155 research outputs found

    Difference Equations and Highest Weight Modules of U_q[sl(n)]

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    The quantized version of a discrete Knizhnik-Zamolodchikov system is solved by an extension of the generalized Bethe Ansatz. The solutions are constructed to be of highest weight which means they fully reflect the internal quantum group symmetry.Comment: 9 pages, LaTeX, no figure

    Matrix difference equations for the supersymmetric Lie algebra sl(2,1) and the `off-shell' Bethe ansatz

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    Based on the rational R-matrix of the supersymmetric sl(2,1) matrix difference equations are solved by means of a generalization of the nested algebraic Bethe ansatz. These solutions are shown to be of highest-weight with respect to the underlying graded Lie algebra structure.Comment: 10 pages, LaTex, references and acknowledgements added, spl(2,1) now called sl(2,1

    Multicenter data acquisition made easy

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    <p>Abstract</p> <p>Background</p> <p>The process for data collection in multicenter trials may be troublesome and expensive. We report our experience with the spreadsheet function in Googledocs for this purpose.</p> <p>Methods</p> <p>In Googledocs the data manager creates a form similar to the paper case record form, which will function as a decentral data entry module. When the forms are submitted, they are presented in a spreadsheet in Googledocs, which can be exported to different standard spreadsheet formats.</p> <p>Results</p> <p>For a multicenter randomized clinical trial with five different participating hospitals we created a decentral data entry module using the spreadsheet function in Googledocs. The study comprised 332 patients (clinicaltrials.gov identifier: NCT00815698) with five visits per patient. One person at each study site entered data from the original paper based case report forms which were kept at the study sites as originals. We did not experience any technical problems using the system.</p> <p>Conclusions</p> <p>The system allowed for decentral data entry, and it was easy to use, safe, and free of charge. The spreadsheet function in Googledocs may potentially replace current expensive solutions for data acquisition in multicenter trials.</p> <p>Trial registration</p> <p>clinicaltrials.gov NCT00815698</p

    The nested SU(N) off-shell Bethe ansatz and exact form factors

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    The form factor equations are solved for an SU(N) invariant S-matrix under the assumption that the anti-particle is identified with the bound state of N-1 particles. The solution is obtained explicitly in terms of the nested off-shell Bethe ansatz where the contribution from each level is written in terms of multiple contour integrals.Comment: This work is dedicated to the 75th anniversary of H. Bethe's foundational work on the Heisenberg chai

    New integrable extension of the Hubbard chain with variable range hopping

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    New integrable variant of the one-dimensional Hubbard model with variable-range correlated hopping is studied. The Hamiltonian is constructed by applying the quantum inverse scattering method on the infinite interval at zero density to the one-parameter deformation of the L-matrix of the Hubbard model. By construction, this model has Y(su(2))⊕\oplusY(su(2)) symmetry in the infinite chain limit. Multiparticle eigenstates of the model are investigated through this method.Comment: 25 pages, LaTeX, no figure

    Safety of dabigatran etexilate for the secondary prevention of venous thromboembolism in children

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    This open-label, single-arm, prospective cohort trial is the first phase 3 safety study to describe outcomes in children treated with dabigatran etexilate for secondary venous thromboembolism (VTE) prevention. Eligible children aged 12 to &lt;18 years (age stratum 1), 2 to &lt;12 years (stratum 2), and &gt;3 months to &lt;2 years (stratum 3) had an objectively confirmed diagnosis of VTE treated with standard of care (SOC) for ‡3 months, or had completed dabigatran or SOC treatment in the DIVERSITY trial (NCT01895777) and had an unresolved clinical thrombosis risk factor requiring further anticoagulation. Children received dabigatran for up to 12 months, or less if the identified VTE clinical risk factor resolved. Primary end points included VTE recurrence, bleeding events, and mortality at 6 and 12 months. Overall, 203 children received dabigatran, with median exposure being 36.3 weeks (range, 0-57 weeks); 171 of 203 (84.2%) and 32 of 203 (15.8%) took capsules and pellets, respectively. Overall, 2 of 203 children (1.0%) experienced on-treatment VTE recurrence, and 3 of 203 (1.5%) experienced major bleeding events, with 2 (1.0%) reporting clinically relevant nonmajor bleeding events, and 37 (18.2%) minor bleeding events. There were no on-treatment deaths. On-treatment postthrombotic syndrome was reported for 2 of 162 children (1.2%) who had deep vein thrombosis or central-line thrombosis as their most recent VTE. Pharmacokinetic/pharmacodynamic relationships of dabigatran were similar to those in adult VTE patients. In summary, dabigatran showed a favorable safety profile for secondary VTE prevention in children aged from &gt;3 months to &lt;18 years with persistent VTE risk factor(s). This trial was registered at www.clinicaltrials.gov as #NCT02197416. (Blood. 2020;135(7):491-504

    Gyromagnetic remanence acquired by greigite (Fe3S4) during static three-axis alternating field demagnetization

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    A magnetic study was carried out on lacustrine sediments from the Zoigebasin, Tibetan Plateau, in order to obtain a better understanding ofpalaeoclimatic changes there. Gyromagnetic remanence (GRM) acquisitionis unexpectedly observed during static three-axis alternating field (AF)demagnetization in about 20 per cent of a large number of samples. X-raydiffraction (XRD) analysis on a magnetic extract clearly shows thatgreigite is the dominant magnetic mineral carrier. Scanning electronmicroscopy (SEM) reveals that the greigite particles are in the grainsize range of 200-300 nm, possibly in the single-domain state. Greigiteclumps of about 3 mu m size are sealed by silicates. Fitting of XRDpeaks yields a crystalline coherence length of about 15 nm, indicatingthat the particles seen in the SEM are polycrystalline.GRM intensities of most samples are of the same order as the NRM, whileothers show much stronger GRM although their magnetic properties aresimilar. Variation of the demagnetization sequence confirms that GRM ismainly produced perpendicular to the AF direction. The anisotropydirection can be derived from GRM, but more systematic studies areneeded for detailed conclusions. An attempt to correct for GRM faileddue to high GRM intensities and because smaller GRM acquisition was alsofound along the demagnetization axis. Behaviours of acquisition and AFdemagnetization of GRM are comparable with those of NRM, ARM, IRM,indicating fine grain sizes of remanence carriers

    Lung Function after the Minimal Invasive Pectus Excavatum Repair (Nuss Procedure)

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    Background The Nuss procedure was introduced at our center in 1999. The operation was mainly performed for cosmesis. Little information is available regarding the influence of this operation on lung function. Methods The aim of this study, a prospective analysis, was to analyze the effect of the Nuss procedure on lung function variables. Between 1999 and 2007 a total of 203 patients with pectus excavatum were treated with the Nuss procedure, of whom 145 (104 male, 41 female) were located at Emma Children’s Hospital. In the latter subset of consecutive patients, static lung function variables [total lung capacity (TLC), functional residual capacity (FRC), vital capacity (VC)] and dynamic lung function variables [forced expired volume in 1 s (FEV1), maximum expiratory flow (MEF50)] were performed using spirometry and body box measurements at four time points: prior to operation Some of these data were presented at the International Surgical Week

    Modified Chrispin-Norman chest radiography score for cystic fibrosis: observer agreement and correlation with lung function

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    Contains fulltext : 96114.pdf ( ) (Closed access)OBJECTIVE: To test observer agreement and two strategies for possible improvement (consensus meeting and reference images) for the modified Chrispin-Norman score for children with cystic fibrosis (CF). METHODS: Before and after a consensus meeting and after developing reference images three observers scored sets of 25 chest radiographs from children with CF. Observer agreement was tested for line, ring, mottled and large soft shadows, for overinflation and for the composite modified Chrispin-Norman score. Correlation with lung function was assessed. RESULTS: Before the consensus meeting agreement between observers 1 and 2 was moderate-good, but with observer 3 agreement was poor-fair. Scores correlated significantly with spirometry for observers 1 and 2 (-0.72<R<-0.42, P < 0.05), but not for observer 3. Agreement with observer 3 improved after the consensus meeting. Reference images improved agreement for overinflation and mottled and large shadows and correlation with lung function, but agreement for the modified Chrispin-Norman score did not improve further. CONCLUSION: Consensus meetings and reference images improve among-observer agreement for the modified Chrispin-Norman score, but good agreement was not achieved among all observers for the modified Chrispin-Norman score and for bronchial line and ring shadows
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