Normalized Peak Intensities Research Articles

Transport and x-ray photoelectron spectroscopy properties of (Ni1−xCux)Mn2O4 and Ni(Mn2−yCuy)O4

The temperature dependence of the electrical resistivity and the thermoelectric power in (Ni1−xCux)Mn2O4 (x = 0 to 0.5) and Ni(Mn2−yCuy)O4 (y = 0 to 0.2) are investigated. The electrical resistivity of samples with x < 0.1 appears to be hardly changed with increasing Cu content. In all of the samples, the electron transfer is thermally activated and shows semiconducting behavior. The electric conductivity is described by a small polaron hopping mechanism except for x ≥ 0.3. The thermoelectric power at 100 °C is found to change sign from negative to positive with Cu substitution both in (Ni1−xCux)Mn2O4 and Ni(Mn2−yCuy)O4. Furthermore, the thermoelectric powers of these samples with x, y < 0.1 are found to change sign from negative to positive with increasing temperature. The valence distribution of the Mn ions is estimated using x-ray photoelectron spectroscopy. The peak intensity ratio of Mn3+/Mn4+ is maximized whereas that of Ni3+/Ni2+ is minimized at about x, y = 0.05 to 0.07. These results suggest that the Mn4+ and Ni2+ ions change disproportionately into Mn3+ and Ni3+ ions with increasing Cu content up to x, y = 0.1. The valence states of Ni in the system are in accordance with those of Mn, which is necessary in order to maintain charge neutrality and oxygen stoichiometry. The normalized peak intensity of the charge transfer satellite peak of Mn 2p3/2 is rapidly increased by Cu substitution up to x, y = 0.1. With further Cu substitution when x, y > 0.1, the ratio of increase in the peak intensity of the charge transfer satellite is decreased. These facts suggest that the decrease of electrical resistivity when x, y ≥ 0.1 is caused by an increase of holes having O 2p character, and the changes of sign in the thermoelectric power might take care of the competition between the electron conduction term and the hole conduction term caused by the charge transfer from O 2p to transition metal 3d orbitals.

Luminescence enhancement from Si-based materials by introducing a photonic crystal double-heterostructure slot waveguide microcavity

We demonstrate a novel SOI-based photonic crystal (PC) double-heterostructure slot waveguide microcavity constructed by cascading three PC slot waveguides with different slot widths, and simulate the luminescence enhancement of sol-gel Erdoped SiO2 filled in the microcavity by finite-difference time-domain (FDTD) method. The calculated results indicate that a unique sharp resonant peak dominates in the spectrum at the expected telecommunication wavelength of 1.5509 μm, with very high normalized peak intensity of ∼108. The electromagnetic field of the resonant mode exhibits the strongest in the microcavity, and decays rapidly to zero along both sides, which means that the resonant mode field is well confined in the microcavity. The simulation results fully verify the enhancement of luminescence by PC double-heterostructure slot waveguide microcavity theoretically, which is a promising way to realize the high-efficiency luminescence of Si-based materials.

A magnetic bead‐based serum proteomic fingerprinting method for parallel analytical analysis and micropreparative purification

ProteinChip surface-enhanced laser desorption/ionization technology and magnetic beads-based ClinProt system are commonly used for semi-quantitative profiling of plasma proteome in biomarker discovery. Unfortunately, the proteins/peptides detected by MS are non-recoverable. To obtain the protein identity of a MS peak, additional time-consuming and material-consuming purification steps have to be done. In this study, we developed a magnetic beads-based proteomic fingerprinting method that allowed semi-quantitative proteomic profiling and micropreparative purification of the profiled proteins in parallel. The use of different chromatographic magnetic beads allowed us to obtain different proteomic profiles, which were comparable to those obtained by the ProteinChip surface-enhanced laser desorption/ionization technology. Our assays were semi-quantitative. The normalized peak intensity was proportional to concentration measured by immunoassay. Both intra-assay and inter-assay coefficients of variation of the normalized peak intensities were in the range of 4-30%. Our method only required 2 microL of serum or plasma for generating enough proteins for semi-quantitative profiling by MALDI-TOF-MS as well as for gel electrophoresis and subsequent protein identification. The protein peaks and corresponding gel spots could be easily matched by comparing their intensities and masses. Because of its high efficiency and reproducibility, our method has great potentials in clinical research, especially in biomarker discovery.

Structural, optical and electrical properties of Co‐evaporated CuCl/KCl films

AbstractThe behaviour of co‐evaporated CuCl/KCl films, with a varying weight percentage of KCl from 0% – 15%, has been investigated using structural, optical and electrical characterisation techniques. Room temperature X‐ray diffraction (XRD) measurements reveal that the deposited films on glass substrates were zincblende in structure and preferentially oriented in the CuCl (111) plane irrespective of the percentage of KCl. Temperature dependent photoluminescence (PL) measurements on all samples exhibit various excitonic luminescence processes. Further to this, the normalized peak intensity (Z3 ∼ 384 nm) of the 95% CuCl/5% KCl evaporated film is twice that of undoped film due to possible filling of some of the anion vacancies which may reduce the luminescence intensity of the film. The conductivity of the deposited films was found to increase with increasing KCl content. An interstitial hopping mechanism of K+ in a predominantly CuCl crystal was used to explain the increase in the electrical conductivity of the co‐evaporated films. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Combination of 1H Nuclear Magnetic Resonance Spectroscopy and Liquid Chromatography/Mass Spectrometry with Pattern Recognition Techniques for Evaluation of Metabolic Profile Associated with Albuminuria

A method using 1H NMR and LC/MS with pattern recognition tools such as principal component analysis (PCA) and orthogonal projection to latent structure discriminant analysis (O-PLS-DA) was used to study the urinary metabolic profiles associated with an increase in urinary albumin in a general population. The normalized peak intensities obtained from 1H NMR and LC/MS with nonparametric two-tailed Mann-Whitney analysis was used for the identification of network of potential biomarkers corresponding to the increase of albumin in urine. The specificity of detecting the stated metabolites by 1H NMR and LC/MS was demonstrated. Our preliminary data obtained demonstrated that LC/MS may produce more distinctive metabolic profiles. For the patient group, changes in alanine, kyneurnic acid, and xanthurenic acid might be associated with changes in the tryptophan metabolism. At the same time, other metabolites that were involved in citric acid cycle, amino acid metabolism, and cellular functions were affected in the patient group. The proposed approach provided a comprehensive picture of the metabolic changes induced by the increase of protein in urine and demonstrated the advantages of using multiple diagnostic biomarkers. At the same time, the current work was demonstrated as a potential cost-effective solution of high-throughput analysis with pattern recognition tools as applied here in a real clinical situation.

Validation of phylogenetic signals in amplified fragment length data: testing the utility and reliability in closely related taxa

BackgroundDiscriminating taxa with the nuclear marker, amplified fragment length polymorphism (AFLP) has been accomplished for various organisms in economic, ecological, and evolutionary studies. The protocol available for AFLP generation does not require prior knowledge of the genome; however, it is often extensively modified to fit the needs of the researcher. Modification of this protocol for new labs is intimidating and time-consuming, particularly for taxa in which AFLP have not been previously developed. Furthermore, determining what constitutes quality output during different stages of fragment generation is not well defined and this may further hinder the use AFLP by new researchers.FindingsWe present a step-by-step AFLP protocol, using flourophore-labeled primers for use with automated sequencers, including examples of both successful and unsuccessful results. We sufficiently normalized peak intensity and standardized allele calling across all samples for each primer combination. Repeatability was assessed with a phylogenetic tree in which replicate samples clustered together using the minimum evolution procedure. We found differences greater than 10% in allele position among replicated samples would cause replicates to no longer cluster. To minimize offset allele positions, we suggest that researchers analyze different primer combinations at the same time using multiple dyes with the automated sequencer to minimize mismatched alleles across replicates.ConclusionFor researchers wanting to use AFLP, this molecular technique is difficult and time-consuming to develop. Clarifying what constitutes quality output for each step in AFLP generation will help to reduce redundant trials in protocol development and, in turn, advance the discipline of population genetics.

Use of a panel of proteomic markers to improve the sensitivity of CA125 for detecting stage I epithelial ovarian cancer

5542 Background: Given the low prevalence of ovarian cancer, a successful strategy for early detection will require both high sensitivity (>90%) and specificity (99.6%) to achieve a positive predictive value of 10%. The requisite specificity might be attained through a two stage strategy that utilizes an abnormal value for serum marker(s) to prompt the performance of transvaginal sonography (TVS) in a limited number (2–5%) of women, reducing the specificity required for serum markers to 95–98%. Optimal sensitivity might be achieved by combining CA125 with other biomarkers. Methods: A training set from MDACC that included serum samples from patients with epithelial ovarian cancer (22 stage I and 19 stage II), 40 with benign disease and 99 healthy individuals, was analyzed using the CA125II immunoassay and SELDI-TOF-MS protocols to measure 7 proteins [transthyretin, Apo-A1, transferrin, hepcidin, ß2M, CTAP3, and ITIH4]. Using normalized peak intensity data, statistical models were fit by logistic regression, followed by stepwise optimization of factors retained in the models determined by optimizing the Akaike Information Criterion. A validation set from the GOG included 136 stage I ovarian cancers, 140 benign pelvic masses and 50 healthy controls from the GOG supplemented with 124 healthy controls from MDACC. Results: In the training set analysis, CA125 (>35 U/mL) alone distinguished stage I patients from healthy women with 68 % sensitivity, the 7 biomarkers exhibited 50% sensitivity and a combination of CA125 and the panel of 7 biomarkers achieved a sensitivity of 80% at 98% specificity. The combination separated patients with stage I-II ovarian cancer from benign and normal samples with 85% sensitivity. In the validation set, CA125 (>35U/ml) exhibited a sensitivity of 79% for stage I, whereas the marker panel + CA125 produced a sensitivity of 87% at 95% specificity (P= 0.015, McNemar’s test). The combined panel also detected 38% of benign lesions, but these should be further distinguished during a second stage of screening with TVS. Conclusions: Combining a panel of 7 proteomic markers with CA125 could provide a first step in a sequential two-stage strategy with TVS for early detection of ovarian cancer. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Vermillion, Inc. Fujirebio Diagnostics Inc Vermillion, Inc. Fujirebio Diagnostics Inc, Vermillion, Inc. Fujirebio Diagnostics Inc

Nano-Structured TiN Thin Films Deposited by Single Ion Beam Reactive Sputtering

The reactive sputter deposition of TiN thin films onto glass substrate at the ambient temperature using a homemade broad beam argon ion source was investigated in order to deposit the films with nanostructural characteristics. While constant Ar beam energy of 2 keV was used, the N2 partial pressure and the substrate current, adjusted by different accelerator grid potentials (Vacc) were varied. A negative substrate bias voltage (100 V) was additionally applied. The TiN film structure was investigated by XRD and STM methods. All deposited films exhibited (220) preferred orientation, and the change in normalized peak intensity (I220/d), lattice spacing (d220) and full-with at half-maximum (FWHM) were investigated. As a result of higher energy bombardment with 100 V negative substrate bias, compared to the substrate current change with Vacc, nearly constant (220) peak broadening with the increase of N2 partial pressure was obtained. The measured grain diameter (STM and XRD) confirms that the grain size is less than 12 nm, and the (220) preferred orientation was disturbed but not destructed.

Dynamic spin structure factor ofSrCu2(BO3)2at finite temperatures

Using finite temperature Lanczos technique on finite clusters we calculate dynamical spin structure factor of the quasi-two-dimensional dimer spin liquid $\mathrm{Sr}{\mathrm{Cu}}_{2}{(\mathrm{B}{\mathrm{O}}_{3})}_{2}$ as a function of wave vector and temperature. At low temperatures the peak belonging to the lowest spin excitations is split due to spin anisotropy, in accord with the experimental data. Unusual temperature dependence of calculated spectra is as well in agreement with inelastic neutron scattering measurements. Normalized peak intensities of the single-triplet peak are $\mathbf{q}$ independent, their temperature dependence is analyzed in terms of thermodynamic quantities.

Gleevec (STI571) Influences Metabolic Enzyme Activities and Glucose Carbon Flow toward Nucleic Acid and Fatty Acid Synthesis in Myeloid Tumor Cells

Chronic myeloid leukemia cells contain a constitutively active Bcr-Abl tyrosine kinase, the target protein of Gleevec (STI571) phenylaminopyrimidine class protein kinase inhibitor. Here we provide evidence for metabolic phenotypic changes in cultured K562 human myeloid blast cells after treatment with increasing doses of STI571 using [1,2-13C2]glucose as the single tracer and biological mass spectrometry. In response to 0.68 and 6.8 microm STI571, proliferation of Bcr-Abl-positive K562 cells showed a 57% and 74% decrease, respectively, whereas glucose label incorporation into RNA decreased by 13.4% and 30.1%, respectively, through direct glucose oxidation, as indicated by the decrease in the m1/Sigma(m)n ratio in RNA. Based on the in vitro proliferation data, the IC50 of STI571 in K562 cultures is 0.56 microm. The decrease in 13C label incorporation into RNA ribose was accompanied by a significant fall in hexokinase and glucose-6-phosphate 1-dehydrogenase activities. The activity of transketolase, the enzyme responsible for nonoxidative ribose synthesis in the pentose cycle, was less affected, and there was a relative increase in glucose carbon incorporation into RNA through nonoxidative synthesis as indicated by the increase in the m2/Sigma(m)n ratio in RNA. The restricted use of glucose carbons for de novo nucleic acid and fatty acid synthesis by altering metabolic enzyme activities and pathway carbon flux of the pentose cycle constitutes the underlying mechanism by which STI571 inhibits leukemia cell glucose substrate utilization and growth. The administration of specific hexokinase/glucose-6-phosphate 1-dehydrogenase inhibitor anti-metabolite substrates or competitive enzyme inhibitor compounds, alone or in combination, should be explored for the treatment of STI571-resistant advanced leukemias as well as that of Bcr-Abl-negative human malignancies.

Simulation of Multilayer Defects in Extreme Ultraviolet Masks

We have employed a scalar simulation based on Fresnel formulas to predict approximately how strongly a multilayer defect in a reflective mask affects the aerial image in extreme ultraviolet lithography. This method enables us to obtain the field reflected from a defective mask, using considerably fewer computational resources than those required for a rigorous electromagnetic simulation. This method was applied to two-dimensional masks with multilayer defects modeled by a simple structure in which the coverage profile was identical throughout the layers. For such defects, we confirmed the validity of the scalar simulation by comparing the normalized peak intensity to that obtained from an electromagnetic simulation. The dependence of the printability of a defect on its size and position is also discussed.

Surface characterization of poly(styrene-co-p-hexafluorohydroxyisopropyl-?-methyl styrene) copolymers by ToF-SIMS, XPS and contact angle measurements

A series of spin-cast films of poly(styrene-co-p-hexafluorohydroxyisopropyl-α-methyl styrene) (poly(St-co-HFMS)) copolymers were analysed by x-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and contact angle measurements. The XPS results showed that the surface chemical composition of the copolymers was the same as that of the bulk. The water contact angle decreased slightly with the HFMS content, indicating that there was no fluorine segregation on the surface. This result showed that the decrease of the surface energy due to the presence of the fluorinated groups was offset by the presence of the polar hydroxyl group. The characteristic peaks of poly(St-co-HFMS) could be distinguished from those of polystyrene in both positive and negative ToF-SIMS spectra. Our analyses have demonstrated that normalized peak intensities and relative intensities of the characteristic peaks can produce useful quantitative results. Copyright © 2000 John Wiley & Sons, Ltd.

Simultaneous genetic typing from multiple short tandem repeat loci using a 96-capillary array electrophoresis system.

Short tandem repeat (STR) markers are highly polymorphic and widely used in human identification and genetic mapping. We demonstrate fast and reliable genotyping based on the four STR loci vWF, THO1, TPOX, CSF1PO by multiple-capillary array electrophoresis. Extracted human genomic DNA was amplified by polymerase chain reaction (PCR). The PCR products were mixed with pooled allelic ladder as an absolute standard and coinjected from a 96-vial tray. Separations were performed in polyvinylpyrrolidone (PVP) sieving matrix with a one-hour turnaround time, with no degradation over 27 runs. Simultaneous one-color laser-induced fluorescence detection was achieved by using a charge-coupled device (CCD) camera. The allele peaks for the unknown sample were identified by comparing the normalized peak intensities of the mixtures to those of the pooled ladder by using a straightforward algorithm. An extremely high level of confidence in matching the bands was indicated with negligible crosstalk (< 0.89%) between adjacent capillaries. This scheme is applicable for STR genotyping with high resolution, high speed and high throughput.

Kinetics of hydrolysis of PCl5 in situ as evaluated from the partial hydrolysis products formed in [18O]water

The in situ hydrolysis products of PCl 5 1, namely POCl 3 , HPO 2 Cl 2 , H 2 PO 3 Cl and H 3 PO 4 5, were identified and their mol proportions measured at different extents of overall hydrolysis (from 7.0 to 93%). Partial hydrolysis in 95 atom % [ 18 O]H 2 O, step 1, was followed by complete hydrolysis in non-enriched water, step 2. The phosphoric acid isotopomers obtained at step 2 were derived from mixtures that contained from 0 to 4 18 O atoms per phosphate incorporated at step 1, depending upon the composition of the mixtures formed at step 1. The relative mol proportions of mixtures were deduced by regression analysis of the normalized peak intensities of the trimethyl phosphate isotopomer cluster at m/z = 140, 142 . . . 148 (obtained by electron-impact GC analysis). The mixture compositions were used to evaluate kinetically a sequential, irreversible model for hydrolysis of PCl 5 . The relative values obtained for apparent hydrolysis constants and the species to which they were attributed were: PCl 5 , 1.0; POCl 3 , 0.24; PO 2 Cl 2 - , 0.02; with that for HPO 3 Cl - being too great to measure. These values accurately predicted the composition of mixtures in all but a narrow range of overall hydrolysis between 60 and 70% where the hitherto undetected monochloro acid accumulated in yields up to 30%. As the water content becomes small with respect to the acid components in this region, the equilibrium between the monoanion and undissociated forms of the acids is shifted in favour of the undissociated acids (the final end products as the mixture becomes anhydrous). The relative rate constants in this region were estimated to be 0.02 and 0.08 for HPO 2 Cl 2 and H 2 PO 3 Cl, respectively, thereby accounting for accumulation of the monochloro acid in this range. It is proposed that under these conditions the rates of hydrolysis of the mono and dichloro components are comparable because both components are present largely in their free acid forms which undergo hydrolysis by an associative mechanism.

Evolution of the density of graphite-like defects during CVD diamond growth

Abstract In order to quantitatively measure the quality of CVD diamond by Raman spectroscopy the spectra of diamond films were decomposed into Raman peaks and luminescence bands. The evolution of the diamond and “G-band” Raman peaks were studied as a function of film thickness for two different growth morphologies. A normalization procedure was used to eliminate the effects on signal intensities of varying probe size, light absorption and scattering. Electron spin resonance was applied to scale normalized peak intensities in terms of defect densities. The grain structure of the thin films strongly affects the normalized G-band intensity. It is demonstrated that graphite-like defects are concentrated in grain boundaries.

Astigmatism together with longitudinal focal shift in off-axis optical systems

In many laser applications optical systems are employed to focus off-axis beams that only partially fill the system aperture. In this paper analytical expressions that give the position of the diffraction focus, normalized peak intensity, and tolerance conditions for uniform and Gaussian off-axis beams in an optical system which suffers from astigmatism together with longitudinal focal shift aberration are obtained on the basis of diffraction theory. The results are useful for designing focusing systems for use with laser beams.

Detection of the presence and location of residual hydrogen in perfluorinated polyalkylether fluids using polarization transfer 13C nuclear magnetic resonance spectroscopy

A series of perfluorinated polyalkylether (PFPE) fluids was analyzed for residual hydrogen bonded to the polymeric backbone and the specific site of this bonded hydrogen in the molecular framework. Residual hydrogen bound to carbon within the predominantly perfluorinated molecular structure has been associated with thermooxidative instability [1] and is therefore of interest as a potential indicator of stability among samples. Application of an 1H to 13C polarization-transfer Nuclear Magnetic Resonance (NMR) technique provides spectra which contain peaks arising only for carbon atoms with directly bonded hydrogen. Such simplified spectra enable detection and unambiguous assignment of hydrogen atom binding site(s) using carbon-fluorine scalar couplings, and thereby provide a means of potentially assessing thermooxidative instability due to residual hydrogen. The relative concentration of carbon with attached hydrogen among samples was then estimated from the normalized peak intensities in the proton-decoupled 13C spectra using the assignments from the polarization- transfer experiment.

Raman scattering study of low dose Si±-implanted GaAs used for metal-semiconductor field-effect transistor fabrication

The annealing of the lattice damage introduced by Si+ implantation into GaAs as well as the electrical activation of the dopant has been studied by Raman scattering. Implantation doses (4×1012–1×1013 cm−2) and annealing conditions (800–1040 °C for 5 s) were used which are typical for GaAs metal-semiconductor field-effect transistor fabrication. The normalized peak intensity of the longitudinal optical (LO) phonon-plasmon coupled mode is found to correlate with the sheet of conductivity, i.e., it probes the electrical activation. The lattice perfection, in contrast, is most sensitively measured by resonant 2LO-phonon scattering.

Chemical and structural properties of the Pd/Si interface during the initial stages of silicide formation

The initial stage of silicide formation at the Pd/Si interface has been investigated during Pd deposition on the Si(111) surface using a combination of AES and TEM techniques. The formation of silicide was found to change the valence state of Si significantly as observed from the shape change of the Si LVV Auger spectra. The ratios of the normalized peak intensities were used to calibrate the composition and the thickness of the reacted layer. The calibration results coupled with TEM phase identification showed uniform formation of the Pd2Si compound even at room temperature up to about 10 Å Pd coverage. Using thin Pd coverages of about 10 Å, epitaxial growth of Pd2Si was not observed on sputter-cleaned Si surfaces. Crystalline order was clearly observed at the Pd2Si/Si interface in annealed samples with less than 4 Å Pd2Si, indicating a relatively sharp interface with no significant amorphous-like structural disorder.