bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological applications of near- IR fourier-transform Raman microspectroscopy
Authors: Ozaki Yukihiro 
Published: June 2020

Recently-developed near-infrared Fourier transform (FT)-Raman spectroscopy has received keen interest of researchers in bio-Raman field because near-infrared excitation can avoid mostly fluorescence and photodecomposition, which have been two major drawbacks of Raman spectroscopy in its biological and medical applications. Introduction of FT-Raman microspectroscopy makes near-infrared FT-Raman spectroscopy more useful for studying biomedical materials. The purpose of the present paper is to demonstrate the potential of near-infrared FT-Raman microspectroscopy in nondestructive structural analysis of biological systems. Photosynthetic bacteria is taken up here as an example.The FT-Raman spectra of the photosynthetic bacteria were measured with a JEOL JRS-FT6500N FT-Raman spectrometer equipped with an optical microscopy. Excitation wavelength at 1064-nm was provided by a CW Nd:YAG laser (CVI YAGMAX c-92), and the laser power at the sample position was typically 150 mW. All the data were collected at a spectral resolution of 8 cm-1 and spatial resolution of 8 μm.
Microstructure of superconductor bulk materials and thin films
Authors: Huong Pham V. 
Published: June 2020

The microstructure of single crystals of Y-Ba-Cu-O, Bi-Sr-Ca-Cu-O and Tl-Ba-Ca-Cu-O prepared by different methods were studied by various physical techniques, in particular by Raman microspectroscopy.Correlations have been established between Raman spectra and structure, allowing the determination of crystalline geometry of the material versus the composition and the preparation parameters.For YBa2Cu3Ox, a relationship: x = 0.025 VH - 5.57 is proposed and permits to evaluate the oxygen content by measuring simply in ZZ scattering geometry the Cu-O stretching mode V'H along the c axis of the crystal. This frequency varies from 465 cm-1 in YBa2Cu3O6 to 503 cm-l in YBa2Cu3O7 (Fig.l).This technique also offers the possibility to follow the structural conversion Y124 into Y123 and TI2212 into TI1212 (Fig.2) by appropriate thermal treatment. The preferentiel departure of the “CuO” or “TIO” chain/layer (Fig.3) is explained by weaker interaction forces between these layers and the adjacent ones, compared to those between the remaining layers. This helps to predict the localization of an eventual intercation in Y123 and TI1212.
Elemental changes in hepatocyte couplet cell cultures following treatment with vasopressin
Authors: Tsukada N. , Ackerley CA. , Phillips M.J. 
Published: June 2020

Hepatocyte couplet cell cultures have been used as a cell model to study the contractile nature of the bile canaliculus. It is generally accepted that a rise in cytoplasmic Ca activates the actomyosin ATPase resulting in the contraction of the pericanalicular actomyosin complex and the closure of the bile canaliculus. Vasopressin, a Ca mobilizing hormone, has been shown to increase the cytoplasmic Ca and induce bile canalicular contraction.In the present study rat hepatocyte couplet cultures were prepared as described by Oshio and Phillips. After 4 hours the volume of the culture media was decreased and the cells were liberated from the culture surface with a rubber policeman. Cells were then treated with vasopressin at a concentration of 10-9 M for time periods of 0, 30, 60,90, 120, 180, 240 and 300 seconds and drops of cell suspension were frozen by either slam freezing them on a liquid nitrogen cooled, highly polished copper anvil or plunge freezing them into liquid nitrogen cooled ethane.
Quantitative EELS mapping of biological thin sections
Authors: Wang Y.Y. , Shao Z. , Ho R. , Somlyo A.V. , Somlyo A.P. 
Published: June 2020

X-ray microanalysis and electron energy loss spectroscopy are reliable methods for determining at high spatial resolution the local composition of biological materials. EELS imaging, although potentially more sensitive than X-ray analysis, is complicated by the large background of EELS spectra. The conventional power law fitting of the EELS background can only be used for analysis of high concentrations and/or very thin sections (t< 0.3 λ) and it is not reliable for mapping low elemental concentrations. For the detection of low elemental concentrations at high spatial resolution, the background subtraction of the EELS spectrum and correction of long term microscope drift are critical, and limit the use of conventional energy filtered transmission electron microscopy. Therefore, we used energy filtered STEM with multiple least squares fitting, including the plural plasmon contribution to the background, to obtain quantitative phosphorus (P) and calcium (Ca) concentration maps of cryosections.The failure of the power law is due to the plural scattering contributions to the Background.
X-ray microanalysis of intracellular ions in epithelial tissues
Authors: Rick Roger 
Published: June 2020

Electron probe x-ray microanalysis provides a powerful tool in studying transepithelial ion transport mechanisms as it allows the quantitative detection of diffusible ions on a cellular and subcellular scale. The high spatial resolution afforded by this method is of particular advantage in epithelial tissues that are composed of different cell types and cases in which the transcellular transport pathway might involve different intracellular compartments. In the following, the methods applied in several studies are described, with emphasis on some recent modifications.The tissues are frozen by rapid immersion in liquified ethane kept at -180°C. Support systems for different epithelial preparations have been developed to facilitate freezing and maintain the functional state of the epithelium immediately up to the moment of freezing. A fluid-clamp technique is used to mount the tissue for sectioning (Figure 1). Sections are cut dry at -140°C and a nominal thickness of 200 nm using 40° glass knifes. The sections are picked up from the back of the knife by a fire-polished wire probe (1 μm tip diameter) and placed on a parlodion film which is suspended over a 2 mm opening in a special beryllium carrier disc.
An analytical and ultrastructural investigation of bone mineral in brittle bone disease (osteogenesis imperfecta).
Authors: Cassella J.P. , Catterall A.C. , Stamp T.C.B. , Yousuf Ali S. 
Published: June 2020

No single analytical technique will provide all the information necessary for the interpretation of a complex biological system. The mineralisation of bone is no exception, especially in a pathological situation. Brittle Bone disease, a genetically and biochemically heterogeneous group of disorders is characterised by the ease and frequency of bone fracture. Although Type I procollagen mutations have been detected, few reports exist of the mineral and its relationship with the altered collagen.X-Ray Microanalysis (XRMA), X-Ray Powder Diffraction (XRPD), Fourier Transform Infra Red spectroscopy (FTIR) and31p Nuclear Magnetic Resonance spectroscopy (31P NMR) were used to study the composition, structure and resonance of the calcium-phosphate (Ca-P) in bone. Specimens of bone were fixed in 2.5% gluteraldehyde solution (18 hours) at 40C. The specimens were cut into small pieces (1-3mm3) during the first hour of fixation, followed by secondary fixation in 1% osmium tetroxide. The tissue was dehydrated through a graded series of ethanols before vacuum infiltration and embedding in Spurr's resin for 18 hours at 600C.
Testing ZAF and related procedures
Authors: Heinrich Kurt F. J. 
Published: June 2020

Conventional ZAF procedures, Pouchou and Pichoir's PAP and XPP procedures (transcribed into a ZAF format), Scott and Love's procedure, and the f(ρz) procedures by Brown and by Packwood (all described in ref.) were tested by a modular program in Turbopascal which permits selecting separately the procedures for electron deceleration, backscattering (except the ϕ(ρz) procedures),absorption, fluorescence by characteristic and by continuous radiation. Parameters such as the absorption coefficient, the J factor, fluorescent yield and inner shell cross section can also be selected from the menu.The data used for the evaluation are from binary specimens. They were collected from publications by various authors, with addition of some unpublished data generated at NBS by R. Marinenko and H. Konuma. The following data types were excluded:
1.most data obtained with x-ray emergence angles below 30°.2.single values, not corroborated by measurements of other concentrations or under other experimental conditions.3.sets of measurements showing lack of internal consistency.
In-depth profiling with the electron-probe microanalyzer
Authors: Bastin G. F. , Dijkstra J. M. , Heijligers H. J. M. 
Published: June 2020

In a recent publication we have given a brief outline of the procedure we followed in extending our “PROZA” φ(ρ·z) bulk matrix correction program into a thin film analysis program. With such a program it is possible to determine film thicknesses and compositions of a number of films simultaneously using measured intensity ratios of all elements involved as input. As long as each particular element in the layered system is confined only to one specific layer or the substrate only one measurement for each element at one suitable accelerating voltage will be sufficient to find thicknesses and compositions in a double iterative procedure. If one or more elements occur in more than one film or also in the substrate then more measurements over a suitable range in accelerating voltages are necessary.The ultimate challenge in multi-layer analysis is, beyond any doubt, the determination of the concentration-distribution as a function of depth for all the elements in a particular matrix.
Monte Carlo Simulation of Background in electron spectroscopies
Authors: Shimizu Ryuichi , Yoshikawa Hideki 
Published: June 2020

Recent progress in getting precise knowledge on inelastic scattering, particularly, on dielectric functions for various types of material has been enabling the electron spectroscopic spectra obtained by Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and reflection electron energy loss spectroscopy (REELS) to be reproduced theoretically with considerable success. For this Monte Carlo simulation is probably most powerful tool, leading to more comprehensive understanding of not only the signal generation but also the background formation.In this paper we present a Monte Carlo simulation approach based on the uses of Mott-scattering cross section and appropriate dielectric function for describing elastic scattering and inelastic scatterings, respectively. With respect to the dielectric function one can use, to good approximation in general, the optical dielectric constants from the data base provided by synchrotron radiation facilities.As typical examples of the Monte Carlo simulation the applications to the AES, XPS, and REELS are shown in Figs. 1, 2, and 3, respectively. The N(E)-spectrum in Fig.l demonstrates how the Monte Carlo simulation describes the energy loss spectrum due to plasmon excitation near at primary energy, general shape of energy distributions of backscattered electrons and secondary electrons.
An application of photoemission microscopy to failure analysis of complex silicon integrated circuits
Authors: Golijanin Danilo 
Published: June 2020

Emission of visible light from forward and reverse biased silicon p-n junctions due to the radiative electron-hole recombination has been known since the mid-50s. The weak light emission was also seen from a silicon-dioxide dielectric in an integrated gate oxide capacitor formed between a polysilicon gate and an (n or p) well in an integrated circuit. The difference in carrier energies for each of these recombination mechanisms gives rise to a specific photon wavelength (energy) distribution in the visible range. All photoemitting events are characterized by a very low level light intensity due to the low quantum efficiency of about 10−5 - 10−4 photons per one electron-hole recombination.The first practical photoemission microscope was constructed by Khurana and Chiang. They took the advantage of the advances in night vision technology and used it for imaging the faint ("invisible") light coming from various silicon structures. A typical photoemission microscope consists of an x-y-z stage with the device holder, an optical microscope, a lightsensitive camera all set within a light-tight enclosure and a computer system for image acquisition and processing.
Measurement of silver diffusion in thick-film resistors by energy-dispersive x-ray techniques
Authors: Bonavita James C 
Published: June 2020

Material from some silver terminations used in metal-ceramic circuit applications can diffuse into the overprinted thick film resistor layers when the chips are repeatedly heated to a series of firing temperatures (∼850°C) during the fabrication process. Both materials have complex glass-based compositions and interdiffusion depends on the combination of materials, and conditions, involved. A discoloration is observed due to the migration of silver, in the form of the oxide, and the electrical properties of the resistor may be significantly modified. As might be expected, the deviation from ideal behavior, and therefore changes in resistor properties, are more serious for the smaller geometry resistors bridging narrow gaps between the silver conductor tracks.Direct SEM energy dispersive x-ray (EDX) analysis in plan view (Fig.1) of selected regions of complete chips - without any additional specimen preparation - has been used to determine the extent of the migration into the bridging region of the resistor. The measured lateral range of the silver cation migration is up to ∼500μm : this is much larger than the typical ∼10μm thickness of the resistor layer.
Microanalyses of antarctica micrometeorites
Authors: Maurette M. , Perreau M. 
Published: June 2020

About 260 tonnes of ultraclean blue ice were recently melted and filtered on the Antarctic ice sheet (in January 1991, at Cap-Prudhomme, near the french station of Dumont d'Urville) as to collect all grains with sizes > 25 μm. In the best size fraction (50-100μm) about 10% of the grains are unmelted antarctic micrometeorites (AMMs) with a chondritic composition. About 50% of these grains are complex aggregates of submicron-sized grains. Their characterization, which is very difficult, requires a panoply of analytical techniques allowing their analyses at all scales of magnification between 106 μm3 and 10-4 μm3. We review below analyses performed by various groups, and discuss briefly some of their preliminary implications to various fields of Science.The "large" size of the AMMs allows their multidisciplinary investigations. With a binocular we start selecting an aliquot of ≈50 dark grains showing irregular shapes, and which usually contains about 70% AMMs. Each grain is broken into about 4 fragments and their multidisciplinary analysis proceeds as follow: (1) Polished sections. The largest of these fragments are mounted in an epoxy disc and polished.
An x-ray microprobe based upon a close-coupled focal-spot / glass capillary arrangement
Authors: Carpenter D. A. , Taylor M. A. 
Published: June 2020

The development of intense sources of x rays has led to renewed interest in the use of microbeams of x rays in x-ray fluorescence analysis. Sparks pointed out that the use of x rays as a probe offered the advantages of high sensitivity, low detection limits, low beam damage, and large penetration depths with minimal specimen preparation or perturbation. In addition, the option of air operation provided special advantages for examination of hydrated systems or for nondestructive microanalysis of large specimens.The disadvantages of synchrotron sources prompted the development of laboratory-based instrumentation with various schemes to maximize the beam flux while maintaining small point-to-point resolution. Nichols and Ryon developed a microprobe using a rotating anode source and a modified microdiffractometer. Cross and Wherry showed that by close-coupling the x-ray source, specimen, and detector, good intensities could be obtained for beam sizes between 30 and 100μm. More importantly, both groups combined specimen scanning with modern imaging techniques for rapid element mapping.
Analysis of individual microscopic particles by means of synchrotron radiation induced x-ray micro fluorescence
Authors: Janssens K. , Adams F. , Rivers M.L. , Jones K.W. 
Published: June 2020

Micro-SXRF (Synchrotron X-ray Fluorescence) or micro-SRIXE (Synchrotron Radiation Induced X-ray Emission) is a microanalytical technique which combines the sensitivity of more conventional microchemical methods such as Secondary Ion Microscopy (SIMS) and μ-PIXE (Proton Induced X-ray Emission) with the non-destructive and quantitative character of X-ray fluorescence analysis. The detection limits attainable at current SXRF-facilities are situated in the ppm (and in favourable cases the sub-ppm) range. The sensitivity of SRIXE can be used advantageously in individual particle analysis. This type of analysis is used, e.g., for studying sources of athmospheric pollution. Analysis of standard NIST micro-spheres at the NSLS-SRIXE facility yielded minimum detection limits in the 1 to 100 ppm range for particle sizes of around 10 to 30 μm.An interesting approach to individual particle characterisation is by means of electron microprobe analysis (EPMA). By using the backscattered electron signals, in an automated fashion, particles can be easily located on a filter substrate and their size and shape determined.
Multitechnique problem solving using EDS/EPMA and surface analysis
Authors: Simko Steven J. , Waldo Richard A. 
Published: June 2020

Thin films are used in a wide range of modern technologies. Examples include sensors, antiwear coatings, optical coatings, and integrated circuits. A variety of methods have evolved for characterizing thin films in the thickness range of 1 monolayer to several micrometers. Electron probe microanalysis (EPMA) or energy dispersive x-ray spectroscopy (EDS) are two methods for characterizing thicker films (>1 μm). In these techniques, the sampling depth depends on the penetration depth of the primary electron beam which can be controlled by changing the electron beam energy. Thin films can also be characterized using line scans on specimens prepared as polished cross-sections or after angle lapping. For extremely thin films (<3 nm), techniques with high surface sensitivity such as Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS) are commonly employed. Sampling depth depends on the attenuation length of the emitted photoelectrons or Auger electrons.Electron spectroscopy techniques are also used to characterize thicker films by adding a microsectioning method to the experiment, most commonly ion sputtering.
Inner-Shell Ionization Cross Sections
Authors: Powell C. J. 
Published: June 2020

Values of cross sections for ionization of inner-shell electrons by electron impact are required for electron probe microanalysis, Auger-electron spectroscopy, and electron energy-loss spectroscopy. The present author has reviewed measurements and calculations of inner-shell ionization cross sections. This paper is an update and summary of these previous reviews.It is convenient to start with the Bethe equation for inner-shell ionization cross sections which is frequently used (and misused) in x-ray microanalysis:(1)where σnℓ is the cross section for ionization of the nℓ shell with binding energy Enℓ by incident electrons of energy E. The terms bnℓ and cnℓ are the Bethe parameters discussed further below. It has been assumed in the derivation of Eq. (1) that E ≫ Enℓ ; this requirement will also be discussed. Finally, it has been assumed here that E is low enough (≲50 keV) so that a relativistic correction is unnecessary.The extent to which a given set of measured or calculated cross-section data is consistent with Eq. (1) can be determined from a Fano plot in which σnℓE is plotted versus ℓnE; if such a plot is linear, Eq. (1) is consistent with the data and values of the Bethe parameters can be easily derived.
Electron Energy-Loss Near-Edge Structures as a Probe of Solids
Authors: Engel W. , Sauer H. 
Published: June 2020

In general, core-level spectra show a very pronounced structure beyond the edge up to about 20 eV. This is called the near-edge structure, and in the case of electron energy-loss spectra its acronym is ELNES. ELNES is due to transitions of electrons from a particular core level to the lowest unoccupied states in the solid. This provides information about the local electronic structure of the solid at the site of the excited atom, and may depend very sensitively on the arrangement of the neighbouring atoms.This effect is demonstrated in a series of Ti 2p core-level spectra shown in Figs. 1 and 3 which have been obtained from various tetravalent titanium compounds. In all these compounds the Ti4+ ions are surrounded by 6 oxygen atoms but they form perfect octahedra only in the case of SrTi O3. In the other compounds the oxygen octahedra are more or less distorted, giving rise to a splitting or broadening of peaks.
An Application of 200kV Ultrahigh Resolution Analytical Electron Microscope
Authors: Suzuki M. , Kaneyama T. , Watanabe E. , Naruse M. , Kokubo Y. 
Published: June 2020

A 200 kV ultrahigh resolution analytical electron microscope (UHRAEM), JEM-2010, enables both ultrahigh resolution imaging with a theoretical point resolution of 0.194 nm and nm-area analysis. In this paper, its preliminary data for x-ray analysis (Energy Dispersive X ray Spectroscopy: EDS) and its application data will be shown.An objective lens polepiece has been designed to minimize the spherical aberration coefficient (Cs) of the prefield and thereby increase the probe current in small probe size for nm-area EDS analysis. Measured values of Cs and chromatic aberration coefficient (Cc) are 0.5 mm and 1.0 mm, respectively. Fig. 1 shows a theoretical relation between the illumination angle and probe size of this objective lens on the assumption that the brightness of electrons is 6×106A/cm2• str in a LaB6cathode. This calculation shows that an electron probe smaller than 1 nm in diameter is available even with a probe current of 10 pA.
Post-Spectrometer Instrumentation for STEM
Authors: McMullan D. , Rodenburg J.M. , Pike W.T. 
Published: June 2020

A charge-coupled device (CCD) is being used for parallel recording on the EELS spectrometer of the V-G HB501 STEM in the Cavendish. Three quadrupole lenses are provided for focussing the EELS spectrum and, unlike in some other similar systems, the spectrometer slit has been retained. This was done so that the spectrometer could still be used for serial acquisition of EELS spectra and for energy-filtered imaging, although it would be preferable, and was envisaged as a later development, to have the first quadrupole positioned before the dispersion plane of the spectrometer; the slit would have been simulated by a suitably masked scintillator for the bright field detector.However it has proved advantageous to keep the slit so that microdiffraction patterns can be imaged through the spectrometer. The recording of high quality diffraction patterns in the HB501 STEM has not been straightforward: Grigson recording is far too slow, and although the standard microscope is provided with a phosphor screen and TV and film cameras, the speed and resolution are rather poor.