76 research outputs found

    Impact of a National Guideline on Antibiotic Selection for Hospitalized Pneumonia.

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    BACKGROUND: We evaluated the impact of the 2011 Pediatric Infectious Diseases Society/Infectious Diseases Society of America pneumonia guideline and hospital-level implementation efforts on antibiotic prescribing for children hospitalized with pneumonia. METHODS: We assessed inpatient antibiotic prescribing for pneumonia at 28 children\u27s hospitals between August 2009 and March 2015. Each hospital was also surveyed regarding local implementation efforts targeting antibiotic prescribing and organizational readiness to adopt guideline recommendations. To estimate guideline impact, we used segmented linear regression to compare the proportion of children receiving penicillins in March 2015 with the expected proportion at this same time point had the guideline not been published based on a projection of a preguideline trend. A similar approach was used to estimate the short-term (6-month) impact of local implementation efforts. The correlations between organizational readiness and the impact of the guideline were estimated by using Pearson\u27s correlation coefficient. RESULTS: Before guideline publication, penicillin prescribing was rare ( CONCLUSIONS: The publication of the Pediatric Infectious Diseases Society/Infectious Diseases Society of America guideline was associated with sustained increases in the use of penicillins for children hospitalized with pneumonia. Local implementation efforts may have enhanced guideline adoption and appeared more relevant than hospitals\u27 organizational readiness to change

    Formaldehyde Densitometry of Galactic Star-Forming Regions Using the H2CO 3(12)-3(13) and 4(13)-4(14) Transitions

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    We present Green Bank Telescope (GBT) observations of the 3(12)-3(13) (29 GHz) and 4(13)-4(14) (48 GHz) transitions of the H2CO molecule toward a sample of 23 well-studied star-forming regions. Analysis of the relative intensities of these transitions can be used to reliably measure the densities of molecular cores. Adopting kinetic temperatures from the literature, we have employed a Large Velocity Gradient (LVG) model to derive the average hydrogen number density [n(H2)] within a 16 arcsecond beam toward each source. Densities in the range of 10^{5.5}--10^{6.5} cm^{-3} and ortho-formaldehyde column densities per unit line width between 10^{13.5} and 10^{14.5} cm^{-2} (km s^{-1})^{-1} are found for most objects, in general agreement with existing measurements. A detailed analysis of the advantages and limitations to this densitometry technique is also presented. We find that H2CO 3(12)-3(13)/4(13)-4(14) densitometry proves to be best suited to objects with T_K >~ 100 K, above which the H2CO LVG models become relatively independent of kinetic temperature. This study represents the first detection of these H2CO K-doublet transitions in all but one object in our sample. The ease with which these transitions were detected, coupled with their unique sensitivity to spatial density, make them excellent monitors of density in molecular clouds for future experiments. We also report the detection of the 9_2--8_1 A^- (29 GHz) transition of CH3OH toward 6 sources.Comment: 17 pages; 6 figures; Accepted by Ap

    Perspectives on Astrophysics Based on Atomic, Molecular, and Optical (AMO) Techniques

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    About two generations ago, a large part of AMO science was dominated by experimental high energy collision studies and perturbative theoretical methods. Since then, AMO science has undergone a transition and is now dominated by quantum, ultracold, and ultrafast studies. But in the process, the field has passed over the complexity that lies between these two extremes. Most of the Universe resides in this intermediate region. We put forward that the next frontier for AMO science is to explore the AMO complexity that describes most of the Cosmos.Comment: White paper submission to the Decadal Assessment and Outlook Report on Atomic, Molecular, and Optical (AMO) Science (AMO 2020

    LOFAR 150-MHz observations of SS 433 and W50

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    We present Low-Frequency Array (LOFAR) high-band data over the frequency range 115-189 MHz for the X-ray binary SS 433, obtained in an observing campaign from 2013 February to 2014 May. Our results include a deep, wide-field map, allowing a detailed view of the surrounding supernova remnant W50 at low radio frequencies, as well as a light curve for SS 433 determined from shorter monitoring runs. The complex morphology of W50 is in excellent agreement with previously published higher frequency maps; we find additional evidence for a spectral turnover in the eastern wing, potentially due to foreground free-free absorption. Furthermore, SS 433 is tentatively variable at 150 MHz, with both a debiased modulation index of 11 per cent and a Χ 2 probability of a flat light curve of 8.2 × 10 -3 . By comparing the LOFAR flux densities with contemporaneous observations carried out at 4800 MHz with the RATAN-600 telescope, we suggest that an observed ~0.5-1 Jy rise in the 150-MHz flux density may correspond to sustained flaring activity over a period of approximately 6 months at 4800 MHz. However, the increase is too large to be explained with a standard synchrotron bubble model. We also detect a wealth of structure along the nearby Galactic plane, including the most complete detection to date of the radio shell of the candidate supernova remnant G38.7-1.4. This further demonstrates the potential of supernova remnant studies with the current generation of low-frequency radio telescopes

    Perspectives on Astrophysics Based on Atomic, Molecular, and Optical (AMO) Techniques

    Get PDF
    About two generations ago, a large part of AMO science was dominated by experimental high energy collision studies and perturbative theoretical methods. Since then, AMO science has undergone a transition and is now dominated by quantum, ultracold, and ultrafast studies. But in the process, the field has passed over the complexity that lies between these two extremes. Most of the Universe resides in this intermediate region. We put forward that the next frontier for AMO science is to explore the AMO complexity that describes most of the Cosmos

    The coalescence of combustion-sprayed ethylene-methacrylic acid copolymer

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    A design of experiments approach was employed to study the coalescence of combustion-sprayed ethylene methacrylic acid copolymer (EMAA). The powder feed rate, stand-off distance, substrate temperature, propane flow rate, and compressed air flow rate were studied by using a 25-1 factorial design matrix. Empirical models were developed to predict coating surface roughness, coating temperature and splat elongation ratio. Such methods allow process optimization, estimation of interactions among parameters, and the determination of the factors which influence the coalescence of ethylene-methacrylic acid copolymer coatings

    Mechanical properties of spray-formed composite structures

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    In this study, ethylene methacrylic acid copolymer (EMAA) was used as the matrix to produce EMAA/Al2O3 and EMAA/NiCr composite coatings from dry-blended powder mixtures. This work was conducted to determine processing concerns when using similar sized reinforcement particles of different density in a flame-spray process. This work has utility for applications that require a reduction in mechanical wear and/or to confer upon a polymeric deposit a certain functional property by the introduction of value-added powder. Free-standing coatings were produced to test the mechanical properties of the sprayed deposit. The effects of the filler content on the secant modulus, yield stress, and tensile strength are discussed. The differences in deposition efficiencies among the EMAA, Al2O 3, and NiCr are highlighted with respect to particle size and density

    Mechanical properties of metal- and ceramic-polymer composites formed via thermal spray consolidation: extended abstract

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    Polymeric composites, with either metallic or ceramic fillers, have been manufactured by thermal spray, and their mechanical properties have been measured. The advantage of this technology is that it allows on-site manufacture and is a repairable composite system, with virtually no cure time and no release of volatile organic compounds. Fracture mechanisms have been studied to examine mechanical modeling of the composite system
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