3,961 research outputs found

    Approach to Rectal Cancer Surgery

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    Rectal cancer is a distinct subset of colorectal cancer where specialized disease-specific management of the primary tumor is required. There have been significant developments in rectal cancer surgery at all stages of disease in particular the introduction of local excision strategies for preinvasive and early cancers, standardized total mesorectal excision for resectable cancers incorporating preoperative short- or long-course chemoradiation to the multimodality sequencing of treatment. Laparoscopic surgery is also increasingly being adopted as the standard rectal cancer surgery approach following expertise of colorectal surgeons in minimally invasive surgery gained from laparoscopic colon resections. In locally advanced and metastatic disease, combining chemoradiation with radical surgery may achieve total eradication of disease and disease control in the pelvis. Evidence for resection of metastases to the liver and lung have been extensively reported in the literature. The role of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal metastases is showing promise in achieving locoregional control of peritoneal dissemination. This paper summarizes the recent developments in approaches to rectal cancer surgery at all these time points of the disease natural history

    An examination of the influence of emotional solidarity on value cocreation with international muslim travelers

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    Given the rising Muslim travel market and the scarcity of research on Muslim inbound market, it is important to elucidate how international Muslim travelers are perceived through the lens of residents in non-Islamic countries. This study provided an insight into how value cocreation is created through emotional solidarity and attitudes in the context of the Muslim travel market. Results of the structural model for American residents were comparatively similar to those of their Korean counterparts, which is indicative of both countries’ acceptance and tolerance of international Muslim travelers. In particular, residents’ openness to experience and the perceived benefit of international Muslim travelers for development of the tourist destination were significant predictors of emotional solidarity. Residents’ emotional solidarity subsequently explained their attitude toward international Muslim travelers. Attitude toward international Muslim travelers would lead to a positive attitude toward Muslim tourism, which in turn, triggered value cocreation behavior with international Muslim travelers.info:eu-repo/semantics/acceptedVersio

    Evidence for Factorization in Three-body B --> D(*) K- K0 Decays

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    Motivated by recent experimental results, we use a factorization approach to study the three-body B --> D(*) K- K0 decay modes. Two mechanisms are proposed for kaon pair production: current-produced (from vacuum) and transition (from B meson). The Bbar0 --> D(*)+ K- K0 decay is governed solely by the current-produced mechanism. As the kaon pair can be produced only by the vector current, the matrix element can be extracted from e+ e- --> K Kbar processes via isospin relations. The decay rates obtained this way are in good agreement with experiment. Both current-produced and transition processes contribute to B- --> D(*)0 K- K0 decays. By using QCD counting rules and the measured B- --> D(*)0 K- K0 decay rates, the measured decay spectra can be understood.Comment: 17 pages, 6 figure

    Low-Mass Baryon-Antibaryon Enhancements in B Decays

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    The nature of low-mass baryon-antibaryon enhancements seen in B decays is explored. Three possibilities include (i) states near threshold as found in a model by Nambu and Jona-Lasinio, (ii) isoscalar states with JPC=0±+J^{PC} = 0^{\pm +} coupled to a pair of gluons, and (iii) low-mass enhancements favored by the fragmentation process. Ways of distinguishing these mechanisms using angular distributions and flavor symmetry are proposed.Comment: 8 pages, LaTeX, no figures, to be submitted to Phys. Rev. D. One reference adde

    Phenomenological Consequences of Right-handed Down Squark Mixings

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    The mixings of dRd_R quarks, hidden from view in Standard Model (SM), are naturally the largest if one has an Abelian flavor symmetry. With supersymmetry (SUSY) their effects can surface via d~R\tilde d_R squark loops. Squark and gluino masses are at TeV scale, but they can still induce effects comparable to SM in BdB_d (or BsB_s) mixings, while D0D^0 mixing could be close to recent hints from data. In general, CP phases would be different from SM, as may be indicated by recent B Factory data. Presence of non-standard soft SUSY breakings with large tanβ\tan\beta could enhance bdγb\to d\gamma (or sγs\gamma) transitions.Comment: Version to appear in Phys. Rev. Let

    Nonleptonic charmless two-body BATB \to AT decays

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    In this work we have studied hadronic charmless two-body B decays involving p-wave mesons in final state. We have calculated branching ratios of BATB\to AT decays (where AA and TT denotes a 3P1^3P_1 axial-vector and a tensor meson, respectively), using BTB \to T form factors obtained in the covariant light-front (CLF) approach, and the full effective Hamiltonian. We have obtained that B(B0a1+a2)=42.47×106\mathcal{B}(B^{0} \to a_{1}^{+}a_{2}^{-}) =42.47 \times10^{-6}, B(B+a1+a20)=22.71×106\mathcal{B}(B^{+} \to a_{1}^{+}a_{2}^{0}) = 22.71 \times10^{-6}, B(Bf1K2)=(2.84)×106\mathcal{B}(B \to f_{1}K_{2}^{*}) = (2.8-4) \times 10^{-6} (with f1=,f1(1285),f1(1420)f_{1}=, f_{1}(1285),f_{1}(1420)) for θ3P1=53.2\theta_{^{3}P_{1}} = 53.2^{\circ}, B(Bf1(1420)K2)=(5.916.42)×106\mathcal{B}(B \to f_{1}(1420)K_{2}^{*}) = (5.91-6.42) \times 10^{-6} with θ3P1=27.9\theta_{^{3}P_{1}} = 27.9^{\circ}, B(BK1a2)=(1.75.7)[19.3]×106\mathcal{B}(B \to K_{1}a_{2})= (1.7 - 5.7) [1-9.3] \times10^{-6} for θK1=37[58]\theta_{K_{1}} = -37^{\circ} [-58^{\circ}] where K1=K1(1270),K1(1400)K_1 = K_1(1270), K_1(1400). It seems that these decays can be measured in experiments at BB factories. Additionally, we have found that B(BK1(1270)a2)/B(BK1(1400)a2)\mathcal{B}(B \to K_{1}(1270)a_{2})/\mathcal{B}(B \to K_{1}(1400)a_{2}) and B(Bf1(1420)K2)/B(Bf1(1285)K2)\mathcal{B}(B \to f_1(1420)K_{2}^{*})/\mathcal{B}(B \to f_1(1285)K_{2}^{*}) ratios could be useful to determine numerical values of mixing angles θK1\theta_{K_{1}} and θ3P1\theta_{^{3}P_{1}}, respectively.Comment: 12 page

    The Fourth Element: Characteristics, Modelling, and Electromagnetic Theory of the Memristor

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    In 2008, researchers at HP Labs published a paper in {\it Nature} reporting the realisation of a new basic circuit element that completes the missing link between charge and flux-linkage, which was postulated by Leon Chua in 1971. The HP memristor is based on a nanometer scale TiO2_2 thin-film, containing a doped region and an undoped region. Further to proposed applications of memristors in artificial biological systems and nonvolatile RAM (NVRAM), they also enable reconfigurable nanoelectronics. Moreover, memristors provide new paradigms in application specific integrated circuits (ASICs) and field programmable gate arrays (FPGAs). A significant reduction in area with an unprecedented memory capacity and device density are the potential advantages of memristors for Integrated Circuits (ICs). This work reviews the memristor and provides mathematical and SPICE models for memristors. Insight into the memristor device is given via recalling the quasi-static expansion of Maxwell's equations. We also review Chua's arguments based on electromagnetic theory.Comment: 28 pages, 14 figures, Accepted as a regular paper - the Proceedings of Royal Society

    LAF1, a MYB transcription activator for phytochrome A signaling

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    The photoreceptor phytochrome (phy) A has a well-defined role in regulating gene expression in response to specific light signals. Here, we describe a new Arabidopsis mutant, laf1 (long after far-red light 1) that has an elongated hypocotyl specifically under far-red light. Gene expression studies showed that laf1 has reduced responsiveness to continuous far-red light but retains wild-type responses to other light wavelengths. As far-red light is only perceived by phyA, our results suggest that LAF1 is specifically involved in phyA signal transduction. Further analyses revealed that laf1 is affected in a subset of phyA-dependent responses and the phenotype is more severe at low far-red fluence rates. LAF1 encodes a nuclear protein with strong homology with the R2R3-MYB family of DNA-binding proteins. Experiments using yeast cells identified a transactivation domain in the C-terminal portion of the protein. LAF1 is constitutively targeted to the nucleus by signals in its N-terminal portion, and the full-length protein accumulates in distinct nuclear speckles. This accumulation in speckles is abolished by a point mutation in a lysine residue (K258R), which might serve as a modification site by a small ubiquitin-like protein (SUMO)
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