bluuebunny/crossref_metadata_2025 huggingface dataset:
A testbed for wide-field, high-resolution, gigapixel-class cameras
Authors: Kittle David S. , Marks Daniel L. , Son Hui S. , Kim Jungsang , Brady David J.
Published: May 2013

The high resolution and wide field of view (FOV) of the AWARE (Advanced Wide FOV Architectures for Image Reconstruction and Exploitation) gigapixel class cameras present new challenges in calibration, mechanical testing, and optical performance evaluation. The AWARE system integrates an array of micro-cameras in a multiscale design to achieve gigapixel sampling at video rates. Alignment and optical testing of the micro-cameras is vital in compositing engines, which require pixel-level accurate mappings over the entire array of cameras. A testbed has been developed to automatically calibrate and measure the optical performance of the entire camera array. This testbed utilizes translation and rotation stages to project a ray into any micro-camera of the AWARE system. A spatial light modulator is projected through a telescope to form an arbitrary object space pattern at infinity. This collimated source is then reflected by an elevation stage mirror for pointing through the aperture of the objective into the micro-optics and eventually the detector of the micro-camera. Different targets can be projected with the spatial light modulator for measuring the modulation transfer function (MTF) of the system, fiducials in the overlap regions for registration and compositing, distortion mapping, illumination profiles, thermal stability, and focus calibration. The mathematics of the testbed mechanics are derived for finding the positions of the stages to achieve a particular incident angle into the camera, along with calibration steps for alignment of the camera and testbed coordinate axes. Measurement results for the AWARE-2 gigapixel camera are presented for MTF, focus calibration, illumination profile, fiducial mapping across the micro-camera for registration and distortion correction, thermal stability, and alignment of the camera on the testbed.
Comprehensive analysis of alternating current electrokinetics induced motion of colloidal particles in a three-dimensional microfluidic chip
Authors: Honegger Thibault , Peyrade David
Published: May 2013

AC electrokinetics is becoming a strategic tool for lab-on-a-chip systems due to its versatility and its high level of integration. The ability to foreseen the behaviour of fluids and particles under non-uniform AC electric fields is important to allow new generations of devices. Though most of studies predicted motion of particles in co-planar electrodes configurations, we explore a pure 3-D AC electrokinetic effect that can open the way to enhance contact-less handling throughout the microchannel. By fabricating 3D microfluidic chips with a bi-layer electrodes configuration where electrodes are patterned on both sides of the microfluidic channel, we present a detailed study of the AC electrokinetic regimes that govern particles motion suspended in different host media subjected to a non-uniform AC electric field that spreads through the cross-section of the microchannel. We simulate and observe the motion of 1, 5, and 10 μm polystyrene particles relative to the electrodes and provide an insight on the competition between electro-hydrodynamical forces and dielectrophoresis. We demonstrate that using relevant electrode designs combined with the appropriate applied AC potential, particles can be handled in 3-D in the micro-channel at a single or a collective level in several medium conductivities. Both numerical simulations and experimental results provide a useful basis for future biological applications.
Vibrational convective instability of a binary electrolyte layer between plane horizontal electrodes
Authors: Volgin V. M. , Davydov A. D.
Published: May 2013

The stability of a mechanical quasi-equilibrium state of a binary electrolyte layer between planar horizontal electrodes subjected to high-frequency vibration is studied theoretically. It is assumed that reversible anodic metal dissolution and cathodic reactions proceed at the layer boundaries (metal electrode surfaces). A linear analysis of the convective stability is based on a system of equations for averaged fields of hydrodynamic velocity, concentration, and electric potential. An analytical solution to the stability problem with respect to the long-wave perturbations is obtained for positive and negative Rayleigh numbers. It is shown that the Rayleigh number corresponding to the boundary of long-wave instability depends on the direction of vibration, transport properties of the solution, and vibration frequency and amplitude. Approximate analytical solutions of the problem for monotonic instability under horizontal and vertical vibrations are obtained. The stability boundaries of mechanical quasi-equilibrium state of a binary electrolyte layer are determined by solving numerically at various values of transport properties of solution, vibration direction, and electrolysis conditions. It is found that, in contrast to thermal vibrational convection, in the case of concentration vibrational convection, absolute stability cannot be reached. A range of parameters, where the long-wave perturbations are critical, is determined. The monotonic and oscillatory types of instability are analyzed and the results of approximate analytical and numerical solutions are compared and show good agreement.
A “configurational entropy-loss” law for non-Arrhenius relaxation in disordered systems
Authors: Wang Yi-zhen , Zhang X. Frank , Zhang Jin-xiu
Published: May 2013

From Nowick's self-induced ordering theory, we develop a new configurational entropy relation to describe the non-Arrhenius temperature (T)-dependent relaxation in disordered systems. Both the loss of configurational entropy and the coupling interaction among relaxing units (RUs) are explicitly introduced in this relation; thus, this relation offers a novel connection, which differs from the Adam-Gibbs (A-G) entropy relation, between kinetics and thermodynamics, and this relation generalizes several well-known currently used relations. The present relation can provide direct and more accurate estimates of (i) the intrinsic activation enthalpy, (ii) the T-evolution of the configurational entropy loss of the system, and (iii) the self-induced ordering temperature Tc, which characterizes the coupling interaction among RUs. The application of the theory to experimental data for the relaxation time in typical organic liquids demonstrates the validity of the theory.
Lateral inhomogeneity of the Mg/(Zn+Mg) composition at the (Zn,Mg)O/CuIn(S,Se)2 thin-film solar cell interface revealed by photoemission electron microscopy
Authors: Bär M. , Theisen J.-P. , Wilks R. G. , Erfurth F. , Félix R. , Gerlach D. , Haas S. , Tati Bismaths L. , Reinert F. , Kronast F. , Niesen T. P. , Palm J. , Visbeck S. , Weinhardt L.
Published: May 2013

Spatial variations in the chemical composition of the (Zn,Mg)O/CuIn(S,Se)2 thin-film solar cell interface were studied by photoemission electron microscopy (PEEM). Energy filtered PEEM images indicate significant differences in the magnesium and zinc distribution. Local photoemission measurements reveal a relative difference in the derived Mg/(Zn+Mg) composition of the (Zn,Mg)O material of up to (11.4 ± 0.7)%, which can be expected to induce band gap fluctuations of (60 ± 30) meV. Furthermore, local areas with significant accumulations of sodium could be observed.
Baker-Akhiezer functions and generalised Macdonald-Mehta integrals
Authors: Feigin M. V. , Hallnäs M. A. , Veselov A. P.
Published: May 2013

For the rational Baker-Akhiezer functions associated with special arrangements of hyperplanes with multiplicities we establish an integral identity, which may be viewed as a generalisation of the self-duality property of the usual Gaussian function with respect to the Fourier transformation. We show that the value of properly normalised Baker-Akhiezer function at the origin can be given by an integral of Macdonald-Mehta type and explicitly compute these integrals for all known Baker-Akhiezer arrangements. We use the Dotsenko-Fateev integrals to extend this calculation to all deformed root systems, related to the non-exceptional basic classical Lie superalgebras.
Domain evolution processes during poling of a near-morphotropic Pb(Zr, Ti)O3 ceramic
Authors: Kim K. L. , Tsou N. T. , Huber J. E.
Published: May 2013

Domain wall motion during the poling of near-morphotropic Pb(Zr,Ti)O3 PZT was observed using Piezoresponse Force Microscopy (PFM). Poling was conducted on bulk polycrystalline PZT in a series of steps, interrupted by vertical PFM scans, which were used to identify the domain evolution processes. The mechanisms of evolution in complex domain patterns such as herringbone and checkerboard structures are revealed. Of interest, in the case of a herringbone pattern consisting of two sets of lamellae angled to each other, one set of lamellae expands and is observed to overwrite the other, transforming the herringbone structure into a single lamination. Also, lengthening without broadening, and simultaneous lengthening and broadening of lamellar domain bands in checkerboard structures are observed. The observations show that 180° and non-180° domain switching can occur simultaneously in complex domain patterns. Methods are developed for identifying the polarization directions of the individual domains in near-morphotropic PZT. The methods combine a knowledge of the compatible domain configurations with crystallographic data from electron backscatter diffraction and PFM data. The resulting map of polarization directions enables clear identification of the polarization switching mechanisms.
Dopant migration effects in terahertz quantum cascade lasers
Authors: Deutsch C. , Detz H. , Krall M. , Brandstetter M. , Zederbauer T. , Andrews A. M. , Schrenk W. , Strasser G. , Unterrainer K.
Published: May 2013

We demonstrate that dopant migration and the resulting impurity scattering can strongly influence the performance of GaAs/Al0.15Ga0.85As terahertz quantum cascade lasers. A nominally symmetric structure allows us to compare the negative and positive bias behavior of the very same device. Dopants, migrated towards the upper laser level during sample growth, degrade the lasing performance due to enhanced impurity scattering rates. The consequences are a higher threshold current (+30%) and reduced optical output power (–29%) in the affected operating direction. This polarity dependent performance is reversed in an asymmetrically doped sample, which imitates the migration of dopants against the growth direction.
Modeling of plasticity and fracture of metals at shock loading
Authors: Mayer A. E. , Khishchenko K. V. , Levashov P. R. , Mayer P. N.
Published: May 2013

In this paper, we present a model of dislocation plasticity and fracture of metals, which in combination with the wide-range equation of state and the continuum mechanics equations is a necessary component for simulation of the shock-wave loading. We take into account immobilization of dislocations and nucleation of micro-voids in weakened zones of substance; this is distinguished feature of the present version of the model. Accounting of the dislocations immobilization provides a better description of the unloading wave structure, while the detailed consideration of processes in the weakened zones expands the domain of applicability of fracture model to higher strain rates. We compare our results with the experimental data for the shock loading of aluminum, copper, and nickel samples; the comparison indicates satisfactory description of the elastic precursor, unloading wave, and spall pulse. Using the model, we investigate intently the early stage of the shock formation in solids; it is found out that the elastic precursor is formed even for a strong shock wave, and initially the precursor has very large amplitude and propagation velocity.
Peregrine breather revisited
Authors: Shemer L. , Alperovich L.
Published: May 2013

Results of experiments on the evolution of the Peregrine breather (PB) in a wave tank are presented and compared with numerical simulations based on the Nonlinear Schrödinger (NLS) and the Dysthe equations. The experiments demonstrate notable deviation from the NLS solution due to significant asymmetric widening of the spectrum. Good agreement of measurements with the solutions of the Dysthe equation is obtained. Contrary to the PB NLS soliton, no return to the initial undisturbed wave train can be expected.
Young-Lippmann equation revisited for nano-suspensions
Authors: Orejon Daniel , Sefiane Khellil , Shanahan Martin E. R.
Published: May 2013

We present the results of an experimental study investigating electrowetting effects in nano-suspension drops. Wetting of sessile drops of titanium oxide (TiO2) nano-particles dispersed in deionised water was studied under a DC voltage potential. The presence of nano-particles is found to further enhance spreading of drops when a DC potential is applied. Results are explained based on the change in interfacial energy induced by nano-particle adsorption at the solid-liquid interface. An amendment of the Young-Lippmann equation accounting for the presence of nano-particles is proposed. The electrowetting expression proposed is validated against the experimental data for substrates with various dielectric thicknesses.
Superconductor/ferromagnet heterostructures exhibit potential for significant reduction of hysteretic losses
Authors: Krüger Philipp , Grilli Francesco , Vojenčiak Michal , Zermeño Victor M. R. , Demencik Eduard , Farinon Stefania
Published: May 2013

First experimental observations of the ferromagnetic shielding effect in high-Tc superconducting coated conductors were carried out. Experimental results were compared to simulations calling upon finite-element calculations based on the H-formulation of Maxwell equations to model superconducting strips with ferromagnetic shields. Samples of copper-stabilized coated conductors were electroplated with nickel shields and afterwards characterized. Both externally applied oscillating transverse magnetic fields as well as transport currents were studied. Having observed promising gains with respect to the reduction of ac losses in both cases, we further investigated the potential of ferromagnetic shielding. The numerical model was able to reproduce and also predict experimental results very well and will serve as an indispensable tool to determine the potential of soft ferromagnetic materials to significantly reduce hysteretic losses.
Spectral dispersion of ultrafast optical limiting in Coumarin-120 by white-light continuum Z-scan
Authors: Anand Benoy , Roy Nivya , Siva Sankara Sai S. , Philip Reji
Published: May 2013

Measurement of the wavelength dispersion of optical limiting in materials can provide invaluable information useful for laser safety device applications. However, it can be a tedious task when conventional tunable laser sources like the optical parametric amplifier are employed for excitation. Here we report the spectral dispersion of ultrafast optical limiting in the laser dye Coumarin-120 in the wavelength region 630 to 900 nm, measured in a single Z-scan, using the white-light continuum as the excitation source. Optical limiting is found to arise from two-photon absorption, and its spectrum agrees very well in shape with the linear absorption spectrum.
Resonance enhancement of difference-frequency generation through localized surface plasmon excitation
Authors: Fang Xu , Yaginuma Shin , Kubo Wakana , Tanaka Takuo
Published: May 2013

We report the experimental observation of difference-frequency generation in gold nanoparticles under localized surface plasmon excitation. A zero-delay peak is detected in the differential transmission signal for a gold nanoparticle film with a MgF2 overlayer, showing that the energy transfer from pump light to probe light through the difference-frequency generation is resonantly enhanced by the excitation. This peak of differential transmission decreases in strength with higher probe fluences. Both the enhancement and the power dependence of the difference-frequency generation are explained by modeling the localized surface plasmons as a nonlinear Lorentz resonator.
Bidirectional optical switch based on electrowetting
Authors: Liu Chao , Li Lei , Wang Qiong-Hua
Published: May 2013

In this paper, we demonstrate a bidirectional optical switch based on electrowetting. Four rectangular polymethyl methacrylate substrates are stacked to form the device and three ITO electrodes are fabricated on the bottom substrate. A black liquid droplet is placed on the middle of the ITO electrode and surrounded by silicone oil. When we apply a voltage to one ITO electrode, the droplet stretches and moves in one direction and a light beam is covered by the stretched droplet, while the droplet yields a space to let the original blocked light pass through. Due to the shift of the droplet, our device functions as a bidirectional optical switch. Our experiment shows that the device can obtain a wide optical attenuation from ∼1 dB to 30 dB and the transmission loss is ∼0.67 dB. The response time of the device is ∼177 ms. The proposed optical switch has potential applications in variable optical attenuators, electronic displays, and light shutters.
Laser-scanning Doppler photoacoustic microscopy based on temporal correlation
Authors: Song Wei , Liu Wenzhong , Zhang Hao F.
Published: May 2013

We present a methodology to measure absolute flow velocity using laser-scanning photoacoustic microscopy. To obtain the Doppler angle, the angle between ultrasonic detection axis and flow direction, we extracted the distances between the transducer and three adjacent scanning points along the flow and repeatedly applied the law of cosines. To measure flow velocity along the ultrasonic detection axis, we calculated the time shift between two consecutive photoacoustic waves at the same scanning point, then converted the time shift to velocity according to the sound velocity and time interval between two laser illuminations. We verified our method by imaging flow phantoms.
Negative compressibility observed in graphene containing resonant impurities
Authors: Chen X. L. , Wang L. , Li W. , Wang Y. , He Y. H. , Wu Z. F. , Han Y. , Zhang M. W. , Xiong W. , Wang N.
Published: May 2013

We observed negative compressibility in monolayer graphene containing resonant impurities under different magnetic fields. Hydrogenous impurities were introduced into graphene by electron beam (e-beam) irradiation. Resonant states located in the energy region of ±0.04 eV around the charge neutrality point were probed in e-beam-irradiated graphene capacitors. Theoretical results based on tight-binding and Lifshitz models agreed well with experimental observations of graphene containing a low concentration of resonant impurities. The interaction between resonant states and Landau levels was detected by varying the applied magnetic field. The interaction mechanisms and enhancement of the negative compressibility in disordered graphene are discussed.
Investigation of the release of Si from SiO2 during the formation of manganese/ruthenium barrier layers
Authors: McCoy A. P. , Casey P. , Bogan J. , Byrne C. , Hughes G.
Published: May 2013

The thermodynamic and structural stability of ruthenium-manganese diffusion barriers on SiO2 is assessed. A ∼2 nm film composed of partially oxidized manganese (MnOx where x < 1) was deposited on a 3 nm thick Ru film and the Mn-MnOx/Ru/SiO2 structure was subsequently thermally annealed. X-ray photoelectron spectroscopy and secondary ion mass spectroscopy studies suggest the release and upward diffusion of Si from the dielectric substrate as a result of manganese-silicate formation at the Ru/SiO2 interface. The migration of Si up through the Ru film results in further manganese-silicate formation upon its interaction with the Mn-MnOx deposited layer.
Pressure-sensing based on photothermally coupled operation of micromechanical beam resonator
Authors: Kim D. H. , Lee E. J. , Cho M. R. , Kim C. S. , Park Y. D. , Kouh T.
Published: May 2013

Here, we demonstrate the pressure-sensing scheme based on the photothermal effect in the miniaturized beam resonator in the moderate pressure range. Since the resonance frequency of the small beam resonator under thermal stress can be easily modulated by the convective cooling of the gas molecules, the pressure change has been monitored by tracking the frequency shift under constant optical power. Our experimental measurements as well as the analytical model show that the described technique ensures the fast response to the external pressure variation with high responsivity as well as much sought-after scalability, desirable for many technological applications.
Modulation of Dirac points and band-gaps in graphene via periodic fullerene adsorption
Authors: Liu Xiao , Wen Yanwei , Chen Zhengzheng , Lin Hao , Chen Rong , Cho Kyeongjae , Shan Bin
Published: May 2013

The structural, energetic and electronic properties of periodic graphene nanobud (PGNB) with small-diameter fullerenes (C20, C34, C42, and C60) adsorbed have been investigated by first-principles plane wave method. The bond-to-ring cycloaddition is found to be energetically most stable among various configurations and the minimum energy paths of different-sized fullerenes attaching to graphene indicate that smaller fullerene shows lower energy barriers due to its larger surface curvature. For perfectly ordered adsorption, band structures analyses by both density functional theory (DFT) and tight binding (TB) methods show that the Dirac cone of graphene can be generally preserved despite the sp2 to sp3 bond hybridization change for selected carbon atoms in graphene sheet. However, the position of the Dirac points inside the Brillouin zone has a shift from the hexagonal corner and can be effectively modulated by changing the fullerenes’ concentration. For practical applications, we show that a considerable band gap (∼0.35 eV) can be opened by inducing randomness in the orientation of the fullerene adsorption and an effective order parameter is identified that correlates well with the magnitude of the band gap opening.
Strain dependent magnetocaloric effect in La0.67Sr0.33MnO3 thin-films
Authors: Kumar V. Suresh , Chukka Rami , Chen Zuhuang , Yang Ping , Chen Lang
Published: May 2013

The strain dependent magnetocaloric properties of La0.67Sr0.33MnO3 thin films deposited on three different substrates (001) LaAlO3 (LAO), (001) SrTiO3 (STO), and (001) La0.3Sr0.7Al0.65Ta0.35O9 (LSAT) have been investigated under low magnetic fields and around magnetic phase transition temperatures. Compared to bulk samples, we observe a remarkable decrease in the ferromagnetic transition temperature that is close to room temperature, closely matched isothermal magnetic entropy change and relative cooling power values in tensile strained La0.67Sr0.33MnO3 films. The epitaxial strain plays a significant role in tuning the peak position of isothermal magnetic entropy change towards room temperature with improved cooling capacity.
Effect of stenting after laryngotracheal reconstruction in a subglottic stenosis model
Authors: Jewett Brian S. , Cook Raymond D. , Johnson Kenneth L. , Logan Thomas C. , Shockley William W.
Published: May 2013

OBJECTIVES

This study addresses the impact of stenting on early wound healing after laryngotracheal reconstruction (LTR) in a rabbit model with established subglottic stenosis.

METHODS

Subglottic stenosis was created in 42 New Zealand white rabbits through a transoral, endoscopic technique. Three weeks later, endoscopy and axial CT were performed to document and grade the degree of stenosis. Subsequently, LTR was performed in all animals, with half of the animals receiving an intraluminal stent. Four rabbits from each group were euthanized on postoperative days 6, 9, 14, 21, and 28. Measurements of graft vascularization were obtained with a computerized image measurement program, and a comparison was made regarding the rate of vascularization.

RESULTS

There was a statistically significant increase in the rate of vascularization in the stented group (mean 75% ± 5% vs 56% ± 3% at day 14;P< 0.05). However, clinical and radiographic comparisons of the stented and nonstented specimens revealed a trend toward increased mucosal edema and granulation tissue in the stented group at later time intervals (days 21 and 28).

CONCLUSION

This analysis suggests that stenting does not inhibit graft vascularization in the early postoperative period after LTR; however, complications were seen in the stented group at longer time intervals.
Efficacy of serologic testing in asymmetric sensorineural hearing loss
Authors: Sabini Paul , Sclafani Anthony P.
Published: May 2013

PURPOSE

The goal of this study was to determine the efficacy of a detailed questionnaire, auditory brain stem response testing (ABR), MRI, and an extensive battery of serologic tests in diagnosing asymmetric sensorineural hearing loss (ASNHL).

METHODS AND MATERIAL

Patients with audiograms demonstrating ASNHL of 10 dB or greater in 2 consecutive frequencies or 15 dB in any 1 frequency between 250 and 6000 Hz were asked to participate. Patients underwent MRI scanning of the cerebellopontine angle, internal auditory canals, and posterior fossa with gadolinium contrast, ABR, and an extensive battery of tests. The causative diagnosis was made by the individual clinician based on each patient's history, physical examination, and test results.

RESULTS

Forty‐five patients completed the study. A review of the data confirmed the utility of a detailed history and physical examination, MRI, and fluorescent treponemal antibody test in all cases. Erythrocyte sedimentation rate, glycosylated hemoglobin, Lyme antibody titers, and total hemolytic component (CH50) were helpful in selected cases. Thyroid function testing, complete blood count, Sequential Multiple Analysis‐7, prothrombin time/partial thromboplastin time, lipid profile, and ABR were of no value in these patients.

CONCLUSION

A careful history and physical examination, MRI, and fluorescent treponemal antibody test should be performed for the evaluation of all patients with ASNHL; however, more extensive serologic testing, including sedimentation rate, glycosylated hemoglobin, Lyme antibody titers, and CH50, should be selectively performed, based on a suggestive history or suspicious physical findings.
Dexamethasone pharmacokinetics in the inner ear: Comparison of route of administration and use of facilitating agents
Authors: Chandrasekhar Sujana S. , Rubinstein Ran Y. , Kwartler Jed A. , Gatz Michael , Connelly Patricia E. , Huang Elizabeth , Baredes Soly
Published: May 2013

There is growing otologic interest in treating inner ear disorders, such as sudden sensorineural hearing loss and acute or unremitting Meniere's disease, with intratympanic dexamethasone (IT‐DEX). Although anecdotally reported, there are no scientific clinical papers and few prior laboratory research publications on the subject. This study compares perilymph dexamethasone concentrations after systemic and intratympanic administration and assesses the role of 3 potential transport facilitators of IT‐DEX into perilymph. Forty guinea pigs (79 ears) were randomly separated into 5 groups. Dexamethasone levels were measured by radioimmunoassay. IT‐DEX resulted in higher perilymph steroid levels than intravenous dexamethasone (P < 0.05). Histamine facilitator resulted in significantly higher perilymph steroid levels than IT‐DEX alone (P < 0.05). Neither hyaluronic acid nor dimethylsulfoxide was a potent facilitator. This study demonstrates that IT‐DEX administration results in superior perilymph levels within 1 hour of administration and does not result in systemic absorption. Histamine is a potent facilitating agent. The clinical implications are considerable.
Health status in patients with disturbed sleep and obstructive sleep apnea
Authors: Gliklich Richard E. , Taghizadeh Farhan , Winkelman John W.
Published: May 2013

The health status of 435 consecutive patients with sleep disturbances necessitating polysomnography was investigated. Patients underwent overnight polysomnography and health status assessment, including the Medical Outcomes Study SF‐36 Health Survey and the Pittsburgh Sleep Quality Index. Based on a respiratory distress index (RDI) greater than 10 to define apnea, patients with apnea were significantly (P < 0.05) more likely to be male, be older, and have higher body mass index and lower oxygen saturation levels than patients without apnea. Multiple domains of the SF‐36 Health Survey and the Pittsburgh Sleep Quality Index were significantly worse (P < 0.05) for this population when normative data were compared. Although few differences were observed between the apneic and nonapneic patients when a cutoff point for apnea was defined as an RDI greater than 10 or 20, increasing RDI was significantly associated with worsening physical functioning scores. Overall, decrements in health status measures were more strongly correlated with the number of oxygen desaturations below 85% than with increasing RDI. We conclude that patients with sleep disturbances demonstrate significant decrements in general and sleep‐specific health status, but these decrements are more closely associated with oxygen desaturation than RDI.
Magnetic resonance imaging of the facial nerve in children with idiopathic facial paralysis
Authors: Burgio Don L. , Siddique Shoab , Haupert Michael , Meleca Robert J.
Published: May 2013

The role of gadolinium‐enhanced MRI (Gd‐MRI) in the diagnosis of idiopathic facial paralysis (IFP) in children is not well defined. Fourteen children with IFP were evaluated to assess the use of Gd‐MRI for the presence and pattern of enhancement and its usefulness in predicting the recovery of facial function. Six of 14 children had enhancement of the facial nerve on Gd‐MRI, whereas 8 had none. Enhancement was noted in the tympanic, mastoid, and most commonly in the distal intracanalicular and labyrinthine segments. The average time from onset of paresis to recovery in patients with enhancement was 19.3 weeks, whereas in those with no enhancement, mean recovery time was 9.5 weeks (P = 0.003, t test). All 14 patients eventually had recovery to House‐Brackmann grade I or II. Gd‐MRI is not required for all children with IFP but may yield information about the time course of recovery of facial function.
Sensory recovery in melolabial flaps used for oral cavity reconstruction
Authors: Civantos Francisco J. , Roth Jeffrey , Goodwin W. Jarrard , Weed Donald T.
Published: May 2013

Current literature advocates the use of complex reinnervated free flaps to re‐establish oral sensation after resection of oral cavity cancers. It has been demonstrated that noninnervated flaps can also re‐establish sensation. We assessed the return of sensation in local melolabial flaps used in oral reconstruction. Seven patients underwent sensory testing at intervals from 12 to 18 months after surgery. The ability to distinguish differences in temperature was present in all patients. Spontaneous return of sensitivity to touch was documented by clinical testing in 71% of the patients. Less return of sensation was seen in flaps used for defects of the buccal mucosa relative to the floor of mouth. We conclude that spontaneous return of flap sensation does occur with local melolabial flaps. Given the simplicity of these procedures, melolabial flaps represent a reasonable alternative in floor‐of‐mouth reconstruction for selected patients.
Deterioration of intraoral recognition of shapes after treatment of oral and pharyngeal cancer
Authors: Bodin Ingrid , Lind Magnus , Henningsson Gunilla , Isberg Annika
Published: May 2013

Thirty patients with diagnosed malignant tumors of the oral cavity or pharynx were tested in regards to intraoral shape recognition at 4 test occasions: before all treatment, after radiotherapy, 6 months after surgery, and 1 year after surgery. They were compared within groups as well as with a group of healthy reference individuals of the same age who underwent the same test procedure at a 2‐month interval. The tumor itself did not influence the capability of shape recognition. The reference individuals demonstrated significantly better results on the second test occasion, which is known as a learning effect. Learning improvement was not seen in the patients whose second test occasions were after radiotherapy, implying an impediment amounting to the magnitude of the learning effect. At 6 months after surgery the patients' capabilities of shape recognition had deteriorated significantly with no difference between the oral cancer group and the pharyngeal cancer group. No spontaneous rehabilitation had taken place 1 year after surgery. The presence or absence of surgical lingual nerve damage did not influence the results. The nonoperated side does not compensate for the operated one. It is plausible that decreased oral sensory acuity in recognizing the shape of the bolus contributes to postoperative swallowing problems.
Diagnosis and documentation of central nervous system dysfunctions with craniocorpography after surgical removal of acoustic neurinomas
Authors: Gomez‐Angel Diego , Fierek Oliver , Madrazo Juan , O'Connor‐Reina Carlos , Galera‐Ruiz Hugo
Published: May 2013

Among other tests, craniocorpography (CCG) was performed in 21 patients after acoustic neurinoma surgery. After surgery, 17 patients (81%) had a developing vestibular compensation or an already normal CCG pattern; 3 patients (14%) had signs of persisting central nervous system dysfunction, either localized to the brain stem or in combination with a cerebellar dysfunction, and 1 patient showed a delayed but sufficient compensation after removal of a neurinoma that compressed central nervous system structures. Brain stem and cerebellar dysfunctions caused by tumor compression demonstrated a better vestibular compensation than dysfunctions caused by surgical manipulation, despite no evidence of cerebellar alteration. As an adjunct to complete neuro‐otologic and neurologic examinations CCG could become a useful tool in the topodiagnosis of central nervous system dysfunctions after acoustic neurinoma surgery and therefore in the documentation and follow‐up process of these patients.
Benefits of cochlear implantation in elderly patients
Authors: Shin Young‐Je , Fraysse Bernard , Deguine Olivier , Valès Olivier , Laborde Marie‐Laurence , Bouccara Didier , Sterkers Olivier , Uziel Alain
Published: May 2013

Cochlear implantation in elderly patients is a questionable subject. The purpose of this study was to evaluate the procedure and its outcome, the postoperative course, and the audiologic and social benefits of cochlear implantation in this population. Twenty‐seven patients older than 60 years were compared with a control group of 15 adult patients. This retrospective study analyzed data concerning the outcome of the procedure, postoperative course, postoperative orthophonic test results, and answers of a questionnaire assessing the changes in communication, perception, and social outcomes. The procedure was uneventful in both groups. Minor complications were not more frequent in elderly patients. Orthophonic test results were comparable in both groups. At 12 months, 83% of the elderly patients had an open‐set speech discrimination score above 60%. The benefits of cochlear implantation in terms of the quality of life are not statistically different with younger patients. Cost‐utility analysis might support these findings.
Effect of gastroesophageal reflux on hypertrophy of the base of the tongue
Authors: Mamede Rui Celso Martins , De Mello‐Filho Francisco Verissimo , Vigário Lineu celso , Dantas Roberto Oliveira
Published: May 2013

The objective of this study was to determine a possible association between pharyngolaryngeal signs of gastroesophageal reflux (GER) and hypertrophy of the lymphoid follicles at the base of the tongue (HBT). For this purpose, 306 patients submitted to videolaryngoscopy were studied retrospectively and classified according to the presence and size of follicles on the base of the tongue. HBT was considered to be present when the follicles prevented the view of the vallecula. The patients were grouped according to the presence of videolaryngoscopic signs of GER and further subdivided according to the presence of esophageal, pharyngolaryngeal, and esophagopharyngolaryngeal symptoms, with an attempt made to relate these symptoms to the presence of HBT. HBT was detected in 62.4% (63/101) of the patients with signs of GER and in 29.3% (60/205) of patients with no signs of GER. When HBT incidence was studied according to the symptoms reported by the patient, the condition was found to be present in 57.2% (8/14) of patients with exclusively esophageal symptoms, in 63.6% (21/33) with esophagopharyngolaryngeal symptoms, and in 75% (15/20) with exclusively pharyngolaryngeal symptoms. We conclude therefore that HBT is associated with GER.
Quantitative molecular assays for evaluating changes in broiler gut microbiota linked with diet and performance
Authors: Torok V. A. , Dyson C. , McKay A. , Ophel-Keller K.
Published: May 2013

Changes in the levels of specific gut bacteria have been linked to improved broiler feed efficiency. Quantitative polymerase chain reaction (qPCR) assays were developed to five potential performance-related bacteria (Lactobacillus salivarius, L. crispatus, L. aviarius, Gallibacterium anatis and Escherichia coli) and generic eubacteria. These were used to screen broiler gut samples from four geographically diverse Australian feeding trials showing significant treatment-related differences in feed efficiency. It was our aim to validate the association of particular bacteria with broiler feed efficiency across a broad range of environmental and dietary conditions, and hence to evaluate their predictive potential for monitoring broiler performance. Across trials L. salivarius, L. crispatus, L. aviarius, E. coli and total eubacterial numbers were significantly altered by diet, environment (litter), and/or sex of birds. Furthermore, changes in the numbers of these gut bacteria were significantly linked to broiler performance. Lactobacilli and total eubacteria were significantly decreased in birds that were more feed efficient. E. coli was not consistently linked with either improved or decreased performance and these discrepancies may be due to differences at the strain level which were not detectable using our assays. G. anatis was detected only in two of the four trials and found not to be significantly linked with broiler performance. These qPCR assays have been useful in either validating or disproving previous reported findings for the association of specific gut bacteria with broiler feed efficiency. This qPCR format can be easily expanded to include other organisms and used as a quantitative screening tool in evaluating dietary additives for improved broiler production.
Effect of nest temperature on hatchling phenotype of loggerhead turtles (Caretta caretta) from two South Pacific rookeries, Mon Repos and La Roche Percée
Authors: Read Tyffen , Booth David T. , Limpus Colin J.
Published: May 2013

La Roche Percée, in New Caledonia, is the most important loggerhead turtle rookery outside of Australia for the eastern Pacific genetic stock. The females nesting on this beach are genetically similar to the females found at the Mon Repos rookery in Queensland, Australia. This study shows how nest temperature affects the phenotype of genetically similar populations. During the 2010–11 breeding season, mean nest temperatures were significantly higher at La Roche Percée (31.8°C) than at Mon Repos (29.5°C) and the mean for the three-days-in-a-row maximum nest temperatures was also significantly higher at La Roche Percée (34.6°C), than at Mon Repos (31.7°C). Differences were found in mean hatching success (La Roche Percée 83 ± 3%, Mon Repos 96 ± 2%) and emergence success (La Roche Percée 76 ± 3%, Mon Repos 93 ± 3%). Hatchlings from La Roche Percée also had significantly lower fitness characteristics, having smaller carapace size (La Roche Percée 1565 ± 7 mm2, Mon Repos 1634 ± 5 mm2), slower self-righting times (La Roche Percée 4.7 ± 0.1 s, Mon Repos 2.7 ± 0.1 s) and slower crawling speed in terms of both absolute speed and body lengths per second (La Roche Percée 2.5 ± 0.2 cm s–1 or 0.57 ± 0.05 body lengths s–1, Mon Repos 4.6 ± 0.1 cm s–1 or 1.04 ± 0.02 body lengths s–1). Nest temperatures at La Roche Percée approached the upper limit of embryo thermal tolerance towards the end of incubation (34°C) and this condition may contribute to the lower hatching and emergence success and lower fitness characteristics of hatchlings at the La Roche Percée rookery.
Classifying spaces of degenerating mixed Hodge structures, III: Spaces of nilpotent orbits
Authors: Kato Kazuya , Nakayama Chikara , Usui Sampei
Published: May 2013

We construct toroidal partial compactifications of the moduli spaces of mixed Hodge structures with polarized graded quotients. They are moduli spaces of log mixed Hodge structures with polarized graded quotients. We construct them as the spaces of nilpotent orbits.
Predicting XAFS scattering path cumulants and XAFS spectra for metals (Cu, Ni, Fe, Ti, Au) using molecular dynamics simulations
Authors: Karolewski M. A. , Cavell R. G. , Gordon R. A. , Glover C. J. , Cheah M. , Ridgway M. C.
Published: May 2013

The ability of molecular dynamics (MD) simulations to support the analysis of X-ray absorption fine-structure (XAFS) data for metals is evaluated. The low-order cumulants (ΔR, σ2,C3) for XAFS scattering paths are calculated for the metals Cu, Ni, Fe, Ti and Au at 300 K using 28 interatomic potentials of the embedded-atom method type. The MD cumulant predictions were evaluated within a cumulant expansion XAFS fitting model, using global (path-independent) scaling factors. Direct simulations of the corresponding XAFS spectra, χ(R), are also performed using MD configurational data in combination with theFEFFab initiocode. The cumulant scaling parameters compensate for differences between the real and effective scattering path distributions, and for any errors that might exist in the MD predictions and in the experimental data. The fitted value of ΔRis susceptible to experimental errors and inadvertent lattice thermal expansion in the simulation crystallites. The unadjusted predictions of σ2vary in accuracy, but do not show a consistent bias for any metal except Au, for which all potentials overestimate σ2. The unadjustedC3predictions produced by different potentials display only order-of-magnitude consistency. The accuracy of direct simulations of χ(R) for a given metal varies among the different potentials. For each of the metals Cu, Ni, Fe and Ti, one or more of the tested potentials was found to provide a reasonable simulation of χ(R). However, none of the potentials tested for Au was sufficiently accurate for this purpose.
Accuracy evaluation in temperature-dependent EXAFS measurements of CdTe
Authors: Abd el All N. , Thiodjio Sendja B. , Grisenti R. , Rocca F. , Diop D. , Mathon O. , Pascarelli S. , Fornasini P.
Published: May 2013

The evaluation of uncertainty in temperature-dependent EXAFS measurements is discussed, considering the specific case of a recent experiment performed on CdTe. EXAFS at both Cd and TeK-edges was measured at different times and at different beamlines in a temperature range from 5 to 300 K. Attention is focused on the nearest-neighbours parameters: bond thermal expansion, parallel and perpendicular mean-square relative displacements and the third cumulant. Different causes of uncertainty, a comparison of experimental results with theoretical models, the difference between EXAFS and crystallographic thermal expansions and the meaning of the third cumulant are discussed.
Clinical effects of stereotactic radiation surgery in patients with metastatic melanoma
Authors: Mikoshiba Asuka , Uhara Hisashi , Murata Hiroshi , Okuyama Ryuhei
Published: May 2013

We examined the effectiveness of stereotactic radiation surgery (SRS) in 14 patients with brain metastasis in our hospital. The age of the patients ranged 45–85 years old (mean, 65). Brain metastasis was detected by neurological symptoms in seven patients and by regular imaging examination in the remaining patients. The number of metastatic lesions in the brain before SRS ranged 1–11 (median, 2). The treatment number of SRS was 1–4 times (median, 2). Six of 14 patients had neurological symptoms before SRS. Overall survival (OS) after SRS was 1.7–21.2 months (median, 8.2). The progression‐free survival (PFS) after SRS was 0.9–10.5 months (median, 2.2). The result of univariate analysis showed that the application of two or more courses of SRS was significantly related to OS (P = 0.005). Single metastatic lesion (P = 0.051) and no extracranial lesion (P = 0.055) showed a slight tendency to be related to disease‐free survival (DFS). Neither lactate dehydrogenase nor neurological symptoms were significantly related to OS or DFS. Although OS and DFS after SRS were not very long, the treatment of brain metastases has the potential to prevent neurological events. Repeating SRS may be accepted as a local therapy in the multimodal approach including new molecular targeting drugs for metastatic melanoma.
Prevalence and viral DNA loads of three novel human polyomaviruses in skin cancers from Japanese patients
Authors: Imajoh Masayuki , Hashida Yumiko , Nakajima Hideki , Sano Shigetoshi , Daibata Masanori
Published: May 2013

Merkel cell polyomavirus (MCPyV), human polyomaviruses 6 (HPyV6) and 7 (HPyV7) are novel human polyomaviruses. This study investigated their detection rates and DNA loads in various skin cancers from Japanese patients. MCPyV, HPyV6 and HPyV7 were detected in 22.2%, 3.2% and 1.6% of squamous cell carcinomas, 18.0%, 2.0% and 4.0% of basal cell carcinomas, and 19.1%, 4.3% and 4.3% of melanomas, respectively. Quantitative real‐time polymerase chain reaction showed that their DNA loads were low. These findings provide the first evidence of the prevalence of HPyV6 and HPyV7 in skin cancers in Asia. Nucleotide differences were found in the large T‐sequenced region between Japanese and North American isolates: a nucleotide substitution of A to G for HPyV6; and a nucleotide substitution of T to C and the insertion of a gap for HPyV7. This suggested that two genotypes of HPyV6 and HPyV7 would be present and associated with geographical origin.
Physiological mechanisms for the increase in renal solute‐free water clearance by a glucagon‐like peptide‐1 mimetic
Authors: Kutina Anna V , Marina Anna S , Shakhmatova Elena I , Natochin Yury V
Published: May 2013

The aim of the present study was to clarify the mechanisms mediating the effect of a glucagon‐like peptide‐1 (GLP‐1) mimetic on solute‐free water excretion in rats.

The GLP‐1 mimetic exenatide (0.05–5.0 nmol/kg, i.m.), alone and in combination with either a vasopressin V2 receptor antagonist (15 nmol/kg, i.p.) or vasopressin (0.01 nmol/kg, i.m.), was injected into control and water‐loaded (water 10–50 mL/kg, p.o., or 50 mL/kg of 0.6% NaCl, i.p.) rats to evaluate the role of collecting duct water permeability in the hydrouretic effect. Urinary prostaglandin (PG) E2 excretion and the effects of diclofenac (5 mg/kg, i.m.) and GLP‐1 receptor antagonist (0.15 μmol/kg, i.p.) on exenatide action were assessed.

The hydrouretic effect of exenatide was equivalent following oral or intraperitoneal water loading, and was proportional to the volume of water administered. Injection of exenatide, under conditions of a maximal decrease in collecting duct water permeability (V2 receptor antagonist administration in water‐loaded rats), additionally stimulated solute‐free water formation. The GLP‐1 receptor antagonist weakened the hydrouretic action of exenatide. Urinary PGE2 excretion increased following water loading (47 ± 6 vs 24 ± 4 ng/kg over a 30 min period) and was enhanced as a result of additional exenatide injection (69 ± 10 ng/kg). Diclofenac and vasopressin delayed the hydrouretic effect of exenatide.

The effect of exenatide on solute‐free water clearance in water‐loaded rats is presumably mediated by stimulation of PGE2 secretion and reinforcement of tubular fluid influx from the proximal tubule to the distal segment of the nephron and collecting duct.