Determination of Hydrogen Diffusion Parameters of Ferritic Steel from Electrochemical Permeation Measurement under Tensile Loads

The hydrogen permeation experiment, performed with a stepwise permeation sequence involving "1st permeation-desorption-2nd permeation under loading, demonstrates that fine blister cracks are frequently observed on the steel surface in hydrogen charging side after the 2nd permeation under the load over 95% of yield strength of the steel. To accommodate the experimental phenomena under the loading conditions, a numerical model is developed for determination of hydrogen diffusion parameters of the sour-resistant ferritic steel evaluated under tensile stress in plastic ranges. To solve the modified diffusion equation, a numerical finite difference method (FDM) is employed. The diffusion parameters determined by curve-fitting with the newly proposed diffusion equation indicates that, with the transition of mechanical domain from local-plasticity to generalized-plasticity, a big increase in the crack formation rate and hydrogen capture rate per irreversible trap are observed. It suggests that the transition probability for hydrogen transport from interstitial lattice site to irreversible trap site increases with the stress level. (C) The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.1110Ysciescopu

Ferromagnetic properties of Zn1-xMnxO epitaxial thin films

We report on ferromagnetic characteristics of Zn1-xMnxO (x=0.1 and 0.3) thin films grown on Al2O3(00.1) substrates using laser molecular-beam epitaxy. By increasing the Mn content, the films exhibited increases in both the c-axis lattice constant and fundamental band gap energy. The Curie temperature obtained from temperature-dependent magnetization curves was 45 K for the film with x=0.3, depending on the Mn composition in the films. The remanent magnetization and coercive field of Zn0.9Mn0.1O at 5 K were 0.9 emu/g and 300 Oe, respectively. For Zn0.7Mn0.3O, the remanent magnetization at 5 K increased to 3.4 emu/g. (C) 2002 American Institute of Physics.open11509532sciescopu

Oral health and later coronary heart disease: Cohort study of one million people

AIMS: Systematic reviews report an association between poorer oral health and an increased risk of coronary heart disease. This contentious relationship may not be causal but existing studies have been insufficiently well powered comprehensively to examine the role of confounding, particularly by cigarette smoking. Accordingly, we sought to examine the role of smoking in generating the relationship between oral health and coronary heart disease in life-long non-smokers. METHODS AND RESULTS: In the Korean Cancer Prevention Study, 975,685 individuals (349,579 women) aged 30–95 years had an oral examination when tooth loss, a widely used indicator of oral health, was ascertained. Linkage to national mortality and hospital registers over 21 years of follow-up gave rise to 64,784 coronary heart disease events (19,502 in women). In the whole cohort, after statistical adjustment for age, there was a moderate, positive association between tooth loss and coronary heart disease in both men (hazard ratio for seven or more missing teeth vs. none; 95% confidence interval 1.08; 1.02, 1.14; Ptrend across tooth loss groups <0.0001) and women (1.09; 1.01, 1.18; Ptrend 0.0016). Restricting analyses to a subgroup of 464,145 never smokers (25,765 coronary heart disease events), however, resulted in an elimination of this association in men (1.01; 0.85, 1.19); Ptrend 0.7506) but not women (1.08; 0.99, 1.18; Ptrend 0.0086). CONCLUSION: In men in the present study, the relationship between poor oral health and coronary heart disease risk appeared to be explained by confounding by cigarette smoking so raising questions about a causal link

Genetic Comparison of Stemness of Human Umbilical Cord and Dental Pulp

published_or_final_versio

Sensitivity and Noise in THz Photoconductive Metasurface Detectors

Photoconductive antenna THz detectors based on highly absorbing LT-GaAs metasurfaces enable high sensitivity and high signal-to-noise ratio (> 106) at optical gate powers as low as 5 μW. By investigating the dependence of detector performance on optical gate power, we compare several metasurface detectors with standard PCAs and develop a general model for quantifying the sensitivity and optimal gate power for detector operation. We also show that the LT-GaAs metasurface can even enhance sub bandgap absorption, enabling the use of these detectors in telecom wavelength systems

Predictions from Heavy New Physics Interpretation of the Top Forward-Backward Asymmetry

We derive generic predictions at hadron colliders from the large forward-backward asymmetry observed at the Tevatron, assuming the latter arises from heavy new physics beyond the Standard Model. We use an effective field theory approach to characterize the associated unknown dynamics. By fitting the Tevatron t \bar t data we derive constraints on the form of the new physics. Furthermore, we show that heavy new physics explaining the Tevatron data generically enhances at high invariant masses both the top pair production cross section and the charge asymmetry at the LHC. This enhancement can be within the sensitivity of the 8 TeV run, such that the 2012 LHC data should be able to exclude a large class of models of heavy new physics or provide hints for its presence. The same new physics implies a contribution to the forward-backward asymmetry in bottom pair production at low invariant masses of order a permil at most.Comment: 11 pages, 6 figures. v2: added remarks on EFT validity range, dijet bounds and UV completions; matches published versio

Electrical conductivity and electromagnetic interference shielding of multiwalled carbon nanotube composites containing Fe catalyst

Thin and flexible composite films of raw or purified multiwalled carbon nanotube (MWCNT) with various mass fractions and poly(methylmethacrylate) (PMMA) were synthesized for electromagnetic interference (EMI) shielding material. From scanning electron microscopy and high-resolution transmission electron microscopy photographs, we observed the formation of a conducting network through MWCNTs in an insulating PMMA matrix and the existence of an Fe catalyst in MWCNTs. The dc conductivity (sigma(dc)) of the systems increased with increasing MWCNT mass fraction, showing typical percolation behavior. The measured EMI shielding efficiency (SE) of MWCNT-PMMA composites by using the extended ASTM D4935-99 method (50 MHz-13.5 GHz) increased with increasing MWCNT mass fraction as sigma(dc). The highest EMI SE for raw MWCNT-PMMA composites was similar to27 dB, indicating commercial use for far-field EMI shielding. The contribution of absorption to total EMI SE of the systems is larger than that of reflection. Based on magnetic permeability, we suggest raw MWCNTs and their composites can be used for near-field EMI shielding.open28629

Vaccinia-related kinase 1 promotes hepatocellular carcinoma by controlling the levels of cell cycle regulators associated with G1/S transition

We identified the specific role of vaccinia-related kinase 1 (VRK1) in the progression of hepatocellular carcinoma (HCC) and evaluated its therapeutic and prognostic potential. VRK1 levels were significantly higher in HCC cell lines than a normal hepatic cell line, and were higher in HCC than non-tumor tissue. VRK1 knockdown inhibited the proliferation of SK-Hep1, SH-J1 and Hep3B cells; moreover, depletion of VRK1 suppressed HCC tumor growth in vivo. We also showed that VRK1 knockdown increased the number of G1 arrested cells by decreasing cyclin D1 and p-Rb while upregulating p21 and p27, and that VRK1 depletion downregulated phosphorylation of CREB, a transcription factor regulating CCND1. Additionally, we found that luteolin, a VRK1 inhibitor, suppressed HCC growth in vitro and in vivo, and that the aberrant VRK1 expression correlated with poor prognostic features of HCC. High levels of VRK1 were associated with shorter overall and disease-free survival and higher recurrence rates. Taken together, our findings suggest VRK1 may act as a tumor promoter by controlling the level of cell cycle regulators associated with G1/S transition and could potentially serve as a therapeutic target and/or prognostic biomarker for HCC.1110Ysciescopu

Nonlinear Terahertz Generation in Semiconductor Metasurfaces

We demonstrate ultra-thin semiconductor metasurfaces for generation of THz pulses. By investigating the dependence of the THz amplitude and phase on excitation field polarization and crystal orientation, we deduce that the underlying THz emission mechanism in metasurfaces differs from bulk semiconductor wafers with second order nonlinearity playing a dominant role. The metasurface enables control of the THz phase and can therefore be used to spatially structure the THz emitted field. We use this effect to design and demonstrate a metasurface which simultaneously emits and focusses THz pulses

Classification of facial periâ implant soft tissue dehiscence/deficiencies at single implant sites in the esthetic zone

BackgroundThe incidence of a periâ implant soft tissue dehiscence/deficiency (PSTD) is not a rare finding. Despite multiple previous attempts aimed at correcting the PSTDs, a classification of these conditions has not yet been proposed. This lack in the literature may also lead to discrepancies in the reported treatment outcomes and thus misinform the clinician or the readers. The aim of the present article was therefore to present a classification of periâ implant PSTD at a single implant site.MethodsFour classes of PSTDs were discussed based on the position of the gingival margin of the implantâ supported crown in relation to the homologous natural tooth. In addition, the buccoâ lingual position of the implant head was also taken into consideration. Each class was further subdivided based on the height of the anatomical papillae.ResultsSubsequently, for each respective category a surgical approach (including bilaminar techniques, the combined prostheticâ surgical approach or soft tissue augmentation with a submerged healing) was also suggested.ConclusionThis paper provides a new classification system for describing PSTDs at single implant sites, with the appropriate recommended treatment protocol.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151905/1/jper10351_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151905/2/jper10351.pd