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Adult ventilator-associated event (VAE) definitions include ventilator-associated conditions (VAC) and subcategories for infection-related ventilator-associated complications (IVAC) and possible ventilator-associated pneumonia (PVAP). We explored these definitions for children.
Pediatric, cardiac, or neonatal intensive care units (ICUs) in 6 US hospitals
Patients ≤18 years old ventilated for ≥1 day
We identified patients with pediatric VAC based on previously proposed criteria. We applied adult temperature, white blood cell count, antibiotic, and culture criteria for IVAC and PVAP to these patients. We matched pediatric VAC patients with controls and evaluated associations with adverse outcomes using Cox proportional hazards models.
In total, 233 pediatric VACs (12,167 ventilation episodes) were identified. In the cardiac ICU (CICU), 62.5% of VACs met adult IVAC criteria; in the pediatric ICU (PICU), 54.2% of VACs met adult IVAC criteria; and in the neonatal ICU (NICU), 20.2% of VACs met adult IVAC criteria. Most patients had abnormal white blood cell counts and temperatures; we therefore recommend simplifying surveillance by focusing on “pediatric VAC with antimicrobial use” (pediatric AVAC). Pediatric AVAC with a positive respiratory diagnostic test (“pediatric PVAP”) occurred in 8.9% of VACs in the CICU, 13.3% of VACs in the PICU, and 4.3% of VACs in the NICU. Hospital mortality was increased, and hospital and ICU length of stay and duration of ventilation were prolonged among all pediatric VAE subsets compared with controls.
We propose pediatric AVAC for surveillance related to antimicrobial use, with pediatric PVAP as a subset of AVAC. Studies on generalizability and responsiveness of these metrics to quality improvement initiatives are needed, as are studies to determine whether lower pediatric VAE rates are associated with improvements in other outcomes.
A new and unique radiocarbon accelerator mass spectrometry (AMS) facility has been constructed at the Woods Hole Oceanographic Institution. The defining characteristic of the new system is its large-gap optical elements that provide a larger-than-standard beam acceptance. Such a system is ideally suited for high-throughput, high-precision measurements of 14C. Details and performance of the new system are presented.
We describe a versatile infrared camera/spectrograph, IRIS, designed and constructed at the Anglo-Australian Observatory for use on the Anglo-Australian Telescope. A variety of optical configurations can be selected under remote control to provide several direct image scales and a few low-resolution spectroscopic formats. Two cross-dispersed transmission echelles are of novel design, as is the use of a modified Bowen-Burch system to provide a fast f/ratio in the widest-field option. The drive electronics includes a choice of readout schemes for versatility, and continuous display when the array is not taking data, to facilitate field acquisition and focusing.
The linearity of the detector has been studied in detail. Although outwardly good, slight nonlinearities prevent removal of fixed-pattern noise from the data without application of a cubic linearising function.
Specific control and data-reduction software has been written. We describe also a scanning mode developed for spectroscopic imaging.
Our knowledge of the universe comes from recording the photon and particle fluxes incident on the Earth from space. We thus require sensitive measurement across the entire energy spectrum, using large telescopes with efficient instrumentation located on superb sites. Technological advances and engineering constraints are nearing the point where we are recording as many photons arriving at a site as is possible. Major advances in the future will come from improving the quality of the site. The ultimate site is, of course, beyond the Earth’s atmosphere, such as on the Moon, but economic limitations prevent our exploiting this avenue to the degree that the scientific community desires. Here we describe an alternative, which offers many of the advantages of space for a fraction of the cost: the Antarctic Plateau.
In late 2011 the New Zealand Ministry for Primary Industries reported an increase in confirmed laboratory diagnoses of salmonellosis in dairy herds. To identify risk factors for herd-level outbreaks of salmonellosis we conducted a case-control study of New Zealand dairy herds in 2011–2012. In a multivariable analysis, use of continuous feed troughs [adjusted odds ratio (aOR) 6·2, 95% confidence interval (CI) 2·0–20], use of pelletized magnesium supplements (aOR 10, 95% CI 3·3–33) and use of palm kernel meal as a supplementary feed (aOR 8·7, 95% CI 2·5–30) were positively associated with a herd-level outbreak of salmonellosis between 1 July 2011 and 31 January 2012. We conclude that supplementary feeds used on dairy farms (regardless of type) need to be stored and handled appropriately to reduce the likelihood of bacterial contamination, particularly from birds and rodents. Magnesium supplementation in the pelletized form played a role in triggering outbreaks of acute salmonellosis in New Zealand dairy herds in 2011–2012.
The resonance lines of Mgii occur at wavelengths (2802.7 Å, 2795.5 Å) just beyond the extinction limit of the Earth's atmosphere. At such wavelengths sophisticated optical techniques can now be employed and this fact, together with the high cosmic abundance of magnesium, makes these lines particularly important for study in UV Astronomy. In the case of the Sun, the lines consist of a broad absorption with a pronounced emission core.
Calculations based on Poisson-Boltzmann theory are used to investigate the equilibrium properties of an electrolyte containing TcO4− and SO42− ions near the surface of amorphous silica. The calculations show that the concentration of TcO4− is greater than SO42− at distances less than 1 nm from the surface due to the negative charge density caused by deprotonation of the amorphous silica silanol groups. At lower pH, the surface becomes protonated and the magnitude of this effect is reduced. These results have implications for the potential use of oxyanion-SAMMS for the environmental remediation of water contaminated with 99Tc.
The use of inert markers in broiler diets eliminates the need to quantitatively evaluate feed intake and excreta output to determine diet digestibility, and enables nutrient uptake at specific points along the gastrointestinal tract to be examined. Titanium dioxide (TiO2) is commonly used for this purpose and measured using a UV-spectrophotometric assay. Two experiments were conducted to observe whether an inductively coupled plasma optical emission spectrophotometer (ICP-OES) assay is able to replace the UV-spectroscopy assay for rapid analysis of TiO2 in broiler feed and ileal digesta samples. In the first experiment, TiO2 was added at 5 g/kg to 19 broiler diets. Ross 308 male broilers (n=452) fed these diets were involved in a series of digestion studies to determine ileal digesta recovery of TiO2. In the second experiment, defined amounts of TiO2 were added to ileal digesta samples from Ross 308 male broilers (n=176) and TiO2 recoveries were determined. The feed and ileal samples from both experiments were analysed by both UV-spectroscopy and ICP-OES, and relatedness of the findings from the two assays was determined. Overall relatedness of the two assays was strong for determination of TiO2 concentration in both the broiler diets and ileal digesta samples (r=0.908 and r=0.884, respectively). Overall recovery of supplemented TiO2 was 97.62% by the UV-spectroscopy assay and 98.77% by the ICP-OES assay. The ICP-OES assay in this study was as accurate as spectrophotometric determination for the quantification of TiO2 content. The ICP-OES method can also be used to analyse several elements within one assay, with a single preparation step, and thus the measurement of TiO2 may be incorporated into the analysis of other minerals. Time and resources dedicated to determining diet digestibility in broilers could be minimised by using the ICP-OES assay to replace the UV-spectroscopy assay when measuring TiO2 concentration.
A study was conducted to evaluate a natural carbohydrate fraction Actigen™ (NCF), derived from mannanoligosaccharide, in feed on growth performance, intestinal morphology and goblet cell number and area of male broilers'. Dietary treatments included: 1) control diet (antibiotic and NCF free), 2) NCF at 200 g/t, 3) NCF at 400 g/t, and 4) NCF 800 g/t. Two hundred and forty birds were placed into 12 replicate pens per treatment (5 birds/pen), sixty birds per treatment. Body weight and feed intake were recorded weekly up to day 42. At this time a 2.5cm section of jejunum and duodenum were excised post mortem for morphological analysis. Birds fed 200 g/t and 800 g/t NCF were significantly (P < 0.01) heavier from day 14 onwards than the control birds. Feed intake was significantly higher in birds fed 200 g/t NCF compared to those fed the control at 21 and 35 days (P < 0.05). Diets containing 200 g/t and 800 g/t of NCF significantly decreased broiler feed conversion ratio (FCR) compared to the control in the first phase (1–14 days) (P < 0.01) and levels of NCF decreased FCR (P < 0.05) in the second phase (15–28 days). NCF had no significant effect on villus height, villus width, crypt depth or villus to crypt ratio in either duodenum or jejunum. NCF did not significantly affect goblet cell area or goblet cell number in the duodenum, however, in the jejunum, 800 g/t NCF significantly (P < 0.05) increased goblet cell area over the control. In conclusion, NCF showed a positive effect on broiler performance in the starter and grower phases, and increased goblet cell area in the jejunum, suggesting higher levels of mucin production. This indicated that the performance benefit of NCF could be age-dependent, with younger birds responding more than the older ones. There were no additional benefits to performance when feeding NCF for a longer period (after 28 d of age), however it is postulated that birds fed NCF would have greater defence to pathogenic challenge through increased storage capacity of mucin.
Spectra from 1 to 2·5 μm, at 230–430 spectral resolution, are presented of the fluorescent molecular hydrogen line emission from two locations in the reflection nebula NGC 2023. Over 100 H2 lines can be identified in the spectra, although blending and poor atmospheric transmission mean that reliable level column densities can only be obtained from 35 lines. This latter group includes lines from v = 1–8 and v = 10, spanning an energy range from 6000 to 45,000 K above the ground state. These data may be used to constrain models of photodissociation regions and of fluorescent excitation for molecular hydrogen.
We have developed a 350 μm radiometer to perform automated site testing in remote regions of Antarctica. In summer 2000–2001 the instrument operated at Concordia, a new station under construction at Dome C on the Antarctic Plateau. We present the results, and compare them with the atmospheric opacity measured at the South Pole in the same five-week period. During these five weeks, observing conditions at Dome C were, on average, substantially better than those at the South Pole.
A survey of the Milky Way disk and the Magellanic System at the wavelengths of the 21-cm atomic hydrogen (H i) line and three 18-cm lines of the OH molecule will be carried out with the Australian Square Kilometre Array Pathfinder telescope. The survey will study the distribution of H i emission and absorption with unprecedented angular and velocity resolution, as well as molecular line thermal emission, absorption, and maser lines. The area to be covered includes the Galactic plane (|b| < 10°) at all declinations south of δ = +40°, spanning longitudes 167° through 360°to 79° at b = 0°, plus the entire area of the Magellanic Stream and Clouds, a total of 13 020 deg2. The brightness temperature sensitivity will be very good, typically σT≃ 1 K at resolution 30 arcsec and 1 km s−1. The survey has a wide spectrum of scientific goals, from studies of galaxy evolution to star formation, with particular contributions to understanding stellar wind kinematics, the thermal phases of the interstellar medium, the interaction between gas in the disk and halo, and the dynamical and thermal states of gas at various positions along the Magellanic Stream.
Affordable, high quality SiC wafers are very desirable for a variety of new technologies including GaN based lighting, RF, and high-power electronics based on wide band gap materials. At Litton Airtron we have a major effort in the growth and characterization of SiC. We will present data on 35, 50 and 75-mm diameter crystals. We are growing both n-type, semiinsulating 4H, 6H, and 15R material. A variety of characterization techniques are being used at Litton Airtron to determine wafer quality. These include Raman microscopy, digital wafer photography, and crossed polarizer images. Raman spectroscopy is an excellent probe of polytype and carrier concentration for n-type materials; in addition it can be done at room temperature and is sufficiently fast that it can be used in an industrial environment. The use of digital photography allows for the collection of images that can be quantitatively analyzed and archived.
Linear Muffin Tin Orbital and Linearly Augmented Plane Wave calculations of equations of state were performed for observed and hypothetical ordered structures in the NiAl-NiTi system. Total energies were parameterized in both the Connolly-Williams and ∈-G approximations, and the resulting parameters were used to calculate theoretical phase diagrams by the cluster variation method. Third nearest neighbor Al-Ti pairwise interactions are predicted to be strongly repulsive, and to be a major cause of observed B2+L21 two phase fields.
A new phosphate substituted phosphazene trimer [N3P3Cl5(OP(O)Ph2)] has been synthesized and characterized by 31p NMR and Raman spectroscopy. The course of each solution-state substitution was followed with 31P NMR, and this technique was used to determine the best reaction conditions for the experiment. Information such as phosphorus to phosphorus connectivity and purity were analyzed. This paper will discuss the synthesis and characterization of phosphazene moieties which are substituted by phosphorus(V) centered substituents.
The logical development of thermally stable polymers is based upon forming true molecular composites comprised of both polymer and ceramic components. This paper describes our initial studies on the synthesis of composite materials that are expected to produce films with thermal stability to 500°C.
Transport, Raman and XPS measurements were made on SI-implanted (1.7×1013cm−2, 50keV) and rapid-thermal annealed (100) and (211) GaAs substrates In an effort to distinguish differences between the two orientations. With these techniques, no significant differences were found. The implant-damage depth was about 1200Å for both orientations, with slightly higher near-surface damage (and lower mobility) apparent for (211). No unusual features in the (211) carrier concentration profile, as was previously reported, were evident.
Ultraviolet reflectivity, surface chemistry and electrical measurements are reported for Ar+-ion bombarded (100) GaAs surfaces, with ion energies from 0.5 to 4 keV. Changes in reflectivity spectra, surface stoichiometry and Schottky diode parameters are reported as functions of ion energy.
A series of alumina particles coated with inorganic polymers, that have utility as preceramic dispersants, have been pyrolyzed and the products of the pyrolysis studied to help determine the possible decomposition routes. The inorganic polymers, bis(amino)polyphosphazenes and siloxanes, appear to undergo loss of the organic sidechains via a nucleophilic process which would incorporate inorganic backbone into the alumina matrix. The bis(alkoxy)polyphosphazenes decompose by nucleophilic attachment but also exhibit polymer loss by formation of cyclic oligomers.