1,416 research outputs found

    Twist-3 light-cone distribution amplitudes of the scalar mesons within the QCD sum rules and their application to the BSB \to S transition form factors

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    We investigate the twist-3 light-cone distribution amplitudes (LCDAs) of the scalar mesons a0a_0, K0K^{\ast}_0 and f0f_0 within the QCD sum rules. The QCD sum rules are improved by a consistent treatment of the sizable ss-quark mass effects within the framework of the background field approach. Adopting the valence quark component (qˉ1q2)(\bar{q}_1 q_2) as the dominant structure of the scalar mesons, our estimation for their masses are close to the measured a0(1450)a_0(1450), K0(1430)K^{\ast}_0(1430) and f0(1710)f_0(1710). From the sum rules, we obtain the first two non-zero moments of the twist-3 LCDAs ϕa0s,σ\phi^{s,\sigma}_{a_0}: ξs,a02(4)=0.369  (0.245)\langle \xi_{s,a_0}^{2(4)} \rangle=0.369 \;(0.245) and ξσ,a02(4)=0.203  (0.093)\langle \xi_{\sigma,a_0}^{2(4)} \rangle=0.203 \;(0.093); those of the twist-3 LCDAs ϕK0s,σ\phi_{K^*_0}^{s,\sigma}: ξs,K01(2)=0.004  (0.355)\langle \xi_{s,K^{\ast}_0}^{1(2)} \rangle =0.004\;(0.355) and ξσ,K01(2)=0.018  (0.207)\langle \xi_{\sigma,K^{\ast}_0}^{1(2)} \rangle =0.018\;(0.207); and those of the twist-3 LCDAs ϕf0s,σ\phi_{f_0}^{s,\sigma}: ξs,f02(4)=0.335  (0.212)\langle \xi_{s,f_0}^{2(4)} \rangle=0.335 \;(0.212) and ξσ,f02(4)=0.196  (0.088)\langle \xi_{\sigma,f_0}^{2(4)} \rangle=0.196 \; (0.088), respectively. As an application of those twist-3 LCDAs, we study the BSB \to S transition form factors by introducing proper chiral currents into the correlator, which is constructed such that the twist-3 LCDAs give dominant contribution and the twist-2 LCDAs make negligible contribution. Our results of the BSB \to S transition form factors at the large recoil region q20q^2 \simeq 0 are consistent with those obtained in the literature, which inversely shows the present twist-3 LCDAs are acceptable.Comment: 14 pages, 12 figures, 7 table

    Methylenetetrahydrofolate reductase polymorphism and capecitabine-induced toxicity in patients with gastric cancer

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    Purpose: To evaluate the effect of methylenetetrahydrofolate reductase (MTHFR) polymorphism on toxicity in gastric cancer (GC) patients treated with capecitabine. Methods: One hundred and twenty-six GC patients were treated with capecitabine in the study. DNA from GC patients was genotyped for MTHFR A1298C using direct sequencing. Toxicity evaluations were graded. Clinical response was assessed. Results: In 87.3 % of the patients, capecitabine toxicity was observed. As for MTHFR A1298C polymorphism, 55.6 % patients who exhibited it were associated with reduced MTHFR activity. MTHFR A1298C was associated with capecitabine-related toxicity (p = 0.008); in addition, MTHFR A1298C was significantly associated with gastrointestinal toxicity (p = 0.026), but not with other types of toxicity. Conclusion: The findings suggest that MTHFR A1298C may be useful for predicting toxicity in GC patients receiving capecitabine treatment, especially gastrointestinal toxicity. Keywords: MTHFR, Polymorphism, Gastric cancer, Toxicit

    Bis{2-[(1H-pyrrol-2-yl)methyl­imino­meth­yl]phenolato-κ2 N,O}zinc(II)

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    In the title compound, [Zn(C12H11N2O)2], the ZnII atom, lying on an inversion center, is coordinated by two O atoms and two N atoms from two salicylal Schiff base ligands in a distorted square-planar geometry. A three-dimensional network is formed by inter­molecular C—H⋯N hydrogen bonds and C—H⋯π contacts

    An ECG-on-Chip with QRS Detection & Lossless Compression for Low Power Wireless Sensors

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    IEEE Transactions on Circuits and Systems II: Express BriefsPP991-

    The yeast prion protein Ure2: Structure, function and folding

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    The Saccharomyces cerevisiae protein Ure2 functions as a regulator of nitrogen metabolism and as a glutathione-dependent peroxidase. Ure2 also has the characteristics of a prion, in that it can undergo a heritable conformational change to an aggregated state; the prion form of Ure2 loses the regulatory function, but the enzymatic function appears to be maintained. A number of factors are found to affect the prion properties of Ure2, including mutation and expression levels of molecular chaperones, and the effect of these factors on structure and stability are being investigated. The relationship between structure, function and folding for the yeast prion Ure2 are discussed
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