164 research outputs found

    Extracorporeal life support in pediatric trauma: a systematic review

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    Introduction Extracorporeal membrane oxygenation (ECMO) was once thought to be contraindicated in trauma patients, however ECMO is now used in adult patients with post-traumatic acute respiratory distress syndrome (ARDS) and multisystem trauma. Despite acceptance as a therapy for the severely injured adult, there is a paucity of evidence supporting ECMO use in pediatric trauma patients. Methods An electronic literature search of PubMed, MEDLINE, and the Cochrane Database of Collected Reviews from 1972 to 2018 was performed. Included studies reported on ECMO use after trauma in patients ≤18 years of age and reported outcome data. The Institute of Health Economics quality appraisal tool for case series was used to assess study quality. Results From 745 studies, four met inclusion criteria, reporting on 58 pediatric trauma patients. The age range was <1–18 years. Overall study quality was poor with only a single article of adequate quality. Twenty-nine percent of patients were cannulated at adult centers, the remaining at pediatric centers. Ninety-one percent were cannulated for ARDS and the remaining for cardiovascular collapse. Overall 60% of patients survived and the survival rate ranged from 50% to 100%. Seventy-seven percent underwent venoarterial cannulation and the remaining underwent veno-venous cannulation. Conclusion ECMO may be a therapeutic option in critically ill pediatric trauma patients. Consideration should be made for the expansion of ECMO utilization in pediatric trauma patients including its application for pediatric patients at adult trauma centers with ECMO capabilities

    Global constants in (2+1)--dimensional gravity

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    The extended conformal algebra (so)(2,3) of global, quantum, constants of motion in 2+1 dimensional gravity with topology R x T^2 and negative cosmological constant is reviewed. It is shown that the 10 global constants form a complete set by expressing them in terms of two commuting spinors and the Dirac gamma matrices. The spinor components are the globally constant holonomy parameters, and their respective spinor norms are their quantum commutators.Comment: 14 pages, to appear in Classical and Quantum Gravity, Spacetime Safari: Essays in Honor of Vincent Moncrief on the Classical Physics of Strong Gravitational Field

    Hamiltonian structure of 2+1 dimensional gravity

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    A summary is given of some results and perspectives of the hamiltonian ADM approach to 2+1 dimensional gravity. After recalling the classical results for closed universes in absence of matter we go over the the case in which matter is present in the form of point spinless particles. Here the maximally slicing gauge proves most effective by relating 2+1 dimensional gravity to the Riemann- Hilbert problem. It is possible to solve the gravitational field in terms of the particle degrees of freedom thus reaching a reduced dynamics which involves only the particle positions and momenta. Such a dynamics is proven to be hamiltonian and the hamiltonian is given by the boundary term in the gravitational action. As an illustration the two body hamiltonian is used to provide the canonical quantization of the two particle system.Comment: 13 pages,2 figures,latex, Plenary talk at SIGRAV2000 Conferenc

    Expansion-induced contribution to the precession of binary orbits

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    We point out the existence of new effects of global spacetime expansion on local binary systems. In addition to a possible change of orbital size, there is a contribution to the precession of elliptic orbits, to be added to the well-known general relativistic effect in static spacetimes, and the eccentricity can change. Our model calculations are done using geodesics in a McVittie metric, representing a localized system in an asymptotically Robertson-Walker spacetime; we give a few numerical estimates for that case, and indicate ways in which the model should be improved.Comment: revtex, 7 pages, no figures; revised for publication in Classical and Quantum Gravity, with minor changes in response to referees' comment

    A case of iliac crest avulsion with peritoneal disruption and bowel herniation after blunt trauma

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    Pelvic fractures account for approximately 3% of all blunt traumatic skeletal injuries. Pelvic fractures are most commonly caused by motor vehicle accidents (60%), falls from a height (30%), and crush injuries (10%). Pelvic fractures are a marker for high-energy trauma and are often associated with other life-threatening injuries. Over 80% of patients with unstable pelvic fractures will be found to have additional musculoskeletal injuries. Although the mortality rate in patients with pelvic fractures has been declining in recent years due to the robustness of the US trauma system, the incidence is increasing due to the higher rate of high-speed motor vehicle collisions

    Translating the Statistical Representation of the Effects of Education Interventions Into More Readily Interpretable Forms

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    This paper is directed to researchers who conduct and report education intervention studies. Its purpose is to stimulate and guide them to go a step beyond reporting the statistics that emerge from their analysis of the differences between experimental groups on the respective outcome variables. With what is often very minimal additional effort, those statistical representations can be translated into forms that allow their magnitude and practical significance to be more readily understood by the practitioners, policymakers, and even other researchers who are interested in the intervention that was evaluated

    The Quantum Modular Group in (2+1)-Dimensional Gravity

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    The role of the modular group in the holonomy representation of (2+1)-dimensional quantum gravity is studied. This representation can be viewed as a "Heisenberg picture", and for simple topologies, the transformation to the ADM "Schr{\"o}dinger picture" may be found. For spacetimes with the spatial topology of a torus, this transformation and an explicit operator representation of the mapping class group are constructed. It is shown that the quantum modular group splits the holonomy representation Hilbert space into physically equivalent orthogonal ``fundamental regions'' that are interchanged by modular transformations.Comment: 23 pages, LaTeX, no figures; minor changes and clarifications in response to referee (basic argument and conclusions unaffected

    Handover Practices in Trauma and Acute Care Surgery: A Multicenter Survey Study

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    BACKGROUND: The handover period has been identified as a particularly vulnerable period for communication breakdown leading to patient safety events. Clear and concise handover is especially critical in high-acuity care settings such as trauma, emergency general surgery, and surgical critical care. There is no consensus for the most effective and efficient means of evaluating or performing handover in this population. We aimed to characterize the current handover practices and perceptions in trauma and acute care surgery. METHODS: A survey was sent to 2265 members of the Eastern Association for the Surgery of Trauma via email regarding handoff practices at their institution. Respondents were queried regarding their practice setting, average census, level of trauma center, and patients (trauma, emergency general surgery, and/or intensive care). Data regarding handover practices were gathered including frequency of handover, attendees, duration, timing, and formality. Finally, perceptions of handover including provider satisfaction, desire for improvement, and effectiveness were collected. RESULTS: Three hundred eighty surveys (17.1%) were completed. The majority (73.4%) of respondents practiced at level 1 trauma centers (58.9%) and were trauma/emergency general surgeons (86.5%). Thirty-five percent of respondents reported a formalized handover and 52% used a standardized tool for handover. Only 18% of respondents had ever received formal training, but most (51.6%) thought this training would be helpful. Eighty-one percent of all providers felt handover was essential for patient care, and 77% felt it prevented harm. Seventy-two percent thought their handover practice needed improvement, and this was more common as the average patient census increased. The most common suggestions for improvement were shorter and more concise handover (41.6%), different handover medium (24.5%), and adding verbal communication (13.9%). CONCLUSION: Trauma and emergency general surgeons perceive handover as essential for patient care and the majority desire improvement of their current handover practices. Methods identified to improve the handover process include standardization, simplification, and verbal interaction, which allows for shared understanding. Formal education and best practice guidelines should be developed

    BRAHMA ATPase of the SWI/SNF Chromatin Remodeling Complex Acts as a Positive Regulator of Gibberellin-Mediated Responses in Arabidopsis

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    SWI/SNF chromatin remodeling complexes perform a pivotal function in the regulation of eukaryotic gene expression. Arabidopsis (Arabidopsis thaliana) mutants in major SWI/SNF subunits display embryo-lethal or dwarf phenotypes, indicating their critical role in molecular pathways controlling development and growth. As gibberellins (GA) are major positive regulators of plant growth, we wanted to establish whether there is a link between SWI/SNF and GA signaling in Arabidopsis. This study revealed that in brm-1 plants, depleted in SWI/SNF BRAHMA (BRM) ATPase, a number of GA-related phenotypic traits are GA-sensitive and that the loss of BRM results in markedly decreased level of endogenous bioactive GA. Transcriptional profiling of brm-1 and the GA biosynthesis mutant ga1-3, as well as the ga1-3/brm-1 double mutant demonstrated that BRM affects the expression of a large set of GA-responsive genes including genes responsible for GA biosynthesis and signaling. Furthermore, we found that BRM acts as an activator and directly associates with promoters of GA3ox1, a GA biosynthetic gene, and SCL3, implicated in positive regulation of the GA pathway. Many GA-responsive gene expression alterations in the brm-1 mutant are likely due to depleted levels of active GAs. However, the analysis of genetic interactions between BRM and the DELLA GA pathway repressors, revealed that BRM also acts on GA-responsive genes independently of its effect on GA level. Given the central position occupied by SWI/SNF complexes within regulatory networks controlling fundamental biological processes, the identification of diverse functional intersections of BRM with GA-dependent processes in this study suggests a role for SWI/SNF in facilitating crosstalk between GA-mediated regulation and other cellular pathways

    Ponzano-Regge model revisited I: Gauge fixing, observables and interacting spinning particles

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    We show how to properly gauge fix all the symmetries of the Ponzano-Regge model for 3D quantum gravity. This amounts to do explicit finite computations for transition amplitudes. We give the construction of the transition amplitudes in the presence of interacting quantum spinning particles. We introduce a notion of operators whose expectation value gives rise to either gauge fixing, introduction of time, or insertion of particles, according to the choice. We give the link between the spin foam quantization and the hamiltonian quantization. We finally show the link between Ponzano-Regge model and the quantization of Chern-Simons theory based on the double quantum group of SU(2)Comment: 48 pages, 15 figure
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