Measurement of the [Formula: see text] meson lifetime using [Formula: see text] decays

The lifetime of the [Formula: see text] meson is measured using semileptonic decays having a [Formula: see text] meson and a muon in the final state. The data, corresponding to an integrated luminosity of [Formula: see text], are collected by the LHCb detector in [Formula: see text] collisions at a centre-of-mass energy of 8 TeV. The measured lifetime is [Formula: see text]where the first uncertainty is statistical and the second is systematic.

Observation of photon polarization in the b→sγ transition

This Letter presents a study of the flavor-changing neutral current radiative B±→K±π∓π±γ decays performed using data collected in proton-proton collisions with the LHCb detector at 7 and 8 TeV center-of-mass energies. In this sample, corresponding to an integrated luminosity of 3  fb-1, nearly 14 000 signal events are reconstructed and selected, containing all possible intermediate resonances with a K±π∓π± final state in the [1.1,1.9]  GeV/c2 mass range. The distribution of the angle of the photon direction with respect to the plane defined by the final-state hadrons in their rest frame is studied in intervals of K±π∓π± mass and the asymmetry between the number of signal events found on each side of the plane is obtained. The first direct observation of the photon polarization in the b→sγ transition is reported with a significance of 5.2σ.

Search for Majorana neutrinos in B- → π+ μ- μ- decays

A search for heavy Majorana neutrinos produced in the B- → π+ μ- μ- decay mode is performed using 3  fb(-1) of integrated luminosity collected with the LHCb detector in pp collisions at center-of-mass energies of 7 and 8 TeV at the LHC. Neutrinos with masses in the range 250 to 5000 MeV and lifetimes from zero to 1000 ps are probed. In the absence of a signal, upper limits are set on the branching fraction B(B- → π+ μ- μ-) as functions of neutrino mass and lifetime. These limits are on the order of 10(-9) for short neutrino lifetimes of 1 ps or less. Limits are also set on the coupling between the muon and a possible fourth-generation neutrino.

Measurement of the Bs(0) → Ds-Ds+ and Bs(0) → D-Ds+ effective lifetimes

The first measurement of the effective lifetime of the B(s)(0) meson in the decay B(s)(0) → Ds-Ds+ is reported using a proton-proton collision data set, corresponding to an integrated luminosity of 3 fb(-1), collected by the LHCb experiment. The measured value of the B(s)(0) → Ds-Ds+ effective lifetime is 1.379 ± 0.026 ± 0.017 ps, where the uncertainties are statistical and systematic, respectively. This lifetime translates into a measurement of the decay width of the light B(s)(0) mass eigenstate of ΓL = 0.725 ± 0.014 ± 0.009 ps(-1). The B(s)(0) lifetime is also measured using the flavor-specific B(s)(0)→ D-Ds+ decay to be 1.52 ± 0.15 ± 0.01 ps.

Observation of B(s)(0) → J/ψ f1(1285) decays and measurement of the f1(1285) mixing angle

Decays of B(s)(0) and B(0) mesons into J/ψ π+π-π+π- final states, produced in pp collisions at the LHC, are investigated using data corresponding to an integrated luminosity of 3 fb-1 collected with the LHCb detector. B(s)(0) → J/ψ f1(1285) decays are seen for the first time, and the branching fractions are measured. Using these rates, the f1(1285) mixing angle between strange and nonstrange components of its wave function in the qq structure model is determined to be ±(24.0-2.6-0.8+3.1+0.6)°. Implications on the possible tetraquark nature of the f1(1285) are discussed.

Measurements of indirect CP asymmetries in D0 → K- K+ and D0 → π- π+ decays

A study of indirect CP violation in D0 mesons through the determination of the parameter AΓ is presented using a data sample of pp collisions, corresponding to an integrated luminosity of 1.0  fb(-1), collected with the LHCb detector and recorded at the center-of-mass energy of 7 TeV at the LHC. The parameter AΓ is the asymmetry of the effective lifetimes measured in decays of D0 and D0 mesons to the CP eigenstates K- K+ and π- π+. Fits to the data sample yield AΓ(KK)=(-0.35±0.62±0.12)×10(-3) and AΓ(ππ)=(0.33±1.06±0.14)×10(-3), where the first uncertainties are statistical and the second systematic. The results represent the world's best measurements of these quantities. They show no difference in AΓ between the two final states and no indication of CP violation.

Model fit to experimental data for foam-assisted deep vadose zone remediation

This study investigates how a foam model, developed in Roostapour and Kam [1], can be applied to make a fit to a set of existing laboratory flow experiments in an application relevant to deep vadose zone remediation. This study reveals a few important insights regarding foam-assisted deep vadose zone remediation: (i) the mathematical framework established for foam modeling can fit typical flow experiments matching wave velocities, saturation history, and pressure responses; (ii) the set of input parameters may not be unique for the fit, and therefore conducting experiments to measure basic model parameters related to relative permeability, initial and residual saturations, surfactant adsorption and so on should not be overlooked; and (iii) gas compressibility plays an important role for data analysis, thus should be handled carefully in laboratory flow experiments. Foam kinetics, causing foam texture to reach its steady-state value slowly, may impose additional complications.

Measurement of CP violation in the phase space of B± → K+ K- π± and B± → π+ π- π± decays

The charmless decays B± → K+ K- π± and B± → π+ π- π± are reconstructed in a data set of pp collisions with an integrated luminosity of 1.0  fb(-1) and center-of-mass energy of 7 TeV, collected by LHCb in 2011. The inclusive charge asymmetries of these modes are measured to be A(CP)(B± → K+ K- π±) = -0.141±0.040  (stat)±0.018 (syst)±0.007(J/ψ K±) and A(CP)(B± → π+ π- π±) = 0.117±0.021 (stat)±0.009 (syst)±0.007(J/ψ K±), where the third uncertainty is due to the CP asymmetry of the B± → J/ψK± reference mode. In addition to the inclusive CP asymmetries, larger asymmetries are observed in localized regions of phase space.

Study on plasmatic metabolomics of Uygur patients with essential hypertension based on nuclear magnetic resonance technique

OBJECTIVE

Metabolomics is the analysis of the global constitution of endogenous metabolites in cells, tissue, and bodily fluids based on analysis techniques with high output, high sensitivity, and high resolution. The physiological and pathological state of the subject investigated could be identified and analyzed through examining metabolite changes. In this study, 1H-NMR metabolomics was employed to study plasma metabolites of both Uygur patients with hypertension and healthy people, thereby filtering out characteristic metabolites for Uygur patients with hypertension. The pathogenesis of hypertension was discussed via metabolic pathways.

PATIENTS AND METHODS

A total of 256 Uygur subjects were recruited for this study and divided into two groups, namely hypertension group (157 Uygur patients with hypertension) and normal group (99 healthy Uygur subjects). They were all taken from epidemiological surveys on the Uygur people of Qira County, Hotan, and Xinjiang between 2009 and 2012 conducted by Hypertension Research Group of Xinjiang Medical University. Furthermore, all subjects have Uygur blood within three generations. For the hypertension group, the recruitment criteria is systolic blood pressure (SBP) ≥ 140 mmHg (lmmHg = 0.133 kPa) and/or diastolic blood pressure (DBP) ≥ 90 mmHg at rest. Patients who had taken antihypertensive drugs within two weeks and those who were diagnosed with essential hypertension (EH) were also included in this group, while patients with secondary hypertension, myocardiosis, congenital heart disease, and rheumatic valvular heart disease were not included. In the healthy normal-pressure group, blood pressures were within normal range: SBP < 140 mmHg, DBP < 90 mmHg, without history of antihypertensive drugs, cardiovascular and cerebrovascular diseases, and liver/kidney diseases. All subjects were measured separately with Inova600 nuclear magnetic resonance (NMR) spectrometer to conduct the 1H-NMR experiment. Serum specimens from both the hypertension group and the healthy control group were used for NMR spectrograms before data pre-processing, where aggregate analysis was performed for NMR data/metabolic information with principal component analysis (PCA). Then, partial least squares discriminant analysis (PLS-DA) was employed to classify and predict different groups of specimens, and orthogonal partial least squares discriminant analysis (OPLS-DA) was conducted to cross-validate the quality of the models. Statistical analysis was further performed to test significance of the correlation coefficient to determine differential metabolic components in serums of both groups of subjects. Based on the information from the differential metabolic components, a metabolic pathway network related to hypertension could be constructed, thereby revealing potential biomarkers for hypertension.

RESULTS

Clinical data showed that subjects in the two groups were not significantly different with respect to age, weight, and height, as well as lipid indices, including TG, LDL (p > 0.05), while FPG, SBP, DBP, HDL, and TC were significantly different between the two groups (p < 0.05). OPLS-DA results demonstrated that integral quantities of principal components were mainly distributed within four areas of the ellipse scatter diagram (95% confidence interval). From the score plot and 3D distribution diagram, it can be observed that the distribution areas for the two groups are completely separate, thereby indicating that the serum of the Uygur hypertension patients is significantly different from that of healthy subjects in terms of metabolic components. OPLS-DA results indicate that differences in metabolic components are significant between the two groups, and 12 different metabolites were identified. Compared to healthy subjects, patients with hypertension possess a much lower quantity of many amino acids, including valine, alanine, pyroracemic acid, inose, p-hydroxyphenylalanine, and methylhistidine, among others (p < 0.05), with a significant increase in VLDL, LDL, lactic acid, and acetone (p < 0.05).

CONCLUSIONS

The 1H-NMR metabolomics process, in combination with OPLS-DA pattern identification, is an effective way to differentiate the serum metabolites characteristic of hypertension patients. Pattern identification analysis of NMR spectrum data with OPLS-DA could identify metabolites of hypertension patients versus healthy subjects. The metabolic phenotype of Uygur hypertension patients shows significant heteromorphosis, with the 12 characteristic metabolites as potential biomarkers of hypertension.

Measurement of D0-D0 mixing parameters and search for CP violation using D0 → K+ π- decays

Measurements of charm mixing parameters from the decay-time-dependent ratio of D0 → K+ π- to D0 → K- π+ rates and the charge-conjugate ratio are reported. The analysis uses data, corresponding to 3  fb(-1) of integrated luminosity, from proton-proton collisions at 7 and 8 TeV center-of-mass energies recorded by the LHCb experiment. In the limit of charge-parity (CP ) symmetry, the mixing parameters are determined to be x'2=(5.5±4.9)×10(-5), y'=(4.8±1.0)×10(-3), and RD=(3.568±0.066)×10(-3). Allowing for CP violation, the measurement is performed separately for D0 and D0 mesons yielding AD=(-0.7±1.9)%, for the direct CP-violating asymmetry, and 0.75<|q/p|<1.24 at the 68.3% confidence level, for the parameter describing CP violation in mixing. This is the most precise determination of these parameters from a single experiment and shows no evidence for CP violation.

Measurement of J/ψ polarization in pp collisions at [Formula: see text]

An angular analysis of the decay J/ψ→μ+μ- is performed to measure the polarization of prompt J/ψ mesons produced in pp collisions at [Formula: see text]. 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, pT, and rapidity, y, of the J/ψ meson, in the kinematic region 2 Collapse

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Measurement of form-factor-independent observables in the decay B0→K(*0)μ(+)μ(-)

We present a measurement of form-factor-independent angular observables in the decay B(0)→K*(892)(0)μ(+)μ(-). The analysis is based on a data sample corresponding to an integrated luminosity of 1.0 fb(-1), collected by the LHCb experiment in pp collisions at a center-of-mass energy of 7 TeV. Four observables are measured in six bins of the dimuon invariant mass squared q² in the range 0.1<q²<19.0 GeV²/c(4). Agreement with recent theoretical predictions of the standard model is found for 23 of the 24 measurements. A local discrepancy, corresponding to 3.7 Gaussian standard deviations is observed in one q² bin for one of the observables. Considering the 24 measurements as independent, the probability to observe such a discrepancy, or larger, in one is 0.5%.

Observation of the decay B(c)(+) → B(s)(0)π+

The result of a search for the decay B(c)(+) → B(s)(0) π+ is presented, using the B(s)(0) → D(s)(-)π+ and B(s)(0) → J/ψ Ø channels. The analysis is based on a data sample of pp collisions collected with the LHCb detector, corresponding to an integrated luminosity of 1 fb(-1) taken at a center-of-mass energy of 7 TeV, and 2 fb(-1) taken at 8 TeV. The decay B(c)(+) → B(s)(0)π+ is observed with significance in excess of 5 standard deviations independently in both decay channels. The measured product of the ratio of cross sections and branching fraction is [σ(B(c)(+))/σ(B(s)(0))] × B(B(c)(+)→ B(s)(0)π+) = [2.37 ± 0.31 (stat)± 0.11 (syst)(-0.13)(+0.17)(τ(B)(c)(+)))] × 10(-3), in the pseudorapidity range 2<η(B)<5, where the first uncertainty is statistical, the second is systematic, and the third is due to the uncertainty on the B(c)(+) lifetime. This is the first observation of a B meson decaying to another B meson via the weak interaction.

Measurement of the CP asymmetry in B(+)→K(+)μ(+)μ(-) decays

A measurement of the CP asymmetry in B(+)→K(+)μ(+)μ(-) decays is presented using pp collision data, corresponding to an integrated luminosity of 1.0 fb(-1), recorded by the LHCb experiment during 2011 at a center-of-mass energy of 7 TeV. The measurement is performed in seven bins of μ(+)μ(-) invariant mass squared in the range 0.05<q2<22.00 GeV2/c4, excluding the J/ψ and ψ(2S) resonance regions. Production and detection asymmetries are corrected for using the B(+)→J/ψK(+) decay as a control mode. Averaged over all the bins, the CP asymmetry is found to be A(CP)=0.000±0.033 (stat)±0.005 (syst)±0.007 (J/ψK), where the third uncertainty is due to the CP asymmetry of the control mode. This is consistent with the standard model prediction.

Search for the lepton-flavor-violating decays B(s)0→e(±)μ(∓) and B0→e(±)μ(∓)

A search for the lepton-flavor-violating decays B(s)0→e(±)μ(∓) and B0→e(±)μ(∓) is performed with a data sample, corresponding to an integrated luminosity of 1.0 fb(-1) of pp collisions at √s=7 TeV, collected by the LHCb experiment. The observed number of B(s)0→e(±)μ(∓) and B0→e(±)μ(∓) candidates is consistent with background expectations. Upper limits on the branching fractions of both decays are determined to be B(B(s)0→e(±)μ(∓))<1.1(1.4)×10(-8) and B(B0→e(±)μ(∓))<2.8(3.7)×10(-9) at 90% (95%) confidence level (C.L.). These limits are a factor of 20 lower than those set by previous experiments. Lower bounds on the Pati-Salam leptoquark masses are also calculated, M(LQ)(B(s)0→e(±)μ(∓))>101 TeV/c(2) and M(LQ)(B0→e(±)μ(∓))>126 TeV/c(2) at 95% C.L., and are a factor of 2 higher than the previous bounds.

Observation of a resonance in B+ → K+ μ+ μ- decays at low recoil

A broad peaking structure is observed in the dimuon spectrum of B+ → K+ μ+ μ- decays in the kinematic region where the kaon has a low recoil against the dimuon system. The structure is consistent with interference between the B+ → K+ μ+ μ- decay and a resonance and has a statistical significance exceeding six standard deviations. The mean and width of the resonance are measured to be 4191(-8)(+9)  MeV/c2 and 65(-16)(+22)  MeV/c2, respectively, where the uncertainties include statistical and systematic contributions. These measurements are compatible with the properties of the ψ(4160) meson. First observations of both the decay B+ → ψ(4160)K+ and the subsequent decay ψ(4160) → μ+ μ- are reported. The resonant decay and the interference contribution make up 20% of the yield for dimuon masses above 3770  MeV/c2. This contribution is larger than theoretical estimates.

Precision measurement of the Λb(0) baryon lifetime

The ratio of the Λb(0) baryon lifetime to that of the B(0) meson is measured using 1.0  fb(-1) of integrated luminosity in 7 TeV center-of-mass energy pp collisions at the LHC. The Λb(0) baryon is observed for the first time in the decay mode Λb(0)→J/ψpK-, while the B(0) meson decay used is the well known B(0)→J/ψπ+ K- mode, where the π+ K- mass is consistent with that of the K(*0)(892) meson. The ratio of lifetimes is measured to be 0.976±0.012±0.006, in agreement with theoretical expectations based on the heavy quark expansion. Using previous determinations of the B(0) meson lifetime, the Λb(0) lifetime is found to be 1.482±0.018±0.012  ps. In both cases, the first uncertainty is statistical and the second systematic.

Measurement of CP violation in the phase space of B±→K± π+ π- and B±→K± K+ K- decays

The charmless decays B±→K± π+ π- and B±→K± K+ K- are reconstructed using data, corresponding to an integrated luminosity of 1.0  fb(-1), collected by LHCb in 2011. The inclusive charge asymmetries of these modes are measured as ACP(B±→K± π+ π-)=0.032±0.008 (stat)±0.004 (syst)±0.007(J/ψK±) and ACP(B±→K± K+ K-)=-0.043±0.009 (stat)±0.003 (syst)±0.007(J/ψK±), where the third uncertainty is due to the CP asymmetry of the B±→J/ψK± reference mode. The significance of ACP(B±→K± K+ K-) exceeds three standard deviations and is the first evidence of an inclusive CP asymmetry in charmless three-body B decays. In addition to the inclusive CP asymmetries, larger asymmetries are observed in localized regions of phase space.

Measurement of the Bs(0)→μ+ μ- branching fraction and search for B(0)→μ+ μ- decays at the LHCb experiment

A search for the rare decays Bs(0)→μ+ μ- and B(0)→μ+ μ- is performed at the LHCb experiment. The data analyzed correspond to an integrated luminosity of 1  fb(-1) of pp collisions at a center-of-mass energy of 7 TeV and 2  fb(-1) at 8 TeV. An excess of Bs(0)→μ+ μ- signal candidates with respect to the background expectation is seen with a significance of 4.0 standard deviations. A time-integrated branching fraction of B(Bs(0)→μ+ μ-)=(2.9(-1.0)(+1.1))×10(-9) is obtained and an upper limit of B(B(0)→μ+ μ-)<7.4×10(-10) at 95% confidence level is set. These results are consistent with the standard model expectations.

Clinical significance of serum hepcidin-25 levels in predicting invasive fungal disease in patients after transplantation

BACKGROUND

Currently, it is important to identify a good biomarker to predict treatment-related complications in patients with transplantation. This study aimed to evaluate the significance of serum hepcidin-25 in predicting invasive fungal disease (IFD) after transplantation.

PATIENTS AND METHODS

A total of 57 patients who underwent transplantation were included in this study, and their serum samples were obtained and stored at -80°C for analysis. The serum hepcidin-25 were assayed using enzyme-liked immunosorbent assay (ELISA), and hypersensitive C reactive protein (hsCRP) and 1,3-beta-D glucan were measured using standard laboratory techniques. These indices were monitored weekly, from one week before transplantation to four weeks after transplantation.

RESULTS

The median pretransplant serum hepcidin-25 level was 37.00 ng/mL which was higher than that of healthy volunteers (p < 0.001). Because the higher hepcidin-25 level of the third tertile among the patients was 39.855 ng/mL, we set a cutoff level of 40 ng/mL to divide them into low- and high-hepcidin-25 groups (n = 38 and 19, respectively). The prevalences of the documented infection in the two groups were 2.6% and 26%, respectively (p = 0.019). The high-hepcidin-25 group was monitored after transplantation. The hepcidin-25 level peaked one week after transplantation, followed by gradual decrease. The plasma (1-3)-beta-D-glucan reached the summit two week. The proven of IFD was delayed 10 days on average after hepcidin-25 had arrived summit and 5 days after (1-3)-beta-D-glucan peaked.

CONCLUSIONS

 The pretransplant serum hepcidin-25 level would be a useful indicator for predicting the risk of infection after transplantation; and the dynamic changes of hepcidin-25 in patients with high-hepcidin-25 group would help to predict IFD after transplantation.

First measurement of the CP-violating phase in Bs(0) → ϕϕ decays

A first flavor-tagged measurement of the time-dependent CP-violating asymmetry in B(s)(0) → ϕϕ decays is presented. In this decay channel, the CP-violating weak phase arises due to CP violation in the interference between B(s)(0)-B(s)(0) mixing and the b → sss gluonic penguin decay amplitude. Using a sample of pp collision data corresponding to an integrated luminosity of 1.0 fb(-1) and collected at a center-of-mass energy of 7 TeV with the LHCb detector, 880 B(s)(0) → ϕϕ signal decays are obtained. The CP-violating phase is measured to be in the interval [-2.46,-0.76] rad at a 68% confidence level. The p value of the standard model prediction is 16%.

Measurements of the branching fractions of [Formula: see text] decays

The branching fractions of the decay [Formula: see text] for different intermediate states are measured using data, corresponding to an integrated luminosity of 1.0 fb^-1, collected by the LHCb experiment. The total branching fraction, its charmless component [Formula: see text] and the branching fractions via the resonant [Formula: see text] states η_c (1S) and ψ(2S) relative to the decay via a J/ψ intermediate state are [Formula: see text] Upper limits on the B⁺ branching fractions into the η_c (2S) meson and into the charmonium-like states X(3872) and X(3915) are also obtained.

First observation of CP violation in the decays of B(s)0 mesons

Using pp collision data corresponding to an integrated luminosity of 1.0 fb(-1) and collected by LHCb in 2011 at a center-of-mass energy of 7 TeV, we report the measurement of direct CP violation in B(s)(0)→K(-)π(+) decays, A(CP)(B(s)(0)→K(-)π(+)=0.27±0.04 (stat)±0.01 (syst), with significance exceeding 5 standard deviations. This is the first observation of CP violation in the decays of B(s)(0) mesons. Furthermore, we provide an improved determination of direct CP violation in B(0)→K(+)π(-) decays, A(CP)(B(0)→K(+)π(-)=-0.080±0.007 (stat)±0.003 (syst), which is the most precise measurement of this quantity to date.

Determination of the X(3872) meson quantum numbers

The quantum numbers of the X(3872) meson are determined to be J(PC)=1(++) based on angular correlations in B(+)→X(3872)K(+) decays, where X(3872)→π(+)π(-)J/ψ and J/ψ→μ(+)μ(-). The data correspond to 1.0 fb(-1) of pp collisions collected by the LHCb detector. The only alternative assignment allowed by previous measurements J(PC)=2(-+) is rejected with a confidence level equivalent to more than 8 Gaussian standard deviations using a likelihood-ratio test in the full angular phase space. This result favors exotic explanations of the X(3872) state.

Search for rare B(0)((s))→μ(+)μ(-)μ(+)μ(-) decays

A search for the decays B(0)((s))→μ(+)μ(-)μ(+)μ(-) and B(0)→μ(+)μ(-)μ(+)μ(-) is performed using data, corresponding to an integrated luminosity of 1.0 fb(-1), collected with the LHCb detector in 2011. The number of candidates observed is consistent with the expected background and, assuming phase-space models of the decays, limits on the branching fractions are set: B(B(s)(0)→μ(+)μ(-)μ(+)μ(-))<1.6(1.2)×10(-8) and B(B(0)→μ(+)μ(-)μ(+)μ(-))<6.6(5.3)×10(-9) at 95% (90%) confidence level. In addition, limits are set in the context of a supersymmetric model which allows for the B((s))(0) meson to decay into a scalar (S) and pseudoscalar particle (P), where S and P have masses of 2.5 GeV/c and 214.3 MeV/c, respectively, both resonances decay into μ(+)μ(-). The branching fraction limits for these decays are B(B(s)(0)→SP)<1.6(1.2)×10(-8) and B(B(0)→SP)<6.3(5.1)×10(-9) at 95% (90%) confidence level.

Measurement of the forward energy flow in pp collisions at [Formula: see text]

The energy flow created in pp collisions at [Formula: see text] is studied within the pseudorapidity range 1.9<η<4.9 with data collected by the LHCb experiment. The measurements are performed for inclusive minimum-bias interactions, hard scattering processes and events with an enhanced or suppressed diffractive contribution. The results are compared to predictions given by Pythia-based and cosmic-ray event generators, which provide different models of soft hadronic interactions.

Serum biomarkers and the prognosis of AMI patients

BACKGROUND

It has been proven that serum lactate dehydrogenase (LDH) and total bilirubin (TB) increase during acute myocardial infarction (AMI). However, how they influence the prognosis of AMI patients is still not completely known.

METHODS

A total of 239 patients diagnosed with AMI and admitted to the Fourth Clinical Hospital of Harbin Medical University, between 2007 and 2008, were enrolled in this study. All the patients had not undergone primary percutaneous coronary intervention (PCI) because the time window (24 h) was missed. They all underwent PCI 1 week after the onset of symptoms. Serum high-sensitivity C-reactive protein (hs-CRP), TB, LDH, and other biomarkers were determined between 24 and 48 h of symptom onset. All of the patients were followed up for an average of 3.2±0.4 years for occurrence of major adverse cardiac events (MACE).

RESULTS

Patients with MACE had significantly higher levels of hs-CRP, LDH, cystatin C, uric acid, a higher ratio of LDH and TB (LDH/TB), and a lower level of TB: 8.48±3.84 vs. 2.13±1.32 μmol/l, p<0.01; 1,355.8±654.3 vs. 1,151.7±415.4 U/l, p<0.01; 1.69±0.76 vs. 1.00±0.46 mg/l, p<0.01; 419.6±109.2 vs. 343.2±108.2 μmol/l, p<0.01 and 141.1±46.2 vs. 61.2±26.5, p<0.01; 18.3±6.7 vs. 14.8±6.6 mg/l, p<0.01, respectively. In the multivariate COX analysis, LDH, cystatin C, and LDH/TB were significantly associated with the prognosis of these patients.

CONCLUSIONS

Patients under higher oxidative stress tend to have more MACE. LDH, cystatin C, and LDH/TB are strongly related to the prognosis of AMI patients undergoing elective PCI.

Measurement of the Λ(b)(0), Ξ (b)(-), and Ω(b((-) Baryon masses

Bottom baryons decaying to a J/ψ meson and a hyperon are reconstructed using 1.0 fb(-1) of data collected in 2011 with the LHCb detector. Significant Λ(b)(0) → J/ψΛ, Ξ(b((-) → J/ψΞ(-) and Ω(b)(-) → J/ψΩ(-) signals are observed and the corresponding masses are measured to be M(Λ(b)(0))=5619.53 ± 0.13(stat.) ± 0.45(syst.) MeV/c(2), M(Ξ(b)(-)) = 5795.8 ± 0.9(stat.) ± 0.4(syst.) MeV/c(2), M(Ω(b)(-)) = 6046.0 ± 2.2(stat.) ± 0.5(syst.) MeV/c(2) , while the differences with respect to the Λ(b)(0) mass are M(Ξ(b)(-))-M(Λ(b)(0))=176.2 ± 0.9(stat.) ± 0.1(syst.) MeV/c(2), M(Ω(b)(-))-M(Λ(b)(0))=426.4 ± 2.2(stat.) ± 0.4(syst.) MeV/c(2). These are the most precise mass measurements of the Λ(b)(0), Ξ(b)(-) and Ω(b)(-) baryons to date. Averaging the above Λ(b)(0) mass measurement with that published by LHCb using 35 pb(-1) of data collected in 2010 yields M(Λ(b)(0)) = 5619.44 ± 0.13(stat.)± 0.38(syst.) MeV/c(2).

First observation of the decay Bs2*(5840)(0)→B*+ K- and studies of excited Bs(0) mesons

The properties of the orbitally excited (L=1) Bs(0) states are studied by using 1.0  fb(-1) of pp collisions at sqrt[s]=7  TeV collected with the LHCb detector. The first observation of the Bs2*(5840)(0) meson decaying to B*+ K- is reported, and the corresponding branching fraction measured relative to the B+ K- decay mode. The Bs1(5830)(0)→B*+ K- decay is observed as well. The width of the Bs2*(5840)(0) state is measured for the first time, and the masses of the two states are determined with the highest precision to date. The observation of the Bs2*(5840)(0)→B*+ K- decay favors the spin-parity assignment J(P)=2+ for the Bs2*(5840)(0) meson. In addition, the most precise measurement of the mass difference m(B*+)-m(B+)=45.01±0.30(stat)±0.23(syst)  MeV/c(2) is obtained.

Observation of D0-D0 oscillations

We report a measurement of the time-dependent ratio of D(0) → K(+) π- to D(0) → K(-) π(+) decay rates in D(*+)-tagged events using 1.0 fb(-1) of integrated luminosity recorded by the LHCb experiment. We measure the mixing parameters x('2) = (-0.9 ± 1.3) × 10(-4), y' = (7.2 ± 2.4) × 10(-3), and the ratio of doubly-Cabibbo-suppressed to Cabibbo-favored decay rates R(D) = (3.52 ± 0.15) × 10^{-3}, where the uncertainties include statistical and systematic sources. The result excludes the no-mixing hypothesis with a probability corresponding to 9.1 standard deviations and represents the first observation of D0-D0 oscillations from a single measurement.

Measurement of the CP asymmetry in B(0)→K(*0)μ(+)μ(-) decays

A measurement of the CP asymmetry in B(0)→K(*0)μ(+)μ(-) decays is presented, based on 1.0 fb(-1) of pp collision data recorded by the LHCb experiment during 2011. The measurement is performed in six bins of invariant mass squared of the μ(+)μ(-) pair, excluding the J/ψ and ψ(2S) resonance regions. Production and detection asymmetries are removed using the B(0)→J/ψK(*0) decay as a control mode. The integrated CP asymmetry is found to be -0.072±0.040(stat)±0.005(syst), consistent with the standard model.

Rheological behavior of xanthan gum solution related to shear thinning fluid delivery for subsurface remediation

Xanthan gum solutions are shear thinning fluids which can be used as delivery media to improve the distribution of remedial amendments injected into heterogeneous subsurface environments. The rheological behavior of the shear thinning solution needs to be known to develop an appropriate design for field injection. In this study, the rheological properties of xanthan gum solutions were obtained under various chemical and environmental conditions relevant to delivery of remedial amendments to groundwater. Higher xanthan concentration raised the absolute solution viscosity and increased the degree of shear thinning. Addition of remedial amendments (e.g., phosphate, sodium lactate, ethyl lactate) caused the dynamic viscosity of xanthan solutions to decrease, but they maintained shear-thinning properties. Use of mono- and divalent salts (e.g., Na(+), Ca(2+)) to increase the solution ionic strength also decreased the dynamic viscosity of xanthan and the degree of shear thinning, although the effect reversed at high xanthan concentrations. A power law analysis showed that the consistency index is a linear function of the xanthan concentration. The degree of shear thinning, however, is best described using a logarithmic function. Mechanisms to describe the observed empiricism have been discussed. In the absence of sediments, xanthan solutions maintained their viscosity for months. However, the solutions lost their viscosity over a period of days to weeks when in contact with site sediment. Loss of viscosity is attributed to physical and biodegradation processes.

First evidence for the decay B(s)(0)→μ+ μ-

A search for the rare decays B(s)(0)→μ+ μ- and B(0)→μ+ μ- is performed with data collected in 2011 and 2012 with the LHCb experiment at the Large Hadron Collider. The data samples comprise 1.1  fb(-1) of proton-proton collisions at sqrt[s]=8  TeV and 1.0  fb(-1) at sqrt[s]=7  TeV. We observe an excess of B(s)(0)→μ+ μ- candidates with respect to the background expectation. The probability that the background could produce such an excess or larger is 5.3×10(-4) corresponding to a signal significance of 3.5 standard deviations. A maximum-likelihood fit gives a branching fraction of B(B(s)(0)→μ+ μ-)=(3.2(-1.2)(+1.5))×10(-9), where the statistical uncertainty is 95% of the total uncertainty. This result is in agreement with the standard model expectation. The observed number of B(0)→μ+ μ- candidates is consistent with the background expectation, giving an upper limit of B(B(0)→μ+ μ-)<9.4×10(-10) at 95% confidence level.

Path entanglement of continuous-variable quantum microwaves

Path entanglement constitutes an essential resource in quantum information and communication protocols. Here, we demonstrate frequency-degenerate entanglement between continuous-variable quantum microwaves propagating along two spatially separated paths. We combine a squeezed and a vacuum state using a microwave beam splitter. Via correlation measurements, we detect and quantify the path entanglement contained in the beam splitter output state. Our experiments open the avenue to quantum teleportation, quantum communication, or quantum radar with continuous variables at microwave frequencies.

Measurements of B(c)+ production and mass with the B(c)+ → J/ψπ+ decay

Measurements of B(c)(+) production and mass are performed with the decay mode B(c)(+)→J/ψπ(+) using 0.37 fb(-1) of data collected in pp collisions at √[s]=7 TeV by the LHCb experiment. The ratio of the production cross section times branching fraction between the B(c)(+)→J/ψπ(+) and the B(+)→J/ψK(+) decays is measured to be (0.68±0.10(stat)±0.03(syst)±0.05(lifetime))% for B(c)(+) and B(+) mesons with transverse momenta p(T)>4 GeV/c and pseudorapidities 2.5<η<4.5. The B(c)(+) mass is directly measured to be 6273.7±1.3(stat)±1.6(syst) MeV/c(2), and the measured mass difference with respect to the B(+) meson is M(B(c)(+))-M(B(+))=994.6±1.3(stat)±0.6(syst) MeV/c(2).

Observation of excited Λ(b)(0) baryons

Using pp collision data corresponding to 1.0 fb(-1) integrated luminosity collected by the LHCb detector, two narrow states are observed in the Λ(b)(0)π(+)π(-) spectrum with masses 5911.97±0.12(stat)±0.02(syst)±0.66(Λ(b)(0) mass) MeV/c(2) and 5919.77±0.08(stat)±0.02(syst)±0.66(Λ(b)(0) mass) MeV/c(2). The significances of the observations are 5.2 and 10.2 standard deviations, respectively. These states are interpreted as the orbitally excited Λ(b)(0) baryons, Λ(b)(*0)(5912) and Λ(b)(*0)(5920).

Measurement of the B¯(s)(0) effective lifetime in the J/ψf0(980) final state

The effective lifetime of the B ¯(s)(0) meson in the decay mode B¯(s)(0)→J/ψf(0)(980) is measured using 1.0 fb(-1) of data collected in pp collisions at √s=7 TeV with the LHCb detector. The result is 1.700±0.040±0.026 ps, where the first uncertainty is statistical and the second systematic. As the final state is CP-odd, and CP violation in this mode is measured to be small, the lifetime measurement can be translated into a measurement of the decay width of the heavy B¯(s)(0) mass eigenstate, Γ(H)=0.588±0.014±0.009 ps(-1).

Observation of B0→D¯(0)K(+)K(-) and evidence for B(s)(0)→D¯(0)K(+)K(-)

The first observation of the decay B0→D¯(0)K(+)K(-) is reported from an analysis of 0.62 fb(-1) of pp collision data collected with the LHCb detector. Its branching fraction is measured relative to that of the topologically similar decay B(0)→D ¯(0)π(+)π(-) to be (B(B(0)→D¯(0)K(+)K(-))/B(B(0)→D¯(0)π(+)π(-))=0.056±0.011±0.007,where the first uncertainty is statistical and the second is systematic. The significance of the signal is 5.8σ. Evidence, with 3.8σ significance, for B(s)(0)→D¯(0)K(+)K(-) decays is also presented. The relative branching fraction is measured to be B(B(s)(0)→D¯(0)K(+)K(-))/B(B(0)→D¯(0)K(+)K(-))=0.90±0.27±0.20. These channels are of interest to study the mechanisms behind hadronic B decays, and open new possibilities for CP violation analyses with larger data sets.

Prevalence of multidrug-resistant gram-negative bacilli producing extended-spectrum β-lactamases (ESBLs) and ESBL genes in solid organ transplant recipients

BACKGROUND

Multidrug-resistant (MDR) gram-negative bacilli pose a serious and rapidly emerging threat to recipients of solid organ transplants (SOTs). However, extended-spectrum β-lactamases (ESBLs), as one of the cardinal mechanisms of resistance to antimicrobial agents in SOT recipients, remain obscure. The aim of this study was to investigate the prevalence of strains producing ESBLs in SOT patients with MDR gram-negative bacilli infections and to identify the ESBL genes carried by them.

MATERIALS AND METHODS

Isolates from various clinical specimens of SOT recipients were identified using the VITEK 2 system, and their antibiotic sensitivity was determined by the 2-fold agar dilution method. Isolates suspected of producing ESBL enzymes were tested by an ESBL phenotypic confirmatory method, and the ESBL genotypes were determined by the polymerase chain reaction and sequencing.

RESULTS

A total of 80 MDR gram-negative strains were isolated from 350 SOT recipients. Among these strains, 42 (52.5%) had an ESBL-positive phenotype; 33 (42.3%) patients with ESBL-positive infection were found. Molecular analysis showed that most of the isolates harbored blaCTX-M-9 (78.6%), blaTEM (81.0%), and blaSHV (69.0%) genes. All the ESBL-producing strains were susceptible to carbapenems.

CONCLUSIONS

MDR gram-negative isolates from SOT recipients are frequently ESBL producers. TEM and CTX-M9 were the predominant ESBL types.

Measurement of relative branching fractions of B decays to ψ(2S) and J/ψ mesons

The relative rates of B-meson decays into J/ψ and ψ(2S) mesons are measured for the three decay modes in pp collisions recorded with the LHCb detector. The ratios of branching fractions ([Formula: see text]) are measured to be [Formula: see text] where the third uncertainty is from the ratio of the ψ(2S) and J/ψ branching fractions to μ⁺μ^-.