2,214 research outputs found
Electronic structure and enhanced visible light absorption of N, B-codoped TiO2
We present the GGA+U calculations to investigate the electronic structure and
visible light absorption of the N, B-codoped anatase TiO2. The NsBi
(substitutional N, interstitial B) codoped TiO2 produces significant Ti 3d and
N 2p mid-gap states when the distance of N and B atoms is far, and the NiBi
(interstitial N and B) and NsBs (substitutional N and B) codoped TiO2 prefer to
form localized p states at 0.3-1.2 eV above the valence band maximum. Further,
the optical band edges of the three codoped systems shift slightly to the
visible region, but only the far distance NsBi codoped TiO2 shows an obvious
visible optical transition. These results indicate that the NsBi codoped TiO2
has a dominant contribution to the visible absorption of the N, B-codoped TiO2.Comment: 4 pages, 4 figures, 17 reference
Fatty acid desaturase (FADS) gene polymorphisms and insulin resistance in association with serum phospholipid polyunsaturated fatty acid composition in healthy Korean men: cross-sectional study
<p>Abstract</p> <p>Background</p> <p>We investigated the relationship between fatty acid desaturase (<it>FADS</it>) gene polymorphisms and insulin resistance (IR) in association with serum phospholipid polyunsaturated fatty acid (FA) composition in healthy Korean men.</p> <p>Methods</p> <p>Healthy men (n = 576, 30 ~ 79 years old) were genotyped for rs174537 near <it>FADS1 </it>(<it>FEN1</it>-10154G>T), <it>FADS2 </it>(rs174575C>G, rs2727270C>T), and <it>FADS3 </it>(rs1000778C>T) SNPs. Dietary intake, serum phospholipid FA composition and HOMA-IR were measured.</p> <p>Results</p> <p>Fasting insulin and HOMA-IR were significantly higher in the rs174575G allele carriers than the CC homozygotes, but lower in the rs2727270T allele carriers than the CC homozygotes. The proportion of linoleic acid (18:2ω-6, LA) was higher in the minor allele carriers of <it>FEN1</it>-10154G>T, rs174575C>G and rs2727270C>T than the major homozygotes, respectively. On the other hand, the proportions of dihomo-γ-linolenic acid (20:3ω-6, DGLA) and arachidonic acid (20:4ω-6, AA) in serum phospholipids were significantly lower in the minor allele carriers of <it>FEN1</it>-10154 G>T carriers and rs2727270C>T than the major homozygotes respectively. AA was also significantly lower in the rs1000778T allele carriers than the CC homozygotes. HOMA-IR positively correlated with LA and DGLA and negatively with AA/DGLA in total subjects. Interestingly, rs174575G allele carriers showed remarkably higher HOMA-IR than the CC homozygotes when subjects had higher proportions of DLGA (≥1.412% in total serum phospholipid FA composition) (<it>P </it>for interaction = 0.009) or of AA (≥4.573%) (<it>P </it>for interaction = 0.047).</p> <p>Conclusion</p> <p>HOMA-IR is associated with <it>FADS </it>gene cluster as well as with FA composition in serum phospholipids. Additionally, HOMA-IR may be modulated by the interaction between rs174575C>G and the proportion of DGLA or AA in serum phospholipids.</p
Analysis of Density Matrix reconstruction in NMR Quantum Computing
Reconstruction of density matrices is important in NMR quantum computing. An
analysis is made for a 2-qubit system by using the error matrix method. It is
found that the state tomography method determines well the parameters that are
necessary for reconstructing the density matrix in NMR quantum computations.
Analysis is also made for a simplified state tomography procedure that uses
fewer read-outs. The result of this analysis with the error matrix method
demonstrates that a satisfactory accuracy in density matrix reconstruction can
be achieved even in a measurement with the number of read-outs being largely
reduced.Comment: 7 pages, title slightly changed and references adde
The role of speculative trade in market efficiency: Evidence from a betting exchange
Does speculative trade reduce mispricing and help create efficient markets or does it drive prices further from fundamentals? We analyze betting exchange trading on 9,562 UK horse races in 2013 and 2014 to find out. Crucially, as each race is run, the fundamental value of bets is unambiguously revealed. We find that the volume of trade is predictive of fundamentals, suggesting that speculative trade is on average conducive to market efficiency. However, much of this effect is concentrated in the in-running period during races when, even without trade, asset fundamentals would be revealed seconds later
Prevalence of overweight and obesity among Chinese Yi nationality: a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Overweight and obesity are considered a serious health problem. There are little data on the prevalence of overweight and obesity among the Yi ethnic group in China. This study aimed to investigate the epidemiologic features of overweight/obesity among Chinese Yi nationality.</p> <p>Methods</p> <p>A cross-sectional study, including 1255 subjects aged 20-75 years, was carried out in Liangshan Yi Autonomous Prefecture of Sichuan province from 2007 to 2008. Overweight/overall obesity was defined by World Health Organization (WHO) or the Working Group on Obesity in China.</p> <p>Results</p> <p>Overall, the prevalence of overweight and obesity was 19.0% and 2.9%, respectively, based on the WHO definition, while it was 21.0% and 7.4%, respectively, according to the Working Group on Obesity in China, which is similar to data reported in the 2002 Chinese National Nutrition and Health Survey. Urban residents had a significantly higher prevalence of obesity (WHO criteria: 4.3% vs 1.7% <it>p </it>= 0.008; China criteria: 11.4% vs 3.7%, <it>p </it>< 0.001) and overweight (WHO criteria: 28.9% vs 8.9% <it>p </it>< 0.001; China criteria: 31.2% vs 10.4%, <it>p </it>< 0.001) than that in rural residents. Older age, a family history of obesity, higher income, drinking and urban residence were significantly associated with an increased risk of overweight/obesity.</p> <p>Conclusions</p> <p>The prevalence of overweight/obesity in the Yi nationality is similar to that in Chinese adults 5 years ago. However, urban residents have a much higher prevalence of overweight/obesity than their rural counterparts. Lifestyle and diet patterns associated with socioeconomic status may explain the difference between urban and rural residents. The prevention of overweight/obesity among urban inhabitants deserves more attention in national health education programs.</p
Polymer strategies in perovskite solar cells
Since their emergence in 2013, perovskite solar cells have reached remarkable efficiencies exceeding 22%. Such rapid development of this technology has been possible, in part, due to the feed of ideas from previous research in organic photovoltaics (OPVs) and light emitting diodes (OLEDs). This comprehensive review discusses the various polymer strategies that have led to the success of perovskite devices: from hole and electron transporting materials to polymer templating agents. This review further covers how these strategies potentially serve to overcome the two major obstacles that stand in the way of global implementation of perovskite solar cells; stability and J-V curve hysteresis. Through reference and comparison of OPV, OLED, and perovskite technologies, we highlight the need for a unified approach to establish appropriate control systems and ageing protocols that are necessary to further research in this exciting direction. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 549–568
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
Novel mechanisms of endothelial dysfunction in diabetes
Diabetes mellitus is a major risk factor for cardiovascular morbidity and mortality. This condition increases the risk of developing coronary, cerebrovascular, and peripheral arterial disease fourfold. Endothelial dysfunction is a major contributor to the pathogenesis of vascular disease in diabetes mellitus patients and has recently received increased attention. In this review article, some recent developments that could improve the knowledge of diabetes-induced endothelial dysfunction are discussed
Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV
The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration
- …