1,096 research outputs found

    Managing Opioid-Tolerant Patients in the Perioperative Surgical Home.

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    Management of acute postoperative pain is important to decrease perioperative morbidity and improve patient satisfaction. Opioids are associated with potential adverse events that may lead to significant risk. Uncontrolled pain is a risk factor in the transformation of acute pain to chronic pain. Balancing these issues can be especially challenging in opioid-tolerant patients undergoing surgery, for whom rapidly escalating opioid doses in an effort to control pain can be associated with increased complications. In the perioperative surgical home model, anesthesiologists are positioned to coordinate a comprehensive perioperative analgesic plan that begins with the preoperative assessment and continues through discharge

    Energy density functional on a microscopic basis

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    In recent years impressive progress has been made in the development of highly accurate energy density functionals, which allow to treat medium-heavy nuclei. In this approach one tries to describe not only the ground state but also the first relevant excited states. In general, higher accuracy requires a larger set of parameters, which must be carefully chosen to avoid redundancy. Following this line of development, it is unavoidable that the connection of the functional with the bare nucleon-nucleon interaction becomes more and more elusive. In principle, the construction of a density functional from a density matrix expansion based on the effective nucleon-nucleon interaction is possible, and indeed the approach has been followed by few authors. However, to what extent a density functional based on such a microscopic approach can reach the accuracy of the fully phenomenological ones remains an open question. A related question is to establish which part of a functional can be actually derived by a microscopic approach and which part, on the contrary, must be left as purely phenomenological. In this paper we discuss the main problems that are encountered when the microscopic approach is followed. To this purpose we will use the method we have recently introduced to illustrate the different aspects of these problems. In particular we will discuss the possible connection of the density functional with the nuclear matter Equation of State and the distinct features of finite size effects proper of nuclei.Comment: 20 pages, 6 figures,Contribution to J. Phys G, Special Issue, Focus Section: Open Problems in Nuclear Structur

    On the Differential Geometry of GLq(1∣1)GL_q(1| 1)

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    The differential calculus on the quantum supergroup GLq(1∣1)_q(1| 1) was introduced by Schmidke {\it et al}. (1990 {\it Z. Phys. C} {\bf 48} 249). We construct a differential calculus on the quantum supergroup GLq(1∣1)_q(1| 1) in a different way and we obtain its quantum superalgebra. The main structures are derived without an R-matrix. It is seen that the found results can be written with help of a matrix R^\hat{R}Comment: 14 page

    Equation-of-state dependence of the gravitational-wave signal from the ring-down phase of neutron-star mergers

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    Neutron-star (NS) merger simulations are conducted for 38 representative microphysical descriptions of high-density matter in order to explore the equation-of-state dependence of the postmerger ring-down phase. The formation of a deformed, oscillating, differentially rotating very massive NS is the typical outcome of the coalescence of two stars with 1.35 M⊙M_{\odot} for most candidate EoSs. The oscillations of this object imprint a pronounced peak in the gravitational-wave (GW) spectra, which is used to characterize the emission for a given model. The peak frequency of this postmerger GW signal correlates very well with the radii of nonrotating NSs, and thus allows to constrain the high-density EoS by a GW detection. In the case of 1.35-1.35 M⊙M_{\odot} mergers the peak frequency scales particularly well with the radius of a NS with 1.6 M⊙M_{\odot}, where the maximum deviation from this correlation is only 60 meters for fully microphysical EoSs which are compatible with NS observations. Combined with the uncertainty in the determination of the peak frequency it appears likely that a GW detection can measure the radius of a 1.6 M⊙M_{\odot} NS with an accuracy of about 100 to 200 meters. We also uncover relations of the peak frequency with the radii of nonrotating NSs with 1.35 M⊙M_{\odot} or 1.8 M⊙M_{\odot}, with the radius or the central energy density of the maximum-mass Tolman-Oppenheimer-Volkoff configuration, and with the pressure or sound speed at a fiducial rest-mass density of about twice nuclear saturation density. Furthermore, it is found that a determination of the dominant postmerger GW frequency can provide an upper limit for the maximum mass of nonrotating NSs. The prospects for a detection of the postmerger GW signal and a determination of the dominant GW frequency are estimated to be in the range of 0.015 to 1.2 events per year with the upcoming Advanced LIGO detector.Comment: 29 pages, 28 figures, accepted for publication in Phys. Rev.

    Low-Rank Decompositions of Three-Nucleon Forces via Randomized Projections

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    Ab initio calculations for nuclei and nuclear matter are limited by the computational requirements of processing large data objects. In this work, we develop low-rank singular value decompositions for chiral three-nucleon interactions, which dominate these limitations. In order to handle the large dimensions in representing three-body operators, we use randomized decomposition techniques. We study in detail the sensitivity of different three-nucleon topologies to low-rank matrix factorizations. The developed low-rank three-nucleon interactions are benchmarked in Faddeev calculations of the triton and ab initio calculations of medium-mass nuclei. Exploiting low-rank properties of nuclear interactions will be particularly important for the extension of ab initio studies to heavier and deformed systems, where storage requirements will exceed the computational capacities of the most advanced high-performance-computing facilities.Comment: 7 pages, 4 figure

    First direct mass-measurement of the two-neutron halo nucleus 6He and improved mass for the four-neutron halo 8He

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    The first direct mass-measurement of 6^{6}He has been performed with the TITAN Penning trap mass spectrometer at the ISAC facility. In addition, the mass of 8^{8}He was determined with improved precision over our previous measurement. The obtained masses are mm(6^{6}He) = 6.018 885 883(57) u and mm(8^{8}He) = 8.033 934 44(11) u. The 6^{6}He value shows a deviation from the literature of 4σ\sigma. With these new mass values and the previously measured atomic isotope shifts we obtain charge radii of 2.060(8) fm and 1.959(16) fm for 6^{6}He and 8^{8}He respectively. We present a detailed comparison to nuclear theory for 6^6He, including new hyperspherical harmonics results. A correlation plot of the point-proton radius with the two-neutron separation energy demonstrates clearly the importance of three-nucleon forces.Comment: 4 pages, 2 figure

    A multifaceted quality improvement project improves intraoperative redosing of surgical antimicrobial prophylaxis during pediatric surgery

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    BackgroundAccurate intraoperative antibiotic redosing contributes to prevention of surgical site infections in pediatric patients. Ensuring compliance with evolving national guidelines of weight‐based, intraoperative redosing of antibiotics is challenging to pediatric anesthesiologists.AimsOur primary aim was to increase compliance of antibiotic redoses at the appropriate time and appropriate weight‐based dose to 70%. Secondary aims included a subset analysis of time compliance and dose compliance individually, and compliance based on order entry method of the first dose (verbal or electronic).MethodsAt a freestanding, academic pediatric hospital, we reviewed surgical cases between May 1, 2014, and October 31, 2017 requiring antibiotic redoses. After an institutional change in cefazolin dosing in May 2015, phased interventions to improve compliance included electronic countermeasures to display previous and next dose timing, an alert 5 minutes prior to next dose, and weight‐based dose recommendation (September 2015). Physical countermeasures include badge cards, posting of guidelines, and updates to housestaff manual (September 2015). Statistical process control charts were used to assess overall antibiotic redose compliance, time compliance, and dose compliance. The chi‐square test was used to analyze group differences.ResultsA total of 3015 antibiotic redoses were administered during 2341 operative cases between May 1, 2014, and October 31, 2017. Mean monthly compliance with redosing was 4.3% (May 2014‐April 2015) and 73% (November 2015‐October 2017) (P < 0.001). Dose‐only compliance increased from 76% to 89% (P < 0.001), and time‐only compliance increased from 4.9% to 82% (P < 0.001). After implementation of countermeasures, electronic order entry compared with verbal order was associated with higher dose compliance, 90% vs 86% (P = 0.015).ConclusionThis quality improvement project, utilizing electronic and physical interventions, was effective in improving overall prophylactic antibiotic redosing compliance in accordance with institutional redosing guidelines.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150557/1/pan13651_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150557/2/pan13651.pd

    The current state of antifungal stewardship among pediatric antimicrobial stewardship programs

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    OBJECTIVE: To characterize the current state of antifungal stewardship practices and perceptions of antifungal use among pediatric antimicrobial stewardship programs (ASPs). DESIGN: We developed and distributed an electronic survey, which included 17 closed-ended questions about institutional antifungal stewardship practices and perceptions, among pediatric ASPs. PARTICIPANTS: ASP physicians and pharmacists of 74 hospitals participating in the multicenter Sharing Antimicrobial Reports for Pediatric Stewardship (SHARPS) Collaborative. RESULTS: We sent surveys to 74 hospitals and received 68 unique responses, for a response rate of 92%. Overall, 63 of 68 the respondent ASPs (93%) reported that they conduct 1 or more antifungal stewardship activities. Of these 68 hospital ASPs, 43 (63%) perform prospective audit and feedback (PAF) of antifungals. The most common reasons reported for not performing PAF of antifungals were not enough time or resources (19 of 25, 76%) and minimal institutional antifungal use (6 of 25, 24%). Also, 52 hospitals (76%) require preauthorization for 1 or more antifungal agents. The most commonly restricted antifungals were isavuconazole (42 of 52 hospitals, 80%) and posaconazole (39 of 52 hospitals, 75%). Furthermore, 33 ASPs (48%) agreed or strongly agreed that antifungals are inappropriately used at their institution, and only 25 of 68 (37%) of ASPs felt very confident making recommendations about antifungals. CONCLUSIONS: Most pediatric ASPs steward antifungals, but the strategies employed are highly variable across surveyed institutions. Although nearly half of respondents identified inappropriate antifungal use as a problem at their institution, most ASPs do not feel confident making recommendations about antifungals. Future studies are needed to determine the rate of inappropriate antifungal use and the best antifungal stewardship strategies

    Ground-State Electromagnetic Moments of Calcium Isotopes

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    High-resolution bunched-beam collinear laser spectroscopy was used to measure the optical hyperfine spectra of the 43−51^{43-51}Ca isotopes. The ground state magnetic moments of 49,51^{49,51}Ca and quadrupole moments of 47,49,51^{47,49,51}Ca were measured for the first time, and the 51^{51}Ca ground state spin I=3/2I=3/2 was determined in a model-independent way. Our results provide a critical test of modern nuclear theories based on shell-model calculations using phenomenological as well as microscopic interactions. The results for the neutron-rich isotopes are in excellent agreement with predictions using interactions derived from chiral effective field theory including three-nucleon forces, while lighter isotopes illustrate the presence of particle-hole excitations of the 40^{40}Ca core in their ground state.Comment: Accepted as a Rapid Communication in Physical Review
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