367 research outputs found

    In Vivo Biocompatibility Study of Electrospun Chitosan Microfiber for Tissue Engineering

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    In this work, we examined the biocompatibility of electrospun chitosan microfibers as a scaffold. The chitosan microfibers showed a three-dimensional pore structure by SEM. The chitosan microfibers supported attachment and viability of rat muscle-derived stem cells (rMDSCs). Subcutaneous implantation of the chitosan microfibers demonstrated that implantation of rMDSCs containing chitosan microfibers induced lower host tissue responses with decreased macrophage accumulation than did the chitosan microfibers alone, probably due to the immunosuppression of the transplanted rMDSCs. Our results collectively show that chitosan microfibers could serve as a biocompatible in vivo scaffold for rMDSCs in rats

    Gaming disorder: its delineation as an important condition for diagnosis, management and prevention

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    Online gaming has greatly increased in popularity in recent years, and with this has come a multiplicity of problems due to excessive involvement in gaming. Gaming disorder, both online and offline, has been defined for the first time in the draft of 11th revision of the International Classification of Diseases (ICD-11). National surveys have shown prevalence rates of gaming disorder/addiction of 10%–15% among young people in several Asian countries and of 1%–10% in their counterparts in some Western countries. Several diseases related to excessive gaming are now recognized, and clinics are being established to respond to individual, family, and community concerns, but many cases remain hidden. Gaming disorder shares many features with addictions due to psychoactive substances and with gambling disorder, and functional neuroimaging shows that similar areas of the brain are activated. Governments and health agencies worldwide are seeking for the effects of online gaming to be addressed, and for preventive approaches to be developed. Central to this effort is a need to delineate the nature of the problem, which is the purpose of the definitions in the draft of ICD-11

    Observation of Bs->Ds(*)+Ds(*)- using e+e- collisions and a determination of the Bs-Bsbar width difference \Delta\Gamma_s

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    We have made the first observation of Bs->Ds(*)+Ds(*)- decays using 23.6 fb-1 of data recorded by the Belle experiment running on the Upsilon(5S) resonance. The branching fractions are measured to be B(B^0_s\ra D^+_s D^-_s) = (1.0\,^{+0.4}_{-0.3}\,^{+0.3}_{-0.2})%, B(B^0_s\ra D^{*\pm}_s D^{\mp}_s) = (2.8\,^{+0.8}_{-0.7}\,\pm 0.7)%, and B(B^0_s\ra D^{*+}_s D^{*-}_s) = (3.1\,^{+1.2}_{-1.0}\,\pm 0.8)%; the sum is B(B^0_s\ra D^{(*)+}_s D^{(*)-}_s) = (6.9\,^{+1.5}_{-1.3}\,\pm 1.9)%. Assuming Bs->Ds(*)+Ds(*)- saturates decays to CP-even final states, the branching fraction determines the ratio \Delta\Gamma_s/cos(\phi), where \Delta\Gamma_s is the difference in widths between the two Bs-Bsbar mass eigenstates, and \phi is a CP-violating weak phase. Taking CP violation to be negligibly small, we obtain \Delta\Gamma_s/\Gamma_s = 0.147^{+0.036}_{-0.030}(stat.)^{+0.044}_{-0.042}(syst.), where \Gamma_s is the mean decay width.Comment: 13 pages, 2 figures, 2 tables. v2: text added for clarification, version published in Phys. Rev. Letter

    Observation of B+ -> Dbar*0 tau+ nu_tau and Evidence for B+ -> Dbar^0 tau+ nu_tau at Belle

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    We present measurements of B+ -> Dbar*0 tau+ nu_tau and B+ -> Dbar^0 tau+ nu_tau decays in a data sample of 657 x 10^6 BBbar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. We find 446^{+58}_{-56} events of the decay B+ -> Dbar*0 tau+ nu_tau with a significance of 8.1 standard deviations, and 146^{+42}_{-41} events of the decay B+ -> Dbar0 tau+ nu_tau with a significance of 3.5 standard deviations. The latter signal provides the first evidence for this decay mode. The measured branching fractions are B(B+ -> Dbar*0 tau+ nu_tau)=(2.12^{+0.28}_{-0.27} (stat) +- 0.29 (syst)) % and B(B+ -> Dbar0 tau+ nu_tau)=(0.77 +- 0.22 (stat) +- 0.12 (syst)) %.Comment: 6 pages, 4 figures, submitted to Phys. Rev. Let

    Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV) using tagged cardiovascular magnetic resonance (CMR) and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium.</p> <p>Methods</p> <p>3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain) at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix). The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis.</p> <p>Results</p> <p>The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6%) than non-stenotic segment (-18.8 ± 10.2%, p < 0.0001). There was no difference in epicardial C-strain between the two groups. Use of cutoff thresholds for subendocardial C-strain differentiated stenotic segments from non-stenotic segments with a sensitivity of 77%, a specificity of 70%, and areas under the curve (AUC) of 0.76. The absolute subendocardial C-strain was significantly lower for ischemic (-6.7 ± 13.1%) than non-ischemic segments (-21.6 ± 7.0%, p < 0.0001). The absolute epicardial C-strain was also significantly lower for ischemic (-5.1 ± 7.8%) than non-ischemic segments (-9.6 ± 9.1%, p < 0.05). Use of cutoff thresholds for subendocardial C-strain differentiated ischemic segments from non-ischemic segments with sensitivities of 86%, specificities of 84%, and AUC of 0.86.</p> <p>Conclusions</p> <p>Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.</p

    Measurement of CP violating asymmetries in B^0 -> K^+K^- K^0_S decays with a time-dependent Dalitz approach

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    We report a measurement of CPCP violating asymmetries in B0(B0)K+KKS0B^0(\overline{B}^0) \to K^+ K^- K^0_S decays with a time-dependent Dalitz approach. This analysis is based on a data sample of 657×106657\times 10^6 BBB\overline{B} pairs accumulated at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. As the result of an unbinned maximum likelihood fit to the selected candidates, the mixing-induced and direct CPCP violation parameters, ϕ1eff\phi^{\rm eff}_1 and ACP{\cal A}_{CP} are obtained for B0ϕ(1020)KS0B^0 \to \phi(1020) K^0_S, B0f0(980)KS0B^0 \to f_0(980) K^0_S and other B0K+KKS0B^0 \to K^+ K^- K^0_S decays. We find four solutions that describe the data. There are \{eqnarray*} \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (32.2 \pm 9.0 \pm 2.6 \pm 1.4)^{\circ}; \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (26.2 \pm 8.8 \pm 2.7 \pm 1.2)^{\circ};\\ \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (27.3 \pm 8.6 \pm 2.8 \pm 1.3)^{\circ}\; {\rm and}\\ \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (24.3 \pm 8.0 \pm 2.9 \pm 5.2)^{\circ}.{eqnarray*}\ The values for the CPCP violating phase in B0ϕ(1020)KS0B^0\to \phi(1020) K^0_S are similar but other properties of the Dalitz plot are quite different for the four solutions. These four solutions have consistent ϕ1eff\phi^{\rm eff}_1 values for all three BB meson decay channels and none of them deviates significantly from the values measured in B(ccˉ)K0B \to (c\bar{c}) K^0 decays with the currently available statistics. In addition, we find no significant direct CPCP violation.Comment: submitted to PR

    Measurement of CP violating asymmetries in B^0 -> K^+K^- K^0_S decays with a time-dependent Dalitz approach

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    We report a measurement of CPCP violating asymmetries in B0(B0)K+KKS0B^0(\overline{B}^0) \to K^+ K^- K^0_S decays with a time-dependent Dalitz approach. This analysis is based on a data sample of 657×106657\times 10^6 BBB\overline{B} pairs accumulated at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. As the result of an unbinned maximum likelihood fit to the selected candidates, the mixing-induced and direct CPCP violation parameters, ϕ1eff\phi^{\rm eff}_1 and ACP{\cal A}_{CP} are obtained for B0ϕ(1020)KS0B^0 \to \phi(1020) K^0_S, B0f0(980)KS0B^0 \to f_0(980) K^0_S and other B0K+KKS0B^0 \to K^+ K^- K^0_S decays. We find four solutions that describe the data. There are \{eqnarray*} \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (32.2 \pm 9.0 \pm 2.6 \pm 1.4)^{\circ}; \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (26.2 \pm 8.8 \pm 2.7 \pm 1.2)^{\circ};\\ \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (27.3 \pm 8.6 \pm 2.8 \pm 1.3)^{\circ}\; {\rm and}\\ \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (24.3 \pm 8.0 \pm 2.9 \pm 5.2)^{\circ}.{eqnarray*}\ The values for the CPCP violating phase in B0ϕ(1020)KS0B^0\to \phi(1020) K^0_S are similar but other properties of the Dalitz plot are quite different for the four solutions. These four solutions have consistent ϕ1eff\phi^{\rm eff}_1 values for all three BB meson decay channels and none of them deviates significantly from the values measured in B(ccˉ)K0B \to (c\bar{c}) K^0 decays with the currently available statistics. In addition, we find no significant direct CPCP violation.Comment: submitted to PR

    Study of B^0 -> rho^0 rho^0 decays, implications for the CKM angle phi_2 and search for other B^0 decay modes with a four-pion final state

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    We present a study of the branching fraction of the decay B^0->rho0rho0 and the fraction of longitudinally polarized rho0 mesons in this decay. The results are obtained from the final data sample containing 772 million BBbar pairs collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We find 166 +- 59 B^0 -> rho0 rho0 events (including systematic uncertainties), corresponding to a branching fraction of B(B^0->rho0rho0) = (1.02 +- 0.30 (stat) +- 0.15 (syst)) x 10^{-6} with a significance of 3.4 standard deviations and a longitudinal polarization fraction fL = 0.21^{+0.18}_{-0.22} (stat) +- 0.15 (syst). We use the longitudinal polarization fraction to determine the Cabibbo-Kobayashi-Maskawa matrix angle phi_2 = (84.9 +- 13.5) degrees through an isospin analysis in the B->rhorho system. We furthermore find 149 +- 49 B^0->f0rho0 events, corresponding to B(B^0->f0rho0) x B(f0->pi+pi-) = (0.78 +- 0.22 (stat) +- 0.11 (syst)) x 10^{-6}, with a significance of 3.1 standard deviations. We find no other significant contribution with the same final state, and set upper limits at 90% confidence level on the (product) branching fractions, B(B^0->pi+pi-pi+pi-)rho0pi+pi-)<12.0 x 10^{-6}, B(B^0->f0pi+pi-) x B(f0->pi+pi-) f0f0) x B(f0->pi+pi-)^{2} < 0.2 x 10^{-6}.Comment: 21 pages, 20 figures, conference paper for the 2012th CKM workshop, submitted to PR

    Observation of D0Dˉ0D^0-\bar{D}^0 Mixing in e+ee^+e^- Collisions

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    We observe D0Dˉ0D^0-\bar{D}^0 mixing in the decay D0K+πD^0\rightarrow K^+\pi^- using a data sample of integrated luminosity 976 fb1^{-1} collected with the Belle detector at the KEKB e+ee^+e^- asymmetric-energy collider. We measure the mixing parameters x2=(0.09±0.22)×103{x'}^2 = (0.09\pm0.22)\times 10^{-3} and y=(4.6±3.4)×103y' = (4.6\pm3.4)\times 10^{-3} and the ratio of doubly Cabibbo-suppressed to Cabibbo-favored decay rates RD=(3.53±0.13)×103R_D = (3.53\pm0.13)\times 10^{-3}, where the uncertainties are statistical and systematic combined. Our measurement excludes the no-mixing hypothesis at the 5.1 standard deviation level.Comment: 6 pages, 4 figure

    Search for Time-Dependent CPT Violation in Hadronic and Semileptonic B Decays

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    We report a new sensitive search for CPT violation, which includes improved measurements of the CPT-violating parameter z and the total decay-width difference normalized to the averaged width DeltaGamma_d/Gamma_d of the two Bd mass eigenstates. The results are based on a data sample of 535 x 10^6 BBbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We obtain Re(z) = [+1.9 +/- 3.7 (stat) +/- 3.3 (syst)] x 10^{-2}, Im(z) = [-5.7 +/- 3.3 (stat) +/- 3.3 (syst)] x 10^{-3}, and DeltaGamma_d/Gamma_d = [-1.7 +/- 1.8 (stat) +/- 1.1 (syst)] x 10^{-2}, all of which are consistent with zero. This is the most precise single measurement of these parameters in the neutral B-meson system to date.Comment: 7 pages, 3 figures, 2 tables, LaTeX; addition of supplemental information, corrections of typos, results unchange
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