bluuebunny/crossref_metadata_2025 huggingface dataset:
Photocatalytic degradation of phenol using Au/Bi2WO6 composite microspheres under visible‐light irradiation
Authors: Liu Jian‐Yi , Bai Yang , Wang Ping‐Quan
Published: May 2013

Gold loaded Bi2WO6 (Au/Bi2WO6) nanosheet‐based microspheres were prepared via a hydrothermal method combined with an in‐situ reduction approach. The products were characterised by scanning electron microscopy, a high‐resolution transmission electron microscope, X‐ray diffraction, energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy and UV–vis diffuse reflectance. The characterisation results revealed that it was the Au nanoparticles deposited on Bi2WO6 microspheres. A photocatalytic test for the degradation of phenol proved that Au loading was an effective means to enhance the photocatalytic activity of Bi2WO6 nanosheet‐based microspheres under visible‐light irradiation (λ > 420 nm). The photocatalytic mechanism over the Au/Bi2WO6 was analysed by active species trapping experiments. The main active species •OH for the photocatalytic test was produced by two pathways, that is, photogenerated holes oxidised water molecules to form •OH (oxidative pathway), and O2 captured the photogenerated electron to generate •O2 − and subsequently produce •OH (reductive pathway).
Humidity‐dependant compression properties of graphene oxide foams prepared by freeze‐drying technique
Authors: Ming Renhu , Ding Yanhuai , Chang Feihu , He Xing , Feng Jiqiang , Wang Chengfu , Zhang Ping
Published: May 2013

Microstructured graphene oxide (GO) foams were prepared by a freeze‐drying technique. The morphology, structure and compression properties of the GO foams were characterised by X‐ray diffraction, Fourier transform infrared spectroscopy, atomic force microscopy and an electronic universal‐testing machine. The unique pore structure made the GO foam easy to recover after compression. Furthermore, the compression properties of GO foam exhibited a humidity sensitivity, and the compressive strength was reduced by decreasing the relative humidity.
Facile synthesis of silver‐modified functionalised graphene oxide nanocomposite with enhanced antibacterial property
Authors: Wu Menglong , Lu Daban , Zhao Yue , Ju Tianzhen
Published: May 2013

Silver nanoparticles (Ag NPs)‐modified poly(diallyldimethylammonium chloride) (PDDA) functionalised graphene oxide (GO) nanocomposite was synthesised via a simple electrostatic attract assembly and used as an antibacterial material. The synthesised nanocomposite was characterised by UV–vis spectra, X‐ray diffraction and transmission electron microscopy. The antibacterial properties of the nanocomposite were investigated against Gram‐negative bacteria Escherichia coli and Gram‐positive bacteria Bacillus cereus. The results showed that the nanocomposite displayed excellent antibacterial properties in comparison with Ag NPs, which is attributed to the synergistic effect of Ag NPs and the PDDA–GO sheets. Thus, the as‐prepared nanocomposite in this study may be used as an effective antibacterial material.
Integrated carbon spheres on nickel foam as electrode for supercapacitors
Authors: Wei Jiatong , Lin Guannan , Wang Yan , He Xinping , Zhao Chun , Zhao Xu
Published: May 2013

Integrated carbon spheres in the manner of agglomerate of joined ones were grown on nickel foam substrates by a hydrothermal technique, which could be directly used as an electrode for supercapacitors. This avoided the exploitation of adhesive and thereby significantly decreased the resistance of the electrode. The electrode exhibited a rectangular cyclic voltammogram even at a high scan rate of 10 mV/s and its specific capacitance was as high as 196.43 F/g at the current density of 1 A/g.
Design and fabrication of hollow out‐of‐plane silicon microneedles
Authors: Jurčíček Petr , Zou Helin , Zhang Shuiping , Liu Chong
Published: May 2013

The design and fabrication of hollow out‐of‐plane silicon microneedles that mimic the function and dimensions of a mosquito's mouthparts are proposed. Two‐step etching and deep reactive ion etching from both sides of the wafer were used to etch the boreholes completely and to ensure the holes have lateral smoothness. Microneedles composed of {411} exterior crystal planes were formed by anisotropic etching in 40% KOH solution at a water‐bath temperature of 87°C. Finally, hollow silicon microneedles with a shank height of 100–120 µm and needle borehole diameter of 10–25 µm were fabricated. Flow rate tests using hollow microneedles were performed and demonstrated that the correlation between the flow rate and the inner diameter follows the Hagen‐Poiseuille law. Sample tests were performed using pig skin and have shown that the microneedles have sufficient strength to withstand breakup. The microneedles, that the authors fabricated by using the microelectromechanical system, have potential applications in painless transdermal drug delivery systems.
Microemulsion‐mediated solvothermal synthesis of hollow Co–Ni ferrite nanoparticle tubes and their magnetic properties
Authors: Gao Ying , Zhao Yun , Fu Min , Jiao Qingze , Li Hansheng
Published: May 2013

Hollow cobalt–nickel (Co–Ni) ferrite tubes with a diameter of about 200–400 nm and a length of several micrometres were synthesised by a microemulsion‐based solvothermal method in combination with calcination at 500°C. The morphologies and structures of the Co–Ni ferrite tubes and their precursors of Co/Ni/Fe composite oxalate were characterised using a transmission electron microscopy, field emission scanning electron microscopy and an X‐ray diffractometer. Magnetisation measurement was carried out using a vibrating sample magnetometer at room temperature. The saturation, magnetisation and coercivity of Co0.5Ni0.5Fe2O4 nanoparticle tubes could reach 19.645 emu/g and 722.35 Oe, respectively. Therefore Co–Ni ferrite tubes could be easily prepared using this method and might be applied as catalysts, magnetic materials and microwave absorbers.
Non‐resonant electrostatic energy harvester for wideband applications
Authors: Bu Ling , Wu Xiaoming , Wang Xiaohong , Liu Litian
Published: May 2013

Presented is a novel non‐resonant electrostatic energy harvester targeted at the wideband frequency response for micro‐system powering. To boost non‐resonance power output under low frequency, the vertical gap changing method is adopted to induce variable charges, which generates approximately 17 times of charge change compared with the conventional method of laterally changing overlap area (at 1 mm gap). Further, to boost the low frequency and non‐resonant power generating capability, the differential structure is adopted to achieve doubled output voltages. Testing results reveal that optimal output power occurs when the inner plate is of large effective movement range and large relative displacement with surrounding electrets. Maximally, 3.9–7.0 V voltage and 0.2–0.7 μW power are achieved over the 5–120 Hz frequency range.
Gyro-fluid and two-fluid theory and simulations of edge-localized-modes
Authors: Xu X. Q. , Xi P. W. , Dimits A. , Joseph I. , Umansky M. V. , Xia T. Y. , Gui B. , Kim S. S. , Park G. Y. , Rhee T. , Jhang H. , Diamond P. H. , Dudson B. , Snyder P. B.
Published: May 2013

This paper reports on the theoretical and simulation results of a gyro-Landau-fluid extension of the BOUT++ code, which contributes to increasing the physics understanding of edge-localized-modes (ELMs). Large ELMs with low-to-intermediate-n peeling-ballooning (P-B) modes are significantly suppressed due to finite Larmor radius (FLR) effects when the ion temperature increases. For type-I ELMs, it is found from linear simulations that retaining complete first order FLR corrections as resulting from the incomplete “gyroviscous cancellation” in Braginskii's two-fluid model is necessary to obtain good agreement with gyro-fluid results for high ion temperature cases (Ti≽3  keV) when the ion density has a strong radial variation, which goes beyond the simple local model of ion diamagnetic stabilization of ideal ballooning modes. The maximum growth rate is inversely proportional to Ti because the FLR effect is proportional to Ti. The FLR effect is also proportional to toroidal mode number n, so for high n cases, the P-B mode is stabilized by FLR effects. Nonlinear gyro-fluid simulations show results that are similar to those from the two-fluid model, namely that the P-B modes trigger magnetic reconnection, which drives the collapse of the pedestal pressure. Due to the additional FLR-corrected nonlinear E × B convection of the ion gyro-center density, for a ballooning-dominated equilibrium the gyro-fluid model further limits the radial spreading of ELMs. In six-field two fluid simulations, the parallel thermal diffusivity is found to prevent the ELM encroachment further into core plasmas and therefore leads to steady state L-mode profiles. The simulation results show that most energy is lost via ion channel during an ELM event, followed by particle loss and electron energy loss. Because edge plasmas have significant spatial inhomogeneities and complicated boundary conditions, we have developed a fast non-Fourier method for the computation of Landau-fluid closure terms based on an accurate and tunable approximation. The accuracy and the fast computational scaling of the method have been demonstrated.
Ponderomotive force on solitary structures created during radiation pressure acceleration of thin foils
Authors: Tripathi Vipin K. , Sharma Anamika
Published: May 2013

We estimate the ponderomotive force on an expanded inhomogeneous electron density profile, created in the later phase of laser irradiated diamond like ultrathin foil. When ions are uniformly distributed along the plasma slab and electron density obeys the Poisson's equation with space charge potential equal to negative of ponderomotive potential,  ϕ=−ϕp=−(mc2/e)(γ−1), where γ=(1+|a|2)1/2, and |a| is the normalized local laser amplitude inside the slab; the net ponderomotive force on the slab per unit area is demonstrated analytically to be equal to radiation pressure force for both overdense and underdense plasmas. In case electron density is taken to be frozen as a Gaussian profile with peak density close to relativistic critical density, the ponderomotive force has non-monotonic spatial variation and sums up on all electrons per unit area to equal radiation pressure force at all laser intensities. The same result is obtained for the case of Gaussian ion density profile and self consistent electron density profile, obeying Poisson's equation with ϕ=−ϕp.
Resistive instability in a Hall plasma discharge under ionization effect
Authors: Malik Hitendra K. , Singh Sukhmander
Published: May 2013

A systematic study is presented for low frequency resistive instability in a Hall plasma discharge under the effect of collisions, ionization, and finite temperature of ions and electrons by considering finite axial wave number. For this, a two dimensional dispersion equation is derived and solved numerically. Analytical calculations are also performed for obtaining the expression of growth rate and to discuss the limiting cases of equal axial (kx) and azimuthal (ky) wave numbers. The instability with higher growth rate is realized in the presence of ionization; the same is the case for equal wave numbers (kx=ky). However, the instability is suppressed when the ions and electrons carry higher temperatures, and weak effect of the electron temperature is observed for the case kx=ky.
The two dimensional motion of a particle in an inverse square potential: Classical and quantum aspects
Authors: Martínez-y-Romero R. P. , Núñez-Yépez H. N. , Salas-Brito A. L.
Published: May 2013

The classical 2D dynamics of a particle moving under an inverse square potential, −k/r2, is analysed. We show that such problem is an example of a geometric system since its negative energy orbits are equivalent to free motion on a certain hypersurface. We then solve in momentum space, the corresponding unrenormalized quantum problem showing that there is no discrete energy spectrum and, particularly, no ground state.
Solution-processed ZnO nanoparticle-based transistors via a room-temperature photochemical conversion process
Authors: Lin Yen-Hung , Faber Hendrik , Rossbauer Stephan , Anthopoulos Thomas D.
Published: May 2013

We report on zinc oxide (ZnO) nanoparticle-based transistors in which the solution-processed semiconducting layers are post-treated using UV light irradiation instead of high temperature annealing. Field-effect transistors based on these ZnO nanoparticle films exhibit n-channel characteristics with electron mobilities on the order of ∼10−3 cm2 V−1s−1—a value comparable to that obtained from devices thermally annealed at 250 °C. Because of the photochemical nature of the process, the sample temperature during UV irradiation remains low and close to room temperature. This enables facile fabrication of ZnO transistors onto inexpensive, temperature-sensitive substrate materials such as plastic.
Sound absorbing property of porous metal materials with high temperature and high sound pressure by turbulence analogy
Authors: Hui Wu Jiu , Hu Zhi Ping , Zhou Han
Published: May 2013

A quantitative theoretical model is presented to investigate the sound absorbing property of porous metal materials with high temperature and high sound pressure based on Kolmogorov turbulence theory in this paper. The porous materials have a large number of anomalous pores with similar scale, and these irregular pores could be considered as quasi-periodic structure that is very similar to the small-scale turbulence. Therefore, Kolmogorov turbulence theory is adopted to analyze the wave propagation inside the porous metal materials, in which the characteristic velocity and characteristic scale can be obtained by the nondimensional analysis method. Furthermore, the acoustical pressure amplitude in the porous metal materials under high temperature and high sound pressure level can be figured out with respect to metal wire diameter, porosity, and other parameters. It is shown quantitatively that the acoustic pressure amplitude goes up with an increase in the temperature and/or the sound pressure level. This model is verified by the well agreement between the theoretical and experimental results. It could provide a reliable theoretical guidance for the applications of porous metal materials in the area of vibration and noise control under high temperature and high sound pressure level.
Direct pulsed laser crystallization of nanocrystals for absorbent layers in photovoltaics: Multiphysics simulation and experiment
Authors: Zhang Martin Y. , Nian Qiong , Shin Yung , Cheng Gary J.
Published: May 2013

Direct pulsed laser crystallization (DPLC) of nanoparticles of photoactive material—Copper Indium Selenide (nanoCIS) is investigated by multiphysics simulation and experiments. Laser interaction with nanoparticles is fundamentally different from their bulk counterparts. A multiphysics electromagnetic-heat transfer model is built to simulate DPLC of nanoparticles. It is found smaller photoactive nanomaterials (e.g., nanoCIS) require less laser fluence to accomplish the DPLC due to their stronger interactions with incident laser and lower melting point. The simulated optimal laser fluence is validated by experiments observation of ideal microstructure. Selectivity of DPLC process is also confirmed by multiphysics simulation and experiments. The combination effects of pulse numbers and laser intensity to trigger laser ablation are investigated in order to avoid undesired results during multiple laser processing. The number of pulse numbers is inversely proportional to the laser fluence to trigger laser ablation.
Impact of Ti doping in Sm2O3 dielectric on electrical characteristics of a-InGaZnO thin-film transistors
Authors: Chen Fa-Hsyang , Her Jim-Long , Mondal Somnath , Hung Meng-Ning , Pan Tung-Ming
Published: May 2013

We investigated the impact of Ti doping in the Sm2O3 dielectric on the electrical stress-induced instability in amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). With increasing stress time in a-IGZO TFT devices, a small initial positive shift followed by a negative shift of threshold voltage is characterized in the Sm2O3 dielectric, whereas only positive shift of threshold voltage is observed for Ti-doped Sm2O3 dielectric. The positive shift of the threshold voltage can be explained by charge trapping in the Sm2O3 film and/or the Sm2O3/IGZO interfaces, while the negative shift of threshold voltage is probably due to the extra charges from the IGZO channel by self-heating effect.
Depth resolved studies of SrTiO3 defects using x-ray excited optical luminescence and cathodoluminescence
Authors: Rosenberg R. A. , Choi Y. , Vijayalakshmi K. , Kareev M. , Tchakhalian J. , Balaz Snjezana , Brillson L. J.
Published: May 2013

We have performed comparative depth-dependent x-ray excited optical luminescence (XEOL) and depth resolved cathodoluminescence spectroscopy measurements in order to understand the native point defect distribution in three SrTiO3 samples. Both techniques found surface segregation of Ti3+ defects, but apparent differences in the oxygen vacancy distribution. Due to the lower excitation flux densities employed in XEOL, there is a delayed onset (“dead layer”) revealed in the oxygen defect depth distribution, which results from band bending near the surface. By modeling the data, we are able to estimate the Ti3+ depth distribution and the depletion layer width.
Inactivation of Microcystis aeruginosa using dielectric barrier discharge low-temperature plasma
Authors: Pu Sichuan , Chen Jierong , Wang Gang , Li Xiaoyong , Ma Yun
Published: May 2013

The efficiency of Microcystis aeruginosa plasma inactivation was investigated using dielectric barrier discharge low-temperature plasma. The inactivation efficiency was characterized in terms of optical density. The influence of electrical and physicochemical parameters on M. aeruginosa inactivation was studied to determine the optimal experimental conditions. The influence of active species was studied. The proliferation of the M. aeruginosa cells was significantly decreased under plasma exposure. The morphologic changes in M. aeruginosa were characterized under scanning electron microscopy. These results suggest that the low-temperature plasma technology is a promising method for water pollution control.
Chemical identification of luminescence due to Sn and Sb in ZnO
Authors: Cullen J. , Byrne D. , Johnston K. , McGlynn E. , Henry M. O.
Published: May 2013

We show that the I10 line in ZnO photoluminescence is associated with Sn impurities. The evidence comes from material implanted with radioactive 117Ag, which decays through 117Cd and 117In to stable 117Sn, and 121Ag, which decays through the same chain to stable 121Sb. Supporting evidence is provided by ZnO:Sn prepared by the in-diffusion of stable Sn. Furthermore, the I2 and I9 lines are shown conclusively to be due to In, confirming earlier identifications in the literature. We also observe shallow bound exciton emission at 3.3643(3) eV due to Sb impurities produced at the end of the decay chain of 121Ag.
Dislocation and antiphase domain free microscale GaAs crystals grown on SiO2 from (001) Si nano-areas
Authors: Renard C. , Cherkasin N. , Jaffre A. , Vincent L. , Michel A. , Molière T. , Hamouche R. , Yam V. , Alvarez J. , Fossard F. , Mencaraglia D. , Bouchier D.
Published: May 2013

The epitaxial lateral overgrowth of microscale GaAs crystals on a 0.6 nm thick SiO2 layer from nanoscale Si seeds is investigated in order to develop GaAs monolithic hetero-epitaxy onto (001) Si. The nucleation from small width openings enables to avoid the emission of misfit dislocations and the formation of antiphase domains. Consequently, the interface between the GaAs island and the SiO2 layer remains perfectly sharp and free of defects. The only defects found by transmission electron microscopy in each island are pairs of twins, and a simple model based on the anisotropy of zinc blende crystal is proposed to explain their formation. Micro-photoluminescence measurements performed at room temperature show that these twins are not detrimental for the quality of microscale GaAs crystals.
Carrier dynamics in linearly and step graded bandgap Zn1−xCdxO structures
Authors: Trunk M. , Galeckas A. , Venkatachalapathy V. , Azarov A. Yu. , Kuznetsov A. Yu.
Published: May 2013

We report on the time-resolved photoluminescence studies of step-like and linearly graded bandgap ZnCdxO (x = 0% – 60%) structures. The key carrier transport properties essential to the concept of variable bandgap absorbers are addressed, including radiative and nonradiative lifetime, diffusion and drift in the built-in field, and surface and interface recombination. A comprehensive set of depth-resolved recombination time parameters is presented revealing the individual roles of internal electric fields, built-in strain, and resultant polarization fields as well as of misfit strain at interfaces on the carrier dynamics.
Fe3O4-nanoparticles within porous silicon: Magnetic and cytotoxicity characterization
Authors: Granitzer P. , Rumpf K. , Tian Y. , Akkaraju G. , Coffer J. , Poelt P. , Reissner M.
Published: May 2013

The magnetic properties of porous silicon/Fe3O4 composites are investigated with respect to the adjustability of the blocking temperature along with an evaluation of any size-dependent changes in cytocompatibility. Fe3O4-nanoparticles have been infiltrated within mesoporous silicon, resulting in a system with tunable magnetic properties due to the matrix-morphology, the loading of the nanoparticles, and their size. In order to provide basic information regarding its suitability as a therapeutic platform, the cytotoxicity of these composites have been investigated by a trypan blue exclusion assay with respect to human embryonic kidney 293 cells, and the results compared with cell-only and known cytotoxic controls.
Endolymphatic mastoid shunt: A reevaluation of efficacy
Authors: Welling D. Bradley , Nagaraja H. N.
Published: May 2013

OBJECTIVES

The main goal of this paper was to statistically reevaluate the efficacy of the endolymphatic shunt procedure for Meniere's disease.

METHODS

Thomsen et al (Arch Otolaryngol 1981; 107:271‐7) reported on the placebo effect in surgery for Meniere's disease in a controlled double‐blind study. Thirty patients with typical Meniere's disease in whom medical treatment failed participated in the study. A placebo‐controlled blinded surgical study has not since been replicated. We performed a retrospective statistical analysis using data extracted from the published report and reanalyzed it using both the original and new statistical measures and techniques.

RESULTS

The original conclusions drawn by Thomsen et al differed considerably from ours in 5 key areas, including postoperative vertigo, nausea and vomiting, tinnitus, and combined score.

CONCLUSIONS

This analysis strongly supports the effectiveness of the endolymphatic shunt in the management of Meniere's disease and refutes the placebo effect previously proposed.
Surgery and obstructive sleep apnea: Long‐term clinical outcomes
Authors: Riley Robert W. , Powell Nelson B. , Li Kasey K. , Troell Robert J. , Guilleminault Christian
Published: May 2013

OBJECTIVE

Outcome data on the surgical treatment of obstructive sleep apnea are, in general, based on short‐term follow‐up (<6‐9 months). This examination was undertaken to assess long‐term results.

METHODS

Forty patients who underwent soft tissue and skeletal surgery were the subjects of this review. Methods of evaluation included polysomnographic variables (respiratory disturbance index [RDI], low oxyhemoglobin desaturation [LSAT]), body mass index, quality‐of‐life assessments, roentgenographic analysis, and complications. Statistical analysis used the SAS 6.12 system.

RESULTS

Thirty‐six of 40 patients (90%) showed long‐term clinical success. The mean preoperative RDI, nasal continuous positive airway pressure RDI, and long‐term RDI were 71.2 ± 27.0, 7.6 ± 5.2 and 7.6 ± 5.1, respectively. The mean preoperative LSAT, nasal continuous positive airway pressure LSAT, and long‐term LSAT were 67.5% ± 14.8%, 87.1% ± 3.2%, and 86.3% ± 3.9%, respectively. The mean follow‐up was 50.7 ± 31.9 months. The patients showed a statistically significant long‐term weight gain (P = 0.0002) compared with their 6‐month postoperative level (body mass index 31.4 ± 6.7 vs 32.2 ± 6.3). There was a positive correlation with the amount of skeletal advancement and clinical outcome.

CONCLUSION

Comprehensive evaluation and surgical treatment can result in successful long‐term clinical outcome.
Pharyngeal suspension suture with Repose bone screw for obstructive sleep apnea
Authors: Woodson B. Tucker , Derowe ARI , Hawke Michael , Wenig Barry , Ross E. B. , Katsantonis George P. , Mickelson Samuel A. , Bonham Robert E. , Benbadis Selim
Published: May 2013

OBJECTIVE

Multilevel surgery for obstructive sleep apnea syndrome (OSA) may improve success. This study's goal is to prospectively evaluate the feasibility and short‐term subjective effectiveness of a new tongue‐suspension technique.

METHODS

A multicenter nonrandomized open enrollment trial used the Repose device to treat tongue obstruction in 39 snoring and OSA patients. Outcomes include 1‐ and 2‐month subjective reports of general health, snoring, and sleep.

RESULTS

Twenty‐three patients completed 1 month and 19 completed 2 months of follow‐up. In OSA patients, activity level, energy/fatigue, and sleepiness improved. Two‐month outcomes were less (activity level, energy/fatigue, and sleepiness). Fewer changes were observed in snorers than in OSA patients. There were 6 complications (18%), including sialadenitis (4), gastrointestinal bleeding (1), and dehydration (1) after the procedure.

CONCLUSION

A pharyngeal suspension suture changes subjective outcomes. Improvement is incomplete. The procedure is nonexcisional, but significant complications may occur. Further evaluation is required to demonstrate effectiveness.
Midline radiofrequency tissue reduction of the palate for bothersome snoring and sleep‐disordered breathing: A clinical trial
Authors: Coleman Sean C. , Smith Timothy L.
Published: May 2013

This study is a prospective, nonrandomized clinical trial initiated to assess the safety and efficacy of radiofrequency tissue reduction of the palate for the treatment of bothersome snoring and sleep‐disordered breathing. Twelve healthy volunteers with socially disruptive snoring underwent a baseline polysomnogram along with a battery of visual analog scales (VASs) to measure daytime sleepiness, snoring level, pain, and disturbances of speech and swallowing. After radiofrequency tissue reduction of the palate, they were re‐evaluated with a mean follow‐up after the final procedure of 15.7 ± 5.1 (mean ± SD) weeks. As rated by the bed partner, a significant reduction in the level of snoring occurred in all 12 patients, with a mean pretreatment snoring level of 8.3 ± 2.1 to a mean posttreatment snoring level of 2.1 ± 1.4. (Student t test, P < 0.0001) These patients required an average of 2.3 treatment sessions each. Nine of 12 had a reduction in snoring from a bothersome level (VAS range 5‐10) to a nonbothersome level (VAS range 0‐3). Daytime sleepiness as measured by the Epworth Sleepiness Scale (0‐24) decreased from 10.8 ± 4.4 to 8.3 ± 4.1 (P = 0.011). Posttreatment pain was considered absent or minimal in 11 of 12 patients and was managed with acetaminophen. No significant adverse events or complications were reported.
Conductive hearing loss associated with pressure equalization tubes
Authors: Estrem Scott A. , Batra Pete S.
Published: May 2013

Pressure equalization (PE) tube placement traditionally has been used to lessen conductive hearing loss with chronic middle ear effusion. It is assumed that the small diameter of the tube should not interfere with the conduction of sound. In this article we present 5 patients in whom placement of a PE tube resulted in significantly worse conductive hearing. Occlusion of the PE tube with cigarette paper or Gelfoam improved hearing, as documented with audiometry. The average conductive hearing losses attributable to the ventilation tube for this series of patients were 22, 17, 15, 13, 4, and 10 dB at the frequencies of 250, 500, 1000, 2000, 4000, and 8000 Hz, respectively. This amount of change attributable to PE tubes in this small selection of patients is much greater than would be commonly appreciated. We conclude that the opening in the tympanic membrane provided by PE tubes can potentially result in a significant conductive hearing loss. Discussion includes those conditions in which reduced hearing may be more likely to occur.
Nitric oxide is a mediator of the late‐phase response in an animal model of nasal allergy
Authors: Durland William F. , Lane Andrew P. , Durland Kimberly W. , Smith Timothy L. , Johnson Kenneth L. , Prazma Jiri , Pillsbury Harold C.
Published: May 2013

The presence of nitric oxide (NO) in the nose is well documented; however, the role of this molecule in nasal physiology is still poorly understood. Our laboratory has previously demonstrated that NO is a mediator of the immediate secretory response to an intranasal histamine challenge in a rat model of nasal allergy. Histamine challenge, however, does not elicit a late‐phase response (LPR). To study the role of NO in the LPR, we developed a model of nasal allergy in which brown Norway rats are actively sensitized to the allergen ovalbumin and later challenged intranasally with either phosphatebuffered saline solution (vehicle), ovalbumin in vehicle, or ovalbumin and the NO synthase inhibitor N‐nitro‐L‐arginine methyl ester. In each experiment, nasal lavage samples were collected 30, 120, 240, and 360 minutes after challenge. Lavage samples were analyzed for albumin content by ELISA, inflammatory cell concentration with a hemocytometer, and evidence of inflammation by light microscopy. Blocking NO synthesis with N‐nitro‐L‐arginine methyl ester significantly inhibited both albumin exudation and inflammatory cell influx into the nasal cavity during the LPR. These data suggest that NO plays a role in the LPR of nasal allergy.
Cochlear implantation: Minimal hair removal technique
Authors: Roberson Joseph B. , Stidham Katrina R. , Scott Kenneth M. , Tonokawa Lisa
Published: May 2013

This prospective study was undertaken to evaluate the safety and patient acceptance of minimal hair removal during cochlear implantation. Forty‐six consecutive patients (17 adults, 29 children; age range 13 months to 84 years) received cochlear implantation with a minimal hair removal technique. A questionnaire was used to evaluate acceptance and value of this technique among the first 15 patients and parents. Postoperative examinations were completed 1 and 4 weeks after implantation. Patients were monitored for complications, which included 3 cases of transient seroma, 2 cases of transient dysequilibrium, 2 individual electrode failures, and 1 facial nerve stimulation. Importantly, no wound infections were documented. Use of a small shave technique did not increase surgical risk. This technique has proved to be cosmetically and psychologically more desirable for the patients and their families than complete hair removal in the operative field.
Correlation of neural cell adhesion molecules with perineural spread of squamous cell carcinoma of the head and neck
Authors: Vural Emre , Hutcheson James , Korourian Soheila , Kechelava Sofia , Hanna Ehab
Published: May 2013

Perineural spread (PNS) is a poor prognostic factor associated with increased risk of local recurrence and nodal metastasis and reduced survival of patients with squamous cell carcinoma of the head and neck (SCCHN). There is some evidence to indicate that neural cell adhesion molecules (NCAMs) may play a role in PNS of a variety of tumor types. We performed this study to investigate whether NCAM expression can be used as a predictor of PNS in SCCHN. The surgical specimens of 66 patients with SCCHN were evaluated with monoclonal IgG antibody immunoperoxidase staining for NCAM. Of the 41 specimens with PNS, 38 (93%) showed evidence of NCAM expression. In contrast, only 9 specimens (36%) without PNS expressed NCAMs. The difference in NCAM expression between the study and control groups was statistically significant (P < 0.01).
Long‐term results with hydroxylapatite middle ear implants
Authors: Goldenberg Robert A. , Driver Mark
Published: May 2013

PURPOSE

This study evaluated long‐term results in patients who had ossicular reconstruction with a Goldenberg hydroxylapatite implant.

METHODS

A total of 233 patients underwent implantation; of these, 77 had 5‐year or longer follow‐up and are the subjects of this study of long‐term hearing results. All 233 patients were included for analysis of extrusion rate and postoperative otorrhea.

RESULTS

The hearing success rate at long‐term follow‐up was 56.8%; the mean air‐bone gap was 21.1 dB. Prosthesis extrusion occurred in 5.29% of the 233 patients, and visible slippage occurred in 7.7%. Overall, 50.6% of patients met the criteria for successful hearing, which included no extrusion and a dry ear. Better hearing before surgery and presence of the malleus long process were factors associated with a successful hearing result, as was tympanoplasty alone and canal wall up tympanomastoidectomy.

CONCLUSION

Hydroxylapatite hybrid prostheses provide stable hearing results over time with low extrusion and a dry ear overall.
Unrecognized benign paroxysmal positional vertigo in elderly patients
Authors: Oghalai John S. , Manolidis Spiros , Barth Justine L. , Stewart Michael G. , Jenkins Herman A.
Published: May 2013

Balance disorders in elderly patients are associated with an increased risk of falls but are often difficult to diagnose because of comorbid chronic medical problems. We performed a cross‐sectional study to determine the prevalence of unrecognized benign paroxysmal positional vertigo (BPPV) and associated lifestyle sequelae in a public, inner‐city geriatric population. Dizziness was found in 61% of patients, whereas balance disorders were found in 77% of patients. Nine percent were found to have unrecognized BPPV. Multivariate analysis demonstrated that the presence of a spinning sensation and the absence of a lightheadedness sensation predicted the presence of unrecognized BPPV. Patients with unrecognized BPPV were more likely to have reduced activities of daily living scores, to have sustained a fall in the previous 3 months, and to have depression. These data indicate that unrecognized BPPV is common within the elderly population and has associated morbidity. Further prospective studies are warranted.
Dynamics of nasopharyngitis in children
Authors: Brook Itzhak , Gober Alan E.
Published: May 2013

PURPOSE

Our goal was to characterize the dynamics and bacterial interaction of the aerobic and anaerobic flora of nasal discharge of children at different stages of uncomplicated nasopharyngitis.

METHODS AND PATIENTS

Serial semiquantitative nasopharyngeal (NP) and quantitative nasal discharge (ND) cultures were taken every 3 to 5 days from 20 children in whom purulent discharge eventually developed (group 1), and a single culture was obtained from a group of 20 who had only clear discharge (group 2).

RESULTS

Aerobic and anaerobic bacteria were isolated from all NP cultures. Bacterial growth was present in 8 (40%) NDs of group 2. Only 7 (35%) of the clear NDs of group 1 showed bacterial growth; the number increased to 14 (70%) at the mucoid stage and 20 (100%) at the purulent stage. It declined to 6 (30%) at the final clear stage. The number of species and total number of organisms increased in the NDs of group 1. Group 1 patients had higher recovery rates of Streptococcus pneumoniae and Haemophilus influenzae in their NP cultures than group 2 patients (P < 0.05). During the purulent stage, Peptostreptococcus species were isolated in 15 (75%), Fusobacterium species in 10 (50%), Prevotella species in 9 (45%), H influenzae in 8 (40%), S pneumoniae in 6 (30%), and β‐hemolytic streptococci in 5 (25%) of group 1 NDs. This was higher than their recovery in the clear stages of both groups and the mucoid stage of group 1. A total of 8 organisms capable of interfering with the growth of potential pathogens were isolated from the NPs of group 1, as compared with 35 from group 2 (P < 0.001).

CONCLUSIONS

The development of purulent nasopharyngitis is associated with the pre‐existing presence of potential pathogens and the absence of interfering organisms.
Health status in allergic rhinitis
Authors: Corey Jacquelynne P. , Kemker Bryan J. , Branca Joseph T. , Kuo Felicia , Chang Yuchiao , Gliklich Richard E.
Published: May 2013

Although valid and reliable instruments exist to measure the quality of life of allergic rhinitis patients, a statistically sensitive and clinically meaningful way to evaluate patients undergoing immunotherapy has not been reported. A 21‐site prospective, observational study was performed in a population of consecutive patients with allergic rhinitis. Baseline general health measures revealed significant (P < 0.05) decrements from reported normative levels in 8 domains for patients choosing to undergo immunotherapy and 5 domains for patients choosing not to undergo immunotherapy. The General Health Survey was less sensitive in detecting change than the Nasal Health Survey (Chronic Sinusitis Survey) and allergy‐specific (Rhinoconjunctivitis Quality of Life Questionnaire and Allergy Outcome Survey) surveys. Severity of symptoms was associated with both the likelihood to choose immunotherapy and the likelihood for early improvement. We conclude that general and conditionspecific measures can be used to observe patients after immunotherapy; however, obtaining baseline data and controlling for seasonality are important considerations.
Prevalence of unsuspected acoustic neuroma found by magnetic resonance imaging
Authors: Anderson Timothy D. , Loevner Laurie A. , Bigelow Douglas C. , Mirza Natasha
Published: May 2013

OBJECTIVES

Acoustic neuromas (ANs) comprise 6% of intracranial tumors. Population and autopsy studies have widely divergent estimates of AN incidence. With widespread use of MRI, asymptomatic ANs will be identified, which should improve estimates of the prevalence of this tumor.

METHODS

The reports of all brain MRI scans during a 5‐year period were retrospectively searched for the diagnosis of AN. MRIs obtained because of a suspicion of AN were discarded, leaving only the unsuspected ANs.

RESULTS

A total of 24,246 MRI studies were performed during this time period. Seventeen patients had unsuspected ANs. Eight tumors were smaller than 1 cm, 6 were between 1 and 2 cm, and 3 were 2 cm or larger. For all MRI scans, we found 7.0 unsuspected ANs per 10,000 brain MRI studies (0.07%).

CONCLUSION

The true prevalence of AN is likely greater than the 10 per million per year previously reported. This implies that there may be a larger number of asymptomatic ANs than previously suspected.
Botulinum toxin injection of the cricopharyngeus muscle for the treatment of dysphagia
Authors: Ahsan Syed F. , Meleca Robert J. , Dworkin James Paul
Published: May 2013

OBJECTIVE

This study was conducted to evaluate, subjectively and objectively, the diagnostic and therapeutic effects of botulinum toxin (Botox) in patients with dysphagia caused by cricopharyngeus (CP) muscle spasm and/or hypertonicity.

METHODS

A retrospective chart review was done of 5 patients with normally functioning larynges treated with CP Botox injection for dysphagia caused by perceived spasm. Subjective measures of swallowing function after injection were obtained with a patient questionnaire. Objective data were obtained both before and after surgery by one or more of the following tests: modified barium swallow study, manometry, videostroboscopy, and fiberoptic endoscopic evaluation of swallowing. Quality‐of‐life measures were obtained with a swallowing rating scale.

RESULTS

Overall, all patients had initial improvement in swallowing after Botox injection. The duration of benefit was from 2 to 14 months. There were no complications. Four of 5 patients had long‐term benefits, as evidenced by decreased or eliminated aspiration symptoms, removal of tracheotomy, ability to eat solid foods, and weight gain. One patient continues to have poor swallowing function.

CONCLUSION

Botox injection of the CP muscle to treat dysphagia is effective in patients with underlying muscle spasm or hypertonicity. A positive response to Botox can also help confirm the diagnosis of CP muscle spasm.
Malignant peripheral nerve sheath tumors of the head and neck: Analysis of prognostic factors
Authors: Loree Thom R. , North James H. , Werness Bruce A. , Nangia Rina , Mullins Alan P. , Hicks Wesley L.
Published: May 2013

Malignant peripheral nerve sheath tumors of the head and neck region are uncommon and may be associated with neurofibromatosis or occur in a sporadic manner. This is a retrospective review of 17 patients with these tumors who were treated at a single institution. Analysis of clinical and pathologic factors that influenced outcome was performed. There were 9 men and 8 women. Seven patients had a history of neurofibromatosis. Radiotherapy was implicated as a possible etiologic factor in 4 patients. The neck was the most frequently involved site. Overall survival at 5 years was 52%. Survival was improved for women and for patients with lowgrade tumors. Age, tumor site, and size had no impact on survival. Survival was worse for patients with neurofibromatosis than for those with the sporadic form of the disease (P= 0.02). Survival was calculated by the method of Kaplan and Meier. The significance of such results was based on results of the log rank test. Local recurrence correlated with tumor size and resection margin status. No local recurrences occurred in those patients who had negative margins of resection and received adjuvant radiotherapy. Tumor grade was predictive of the development of distant metastases. Negative margins of resection are essential for obtaining local control, and the addition of adjuvant radiotherapy may be beneficial in this group. Salvage surgery for local recurrence is possible in some patients.
Net-avoidance behaviour in platypuses
Authors: Griffiths Josh , Kelly Tom , Weeks Andrew
Published: May 2013

It has been suggested that platypuses (Ornithorhynchus anatinus) may avoid nets following capture, compromising abundance estimates using mark–recapture models. Here, we present the first direct evidence of net avoidance behaviour by the platypus. Using acoustic telemetry, we record a platypus bypassing several nets following capture. Understanding variation in capture probabilities will lead to better estimation of platypus abundance, which is currently lacking.
Ballet dancers cardiorespiratory, oxidative and muscle damage responses to classes and rehearsals
Authors: Rodrigues‐Krause Josianne , Krause Mauricio , Cunha Giovani dos Santos , Perin Diana , Martins Jocelito B. , Alberton Cristine Lima , Schaun Maximiliano I. , De Bittencourt Paulo Ivo Homem , Reischak‐Oliveira Alvaro
Published: May 2013

This study aimed to describe and compare ballet dancers' cardiorespiratory responses, muscle damage and oxidative stress levels during a ballet class (practice of isolated ballet exercises performed with barre/hand‐rail support and across‐the‐floor movements to improve technical skills) and rehearsal (practice of ballet choreography involving technical‐artistic skills to improve dancers' performance for shows). The 12 advanced female ballet dancers undertook three exercise sessions: maximum effort test, class and rehearsal. Heart rate (HR) and oxygen consumption (V̇O2) were continuously measured. Lactate was determined before 15 min and after class and rehearsal. Blood was sampled pre, post and 48 h after class and rehearsal for creatine kinase (CK), lipid peroxides (LPO) and glutathione analysis (GSSG/GSH). Class was of lower intensity than rehearsal as shown by V̇O2, HR and lactate values: V̇O2 (mL.kg−1.min−1): 14.5±2.1 vs 19.1±1.7 (p < 0.001); HR (bpm.min−1): 145.7±17.9 vs 174.5±13.8 (p < 0.001); lactate (mmol.L−1): 4.2±1.1 vs 5.5±2.7 (p = 0.049). CK (IU) increased following class and rehearsal, remaining high 48 h after: class (pre = 109.3±48.5; post = 144±60; 48 h = 117.2±64.6); rehearsal (pre = 78.6±52.1; post = 122±70.7; 48 h = 104.9±89.5). LPO (µM) increased from pre‐class (1.27±0.19) to post‐class (1.41±0.19) and went down after 48 h (1.20±0.22). No LPO time‐course changes followed the rehearsal. GSSG/GSH decreased 48 h after class and rehearsal. Greater increases in LPO post‐class suggest it promotes CK release by an oxidative membrane‐damage mechanism. Physiological increases of LPO and CK in class indicate it prepares the dancers for exercise‐induced oxidative stress and muscle damage during rehearsals. Ballet dancers' muscle damage and oxidative stress responses seem not to be dependent on exercise intensity based on V̇O2 responses.
Repeated supra‐maximal sprint cycling with and without sodium bicarbonate supplementation induces endothelial microparticle release
Authors: Kirk Richard J. , Peart Daniel J. , Madden Leigh A. , Vince Rebecca V.
Published: May 2013

Under normal homeostatic conditions, the endothelium releases microparticles (MPs), which are known to increase under stressful conditions and in disease states. CD105 (endoglin) and CD106 (vascular cell adhesion molecule‐1) are expressed on the surface of endothelial cells and increased expression in response to stress may be observed. A randomised‐controlled double‐blinded study aimed to examine the use of endothelial MPs as a marker for the state of one's endothelium, as well as whether maintaining acid–base homeostasis affects the release of these MPs. This study tested seven healthy male volunteers, who completed a strenuous cycling protocol, with venous blood analysed for CD105+ and CD106+ MPs by flow cytometry at regular intervals. Prior to each trial participants consumed either 0.3 g·kg−1 body mass of sodium bicarbonate (NaHCO3), or 0.045 g·kg−1 body mass of sodium chloride (NaCl). A significant rise in endothelial CD105+ MPs and CD106+ MPs (p<0.05) was observed at 90 min post‐exercise. A significant trend was shown for these MPs to return to resting levels 180 min post‐exercise in both groups. No significance was found between experimental groups, suggesting that maintaining acid–base variables closer to basal levels has little effect upon the endothelial stress response for this particular exercise mode. In conclusion, strenuous exercise is accompanied by MP release and the endothelium is able to rapidly recover in healthy individuals, whilst maintaining acid–base homeostasis does not attenuate the MP release from the endothelium after exercise.
Rules versus Discretion in Food Storage Policies
Authors: Gouel Christophe
Published: May 2013

This article compares various policies in a rational expectations food storage model with risk‐averse consumers and missing insurance markets calibrated to represent a developing country. I consider an optimal storage policy under discretion and two optimal simple rules: a constant private storage subsidy and a price band. The storage subsidy achieves welfare gains similar to the discretionary policy. The price band maximizing social welfare is a price‐peg scheme: The floor and ceiling prices are the same, and the capacity constraint represents 11% of the steady‐state production level. This price band achieves three‐quarters of the gains from the optimal policy under discretion.