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In 2007, the American Heart Association modified the infective endocarditis prophylaxis guidelines by limiting the use of antibiotics in patients with cardiac conditions associated with the highest risk of adverse outcomes after infective endocarditis. Our objective was to evaluate current practice for infective endocarditis prophylaxis among paediatric cardiologists.
A web-based survey focussing on current practice, describing the use of antibiotics for infective endocarditis prophylaxis in various congenital and acquired heart diseases, was distributed via e-mail to paediatric cardiologists. The survey was kept anonymous and was distributed twice.
Data from 253 participants were analysed. Most paediatric cardiologists discontinued infective endocarditis prophylaxis in patients with simple lesions such as small ventricular septal defect, patent ductus arteriosus, and bicuspid aortic valve without stenosis or regurgitation; however, significant disagreement persists in prescribing infective endocarditis prophylaxis in certain conditions such as rheumatic heart disease, Fontan palliation without fenestration, and the Ross procedure. Use of antibiotic prophylaxis in certain selected conditions for which infective endocarditis prophylaxis has been indicated as per the current guidelines varies from 44 to 83%. Only 44% follow the current guidelines exclusively, and 34% regularly discuss the importance of oral hygiene with their patients at risk for infective endocarditis.
Significant heterogeneity still persists in recommending infective endocarditis prophylaxis for several cardiac lesions among paediatric cardiologists. More than half of the participants (56%) do not follow the current guidelines exclusively in their practice. Counselling for optimal oral health in patients at risk for infective endocarditis needs to be optimised in the current practice.
From the photoinduced transport of energy that accompanies photosynthesis to the transcontinental transmission of optical data that enable the Internet, our world relies and thrives on optical signals. To highlight the importance of optics to society, the United Nations designated 2015 as “The International Year of Light and Light-based Technologies.” Although conventional optical technologies are limited by diffraction, plasmons—collective oscillations of free electrons in a conductor—allow optical signals to be tailored with nanoscale precision. Following decades of fundamental research, several plasmonic technologies have now emerged on the market, and numerous industrial breakthroughs are imminent. This article highlights recent industrially relevant advances in plasmonics, including plasmonic materials and devices for energy; for medical sensing, imaging, and therapeutics; and for information technology. Some of the most exciting industrial applications include solar-driven water purifiers, cell phone Raman spectrometers, high-density holographic displays, photothermal cancer therapeutics, and nanophotonic integrated circuits. We describe the fundamental scientific concepts behind these and related technologies, as well as the successes and challenges associated with technology transfer.
A community outbreak of legionellosis occurred in Barrow-in-Furness, Cumbria, during July and August 2002. A descriptive study and active case-finding were instigated and all known wet cooling systems and other potential sources were investigated. Genotypic and phenotypic analysis, and amplified fragment length polymorphism of clinical human and environmental isolates confirmed the air-conditioning unit of a council-owned arts and leisure centre to be the source of infection. Subsequent sequence-based typing confirmed this link. One hundred and seventy-nine cases, including seven deaths [case fatality rate (CFR) 3·9%] were attributed to the outbreak. Timely recognition and management of the incident very likely led to the low CFR compared to other outbreaks. The outbreak highlights the responsibility associated with managing an aerosol-producing system, with the potential to expose and infect a large proportion of the local population and the consequent legal ramifications and human cost.
Single layers of Co82?l8 with thickness in me ranee of 100–1500Å and multilayers of Co-Cr/Al with Co-Cr thickness in the range of 100–200A and Al at 7Å were prepared by dc magnetron sputtering. The films were deposited on to Si (111) and glass substrates at room temperature. A 100Å thick Al buffer layer was deposited to improve the c-axis orientation. X-ray diffraction (XRD) Measurements on the multilayers show a predominant Co-Cr (00.2) peak. Polar Magneto-optic measurements were performed to determine the Kerr rotation (θK) and figure of Merit. The results indicated an enhancement in the figure of merit at λ = 632.8 nm for the multilayered structures compared to single layer samples. All of the films show a 4πMs value around 6 kG and ferromagnetic resonance measurements indicate an enhancement in the perpendicular anisotropy field for the 150Å multilayered sample.
To determine if instituting an Emergency Department (ED) fast-track area would increase efficiency in patient flow, improve utilization of limited resources, and identify critical versus non-critical patients during disaster relief in Port au Prince, Haiti.
A survey was conducted at L'Hôpital de l'Université d'Etat d'Haïti (HUEH) in Port au Prince, Haiti by Emergency physicians and nurses from SUNY Downstate Medical Center on a disaster relief mission following the 2010 earthquake. The following variables were obtained to assess ED effectiveness: number of patients, acuity level, chief complaints, critical interventions, waiting times, length of stay, specialty service coverage and physical plant space. Additionally, existing practitioners were surveyed regarding existing ED practices. ED operation flow maps were created.
The assessment revealed a large volume of low-acuity patients mixed with high-acuity patients without identification of acuity level, time of arrival, or designated area for treatment. Although literature reports routine use of START triage, this was not being implemented in this setting. Results of implementing a fast track area included: (1) Improved identification of patients needing immediate treatment. (2) Increased flow of low acuity patients in designated fast track areas. (3) Improved triage protocols maximized appropriate use of resources, and expedited subspecialty consultation.
By instituting well-accepted, validated patient flow systems and reinforcing communication regarding resources available and the use of geographic space, better management of incoming emergency patients was achieved.
Upon arrival of the SUNY Downstate Medical Center team for their disaster relief mission in Port au Prince, Haiti, it was observed that obstacles to patient care were directly related to difficulty in locating supplies and medications in a timely manner. In addition, staffing schedules had not been correlated to patient flow patterns.
A survey was conducted at L'Hôpital de l'Université d'Etat d'Haïti (HUEH) in Port au Prince, Haiti by Emergency physicians and nurses from SUNY Downstate Medical Center. The following variables were obtained to assess existing resources: number and types of providers available, provider staffing schedules, medication/supply inventories and management systems. Basic ED operation and supply system flow maps were created.
The assessment revealed a large volume of patients presenting in the early morning. Night shifts were inconsistently staffed with ED physicians. Although medications and supplies were reported to be available on-site, they were not tracked, inventoried, or centrally managed. As a result, this increased time to treatment and practitioner fatigue. Process improvements included: (1) Institution of swing and night shifts accommodated peak patient volumes, decreased waiting times, provided care for critical patients during off-peak hours, and decreased physician fatigue. (2) Identification and labeling of existing medications/supplies facilitated more accurate management of inventories and decreased time to treatment and disposition.
Process improvement through systematic analysis led to better disaster resource utilization in this tent hospital.
To report an unusual case of fungal mastoiditis caused by entomophthorales in an immunocompetent patient, and its management.
Case report with a review of the literature.
A 13-year-old girl presented to us with a mastoid abscess. Entomophthoromycotic infection of the mastoid was diagnosed on histopathological examination, and subsequently treated with surgical debridement and amphotericin B injection.
This is the first reported case of mastoid abscess secondary to entomophthoromycosis. Early detection and treatment contributed to this patient's good outcome.
An alternate array of Pd/AlN/Si and Al/AlN/Si metal-insulator-semiconductor (MIS) devices has been developed using plasma source molecular beam epitaxy (PSMBE) method for deposition of AlN on Si and magnetron sputtering for deposition of Pd and Al electrodes (via mask) on AlN. Both devices show essentially identical capacitance (C) versus voltage (V) characteristics of the typical MIS capacitor. However, the C-V characteristic of a Pd-device shows a clear shift in the presence hydrogen, while that of an Al-device shows no shift. These sensors were characterized using C(V) and C(time) measurements under varying hydrogen concentration. The effects of oxygen and hydrocarbon gases on the sensors were also studied. The Pd-device responds selectively to hydrogen. These results suggest the possibility of fabricating a balanced sensor structure, which might have significant practical importance, as it would cancel all thermal and material sources of drift in the electrical component of the sensor response.
A series of epitaxial InxAl1−xN alloy films (thickness ~ 150 nm) with 0 ≤ × ≤ 1.0 were grown by Plasma Source Molecular Beam Epitaxy (PSMBE) on sapphire (0001) at a low substrate temperature of 375 °C. X-ray diffraction (XRD) measurements confirm a c-axis oriented epitaxial growth of alloy films without any alloy segregation. However, the degree of crystalline mosaicity, compositional fluctuation and surface roughness, all increase with increasing x. The direct energy band gap of alloy films were determined using optical (UV-VIS) transmission and reflection measurements. The observed bowing of the direct gap versus x plot, when compared to the theoretical prediction, is less pronounced than seen in earlier studies reported in literature. Electrical resistivity and Hall effect measurements show n-type electrical conductivity in these alloys with carrier concentrations ~1019-1020 cm−3 for x > 0.5.
Silica-precipitating polypeptides were deposited onto an indium tin oxide (ITO) surface from bulk solution with and without the assistance of an externally applied electrostatic field. Exposure of the peptide-coated surface to an alkoxide precursor produced biosilica structures that were securely attached to the electrode surface. The silica morphologies resulting from the test cases using an externally applied electrostatic field during peptide deposition were distinct from the morphologies resulting from cases without an applied field. The silica morphologies observed on the ITO surface were different from the usual silica morphology resulting from static conditions. Peptide size was also shown to influence resulting biosilica morphology. The experimental results presented herein demonstrate the feasibility of creating biosilica nanostructures with controlled morphologies using polypeptides in vitro.
An AlN (insulator) MIS Hydrogen Sensor was created using plasma source molecular beam epitaxy (PSMBE) deposition on Si (111) and 6H-SiC. A Pd layer was deposited on top of the AlN film via magnetron sputtering technique utilizing a hard mask. Pd was chosen since H2 readily diffuses within its bulk, thus Pd acts not only as a metal electrode of the MIS structure, but also as a catalyst for hydrogen dissociation. To optimize the design structure several sensors with different AlN and Pd thickness have been developed. RHEED and XRD measurements show that AlN film is epitaxial on both Si (111) and 6H-SiC substrates. The sensors were characterized using capacitance versus voltage C(V) and I(V) measurements, at different frequencies ranging from 1kHz to 1 MHz. Shifts in the C-V and I-V curves occurred with the introduction of hydrogen in the chamber. The temperature, hydrogen partial pressure, effects of oxygen and hydrocarbon gases, insulator and metal thicknesses on sensor response were analyzed.
We have extended our previous investigation of the electrical characteristics of a Pd/AlN/Si thin film sensor for varying thicknesses of AlN, from 300–2000Å. The capacitance vs. voltage, C(V), and conductance vs. voltage, G(V), measurements were utilized to investigate the presence of surface states within the Si gap at the AlN/Si interface. Our previous experiments on 500Å AlN did show the presence of interface traps, with an estimated surface density between 8×1014 and 1.5×1015 m−2eV−1 . In our present work we've examined the effect of AlN thickness on the density of these interface traps. The density is dependent on AlN thickness. The thinner devices, 300Å, showed an interface trap density of 20–30×1015 m−2eV−1. The interface trap density decreased with increasing thickness up to 500Å, where the density remained relatively constant at about 1–5×1015 m−2eV−1 for thicknesses up to 2000Å. We have also shown that the interface trap density is independent of annealing.
Ferromagnetic resonance (FMR) measurements on Co films of thicknesses 10–100 Å grown on GaAs (110) and Au (111) substrates have been made as a function of dc magnetic field orientation in a plane perpendicular to the film. Experimental data were fitted by writing the energy density expression including uniaxial perpendicular anisotropy terms up to second order and bulk anisotropy terms. Co films grown on Au (111) substrates show consistently a higher uniaxial perpendicular anisotropy compared to those grown on GaAs (110) for the same thickness of Co. This is attributed to stress induced anisotropy due to a lattice mismatch between Au (111) and Co layers.
The precise pore sizes defined by crystalline zeolite lattices have led to intensive research on zeolite membranes. Unfortunately zeolites have proven to be extremely difficult to prepare in a defect-free thin film form needed for membrane flux and selectivity. We introduce tetrapropylammonium TPA (a structure directing agent for zeolite ZSM-5) into a silica sol and exploit the development of high solvation stresses to create templated amorphous silicas with pore apertures comparable in size to those of ZSM-5. 29Si and 2H NMR experiments were performed to evaluate the efficacy of our templating approach. The 29Si NMR spectrum of the silica matrix was observed by an intermolecular cross-polarization experiment between the 1H nuclei of TPA and the 29Si nuclei in the silica matrix. The efficiency of the cross-polarization interaction was used to investigate the degree to which the matrix formed a tight cage surrounding the template molecule. Bulk xerogels, prepared by gelation and slow drying of the corresponding sols, exhibited only weak interactions between the two sets of nuclei. Thin film xeorgels, where drying stresses are greater, resulted in significantly increased interactions. Analogous materials were prepared using fully deuterated TPA. The 2H NMR wideline spectra consisted of a partially narrowed resonance, corresponding to template molecules which were undergoing restricted rotational motion, and an isotropically narrowed resonance, corresponding to molecules which were undergoing rapid rotational motion. The number of isotropically rotating template molecules decreased for the thin film specimens, consistent with improved templating of amorphous silica by TPA.
An MIS Hydrogen sensor with a Pd0.96Cr0.04/AlN/Si structure was fabricated, exhibiting the dynamic range considerably wider than that of analogous devices with pure Pd gates. A useful response could be obtained for Hydrogen concentrations as large as 50, 000 ppm. Although the response amplitude was much reduced at the lower concentrations, satisfactory signal to noise down to 50 ppm could be obtained. The saturating magnitude of the electrical response is in the range of 0.1 to 0.5 V, which is the same as that for the pure Pd gated devices, inspite of the 3 orders of magnitude difference in the saturation hydrogen concentration. This result will be discussed in terms of the response mechanism of these devices.
Zn1−xCoxO (x = 0.0 – 0.047) thin films (thickness ∼0.5 – 1 μm) have been prepared on sapphire substrates using metalorganic decomposition (MOD) method. The X-ray diffraction and Raman scattering studies indicate films to be polycrystalline ZnO with wurtzite structure. The optical absorption spectra show an expected bandgap of ∼3.2 eV. The magnetization studies show that the as prepared films lack the room temperature ferromagnetic order, whereas the films when vacuum annealed at a temperature 500 – 600 °C acquire ferromagnetic ordering at room temperature. Further, the observed ferromagnetism (FM) appears only for a limited range of Co concentration, 0.03 < x < 0.10 (after heat treating in vacuum at 550 °C), and it reversibly disappears upon re-annealing in air. The data presented here seem to suggest that the appearance of ferromagnetic order is dictated by both the oxygen defects and the critical concentration of Co, and thus may lend support to a recent model proposed by Coey et al. [Nature Materials4, 173 (2005)].
The Raman spectra of low and highly degenerate InN films grown by conventional Molecular Beam Epitaxy (MBE) and Plasma Source Molecular Beam Epitaxy (PSMBE) have been studied using visible (514.5 nm) and near infrared (785 nm) excitation wavelengths. The MBE grown InN films have a low electron carrier concentration, ne < 2.0 × 1019 cm−3, exhibiting an optical bandgap absorption edge of 0.6 to 0.7 eV. On the other hand PSMBE grown InN samples are highly degenerate with ne > 3 × 1020 cm−3 with an observed optical bandgap ranging from 1.5 to 1.9 eV. Raman spectra of low degenerate InN films show sharp E2 and A1(LO) modes whereas spectra of highly degenerate InN films show rather broad features indicating the presence of a large number of structural defects. In the latter samples a resonance enhanced Raman scattering is observed especially with 785 nm excitation energy, where the excitation energy matches the optical energy bandgap. Another interesting observation is that the expected coupled plasmon LO-phonon modes are not detected in these films, rather a phonon mode is observed at the location of the unscreened A1(LO) mode. The observation of unscreened LO-phonon, and the absence of coupled plasmon LO-phonon modes have been attributed to Landau damping of the higher energy mode and coupling of the lower energy mode with the electron-hole pair excitations leading to the emergence of a mode very close to the A1(LO) mode.
The optical and electrical properties of InN films with different levels of carrier concentrations have been investigated. Hall effect measurements at room temperature show that the InN films are n-type with carrier concentration, ne, ranging from ∼ 7 ×1017 cm-3 to ∼ 3 × 1020 cm-3 and corresponding mobility, //, of ∼ 1300 to 50 cm2V-1S-1. Optical absorption spectra of these films show a bandgap absorption edge ∼ 0.6 eV for the InN sample with the lowest ne, and 1.5 eV for the InN sample with the highest ne. However, after corrections for the degeneracy effects, all samples show an intrinsic Eg ∼ (0.60 ± 0.05) eV. Temperature dependent (5 – 600 K) electrical measurements show that ne is nearly independent of temperature below 300 K, perhaps due to the presence of donor energy levels resonating with the InN conduction band. However, all the samples show an exponential increase in ne above 300 K due to excitation of other shallow donor like sources. Mobility versus temperature graph shows a maximum ∼ 200 K for InN film with ne = 7 × 1017 cm-3 and moves towards lower temperature with increasing ne.
Computational models for human decision making are typically based on the properties of bistable dynamical systems where each attractor represents a different decision. A limitation of these models is that they do not readily account for the fragilities of human decision making, such as “choking under pressure”, indecisiveness and the role of past experiences on current decision making. Here we examine the dynamics of a model of two interacting neural populations with mutual time–delayed inhibition. When the input to each population is sufficiently high, there is bistability and the dynamics is determined by the relationship of the initial function to the separatrix (the stable manifold of a saddle point) that separates the basins of attraction of two co–existing attractors. The consequences for decision making include long periods of indecisiveness in which trajectories are confined in the neighborhood of the separatrix and wrong decision making, particularly when the effects of past history and irrelevant information (“noise”) are included. Since the effects of delay, past history and noise on bistable dynamical systems are generic, we anticipate that similar phenomena will arise in the setting of other physical, chemical and neural time–delayed systems which exhibit bistability.