bluuebunny/crossref_metadata_2025 huggingface dataset:
Entzugsdelir nach Missbrauch von GHB-(Gamma-Hydroxybutyrat) und seiner Vorstufen
Authors: Zepf Florian D. , Holtmann Martin , Duketis Eftichia , Maier Joachim , Radeloff Daniel , Schirman Shella , Wagner Angela , Poustka Fritz , Wöckel Lars
Published: September 2009

Hintergrund: Der chronische Missbrauch von Gamma-Hydroxybutyrat (GHB) als Designerdroge, sowie seiner beiden physiologischen Vorläufermoleküle Gamma-Butyrolakton (GBL) und 1,4-Butanediol (1,4-BD), stellt eine Problematik für den Kinder- und Jugendpsychiater dar. Vor allem der akute Entzug von GHB ist aufgrund seines zum Teil protrahierten Verlaufs mit deliranten und kardiovaskulären Symptomen auch für den Kinder- und Jugendpsychiater von Bedeutung. Methodik: In der vorliegenden Arbeit werden biologische und theoretische Grundlagen zum GHB-/GBL-/1,4-BD-Entzugssyndrom, sowie ausgewählte bisher in der Literatur berichtete Kasuistiken eines schweren GHB-/GBL-Entzugssyndroms in Bezug auf eine mögliche Therapie zusammengestellt. Ergebnisse: Bei der Therapie eines akuten GHB-Entzugssyndroms zeigte sich in mehreren Fällen eine hoch dosierte Verabreichung von Benzodiazepinen als eine wirksame und günstige Therapieoption. Berichtete Komplikationen waren neben den pharmakologischen Nebenwirkungen einer Therapie mit Benzodiazepinen vor allem Symptome einer Dystonie nach einer meist zuerst begonnenen erfolglosen Neuroleptika-Therapie. Weitere Probleme stellten vegetative Entgleisungen, EKG-Veränderungen bis hin zu tödlichen kardialen Komplikationen, und Rhabdomyolyse bis hin zum akuten Nierenversagen dar. Schlussfolgerungen: Das GHB-Entzugssyndrom stellt ein lebensbedrohliches Krankheitsbild dar, dessen Behandlung intensivmedizinischer und internistischer stationärer Maßnahmen bedarf. Die rechtzeitige Diagnose ist für den Kinder- und Jugendpsychiater von entscheidender Bedeutung.
Bestimmung der konkurrenten Validität des CRAFFT-d
Authors: Tossmann Peter , Kasten Lorenz , Lang Peter , Strüber Evelin
Published: September 2009

Fragestellung: Überprüft wurde, wie gut der CRAFFT-d problematischen Alkoholkonsum bei Jugendlichen identifizieren kann. Methodik: Die Kriteriumsvalidität des CRAFFT-d wurde anhand eines zweiten Tests erfasst. Parallel zum CRAFFT-d wurde der Alcohol Use Disorders Identification Test (AUDIT) verwendet. Es wurde überprüft, in wie weit die erzielten Urteile übereinstimmen. Die Instrumente wurden im Rahmen der Webseite www.drugcom.de («check your drinking») eingesetzt. Ergebnisse: Von den 12250 befragten Jugendlichen wiesen 54.2 % nach dem AUDIT und 63.6 % nach dem CRAFFT-d einen problematischen Alkoholkonsum auf. Die Testergebnisse zeigen eine hohe Übereinstimmung (Phi φ = .57; χ² 3978.671**, df = 1, p > .001). Bei einem Cut-off-Wert von 2 Punkten erzielte der CRAFFT-d eine Sensitivität von 88.8 % und eine Spezifität von 66.2 %. Schlussfolgerung: Die Ergebnisse der Untersuchung legen nahe, dass der CRAFFT-d ein geeignetes Instrument zur Früherkennung von problematischem Alkoholkonsum bei Jugendlichen sein kann. Eine weitere Validierung anhand diagnostischer Kriterien ist jedoch nötig.
Anorexia nervosa und Nervus peronaeus-Läsion
Authors: Weber Peter , Rost Barbara
Published: September 2009

Magersucht ist mit einer Vielzahl möglicher medizinischer Komplikationen assoziiert. In Folge des Ernährungsmangels sind weiterhin verschiedene zentrale neurologische Komplikationen beschrieben, währenddessen periphere Nervenläsionen eher selten beobachtet werden. Wir berichten über ein 14 8/12jähriges Mädchen mit einer Magersucht, die das klinische Bild einer akuten Nervus peronäus-Läsion links zeigte. Die Prognose peripherer Läsionen im Rahmen einer Anorexie ist bei angemessener Behandlung gut. Anorektische Patienten mit neurologischen Symptomen bedürfen einer interdisziplinären Betreuung.
Metachrones Vierfach-Malignom - zufällige Häufung oder Tumorsyndrom?
Authors: Schrofer  , Villiger  , Cathomas
Published: September 2009

Hintergrund: Mehrfach-Malignome (Definition: drei oder mehr maligne Neoplasien unterschiedlicher Tumorentitäten beim selben Patienten), können – abgesehen von einer denkbaren zufälligen Häufung – im Rahmen von hereditären Tumorsyndromen, bei chronischer Toxinexposition, bei Immundefizienz oder als Sekundärtumoren nach vorausgegangener Malignomtherapie (Radio- und/oder Chemotherapie) auftreten. Fallbericht: Wir präsentieren den Fall einer aktuell beschwerdefreien Patientin mit im Verlauf von 30 Jahren vier manifesten Malignomen: Malignes Melanom (1976), Liposarkom (1983), Appendix-Karzinom (2006) und follikuläres Lymphom (2006). Diskussion: Es erstaunt nicht nur die Tumorvielfalt, sondern insbesondere auch das rezidivfreie Langzeitüberleben der ehemals generalisierten Haut- und Weichteilmalignome (malignes Melanom und Liposarkom). Die Vollremission in Bezug auf diese beiden Malignome ist durch die durchgeführten Therapien (wiederholte Tumorresektionen, Chemotherapie mit Ifosfamid) schwer zu erklären. Das nach über 20 Jahren manifeste follikuläre Lymphom kann als Sekundärmalignom nach Chemotherapie betrachtet werden. Es werden Überlegungen zur Pathogenese von Mehrfachtumoren (Tumorigenizität) angestellt.
Quantification of the contribution of pedogenic magnetic minerals to magnetic susceptibility of loess and paleosols on Chinese Loess Plateau: Paleoclimatic implications
Authors: Xie Qiaoqin , Chen Tianhu , Xu Huifang , Chen Jun , Ji Junfeng , Lu Huayu , Wang Xiaoyong
Published: September 2009

This study investigates the grain size–dependent properties of magnetic minerals in Chinese loess samples with an aim to better understand the contribution of pedogenesis to magnetic susceptibility enhancement of the paleosols. Samples of loess and paleosol were divided into two fractions, magnetic extracts and residues, by extraction in a weak magnetic field. Both the raw samples of loess and paleosol (i.e., before magnetic extraction) and the samples of residues after magnetic extraction were then separated into five grain size fractions by gravitational settling and centrifugation. Low‐field magnetic susceptibility (MS) and the frequency‐dependent MS of these samples were measured, and samples treated with citrate‐bicarbonate‐dithionite (CBD) to remove the iron oxides were also analyzed. For loess samples, coarse grains (≥2μm) contribute more than 50% of the magnetic signal. The ≤0.3 μm fraction, considered to be of pedogenic origin, contributes 22% (before magnetic extraction) or 36% (after magnetic extraction) of the magnetic signal in loess. A different pattern is found in the paleosol samples. For these samples, the ≤0.3 μm fraction contributes >60% (before magnetic extraction) or 71% (after extraction) to the bulk MS. In addition, 91% of the magnetic signal in paleosol S5 is CBD extractable. The CBD technique is able to extract pedogenic superfine‐grained magnetic particles and coarse dust magnetic particles. These results confirm that pedogenesis leads to enhanced MS and helps to quantify the multiple origins of the bulk magnetic material that defines loess and paleosol MS. This approach provides a reliable estimate of the contribution of pedogenic magnetic materials to MS. Our study indicates that multiple methods should be employed in analyzing paleoclimatic changes recorded by MS in the Chinese loess‐paleosol sequences.
Long‐range temporal correlations of ocean surface currents
Authors: Ashkenazy Yosef , Gildor Hezi
Published: September 2009

We study the temporal correlations of sea surface currents at the Gulf of Eilat (also known as Gulf of Aqaba) and find long‐range temporal correlations, from a timescale of several hours to a timescale of several months. This is done using the Fourier transform and the Detrended Fluctuation Analysis methods. We also find weak volatility correlations that indicate nonlinearity of surface currents. We use the time‐dependent surface Ekman layer model to test whether the source of these correlations is the wind. It is found that the wind by itself actually leads to stronger temporal correlations than observed, as well as enhanced diurnal periodicity; other nonlinear terms as well as tides, convection, and spatial variability may weaken the temporal correlations imposed by the wind. Our results show significant spatial variability of correlation exponents even in this small region (6 × 10 km); in addition, stronger correlations are observed during winter.
Definition of new equivalent indices of Horton‐Strahler ratios for the derivation of the Geomorphological Instantaneous Unit Hydrograph
Authors: Moussa Roger
Published: September 2009

The Horton‐Strahler concept has been important in river basin geomorphology; it describes scaling properties and identifies GIUH but has also attracted criticisms, because it depends on the threshold area S, which is used to extract the channel network from digital elevation models (DEM), on the position of the outlet and on the few number of ratios used to identify the scaling laws. To overcome these limitations, this paper proposes new indices independently of S and which have similar properties than the Horton‐Strahler ratios. Applications were conducted on seven French basins. The methodology consists on analyzing the morphometric properties, such as the drained area, the number of sources, and the length of the channel network as a function of S. The results show that Horton‐Strahler ratios vary considerably with S. Particularly, while the Ω‐order length LΩ is a staircase function of S, results show that the channel network is articulated around two main nodes independent of S, which are descriptors of LΩ. Then, we compared the properties of Horton‐Strahler laws to those obtained from self‐similarity analysis, which enables to define new indices independent of S. These indices are calculated automatically from DEM, have similar properties as the Horton‐Strahler ratios, and are used to calculate the GIUH independently of S. The four new descriptors RBe, RLe, RAe, and Le, which have similar properties as RB, RL, RA, and LΩ respectively, are equivalent to those of Horton‐Strahler's laws and can be used as indicators of hydrological similarity for catchment comparison and regionalization.
Evidence for water‐filled cracks in earthquake source regions
Authors: Lin Guoqing , Shearer Peter M.
Published: September 2009

We identify lowered Vp/Vs ratios near earthquake source regions in southern California using observations from a seismic tomography model and high‐resolution local Vp/Vs estimates using waveform cross‐correlation data from within similar event clusters. The median tomographic Vp/Vs ratio is 1.716 ± 0.008 at all the relocated crustal earthquake locations, compared to the background median value of 1.729 ± 0.007 for the tomography model, although the error estimates overlap slightly. The median in situ Vp/Vs ratio of 1.673 ± 0.022 within the similar event clusters suggests that tomographic studies are overestimating Vp/Vs at source regions. Interpretation of Vp/Vs anomalies is complicated by the scatter in values obtained for individual clusters and in comparisons to absolute Vp and Vs velocities in the tomography model. However, the low Vp/Vs ratios measured for the seismicity clusters are hard to explain with known rocks and suggest the presence of water‐filled cracks with several percent porosity in earthquake source regions in southern California, which likely has an effect on faulting and earthquake activity.
Impact of midlatitude stationary waves on regional Hadley cells and ENSO
Authors: Caballero Rodrigo , Anderson Bruce T.
Published: September 2009

Stationary planetary waves are excited in the midlatitudes, propagate equatorward and are absorbed in the subtropics. The impact these waves have on the tropical climate has yet to be fully unraveled. Previous work has shown that interannual variability of zonal‐mean stationary eddy stress is well correlated with interannual variability in Hadley cell strength. A separate line of research has shown that changes in midlatitude planetary waves local to the Pacific strongly affect ENSO variability. Here, we show that the two phenomena are in fact closely connected. Interannual variability of wave activity flux impinging on the subtropical central Pacific affects the local Hadley cell. The associated changes in subtropical subsidence affect the surface pressure field and wind stresses, which in turn affect ENSO. As a result, a winter with an anomalously weak Hadley cell tends to be followed a year later by an El Niño event.
Validation of operational GRAS radio occultation data
Authors: von Engeln A. , Healy S. , Marquardt C. , Andres Y. , Sancho F.
Published: September 2009

GRAS RO (radio occultations) are validated against co‐located ECMWF and COSMIC data and by ECMWF impact trials. We focus on closed‐loop data at impact heights above 8 km. Results confirm the high GRAS quality and robustness, showing lower noise than COSMIC and more occultations per day/satellite. Mean differences to ECMWF and COSMIC from 18 km to 35 km show about 0.1% smaller GRAS BAs (bending angles). Around 40 km, ECMWF shows on average about 1% smaller BAs, which may be related to microwave radiances assimilation. Recent ECMWF updates, putting more weight on RO here, reduce this bias. COSMIC co‐locations reveal smaller GRAS BAs up to about 50 km, probably partly caused by COSMIC smoothing; this is currently revised. ECMWF forecast trials show similar positive GRAS, COSMIC impacts for Southern latitudes standard deviations, although GRAS provides about 60% fewer occultations. It also demonstrates that more RO instruments are beneficial, particularly for the tropics and Northern latitudes.
Multipoint observations of Pc1‐2 waves in the afternoon sector
Authors: Morley Steven K. , Ables Sean T. , Sciffer Murray D. , Fraser Brian J.
Published: September 2009

Coordinated observations from GOES‐9, DMSP F‐13, and Chokurdakh (CHD) have shown concurrent Pc1‐2 band wave activity in the late afternoon sector, close to 16 MLT. The left‐hand polarization of the waves in space indicates that these are electromagnetic ion cyclotron (EMIC) waves. In the region of field line conjunction, DMSP also observed 6–30 keV energy ion precipitation. We have examined the propagation of the EMIC waves from the magnetosphere to the ionosphere using both time series analysis and a 2‐D magnetohydrodynamic model. Our analysis suggests that the EMIC are generated by interactions with cold plasma within a drainage plume, consistent with theory, and that the waves primarily propagate earthward along geomagnetic field lines at the eastward (outer) edge of the plume.
Cryopreservation of cell/hydrogel constructs based on a new cell-assembling technique
Authors: Wang Xiaohong , Xu Huirong , Yan Yongnian , Zhang Renji
Published: September 2009

Organ manufacturing products hold the promise to be used widely in the future for complex organ failings. The cryopreservation of the product is a very important step in the commercialization activities. In this article, a new cell cryopreservation technique, whereby, cryoprotectants were directly incorporated into the cell/hydrogel constructs, prototyped according to the predesigned structure and then subjected to a special freezing/thawing process. The rheological and hydration properties of the cryopreservation systems indicated that the hydratabilities of the gelatin/alginate hydrogels were greatly increased while the eutectic temperatures were greatly decreased by the addition of glycerol. Dextran-40 was found to be effective to improve the cell survival when incorporated with glycerol. The optimal volume concentration of the cryopretectans was 2.5% (v/v) glycerol and 5% (g/mL) dextran-40 in the gelatin/alginate hydrogel. Under these conditions, the cell viability in the construct was 96.3 ± 3.4%. Microscopic, thiazolyl blue (MTT) and hematoxylin and eosin (HE) staining results all indicated that the cells began to proliferate after thawing. The cells in the gelatin/alginate hydrogel with both glycerol and dextran-40 had greater proliferations than with only glycerol or dextran-40. This approach holds promise for a variety of applications in cell assembly for high-throughput drug screening and complex organ manufacturing areas.
Exploring the Importance of Emotional Competence in Children With Complex Communication Needs
Authors: Blackstone Sarah W. , Wilkins David P.
Published: September 2009

Research has shown that children with significant language impairments lag behind their typically developing peers in communicative and emotional competence. This article explores the importance of emotional competence in children with complex communication needs (CCN) and provides tools and strategies for individuals working with children with CCN.
Cochlear Implant Outcomes for Children With Auditory Neuropathy Spectrum Disorder
Authors: Leigh Jaime , Rance Gary , Dettman Shani , Dowell Richard
Published: September 2009

Cochlear implantation is currently the intervention option of choice for many children with auditory neuropathy spectrum disorder (ANSD) who are unable to obtain benefit from conventional amplification. The aim of this study was to review the speech perception and language outcomes for children with ANSD who had received a cochlear implant and highlight specific clinical considerations for working with this population of children with hearing impairment who are being considered for implantation. Finds for the group of 17 children with ANSD using cochlear implants were compared to previously reported outcomes for children with sensori-neural (SN) type hearing loss using cochlear implants.

Two children, identified with cochlear nerve deficiency pre-operatively, received no useful auditory percepts from their cochlear implant and discontinued device use. The remaining children demonstrated speech perception and language outcomes comparable to those observed for SN hearing loss peers using cochlear implants.

This paper highlights a number of considerations for clinicians to be aware of and the importance of careful counseling pre-operatively regarding the potential for less-than-optimal outcomes, particularly for those children identified with cochlear nerve deficiency.
Intervention for Children With Cochlear Implants: Maximizing Auditory Benefits of Bilateral Hearing
Authors: MacIver-Lux Karen
Published: September 2009

Bilateral cochlear implantation has become the standard of care for children with bilateral profound hearing loss. To achieve optimal benefit from bilateral cochlear implants, an intensive rehabilitation program focusing on auditory skills development is necessary. There are several aspects of rehabilitative intervention that are unique when serving children with bilateral cochlear implants. The following article highlights these aspects with specific focus on neuromaturation of the central auditory nervous system, effects of maturation on auditory processes, characteristics of therapy sessions for children with bilateral cochlear implants, research with children with bilateral cochlear implants and implications for therapy, and case studies describing auditory verbal therapy and auditory skills training for children with bilateral cochlear implants.
Cell Replacement Therapy in the Inner Ear: Implications for Cochlear Implantation
Authors: Belzner Katherine A. , Ryals Brenda M.
Published: September 2009

This article provides an overview of recent advances in inner ear cell replacement therapy. Current strategies designed both to initiate hair cell regeneration and maintain or regenerate neural cells are reviewed. Using animal models, investigators have shown that hearing loss from hair cell and neural degeneration can be reversed through molecular and genetic manipulation. Successful strategies in animal models have included the use of growth factors, stem cells, and gene therapy. One significant challenge for the use of these strategies in humans is the development of safe, efficient, and targeted drug delivery systems. Using animal models investigators have shown that cochlear implants can be used to deliver growth factors, such as neurotrophins to the inner ear. Targeting the appropriate neural elements will be important for future application of this technique in humans. Finally, the prognosis for hearing restoration through cell replacement or maintenance therapy will certainly be influenced by the underlying etiology of the hearing loss. Audiologists will play a critical role in the future determination of candidacy for these therapeutic approaches.
Optical and spin coherence of excitons in zinc-blende GaN
Authors: Brimont C. , Gallart M. , Crégut O. , Hönerlage B. , Gilliot P. , Lagarde D. , Balocchi A. , Amand T. , Marie X. , Founta S. , Mariette H.
Published: September 2009

The carrier recombination processes and the relaxation dynamics of spin-polarized excitons in cubic epitaxial GaN have been investigated by time-resolved photoluminescence and pump-probe spectroscopy experiments. We evidence a very fast exciton spin relaxation τS∼0.3 ps that is influenced by both the high defect concentration and the strong electron-hole exchange interaction. Spectral oscillatory features of the transient reflectivity are observed for negative delays that allow us to determine the exciton optical dephasing time T2.
Original shaped nanowire metal-oxide-semiconductor field-effect transistor with enhanced current characteristics based on three-dimensional modeling
Authors: Pons N. , Cavassilas N. , Michelini F. , Raymond L. , Bescond M.
Published: September 2009

This work presents original nanowire transistor architectures leading to device performance improvement. The influence of channel geometrical patterns on nanowire metal-oxide-semiconductor-field-effect-transistor characteristics is investigated using three-dimensional real-space quantum-mechanical simulations. Our study shows that indented channel improves the on-off current ratio (Ion/Ioff) by 32%. This remarkable result is induced by both quasiresonances in the on-regime and more significantly by the presence of a thicker channel potential barrier in the subthreshold domain. We then demonstrate that an optimized indented channel represents a manufacturable opportunity to have a much better control of short channel effects in nanowire transistors.
Combinatorial investigation of (Ti1−xNbx)2AlC
Authors: Scabarozi T. H. , Gennaoui C. , Roche J. , Flemming T. , Wittenberger K. , Hann P. , Adamson B. , Rosenfeld A. , Barsoum M. W. , Hettinger J. D. , Lofland S. E.
Published: September 2009

We have synthesized thin films of (Ti1−xNbx)2AlC by combinatorial method on TiC (111) seed layers grown on c-axis sapphire (Al2O3) substrates at 900 °C using magnetron sputter. X-ray diffraction showed the films to be c-axis oriented and epitaxial, and films contained a minor secondary phase of (Ti,Nb)C, irrespective of stoichiometry. Most notably, Raman spectroscopy suggest a sizable increase in the elastic modulus in the Nb-rich region as compared to either of the end members.
Long term operation of high quantum efficiency GaAs(Cs,O) photocathodes using multiple recleaning by atomic hydrogen
Authors: Orlov D. A. , Krantz C. , Wolf A. , Jaroshevich A. S. , Kosolobov S. N. , Scheibler H. E. , Terekhov A. S.
Published: September 2009

Atomic hydrogen, produced by thermal dissociation of H2 molecules inside a hot tungsten capillary, is shown to be an efficient tool for multiple recleaning of degraded surfaces of high quantum efficiency transmission-mode GaAs photocathodes within an ultrahigh vacuum (UHV) multichamber photoelectron gun. Ultraviolet quantum yield photoemission spectroscopy has been used to study the removal of surface pollutants and the degraded (Cs,O)-activation layer during the cleaning procedure. For photocathodes grown by the liquid-phase epitaxy technique, the quantum efficiency is found to be stable at about 20% over a large number of atomic hydrogen cleaning cycles. A slow degradation of the quantum efficiency is observed for photocathodes grown by metal-organic chemical vapor deposition, although they reached a higher initial quantum efficiency of about 30%–35%. Study of the spatial distributions of photoluminescence intensity on these photocathodes proved that this overall degradation is likely due to insertion of a dislocation network into the mechanically strained photocathode heterostructures during multiple heating cycles and is not due to the atomic hydrogen treatment itself.
A robust analysis of the actuation of a carbon-nanotube-based nanoswitch with sidewall slip
Authors: Wu Yu-Chiao , Adams George G.
Published: September 2009

Carbon nanotubes (CNTs) have been widely used in a variety of research in nanoelectromechanical devices due to their excellent mechanical and electrical properties. This study focuses on the modeling and simulation of the actuation of a CNT-based nanoswitch. The CNT is modeled as a wire spanning a trench with displacement-induced tension and negligible bending stiffness. A distributed force is exerted on the nanotube due to the electrical potential difference between it and the trench electrode. This action causes the CNT to deflect toward the electrode. The phenomenon called snap-through occurs when the voltage exceeds a local maximum. The governing equation of the wire is a second-order nonlinear ordinary differential equation (ODE), which is solved by reducing it to a first-order ODE. After removing the singularity in the integral, we apply a numerical integration method. The use of this procedure gives complete results in the entire stable and unstable domains without any convergence issues. This is in contrast to the more traditional method of using finite differences directly to the second-order nonlinear equation, which requires an iterative technique and often fails to converge. The effect of slip in the section of the CNT lying on the substrate is also considered. Slip lowers the induced internal axial force, thereby decreasing the applied voltage needed for actuation.
Scanning tunneling microscopy and spectroscopy of the phase change alloy Ge1Sb2Te4
Authors: Subramaniam D. , Pauly C. , Liebmann M. , Woda M. , Rausch P. , Merkelbach P. , Wuttig M. , Morgenstern M.
Published: September 2009

Scanning tunneling microscopy and spectroscopy have been employed to reveal the evolution of the band gap and the Fermi level as a function of the annealing temperature for Ge1Sb2Te4, a promising material for phase change memory applications. The band gap decreases continuously from 0.65 eV in the amorphous phase via 0.3 eV in the metastable crystalline phase to zero gap in the stable crystalline phase. The Fermi level moves from the center of the gap in the amorphous phase close to the valence band within the crystalline phases. Moreover, the metastable phase has been imaged with atomic resolution, presumably showing the Te lattice at negative sample bias and the Ge/Sb/vacancy lattice at positive bias.
Conductance and I-V characteristics of Au/BPY/Au single molecule junctions
Authors: Horiguchi Kazunori , Kurokawa Shu , Sakai Akira
Published: September 2009

We have investigated the low bias conductance and I-V characteristics of single 4,4′-bipyridine (BPY) molecule connected to gold electrodes at room temperature. Exploiting the mechanical controllable break junction technique we statistically determined the most preferred conductance value of Au/BPY/Au single molecule junctions. The measured conductance, 0.01G0 (G0 is the conductance quantum unit), is in good agreement with two of the previous experiments using scanning tunnel microscopy break junctions. The I-V characteristics of the Au/BPY/Au junction have been directly measured by varying the bias up to ±0.5 V while holding the junction at its single molecule state. By comparing the obtained I-V curves with those of the Au/1,4-benzenedithiol (BDT)/Au junction, we observed differences in the energy level alignment of BPY and BDT molecules with respect to the Au electrode.
Cavity origin and influence on reliability in lead zirconate titanate thin film capacitors
Authors: Chentir Mohamed-Tahar , Ventura Laurent , Bouyssou Émilien , Anceau Christine
Published: September 2009

This paper deals with the origin of void defects in lead zirconale titanate (PZT) microstructure, appearing after top electrode postdeposition heat treatment. The process conditions of void apparition are especially investigated, as well as the consequences of these defects on capacitor’s electrical properties. We point out that structures presenting the biggest cavities exhibit the shortest time to breakdown (tbd). This result indicates that cavities might play an important role in PZT capacitor degradation mechanisms.
Improved performance of In(Ga)As/GaAs quantum dot solar cells via light scattering by nanoparticles
Authors: McPheeters C. O. , Hill C. J. , Lim S. H. , Derkacs D. , Ting D. Z. , Yu E. T.
Published: September 2009

InAs quantum dots have been used to extend the absorption edge of InGaAs/GaAs quantum well solar cells from 940 to ∼1100 nm. In order to improve absorption of infrared radiation by the thin (300 nm) active layer, we exploit its high refractive index, which acts as a waveguide for certain frequencies of light. Surface-deposited nanoparticles scatter incident radiation into waveguide modes of the devices, yielding improved infrared photocurrent generation of at least 10% at all wavelengths between 700 and 1100 nm, short-circuit current density increases of up to 16%, and corresponding gains in power conversion efficiency.
Tuning of threshold voltage by interfacial carrier doping in organic single crystal ambipolar light-emitting transistors and their bright electroluminescence
Authors: Nakanotani Hajime , Saito Masatoshi , Nakamura Hiroaki , Adachi Chihaya
Published: September 2009

Organic light-emitting field-effect transistors, based on a p-bis[(p-styryl)styryl] benzene (P5V4) single crystal, that possess high mobilities of over 0.1 cm2/V s for both electrons and holes were fabricated. For a small charge injection barrier and successive formation of high exciton density in the carrier recombination zone, the hole accumulation threshold voltage was significantly reduced by interfacial hole doping based on electron transfer from P5V4 molecules to a molybdenum oxide layer. The threshold voltage for hole accumulation was drastically decreased from −80±3 to 2±3 V, leading to dual charge injection and accumulation of a very high current density of J>100 A cm−2 with intense edge electroluminescence.
Polarization retention of thin ferroelectricya capacitors
Authors: Park Youn Jung , Chang Jiyoun , Kang Seok Ju , Park Cheolmin
Published: September 2009

Excellent retention of the initial remanent polarizations was observed in ca. 200 nm thick ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) film capacitors with the writing pulse amplitude and time width of ±20 V and 1 ms, respectively, over 200 h at 80 °C. The opposite state program turned out more sensitive to retention deterioration than the same state one in both switching and nonswitching mode when either writing pulse amplitude or time width decreases. Nonswitching retention in the opposite state mode is in particular one of the most critical properties for designing a ferroelectric polymer capacitor memory.
Investigation on −c-InN and a-InN:Mg field effect transistors under electrolyte gate bias
Authors: Lu Yen-Sheng , Chang Yuh-Hwa , Hong Yu-Liang , Lee Hong-Mao , Gwo Shangjr , Yeh J. Andrew
Published: September 2009

The electrical properties of N-polar undoped InN and nonpolar a-InN:Mg ion sensitive field effect transistors (ISFETs) have been investigated by electrolyte-gate-biased current-voltage (IDS-VGS) measurements. IDS-VGS characteristics reveal that the a-InN:Mg ISFETs have a large (∼52%) current variation ratio at a gate bias of 0.3 V with respect to the unbiased one, which is higher than that from the undoped InN ISFETs (∼18% and <0.1% for 10-nm and 1-μm-thick −c-InN epilayers, respectively). The a-InN:Mg ISFETs can also function as a pH sensor with a sensitivity of 56.5 mV/pH and a response time less than 10 s.
Mesoscopic lattice Boltzmann modeling of soft-glassy systems: Theory and simulations
Authors: Benzi R. , Sbragaglia M. , Succi S. , Bernaschi M. , Chibbaro S.
Published: September 2009

A multicomponent lattice Boltzmann model recently introduced [R. Benzi et al., Phys. Rev. Lett. 102, 026002 (2009)] to describe some dynamical behaviors of soft-flowing materials is theoretically analyzed. Equilibrium and transport properties are derived within the framework of a continuum free-energy formulation and checked against numerical simulations. Due to the competition between short-range interspecies repulsion and midrange intraspecies attraction, the model is shown to give rise to a very rich configurational dynamics of the density field, exhibiting numerous features of soft-flowing materials such as long-time relaxation due to caging effects, enhanced viscosity and structural arrest, aging under moderate shear, and shear-thinning flow above a critical shear threshold.
Symmetry breaking and self-consistent rotation of magnetic islands in neoclassical viscous regimes
Authors: Lazzaro E.
Published: September 2009

Classical or neoclassical tearing modes (NTMs) perturb the ideal axisymmetry of tokamaks. As a consequence of symmetry breaking a neoclassical toroidal viscosity (NTV) appears, that depends on the island amplitude. This work shows that in the low collisionality regimes NTV has a key role in determining self-consistently the magnetic island velocity and at the same time modifies significantly the ion polarization current effects on NTM instability. This finding can provide a better understanding of the mechanism of onset of NTMs, observed experimentally, and improve the concepts for their control or avoidance.
Piezoelectric nanoelectromechanical resonators based on aluminum nitride thin films
Authors: Karabalin R. B. , Matheny M. H. , Feng X. L. , Defaÿ E. , Le Rhun G. , Marcoux C. , Hentz S. , Andreucci P. , Roukes M. L.
Published: September 2009

We demonstrate piezoelectrically actuated, electrically tunable nanomechanical resonators based on multilayers containing a 100-nm-thin aluminum nitride (AlN) layer. Efficient piezoelectric actuation of very high frequency fundamental flexural modes up to ∼80 MHz is demonstrated at room temperature. Thermomechanical fluctuations of AlN cantilevers measured by optical interferometry enable calibration of the transduction responsivity and displacement sensitivities of the resonators. Measurements and analyses show that the 100 nm AlN layer employed has an excellent piezoelectric coefficient, d31=2.4 pm/V. Doubly clamped AlN beams exhibit significant frequency tuning behavior with applied dc voltage.
Quantifying interlayer exchange coupling via layer-resolved hysteresis loops in antiferromagnetically coupled manganite/nickelate superlattices
Authors: Park Jihwey , Lee Dong Ryeol , Choi Yongseong , Freeland John W. , Lee Ki Bong , Sihna Sunil K. , Nikolaev K. R. , Goldman Allen M.
Published: September 2009

In superlattices made of a half metallic ferromagnet La2/3Ba1/3MnO3(LBMO) and a metallic paramagnet LaNiO3(LNO), the field dependence of the LBMO magnetization was studied using depth- and element-sensitive x-ray resonant magnetic scattering measurements. The superlattices have ten bilayers of LBMO and LNO, and the LBMO layers were antiferromagnetically coupled across LNO spacer layers. From the x-ray measurements, the magnetic hysteresis loop of each LBMO layer was obtained, and subsequently the obtained layer-resolved LBMO hysteresis loops were utilized to determine the interlayer exchange coupling.
Tearing relaxation and the globalization of transport in field-reversed configurations
Authors: Steinhauer Loren , Barnes D. C.
Published: September 2009

Tearing instability of field-reversed configurations (FRC) is investigated using the method of neighboring equilibria. It is shown that the conducting wall position in experiment lies very close to the location needed for tearing stability. This strongly suggests that vigorous but benign tearing modes, acting globally, are the engine of continual self-organization in FRCs, i.e., tearing relaxation. It also explains the “profile consistency” and anomalous loss rate of magnetic flux. In effect, tearing globalizes the effect of edge-driven transport.
Light emitting ambipolar field-effect transistors of 2,5-bis(4-biphenyl)bithiophene single crystals with anisotropic carrier mobilities
Authors: Wang Yan , Kumashiro Ryotaro , Li Zhaofei , Nouchi Ryo , Tanigaki Katsumi
Published: September 2009

Ambipolar carrier injection is observed in organic field-effect transistors (FETs) based on 2,5-bis(4-biphenylyl)bithiophene single crystals. The device shows carrier mobilities of 0.04 and 0.02 cm2 V s for holes and electrons, respectively. Strong edge emission is observed, and the emission zone shifts upon the applied gate voltage. Hysteresis is found mainly in the ambipolar and electron-dominated regions. The electron mobility is significantly more sensitive to the transport direction than the hole mobility, suggesting that tuning the transport direction is very important to realize amplified spontaneous emission in organic FETs.
Scattering of an entropy disturbance into sound by a symmetric thin body
Authors: Bodony Daniel J.
Published: September 2009

The interaction of a convecting entropy disturbance, such as generated by a gas turbine combustor, with a solid object is known to generate sound. The sound generation is due to the (i) acceleration of the convected disturbance by the mean flow and (ii) satisfaction of the wall-boundary condition on the object. This process, which leads to the so-called indirect combustion noise, is known to be present in modern gas turbine engines but its specific details are not known, including its overall contribution to the acoustic signature of the engine and its influence on the combustor. Computational and analytical results are presented to examine the sound field created by a localized entropy disturbance convecting in the vicinity of a symmetric thin body. Unsteady calculations of the compressible Euler equations are used to directly compute the radiated sound. Rapid distortion theory is used to develop the relevant scalings of the sound source and, when combined with a low-frequency Green’s function, to estimate the dominant radiated field. It is found that the source structure is dominated by a streamwise-oriented dipole, with the most important interactions occurring near the stagnation points.
Towards an integrated service response to the link between legal and health issues
Authors: Noone Mary Anne
Published: September 2009

International research that confirms links between health issues and legal needs and the prevalence of non-legal services as the first port of call for assistance with legal problems has reinvigorated interest in providing integrated legal and health services. This article details research that indicates experiencing ‘justiciable events’ (problems for which there is a potential legal remedy) leads to stress, anxiety and deterioration in physical or mental health problems. Health consequences are identified for those that do not obtain appropriate and timely legal assistance. People often experience clusters of legal and non-legal problems that require a range of responses. For those that seek assistance with their justiciable event, most seek this assistance from non-legal sources. Within the legal aid sector, these research findings are considered compelling reasons to integrate legal, health and welfare services. However, the co-ordination and collocation of legal and non-legal services (particularly for disadvantaged communities) is not a straightforward solution. Drawing on the experience of several examples of integrated approaches in legal, health and welfare service delivery including the longstanding arrangements between the West Heidelberg Community Legal Service, which is collocated with Banyule Community Health, a range of challenges facing those agencies wishing to develop relationships to provide integrated legal, health and welfare services are identified.
A simple ligand that selectively targets CUG trinucleotide repeats and inhibits MBNL protein binding
Authors: Arambula Jonathan F. , Ramisetty Sreenivasa Rao , Baranger Anne M. , Zimmerman Steven C.
Published: September 2009

This work describes the rational design, synthesis, and study of a ligand that selectively complexes CUG repeats in RNA (and CTG repeats in DNA) with high nanomolar affinity. This sequence is considered a causative agent of myotonic dystrophy type 1 (DM1) because of its ability to sequester muscleblind-like (MBNL) proteins. Ligand 1 was synthesized in two steps from commercially available compounds, and its binding to CTG and CUG repeats in oligonucleotides studied. Isothermal titration calorimetry studies of 1 with various sequences showed a preference toward the T-T mismatch (
K
d
of 390 ± 80 nM) with a 13-, 169-, and 85-fold reduction in affinity toward single C-C, A-A, and G-G mismatches, respectively. Binding and Job analysis of 1 to multiple CTG step sequences revealed high affinity binding to every other T-T mismatch with negative cooperativity for proximal T-T mismatches. The affinity of 1 for a (CUG)
4
step provided a
K
d
of 430 nM with a binding stoichiometry of 1:1. The preference for the U-U in RNA was maintained with a 6-, >143-, and >143-fold reduction in affinity toward single C-C, A-A, and G-G mismatches, respectively. Ligand 1 destabilized the complexes formed between MBNL1N and (CUG)
4
and (CUG)
12
with IC
50
values of 52 ± 20 μM and 46 ± 7 μM, respectively, and
K
i
values of 6 ± 2 μM and 7 ± 1 μM, respectively. These values were only minimally altered by the addition of competitor tRNA. Ligand 1 does not destabilize the unrelated RNA-protein complexes the U1A-SL2 RNA complex and the Sex lethal-
tra
RNA complex. Thus, ligand 1 selectively destabilizes the MBNL1N-poly(CUG) complex.
The phytohormone precursor OPDA is isomerized in the insect gut by a single, specific glutathione transferase
Authors: Dąbrowska Paulina , Freitak Dalial , Vogel Heiko , Heckel David G. , Boland Wilhelm
Published: September 2009

Oxylipins play important roles in stress signaling in plants. The compound 12-oxophytodienoic acid (
cis
-OPDA) is an early biosynthetic precursor of jasmonic acid (JA), the key phytohormone orchestrating the plant anti-herbivore defense. When consumed by feeding Lepidopteran larvae, plant-derived
cis
-OPDA suffers rapid isomerization to
iso
-OPDA in the midgut and is excreted in the frass. Unlike OPDA epimerization (yielding
trans
-OPDA), the formation of
iso
-OPDA is enzyme-dependent, and is catalyzed by an inducible glutathione transferase (GSTs) from the larval gut. Purified GST fractions from the gut of Egyptian cotton leafworm (
Spodoptera littoralis
) and cotton bollworm (
Helicoverpa armigera
) both exhibited strong OPDA isomerization activity, most likely via transient formation of a glutathione-OPDA conjugate. Out of 16 cytosolic GST proteins cloned from the gut of cotton bollworm larvae and expressed in
E. coli
, only one catalyzed the OPDA isomerization. The biological function of the double bond shift might be seen in an inactivation of
cis
-OPDA, similar to the inactivation of prostaglandin A1 to prostaglandin B1 in mammalian tissue. The enzymatic isomerization is particularly widespread among generalist herbivores that have to cope with various amounts of
cis
-OPDA in their spectrum of host plants.
Assembly of the Cdc45-Mcm2–7-GINS complex in human cells requires the Ctf4/And-1, RecQL4, and Mcm10 proteins
Authors: Im Jun-Sub , Ki Sang-Hee , Farina Andrea , Jung Dong-Soo , Hurwitz Jerard , Lee Joon-Kyu
Published: September 2009

In eukaryotes, the activation of the prereplicative complex and assembly of an active DNA unwinding complex are critical but poorly understood steps required for the initiation of DNA replication. In this report, we have used bimolecular fluorescence complementation assays in HeLa cells to examine the interactions between Cdc45, Mcm2–7, and the GINS complex (collectively called the CMG complex), which seem to play a key role in the formation and progression of replication forks. Interactions between the CMG components were observed only after the G
1
/S transition of the cell cycle and were abolished by treatment of cells with either a CDK inhibitor or siRNA against the Cdc7 kinase. Stable association of CMG required all three components of the CMG complex as well as RecQL4, Ctf4/And-1, and Mcm10. Surprisingly, depletion of TopBP1, a homologue of Dpb11 that plays an essential role in the chromatin loading of Cdc45 and GINS in yeast cells, did not significantly affect CMG complex formation. These results suggest that the proteins involved in the assembly of initiation complexes in human cells may differ somewhat from those in yeast systems.
PD-1+memory phenotype CD4+T cells expressing C/EBPα underlie T cell immunodepression in senescence and leukemia
Authors: Shimatani Kenichiro , Nakashima Yasuhiro , Hattori Masakazu , Hamazaki Yoko , Minato Nagahiro
Published: September 2009

Although altered T cell function plays a part in immunosenescence, the mechanisms remain uncertain. Here we identify a bona fide age-dependent PD-1+memory phenotype (MP) CD4+T cell subpopulation that hardly proliferates in response to T cell receptor (TCR) stimulation and produces abundant osteopontin at the cost of typical T cell lymphokines. These T cells demonstrate impaired repopulation in Rag2−/−mice, but a homeostatic proliferation in γ-ray–irradiated mice. These T cells also reveal a unique molecular signature, including a strong expression of C/EBPα normally expressed in myeloid-lineage cells, with diminished c-Myc and cyclin D1. Transduction ofCebpain regular CD4+T cells inhibited the TCR-mediated proliferation withc-Mycandcyclin D1repression and caused a striking activation ofSpp1encoding osteopontin along with concomitant repression of T cell lymphokine genes. Although these T cells gradually increase in number with age and become predominant at the senescent stage in normal mice, the generation is robustly accelerated during leukemia. In both conditions, their predominance is associated with the diminution of specific CD4+T cell response. The results suggest that global T cell immunodepression in senescence and leukemia is attributable to the increase in PD-1+MP CD4+T cells expressing C/EBPα.
Perceptual simulations and linguistic representations have differential effects on speeded relatedness judgements and recognition memory
Authors: Tse Chi-Shing , Kurby Christopher A. , Du Feng
Published: September 2009

We examined the effect of spatial iconicity (a perceptual simulation of canonical locations of objects) and word-order frequency on language processing and episodic memory of orientation. Participants made speeded relatedness judgements to pairs of words presented in locations typical of their real-world arrangements (e.g., ceiling on top and floor on bottom). They then engaged in a surprise orientation recognition task for the word pairs. We replicated Louwerse's (2008) finding that word-order frequency has a stronger effect on semantic relatedness judgements than does spatial iconicity. This is consistent with recent suggestions that linguistic representations have a stronger impact on immediate decisions about verbal materials than do perceptual simulations. In contrast, spatial iconicity enhanced episodic memory of orientation to a greater extent than word-order frequency did. This new finding indicates that perceptual simulations have an important role in episodic memory. Results are discussed with respect to theories of perceptual representation and linguistic processing.