1,879 research outputs found

    Electrically Switchable Photonic Molecule Laser

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    We have studied the coherent intercavity coupling of the evanescent fields of the whispering gallery modes of two terahertz quantum-cascade lasers implemented as microdisk cavities. The electrically pumped single-mode operating microcavities allow to electrically control the coherent mode coupling for proximity distances of the cavities up to 30-40 \mu\m. The optical emission of the strongest coupled photonic molecule can be perfectly switched by the electrical modulation of only one of the coupled microdisks. The threshold characteristics of the strongest coupled photonic molecule demonstrates the linear dependence of the gain of a quantum-cascade laser on the applied electric field.Comment: 4 pages, 4 figure

    Spin Structure of the Proton from Polarized Inclusive Deep-Inelastic Muon-Proton Scattering

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    We have measured the spin-dependent structure function g1pg_1^p in inclusive deep-inelastic scattering of polarized muons off polarized protons, in the kinematic range 0.003<x<0.70.003 < x < 0.7 and 1GeV2<Q2<60GeV21 GeV^2 < Q^2 < 60 GeV^2. A next-to-leading order QCD analysis is used to evolve the measured g1p(x,Q2)g_1^p(x,Q^2) to a fixed Q02Q^2_0. The first moment of g1pg_1^p at Q02=10GeV2Q^2_0 = 10 GeV^2 is Γp=0.136±0.013(stat.)±0.009(syst.)±0.005(evol.)\Gamma^p = 0.136\pm 0.013(stat.) \pm 0.009(syst.)\pm 0.005(evol.). This result is below the prediction of the Ellis-Jaffe sum rule by more than two standard deviations. The singlet axial charge a0a_0 is found to be 0.28±0.160.28 \pm 0.16. In the Adler-Bardeen factorization scheme, Δg2\Delta g \simeq 2 is required to bring ΔΣ\Delta \Sigma in agreement with the Quark-Parton Model. A combined analysis of all available proton and deuteron data confirms the Bjorken sum rule.Comment: 33 pages, 22 figures, uses ReVTex and smc.sty. submitted to Physical Review

    International survey on the management of esophageal atresia

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    IntroductionBecause many aspects of the management of esophageal atresia (EA) are still controversial, we evaluated the practice patterns of this condition across Europe. MethodsA survey was completed by 178 delegates (from 45 [27 European] countries; 88% senior respondents) at the EUPSA-BAPS 2012. ResultsApproximately 66% of respondents work in centers where more than five EA repairs are performed per year. Preoperatively, 81% of respondents request an echocardiogram, and only 43% of respondents routinely perform preoperative bronchoscopy. Approximately 94% of respondents prefer an open approach, which is extrapleural in 71% of respondents. There were no differences in use of thoracoscopy between Europeans (10%) and non-Europeans (11%, p=nonsignificant). Approximately 60% of respondents measure the gap intraoperatively. A transanastomotic tube (90%) and chest drain (69%) are left in situ. Elective paralysis is adopted by 56% of respondents mainly for anastomosis tension (65%). About 72% of respondents routinely request a contrast study on postoperative day 7 (2-14). Approximately 54% of respondents use parenteral nutrition, 40% of respondents start transanastomotic feeds on postoperative day 1, and 89% of respondents start oral feeds after postoperative day 5. Pure EA: 46% of respondents work in centers that repair two or more than two pure EA a year. About 60% of respondents opt for delayed primary anastomosis at 3 months (1-12 months) with gastrostomy formation without esophagostomy. Anastomosis is achieved with open approach by 85% of respondents. About 47% of respondents attempt elongation of esophageal ends via Foker technique (43%) or with serial dilations with bougies (41%). Approximately 67% of respondents always attempt an anastomosis. Gastric interposition is the commonest esophageal substitution. ConclusionMany aspects of EA management are lacking consensus. Minimally invasive repair is still sporadic. We recommend establishment of an EA registry

    Neoadjuvant bevacizumab and anthracycline-taxane-based chemotherapy in 678 triple-negative primary breast cancers; results from the geparquinto study (GBG 44)†

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    Background We evaluated the pathological complete response (pCR) rate after neoadjuvant epirubicin, (E) cyclophosphamide (C) and docetaxel containing chemotherapy with and without the addition of bevacizumab in patients with triple-negative breast cancer (TNBC). Patients and methods Patients with untreated cT1c-4d TNBC represented a stratified subset of the 1948 participants of the HER2-negative part of the GeparQuinto trial. Patients were randomized to receive four cycles EC (90/600 mg/m2; q3w) followed by four cycles docetaxel (100 mg/m2; q3w) each with or without bevacizumab (15 mg/kg; q3w) added to chemotherapy. Results TNBC patients were randomized to chemotherapy without (n = 340) or with bevacizumab (n = 323). pCR (ypT0 ypN0, primary end point) rates were 27.9% without and 39.3% with bevacizumab (P = 0.003). According to other pCR definitions, the addition of bevacizumab increased the pCR rate from 30.9% to 41.8% (ypT0 ypN0/+; P = 0.004), 36.2% to 46.4% (ypT0/is ypN0/+; P = 0.009) and 32.9% to 43.3% (ypT0/is ypN0; P = 0.007). Bevacizumab treatment [OR 1.73, 95% confidence interval (CI) 1.23-2.42; P = 0.002], lower tumor stage (OR 2.38, 95% CI 1.24-4.54; P = 0.009) and grade 3 tumors (OR 1.68, 95% CI 1.14-2.48; P = 0.009) were confirmed as independent predictors of higher pCR in multivariate logistic regression analysis. Conclusions The addition of bevacizumab to chemotherapy in TNBC significantly increases pCR rate

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    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

    Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

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    Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition

    BRCA2 polymorphic stop codon K3326X and the risk of breast, prostate, and ovarian cancers

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    Background: The K3326X variant in BRCA2 (BRCA2*c.9976A&gt;T; p.Lys3326*; rs11571833) has been found to be associated with small increased risks of breast cancer. However, it is not clear to what extent linkage disequilibrium with fully pathogenic mutations might account for this association. There is scant information about the effect of K3326X in other hormone-related cancers. Methods: Using weighted logistic regression, we analyzed data from the large iCOGS study including 76 637 cancer case patients and 83 796 control patients to estimate odds ratios (ORw) and 95% confidence intervals (CIs) for K3326X variant carriers in relation to breast, ovarian, and prostate cancer risks, with weights defined as probability of not having a pathogenic BRCA2 variant. Using Cox proportional hazards modeling, we also examined the associations of K3326X with breast and ovarian cancer risks among 7183 BRCA1 variant carriers. All statistical tests were two-sided. Results: The K3326X variant was associated with breast (ORw = 1.28, 95% CI = 1.17 to 1.40, P = 5.9x10- 6) and invasive ovarian cancer (ORw = 1.26, 95% CI = 1.10 to 1.43, P = 3.8x10-3). These associations were stronger for serous ovarian cancer and for estrogen receptor–negative breast cancer (ORw = 1.46, 95% CI = 1.2 to 1.70, P = 3.4x10-5 and ORw = 1.50, 95% CI = 1.28 to 1.76, P = 4.1x10-5, respectively). For BRCA1 mutation carriers, there was a statistically significant inverse association of the K3326X variant with risk of ovarian cancer (HR = 0.43, 95% CI = 0.22 to 0.84, P = .013) but no association with breast cancer. No association with prostate cancer was observed. Conclusions: Our study provides evidence that the K3326X variant is associated with risk of developing breast and ovarian cancers independent of other pathogenic variants in BRCA2. Further studies are needed to determine the biological mechanism of action responsible for these associations

    Large enhancement of deuteron polarization with frequency modulated microwaves

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    We report a large enhancement of 1.7 in deuteron polarization up to values of 0.6 due to frequency modulation of the polarizing microwaves in a two liters polarized target using the method of dynamic nuclear polarization. This target was used during a deep inelastic polarized muon-deuteron scattering experiment at CERN. Measurements of the electron paramagnetic resonance absorption spectra show that frequency modulation gives rise to additional microwave absorption in the spectral wings. Although these results are not understood theoretically, they may provide a useful testing ground for the deeper understanding of dynamic nuclear polarization.Comment: 10 pages, including the figures coming in uuencoded compressed tar files in poltar.uu, which also brings cernart.sty and crna12.sty files neede
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