Objective:To evaluate the value of 3D printing assisted pedicle screw placement in the treatment of thoracolumbar spinal fractures.Methods: 56 cases of thoracolumbar spinal fractures patients underwent 3D printing ass...Objective:To evaluate the value of 3D printing assisted pedicle screw placement in the treatment of thoracolumbar spinal fractures.Methods: 56 cases of thoracolumbar spinal fractures patients underwent 3D printing assisted pedicle screw placement (study group) and another 56 cases of thoracolumbar spinal fractures patients underwent conventional screw placement (control group) in our department from February 2016 to September 2017 were selected. Then the surgical related indicators, JOA score, the reduction of injured vertebrae and complications were recorded and compared between groups at different time points, including, before operation (T0), postoperative 1mon (T1), postoperative 6mon (T2) and postoperative 12mon (T3).Results: The operation time, intraoperative X-ray fluoroscopy frequency and intraoperative blood loss in the study group were significantly lower than those in the control group (P<0.05), meanwhile the accuracy rate of screw placement was significantly higher than that of the control group (P<0.05). JOA scores at T1, T2 and T3 in both groups were significantly higher than those at T0 (P<0.05), and JOA scores at all postoperative time points in the study group were significantly higher than those in the control group (P<0.05). Compared with T0, the ratio of the anterior and posterior border height of injured vertebrae in the two groups at T2 was significantly increased (P<0.05), while the Cobb Angle of sagittal kyphoid significantly was decreased (P<0.05). Meanwhile, the reduction of injured vertebrae in the study group was significantly better than that the control group at T2 (P<0.05). The incidence of complications in the study group was significantly lower than that in the control group (P<0.05).Conclusion: The application of 3D printing assisted pedicle screw placement in the treatment has the advantages of less injury to patients, good prognosis and high safety, which is worthy of clinical application.展开更多
In this work,we investigate the quasi-two-body decays B_(c)→D^(*)h→Dπhwithh=(K^(0),π^(0),η,η′)using the perturbative QCD(PQCD)approach.The description of final state interactions of the Dπpair is achieved thro...In this work,we investigate the quasi-two-body decays B_(c)→D^(*)h→Dπhwithh=(K^(0),π^(0),η,η′)using the perturbative QCD(PQCD)approach.The description of final state interactions of the Dπpair is achieved through the two-meson distribution amplitudes(DAs),which are normalized to the time-like form factor.The PQCD predictions on the branching ratios of the quasi-two-body decays B_(c)→D^(*)h→Dπh show an obvious hierarchy:Br(B^(+)_(c)→D^(∗+)K^(0)→D^(0)π^(+)K^(0))=(5.22^(+0.86)_(-0.74))×10^(-6),Br(B^(+)_(c)→D^(∗+)π^(0)→D^(0)π^(+)π^(0))=(0.93±0.26)×10^(-7),Br(B^(+)_(c)→D^(∗+)η→D^(0)π^(+)η)=(2.83^(+0.59)_(-0.52))×10^(-8)and Br(B^(+)_(c)→D^(∗+)η′→D^(0)π^(+)η′)=(1.89+0.40-0.36)×10^(-8).From the invariant mass m Dπ-dependence of the decay spectrum for each channel,one can find that the branching fraction is concentrated in a narrow region around the D*pole mass.Thus,one can obtain the branching ratios for the corresponding two-body decays B_(c)→D^(*+)h under the narrow-width approximation.We find that the branching ratios of the decays B_(c)→D^(*+)h are consistent with the previous PQCD calculations within errors.These predictions will be tested in future experiments.展开更多
We study the Bc,u,d→X(3872)P decays in the perturbative QCD(PQCD)approach,involving the puzzling resonance X(3872),where P represents a light pseudoscalar meson(K orπ).Assuming X(3872)to be a 1++charmonium state,we ...We study the Bc,u,d→X(3872)P decays in the perturbative QCD(PQCD)approach,involving the puzzling resonance X(3872),where P represents a light pseudoscalar meson(K orπ).Assuming X(3872)to be a 1++charmonium state,we obtain the following results.(a)The branching ratios of the Bc+→X(3872)π+and Bc+→X(3872)K+decays are consistent with the results predicted by the covariant light-front approach within errors;however,they are larger than those given by the generalized factorization approach.(b)The branching ratio of the B+→X(3872)K+decay is predicted as(3.8-1.0+1.1)×10-4,which is smaller than the previous PQCD calculation result but still slightly larger than the upper limits set by Belle and BaBar.Hence,we suggest that the B0,+→X(3872)K0,+decays should be precisely measured by the LHCb and Belle II experiments to help probe the inner structure of X(3872).(c)Compared with the Bu,d→X(3872)K decays,the Bu,d→X(3872)πdecays have significantly smaller branching ratios,which drop to values as low as 10-6.(d)The direct CP violations of these considered decays are small(10-3~10-2)because the penguin contributions are loop suppressed compared to the tree contributions.The mixing-induced CP violation of the B→X(3872)K0S decay is highly consistent with the current world average value sin 2β=(69.9±1.7)%.Experimentally testing the results for the branching ratios and CP violations,including the implicit SU(3)and isospin symmetries of these decays,helps probe the nature of X(3872).展开更多
In this study,we investigate quasi-two-body B_((s))→K^(*)γ→Kπγ decays in the perturbative QCD approach.Two-meson distribution amplitudes are introduced to describe the final state interactions of the Kπpair,whic...In this study,we investigate quasi-two-body B_((s))→K^(*)γ→Kπγ decays in the perturbative QCD approach.Two-meson distribution amplitudes are introduced to describe the final state interactions of the Kπpair,which involve time-like form factors and Gegenbauer polynomials.We calculate the CP averaged branching ratios of the B_((s))→K^(*)γ→Kπγ decays.Our results are in agreement with newly updated data measured by Belle Ⅱ.This suggests that it is more appropriate to analyze these quasi-two-body B decays in the three-body framework than the two-body framework.We also predict direct CP asymmetries for the considered decay modes and find that A_CP(B_(u,d)→K^(*)γ→Kπγ) is small and less than 1% in magnitude,whereas A_CP(B_(s)→K^(*)γ→Kπγ)is larger and can reach a few percent.Our predictions can be tested in future B meson experiments.展开更多
文摘Objective:To evaluate the value of 3D printing assisted pedicle screw placement in the treatment of thoracolumbar spinal fractures.Methods: 56 cases of thoracolumbar spinal fractures patients underwent 3D printing assisted pedicle screw placement (study group) and another 56 cases of thoracolumbar spinal fractures patients underwent conventional screw placement (control group) in our department from February 2016 to September 2017 were selected. Then the surgical related indicators, JOA score, the reduction of injured vertebrae and complications were recorded and compared between groups at different time points, including, before operation (T0), postoperative 1mon (T1), postoperative 6mon (T2) and postoperative 12mon (T3).Results: The operation time, intraoperative X-ray fluoroscopy frequency and intraoperative blood loss in the study group were significantly lower than those in the control group (P<0.05), meanwhile the accuracy rate of screw placement was significantly higher than that of the control group (P<0.05). JOA scores at T1, T2 and T3 in both groups were significantly higher than those at T0 (P<0.05), and JOA scores at all postoperative time points in the study group were significantly higher than those in the control group (P<0.05). Compared with T0, the ratio of the anterior and posterior border height of injured vertebrae in the two groups at T2 was significantly increased (P<0.05), while the Cobb Angle of sagittal kyphoid significantly was decreased (P<0.05). Meanwhile, the reduction of injured vertebrae in the study group was significantly better than that the control group at T2 (P<0.05). The incidence of complications in the study group was significantly lower than that in the control group (P<0.05).Conclusion: The application of 3D printing assisted pedicle screw placement in the treatment has the advantages of less injury to patients, good prognosis and high safety, which is worthy of clinical application.
基金Supported by the National Natural Science Foundation of China(11347030)the Program of Science and Technology Innovation Talents in Universities of Henan Province,China(14HASTIT037)the Natural Science Foundation of Henan Province,China(232300420116)
文摘In this work,we investigate the quasi-two-body decays B_(c)→D^(*)h→Dπhwithh=(K^(0),π^(0),η,η′)using the perturbative QCD(PQCD)approach.The description of final state interactions of the Dπpair is achieved through the two-meson distribution amplitudes(DAs),which are normalized to the time-like form factor.The PQCD predictions on the branching ratios of the quasi-two-body decays B_(c)→D^(*)h→Dπh show an obvious hierarchy:Br(B^(+)_(c)→D^(∗+)K^(0)→D^(0)π^(+)K^(0))=(5.22^(+0.86)_(-0.74))×10^(-6),Br(B^(+)_(c)→D^(∗+)π^(0)→D^(0)π^(+)π^(0))=(0.93±0.26)×10^(-7),Br(B^(+)_(c)→D^(∗+)η→D^(0)π^(+)η)=(2.83^(+0.59)_(-0.52))×10^(-8)and Br(B^(+)_(c)→D^(∗+)η′→D^(0)π^(+)η′)=(1.89+0.40-0.36)×10^(-8).From the invariant mass m Dπ-dependence of the decay spectrum for each channel,one can find that the branching fraction is concentrated in a narrow region around the D*pole mass.Thus,one can obtain the branching ratios for the corresponding two-body decays B_(c)→D^(*+)h under the narrow-width approximation.We find that the branching ratios of the decays B_(c)→D^(*+)h are consistent with the previous PQCD calculations within errors.These predictions will be tested in future experiments.
基金Supported by the National Natural Science Foundation of China(11347030)the Program of Science and Technology Innovation Talents in Universities of Henan Province(14HASTIT037)。
文摘We study the Bc,u,d→X(3872)P decays in the perturbative QCD(PQCD)approach,involving the puzzling resonance X(3872),where P represents a light pseudoscalar meson(K orπ).Assuming X(3872)to be a 1++charmonium state,we obtain the following results.(a)The branching ratios of the Bc+→X(3872)π+and Bc+→X(3872)K+decays are consistent with the results predicted by the covariant light-front approach within errors;however,they are larger than those given by the generalized factorization approach.(b)The branching ratio of the B+→X(3872)K+decay is predicted as(3.8-1.0+1.1)×10-4,which is smaller than the previous PQCD calculation result but still slightly larger than the upper limits set by Belle and BaBar.Hence,we suggest that the B0,+→X(3872)K0,+decays should be precisely measured by the LHCb and Belle II experiments to help probe the inner structure of X(3872).(c)Compared with the Bu,d→X(3872)K decays,the Bu,d→X(3872)πdecays have significantly smaller branching ratios,which drop to values as low as 10-6.(d)The direct CP violations of these considered decays are small(10-3~10-2)because the penguin contributions are loop suppressed compared to the tree contributions.The mixing-induced CP violation of the B→X(3872)K0S decay is highly consistent with the current world average value sin 2β=(69.9±1.7)%.Experimentally testing the results for the branching ratios and CP violations,including the implicit SU(3)and isospin symmetries of these decays,helps probe the nature of X(3872).
基金Supported in part by the National Natural Science Foundation of China under(11347030)the Program of Science and Technology Innovation Talents in Universities of Henan Province(14HASTIT037)。
文摘In this study,we investigate quasi-two-body B_((s))→K^(*)γ→Kπγ decays in the perturbative QCD approach.Two-meson distribution amplitudes are introduced to describe the final state interactions of the Kπpair,which involve time-like form factors and Gegenbauer polynomials.We calculate the CP averaged branching ratios of the B_((s))→K^(*)γ→Kπγ decays.Our results are in agreement with newly updated data measured by Belle Ⅱ.This suggests that it is more appropriate to analyze these quasi-two-body B decays in the three-body framework than the two-body framework.We also predict direct CP asymmetries for the considered decay modes and find that A_CP(B_(u,d)→K^(*)γ→Kπγ) is small and less than 1% in magnitude,whereas A_CP(B_(s)→K^(*)γ→Kπγ)is larger and can reach a few percent.Our predictions can be tested in future B meson experiments.
