687 research outputs found

    Effect of a poloxamer 407-based thermosensitive gel on minimization of thermal injury to diaphragm during microwave ablation of the liver.

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    AIM: To assess the insulating effect of a poloxamer 407 (P407)-based gel during microwave ablation of liver adjacent to the diaphragm. METHODS: We prepared serial dilutions of P407, and 22.5% (w/w) concentration was identified as suitable for ablation procedures. Subsequently, microwave ablations were performed on the livers of 24 rabbits (gel, saline, control groups, n = 8 in each). The P407 solution and 0.9% normal saline were injected into the potential space between the diaphragm and liver in experimental groups. No barriers were applied to the controls. After microwave ablations, the frequency, size and degree of thermal injury were compared histologically among the three groups. Subsequently, another 8 rabbits were injected with the P407 solution and microwave ablation was performed. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and creatinine (Cr) in serum were tested at 1 d before microwave ablation and 3 and 7 d after operation. RESULTS: In vivo ablation thermal injury to the adjacent diaphragm was evaluated in the control, saline and 22.5% P407 gel groups (P = 0.001-0.040). However, there was no significant difference in the volume of ablation zone among the three groups (P \u3e 0.05). Moreover, there were no statistical differences among the preoperative and postoperative gel groups according to the levels of ALT, AST, BUN and Cr in serum (all P \u3e 0.05). CONCLUSION: Twenty-two point five percent P407 gel could be a more effective choice during microwave ablation of hepatic tumors adjacent to the diaphragm. Further studies for clinical translation are warranted

    Evidence of a resonant structure in the e+e−→π+D0D∗−e^+e^-\to \pi^+D^0D^{*-} cross section between 4.05 and 4.60 GeV

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    The cross section of the process e+e−→π+D0D∗−e^+e^-\to \pi^+D^0D^{*-} for center-of-mass energies from 4.05 to 4.60~GeV is measured precisely using data samples collected with the BESIII detector operating at the BEPCII storage ring. Two enhancements are clearly visible in the cross section around 4.23 and 4.40~GeV. Using several models to describe the dressed cross section yields stable parameters for the first enhancement, which has a mass of 4228.6 \pm 4.1 \pm 6.3 \un{MeV}/c^2 and a width of 77.0 \pm 6.8 \pm 6.3 \un{MeV}, where the first uncertainties are statistical and the second ones are systematic. Our resonant mass is consistent with previous observations of the Y(4220)Y(4220) state and the theoretical prediction of a DDˉ1(2420)D\bar{D}_1(2420) molecule. This result is the first observation of Y(4220)Y(4220) associated with an open-charm final state. Fits with three resonance functions with additional Y(4260)Y(4260), Y(4320)Y(4320), Y(4360)Y(4360), ψ(4415)\psi(4415), or a new resonance, do not show significant contributions from either of these resonances. The second enhancement is not from a single known resonance. It could contain contributions from ψ(4415)\psi(4415) and other resonances, and a detailed amplitude analysis is required to better understand this enhancement

    Study of J/ψJ/\psi and ψ(3686)→Σ(1385)0Σˉ(1385)0\psi(3686)\rightarrow\Sigma(1385)^{0}\bar\Sigma(1385)^{0} and Ξ0Ξˉ0\Xi^0\bar\Xi^{0}

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    We study the decays of J/ψJ/\psi and ψ(3686)\psi(3686) to the final states Σ(1385)0Σˉ(1385)0\Sigma(1385)^{0}\bar\Sigma(1385)^{0} and Ξ0Ξˉ0\Xi^0\bar\Xi^{0} based on a single baryon tag method using data samples of (1310.6±7.0)×106(1310.6 \pm 7.0) \times 10^{6} J/ψJ/\psi and (447.9±2.9)×106(447.9 \pm 2.9) \times 10^{6} ψ(3686)\psi(3686) events collected with the BESIII detector at the BEPCII collider. The decays to Σ(1385)0Σˉ(1385)0\Sigma(1385)^{0}\bar\Sigma(1385)^{0} are observed for the first time. The measured branching fractions of J/ψJ/\psi and ψ(3686)→Ξ0Ξˉ0\psi(3686)\rightarrow\Xi^0\bar\Xi^{0} are in good agreement with, and much more precise, than the previously published results. The angular parameters for these decays are also measured for the first time. The measured angular decay parameter for J/ψ→Σ(1385)0Σˉ(1385)0J/\psi\rightarrow\Sigma(1385)^{0}\bar\Sigma(1385)^{0}, α=−0.64±0.03±0.10\alpha =-0.64 \pm 0.03 \pm 0.10, is found to be negative, different to the other decay processes in this measurement. In addition, the "12\% rule" and isospin symmetry in the J/ψJ/\psi and ψ(3686)→ΞΞˉ\psi(3686)\rightarrow\Xi\bar\Xi and Σ(1385)Σˉ(1385)\Sigma(1385)\bar{\Sigma}(1385) systems are tested.Comment: 11 pages, 7 figures. This version is consistent with paper published in Phys.Lett. B770 (2017) 217-22

    Measurements of absolute hadronic branching fractions of Λc+\Lambda_{c}^{+} baryon

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    Using 567pb−1567\rm{pb}^{-1} of e+e−e^+e^- collisions recorded at s=4.599GeV\sqrt{s}=4.599\rm{GeV} with the BESIII detector, we report first measurements of absolute hadronic branching fractions of Cabibbo-favored decays of the Λc+\Lambda_{c}^{+} baryon with a double-tag technique. A global least-square fitter is utilized to improve the measured precision. Among the measurements for twelve Λc+\Lambda_{c}^{+} decay modes, the branching fraction for Λc+→pK−π+\Lambda_{c}^{+} \rightarrow pK^-\pi^+ is determined to be (5.84±0.27±0.23)%(5.84\pm0.27\pm0.23)\%, where the first uncertainty is statistical and the second is systematic. In addition, the measurements of the branching fractions of the other eleven Cabbibo-favored hadronic decay modes are significantly improved

    Observation of e+e−→ωχc1,2e^+e^- \rightarrow \omega \chi_{c1,2} near s\sqrt{s} = 4.42 and 4.6 GeV

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    Based on data samples collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energies s>\sqrt{s} > 4.4 GeV, the processes e+e−→ωχc1,2e^+e^- \rightarrow \omega \chi_{c1,2} are observed for the first time. With an integrated luminosity of 1074pb−11074 pb^{-1} near s=\sqrt{s} = 4.42 GeV, a significant ωχc2\omega \chi_{c2} signal is found, and the cross section is measured to be (20.9 \pm 3.2 \pm 2.5)\pb. With 567pb−1567 pb^{-1} near s=\sqrt{s} = 4.6 GeV, a clear ωχc1\omega \chi_{c1} signal is seen, and the cross section is measured to be (9.5 \pm 2.1 \pm 1.3) \pb, while evidence is found for an ωχc2\omega \chi_{c2} signal. The first errors are statistical and the second are systematic. Due to low luminosity or low cross section at other energies, no significant signals are observed. In the ωχc2\omega \chi_{c2} cross section, an enhancement is seen around s=\sqrt{s} = 4.42 GeV. Fitting the cross section with a coherent sum of the ψ(4415)\psi(4415) Breit-Wigner function and a phase space term, the branching fraction B(ψ(4415)→ωχc2)\mathcal{B}(\psi(4415)\to\omega\chi_{c2}) is obtained to be of the order of 10−310^{-3}.Comment: 7 pages, 3 figure

    Improved measurement of the absolute branching fraction of D+→Kˉ0μ+νμD^{+}\rightarrow \bar K^0 \mu^{+}\nu_{\mu}

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    By analyzing 2.93 fb−1^{-1} of data collected at s=3.773\sqrt s=3.773 GeV with the BESIII detector, we measure the absolute branching fraction B(D+→Kˉ0μ+νμ)=(8.72±0.07stat.±0.18sys.)%{\mathcal B}(D^{+}\rightarrow\bar K^0\mu^{+}\nu_{\mu})=(8.72 \pm 0.07_{\rm stat.} \pm 0.18_{\rm sys.})\%, which is consistent with previous measurements within uncertainties but with significantly improved precision. Combining the Particle Data Group values of B(D0→K−μ+νμ){\mathcal B}(D^0\to K^-\mu^+\nu_\mu), B(D+→Kˉ0e+νe){\mathcal B}(D^{+}\rightarrow\bar K^0 e^{+}\nu_{e}), and the lifetimes of the D0D^0 and D+D^+ mesons with the value of B(D+→Kˉ0μ+νμ){\mathcal B}(D^{+}\rightarrow\bar K^0 \mu^{+}\nu_{\mu}) measured in this work, we determine the following ratios of partial widths: Γ(D0→K−μ+νμ)/Γ(D+→Kˉ0μ+νμ)=0.963±0.044\Gamma(D^0\to K^-\mu^+\nu_\mu)/\Gamma(D^{+}\rightarrow\bar K^0\mu^{+}\nu_{\mu})=0.963\pm0.044 and Γ(D+→Kˉ0μ+νμ)/Γ(D+→Kˉ0e+νe)=0.988±0.033\Gamma(D^{+}\rightarrow\bar K^0 \mu^{+}\nu_{\mu})/\Gamma(D^{+}\rightarrow\bar K^0 e^{+}\nu_{e})=0.988\pm0.033.Comment: 9 pages; 8 figure

    Determination of the number of J/ψJ/\psi events with inclusive J/ψJ/\psi decays

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    A measurement of the number of J/ψJ/\psi events collected with the BESIII detector in 2009 and 2012 is performed using inclusive decays of the J/ψJ/\psi . The number of J/ψJ/\psi events taken in 2009 is recalculated to be (223.7±1.4)×106(223.7\pm1.4)\times 10^6, which is in good agreement with the previous measurement, but with significantly improved precision due to improvements in the BESIII software. The number of J/ψJ/\psi events taken in 2012 is determined to be (1086.9±6.0)×106(1086.9\pm 6.0)\times 10^6. In total, the number of J/ψJ/\psi events collected with the BESIII detector is measured to be (1310.6±7.0)×106(1310.6\pm 7.0)\times 10^6, where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible.Comment: 10 pages, 6 figure

    Observation of hch_{c} radiative decay hc→γη′h_{c} \rightarrow \gamma \eta' and evidence for hc→γηh_{c} \rightarrow \gamma \eta

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    A search for radiative decays of the PP-wave spin singlet charmonium resonance hch_c is performed based on 4.48×1084.48 \times 10^{8} ψ′\psi' events collected with the BESIII detector operating at the BEPCII storage ring. Events of the reaction channels hc→γη′h_{c} \rightarrow \gamma \eta' and γη\gamma \eta are observed with a statistical significance of 8.4σ8.4 \sigma and 4.0σ4.0 \sigma, respectively, for the first time. The branching fractions of hc→γη′h_{c} \rightarrow \gamma \eta' and hc→γηh_{c} \rightarrow \gamma \eta are measured to be B(hc→γη′)=(1.52±0.27±0.29)×10−3\mathcal{B}(h_{c} \rightarrow \gamma \eta')=(1.52 \pm 0.27 \pm 0.29)\times10^{-3} and B(hc→γη)=(4.7±1.5±1.4)×10−4\mathcal{B}(h_{c} \rightarrow \gamma \eta)=(4.7 \pm 1.5 \pm 1.4)\times10^{-4}, respectively, where the first errors are statistical and the second are systematic uncertainties.Comment: 7 pages, 2 figure
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