bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Grazing Incidence X-Ray Diffraction to Polymer Blends
Authors: Garbauskas Mary F. , LeGrand Donald G. , Goehner Raymond P. 
Published: March 2019

AbstractThe physical properties of polymer blends consisting of one or more crystallizable components are affected by the microstructure of these materials. In particular, the degree of crystallinity can be influenced by processing parameters, and the crystallinity, as well as the phase distribution, may vary as a function of depth through an injection molded part. Conventional x-ray diffraction techniques can provide information regarding both phase composition and degree of crystallinity, but, because of the relative transparency of these materials to wavelengths generally available in the laboratory, these techniques provide information representative of only the bulk. By employing parallel beam optics at varying grazing incidence angles, the x-ray sampling depth can be varied without loss of resolution, This technique can be used to vary the effective analysis depth from the top several hundred angstroms for low grazing incidence to centimeters for transmission diffraction patterns, Grazing incidence techniques have found initial application in the characterization of thin metallic and ceramic films. This paper demonstrates the feasibility of using parallel beam optics to depth profile low atomic number materials. The specific application of this technique to the characterization of injection molded polymers, including a blend of bisphenol-A polycarbonate (PC) and polybutylene terephthalate (PBT), will be presented.
Determination of the Coherency Strain of γ and γ′ Phases in Nickel-Base Superalloys at High Temperatures
Authors: Ohno Katsumi , Yokokawa Tadaharu , Yamagata Toshihiro , Harada Hiroshi , Yamazaki Michio , Ohsumi Kazumasa 
Published: March 2019

AbstractA method for using syncrotoron-radiation parallel-beam X-ray diffractometry for precise lattice parameters and strains of γ-γ′ type Nickel base superalloys at elevated temperature is described. The superalloys have γ′ precipitates which are an ordered L12 structure based on Ni3Al, in y-matrices having a disordered FCC structure. Lattice misfit between γ and γ′ phases was very small and peaks reflected from γ and γ′ phases made unresolved clusters of peaks.Profile fitting with a pseudo-Voigt function is used to resolve overlapping peaks. Instrumental broadening of the peak profile was removed using a deconvolution method. The standard errors of the calculated peak angle were less than 0.002°. The elastic strain of the γ′ precipitates in the alloys were smaller than those of γ-matrices.
A New Position Sensitive Detector for X-Ray Diffractometry
Authors: Radtke J. L. , Beard D. W. 
Published: March 2019

AbstractPosition sensitive detectors provide efficient X-ray detection over large solid angles; this capability has revolutionized X-ray diffractometry by reducing data collection time. This paper describes testing of a new single-axis position sensitive detector designed to locate 0.6-2 Angstrom X-rays. Dead time, quantum efficiency, energy resolution, and spatial resolution were measured. Standard powder diffraction patterns were observed with the detector, and data sets are presented. The impact of detector performance parameters on diffraction experiments is discussed.
Characterization of Structural Inhomogeneities in GaAs/AIGaAs Superlattices
Authors: Huang P. C. , Stock S. R. , Torabi A. , Summers C. J. 
Published: March 2019

AbstractThin films containing periodic chemical or strain modulation (e.g. artificial superlattices or SL) are often characterized nondestructively by X-ray double-axis diffractometry. The satellite peaks from the modulated structure allow analysis of layer structure, elemental concentration and strain profile. This paper focuses on the effect of layer uniformity on the rocking curves of (001) GaAs/AlxGa1-xAsSL. Double-axis diffractometry for results from MBE samples with 800 Å SL periods and x=0.35 are compared for GaAs/AlGaAs layer thicknesses of 350/450, 400/400 and 450/350 Å. Symmetric (004) and asymmetric (315) diffraction planes are used to measure parallel and perpendicular misfit strains, layer periodicity and aluminum concentration. A modified kinematical scattering model, correcting for absorption and extinction, is used to calculate the satellite peak intensities and spacings. The relative thicknesses of GaAs and AlGaAs and the aluminum elemental concentration are optimized by matching with experimental results. The effect of nonuniform layer thickness on SL peak intensities is also investigated. The experimental results, the modified kinematical scattering calculations and dynamical theory agree closely for the 3-4 /zm thickness layers studied.
X-ray Diffraction of Plasma Nitrided Ti-6AI-4V
Authors: Raveh A. , Kimmel G. , Avni R. , Grill A. 
Published: March 2019

AbstractTi-6Al-4V alloy has been nitrided in plasmas of N2 -H2 -Ar. The structure has been characterized by X-ray diffraction (XRD) for the determination of the products formed. The information was supported by elemental analysis with Auger Electron Spectroscopy (AES).Three phases were identified as follows: δ-TiN, ε-Ti2N and α'-Ti (solid solution of nitrogen in titanium). The gas-feed composition affects the nitriding process as found from phase orientation and relative concentration of the products.
Stress Analysis of Thin-Film SmS Using a Seemann- Bohlin Diffractometer
Authors: Moore Fergus E. 
Published: March 2019

AbstractX-ray diffraction is especially useful in analyzing the phase-transition response of thin-film SmS to strain impressed by the two-dimensional constraints of the substrate. A biaxial-stress model is applied and extended to a randomly-oriented crystalline film. The changes in macrostress, the compliance tensor and effective Poisson's ratio are evaluated near the hulk phase transition. An analysis of crystallite size and microstrain broadening is also presented including broadening effects due to biaxial macrostrain on the randomly-oriented crystallites. These results illustrate the effect of a constraining, biaxial-stress field on the unusual elastic character of samarium monosulfide. It is demonstrated that the thin-film geometry suppresses the first-order phase transition allowing only linear changes between the semiconducting and metallic states.
On the Selection of the Value for the Experimental Wavelength in Powder Diffraction Measurements
Authors: Jenkins Ron 
Published: March 2019

AbstractWith the increasing use of automated powder diffractometers, more and more reliance is being placed on peak searching and α2 stripping software to allocate a wavelength for the calculation of the d-value from the observed peak maxima. The complications in the correct allocation of the wavelength are well known and include problems due to the polychromatic nature of the diffracted X-ray beam, changes in the angular dispersion of the diffractometer over the angular range of the experimental data, and effects of instrument geometric aberrations on the profile shape. Further difficulties may accrue because of idiosyncrasy of the peak searching arid α2 stripping software.
Simultaneous Determination of the Thickness and Composition of Thin Film Samples Using Fundamental Parameters
Authors: Willis James E. 
Published: March 2019

The use of empirical analysis techniques for the simultaneous determination of the thickness and composition of thin film samples usually requires a suite of well characterized similar type standards. While this may be adequate for a quality control application, this requirement severely limits the utility of X-ray fluorescence in the analysis of thin films in a service lab or research environment.The use of fundamental parameters in the analysis of thin films allows the simultaneous determination of the thickness and composition of single and multiple layer thin film unknown samples without the use of similar type standards.
Internal Stress in an Alumina/Silicon Carbide Whisker Composite
Authors: Oden M. , Ericsson T. , Cohen J. B. 
Published: March 2019

The internal stress state in a Al2O3-SiC composite has been studied with X-ray diffraction and with calculations with a modified Eshelby model. The influence (on the internal stress state) of volume fraction, temperature, geometric shape, and the orientation of the silicon carbide particles are discussed. The stress tensors were measured in both the matrix and in the reinforcing phase, and the macro- and microstresses were separated for ail the components. Good agreement with the microstresses for the Eshelby model is found in all cases.Results from X-ray diffraction experiments at low temperature (45-295 K) on the coefficient of thermal expansion are also presented.
Determination of Thickness and Composition of Thin AlxGa1-xAs Films on GaAs substrates by Total Electron Yield (Tey) Measurements
Authors: Ebel Horst , Svagera Robert , Ebel Maria F. , Zagler Norbert 
Published: March 2019

In our paper “Determination of thickness and composition of thin AlxGa1-xAs layers on GaAs by total electron yield (TEY)” we described the principles of the determination of thickness t and Al concentration x employing TEY. The essential experimental quantities are the absorption edge jumps of the-eleraents measured in TEY-mode:Since the problem asks for the quantification of two unknowns (x,t), at least two TEYjumps are needed. The K jumps of Al and Ga deliver reliable information. From the theoretical approach1,2 of quantitative TEY a nearly linear relationship between the measured TEY jumps and the composition (in wt%) has to be expected. The As concentration varies over the interesting composition range 0<x<0.6 from approximately 50 to 60wt% and causes a similar variation of the TEY jump versus x. In combination with the statistical significance of the experimental data we neglect the TEY K jump information from As.
Light Element Analysis Using Txrf
Authors: Fukuda T. , Shoji T. , Funabashi M. , Utaka T. , Arai T. , Miyazaki K. , Shimazaki A. , Wilson R. 
Published: March 2019

Over the past few years there has been substantial progress in the TXRF analysis of heavy element surface contamination on silicon wafers. Further advances and improvements are desired in the analytical performance and hardware. Extension of the analytical range to include the light elements is particularly desirable.In the case of light element analysis, sodium and aluminum impurities have been monitored in the IC production process. The increase of the sodium impurity in a silicon wafer gives rise to a decrease in the insulation in IC devices and the growth of the SiO2 film is disturbed by the prsence of aluminum impurity on the silicon wafer surface.
Quantitative Xrfa of Carbon in a Special Matrix by the Fundamental Parameter Method
Authors: Weber Franz A. , Silva Luiz. B. Da , Barbee Troy W. , Ciarlo Dino , Mantler Michael 
Published: March 2019

SummaryWe report on results obtained from experiments using specially prepared carbon substrates and treatment of the data by means of recently introduced theory. Medium Z grids with known parameters have been coated on top of pyrolytic carbon substrates to achieve well defined absorption geometries. The various copper grids exhibit satisfactory performance in terms of mechanical stability, homogeneity and uniformity of the coating. A detailed study of the measurement results shows that there is a more rapid increase of the associated C-Kα countrate from the coated samples compared to the pure elements and is attributed to the contribution of secondary enhancement effects, including those resulting from photoelectrons generated after the primary ionization.
Immobilization of Protein A on Monodisperse Magnetic Nanoparticles for Biomedical Applications
Authors: Thanh Bui Trung , Van Sau Nguyen , Ju Heongkyu , Bashir Mohammed J. K. , Jun Hieng Kiat , Phan Thang Bach , Ngo Quang Minh , Tran Ngoc Quyen , Hai Tran Hoang , Van Pham Hung , Nguyen Tan Tai 
Published: March 2019

We presented synthesis and physical characterization of iron oxide magnetic nanoparticles (Fe3O4) for biomedical applications in the size range of 10-30 nm. Magnetic nanoparticles were synthesized by the coprecipitation method, and the particles’ size was controlled by two different injection methods of sodium hydroxide (NaOH). The synthesized magnetic nanoparticles were then modified by using series of linkers including tetraethyl orthosilicate (TEOS), 3-aminopropyltriethoxysilane (APTES), and glutaraldehyde (GA) to generate the structure of Fe3O4/SiO2/NH2/CHO, which can be used for immobilization of protein A. Additionally, we used transmission electron microscopy (TEM), X-ray powder diffraction (XRD), vibrating-sample magnetometry (VSM), and Fourier-transform infrared spectroscopy (FTIR), for characterization of properties and structure of the nanoparticles. An immobilization of protein A on magnetic nanoparticles was studied with a UV-Vis spectrum (UV-Vis) and fluorescence electron microscopy and Bradford method. Results showed that an XRD spectrum with a peak at (311) corresponded to the standard peak of magnetic nanoparticles. In addition, the magnetic nanoparticles withd≥30 nm have higher saturation magnetizations in comparison with the smaller ones withd≤10 nm. However, the smaller magnetic nanoparticles offered higher efficiency for binding of protein A, due to the high surface/volume ratio. These particles with functional groups on their surface are promising candidates for biomedical applications, e.g., drug delivery, controlled drug release, or disease diagnosis in point-of-care test.
Atheroprotective Flow Upregulates ITPR3 (Inositol 1,4,5-Trisphosphate Receptor 3) in Vascular Endothelium via KLF4 (Krüppel-Like Factor 4)-Mediated Histone Modifications
Authors: He Ming , Huang Tse-Shun , Li Shuai , Hong Hsiao-Chin , Chen Zhen , Martin Marcy , Zhou Xin , Huang Hsi-Yuan , Su Shu-Han , Zhang Jiao , Wang Wei-Ting , Kang Jian , Huang Hsien-Da , Zhang Jin , Chien Shu , Shyy John Y.-J. 
Published: March 2019

Objective—
The topographical distribution of atherosclerosis in vasculature underscores the importance of shear stress in regulating endothelium. With a systems approach integrating sequencing data, the current study aims to explore the link between shear stress-regulated master transcription factor and its regulation of endothelial cell (EC) function via epigenetic modifications.

Approach and Results—

H3K27ac (acetylation of histone 3 lysine 27)-ChIP-seq (chromatin immunoprecipitation followed by high throughput sequencing), ATAC-seq (an assay for transposase-accessible chromatin-sequencing), and RNA-seq (RNA-sequencing) were performed to investigate the genome-wide epigenetic regulations in ECs in response to atheroprotective pulsatile shear stress (PS). In silico prediction revealed that KLF4 binding motifs were enriched in the PS-enhanced H3K27ac regions. By integrating PS- and KLF4-modulated H3K27ac, we identified 18 novel PS-upregulated genes. The promoter regions of these genes showed an overlap between the KLF4-enhanced assay for transposase-accessible chromatin signals and the PS-induced H3K27ac peaks. Experiments using ECs isolated from mouse aorta, lung ECs from EC-KLF4-TG versus EC-KLF4-KO mice, and atorvastatin-treated ECs showed that ITPR3 (inositol 1,4,5-trisphosphate receptor 3) was robustly activated by KLF4 and statins. KLF4 ATAC-qPCR (quantitative polymerase chain reaction) and ChIP-qPCR further demonstrated that a specific locus in the promoter region of the
ITPR3
gene was essential for KLF4 binding, H3K27ac enrichment, chromatin accessibility, RNA polymerase II recruitment, and ITPR3 transcriptional activation. Deletion of this KLF4 binding locus in ECs by using CRISPR-Cas9 resulted in blunted calcium influx, reduced expression of endothelial nitric oxide synthase, and diminished nitric oxide bioavailability.

Conclusions—

These results from a novel multiomics study suggest that KLF4 is crucial for PS-modulated H3K27ac that allow the transcriptional activation of ITPR3. This novel mechanism contributes to the Ca
2+
-dependent eNOS (endothelial nitric oxide synthase) activation and EC homeostasis.
Parental smoking and the risk of congenital heart defects in offspring: An updated meta-analysis of observational studies
Authors: Zhao Lijuan , Chen Lizhang , Yang Tubao , Wang Lesan , Wang Tingting , Zhang Senmao , Chen Letao , Ye Ziwei , Zheng Zan , Qin Jiabi 
Published: March 2019

Objective Although previous reviews confirmed maternal active smoking was significantly associated with risk of fetal congenital heart defects (CHDs), association between maternal passive smoking and paternal smoking and risk of CHDs is inconclusive nowadays; furthermore, a complete overview is lacking. A meta-analysis of observational studies was conducted to assess the risk of CHDs associated with maternal active and passive smoking and paternal smoking. Methods Seven electronic databases were searched for qualified research up to June 2018. We summarized study characteristics and the summary risk estimates were calculated using either the random-effect model or fixed-effect model. Sensitivity and subgroup analysis were carried out to identify the potential heterogeneity moderators. Results One hundred and twenty-five studies involving 137,574 CHDs cases in 8,770,837 study participants were included. Overall, maternal active (risk ratio (RR) = 1.25; 95% confidence interval (CI): 1.16–1.34; p < 0.01) and passive (RR = 2.24, 95% CI: 1.81–2.77; p < 0.01) smoking as well as paternal active smoking (RR = 1.74, 95% CI: 1.48–2.06; p < 0.01) were significantly associated with CHDs risk. For specific CHD subtypes, our study showed that maternal active smoking was significantly associated with risk of atrial septal defect (RR = 1.27, 95% CI: 1.02–1.59; p = 0.03) and right ventricular outflow tract obstruction (RR = 1.43, 95% CI: 1.04–1.97; p = 0.03). Relevant heterogeneity moderators have been identified by subgroup analysis. Sensitivity analysis yielded consistent results. Conclusion Maternal active smoking, maternal passive smoking as well as paternal smoking all increased the risk of CHDs in offspring. Preventing parental smoking during peri-pregnancy is a priority for CHDs prevention.
Retrospective Survival Analysis of Patients With Resected Pancreatic Ductal Adenocarcinoma and a Germline BRCA or PALB2 Mutation
Authors: Yu Shun , Agarwal Parul , Mamtani Ronac , Symecko Heather , Spielman Kelsey , O’Hara Mark , O’Dwyer Peter J. , Schneider Charles , Teitelbaum Ursina , Nathanson Katherine L. , Domchek Susan M. , Reiss Kim A. 
Published: March 2019

PURPOSE Germline mutations in the homologous recombination genes BRCA1, BRCA2, and PALB2 confer an increased risk for pancreatic ductal adenocarcinoma (PDAC). Tumors associated with mutations in homologous recombination genes are sensitive to DNA-damaging agents. We retrospectively studied patients with resected PDAC and a pathogenic germline mutation in one of these three genes. The planned analyses included overall survival (OS) and changes therein when platinum chemotherapy was used in the perioperative setting. MATERIALS AND METHODS Thirty-two individuals with pathogenic germline mutations in BRCA1, BRCA2, or PALB2 and resected PDAC (mutation positive) were matched in a 1:2 fashion to patients who were noncarriers or untested (mutation negative) by age, year of diagnosis, stage, and sex. Patients were identified via one of two available databases at University of Pennsylvania: the Basser Center for BRCA Registry or the electronic medical record. The primary outcome was OS. RESULTS Patients in the mutation-positive group had a median OS (mOS) of 46.6 months; those in the mutation-negative group had an mOS of 23.2 months (hazard ratio [HR], 0.49; 95% CI, 0.27 to 0.88). With platinum exposure in the perioperative setting, mOS in the mutation-positive group had not yet been met versus a mOS of 23.1 months in the mutation-negative group (HR, 0.12; 95% CI, 0.01 to 1.00). When neither group was treated with platinum, there was no significant OS difference between groups (HR, 0.52; 95% CI 0.12 to 2.24). Patients in the mutation-positive group who received perioperative treatment with platinum had a trend toward improved mOS compared with those who did not (HR, 0.15; 95% CI, 0.02 to 1.23; P = .07). CONCLUSION Platinum-based chemotherapy may confer a survival benefit in patients with resected PDAC and a pathogenic germline BRCA1, BRCA2, or PALB2 mutation. Knowledge of a germline mutation may be important to determine best choice of perioperative chemotherapy.
Weight Training and Risk of 10 Common Types of Cancer
Authors: MAZZILLI KAITLYN M. , MATTHEWS CHARLES E. , SALERNO ELIZABETH A. , MOORE STEVEN C. 
Published: March 2019

ABSTRACT

Introduction
Ample data support that leisure time aerobic moderate to vigorous physical activity (MVPA) is associated with lower risk of at least seven types of cancer. However, the link between muscle-strengthening activities and cancer etiology is not well understood. Our objective was to determine the association of weight lifting with incidence of 10 common cancer types.

Methods
We used multivariable Cox regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) for association of weight lifting with incidence of 10 cancer types in the National Institutes of Health-American Association of Retired Persons Diet and Health Study follow-up. Weight lifting was modeled continuously and categorically. Dose–response relationships were evaluated using cubic restricted spline models. We explored whether associations varied by subgroups defined by sex, age, and body mass index using the Wald test for homogeneity. We examined joint categories of MVPA and weight lifting in relation to cancer risk for significant associations.

Results
After adjusting for all covariates including MVPA, we observed a statistically significant lower risk of colon cancer (P
trend = 0.003) in individuals who weight lifted; the HR and 95% CI associated with low and high weight lifting as compared with no weight lifting were 0.75 (95% CI, 0.66–0.87) and 0.78 (95% CI, 0.61–0.98), respectively. The weight lifting-colon cancer relationship differed between men and women (any weight lifting vs no weight lifting: HRmen = 0.91; 95% CI, 0.84–0.98; HRwomen = 1.00; 95% CI, 0.93–1.08; P
interaction = 0.008). A lower risk of kidney cancer among weight lifters was observed but became nonsignificant after adjusting for MVPA (P
trend = 0.06), resulting in an HR of 0.94 (95% CI, 0.78–1.12) for low weight lifting and 0.80 (95% CI, 0.59–1.11) for high weight lifting.

Conclusions
Participants who engaged in weight lifting had a significantly lower risk of colon cancer and a trend toward a lower risk of kidney cancer than participants who did not weight lift.