Search

Total laryngectomy and end tracheal stoma formation are often required to treat advanced laryngeal cancer. Resources on the internet are commonly accessed by patients as a source of healthcare information. YouTube™, the most popular video-hosting website, is one such resource. The aims of this study were to assess the thematic content of the most viewed YouTube™ videos concerning laryngectomy for laryngeal cancer and to evaluate user response to these videos. A search of YouTube™ was performed and data were extracted from videos with > 100 views. Upload source, number of views, likes, dislikes and comments were collected and the content of comments was analysed. User response was compared between upload sources using Kruskal–Wallis testing. Inductive thematic analysis of video content was performed to identify overarching themes and subthemes. A total of 96 videos were identified, 16 uploaded by patients, 24 by individual healthcare professionals and 56 by professional healthcare institutions. There were 1214,503 views and no significant differences in the number of views, likes or dislikes between upload sources. Three overarching themes and 17 subthemes were identified. Comments were most frequently characterised as offering praise. YouTube™ has been shown to be a popular platform for sharing information about laryngectomy for laryngeal cancer. There is a lack of data concerning the quality of this information, however, and future work should focus on assessing this. Trusted institutions could make use of this medium to disseminate high-quality information to their patients, and to the wider public.

Thin-film multilayer structures with up to 20 repeat layers have been grown in a high-vacuum chamber by sequential deposition of aluminum (Al) and fullerene (${\mathrm{C}}_{60}$) onto room-temperature substrates. The periodicity of the layers is confirmed by x-ray-diffraction and in situ resistance measurements. The presence of underlying layers of ${\mathrm{C}}_{60}$ reduces the critical thickness at which Al becomes conducting from \ensuremath{\sim}35 to \ensuremath{\sim}20 \AA{}. In addition, there is a sudden increase in resistance that occurs when each Al layer is covered by a monolayer of ${\mathrm{C}}_{60}$. These observations, together with the measurement of a downward shift in frequency of a considerably broadened Raman-active ${\mathit{A}}_{\mathit{g}}$(2) pentagonal-pinch mode, imply that up to six electrons per ${\mathrm{C}}_{60}$ are transferred from the Al to the ${\mathrm{C}}_{60}$ layer. This demonstration of charge transfer across planar metal-${\mathrm{C}}_{60}$ interfaces suggests that multilayers may be a useful vehicle for forming fullerene interface compounds in two-dimensional structures.

Systematic studies have been performed on 1000 Å YBa2Cu3O7−δ films produced by the BaF2 process and annealed in an oxygen partial pressure (Po2) range from 740 Torr to 10 mTorr as well as a temperature range from 600 to 1050 °C. The results show that while high quality films can be annealed in a wide range of oxygen partial pressure, they have different characteristics. In general, crystalline quality and Tc are optimized at high Po2 and high annealing temperature, while strong flux pinning and low normal state resistivity are achieved at lower values of both variables. Under optimized low Po2 conditions, an ion channeling Xmin of 6% is obtained on films as thick as 5000 Å. This study will serve as a useful guide to tailoring film properties to the application at hand.

Single-crystal epitaxial thin films of the isotropic metallic oxides Sr1–xCaxRuO3 (0 ≤ x ≤ 1) were grown on miscut SrTiO3(100) substrates in situ by 90° off-axis sputtering. These thin films exhibit low isotropic resistivities, excellent chemical and thermal stability, good surface smoothness, and high crystalline quality. Furthermore, the lattice parameters and magnetic properties can be varied by simply changing the strontium/calcium ratio. These epitaxial thin films, and their multilayer structures with other oxide materials, can be used for the fabrication of superconducting, ferroelectric, magneto-optic, and electro-optic devices.

Epitaxial films of Ba2YCu3O7−δ (BYCO), as thin as 250 Å and with Jc's approaching those for the best in situ grown films, can be formed by coevaporating BaF2, Y, and Cu followed by a two-stage anneal. These results extend the work of R. Feenstra et al. [J. Appl. Phys. 69, 6569 (1991)] for film thicknesses >2000 Å. This involves using low oxygen partial pressure [p(O2) = 4.3 Torr] during the high temperature portion of the anneal, which we vary from Ta = 600 to 950 °C. The BYCO melt line is seen to be the upper limit for Ta. The use of lower p(O2) shifts the window for stable BYCO film growth to lower temperature. The lower growth temperature required for the low p(O2) process allows the formation of smooth films with greater microstructural disorder than for films grown in p(O2) = 740 Torr at higher Ta, resulting in higher Jc values by a factor of four. The relationship between the Ta required to grow films with the strongest pinning force and p(O2) is log [p(O2)] ∝ Ta−1, independent of growth method (in situ or ex situ) over a range of five orders of magnitude in p(O2).

The correlations between structural quality and superconducting behavior in 1000‐A‐thick Ba2YCu3O7−δ (BYCO) films grown on LaAlO3(100) from the coevaporation of BaF2, Y, and Cu, followed by an optimized ex situ annealing process are reported. Epitaxial films with smooth, laminar morphology and excellent crystallinity can be grown to have critical current density Jc values nearly identical to single crystals. This finding contrasts with the typical observation that Jc values in thin films of BYCO are very high compared to those of single crystals. This is attributed to a greater density of flux pinning sites due to structural defects within the films. The most crystalline films presented here have penetration length λ∼2000 A with temperature dependencies described well by the Bardeen–Cooper–Schrieffer (BCS) theory. Material disorder of two types can be controlled by the high‐temperature stage Ta of the annealing process. The first type is point defects and dislocations the same size or smaller than the coh...

The superconducting and structural properties of Ba2YCu3O7−x (BYCO) films on LaAlO3(100) substrates can be improved by carefully optimizing the post‐deposition annealing parameters. Films are grown by co‐deposition of BaF2, Y, and Cu in the correct stoichiometric ratio to within 1% of 2:1:3. Annealing parameters in an ex situ furnace, including the ambient, annealing temperature, oxidation temperature, and duration of anneals are systematically studied. Films are characterized for epitaxial quality (χmin), morphology, critical temperature (Tc), sharpness of the superconducting transition (ΔT), and critical current density (Jc). For example, beyond simply dissociating BaF2, the use of wet O2 appears to prevent the agglomeration of oxides during the initial heating process, and then act to thermodynamically stabilize the basic BYCO film structure at high temperatures after being formed. Comparisons are made with the best single‐crystal BYCO structural and electrical data available. The optimized films have ...

Stoichiometric deviations of up to ±5% in Ba2YCu3O7−δ, thin films grown by coevaporation on LaAlO3(100) substrates are found to cause (1) a decrease of the critical current density (Jc) of up to an order of magnitude, (2) a depression of the critical temperature (Tc) and a broadening of the superconducting transition width (ΔT), (3) a deterioration of the surface morphology, and (4) a decrease in the crystallinity of the films. The data indicate that composition deviations of greater than ±1% result in degradation of film quality. These findings have significant implications for the degree of composition control required during deposition to produce films with optimized properties.

We report the ex situ growth of 1000 and 2000 A epitaxial Ba2YCu3O7−x (BYCO) filmsonLaAlO3 (001 with surface morphologies and crystallinity generally associated with high quality in situ films. Films are grown by co-depositing BaF2, Y and Cu in a stoichiometric ratio within 1% of 2:1:3, followed by annealing in a two-stage process in a tube furnace. By optimizing the annealing conditions, excellent crystallinity is obtained, with χmin∼ 2–4] from Rutherford backscattering/channeling. These films have sharp superconducting resistance transitions at 90–91 K. Critical current densities at 77 K are ∼ 106 A/cm2 in zero magnetic field and ⪅ 105 A/cm2 in H =0.9 T oriented perpendicular to the ab plane of the films.

We report the fabrication and characterization of zinc‐indium‐oxide films with similar electrical conductivity and better transparency in both the visible and infrared compared with indium–tin–oxide, a widely used transparent conductor in many technological applications. Dramatically superior transmission properties in the 1–1.5 μm range in particular make zinc–indium–oxide attractive for use in infrared devices, where transparent electrodes are required. Resisitivities as low as 400 μΩ cm result from doping with small quantities of Sn; Al, Ga, and Ge are also effective dopants. Deposition on glass and quartz substrates as amorphous films by pulsed laser deposition and dc reactive sputtering is described.

GaInO3 is recently identified transparent conducting material which is structurally and chemically distinct from indium tin oxide [R. J. Cava, J. M. Phillips, J. Kwo, G. A. Thomas, R. B. van Dover, S. A. Carter, J. J. Krajewski, W. F. Peck, Jr., J. H. Marshall, and D. H. Rapkine, Appl. Phys. Lett. 64, 2071 (1994)]. We have used both dc reactive sputtering in the on‐ and off‐axis geometries and pulsed laser deposition to grow films of this material. Layers of pure GaInO3 as well as those partially substituted with Ge for Ga or Sn for In have been studied. Both growth techniques are capable of producing films with conductivity ∼400 (Ω cm)−1 and transmission as high as 90% throughout the visible spectrum for ∼1‐μm‐thick films. The growth techniques differ in the morphology of the films produced as well as in the degree of dopant incorporation that can be achieved. A post‐growth anneal in H2 can help produce an optimized oxygen content and a reduction of resistivity. Hall measurements indicate a carrier conce...

Epitaxial ferroelectric SrRuO3/Pb(Zr0.52Ti0.48)O3/SrRuO3 heterostructures have been fabricated employing isotropic metallic oxide electrodes on (100) SrTiO3 and (100) Si with an yttria stabilized zirconia buffer layer. The structures have been grown in situ by 90° off‐axis sputtering, which allows the growth of uniform stoichiometric films over large areas with excellent step coverage. X‐ray diffraction, Rutherford backscattering spectroscopy, and cross‐sectional transmission electron microscopy reveal high crystalline quality and coherent interfaces. They exhibit superior fatigue characteristics over those made with metal electrodes, showing little degradation over 1010 cycles, with a large remnant polarization.

We have studied the precipitates in YBa2Cu3O7−δ(YBCO) thin films grown by the BaF2 process in pO2=4 Torr and 700 °C. While stoichiometric films result in BaCuO2 surface precipitates, we have found Y2Cu2O5 precipitates embedded in the matrix of the same film. Off stoichiometric films with Ba/Y

Epitaxial Ba2YCu3O7−δ (BYCO) films grown by the ex situ BaF2 process are comparable to single crystals both in crystalline quality and the value and temperature dependence of the critical current (Jc) in an applied magnetic field in the BYCO (001) direction of Ha=0.9 T. With the appropriate dose of either 2 MeV H+ or 135Xe+, we can enhance Jc by a factor of 2 in Ha=0.9 T with little effect on Tc. This is significantly greater than the ∼25% enhancement previously reported for epitaxial BYCO films grown by in situ techniques [Roas, Hensel, and Saemann‐Ischenko, Appl. Phys. Lett. 54, 1051 (1989)]. This provides the opportunity to isolate the induced defects and study their properties.

The authors have studied the properties of 100-nm films of Ba/sub 2/YCu/sub 3/O/sub 7- delta / (BYCO) grown on LaAlO/sub 3/

The interaction between divalent cations and quinolones and the mechanism by which the former antagonizes the antimicrobial activities of the latter were investigated. In the presence of either magnesium or calcium chloride, the MICs of 18 quinolones for Gram-positive and Gram-negative bacteria increased. Accumulation of and inhibition of DNA synthesis by quinolones were decreased in the presence of magnesium chloride while, in the presence of EDTA, there was no increase in the concentration of accumulated quinolone for any of the agents tested. Only with nalidixic acid was there enhancement of the inhibition of DNA synthesis. Chelation of selected quinolones by magnesium was demonstrated with a fluorescence assay which showed that the extent to which fluorescence (consistent with chelation) was enhanced varied with the quinolone. Assessment of the strength of the magnesium-quinolone complexes with the chelating agent EDTA demonstrated that some of the complexes could be broken. Thin layer chromatography of quinolones and quinolone-magnesium complexes provided evidence that the components of the complex were probably combined in a ratio of 1:1 and that reduced intracellular accumulation of the quinolones in the presence of magnesium was unlikely to be due to a complex being too bulky to be taken through the porin channels. In contrast with permeabilizers which are known to utilize the self-promoted uptake pathway, none of the quinolones studied permeabilized Gram-negative bacteria to lysozyme, caused enhanced fluorescence to 1-N-phenyl-naphthylamine (NPN) or increased the leakage of periplasmic beta-lactamase into the culture medium. The reduced activities of the quinolones in the presence of divalent cations may be the result of the chelation of exogenous ions and, possibly, lipopolysaccharide- or lipoteichoic acid-associated magnesium ions, thereby resulting in less drug being available to enter the bacterium. Alternatively, reduced activity may be due to a fundamental effect on the interaction between quinolones and their target DNA gyrase.

We have studied the properties of two types of transparent conducting oxides grown by pulsed laser deposition (PLD) on quartz substrates. We have grown films of ITO with resistivity as low as 250 μΩ-cm and with absorption coefficient < 600 cm−1 throughout the visible spectrum. Even films deposited at room temperature can have ρ < 500 μΩ-cm, although the optical transmission characteristics are worse than those of commercially available ITO. Important parameters governing film quality include the oxygen partial pressure during film deposition and substrate temperature. GaInO3 is a recently identified transparent conducting material which is structurally distinct from ITO. Films have been grown with no intentional dopants and with either Ge substitution for Ga or Sn substitution for In. Doping concentrations as high as 10 at. % have been studied. There is no evidence for dopant segregation. Films with resistivities as low as 3 μΩ-cm have been achieved, and the absorption coefficient can be less than 500 cm−1 throughout the entire visible spectrum.

The effect that the presence or absence of interfacial C60 layers has on the nucleation and subsequent growth of overlying thin metal films has been studied using in situ resistivity measurements. Comparisons are made for Al and Cu films grown on quartz and yttria stabilized zirconia (YSZ) substrates. Our results indicate that electron donation across M/C60 (M=Al, Cu) interfaces reduces the percolation threshold for conductivity while simultaneously giving rise to an increased resistance in the metal due to electron depletion. Additional physical processes that are taken into account include the effect of different interfacial energies at the M/C60 and M/substrate boundaries and the effect of substrate tunneling between percolating metallic islands during the initial stages of film growth.

We have made NiFe2O4 films by rf sputtering using the 90 °off-axis geometry. Films grown at 600°C on SrTiO3 and Y.15Zr.85O2 substrates are single crystals with (100) and (110) texture, respectively, but exhibit a very large and unexpected random anisotropy. A postdeposition air anneal at ˜1000°C has little effect on the crystallinity of the films but almost completely eliminates the random anisotropy; the remaining anisotropy is consistent with expected (bulk) values. A decrease of the saturation magnetization, indicating degradation, was observed for films on SrTiO3 (but not Y.15Zr.85O2) annealed at 1300°C.

The growth mechanism of YBa2Cu3O7−δ thin films grown by the BaF2 post annealing process at low oxygen partial pressure have been studied by transmission electron microscopy. Under the annealing conditions of % MathType!MTEF!2!1!+- % feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqr1ngB % PrgifHhDYfgasaacH8srps0lbbf9q8WrFfeuY-Hhbbf9v8qqaqFr0x % c9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8fr % Fve9Fve9Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaacaWGWb % WaaSbaaSqaaiaad+eadaWgaaadbaGaaGOmaaqabaaaleqaaOGaeyyp % a0JaaGinaaaa!3C62! $${p_{{O_2}}} = 4$$ pO2=4 Torr and 700°C, BaCuO2 and Y2Cu2O5 precipitates develop from stoichiometric film precursors of YBCO during annealing. A growth model is proposed based on the observations. In addition, early stage nucleation and growth of both c- and a-axis oriented grains at the substrate interface were observed in quench annealed cross-sectional samples. 90° [100] symmetrical boundaries form between the a- and c-axis oriented grains. The possible effects of these boundaries are discussed.

Single-crystal epitaxial thin films of the isotropic metallic oxides Sr1-xCaxRuO(3) (0/= x/= 1) were grown on miscut SrTiO(3)(100) substrates in situ by 90 degrees off-axis sputtering. These thin films exhibit low isotropic resistivities, excellent chemical and thermal stability, good surface smoothness, and high crystalline quality. Furthermore, the lattice parameters and magnetic properties can be varied by simply changing the strontium/calcium ratio. These epitaxial thin films, and their multilayer structures with other oxide materials, can be used for the fabrication of superconducting, ferroelectric, magneto-optic, and electro-optic devices.

Epitaxial Ba2YCu3O7-δ (BYCO) films grown by the ex situ BaF2 process are comparable to single crystals both in crystalline integrity (RBS/ion channeling χmin < 3%) and the value and temperature dependence of the critical current (Jc) in an applied magnetic field in the BYCO (001) direction of Ha = 0.9T. With the appropriate dose of either 2 MeV H+ or 135Xe+, we are able to enhance Jc by a factor of 2 in H = 0.9T with little effect on Tc. The ability to change Jc by such a large factor in these films is a prerequisite for isolation and study of the induced defects and study their properties.

GaInO3, a layered material with the β Ga2O3 crystal structure, can be doped with electrons through the introduction of oxygen deficiency, Sn doping for In, or Ge doping for Ga. At atomic doping levels of 10% or less, resistivities as low as 3 mΩ cm are obtained. In contrast to polycrystalline indium tin oxide (ITO), which is distinctly green, conductive gallium indium oxide is light grey with no visible coloration. Thin films of doped GaInO3 display good transparency over the whole optical window, superior to that of ITO in the green‐blue region.

We have investigated the properties of NiFe2O4 thin films prepared by laser ablation of a stoichiometric NiFe2O4 target. Textured polycrystalline films were obtained on a‐SiO2 as well as on various substrates with Au, Ag, Pt, and MgF2 buffer layers. Epitaxially oriented films were obtained on MgO, (1102)‐oriented Al2O3, (1120)‐oriented Al2O3, Y‐stabilized ZrO2 (YSZ), and SrTiO3, although the crystalline quality of the films varied. Contamination by diffusion from the substrate and strains induced by both lattice constant mismatch and differential thermal expansion degraded the magnetic properties of the films, and in some cases decreased the electrical resistivity as well. By choosing the right substrate (YSZ), temperature (600 °C), and PO2 (0.01 mT), we are able to prepare epitaxial films with bulk saturation magnetization (Ms=270 G) and fairly low anisotropy (K∼105 erg/cm3) as inferred by torque magnetometry. These films and bilayers are expected to be useful in a variety of fundamental investigations...

Mesure d'impedance avec des electrodes a disque rotatif, en fonction du potentiel et de la densite de courant

Gel permeation chromatography and infrared spectra have been used to characterize several poly(phenylene oxide) films formed by the anodic oxidation of aqueous phenol solutions. For the 2,6‐dimethyl derivative, the molecular weight distribution extends to 10,000. Infrared spectra confirm a head‐to‐tail coupling structure. Results are also reported for films derived from 4‐t‐butylphenol and 2,4,6‐trimethylphenol.

Anodic electrochemical dissolution of metals is often used in commercial electropolishing, and the copper/phosphoric acid system is a classic example. Surface films are believed essential for polishing, but their composition and role remain elusive. Current oscillations, which may be excited, have been attributed to film formation and breakdown. This study examines the information obtained from voltammetric measurements using rotating disk electrodes. Steady‐state currents are limited by a diffusion process whose rate is dependent only upon the solution viscosity and is otherwise independent of its composition. Our results indicate a key role for water and suggest that the film may be a highly viscous, dehydrated surface layer. The oscillations are due to negative impedance surface characteristics.

Four compounds, N,N,N',N'-tetramethyl-p-phenylene diamine, N,N,N',N'-tetramethyl-benzidine, 4,4'-bis(dimethylamino)azobenzene and bis(4-dimethylaminophenylimino)sulfur (BAPIS) were examined electrochemically and spectroscopically. Each was shown to be a fairly good donor forming in its first oxidation state a radical-cation. The latter two materials surprisingly exhibited only single one-electron oxidations. Conformational flexibility about the -NSN- unit was studied by NMR spectroscopy and ab initio molecular orbital theory. The experimental ΔG* for a cis-trans to trans-cis interconversion in BAPIS was found to be 11.9 kcal/mole. The four donors all form 1:1 adducts with TCNQ. The compaction resistances of the complexes have been measured as a function of temperature. Of the four, (BAPIS)(TCNQ) appears to be a one-dimensional material. The other three complexes behave as typical mixed stack organic semiconductors.

Ambient temperature measurements of the crystallographic cell parameters for oxygen deficient Ba 2 YCu 3 O 7−δ prepared by gettered annealing indicate the presence of microscopic differences in the oxygen configuration at fixed δ dependent on annealing temperature. The loss of superconductivity with increasing oxygen deficiency is shown to be due to a step-like increase in length of the plane copper-apical oxygen bond, and not to the orthorhombic to tetragonal transition. The crystal structure of the 84K superconductor Bi 2 Sr 2 CaCu 2 O 8+δ is described, as is the stabilization of 110K superconductivity via partial Pb/Bi substitution with long time annealing.

Mesure de l'impedance de couches de 250 A, il se produit une relaxation de polarisation a l'interface metal/polymere/electrolyte

Electroactive poly(aniline) films, which are electronic conductors in their oxidized form, can be electrochemically formed on metal electrode surfaces. Above in acid solutions, oxidized films undergo a partially reversible transition to an insulating state. Impedance measurements have been used to characterize the electrical properties of these films under potentiostatic conditions and during potential cycling. In addition to probing their electronic conductivity, such measurements yield information regarding ionic conduction, charge capacity, and relaxation processes. The gradual loss of activity which occurs in the oxidized, insulating state is accompanied by a major loss of electronic conductivity and a lesser decrease in charge capacitance.

The way in which the changing structure of dairy farming is affecting hygiene on the farm is considered. Increasing herd size and automation of milking equipment have resulted in larger milking plants, which in turn have led to higher rates of milking and more complex plants to be cleaned. The three main sources of contamination in ex-farm milk, that is the udder, teat surfaces and milking equipment, remain but new aspects within these areas need to be considered. The importance of detecting clinical mastitis. preparing cows for milking, cleaning equipment and cooling milk is discussed.

Electron spin resonance is employed to study pairs of nitroxide radicals in the plastic phase of dl−camphene. Both Δm = 1 and Δm = 2 transitions are observed, and an adiabatic theory is presented for the dependence of the absorption intensity, second−order shift, and linewidth of the latter transitions upon radical pair distributions and motions. Results are interpreted by a model in which radicals are nearly randomly distributed over lattice sites, lattice vacancies are thermally generated, and radical diffusion occurs by a vacancy mechanism. The enthalpies for vacancy formation and radical diffusion are, respectively, 4.6 and 11 kcal/mole, while at the melting point D ? 10−7 cm2/sec.