191 research outputs found

    Hadronic decays of B→a1(1260)b1(1235)B \to a_1(1260) b_1(1235) in the perturbative QCD approach

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    We calculate the branching ratios and polarization fractions of the B→a1b1B \to a_1 b_1 decays in the perturbative QCD(pQCD) approach at leading order, where a1a_1(b1b_1) stands for the axial-vector a1(1260)[b1(1235)]a_1(1260)[b_1(1235)] state. By combining the phenomenological analyses with the perturbative calculations, we find the following results: (a) the large decay rates around 10−510^{-5} to 10−610^{-6} of the B→a1b1B \to a_1 b_1 decays dominated by the longitudinal polarization(except for the B+→b1+a10B^+ \to b_1^+ a_1^0 mode) are predicted and basically consistent with those in the QCD factorization(QCDF) within errors, which are expected to be tested by the Large Hadron Collider and Belle-II experiments. The large B0→a10b10B^0 \to a_1^0 b_1^0 branching ratio could provide hints to help explore the mechanism of the color-suppressed decays. (b) the rather different QCD behaviors between the a1a_1 and b1b_1 mesons result in the destructive(constructive) contributions in the nonfactorizable spectator diagrams with a1(b1)a_1(b_1) emission. Therefore, an interesting pattern of the branching ratios appears for the color-suppressed B0→a10a10,a10b10,B^0 \to a_1^0 a_1^0, a_1^0 b_1^0, and b10b10b_1^0 b_1^0 modes in the pQCD approach, Br(B0→b10b10)>Br(B0→a10b10)≳Br(B0→a10a10)Br(B^0 \to b_1^0 b_1^0) > Br(B^0 \to a_1^0 b_1^0) \gtrsim Br(B^0 \to a_1^0 a_1^0), which is different from Br(B0→b10b10)∌Br(B0→a10b10)≳Br(B0→a10a10)Br(B^0 \to b_1^0 b_1^0) \sim Br(B^0 \to a_1^0 b_1^0) \gtrsim Br(B^0 \to a_1^0 a_1^0) in the QCDF and would be verified at future experiments. (c) the large naive factorization breaking effects are observed in these B→a1b1B \to a_1 b_1 decays. Specifically, the large nonfactorizable spectator(weak annihilation) amplitudes contribute to the B0→b1+a1−(B+→a1+b10  and  B+→b1+a10)B^0 \to b_1^+ a_1^-(B^+ \to a_1^+ b_1^0\; {\rm and}\; B^+ \to b_1^+ a_1^0) mode(s), which demand confirmations via the precise measurements.Comment: 13 pages, 1 figure, 5 tables, revtex fil

    Femtosecond laser-induced modification at aluminum/diamond interface

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    We investigated femtosecond-laser-induced modification at an Al/diamond interface. The interface was irradiated from the backside through the diamond substrate, which is transparent to the laser beam. Extremely high pulse energies, i.e., 200 and 100 ”J/pulse, were used to irradiate the interface. The cross-section of the laser-irradiated line was observed with conventional and high-voltage transmission electron microscopy. The modification of the laser-irradiated interface was characterized by the formation of an amorphous phase sandwiched between the deformed Al film and the diamond substrate. The major chemical component of the amorphous phase was identified as carbon, blown from the diamond substrate. The newly formed interface between the amorphous phase and the diamond substrate was concave. In addition, a fine ripple structure with an average spacing one-quarter the wavelength of the laser light was formed only in the sample irradiated by the higher-energy pulses

    Evaluation of Infliximab Effects on Gastrointestinal Bleeding in Crohn's Disease Using Double-Balloon Endoscopy

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    Tumor necrosis factor α plays an important role in the pathogenesis of Crohn's disease (CD). The effects of infliximab on gastrointestinal bleeding in CD have not yet been fully evaluated. Herein we describe three CD cases who presented with gastrointestinal bleeding and received infliximab treatment. In case 1, double-balloon endoscopy showed a large ulcer with several irregularly shaped ulcers in the terminal ileum; 8 weeks after infliximab administration, complete healing of all lesions was observed. In case 2, double-balloon endoscopy showed linear ulcers and mucosal edema in the jejunum and ileum; 5 weeks after infliximab administration, all lesions were decreased in size and were healed. In case 3, double-balloon endoscopy revealed ulcerations and stenosis in the terminal ileum; 12 weeks after infliximab administration, ulcer healing and an increased diameter of the ileal stenosis were observed. These three cases have been receiving ongoing infliximab maintenance therapy and are currently symptom-free. Infliximab thus appears to be useful for treatment of gastrointestinal bleeding in CD patients

    Study protocol of the SACURA trial: a randomized phase III trial of efficacy and safety of UFT as adjuvant chemotherapy for stage II colon cancer

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    BACKGROUND: Adjuvant chemotherapy for stage III colon cancer is internationally accepted as standard treatment with established efficacy, but the usefulness of adjuvant chemotherapy for stage II colon cancer remains controversial. The major Western guidelines recommend adjuvant chemotherapy for “high-risk stage II” cancer, but this is not clearly defined and the efficacy has not been confirmed. METHODS/DESIGN: SACURA trial is a multicenter randomized phase III study which aims to evaluate the superiority of 1-year adjuvant treatment with UFT to observation without any adjuvant treatment after surgery for stage II colon cancer in a large population, and to identify “high-risk factors of recurrence/death” in stage II colon cancer and predictors of efficacy and adverse events of the chemotherapy. Patients aged between 20 and 80 years with curatively resected stage II colon cancer are randomly assigned to a observation group or UFT adjuvant therapy group (UFT at 500–600 mg/day as tegafur in 2 divided doses after meals for 5 days, followed by 2-day rest. This 1-week treatment cycle is repeated for 1 year). The patients are followed up for 5 years until recurrence or death. Treatment delivery and adverse events are entered into a web-based case report form system every 3 months. The target sample size is 2,000 patients. The primary endpoint is disease-free survival, and the secondary endpoints are overall survival, recurrence-free survival, and incidence and severity of adverse events. In an additional translational study, the mRNA expression of 5-FU-related enzymes, microsatellite instability and chromosomal instability, and histopathological factors including tumor budding are assessed to evaluate correlation with recurrences, survivals and adverse events. DISCUSSION: A total of 2,024 patients were enrolled from October 2006 to July 2010. The results of this study will provide important information that help to improve the therapeutic strategy for stage II colon cancer. TRIAL REGISTRATION: ClinicalTrials.gov NCT00392899

    TGF-ÎČ-dependent reprogramming of amino acid metabolism induces epithelial–mesenchymal transition in non-small cell lung cancers

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    Epithelial–mesenchymal transition (EMT)—a fundamental process in embryogenesis and wound healing—promotes tumor metastasis and resistance to chemotherapy. While studies have identified signaling components and transcriptional factors responsible in the TGF-ÎČ-dependent EMT, whether and how intracellular metabolism is integrated with EMT remains to be fully elucidated. Here, we showed that TGF-ÎČ induces reprogramming of intracellular amino acid metabolism, which is necessary to promote EMT in non-small cell lung cancer cells. Combined metabolome and transcriptome analysis identified prolyl 4-hydroxylase α3 (P4HA3), an enzyme implicated in cancer metabolism, to be upregulated during TGF-ÎČ stimulation. Further, knockdown of P4HA3 diminished TGF-ÎČ-dependent changes in amino acids, EMT, and tumor metastasis. Conversely, manipulation of extracellular amino acids induced EMT-like responses without TGF-ÎČ stimulation. These results suggest a previously unappreciated requirement for the reprogramming of amino acid metabolism via P4HA3 for TGF-ÎČ-dependent EMT and implicate a P4HA3 inhibitor as a potential therapeutic agent for cancer

    Computational assessment of insulin secretion and insulin sensitivity from 2-h oral glucose tolerance tests for clinical use for type 2 diabetes

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    In type 2 diabetes mellitus, glucose homeostasis is tightly maintained through insulin secretion and insulin sensitivity. Therefore, finding an accurate method to assess insulin secretion and sensitivity using clinically available data would enhance the quality of diabetic medical care. In an effort to find such a method, we developed a computational approach to derive indices of these factors using a 2-h oral glucose tolerance test (OGTT). To evaluate our method, clinical data from subjects who received an OGTT and a glucose clamp test were examined. Our insulin secretion index was significantly correlated with an analogous index obtained from a hyperglycemic clamp test (r = 0.90, n = 46, p < 0.001). Our insulin sensitivity index sensitivity was also significantly correlated with an analogous index obtained from a hyperinsulinemic-euglycemic clamp test (r = 0.56, n = 79, p < 0.001). These results suggest that our method can potentially provide an accurate and convenient tool toward improving the management of diabetes in clinical practice by assessing insulin secretion and insulin sensitivity
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