resolution of PCF-imaging was lower than that of off-axis electron holography, since it is limited by the observed fringe spacing [2].
We report that the real resolution of PCF-imaging can be improved significantly with help of a novel phase amplification method.
Probability of Seeing (001) Cross-Fringes in a Random Cubic Nanocrystal Image
Authors: Qin W , Fraundorf P 
Published: July 2020

Abstract
As a crystal gets smaller, diffraction spots stay visible for larger deviations from the Bragg condition. The upper limit of such deviations is connected to the threshold for getting lattice fringes in TEM images. This in turn allows one to quantify the probability of seeing cross lattice fringes along a certain zone axis. In this abstract we examine a simple semi-empirical model for the probability of detecting (001) zone cross-fringes of a spherical crystal of cubic lattice.
The upper limit for the deviation of crystal orientation from the exact Bragg condition, without losing cross fringes down a given zone, is expressed as the maximum half-angle θ1 between the zone and the electron beam. The solid angle σ subtended by a cone with this half-angle is proportional to the probability px that a randomly-oriented crystal will show the cross-fringes associated with that zone. A schematic, illustrating the principle used to calculate the probability of seeing cross-fringes, is given in Figure 1.
Morphology and Orientation Relationships of Ge Precipitates in Ag-Ge Alloys
Authors: Luo CP , Dahmen U 
Published: July 2020

Abstract
Ag-Ge forms a simple binary eutectic with only two solid phases - a Ag-rich fee phase and a Ge-rich diamond-cubic phase, both with very limited solid solubility for the other element. Because both phases are cubic and there are no intermediate compounds, precipitation of Ge in an Al matrix might be expected to be crystallographically and morphologically simple. However, previous investigations of similar alloys (Al-Ge and Al-Si) have shown that precipitation in such apparently simple eutectic systems can be surprisingly complex [1,2]. For example, it was found that Ge precipitation in Al-Ge alloys depends sensitively on the availability of lattice vacancies and that at least five different orientation relationships and even more types of morphologies can form during aging after a quench. In the course of that work it was discovered that twinning is a key factor in the development of precipitate morphologies. To understand the role of twinning in precipitation this study investigates the characteristics of precipitation in Al-Ge alloys.
Atomic Structure of Y2O3:Eu/LaA1O3 Interfaces
Authors: Gao H-J , Fan XD , Kumar D , Cho KG , Singh RK , Pennycook SJ 
Published: July 2020

Abstract
There has been intense interest in preparing single crystalline yttrium oxide (Y2O3) thin films for applications in ultra-large scale integration (ULSI) gate insulators, ULSI capacitors, and, by addition of suitable dopant species, for electroluminescent devices. Y2O3 has a C-type rare-earth sesquioxide structure, closely related to the fluorite structure with a cell parameter a= 1.060 nm and space group Th (Ia3). LaAIO3 (LAO) is a rhombohedral structure with lattice parameters a = 0.378 nm, θ ≤ 90.5°. The lattice mismatch with the &lt;110&gt; direction of the YO is therefore less than 0.8%, and so we would anticipate epitaxial growth of single crystalline YO thin films on the LAO (001) substrate to be feasible. Eu activated YO thin films were deposited by laser ablation on (001) LAO substrates. TEM bright field images and electron diffraction patterns were recorded in a Philips EM-400 electron microscope operated at lOOkV. Z-contrast imaging was conducted in a VG HB603 STEM at 300kV. In this presentation, we will report the epitaxial growth of YO thin films doped with ∼ wt 4% Eu on a LaAlO3 substrate, and the atomic structure of the interface.
Interfacial Structure of Metastable 4H-BaRuO3 Thin Film on (111) SrTiO3 Substrate
Authors: Ding Q , Tian W , Lee M K , Eom E B , Pan X Q 
Published: July 2020

Abstract
BaRuO3 chemically belongs to ARuO3 family. It has unique hexagonal structure rather than an orthorhombic GdFeO3-type structure of other members, such as SrRuO3 and CaRuO3. The structure of ARuO3 compounds can be described on the basis of the close-packed stacking of AO3 layers in which the center of oxygen octahedra is occupied by ruthenium. A number of polymorph structures exist by mixing the cubic and hexagonal close-packed stacking of AO3 layers.
Up to date, only three polymorph structures have been observed in BaRuO3 bulk materials, which are denoted by 4H, 6H and 9R structure. The 9R structure (Fig. 1 (a)) is most stable at 1100 °C at atmosphere pressure. As pressure is increased, the 9R structure will transform through metastable 4H structure (Fig. 1(b)) to metastable 6H structure. The physical properties of BaRu03 polymorphs differ significantly with the variation of the structure. Hence, it is desirable to form phase pure polymorphs of BaRuO3 to examine the structure-property relationship.
Silicon Wafer Bonding: Effect of Wafer Surface Treatment on Interface Structure and Chemistry
Authors: Cox MJ , Kim MJ , Xu Hong , Carpenter RW 
Published: July 2020

Abstract
The two most important characteristics of any surface considered for wafer bonding are cleanliness, surface smoothness and macroscopic flatness. Silicon wafers in the as-received condition have a native oxide on the surface several nanometers thick [1], Figure la shows that they also have a layer of hydrocarbons. While they are not clean, they are smooth. Our wafers were plasma or ion cleaned, chemically treated, and ultra high vacuum (UHV) thermal desorption annealed in different combinations to find the best method for providing smooth, contamination free substrates that will produce an atomically flat, chemically clean Si/Si bonded interface.
The first approach was a single step process to remove the contaminants and then bond the clean wafers. Cleaning was accomplished by ion bombardment of the surface in an UHV chamber with base pressure 1x109 Torr. This ion cleaning chamber is connected between the UHV (2x10-10 ) bonding chamber and UHV (1x10-10) analysis chamber, allowing wafers to be cleaned, analyzed, and bonded without breaking vacuum [2].
HRTEM Image Simulations for Gate Oxide Metrology
Authors: Taylor S , Mardinly J , O'Keefe MA , Gronsky R 
Published: July 2020

Abstract
High resolution transmission electron microscopy (HRTEM) has found extensive use in the semiconductor industry for performing device metrology and characterization. However, shrinking device dimensions (gate oxides are rapidly approaching 10Å) present challenges to the use of HRTEM for many applications, including gate oxide metrology. In this study, we performed HRTEM image simulations of a MOSFET device to examine the accuracy of HRTEM in measuring gate oxide thickness. Length measurements extracted from simulated images were compared to actual dimensions in the model structure to assess TEM accuracy. The effects of specimen tilt, specimen thickness, objective lens defocus and coefficient of spherical aberration (CS) on measurement accuracy were explored for nominal 10Å and 16Å gate oxide thicknesses.
The gate oxide was modeled as an amorphous silicon oxide situated between a gate electrode and substrate, both modeled as single crystal Si(100). Image simulations of the sandwich structure were performed in cross-section (with Si[110] parallel to beam direction) using the multislice approximation for a 200 kV microscope with Cs=0.5mm.
Real Time Observations of Nanopipe Formation, Dislocation Motion and Nitrogen Desorption in GaN
Authors: Bailey GW , McKernan S , Price RL , Walck SD , Charest P-M , Gauvin R , Stach EA , Kisielowski CF , Wong WS , Sands T , Cheung NW 
Published: July 2020

Abstract
GaN and related wide band gap semiconductor alloys have received considerable attention over the past several years because of their utility in short wavelength opto-electronic and high power / high frequency devices. In most cases, GaN alloys are grown heteroepitaxially on (0001) single crystal sapphire. Due to the high lattice mismatch between GaN and sapphire, typical dislocation densities in these films vary from as high as 1010 cm-2 to, at best, 108 cm-2. Hollow core dislocations - also known as nanopipes - are also frequently observed. The presence of high defect densities is widely believed to limit the performance of GaN based electronic devices, especially the lifetime of commercially important blue and green laser diodes.
In this work, we present real time, in-situ TEM observations of the formation mechanism of nanopipes in single crystal GaN.
Effects of Confinement on Arborescent Graft Polystyrene Particle Shape
Authors: Chou TM , Aitouchen A , Libera M , Briber RM , Gauthier M 
Published: July 2020

Abstract
Arborescent graft polymers are highly branched materials synthesized by grafting multiple generations of macromolecular precursors on a central core [1,2]. They can be synthesized with controllable size and molecular weight depending on the number of generations and the precursor molecular weight. They possess many of the unique structural [3], thermodynamic, and rheological [4] properties of dendrimers but do so on a length scale roughly one order of magnitude higher. This research describes the effect of confinement on the shape of arborescent graft polystyrene (PS).
This work used 3rd generation arborescent graft PS synthesized with 5kg/mole linear polystyrene precursor (G3- 5K). The G3-5K PS sample was mixed to a dilution of approximately 0.005 wt% in toluene. A single drop of solution was placed on either a holey-carbon film or an ultrathin continuous carbon film. The solvent was evaporated under ambient conditions. A Philips CM20 FEG TEM/STEM equipped with a Gatan 666 PEELS and a 679 multiscan CCD camera was used to study the structure of these specimens.
Quantitative Transmission Electron Microtomography of Complex Bicontinuous Polymer Nanostructures
Authors: Spontak RJ , Jinnai H , Braunfeld MB , Agard DA 
Published: July 2020

Abstract
Nanostructured polymers constitute an increasingly important class of materials. Investigations into the formation of nanostructural elements in microphase-ordered block copolymers have elucidated universal mechanisms of self-organization in soft-condensed matter, since topologically comparable nanostructures develop in biological and surfactant systems. Emerging applications of such polymers include nanotemplates for inorganic materials, optical switches and nanoreactors. Despite all the efforts that have focused on these materials in previous years, basic questions regarding the characteristics of these nanostructures, especially those exhibiting bicontinuity, persist. While most attempts to address these questions have relied on small-angle scattering, a real-space approach to this problem compares slices of simulated nanostructures to 2-D transmission electron microscopy (TEM) images. An alternate strategy is transmission electron microtomography (TEMT), which utilizes 3-D images (reconstructed from a series of 2-D images collected at sequential tilt angles) for detailed structural analysis. Using this method, we have, for instance, recently confirmed that packing frustration,
Development of a 1MV-Field-Emission Electron Microscope II. Performance
Authors: Kawasaki T , Yoshida T , Gorai M , Akashi T , Matsui I , Furutsu T , Kamimura O , Matsuda T , Osakabe N , Tonomura A , Kitazawa K 
Published: July 2020

Abstract
The development of increasingly coherent and penetrating electron beams in electron microscopy will hasten progress in such fields as high resolution imaging, electron holography, and material structure investigation. Now that we have completed the development of the 1MV-FE- TEM (H-1000FT), we report its performance from the viewpoint of coherent illumination.
We observed thin films of gold in testing the high-resolution performance of H-1000FT.Crystal lattice fringes are formed from the interference between Bragg diffracted electron waves. In TEM observation of the films, the visibility of the fringes depends on the coherence of the electron wave and the overall stability of the microscope. Here, we calculated chromatic aberration-limited resolution d, given by ∼-(Δ ƛ)1/2, to be ∼ 0.6 Å (Δ:focus spread). We then slightly tilted the illumination to partially escape from the chromatic effect and to enable us to a shorter spacing lattice image. Figure 1 shows a lattice fringe image we obtained for a Au thin film, in which lattice fringes of 0.498 Å are clearly visible.
A Low Cost Configuration for Internetwork Telemicroscopy
Authors: Dorward D W 
Published: July 2020

Abstract
Advances in internetwork data transmission rates and reductions in the cost of imaging components and applications have facilitated real-time sharing of video, still images, and microscope operating systems with collaborators or observers at remote locations. Specialized direct and web-based systems for transmission electron microscopy have been described previously. However, in order to develop a generic and flexible means of sharing live images and data from light, scanning electron, and transmission electron microscope instruments, a telemicroscopy system was configured using readily available components and software that can be adapted for use with most common computer operating and networking systems.
Figure 1 diagrams the general configuration used in our laboratory. Input devices can include inexpensive desktop digital or analog video cameras, specialized fast or slow scan CCD cameras, and the analog video-screen signal generated by scanning electron microscopes. For transmission through TCP/IP networks, analog signals must be digitized with a frame grabber card.