bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microscopic Detection of Early Cancerous Changes in Bladder Tissue by Autofluorescence
Authors: T.Arendt Joseph , M.Cothren Robert 
Published: July 2020

Abstract
The intrinsic fluorescence achieved without dyes (autofluorescence) of bladder tissue, benign mucosa and the various stages of transitional cell carcinoma (TCC), is being characterized. D'Hallewin, et al., and Koenig, et al., are testing autofluorescence spectroscopy for detecting bladder carcinoma using an optical fiber probe inserted down the auxiliary channel of an endoscope. These studies do not include fluorescent microscopy to directly examine the fluorescing structures (fluorophores) within the tissue. Therefore, frozen unstained sections are being imaged on a fluorescence microscope to identify and reveal the morphology and location of the fluorophores. Tissue biopsies taken at endoscopy are immediately frozen in liquid nitrogen. Later, the tissue is cut into 5 μm sections. Serial sections are alternately imaged frozen on the fluorescence microscope or stained with hematoxylin-and-eosin (H&E). The H&E stained slides are reviewed by a pathologist.
A 75-W xenon arc lamp fitted with a 380-nm narrow-band interference filter is coupled to microscope slides on the stage of an Olympus MT-2 inverted microscope.
Confocal Raman Line-Scanned Imaging of Complex Geological and Histological Thin Sections
Authors: Adar Fran , Bernard Roussel , Wang Alian , Hawi Shari , Nithipathikom Kasem 
Published: July 2020

Abstract
Chemical imaging of complex multi-component materials has important potential for the analyst in many fields of research. Raman imaging is of particular interest for several reasons. The Raman spectra contain detailed information on chemical species and crystalline phase. Because the Raman effect is excited by optical radiation, the spatial resolution, which is proportional to the wavelength of the light, is better than 1 μm. and with near field optical techniques currently under development, there is potential for even higher spatial resolution in the chemical image.
The methods used to produce an image fall into essentially two categories - global imaging and confocal mapping. When creating global images, a large area of the sample is bathed in laser light. The light scattered by the sample is filtered to select a Raman band, and then that light is used to create an image of the sample on a two-dimensional detector.
Volumetric Raman Spectral Imaging With a Confocal Raman Microscope: Image Modalities and Applications
Authors: Brenan Colin JH , Hunter Ian W , Korenberg Michael J 
Published: July 2020

Abstract
Confocal Raman microscopy is an invaluable tool for non-invasive three-dimensional (3-D) analysis and visualization of chemically heterogeneous samples. The confocal Raman microscope (CRM) combines focused laser illumination with spatially filtered detection to define in the sample a localized volume element (voxel) from which scattered or reflected light is detected. Attenuation of light from outside the voxel by the pinhole spatial filter increases image contrast and results in voxel sizes typically &lt;10−18 m3. Moving the specimen relative to the voxel and recording the scattered light Raman spectrum at each scan position generates a Raman spectrally-encoded 3-D sample image for non-invasive in situ differentiation between optically similar yet chemically distinct materials.
The motivation for the present work stems from our application of continuum modeling techniques as the mathematical framework for development of physiologically realistic biosystem models. A Type 2 correlation-based confocal scanning laser microscope (CSLM) integrated with a high performance, parallel-drive micro-motion robot (MR-1) was built for spatially-distributed acquisition of optical and mechanical data within a &lt; 1 mm3 workspace volume.
Characterising the Morphology of Polymer Articles Using Polarised FTIR Reflectance and Raman Microscopies.
Authors: Everall NJ , Chalmers JM 
Published: July 2020

Abstract
The optical and mechanical performance of polymer articles is often very strongly influenced by the crystallinity and degree of molecular orientation in the polymer. It is therefore important to have available techniques for measuring and mapping these parameters over article surfaces and through wall thicknesses, on scales from centimetres to microns. It is also desirable that these techniques do not in themselves perturb the morphology of the polymer, for example by introducing excess orientation or crystallinity through sectioning.
In this paper we will show how Raman microscopy can provided a useful approach for mapping polymer crystallinity on the micron scale, particularly when coupled with multivariate calibration techniques for data analysis. The acquisition and treatment of data to obtain crystallinity information will be described in detail. We will also describe the development and application of polarised FTIR specular reflectance and attenuated total reflection (ATR) microbeam techniques for quantifying and mapping surface orientation of polymer articles.
Quantitative Analysis of Metal Nanoparticles
Authors: Lyman Charles E 
Published: July 2020

Abstract
Analysis of nanosize particles by x-ray emission spectrometry in the analytical electon microscope (AEM) is limited by the level of electron current that can be placed in a 1-2 nm excitation beam and by the consequent electron beam damage. The current in the beam limits the number of x-ray counts generated in the particle, while the beam damage may cause changes in particle chemistry, structure, orientation, and location. The objective of “ultimate AEM analysis” is to make useful measurements right up to the limit where beam damage prohibits analysis.
Elemental analysis of sub-10nm metal particles supported on a ceramic support requires a field-emission source operating at 100-300 kV to generate a significant number of x-ray counts from the area under the beam in a reasonable time [1]. The high current density in the beam of such an instrument can cause damage to the particle or to the underlying support material.
Capabilities and Limitations of Biological Electron Energy-Loss Spectroscopy
Authors: Leapman RD , Andrews SB 
Published: July 2020

Abstract
Perhaps the ultimate aim of analytical electron microscopy in biology is to detect single atoms or ions bound to isolated macromolecular assemblies and small cellular organelles rapidly frozen in their native state. Although the meaningful spatial resolution in such analyses is limited to ∽10 nm or more by radiation damage, the high intrinsic sensitivity of electron energy-loss spectroscopy (EELS) coupled with recent developments seems to make this rather ambitious goal—originally proposed some twenty years ago—within reach. Here we describe examples where EELS has been able to detect surprisingly small numbers of atoms in biological specimens and discuss some fundamental limits that are encountered as well as some possible strategies for circumventing these difficulties.
In our laboratory we have used a scanning transmission electron microscope (STEM) equipped with a field-emission source and parallel-detection EELS because the probe size and collection efficiency of this instrument are optimized to give the lowest detectable number of atoms and lowest detectable atomic fraction.
X-Ray Microscopy Projects In Aarhus
Authors: Medenwaldt R , Abraham J , E.UggerhØj E , Vollrath F , SØgaard E 
Published: July 2020

Abstract
X-ray microscopy with soft X-rays is well suited for investigations of aqueous samples of some microns thickness when the resolution is required to be better than in visible light microscopy an not better than 30 nm. Sample preparation is as simple as for light microscopy, i.e. no fixation or metal coating is needed.
In Aarhus, an X-ray microscope is used for investigations in fields as biology, medicine and soil sciences. A ray diagram of the Aarhus X-ray microscope is shown in Fig.l. Synchrotron radiation at a wavelength of 2.4 nm from the Aarhus Storage Ring is focused by a condenser zone plate onto an object. Another zone plate as an objective behind the object forms the image on a CCD camera. Objects are located under atmospheric pressure. For dry samples, almost any kind of holder can be mounted in the microscope. Wet samples are placed between thin silicon foils in a sealed chamber. With typical liquid layer thickness of 5-15 µm, samples can be kept in the chamber for many hours without drying out.
What X-Ray Microanalysis Can Tell Us About The Regulation of Intracellular Calcium
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Andrews SB , Pivovarova NB , Pozzo-Miller LD , Leapman RD 
Published: July 2020

Abstract
Many cell functions, including such critical processes as secretion, neuronal communication, muscle contraction, and even gene expression, are regulated by spatial and temporal changes in the intracellular concentration of Ca2+ ions. The high spatial resolution and analytical sensitivity of energy dispersive x-ray (EDX) microanalysis are ideally suited to characterizing biologically relevant changes in total concentration of cellular Ca. However, EDX results have not yet had a wide impact in the field of Ca regulation, with most laboratories preferring to focus on optically measured changes in free Ca concentrations as the important determinant of biological activity. This paper advocates a more positive perspective for the role of EDX microanalysis in studies of Ca regulation.
It is well known that the large majority of cellular Ca is in the bound form, with typical bound/free ratios on the order of l03-104 5. However, the most dramatic changes during Ca2+ -dependent cell activation occur as transients in the free Ca2+ pool.
Elevated Cytoplasmic Sodium and Chloride Is Associated With Purinergic Receptor Stimulation of Rat Ventricular Myocytes: Implications For Myocardial Ischemia
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Bond Meredith , Zhang Bin-Xian , Desnoyer Russell W 
Published: July 2020

Abstract
During myocardial ischemia, several factors have been identified which contribute to the development of cardiac arrhythmias. These include membrane depolarization, increased cytosolic Na+ and decreased intracellular pH. This increase in intracellular Na+ has been shown to be associated with the development of ventricular arrhythmias. Changes in intracellular Cl- may also be involved in development of cardiac arrhythmias since decreasing extracellular Cl- concentration in the perfusion medium can prevent development of arrhythmias during myocardial ischemia in vitro. Extracellular ATP is known to increase in the heart during myocardial ischemia. ATP activation of p2 purinergic receptors on cardiac myocytes has been proposed to contribute to the initiation of the arrhythmias and ventricular fibrillations which characterize myocardial ischemia. Activation of p2 purinergic receptors results in membrane depolarization and decreased intracellular pH, thus reproducing some of the changes that occur during ischemia. We recently showed that activation of p2 purinergic receptors in both quiescent and electrically stimulated ventricular myocytes triggers spontaneous oscillatory contractions and Ca2+ transients.
Recording, Processing and Extracting Information From Sequences of Spatially Resolved Eels Spectra
Authors: Brun N , Colliex C , Suenaga K , Tencé M , Bonnet N 
Published: July 2020

Abstract
The sophisticated acquisition procedures now available in time or space resolved spectroscopies, also known as spectrum-imaging modes, produce large amounts of data which require specific developments for efficient processing and information extraction. For instance, in electron energy-loss spectroscopy (EELS), a line-spectrum consists of typically one hundred spectra recorded at regular intervals when scanning the subnanometer incident electron probe across the feature of interest: interfaces, multilayers or nanostructures of various shapes and dimensions. The useful information in any of these spectra depends on many factors such as the problem under investigation, the involved energy-loss range or the signal-to-noise ratio of the different features. However it is generally contained in the spectral changes, as well in energy channel as in position along the sequence.
To detect, measure and identify these variations, new methods have to be developed and the accompanying algorithms to be implemented. A first category encompasses all the routines which apply successively to all spectra in the sequence the well-known software which have been elaborated for processing individual spectra.
Energy-Filtered Imaging and Spectrum Imaging: Which One Should I Choose?
Authors: Crozier PA 
Published: July 2020

Abstract
There are now several commercially available methods for performing spatially resolved electron energy-loss spectroscopy in a transmission electron microscopy. In the energy-filtering electron microscope (EFEM), an Omega filter (Zeiss 912) or a post-column magnetic-prism filter (Gatan Imaging Filter) forms an electron image with electrons of a selected energy loss. A series of such images are acquired to provide spatially resolved information on sections of the energy-loss spectrum. These images can be processed to yield elemental maps from areas of interest in the material. In the spectrum imaging method (EMISPEC System), a small focused electron probe is rastered over the sample and a parallel energy-loss spectrum acquired from each point in the selected area. These spectra are then batch processed and information like elemental distributions extracted and displayed in the form of a map. Each of these two approaches has advantages and disadvantages and the appropriate choice is often dictated by factors such as time constraints, sample stability and the nature of the information of interest.
Electron Energy-Loss Spectrum Profiling of Polymer-Polymer Interfaces
Authors: Siangchaew K , Arayasantiparb D , Libera M 
Published: July 2020

Abstract
The spatially-resolved structure and composition of amorphous or semicrystalline polymer-polymer interfaces are poorly understood. The absence of atomic-level periodicity precludes many of the transmission electron-optical techniques that have been so fruitful in studying interfaces in polycrystalline inorganic materials. Similarly, there has been relatively little work done on spatially-resolved spectroscopic analysis of polymer-polymer interfaces to determine chemical widths, largely because of concerns over electron-beam damage. Digital microscope control and parallel spectral acquisition provide for low-dose exposure, quantification of dose, and efficient data collection which open new windows to study polymer interfaces.
This research is studying various multiphase polymer systems by focused-probe spectroscopic analysis to identify appropriate spectral features, data acquisition protocols, and background-modeling/data-processing algorithms in order to establish chemical widths characteristic of specific polymer-polymer interfaces (1). This research uses a 200keV Philips CM20 FEG TEM/STEM with a Gatan 666 PEELS spectrometer and an Emispec digital data acquisition/control system.
Eels Study of Valence State and Oxygen Vacancies In Magnetoresistive Oxides
Authors: Wang ZL , Yin JS 
Published: July 2020

Abstract
Colossal magnetoresistive (CMR) has been observed in a class of oxides, La1-xAxMnO3 (A = Ca, Sr, or Ba). Transition and rare earth metal elements with mixed valences are usually present in these materials for stimulating structural and chemical evolutions, leading to specific functionality. The partial substitution of trivalent La3+ by divalent element A2+ is balanced by the conversion of Mn valence states between Mn3+ and Mn4+ and the creation of oxygen vacancies as well, since the ionic structure of La1-xAxMnO3-y is proposed to be

in which the valence conversion is the key for determining the material's properties. In practice, quantifying of oxygen vacancies is a challenge to existing microscopy techniques particularly for thin film specimens because of the strong effect from the defects at the substrate-film interface and the surface disordering.
Intermediate Voltage Aem's: Have They Fulfilled Their Potentials?
Authors: Zaluzec Nestor J 
Published: July 2020

Abstract
For the last few years analytical developments in intermediate voltage AEM's have remained relatively quiescent. We have instead seen a number of improvements in the basic microscope mainly along the lines of microprocessor controls, automation, and of course improvements in image resolution and electron sources. Since the spectroscopic technologies (XEDS, EELS) have seemed to reach a mid-term plateau it is appropriate to consider whether or not we have achieved the expectations in these methodologies that we predicted nearly a decade ago.
In XEDS, there are three topics to consider: signal, sensitivity and quantification. In AEM's employing conventional electron sources we expected that as a function of accelerating voltage (E0) we should realize a continuous increase in intensity even though the ionization cross-section decreases with kV, and this has been realized (figure 1). It occurs simply due to the fact that the increase in probe current with E0 is more rapid than the more slowly decreasing ionization cross-section.
Rocking-Beam Spectrum Images and Alchemi of Ni50Al40Fe10
Authors: Anderson Ian M , Bentley Jim 
Published: July 2020

Abstract
A spectrum image can be acquired with a scanning transmission electron microscope (STEM) by translating a focused probe over a two-dimensional area of a specimen and acquiring a spectrum at an array of positions of the probe. Analogously, a rocking-beam spectrum image is formed when the incident electron beam is tilted relative to the specimen and a series of spectra is acquired from a single volume of the specimen. The orientation-dependence of such a series of spectra can be used to extract the atomic site-distributions of an ordered alloy or compound. One of the drawbacks of spectrum image acquisition is that the raw images are typically files of many megabytes, whereas the actual information of interest may be reducible to a fraction of this size. The dimension of the data set may be reduced by a number of methods. For example, Rossouw and coworkers have acquired rocking-beam X-ray maps for the characterization of atomic site-distributions in titanium aluminide intermetallic alloys.
Elemental Mapping at Grain Boundaries in Alloy X-750 by EFTEM
Authors: Bentley J , Evans N D , Kenik E A 
Published: July 2020

Abstract
Alloy X-750 is a γ -strengthened, nickel-base alloy used in demanding high-temperature applications. The HTH commercial heat treatment condition provides excellent strength and good corrosion resistance. However, the resultant precipitate structure is complex with fine (˜20 nm) intragranular γ' phase and copious intergranular precipitation of at least four phases (γ', M23C6, M23B6, and TiN). The intergranular precipitation causes localized grain boundary migration and results in a convoluted grain boundary structure. Such complex grain boundary microstructures increase the difficulty of phase identification and interfacial composition measurements by traditional analytical electron microscopy methods. Elemental mapping by EFTEM is a useful additional or alternative technique for characterizing such structures. A Gatan Imaging Filter (GIF) on a Philips CM30 (LaB6) was used in the current investigation. Experimental details have been summarized elsewhere.
Elemental maps of Cr, Ti, and Ni (net L23 intensities) are presented in Fig. la-c for a typical grain boundary region of a HTH heat treated specimen.
Practical Factors Affecting the Quantification of Elemental Concentrations in Beam-Sensitive Ceramics by EFTEM
Authors: Rice P M , Alexander K B 
Published: July 2020

Abstract
In order to obtain high spatial resolution microchemical data from beam-sensitive materials, alternative techniques which avoid the use of fine probes, such as energy-filtered imaging techniques must be used. Robust quantification procedures are currently under development. The quantification procedure which yields images whose intensities are proportional to the elemental concentrations (atoms per unit volume) has already been determined. The net core-loss intensity images, Si, can be corrected for diffraction contrast by normalization with low loss images, whereas thickness variations are corrected by normalization with t/λ, maps. This procedure has been shown to give the correct value for the concentration ratio between two phases for a single elemental map.1 Determining concentration ratios between two elements in the same phase can actually be simpler, in theory, than the above procedure since it only requires dividing the net core-loss intensity images of two elements and correcting for the difference in cross-section (Cx/Cy = [Sx/Sy][(σy/(σx])- However, there are a few practical factors that must be considered in practice.
Enhanced Esi-Detection of Metal Using the Core-Edges at Energy-Loss Below 100 Ev
Authors: Troester H , Haking A , Richter K , Probst W , Trendelenburg M F 
Published: July 2020

Abstract
ESI (electron spectroscopic imaging)-detection methods are mainly based on the core edges above 100 eV (see, as an example, Ref. 1). However, it would be of major interest to use the high intensity values in the low-loss region below 100 eV. There are at least two elements of general interest for biological applications showing core edges in this region: Au (O2,3 ) and Fe (M 2,3 )• Since colloidal gold and ferritin are used to label targets in biological samples at high spatial resolution we started our study aiming at iron-detection (iron-maximum at 62 eV comparable to gold-maximum at 65 eV).
Ferritin (Ref. 2) contains about 200 to 2000 iron atoms in a densely packed core representing an ideal prerequisite for ESI-detection. Furthermore, ferritin used to be a common marker in conventional transmission electron microscopy in the past. The contrast produced by ferritin in a conventional transmission electron microscope (CTEM) is not specific for iron but only for a dense region in the specimen.
Quantitative Convergent Beam Electron Diffraction (CBED) Measurements of Low-Order Structure Factors in Nickel
Authors: Saunders M , Fox A G , Midgley P A 
Published: July 2020

Abstract
The introduction of quantitative CBED techniques in recent years has led to experimental studies of charge densities in crystalline materials with unprecedented accuracy. Despite these successes, the development process is still on-going with the aim of gaining a better understanding of the techniques. With this in mind, we have undertaken a systematic study of the low-order structure factors of nickel using the ZAPMATCH zone-axis pattern matching technique of Bird and Saunders. In this approach, a set of low-order structure factors (both elastic and absorptive components) is adjusted until a best-fit is obtained between a many-beam simulation and an elastic filtered zone-axis pattern. Additional higher-order structure factors are included to converge the scattering potential but are kept fixed at neutral atom values during the fit. The questions we set out to address are (i) how to choose the correct number of structure factors to refine from a given data-set, (ii) are the absorptive structure factor components we refine of any use, and (iii) can we determine Debye-Waller factors at the same time as we measure the charge density? The first two points are discussed here.