Observation of Two Resonances in the Λ_{b}^{0}π^{±} Systems and Precise Measurement of Σ_{b}^{±} and Σ_{b}^{*±} Properties

The first observation of two structures consistent with resonances in the final states Λ_{b}^{0}π^{-} and Λ_{b}^{0}π^{+} is reported using samples of pp collision data collected by the LHCb experiment at sqrt[s]=7 and 8 TeV, corresponding to an integrated luminosity of 3  fb^{-1}. The ground states Σ_{b}^{±} and Σ_{b}^{*±} are also confirmed and their masses and widths are precisely measured.

Osteoporotic Changes in the Periodontium Impair Alveolar Bone Healing

Osteoporosis is associated with decreased bone density and increased bone fragility, but how this disease affects alveolar bone healing is not clear. The objective of this study was to determine the extent to which osteoporosis affects the jaw skeleton and then to evaluate possible mechanisms whereby an osteoporotic phenotype might affect the rate of alveolar bone healing following tooth extraction. Using an ovariectomized mouse model coupled with micro-computed tomographic imaging, histologic, molecular, and cellular assays, we first demonstrated that the appendicular and jaw skeletons both develop osteoporotic phenotypes. Next, we demonstrated that osteoporotic mice exhibit atrophy of the periodontal ligament (PDL) and that this atrophy was accompanied by a reduction in the pool of osteoprogenitor cells in the PDL. The paucity of PDL-derived osteoprogenitor cells in osteoporotic mice was associated with significantly slower extraction socket healing. Collectively, these analyses demonstrate that the jaw skeleton is susceptible to the untoward effects of osteoporosis that manifest as thinner, more porous alveolar bone, PDL thinning, and slower bone repair. These findings have potential clinical significance for older osteopenic patients undergoing reconstructive procedures.

Molecular Basis for Periodontal Ligament Adaptation to In Vivo Loading

A soft food diet leads to changes in the periodontal ligament (PDL). These changes, which have been recognized for more than a century, are ascribed to alterations in mechanical loading. While these adaptive responses have been well characterized, the molecular, cellular, and mechanical mechanisms underlying the changes have not. Here, we implicate Wnt signaling in the pathoetiology of PDL responses to underloading. We show that Wnt-responsive cells and their progeny in the PDL space exhibit a burst in proliferation in response to mastication. If an animal is fed a soft diet from the time of weaning, then this burst in Wnt-responsive cell proliferation is quelled; as a consequence, both the PDL and the surrounding alveolar bone undergo atrophy. Returning these animals to a hard food diet restores the Wnt signaling in PDL. These data provide, for the first time, a molecular mechanism underlying the adaptive response of the PDL to loading.

Jia-Wei-Si-Miao-Wan alleviates acute gouty arthritis by targeting NLRP3 inflammasome

Gout is a common metabolic disease and acute gouty arthritis (AGA) is one of the important complications. Jia-Wei-Si-Miao-Wan is a newly developed drug for treating acute gouty arthritis, but the molecular mechanism has not been completely clarified. Thus, this study was aimed to explore the regulation of Jia-Wei-Si-Miao-Wan on NLRP3 inflammasome and TLR/NF-κB signaling, which are two important signaling pathways in inflammation. AGA rat model was established by injecting monosodium urate into the right knee. Colchicine and Jia-Wei-Si-Miao-Wan were administrated by gavage. The circumference of the knee was measured. IL-1β and IL-18 level in the flushing fluid was detected by enzyme linked immunosorbent assay (ELISA). Western blot, immunohistochemistry and quantitative real-time RT-PCR were used to detect the protein and mRNA expression of TLR4, NLRP3, ASC, caspase-1, NF-κB and p-NF-κB. The results showed that IL-1β and IL-18 level in the flushing fluid was increased and TLR4, NLRP3, ASC, caspase-1, NF-κB and p-NF-κB expressions were up-regulated after the establishment of AGA rat model. Colchicine and Jia-Wei-Si-Miao-Wan administration could alleviate the inflammation in the knee by inhibiting NLRP3 inflammasome and TLR/NF-κB signaling. In vivo data showed that the therapeutic effect of Jia-Wei-Si-Miao-Wan could be comparable with colchicine but had lower hepatic and renal toxicity. In conclusion, Targeting NLRP3 inflammasome and TLR/NF-κB signaling by Jia-Wei-Si-Miao-Wan could be effective in treating AGA.

Evidence for an η c ( 1 S ) π - resonance in B 0 → η c ( 1 S ) K + π - decays

A Dalitz plot analysis of B 0 → η c ( 1 S ) K + π - decays is performed using data samples of pp collisions collected with the LHCb detector at centre-of-mass energies of s = 7 , 8 and 13 Te V , corresponding to a total integrated luminosity of 4.7 fb - 1 . A satisfactory description of the data is obtained when including a contribution representing an exotic η c ( 1 S ) π - resonant state. The significance of this exotic resonance is more than three standard deviations, while its mass and width are 4096 ± 20 - 22 + 18 Me V and 152 ± 58 - 35 + 60 Me V , respectively. The spin-parity assignments J P = 0 + and J P = 1 - are both consistent with the data. In addition, the first measurement of the B 0 → η c ( 1 S ) K + π - branching fraction is performed and gives B ( B 0 → η c ( 1 S ) K + π - ) = ( 5.73 ± 0.24 ± 0.13 ± 0.66 ) × 10 - 4 , where the first uncertainty is statistical, the second systematic, and the third is due to limited knowledge of external branching fractions.

Search for lepton-flavour-violating decays of Higgs-like bosons

A search is presented for a Higgs-like boson with mass in the range 45 to 195 GeV / c 2 decaying into a muon and a tau lepton. The dataset consists of proton-proton interactions at a centre-of-mass energy of 8 TeV , collected by the LHCb experiment, corresponding to an integrated luminosity of 2 fb - 1 . The tau leptons are reconstructed in both leptonic and hadronic decay channels. An upper limit on the production cross-section multiplied by the branching fraction at 95% confidence level is set and ranges from 22 pb for a boson mass of 45 GeV / c 2 to 4 pb for a mass of 195 GeV / c 2 .

Measurement of Antiproton Production in p-He Collisions at sqrt[s_{NN}]=110 GeV

The cross section for prompt antiproton production in collisions of protons with an energy of 6.5 TeV incident on helium nuclei at rest is measured with the LHCb experiment from a data set corresponding to an integrated luminosity of 0.5  nb^{-1}. The target is provided by injecting helium gas into the LHC beam line at the LHCb interaction point. The reported results, covering antiproton momenta between 12 and 110  GeV/c, represent the first direct determination of the antiproton production cross section in p-He collisions, and impact the interpretation of recent results on antiproton cosmic rays from space-borne experiments.

LncRNA GASL1 inhibits tumor growth of non-small cell lung cancer by inactivating TGF-β pathway

OBJECTIVE

Growth-Arrest Associated lncRNA 1 (GASL1) is a newly discovered lncRNA that plays a role as tumor suppressor gene in liver cancer, while its involvement in other malignancies is unknown. We aimed to investigate the involvement of GASL1 in non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

Tumor tissue and adjacent healthy tissues were collected from 98 patients with NSCLC, and blood samples were collected from both NSCLC patients and healthy controls to detect GASL1 expression. All patients were followed up for 5 years and the diagnostic and prognostic values of GASL1 for NSCLC were evaluated by ROC curve analysis and survival curve analysis, respectively. Correlations between serum levels of GASL1 and clinicopathological data of NSCLC patients were analyzed by Chi-square test. GASL1 overexpression and knockdown cancer cell lines were constructed and the effects on transforming growth factor β1 (TGF-β1) expression and cell proliferation were explored by Western blot and CCK-8 assay, respectively.

RESULTS

We found that lncRNA GASL1 expression was significantly downregulated in tumor tissues than in adjacent healthy tissues. Serum level of GASL1 was also lower in cancer patients than in healthy controls. Serum GASL1 is a sensitive diagnostic biomarker for NSCLC, and low expression level of GASL1 indicated short postoperative survival time. Overexpression of GASL1 upregulated, while GASL1 knockdown downregulated TGF-β1 expression. GASL1 overexpression inhibited, and GASL1 knockdown promoted cancer cell proliferation.

CONCLUSIONS

We found that lncRNA GASL1 may inhibit tumor growth of NSCLC by downregulating TGF-β1.

First Observation of the Doubly Charmed Baryon Decay Ξ_{cc}^{++}→Ξ_{c}^{+}π^{+}

The doubly charmed baryon decay Ξ_{cc}^{++}→Ξ_{c}^{+}π^{+} is observed for the first time, with a statistical significance of 5.9σ, confirming a recent observation of the baryon in the Λ_{c}^{+}K^{-}π^{+}π^{+} final state. The data sample used corresponds to an integrated luminosity of 1.7  fb^{-1}, collected by the LHCb experiment in pp collisions at a center-of-mass energy of 13 TeV. The Ξ_{cc}^{++} mass is measured to be 3620.6±1.5(stat)±0.4(syst)±0.3(Ξ_{c}^{+})  MeV/c^{2} and is consistent with the previous result. The ratio of branching fractions between the decay modes is measured to be [B(Ξ_{cc}^{++}→Ξ_{c}^{+}π^{+})×B(Ξ_{c}^{+}→pK^{-}π^{+})]/[B(Ξ_{cc}^{++}→Λ_{c}^{+}K^{-}π^{+}π^{+})×B(Λ_{c}^{+}→pK^{-}π^{+})]=0.035±0.009(stat)±0.003(syst).

Successful Transplantation of "Black Kidneys" Due to Myoglobin Nephropathy

Four kidneys from 2 young donors suffering from rhabdomyolysis were rejected for transplantation at the time of procurement because of their severely bruised and black gross appearance. A frozen section revealed a focal tubular injury filled with granular pigmented casts which an immunohistochemistry confirmed to be myoglobin. The 4 kidneys were transplanted successfully and all recipients recovered normal renal function with no delay. These cases indicate that kidneys with patchy black gross appearance caused by myoglobin casts secondary to rhabdomyolysis is not a contraindication for transplantation.

Velocity-space sensitivity of time-of-flight neutron spectrometer at EAST in deuterium plasma

The Time-Of-Flight Enhanced Diagnostics (TOFED) neutron spectrometer with a double-ring structure has been installed at the Experimental Advanced Superconducting Tokamak (EAST) to perform advanced neutron emission spectroscopy diagnosis for deuterium plasma. In order to reduce the random coincidence from the background neutrons and gamma-rays, TOFED was moved outside the experimental hall and placed in the newly-built nuclear diagnostics laboratory in 2017. In this paper, the instrument-specific weight functions of TOFED are derived by taking the instrument response matrix and the radial line of sight in this new layout into consideration. The results show that the instrument is predominantly sensitive to counter-passing particles in the region where time-of-flights < 69.4 ns, while events at higher time-of-flights (corresponding lower neutron energies) are mostly representative of co-passing ions. The instrument-specific weight functions express the relationship between data in a given channel of the spectrum and the velocity space region that contributes to that. The results can be applied for energetic particle physics studies at EAST, in particular to compare data from different diagnostic techniques.

Measurement of Angular and CP Asymmetries in D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} Decays

The first measurements of the forward-backward asymmetry of the dimuon pair (A_{FB}), the triple-product asymmetry (A_{2ϕ}), and the charge-parity-conjugation asymmetry (A_{CP}), in D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} decays are reported. They are performed using data from proton-proton collisions collected with the LHCb experiment from 2011 to 2016, corresponding to a total integrated luminosity of 5  fb^{-1}. The asymmetries are measured to be A_{FB}(D^{0}→π^{+}π^{-}μ^{+}μ^{-})=(3.3±3.7±0.6)%, A_{2ϕ}(D^{0}→π^{+}π^{-}μ^{+}μ^{-})=(-0.6±3.7±0.6)%, A_{CP}(D^{0}→π^{+}π^{-}μ^{+}μ^{-})=(4.9±3.8±0.7)%, A_{FB}(D^{0}→K^{+}K^{-}μ^{+}μ^{-})=(0±11±2)%, A_{2ϕ}(D^{0}→K^{+}K^{-}μ^{+}μ^{-})=(9±11±1)%, A_{CP}(D^{0}→K^{+}K^{-}μ^{+}μ^{-})=(0±11±2)%, where the first uncertainty is statistical and the second systematic. The asymmetries are also measured as a function of the dimuon invariant mass. The results are consistent with the standard model predictions.

Measurement of the Ω_{c}^{0} Baryon Lifetime

We report a measurement of the lifetime of the Ω_{c}^{0} baryon using proton-proton collision data at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3.0  fb^{-1} collected by the LHCb experiment. The sample consists of about 1000  Ω_{b}^{-}→Ω_{c}^{0}μ^{-}ν[over ¯]_{μ}X signal decays, where the Ω_{c}^{0} baryon is detected in the pK^{-}K^{-}π^{+} final state and X represents possible additional undetected particles in the decay. The Ω_{c}^{0} lifetime is measured to be τ_{Ω_{c}^{0}}=268±24±10±2  fs, where the uncertainties are statistical, systematic, and from the uncertainty in the D^{+} lifetime, respectively. This value is nearly four times larger than, and inconsistent with, the current world-average value.

ELF3 is an antagonist of oncogenic-signalling-induced expression of EMT-TF ZEB1

Background: Epithelial-to-mesenchymal transition (EMT) is a key step in the transformation of epithelial cells into migratory and invasive tumour cells. Intricate positive and negative regulatory processes regulate EMT. Many oncogenic signalling pathways can induce EMT, but the specific mechanisms of how this occurs, and how this process is controlled are not fully understood. Methods: RNA-Seq analysis, computational analysis of protein networks and large-scale cancer genomics datasets were used to identify ELF3 as a negative regulator of the expression of EMT markers. Western blotting coupled to siRNA as well as analysis of tumour/normal colorectal cancer panels was used to investigate the expression and function of ELF3. Results: RNA-Seq analysis of colorectal cancer cells expressing mutant and wild-type β-catenin and analysis of colorectal cancer cells expressing inducible mutant RAS showed that ELF3 expression is reduced in response to oncogenic signalling and antagonizes Wnt and RAS oncogenic signalling pathways. Analysis of gene-expression patterns across The Cancer Genome Atlas (TCGA) and protein localization in colorectal cancer tumour panels showed that ELF3 expression is anti-correlated with β-catenin and markers of EMT and correlates with better clinical prognosis. Conclusions: ELF3 is a negative regulator of the EMT transcription factor (EMT-TF) ZEB1 through its function as an antagonist of oncogenic signalling.

Observation of a New Ξ_{b}^{-} Resonance

From samples of pp collision data collected by the LHCb experiment at sqrt[s]=7, 8 and 13 TeV, corresponding to integrated luminosities of 1.0, 2.0 and 1.5  fb^{-1}, respectively, a peak in both the Λ_{b}^{0}K^{-} and Ξ_{b}^{0}π^{-} invariant mass spectra is observed. In the quark model, radially and orbitally excited Ξ_{b}^{-} resonances with quark content bds are expected. Referring to this peak as Ξ_{b}(6227)^{-}, the mass and natural width are measured to be m_{Ξ_{b}(6227)^{-}}=6226.9±2.0±0.3±0.2  MeV/c^{2} and Γ_{Ξ_{b}(6227)^{-}}=18.1±5.4±1.8  MeV/c^{2}, where the first uncertainty is statistical, the second is systematic, and the third, on m_{Ξ_{b}(6227)^{-}}, is due to the knowledge of the Λ_{b}^{0} baryon mass. Relative production rates of the Ξ_{b}(6227)^{-}→Λ_{b}^{0}K^{-} and Ξ_{b}(6227)^{-}→Ξ_{b}^{0}π^{-} decays are also reported.

Measurement of the Lifetime of the Doubly Charmed Baryon Ξ_{cc}^{++}

The first measurement of the lifetime of the doubly charmed baryon Ξ_{cc}^{++} is presented, with the signal reconstructed in the final state Λ_{c}^{+}K^{-}π^{+}π^{+}. The data sample used corresponds to an integrated luminosity of 1.7  fb^{-1}, collected by the LHCb experiment in proton-proton collisions at a center-of-mass energy of 13 TeV. The Ξ_{cc}^{++} lifetime is measured to be 0.256_{-0.022}^{+0.024}(stat)±0.014(syst)  ps.

Amplitude Analysis of the Decay B[over ¯]^{0}→K_{S}^{0}π^{+}π^{-} and First Observation of the CP Asymmetry in B[over ¯]^{0}→K^{*}(892)^{-}π^{+}

The time-integrated untagged Dalitz plot of the three-body hadronic charmless decay B[over ¯]^{0}→K_{S}^{0}π^{+}π^{-} is studied using a pp collision data sample recorded with the LHCb detector, corresponding to an integrated luminosity of 3.0  fb^{-1}. The decay amplitude is described with an isobar model. Relative contributions of the isobar amplitudes to the B[over ¯]^{0}→K_{S}^{0}π^{+}π^{-} decay branching fraction and CP asymmetries of the flavor-specific amplitudes are measured. The CP asymmetry between the conjugate B[over ¯]^{0}→K^{*}(892)^{-}π^{+} and B^{0}→K^{*}(892)^{+}π^{-} decay rates is determined to be -0.308±0.062.

Studies of the resonance structure in D 0 → K ∓ π ± π ± π ∓ decays

Amplitude models are constructed to describe the resonance structure of D 0 → K - π + π + π - and D 0 → K + π - π - π + decays using pp collision data collected at centre-of-mass energies of 7 and 8 TeV with the LHCb experiment, corresponding to an integrated luminosity of 3.0  f b - 1 . The largest contributions to both decay amplitudes are found to come from axial resonances, with decay modes D 0 → a 1 ( 1260 ) + K - and D 0 → K 1 ( 1270 / 1400 ) + π - being prominent in D 0 → K - π + π + π - and D 0 → K + π - π - π + , respectively. Precise measurements of the lineshape parameters and couplings of the a 1 ( 1260 ) + , K 1 ( 1270 ) - and K ( 1460 ) - resonances are made, and a quasi model-independent study of the K ( 1460 ) - resonance is performed. The coherence factor of the decays is calculated from the amplitude models to be R K 3 π = 0.459 ± 0.010 ( stat ) ± 0.012 ( syst ) ± 0.020 ( model ) , which is consistent with direct measurements. These models will be useful in future measurements of the unitary-triangle angle γ and studies of charm mixing and C P violation.

Evidence for the Rare Decay Σ^{+}→pμ^{+}μ^{-}

A search for the rare decay Σ^{+}→pμ^{+}μ^{-} is performed using pp collision data recorded by the LHCb experiment at center-of-mass energies sqrt[s]=7 and 8 TeV, corresponding to an integrated luminosity of 3  fb^{-1}. An excess of events is observed with respect to the background expectation, with a signal significance of 4.1 standard deviations. No significant structure is observed in the dimuon invariant mass distribution, in contrast with a previous result from the HyperCP experiment. The measured Σ^{+}→pμ^{+}μ^{-} branching fraction is (2.2_{-1.3}^{+1.8})×10^{-8}, where statistical and systematic uncertainties are included, which is consistent with the standard model prediction.

Interferon-gamma response to the treatment of active pulmonary and extra-pulmonary tuberculosis

BACKGROUND

Interferon-gamma (IFN-γ) release assays (IGRAs) are used to diagnose tuberculosis (TB) but not to measure treatment response.

OBJECTIVE

To measure IFN-γ response to active anti-tuberculosis treatment.

DESIGN

Patients from the Henan Provincial Chest Hospital, Henan, China, with TB symptoms and/or signs were enrolled into this prospective, observational cohort study and followed for 6 months of treatment, with blood and sputum samples collected at 0, 2, 4, 6, 8, 16 and 24 weeks. The QuantiFERON® TB-Gold assay was run on collected blood samples. Participants received a follow-up telephone call at 24 months to determine relapse status.

RESULTS

Of the 152 TB patients enrolled, 135 were eligible for this analysis: 118 pulmonary (PTB) and 17 extra-pulmonary TB (EPTB) patients. IFN-γ levels declined significantly over time among all patients (P = 0.002), with this decline driven by PTB patients (P = 0.001), largely during the initial 8 weeks of treatment (P = 0.019). IFN-γ levels did not change among EPTB patients over time or against baseline culture or drug resistance status.

CONCLUSION

After 6 months of effective anti-tuberculosis treatment, IFN-γ levels decreased significantly in PTB patients, largely over the initial 8 weeks of treatment. IFN-γ concentrations may offer some value for monitoring anti-tuberculosis treatment response among PTB patients.

Measurement of the Ratio of the B^{0}→D^{*-}τ^{+}ν_{τ} and B^{0}→D^{*-}μ^{+}ν_{μ} Branching Fractions Using Three-Prong τ-Lepton Decays

The ratio of branching fractions R(D^{*-})≡B(B^{0}→D^{*-}τ^{+}ν_{τ})/B(B^{0}→D^{*-}μ^{+}ν_{μ}) is measured using a data sample of proton-proton collisions collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3  fb^{-1}. For the first time, R(D^{*-}) is determined using the τ-lepton decays with three charged pions in the final state. The B^{0}→D^{*-}τ^{+}ν_{τ} yield is normalized to that of the B^{0}→D^{*-}π^{+}π^{-}π^{+} mode, providing a measurement of B(B^{0}→D^{*-}τ^{+}ν_{τ})/B(B^{0}→D^{*-}π^{+}π^{-}π^{+})=1.97±0.13±0.18, where the first uncertainty is statistical and the second systematic. The value of B(B^{0}→D^{*-}τ^{+}ν_{τ})=(1.42±0.094±0.129±0.054)% is obtained, where the third uncertainty is due to the limited knowledge of the branching fraction of the normalization mode. Using the well-measured branching fraction of the B^{0}→D^{*-}μ^{+}ν_{μ} decay, a value of R(D^{*-})=0.291±0.019±0.026±0.013 is established, where the third uncertainty is due to the limited knowledge of the branching fractions of the normalization and B^{0}→D^{*-}μ^{+}ν_{μ} modes. This measurement is in agreement with the standard model prediction and with previous results.

Biomechanics of Immediate Postextraction Implant Osseointegration

The aim of this study was to gain insights into the biology and mechanics of immediate postextraction implant osseointegration. To mimic clinical practice, murine first molar extraction was followed by osteotomy site preparation, specifically in the palatal root socket. The osteotomy was positioned such that it removed periodontal ligament (PDL) only on the palatal aspect of the socket, leaving the buccal aspect undisturbed. This strategy created 2 distinct peri-implant environments: on the palatal aspect, the implant was in direct contact with bone, while on the buccal aspect, a PDL-filled gap existed between the implant and bone. Finite element modeling showed high strains on the palatal aspect, where bone was compressed by the implant. Osteocyte death and bone resorption predominated on the palatal aspect, leading to the loss of peri-implant bone. On the buccal aspect, where finite element modeling revealed low strains, there was minimal osteocyte death and robust peri-implant bone formation. Initially, the buccal aspect was filled with PDL remnants, which we found directly provided Wnt-responsive cells that were responsible for new bone formation and osseointegration. On the palatal aspect, which was devoid of PDL and Wnt-responsive cells, adding exogenous liposomal WNT3A created an osteogenic environment for rapid peri-implant bone formation. Thus, we conclude that low strain and high Wnt signaling favor osseointegration of immediate postextraction implants. The PDL harbors Wnt-responsive cells that are inherently osteogenic, and if the PDL tissue is healthy, it is reasonable to preserve this tissue during immediate implant placement.

Physiological responses to swimming fatigue in juvenile largemouth bronze gudgeon Coreius guichenoti

Stepped velocity tests were conducted on juvenile largemouth bronze gudgeon Coreius guichenoti in a swim tunnel respirometer, and oxygen consumption increased with swimming speed to fatigue and then decreased during recovery. Serum levels of total protein, glucose and triglycerides initially decreased, increased at fatigue and then decreased during recovery. Levels stabilized after 120 min, corresponding to the time necessary to recover from fatigue.

Measurement of the Ratio of Branching Fractions B(B_{c}^{+}→J/ψτ^{+}ν_{τ})/B(B_{c}^{+}→J/ψμ^{+}ν_{μ})

A measurement is reported of the ratio of branching fractions R(J/ψ)=B(B_{c}^{+}→J/ψτ^{+}ν_{τ})/B(B_{c}^{+}→J/ψμ^{+}ν_{μ}), where the τ^{+} lepton is identified in the decay mode τ^{+}→μ^{+}ν_{μ}ν[over ¯]_{τ}. This analysis uses a sample of proton-proton collision data corresponding to 3.0  fb^{-1} of integrated luminosity recorded with the LHCb experiment at center-of-mass energies of 7 and 8 TeV. A signal is found for the decay B_{c}^{+}→J/ψτ^{+}ν_{τ} at a significance of 3 standard deviations corrected for systematic uncertainty, and the ratio of the branching fractions is measured to be R(J/ψ)=0.71±0.17(stat)±0.18(syst). This result lies within 2 standard deviations above the range of central values currently predicted by the standard model.

Wnt-Responsive Odontoblasts Secrete New Dentin after Superficial Tooth Injury

The objective of our experiments was to identify new therapeutic strategies to stimulate dentin formation in an adult tooth. To address this objective, we evaluated dentin production in 2 acute trauma models: one involving a pulp exposure and the other involving a superficial dentin injury. Molecular, cellular, and histologic analyses revealed that in response to a severe injury, where the pulp is exposed to the oral cavity, cell death is rampant and the repair response initiates from surviving pulp cells and, to a lesser extent, surviving odontoblasts. When an injury is superficial, as in the case of a dentin injury model, then disturbances are largely confined to pulp tissue immediately underneath the damaged dentin tubules. We found that the pulp remained vital and innervated; primary odontoblasts upregulated HIF1α; and the rate of mineralization was significantly increased. A tamoxifen-inducible Axin2^CreERT2/+; R26R ^mTmG/+ reporter strain was then used to demonstrate that a population of long-lived Wnt-responsive odontoblasts, which secreted dentin throughout the life of the animal, were responsible for depositing new dentin in response to a superficial injury. Amplifying Wnt signaling in the pulp stimulates dentin secretion, and in the dentin injury model, we show that a liposomal formulation of human WNT3A protein passes through dentinal tubules and is capable of upregulating Wnt signaling in the pulp. These data provide strong proof of concept for a therapeutic pulp-capping material to stimulate Wnt signaling in odontoblasts and thus improve the pulp repair response.

Prevalence and natural course of occult hepatitis B virus infection in residents of 2 communities of Wuwei City, Gansu Province, China

Occult hepatitis B infection (OBI) is characterized by serum hepatitis B surface antigen (HBsAg) negative and hepatitis B virus (HBV) DNA positive (HBsAg-/HBV DNA+). Occult hepatitis B infection in community-based populations has been scarcely investigated, and OBI outcomes remain unclear, especially in Wuwei, a region located in Northwest China. This region is one of the areas in China that has the highest prevalence of chronic HBV infection. A prospective study was performed in the general population of 2 towns of Wuwei from June 2011 to May 2014. A questionnaire was used to collect demographic and medical data, and serum samples were collected from the participants and stored until analysis. DNA was detected using quantitative PCR (qPCR) or nested PCR, the HBV DNA from HBV DNA-positive or possible positive (below the detection limit) subjects was extracted and amplified by nested PCR, and the PCR products were sequenced. Sequence analysis was performed using the Mega 6.0 program and CLC sequence viewer software. Hepatitis B virus DNA was detected in 90 of 3,080 HBsAg-negative subjects, and the prevalence of OBI in the study population was 2.92% (90/3,080, 95% CI: 2.33%-3.51%). Hepatitis B virus genomes in 51 of 80 objects (63.75%) contained mutations in the "a" determinant of HBsAg. After 2 years follow-up, 42 of 90 HBV DNA of OBI subjects remained positive, and the natural clearance rate of OBI subjects was 53.3%. Occult hepatitis B infection prevalence in this cohort was much lower than chronic HBV infection in the same region. HBV DNA was cleared in most OBI subjects during the 2 year period. Our data suggest that some OBI may represent a late stage of resolving the HBV infection process.

Search for Dark Photons Produced in 13 TeV pp Collisions

Searches are performed for both promptlike and long-lived dark photons, A^{'}, produced in proton-proton collisions at a center-of-mass energy of 13 TeV, using A^{'}→μ^{+}μ^{-} decays and a data sample corresponding to an integrated luminosity of 1.6  fb^{-1} collected with the LHCb detector. The promptlike A^{'} search covers the mass range from near the dimuon threshold up to 70 GeV, while the long-lived A^{'} search is restricted to the low-mass region 214<m(A^{'})<350  MeV. No evidence for a signal is found, and 90% confidence level exclusion limits are placed on the γ-A^{'} kinetic-mixing strength. The constraints placed on promptlike dark photons are the most stringent to date for the mass range 10.6<m(A^{'})<70  GeV, and are comparable to the best existing limits for m(A^{'})<0.5  GeV. The search for long-lived dark photons is the first to achieve sensitivity using a displaced-vertex signature.

A Wnt-Responsive PDL Population Effectuates Extraction Socket Healing

Stem cells residing in the periodontal ligament (PDL) support the homeostasis of the periodontium, but their in vivo identity, source(s), and function(s) remain poorly understood. Here, using a lineage-tracing mouse strain, we identified a quiescent Wnt-responsive population in the PDL that became activated in response to tooth extraction. The Wnt-responsive population expanded by proliferation, then migrated from the PDL remnants that remained attached to bundle bone, into the socket. Once there, the Wnt-responsive progeny upregulated osteogenic protein expression, differentiated into osteoblasts, and generated the new bone that healed the socket. Using a liposomal WNT3A protein therapeutic, we showed that a single application at the time of extraction was sufficient to accelerate extraction socket healing 2-fold. Collectively, these data identify a new stem cell population in the intact periodontium that is directly responsible for alveolar bone healing after tooth removal.

Inducible displacement of cemented tibial components ten years after total knee arthroplasty

Aims

The aim of this study was to evaluate the long-term inducible displacement of cemented tibial components ten years after total knee arthroplasty (TKA).

Patients and Methods

A total of 15 patients from a previously reported prospective trial of fixation using radiostereometric analysis (RSA) were examined at a mean of 11 years (10 to 11) postoperatively. Longitudinal supine RSA examinations were acquired at one week, one year, and two years postoperatively and at final follow-up. Weight-bearing RSA examinations were also undertaken with the operated lower limb in neutral and in maximum internal rotation positions. Maximum total point motion (MTPM) was calculated for the longitudinal and inducible displacement examinations (supine versus standing, standing versus internal rotation, and supine versus standing with internal rotation).

Results

All patients showed some inducible displacement. Two patients with radiolucent lines had greater mean standing-supine MTPM displacement (1.35; sd 0.38) compared with the remaining patients (0.68; sd 0.36). These two patients also had a greater mean longitudinal MTPM at ten years (0.64; sd 0.50) compared with the remaining patients (0.39; sd 0.13 mm).

Conclusion

Small inducible displacements in well-fixed cemented tibial components were seen ten years postoperatively, of a similar magnitude to that which has been reported for well-fixed components one to two years postoperatively. Greater displacements were found in components with radiolucent lines. Cite this article: Bone Joint J 2018;100-B:170–5.

Effect of lactic acid bacteria-treated King grass silage on the performance traits and serum metabolites in New Zealand white rabbits (Oryctolagus cuniculus)

This study examined the effects of Lactobacillus plantarum and Pediococcus acidilactici-treated silage of King grass (Pennisetum purpureophoides) on the productive traits and blood biochemistry of New Zealand white (NZW) rabbits. King grass was ensiled without or with L. plantarum (T1), P. acidilactici (T2) and P. acidilactici + L. plantarum (T3). A total of 72 male NZW rabbits (6 weeks) of similar weight and appearance were housed in groups in metallic cages in a completely randomized design. The performance traits, daily feed intake, body weight gain and feed convention ratio were not affected by the silage treatment. Triglyceride and alanine aminotransferase (ALT) concentration was increased (p < .05) in T2 (0.92 mmol/L) compared to the other treatments. The superoxide dismutase (SOD), phosphorous (P) and magnesium (Mg) increased (p < .05) in T1 (658.01 nmol/ml, 5.1 mg/kg and 2.43 mg/kg, respectively) compared to the control and other experimental groups. Cu and Mn decreased (p < .05), while Zn increased (p < .05) in the treated groups compared to the control. The CP decreased (p < .05) in the treatment groups compared to the control. Neutral detergent fibre (NDF) increased (p < .05) in T2 (54.40%) compared to the other treatments. The inoculation of lactic acid bacteria-treated King grass silage supplementation positively affected rabbit performance and improved blood cholesterol profile, antioxidant status and improve nutrients digestibility.

First Observation of the Rare Purely Baryonic Decay B^{0}→pp[over ¯]

The first observation of the decay of a B^{0} meson to a purely baryonic final state, B^{0}→pp[over ¯], is reported. The proton-proton collision data sample used was collected with the LHCb experiment at center-of-mass energies of 7 and 8 TeV and corresponds to an integrated luminosity of 3.0  fb^{-1}. The branching fraction is determined to be B(B^{0}→pp[over ¯])=(1.25±0.27±0.18)×10^{-8}, where the first uncertainty is statistical and the second systematic. The decay mode B^{0}→pp[over ¯] is the rarest decay of the B^{0} meson observed to date. The decay B_{s}^{0}→pp[over ¯] is also investigated. No signal is seen and the upper limit B(B_{s}^{0}→pp[over ¯])<1.5×10^{-8} at 90% confidence level is set on the branching fraction.

χ_{c1} and χ_{c2} Resonance Parameters with the Decays χ_{c1,c2}→J/ψμ^{+}μ^{-}

The decays χ_{c1}→J/ψμ^{+}μ^{-} and χ_{c2}→J/ψμ^{+}μ^{-} are observed and used to study the resonance parameters of the χ_{c1} and χ_{c2} mesons. The masses of these states are measured to be m(χ_{c1})=3510.71±0.04(stat)±0.09(syst)  MeV and m(χ_{c2})=3556.10±0.06(stat)±0.11(syst)  MeV, where the knowledge of the momentum scale for charged particles dominates the systematic uncertainty. The momentum-scale uncertainties largely cancel in the mass difference m(χ_{c2})-m(χ_{c1})=45.39±0.07(stat)±0.03(syst)  MeV. The natural width of the χ_{c2} meson is measured to be Γ(χ_{c2})=2.10±0.20(stat)±0.02(syst)  MeV. These results are in good agreement with and have comparable precision to the current world averages.

Updated search for long-lived particles decaying to jet pairs

A search is presented for long-lived particles with a mass between 25 and 50 GeV / c 2 and a lifetime between 2 and 500 ps, using proton-proton collision data corresponding to an integrated luminosity of 2.0 fb - 1 , collected by the LHCb detector at centre-of-mass energies of 7 and 8 TeV. The particles are assumed to be pair-produced in the decay of a 125 GeV / c 2 Standard-Model-like Higgs boson. The experimental signature is a single long-lived particle, identified by a displaced vertex with two associated jets. No excess above background is observed and limits are set on the production cross-section as a function of the mass and lifetime of the long-lived particle.

Observation of D^{0} Meson Decays to π^{+}π^{-}μ^{+}μ^{-} and K^{+}K^{-}μ^{+}μ^{-} Final States

The first observation of the D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} decays is reported using a sample of proton-proton collisions collected by LHCb at a center-of-mass energy of 8 TeV, and corresponding to 2  fb^{-1} of integrated luminosity. The corresponding branching fractions are measured using as normalization the decay D^{0}→K^{-}π^{+}[μ^{+}μ^{-}]_{ρ^{0}/ω}, where the two muons are consistent with coming from the decay of a ρ^{0} or ω meson. The results are B(D^{0}→π^{+}π^{-}μ^{+}μ^{-})=(9.64±0.48±0.51±0.97)×10^{-7} and B(D^{0}→K^{+}K^{-}μ^{+}μ^{-})=(1.54±0.27±0.09±0.16)×10^{-7}, where the uncertainties are statistical, systematic, and due to the limited knowledge of the normalization branching fraction. The dependence of the branching fraction on the dimuon mass is also investigated.

Search for Baryon-Number Violating Ξ_{b}^{0} Oscillations

A search for baryon-number violating Ξ_{b}^{0} oscillations is performed with a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 3  fb^{-1}. The baryon number at the moment of production is identified by requiring that the Ξ_{b}^{0} come from the decay of a resonance Ξ_{b}^{*-}→Ξ_{b}^{0}π^{-} or Ξ_{b}^{'-}→Ξ_{b}^{0}π^{-}, and the baryon number at the moment of decay is identified from the final state using the decays Ξ_{b}^{0}→Ξ_{c}^{+}π^{-},Ξ_{c}^{+}→pK^{-}π^{+}. No evidence of baryon-number violation is found, and an upper limit at the 95% confidence level is set on the oscillation rate of ω<0.08  ps^{-1}, where ω is the associated angular frequency.

Improved limit on the branching fraction of the rare decay K S 0 → μ + μ -

A search for the decay K S 0 → μ + μ - is performed, based on a data sample of proton-proton collisions corresponding to an integrated luminosity of 3 fb - 1 , collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV . The observed yield is consistent with the background-only hypothesis, yielding a limit on the branching fraction of B ( K S 0 → μ + μ - ) < 0.8 ( 1.0 ) × 10 - 9 at 90 % ( 95 % ) confidence level. This result improves the previous upper limit on the branching fraction by an order of magnitude.

Observation of the Doubly Charmed Baryon Ξ_{cc}^{++}

A highly significant structure is observed in the Λ_{c}^{+}K^{-}π^{+}π^{+} mass spectrum, where the Λ_{c}^{+} baryon is reconstructed in the decay mode pK^{-}π^{+}. The structure is consistent with originating from a weakly decaying particle, identified as the doubly charmed baryon Ξ_{cc}^{++}. The difference between the masses of the Ξ_{cc}^{++} and Λ_{c}^{+} states is measured to be 1334.94±0.72(stat.)±0.27(syst.)  MeV/c^{2}, and the Ξ_{cc}^{++} mass is then determined to be 3621.40±0.72(stat.)±0.27(syst.)±0.14(Λ_{c}^{+})  MeV/c^{2}, where the last uncertainty is due to the limited knowledge of the Λ_{c}^{+} mass. The state is observed in a sample of proton-proton collision data collected by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.7  fb^{-1}, and confirmed in an additional sample of data collected at 8 TeV.

Study of charmonium production in b -hadron decays and first evidence for the decay B s 0 → ϕ ϕ ϕ

Using decays to ϕ -meson pairs, the inclusive production of charmonium states in b -hadron decays is studied with pp collision data corresponding to an integrated luminosity of 3.0 fb - 1 , collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting by B C ≡ B ( b → C X ) × B ( C → ϕ ϕ ) the inclusive branching fraction of a b hadron to a charmonium state C that decays into a pair of ϕ mesons, ratios R C 2 C 1 ≡ B C 1 / B C 2 are determined as R η c ( 1 S ) χ c 0 = 0.147 ± 0.023 ± 0.011 , R η c ( 1 S ) χ c 1 = 0.073 ± 0.016 ± 0.006 , R η c ( 1 S ) χ c 2 = 0.081 ± 0.013 ± 0.005 , R χ c 0 χ c 1 = 0.50 ± 0.11 ± 0.01 , R χ c 0 χ c 2 = 0.56 ± 0.10 ± 0.01 and R η c ( 1 S ) η c ( 2 S ) = 0.040 ± 0.011 ± 0.004 . Here and below the first uncertainties are statistical and the second systematic. Upper limits at 90% confidence level for the inclusive production of X(3872), X(3915) and χ c 2 ( 2 P ) states are obtained as R χ c 1 X ( 3872 ) < 0.34 , R χ c 0 X ( 3915 ) < 0.12 and R χ c 2 χ c 2 ( 2 P ) < 0.16 . Differential cross-sections as a function of transverse momentum are measured for the η c ( 1 S ) and χ c states. The branching fraction of the decay B s 0 → ϕ ϕ ϕ is measured for the first time, B ( B s 0 → ϕ ϕ ϕ ) = ( 2.15 ± 0.54 ± 0.28 ± 0 . 21 B ) × 10 - 6 . Here the third uncertainty is due to the branching fraction of the decay B s 0 → ϕ ϕ , which is used for normalization. No evidence for intermediate resonances is seen. A preferentially transverse ϕ polarization is observed. The measurements allow the determination of the ratio of the branching fractions for the η c ( 1 S ) decays to ϕ ϕ and p p ¯ as B ( η c ( 1 S ) → ϕ ϕ ) / B ( η c ( 1 S ) → p p ¯ ) = 1.79 ± 0.14 ± 0.32 .