bluuebunny/crossref_metadata_2025 huggingface dataset:
Supreme Court Hears Case About Regulating Power Plants
Authors: Showstack Randy
Published: March 2015

In a case about power plant emissions, arguments focused on whether the Environmental Protection Agency properly interpreted a regulation and on dramatically different cost-benefit analyses.
Analysis of 1,545 Fractures of Facial Region—A Retrospective Study
Authors: Gaddipati Rajasekhar , Ramisetti Sudhir , Vura Nandagopal , Reddy K.Rajiv , Nalamolu Bhargav
Published: March 2015

Incidence and etiology of facial fractures vary from region to region due to various constituents. This study was carried to evaluate the patterns and distribution of fractures in the facial region among different age groups of patients in both males and females caused due to various etiologies. This is a retrospective epidemiological study, which was performed on patients with fractures in the maxillofacial region during a period of 2005 to 2013 at Mamata Dental College and Hospital, Khammam, India. A total of 1,015 patients with 1,545 fractures were referred for treatment to department of oral and maxillofacial injuries surgery, of Mamata Dental College and Hospital, with a mean age of 31.19. The ratio of males (859):females (156) is 5.5:1. Injuries caused by motorbike injuries (34.9%) are highest. The highest frequency of fractures caused by various reasons is seen more in third decade (39%). Mandible (43.81%) is the most common fracture site in the face. Among soft tissue injuries most commonly seen are lacerations (43%). This study differentiates the etiological factors causing facial trauma in several age groups. Results of this study suggest outcomes indicate that more reliance on individual transport on motor vehicles has increased the frequency of facial bone fractures. Regardless of age, motor vehicle accidents were high in all age groups except the first decade of life and above 60 years of age when traffic accidents dominated. Thus effectiveness of current preventive measures is to be assessed, followed by instituting new guidelines for prevention and inflexible traffic rules shall be levied. More epidemiological surveys can, if encouraged to measure the frequency of fractures, better the world.
Distal Junctional Disease after Occipitothoracic Fusion for Rheumatoid Cervical Disorders: Correlation with Cervical Spine Sagittal Alignment
Authors: Tanouchi Tetsu , Shimizu Takachika , Fueki Keisuke , Ino Masatake , Toda Naofumi , Manabe Nodoka , Itoh Kanako
Published: March 2015

Study Design

Retrospective radiographic study.

Objective

We have performed occipitothoracic (OT) fusion for severe rheumatoid cervical disorders since 1991. In our previous study, we reported that the distal junctional disease occurred in patients with fusion of O–T4 or longer due to increased mechanical stress. The present study further evaluated the association between the distal junctional disease and the cervical spine sagittal alignment.

Methods

Among 60 consecutive OT fusion cases between 1991 and 2010, 24 patients who underwent O–T5 fusion were enrolled in this study. The patients were grouped based on whether they developed postoperative distal junctional disease (group F) or not (group N). We measured pre- and postoperative O–C2, C2–C7, and O–C7 angles and evaluated the association between these values and the occurrence of distal junctional disease.

Results

Seven (29%) of 24 patients developed adjacent-level vertebral fractures as distal junctional disease. In group F, the mean pre- and postoperative O–C2, C2–C7, and O–C7 angles were 12.1 and 16.8, 7.2 and 11.2, and 19.4 and 27.9 degrees, respectively. In group N, the mean pre- and postoperative O–C2, C2–C7, and O–C7 angles were 15.9 and 15.0, 4.9 and 5.8, and 21.0 and 20.9 degrees, respectively. There were no significant differences between the two groups. The difference in the O–C7 angle (postoperative angle − preoperative angle) in group F was significantly larger than that in group N ( p = 0.04).

Conclusion

Excessive correction of the O–C7 angle (hyperlordotic alignment) is likely to cause postoperative distal junctional disease following the OT fusion.
A Worldwide Analysis of the Reliability and Perceived Importance of an Injury to the Posterior Ligamentous Complex in AO Type a Fractures
Authors: Schroeder Gregory D. , Kepler Christopher K. , Koerner John D. , Oner F. Cumhur , Fehlings Michael G. , Aarabi Bizhan , Dvorak Marcel F. , Reinhold Max , Kandziora Frank , Bellabarba Carlo , Chapman Jens R. , Vialle Luiz R. , Vaccaro Alexander R.
Published: March 2015

Study Design

Survey of spine surgeons.

Objective

To determine the reliability with which international spine surgeons identify a posterior ligamentous complex (PLC) injury in a patient with a compression-type vertebral body fracture (type A).

Methods

A survey was sent to all AOSpine members from the six AO regions of the world. The survey consisted of 10 cases of type A fractures (2 subtype A1, 2 subtype A2, 3 subtype A3, and 3 subtype A4 fractures) with appropriate imaging (plain radiographs, computed tomography, and/or magnetic resonance imaging), and the respondent was asked to identify fractures with a PLC disruption, as well as to indicate if the integrity of the PLC would affect their treatment recommendation.

Results

Five hundred twenty-nine spine surgeons from all six AO regions of the world completed the survey. The overall interobserver reliability in determining the integrity of the PLC was slight (kappa = 0.11). No substantial regional or experiential difference was identified in determining PLC integrity or its absence; however, a regional difference was identified ( p < 0.001) in how PLC integrity influenced the treatment of type A fractures.

Conclusion

The results of this survey indicate that there is only slight international reliability in determining the integrity of the PLC in type A fractures. Although the biomechanical importance of the PLC is not in doubt, the inability to reliably determine the integrity of the PLC may limit the utility of the M1 modifier in the AOSpine Thoracolumbar Spine Injury Classification System.
Can a Thoracolumbar Injury Severity Score be Uniformly Applied from T1 to L5 or Are Modifications Necessary?
Authors: Schroeder Gregory D. , Kepler Christopher K. , Koerner John D. , Oner F. Cumhur , Fehlings Michael G. , Aarabi Bizhan , Schnake Klaus J. , Rajasekaran Shanmuganathan , Kandziora Frank , Vialle Luiz R. , Vaccaro Alexander R.
Published: March 2015

Study Design

Literature review.

Objective

The aim of this review is to highlight challenges in the development of a comprehensive surgical algorithm to accompany the AOSpine Thoracolumbar Spine Injury Classification System.

Methods

A narrative review of the relevant spine trauma literature was undertaken with input from the multidisciplinary AOSpine International Trauma Knowledge Forum.

Results

The transitional areas of the spine, in particular the cervicothoracic junction, pose unique challenges. The upper thoracic vertebrae have a transitional anatomy with elements similar to the subaxial cervical spine. When treating these fractures, the surgeon must be aware of the instability due to the junctional location of these fractures. Additionally, although the narrow spinal canal makes neurologic injuries common, the small pedicles and the inability to perform an anterior exposure make decompression surgery challenging. Similarly, low lumbar fractures and fractures at the lumbosacral junction cannot always be treated in the same manner as fractures in the more cephalad thoracolumbar spine. Although the unique biomechanical environment of the low lumbar spine makes a progressive kyphotic deformity less likely because of the substantial lordosis normally present in the low lumbar spine, even a fracture leading to a neutral alignment may dramatically alter the patient's sagittal balance.

Conclusion

Although the new AOSpine Thoracolumbar Spine Injury Classification System was designed to be a comprehensive thoracolumbar classification, fractures at the cervicothoracic junction and the lumbosacral junction have properties unique to these junctional locations. The specific characteristics of injuries in these regions may alter the most appropriate treatment, and so surgeons must use clinical judgment to determine the optimal treatment of these complex fractures.
A novel and facile decay path of Criegee intermediates by intramolecular insertion reactions via roaming transition states
Authors: Nguyen Trong-Nghia , Putikam Raghunath , Lin M. C.
Published: March 2015

We have discovered a new and highly competitive product channel in the unimolecular decay process for small Criegee intermediates, CH2OO and anti/syn-CH3C(H)OO, occurring by intramolecular insertion reactions via a roaming-like transition state (TS) based on quantum-chemical calculations. Our results show that in the decomposition of CH2OO and anti-CH3C(H)OO, the predominant paths directly produce cis-HC(O)OH and syn-CH3C(O)OH acids with >110 kcal/mol exothermicities via loose roaming-like insertion TSs involving the terminal O atom and the neighboring C–H bonds. For syn-CH3C(H)OO, the major decomposition channel occurs by abstraction of a H atom from the CH3 group by the terminal O atom producing CH2C(H)O–OH. At 298 K, the intramolecular insertion process in CH2OO was found to be 600 times faster than the commonly assumed ring-closing reaction.
Crystallization of Lennard-Jones nanodroplets: From near melting to deeply supercooled
Authors: Malek Shahrazad M. A. , Morrow Gregory P. , Saika-Voivod Ivan
Published: March 2015

We carry out molecular dynamics (MD) and Monte Carlo (MC) simulations to characterize nucleation in liquid clusters of 600 Lennard-Jones particles over a broad range of temperatures. We use the formalism of mean first-passage times to determine the rate and find that Classical Nucleation Theory (CNT) predicts the rate quite well, even when employing simple modelling of crystallite shape, chemical potential, surface tension, and particle attachment rate, down to the temperature where the droplet loses metastability and crystallization proceeds through growth-limited nucleation in an unequilibrated liquid. Below this crossover temperature, the nucleation rate is still predicted when MC simulations are used to directly calculate quantities required by CNT. Discrepancy in critical embryo sizes obtained from MD and MC arises when twinned structures with five-fold symmetry provide a competing free energy pathway out of the critical region. We find that crystallization begins with hcp-fcc stacked precritical nuclei and differentiation to various end structures occurs when these embryos become critical. We confirm that using the largest embryo in the system as a reaction coordinate is useful in determining the onset of growth-limited nucleation and show that it gives the same free energy barriers as the full cluster size distribution once the proper reference state is identified. We find that the bulk melting temperature controls the rate, even though the solid-liquid coexistence temperature for the droplet is significantly lower. The value of surface tension that renders close agreement between CNT and direct rate determination is significantly lower than what is expected for the bulk system.
Conduction-coupled Tesla transformer
Authors: Reed J. L.
Published: March 2015

A proof-of-principle Tesla transformer circuit is introduced. The new transformer exhibits the high voltage-high power output signal of shock-excited transformers. The circuit, with specification of proper circuit element values, is capable of obtaining extreme oscillatory voltages. The primary and secondary portions of the circuit communicate solely by conduction. The destructive arcing between the primary and secondary inductors in electromagnetically coupled transformers is ubiquitous. Flashover is eliminated in the new transformer as the high-voltage inductors do not interpenetrate and so do not possess an annular volume of electric field. The inductors are remote from one another. The high voltage secondary inductor is isolated in space, except for a base feed conductor, and obtains earth by its self-capacitance to the surroundings. Governing equations, for the ideal case of no damping, are developed from first principles. Experimental, theoretical, and circuit simulator data are presented for the new transformer. Commercial high-temperature superconductors are discussed as a means to eliminate the counter-intuitive damping due to small primary inductances in both the electromagnetic-coupled and new conduction-coupled transformers.
Anisotropic linear forcing for synthetic turbulence generation in large eddy simulation and hybrid RANS/LES modeling
Authors: de Laage de Meux B. , Audebert B. , Manceau R. , Perrin R.
Published: March 2015

A general forcing method for Large Eddy Simulation (LES) is proposed for the purpose of providing the flow with fluctuations that satisfy a desired statistical state. This method, the Anisotropic Linear Forcing (ALF) introduces an unsteady linear tensor function of the resolved velocity which acts as a restoring force in the mean velocity and resolved stress budgets. The ALF generalizes and extends several forcing previously proposed in the literature. In order to make it possible to impose the integral length scale of the turbulence generated by the forcing term, an alternative formulation of the ALF, using a differential spatial filter, is proposed and analyzed. The anisotropic forcing of the Reynolds stresses is particularly attractive, since unsteady turbulent fluctuations can be locally enhanced or damped, depending on the target stresses. As such, it is shown that the ALF is an effective method to promote turbulent fluctuations downstream of the LES inlet or at the interface between RANS and LES in zonal hybrid RANS/LES modeling. The detailed analysis of the influence of the ALF parameters in spatially developing channel flows and hybrid computations where the ALF target statistics are given by a RANS second-moment closure show that this original approach performs as well as the synthetic eddy method. However, since the ALF method is more flexible and significant computational savings are obtained, the method appears a promising all-in-one solution for general embedded LES simulations.
Weak links between fast mobility and local structure in molecular and atomic liquids
Authors: Bernini S. , Puosi F. , Leporini D.
Published: March 2015

We investigate by molecular-dynamics simulations, the fast mobility—the rattling amplitude of the particles temporarily trapped by the cage of the neighbors—in mildly supercooled states of dense molecular (linear trimers) and atomic (binary mixtures) liquids. The mixture particles interact by the Lennard-Jones potential. The non-bonded particles of the molecular system are coupled by the more general Mie potential with variable repulsive and attractive exponents in a range which is a characteristic of small n-alkanes and n-alcohols. Possible links between the fast mobility and the geometry of the cage (size and shape) are searched. The correlations on a per-particle basis are rather weak. Instead, if one groups either the particles in fast-mobility subsets or the cages in geometric subsets, the increase of the fast mobility with both the size and the asphericity of the cage is revealed. The observed correlations are weak and differ in states with equal relaxation time. Local forces between a tagged particle and the first-neighbour shell do not correlate with the fast mobility in the molecular liquid. It is concluded that the cage geometry alone is unable to provide a microscopic interpretation of the known, universal link between the fast mobility and the slow structural relaxation. We suggest that the particle fast dynamics is affected by regions beyond the first neighbours, thus supporting the presence of collective, extended fast modes.
Excluded volume effects in compressed polymer brushes: A density functional theory
Authors: Chen Cangyi , Tang Ping , Qiu Feng , Shi An-Chang
Published: March 2015

A classical density functional theory (DFT) is applied to investigate the behavior of compressed polymer brushes composed of hard-sphere chains. The excluded volume interactions among the chain segments are explicitly treated. Two compression systems are used to study the behavior of brush-wall and brush-brush interactions. For the brush-brush systems, an obvious interpenetration zone has been observed. The extent of the interpenetration depends strongly on the grafting density. Furthermore, the repulsive force between the brush and wall or between the two brushes has been obtained as a function of the compression distance. Compared to the prediction of the analytic self-consistent field theory, such force increases more rapidly in the brush-wall compression with high polymer grafting densities or at higher compressions. In the brush-brush compression system, the interpenetration between the two compressed brushes creates a “softer” interaction. The influence of hard-sphere solvents on the behavior of compressed brushes is also discussed.
Experimental and numerical evaluation of freely spacing-tunable multiwavelength fiber laser based on two seeding light signals
Authors: Yuan Yijun , Yao Yong , Yi Miao , Guo Bo , Yang Yanfu , Tian JiaJun
Published: March 2015

A model of multiwavelength erbium-doped fiber laser (MEFL), which takes into account the impact of fiber attenuation on the four-wave-mixing (FWM), is proposed. Using this model, we numerically study the output characteristics of the MEFL based on FWM in a dispersion shift fiber with two seeding light signals (TSLS) and experimentally verify these characteristics. The numerical and experimental results show that the number of output channels can be increased with the increase of the erbium-doped fiber pump power. In addition, by decreasing the spacing of TSLS and increasing the power of TSLS, the number of output channels can be increased. However, when the power of TSLS exceeds a critical value, the number of output channels decreases. The results by numerical simulation are consistent with experimental observations from the MEFL.
Analysis of magnetic noises in two-dimensional magnetic recording readers
Authors: Liu Z. J. , Yuan Z. M. , Ong Chun-Lian , Guchang Han , Ang Shiming
Published: March 2015

A model is introduced in this paper to describe the effects of thermal magnetic noises in the read sensor under off-track reading conditions taking into account the influence of the magnetic field generated by the recorded magnetization patterns on the medium. Our numerical studies show that there exist additional noises in the hard biased reader, depending on recorded patterns on the magnetic media. The influence of the recorded magnetic patterns is not only on the variation in reader resistance but also on the high frequency noises caused primarily by the thermal fluctuations. The theoretical analysis is based on the micromagnetic modeling of the state of magnetization in read sensor taking into account of its external magnetic fields due to both the hard bias and the media magnetization patterns. The effect of the thermal agitation of the gyromagnetical precession of magnetizations is evaluated by considering the angular magnetic noise.
Influence of classical electromagnetic effects on current-induced domain wall motion in a perpendicularly magnetized nanowire
Authors: Komine Takashi , Aono Tomosuke , Ando Ryo
Published: March 2015

The influence of classical electromagnetic effects such as applied current field and eddy current field on current-induced domain wall motion in a perpendicularly magnetized nanowire was investigated using a micromagnetic framework. The method used to calculate these fields was derived from Maxwell equation in order to estimate the effect of an attached non-magnetic (NM) layer. We demonstrate an applied current field and an eddy current field in a perpendicularly magnetized nanowire with and without a non-magnetic layer. Without a NM layer, the eddy current field causes a small correction in the Gilbert damping with a wall angle dependence. Adding a NM layer enhances the effective Gilbert damping, especially, in terms of wall rotation. Furthermore, an applied current field strongly affects the current-induced domain wall motion, and significantly changes the critical current density and the Walker breakdown.
A neural approach for the numerical modeling of two-dimensional magnetic hysteresis
Authors: Cardelli E. , Faba A. , Laudani A. , Riganti Fulginei F. , Salvini A.
Published: March 2015

This paper deals with a neural network approach to model magnetic hysteresis at macro-magnetic scale. Such approach to the problem seems promising in order to couple the numerical treatment of magnetic hysteresis to FEM numerical solvers of the Maxwell's equations in time domain, as in case of the non-linear dynamic analysis of electrical machines, and other similar devices, making possible a full computer simulation in a reasonable time. The neural system proposed consists of four inputs representing the magnetic field and the magnetic inductions components at each time step and it is trained by 2-d measurements performed on the magnetic material to be modeled. The magnetic induction B is assumed as entry point and the output of the neural system returns the predicted value of the field H at the same time step. A suitable partitioning of the neural system, described in the paper, makes the computing process rather fast. Validations with experimental tests and simulations for non-symmetric and minor loops are presented.
Communication: Improved pair approximations in local coupled-cluster methods
Authors: Schwilk Max , Usvyat Denis , Werner Hans-Joachim
Published: March 2015

In local coupled cluster treatments the electron pairs can be classified according to the magnitude of their energy contributions or distances into strong, close, weak, and distant pairs. Different approximations are introduced for the latter three classes. In this communication, an improved simplified treatment of close and weak pairs is proposed, which is based on long-range cancellations of individually slowly decaying contributions in the amplitude equations. Benchmark calculations for correlation, reaction, and activation energies demonstrate that these approximations work extremely well, while pair approximations based on local second-order Møller-Plesset theory can lead to errors that are 1-2 orders of magnitude larger.
High-frequency signal transmission through single-atom contacts of Au and Pt
Authors: Aoyama Shodai , Kurokawa Shu , Sakai Akira
Published: March 2015

Signal transmission through atom-sized contacts of Au and Pt has been studied at room temperature for frequencies from 9 kHz to 1 GHz and for conductances (1−10)G0 (G≡2e2/h is the quantum unit of conductance). We measured the frequency spectrum of S parameter S21=|S21|eiθ and found θ∼0 up to 1 GHz for all contacts irrespective of their conductance. Our observations directly prove that the atom-sized contacts of Au and Pt, including their single-atom contacts, behave as a pure resistance in the RF regime.
Geometric phase and entanglement of Raman photon pairs in the presence of photonic band gap
Authors: Berrada K. , Ooi C. H. Raymond , Abdel-Khalek S.
Published: March 2015

Robustness of the geometric phase (GP) with respect to different noise effects is a basic condition for an effective quantum computation. Here, we propose a useful quantum system with real physical parameters by studying the GP of a pair of Stokes and anti-Stokes photons, involving Raman emission processes with and without photonic band gap (PBG) effect. We show that the properties of GP are very sensitive to the change of the Rabi frequency and time, exhibiting collapse phenomenon as the time becomes significantly large. The system allows us to obtain a state which remains with zero GP for longer times. This result plays a significant role to enhance the stabilization and control of the system dynamics. Finally, we investigate the nonlocal correlation (entanglement) between the pair photons by taking into account the effect of different parameters. An interesting correlation between the GP and entanglement is observed showing that the PBG stabilizes the fluctuations in the system and makes the entanglement more robust against the change of time and frequency.
Elastic anisotropy, vibrational, and thermodynamic properties of U2Ti intermetallic compound with AlB2-type structure under high pressure up to 100 GPa
Authors: Yang Jinwen , Gao Tao , Liu Benqiong , Sun Guangai , Chen Bo
Published: March 2015

Structural, elastic anisotropy, dynamical, and thermodynamic properties of U2Ti have been studied by employing density functional theory and density functional perturbative theory. The optimized lattice parameters a, c, unit volume V, bulk modulus B, and bond lengths dU-U, dU-Ti of U2Ti are in favorable agreement with the available experimental data and other theoretical values. The elastic constants under pressure were obtained using “energy-strain” method. The polycrystalline modulus, Poisson's ratio, brittle/ductile characteristics, Debye temperature and the integration of elastic wave velocities over different directions, and hardness under pressure are also evaluated successfully. The anisotropy of the directional bulk modulus and the Young's modulus is systematically predicted for the first time. It turns out that U2Ti should be stabilized mechanically up to 100 GPa, this compound just possesses slightly elastic anisotropy at zero pressure; however, the anisotropy becomes more and more significant with the increasing pressure. In particular, the phonon dispersion curves and phonon density of state under pressure are reported for the first time. The Raman and infrared-active phonon modes at Г point are further assigned. Our results indicate that U2Ti is also stable dynamically up to 100 GPa. Additionally, within the calculated phonon density of states, the thermodynamic properties are predicted.
Formation of BaSi2 heterojunction solar cells using transparent MoOx hole transport layers
Authors: Du W. , Takabe R. , Baba M. , Takeuchi H. , Hara K. O. , Toko K. , Usami N. , Suemasu T.
Published: March 2015

Heterojunction solar cells that consist of 15 nm thick molybdenum trioxide (MoOx, x < 3) as a hole transport layer and 600 nm thick unpassivated or passivated n-BaSi2 layers were demonstrated. Rectifying current-voltage characteristics were observed when the surface of BaSi2 was exposed to air. When the exposure time was decreased to 1 min, an open circuit voltage of 200 mV and a short circuit current density of 0.5 mA/cm2 were obtained under AM1.5 illumination. The photocurrent density under a reverse bias voltage of −1 V reached 25 mA/cm2, which demonstrates the significant potential of BaSi2 for solar cell applications.
Effect of severe plastic deformation on the specific heat and magnetic properties of cold rolled Gd sheets
Authors: Taskaev S. , Skokov K. , Khovaylo V. , Buchelnikov V. , Pellenen A. , Karpenkov D. , Ulyanov M. , Bataev D. , Usenko A. , Lyange M. , Gutfleisch O.
Published: March 2015

We report on specific heat and magnetic properties of thin Gd sheets obtained by means of a cold rolling technique. At temperatures well below Curie temperature TC, the cold rolling has a minor impact on the specific heat Cp. However, a well defined λ-type anomaly of Cp seen in the vicinity of TC in a polycrystalline Gd sample is markedly suppressed in the severely deformed samples. Depression of the λ peak is due to a large decrease of magnetization that presumably originates in a local magnetic anisotropy induced by the severe plastic deformation. Results of calculation of magnetocaloric effect from the Cp and magnetization data indicate that the magnetocaloric effect gradually decreases as the degree of plastic deformation increases. This trend is further confirmed by the direct measurements of the adiabatic temperature change ΔTad.
Highly enhanced green emission from InGaN quantum wells due to surface plasmon resonance on aluminum films
Authors: Tateishi Kazutaka , Funato Mitsuru , Kawakami Yoichi , Okamoto Koichi , Tamada Kaoru
Published: March 2015

Photoluminescence (PL) from InGaN/GaN quantum wells was highly enhanced by the surface plasmon (SP) resonance on aluminum thin films. The enhancement ratio of green emission reached 80, which was much larger than the previously reported enhancements on silver films. The resulting large enhancement should be attributed to an ∼20-fold enhancement of the excitation efficiency and ∼4-fold enhancement of the emission efficiency by the excitation and emission spectra. The temperature dependence of the PL intensities and the time-resolved PL measurements were also performed to understand the detailed mechanism. We concluded that the resonance between the excitation light and the SP on the Al surface should improve the excitation efficiency, i.e., the light absorption efficiency. This result suggests that the Al films have an extraordinary photon confinement effect, which are unique properties of plasmonics with Al and should be useful for new and wider applications.
Gilbert damping of ferromagnetic metals incorporating inhomogeneous spin dynamics
Authors: Umetsu Nobuyuki , Miura Daisuke , Sakuma Akimasa
Published: March 2015

The effects of inhomogeneous spin dynamics on magnetic damping in ferromagnetic metals are studied. On the basis of linear response theory, we derive the microscopic expression for the Gilbert damping term in a two-dimensional electron gas interacting with the magnetization via exchange coupling in the presence of Rashba spin-orbit coupling (SOC). In the spin wave propagating with the wave vector, q, the behavior of q-dependent damping can be explained in terms of both inter- and intra-band spin excitations. The spatially dependent damping torques originating from Rashba SOC that cancel out in a uniform precession system distort the circular orbit of a magnetization-precession trajectory in the presence of inhomogeneous spin dynamics.
Modulated multiferroic phases and electric polarization in Mn1−xRuxWO4+δ
Authors: Yu H. W. , Li X. , Xie Y. L. , Yan Z. B. , Zhou X. H. , Liu J.-M.
Published: March 2015

In this work, we investigate the multiferroic phase stability against 4d Ru substitution of 3d Mn in Mn1−xRuxWO4+δ. The Ru substitution results in both Ru3+ and Ru4+ occupations at the Mn sites, while oxygen interstitials in the lattice are expected owing to the charge neutrality requirement. It is suggested that the local electric dipoles as induced by the charge valence variations of Ru cancel with each others, making no contribution to the ferroelectric polarization. The Ru-substitution induced lattice distortion and chemical disorder may be responsible for the enhanced stability of the ferroelectric AF2 phase over the non-ferroelectric AF1 phase, thus leading to the observed polarization enhancement.
The structure, magnetostriction, and hysteresis of (Tb0.3Dy0.7Fe1.9)1−x(Tb0.15Ho0.85Fe1.9)x alloys
Authors: Wang Bowen , Lv Yan , Li Guolu , Huang Wenmei , Weng Ling , Cui Baozhi
Published: March 2015

The (Tb0.3Dy0.7Fe1.9)1−x(Tb0.15Ho0.85Fe1.9)x alloys were prepared in an arc furnace under high purity argon. The as-cast samples wrapped in Mo foil were sealed in a silica tube filled with high purity argon and were homogenized at 1000 °C for 1 day and at 950 °C for 5 days. Then, the homogenized specimens with 5 mm in diameter and 8 mm in length were annealed under the magnetic field of 320 kA/m. The static measurement of magnetostriction (λ//, λ⊥) was made by standard strain gauge, and the magnetization M was measured by a vibrating sample magnetometer. It is found that the main phase of annealed (Tb0.3Dy0.7Fe1.9)1−x(Tb0.15Ho0.85Fe1.9)x alloys is the (Tb,Dy,Ho)Fe2 phase with the MgCu2-type structure. The magnetostriction λ// and magnetization M of (Tb0.3Dy0.7Fe1.9)1−x(Tb0.15Ho0.85Fe1.9)x alloys increases with increasing x from x = 0.1 to x = 0.3 when H < 240 kA/m. The hysteresis becomes small with increasing x when x ≤ 0.3. For magnetically annealed rod alloys, the magnetostriction markedly increases and reaches 1080 × 10−6 for x = 0.3 when H = 240 kA/m.
Evaporation-based microfluidic production of oil-free cell-containing hydrogel particles
Authors: Fan Rong , Naqvi Kubra , Patel Krishna , Sun Jun , Wan Jiandi
Published: March 2015

We demonstrate an evaporation-based microfluidic strategy to produce oil-free cell containing hydrogel particles. Perfluoro-n-pentane, which is used as the continuous oil phase to generate cell-containing hydrogel (Extracel) particles, is removed at an elevated temperature. Human colon cancer cells (HCT116) encapsulated in the hydrogel particles show higher viability than cells encapsulated in particles that are produced via a non-evaporative oil phase. In addition, single HCT116 cells can be cultured for a week in such particles and respond to inflammatory stimuli, highlighting the potential applications of the developed strategy for 3D cell culture, drug testing, and cell-based drug delivery.
Tuning the resistive switching properties of TiO2−x films
Authors: Ghenzi N. , Rozenberg M. J. , Llopis R. , Levy P. , Hueso L. E. , Stoliar P.
Published: March 2015

We study the electrical characteristics of TiO2−x-based resistive switching devices fabricated with different oxygen/argon flow ratio during the oxide thin film sputtering deposition. Upon minute changes in this fabrication parameter, three qualitatively different device characteristics were accessed in the same system, namely, standard bipolar resistive switching, electroforming-free devices, and devices with multi-step breakdown. We propose that small variations in the oxygen/ argon flow ratio result in relevant changes of the oxygen vacancy concentration, which is the key parameter determining the resistive switching behavior. The coexistence of percolative or non-percolative conductive filaments is also discussed. Finally, the hypothesis is verified by means of the temperature dependence of the devices in low resistance state.
A Gaussian treatment for the friction issue of Lennard-Jones potential in layered materials: Application to friction between graphene, MoS2, and black phosphorus
Authors: Jiang Jin-Wu , Park Harold S.
Published: March 2015

The Lennard-Jones potential is widely used to describe the interlayer interactions within layered materials like graphene. However, it is also widely known that this potential strongly underestimates the frictional properties for layered materials. Here, we propose to supplement the Lennard-Jones potential by a Gaussian-type potential, which enables more accurate calculations of the frictional properties of two-dimensional layered materials. Furthermore, the Gaussian potential is computationally simple as it introduces only one additional potential parameter that is determined by the interlayer shear mode in the layered structure. The resulting Lennard-Jones-Gaussian potential is applied to compute the interlayer cohesive energy and frictional energy for graphene, MoS2, black phosphorus, and their heterostructures.
Rhombohedral magnetostriction in dilute iron (Co) alloys
Authors: Jones Nicholas J. , Petculescu Gabriela , Wun-Fogle Marilyn , Restorff J. B. , Clark Arthur E. , Hathaway Kristl B. , Schlagel Deborah , Lograsso Thomas A.
Published: March 2015

Iron is a well-utilized material in structural and magnetic applications. This does not mean, however, that it is well understood, especially in the field of magnetostriction. In particular, the rhombohedral magnetostriction of iron, λ111, is anomalous in two respects: it is negative in sign, in disagreement with the prediction of first principles theory, and its magnitude decreases with increasing temperature much too rapidly to be explained by a power law dependence on magnetization. These behaviors could arise from the location of the Fermi level, which leaves a small region of the majority 3d t2g states unfilled, possibly favoring small internal displacements that split these states. If this view is correct, adding small amounts of Co to Fe fills some of these states, and the value of λ111 should increase toward a positive value, as predicted for perfect bcc Fe. We have measured the magnetostriction coefficients (λ111 and λ100) of pure Fe, Fe97Co3, and Fe94Co6 single crystals from 77 K to 450 K. Resonant ultrasound spectroscopy has been used to check for anomalies in the associated elastic constants, c44 and c′. The additional electrons provided by the cobalt atoms indeed produced positive contributions to both magnetostriction constants, λ111 and λ100, exhibiting an increase of 2.8 × 10−6 per at. % Co for λ111 and 3.8 × 10−6 per at. % Co for λ100.
Restorative effect of oxygen annealing on device performance in HfIZO thin-film transistors
Authors: Ha Tae-Jun
Published: March 2015

Metal-oxide based thin-film transistors (oxide-TFTs) are very promising for use in next generation electronics such as transparent displays requiring high switching and driving performance. In this study, we demonstrate an optimized process to secure excellent device performance with a favorable shift of the threshold voltage toward 0V in amorphous hafnium-indium-zinc-oxide (a-HfIZO) TFTs by using post-treatment with oxygen annealing. This enhancement results from the improved interfacial characteristics between gate dielectric and semiconductor layers due to the reduction in the density of interfacial states related to oxygen vacancies afforded by oxygen annealing. The device statistics confirm the improvement in the device-to-device and run-to-run uniformity. We also report on the photo-induced stability in such oxide-TFTs against long-term UV irradiation, which is significant for transparent displays.
Population structure and genetic diversity of the black-footed rock-wallaby (Petrogale lateralis MacDonnell Ranges race)
Authors: Ruykys Laura , Lancaster Melanie L.
Published: March 2015

Genetic diversity is a critical determinant of the persistence of populations because it enables animals to evolve and adapt to environmental change. Black-footed rock-wallabies (Petrogale lateralis MacDonnell Ranges race), or warru, once occupied virtually all suitable habitat within the arid zone of central Australia. However, only two metapopulations now remain in the southern portion of this race’s range (South Australia) and a recovery program has involved both in- and ex-situ conservation initiatives. To establish whether genetic factors such as inbreeding may be inhibiting population recovery, the current study examined the population structure and genetic diversity of animals in the three largest-known extant colonies using six polymorphic microsatellite loci. Bayesian and frequency-based assignment tests revealed substantial population structuring (pairwise FST values 0.122–0.278), congruent with geographically distinct colonies. There was some evidence of dispersal, with two migrants identified across two colonies, but little evidence for extensive interbreeding among colonies. Population substructure was evidenced by high values of FIS in one colony. All populations possessed relatively high levels of genetic diversity (allelic richness: 5.1–7.5, heterozygosity: 0.70–0.72). On the basis of a genetic analysis of parentage, approximately half of all males and females in the known metapopulations produced offspring. This has likely contributed to the retention of genetic diversity across colonies. These findings have implications for the management of both the in- and ex-situ warru populations.
MSA-PAD: DNA multiple sequence alignment framework based on PFAM accessed domain information
Authors: Balech Bachir , Vicario Saverio , Donvito Giacinto , Monaco Alfonso , Notarangelo Pasquale , Pesole Graziano
Published: March 2015

Summary: Here we present the MSA-PAD application, a DNA multiple sequence alignment framework that uses PFAM protein domain information to align DNA sequences encoding either single or multiple protein domains. MSA-PAD has two alignment options: gene and genome mode.

Availability and Implementation: MSA-PAD is available as a web application (https://recasgateway.ba.infn.it/) and as two Taverna workflows corresponding to two alignment modes (Gene mode: http://www.myexperiment.org/workflows/4549.html; Genome Mode: http://www.myexperiment.org/workflows/4551.html).

Contact:  g.pesole@ibbe.cnr.it

Supplementary information:  Supplementary data are available at Bioinformatics online.
Near-IR imaging of T Cha: evidence for scattered-light disc structures at Solar system scales
Authors: Cheetham A. , Huélamo N. , Lacour S. , de Gregorio-Monsalvo I. , Tuthill P.
Published: March 2015

T Chamaeleontis is a young star surrounded by a transitional disc, and a plausible candidate for ongoing planet formation. Recently, a substellar companion candidate was reported within the disc gap of this star. However, its existence remains controversial, with the counter-hypothesis that light from a high-inclination disc may also be consistent with the observed data. The aim of this work is to investigate the origin of the observed closure phase signal to determine if it is best explained by a compact companion. We observed T Cha in the L′ and Ks filters with sparse aperture masking, with seven data sets covering a period of 3 years. A consistent closure phase signal is recovered in all L′ and Ks data sets. Data were fitted with a companion model and an inclined circumstellar disc model based on known disc parameters: both were shown to provide an adequate fit. However, the absence of expected relative motion for an orbiting body over the 3-year time baseline spanned by the observations rules out the companion model. Applying image reconstruction techniques to each data set reveals a stationary structure consistent with forward scattering from the near edge of an inclined disc.
Outer rotation curve of the Galaxy with VERA. II. Annual parallax and proper motion of the star-forming region IRAS 21379+5106
Authors: Nakanishi Hiroyuki , Sakai Nobuyuki , Kurayama Tomoharu , Matsuo Mitsuhiro , Imai Hiroshi , Burns Ross A. , Ozawa Takeaki , Honma Mareki , Shibata Katsunori M. , Kawaguchi Noriyuki
Published: March 2015

We conducted astrometric very long baseline interferometry (VLBI) observations of water-vapor maser emission in the massive star-forming region IRAS 21379+5106 in order to measure the annual parallax and proper motion, using VLBI Exploration of Radio Astrometry (VERA). The annual parallax measured 0.262 ± 0.031 mas, corresponding to a distance of $3.82^{+0.51}_{-0.41}\:$kpc. The proper motion was (μαcos δ, μδ) = (−2.74 ± 0.08, −2.87 ± 0.18) mas yr−1. By using this result, the Galactic rotational velocity was estimated to be Vθ = 218 ± 19 km s−1 at the galactocentric distance R = 9.22 ± 0.43 kpc, when we adopted the Galactic constants R0 = 8.05 ± 0.45 kpc and V0 = 238 ± 14 km s−1. With the newly determined distance, the bolometric luminosity of the central young stellar object was reestimated to be (2.15 ± 0.54) × 103 L⊙, which corresponds to the spectral type of B2–B3. The maser features were found to be distributed along a straight line extending from the southwest to the northeast. In addition, a vector map of the internal motions, constructed from the residual proper motions, implies that the maser features trace a bipolar flow, and that it cannot be explained by simple ballistic motions.
Brachytherapy-based Accelerated Partial Breast Irradiation Provides Equivalent 10-Year Outcomes to Whole Breast Irradiation
Authors: Wobb Jessica L. , Shah Chirag , Chen Peter Y. , Wallace Michelle , Ye Hong , Jawad Maha S. , Grills Inga S.
Published: March 2015

Introduction:

Although whole breast irradiation (WBI) represents the standard radiotherapy technique in breast conserving therapy, accelerated partial breast irradiation (APBI) has emerged as an option to reduce treatment duration with comparable clinical outcomes. The purpose of this analysis is to present long-term clinical outcomes between WBI and APBI.

Methods:

A total of 3009 patients were treated with breast conserving therapy at a single institution between 1980 and 2012. Among them, 2528 patients received WBI and 481 received APBI (interstitial or balloon based). A matched-pair analysis was performed with patients matched by age (±3 years), stage (T-stage vs. T1 vs. T2), and estrogen receptor status (+/−). All patients had a minimum of 12 months follow-up. A total of 274 matches (ratio 1:1) were made.

Results:

No differences between groups were noted with respect to clinicopathologic features; WBI patients demonstrated a trend for slightly larger tumors (1.3 vs. 1.1 cm, P=0.06). At 10 years, no differences were noted with respect to rates of ipsilateral breast tumor recurrence (4% vs. 4%, P=0.11), regional recurrence (1% vs. 1%, P=0.20), contralateral breast failure (9% vs. 3%, P=0.06), or distant metastases (3% vs. 6%, P=0.47) for WBI and APBI, respectively. In addition, 10-year disease-free survival (93% vs. 91%, P=0.10) and overall survival (83% vs. 75%, P=0.34) were similar. Long-term cosmesis was good to excellent in 94% of WBI patients versus 95% of APBI patients (P=0.78).

Conclusions:

At 10 years, no differences in recurrence or survival were found between patients undergoing WBI or brachytherapy-based APBI.
Protocol for Reducing Time to Antibiotics in Pediatric Patients Presenting to an Emergency Department With Fever and Neutropenia
Authors: Cohen Clay , King Amber , Lin Chee Paul , Friedman Gregory K. , Monroe Kathy , Kutny Matthew
Published: March 2015

Objectives

Patients with febrile neutropenia are at high risk of morbidity and mortality from infectious causes. Decreasing time to antibiotic (TTA) administration is associated with improved patient outcomes. We sought to reduce TTA for children presenting to the emergency department with fever and neutropenia.

Methods

In a prospective cohort study with historical comparison, TTA administration was evaluated in patients with neutropenia presenting to the Children's of Alabama Emergency Department. A protocol was established to reduce delays in antibiotic administration and increase the percentage of patients who receive treatment within 60 minutes of presentation. One hundred pre-protocol patient visits between August 2010 and December 2011 were evaluated and 153 post-protocol visits were evaluated between August 2012 and September 2013. We reviewed individual cases to determine barriers to rapid antibiotic administration.

Results

Antibiotics were administered in 96.9 ± 57.8 minutes in the pre-protocol patient group, and only 35% of patients received antibiotics within 60 minutes of presentation and 70% received antibiotics within 120 minutes. After implementation of the protocol, TTA for neutropenic patients was decreased to 64.3 ± 28.4 minutes (P < 0.0001) with 51.4% receiving antibiotics within 60 minutes and 93.2% within 120 minutes.

Conclusions

Implementing a standard approach to patients at risk for neutropenia decreased TTA. There are numerous challenges in providing timely antibiotics to children with febrile neutropenia. Identified delays included venous access (time to effect of topical anesthetics, and difficulty obtaining access), physicians waiting on laboratory results, and antibiotic availability.