bluuebunny/crossref_metadata_2025 huggingface dataset:
Threshold photoelectron study of naphthalene, anthracene, pyrene, 1,2-dihydronaphthalene, and 9,10-dihydroanthracene
Authors: Mayer Paul M. , Blanchet Valerie , Joblin Christine
Published: June 2011

Threshold photoelectron spectra (TPESs) were obtained for naphthalene, anthracene, pyrene, 1,2-dihydronaphthalene, and 9,10-dihydroanthracene using imaging photoelectron photoion coincidence spectroscopy, from threshold to a photon energy of ∼20 eV. Outer valence Green's function calculations at the OVGF/cc-pVTZ level of theory were used to assign molecular orbitals to the observed TPES features. There is generally good agreement between the predicted and observed bands. Threshold regions for each molecule exhibit vibrational structure which is readily assigned based on previous PES studies. While the measured adiabatic ionization energies (IEa) for naphthalene, anthracene, and pyrene are in good agreement with previous works, new values are reported for the two dihydro species (1,2-dihydronaphthalene, 8.010 ± 0.010 eV and 9,10-dihydroanthracene, 8.335 ± 0.010 eV). A comparison is also made with the G3//B3LYP composite method, which consistently overestimates the IE values by 0.06–0.09 eV. The double ionization energies for anthracene and pyrene have been measured to be 19.3 ± 0.2 and 19.8 ± 0.2 eV, respectively.
High thermoelectric figure of merit in the Cu3SbSe4-Cu3SbS4 solid solution
Authors: Skoug Eric J. , Cain Jeffrey D. , Morelli Donald T.
Published: June 2011

We report thermoelectric properties of selected compounds from the Cu3SbSe4-Cu3SbS4 system. Additional phonon scattering due to the disordered arrangement of Se and S atoms reduces the lattice thermal conductivity to near its minimum possible value at high temperature. The hole concentration is optimized at approximately 2.0 × 1020 cm−3 by doping with 3% Ge on the Sb site. Compounds of the form Cu3Sb1−yGeySe4−xSx (x = 0.8 and 1.2, y = 0.02 and 0.03) all have dimensionless thermoelectric figure of merit in excess of 0.8 at 650 K, with a maximum value of 0.89 for x = 1.2, y = 0.03.
Ultrasonic control of terahertz radiation via lattice anharmonicity in LiNbO3
Authors: Poolman R. H. , Ivanov A. L. , Muljarov E. A.
Published: June 2011

We propose a tunable terahertz (THz) filter using the resonant acousto-optic (RAO) effect. We present a design based on a transverse optical (TO) phonon mediated interaction between a coherent acoustic wave and the THz field in LiNbO3. We predict a tunable range for the filter of up to 4 THz via the variation of the acoustic frequency between 0.1 and 1 GHz. The RAO effect in this case is due to cubic and quartic anharmonicities between TO phonons and the acoustic field. The effect of the interference between the anharmonicities is also discussed.
The influence of Hausdorff dimension on plasmonic antennas with Pascal’s triangle geometry
Authors: Sederberg S. , Elezzabi A. Y.
Published: June 2011

We introduce fractal geometry to the common bowtie antenna and investigate the influence of a key fractal parameter, Hausdorff dimension, on the broadband spectral response of the antenna. Length scaling trends are presented for antennas having various Hausdorff dimensions. We show that antennas with Pascal’s triangle geometry accommodate resonances that are red-shifted when compared to a standard bowtie antenna having the same size. Furthermore, increasing the Hausdorff dimension of the antenna blue shifts its resonance. By designing nanoplasmonic antennas with Pascal’s triangle geometry, the resonance conditions may be varied while the antenna dimensions are kept constant.
Current-induced cleaning of adsorbates from suspended single-walled carbon nanotube diodes
Authors: Malapanis Argyrios , Comfort Everett , Ung Lee Ji
Published: June 2011

Due to their large surface-to-volume ratio compared to that of a bulk semiconductor, carbon nanotubes are very sensitive to their environment. Their properties can be dramatically changed by simple exposure to air. Here, we show that the electronic and optical properties of p-n diodes fabricated with single-walled carbon nanotubes degrade over time with exposure to ambient conditions, mainly due to adsorption onto the tube’s suspended part, which creates band-gap states. Most importantly, we demonstrate a simple technique—current annealing—that can thermally reverse such degradation.
Inert gas jets for growth control in electron beam induced deposition
Authors: Henry M. R. , Kim S. , Rykaczewski K. , Fedorov A. G.
Published: June 2011

An inert, precursor free, argon jet is used to control the growth rate of electron beam induced deposition. Adjustment of the jet kinetic energy/inlet temperature can selectively increase surface diffusion to greatly enhance the deposition rate or deplete the surface precursor due to impact-stimulated desorption to minimize the deposition or completely clean the surface. Physical mechanisms for this process are described. While the electron beam is also observed to generate plasma upon interaction with an argon jet, our results indicate that plasma does not substantially contribute to the enhanced deposition rate.
On the effect of Ti on the stability of amorphous indium zinc oxide used in thin film transistor applications
Authors: Lee Sunghwan , Paine David C.
Published: June 2011

In2O3-based amorphous oxide channel materials are of increasing interest for thin film transisitor applications due, in part, to the remarkable stability of this class of materials amorphous structure and electronic properties. We report that this stability is degraded in the presence of Ti, which is widely used as a contact and/or adhesion layer. A cross-sectional transmission electron microscopy analysis, supported by glancing incident angle x-ray and selected area diffraction examination, shows that amorphous indium zinc oxide in contact with Ti undergoes crystallization to the bixbyite phase and reacts to form the rutile phase of TiO2 at a temperature of 200 °C. A basic thermodynamic analysis is presented and forms the basis of a model that describes both the crystallization and the resistivity decrease.
Self-consistent physical modeling of set/reset operations in unipolar resistive-switching memories
Authors: Bocquet Marc , Deleruyelle Damien , Muller Christophe , Portal Jean-Michel
Published: June 2011

This Letter deals with a self-consistent physical model for set/reset operations involved in unipolar resistive switching memories integrating a transition metal oxide. In this model, set operation is described in terms of a local electrochemical reduction of the oxide leading to the formation of metallic conductive filaments. Beside, reset operation relies on the thermally assisted destruction of the formed metallic filaments by Joule heating effect. An excellent agreement is demonstrated with numerous published experimental data suggesting that this model can be confidently implemented into circuit simulators for design purpose.
Enhanced Faraday rotation in magnetophotonic crystal infiltrated with graphene
Authors: Da Haixia , Liang Gengchiau
Published: June 2011

We investigate the Faraday rotation angle of a bilayer structure composed of graphene and SiC using the transfer matrix method and find that the cyclotron resonance frequency is highly sensitive to the magnetic field due to the Dirac quasiparticles characteristics of graphene. As a truly single atomic sheet, the giant Faraday rotation angle in graphene originates from its two dimensional free carriers distributions. Compared to the bilayer structure in experiments, further enhancement in the Faraday rotation can be achieved in a designed magnetophotonic crystal infiltrated with graphene because of graphene’s nonreciprocity. The sensitivity of the optical conductivity of graphene on the magnetic field indicates its possibility of realizing tunable magnetooptical effects.
Epitaxial growth of Heusler alloy Co2MnSi/MgO heterostructures on Ge(001) substrates
Authors: Li Gui-fang , Taira Tomoyuki , Matsuda Ken-ichi , Arita Masashi , Uemura Tetsuya , Yamamoto Masafumi
Published: June 2011

We prepared Heusler alloy Co2MnSi/MgO heterostructures on single-crystal Ge(001) substrates through magnetron sputtering for Co2MnSi and electron beam evaporation for MgO as a promising candidate for future generation spin-based functional devices. Structural investigations showed that the Co2MnSi/MgO heterostructure was grown epitaxially on a Ge(001) substrate with extremely smooth and abrupt interfaces and showed the L21 structure for the Co2MnSi film. Furthermore, a sufficiently high saturation magnetization (μs) value of 5.1 µB/f.u. at 10 K, which is close to the theoretically predicted μs of 5.0 µB/f.u. for half-metallic Co2MnSi, was obtained for prepared Co2MnSi films.
Inelastic scattering of surface plasmons in oscillating metallic waveguides
Authors: Wang Bing , Teng Jinghua , Yuan Xiaocong
Published: June 2011

By using a metal-insulator-metal waveguide with temporally oscillating core width, the single frequency of incident surface plasmon polaritons (SPPs) could be converted to many discrete frequencies with equivalent intervals. The conversion efficiency is affected by the waveguide structure and also the amplitude and frequency of the oscillation. Finite-difference time-domain simulations revealed that the SPP frequency shift behavior is analogous to the spatial light diffraction in optical waveguide arrays. The discrete frequencies of SPPs can further be controlled by varying the initial phase of the waveguide core width oscillation. The results are explained analytically using the coupled mode theory.
Enhancement of reflective second harmonic generation using periodically arrayed silver-island films
Authors: Hsu Chia-Jung , Chiu Kuo-Pin , Lue Juh-Tzeng , Yao Lo Kuang
Published: June 2011

The characteristics of angle-resolved optical second harmonic generation (SHG) reflectance from periodically arrayed silver-island films were investigated. The silver-island films were fabricated using micro-spherical lithography. The SHG intensity from these arrays was more than one order of magnitude greater than that of flat silver films for some angles of incidence. This enhancement arises from the excitation of surface plasmon resonance at the pumping frequency. We found this resonance by analyzing the reciprocal lattice phase-matching condition for the silver-island films. The predicted surface plasmon wave vectors are in good agreement with those obtained using three-dimensional finite-difference time-domain numerical simulations.
Scaling of flat band potential and dielectric constant as a function of Ta concentration in Ta-TiO2 epitaxial films
Authors: Zhao Y. L. , Barman A. Roy , Dhar S. , Annadi A. , Motapothula M. , Wang Jinghao , Su Haibin , Breese M. , Venkatesan T. , Wang Q.
Published: June 2011

Electrochemical impedance spectroscopy measurements of pulsed laser deposited single crystal anatase TiO2 thin films with various concentrations of Ta substituting for Ti were carried out. The qualities of the films were characterized by X-ray diffraction and Rutherford back scattering-channeling measurements. UV-visible measurements show a systematic increase of the bandgap with Ta incorporation. Corresponding Mott-Schottky plot was applied to obtain a continuous shift of the flat band potential with increasing free charge carrier (provided by Ta) concentration. This was verified theoretically by ab initio calculation which shows that extra Ta d-electrons occupy Ti t2g orbital with increasing Ta concentration, thereby pushing up the Fermi level. The Mott-Schottky results were consistent when compared with Hall effect and temperature dependent resistivity measurements. From the measured deviation of carrier densities from Hall and Mott-Schottky measurements we have estimated the static dielectric constant of the TiO2 as a function of Ta incorporation, not possible from capacitive measurements.
Defect-induced magnetism in undoped wide band gap oxides: Zinc vacancies in ZnO as an example
Authors: Xing G. Z. , Lu Y. H. , Tian Y. F. , Yi J. B. , Lim C. C. , Li Y. F. , Li G. P. , Wang D. D. , Yao B. , Ding J. , Feng Y. P. , Wu T.
Published: June 2011

To shed light on the mechanism responsible for the weak ferromagnetism in undoped wide band gap oxides, we carry out a comparative study on ZnO thin films prepared using both sol-gel and molecular beam epitaxy (MBE) methods. Compared with the MBE samples, the sol-gel derived samples show much stronger room temperature ferromagnetism with a magnetic signal persisting up to ∼740 K, and this ferromagnetic order coexists with a high density of defects in the form of zinc vacancies. The donor-acceptor pairs associated with the zinc vacancies also cause a characteristic orange-red photoluminescence in the sol-gel films. Furthermore, the strong correlation between the ferromagnetism and the zinc vacancies is confirmed by our first-principles density functional theory calculations, and electronic band alteration as a result of defect engineering is proposed to play the critical role in stabilizing the long-range ferromagnetism.
Transparent thin film polarizing and optical control systems
Authors: Tabiryan Nelson V. , Nersisyan Sarik R. , White Timothy J. , Bunning Timothy J. , Steeves Diane M. , Kimball Brian R.
Published: June 2011

We show that a diffractive waveplate can be combined with a phase retardation film for fully converting light of arbitrary polarization state into a polarized light. Incorporating a photonic bandgap layer into a system of such polarizers that unify different polarization states in the input light into a single polarization state at its output, rather than absorbing or reflecting half of it, we developed and demonstrated a polarization-independent optical controller capable of switching between transmittive and reflective states. The transition between those states is smoothly controlled with low-voltage and low-power sources. Using versatile fabrication methods, this “universally polarizing optical controller” can be integrated into a thin package compatible with a variety of display, spatial light modulation, optical communication, imaging and other photonics systems.
Saccadic Remapping in Hemianopia
Authors: Ritchie K L , Hunt A R , Sahraie A
Published: June 2011

We experience visual stability despite shifts of the visual array across the retina produced by eye movements. The visual system predicts the retinal consequences of saccades through a process known as saccadic remapping. We explored remapping in damaged visual cortex by presenting a stimulus in the blind field of a patient with hemianopia. Reported awareness was elevated when a saccade was about to bring the stimulated location into the sighted field, even though the stimulus was removed before the saccade began and so never stimulated the sighted field. The presence of a blind-field stimulus before saccade also increased sensitivity to a near-threshold sighted-field stimulus that was presented at the same spatial location after saccade. The results suggest early visual areas are not necessary for remapping, but play a role in verifying predictions about the retinal positions of post-saccadic targets generated by remapping.
Feedback Does Not Cleanse Brightness Judgments of Contrast and Assimilation Effects
Authors: Kies S
Published: June 2011

Judgments of the brightness of a test patch are strongly influenced by contrast and assimilation. However, the experiments that document these effects typically do not use feedback. We wondered whether observers might have access to strategies that were cleansed of these effects if they were given trial-by-trial feedback. In this study, observers viewed a 3.33° diameter Test-disk surrounded by an annular ring of what appeared to be homogenous visual noise; their task was to judge whether the luminance of the Test-disk was higher or lower than that of the fixed gray background outside the annulus. Although the annulus looked like a ring of visual noise on each trail, it was actually composed of a random, weighted sum of 11 orthogonal basis images: 5 noise images (which were constrained to contribute 94.8% of the energy in the noisy annulus) and 6 concentric annuli (which collectively covered the same region as each of the noise basis images and which contributed the remaining 5.2% of the energy). Data were collected for four display durations: 13, 27, 53, and 107ms. In each case, logistic regression was used to determine the influence exerted on the participant's judgments by the 11 basis components. Performance was similar for the four display durations. The innermost annulus exerted a contrast effect: Test-disk contrast judgments were negatively correlated with inner-annulus contrast. However, for four of the five participants, judgments tended to be positively correlated with the contrasts of the outermost two annuli. Plausibly, this latter effect reflects assimilation by the Test-disk of annulus brightness induced by contrast of the outer annular strip with the background. Thus, the feedback supplied did not enable observers to escape contrast and assimilation effects.
Global Properties of Natural Scenes Shape Local Properties of Human Edge Detectors
Authors: Neri P
Published: June 2011

Visual cortex analyzes images by first extracting relevant details (eg, edges) via a large array of specialized detectors. The resulting edge map is then relayed to a processing pipeline, the final goal of which is to attribute meaning to the scene. As this process unfolds, does the global interpretation of the image affect how local feature detectors operate? The results show that some aspects of local processing were significantly affected by scene manipulations that were specifically probing the higher-level semantic interpretation of the scene. It may therefore be inaccurate to regard early feature detectors as operating completely outside the domain of higher-level vision.
Consensus Coding as a Tool in Visual Appearance Research
Authors: Simmons D R , Tawde S , Ayoub A F
Published: June 2011

A common problem in visual appearance research is how to quantitatively characterise the visual appearance of a region of an image which is categorised by human observers in the same way. An example of this is scarring in medical images (Ayoub et al, 2010, The Cleft-Palate Craniofacial Journal, in press). We have argued that “scarriness” is itself a visual appearance descriptor which summarises the distinctive combination of colour, texture and shape information which allows us to distinguish scarred from non-scarred tissue (Simmons et al, ECVP 2009). Other potential descriptors for other image classes would be “metallic”, “natural”, or “liquid”. Having developed an automatic algorithm to locate scars in medical images, we then tested “ground truth” by asking untrained observers to draw around the region of scarring. The shape and size of the scar on the image was defined by building a contour plot of the agreement between observers' outlines and thresholding at the point above which 50% of the observers agreed: a consensus coding scheme. Based on the variability in the amount of overlap between the scar as defined by the algorithm, and the consensus scar of the observers, we have concluded that the algorithm does not completely capture the putative appearance descriptor “scarriness”. A simultaneous analysis of qualitative descriptions of the scarring by the observers revealed that other image features than those encoded by the algorithm (colour and texture) might be important, such as scar boundary shape. This approach to visual appearance research in medical imaging has potential applications in other application areas, such as botany, geology and archaeology.
Localization of electrons due to orbitally ordered bi-stripes in the bilayer manganite La

2-2
x

Sr

1+2
x

Mn
2
O
7
(
x
∼ 0.59)
Authors: Sun Z. , Wang Q. , Fedorov A. V. , Zheng H. , Mitchell J. F. , Dessau D. S.
Published: June 2011

Electronic phases with stripe patterns have been intensively investigated for their vital roles in unique properties of correlated electronic materials. How these real-space patterns affect the conductivity and other properties of materials (which are usually described in momentum space) is one of the major challenges of modern condensed matter physics. By studying the electronic structure of La

2-2
x

Sr

1+2
x

Mn
2
O
7
(
x
 ∼ 0.59) and in combination with earlier scattering measurements, we demonstrate the variation of electronic properties accompanying the melting of so-called bi-stripes in this material. The static bi-stripes can strongly localize the electrons in the insulating phase above
T

c

 ∼ 160 K, while the fraction of mobile electrons grows, coexisting with a significant portion of localized electrons when the static bi-stripes melt below
T

c

. The presence of localized electrons below
T

c

suggests that the melting bi-stripes exist as a disordered or fluctuating counterpart. From static to melting, the bi-stripes act as an atomic-scale electronic valve, leading to a “colossal” metal-insulator transition in this material.
A yeast-based assay identifies drugs active against human mitochondrial disorders
Authors: Couplan Elodie , Aiyar Raeka S. , Kucharczyk Roza , Kabala Anna , Ezkurdia Nahia , Gagneur Julien , St. Onge Robert P. , Salin Bénédicte , Soubigou Flavie , Le Cann Marie , Steinmetz Lars M. , di Rago Jean-Paul , Blondel Marc
Published: June 2011

Due to the lack of relevant animal models, development of effective treatments for human mitochondrial diseases has been limited. Here we establish a rapid, yeast-based assay to screen for drugs active against human inherited mitochondrial diseases affecting ATP synthase, in particular NARP (neuropathy, ataxia, and retinitis pigmentosa) syndrome. This method is based on the conservation of mitochondrial function from yeast to human, on the unique ability of yeast to survive without production of ATP by oxidative phosphorylation, and on the amenability of the yeast mitochondrial genome to site-directed mutagenesis. Our method identifies chlorhexidine by screening a chemical library and oleate through a candidate approach. We show that these molecules rescue a number of phenotypes resulting from mutations affecting ATP synthase in yeast. These compounds are also active on human cybrid cells derived from NARP patients. These results validate our method as an effective high-throughput screening approach to identify drugs active in the treatment of human ATP synthase disorders and suggest that this type of method could be applied to other mitochondrial diseases.
Unravelling evolutionary strategies of yeast for improving galactose utilization through integrated systems level analysis
Authors: Hong Kuk-Ki , Vongsangnak Wanwipa , Vemuri Goutham N. , Nielsen Jens
Published: June 2011

Identification of the underlying molecular mechanisms for a derived phenotype by adaptive evolution is difficult. Here, we performed a systems-level inquiry into the metabolic changes occurring in the yeast
Saccharomyces cerevisiae
as a result of its adaptive evolution to increase its specific growth rate on galactose and related these changes to the acquired phenotypic properties. Three evolved mutants (62A, 62B, and 62C) with higher specific growth rates and faster specific galactose uptake were isolated. The evolved mutants were compared with a reference strain and two engineered strains, SO16 and PGM2, which also showed higher galactose uptake rate in previous studies. The profile of intermediates in galactose metabolism was similar in evolved and engineered mutants, whereas reserve carbohydrates metabolism was specifically elevated in the evolved mutants and one evolved strain showed changes in ergosterol biosynthesis. Mutations were identified in proteins involved in the global carbon sensing Ras/PKA pathway, which is known to regulate the reserve carbohydrates metabolism. We evaluated one of the identified mutations,

RAS2
Tyr112

, and this mutation resulted in an increased specific growth rate on galactose. These results show that adaptive evolution results in the utilization of unpredicted routes to accommodate increased galactose flux in contrast to rationally engineered strains. Our study demonstrates that adaptive evolution represents a valuable alternative to rational design in bioengineering of improved strains and, that through systems biology, it is possible to identify mutations in evolved strain that can serve as unforeseen metabolic engineering targets for improving microbial strains for production of biofuels and chemicals.
Homeodomain transcription factor and tumor suppressor
Prep1
is required to maintain genomic stability
Authors: Iotti Giorgio , Longobardi Elena , Masella Silvia , Dardaei Leila , De Santis Francesca , Micali Nicola , Blasi Francesco
Published: June 2011

Prep1
is a homeodomain transcription factor that is essential in embryonic development and functions in the adult as a tumor suppressor. We show here that
Prep1
is involved in maintaining genomic stability and preventing neoplastic transformation. Hypomorphic homozygous

Prep1
i/i

fetal liver cells and mouse embryonic fibroblasts (MEFs) exhibit increased basal DNA damage and normal DNA damage response after γ-irradiation compared with WT. Cytogenetic analysis shows the presence of numerous chromosomal aberrations and aneuploidy in very early-passage

Prep1
i/i

MEFs. In human fibroblasts, acute
Prep1
down-regulation by siRNA induces DNA damage response, like in

Prep1
i/i

MEFs, together with an increase in heterochromatin-associated modifications: rapid increase of histone methylation and decreased transcription of satellite DNA. Ectopic expression of Prep1 rescues DNA damage and heterochromatin methylation. Inhibition of Suv39 activity blocks the chromatin but not the DNA damage phenotype. Finally,
Prep1
deficiency facilitates cell immortalization, escape from oncogene-induced senescence, and H-Ras
V12
–dependent transformation. Importantly, the latter can be partially rescued by restoration of Prep1 level. The results show that the tumor suppressor role of
Prep1
is associated with the maintenance of genomic stability.
The effects of mortality salience on escalation of commitment
Authors: Yen Chih‐Long , Lin Chun‐Yu
Published: June 2011

Based on propositions derived from terror management theory (TMT), the current study proposes that people who are reminded of their mortality exhibit a higher degree of self‐justification behavior to maintain their self‐esteem. For this reason, they could be expected to stick with their previous decisions and invest an increasing amount of resources in those decisions, despite the fact that negative feedback has clearly indicated that they might be on a course toward failure (i.e., “escalation of commitment”). Our experiment showed that people who were reminded of their mortality were more likely to escalate their level of commitment by maintaining their current course of action. Two imaginary scenarios were tested. One of the scenarios involved deciding whether to send additional troops into the battlefield when previous attempts had failed; the other involved deciding whether to continue developing an anti‐radar fighter plane when the enemy had already developed a device to detect it. The results supported our hypothesis that mortality salience increases the tendency to escalate one's level of commitment.
Kinetic theory of the turbulent energy pinch in tokamak plasmas
Authors: Wang Lu , Diamond P.H.
Published: June 2011

The turbulent energy fluxes, including up-gradient ‘energy pinch’ effects, are derived using the nonlinear bounce-kinetic equation for trapped electrons and the nonlinear gyrokinetic equation for ions in toroidal geometry. The quasi-universal type of inward turbulent equipartition (TEP) energy pinch is recovered for both ions and trapped electrons, with different field dependence coefficients due to toroidal effects. A contribution from the density gradient to an outward convective energy flux is also obtained. The direction of the total energy convection is primarily determined by the competition between the TEP energy pinch and the outward density gradient driven energy convection. The magnetic shear dependence of the electron energy pinch is discussed. The energy pinches can provide possible explanations for some puzzling experimental observations.
A New TaqMan Real-Time Polymerase Chain Reaction Assay for Quantification of Fusarium virguliforme in Soil
Authors: Mbofung G. C. Y. , Fessehaie A. , Bhattacharyya M. K. , Leandro L. F. S.
Published: June 2011

The quantification of the soilborne pathogen Fusarium virguliforme inoculum in soil is important for epidemiological studies of soybean sudden death syndrome (SDS). Classical dilution plating methods to determine inoculum density in soil have yielded inconsistent results due to slow growth, variable colony morphology of the pathogen, and the presence of other fungi with similar phenotype. A TaqMan real-time polymerase chain reaction assay was developed based on sequences of the FvTox1 gene of F. virguliforme. The gene differed by four single-nucleotide proteins from the other SDS-causing species. Assay specificity was tested on 48 fungal isolates that varied in taxonomic relatedness. Assay sensitivity was appraised on 10-fold serial dilutions of genomic DNA, conidia suspensions, and soil spiked with conidia. Applicability of the assay was evaluated on field and greenhouse soil samples, and on roots of symptomatic plants. The assay detected only DNA sequences specific to F. virguliforme. The detection limit of the assay was 5 pg/μl, 1,000 conidia/ml, and 1,000 conidia/g soil for genomic DNA, conidial suspensions, and soil with conidia, respectively. The assay was specific to F. virguliforme and was used successfully to quantify inoculum density in soil and soybean roots. The assay can be used as a diagnostic tool for rapid screens of field and greenhouse soil, and for symptomatic and asymptomatic plants.
Colonization of Citrus Seed Coats by ‘CandidatusLiberibacter asiaticus’: Implications for Seed Transmission of the Bacterium
Authors: Hilf Mark E.
Published: June 2011

Huanglongbing is an economically damaging disease of citrus associated with infection by ‘Candidatus Liberibacter asiaticus’. Transmission of the organism via infection of seeds has not been demonstrated but is a concern since some citrus varieties, particularly those used as rootstocks in commercial plantings are propagated from seed. We compared the incidence of detection of ‘Ca. Liberibacter asiaticus’ DNA in individual fruit peduncles, seed coats, seeds, and in germinated seedlings from ‘Sanguenelli’ sweet orange and ‘Conners’ grapefruit fruits sampled from infected trees. Using real-time quantitative PCR (qPCR) we detected pathogen DNA in nucleic acid extracts of 36 and 100% of peduncles from ‘Sanguenelli’ and from ‘Conners’ fruits, respectively. We also detected pathogen DNA in extracts of 37 and 98% of seed coats and in 1.6 and 4% of extracts from the corresponding seeds of ‘Sanguenelli’ and ‘Conners’, respectively. Small amounts of pathogen DNA were detected in 10% of ‘Sanguenelli’ seedlings grown in the greenhouse, but in none of 204 extracts from ‘Conners’ seedlings. Pathogen DNA was detected in 4.9% and in 89% of seed coats peeled from seeds of ‘Sanguenelli’ and ‘Conners’ which were germinated on agar, and in 5% of ‘Sanguenelli’ but in none of 164 ‘Conners’ seedlings which grew from these seeds on agar. No pathogen DNA was detected in ‘Ridge Pineapple’ tissue at 3 months post-grafting onto ‘Sanguenelli’ seedlings, even when pathogen DNA had been detected initially in the ‘Sanguenelli’ seedling. Though the apparent colonization of ‘Conners’ seeds was more extensive and nearly uniform compared with ‘Sanguenelli’ seeds, no pathogen DNA was detected in ‘Conners’ seedlings grown from these seeds. For either variety, no association was established between the presence of pathogen DNA in fruit peduncles and seed coats and in seedlings.
Use of Recombinant Factor VIIa in Patients with Amniotic Fluid Embolism
Authors: Leighton Barbara L. , Wall Michael H. , Lockhart Ellen M. , Phillips Louise E. , Zatta Amanda J.
Published: June 2011

Background

Patients with amniotic fluid embolism (AFE) (major cardiac and pulmonary symptoms plus consumptive coagulopathy) have high circulating tissue factor concentrations. Recombinant factor VIIa (rVIIa) has been used to treat hemorrhage in AFE patients even though rVIIa can combine with circulating tissue factor and form intravascular clots. A systematic review was done of case reports from 2003 to 2009 of AFE patients with massive hemorrhage who were and were not treated with rVIIa to assess the thrombotic complication risk.

Methods

MEDLINE was searched for case reports of AFE patients receiving rVIIa (rVIIa cases) and of AFE patients who received surgery to control bleeding but no rVIIa (cohorts who did not receive rVIIa). Additional AFE case reports were obtained from the Food and Drug Administration, the Australian and New Zealand Haemostasis Registry, and scientific meeting abstracts. The risk of a negative outcome (permanent disability or death) in rVIIa cases versus cohorts who did not receive rVIIa was calculated using risk ratio and 95% confidence interval.

Results

Sixteen rVIIa cases and 28 cohorts were identified who did not receive rVIIa. All patients had surgery to control bleeding. Death, permanent disability, and full recovery occurred in 8, 6, and 2 rVIIa cases and 7, 4, and 17 cohorts who did not receive rVIIa (risk ratio 2.2, 95% CI 1.4-3.7 for death or permanent disability vs. full recovery).

Conclusion

Recombinant factor VIIa cases had significantly worse outcomes than cohorts who did not receive rVIIa. It is recommended that rVIIa be used in AFE patients only when the hemorrhage cannot be stopped by massive blood component replacement.
Estimating Anesthesia Time Using the Medicare Claim
Authors: Silber Jeffrey H. , Rosenbaum Paul R. , Even-Shoshan Orit , Mi Lanyu , Kyle Fabienne A. , Teng Yun , Bratzler Dale W. , Fleisher Lee A.
Published: June 2011

Introduction

Procedure length is a fundamental variable associated with quality of care, though seldom studied on a large scale. The authors sought to estimate procedure length through information obtained in the anesthesia claim submitted to Medicare to validate this method for future studies.

Methods

The Obesity and Surgical Outcomes Study enlisted 47 hospitals located across New York, Texas, and Illinois to study patients undergoing hip, knee, colon, and thoracotomy procedures. A total of 15,914 charts were abstracted to determine body mass index and initial patient physiology. Included in this abstraction were induction, cut, close, and recovery room times. This chart information was merged to Medicare claims that included anesthesia Part B billing information. Correlations between chart times and claim times were analyzed, models developed, and median absolute differences in minutes calculated.

Results

Of the 15,914 eligible patients, there were 14,369 for whom both chart and claim times were available for analysis. For these 14,369, the Spearman correlation between chart and claim time was 0.94 (95% CI 0.94, 0.95), and the median absolute difference between chart and claim time was only 5 min (95% CI: 5.0, 5.5). The anesthesia claim can also be used to estimate surgical procedure length, with only a modest increase in error.

Conclusion

The anesthesia bill found in Medicare claims provides an excellent source of information for studying surgery time on a vast scale throughout the United States. However, errors in both chart abstraction and anesthesia claims can occur. Care must be taken in the handling of outliers in these data.
Neural Correlates of Chronic Low Back Pain Measured by Arterial Spin Labeling
Authors: Wasan Ajay D. , Loggia Marco L. , Chen Li Q. , Napadow Vitaly , Kong Jian , Gollub Randy L.
Published: June 2011

Background

The varying nature of chronic pain (CP) is difficult to correlate to neural activity using typical functional magnetic resonance imaging methods. Arterial spin labeling is a perfusion-based imaging technique allowing the absolute quantification of regional cerebral blood flow, which is a surrogate measure of neuronal activity.

Methods

Subjects with chronic low back and radicular pain and matched healthy normal subjects, undergoing identical procedures, participated in three sessions: a characterization and training session and two arterial spin labeling sessions. In the first imaging session, CP (if any) was exacerbated using clinical maneuvers; in the second session, noxious heat was applied to the affected leg dermatome, the intensity of which was matched to the pain intensity level of the CP exacerbations for each back pain subject.

Results

The clinically significant worsening of ongoing CP (≤ 30%, n = 16) was associated with significant regional blood flow increases (6-10 mm/100 g of tissue/min, P less than 0.01) within brain regions known to activate with experimental pain (somatosensory, prefrontal, and insular cortices) and in other structures observed less frequently in experimental pain studies, such as the superior parietal lobule (part of the dorsal attention network). This effect is specific to changes in ongoing CP as it is observed during worsening CP, but it is not observed after thermal pain application, or in matched, pain-free healthy controls.

Conclusions

Study findings demonstrate the use of arterial spin labeling to investigate the neural processing of CP, and these findings are a step forward in the quest for objective biomarkers of the chronic pain experience.
Coeliac Disease Diagnosis
Authors: Ribes‐Koninckx C. , Mearin ML. , Korponay‐Szabó IR. , Shamir R. , Husby S. , Ventura A. , Branski D. , Catassi C. , Koletzko S. , Mäki M. , Troncone R. , Zimmer KP. ,   ESPGHAN Working Group on Coeliac Disease Diagnosis
Published: June 2011

Background and Objectives:

A revision of criteria for diagnosing coeliac disease (CD) is being conducted by The European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN). In parallel, we have performed a survey aimed to evaluate present practices for CD among paediatric gastroenterologists and to learn their views on the need for modification of present criteria for CD diagnosis.

Patients and Methods:

Questionnaires were distributed to experienced paediatric gastroenterologists (ESPGHAN members) via the Internet.

Results:

Overall, 95 valid questionnaires were available for analysis, pertaining to 28 different countries, with the majority of responders treating patients with CD for >15 years. Only about 12% of the responders comply with present criteria, noncompliance being related mainly to the challenge policy. Approximately 90% request a revision and modification of the present criteria. Forty‐four percent want to omit the small bowel biopsy in symptomatic children with positive anti‐tissue transglutaminase immunoglobulin (Ig) A or endomysial IgA antibodies, especially if they are DQ2/DQ8 positive. For silent cases detected by screening with convincingly positive anti‐tissue transglutaminase IgA or EMA IgA, about 30% consider that no small bowel biopsy should be required in selected cases. Adding human leukocyte antigen typing in the diagnostic workup was asked for by 42% of the responders. As for gluten challenge, a new policy is advocated restricting its obligation to cases whenever the diagnosis is doubtful or unclear.

Conclusions:

Based on these opinions, revision of the ESPGHAN criteria for diagnosing CD is urgently needed.
Pharmacokinetics and Safety of Dexlansoprazole MR in Adolescents With Symptomatic GERD
Authors: Kukulka Michael , Wu Jingtao , Perez Maria Claudia
Published: June 2011

Objectives:

Dexlansoprazole MR 30 mg once daily (QD) is approved in adults for the treatment of symptomatic nonerosive gastroesophageal reflux disease (GERD) and maintenance of healed erosive esophagitis (EE); 60 mg is approved for healing EE. The present study assesses the pharmacokinetic (PK) profile and safety of dexlansoprazole MR in adolescent patients.

Patients and Methods:

Phase 1, open‐label, parallel‐group, multicenter study in male and female adolescents (12–17 years) with GERD. Patients were randomized to receive dexlansoprazole MR (30 or 60 mg, QD) for 7 days. Blood samples to determine dexlansoprazole plasma concentrations were drawn over a 24‐hour period after dosing on day 7. Dexlansoprazole plasma concentrations and PK parameters were summarized by dose group. Safety assessments included monitoring of adverse events (AEs).

Results:

Thirty‐six patients (mean age 14.6 years), 14 boys and 22 girls, were randomized, with PK data available for 35 patients. The overall exposure of dexlansoprazole after administration of the 60‐mg capsule was slightly less than double the exposure from the 30‐mg capsule. Cmax (691 and 1136 ng/mL) and area under the plasma concentration time curve (2886 and 5120 ng · h/mL) values for the 30‐ and 60‐mg doses, respectively, were similar to results from previous phase 1 studies in healthy adults. Twelve of 36 patients (33.3%) experienced a total of 21 treatment‐emergent AEs. All of the AEs were considered to be of mild severity.

Conclusions:

The PK data for dexlansoprazole MR 30‐ and 60‐mg capsules in adolescent patients with symptomatic GERD were similar to those in healthy adults. Both doses were well tolerated.
Keratinocyte sensitization to tumour necrosis factor-induced nuclear factor kappa B activation by the E2 regulatory protein of human papillomaviruses
Authors: Boulabiar Manel , Boubaker Samir , Favre Michel , Demeret Caroline
Published: June 2011

Human papillomavirus (HPV) life cycle requires extensive manipulation of cell signalling to provide conditions adequate for viral replication within the stratified epithelia. In this regard, we show that the E2 regulatory protein of α, β and μ-HPV genotypes enhances tumour necrosis factor (TNF)-induced activation of nuclear factor kappa B (NF-κB). This activation is mediated by the N-terminal domain of E2, but does not rely on its transcriptional properties. It is independent of the NF-κB regulator Tax1BP1, which nevertheless interacts with all the E2 proteins. E2 specifically activates NF-κB pathways induced by TNF, while interleukin-1-induced pathways are not affected. E2 stimulates the activating K63-linked ubiquitination of TRAF5, and interacts with both TRAF5 and TRAF6. Our data suggest that E2 potentiates TNF-induced NF-κB signalling mediated by TRAF5 activation through direct binding. Since NF-κB controls epithelial differentiation, this activity may be involved in the commitment of infected keratinocytes to proliferation arrest and differentiation, both required for the implementation of the productive viral cycle.
Combination of pigment epithelium‐derived factor with radiotherapy enhances the antitumor effects on nasopharyngeal carcinoma by downregulating vascular endothelial growth factor expression and angiogenesis
Authors: Xu Zumin , Fang Shuhuan , Zuo Yufang , Zhang Yang , Cheng Rui , Wang Qingsong , Yang Zhonghan , Cai Weibin , Ma Jianxing , Yang Xia , Gao Guoquan
Published: June 2011

Nasopharyngeal carcinoma (NPC), which has the highest incidence in South China, is mainly treated by radiotherapy. However, the survival rate remains low. Angiogenesis is closely correlated with progress of NPC. Thus, the combination of anti‐angiogenesis with radiation is an attractive strategy for NPC treatment. A heterogenic xenografted human NPC nude mice model was established to investigate the effect of pigment epithelium‐derived factor (PEDF), a potent anti‐angiogenic factor, and the combined effect of PEDF and radiotherapy on nasopharyngeal carcinoma. Pigment epithelium‐derived factor remarkably suppressed the growth of NPC by 43.52% and decreased the tumor microvessel density (MVD). Pigment epithelium‐derived factor had no effects on the proliferation and apoptosis of NPC cell lines by MTT and flow cytometry assay. However, PEDF decreased vascular endothelial growth factor (VEGF) in NPC cell lines by downregulation of hypoxia‐inducible factor 1α, a crucial transcriptional factor for VEGF expression, as demonstrated by western blotting and immunofluorescent staining assay. Interestingly, irradiation alone could also effectively downregulate VEGF and MVD of xenografted tumor, which indicates that irradiation suppresses NPC not only by killing tumor cells but also through anti‐angiogenesis. Furthermore, combined treatment of PEDF with irradiation enhanced the antitumor efficacy. The MVD and VEGF in the combined therapy were much less than in the treatment with PEDF or radiotherapy alone. Our observation demonstrated that the combination of PEDF with radiotherapy enhances the efficacy of the antitumor effect on NPC by the coordinated inhibition on angiogenesis, which implies the potential role of PEDF as an adjuvant agent for NPC treatment. (Cancer Sci 2011; 102: 1789–1798)
EW‐7203, a novel small molecule inhibitor of transforming growth factor‐β (TGF‐β) type I receptor/activin receptor‐like kinase‐5, blocks TGF‐β1‐mediated epithelial‐to‐mesenchymal transition in mammary epithelial cells
Authors: Park Chul‐Yong , Kim Dae‐Kee , Sheen Yhun Yhong
Published: June 2011

Recently, small molecule inhibitors of transforming growth factor‐β (TGF‐β) type I receptor kinase/activin receptor‐like kinase‐5 (ALK5) have been developed to target TGF‐β signalling as a therapeutic strategy for combating cancer. In the present study, the authors examined a novel small molecule inhibitor of ALK5, 3‐((5‐([1,2,4]triazolo[1,5‐a]pyridin‐6‐yl)‐4‐(6‐methylpyridin‐2‐yl)thiazol‐2‐ylamino)methyl)benzonitrile (EW‐7203) in breast cancer cells to determine if it has potential for cancer treatment. The inhibitory effects of EW‐7203 on TGF‐β‐induced Smad signalling and epithelial‐to‐mesenchymal transition (EMT) were investigated in mammary epithelial cells using luciferase reporter assays, immunoblotting, confocal microscopy and wound healing assays. In addition, the suppressive effects of EW‐7203 on mammary cancer metastasis to the lung were examined using a Balb/c xenograft model system. The novel ALK5 inhibitor, EW‐7203, inhibited the TGF‐β1‐stimulated transcriptional activation of p3TP‐Lux and pCAGA12‐Luc. In addition, EW‐7203 decreased phosphorylated Smad2 levels and the nuclear translocation of Smad2 was increased by TGF‐β1. In addition, EW‐7203 inhibited TGF‐β1‐induced EMT and wound healing of NMuMG cells. Furthermore, in xenografted Balb/c mice, EW‐7203 inhibited metastasis to the lung from breast tumors. The novel ALK5 inhibitor, EW‐7203, efficiently inhibited TGF‐β1‐induced Smad signalling, EMT and breast tumor metastasis to the lung in vivo, demonstrating that EW‐7203 has therapeutic potential for breast cancer metastasis to the lung. (Cancer Sci 2011; 102: 1889–1896)
Test–retest reliability of the oxygen uptake efficiency slope in surgical patients
Authors: Phypers B. J. , Robiony‐Rogers D. , Pickering R. M. , Garden A. L.
Published: June 2011

The oxygen uptake efficiency slope is a measure of cardiopulmonary fitness, that can be obtained from a sub‐maximal cardiopulmonary exercise test. It has been evaluated in medical patients but its reliability in surgical populations remains uncertain. We conducted a test–retest study with the aim of establishing the reliability of the oxygen uptake efficiency slope in relation to that of the anaerobic threshold and peak oxygen uptake, in general surgical patients. Twenty‐six patients over 60 years old completed two symptom‐limited, incremental cycle ergometry tests within 7 days. The mean (SD) anaerobic threshold was 13.0 (3.0) mlO2.kg−1.min−1. There were no significant differences between mean test and retest values of anaerobic threshold (p = 0.50), peak oxygen uptake (p = 0.76) or oxygen uptake efficiency slope (p = 0.42). Reliability coefficients (95% CI) for the anaerobic threshold, oxygen uptake efficiency slope and peak oxygen uptake were 66.7% (45.3–87.9%), 89.0% (81.0–96.9%) and 91.7% (85.7–97.8%), respectively. The oxygen uptake efficiency slope was determined easily in all patients and found to have excellent reliability. Its clinical utility in determining pre‐operative fitness warrants further evaluation.