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To assess potential transmission of antibiotic-resistant organisms (AROs) using surrogate markers and bacterial cultures.
A 1,260-bed tertiary-care academic medical center.
The study included 25 patients (17 of whom were on contact precautions for AROs) and 77 healthcare personnel (HCP).
Fluorescent powder (FP) and MS2 bacteriophage were applied in patient rooms. HCP visits to each room were observed for 2–4 hours; hand hygiene (HH) compliance was recorded. Surfaces inside and outside the room and HCP skin and clothing were assessed for fluorescence, and swabs were collected for MS2 detection by polymerase chain reaction (PCR) and selective bacterial cultures.
Transfer of FP was observed for 20 rooms (80%) and 26 HCP (34%). Transfer of MS2 was detected for 10 rooms (40%) and 15 HCP (19%). Bacterial cultures were positive for 1 room and 8 HCP (10%). Interactions with patients on contact precautions resulted in fewer FP detections than interactions with patients not on precautions (P < .001); MS2 detections did not differ by patient isolation status. Fluorescent powder detections did not differ by HCP type, but MS2 was recovered more frequently from physicians than from nurses (P = .03). Overall, HH compliance was better among HCP caring for patients on contact precautions than among HCP caring for patients not on precautions (P = .003), among nurses than among other nonphysician HCP at room entry (P = .002), and among nurses than among physicians at room exit (P = .03). Moreover, HCP who performed HH prior to assessment had fewer fluorescence detections (P = .008).
Contact precautions were associated with greater HCP HH compliance and reduced detection of FP and MS2.
To evaluate healthcare worker (HCW) risk of self-contamination when donning and doffing personal protective equipment (PPE) using fluorescence and MS2 bacteriophage.
Prospective pilot study.
A total of 36 HCWs were included in this study: 18 donned/doffed contact precaution (CP) PPE and 18 donned/doffed Ebola virus disease (EVD) PPE.
HCWs donned PPE according to standard protocols. Fluorescent liquid and MS2 bacteriophage were applied to HCWs. HCWs then doffed their PPE. After doffing, HCWs were scanned for fluorescence and swabbed for MS2. MS2 detection was performed using reverse transcriptase PCR. The donning and doffing processes were videotaped, and protocol deviations were recorded.
Overall, 27% of EVD PPE HCWs and 50% of CP PPE HCWs made ≥1 protocol deviation while donning, and 100% of EVD PPE HCWs and 67% of CP PPE HCWs made ≥1 protocol deviation while doffing (P=.02). The median number of doffing protocol deviations among EVD PPE HCWs was 4, versus 1 among CP PPE HCWs. Also, 15 EVD PPE protocol deviations were committed by doffing assistants and/or trained observers. Fluorescence was detected on 8 EVD PPE HCWs (44%) and 5 CP PPE HCWs (28%), most commonly on hands. MS2 was recovered from 2 EVD PPE HCWs (11%) and 3 CP PPE HCWs (17%).
Protocol deviations were common during both EVD and CP PPE doffing, and some deviations during EVD PPE doffing were committed by the HCW doffing assistant and/or the trained observer. Self-contamination was common. PPE donning/doffing are complex and deserve additional study.
This was a randomized controlled pilot study of Lactobacillus rhamnosus GG versus standard of care to prevent gastrointestinal multidrug-resistant organism colonization in intensive care unit patients. Among 70 subjects, there were no significant differences in acquisition or loss of any multidrug-resistant organisms (P>.05) and no probiotic-associated adverse events.
Infect. Control Hosp. Epidemiol. 2015;36(12):1451–1454
The MIAMI* facility at the University of Huddersfield is one of a number of facilities worldwide that permit the ion irradiation of thin foils in-situ in a transmission electron microscope. MIAMI has been developed with a particular focus on enabling the in-situ implantation of helium and hydrogen into thin electron transparent foils, necessitating ion energies in the range 1 – 10 keV. In addition, however, ions of a variety of species can be provided at energies of up to 100 keV (for singly charged ions), enabling studies to focus on the build up of radiation damage in the absence or presence of implanted gas.
This paper reports on a number of ongoing studies being carried out at MIAMI, and also at JANNuS (Orsay, France) and the IVEM / Ion Accelerator Facility (Argonne National Lab, US). This includes recent work on He bubbles in SiC and Cu; the former work concerned with modification to bubble populations by ion and electron beams and the latter project concerned with the formation of bubble super-lattices in metals.
A study is also presented consisting of experiments aimed at shedding light on the origins of the dimensional changes known to occur in nuclear graphite under irradiation with either neutrons or ions. Single crystal graphite foils have been irradiated with 60 keV Xe ions in order to create a non-uniform damage profile throughout the foil thickness. This gives rise to varying basal-plane contraction throughout the foil resulting in almost macroscopic (micron scale) deformation of the graphite. These observations are presented and discussed with a view to reconciling them with current understanding of point defect behavior in graphite.
*Microscope and Ion Accelerator for Materials Investigations
Long PCR followed by nested PCR has previously been used to determine CYP2A6 160H alleles,
but the method proved unreliable. We have optimized this approach in a DNA bank of 1032 subjects
(age range 59–74 years) to give reliable results, yielding indirect molecular evidence and very strong
statistical evidence of hitherto unrecognized common alleles (designated O) recalcitrant to the long
PCR. Coding three alleles (160L, 160H and O) and an approach to association analysis originally
developed to deal with null alleles implicit in ABO blood group phenotyping, the contribution of
160H (functionally null) to reduced smoking habit has been clearly measured for the first time,
unconfounded by alleles null to the long PCR. The most significant findings (p < 0.01) are that the
possession of a 160H allele, compared with not possessing a 160H allele, is associated with a mean
age of starting regular smoking 3 years later (95% CI±1.93 years, average start age 20–21 years
rather than 17–18 years); and that the average likelihood of quitting smoking at any time is 1.75 fold
(95% CI. 1.17–2.61) for those possessing an 160H allele compared with those who have no 160H
allele. This suggests that a smoking subject with a genotype predicted to confer 50% of the ability
to eliminate nicotine via the CYP2A6 pathway has almost twice the likelihood of quitting smoking.
Systematic Mn K-edge x-ray absorption spectroscopy (XAS) measurements on samples of La1-xSrxMnO3, which are precursors to colossal magnetoresistive (CMR) materials, are reported. Detailed results on the edge or chemical shift as a function of Sr concentration (hole doping) and sample preparation (air vs oxygen annealed), are discussed. For comparison, a systematic XANES study of the Mn K-edge energy shift, denoting valence change in Mn, has been made in standard manganese oxide systems. Contrary to expectations, the variation in near-edge energies for Mn in La0.725Sr0.275MnO3 were small when compared to the difference between that for manganese oxide standards of nominal valence of +3 and +4 (Mn2O3 and MnO2).
Time-resolved in situ neutron powder diffraction and Rietveld refinement have been used to study the synthesis of Bi-2212 from hydroxide precursors in a 2% O2 atmosphere. Bi-2212 was found to form within the temperature range 770–800 °C. Studies at 800 °C show that Bi-2212 grows rapidly at the expense of Bi-2201. Upon lowering the temperature to 500 °C and changing the atmosphere to Ar, a rapid increase in the lattice parameters was observed. We attribute this change to the loss of oxygen from the Bi-2212 lattice. The final material exhibited a Tc of 94 K.
Neutron powder diffraction studies of the layered compounds R1.2Sr1.8Mn2O7, (R = La,Pr, Nd), RSr2Mn2O7 (R = Pr,Nd),and La1.4Sr1.6Mn2O7 show that the degree of distortion of the MnO6 octahcdra do not correlate with the appearance of a metal-insulator (MI) transition in these compounds. Instead, the in-plane Mn-O bond length appears to be a better indicator of the electronic behavior. Detailed bulk magnetization studies on single crystal La1.2Sr1.8Mn2O7 show thai there are three magnetic regimes as a function of temperature: paramagnetic insulator, short-range ordered (SRO) fcrrromangct, and long-range ordered (LRO) fcrromagnct. Scaling analysis indicates that a 2D finite-size XY model is an appropriate description of the magnetic state in the SRO regime.
The capabilities of the X-ray Timing Explorer (XTE) are described with particular attention paid to current scientific problems it will address from galactic neutron star systems to active galactic nuclei. It features a low-background continuous 2-200 keV response with large apertures (a 0.63-m2 proportional counter array and a 0.16-m2 dual rocking NaI/CsI scintillation array). Rapid response (in hours) to temporal phenomena, e.g. transients, is obtained by virtue of a scanning all-sky monitor and rapid maneuverability. XTE will carry out detailed energy-resolved studies of phenomena close to neutron stars (e.g. QPO’s) because of its sub-millisecond timing (to 10 μs), its high telemetry rates (to 256 kb/s), and the high throughput of its data system (to ≳ 2 × 105 c s−1).
The phonon densities-of-states (DOS) of superconducting Ba1−xKxBi16O3 and Ba1−xKxBi18O3 (x=0.4) are determined using molecular dynamics (MD) simulations and inelastic neutron scattering measurements. The reference isotope-effect exponent is obtained from the mass variation of the first frequency moment of the phonon DOS. The energy gap, oxygen isotope-effect exponent and electron tunneling characteristics are calculated within the framework of Eliashberg theory of electron-phonon coupling.
Temperature-dependent positron lifetime experiments have been performed from room temperature to cryogenic temperatures on Ba1−xKxBiO3. for x=0.4 and 0.5. From the temperature dependence of the positron lifetime in the normal state, we observe a clear signature of competition between separate defect populations to trap the positron. Theoretical calculations of lifetimes of free or trapped positrons have been performed on Ba1−xKxBiO3, to help identify these defects. Lifetime measurements separated by long times have been performed and evidence of aging effects in the sample defect populations is seen in these materials.
A recent effort in archaeological critique by Cordell et al. (1987) is undermined by confusion, misunderstanding, and misrepresentation. This comment on their paper illustrates how confusion may arise when the literature of the American Southwest is not read carefully and the causes of variability in the archaeological record are understood incompletely.
We have determined the crystal structures of five phases in the Bal-xKxBiO3 system for 0≤x≤0.5 and 10K≤T≤473K. Superconductivity occurs only in a cubic perovskite phase with the maximum Tc at the transition to an orthorhombic, Ibmm, phase. The commensurate structure of this orthorhombic phase, which involves only tilting of the Bi06 octahedra, provides no explanation for its non-metallic behavior. However, an incommensurate structural modulation, observed by electron diffraction, may provide a rationalization. Thus, the maximum Tc at the phase boundary may result from competition between superconductivity and a charge density wave. Further studies of the phase diagram at high temperatures, where controlled oxygen atmospheres are required, reveal an unusual reentrant formation of a potassium-containing impurity phase which explains the need for synthesis techniques that involve initially reacting in a reducing atmosphere, followed by oxygenation at lower temperature.
Single‐phase samples of (Ba1‐xKx)(Bi1‐xSby)O3 have been synthesized over a limited compositional range using a two‐step procedure: high‐temperature firing in a low oxygen partial pressure followed by low‐temperature oxygen annealing. For y=0 and 0.37<x<0.50, samples have a simple cubic structure and are bulk superconductors with Tc gradually decreasing from 30 to 22K as x increases to 0.50. For fixed x and y>0 samples are superconducting again with a simple cubic structure and with Tc gradually decreasing as y increases.
Eu2.xCexCuO4±δ (0 ≤ x ≤ 0.17) has been synthesized with the tetragonal T’ structure. AC susceptibility and resistance measurements show that Eu2‐xCexCuO4±δ becomes superconducting with τc∼13 K for x= 0.15 and 0.17, when prepared under reducing conditions. The 151Eu Mossbauer shift shows that the Euvalence falls into a narrow range near Eu 3+ . The temperature dependence of the Mossbauer absorption yields a Debye temperature of 319 K for the Eu ion in Eu1.85Ce0.15CuO4±δ
We have studied mixed-phase samples of bulk LazCuO4 using neutron powder diffraction, thermogravimetric analysis and resistivity measurements. Samples fired at 950°C and slowly cooled form in the K2NiF4 structure with CuO impurities for z<2 and La2O3 impurities for z>2. Neither La-vacancies nor stacking defects were found. The bulk resistivity of the samples show semiconducting behavior which is shorted at 38K by small amounts of superconducting material. The superconductivity is due to the presence of an oxygen-rich phase with stoichiometry La2CuO4.08. The occurrence of superconductivity in pure La2CuO4.08 with the same Tc as observed in the doped La1.85 Sr0.15CuO4 indicates that the excess oxygen provides the same level of doping as metal-ion substitution.
Superconducting Ba0.6K0.4BiO3, with a Tc of 30K, shows a large 18O isotope effect which indicates that phonons are involved in the pairing mechanism. Infrared reflectivity measurements indicate a value for the superconducting gap consistent with moderate coupling (2Δ/kTc = 3.5 ± 0.5). A mediating energy for pairing of about 40 meV would be required to obtain a Tc of 30K. Strong coupling of electrons by optical phonons (which are present in this material with energies up to 80 meV) could account for the observed transition temperature. Recent tunneling spectroscopy shows the presence of strongly coupled optical phonons in the 40 to 70 meV region, indicating that superconductivity in this material may be phonon mediated.
1. Duplicate diet analysis for energy, protein, zinc and copper with estimates of biochemical status for Zn and Cu were undertaken in twenty-one elderly long-stay inpatients (mean age 82 (range 63–89) years) consuming their customary hospital diet and in a stable medical condition. Fourteen patients had a long-standing and significant healing problem, either a leg ulcer or pressure sore.
2. Mean daily intakes of energy (5·2 MJ), protein (45 g), Zn (85 μmol) and Cu (14 μmol) were low in comparison with both official recommendations and levels of intake at which metabolic equilibrium was observed in healthy elderly people studied by the same methods (Bunker et al. 1984a).
3. Mean leucocyte Zn (9 pmol/106 cells) and Cu (7·5 pmol/106cells) were low in comparison with results from healthy elderly people (Bunker et al. 1984a), implying suboptimal status for these elements. Those patients with healing problems tended to have the lower values within the range.
4. Recommendations are made with respect to improving nutritional status in this disadvantaged group of people.