8,359 research outputs found

    Virtual contributions from Dβˆ—(2007)0D^{\ast}(2007)^0 and Dβˆ—(2010)Β±D^{\ast}(2010)^{\pm} in the Bβ†’DΟ€hB\to D\pi h decays

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    We study the quasi-two-body decays Bβ†’Dβˆ—hβ†’DΟ€hB\to D^*h \to D\pi h with h=(Ο€,K)h=(\pi, K) in the perturbative QCD approach and focus on the virtual contributions from the off-shell Dβˆ—(2007)0D^{\ast}(2007)^0 and Dβˆ—(2010)Β±D^{\ast}(2010)^{\pm} in the four measured decays BΛ‰0β†’D0Ο€+Ο€βˆ’\bar B^0 \to D^0\pi^+\pi^-, BΛ‰0β†’D0Ο€+Kβˆ’\bar B^0\to D^0\pi^+K^-, Bβˆ’β†’D+Ο€βˆ’Ο€βˆ’B^- \to D^+\pi^-\pi^- and Bβˆ’β†’D+Ο€βˆ’Kβˆ’B^- \to D^+\pi^-K^-. For the BΛ‰0β†’Dβˆ—+Ο€βˆ’β†’D0Ο€+Ο€βˆ’\bar B^0 \to D^{*+}\pi^-\to D^0\pi^+\pi^- and BΛ‰0β†’Dβˆ—+Kβˆ’β†’D0Ο€+Kβˆ’\bar B^0\to D^{*+}K^-\to D^0\pi^+K^- decays, their branching fractions concentrate in a very small region of mD0Ο€+m_{D^0\pi^+} near Dβˆ—+D^{*+} pole mass, and the virtual contributions from Dβˆ—+D^{*+}, in the region mD0Ο€+>2.1m_{D^0\pi^+}>2.1 GeV, are about 5%5\% of the corresponding quasi-two-body results. We define two ratios RDβˆ—+R_{D^{*+}} and RDβˆ—0R_{D^{*0}}, from which we conclude that the flavor-SU(3)SU(3) symmetry will be maintained for the Bβ†’Dβˆ—hβ†’DΟ€hB\to D^* h\to D\pi h decays with very small breaking at any physical value of the mDΟ€m_{D\pi}. The Bβˆ’β†’Dβˆ—0Ο€βˆ’β†’D0Ο€0Ο€βˆ’B^-\to D^{*0}\pi^-\to D^0\pi^0\pi^- and Bβˆ’β†’Dβˆ—0Kβˆ’β†’D0Ο€0Kβˆ’B^-\to D^{*0}K^-\to D^0\pi^0K^- decays can be employed as a constraint for the Dβˆ—0D^{*0} decay width, with preferred values consistent with previous theoretical predictions for this quantity.Comment: 12 pages, 5 figures. Published versio

    Relationship between CYP1A1 polymorphisms and invasion and metastasis of breast cancer

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    AbstractObjectiveTo investigate the relationship between CYP1A1 genetic polymorphisms and the invasion and metastasis of breast cancer.MethodsThe CYP1A1 gene polymorphism (an T-C transversion at nucleotide position 3801) was detected by the polymerase chain reaction and restriction fragment length polymorphism in 80 cases with breast cancer and 60 samples of normal breast tissue. The difference in genotypic distribution frequency between the groups, the correlation between the genotypes and the factors related to prognosis were analyzed.ResultsThe incidence of homozygous and variant genotypes had no difference between the breast cancer group and controls group (P=0.746). The proportion of variant genotype increased as clinical stage (P=0.006) advanced, as well as with increased numbers of lymph node metastases (P=0.010).ConclusionsIn patients with breast cancer there is a correlation between the CYP1A1 CC allele and some factors indicating poor prognosis, including more lymph node metastases as well as a more advanced clinical stage

    Strong Convergence Theorems for Equilibrium Problems and Fixed Point Problems in Hilbert Spaces

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    We introduce an Ishikawa iterative scheme by the viscosity approximate method for finding a common element of the set of solutions of an equilibrium problem and the set of fixed points of a nonexpansive mapping in Hilbert space. Then, we prove some strong convergence theorems which extend and generalize S. Takahashi and W. Takahashi's results (2007)
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