bluuebunny/crossref_metadata_2025 huggingface dataset:
Pflegeentwicklung der Solothurner Spitäler. Unterwegs zu klinisch orientierter Pflegeexpertise und Praxisentwicklung
Authors: Barandun Schäfer Ursi , Hirsbrunner Therese , Jäger Susanne , Näf Ernst , Römmich Sabine , Horlacher Kathrin
Published: January 2011

In der Solothurner Spitäler AG (soH) sind 13 akademisch ausgebildete Pflegeexpertinnen verantwortlich für die Weiterentwicklung der Pflege. Ziel ist eine patientenorientierte, wirksame, zweckmäßige und wirtschaftliche Pflege. Die Strategie beinhaltet folgende Schwerpunkte: a) Expertenpflege von Patienten in anspruchsvollen Situationen; b) Vertiefung von Pflegemethoden wie Pflegeprozess, Bezugspflege sowie Skill- und Grademix, und c) Praxisentwicklungsprojekte bezogen auf spezifische Patientengruppen. Erste qualitative und quantitative Resultate zeigten, dass die befragten Pflegenden zweier Akutstationen die klinische Tätigkeit der Pflegeexpertin als positiv für Patienten und Team bewerteten. Dort, wo die Bezugspflege eingeführt wurde, betrug der Durchdringungsgrad 81 bis 90 Prozent und nach einem Sturzpräventionsprojekt in der geriatrischen Rehabilitation sank die Sturzrate von 8,2 auf 5,5 pro 1000 Pflegetage. Ein Vergleich mit der Literatur zeigt, dass Pflegeexpertinnen der soH bei der klinischen Tätigkeit und den Praxisentwicklungsprojekten als spezialisierte Advanced Practice Nurses arbeiten. Bei der Umsetzung und Vertiefung von Pflegemethoden sind sie jedoch als Generalistinnen tätig. Wichtig für den Erfolg sind ihre Eingliederung in die Hierarchie, in die Pflegeteams und die interprofessionelle Zusammenarbeit. Wesentlich sind auch Kompetenzen in Transformationalem Leadership auf allen Führungsebenen.
David Walker Receives 2010 Harry H. Hess Medal
Authors: Agee Carl B. , Walker David
Published: January 2011

David Walker was awarded the 2010 Harry H. Hess Medal at the AGU Fall Meeting Honors Ceremony, held on 15 December 2010 in San Francisco, Calif. The medal is for “outstanding achievements in research of the constitution and evolution of Earth and other planets.”
New Editors for Eos
Authors: Richman Barbara T.
Published: January 2011

Two new editors have been appointed to the Eos editorial board. José D. Fuentes of the Department of Meteorology at Pennsylvania State University is the new editor for atmospheric sciences. He succeeds Hassan Virji, who served as editor from mid‐2006 to early 2010. David Halpern, a senior research scientist at the Jet Propulsion Laboratory who is currently on assignment at NASA headquarters in Washington, D. C., is the new editor for ocean sciences.
Healthy aging and disease: role for telomere biology?
Authors: Zhu Haidong , Belcher Matthew , van der Harst Pim
Published: January 2011

Aging is a biological process that affects most cells, organisms and species. Human aging is associated with increased susceptibility to a variety of chronic diseases, including cardiovascular disease, Type 2 diabetes, neurological diseases and cancer. Despite the remarkable progress made during the last two decades, our understanding of the biology of aging remains incomplete. Telomere biology has recently emerged as an important player in the aging and disease process.
Note: A heated-air curtain design using the Coanda effect to protect optical access windows in high-temperature, condensing, and corrosive stack environments
Authors: Williams Gustavious Paul , Keenan Thomas L. , Herning James , Kimblin Clare , DiBenedetto John , Anthony Glen
Published: January 2011

We present an air knife design for creating a heated air curtain to protect optical infrared access windows in high-temperature, condensing, and corrosive stack environments. The design uses the Coanda effect to turn the air curtain and to attach the air curtain to the window surface. The design was tested and verified on our 24 m stack and used extensively over a 6 yr period on several release stacks. During testing and subsequent use no detrimental changes to access window materials have been noted. This design allows stack monitoring without significantly affecting the stack flow profile or chemical concentration.
A high sensitivity ultralow temperature RF conductance and noise measurement setup
Authors: Parmentier F. D. , Mahé A. , Denis A. , Berroir J.-M. , Glattli D. C. , Plaçais B. , Fève G.
Published: January 2011

We report on the realization of a high sensitivity RF noise measurement scheme to study small current fluctuations of mesoscopic systems at milli-Kelvin temperatures. The setup relies on the combination of an interferometric amplification scheme and a quarter-wave impedance transformer, allowing the measurement of noise power spectral densities with gigahertz bandwidth up to five orders of magnitude below the amplifier noise floor. We simultaneously measure the high frequency conductance of the sample by derivating a portion of the signal to a microwave homodyne detection. We describe the principle of the setup, as well as its implementation and calibration. Finally, we show that our setup allows to fully characterize a subnanosecond on-demand single electron source. More generally, its sensitivity and bandwidth make it suitable for applications manipulating single charges at GHz frequencies.
Theoretical study of isomerization and decomposition of propenal
Authors: Chin Chih-Hao , Lee Shih-Huang
Published: January 2011

We investigated the dynamics of isomerization and multi-channel dissociation of propenal (CH2CHCHO), methyl ketene (CH3CHCO), hydroxyl propadiene (CH2CH2CHOH), and hydroxyl cyclopropene (cyclic-C3H3-OH) in the ground potential-energy surface using quantum-chemical calculations. Optimized structures and vibrational frequencies of molecular species were computed with method B3LYP/6-311G(d,p). Total energies of molecules at optimized structures were computed at the CCSD(T)/6-311+G(3df,2p) level of theory. We established the potential-energy surface for decomposition to CH2CHCO + H, CH2CH + HCO, CH2CH2/CH3CH + CO, CHCH/CH2C + H2CO, CHCCHO/CH2CCO + H2, CHCH + CO + H2, CH3 + HCCO, CH2CCH + OH, and CH2CC/cyclic-C3H2 + H2O. Microcanonical rate coefficients of various reactions of trans-propenal with internal energies 148 and 182 kcal mol−1 were calculated using Rice–Ramsperger–Kassel–Marcus and Variational transition state theories. Product branching ratios were derivable using numerical integration of kinetic master equations and the steady-state approximation. The concerted three-body dissociation of trans-propenal to fragments C2H2 + CO + H2 is the prevailing channel in present calculations. In contrast, C3H3O + H, C2H3 + HCO and C2H4 + CO were identified as major channels in the photolysis of trans-propenal. The discrepancy between calculations and experiments in product branching ratios indicates that the three major photodissociation channels occur mainly on an excited potential-energy surface whereas the other channels occur mainly on the ground potential-energy surface. This work provides profound insight in the mechanisms of isomerization and multichannel dissociation of the system C3H4O.
Magnetic shield for turbomolecular pump of the Magnetized Plasma Linear Experimental device at Saha Institute of Nuclear Physics
Authors: Biswas Subir , Chattopadhyay Monobir , Pal Rabindranath
Published: January 2011

The turbo molecular pump of the Magnetized Plasma Linear Experimental device is protected from damage by a magnetic shield. As the pump runs continuously in a magnetic field environment during a plasma physics experiment, it may get damaged owing to eddy current effect. For design and testing of the shield, first we simulate in details various aspects of magnetic shield layouts using a readily available field design code. The performance of the shield made from two half cylinders of soft iron material, is experimentally observed to agree very well with the simulation results.
An algorithm for calculating atomic D states with explicitly correlated Gaussian functions
Authors: Sharkey Keeper L. , Bubin Sergiy , Adamowicz Ludwik
Published: January 2011

An algorithm for the variational calculation of atomic D states employing n-electron explicitly correlated Gaussians is developed and implemented. The algorithm includes formulas for the first derivatives of the Hamiltonian and overlap matrix elements determined with respect to the Gaussian nonlinear exponential parameters. The derivatives are used to form the energy gradient which is employed in the variational energy minimization. The algorithm is tested in the calculations of the two lowest D states of the lithium and beryllium atoms. For the lowest D state of Li the present result is lower than the best previously reported result.
An upper limit to kinetic fragility in glass-forming liquids
Authors: Wang Li-Min , Mauro John C.
Published: January 2011

The kinetic fragility of a liquid is correlated to the magnitude of enthalpy hysteresis in various glass-forming materials during thermal cycling across the glass transition. While the lower bound of liquid fragility is well known, there has been little research into the possibility of an inherent upper limit to fragility. In this paper, we present a theoretical argument for the existence of a maximum fragility and show that the correlation between fragility and enthalpy hysteresis allows for an empirical evaluation of the upper limit of fragility. This upper limit occurs as the enthalpy hysteresis involved in thermal cycling about the glass transition approaches zero, leading to $m_{\max } \approx 175$mmax≈175. This result agrees remarkably well with our previous estimate. The dynamics of maximum fragility liquids are discussed, and a critical temperature of ∼1.5 Tg (where Tg is the glass transition temperature) is revealed where a transition from nonexponential to exponential structural relaxation occurs.
A telemedicine instrument for Internet-based home monitoring of thoracoabdominal motion in patients with respiratory diseases
Authors: da Silva Junior Evert Pereira , Esteves Guilherme Pompeu , Dames Karla Kristine , Melo Pedro Lopes de
Published: January 2011

Changes in thoracoabdominal motion are highly prevalent in patients with chronic respiratory diseases. Home care services that use telemedicine techniques and Internet-based monitoring have the potential to improve the management of these patients. However, there is no detailed description in the literature of a system for Internet-based monitoring of patients with disturbed thoracoabdominal motion. The purpose of this work was to describe the development of a new telemedicine instrument for Internet-based home monitoring of thoracoabdominal movement. The instrument directly measures changes in the thorax and abdomen circumferences and transfers data through a transmission control protocol/Internet protocol connection. After the design details are described, the accuracy of the electronic and software processing units of the instrument is evaluated by using electronic signals simulating normal subjects and individuals with thoracoabdominal motion disorders. The results obtained during in vivo studies on normal subjects simulating thoracoabdominal motion disorders showed that this new system is able to detect a reduction in abdominal movement that is associated with abnormal thoracic breathing (p < 0.0001) and the reduction in thoracic movement during abnormal abdominal breathing (p < 0.005). Simulated asynchrony in thoracoabdominal motion was also adequately detected by the system (p < 0.0001). The experimental results obtained for patients with respiratory diseases were in close agreement with the expected values, providing evidence that this instrument can be a useful tool for the evaluation of thoracoabdominal motion. The Internet transmission tests showed that the acquisition and analysis of the thoracoabdominal motion signals can be performed remotely. The user can also receive medical recommendations. The proposed system can be used in a spectrum of telemedicine scenarios, which can reduce the costs of assistance offered to patients with respiratory diseases.
Fluid–solid transition in hard hypersphere systems
Authors: Estrada C. D. , Robles M.
Published: January 2011

In this work we present a numerical study, based on molecular dynamics simulations, to estimate the freezing point of hard spheres and hypersphere systems in dimension D = 4, 5, 6, and 7. We have studied the changes of the radial distribution function (RDF) as a function of density in the coexistence region. We started our simulations from crystalline states with densities above the melting point, and moved down to densities in the liquid state below the freezing point. For all the examined dimensions (including D = 3), it was observed that the height of the first minimum of the RDF changes in an almost continuous way around the freezing density and resembles a second order phase transition. With these results we propose a numerical method to estimate the freezing point as a function of the dimension D using numerical fits and semiempirical approaches. We find that the estimated values of the freezing point are very close to the previously reported values from simulations and theoretical approaches up to D = 6, reinforcing the validity of the proposed method. This was also applied to numerical simulations for D = 7 giving new estimations of the freezing point for this dimensionality.
Complex phase behavior of the system of particles with smooth potential with repulsive shoulder and attractive well
Authors: Fomin Yu. D. , Tsiok E. N. , Ryzhov V. N.
Published: January 2011

We report a detailed simulation study of the phase behavior of core-softened system with attractive well. Different repulsive shoulder widths and attractive well depths are considered which allows to monitor the influence of repulsive and attractive forces on the phase diagram of the system. Thermodynamic anomalies in the systems are also studied. It is shown that the diffusion anomaly is stabilized by small attraction.
Multicomponent ballistic transport in narrow single wall carbon nanotubes: Analytic model and molecular dynamics simulations
Authors: Mutat T. , Adler J. , Sheintuch M.
Published: January 2011

The transport of gas mixtures through molecular-sieve membranes such as narrow nanotubes has many potential applications, but there remain open questions and a paucity of quantitative predictions. Our model, based on extensive molecular dynamics simulations, proposes that ballistic motion, hindered by counter diffusion, is the dominant mechanism. Our simulations of transport of mixtures of molecules between control volumes at both ends of nanotubes give quantitative support to the model's predictions. The combination of simulation and model enable extrapolation to longer tubes and pore networks.
Self-assembled oxide nanopillars in epitaxial BaFe2As2 thin films for vortex pinning
Authors: Zhang Yi , Nelson Christopher T. , Lee Sanghan , Jiang Jianyi , Bark Chung Wung , Weiss Jeremy D. , Tarantini Chiara , Folkman Chad M. , Baek Seung-Hyub , Hellstrom Eric E. , Larbalestier David C. , Eom Chang-Beom , Pan Xiaoqing
Published: January 2011

We report the structure and chemistry of the self-assembled oxide nanopillars that form in superconducting Co-doped BaFe2As2 thin film grown by pulsed laser deposition. The oxide nanopillars consist of a BaFeO2 phase, form epitaxially on the SrTiO3 template, and grow coherently with the BaFe2As2 film. The nanopillars are square with a uniform size of 4–5 nm, which is close to twice the superconducting coherence length. Despite a volume content of ∼5%, the nanopillars do not degrade the structural quality of the BaFe2As2 matrix. Indeed the nanopillars provide exceptionally strong vortex pinning and high critical current density due to the very close correlation of pillar and vortex core diameters.
Nonadiabatic molecular dynamics of photoexcited ${\rm Li}_2^+{\rm Ne}_n$ Li 2+ Ne n clusters
Authors: Zanuttini D. , Douady J. , Jacquet E. , Giglio E. , Gervais B.
Published: January 2011

We investigate the relaxation of photoexcited \documentclass[12pt]{minimal}\begin{document}${\rm Li}_2^+$\end{document} Li 2+ chromophores solvated in Nen clusters (n = 2–22) by means of molecular dynamics with surface hopping. The simplicity of the electronic structure of these ideal systems is exploited to design an accurate and computationally efficient model. These systems present two series of conical intersections between the states correlated with the Li++Li(2s) and Li++Li(2p) dissociation limits of the \documentclass[12pt]{minimal}\begin{document}${\rm Li}_2^+$\end{document} Li 2+ molecule. Frank–Condon transition from the ground state to one of the three lowest excited states, hereafter indexed by ascending energy from 1 to 3, quickly drives the system toward the first series of conical intersections, which have a tremendous influence on the issue of the dynamics. The states 1 and 2, which originate in the Frank–Condon area from the degenerated nondissociative 12Πu states of the bare \documentclass[12pt]{minimal}\begin{document}${\rm Li}_2^+$\end{document} Li 2+molecule, relax mainly to Li++Li(2s) with a complete atomization of the clusters in the whole range of size n investigated here. The third state, which originates in the Frank–Condon area from the dissociative \documentclass[12pt]{minimal}\begin{document}$1^2\Sigma _u^+$\end{document}12Σu+ state of the bare \documentclass[12pt]{minimal}\begin{document}${\rm Li}_2^+$\end{document} Li 2+ molecule, exhibits a richer relaxation dynamics. Contrary to intuition, excitation into state 3 leads to less molecular dissociation, though the amount of energy deposited in the cluster by the excitation process is larger than for excitation into state 1 and 2. This extra amount of energy allows the system to reach the second series of conical intersections so that approximately 20% of the clusters are stabilized in the \documentclass[12pt]{minimal}\begin{document}$2^2\Sigma _g^+$\end{document}22Σg+ state potential well for cluster sizes n larger than 6.
Velocity scaling for optimizing replica exchange molecular dynamics
Authors: Kouza Maksim , Hansmann Ulrich H. E.
Published: January 2011

We discuss the use of velocity rescaling for generating rejection-free exchange moves in replica exchange molecular dynamics. We test the efficiency of this approach for a common test case, the trp-cage protein. Advantages and limitations of the approach are discussed and possible extensions outlined.
Two-channel conduction through polyacenes—Extension of the source–sink potential method to multichannel coupling to leads
Authors: Dumont Randall S.
Published: January 2011

The source and sink potential method of Goyer et al. [J. Chem. Phys. 126, 144104 (2007)] is extended to the case of multichannel coupling to leads. The formulation leads to a nonlinear equation for just one (the elastic) reflection coefficient. Solution of this equation, in general, requires repeated computation of an n × n determinant, where n is the number of supermolecule basis functions directly coupled to the source lead, as opposed to a determinant with order equal to the full size of supermolecule basis. The method is applied to a Hückel model of two-channel polyacene conduction. A simple model of resonance lineshapes is developed in case of weak coupling to leads. The model accurately relates peak characteristics to orbital probabilities associated with the eigenvectors of the isolated molecule Hamiltonian. The model shows how orbital probabilities that give rise to transmission resonances (i.e., 100% transmission), in the case of single-channel conduction, give rise to equal probabilities (of 1/4) for the two reflections and two transmissions, in the case of two-channel conduction. The model also shows how splitting of degenerate eigenvalues of the isolated molecule Hamiltonian results in overlapping resonances characterized by a single complex lineshape.
Pneumatic control of a liquid-core/liquid-cladding waveguide as the basis for an optofluidic switch
Authors: Lim Jong-Min , Urbanski John Paul , Thorsen Todd , Yang Seung-Man
Published: January 2011

We have developed a 2×3 optofluidic switch based on the pneumatic control of a liquid-core/liquid-cladding (L2) waveguide using monolithic microvalves in a multilayer poly(dimethylsiloxane) microfluidic device. In the proposed system, the incident beam to be coupled to the L2 waveguide and the flow direction of the L2 waveguide can be varied by the pneumatic actuation of the monolithic microvalves in the upstream and downstream regions, respectively. The time required for the transitions between different states of the optofluidic switch (tR) was about 30 ms.
Photoresponse in photoconductor devices fabricated from HgTe-HgCdTe superlattices
Authors: Hatch S. D. , Musca C. A. , Becker C. R. , Dell J. M. , Faraone L.
Published: January 2011

Results of photoresponse measurements performed on long-wave infrared photoconductors fabricated from HgTe-HgCdTe superlattices grown by molecular beam epitaxy are presented. Absolute spectral photoresponse measurements as a function of temperature and applied electric field have be undertaken, with the peak photoresponse of 3.3×103 V/W measured at 100 K. Sweepout effects were observed for fields greater than 20 V/cm and quantum efficiencies approaching 80% for 5 μm thick devices have been predicted from absorption measurements of grown material.
Pulsed-field ionization zero electron kinetic energy spectrum of the ground electronic state of BeOBe+
Authors: Antonov Ivan O. , Barker Beau J. , Heaven Michael C.
Published: January 2011

The ground electronic state of BeOBe+ was probed using the pulsed-field ionization zero electron kinetic energy photoelectron technique. Spectra were rotationally resolved and transitions to the zero-point level, the symmetric stretch fundamental and first two bending vibrational levels were observed. The rotational state symmetry selection rules confirm that the ground electronic state of the cation is 2Σg+. Detachment of an electron from the HOMO of neutral BeOBe results in little change in the vibrational or rotational constants, indicating that this orbital is nonbonding in nature. The ionization energy of BeOBe [65480(4) cm−1] was refined over previous measurements. Results from recent theoretical calculations for BeOBe+ (multireference configuration interaction) were found to be in good agreement with the experimental data.
Resolution of the transfer direction of field-evaporated gold atoms for nanofabrication and microelectromechanical system applications
Authors: Yang Z. , Hoffmann S. , Lichtenwalner D. J. , Krim J. , Kingon A. I.
Published: January 2011

Field evaporation is an important phenomenon utilized in probe-based nanofabrication as well as a potential factor in contact reliability of microelectromechanical system (MEMS) switches. Previous studies have left the issue of transfer direction unresolved on account of uncertainties associated with sample geometry effects. We report a resolution of the transfer direction employing techniques to study field-induced transfer in both MEMS switches and atomic force microscope configurations. The results suggest the formation of positive gold ions that are transferred in the direction of the electric field, and confirm field evaporation as a material transport mechanism in MEMS switches.
A generalized-gradient approximation exchange hole model for dispersion coefficients
Authors: Steinmann Stephan N. , Corminboeuf Clemence
Published: January 2011

A simple method for computing accurate density-dependent dispersion coefficients is presented. The dispersion coefficients are modeled by a generalized gradient-type approximation to Becke and Johnson's exchange hole dipole moment formalism. Our most cost-effective variant, based on a disjoint description of atoms in a molecule, gives mean absolute errors in the C6 coefficients for 90 complexes below 10%. The inclusion of the missing long-range van der Waals interactions in density functionals using the derived coefficients in a pair wise correction leads to highly accurate typical noncovalent interaction energies.
YBa
2
Cu
3
O
7
−
δ
quasioptical detectors for fast time-domain analysis of terahertz synchrotron radiation
Authors: Probst P. , Scheuring A. , Hofherr M. , Rall D. , Wünsch S. , Il’in K. , Siegel M. , Semenov A. , Pohl A. , Hübers H.-W. , Judin V. , Müller A.-S. , Hoehl A. , Müller R. , Ulm G.
Published: January 2011

Thin YBa2Cu3O7−δ (YBCO) film detectors embedded into a log-spiral planar antenna were implemented for the detection and analysis of ultrashort terahertz pulses emitted by electron bunches in a synchrotron storage ring. In the direct detection mode terahertz radiation pulses from single electron bunches were resolved. A response time of 45 ps was determined as the full width at half maximum of the voltage transient at the output of the detection system. The sensitivity of the YBCO detector to pulsed terahertz radiation was 70 mV/pJ along with a sensitivity of 30 V/W for continuous radiation at 0.8 THz and a very broad dynamic range of over 30 dB. We found experimental evidences of a nonbolometric nature of the detection mechanism.
Photoisomerization mechanism of 4-methylpyridine explored by electronic structure calculations and nonadiabatic dynamics simulations
Authors: Cao Jun , Fang Qiu , Fang Wei-Hai
Published: January 2011

In the present paper, different electronic structure methods have been used to determine stationary and intersection structures on the ground (S0) and 1ππ* (S2) states of 4-methylpyridine, which is followed by adiabatic and nonadiabatic dynamics simulations to explore the mechanistic photoisomerization of 4-methylpyridine. Photoisomerization starts from the S2(1ππ*) state and overcomes a small barrier, leading to formation of the prefulvene isomer in the S0 state via a S2/S0 conical intersection. The ultrafast S2 → S0 nonradiative decay and low quantum yield for the photoisomerization reaction were well reproduced by the combined electronic structure calculation and dynamics simulation. The prefulvene isomer was assigned as a long-lived intermediate and suggested to isomerize to 4-methylpyridine directly in the previous study, which is not supported by the present calculation. The nonadiabatic dynamics simulation and electronic structure calculation reveal that the prefulvene isomer is a short-lived intermediate and isomerizes to benzvalene form very easily. The benzvalene form was predicted as the stable isomer in the present study and is probably the long-lived intermediate observed experimentally. A consecutive light and thermal isomerization cycle via Dewar isomer was determined and this cycle mechanism is different from that reported in the previous study. It should be pointed out that formation of Dewar isomer from the S2(1ππ*) state is not in competition with the isomerization to the prefulvene form. The Dewar structure observed experimentally may originate from other excited states.
Binding of deposited gold clusters to thiol self-assembled monolayers on Au(111) surfaces
Authors: Costelle Leila , Järvi Tommi T. , Räisänen Minna T. , Tuboltsev Vladimir , Räisänen Jyrki
Published: January 2011

We study the mechanisms involved in Au nanocluster deposition on thiol self-assembled monolayer modified Au(111) surfaces. Molecular dynamics simulations reveal a wide range of cluster-surface binding configurations within a very narrow deposition energy range (0.2–0.6 eV/atom for ∼2.5 nm diameter clusters). These go from noncovalent to full contact and include surprising intermediate cases in which the clusters are bound to the underlying Au(111) surface via molecular links and nanowires. Experiments show that, subsequently, the clusters are covered by thiols and slightly flattened.
Silicon nanowires for high-specificity and high-selectivity sensors under low-frequency scanning
Authors: He Xiaodie , Guo Chunsheng , Liu Yang , Tsang Chi Him A. , Ma Dorothy Duo Duo , Zhang Ruiqin , Wong Ning-Bew , Kang Zhenhui , Lee Shuit-Tong
Published: January 2011

The high specificity and selectivity of H–Si nanowire bundles, which are single crystalline and composed of pure Si without oxygen, for detecting water (peak at 12 Hz) and ethanol (peak at 70 Hz) in their mixture are measured by a frequency scanning test. The signal amplitude deduced between the work channel and the reference channel {[(VR-VS)/VR]×100%} is defined as the impedance recorded under different scanning frequencies.
Impact of SF6 plasma treatment on performance of TaN–HfO2–InP metal-oxide-semiconductor field-effect transistor
Authors: Wang Yanzhen , Chen Yen-Ting , Zhao Han , Xue Fei , Zhou Fei , Lee Jack C.
Published: January 2011

In this work, the experimental impact of SF6 plasma treatment on the performance of InP metal-oxide-semiconductor field-effect transistors is presented. S and F are incorporated into atomic layer deposited HfO2 via postgate SF6 plasma treatment. The decreased subthreshold swing, gate leakage (Ig), and increased effective channel mobility (μeff) indicate that better interface and bulk oxide quality have been achieved with SF6 plasma treatment due to the formation of stronger Hf–F bonds. Drive current (Id), transconductance (Gm), and effective channel mobility (μeff) are improved by 22.3%, 35%, and 35%, respectively, compared with those of control devices.
Ohmic contact properties of magnetron sputtered Ti3SiC2 on n- and p-type 4H-silicon carbide
Authors: Buchholt K. , Ghandi R. , Domeij M. , Zetterling C.-M. , Lu J. , Eklund P. , Hultman L. , Spetz A. Lloyd
Published: January 2011

Epitaxial Ti3SiC2 (0001) thin film contacts were grown on doped 4H-SiC (0001) using magnetron sputtering in an ultra high vacuum system. The specific contact resistance was investigated using linear transmission line measurements. Rapid thermal annealing at 950 °C for 1 min of as-deposited films yielded ohmic contacts to n-type SiC with contact resistances in the order of 10−4 Ω cm2. Transmission electron microscopy shows that the interface between Ti3SiC2 and n-type SiC is atomically sharp with evidence of interfacial ordering after annealing.
Thermal oxidation of silicon carbide: A comparison of n-type and p-type doped epitaxial layers
Authors: Fu Xiao-An , Okino Kenji , Mehregany Mehran
Published: January 2011

The kinetics of wet thermal oxidation of both n-type and p-type doped 6H-SiC epitaxial layers grown on p-type 6H-SiC wafers has been investigated. The oxidation rates are affected significantly by doping concentration. The kinetics of wet thermal oxidation abides by the Deal–Grove model B. E. Deal and A. S. Grove, [J. Appl. Phys. 36, 3770 (1965)]. The linear oxidation rate constant B/A and the parabolic oxidation rate constant B are obtained by fitting the measured data to the Deal–Grove model.
Strain dependence of thermal conductivity of [0001]-oriented GaN nanowires
Authors: Jung Kwangsub , Cho Maenghyo , Zhou Min
Published: January 2011

The thermomechanical behavior of [0001]-oriented GaN nanowires with 2.26 and 3.55 nm in diameter under tensile loading is analyzed using molecular dynamics simulations with the Green–Kubo method and quantum correction. A phase transformation from wurtzite to a tetragonal structure is observed. The thermal conductivity is found to decrease as the wires undergo tensile deformation and phase transformation, except for the smallest diameter and temperatures above 1495 K at which it remains largely constant as the axial strain increases. The different trends appear to result from phonon behavior changes primarily associated with the surface structures of the nanowires at the different conditions.
ZnO homojunction photodiodes based on Sb-doped p-type nanowire array and n-type film for ultraviolet detection
Authors: Wang Guoping , Chu Sheng , Zhan Ning , Lin Yuqing , Chernyak Leonid , Liu Jianlin
Published: January 2011

ZnO p-n homojunctions based on Sb-doped p-type nanowire array and n-type film were grown by combining chemical vapor deposition (for nanowires) with molecular-beam epitaxy (for film). Indium tin oxide and Ti/Au were used as contacts to the ZnO nanowires and film, respectively. Characteristics of field-effect transistors using ZnO nanowires as channels indicate p-type conductivity of the nanowires. Electron beam induced current profiling confirmed the existence of ZnO p-n homojunction. Rectifying I-V characteristic showed a turn-on voltage of around 3 V. Very good response to ultraviolet light illumination was observed from photocurrent measurements.
Dissection of the relative contribution of the Schizosaccharomyces pombe Ctr4 and Ctr5 proteins to the copper transport and cell surface delivery functions
Authors: Beaudoin Jude , Thiele Dennis J. , Labbé Simon , Puig Sergi
Published: January 2011

The Ctr1 family of proteins mediates high-affinity copper (Cu) acquisition in eukaryotic organisms. In the fission yeastSchizosaccharomyces pombe, Cu uptake is carried out by a heteromeric complex formed by the Ctr4 and Ctr5 proteins. Unlike human andSaccharomyces cerevisiaeCtr1 proteins, Ctr4 and Ctr5 are unable to function independently in Cu acquisition. Instead, both proteins physically interact with each other to form a Ctr4–Ctr5 heteromeric complex, and are interdependent for secretion to the plasma membrane and Cu transport activity. In this study, we usedS. cerevisiaemutants that are defective in high-affinity Cu uptake to dissect the relative contribution of Ctr4 and Ctr5 to the Cu transport function. Functional complementation and localization assays show that the conserved Met-X3-Met motif in transmembrane domain 2 of the Ctr5 protein is dispensable for the functionality of the Ctr4–Ctr5 complex, whereas the Met-X3-Met motif in the Ctr4 protein is essential for function and for localization of the hetero-complex to the plasma membrane. Moreover, Ctr4/Ctr5 chimeric proteins reveal unique properties found either in Ctr4 or in Ctr5, and are sufficient for Cu uptake on the cell surface ofSch. pombecells. Functional chimeras contain the Ctr4 central and Ctr5 carboxyl-terminal domains (CTDs). We propose that the Ctr4 central domain mediates Cu transport in this hetero-complex, whereas the Ctr5 CTD functions in the regulation of trafficking of the Cu transport complex to the cell surface.
Morbilliform drug eruption due to pegylated α‐interferon can show complete regression after switching to non‐pegylated interferon
Authors: BARUT Sener , YUKSEK Jale , SEZER Engin , GUNAL Ozgur , KOSEOGLU Dogan
Published: January 2011

Pegylated or non‐pegylated α‐interferon are frequently used medications for the treatment of both chronic hepatitis B and chronic hepatitis C. Skin disorders, which are mainly comprised of eczematous dermatitis, are frequently seen during treatment with this drug. However, drug eruption or morbilliform eruptions due to interferons have been rarely reported so far. We herein describe a patient who developed morbilliform drug eruption under treatment with pegylated interferon. She was able to continue treatment after switching from pegylated interferon to conventional interferon.
Periorbital edema and erythema: An unusual localization of DLE in a patient with psoriasis
Authors: SERARSLAN Gamze , ATIK Esin , SARIKAYA Gökhan
Published: January 2011

Discoid lupus erythematosus (DLE) is characterized by erythematous, raised, indurated papules or plaques. DLE may rarely present as periorbital erythema and edema. We report the case of a 33‐year‐old woman with psoriasis localized on the trunk and extremities who developed prominent periorbital edema and erythema diagnosed as DLE.
Clinicopathological significance and prognostic value of CD133 expression in triple‐negative breast carcinoma
Authors: Zhao Po , Lu Yali , Jiang Xuege , Li Xiaoying
Published: January 2011

Currently, CD133 is one of the best markers to characterize cancer stem cells and Her‐1 is reported as an important marker for the prognosis of triple‐negative breast cancer. To investigate the relationship between the expression of CD133 and Her‐1 and clinicopathology as well as prognosis in triple‐negative breast cancer, 67 cases of triple‐negative invasive ductal breast carcinoma taken from 422 patients with breast cancer were analyzed by immunohistochemistry and clinicopathology with follow‐up. The CD133 and Her‐1 were expressed as positive in 43.3% (29/67) and 53.7% (36/67) of patients, respectively. The expression of CD133 corresponded to tumor size (P = 0.022), clinical stage (P = 0.001) and lymphatic metastasis (P = 0.001), but not to age and histological grade. By Kaplan–Meier analysis the expression of CD133 was correlative with overall survival (OS) (log rank = 9.346,P = 0.002) and disease free survival (DFS) (log rank = 38.840,P = 0.0001) time of breast cancer patients. The expression of Her‐1 was corresponding to tumor size (P = 0.031), clinical stage (P = 0.005) and lymphatic metastasis (P = 0.002), but not to age and histological grade. By Kaplan–Meier analysis the expression of Her‐1 was correlative with overall survival (OS) (log rank = 7.998,P = 0.005) and DFS (log rank = 4.227,P = 0.040) time of patients with cancer. It is concluded that the expression of CD133 and Her‐1 may be correlative with prognosis in triple‐negative breast cancer. (Cancer Sci2011; 102: 1107–1111)
CaMtw1, a member of the evolutionarily conserved Mis12 kinetochore protein family, is required for efficient inner kinetochore assembly in the pathogenic yeast Candida albicans
Authors: Roy Babhrubahan , Burrack Laura S. , Lone Museer A. , Berman Judith , Sanyal Kaustuv
Published: January 2011

Proper assembly of the kinetochore, a multi‐protein complex that mediates attachment of centromere DNA to spindle microtubules on each chromosome, is required for faithful chromosome segregation. Each previously characterized member of the Mis12/Mtw1 protein family is part of an essential subcomplex in the kinetochore. In this work, we identify and characterize CaMTW1, which encodes the homologue of the human Mis12 protein in the pathogenic budding yeast Candida albicans. Subcellular localization and chromatin immunoprecipitation assays confirmed CaMtw1 is a kinetochore protein. CaMtw1 is essential for viability. CaMtw1‐depleted cells and cells in which CaMtw1 was inactivated with a temperature‐sensitive mutation had reduced viability, accumulated at the G2/M stage of the cell cycle, and exhibited increased chromosome missegregation. CaMtw1 depletion also affected spindle length and alignment. Interestingly, in C. albicans, CaMtw1 and the centromeric histone, CaCse4, influence each other for kinetochore localization. In addition, CaMtw1 is required for efficient kinetochore recruitment of another inner kinetochore protein, the CENP‐C homologue, CaMif2. Mis12/Mtw1 proteins have well‐established roles in the recruitment and maintenance of outer kinetochore proteins. We propose that Mis12/Mtw1 proteins also have important co‐dependent interactions with inner kinetochore proteins and that these interactions may increase the fidelity of kinetochore formation.
Haem release from haemopexin by HxuA allows Haemophilus influenzae to escape host nutritional immunity
Authors: Fournier Clémence , Smith Ann , Delepelaire Philippe
Published: January 2011

Haemophilus influenzae is an obligate human commensal/pathogen. This haem auxotroph must acquire haem from its host to sustain aerobic growth. Haem–haemopexin complexes are one of the potential sources of haem for this microorganism. Haemopexin is a glycoprotein that binds haem with high affinity (subpicomolar Kd) and involved in haem recycling. HxuA, a cell surface protein, is the key to haem acquisition from haemopexin. In this study, we reconstituted a functional Hxu system from H. influenzae in Escherichia coli K‐12 that mediated active haem transport across the outer membrane from haem–haemopexin, in the presence of the inner membrane energy‐transducing TonB–ExbB–ExbD complex from H. influenzae. A secreted variant of HxuA, HxuAdm, was produced in E. coli. HxuAdm functionally complemented an hxuA mutant of H. influenzae for haem–haemopexin acquisition. HxuAdm interacted with haemopexin and haem–haemopexin, with which it formed high‐affinity, stoichiometric complexes. Following the interaction between haem–haemopexin and HxuAdm, haem was no longer bound to its initial high‐affinity site and became accessible to its cognate haem receptor, HxuC. HxuAdm and the HxuAdm–haemopexin complex do not appear to bind haem at detectable levels (affinities below 106 M−1). HxuA thus appears to ‘release’ haem from haem–haemopexin complexes and to prevent haem sequestering by haemopexin.
Complex binding of the FabR repressor of bacterial unsaturated fatty acid biosynthesis to its cognate promoters
Authors: Feng Youjun , Cronan John E.
Published: January 2011

Two transcriptional regulators, the FadR activator and the FabR repressor, control biosynthesis of unsaturated fatty acids in Escherichia coli. FabR represses expression of the two genes, fabA and fabB, required for unsaturated fatty acid synthesis and has been reported to require the presence of an unsaturated thioester (of either acyl carrier protein or CoA) in order to bind the fabA and fabB promoters in vitro. We report in vivo experiments in which unsaturated fatty acid synthesis was blocked in the absence of exogenous unsaturated fatty acids in a ΔfadR strain and found that the rates of transcription of fabA and fabB were unaffected by the lack of unsaturated thioesters. To examine the discrepancy between our in vivo results and the prior in vitro results we obtained active, natively folded forms of the E. coli and Vibrio cholerae FabRs by use of an in vitro transcription–translation system. We report that FabR bound the intact promoter regions of both fabA and fabB in the absence of unsaturated acyl thioesters, but bound the two promoters differently. Native FabR bound the fabA promoter region provided that the canonical FabR binding site is extended by inclusion of flanking sequences that overlap the neighbouring FadR binding site. In contrast, although binding to the fabB operator also required a flanking sequence, a non‐specific sequence could suffice. However, unsaturated thioesters did allow FabR binding to the minimal FabR operator sites of both promoters which otherwise were not bound. Thus unsaturated thioester ligands were not essential for FabR/target DNA interaction, but acted to enhance binding. The gel mobility shift data plus in vivo expression data indicate that despite the remarkably similar arrangements of promoter elements, FadR predominately regulates fabA expression whereas FabR is the dominant regulator of fabB expression. We also report that E. coli fabR expression is not autoregulated. Complementation, qRT‐PCR and fatty acid composition analyses demonstrated that V. cholerae FabR was a functional repressor of unsaturated fatty acid synthesis. However, in contrast to E. coli, gel mobility shift assays indicated that neither E. coli nor V. cholerae FabRs bound the V. cholerae fabB promoter, although both proteins efficiently bound the V. cholerae fabA promoter. This asymmetry was shown to be due to the lack of a FabR binding site within the V. cholerae fabB promoter region.
Mutation of GOGAT prevents pea bacteroid formation and N2 fixation by globally downregulating transport of organic nitrogen sources
Authors: Mulley G. , White J. P. , Karunakaran R. , Prell J. , Bourdes A. , Bunnewell S. , Hill L. , Poole P. S.
Published: January 2011

Mutation of gltB (encoding glutamate oxoglutarate amidotransferase or GOGAT) in RU2307 increased the intracellular Gln : Glu ratio and inhibited amino acid transport via Aap and Bra. The mechanism probably involves global post‐translational inhibition independent of Ntr. Transport was separately restored by increased gene expression of Aap or heterologous transporters. Likewise, second site suppressor mutations in the RNA chaperone Hfq elevated transport by Aap and Bra by increasing mRNA levels. Microarrays showed Hfq regulates 34 ABC transporter genes, including aap, bra and opp. The genes coding for integral membrane proteins and ABC subunits aapQMP braDEFGC were more strongly elevated in the hfq mutants than solute‐binding proteins (aapJ braC). aapQMP and braDEFG are immediately downstream of stem‐loops, indicating Hfq attenuates downstream translation and stability of mRNA, explaining differential expression of ABC genes. RU2307 nodulated peas and bacteria grew down infection threads, but bacteroid development was arrested and N2 was not fixed. This probably results from an inability to synthesize or transport amino acids. However, GOGAT and GOGAT/AldA double mutants carrying suppressor mutations that increased amino acid uptake fixed N2 on pea plants. Thus de novo ammonium assimilation into amino acids is unnecessary in bacteroids demonstrating sufficient amino acids are supplied by plants.
δ13C of leaf‐respired CO2 reflects intrinsic water‐use efficiency in barley
Authors: BARBOUR MARGARET M. , TCHERKEZ GUILLAUME , BICKFORD CHRISTOPHER P. , MAUVE CAROLINE , LAMOTHE MARLENE , SINTON SARAH , BROWN HAMISH
Published: January 2011

Leaf intrinsic water‐use efficiency (WUE), the ratio of photosynthetic rate to stomatal conductance (A/gs), is a key plant trait linking terrestrial carbon and water cycles. A rapid, integrative proxy for A/gs is of benefit to crop breeding programmes aiming to improve WUE, but also for ecologists interested in plant carbon‐water balance in natural systems. We hypothesize that the carbon isotope composition of leaf‐respired CO2 (δ13CRl), two hours after leaves are transferred to the dark, records photosynthetic carbon isotope discrimination and so provides a proxy for A/gs. To test this hypothesis, δ13CRl was measured in four barley cultivars grown in the field at two levels of water availability and compared to leaf‐level gas exchange (the ratio of leaf intercellular to ambient CO2 partial pressure, Ci/Ca, and A/gs). Leaf‐respired CO2 was more 13C‐depleted in plants grown at higher water availability, varied between days as environmental conditions changed, and was significantly different between cultivars. A strong relationship between δ13CRl and δ13C of sucrose was observed. δ13CRl was converted into apparent photosynthetic discrimination (Δ13CRl) revealing strong relationships between Δ13CRl and Ci/Ca and A/gs during the vegetative stage of growth. We therefore conclude that δ13CRl may provide a rapid, integrative proxy for A/gs in barley.
Ultra‐small TiO2 nanoparticles disrupt microtubular networks in Arabidopsis thaliana
Authors: WANG SONGHU , KUREPA JASMINA , SMALLE JAN A.
Published: January 2011

In spite of the mounting concerns, current understanding of the extent and mechanisms of phytotoxicity of manufactured nanomaterials remains limited. Here we show that in Arabidopsis thaliana, ultra‐small anatase TiO2 nanoparticles cause reorganization and elimination of microtubules followed by the accelerated and 26S proteasome‐dependent degradation of tubulin monomers. Similar to other microtubule‐disrupting agents, TiO2 nanoparticles induce isotropic growth of root cells. Because microtubules are essential for the normal function of all eukaryotic cells, these results reveal a potentially important consequence of environmental pollution by this widely used nanomaterial.