bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of the Inverse Monte Carlo Method to Energy-Dispersive X-Ray Fluorescence
Authors: Yacout A.M. , Dunn W.L. 
Published: March 2019

AbstractThe feasibility of utilizing the Inverse Monte Carlo (IMC) method to determine elemental amounts in homogeneous samples from energy-dispersive X-ray fluorescence (EDXRF) measurements has been investigated. IMC is a novel application of standard Monte Carlo that, in principle, allows a rather large class of inverse problems to be solved noniteratively, in the sense that the simulation is not repeated. IMC is implemented by hypothesizing values for the unknown parameters, executing a direct Monte Carlo simulation using these values and scoring the results with factors that contain the unknown parameters. By equating the resulting Monte Carlo estimators to the known measured responses, a system of algebraic equations is formed that may be soluble by standard numerical techniques. Advantages of IMC include the facts that it can be applied to complex (e.g., multidimensional) problems and that it is relatively efficient since the simulation is performed only once. In the EDXRF case, simplified assumptions have been used to construct an approximate IMC solution. The model provides a means to determine the elemental amounts in an unknown sample by treating the unknown composition as a perturbation around the composition of a fixed "reference" sample that contains the same elements as the unknown sample. Primary and secondary X-rays are included in the model. The resulting system of algebraic equations is nonlinear and solutions are obtained via an approximation. Since the model is based on correlated sampling techniques, several unknown samples can be modeled simultaneously provided that they contain the same elements and their compositions are sufficiently close to that of the assumed reference sample. Direct Monte Carlo was used to generate the relative intensities for eighteen different samples in a ternary (Ni-Fe-Cr) system; these results were then used in the IMC model to recover the sample weight fractions. Excellent results were obtained, demonstrating the feasibility of the approach.
The Use of Layered Synthetic Microstructures for Quantitative Analysis of Elements: Boron to Magnesium
Authors: Nicolosi Joseph A. , Groven John P. , Merlo Daryn 
Published: March 2019

Layered Synthetic Microstructures (LSMs) were first reported as commercially available diffracting structures for routine x-ray spectrochemical analysis in 1984 (Nicolosi et al.). Innitially, these devices (PX-1 and PX-2) were intended for use as alternatives for Thallium Acid Phthlate (TAP) and Lead Octadeconate (LOD) for improved stability and diffracted intensity. Improvements in the analytical performance of X-Ray Spectrometers for the elements carbon to magnesium has met, and in some cases exceeded, innitial expectations. Having captured the interest of many new possible applications, developments for LSMs with larger 2d-spacing and greater reflectivity have continued.Previous instruments employing LSMs have had difficulty in measuring X-Ray energies below the carbon K-series characteristic. Below the carbon K-edge energy, several significant phenomenon combine to reduce sensitivity. Among these are: 1) Reduced reflectivity of conventional LSMs, 2) Increased absorption at the polypropylene window of the detector, and 3) Greater electronic noise.
Application of EDXRF Analysis to Continuous Industrial Process Monitoring
Authors: Weakliem J. H. , Kalnicky D. J. 
Published: March 2019

Many manufacturing processes in the chemical industry require frequent monitoring of the composition of the product. Ideally, an analysis of this type should be simple to carry out, rapid, reliable, and not require a seperate analytical laboratory. Energy Dispersive X-Ray Fluorescence (EDXRF), due to its relative simplicity of instrumentation, speed of analysis, and non-destructive nature, is well suited to on-line applications, when used in conjunction with a flow cell.A question that is frequently raised in this type of analysis is: How do the precision and accuracy of these measurements compare with measurements made upon the same solution in sample cups (static). The purpose of this study was to compare the precision and accuracy of on-line with static analyses of the same types of solutions.
Automated Quantitative XRF Analysis of Soda-Lime Glass Utilizing Pattern Recognition
Authors: Klimasara A. J. , Barry T. L. 
Published: March 2019

AbstractA set of programs in Fortran 77 has been written to automate quantitative analysis on the Rigaku SMAX/PDP-11/73 XRF System. The spectrometer can be instructed and Trained to recognize spectral patterns of soda-lime glass or other materials.The method of pattern recognition employed is based on the relative position of spectra-vectors in N-Dimension Euclidean feature space. The distance between 2 vector-points: is used as a classifier.The software correlates between 2 Euclidean feature spaces:- Spectra Feature-Space- Chemistry Feature-SpaceQuantitative results are extracted automatically and printed in laboratory report form. Mathematical modeling with associated software and the results obtained are presented.
Thermal Expansion Behavior of Pure and Doped Cordierite by Time-of-Flight Neutron Diffraction
Authors: Haas J. , Predecki Paul , Faber J. , Hitterman R. L. 
Published: March 2019

AbstarctIn order to reveal the mechanism of the negative c-axis expansion in cordierite (4 MgO 4 Al2O3 10 SiO2), the thermal expansion of cordierite containing small amounts of Cs, Li, B, Ge, Sc and Ni-cations was investigated by time-of-flight neutron diffraction at temperatures between 22 and 750°C. The samples were prepared by melting the constituent oxides followed by quenching and devitrification to obtain the hexagonal form (Indialite). Using the neutron powder diffraction data, the atom positions in the space group P6/mcc were refined by Rietveld least squares analyses.The expansion behavior of the cordierite structure could be explained in terms of the various kinds of constraints and the interatomic bond strengths of the structure. It was found that cordierite doped with Cs-cations shows the largest volume expansion, followed by the Li-doped sample. So-doped cordierite has the lowest volume expansion. All cordierite samples show positive expansion along the a-axis and negative expansion along the c-axis, except the Cs-doped sample which has positive expansion in both directions.
Instrumental Capabilites in X-Ray Diffraction Analysis: Comparative Techniques
Authors: Kincaid P. J. , Newman R. A. , Fawcett T. G. 
Published: March 2019

The following study is an evaluation of several different types of instrumentation available for use in powder x-ray diffraction work. The particular units used are those at the Dow Chemical Company x-ray diffraction lab. The variety of instrumentation allows analyses from routine phase identification to more specialized work such as low-angle x-ray diffraction of polymers and high-resolution analysis for cell parameter refinements.The purpose of this work is to compare the relative capabilities of these different instruments under typical day-to-day operating conditions. While not a comprehensive study, the conclusions drawn should be applicable to powder x-ray diffraction in general.
Elemental and Phase Mapping of Sputtered Binary Plutonium Alloys
Authors: Wallace P. L. , Wien W. L. , Rizzo H. F. , Echeverria A. W. , Goehner R. P. 
Published: March 2019

AbstractIn this article, we demonstrate that the combination of elemental and phase mapping is a very powerful tool for characterizing sputtered, binary plutonium alloys.A specially designed energy-dispersive spectrometer equipped with an automated x-y translational stage was used to measure elemental differences in several disks sputter-coated with binary plutonium alloys. Automated diffractometer scans were obtained from selected areas on the disks by using specially designed sample holders. The elemental differences were then correlated with the phases present and the observed corrosion resistance. The elemental spectra and diffractometer scans were analyzed using a modified version of the SPECPLOT program. This program enables the user to analyze both energy-dispersive elemental data and diffractometer data using a single program.
Grazing Incidence X-Ray Scattering Studies of Single Quantum Wells
Authors: Bates S. , Hatton P.D. , Lucas C.A. , Ryan T.W. , Miles S.J. , Tanner B.K. 
Published: March 2019

AbstractX-ray scattering techniques at grazing incidence have been used to characterize single quantum well hetero–structures. Double–and triple-axis diffractometry has been used to determine lattice mismatch and layer thickness of a 250Å thick layer of AlInAs grown by MBE on an InP substrate and capped by a 45Å GaAs layer. Reflectivity measurements in the triple – crystal mode permit accurate measurement of individual layer thicknesses, relative electron density and interface roughnesses on the Angstrom level.
Oscillations in Interplanar Spacing Vs. sin2ψ a FEM Analysis
Authors: Noyan I. C. , Nguyen L. T. 
Published: March 2019

AbstractRecent studies indicate that, if the stress/strain field within the irradiated volume in an x-ray stress determination experiment is inhomogeneous, oscillations occur in the interplanar spacing vs. sin2ψ plots. There is, however, little work on the degree of inhomogeneity required to cause a given oscillation, the uniqueness of the stress fields that can cause a given set of oscillations, or the error caused by applying the traditional methods currently in use to oscillatory data.In this paper, numerical modeling and eiasto-plastic finite element analysis was used to determine the strain fields in the diffracting volume of a polycrystalline sample under load. The elastic strain fields obtained from the analysis were then averaged over the regions that would diffract in an x-ray experiment/and then correlated to x-ray strain data to obtain an idea of the problems described ahove.
A Comparison of Diffraction Elastic Constants of Steel Measured With X-Rays and Neutrons
Authors: Rudnik P. J. , Krawitz A. D. , Reichel D. G. , Cohen J. B. 
Published: March 2019

AbstractThe diffraction elastic constants have been measured for the 211 and 310 peaks of a high-strength, low-alloy ferritic steel using X-rays and neutrons. The X-ray measurements were performed using both a uniaxial tension and a bending device. The neutron measurements were performed using a uniaxial tensile device. Ten X-ray and four neutron measurements were made for each case. Statistical errors were calculated and compared with the standard deviations of the average values. In addition, neutron measurements were made for the 310 peak utilizing an interior probe volume.The results indicate that the calculated statistical errors and the observed standard deviations were almost the same for each radiation. The X-ray and neutron tensile device measurements yielded similar results within experimental error. Furthermore, the X-ray tensile and bending results were similar as were the neutron internal volume measurements. These results suggest that near-surface X-ray measurements adequately sample the bulk material in the case of steel, and that different measurement techniques can be used to obtain reliable diffraction elastic constants.
X-Ray Diffraction Analysis of Fly ASH
Authors: McCarthy G.J. , Johansen D.M. , Steinwand S.J. , Thedchanamoorthy A. 
Published: March 2019

AbstractMethods for, and results from, x-ray diffraction analysis of large numbers of fly ash samples obtained from U.S. power plants are described. Qualitative XRD indicates that low-calcium/Class F fly ash (usually derived from bituminous coal) consists typically of the crystalline phases quartz, mullite, hematite and magnetite in a matrix of aluminosilicate glass. Highcalcium fly ash (derived from low-rank coal) has a much more complex assemblage of crystalline phases that typically includes these four phases plus lime, periclase, anhydrite, alkali sulfates, tricalcium aluminate, dicalcium silicate, melilite, merwinlte and a sodalite-structure phase. Glass compositions among the particles are more heterogeneous and range from calcium aluminate to sodium calcium aluminosilicate, Every ash studied Is mixed with an internal Intensity standard (rutile) so that Intensity ratios can be used to make comparisons of the relative amounts of crystalline phases. An error analysis was performed to define the level of uncertainty in making these comparisons. These intensity ratios will be used for quantitative XRD phase analyses when reference intensity ratios for each fly ash phase become available.
A Novel X-Ray Powder-Diffractometer, Measuring Preferred-Orientations
Authors: Brouwer Geert 
Published: March 2019

The instrument employs a fully-focussing optical system which allows a wide range of sample-orientations and thus permits determination of the preferred-orientation distribution-function. Hence, measured peak-intensifies can be corrected for non-randomness.The sample performs a planetary motion around the focus of the primary, monochromatic beam. The angle of incidence can be varied over a wide range of values, including both transmission and reflection. The sample can be rotated in its own plane in a controlled manner. Full illumination is obtained in any position of the sample. The diameter of the Rowland-sphere of the powder-optics remains constant and permits the use of a sphericai sample-layer.
X-Ray Fluorescence Spectrometry With Gas Proportional Scintillation Counters
Authors: Conde C.A.N. , dos Santos J.M.F. , Dias Teresa H.V.T. , de Campos A.J.A. , Costa Benilde F.O. 
Published: March 2019

AbstractAn uniform field gas proportional scintillation counter is described for X-ray fluorescence analysis applications requiring large window areas and good energy resolution at rcom temperature. This counter uses continuously purified xenon as the filling gas and a 1 inch diameter window. A quartz window Hamamatsu R562 photomultiplier is used with its window in direct contact with the gas. Measured energy resolutions were in the 12 to 13% range for the 5.9keV X–ray line. X–ray fluorescence spectra for a few samples are presented with excitation by ImC 55Fe and 244cm sources. Measured physical excitation-detection efficiencies are compared with calculated values.
The Evolution of X-ray Analytical Instrumentation at Rigaku Corporation
Authors: Shibata Atsushi 
Published: March 2019

Soon after Von Laue's experiment of X-ray diffraction in 1912, a similar experiment was conducted in Japan by Prof. Terada at University of Tokyo. He made direct observation of Laue spots from rock-sault on a fluorescent screen. In 1914, Prof. Nishikawa also at University of Tokyo photographed Laue spots of spinel. The X-ray generator employed was one designed for medical use. The first X-ray diffractometer in Japan was fabricated in the 1920s at the Institute of Physical and Chemical Research, It was designed with reference to Bragg's spectrometer using an ionization chamber as the X-ray detector.In 1932, X-ray generators and cameras were manufactured by Rigaku Denki Mfg., the predecessor of the present Rigaku Corporation, Shimazu Mfg. and some other few companies. X-ray tubes at the time were Coolidge type demountable tubes.
The Excitation of Low Z Elements by Means of a Cylindrical Graded Multilayer as a High Energy Cut-Off in Edxrf Analysis
Authors: Kanngießer B. , Beckhoff B. 
Published: March 2019

To measure X-ray fluorescence radiation of low Z elements especially requires a very high excitation intensity with an energy as close as possible to the absorption edges. Furthermore, a monochromatization of the excitation radiation and a cut-off of higher energies is desirable in order to reduce the background in the spectral region of interest.A cylindrical graded multilayer was designed and tested to concentrate and to monochromatize the radiation of a thin window Mo fine focus tube. The variation of the dspacing is tuned to reflect the Mo La-radiation of the fine focus tube. The physical dimensions of the cylindrical shape are optimized for concentrating the Mo La tube radiation onto the specimen with a spot size of about 3 mm. This corresponds to the size of the specimens from a time dependent personal aerosol sampler used.The multilayer is characterized with respect to its reflecting, focusing, and monochromatizing properties. Two examples of low Z element analysis are given.
The Perspectives of High-Accuracy X-Ray Fluorescence Analysis - Some Fundamental Aspects and Applications
Authors: Smolniakov V. I. 
Published: March 2019

The fundamental approach to calculating the chemical element content resulting from x-ray fluorescence measurements has been substantiated theoretically. The elaboration of the calculation algorithm has proved the physical-mathematical model for the x-ray fluorescence intensity arising from photon irradiation and spectrometry peculiarities.Special attention has been put on the real processes, in these elaborated algorithms. They take into account all the valuable effects influencing the x-ray fluorescence intensities, as well as the. stability of the equipment measurements. The results of some applications are shown.
GnRH-R–Targeted Lytic Peptide SensitizesBRCAWild-type Ovarian Cancer to PARP Inhibition
Authors: Ma Shaolin , Pradeep Sunila , Villar-Prados Alejandro , Wen Yunfei , Bayraktar Emine , Mangala Lingegowda S. , Kim Mark Seungwook , Wu Sherry Y. , Hu Wei , Rodriguez-Aguayo Cristian , Leuschner Carola , Liang Xiaoyan , Ram Prahlad T. , Schlacher Katharina , Coleman Robert L. , Sood Anil K. 
Published: March 2019

AbstractEP-100 is a synthetic lytic peptide that specifically targets the gonadotropin-releasing hormone receptor on cancer cells. To extend the utility of EP-100, we aimed to identify effective combination therapies with EP-100 for ovarian cancer and explore potential mechanisms of this combination. A series of in vitro (MTT assay, immunoblot analysis, reverse-phase protein array, comet assay, and immunofluorescence staining) and in vivo experiments were carried out to determine the biological effects of EP-100 alone and in combination with standard-of-care drugs. EP-100 decreased the viability of ovarian cancer cells and reduced tumor growth in orthotopic mouse models. Of five standard drugs tested (cisplatin, paclitaxel, doxorubicin, topotecan, and olaparib), we found that the combination of EP-100 and olaparib was synergistic in ovarian cancer cell lines. Further experiments revealed that combined treatment of EP-100 and olaparib significantly increased the number of nuclear foci of phosphorylated histone H2AX. In addition, the extent of DNA damage was significantly increased after treatment with EP-100 and olaparib in comet assay. We performed reverse-phase protein array analyses and identified that the PI3K/AKT pathway was inhibited by EP-100, which we validated with in vitro experiments. In vivo experiment using the HeyA8 mouse model demonstrated that mice treated with EP-100 and olaparib had lower tumor weights (0.06 ± 0.13 g) than those treated with a vehicle (1.19 ± 1.09 g), EP-100 alone (0.62 ± 0.78 g), or olaparib alone (0.50 ± 0.63 g). Our findings indicate that combining EP-100 with olaparib is a promising therapeutic strategy for ovarian cancer.
BI1071, a Novel Nur77 Modulator, Induces Apoptosis of Cancer Cells by Activating the Nur77-Bcl-2 Apoptotic Pathway
Authors: Chen Xiaohui , Cao Xihua , Tu Xuhuang , Alitongbieke Gulimiran , Xia Zebin , Li Xiaotong , Chen Ziwen , Yin Meimei , Xu Dan , Guo Shangjie , Li Zongxi , Chen Liqun , Zhang Xindao , Xu Dingyu , Gao Meichun , Liu Jie , Zeng Zhiping , Zhou Hu , Su Ying , Zhang Xiao-kun 
Published: March 2019

Abstract
Nur77 (also called TR3 or NGFI-B), an orphan member of the nuclear receptor superfamily, induces apoptosis by translocating to mitochondria where it interacts with Bcl-2 to convert Bcl-2 from an antiapoptotic to a pro-apoptotic molecule. Nur77 posttranslational modification such as phosphorylation has been shown to induce Nur77 translocation from the nucleus to mitochondria. However, small molecules that can bind directly to Nur77 to trigger its mitochondrial localization and Bcl-2 interaction remain to be explored. Here, we report our identification and characterization of DIM-C-pPhCF3+MeSO3− (BI1071), an oxidized product derived from indole-3-carbinol metabolite, as a modulator of the Nur77-Bcl-2 apoptotic pathway. BI1071 binds Nur77 with high affinity, promotes Nur77 mitochondrial targeting and interaction with Bcl-2, and effectively induces apoptosis of cancer cells in a Nur77- and Bcl-2–dependent manner. Studies with animal model showed that BI1071 potently inhibited the growth of tumor cells in animals through its induction of apoptosis. Our results identify BI1071 as a novel Nur77-binding modulator of the Nur77-Bcl-2 apoptotic pathway, which may serve as a promising lead for treating cancers with overexpression of Bcl-2.
Targeting the IGF1R/PI3K/AKT Pathway Sensitizes Ewing Sarcoma to BET Bromodomain Inhibitors
Authors: Loganathan Sudan N. , Tang Nan , Holler Albert E. , Wang Nenghui , Wang Jialiang 
Published: March 2019

Abstract
Inhibitors of the bromodomain and extra-terminal domain (BET) family proteins modulate EWS-FLI1 activities in Ewing sarcoma. However, the efficacy of BET inhibitors as a monotherapy was moderate and transient in preclinical models. The objective of this study was to identify the mechanisms mediating intrinsic resistance to BET inhibitors and develop more effective combination treatments for Ewing sarcoma. Using a panel of Ewing sarcoma cell lines and patient-derived xenograft lines (PDX), we demonstrated that IGF1R inhibitors synergistically increased sensitivities to BET inhibitors and induced potent apoptosis when combined with BET inhibitors. Constitutively activated AKT significantly protected Ewing sarcoma cells against BET inhibitors, suggesting that IGF1R regulates responsiveness to BET inhibitors mainly through the PI3K/AKT pathway. Although two Ewing sarcoma cell lines were resistant to IGF1R inhibitors, they retained synergistic response to a combination of BET inhibitors and mTOR inhibitors, suggesting that BET proteins, when IGF1R is not functional, cross-talk with its downstream molecules. Furthermore, the combination of a BET inhibitor and an IGF1R inhibitor induced potent and durable response in xenograft tumors, whereas either agent alone was less effective. Taken together, our results suggest that IGF1R and the downstream PI3K/AKT/mTOR kinase cascade mediate intrinsic resistance to BET inhibitors in Ewing sarcoma. These results provide the proof-of-concept for combining BET inhibitors with agents targeting the IGF1R pathway for treating advanced Ewing sarcoma.