bluuebunny/crossref_metadata_2025_split huggingface dataset:
Up-Conversion and Two-Photon Excitation Fluorescence Properties of Phloxine B.
Authors: Malak Henryk 
Published: July 2020

Abstract
A dye, Phloxine B, a common food coloring and one of the active components of a photoreactive insecticide was recently approved by Food and Drug Administration as D&C Red #28 for use in drugs and cosmetics. Phloxine B is also one of the most widely use stain in fluorescence microscopy. However, in spite of the widespread interest in multi-photon spectroscopy and imaging, no information is available on the electronic transitions properties of Phloxine B with red edge fluorescence excitation and with multi-photon excitation.
In the present report we described the steady state and time-resolved fluorescent properties of Phloxine B with up-convert photon excitation and with two-photon excitation. We examined the electronic transitions properties of Phloxine B when was excited by femtosecond pulses from a mode-locked titanium sapphire laser or a mode-locked optical parametric oscillator laser. Phloxine B under excitation wavelengths above 775 nm was found to display two-photon excitation fluorescence with a spectrum maximum at 580 nm, which emission is consistent with one-photon excitation fluorescence spectrum. At the red edge excitation of Phloxine B, from 590 nm to 650 nm, we observed one-photon excitation fluorescence indicating that Phloxine B behaves like upconverting dye with one-photon excitation process.
Pattern Analysis Meets Cell Biology
Authors: Murphy Robert F , Boland Michael V 
Published: July 2020

Abstract
The widespread availability of automated fluorescence microscope systems has led to an explosion in the acquisition of digital images by biologists. This has created a need for computer applications that automate the analysis of these images and an opportunity to develop new approaches to classical problems. An example is the determination of the subcellular location of a protein from immunofluorescence images (or, more recently, images of GFP fluorescence). Current practice is to compare such images to mental images that a cell biologist has developed over time, and to reach a tentative conclusion about the structure (i.e., organelle) that a protein is found in. Since this determination is subjective, it often must be followed up by double labeling with a marker protein from the suspected structure.
As an initial exploration of the feasibility of automating the determination of subcellular location, we developed a system that is able to classify the localization patterns characteristic of five cellular molecules (proteins and DNA) in Chinese Hamster Ovary (CHO) cells. Images were acquired on an epifluorescence microscope after the cells had been fixed, permeabilized, and labeled with appropriate fluorescent reagents (usually antibodies conjugated to fluorescent dyes). The labels used were directed against a Golgi protein, a lysosomal protein, a nuclear protein, a cytoskeletal protein, and DNA.
Three Dimensional Light Microscopy: Imaging & Corrections for Quantitative Analysis
Authors: Turner JN , hain W , Szarowski DH , Lasek S , Kam L , Can A , Al-Kofahi K , Roysam B 
Published: July 2020

Abstract
There are several forms of three-dimensional (3-D) light microscopy but all utilize the principle of optical section recording, i.e. the 3-D image is a sequence of two-dimensional (2-D) images called optical sections. The optical sections are particular focal planes formed within the thick specimen and usually correspond to the conventional image projections recorded in a light microscope, referred to as x,y projections. The optical sections are recorded for a sequence of focus- or z-positions. This “stack” of 2-D images is the data set for the 3-D image. If quantitative analysis is to be performed on the 3-D images, the choice of the z-dimension increment between 2-D images is especially important, and its value may be more or less critical depending on the analysis algorithm used. A reasonable starting value for this dimension is the depth-of-field of the objective lens, but the actual value may have to be smaller to optimize the image analysis or larger to decrease the influence of photobleaching. The most photostable dyes should be selected and the specimen should be mounted in index-of-refraction matching media with an antioxidant.
The image resolution in all three-dimensions is determined by the 3-D point-spread-function (psf), and as a rough rule of thumb the z-resolution is degraded by a factor of 3 relative to the x,y resolution. To achieve or at least approach isotropic resolution the 3-D image can be deconvolved. Figure 1 shows the 2-D maximum value projection of a 3-D image of a cultured glial cell dual labeled for actin and vinculin before and after deconvolution. The actin fibers and vinculin focal contacts are more clearly resolved after deconvolution. Although a single cultured cell might traditionally be considered a thin object, it is really a thick object if the desired spatial resolution is less than the thickness of the cell. It is desirable to image as deep into a thick object as possible to maximize the tissue volume sampled. However, it has been shown that the image signal decreases with depth into the specimen. Figure 2 demonstrates this effect in a 3-D image of the nuclei of the rat hippocampus that have been labeled with the fluorescent Schiffs reagent acriflavine. In the x,y projection, it is not clear why some nuclei are dimmer than others, but the x,z projection shows that the dimmer ones tend to be deeper in the section. It has been shown that this depth dependent signal attenuation follows the form of an exponential function.
Electron Beam Induced Phase Transformations from Metakaolinite to Mullite
Authors: Kim Y J , Lee S 
Published: July 2020

Abstract
The kaolinite-mullite reaction series by heating has been controversial since the proposal of a new transformation mechanism. Recently energy-filtered electron diffraction data obtained from the specimen furnace-heated at 920 °C indicated that the spinel-type phase coexisted topotactically with metakaolinite. On the other hand, mullite first appeared from the specimen furnace-heated at 940 °C without showing any crystallographic relationship to the parent metakaolinite.
Direct beam heating experiments of the 920 °C-heated specimens using an energy-filtering TEM supported the previous results and ideas. Fig. 1 displays topotactic coexistence of metakaolinite and the spinel-type phase (spots in hexagonal arrangement) before beam heating. Electron beam heating gave rise to a noticeable change in the diffraction pattern, that is, the formation of mullite rings and enhancement of the diffuse intensity around the direct beam shown in Fig. 2. Comparison of EDS data for the specimen before beam heating and after beam heating (Fig. 3) indicates considerable increase of Si and O peaks by beam heating.
Study of Olivine Morphology, Spinifex-Textured Komatiite, by Atomic Force Microscopy
Authors: Coutol Lucia F , Vallet Catherine E 
Published: July 2020

Abstract
Atomic Force Microscopy (AFM) imaging of a komatiite specimen from the Morro do Ferro Greenstone Belt, M.G, Brazil, has revealed thin (0.2 - 2.0 micron in width), randomly oriented olivine crystals (fig. 1a,b), of prismatic shape. The length of such crystals is highly variable, ranging from less than 1 μm to more than 10 μm. The randomly oriented crystals typically occur in three or more distinct directions, indicating that the spinifex texture is reproduced at the micron-scale.
In addition, typical skeletal crystals were observed (figure 1c,d) with width of the order of one micron. Figure 1d is the sketch representation of the skeletal crystal shown on figure 1c Figures 1c,d also show that skeletal crystals sometimes branch out thinner crystals, indicating that nucleation also occurs at the surface of previously crystallized minerals, besides generating isolated new crystal seeds.
It is worth noting that the olivine crystals are characterized as low topographic regions on the AFM images. What distinguishes them from polishing scratches is the fact that scratches typically do not mimic crystal shapes, especially skeletal, or fabrics which are readily seen on different scales, i.e., petrographic sections or hand-specimens.
The Hunt for Red Corrosion: A Study of Microbial Rock Corrosion in Caves
Authors: Spilde MN , Northup D E , Boston PJ 
Published: July 2020

Abstract
A number of cave systems host colorful deposits of what has been termed “corrosion residue” (CR), material that appears to be the breakdown product of bedrock minerals. The CR may be red, pink, orange, ocher, brown gray, or black and usually occurs in a variety of places within caves (ceilings, walls, tops and sides of boulders, etc.). Geologists have hypothesized that CR is the long-term result of upwelling corrosive air. However, discovery of evidence of microbial activity has led to a complimentary explanation that microbes could be active participants in the production of the corrosion residue. These deposits have been cursorily examined in several caves, including Jewel Cave (SD), Lechuguilla and Spider Caves (NM), and Cueva de Villa Luz (Tabasco, Mexico) using microscopy techniques of SEM and TEM, along with EDS and WDS analysis.
In all cases, the CR is a complex mixture of iron and/or manganese oxides, clays, quartz, and corroded bedrock material. In several cases, rare earth element (REE) phosphate minerals and other unusual minerals have been observed. The REE minerals are believed to result from recrystallization of apatite present in the bedrock; rare earth elements are commonly present in trace amounts within the apatite minerals. X-ray diffraction and bulk chemical analysis has shown that Fe3+ makes up the bulk if not all of the Fe-oxides in the CR while microprobe analysis of thin sections of the bedrock has found Fe2+ in dolomite as high as 700 ppm.
Within much of examined material, evidence of microbial life is present in the form of structures shaped like coccoid or filamentous bacteria. There is often a close association of presumptive bacteria with small dissolution pits in corroded fragments of bedrock minerals in the CR (Figure 1). In addition to the putative bacteria, the mineral residue often hosts small star-shaped minerals containing Fe-oxide (Figure 2).
Electron Microprobe Dating of Uraninite from the Mcallister Pegmatite, Alabama
Authors: Bersch Michael G 
Published: July 2020

Abstract
In the early days of geochronology, attempts were made to date U-Th bearing rocks and minerals using the Pb-U-Th chemical method, but fundamental assumptions that all the lead was of radiogenic origin, and the system was closed, often were invalid. With the advent of the U-Th-Pb isotopic and common-lead methods of dating rocks and minerals, the chemical method was deemed clinically dead. However, several workers, for example, Montel et al., Suzuki and Adachi, have recently demonstrated new life for the chemical method. Using, the same theoretical basis as the chemical method, geologically reasonable dates often can be obtained by electron microprobe analysis of U-Th rich monazite (Ca-REE-U-Th phosphate). Other U- or Thrich minerals sometimes can be used to obtain microprobe U-Th-Pb dates, e.g., zircon, xenotime, uraninite.
Microprobe U-Th-Pb dates of uraninites from the McAllister Ta-Sn pegmatite, Coosa County, Alabama, are reported here. The McAllister pegmatite is a NW-SE dike-like body in the western part of the Rockford granite pluton. Polished grain mounts were made from screened table runs of heavy mineral separates. Wodginite (Mn, Sn, Nb, Ta-oxide), tantalite-columbite, zircon, cassiterite comprise most of the grains in the samples. Uraninite occurs as inclusions, generally &lt;0.01 mm, in these grains (Figure 1).
U, Th, Pb concentrations were measured using a JEOL 8600 Superprobe. Operating conditions were 100 nA, 20 kV, and count times up to 200 seconds for peak plus background. The U Mβ, Th Mα, and Pb Mα peaks were measured. Standards were UO2, ThO2, and PbS.
The Golden Age of Microanalysis.
Authors: Heinrich Kurt F J 
Published: July 2020

Abstract
The main initial source of information in the USA concerning the electron probe was a meeting at the Naval Research Laboratories in February 1958, followed in 1960 by a summer school at MIT organized by Prof. Norton and R. Ogilvie. Further visits to the USA and publications in English by the inventor of the instrument, R. Castaing, also contributed to the attention given here to the new technique. Since numerous research laboratories in the USA were keenly interested in the new device, the development of instruments and the contributions to its use were considerable. The relatively small number of active researchers in the field rendered personal connections and cooperation possible and attractive.
Before the availability of American-made commercial microprobes, many investigators built their own instruments. Most of them were not trained as instrument builders, and the usefulness of the resulting devices was somewhat limited. These improvisations in instrument construction ceased once commercial microprobe manufacturers entered the field. Yet, in the process, much was learned and the American investigators contributed significantly to the theory of microanalysis. We realized that, with the limited calculation facilities then available, the complex interactions leading to the x-ray signal had to be treated in simplified ways, and we described ‘approximations’ rather than ‘laws’ in our efforts to understand and quantitatively describe the physical facts. We also came to realize that even where the physical processes were well known, we often lacked the knowledge of the physical parameters required for quantitation and the effect of their uncertainties on the accuracy of the analytical results. Another area in which advances were needed, and soon achieved, was the application of the technique to a wide range of technical and scientific problems. The interaction between manufacturers and users greatly stimulated improvements in the instrument design.
Crystal Spectrometers and Monochromators in Microanalysis
Authors: Wittry D B 
Published: July 2020

Abstract
An x-ray spectrometer is actually a scanning monochromator because two conditions must be satisfied, namely: (1) nλ, = 2d sinθ and (2) θI{= θR to within the rocking curve of the crystal 2Δθ. Before Castaing (B.C.) there were four known types of focussing monochromators, namely: Johann, Johansson, Cauchois, and von Hamos. Castaing was fortunate in having Andre Guinier (well known for his work in x-ray crystallography) as his thesis advisor. Thus, he wisely chose to use a spectrometer of the Johansson type. Had he used a flat crystal spectrometer, the result would have been unsatisfactory and the history of microanalysis would have been significantly different. Many of the spectrometers that were used in the early instruments were either of the Johansson type, in which the crystal planes are curved to a radius of 2R and the surface has a radius of R, the focal circle radius. This is sometimes called exact focussing because rays in the plane of the focal circle converge exactly to a point focus. For simpler construction, the Johann crystal which has the surface parallel to the atomic planes (also curved to a radius of 2R) was sometimes used. While both types provide one-dimensional focussing, the Johansson type is preferred because the effective width of the crystal can be greater.
In addition to the type of geometry used, early instruments developed after Castaing (A.C) also had variations in the mechanism of the crystal movement. Many used a relatively simple mechanism with the crystal and detector moving about a fixed center for the focal circle as shown in Fig. 1A. Some later instruments used curved crystals that were fixed in position, and scanning was accomplished either by rotating the crystal as in Fig. 1B or by a mechanism that flexed the crystal and changed the radius of the focal circle as in Fig. 1C. The most satisfactory arrangement and the one subsequently adopted by most manufacturers of commercial microprobes utilized a linear motion of the crystal carriage with a provision for tilting the crystal so that the focal circle always passed though the x-ray source as shown in Fig. 1D. If the detector moves so that it remains on this focal circle, its motion is along a leaf-shaped curve. With this design it is easy to have a readout proportional to wave length.
Fundamental Constants for Quantitative X-Ray Microanalysis
Authors: C Joy David 
Published: July 2020

Abstract
The development of quantitative X-ray microanalysis in the 1950s spurred the need for knowledge of the many parameters which describe the electron interaction, such as the ionization cross-sections, fluorescent yields, the electron stopping power, mass absorption coefficients, and others. Although classical microanalysis, which proceeds by measurements of the unknown specimen against a standard, can eliminate the need to know many of these parameters accurately, much current microanalysis is done on highly inhomogeneous samples for which comparison with a standard is much less useful procedure. The increased use of low beam energies also means that data is now required for L-, and M-lines which previously have been little used. Consequently there is an enhanced need for a reliable and agreed set of data on which to base calculations.
A common misconception is the belief that all of the quantities that are needed must already have been measured by somebody and so it is simply a matter of accessing this data.
Antimony Delta Doping by Scanning Transmission Electron Microscopy and Electron Energy Loss Spectroscopy
Authors: Vanfleet RR , Muller D , Gossmann H-J , Silcox J 
Published: July 2020

Abstract
MBE techniques allow the fabrication of exceptionally sharp compositional changes such as delta doped layers in semiconductors. Producing these spatially confined doped layers is critical to many innovative device designs. The spatial confinement of these delta doped structures can be less than the measurement resolution of the currently standard SIMS and RBS techniques. This allows only the upper limits on the layer width to be measured. These SIMS and RBS methods are also inadequate for the two dimensional information desired for future device design and development. More recently developed techniques such as Scanning Capacitance Microscopy and spreading resistance measurement give two dimensional information but have similar spatial resolution issues. The Z-contrast nature of Annular Dark Field (ADF) imaging with the complimentary technique of Electron Energy Loss Spectroscopy (EELS) in the Scanning Transmission Electron Microscope (STEM) shows promise for two dimensional dopant profiling with spatial resolution on the atomic scale.
Comparison of STEM EELS Spectrum Imaging vs EFTEM Spectrum Imaging
Authors: Hunt JA , Kothleitner G , Harmon R 
Published: July 2020

Abstract
Electron energy-loss spectroscopy (EELS) in the transmission electron microscope (TEM) analyzes the energy distribution of the probe electrons after they have lost energy within the sample. The resultant energy-losses are characteristic of elemental, chemical, and dielectric properties and are typically measured in one of two ways. Parallel-detection EELS spectrometers (PEELS) acquire large energy ranges of the energy-loss spectrum simultaneously for rapid acquisition of spectral data at a single area. In contrast, the energy filtering TEM (EFTEM) acquires only a single energy band at once, but does so for thousands or even millions of image pixels simultaneously.
Spectrum imaging (SI) involves acquisition of detailed spectroscopic data sufficient for rigorous analysis at each pixel in a digital image. (Fig. la) A STEM EELS spectrum image “data cube” can be acquired by stepping a focused electron probe to each pixel and filling the spectrum image one spectrum at a time.
Image-Spectroscopy: New Developments and Applications
Authors: Thomas PJ , Midgley PA 
Published: July 2020

Abstract
The ability of modern TEMs to acquire a series of energy filtered images opens up new possibilities in energy loss compositional analysis. In particular, an electron spectroscopic imaging (ESI) series may be treated as a 2-D array of spectra whose resolution is dictated by the step size of the image series, as illustrated in Fig (a). This allows standard spectroscopic analysis techniques to be used on the extracted ‘image-spectra’, such as the removal of plural scattering by deconvolution. Examples of this are given in Fig (b) and (c), which show how Fourier-log and Fourier-ratio deconvolution can be used to recover the single scattering distribution (SSD) from both the low-loss and core-loss regions from a Cr specimen. A pure elemental sample is ideal for testing the validity of such analysis techniques for quantitative compositional mapping, and more details of this method will be published elsewhere. Further, for many simple metal systems, such as steels and alloys, and for simple semiconductors it is possible to model the plasmon contribution using a simple Drude-Lorentz model.
Compositional Phase Mapping using True Colour X-Ray Imaging
Authors: J. Statham Peter 
Published: July 2020

Abstract
In conventional x-ray mapping, energy regions are defined to straddle the N x-ray spectral peaks of interest. At each pixel position in the digital image, counts are recorded from each energy region and thus give rise to N element maps of intensity distributions over the field of view. Fig. 1 shows an example set of x-ray maps from a polished test sample. It is clear from the images that there are circular regions of differing composition but it is not immediately obvious which regions have the same composition. Furthermore, in a real sample, phases are unlikely to appear in such regular patterns so the correlations between maps are in general much more difficult to notice.
It is possible to choose two x-ray maps and generate a 2D scatter plot showing the intensity values in both maps for all pixels in the image.
Energy Filtering Transmission Electron Microscopy of Polymers and Hybrid Materials
Authors: Du Chesne Alexander , Ulrich Ralph , Wiesner Ulrich 
Published: July 2020

Abstract
A topic of growing importance is the nano-structuring of inorganic materials by exploiting interactions with self assembling polymers. One example are multiphase polymers.
Driven by the mixing enthalpy, most polymers phase separate below their critical solution temperature. The components of block copolymers are covalently linked, restricting separation to microscopic length scales. Depending on composition, block copolymers form different equilibrium morphologies representing the energetically most favorable balance between- interfacial area and chain conformation.
Mass thickness contrast of polymers is often weak and conventional TEM can thus fail to characterize the morphology unless selective staining methods exist. This is the case for the poly(isoprene)-b-poly(ethyleneoxide) diblock copolymer system (PI-b-PEO) used as a structure directing agent and to provide solubility (see below). Fig. 1 shows the micro-domain morphology of PI-b-PEO where the rubbery phase is selectively stained with OsO4.
Hybrid materials are obtained by addition of an inorganic precursor to a solution of PI-b-PEO in a "mutual" solvent.