bluuebunny/crossref_metadata_2025 huggingface dataset:
Influenza Recycling and Secular Trends in Mortality and Natality
Authors: Azambuja Maria Inês Reinert
Published: June 2011

Secular variations in longevity and in population aging are of huge interest to actuaries. It is shown here that temporal changes in mortality and natality accompany the recycling of influenza A viruses i.e., the re-exposure of human populations, from time to time, to influenza A viruses antigenically similar to viruses (H1, H2, H3) that circulated in the past. Mortality (and natality) change as birth cohorts (whole population and maternal) with specific types and levels of vulnerability to influenza A re-infections, acquired through early-life effects of infection with one (period-specific) influenza A sub-type, course through subsequent influenza A environments over time. Epidemiologic evidence of association between secular trends in mortality (and natality) and interactions between birth-cohort and period effects of influenza A circulation is presented both for the U.K. and the U.S. New interpretations to several epidemiologic and demographic observations follow from this finding.
A New Model of Ageing and Mortality
Authors: Milne Eugene M. G.
Published: June 2011

The Nested Binomial Model presented in this paper is a new approach to modelling mortality and survival in humans and other species that seeks to reconcile individual life course risk trajectories and those population mortality patterns that arise from inter-individual heterogeneity. In describing individual trajectories it partitions mortality risk into two main elements: ‘redundancy’ and ‘interactive risk'. Interactive risk is volatile, increasing or decreasing with time and circumstance, while redundancy is a quantity which declines in a linear and largely invariable fashion throughout life. Although a biological correlate for redundancy is not identified, this assumption allows strikingly realistic modelling of mortality and survival curves, late-life mortality deceleration, Strehler-Mildvan correlation, mortality plateaux and slowing of mortality. Simple assumptions with regard to heterogeneity of parameters within the model allow close approximation to the entire human mortality curve, and provide a rationale for observed and otherwise paradoxical population mortality phenomena. As such, it fulfils biodemographic criteria for a comprehensive theory of ageing. Future challenges are to reconcile its theoretical structure with empirical findings in the biology of ageing and to render it in a form that can become a usable actuarial tool.
Cerebral microvascular endothelium and the pathogenesis of neurodegenerative diseases
Authors: Grammas Paula , Martinez Joseph , Miller Bradley
Published: June 2011

Diseases of the central nervous system (CNS) pose a significant health challenge, but despite their diversity, they share many common features and mechanisms. For example, endothelial dysfunction has been implicated as a crucial event in the development of several CNS disorders, such as Alzheimer disease, Parkinson disease, amyotrophic lateral sclerosis, multiple sclerosis, human immunodeficiency virus (HIV)-1-associated neurocognitive disorder and traumatic brain injury. Breakdown of the blood–brain barrier (BBB) as a result of disruption of tight junctions and transporters, leads to increased leukocyte transmigration and is an early event in the pathology of these disorders. The brain endothelium is highly reactive because it serves as both a source of, and a target for, inflammatory proteins and reactive oxygen species. BBB breakdown thus leads to neuroinflammation and oxidative stress, which are implicated in the pathogenesis of CNS disease. Furthermore, the physiology and pathophysiology of endothelial cells are closely linked to the functioning of their mitochondria, and mitochondrial dysfunction is another important mediator of disease pathology in the brain. The high concentration of mitochondria in cerebrovascular endothelial cells might account for the sensitivity of the BBB to oxidant stressors. Here, we discuss how greater understanding of the role of BBB function could lead to new therapeutic approaches for diseases of the CNS that target the dynamic properties of brain endothelial cells.
The roads and bridges of science
Authors: Breithaupt Holger
Published: June 2011

Research infrastructures are a crucial component of modern biological research, but the EU has not yet figured out how to fund and maintain them.
Regional Cerebral Blood Flow after Marijuana Smoking
Authors: Mathew Roy J. , Wilson William H. , Humphreys Diane F. , Lowe Joe V. , Wiethe Kathryn E.
Published: June 2011

Regional CBF was measured with the 133Xe inhalation technique before and thrice after smoking marijuana of two strengths and placebo in 20 physically and mentally healthy male volunteers with a previous history of exposure to marijuana. They were drug-free at the time of the study. Blood pressure, pulse rate, end-tidal carbon dioxide, end-tidal carbon monoxide, and forehead skin perfusion were quantified during the CBF measurements. Blood samples were drawn for quantification of plasma levels of Δ9-tetrahydrocannabinol (THC) before and during the 2 h after smoking marijuana or placebo. Drug-induced intoxication and changes in mood were quantified with rating scales. Marijuana smoking was associated with bilateral CBF increase, which was maximal 30 min later. Greater CBF increases were seen in the frontal region and right hemisphere. No significant CBF changes were seen after placebo. Pulse rate and respiration increased significantly after marijuana but not placebo. Both marijuana and placebo smoking were associated with increased end-tidal carbon monoxide. CBF increase in both hemispheres correlated significantly with degree of intoxication, plasma levels of THC, and pulse rate.
Enhanced Calcium Uptake by CA1 Pyramidal Cell Dendrites in the Postischemic Phase despite Subnormal Evoked Field Potentials: Excitatory Amino Acid Receptor Dependency and Relationship to Neuronal Damage
Authors: Andiné Peter , Jacobson Ingemar , Hagberg Henrik
Published: June 2011

After 6–12 h of recovery from transient cerebral ischemia, the pyramidal cells of the hipppocampal CA1 region take up excessive amounts of calcium upon electrical stimulation, which has been suggested to be important for the development of delayed neuronal death. The aim of this study was to further characterize this enhanced calcium uptake with respect to time-course of development, relationship to neuronal damage, and amplitude of evoked field potentials as well as the dependency on N-methyl-d-aspartate (NMDA) and non-NMDA receptors. Adult Wistar rats were used and calcium-sensitive microelectrodes were placed in the stratum radiatum of the CA1 hippocampus for recording of the extracellular calcium concentration ([Ca2+]ec) during 20 min of ischemia and for 6 h of reflow. High-frequency stimulation of the perforant pathway elicited burst firing in CA1 and a transient decrease in [Ca2+]ec which reflects neuronal uptake. Shifts in [Ca2+]ec could not be evoked 0–1 h after ischemia. However, from 1–2 h burst firing could be evoked and the accompanying shift in [Ca2+]ec increased thereafter in amplitude with prolonged reflow, exceeded preischemic levels after 4 h, and reached 250 ± 116% (mean ± SD) of control after 6 h of reflow ( p < 0.05). The extracellular reference potential shift during electrical stimulation and the amplitude of evoked field potentials were still subnormal after 6 h [85 ± 25% and 83 ± 25%, respectively (mean ± SD)]. There was a significant correlation between the degree of stimulated calcium uptake at 6 h postischemia and the extent of CA1 damage evaluated 7 days after the ischemic insult ( r = 0.849; p < 0.001). The shifts in [Ca2+]ec were reduced by the NMDA antagonist MK-801 (0.5–2 mg/kg, i.v.) to approximately 50% of the initial level during both control and postischemic conditions ( p < 0.01). The non-NMDA antagonist 2,3-dihydroxy-6-nitro-7-sulfamoylbenzo[ F]quinoxaline (NBQX) (42 ± 13 mg/kg, i.p.; mean ± SD) decreased the amplitude of the evoked field potentials (to 30 ± 28% of control, p < 0.05) and completely abolished the evoked shifts in [Ca2+]ec. In conclusion, the uptake of calcium into CA1 pyramidal cells during electrical stimulation was enhanced already 4 h after ischemia in spite of the fact that other measures of excitability were subnormal. This calcium uptake correlated to the extent of CA1 pyramidal cell damage and was dependent on both NMDA and non-NMDA receptor activation.
Methodological Requirements for Accurate Measurements of Brain and Body Temperature during Global Forebrain Ischemia of Rat
Authors: Miyazawa T. , Hossmann K.-A.
Published: June 2011

The methodological requirements for accurate measurements of brain and body temperature during brain ischemia have been validated in Wistar rats submitted to 30 min of four-vessel occlusion. During ischemia, brains were exposed to three different temperature profiles: Spontaneous cooling from 36 to 31°C ( n = 10), constant hypothermia at 30°C ( n = 19), and constant normothermia at 36°C ( n = 21). Direct and indirect brain temperature recordings were carried out by placing fine thermocouples (200 μm diameter) into the striate nucleus, the temporal muscle, and the epidural space. Body temperature was measured with a flexible thermocouple inserted at various depths into the rectum. Accurate measurements of body temperature required insertion of the rectal probe to a depth of at least 6 cm; lesser insertion resulted in an underestimation of up to 6°C. Accurate estimates of brain temperature were obtained in all three experimental conditions by recording of the epidural temperature. The temperature in the temporal muscle, by contrast, differed from the brain temperature by up to 2°C, depending upon the experimental condition and the duration of ischemia. We therefore suggest that indirect measurements of brain temperature during ischemia are carried out in the epidural space in order to avoid misinterpretations of temperature-sensitive pathological changes.
Errors Introduced by Tissue Heterogeneity in Estimation of Local Cerebral Glucose Utilization with Current Kinetic Models of the [18F]Fluorodeoxyglucose Method
Authors: Schmidt K. , Lucignani G. , Moresco R. M. , Rizzo G. , Gilardi M. C. , Messa C. , Colombo F. , Fazio F. , Sokoloff L.
Published: June 2011

The effects of tissue heterogeneity on the estimation of regional cerebral glucose utilization (rCMRglc) in normal humans with [18F]2-fluoro-2-deoxy-d-glucose ([18F]FDG) and positron emission tomography (PET) were compared with respect to the various kinetic models of the [18F]FDG method. The kinetic models were conventional homogeneous tissue models of the [18F]FDG method, with (4K Model) and without (3K Model) a rate constant to account for an apparent loss of [18F]2-fluoro-2-deoxy-d-glucose-6-phosphate ([18F]FDG-6-P), and a tissue heterogeneity model (TH Model). When either of the kinetic models designed for homogeneous tissues was applied to heterogeneous tissues, estimates of the rate constant for efflux of [18F]FDG from the tissue ( k*2) and of the rate constant for phosphorylation of [18F]FDG ( k*3) decreased as the duration of the experimental period was increased. When the 4K Model was used, estimates of the rate constant for the apparent dephosphorylation of [18F]FDG-6-P ( k*4) were significantly greater than zero and fell with increasing duration of the experimental period. Although the TH Model included no term to describe an apparent dephosphorylation of [18F]FDG-6-P, the fit of the TH Model to the time course of total tissue radioactivity was at least as good as and often better than the fit of the 4K Model in the 120-min period following the pulse of [18F]FDG. Hence, the high estimates of k*4 found in PET studies of ≤120 min can be explained as the consequence of measuring radioactivity in a heterogeneous tissue and applying a model designed for a homogeneous tissue; there remains no evidence of significant dephosphorylation of [18F]FDG-6-P in this time period. Furthermore, use of the 4K Model led to an overestimation of rCMRglc; whole-brain glucose utilization calculated with the 4K Model was >20% higher than values usually obtained in normal humans by the model-independent Kety–Schmidt technique. rCMRglc was accurately estimated by the TH Model and, in experimental periods sufficiently long to minimize the effects of tissue heterogeneity, also by the original 3K Model of the deoxyglucose method.
Influence of the nonlinear bias dependence of the barrier height on measured Schottky-barrier contact parameters
Authors: Bozhkov V. G. , Shmargunov A. V.
Published: June 2011

A numerical investigation of current-voltage characteristics (IVCs) of the ideal metal-semiconductor Schottky-barrier contact (SBC) metal-n-GaAs in the wide range of temperatures, contact diameters and doping levels considering the influence of image force and tunneling effects is presented. The analysis is carried out on the basis of model, taking into account the nonlinear bias dependence of the barrier height (generally, effective one) and assuming that the SBC parameters are determined at constant (specified) current value in the temperature or contact diameter ranges, which corresponds practically to experimental conditions of measurement of SBC parameters. It is shown that such SBCs have behavior peculiarities typical for most real contacts: the “low temperature anomaly” (the ideality factor n increase and the barrier height ϕbm (measured by the saturation current) decrease with temperature decrease), edge effects (increase of n and decrease of ϕbm with contact diameter decrease), the inverse connection between ϕbm and n, when the growth of one of them is followed by the decrease of the other. A simple and very precise analytic representation of the IVC is given for the SBC in wide temperature and doping level ranges. This representation agrees closely with known experimental results. The high-accuracy method of the barrier height determining is proposed on this basis.
Switching of saturation magnetization by carrier injection in YBa2Cu3O7−δ/α-Fe2O3/Nb–SrTiO3 junctions
Authors: Chen Yuansha , Lian Guijun , Xiong Guangcheng , Venkatesan T.
Published: June 2011

Ferromagnetic (FM) α-Fe2O3 layers were deposited on n-type oxide semiconductor substrates of Nb-doped SrTiO3 (NSTO) to form YBa2Cu3O7−δ/α-Fe2O3/NSTO junctions. Multilevel resistance switching behavior was observed in YBa2Cu3O7−δ/α-Fe2O3/NSTO junctions with stable resistive states. The saturation magnetization MS of the YBa2Cu3O7−δ/α-Fe2O3/NSTO junctions was modulated by carrier injection and correlated with the conductivity of the switched state. This is the first report of simultaneous modulation of intrinsic magnetic and transport properties for FM oxide devices by using carrier injection.
Large-signal and high-frequency analysis of nonuniformly doped or shaped pn-junction diodes
Authors: Barybin Anatoly A. , Santos Edval J. P.
Published: June 2011

An analytical theory of nonuniformly doped or shaped pn-junction diodes subjected to large signals at high frequencies is presented. The resulting expressions can be useful to evaluate the performance of semiconductor device modeling software. The transverse averaging technique is employed to reduce the three-dimensional charge carrier transport equations into the quasi-one-dimensional form, with all physical quantities averaged out over the longitudinally varying cross section. Although axial symmetry is assumed, this approach gives rise to useful analytic expressions for the static current–voltage characteristics, the diffusion conductance, and diffusion capacitance as a function of signal amplitude and cross-section nonuniformity.
Hafnium oxide thin films studied by time differential perturbed angular correlations
Authors: Dey C. C. , Dey S. , Bedi S. C. , Das S. K. , Lorenz M. , Grundmann M. , Vogt J. , Butz T.
Published: June 2011

We report on the study of hafnium oxide thin films grown by pulsed laser deposition at various partial oxygen pressures by Time Differential Perturbed Angular Correlations using the nuclear probe 181Hf(β−)181Ta to determine the nuclear quadrupole interaction (NQI), and by x-ray diffraction. The samples were neutron activated and measured at room temperature as received as well as after annealing in air. All spectra exhibited two to three inequivalent probe sites, even after annealing. At 0.3 mbar oxygen partial pressure and annealing for 5 hs at 1073 K the majority (88%) of the sites exhibited NQI parameters as reported for the bulk monoclinic phase [ωQ = 125.4(2) Mrad/s, η = 0.335(5)]. We can exclude amorphous as well as cubic and tetragonal hafnium oxide phases in the annealed samples. There was no indication of room-temperature ferromagnetism.
In situ monitoring of the effects of hydrogen on Pb(Zr,Ti)O3 structure
Authors: Shafiei A. , Oprea C. , Alfantazi A. , Troczynski T.
Published: June 2011

Structural modifications of the lead zirconate titanate [Pb(Zr,Ti)O3] or PZT, subjected to hydrogen, are investigated using online monitoring of the electrical properties of PZT. The changes in PZT properties (dielectric constant and resistance) can be described using well known nucleation and growth equations. It is therefore hypothesized that a new structure forms in PZT upon exposure to hydrogen. Protons are expected to be constituents of this new structure, and the changes of the electrical properties can be attributed to their presence. The growth of the new structure appears to be limited by the diffusion of protons into PZT, and the activation energy for the diffusion of protons is calculated at about 0.442 ± 0.1 eV.
Effect of parallel and antiparallel configuration on magnetic damping in Co/Ag/Co/Gd
Authors: Demirtas S. , Salamon M. B. , Koymen A. R.
Published: June 2011

When two ferromagnetic layers have a common resonance frequency, the usual spin-pumping broadening may be reduced by dynamic exchange coupling. Utilizing the antiferromagnetic coupling between Co and Gd, we explore the change in ferromagnetic resonance accompanying a spontaneous transition from parallel to antiparallel magnetic alignment of two Co films below the compensation temperature Tcomp. Above Tcomp, the data are consistent with conventional models. However, a rapid doubling of magnetic damping accompanies the realignment, which is reminiscent of resistivity changes in giant magnetoresistance.
The decay of turbulence in rotating flows
Authors: Teitelbaum Tomas , Mininni Pablo D.
Published: June 2011

We present a parametric space study of the decay of turbulence in rotating flows combining direct numerical simulations, large eddy simulations, and phenomenological theory. Several cases are considered: (1) the effect of varying the characteristic scale of the initial conditions when compared with the size of the box, to mimic “bounded” and “unbounded” flows; (2) the effect of helicity (correlation between the velocity and vorticity); (3) the effect of Rossby and Reynolds numbers; and (4) the effect of anisotropy in the initial conditions. Initial conditions include the Taylor-Green vortex, the Arn’old-Beltrami-Childress flow, and random flows with large-scale energy spectrum proportional to k4. The decay laws obtained in the simulations for the energy, helicity, and enstrophy in each case can be explained with phenomenological arguments that consider separate decays for two-dimensional and three-dimensional modes and that take into account the role of helicity and rotation in slowing down the energy decay. The time evolution of the energy spectrum and development of anisotropies in the simulations are also discussed. Finally, the effect of rotation and helicity in the skewness and kurtosis of the flow is considered.
Sub-nanosecond switching and acceleration to relativistic energies of field emission electron bunches from metallic nano-tips
Authors: Tsujino S. , Paraliev M. , Kirk E. , Gough C. , Ivkovic S. , Braun H.-H.
Published: June 2011

The authors explore the generation of short electron bunches from a field-emitter array cathode consisting of nanometer-sized metallic tips that is compatible with an acceleration electric field above 10 MV/m. Sub-nanosecond field emission electron bunches were generated by applying fast electrical pulses to an on-chip electron extraction gate electrode of the cathode. The subsequent acceleration of the field emission electron bunches to 5 MeV was demonstrated using the combined diode-RF cavity SwissFEL electron gun test facility.
Direct trap observation in stressed SiO2 with electrically detected magnetic resonance
Authors: Yonamoto Yoshiki , Akamatsu Naotoshi
Published: June 2011

We investigated traps in unstressed/stressed SiO2 thin films with electrically detected magnetic resonance. In the unstressed SiO2, only Eγ′-centers (O3≡Si⋅, ⋅ denotes a dangling bond) were observed. After imposing stresses, SiO2 exhibited soft-breakdown (SBD) or hard-breakdown (HBD) phenomena. The digital noise called random telegraph noise induced by a single trap was seen in the SBD-SiO2. We found that it is a single Eγ′-center. Also, we revealed that analog noises seen in the HBD-SiO2 originate from Si3≡Si⋅ traps. Our observations clearly show a close relationship between breakdown phenomena and traps.
Frequency-shift vs phase-shift characterization of in-liquid quartz crystal microbalance applications
Authors: Montagut Y. J. , García J. V. , Jiménez Y. , March C. , Montoya A. , Arnau A.
Published: June 2011

The improvement of sensitivity in quartz crystal microbalance (QCM) applications has been addressed in the last decades by increasing the sensor fundamental frequency, following the increment of the frequency/mass sensitivity with the square of frequency predicted by Sauerbrey. However, this sensitivity improvement has not been completely transferred in terms of resolution. The decrease of frequency stability due to the increase of the phase noise, particularly in oscillators, made impossible to reach the expected resolution. A new concept of sensor characterization at constant frequency has been recently proposed. The validation of the new concept is presented in this work. An immunosensor application for the detection of a low molecular weight contaminant, the insecticide carbaryl, has been chosen for the validation. An, in principle, improved version of a balanced-bridge oscillator is validated for its use in liquids, and applied for the frequency shift characterization of the QCM immunosensor application. The classical frequency shift characterization is compared with the new phase-shift characterization concept and system proposed.
Compositional dependence of trap density and origin in thin silicon oxynitride film investigated using spin dependent Poole–Frenkel current
Authors: Yonamoto Yoshiki , Inaba Yutaka , Akamatsu Naotoshi
Published: June 2011

The compositional dependence of trap density and origin in thin silicon oxynitride (SiOxNy) films deposited by the low pressure chemical vapor deposition method was investigated using spin dependent Poole–Frenkel (SDPF) current technique. SDPF detected two kinds of traps, K-center (N3Si⋅, where means a dangling bond) and K′-center (N2OSi⋅). With increasing oxygen concentration, the amount of K-center decreases. On the other hand, K′-center increases up to O/O+N=0.25 and then it decreases. We propose the model that the change in the film strain by oxygen atoms induces these phenomena.
The transition from a TEM-like mode to a plasmonic mode in parallel-plate waveguides
Authors: Liu Jingbo , Mendis Rajind , Mittleman Daniel M.
Published: June 2011

We describe subwavelength-resolved measurements of the broadband terahertz field propagating inside a finite-width parallel-plate waveguide. We observe a transition in the spatial mode of the waveguide, in which the energy distribution shifts from the waveguide center to the edges with increasing frequency. This transition is surprisingly abrupt, and depends sensitively on the gap between the waveguide plates. These results may have important implications for a variety of terahertz experiments as well as in the design of optical systems and components in the visible and near-infrared regimes, which rely on plasmonic wave guiding.
Alternative single-reference coupled cluster approaches for multireference problems: The simpler, the better
Authors: Evangelista Francesco A.
Published: June 2011

We report a general implementation of alternative formulations of single-reference coupled cluster theory (extended, unitary, and variational) with arbitrary-order truncation of the cluster operator. These methods are applied to compute the energy of Ne and the equilibrium properties of HF and C2. Potential energy curves for the dissociation of HF and the BeH2 model computed with the extended, variational, and unitary coupled cluster approaches are compared to those obtained from the multireference coupled cluster approach of Mukherjee et al. [J. Chem. Phys. 110, 6171 (1999)] and the internally contracted multireference coupled cluster approach [F. A. Evangelista and J. Gauss, J. Chem. Phys. 134, 114102 (2011)10.1063/1.3559149]. In the case of Ne, HF, and C2, the alternative coupled cluster approaches yield almost identical bond length, harmonic vibrational frequency, and anharmonic constant, which are more accurate than those from traditional coupled cluster theory. For potential energy curves, the alternative coupled cluster methods are found to be more accurate than traditional coupled cluster theory, but are three to ten times less accurate than multireference coupled cluster approaches. The most challenging benchmark, the BeH2 model, highlights the strong dependence of the alternative coupled cluster theories on the choice of the Fermi vacuum. When evaluated by the accuracy to cost ratio, the alternative coupled cluster methods are not competitive with respect to traditional CC theory, in other words, the simplest theory is found to be the most effective one.
The nature of electron correlation in a dissociating bond
Authors: Hollett Joshua W. , McKemmish Laura K. , Gill Peter M. W.
Published: June 2011

We have constructed the unrestricted Hartree-Fock (UHF), restricted Hartree-Fock (RHF), and full configuration interaction (FCI) position and momentum intracules and holes for H⋅⋅⋅H at bond lengths R from 1 to 10 bohrs. We trace the recently discovered inversion of the UHF position hole at intermediate R to over-localization of the spin-orbitals, and support this by a correlation energy component analysis. The RHF and UHF momentum holes are found to be more complicated; however their features are explained through decomposition of electron correlation effects. The UHF momentum hole is also found to invert and exhibits interesting behavior at large R. The RHF (but not UHF) and FCI momentum intracules exhibit Young-type interference patterns related to recent double photoionization experiments. Our analyses yield the most comprehensive picture to date of the behavior of the electrons during homolytic bond fission.
Glow Gel Hand Washing in the Waiting Room: A Novel Approach to Improving Hand Hygiene Education
Authors: Fishbein Anna B. , Tellez Itza , Lin Henry , Sullivan Christine , Groll Mary E.
Published: June 2011

Objectives.

To characterize handwashing behaviors of children and assess the efficacy of a waiting room-based hand hygiene intervention at improving handwashing ability.

Design.

Prospective randomized pilot study.

Setting.

Emergency department waiting room at a freestanding urban pediatric hospital.

Participants.

Children (8–18 years) and their parent.

Intervention.

Participants were randomized to glow gel hand washing without hand hygiene education or glow gel hand washing with hand hygiene education. After participants washed with glow gel, “dirty areas” were illuminated using a black light, and hands were scored. A questionnaire about handwashing behavior was administered. All subjects returned 2–4 weeks after intervention to repeat glow gel hand washing and the questionnaire.

Results.

Sixty pediatric patients and 57 parents were recruited, with 77% of patients returning for follow up. Patients were 50% male, 58% Latino, 28% African American, and 8% Caucasian. At the initial visit, 91% of children reported hand washing after using the bathroom and 78% reported hand washing before dinner. On the basis of objective scoring, all children improved handwashing ability when compared with the initial visit (P = .02) and were more likely to use warm water at follow up (P = .01). Parents did not significantly improve in handwashing ability (P = .73).

Conclusion.

Glow gel hand washing is an effective method to improve children's handwashing ability. This short-term intervention was effective even in the absence of specific hand hygiene education. This intervention could serve as a valuable public health measure to teach hand washing in healthcare settings.
Coagulase-Negative Staphylococcal Infections in the Neonatal Intensive Care Unit
Authors: Jean-Baptiste Naomi , Benjamin Daniel K. , Cohen-Wolkowiez Michael , Fowler Vance G. , Laughon Matthew , Clark Reese H. , Smith P. Brian
Published: June 2011

Background.

Coagulase-negative staphylococci (CoNS) are the most commonly isolated pathogens in the neonatal intensive care unit (NICU). CoNS infections are associated with increased morbidity, including neurodevelopmental impairment.

Objective.

To describe the epidemiology of CoNS infections in the NICU. To determine mortality among infants with definite, probable, or possible CoNS infections.

Methods.

We performed a retrospective cohort study of all blood, urine, and cerebrospinal fluid cultures from samples obtained from infants aged <121 postnatal days.

Setting.

A total of 248 NICUs managed by the Pediatrix Medical Group from 1997 to 2009.

Results.

We identified 16,629 infants with 17,624 episodes of CoNS infection: 1,734 (10%) definite, 3,093 (17%) probable, and 12,797 (73%) possible infections. Infants with a lower gestational age and birth weight had a higher incidence of CoNS infection. When controlling for gestational age, birth weight, and 5-minute Apgar score, we found that infants with definite, probable, or possible CoNS infection had lower mortality (odds ratio [OR], 0.74 [95% confidence interval {CI}: 0.61, 0.89], 0.68 [95% CI, 0.59, 0.79], and 0.69 [95% CI, 0.63, 0.76], respectively) compared with infants who had negative culture results (P<.001). No significant difference in overall mortality was found in infants who had definite CoNS infection compared with those who had probable or possible CoNS infection (OR, 0.93 [95% CI, 0.75, 1.16] and 0.85 [95% CI,0.70,1.03], respectively).

Conclusions.

CoNS infection was strongly related to lower gestational age and birth weight. Infants with clinical sepsis and culture-positive CoNS infection had lower mortality rates than infants with clinical sepsis and negative blood culture results. No difference in mortality between infants with a diagnosis of definite, probable, or possible CoNS infection was observed.
Reporting Catheter-Associated Urinary Tract Infections: Denominator Matters
Authors: Wright Marc-Oliver , Kharasch Maureen , Beaumont Jennifer L. , Peterson Lance R. , Robicsek Ari
Published: June 2011

Objective.

To evaluate two different methods of measuring catheter-associated urinary tract infection (CAUTI) rates in the setting of a quality improvement initiative aimed at reducing device utilization.

Design, Setting, and Patients.

Comparison of CAUTI measurements in the context of a before-after trial of acute care adult admissions to a multicentered healthcare system.

Methods.

CAUTIs were identified with an automated surveillance system, and device-days were measured through an electronic health record. Traditional surveillance measures of CAUTI rates per 1,000 device-days (R1) were compared with CAUTI rates per 10,000 patient-days (R2) before (T1) and after (T2) an intervention aimed at reducing catheter utilization.

Results.

The device-utilization ratio declined from 0.36 to 0.28 between T1 and T2 (P< .001), while infection rates were significantly lower when measured by R2 (28.2 vs 23.2, P = .02). When measured by R1, however, infection rates trended upward by 6% (7.79 vs. 8.28, P = .47), and at the nursing unit level, reduction in device utilization was significantly associated with increases in infection rate.

Conclusions.

The widely accepted practice of using device-days as a method of risk adjustment to calculate device-associated infection rates may mask the impact of a successful quality improvement program and reward programs not actively engaged in reducing device usage.
Respiratory Fluoroquinolone Use and Influenza
Authors: Polgreen Philip M. , Yang Ming , Laxminarayan Ramanan , Cavanaugh Joseph E.
Published: June 2011

We show that respiratory fluoroquinolone use is extremely seasonal and that fluoroquinolone use is strongly associated with influenza. In our time series model, instantaneous influenza activity was a significant predictor of use (P< .0001). Also, we estimated that reducing influenza activity by 20% would reduce prescriptions by 8%.
Device Use Ratio Measured Weekly Can Reliably Estimate Central Line–Days for Central Line–Associated Bloodstream Infection Rates
Authors: Shelly Mark A. , Concannon Cathy , Dumyati Ghinwa ,   Rochester Infection Prevention Group
Published: June 2011

Six hospitals joined to perform surveillance for central line–associated bloodstream infections outside of intensive care units (ICUs). To facilitate the counting of device-days, a weekly measure of the device use ratio was validated as an estimate of central line–days outside the ICU.
Enhanced conversion efficiency in dye-sensitized solar cells with nanocomposite photoanodes
Authors: Jin X Y , Liu Z Y , Lu Y M , Wang X Q , Cai C B , Hu L H , Dai S Y
Published: June 2011

Nanocomposite architectures consisting of conductive carbon nanotubes (CNTs) and nanocrystalline TiO2 films are prepared as photoanodes of dye-sensitized solar cells (DSCs). It is observed that both the electron transport time and electron lifetime decrease with CNT addition, implying that its incorporation is effective in enhancing the electro-conductivity of mesoscopic TiO2 contacts. To rectify CNT orientations, a parallel electric field is applied during the sample preparation, which gives rise to a significant enhancement in the energy conversion efficiency of resultant DSCs. Electrochemical impedance spectroscopy clarifies the photoelectrochemical processes, with enhanced contribution to the efficient electron transport, arising from the increased CNT orientation.
JET snake magnetohydrodynamic equilibria
Authors: Cooper W.A. , Graves J.P. , Sauter O.
Published: June 2011

Magnetohydrodynamic (MHD) equilibrium states with a three-dimensional helical core that display the characteristics of a saturated ideal internal kink mode are computed to model snake structures that have been observed in the JET tokamak (Weller et al 1987 Phys. Rev. Lett.
59 2303). The equilibrium states are calculated with a peaked pressure profile and a weak to moderate reversed core magnetic shear with a minimum safety factor q
min near unity in the neighbourhood of the mid-radius of the plasma. Snake equilibrium states are computed in the range 0.94 < q
min < 1.03. This range aligns with linearly unstable ideal MHD internal kink solutions of the purely axisymmetric branch of the equilibrium states. The energy difference between the bifurcated axisymmetric and helical snake equilibrium solutions is minimal. One very important novelty is that the helical structures are computed with an equilibrium code developed for three-dimensional (3D) stellarator applications in a tokamak context and cannot be obtained with standard Grad–Shafranov equation solvers.
Calculations of lower hybrid current drive in ITER
Authors: Decker J. , Peysson Y. , Hillairet J. , Artaud J.-F. , Basiuk V. , Becoulet A. , Ekedahl A. , Goniche M. , Hoang G.T. , Imbeaux F. , Ram A.K. , Schneider M.
Published: June 2011

A detailed study of lower hybrid current drive (LHCD) in ITER is provided, focusing on the wave propagation and current drive mechanisms. A combination of ray-tracing and Fokker–Planck calculations are presented for various plasma scenarios, wave frequency and polarization. The dependence of the driven current and the location of power deposition upon the coupled wave spectrum is systematically determined, in order to set objectives for the antenna design. The respective effects of finite-power levels, magnetic trapping, and detailed antenna spectra are accounted for and quantitatively estimated. The sensitivity of LHCD to density and temperature profiles is calculated. From the simulation results, an optimum value for the parallel index of refraction is proposed as a compromise between efficiency and robustness with respect to those profile variations. The corresponding current drive efficiency is found to be similar for the two frequencies generally considered for ITER, f = 3.7 GHz and f = 5.0 GHz.
Inward and outward propagation of the floating potential fluctuations in the plasma edge of the TJ-II stellarator
Authors: Pedrosa M.A. , Silva C. , Hidalgo C. , Carralero D. , van Milligen B. , Morera J.
Published: June 2011

The radial structure of plasma fluctuations has been investigated in the plasma boundary region of the TJ-II stellarator. For density above the threshold for edge-sheared flow development potential fluctuations propagate predominantly radially outwards in the scrape-off-layer side of the shear layer, whereas in the edge region side the radial propagation is predominantly radially inwards with an effective velocity in the order of 1–10 km s−1. Results suggest that edge-sheared flows play a role as a source of inward and outward propagating plasma potential fluctuations.
On the fundamental units of a totally real cubic order generated by a unit
Authors: Louboutin Stéphane
Published: June 2011

We give a new and short proof of J. Beers, D. Henshaw, C. McCall, S. Mulay and M. Spindler following a recent result: if

ϵ
\epsilon

is a totally real cubic algebraic unit, then there exists a unit

η
∈

Z

[
ϵ
]

\eta \in \textbf {Z}[\epsilon ]

such that

{
ϵ
,
η
}

\{\epsilon ,\eta \}

is a system of fundamental units of the group

U
ϵ

U_\epsilon

of the units of the cubic order

Z

[
ϵ
]

\textbf {Z}[\epsilon ]

, except for an infinite family for which

ϵ
\epsilon

is a square in

Z

[
ϵ
]

\textbf {Z}[\epsilon ]

and one sporadic exception. Not only is our proof shorter, but it enables us to prove a new result: if the conjugates

ϵ
′

\epsilon ’

and

ϵ
\epsilon

of

ϵ
\epsilon

are in

Z

[
ϵ
]

\textbf {Z}[\epsilon ]

, then the subgroup generated by

ϵ
\epsilon

and

ϵ
′

\epsilon ’

is of bounded index in

U
ϵ

U_\epsilon

, and if

ϵ
>
1
>
|

ϵ
′

|
≥
|
ϵ
|
>
0

\epsilon >1>\vert \epsilon ’ \vert \geq \vert \epsilon \vert >0

and if

ϵ
′

\epsilon ’

and

ϵ
\epsilon

are of opposite sign, then

{
ϵ
,

ϵ
′

}

\{\epsilon ,\epsilon ’\}

is a system of fundamental units of

U
ϵ

U_\epsilon

.
The disk property of coverings of 1-convex surfaces
Authors: Colţoiu Mihnea , Joiţa Cezar
Published: June 2011

Let

X
X

be a 1-convex surface and

p
:

X
~

→
X

p:\tilde X\to X

an (unbranched) covering map. We prove that if

X
~

\tilde X

does not contain an infinite Nori string of rational curves, then

X
~

\tilde X

satisfies the discrete disk property.
The LabelHash Server and Tools for substructure-based functional annotation
Authors: Moll Mark , Bryant Drew H. , Kavraki Lydia E.
Published: June 2011

Summary: The LabelHash server and tools are designed for large-scale substructure comparison. The main use is to predict the function of unknown proteins. Given a set of (putative) functional residues, LabelHash finds all occurrences of matching substructures in the entire Protein Data Bank, along with a statistical significance estimate and known functional annotations for each match. The results can be downloaded for further analysis in any molecular viewer. For Chimera, there is a plugin to facilitate this process.

Availability: The web site is free and open to all users with no login requirements at http://labelhash.kavrakilab.org

Contact:  mmoll@rice.edu

Supplementary Information:  Supplementary data are available at Bioinformatics online.
Reducing ventilator-associated pneumonia in intensive care: Impact of implementing a care bundle*
Authors: Morris Andrew Conway , Hay Alasdair W. , Swann David G. , Everingham Kirsty , McCulloch Corrienne , McNulty Jane , Brooks Odette , Laurenson Ian F. , Cook Brian , Walsh Timothy S.
Published: June 2011

Objectives:

Ventilator-associated pneumonia is the most common intensive care unit-acquired infection. Although there is widespread consensus that evidenced-based interventions reduce the risk of ventilator-associated pneumonia, controversy has surrounded the importance of implementing them as a “bundle” of care. This study aimed to determine the effects of implementing such a bundle while controlling for potential confounding variables seen in similar studies.

Design:

A before-and-after study conducted within the context of an existing, independent, infection surveillance program.

Setting:

An 18-bed, mixed medical–surgical teaching hospital intensive care unit.

Patients:

All patients admitted to intensive care for 48 hrs or more during the periods before and after intervention.

Interventions:

A four-element ventilator-associated pneumonia prevention bundle, consisting of head-of-bed elevation, oral chlorhexidine gel, sedation holds, and a weaning protocol implemented as part of the Scottish Patient Safety Program using Institute of Health Care Improvement methods.

Measurements and Main Results:

Compliance with head-of-bed elevation and chlorhexidine gel were 95%–100%; documented compliance with “wake and wean” elements was 70%, giving overall bundle compliance rates of 70%. Compared to the preintervention period, there was a significant reduction in ventilator-associated pneumonia in the postintervention period (32 cases per 1,000 ventilator days to 12 cases per 1,000 ventilator days; p < .001). Statistical process control charts showed the decrease was most marked after bundle implementation. Patient cohorts staying ≥6 and ≥14 days had greater reduction in ventilator-associated pneumonia acquisition and also had reduced antibiotic use (reduced by 1 and 3 days; p = .008/.007, respectively). Rates of methicillin-resistant Staphylococcus aureus acquisition also decreased (10% to 3.6%; p < .001).

Conclusions:

Implementation of a ventilator-associated pneumonia prevention bundle was associated with a statistically significant reduction in ventilator-associated pneumonia, which had not been achieved with earlier ad hoc ventilator-associated pneumonia prevention guidelines in our unit. This occurred despite an inability to meet bundle compliance targets of 95% for all elements. Our data support the systematic approach to achieving high rates of process compliance and suggest systematic introduction can decrease both infection incidence and antibiotic use, especially for patients requiring longer duration of ventilation.
Glypican‐3 could be an effective target for immunotherapy combined with chemotherapy against ovarian clear cell carcinoma
Authors: Suzuki Shiro , Yoshikawa Toshiaki , Hirosawa Tomoya , Shibata Kiyosumi , Kikkawa Fumitaka , Akatsuka Yoshiki , Nakatsura Tetsuya
Published: June 2011

Glypican‐3 (GPC3) is useful not only as a novel tumor marker, but also as an oncofetal antigen for immunotherapy. We recently established HLA‐A2‐restricted GPC3144‐152 peptide‐specific CTL clones from hepatocellular carcinoma patients after GPC3144‐152 peptide vaccination. The present study was designed to evaluate the tumor reactivity of a HLA‐A2‐restricted GPC3144‐152 peptide‐specific CTL clone against ovarian clear cell carcinoma (CCC) cell lines. The GPC3144‐152 peptide‐specific CTL clone could recognize HLA‐A2‐positive and GPC3‐positive ovarian CCC cell lines on interferon (IFN)‐γ enzyme‐linked immunospot assay and showed cytotoxicity against KOC‐7c cells. The CTL clone recognized naturally processed GPC3‐derived peptide on ovarian CCC cells in a HLA class I‐restricted manner. Moreover, we confirmed that the level of GPC3 expression was responsible for CTL recognition and that subtoxic‐dose chemotherapy made tumor cells more susceptible to the cytotoxic effect of CTL. Thus, it might be possible to treat ovarian CCC patients by combining chemotherapy with immunotherapy. Our data suggest that GPC3 could be an effective target for immunotherapy against ovarian CCC. (Cancer Sci 2011; 102: 1622–1629)
Women’s preferences regarding options for management of atypical, borderline or low‐grade cervical cytological abnormalities: a review of the evidence
Authors: Sadique M. Z. , Legood R.
Published: June 2011

M. Z. Sadique and R. Legood

Women’s preferences regarding options for management of atypical, borderline or low‐grade cervical cytological abnormalities: a review of the evidence

Objectives:  To review the evidence on women’s preferences for and valuation of alternative management pathways following identification of low‐grade cytological abnormalities as part of routine cervical cancer screening. The aim was to identify empirical studies evaluating women’s preferences regarding alternative management pathways and to compare the impact of alternative elicitation methods on results.

Methods:  A systematic review of the literature was conducted using the online bibliographic information service PubMed database. Empirical studies were identified that elicited general preferences, utilities or valuations based on willingness to pay (WTP) with respect to management of low‐grade cytology results. Data were extracted on the methodology used and the empirical results.

Results:  Where quality of life data were elicited directly from patients that were undergoing management of low‐grade abnormalities utilizing direct elicitation techniques such as WTP, general preference questionnaires and the Euroqol, the studies tended towards a preference in favour of HPV testing (and colposcopy referral if HPV positive) rather than repeat cytology. In contrast, where studies included the general population and presented hypothetical scenarios of treatment pathways, and explicitly tried to incorporate assessment of process utility, the evidence indicated a slight tendency to favour repeat cytology.

Conclusion:  Consideration of patient preferences in the management of low‐grade cytology is important for designing screening protocols. The reviewed studies indicate that potentially different conclusions may be drawn depending on the elicitation methodology and selection of participants in the research.