359 research outputs found

    Efficacy and safety of prucalopride in the treatment of chronic constipation

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    Background: Chronic constipation is a common condition that significantly impacts health care utilization, productivity, and quality of life. Laxatives are commonly used, although often insufficient in restoring normal bowel function or providing adequate relief. There remains a significant need for the development of novel agents to optimize treatment of this condition. Prucalopride, a selective, high-affinity 5-hydroxytryptamine 4 receptor agonist, stimulates gastrointestinal and colonic motility and alleviates common symptoms of chronic constipation. Here authors are evaluating efficacy and safety study of this drug in chronic constipation patient.Methods: This is a prospective observational study where chronic constipation patient treated with prucalopride 2 mg daily once were enrolled during 6 month period. Data at one week and four weeks were observed along with adverse effects. Efficacy assessed by the number of Spontaneous Complete Bowel Movements (SCBMs) per week recorded by patient diaries. Patients were defined as responders when they had a mean of three or more SCBMs per week over the whole treatment period. The primary efficacy end point was proportion of responders after 1 week and after 4 weeks of treatment.Results: A total of 43 patients diagnosed with chronic constipation and treated with prucalopride were included in study. The proportions of patients in the present study with at least three SCBMs per week (responders) were 44.2% (19 out of 43 patients) at 1 week and 46.5% (20 out of 43 patients) at 4 weeks. Treatment was well tolerated with minimal side effects. Common adverse effects reported in our study were gastrointestinal disorders like diarrhea, nausea and abdominal pain and nervous system disorders like headache and dizziness.Conclusions: Prucalopride is effective, has a good safety profile, and is well tolerated in chronic constipation treatment

    Towards an effective-action approach to fermion-loop corrections

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    We present a study of the effective action approach to incorporate higher-order effects in e^+e^- -> n fermions. In its minimal version, the effective action approach is found to exhibit problems with unitarity and high-energy behaviour. We identify the origin of these problems by investigating the zero-mode solutions of the Ward Identities. A numerical analysis of the importance of the zero-mode solutions is presented for four-fermion production processes.Comment: 43 pages, 1 figure. Accepted for publication in Nuclear Physics

    Suppression of intrinsic neutron background in the Multi-Grid detector

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    One of the key requirements for neutron scattering instruments is the Signal-to-Background ratio (SBR). This is as well a design driving requirement for many instruments at the European Spallation Source (ESS), which aspires to be the brightest neutron source of the world. The SBR can be effectively improved with background reduction. The Multi-Grid, a large-area thermal neutron detector with a solid boron carbide converter, is a novel solution for chopper spectrometers. This detector will be installed for the three prospective chopper spectrometers at the ESS. As the Multi-Grid detector is a large area detector with a complex structure, its intrinsic background and its suppression via advanced shielding design should be investigated in its complexity, as it cannot be naively calculated. The intrinsic scattered neutron background and its effect on the SBR is determined via a detailed Monte Carlo simulation for the Multi-Grid detector module, designed for the CSPEC instrument at the ESS. The impact of the detector vessel and the neutron entrance window on scattering is determined, revealing the importance of an optimised internal detector shielding. The background-reducing capacity of common shielding geometries, like side-shielding and end-shielding is determined by using perfect absorber as shielding material, and common shielding materials, like B4_{4}C and Cd are also tested. On the basis of the comparison of the effectiveness of the different shielding topologies and materials, recommendations are given for a combined shielding of the Multi-Grid detector module, optimised for increased SBR.Comment: 26 pages, 18 figures, revise

    Counting loop diagrams: computational complexity of higher-order amplitude evaluation

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    We discuss the computational complexity of the perturbative evaluation of scattering amplitudes, both by the Caravaglios-Moretti algorithm and by direct evaluation of the individual diagrams. For a self-interacting scalar theory, we determine the complexity as a function of the number of external legs. We describe a method for obtaining the number of topologically inequivalent Feynman graphs containing closed loops, and apply this to one- and two-loop amplitudes. We also compute the number of graphs weighted by their symmetry factors, thus arriving at exact and asymptotic estimates for the average symmetry factor of diagrams. We present results for the asymptotic number of diagrams up to 10 loops, and prove that the average symmetry factor approaches unity as the number of external legs becomes large.Comment: 27 pages, 17 table

    PHASE - An event generator for six fermion physics at the LHC

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    PHASE is a Monte Carlo event generator, under construction, for all Standard Model processes with six fermions in the final state at the LHC. It employs the full set of tree level Feynman diagrams, taking into account fermion masses for b quarks. The program can generate unweighted events for any subset of all six fermion final states in a single run, by making use of dedicated pre-samples. An interface to hadronization is provided.Comment: 4 pages, Latex, 1 figure. Talk given by E. Accomando at the IX International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT03), KEK, Tsukuba, December 1-5, 200

    Knowledge and practice of antibiotic prophylaxis for infective endocarditis among dental students

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    Background: Infective endocarditis (IE) is a microbial infection of the valves and endocardium of the heart. IE is difficult to treat and has a poor prognosis. Dentists play a major role in preventing IE in susceptible patients. In this study, we evaluate knowledge and practice of antibiotic prophylaxis for IE among dental students, interns and PGs at S. N. Dental College, Kalaburagi.Methods: A cross-sectional study was done by survey using questionnaire. Questionnaire was distributed to 159 dental students, interns and PGs at S. N. Dental College, Kalaburagi. Questionnaire included questions regarding to demographic information and knowledge and practice of the participants about antibiotic prophylaxis for IE.Results: Out of 159 participants 135 provided the response, giving a response rate of 85%. Overall, average of 52.7% of the participants had a good level of knowledge regarding the cardiac conditions that require antibiotic prophylaxis. Participants also had better knowledge regarding dental procedures that require prophylaxis with an average of 75.7%. But only 37.2% prescribed correct drug, dosage and regime of antibiotic prophylaxis.Conclusions: The level of knowledge and practice about antibiotics prophylaxis of IE amongst dental students, interns and PGs at the study site was not at an acceptable level. Awareness is essential because of the cardiac risks associated with the lack of appropriate prophylaxis. Up-to-date and accurate knowledge is mandatory for all dental students, interns and PGs who see and treat patients on a daily basis. This study emphasized the need for continuous education and for formal inclusion of the guidelines in the student’s curriculum

    NLO QCD calculations with HELAC-NLO

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    Achieving a precise description of multi-parton final states is crucial for many analyses at LHC. In this contribution we review the main features of the HELAC-NLO system for NLO QCD calculations. As a case study, NLO QCD corrections for tt + 2 jet production at LHC are illustrated and discussed.Comment: 7 pages, 4 figures. Presented at 10th DESY Workshop on Elementary Particle Theory: Loops and Legs in Quantum Field Theory, Worlitz, Germany, April 25-30, 201

    A First Comparison of the responses of a He4-based fast-neutron detector and a NE-213 liquid-scintillator reference detector

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    A first comparison has been made between the pulse-shape discrimination characteristics of a novel 4^{4}He-based pressurized scintillation detector and a NE-213 liquid-scintillator reference detector using an Am/Be mixed-field neutron and gamma-ray source and a high-resolution scintillation-pulse digitizer. In particular, the capabilities of the two fast neutron detectors to discriminate between neutrons and gamma-rays were investigated. The NE-213 liquid-scintillator reference cell produced a wide range of scintillation-light yields in response to the gamma-ray field of the source. In stark contrast, due to the size and pressure of the 4^{4}He gas volume, the 4^{4}He-based detector registered a maximum scintillation-light yield of 750~keVee_{ee} to the same gamma-ray field. Pulse-shape discrimination for particles with scintillation-light yields of more than 750~keVee_{ee} was excellent in the case of the 4^{4}He-based detector. Above 750~keVee_{ee} its signal was unambiguously neutron, enabling particle identification based entirely upon the amount of scintillation light produced.Comment: 23 pages, 7 figures, Nuclear Instruments and Methods in Physics Research Section A review addresse

    Feynman Rules for the Rational Part of the QCD 1-loop amplitudes

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    We compute the complete set of Feynman Rules producing the Rational Terms of kind R_2 needed to perform any QCD 1-loop calculation. We also explicitly check that in order to account for the entire R_2 contribution, even in case of processes with more than four external legs, only up to four-point vertices are needed. Our results are expressed both in the 't Hooft Veltman regularization scheme and in the Four Dimensional Helicity scheme, using explicit color configurations as well as the color connection language.Comment: 18 pages, 11 figures. Misprints corrected in Appendix A. Version to be published in JHE

    A simulational study of the indirect geometry neutron spectrometer, BIFROST at the European Spallation Source, from neutron source position to detector position

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    The European Spallation Source (ESS) is intended to become the most powerful spallation neutron source in the world and the flagship of neutron science in the upcoming decades. The exceptionally high neutron flux will provide unique opportunities for scientific experiments, but also set high requirements for the detectors. One of the most challenging aspects is the rate capability and in particular the peak instantaneous rate capability, i.e. the number of neutrons hitting the detector per channel or cm2^2 at the peak of the neutron pulse. The primary purpose of this paper is to estimate the incident rates that are anticipated for the BIFROST instrument planned for ESS, and also to demonstrate the use of powerful simulation tools for the correct interpretation of neutron transport in crystalline materials. A full simulation model of the instrument from source to detector position, implemented with the use of multiple simulation software packages is presented. For a single detector tube instantaneous incident rates with a maximum of 1.7 GHz for a Bragg peak from a single crystal, and 0.3 MHz for a vanadium sample are found. This paper also includes the first application of a new pyrolytic graphite model, and a comparison of different simulation tools to highlight their strengths and weaknesses.Comment: 45 pages, 20 figure
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