bluuebunny/crossref_metadata_2025_split huggingface dataset:
Insulin Receptor: Structure Via 3D EM Reconstruction, Crystallography and NMR Reveals Details of Ligand Binding and Mechanism of Transmembrane Signalling
Authors: Ottensmeyer FP , Luo RZT , Beniac DR , Fernandes AB , Yip CC 
Published: July 2020

Abstract
For over 25 years a major effort in electron microscopy of macromolecules has been the determination of the three dimensional structure from the two-dimensional electron micrographs of such specimens. Great success has been realized when the macromolecule or complex takes the form of an array such as a 2D crystal (1,2), a helical structure (3,4) or one with icosahedral symmetry (5,6). However, for molecules which do not form such arrays, and in the limit only exist as single particles, a number of challenges have had to be addressed. No easy averaging of noisy low dose images is possible due to the lack of lateral and rotational symmetry. Random unknown orientations of the particles have to be determined, a process exacerbated by noise if low dose images are used as input. Alternatively, higher dose images result in radiation-induced structural alterations of the macromolecule.
Metal Coating Techniques for Contrast Enhancement of Biological Macromolecular Complexes In HRSEM, STEM and TEM Image Modes
Authors: Apkarian RP , Lee TAT , Conticello VP 
Published: July 2020

Abstract
Modern field emission SEMs fitted with in-lens or near-lens (W.D. = l-3mm.) stages and above-lens SE detectors are capable of imaging 1-5 nm features at high voltage (15-30kV) and 5-10 nm features at low voltage (l-5kV). Ultrathin fine-grain refractory metal coatings were shown to optimize higher-solution (HR) secondary electron imaging of light element specimens especially biological samples. Ambient temperature dried specimens and frozen-hydrated cryo-specimens coated with continuous 1nm-thick metal films and staged in-lens have revealed biologically significant features of molecular dimension in tandem HRSEM and scanning transmission (STEM) modes. Although positive and negative stains have proved useful for general contrast enhancement of TEM specimens these stains alter many of our new genetically synthesized block protein copolymers. Therefore we have turned to non-evaporated metal coatings for contrast enhancement of these specimens in the TEM.
Localization of Green Fluorescent Protein Absorbance by Energy Filtered Transmission Electron Microscopy
Authors: Davis J A , Garces R G , Diao J-Y , Ottensmeyer F P 
Published: July 2020

Abstract
Energy filtered transmission electron microscopy has the potential to provide high resolution, spatially resolved, atomic and chemical information. However, aberrations generated by the electron spectrometer blur the energy resolution and limit the atomic or molecular distributions that can be studied. Energy absorptions corresponding to the visible light range fall below an energy loss of 5 eV. The selection of electrons that have lost an amount of energy corresponding to chromophore absorption by the sample thus requires a spectrometer with a high energy resolution over the full image plane. A corrected prism-mirror-prism filter that has a resolution of 1.1 eV, sufficient to select these low energy loss electrons, was developed and installed by us in a Zeiss EM902. Its imaging capability was verified for a number of different chromophores. The chromophore currently under study is that of the green fluorescent protein (GFP).
Application of Atom Probe Microanalysis for Understanding Microstructure Evolution in Nickel Base Superalloy Welds
Authors: Babu S S , David S A , Miller M K 
Published: July 2020

Abstract
The characterization of the microstructure evolution during welding of nickel base superalloys is required for efficient reuse and reclamation of used and failed components. Previous atom probe analysis of electron-beam and laser-beam welds revealed complex alloying elemental partitioning between the γ and γ phases. Rapid cooling conditions in the weld leads to non-equilibrium partitioning and large amplitude Cr and Co levels in the γ phase. These results indicated that there is a strong relationship between weld cooling rate and the precipitation of γ′ precipitates from the γ phase. To understand and develop predictive models, a systematic investigation of the microstructure evolution in CM247DS alloy under controlled thermomechanical conditions are being performed. This paper describes some recent results on the elemental partitioning between γ and γ′ phases obtained with atom probe microanalysis.
Maxwellian Charge on Ferroelectric Domain Walls in KNBO3
Authors: Krishnan A , Treacy M M J , Bisher M E , Chandra P , Littlewood P B 
Published: July 2020

Abstract
Ferroelectrics are now being used as non-volatile memories, infrared detectors, phased array radar and optical switches. Although the development of commercial ferroelectric devices has advanced in recent years, we still do not have a clear understanding of the basic physics underpinning the behavior of actual ferroelectric devices. Trapped charge and oxygen vacancies are believed to strongly influence domain motion. In order to study these issues, we have designed an in situ TEM holder that can subject ferroelectric crystals to voltage, heat and UV irradiation. Preliminary results on BaTiO3 have been presented in previous reports.
In this study, bulk KNbO3 crystals were mechanically polished and thinned in hot orthophosphoric acid. The resulting thin flakes were attached to copper rings with conductive carbon paint, and electrical wires were glued to the copper rings which act as electrodes. The sample was placed in the cradle of the in situ TEM holder and examined in a Hitachi H9000NAR TEM.
Migration of Sodium in Feldspar by Electron Beam - An Experimental Study
Authors: Natarajan R 
Published: July 2020

Abstract
Quantitative analysis of Na in minerals like feldspar in an Electron Probe Micro Analyser (EPMA) confronts two problems - the first one arising at the time of data acquisiton of Xrays of Na (say Kα) and the second one during conversion of measured xray intensity ratios into true concentration while using certain correction procedure The fall in the count rate of Na xray signals as a function of time under stationary electron beam in EPMA is quite well known. This was attributed to volatilization of Na during electron bombardment. Another explanation for this phenomenon has been that Na+ ions made mobile in the crystal lattice of feldspar by the electron beam, move away from the point of its impact. This results in the fall in the count rate of Na with a corresponding increase in me count rate of matrix element like Si, Al.
Automated Focus of the Microprobe (Z) Using the Optical Signal
Authors: Delisle N , Grillon F , Thiot JF 
Published: July 2020

Abstract
The human eye is very sensitive to fuzziness and can hardly bear seeing blurred images. This situation is still worse for X-ray microanalysis as a defect in focussing the electron beam can induce errors in intensities (in reference 1, a focus deviation of 10 micrometers causes an error of about 5% due to the modification of the Bragg angle). While a human operator can easily modify the Z stage position depending on the optical image seen on the monitor, several hours-long acquisition sessions require an automated way of reproducing the operator behavior.
The basic principle is to use the optical signal delivered by the camera installed on the probe at different Z values, extracting for each step a simple characteristic in the image. The characteristic chosen is the standard deviation of the grey levels, which is easily computed from the histogram moments of order 1 and 2, and should be at its peak value (lowest value on Transmission Electron Microprobes) on the focussed image.
Lorentz TEM Investigation of Magnetic Domains in Epitaxial C-Axis Oriented Co-Cr Thin Films
Authors: Kusinski Greg J 
Published: July 2020

Abstract
Continuous increase in recording densities of the Co-based longitudinal media requires a drastic scaling down of the grain size in order to keep the required signal to noise ratio. However, this approach to increase the areal density will collapse when the grain size reaches the superparamagnetic limit. As an alternative, based on the analysis of the demagnetization mechanisms, Iwasaki and Takemura suggested the possibility of perpendicular magnetic recording (PMR), and computer simulation, predict areal densities of more than 300Gbit/in for this configuration. The c-axis oriented Co-based hep alloys with the magnetocrystaline anisotropy larger than the demagnetizing energy, are good candidates for the PMR media. However, before this type of materials can be realized, the magnetic domain structure must be well characterized. In this paper detailed analyses of the characteristics and shape of the magnetic domains present in the c-axis oriented CoCr films with thickness relevant for the recording industry are discussed.
Interfacial Mismatch and Interface Structure of Epitaxial Pb(Mg1/3Nb2/3)O3 (90%)- PbTiO3 (10%) Relaxor Thin Films
Authors: Yang G Y , Nagarajan V , Wang Z L , Li Y H , Ramesh R 
Published: July 2020

Abstract
Pb(Mg1/3Nb2/3)O3 (PMN)- and its solid solution with PbTiO3 (PT) is one of the lead-based relaxor ferroelectrics and has been the most widely studied materials because of their high dielectric constants and high electrostrictive coefficients. The potential impact of the thin film ferroelectric relaxors in the integrated actuators and sensing applications has stimulated research on the growth and characterization of thin films. Thin films have been made by pulsed-laser deposition (PLD), sol-gel and metalrganic chemical-vapor deposition. It is known that electrical properties may be strongly influenced by the microstructure of films and the interface structures between different phase in such heterostructure systems. In this paper, we report the investigation of interfacial mismatch and interface structure of epitaxial Pb(Mg1/3Nb2/3)O3 (90%)- PbTiO3 (10%) relaxor thin film by high resolution transmission electron microscopy (HRTEM).
Thin film capacitors of Pb(Mg1/3Nb2/3)O3 (90%) - PbTiO3 (10%) (PMN-PT) were grown by PLD on (100)-oriented LaA1O3 (LAO) substrates. La0.5Sr0.5CoO3 (LSCO) layer was deposited as electrode. Cross-sectional transmission electron microscopy samples were prepared following the traditional procedures including cutting, gluing, polishing and ion milling.
Role of Reactive Oxygen Species and NFKB p65 in the Lupus Kidney
Authors: Nishikawa M , Igarashi R , Nakazawa T , Aikawa E 
Published: July 2020

Abstract
Reactive oxygen species (ROS) play an important role in lupus nephritis. It has been known that nuclear factor kB(NFkB) is activated by ROS, and binds to KB element in nucleus. Afterwards, inflammatory cytokines are translated and produced in lymphocytes, macrophages and glomerular cells in the kidney. In this study, we investigated the role of ROS and NFkB p65 in the pathogenesis of lupus nephritis (MRL lpr/lpr mice) by the histochemical and immuno-electron microscopic methods.
A modified Brigg’s method was used to determine the generation of H2O2 in the renal tissue of lupus mice. Tissue samples were incubate in 0.1 MTris maleate buffer (pH 7.4) with 7% sucrose, 1mM CeCl3 and 10 mM aminotriazole at 37 °C for 30 min. After completion of the cytochemical reaction, tissues were fixed in 2% w/v glutaraldehyde in 0.1 M cacodylate buffer (pH 7.4) at 4 °C for 60 min.
Microscopical Investigation of Cotton Chemically Modified to Accept Wool Dyes for Wool/Cotton Blend Textiles
Authors: Boylston Eileen K , Cardamone Jeanette M , Ingber Bruce F , Rice Trisha 
Published: July 2020

Abstract
Renewed interest in textile blends of wool and cotton has led to developments in union dyeing (same shade on both wool and cotton fibers) that has potential for increased markets for both fibers as trans-seasonal apparel. The difficulty of efficiently dyeing wool and cotton to the same shade has limited the availability of yarns and fabrics containing blends of both fibers. In fabrics containing blends of cellulosic cotton and proteinaceous wool, it is generally necessary to employ more than one class of dyes and the process involves several steps with adjustments of pH and temperature. The ARS process provides maximum effectiveness and efficiency for one-step union dyeing. It requires pretreatment before dyeing to impart cationic character to cellulosic cotton so that it can compete with protonated wool for a common anionic dye. Three pre-treatments have been applied.
TEM Sample Preparation for the Semiconductor Industry using the Allied High Tech Multiprep™ Polishing System in Conjunction with the Gat an Broad Beam Gun™ and Graphite Holder and Accessories
Authors: Dobbs Leah L , Ai Rebecca X 
Published: July 2020

Abstract
Due to the decreasing size of components in the semiconductor industry, TEM sample preparation grows increasingly difficult. And at the same time the customer need for TEM analysis increases, along with the urgency to report the data. We have found that TEM sample preparation has been greatly improved using the combination of the Allied High Tech MultiPrep™ System (Figure 1) in conjunction with the Gatan Broad Beam Guns™ with the Graphite Holder and accessories. The technique discussed in this paper will show that this procedure for sample preparation has decreased the time it takes to prepare the sample, decreased the number of failing samples and increased the ability to do high resolution imaging.
The MultiPrep™ is used when repeatability is critical for sample preparation and eliminates the function of holding the polisher by hand. When polishing by hand the amount of force placed on the sample while polishing is inconsistent.
Practical Aspects of FIB Milling: Understanding Ion Beam/Material Interactions
Authors: Prenitzer B I , Kempshall B W , Schwarz S M , Giannuzzi L A , Stevie F A 
Published: July 2020

Abstract
Nanometer scale, high resolution Ga+ ion probes, attainable in commercially available focused ion beam (FIB) instruments, allow imaging, sputtering and deposition operations to be performed with a high degree of spatial precision. Of particular interest is how this precision milling/deposition capability has enabled a wide range of site specific micromachining and microfabrication operations (e.g., TEM, SEM, SIMS, and AUGER specimen preparation and circuit modification). The applications of FIB instruments frequently involve the creation of high aspect ratio features (i.e., deep narrow trenches). Ideally, the sidewalls of an FIB milled feature should be vertical; however, it has been generally observed that the trenches tend to exhibit a gradual sloping. The observed deviation from vertical milling has been attributed to the redeposition of sputtered material, and is especially pervasive at high beam currents and confining trench geometries. A hole milled with an FIB tends to be widest at the top surface and taper down to a point at the bottom.
Focused Ion Beam (FIB): More than Just a Fancy Ion Beam Thinner
Authors: Dravid Vinayak P , Kim Steven , Brewer Luke N 
Published: July 2020

Abstract
The potential utility of FIB for routine (and novel) applications has come to forefront recently due to advances in ion optics which now allow formation of focused ion probe of better than ∼10-20 nm containing current density exceeding several A/cm2, with a liquid metal source (typically Gallium). The small ion probe size, coupled with shallow sputtering depth - yet high sputtering yield of ions, has opened several opportunities in machining, lithography and ion-assisted deposition[ 1-3] These developments, including automation, multi-specimen stages, cross-compatible specimen holders for FIB/TEM/SEM, use of in-situ electron beam (so-called dual beam), coupled with innovations such as the “lift-off process[4], have provided an invaluable set of tools for microelectronic defect characterization. However, re-deposition (contamination), ion implantation/damage especially for desirable thinner sections (&lt;∼50 nm) remain major concerns for further applications.
While much of the excitement in TEM community for FIB is due to thin foil specimen preparation (especially in microelectronics),
The Application of SEM, FIB, LSM, AFM, and EDS Techniques During the Investigation of Failed Micromachined Elctronic Devices
Authors: Schaper Jake , Hopson Theresa , Brutcher Susan 
Published: July 2020

Abstract
Micromachined electronic devices present new challenges for established analytical tools in the semiconductor industry. These types of devices have moving components with spacing tolerances in the submicron domain. These spaces can be accumulation sites for mobile particles within the hermetically sealed device. Particles can then cause electrical malfunctions both random - for freely moving particles - and permanent - for entrapped particles. The problems for the failure analyst are: (1) a valid electrical test, (2) confirmation of the failure site without generating particles during the analysis; (3) the ability to locate and analyze known failure sites after the device is opened. A combination of several analytical tools are required for such tasks.
Surface micromachined devices are made by alternating layers of polysilicon and a sacrificial layer, such as oxide. To make a mechanical part from the deposited layer material, an underlying sacrificial layer is dissolved, thus freeing the element except where it is retained by an attachment to the silicon surface.
Cataract Formation in a Strain of Rats Selected for High Oxidative Stress
Authors: Costello M J , Marsili S , Lane C W , Salganik R I , Albright C D , Peiffer R L 
Published: July 2020

Abstract
The goals were to define the clinical and morphological characteristics of cataract formation in the OXYS strain of rats which are genetically susceptible to oxidative stress. The predominately inherited feature is the high cellular level of glucose uptake. The OXYS strain displays pathological changes in many tissues including blood vessels, liver and lung, which are consistent with increased oxidative damage. Early cataract formation is a prominent feature of this strain.
Rats were examined periodically from birth through the development of mature cataracts with slit lamp biomicroscopy. The morphology of selected stages of cataract development was studied using light and transmission electron microscopy (TEM) as well as immunohistochemical localization of lipid oxidation and DNA oxidation products. Lenses from normal rats of the same age were used as controls. OXYS rats developed cataracts as young as two weeks of age with progression to maturity by one year. Clinically, cataracts appeared initially as either nuclear or subcapsular cortical changes and developed into pronounced nuclear cataracts within months.
Decrease Tyrosine Phosphorylation of Stat3 in Human Myocardium with End-Stage Congestive Heart Failure
Authors: Bailey GW , McKernan S , Price RL , Walck SD , Charest P-M , Gauvin R , Wei C , McLaughlin J S 
Published: July 2020

Abstract
Recent study demonstrated that decrease signal transducer and activator of transcription-3 (STAT3) phosphorylation and increase apoptosis might be a critical point in the transition between compensatory cardiac hypertrophy and heart failure. To date, the protein expression of STAT3 in normal and failing human heart remains unclear. Therefore, the current study was designed to investigate the protein expression of STAT3 in human myocardium with end-stage congestive heart failure (CHF) and compared with that in normal human cardiac tissue.
Human cardiac atrial tissue was obtained from normal subjects (n=5) and end-stage CHF patients (n=5) during cardiac transplantation. To detect the DNA fragmentation, in situ terminal deoxymucleotidyl transferase dUTP nick end labeling (TUNEL) was performed. An average of 1000 nuclei was analyzed for TUNEL study. STAT3 protein expression and phosphorylation of STAT3 were determined by immunohistochemical staining (IHCS) with total STAT3 and phospho-specific STAT3 antibodies.
Secretion of Brain Natriuretic Peptide in Cultured Human Coronary Vascular Smooth Muscle Cells
Authors: Bailey GW , McKernan S , Price RL , Walck SD , Charest P-M , Gauvin R , Lin J , Wei C 
Published: July 2020

Abstract
Brain natriuretic peptide (BNP) is a peptide of cardiac origin which regulates plasma volume as well as vascular tone and growth. Recently, we have reported that brain natriuretic peptide is a potent inhibitor of endothelin-1-mediated proliferation in human coronary vascular smooth muscle cells (HCoVSMC). While brain natriuretic peptide has been reported to be produced and released from atrial and ventricular myocardium, we hypothesize that brain natriuretic peptide may be present and secreted from human coronary vascular smooth muscle cells.
Therefore, the present study was designed to investigate the secretion of brain natriuretic peptide in cultured human coronary vascular smooth muscle cells (HCoVSMC: Clonetics, San Diego, CA). The concentration of brain natriuretic peptide, and its second messenger cGMP, in culture media (48 hours) was determined by radioimmunoassay (Phoenix, Mountain View, CA). The presence of brain natriuretic peptide was determined by immunohistochemical staining using a human brain natriuretic peptide polyclonal antibody.
Expression of Angiotensin II Type 1 and Type 2 Receptor in Human Myocardium with Congestive Heart Failure
Authors: Lau P Y , Cardarelli M G , Wei C 
Published: July 2020

Abstract
Angiotensin II (AH) is a potent vasoconstrictor and mitogenic factor. AH receptors include type 1 (ATI) and type 2 (AT2) receptors. Recent studies demonstrated that both ATI and AT2 receptors expressed in human myocardium. Circulating and local tissue level of AH was increased in severe congestive heart failure (CHF). However, the expression of ATI and AT2 in cardiac tissue with CHF remains controversial. Therefore, the present study was designed to investigate the protein expression of ATI and AT2 receptors in normal human myocardium and in human cardiac tissue with mild and severe CHF.
Human atrial tissues from normal subjects and CHF patients with ischemic cardiomyopathy and dilated cardiomyopathy were obtained from open-heart surgery and cardiac transplantation. ATI and AT2 receptor expression was investigated by immunohistochemical staining (IHCS). The results of IHCS was evaluated by IHCS staining density scores (0, no staining; 1, minimal staining; 2, mild staining; 3, moderate staining; and 4, strong staining).
Increasing Apoptosis-Related Gene Expression in Human Myocardium with Congestive Heart Failure
Authors: Xie D , Wei C 
Published: July 2020

Abstract
Regulation of apoptosis involves a number of genes that can be classified into broad categories. These include genes that act as effectors of apoptosis, such as p53, c-myc, bax, p21- WAF, and genes that primarily suppress apoptosis, such as Bcl-2 gene family. These genes have been reported to be responsible for the modulation of certain stress induced apoptosis and cell cycle arrest.
It has also been reported that apoptosis involved in cardiovascular diseases such as myocardial infarction, reperfusion injury, left ventricular hypertrophy, and hypertension. However, the expression of apoptosis-related genes in human cardiomyocytes in normal subjects and in patients with congestive heart failure (CHF) remains unclear. Therefore, the present study was designed to determine the expression and localization of apoptosis-related genes in human heart.
Five normal subjects and five end-stage CHF human ventricular cardiac tissues were obtained from cardiac transplantation. The expression of p53, p21-WAF and Bcl-2 were determined by immunohistochemical staining (IHCS).