bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soil Colloids and Soil Organic Matter Associativity - the Basis of Soil Structure
Authors: Vrdoljak G , Sposito G 
Published: July 2020

Abstract
In the hierarchical model of soil structure, the lowest scale of structure is the combination of clays &lt; 0.2 um diameter to form 2 um domains. to investigate the basis for soil structure, two highly weathered soils from Brazil (Oxisols) were selected and the &lt; 2 um size fraction extracted by sedimentation for analysis. The first soil used in this study, classified as Xanthic Hapludox, was collected in 1991 at an EMBRAPA research station outside of Manaus, Brazil from a tropical forest site collected from the 0-8 cm depth. The second soil (0-20 cm depth) was sampled from a topographically flat area inside the Brasilia National Park, Brasilia D.F. Brazil by Dr. Flavio Vasconcelos.
The samples were analyzed by NMR spectroscopy, transmission electron microscopy, atomic force microscopy, and scanning electron microscopy. NMR spectroscopy revealed the organic materials within this size fraction consisted predominantly of polysaccharides.
SEM Petrography of Hydrothermally Altered, Metamorphic Monazite in the Quetico Sub-Province of Northeastern Minnesota
Authors: Payne L , Ross L , Bauer R 
Published: July 2020

Abstract
Metasedimentary rocks of the Archean Quetico subprovince of the Superior province in northeastern Minnesota contain monazite that has undergone low-grade hydrothermal alteration and disseminated sulfide mineralization. The area contains multiply deformed, metasedimentary rocks with abundant granitic veins that were subjected to deep burial, deformation, and syntectonic Barrovian metamorphism ranging from kyanite-staurolite grade to sillimanite-muscovite grade. Continued deformation and concomitant granitic intrusion produced rapid decompression and a well-developed high-temperature, low-pressure thermal aureole adjacent to the granitic intrusive bodies. This second metamorphic event is characterized by mineral assemblages containing cordierite or andalusite after staurolite. Subsequent reburial of the area produced prennite/pumpellyite facies regional metamorphism that is widespread but only locally recognized.
The initial aim of this study was to determine the petrographic relationships between monazite, a light rare-earth phosphate, and the surrounding minerals as a basis for absolute age dating, by electron probe microanalyzer (EPMA), of deformation and related metamorphic events.
Electron Microscopic Investigation of FE-Rich Phyllosilicates
Authors: Ma Chi , Eggleton Richard A , Rossman George R 
Published: July 2020

Abstract
Green glauconite-like minerals from Weipa, Australia, which were previously known as glauconite, were determined to be unusual Fe-rich vermicuhte and Fe-rich smectite. This study revealed the structural and chemical nature of these unique phyllosilicates with HRTEM, AEM, SEM and XRD analysis.
The Fe-rich phyllosilicates comprising up to about 15 wt% of the rock occur with various amounts of quartz, mica, feldspar, low-Fe smectite, kaolinite, pyrite and siderite at about 30 meters depth in unweathered marine sediments of the Rolling Downs Formation at Weipa. The proportions of Fe-rich vermiculite and smectite decrease upward and become undetectable in the upper saprolite zone at about 23 m depth.
Two major morphologies of the Fe-rich phyllosilicates were observed. One is of tabular or granular detrital-shaped form (Fig.la); the other is platy or film-like, coating grains and occurring in matrix and fissures (Fig.lb).
Phase Transformations in an Austenitic Stainless Steel Weld During Postweld Heat Treatment
Authors: Burke M G , Nuhfer N T 
Published: July 2020

Abstract
The microstructural development in a Type 309 stainless steel weldment associated with a post-weld heat treatment of 30 h at 580°C has been studied using analytical electron microscopy (AEM). The purpose of post-weld thermal treatments is generally to relieve stresses within the weld, thereby improving performance. Microstructural stability during these thermal treatments is important for the weld; i.e., no deleterious phases should form. in this example, detailed microstructural analyses of a weldment in the as-welded and postweld heat-treated condition have been performed. Microstructural analyses were performed using Philips CM 12 and CM300-FEG analytical electron microscopes equipped with Oxford Instruments ISIS analyzers and LZ5 energy dispersive x-ray spectrometers, and a CM200-FEG analytical electron microscope equipped with a Gatan Image Filter (GIF).
As-Welded Condition:The microstructure of the weld was characterized by the presence of dislocated austenite (γ) and a network of delta (δ) ferrite.
Quantitative Thickness Measurements of Thin Oxides Using Low Energy Loss Filtered TEM Imaging
Authors: Pantel R , Sondergard E , Delille D , Kwakman LFTz 
Published: July 2020

Abstract
A technique for very thin silicon oxide measurements using energy filtered TEM (EFTEM) is presented and applied for BiCMOS technology optimization.
In advanced VLSI circuits, thin silicon oxide layers are used as critical part of active devices such as MOS or bipolar transistors (BiCMOS). Today the 2 nm thick gate oxides of the 0.12 urn generation MOS transistors can be controlled using high resolution TEM (HRTEM). However, for the next generations these measurements will become difficult or will necessitate Cs corrected microscopes'. For the NPN bipolar transistor very thin oxides (less than 0.5 nm) are used at the base-emitter interface to control the forward base (hole) current and improve the transistor current gain. This interface presents generally some roughness and the oxide control is impossible using HRTEM. in this communication we demonstrate a new technique for very thin oxide measurement using low loss energy filtered TEM (EFTEM).
Characterization of Semiconductors Grown in a Rotating Magnetic Field
Authors: Cochrane J , Carpenter P 
Published: July 2020

Abstract
Many different techniques have been used in attempts to minimize defects in single crystal semiconductors. This study examines semiconductors grown in the presence of a rotating magnetic field (RMF). The RMF method is commonly used in metallurgy to stir an electrically conducting liquid during the casting process which can reduce the effects of buoyancy driven convection and enhance the mass transfer process. The variation of heat and mass transfer processes by RMF can be controlled by selecting a specific frequency and strength of the magnetic field. Both numerical modeling and space-based crystal growth experiments using RMF indicate that the application of RMF to solidification of semiconductors will dramatically minimize defects and inclusions.
A ground based program in the Microgravity Research Division at NASA's Marshall Space Flight Center has been studying the effects of RMF on various semiconductor compounds grown by the traveling heater method (THM).
Electron Microscopy in Tumor Diagnosis in 2001
Authors: Shelburne J , Howell D 
Published: July 2020

Abstract
Immunohistochemistry (IH) has revolutionized tumor diagnosis in recent years. The antigenic/molecular information now available is extraordinarily helpful not only in clinical diagnostic work, but also in improving our understanding of the cell biology of neoplasia. As a result, there is now less need for diagnostic conventional transmission electron microscopic (CTEM) studies on neoplasms. For example, lymphomas and leukemias are now largely defined by IH and related techniques such as flow cytometry, not CTEM. A postive S-100 stain in the right setting usually obviates the need to search for melanosomes.
However, CTEM is still a useful tool for surgical pathologists. One important advantage CTEM has over IH is that - like gross observations and the classic H&E section - CTEM can detect features not suspected in advance. This property of CTEM makes it particularly valuable in studying complex and unusual patients/tumors.
Cardiomyocyte Apoptosis in the Outflow Tract in Normal and Abnormal Cardiogenesis
Authors: Watanabe Michiko , Hitomi Midori , Sallee Denver , Jafri Anjum , Rothenberg Florence , der Wee Kathy van , Fisher Steven A 
Published: July 2020

Abstract
Apoptosis peaks within the cardiac outflow tract (OFT) myocardium during chick development (stage 30-31) and coincides with dramatic remodeling of the OFT 4. Apoptosis was assayed by TUNEL, Annexin V, transmission electron microscopy, and Lysotracker Red (Fig. 1-4). These assays reveal that as many as 92% of the apoptotic cells express cardiomyocyte markers. The timing of apoptosis suggests that it may occur to allow proper alignment of the great vessels over their respective ventricles. Our current aims are to determine the consequences of disturbing OFT cardiomyocyte cell death to heart morphogenesis and to elucidate the cellular and molecular components that initiate and regulate this high level of apoptosis.
To enhance apoptosis in the OFT myocardium, recombinant adenoviruses were injected into the pericardial space to deliver the gene for the death ligand Fas-L to the cardiomyocytes of chicken embryos prior to the stages when OFT remodeling occurs.
The Role of Apoptosis in Myocyte Death During Cardiac Hypertrophy
Authors: Goldsmith EC , Davis JG , Yan X , ᒫorell BH , Borg TK , Price RL 
Published: July 2020

Abstract
Apoptotic events can be the result of both cell anchorage-dependent and independent mechanisms. The term “anoikis” has been used to describe apoptotic events resulting from a lack of cell-ECM contact (Frisch and Francis, 1994). The integrin heterodimer α5β1 has been implicated in several systems as providing protection against apoptosis. Previous studies have demonstrated that the α5 integrin subunit is present only during cardiac development and conditions of cardiac hypertrophy and is not found in normal adult rat myocytes (Terracio et al., 1991). Cell anchorage-independent apoptosis can result from a variety of factors including biochemical and mechanical stimulus. Angiotensin II (Ang II) has been implicated as a modulator of myocyte apoptosis acting through the angiotensin II type I receptor (Kajstura et al., 1997). The role of a second Ang II receptor, angiotensin II type 2 receptor, has not been determined. The role of apoptosis in myocyte cell death during heart failure remains unclear.
Mammalian Apoptosis in Whole Neonatal Ovaries, Embryos and Fetal Limbs Using Confocal Microscopy
Authors: Zucker Robert M 
Published: July 2020

Abstract
The emergence of confocal laser scanning microscopy (CLSM) as a technique capable of optically generating serial sections of whole-mount tissue and then reassembling the computer-stored images as a virtual 3-dimensional structure offers a viable alternative to traditional sectioning approaches. However, the imaging of such whole-mounts presents technical problems of its own. One of the major problems with using a confocal microscope to image whole organs and embryos is the depth of penetration of the laser light into the tissue. We have optimized the confocal microscope performance and developed a sample technique that increases the optical resolution of the system.
CLSM has been used to study cellular death (apoptosis) during GD 8-12 normal rat/mouse embryonic development, neonatal ovarian development (PD10-45) and fetal limb development (GD 11-15). LysoTracker Red (LT) was incorporated into the tissue prior to laser excitation. It is aldehyde fixable stain that concentrates into acidic structures or into cells that have high lysosomal activity.
Accelerated Mitochondrial Reactive Oxygen Species Formation Induces OnsẸt of the Mitochondrial Permeability Transition and Mitochondrial Swelling in Cultured Hepatocytes After TNFα Exposure
Authors: Qian Ting , Lemasters John J 
Published: July 2020

Abstract
INTRODUCTION: The mitochondrial permeability transition (MPT) is implicated in mediating TNFα-induced apoptosis in cultured hepatocytes. Opening of permeability transition (PT) pores in the mitochondrial inner membrane causes the MPT. After the MPT, mitochondria swell, the outer membrane bursts, and pro-apoptotic cytochrome c is released into the cytosol. in isolated mitochondria, ROS formation promotes onset of the MPT. However, how mitochondrial ROS formation regulates the MPT in intact cells in TNFα-induced apoptosis is unknown. AIM: The present study was designed to determine the role of mitochondrial ROS formation in TNFα-induced MPT and apoptosis in cultured rat hepatocytes.
METHODS: Hepatocytes expressing an IkB superrepressor were pretreated with 2 μM t-BuOOH 4 hours before TNFα exposure with and without CsA (2 μM, an inhibitor of the PT pore) and the antioxidants, desferal (0.5 mM) or diphenylphenylendiamine (DPPD, 10 μM). Cell viability was monitored by propidium iodide fluorometry.
Gently Down The Stream: Flow Cytometry As Microscopy
Authors: Shapiro Howard M , Shapiro Howard M 
Published: July 2020

Abstract
Flow cytometry is an analytical technique in which optical measurements are made of cells or other biological particles as the cells or particles flow, ideally in single file, in a fluid stream past one or more optical measurement stations. Modern optical flow cytometers typically measure light scattered at small (1-5°) and large (15°-135°) angles to an illuminating laser beam, and fluorescence emitted in three or more discrete spectral bands; the most complex instruments employ three or four spatially separated illuminating beams at different wavelengths and can measure twelve fluorescence signals from each cell or particle analyzed.
Flow cytometry was developed in the 1960's to speed up and automate microspectrophotometry and microfluorometry, which had previously been microscope-based, in order to facilitate development of observer-independent clinical tests which could replace the Papanicolaou smear and the differential leukocyte count. At that time, high-resolution scanning was an extremely slow process; high-intensity sources were restricted to arc lamps, and memory in which images could be stored was expensive.
Sizing Dna Fragments by Ultrasensitive Flow Cytometry
Authors: Jett James H , Habbersett Robert C , Yan Xiaomei , Yoshida Thomas M , Marrone Babetta L , Keller Richard A 
Published: July 2020

Abstract
As originally developed in the 1960's, flow cytometry was primarily a technique for the analysis of mammalian cells. Analysis of cellular constituents such as DNA or cell surface antigens made fluorescent by a variety of reagents has been the main stay of flow cytometric applications. Over the years, flow cytometric analysis techniques have been developed that range from multicellular spheroids containing a million or more cells down to single molecule detection. An outgrowth of single molecule detection capability is DNA fragment size analysis.
DNA fragment size analysis starts with a sample of naked DNA that can be derived from a variety of sources including PCR products, double stranded viral genomes, BAC/PAC clones, and bacterial genomes. For genomic or cloned DNA, restriction enzyme digests are analyzed to produce a fingerprint pattern. The fingerprint, i. e., the distribution of fragment sizes produced by the restriction enzyme digestion, is characteristic of the source of DNA and forms the basis for identifying the source.
Early Events During Invasion of J774 Cells by Listeria Monocytogenes
Authors: Webster Paul 
Published: July 2020

Abstract
The gram positive bacillus, Listeria monocytogenesis a contaminant of the food we eat and although it is a common pathogen in farm animals L. monocytogenesdoes not normally infect humans. However, immunocompromised individuals, infants and the elderly are susceptible to infection. The bacteria, taken into membrane bound phagosomes, use a thiol-activated cytolysin listeriolysin O to disrupt the membrane (LLO) and gain access to the cell cytoplasm. Subsequent actin polymerizations on the bacterial surface induce motility in the cell and long cytoplasmic protrusions at the cell surface that spread bacteria to neighboring cells.
L. monocytogenesenters cells by phagocytosis. By using short infection times of 5 min or less, it was possible to examine early interactions between J774 cells and L. monocytogenes.This study shows that during the early stages of internalization the bacteria are able to modify the protein composition of the forming phagosome membrane.
Analysis for Parent Drug and Drug Metabolite in Rat Liver, Bile Stones, and Bile Using Microscopy, Laser Capture Microdissection and Analytical Chemistry Techniques
Authors: Neilly J , Gagne G , Vogt A , Fagerland J , Miesbauer L , Burton R , Shen J 
Published: July 2020

Abstract
Microscopy, microdissection, and analytical chemistry techniques were used to localize and identify drug and drug metabolites in specimens from drug-treated rats. During a toxicology study in rats of a drug candidate, concretions (stones) were found in the common bile duct, and pigmented material was found in hepatocytes and liver macrophages after long-term exposure to the drug. Because a recent study showed the effective use of microscopy and mass spectrometry (MS) to identify drug metabolite in tissue sections, we used similar methods to confirm that pigmented material in liver cells was drug metabolite. Energy dispersive x-ray spectroscopy (EDS) suggested that drug and/or metabolite were also present in stones.
Pigmented hepatocytes and macrophages in frozen sections of unfixed liver exhibited fluorescence similar to that of parent drug. When excited by UV illumination, these cells fluoresced the same color blue as the bulk drug (Fig. 1).
Ultrastructure of Striatal Dopamine Synapses in Rats with Striatal Dopamine Depletion
Authors: Gray (Jay) Jerome W , Montine Thomas J , Deutch Ariel Y 
Published: July 2020

Abstract
Parkinson's disease (PD) is characterized by rigidity, tremor, bradykinesia, and postural instability. The proximate cause of these symptoms is striatal dopamine (DA) insufficiency. The motor symptoms of PD can be alleviated by DA replacement therapy. However, late in the course of the disease patients appear to become less responsive to DA replacement. This therapeutic change suggests the possibility of structural and/or functional defects in striatal medium spiny neurons, which receive convergent DA and cortical (glutamate) inputs.
To understand the neuronal reorganization occurring in Parkinson's disease, we used ultrastructural methods to examine the striatum of rats with striatal dopaminergic deafferentation induced by unilateral intranigral injection of 6-hydroxydopamine. After a six month survival, rats were deeply anesthetized with pentobarbital and perfused with 4% paraformaldehyde-1 % glutaraldehdyde solution in 0.1M Sorenson's phosphate buffer (pH 7.4). The brains were removed, post-fixed for 12 hours, embedded in paraffin, and coronal sections cut through the striatum and midbrain.
The Effect of Charging on Electron Diffusion in Solids
Authors: Demers Hendrix , Gauvm Raynald 
Published: July 2020

The studies of insulating specimen by using scanning electron microscopy (SEM) or associated microanalytical techniques such as electron probe microanalysis (EPMA), Auger electron spectroscopy (AES), etc., is limited by the charging phenomena. Different techniques have been found to minimize this problem: coating the specimen with a conductor, working at low energy [1], etc. But for a better knowledge of this effect, we have started a study of the mechanisms of charging as well as its effect on the electrons trajectories in the case of an insulating specimen. with the success, in past years, of Monte Carlo (MC) simulation of electron scattering in solid specimens [2], we have been developing a new Monte Carlo program for the simulation of the electron trajectory in insulators.With this program, we want to understand the effect of the trapping charge on a insulating specimen. The new MC will be constructed by adding a succession of refined model. in each step, the model goes deeper in the mechanisms for the charging phenomena.
SRM 482: Revisited After 30 Years
Authors: Windsor Eric , Carlton Robert , Wightal Scott , Lyman Charles 
Published: July 2020

Abstract
The National Institute of Standards and Technology’s (NIST) Standard Reference Material (SRM) 482 was issued by The National Bureau of Standards (NBS) in 1969 i has been continuously available to the public for over 30 years [1]. The standard cons of a set of 6 wires. Each wire is approximately 0.5 mm in diameter and 5 cm long. Tl wires represent different compositions within the binary copper-gold alloy system. Included in the set are the two end member compositions, pure copper and pure gold, along with 4 alloys of nominal composition: Au80-Cu20, Au60-Cu40, Au40-Cu60 an&lt; Au20-Cu80. SRM 482 was produced specifically for the purpose of microanalysis usi the electron probe microanalyzer (EPMA).
Recent metallographic preparation of these wires revealed the presence of surface blemishes on some of the prepared wires (Figure la). Two of the authors from differei affiliations recently prepared cross-sections of SRM wires from separately purchased sets. Each was unaware of the procedures used by the other.
Quantitative X-Rays Microanalysis of 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(ρ z ) 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.
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 proposed. in order to test this correction method, a Monte Carlo program has been developed in order to compute the complete x-ray spectrum, characteristic lines plus bremstrallung, emitted from materials having rough surfaces. Figure [1] shows the geometry of the rough surfaces simulated. The parameters of these surfaces are the summit semi-angle, θ, and the height of the roughness, h.
Edx Spectrum Imaging of Bulk Specimens: Its Role in Quantitative X-Ray Microanalysis
Authors: Anderson IM 
Published: July 2020

Abstract
Energy-dispersive X-ray (EDX) spectrum imaging, where a full spectrum is acquired at each pixel in a rastered image, combines the advantages of imaging and analysis for quantitative compositional mapping. This method has great advantages for the analysis of compositional variations, because the contrast inherent in EDX spectrum images arises from the distinctiveness of the characteristic X-ray spectra in various regions of the surveyed microstructure. EDX spectrum imaging provides for simultaneous spatial, spectral and temporal resolution of the X-rays emitted from the specimen. Many EDX manufacturers have incorporated a spectrum imaging capability within their acquisition and analysis software, and ongoing improvements in computing power will enhance the practicality of spectrum imaging methods, in particular the acquisition, manipulation and analysis of the large raw data files that are generated with this method. This paper surveys the potential role of spectrum imaging in tasks that support true quantitative X-ray microanalysis of bulk specimens: robust qualitative analysis, the construction of representative spectra that describe the specimen, and the extraction of elemental concentrations from the representative spectra.