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We perform a critical assessment of the accuracy of density functional theory (DFT) basedmethods in predicting stable phases within the Co-Pt binary alloy. Statistical mechanical analysis applied to zero kelvin DFT predictions yields finite-temperature results that can be directly compared with experimental measurements. The predicted temperature-composition phase diagram is qualitatively incompatible with experimental observations, indicating that the predicted stability of long-period superstructures as ground states in the Co-Pt binary is incorrect. We also show that recently suggested methods to better align DFT and experiment via the hybrid functional HSE06 are unable to resolve the discrepancies in this system. Our results indicate a need for better verification of DFT based phase stability predictions, and highlight fundamental flaws in the ability of DFT to treat late 3d-5d binary alloys. [ABSTRACT FROM AUTHOR]

Most gas-surface chemical reactions occur via reaction of adsorbed species to form a thermal- energy (∼kT) product; however, some instances exist where an energetic projectile directly reacts with an adsorbate in a single-collision event to form a hyperthermal product (with a kinetic energy of a few eV). Here we show for the first time that 30-300 eV F+ bombardment of fluorinated Ag and Si surfaces produces "ultrafast" F2 products with exit energies of up to 90 eV via a multistep direct-reaction mechanism. Experiments conclusively show that the projectile F atom ends up in the fast molecular product despite the fact that the impact energy is far greater than typical bond energies. [ABSTRACT FROM AUTHOR]

Reflectin is a cationic, block copolymeric protein that mediates the dynamic fine-tuning of color and brightness of light reflected from nanostructured Bragg reflectors in iridocyte skin cells of squids. In vivo, the neuronally activated phosphorylation of reflectin triggers its assembly, driving osmotic dehydration of the membrane-bounded Bragg lamellae containing the protein to simultaneously shrink the lamellar thickness and spacing while increasing their refractive index contrast, thus tuning the wavelength and increasing the brightness of reflectance. In vitro, we show that the reduction in repulsive net charge of the purified, recombinant reflectin—either (for the first time) by generalized anionic screening with salt or by pH titration—drives a finely tuned, precisely calibrated increase in the size of the resulting multimeric assemblies. The calculated effects of phosphorylation in vivo are consistent with these effects observed in vitro. The precise proportionality between the assembly size and charge neutralization is enabled by the demonstrated rapid dynamic arrest of multimer growth by a continual, equilibrium tuning of the balance between the protein's Coulombic repulsion and short-range interactive forces. The resulting stability of reflectin assemblies with time ensures a reciprocally precise control of the particle number concentration, encoding a precise calibration between the extent of neuronal signaling, osmotic pressure, and the resulting optical changes. The charge regulation of reflectin assembly precisely fine-tunes a colligative property-based nanostructured biological machine. A physical mechanism is proposed. [ABSTRACT FROM AUTHOR]

Capillary force assembly (CFA) of colloidal particles usually results in closed-packed films or particle aggregation within topographic features. In this work, it is shown that CFA can also be exploited to both localize and separate nanoparticles (d=50–200 nm) when template shape and wettability are controlled. Well-defined geometric arrangements of one to four closely spaced particles (30–50 nm separation) were realized in large arrays using this technique to demonstrate that particle aggregation during dewetting can be eliminated. Ordered SiO2 nanopillars in tight groupings were obtained by combining low-resolution e-beam lithography (>100 nm) with CFA and etching. This approach provides a simple route to fast and precise placement of nanostructures using relatively low-resolution pattern making techniques. [ABSTRACT FROM AUTHOR]

Resonant excitation of gap mode plasmons between an optical antenna tip and a thin metal film was studied over different tip-surface distance regimes using simultaneous detection of surface reflectance via attenuated total reflection, elastic (Rayleigh) scattering by the antenna tip, and Raman scattering from analytes in the tip-surface gap region. Finite difference time domain optical simulations were used to elucidate the primary mechanisms that influence the optical behavior of this gap plasmonic mode, and spectroscopic measurements were used to demonstrate the effect of the gap mode on the enhancement of Raman and fluorescence signals. In particular, the presence of a gap mode, and the spectral overlap of its resonance with Raman emissions at specific tip-surface distances, can contribute to significant enhancements in Raman scattering signals. [ABSTRACT FROM AUTHOR]

Suspensions of cerium(IV) oxide (CeO2) particles in molten chloride salts were found to be active for molecular oxygen activation when doped with the larger Lanthanides, gadolinium (Gd), praseodymium, (Pr), and samarium, (Sm). The activity for O2 oxidation of gas phase CO on suspended doped ceria in molten mixtures of LiCl–LiBr–KBr and NaCl–KCl is significantly higher than undoped ceria or the salt mixtures alone in the temperature ranges of 350–600 °C, and 700–800 °C, respectively. Surface tension measurements show that the solid doped ceria particles suspended in the melt are contacting the gas–liquid interface of the bubbles. The activity for O2 oxidation of liquid phase MgCl2 in molten MgCl2–KCl to produce Cl2 and solid MgO was also observed to be significantly increased on suspended CeO2 doped with 5 wt% or 10 wt% Gd. The rates of oxidation were observed to increase with catalyst loading. [ABSTRACT FROM AUTHOR]

Comments on the need for self-assessment skills in preparing medical students to be self-regulating physicians. Impact of attitudes and skills to medical education reforms; Self-assessment program steps; Significance of legitimate autonomy in medical practice; Relevance of self-assessment skills to the professional development of students.

Tau protein's reversible assembly and binding of microtubules in brain neurons are regulated by charge-neutralizing phosphorylation, while its hyperphosphorylation drives the irreversible formation of cytotoxic filaments associated with neurodegenerative diseases. However, the structural changes that facilitate these diverse functions are unclear. Here, we analyzed K18, a core peptide of tau, using newly developed spectroelectrochemical instrumentation that enables electroreduction as a surrogate for charge neutralization by phosphorylation, with simultaneous, real-time quantitative analyses of the resulting conformational transitions and assembly. We observed a tipping point between behaviors that paralleled the transition between tau's physiologically required, reversible folding and assembly and the irreversibility of assemblies. The resulting rapidly electroassembled structures represent the first fibrillar tangles of K18 that have been formed in vitro at room temperature without using heparin or other chargecomplementary anionic partners. These methods make it possible to (i) trigger and analyze in real time the early stages of conformational transitions and assembly without the need for preformed seeds, heterogenous coacervation, or crowding; (ii) kinetically resolve and potentially isolate never-before-seen early intermediates in these processes; and (iii) develop assays for additional factors and mechanisms that can direct the trajectory of assembly from physiologically benign and reversible to potentially pathological and irreversible structures. We anticipate wide applicability of these methods to other amyloidogenic systems and beyond. [ABSTRACT FROM AUTHOR]

In this work, immobilization of the often unwanted filaments in dielectric barrier discharges (DBD) is achieved and used for one‐step deposition of patterned coatings. By texturing one of the dielectric surfaces, a discharge containing stationary plasma filaments is ignited in a mix of argon and propargyl methacrylate (PMA) in a reactor operating at atmospheric pressure. From PMA, hydrophobic and hydrophilic chemical and topographical contrasts at sub‐millimeter scale are obtained on silicon and glass substrates. Chemical and physical characterizations of the samples are performed by micrometer‐scale X‐ray photoelectron spectroscopy and infrared imaging and by water contact angle and profilometry, respectively. From the latter and additional information from high‐speed imaging of the plasma phase and electrical measurements, it is suggested that filaments, denser in energetic species, lead to higher deposition rate with higher fragmentation of the precursor, while surface discharges igniting outwards the filaments are leading to smoother and slower deposition. This work opens a new route for a one‐step large‐area chemical and morphological patterning of surfaces at sub‐millimeter scales. Moreover, the possibility to separately deposit coatings from filaments and the surrounding plasma phase can be helpful to better understand the processes occurring during plasma polymerization in filamentary DBD. [ABSTRACT FROM AUTHOR]

We present efficient red InGaN 60 × 60 μm2 micro-light-emitting diodes (μLEDs) with an epitaxial tunnel junction (TJ) contact. The TJ was grown by metal-organic chemical vapor deposition using selective area growth. The red TJ μLEDs show a uniform electroluminescence. At a low current density of 1 A/cm2, the emission peak wavelength is 623 nm with a full-width half maximum of 47 nm. The peak external quantum efficiency (EQE) measured in an integrating sphere is as high as 4.5%. These results suggest a significant progress in exploring high efficiency InGaN red μLEDs using TJ technology. [ABSTRACT FROM AUTHOR]

Red micro-size light-emitting diodes (μLEDs) less than 10 × 10 μm2 are crucial for augmented reality (AR) and virtual reality (VR) applications. However, they remain very challenging since the common AlInGaP red μLEDs with such small size suffer from a dramatic reduction in the external quantum efficiency. In this work, we demonstrate ultra-small 5 × 5 μm2 607 nm amber μLEDs using InGaN materials, which show an EQE over 2% and an ultra-low reverse current of 10−9 A at −5 V. This demonstration suggests promising results of ultra-small InGaN μLEDs for AR and VR displays. [ABSTRACT FROM AUTHOR]

In this study, two methods to tune the emission wavelength of micro-LEDs fabricated on tile patterned compliant GaN-on-porous-GaN pseudo-substrates (PSs) are presented. The mechanical flexibility of porous GaN was utilized to relax the strain induced during the growth of light-emitting diode (LED) structures with n- and p-InGaN layers and enhance the indium incorporation via the composition pulling effect. The first approach involved only varying the size of the PS square tiles used for LED structure regrowth, from 20 × 20 μm2 to 8 × 8 μm2. Higher n-InGaN base layer relaxation with decreasing tile size resulted in a red shift of emission from 525 nm to 561 nm with no change in the growth conditions. The second method involved changing the mole fraction, x, of the n-InxGa1−xN base layer of the LED structure from 0.04 to 0.09 by reducing growth temperature, while maintaining the high temperature growth conditions of the multi-quantum well (MQW) and p-InGaN targeting 530 nm emission. The resulting wavelength shift was a remarkable 536–616 nm due to the stronger composition pulling effect, providing a pathway to enable high indium content MQW active regions to be grown at high temperature. [ABSTRACT FROM AUTHOR]

Light emitting diodes (LEDs), with active blue and green emitting and sacrificial multi-quantum well layers, were epitaxially grown using metal organic chemical vapor deposition on free-standing semipolar (20 2 ¯ 1) GaN substrates. NanoLEDs were then fabricated and released into solution using an approach based on forming a mm-scale mesa, Au–Au thermocompression bonding to a submount, large-area photoelectrochemical etching, and colloidal lithography. Photo- and cathodoluminescence (CL) measurements demonstrated that nanoLEDs were optically active after fabrication and released into the solution. Monte Carlo simulations of the electron trajectory through GaN/InGaN were performed to understand the patterns shown in CL images. The fabrication process developed herein could provide a viable route to highly efficient, nanoscale blue and green light emitters for applications in next-generation display technologies. [ABSTRACT FROM AUTHOR]

Chemical etching and Al2O3 dielectric passivation were used to minimize nonradiative sidewall defects in InGaN/GaN microLEDs (mesa diameter = 2–100 μm), resulting in an increase in external quantum efficiency (EQE) as the LED size was decreased. Peak EQEs increased from 8%–10% to 12%–13.5% for mesa diameters from 100 μm to 2 μm, respectively, and no measurable leakage currents were seen in current density–voltage (J–V) characteristics. The position and shape of EQE curves for all devices were essentially identical, indicating size-independent ABC model (Shockley–Read–Hall, radiative, and Auger recombination) coefficients-behavior that is not typical of microLEDs as the size decreases. These trends can be explained by enhancement in light extraction efficiency (LEE), which is only observable when sidewall defects are minimized, for the smallest LED sizes. Detailed ray-tracing simulations substantiate the LEE enhancements. [ABSTRACT FROM AUTHOR]

There is growing interest in microLED devices with lateral dimensions between 1 and 10 μm. However, reductions in external quantum efficiency (EQE) due to increased nonradiative recombination at the surface become an issue at these sizes. Previous attempts to study size-dependent EQE trends have been limited to dimensions above 5 μm, partly due to fabrication challenges. Here, we present size-dependent EQE data for InGaN microLEDs down to 1 μm in diameter fabricated using a process that only utilizes standard semiconductor processing techniques (i.e., lithography and etching). Furthermore, differences in EQE trends for blue and green InGaN microLEDs are compared. Green wavelength devices prove to be less susceptible to reductions in efficiency with the decreasing size; consequently, green devices attain higher EQEs than blue devices below 10 μm despite lower internal quantum efficiencies in the bulk material. This is explained by smaller surface recombination velocities with the increasing indium content due to enhanced carrier localization. [ABSTRACT FROM AUTHOR]

The statistics of electrical breakdown field (Ebd) of HfO2 and SiO2 thin films has been evaluated over multiple length scales using macroscopic testing of standardized metal-oxide-semiconductor (TiN/SiO2/Si) and metal-insulator-metal (TiN/HfO2/TiN) capacitors (10-2 mm2–10 μm2 area) on a full 200 mm wafer along with conductive-atomic-force microscopy. It is shown that Ebd follows the same Weibull distribution when the data are scaled using the testing area. This overall scaling suggests that the defect density is ∼1015 cm-2 and Ebd is ∼40 MV/cm for nanometer-length scales; as such, breakdown in these materials is most likely initiated by bond breaking rather than punctual defects. [ABSTRACT FROM AUTHOR]

We study methane pyrolysis in a bubble column reactor consisting of a layer of molten NiBi alloy, and a molten salt layer floating on the metal layer. The molten metal is a pyrolysis catalyst; the molten salt layer is added for removing contaminants from the carbon product. Methane is introduced at the bottom of the reactor and the rising bubbles contain reactant and product gases together with metal vapor and flakes of solid carbon. When the bubbles rise through the molten salt layer the metal vapor condenses producing dense liquid metal droplets, which sink to the metal phase; the low-density carbon rises to the top of the salt layer. The carbon generated from the single-phase molten NiBi reactor has a different structure from that produced in the two-phase NiBi/salt reactor. The amount of metal in the carbon product is less than 5 wt %, in the two-phase reactor, compared to 83 wt % in the NiBi single-phase reactor. After subsequent purification steps one obtains solid carbon with less than 2 wt % salt contamination and no detectable metal contamination. Image 1 [ABSTRACT FROM AUTHOR]

• Propane oxidative dehydrogenation and methane halogenation are studied. • Selectivity to propylene of 83% at 71% propane conversion is reported. • Experiments show mixtures of I 2 and Br 2 yield more propylene than either halogen alone. • Kinetic modeling indicates iodine catalyzed bromine dissociation. The oxidative dehydrogenation of propane to propylene can be enhanced through the addition of a halogen to a feed of oxygen and propane. In this paper, we examine halogen-assisted oxidative dehydrogenation by a mixture of I 2 and Br 2. We find that adding a small amount of Br 2 to a feed of I 2 , C 3 H 8 , and O 2 produces propylene with 71% propane conversion and 83% propylene selectivity. Good performance is also obtained if a small amount of I 2 is added to a feed of Br 2 , C 3 H 8 , and O 2. In both cases, the propylene yield is greater than the sum of the yields obtained with iodine and bromine separately. A variety of studies were performed to help understand the reaction mechanism. Methane halogenation was also investigated by using combinations of iodine and bromine to produce methyl iodide, and a microkinetic model was also constructed for methane halogenation in the gas-phase to help understand the mechanism. [ABSTRACT FROM AUTHOR]

[Display omitted] • DASA exhibits ternary photoswitching in solution but binary in polymer blends. • Phase locked UV–Vis detection utilized to track photochemical intermediates. • Polymeric hosts slow photoisomerization without affecting stability. • Stabilizing ternary states of DASA in polymers requires improved quantum efficiency. Molecular photoswitches provide a means for imparting synthetic structures with intrinsically logical and highly tunable photoresponsive properties. One variety of organic photoswitches known as Donor-Acceptor Stenhouse Adducts, or DASAs, are promising candidates for next generation light responsive materials because of their unique ability to stabilize three photochemically distinct isomeric states in solution, while their counterparts are strictly limited to binary state behavior. In this work, we show how polymethacrylate host matrices shift the energetic landscape of DASA relative to solution, prohibiting accumulation of an intermediate third isomeric state by decelerating critical steps in the photoswitching mechanism. Specifically, we employ a dual-wavelength, phase locked detection scheme to probe thermal isomerizations in the switching process that occur at fast (∼ms) time scales that are inaccessible by standard UV–Vis spectroscopic techniques. The results of this study provide valuable insight into the mechanism of multistate DASA reactivity and establish the foundation necessary to guide future efforts in offsetting kinetic matrix effects to enable dynamic, three state photoswitching in polymeric hosts. [ABSTRACT FROM AUTHOR]

A molten salt mixture containing 45 mol % KCl and 55 mol % CuCl2 was investigated as a catalyst for the reaction of HCl with O2 to produce Cl2. The HCl conversion for an HCl:O2 molar feed ratio of 1:2 at 450 °C and a total pressure of 1 atm was 80% at a residence time of less than 1 s in a lab scale bubble column reactor. The equilibrium conversion at this temperature and pressure is 84%. The catalyst system was found to remain stable throughout a continuous 24-h experiment. The use of a mixed transition metal/alkali metal molten salt catalyst for HCl oxidation reduces the volatility of supported chlorides and may avoid the mechanical stability limitations of solid catalysts caused by volume changes between the halide and the oxide. [ABSTRACT FROM AUTHOR]

Metals that are active catalysts for methane (Ni, Pt, Pd), when dissolved in inactive low–melting temperature metals (In, Ga, Sn, Pb), produce stable molten metal alloy catalysts for pyrolysis of methane into hydrogen and carbon. All solid catalysts previously used for this reaction have been deactivated by carbon deposition. In the molten alloy system, the insoluble carbon floats to the surface where it can be skimmed off. A 27% Ni–73% Bi alloy achieved 95% methane conversion at 1065°C in a 1.1-meter bubble column and produced pure hydrogen without CO2 or other by-products. Calculations show that the active metals in the molten alloys are atomically dispersed and negatively charged. There is a correlation between the amount of charge on the atoms and their catalytic activity. [ABSTRACT FROM AUTHOR]

Hydrogen bromide (HBr) oxidation to molecular bromine (Br 2 ) is demonstrated in a chemical looping process using a molten bromide salt. The two-step process is operated at 500 °C and first contacts oxygen with molten KBr-LiBr-NiBr 2 to form Br 2 gas and a suspension of nickel oxide (NiO) particles in one reactor. The oxide suspension is then contacted with HBr to regenerate the bromide salt and produce steam. Sixty-eight metal oxides/bromides were considered. The cyclic interconversion between oxide and bromide, by alternating exposure to HBr and oxygen, at a single temperature was only possible with nickel. In contrast to solid-based chemical looping systems, the liquid bromide salt (NiBr 2 dissolved in KBr-LiBr eutectic) was found to be cycleable without attrition or deactivation. Further, when mixtures of olefins and hydrogen bromide were reacted with the oxide suspension, selective oxidation of HBr was observed without hydrocarbon oxidation. High selectivity for HBr oxidation is due to the solubility of HBr in the molten salt, which allows contact with NiO, whereas, the insoluble hydrocarbons do not contact the reactive oxide. A process model that makes use of reactive separation of HBr from hydrocarbons and process intensification using molten salt-based chemical looping is presented as a potentially lower cost alternative to a process model using conventional separations in bromine-based methane conversion. The total heat exchanged in a corrosive environment in the molten salt based process is 205 MW, and the heat exchanged in a corrosive environment in the conventional process is 581 MW. [ABSTRACT FROM AUTHOR]

Magnetic exchange bias and coercivity of nanogranular NiFe 2 O 4 /NiO thin films, prepared using flow-stabilized microplasmas and post-deposition annealing, have been investigated as a function of ferrimagnet/antiferromagnet phase fraction, grain size, and temperature. Exchange bias (EB) and vertical shifts in hysteresis loops observed in the as-deposited and low-T annealed (≤600 °C) films were attributed to exchange coupling between nanocrystalline NiFe 2 O 4 (~8–10 nm) and a structurally-disordered spin glass (SG)-like phase. At higher annealing temperature (850 °C), the observed EB was found to arise from exchange coupling between NiFe 2 O 4 and NiO, rather than a SG phase, most likely due to reduction of structurally-disordered interfaces and a substantial increase in NiFe 2 O 4 grain size (~26 nm). [ABSTRACT FROM AUTHOR]

A general, substrate-independent method for plasma deposition of nanostructured, crystalline metal oxides is presented. The technique uses a flow-through, micro-hollow cathode plasma discharge (supersonic microplasma jet) with a "remote" ring anode to deliver a highly directed flux of growth species to the substrate. A diverse range of nanostructured materials (e.g., CuO, α-Fe2O3, and NiO) can be deposited on any room temperature surface, e.g., conductors, insulators, plastics, fibers, and patterned surfaces, in a conformal fashion. The effects of deposition conditions, substrate type, and patterning on film morphology, nanostructure, and surface coverage are highlighted. The synthesis approach presented herein provides a general and tunable method to deposit a variety of functional and hierarchical metal oxide materials on many different surfaces. High surface area, conversiontype CuO electrodes for Li-ion batteries are demonstrated as a proof-of-concept example. [ABSTRACT FROM AUTHOR]

Biphasic,nanostructured NiFe2O4/NiO filmsexhibiting exchange bias were synthesized using high-pressure microplasma-baseddeposition. Organometallic Ni and Fe precursors were dissociated viaelectron impact in the hollow cathode region of a supersonic plasmajet with oxygen to form a directed flux of Ni and Fe oxide speciesthat were subsequently spray-deposited on SiO2/Si substratesto form nanostructured thin films. Exchange bias (HE) and coercivity (HC) enhancementwere observed for all films containing NiO after field cooling, indicatingan exchange interaction between NiFe2O4andNiO. HEand HCincreased with NiO content, which may be explained by a concomitantincrease in NiFe2O4/NiO interfacial density.Large HE(∼250 Oe) and HC(∼700 Oe) were measured at 20 K, andexchange bias persisted at high temperatures (305 K) where an HEand HCof 80 and400 Oe were observed, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrochemistry triggered α-helix formation of polylysine. • In situ CD spectroscopy was used to follow structural evolution of polypeptides. • Experiments in D 2 O confirm direct electroreduction of ε-NH 3 +/ND 3 + at a Pt surface. • Direct electroreduction of lysine sidechains can trigger α-helix formation. Reversible electrochemical triggering of the random coil to α-helix conformational transition of polylysine (Lys 10 , Lys 20 , Lys 50) was accomplished at a Pt electrode at potentials < |1| V vs. Ag/AgCl. Direct electroreduction of the N-terminus vs ε-amino groups in Lys sidechains, as well as hydronium reduction and electrolysis, could be easily distinguished and deconvolved using differential pulse voltammetry. Electrochemistry was coupled with in situ UV absorbance and circular dichroism spectroscopies to dynamically follow the evolution of α-helix formation at different potentials. Isotope experiments in H 2 O vs. D 2 O unequivocally confirm that direct electroreduction of ε-NH 3 +/ND 3 + groups in Lys sidechains, rather than electrochemically generated pH gradient-induced deprotonation, leads to subsequent α-helix formation. The site-selective electrochemistry and optical methodologies presented herein can be generalized and extended to interrogate other protonation-sensitive biomolecular systems, and potentially provide access to early intermediates and control over the dynamic structural evolution of peptides and proteins. [ABSTRACT FROM AUTHOR]

AbstractBackground:Therapeutic lung lavage is an emerging treatment for meconium aspiration syndrome (MAS), but the ideal fluid volume and lavage technique remain unclear. Objective:To evaluate the impact of suction technique, chest squeeze and aliquot volume on the efficacy of lung lavage in MAS. Methods:MAS was induced in ventilated 2-week-old piglets using 4 ml/kg of 20 human meconium. Lung lavage with either two 8 ml/kg saline aliquots (n = 5) or a single 15 ml/kg aliquot (n = 6) was performed soon after meconium instillation. Lavage fluid was recovered by three methods performed in sequence: closed suction via a suction adaptor; open suction with the ventilator disconnected, and open suction with manual vibratory chest squeezing. Return fluid was collected separately with each method. Recovery of meconium and lavage fluid was determined and expressed as a proportion of the amount instilled. Results:Closed suction resulted in poor meconium and fluid returns, with recovery of meconium being only 5.2 ± (SD) 2.5 with 2 × 8 ml/kg lavage and 19 ± 11 with a single 15 ml/kg aliquot. Chest squeeze during suction increased recovery of both meconium and lavage fluid. Overall recovery of instilled meconium was greater with 15 ml/kg lavage (45 ± 17) than with two 8 ml/kg aliquots (24 ± 4.5, p = 0.028, repeated-measures ANOVA); the corresponding values for return of lavage fluid were 73 ± 10 and 49 ± 13, respectively (p < 0.01). Conclusions:Open suction, vibratory chest squeezing and an aliquot volume of 15 ml/kg each improve the efficacy of lung lavage in MAS, and merit inclusion in the lavage technique in clinical trials of this therapy.Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Objective: To compare the effectiveness of open and closed endotracheal suction in recovering thin and thick secretions in normal and injured lungs during conventional and high frequency ventilation.Design and Setting: Randomised study in a paediatric intensive care model in the animal research laboratory of a tertiary paediatric hospital.Subjects: 16 New Zealand White rabbits.Interventions: Anaesthetised animals were intubated with a 3.5-mm endotracheal tube. Simulated thin and thick secretions (iopamidol 2 ml, a watery radio-opaque fluid, and fluorescent mucin 1 ml) were instilled in turn 1 cm below the tube tip through a catheter placed via a tracheostomy. Open or closed suction, randomly assigned, was applied for 6s at -140 mmHg using a 6-F gauge catheter. Following lung injury with repeated saline lavage the procedure was repeated on conventional and high frequency ventilation.Measurements and Results: Iopamidol recovery was determined by digitally subtracting the post-contrast and post-suction radiographic images. Mucin recovery was determined by fluorescence assay of the aspirate. In the normal lung similar amounts were recovered by both suction methods. In the lavaged lung closed suction recovered less iopamidol during conventional (22 +/- 7.5%) and high frequency ventilation (11 +/- 2.4%) than open suction (36 +/- 2% and 22 +/- 8.1%, respectively). Mucin recovery was less with closed suction during conventional 32 +/- 28 microl) and high frequency ventilation (30 +/- 31 microl) than with open suction (382 +/- 235 microl and 24 +/- 153 microl).Conclusions: In the injured lung closed suction was less effective than open suction at recovering thin and thick simulated secretions, irrespective of ventilation mode. [ABSTRACT FROM AUTHOR]

Vertically aligned metal oxide nanostructures (e.g., wires, needles, pillars and trees) of CuO, PdO and NiO were synthesized on several substrates (e.g., Si and ITO (indium tin oxide)) using a high-pressure (∼Torr) microplasma-based growth technique. Organometallic precursors were dissociated in the hollow cathode region of a supersonic plasma jet creating a directed flux of metal species (e.g., atoms, metastables, etc) which react with an oxygen background to form crystalline metal oxide films having a variety of nanomorphologies. Spiral-like growth fronts were seen in some cases for CuO, suggesting that nanowire growth may involve screw dislocations. Large area, nanowire films >1 cm2 with good adhesion and electrical connection to ITO substrates were deposited by raster-scanning a single jet. Details of the microplasma operation, the dynamics of the growth process and the resulting materials are discussed. [ABSTRACT FROM AUTHOR]

Examines the operational failure of the 60 T long pulse superconducting magnet. Toughness of the magnet; Sigma phase conversion in the microstructure of the magnet; Finite element stress analysis.