2,886 research outputs found

    Three-body Baryonic anti-B -->Lambda anti-p pi Decays and Such

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    We study decay rates and spectra of anti-B --> Lambda anti-p pi, Sigma0 anti-p pi, Sigma- anti-n pi, Xi0 anti-Sigma+ pi, Xi- anti-Sigma0 pi and Xi- anti-Lambda pi modes under a factorization approach. The baryon pairs are produced through vector, axial vector, scalar and pseudoscalar operators. Previous predictions, including ours, are an order of magnitude too small compared to experiment. By incorporating QCD counting rules and studying the asymptotic behavior, we find an earlier relation between the pseudoscalar and axial vector form factors to be too restrictive. Instead, the pseudoscalar and scalar form factors are related asymptotically. Following this approach, the measured Lambda anti-p pi rate (~4.0x10^{-6}) and spectrum can be understood, and Lambda should be dominantly left-hand polarized, while we expect Br(Sigma0 anti-p pi)~1.6x10^{-6}. These results and other predictions can be checked soon.Comment: 18 pages, 3 figures; use updated Belle results, add Lambda polarization stud

    Supersymmetric Model Contributions to Bd0B^0_d--Bˉd0\bar B^0_d Mixing and Bππ,ργB\to\pi\pi,\rho\gamma Decays

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    Recent results from Belle and BaBar Collaborations hint at a small sin2ϕ1\sin2\phi_1, while the measured BππB\to\pi\pi rate also seems to be on the low side. Supersymmetric (SUSY) models with down squark mixings can account for the deficits in both cases. By studying the origin of SUSY contributions that could impact on Bd0B^0_d--Bˉd0\bar B^0_d mixing and BππB\to\pi\pi decay, we find that the former would most likely arise from left-left or right-right squark mixings, while the latter would come from left-right squark mixings. These two processes in general are not much correlated in the Minimum Supersymmetric Standard Model. If the smallness of BππB\to\pi\pi is due to SUSY models, one would likely have large BργB\to\rho\gamma from chiral enhancement, and the rate could be within present experimental reach. Even if BργB\to\rho\gamma is not greatly enhanced, it could have large mixing dependent CP violation.Comment: 10 pages, 6 figures. Version to appear in Eur. Phys. J.

    Indication for Large Rescatterings in Charmless Rare B Decays

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    The current wealth of charmless B decay data may suggest the presence of final state rescattering. In a factorized amplitude approach, better fits are found by incorporating two SU(3) rescattering phase differences, giving delta ~ 65 degree and sigma ~ 90 - 100 degree. Fitting with unitarity phase phi_3 as a fit parameter gives phi_3 ~ 96 degree, the CP asymmetries A_{pi pi}, S_{pi pi} agree better with BaBar, and the sigma phase is slightly lower. Keeping phi_3 = 60 degree fixed in fit gives S_{pi pi} ~-0.9, which agrees better with Belle. With the sizable delta, sigma rescattering phases as fitted, many direct CP asymmetries flip sign, and B0 --> pi0 pi0, K- K+ rates are of order 10^{-6}, which can be tested soon.Comment: 6 pages, 4 figures, updated, references adde

    The Malaysian Medication Adherence Scale (MALMAS): Concurrent Validity Using a Clinical Measure among People with Type 2 Diabetes in Malaysia.

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    Medication non-adherence is a prevalent problem worldwide but up to today, no gold standard is available to assess such behavior. This study was to evaluate the psychometric properties, particularly the concurrent validity of the English version of the Malaysian Medication Adherence Scale (MALMAS) among people with type 2 diabetes in Malaysia. Individuals with type 2 diabetes, aged 21 years and above, using at least one anti-diabetes agent and could communicate in English were recruited. The MALMAS was compared with the 8-item Morisky Medication Adherence Scale (MMAS-8) to assess its convergent validity while concurrent validity was evaluated based on the levels of glycated hemoglobin (HbA1C). Participants answered the MALMAS twice: at baseline and 4 weeks later. The study involved 136 participants. The MALMAS achieved acceptable internal consistency (Cronbach's alpha=0.565) and stable reliability as the test-retest scores showed fair correlation (Spearman's rho=0.412). The MALMAS has good correlation with the MMAS-8 (Spearman's rho=0.715). Participants who were adherent to their anti-diabetes medications had significantly lower median HbA1C values than those who were non-adherence (7.90 versus 8.55%, p=0.032). The odds of participants who were adherent to their medications achieving good glycemic control was 3.36 times (95% confidence interval: 1.09-10.37) of those who were non-adherence. This confirms the concurrent validity of the MALMAS. The sensitivity of the MALMAS was 88.9% while its specificity was 29.6%. The findings of this study further substantiates the reliability and validity of the MALMAS, in particular its concurrent validity and sensitivity for assessing medication adherence of people with type 2 diabetes in Malaysia

    Rescattering effects in B_{u,d,s}(bar) to D P, D(bar) P decays

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    We study quasi-elastic rescattering effects in B_{u,d,s}(bar) to DP, D(bar)P decays, where P is a light pseudoscalar. The updated measurements of B_{u,d}(bar) to DP decays are used to extract the effective Wilson coefficients a^{eff}_1 ~ 0.90, a^{eff}_2 ~ 0.23, three strong phases delta ~ 53 degree, theta ~ 18 degree, sigma ~ -88 degree, and the mixing angle tau ~ 9 degree. This information is used to predict rates of nineteen B_{s}(bar) to DP and B_{u,d,s}(bar) to D(bar)P decay modes, including modes of interests in the gamma/phi_3 program. Many decay rates are found to be enhanced. In particular, the B_s(bar) to D0 K0 rate is predicted to be 8\times 10^{-4}, which could be measured soon. The rescattering effects on the corresponding B_{u,d,s}(bar) to D(bar)P, DP amplitude ratios r_B, r_{B_s}, and the relative strong phases delta_B, delta_{B_s} are studied. Although the decay rates are enhanced in most cases, r_{B,B_s} values are similar to factorization expectation.Comment: 16 page

    Blockade of Wnt-1 signaling leads to anti-tumor effects in hepatocellular carcinoma cells

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    <p>Abstract</p> <p>Background</p> <p>Hepatocellular carcinoma (HCC) is an aggressive cancer, and is the third leading cause of cancer death worldwide. Standard therapy is ineffective partly because HCC is intrinsically resistant to conventional chemotherapy. Its poor prognosis and limited treatment options make it critical to develop novel and selective chemotherapeutic agents. Since the Wnt/β-catenin pathway is essential in HCC carcinogenesis, we studied the inhibition of Wnt-1-mediated signaling as a potential molecular target in HCC.</p> <p>Results</p> <p>We demonstrated that Wnt-1 is highly expressed in human hepatoma cell lines and a subgroup of human HCC tissues compared to paired adjacent non-tumor tissues. An anti-Wnt-1 antibody dose-dependently decreased viability and proliferation of Huh7 and Hep40 cells over-expressing Wnt-1 and harboring wild type β-catenin, but did not affect normal hepatocytes with undetectable Wnt-1 expression. Apoptosis was also observed in Huh7 and Hep40 cells after treatment with anti-Wnt-1 antibody. In these two cell lines, the anti-Wnt-1 antibody decreased β-catenin/Tcf4 transcriptional activities, which were associated with down-regulation of the endogenous β-catenin/Tcf4 target genes c-Myc, cyclin D1, and survivin. Intratumoral injection of anti-Wnt-1 antibody suppressed <it>in vivo </it>tumor growth in a Huh7 xenograft model, which was also associated with apoptosis and reduced c-Myc, cyclin D1, and survivin expressions.</p> <p>Conclusion</p> <p>Our results suggest that Wnt-1 is a survival factor for HCC cells, and that the blockade of Wnt-1-mediated signaling may offer a potential pathway-specific therapeutic strategy for the treatment of a subgroup of HCC that over-expresses Wnt-1.</p
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