363 research outputs found
Efficacy and safety of prucalopride in the treatment of chronic constipation
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
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
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 BC 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
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
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
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
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
Gamma/neutron classification with SiPM CLYC detectors using frequency-domain analysis for embedded real-time applications
A method for gamma/neutron event classification based on frequency-domain analysis for mixed radiation environments is proposed. In contrast to the traditional charge comparison method for pulse-shape discrimination, which requires baseline removal and pulse alignment, our method does not need any preprocessing of the digitized data, apart from removing saturated traces in sporadic pile-up scenarios. It also features the identification of neutron events in the detector’s full energy range with a single device, from thermal neutrons to fast neutrons, including low-energy pulses, and still provides a superior figure-of-merit for classification.
The proposed frequency-domain analysis consists of computing the fast Fourier transform of a triggered trace and integrating it through a simplified version of the transform magnitude components that distinguish the neutron features from those of the gamma photons. Owing to this simplification, the proposed method may be easily ported to a real-time embedded deployment based on Field-Programmable Gate Arrays or Digital Signal Processors. We target an off-the-shelf detector based on a small CLYC (Cs2LiYCl6:Ce) crystal coupled to a silicon photomultiplier with an integrated bias and preamplifier, aiming at lightweight embedded mixed radiation monitors and dosimeter applications
A First Comparison of the responses of a He4-based fast-neutron detector and a NE-213 liquid-scintillator reference detector
A first comparison has been made between the pulse-shape discrimination
characteristics of a novel 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 He gas volume, the He-based
detector registered a maximum scintillation-light yield of 750~keV to
the same gamma-ray field. Pulse-shape discrimination for particles with
scintillation-light yields of more than 750~keV was excellent in the
case of the He-based detector. Above 750~keV 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
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
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