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.

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.

The visual diagnosis of tuberculous pleuritis under medical thoracoscopy: a retrospective series of 91 cases

BACKGROUND

Despite progress of medical, the fast and accurate diagnosis of tuberculous pleuritis (TP) continues to be a challenge, mainly because of the lack of specific clinical features and the difficulty in isolating the Mycobacterium tuberculosis.

OBJECTIVES

To investigate the role of medical thoracoscopy in definite diagnosis of tuberculous pleuritis, especially the feature of visual diagnosis in tuberculous pleuritis via medical thoracoscopy. We performed a retrospective review of the utility of medical thoracoscopy in tuberculous pleuritis.

PATIENTS AND METHODS

A retrospective chart review was performed of 91 patients who had medical thoracoscopy for suspected TP at the Second Xiangya Hospital from October 1, 2006 to July 30, 2012.

RESULTS

In ninety one cases, 76 patients were diagnosed with TP by pathologic diagnosis. The visual findings via thoracoscopy of 76 TP patients included the following: (1) necrosis (76.32%, n=58), (2) diffuse miliary nodules (64.67%, n=49), (3) single or multiple pleural nodules (14.47%, n=11), (4) hyperemic, edematous and thickened pleura (56.58%, n=43), and (5) pleural adhesions or fibrotic septa (78.95%, n=60), and all of these samples had hydrothorax or loculated effusion. The diagnostic efficiency of visual diagnosis via medical thoracoscopy about tuberculous pleuritis was 93.41%. In the non-invasive test, ADA > 40 u/l with LDH > 200 u/l for TP showed relatively high sensitivity and specificity (73.68%, 80.00%, respectively).

CONCLUSIONS

TP presents a variety of scopic phenotypes under medical thoracoscopy. The experienced pulmonologists visually diagnose TP efficiently and directly via medical thoracoscopy. Medical thoracoscopy with combined biopsy is an accurate and safe method for diagnosing TP.

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.

Predictive value of miR-9 as a potential biomarker for nasopharyngeal carcinoma metastasis

Background:

Nasopharyngeal carcinoma (NPC) has a distinctive geographic distribution and is characterised by its strong tendency of metastasis. We aimed to examine the microRNA (miRNA) expression profiles in plasma samples of NPC patients to explore their clinical significance in disease development and progression.

Methods:

This study was divided into four steps: (1) confirmation of differentially expressed miRNAs using microarray analysis and quantitative PCR validation; (2) comparison of plasma miR-9 levels during NPC progression; (3) evaluation of the predictive performance of plasma miR-9 as a biomarker for NPC metastasis; and (4) comparison of plasma miR-9 levels between pre- and post-treatment samples.

Results:

Plasma microarray profiling identified 33 differentially expressed miRNAs between NPC patients and healthy volunteers. The significantly declined level of miR-9 in NPC patients was confirmed through two-stage validation. The low level of plasma miR-9 was significantly correlated with worse lymphatic invasion and advanced TNM stage. The plasma miR-9 could distinguish locoregional from metastatic NPC cases with a high sensitivity and specificity. Furthermore, the plasma miR-9 level was significantly elevated in post-treatment plasma compared with those pre-treatment samples.

Conclusion:

Our study reports that plasma miR-9 may serve as a useful biomarker to predict NPC metastasis and to monitor tumour dynamics.

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%.

Predictors for dose reduction of antiviral therapy in older patients infected with hepatitis C virus: a meta-regression analysis

Treatment-related adverse events (AE) were more frequent in older patients treated by pegylated interferon (PEG-IFN) plus ribavirin (RBV) for chronic hepatitis C (CHC), and most of them required dose reduction. A meta-regression analysis was conducted to explore the possible reasons for this occurrence. We searched MEDLINE, EMBASE, and Web of Science through May 2013, for clinical trials examining the safety of PEG-IFN plus RBV in elderly patients with CHC. Data were extracted for host, viral, and outcome information. Single-arm meta-analysis was performed to evaluate AE. Meta-regression analysis was conducted to explore predictors for dose reduction secondary to AE. Eighteen observational studies met the inclusion criteria. The overall incidences of AE were 61.3%. Dose reductions due to AE were 54.2%. In patients with genotype 1, the rate of sustained virological response (SVR) was 36.9%. In patients with genotypes 2 or 3, the rate of SVR was 72.8%. Patients with more dose reduction due to AE have a tendency toward a lower likelihood of obtaining SVR (coefficient:-0.529), especially for genotype 1 patients. Host factors (male gender, coefficient 4.403; higher body weight, coefficient 0.140; and advanced fibrosis stage, coefficient 1.582) and viral factors (HCV genotype 1, coefficient 2.279) have a significant impact on dose reduction due to AE. Some host and viral factors affected dose reduction due to AE. Increasing rates of fibrosis with age may play a role as a mechanism affecting dose reduction secondary to AE and SVR in different age groups.

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.

Thrombus-targeted perfluorocarbon-containing liposomal bubbles for enhancement of ultrasonic thrombolysis: in vitro and in vivo study

BACKGROUND

External low-frequency ultrasound (USD) in combination with microbubbles has been reported to recanalize thrombotically occluded arteries in animal models.

OBJECTIVE

The purpose of this study was to examine the enhancing effect of thrombus-targeted bubble liposomes (BLs) developed for fresh thrombus imaging during ultrasonic thrombolysis.

METHODS

In vitro: after the administration of thrombus-targeted BLs or non-targeted BLs, the clot was exposed to low-frequency (27 kHz) USD for 5 min. In vivo: Rabbit iliofemoral arteries were thrombotically occluded, and an intravenous injection of either targeted BLs (n = 22) or non-targeted BLs (n = 22) was delivered. External low-frequency USD (low intensity, 1.4 W cm(-2) , to 12 arteries, and high intensity, 4.0 W cm(-2) , to 10 arteries, for both the targeted BL group and the non-targeted BL group) was applied to the thrombotically occluded arteries for 60 min. In another 10 rabbits, recombinant tissue-type plasminogen activator (rt-PA) was intravenously administered.

RESULTS

In vitro: the weight reduction rate of the clot with targeted BLs was significantly higher than that of the clot with non-targeted BLs. In vivo: TIMI grade 3 flow was present in a significantly higher number of rabbits with USD and targeted BLs than rabbits with USD and non-targeted BLs, or with rt-PA monotherapy. High-intensity USD exposure with targeted BLs achieved arterial recanalization in 90% of arteries, and the time to reperfusion was shorter than with rt-PA treatment (targeted BLs, 16.7 ± 5.0 min; rt-PA, 41.3 ± 14.4 min).

CONCLUSIONS

Thrombus-targeted BLs developed for USD thrombus imaging enhance ultrasonic disruption of thrombus both in vitro and in vivo.

RhoA modulates functional and physical interaction between ROCK1 and Erk1/2 in selenite-induced apoptosis of leukaemia cells

RhoA GTPase dysregulation is frequently reported in various tumours and haematologic malignancies. RhoA, regulating Rho-associated coiled-coil-forming kinase 1 (ROCK1), modulates multiple cell functions, including malignant transformation, metastasis and cell death. Therefore, RhoA/ROCK1 could be an ideal candidate target in cancer treatment. However, the roles of RhoA/ROCK1 axis in apoptosis of leukaemia cells remain elusive. In this study, we explored the effects of RhoA/ROCK1 cascade on selenite-induced apoptosis of leukaemia cells and the underlying mechanism. We found selenite deactivated RhoA/ROCK1 and decreased the association between RhoA and ROCK1 in leukaemia NB4 and Jurkat cells. The inhibited RhoA/ROCK1 signalling enhanced the phosphorylation of Erk1/2 in a Mek1/2-independent manner. Erk1/2 promoted apoptosis of leukaemia cells after it was activated. Intriguingly, it was shown that both RhoA and ROCK1 were present in the multimolecular complex containing Erk1/2. GST pull-down analysis showed ROCK1 had a direct interaction with GST-Erk2. In addition, selenite-induced apoptosis in an NB4 xenograft model was also found to be associated with the RhoA/ROCK1/Erk1/2 pathway. Our data demonstrate that the RhoA/ROCK1 signalling pathway has important roles in the determination of cell fates and the modulation of Erk1/2 activity at the Mek–Erk interplay level.

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.