641 research outputs found

    Randomised controlled trial of specialist nurse intervention in heart failure

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    <p>Objectives. To determine whether specialist nurse intervention improves outcome in patients with chronic heart failure.</p> <p>Design. Randomised controlled trial.</p> <p>Setting. Acute medical admissions unit in a teaching hospital.</p> <p>Participants. 165 patients admitted with heart failure due to left ventricular systolic dysfunction. The intervention started before discharge and continued thereafter with home visits for up to 1 year.</p> <p>Main outcome measures. Time to first event analysis of death from all causes or readmission to hospital with worsening heart failure.</p> <p>Results. 31 patients (37%) in the intervention group died or were readmitted with heart failure compared with 45 (53%) in the usual care group (hazard ratio=0.61, 95% confidence interval 0.33 to 0.96).Compared with usual care, patients in the intervention group had fewer readmissions for any reason (86 v 114, P=0.018), fewer admissions for heart failure (19 v 45, P<0.001) and spent fewer days in hospital for heart failure (mean 3.43 v 7.46 days, P=0.0051).</p> <p>Conclusions. Specially trained nurses can improve the outcome of patients admitted to hospital with heart failure.</p&gt

    Comparative demography and diversity of small mammals in precordilleran temperate rainforests of Southern Chile

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    Small mammals were studied in two southern Chilean temperate rainforests in the precordillean Andes during 2 low-rainfall years following the 1982 El Niño event. Forests had somewhat different levels of canopy, shrub, and herbaceous cover, and species richness of trees but most of the same plants. Most captures were of four sigmodontine rodents, Akodon olivaceus, Abrothrix longipilis, Abrothrix sanborni, and Oligoryzomys longicaudatus; five other species and a putative hybrid were recorded. Maximum numbers were in January-July (late summer to winter) and lower numbers in August-December (late winter to early summer). All species had seasonal reproduction in September-April (spring to autumn). A. olivaceus and A. longipilis generally were long-lived, whereas survival rates were low for O. longicaudatus. Responses after the 1982 El Niño were small, and some populations increased during 1984. Populations of A. olivaceus fluctuated more than those of A. longipilis; those of A. sanborni were low and O. longicaudatus was sporadic and irruptive. Lower-elevational Chilean and precordilleran Argentine forests have similar species composition, but differences in demography and dominance of the former by more widespread, omnivorous A. olivaceus, animalivorous-fungivorous Abrothrix, and granivorous O. longicaudatus. Opportunities for immigration may explain greater homogeneity of populations of small mammals in Chilean rainforests relative to Argentine ones. Although responses to El Niño and subsequent droughts were weak, flowering episodes of bamboo (Chusquea) can have strong effects due to increased availability of food

    An explicit height bound for the classical modular polynomial

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    For a prime m, let Phi_m be the classical modular polynomial, and let h(Phi_m) denote its logarithmic height. By specializing a theorem of Cohen, we prove that h(Phi_m) <= 6 m log m + 16 m + 14 sqrt m log m. As a corollary, we find that h(Phi_m) <= 6 m log m + 18 m also holds. A table of h(Phi_m) values is provided for m <= 3607.Comment: Minor correction to the constants in Theorem 1 and Corollary 9. To appear in the Ramanujan Journal. 17 pages

    Holstein model in infinite dimensions at half-filling

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    The normal state of the Holstein model is studied at half-filling in infinite dimensions and in the adiabatic regime. The dynamical mean-field equations are solved using perturbation expansions around the extremal paths of the effective action for the atoms. We find that the Migdal-Eliashberg expansion breaks down in the metallic state if the electron-phonon coupling λ\lambda exceeds a value of about 1.3 in spite of the fact that the formal expansion parameter λω0/EF\lambda \omega_0/E_F (ω0\omega_0 is the phonon frequency, EFE_F the Fermi energy) is much smaller than 1. The breakdown is due to the appearance of more than one extremal path of the action. We present numerical results which illustrate in detail the evolution of the local Green's function, the self-energy and the effective atomic potential as a function of λ\lambda.Comment: Revtex + 17 postscript figures include

    IRF4 and BATF are critical for CD8(+) T-cell function following infection with LCMV.

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    CD8(+) T-cell functions are critical for preventing chronic viral infections by eliminating infected cells. For healthy immune responses, beneficial destruction of infected cells must be balanced against immunopathology resulting from collateral damage to tissues. These processes are regulated by factors controlling CD8(+) T-cell function, which are still incompletely understood. Here, we show that the interferon regulatory factor 4 (IRF4) and its cooperating binding partner B-cell-activating transcription factor (BATF) are necessary for sustained CD8(+) T-cell effector function. Although Irf4(-/-) CD8(+) T cells were initially capable of proliferation, IRF4 deficiency resulted in limited CD8(+) T-cell responses after infection with the lymphocytic choriomeningitis virus. Consequently, Irf4(-/-) mice established chronic infections, but were protected from fatal immunopathology. Absence of BATF also resulted in reduced CD8(+) T-cell function, limited immunopathology, and promotion of viral persistence. These data identify the transcription factors IRF4 and BATF as major regulators of antiviral cytotoxic T-cell immunity

    Large-space shell-model calculations for light nuclei

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    An effective two-body interaction is constructed from a new Reid-like NNNN potential for a large no-core space consisting of six major shells and is used to generate the shell-model properties for light nuclei from AA=2 to 6. (For practical reasons, the model space is partially truncated for AA=6.) Binding energies and other physical observables are calculated and compare favorably with experiment.Comment: prepared using LaTex, 21 manuscript pages, no figure

    Path integrals approach to resisitivity anomalies in anharmonic systems

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    Different classes of physical systems with sizeable electron-phonon coupling and lattice distortions present anomalous resistivity behaviors versus temperature. We study a molecular lattice Hamiltonian in which polaronic charge carriers interact with non linear potentials provided by local atomic fluctuations between two equilibrium sites. We study a molecular lattice Hamiltonian in which polaronic charge carriers interact with non linear potentials provided by local atomic fluctuations between two equilibrium sites. A path integral model is developed to select the class of atomic oscillations which mainly contributes to the partition function and the electrical resistivity is computed in a number of representative cases. We argue that the common origin of the observed resistivity anomalies lies in the time retarded nature of the polaronic interactions in the local structural instabilities.Comment: 4 figures, to appear in Phys.Rev.B, May 1st (2001

    The types of Mott insulator

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    There are two classes of Mott insulators in nature, distinguished by their responses to weak doping. With increasing chemical potential, Type I Mott insulators undergo a first order phase transition from the undoped to the doped phase. In the presence of long-range Coulomb interactions, this leads to an inhomogeneous state exhibiting ``micro-phase separation.'' In contrast, in Type II Mott insulators charges go in continuously above a critical chemical potential. We show that if the insulating state has a broken symmetry, this increases the likelihood that it will be Type I. There exists a close analogy between these two types of Mott insulators and the familiar Type I and Type II superconductors

    The Dependence of the Superconducting Transition Temperature of Organic Molecular Crystals on Intrinsically Non-Magnetic Disorder: a Signature of either Unconventional Superconductivity or Novel Local Magnetic Moment Formation

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    We give a theoretical analysis of published experimental studies of the effects of impurities and disorder on the superconducting transition temperature, T_c, of the organic molecular crystals kappa-ET_2X and beta-ET_2X (where ET is bis(ethylenedithio)tetrathiafulvalene and X is an anion eg I_3). The Abrikosov-Gorkov (AG) formula describes the suppression of T_c both by magnetic impurities in singlet superconductors, including s-wave superconductors and by non-magnetic impurities in a non-s-wave superconductor. We show that various sources of disorder lead to the suppression of T_c as described by the AG formula. This is confirmed by the excellent fit to the data, the fact that these materials are in the clean limit and the excellent agreement between the value of the interlayer hopping integral, t_perp, calculated from this fit and the value of t_perp found from angular-dependant magnetoresistance and quantum oscillation experiments. If the disorder is, as seems most likely, non-magnetic then the pairing state cannot be s-wave. We show that the cooling rate dependence of the magnetisation is inconsistent with paramagnetic impurities. Triplet pairing is ruled out by several experiments. If the disorder is non-magnetic then this implies that l>=2, in which case Occam's razor suggests that d-wave pairing is realised. Given the proximity of these materials to an antiferromagnetic Mott transition, it is possible that the disorder leads to the formation of local magnetic moments via some novel mechanism. Thus we conclude that either kappa-ET_2X and beta-ET_2X are d-wave superconductors or else they display a novel mechanism for the formation of localised moments. We suggest systematic experiments to differentiate between these scenarios.Comment: 18 pages, 5 figure

    CONSORT Harms 2022 statement, explanation, and elaboration: updated guideline for the reporting of harms in randomized trials.

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    Randomized controlled trials remain the reference standard for healthcare research on effects of interventions, and the need to report both benefits and harms is essential. The Consolidated Standards of Reporting Trials (the main CONSORT) statement includes one item on reporting harms (i.e., all important harms or unintended effects in each group). In 2004, the CONSORT group developed the CONSORT Harms extension; however, it has not been consistently applied and needs to be updated. Here, we describe CONSORT Harms 2022, which replaces the CONSORT Harms 2004 checklist, and shows how CONSORT Harms 2022 items could be incorporated into the main CONSORT checklist. Thirteen items from the main CONSORT were modified to improve harms reporting. Three new items were added. In this article, we describe CONSORT Harms 2022 and how it was integrated into the main CONSORT checklist and elaborate on each item relevant to complete reporting of harms in randomized controlled trials. Until future work from the CONSORT group produces an updated checklist, authors, journal reviewers, and editors of randomized controlled trials should use the integrated checklist presented in this paper
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