9,806 research outputs found

    Electrically detected magnetic resonance of carbon dangling bonds at the Si-face 4H-SiC/SiO2_2 interface

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    SiC based metal-oxide-semiconductor field-effect transistors (MOSFETs) have gained a significant importance in power electronics applications. However, electrically active defects at the SiC/SiO2_2 interface degrade the ideal behavior of the devices. The relevant microscopic defects can be identified by electron paramagnetic resonance (EPR) or electrically detected magnetic resonance (EDMR). This helps to decide which changes to the fabrication process will likely lead to further increases of device performance and reliability. EDMR measurements have shown very similar dominant hyperfine (HF) spectra in differently processed MOSFETs although some discrepancies were observed in the measured gg-factors. Here, the HF spectra measured of different SiC MOSFETs are compared and it is argued that the same dominant defect is present in all devices. A comparison of the data with simulated spectra of the C dangling bond (PbC_\textrm{bC}) center and the silicon vacancy (VSi_\textrm{Si}) demonstrates that the PbC_\textrm{bC} center is a more suitable candidate to explain the observed HF spectra.Comment: Accepted for publication in the Journal of Applied Physic

    Decoherence-based exploration of d-dimensional one-way quantum computation

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    We study the effects of amplitude and phase damping decoherence in d-dimensional one-way quantum computation (QC). Our investigation shows how information transfer and entangling gate simulations are affected for d>=2. To understand motivations for extending the one-way model to higher dimensions, we describe how d-dimensional qudit cluster states deteriorate under environmental noise. In order to protect quantum information from the environment we consider the encoding of logical qubits into physical qudits and compare entangled pairs of linear qubit-cluster states with single qudit clusters of equal length and total dimension. Our study shows a significant reduction in the performance of one-way QC for d>2 in the presence of Markovian type decoherence models.Comment: 8 pages, 11 figures, RevTeX

    The manifest association structure of the single-factor model: insights from partial correlations

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    The association structure between manifest variables arising from the single-factor model is investigated using partial correlations. The additional insights to the practitioner provided by partial correlations for detecting a single-factor model are discussed. The parameter space for the partial correlations is presented, as are the patterns of signs in a matrix containing the partial correlations that are not compatible with a single-factor model

    Effects of Adding Sodium and Fluoride Ions to Glass Ionomer on its Interactions with Sodium Fluoride Solution

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    This investigates the effects of the addition of Na and F ions to a glass ionomer cement in which those ions are not inherently present on its interactions with dilute (0.2%) NaF solution. Both the effect of the solution on the cement\u27s surface morphology and the effect of the cement on the solution in terms of take up of Na+ and F- and of change in pH are to be investigated. These results are to be compared to previous results obtained with glasses which contained both, one, or neither of the ions as components of their glasses. NaF (1.3% by weight in the mixed cement) was added to the powder components of a glass ionomer based on LG30 glass (which contains Al, Si, Ca, P, and O only). Discs of cement were set in moulds at 37°C for 1h then stored in water at 37°C for 3 days. Each test disc was then immersed in 10ml 0.2% NaF solution whereas controls remained immersed in water (N=3 for test and control). Test and control disc surfaces were assessed both qualitatively by electron microscopy and quantitatively by linear profilometry (R(a) values). Potentiometry was used to measure solution pH and Na and F concentrations using a pH electrode and suitable ion selective electrodes both before and after cement immersion. The surface of test specimens was subject considerable disruption with the polysalt cement matrix being removed and residual glass particles being disclosed. The controls showed no such disruption. This effect was reflected in a significant difference of R(a). Such an effect was not shown by test and control surfaces of LG30 but a similar effect was to that shown by LG26 (which contains F as a glass component). Solution pH changed by 1 unit which was much more than the change shown by LG30 or LG26 but is similar to that of AH2 and MP4 cements which both contain Na. The Na and F uptake was much lower than for LG30 whereas that of LG26 was higher than LG30. The Na:F ratio was 0.29:1 compared to 1.26:1 for LG30 (LG26=1.01:1, AH2=1.02:1, MP4=1.04:1). Fluoride addition to a F-free glass ionomer renders it vulnerable to surface disruption by NaF solution showing that fluoride complexes produced in glass dissolution are not necessarily involved in this process. Sodium addition to a Na-free glass ionomer confirms the role of this cement in enhancing pH change in NaF solution. The level of uptake of F- from a NaF solution in much lower than that for the F-free glass ionomer which shows there is no direct relationship between F- uptake and surface disruption. The ratio of Na:F uptake is below 0.3:1, but the pH change is similar to cements where the ratio is close to unity which indicates that F-/OH- interchange is not a significant mechanism even when anion/cation uptake is not balanced. Copyright (C) 2000

    Prolactin prevents hepatocellular carcinoma by restricting innate immune activation of c-Myc in mice

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    Women are more resistant to hepatocellular carcinoma (HCC) than men despite equal exposure to major risk factors, such as hepatitis B or C virus infection. Female resistance is hormone-dependent, as evidenced by the sharp increase in HCC incidence in postmenopausal women who do not take hormone replacement therapy. In rodent models sex-dimorphic HCC phenotypes are pituitary-dependent, suggesting that sex hormones act via the gonadal-hypophyseal axis. We found that the estrogen-responsive pituitary hormone prolactin (PRL), signaling through hepatocyte-predominant short-form prolactin receptors (PRLR-S), constrained TNF receptor-associated factor (TRAF)-dependent innate immune responses invoked by IL-1β, TNF-α, and LPS/Toll-like receptor 4 (TLR4), but not TRIF-dependent poly(I:C)/TLR3. PRL ubiquitinated and accelerated poststimulatory decay of a “trafasome” comprised of IRAK1, TRAF6, and MAP3K proteins, abrogating downstream activation of c-Myc–interacting pathways, including PI3K/AKT, mTORC1, p38 MAPK, and NF-κB. Consistent with this finding, we documented exaggerated male liver responses to immune stimuli in mice and humans. Tumor promotion through, but regulation above, the level of c-Myc was demonstrated by sex-independent HCC eruption in Alb-Myc transgenic mice. PRL deficiency accelerated liver carcinogenesis in Prl[superscript −/−] mice of both sexes. Conversely, pharmacologic PRL mobilization using the dopamine D2 receptor antagonist domperidone prevented HCC in tumor-prone C3H/HeN males. Viewed together, our results demonstrate that PRL constrains tumor-promoting liver inflammation by inhibiting MAP3K-dependent activation of c-Myc at the level of the trafasome. PRL-targeted therapy may hold promise for reducing the burden of liver cancer in high-risk men and women.National Institutes of Health (U.S.) (Grant CA067529

    The Detergent Evaluation Methods and the Washing Machine(PART II)

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    AIC model selection table and associated coefficients for hermit warbler 2013 for all models combined. Column names for the model coefficients use the following notation: coefficient = parameter(covariate) and standard error = SEparameter(covariate). Parameter abbreviations are p = detection probability, psi = initial occupancy, col = colonization/settlement, ext = extinction/vacancy. Parameter(Int) refers to the intercept. ‘nPars’ is the number of parameters estimated in the model. Each model is ranked by its AIC score, which represents how well the model fits the data. A lower ∆AIC (delta) value is indicative of a better model. The probability that the model (of the models tested) would best explain the data is indicated by AICwt

    Warehouse design and planning: A mathematical programming approach

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    The dynamic nature of today's competitive markets compels organizations to an incessant reassessment in an effort to respond to continuous challenges. Therefore, warehouses as an important link in most supply chains, must be continually re-evaluated to ensure that they are consistent with both market's demands and management's strategies. A number of warehouse decision support models have been proposed in the literature but considerable difficulties in applying these models still remain, due to the large amount of information to be processed and to the large number of possible alternatives. In this paper we discuss a mathematical programming model aiming to support some warehouse management and inventory decisions. In particular a large mixed-integer nonlinear programming model (MINLP) is presented to capture the trade-offs among the different inventory and warehouse costs in order to achieve global optimal design satisfying throughput requirements.(undefined)info:eu-repo/semantics/publishedVersio

    Systematic data-querying of large pediatric biorepository identifies novel Ehlers-Danlos Syndrome variant

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    BACKGROUND: Ehlers Danlos Syndrome is a rare form of inherited connective tissue disorder, which primarily affects skin, joints, muscle, and blood cells. The current study aimed at finding the mutation that causing EDS type VII C also known as "Dermatosparaxis" in this family. METHODS: Through systematic data querying of the electronic medical records (EMRs) of over 80,000 individuals, we recently identified an EDS family that indicate an autosomal dominant inheritance. The family was consented for genomic analysis of their de-identified data. After a negative screen for known mutations, we performed whole genome sequencing on the male proband, his affected father, and unaffected mother. We filtered the list of non-synonymous variants that are common between the affected individuals. RESULTS: The analysis of non-synonymous variants lead to identifying a novel mutation in the ADAMTSL2 (p. Gly421Ser) gene in the affected individuals. Sanger sequencing confirmed the mutation. CONCLUSION: Our work is significant not only because it sheds new light on the pathophysiology of EDS for the affected family and the field at large, but also because it demonstrates the utility of unbiased large-scale clinical recruitment in deciphering the genetic etiology of rare mendelian diseases. With unbiased large-scale clinical recruitment we strive to sequence as many rare mendelian diseases as possible, and this work in EDS serves as a successful proof of concept to that effect

    The Application of Multispectral Techniques to Analytical Electron Microscopy

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    The York multispectral analytical electron microscope (MULSAM) was the first instrument specifically designed to acquire and process multiple Auger, X-ray, backscattered electron, elastically scattered electron, scanning electron microscopy (SEM) and specimen absorption current images simultaneously. Analyzing combinations of these signals with multispectral correlation techniques yields more information than would normally be obtained by treating each image separately. This paper reports some of the multispectral methods we have investigated at York which may be of use to other workers. Included are (1) a method that corrects for beam current fluctuations during long acquisition runs which is based on the anti-correlation between SEM and specimen current images, (2) the classification of topography for crystalline specimens by correlation partitioning of backscattered electron images and (3) the enhancement of surface state contrast in multi spectral scanning tunneling microscopy (STM) images using the Hotelling transform. The last example is intended to demonstrate that these techniques can also be applied to other fields in microscopy
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