(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) The ... and B ^sup 0^ mixing frequencies, Deltam ^sub s^ and Deltam ^sub d^, are measured using a data sample corresponding ...to an integrated luminosity of 1.0 fb^sup -1^ collected by the LHCb experiment in pp collisions at a centre of mass energy of 7 TeV during 2011. Around 1.8×10^sup 6^ candidate events are selected of the type ... (+anything), where about half are from peaking and combinatorial backgrounds. To determine the B decay times, a correction is required for the momentum carried by missing particles, which is performed using a simulation-based statistical method. Associated production of muons or mesons allows us to tag the initial-state flavour and so to resolve oscillations due to mixing. We obtain ... The hypothesis of no oscillations is rejected by the equivalent of 5.8 standard deviations for ... and 13.0 standard deviations for B ^sup 0^. This is the first observation of ... mixing to be made using only semileptonic decays.
A silicon swimming robot or pond skating device has been demonstrated. It floats on liquid surfaces using surface tension and is capable of movement using electrowetting on dielectric (EWOD) based ...propulsion. Its dimensions are 6
×
9
mm and the driving mechanism involves first trapping air bubbles within the liquid onto the hydrophobic surface of the device. The air bubbles are then moved using EWOD, which provides the propulsion. The device employs a recently reported
Ta
2
O
5
EWOD technology enabling a driving voltage of ≈15
V, which is low enough for RF power transmission, thus facilitating wire-free movement. A wired version has been measured to move 1.35
mm in 168
ms (a speed of 8
mm
s
−1). This low voltage-EWOD (<15
V) device, fabricated using a CMOS compatible process, is believed to be the world’s smallest swimming MEMS device that has no mechanical moving parts. The paper also reports results of EWOD droplet operation driven by wireless power transmission and demonstrates that such a wireless design can be successfully mounted on a floating EWOD device to produce movement.
Using pp collision data corresponding to an integrated luminosity of 8.5 fb^{-1} recorded by the LHCb experiment at center-of-mass energies of sqrts=7, 8, and 13 TeV, the observation of an excited ...B_{c}^{+} state in the B_{c}^{+}π^{+}π^{-} invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(B_{c}^{+}) MeV/c^{2}, where the last uncertainty is due to the limited knowledge of the B_{c}^{+} mass. It is consistent with expectations of the B_{c}^{*}(2^{3}S_{1})^{+} state reconstructed without the low-energy photon from the B_{c}^{*}(1^{3}S_{1})^{+}→B_{c}^{+}γ decay following B_{c}^{*}(2^{3}S_{1})^{+}→B_{c}^{*}(1^{3}S_{1})^{+}π^{+}π^{-}. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(B_{c}^{+}) MeV/c^{2}, and is consistent with the B_{c}(2^{1}S_{0})^{+} state. These mass measurements are the most precise to date.
A narrow pentaquark state, P_{c}(4312)^{+}, decaying to J/ψp, is discovered with a statistical significance of 7.3σ in a data sample of Λ_{b}^{0}→J/ψpK^{-} decays, which is an order of magnitude ...larger than that previously analyzed by the LHCb Collaboration. The P_{c}(4450)^{+} pentaquark structure formerly reported by LHCb is confirmed and observed to consist of two narrow overlapping peaks, P_{c}(4440)^{+} and P_{c}(4457)^{+}, where the statistical significance of this two-peak interpretation is 5.4σ. The proximity of the Σ_{c}^{+}Dover ¯^{0} and Σ_{c}^{+}Dover ¯^{*0} thresholds to the observed narrow peaks suggests that they play an important role in the dynamics of these states.
A search is performed for the central exclusive production of pairs of charmonia produced in proton-proton collisions. Using data corresponding to an integrated luminosity of collected at ...centre-of-mass energies of 7 and 8 TeV, and pairs are observed, which have been produced in the absence of any other activity inside the LHCb acceptance that is sensitive to charged particles in the pseudorapidity ranges and . Searches are also performed for pairs of P-wave charmonia and limits are set on their production. The cross-sections for these processes, where the dimeson system has a rapidity between 2.0 and 4.5, are measured to be where the upper limits are set at the 90% confidence level. The measured and cross-sections are consistent with theoretical expectations.
An angular analysis of the decay $J/\psi \rightarrow \mu^{+} \mu^{-}$ is performed to measure the polarization of prompt $J/\psi$ mesons produced in $pp$ collisions at $\sqrt{s}=7 \mathrm{TeV}$. The ...dataset corresponds to an integrated luminosity of 0.37 fb$^{-1}$ collected with the LHCb detector. The measurement is presented as a function of transverse momentum, $p_\mathrm{T}$, and rapidity, $y$, of the $J/\psi$ meson, in the kinematic region $2 < p_\mathrm{T} < 15 \mathrm{GeV}/c$ and $2.0
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) An angular analysis of the decay J/psiarrow rightmu ^sup +^ mu ^sup -^ is performed to measure the polarization of prompt ...J/psi mesons produced in pp collisions at ... The dataset corresponds to an integrated luminosity of 0.37 fb^sup -1^ collected with the LHCb detector. The measurement is presented as a function of transverse momentum, p ^sub T^, and rapidity, y, of the J/psi meson, in the kinematic region 2<p ^sub T^<15 GeV/c and 2.0<y<4.5.
These final results from DELPHI searches for the Standard Model (SM) Higgs boson, together with benchmark scans of the Minimal Supersymmetric Standard Model (MSSM) neutral Higgs bosons, used data ...taken at centre-of-mass energies between 200 and 209 GeV with a total integrated luminosity of 224 pb-1. The data from 192 to 202 GeV are reanalysed with improved b-tagging for MSSM final states decaying to four b-quarks. The 95% confidence level lower mass bound on the Standard Model Higgs boson is 114.1 GeV/c2. Limits are also given on the lightest scalar and pseudo-scalar Higgs bosons of the MSSM.
The first observation of the decays B_{(s)}^{0}→J/ψppover ¯ is reported, using proton-proton collision data corresponding to an integrated luminosity of 5.2 fb^{-1}, collected with the LHCb ...detector. These decays are suppressed due to limited available phase space, as well as due to Okubo-Zweig-Iizuka or Cabibbo suppression. The measured branching fractions are B(B^{0}→J/ψppover ¯)=4.51±0.40(stat)±0.44(syst)×10^{-7}, B(B_{s}^{0}→J/ψppover ¯)=3.58±0.19(stat)±0.39(syst)×10^{-6}. For the B_{s}^{0} meson, the result is much higher than the expected value of O(10^{-9}). The small available phase space in these decays also allows for the most precise single measurement of both the B^{0} mass as 5279.74±0.30(stat)±0.10(syst) MeV and the B_{s}^{0} mass as 5366.85±0.19(stat)±0.13(syst) MeV.
Summary
background There is experimental evidence that leptin is required for the development of T helper 1 (Th1)‐mediated autoimmune diseases. However, to our knowledge, there are no studies ...demonstrating such a role in human autoimmune thyroid disease.
objective In the present study we have retrospectively examined patients developing postpartum thyroiditis (PPT), as a model of autoimmune disease, for changes in serum leptin levels during the postpartum period.
materials and methods The study group included 61 women in the first month postpartum who were positive for thyroid peroxidase antibodies (TPOAb+ve). Twenty TPOAb‐negative (–ve), age and body mass index (BMI)‐matched, postpartum women were enrolled as the control group. All subjects were evaluated for BMI, serum leptin values, thyroid function serum free‐triiodiothyronine (FT3), free‐thyroxine (FT4), thyrotropin (TSH) and autoimmunity TPOAb levels and complement activity index (C3 index) at 4, 12, 16, 20 and 24 weeks’ postpartum. During the postpartum period, 32 of 61 TPOAb+ve women (52·4%) showed one or more episodes of thyroid dysfunction (PPTD group), whereas the remaining 29 TPOAb+ve women remained euthyroid throughout the study period (PPTE group). None of the control group developed thyroid dysfunction.
results Four weeks postpartum, TPOAb+ve women showed higher serum leptin values than TPOAb–ve women, despite comparable BMI. At this time, PPTE and PPTD patients showed no significant differences in leptin levels or leptin/BMI ratio. Throughout the postpartum period, PPTD patients maintained significantly higher leptin values and leptin/BMI ratio compared to the healthy women. In PPTE women, however, a significant reduction in leptin levels and leptin/BMI ratio was seen at 12 weeks’ postpartum. This decrease was transient and correlated negatively with the variation in C3 index at the same time. No significant correlation was found between serum leptin variations and FT4 or TSH levels.
conclusions This study has demonstrated that women developing postpartum thyroiditis have higher leptin values compared to the healthy women. The higher levels were maintained for 6 months postpartum. This result would suggest an involvement of leptin in the pathogenesis of postpartum thyroid disease, although further studies are needed to characterize the reciprocal effects of leptin, immune system and thyroid hormones during the course of this disease.
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