157 research outputs found

    Central venous catheter adverse events are not associated with crowding indicators

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    OBJECTIVE: Crowding in the emergency department (ED) impacts a number of important quality and safety metrics. We studied ED crowding measures associated with adverse events (AE) resulting from central venous catheters (CVC) inserted in the ED, as well as the relationship between crowding and the frequency of CVC insertions in an ED cohort admitted to the intensive care unit (ICU). METHODS: We conducted a retrospective observational study from 2008-2010 in an academic tertiary care center. Participants undergoing CVC in the ED or admitted to an ICU were categorized by quartile based on the following: National Emergency Department Overcrowding Scale (NEDOCS); waiting room patients (WR); ED patients awaiting inpatient beds (boarders); and ED occupancy (EDO). Main outcomes were the occurrence of an AE during CVC insertion in the ED, and deferred procedures assessed by frequency of CVC insertions in ED patients admitted to the ICU. RESULTS: Of 2,284 ED patients who had a CVC inserted, 293 (13%) suffered an AE. There was no association between AEs from ED CVCs and crowding scales when comparing the highest crowding level or quartile to all other quartiles: NEDOCS (dangerous crowding [13.1%] vs other levels [13.0%], P = 0.98); number of WR patients (14.0% vs 12.7%, P = 0.81); EDO (13.0% vs 12.9%, P = 0.99); and number of boarding patients (12.0% vs 13.3%), P = 0.21). In a cohort of ED patients admitted to the ICU, there was no association between CVC placement rates in the ED and crowding scales comparing the highest vs all other quartiles: NEDOCS (dangerous crowding 16% vs all others 16%, P = 0.97); WR patients (16% vs 16%, P = 0.82), EDO (15% vs. 17%, P = 0.15); and number of boarding patients (17% vs 16%, P = 0.08). CONCLUSION: In a large, academic tertiary-care center, frequency of CVC insertion in the ED and related AEs were not associated with measures of crowding. These findings add to the evidence that the negative effects of crowding, which impact all ED patients and measures of ED performance, are less likely to impair the delivery of prioritized time-critical interventions

    Deformed Base Antisymmetrized Molecular Dynamics and its Application to ^{20}Ne

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    A new theoretical framework named as deformed base antisymmetrized molecular dynamics that uses the localized triaxially deformed Gaussian as the single particle wave packet is presented. The model space enables us to describe sufficiently well the deformed mean-field structure as well as the cluster structure and their mixed structure within the same framework. The improvement over the original version of the antisymmetrized molecular dynamics which uses the spherical Gaussian is verified by the application to 20Ne^{20}{\rm Ne} nucleus. The almost pure α+16Og.s\alpha + ^{16}{\rm O_{g.s}} cluster structure of the KπK^\pi=00^- band, the distortion of the cluster structure in the KπK^\pi=01+0^+_1 band and the dominance of the deformed mean-field structure of the KπK^\pi=22^- band are confirmed and their observed properties are reproduced. Especially, the intra-band E2 transition probabilities in KπK^\pi=01+0^+_1 and 22^- bands are reproduced without any effective charge. Since it has been long known that the pure α+16Og.s.\alpha + ^{16}{\rm O}_{g.s.} cluster model underestimates the intra-band E2E2 transitions in the KπK^\pi=01+0^+_1 band by about 30%, we consider that this success is due to the sufficient description of the deformed mean-field structure in addition to the cluster structure by the present framework. From the successful description of 20Ne^{20}{\rm Ne}, we expect that the present framework presents us with a powerful approach for the study of the coexistence and interplay of the mean-field structure and the cluster structure

    Comparison of monocyte human leukocyte antigen-DR expression and stimulated tumor necrosis factor alpha production as outcome predictors in severe sepsis: A prospective observational study

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    BACKGROUND: Identifying patients in the immunosuppressive phase of sepsis is essential for development of immunomodulatory therapies. Little data exists comparing the ability of the two most well-studied markers of sepsis-induced immunosuppression, human leukocyte antigen (HLA)-DR expression and lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-ɑ) production, to predict mortality and morbidity. The purpose of this study was to compare HLA-DR expression and LPS-induced TNF-ɑ production as predictors of 28-day mortality and acquisition of secondary infections in adult septic patients. METHODS: A single-center, prospective observational study of 83 adult septic patients admitted to a medical or surgical intensive care unit. Blood samples were collected at three time points during the septic course (days 1–2, days 3–4, and days 6–8 after sepsis diagnosis) and assayed for HLA-DR expression and LPS-induced TNF-ɑ production. A repeated measures mixed model analysis was used to compare values of these immunological markers among survivors and non-survivors and among those who did and did not develop a secondary infection. RESULTS: Twenty-five patients (30.1 %) died within 28 days of sepsis diagnosis. HLA-DR expression was significantly lower in non-survivors as compared to survivors on days 3–4 (p = 0.04) and days 6–8 (p = 0.002). The change in HLA-DR from days 1–2 to days 6–8 was also lower in non-survivors (p = 0.04). Median HLA-DR expression decreased from days 1–2 to days 3–4 in patients who developed secondary infections while it increased in those without secondary infections (p = 0.054). TNF-ɑ production did not differ between survivors and non-survivors or between patients who did and did not develop a secondary infection. CONCLUSIONS: Monocyte HLA-DR expression may be a more accurate predictor of mortality and acquisition of secondary infections than LPS-stimulated TNF-ɑ production in adult medical and surgical critically ill patients. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13054-016-1505-0) contains supplementary material, which is available to authorized users

    Deformed nuclear halos

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    Deformation properties of weakly bound nuclei are discussed in the deformed single-particle model. It is demonstrated that in the limit of a very small binding energy the valence particles in specific orbitals, characterized by a very small projection of single-particle angular momentum onto the symmetry axis of a nucleus, can give rise to the halo structure which is completely decoupled from the rest of the system. The quadrupole deformation of the resulting halo is completely determined by the intrinsic structure of a weakly bound orbital, irrespective of the shape of the core.Comment: LaTeX source (21 pages) and postscript file with figures (15 pages). Accepted to Nucl. Phys.

    Protocol for a prospective, observational cohort study of awareness in mechanically ventilated patients admitted from the emergency department: The ED-AWARENESS study

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    INTRODUCTION: Awareness with paralysis is a complication with potentially devastating psychological consequences for mechanically ventilated patients. While rigorous investigation into awareness has occurred for operating room patients, little attention has been paid outside of this domain. Mechanically ventilated patients in the emergency department (ED) have been historically managed in a way that predisposes them to awareness events: high incidence of neuromuscular blockade use, underdosing of analgesia and sedation, delayed administration of analgesia and sedation after intubation, and a lack of monitoring of sedation targets and depth. These practice patterns are discordant to recommendations for reducing the incidence of awareness, suggesting there is significant rationale to examine awareness in the ED population. METHODS AND ANALYSIS: This is a single centre, prospective cohort study examining the incidence of awareness in mechanically ventilated ED patients. A cohort of 383 mechanically ventilated ED patients will be included. The primary outcome is awareness with paralysis. Qualitative reports of all awareness events will be provided. Recognising the potential problem with conventional multivariable analysis arising from a small number of events (expected less than 10-phenomenon of separation), Firth penalised method, exact logistic regression model or penalised maximum likelihood estimation shrinkage (Ridge, LASSO) will be used to assess for predictors of awareness. ETHICS AND DISSEMINATION: Approval of the study by the Human Research Protection Office has been obtained. This work will be disseminated by publication of peer-reviewed manuscripts, presentation in abstract form at scientific meetings and data sharing with other investigators through academically established means

    Nuclear Alpha-Particle Condensates

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    The α\alpha-particle condensate in nuclei is a novel state described by a product state of α\alpha's, all with their c.o.m. in the lowest 0S orbit. We demonstrate that a typical α\alpha-particle condensate is the Hoyle state (Ex=7.65E_{x}=7.65 MeV, 02+0^+_2 state in 12^{12}C), which plays a crucial role for the synthesis of 12^{12}C in the universe. The influence of antisymmentrization in the Hoyle state on the bosonic character of the α\alpha particle is discussed in detail. It is shown to be weak. The bosonic aspects in the Hoyle state, therefore, are predominant. It is conjectured that α\alpha-particle condensate states also exist in heavier nαn\alpha nuclei, like 16^{16}O, 20^{20}Ne, etc. For instance the 06+0^+_6 state of 16^{16}O at Ex=15.1E_{x}=15.1 MeV is identified from a theoretical analysis as being a strong candidate of a 4α4\alpha condensate. The calculated small width (34 keV) of 06+0^+_6, consistent with data, lends credit to the existence of heavier Hoyle-analogue states. In non-self-conjugated nuclei such as 11^{11}B and 13^{13}C, we discuss candidates for the product states of clusters, composed of α\alpha's, triton's, and neutrons etc. The relationship of α\alpha-particle condensation in finite nuclei to quartetting in symmetric nuclear matter is investigated with the help of an in-medium modified four-nucleon equation. A nonlinear order parameter equation for quartet condensation is derived and solved for α\alpha particle condensation in infinite nuclear matter. The strong qualitative difference with the pairing case is pointed out.Comment: 71 pages, 41 figures, review article, to be published in "Cluster in Nuclei (Lecture Notes in Physics) - Vol.2 -", ed. by C. Beck, (Springer-Verlag, Berlin, 2011

    Improved Measurement of Double Helicity Asymmetry in Inclusive Midrapidity pi^0 Production for Polarized p+p Collisions at sqrt(s)=200 GeV

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    We present an improved measurement of the double helicity asymmetry for pi^0 production in polarized proton-proton scattering at sqrt(s) = 200 GeV employing the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The improvements to our previous measurement come from two main factors: Inclusion of a new data set from the 2004 RHIC run with higher beam polarizations than the earlier run and a recalibration of the beam polarization measurements, which resulted in reduced uncertainties and increased beam polarizations. The results are compared to a Next to Leading Order (NLO) perturbative Quantum Chromodynamics (pQCD) calculation with a range of polarized gluon distributions.Comment: 389 authors, 4 pages, 2 tables, 1 figure. Submitted to Phys. Rev. D, Rapid Communications. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Spallation reactions. A successful interplay between modeling and applications

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    The spallation reactions are a type of nuclear reaction which occur in space by interaction of the cosmic rays with interstellar bodies. The first spallation reactions induced with an accelerator took place in 1947 at the Berkeley cyclotron (University of California) with 200 MeV deuterons and 400 MeV alpha beams. They highlighted the multiple emission of neutrons and charged particles and the production of a large number of residual nuclei far different from the target nuclei. The same year R. Serber describes the reaction in two steps: a first and fast one with high-energy particle emission leading to an excited remnant nucleus, and a second one, much slower, the de-excitation of the remnant. In 2010 IAEA organized a worskhop to present the results of the most widely used spallation codes within a benchmark of spallation models. If one of the goals was to understand the deficiencies, if any, in each code, one remarkable outcome points out the overall high-quality level of some models and so the great improvements achieved since Serber. Particle transport codes can then rely on such spallation models to treat the reactions between a light particle and an atomic nucleus with energies spanning from few tens of MeV up to some GeV. An overview of the spallation reactions modeling is presented in order to point out the incomparable contribution of models based on basic physics to numerous applications where such reactions occur. Validations or benchmarks, which are necessary steps in the improvement process, are also addressed, as well as the potential future domains of development. Spallation reactions modeling is a representative case of continuous studies aiming at understanding a reaction mechanism and which end up in a powerful tool.Comment: 59 pages, 54 figures, Revie
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