bluuebunny/crossref_metadata_2025 huggingface dataset:
Merkel Cell Spinal Metastasis: Management in the Setting of a Poor Prognosis
Authors: Goodwin C. Rory , Mehta Ankit I. , Adogwa Owoicho , Sarabia-Estrada Rachel , Sciubba Daniel M.
Published: January 2015

Study Design

Case report.

Objective

Merkel cell carcinoma is an aggressive neuroendocrine carcinoma with a poor prognosis. Metastatic epidural spinal cord compression (MESCC) is a debilitating disease causing neurologic deficits. The surgical management for MESCC depends on pathology.

Methods

We report a case of Merkel cell carcinoma of the spine and evaluate the treatment paradigms utilized in the prior reports.

Result

A 76-year-old man with a history of Merkel cell carcinoma presented with 2-week history of progressive difficulty ambulating and a solitary T5 epidural mass encasing the spinal cord. The patient underwent a T5 corpectomy with cage placement and T3 to T7 posterior fusion with postoperative neurologic improvement and a return to ambulation. Three weeks postoperatively, the patient re-presented with new-onset weakness and widespread metastatic spinal disease with epidural compression at the T8 level. Six weeks postoperatively, he was placed in hospice care.

Conclusion

Prior reports in the literature demonstrated a poor prognosis for Merkel cell carcinoma metastasis to the spine with survival ranging from 1 to 9 months after diagnosis. Although neurologic decline necessitates a surgical intervention, the assessment of operative benefit should take into account the prognosis associated with the primary tumor subtype.
Spontaneously Resolved Recurrent Cervical Epidural Hematoma in a 37-Week Primigravida
Authors: Iwatsuki Katsuyuki , Deguchi Masao , Hirata Hitoshi , Kanamono Toshihisa
Published: January 2015

Study Design

Case report.

Objective

To describe a patient with a recurrent spontaneous spinal epidural hematoma (SSEH) during pregnancy that had spontaneous remission.

Methods

A 27-year-old primigravida at 37 weeks’ gestation suddenly felt a strong left shoulder pain without any trauma. She had a history of fenestration for a spontaneous cervical hematoma when she was 18 years old. An emergency magnetic resonance imaging revealed a recurrence of the cervical epidural hematoma at the C4–T1 level, but she had no paralysis.

Results

The patient subsequently underwent a cesarean section and delivered a healthy male infant. Her spinal epidural hematoma disappeared. Multislice computed tomography showed no evidence for a vascular malformation or tumor. Three years after the initial cesarean section, she underwent a second one and delivered another male infant.

Conclusions

We report on a rare case of recurrent SSEH during pregnancy with no neurologic deficits that was treated nonoperatively with close observation and resulted in spontaneous resolution. In such patients with no neurologic deficits, nonoperative management with close observation may be a reasonable alternative.
Single photon simultaneous K-shell ionization and K-shell excitation. I. Theoretical model applied to the interpretation of experimental results on H2O
Authors: Carniato S. , Selles P. , Andric L. , Palaudoux J. , Penent F. , Žitnik M. , Bučar K. , Nakano M. , Hikosaka Y. , Ito K. , Lablanquie P.
Published: January 2015

We present in detail a theoretical model that provides absolute cross sections for simultaneous core-ionization core-excitation (K−2V ) and compare its predictions with experimental results obtained on the water molecule after photoionization by synchrotron radiation. Two resonances of different symmetries are assigned in the main K−2V peak and comparable contributions from monopolar (direct shake-up) and dipolar (conjugate shake-up) core-valence excitations are identified. The main peak is observed with a much greater width than the total experimental resolution. This broadening is the signature of nuclear dynamics.
Toward accurate thermochemistry of the 24MgH, 25MgH, and 26MgH molecules at elevated temperatures: Corrections due to unbound states
Authors: Szidarovszky Tamás , Császár Attila G.
Published: January 2015

The total partition functions QT and their first two moments Q′T and Q″T, together with the isobaric heat capacities CpT, are computed a priori for three major MgH isotopologues on the temperature range of T = 100–3000 K using the recent highly accurate potential energy curve, spin-rotation, and non-adiabatic correction functions of Henderson et al. [J. Phys. Chem. A 117, 13373 (2013)]. Nuclear motion computations are carried out on the ground electronic state to determine the (ro)vibrational energy levels and the scattering phase shifts. The effect of resonance states is found to be significant above about 1000 K and it increases with temperature. Even very short-lived states, due to their relatively large number, have significant contributions to QT at elevated temperatures. The contribution of scattering states is around one fourth of that of resonance states but opposite in sign. Uncertainty estimates are given for the possible error sources, suggesting that all computed thermochemical properties have an accuracy better than 0.005% up to 1200 K. Between 1200 and 2500 K, the uncertainties can rise to around 0.1%, while between 2500 K and 3000 K, a further increase to 0.5% might be observed for Q″T and CpT, principally due to the neglect of excited electronic states. The accurate thermochemical data determined are presented in the supplementary material for the three isotopologues of 24MgH, 25MgH, and 26MgH at 1 K increments. These data, which differ significantly from older standard data, should prove useful for astronomical models incorporating thermodynamic properties of these species.
Multilayer film shields for the protection of PMT from constant magnetic field
Authors: Dmitrenko V. V. , Besson David , Nyunt PhyoWai , Grabchikov S. S. , Grachev V. M. , Muraviev-Smirnov C. C. , Ulin S. E. , Uteshev Z. M. , Vlasik K. F.
Published: January 2015

Photomultiplier tubes (PMTs) are widely used in physical experiments as well as in applied devices. PMTs are sensitive to magnetic field, so creation of effective magnetic shields for their protection is very important. In this paper, the results of measurements of shielding effectiveness of multilayer film magnetic shields on PMT-85 are presented. Shields were formed by alternating layers of a material with high magnetic permeability (Ni-Fe) and high electric conductivity—Cu. The maximum number of bilayers reached 45. It is shown that in weak magnetic fields up to 0.5 mT, the output signal amplitude from PMT-85 does not change for all used multilayer shields. In strong magnetic field of 2–4 mT, the output signal amplitude decrease with 10%–40% depending from the number of layers in the shield. The Pulse distribution of PMT-85 in magnetic field 0.2–4 mT slightly changed in the range 1.1%–1.3% for the case when the number of layers do not exceed 10 and practically did not change for a shield with 45 double layers.
Extracting the diffusion tensor from molecular dynamics simulation with Milestoning
Authors: Mugnai Mauro L. , Elber Ron
Published: January 2015

We propose an algorithm to extract the diffusion tensor from Molecular Dynamics simulations with Milestoning. A Kramers-Moyal expansion of a discrete master equation, which is the Markovian limit of the Milestoning theory, determines the diffusion tensor. To test the algorithm, we analyze overdamped Langevin trajectories and recover a multidimensional Fokker-Planck equation. The recovery process determines the flux through a mesh and estimates local kinetic parameters. Rate coefficients are converted to the derivatives of the potential of mean force and to coordinate dependent diffusion tensor. We illustrate the computation on simple models and on an atomically detailed system—the diffusion along the backbone torsions of a solvated alanine dipeptide.
Vibrational predissociation and vibrationally induced isomerization of 3-aminophenol-ammonia
Authors: Heid Cornelia G. , Merrill Wyatt G. , Case Amanda S. , Crim F. Fleming
Published: January 2015

We investigate the vibrational predissociation dynamics of the hydrogen-bonded 3-aminophenol-ammonia cluster (3-AP-NH3) in the OH and NH stretching regions. Vibrational excitation provides enough energy to dissociate the cluster into its constituent 3-AP and NH3 monomers, and we detect the 3-AP fragments via (1 + 1) resonance-enhanced multiphoton ionization (REMPI). The distribution of vibrational states of the 3-AP fragment suggests the presence of two distinct dissociation pathways. The first dissociation channel produces a broad, unstructured feature in the REMPI-action spectrum after excitation of any of the OH or NH stretching vibrations, pointing to a nearly statistical dissociation pathway with extensive coupling among the vibrations in the cluster during the vibrational predissociation. The second dissociation channel produces distinct, resolved features on top of the broad feature but only following excitation of the OH or symmetric NH3 stretch in the cluster. This striking mode-specificity is consistent with strong coupling of these two modes to the dissociation coordinate (the O–H⋯N bond). The presence of clearly resolved transitions to the electronic origin and to the 10a2 + 10b2 state of the cis-3-AP isomer shows that vibrational excitation is driving the isomerization of the trans-3-AP-NH3 isomer to the cis-3-AP-NH3 isomer in the course of the dissociation.
Rotationally inelastic scattering of methyl radicals with Ar and N2
Authors: Tkáč Ondřej , Ma Qianli , Stei Martin , Orr-Ewing Andrew J. , Dagdigian Paul J.
Published: January 2015

The rotationally inelastic scattering of methyl radical with Ar and N2 is examined at collision energies of 330 ± 25 cm−1 and 425 ± 50 cm−1, respectively. Differential cross sections (DCSs) were measured for different final n′ rotational levels (up to n′ = 5) of the methyl radicals, averaged over k′ sub-levels, using a crossed molecular beam machine with velocity map imaging. For Ar as a collision partner, we present a newly constructed ab initio potential energy surface and quantum mechanical scattering calculations of state-resolved DCSs. These computed DCSs agree well with the measurements. The DCSs for both Ar and N2 collision partners are strongly forward peaked for all spectroscopic lines measured. For scattering angles below 60°, the theoretical CD3–Ar DCSs show diffraction oscillations that become less pronounced as n′ increases, but these oscillations are not resolved experimentally. Comparisons are drawn with our recently reported DCSs for scattering of methyl radicals with He atoms.
A novel system for measurement of the transverse electron momentum distribution from photocathodes
Authors: Feng J. , Nasiatka J. , Wan W. , Vecchione T. , Padmore H. A.
Published: January 2015

The transverse momentum of electrons produced by a photocathode contributes significantly to the performance of several different types of accelerator-based light sources, such as Free Electron Lasers, as well as systems designed for ultrafast electron diffraction and dynamic transmission electron microscopy. Minimization of the transverse emittance from photocathodes is the subject of intensive research, and therefore measurement of this parameter is of great importance. Here, we describe a simple system that offers real time measurements of transverse emittance and can be easily integrated into the photocathode fabrication process.
A compact two-dimensional laser scanner based on piezoelectric actuators
Authors: Wei Chen , Sihai Chen , Dong Luo , Guohua Jiao
Published: January 2015

A compact two-dimensional (2D) single-mirror laser scanner has been designed and prototyped that is structurally small and has high accuracy. The mirror of the scanner is driven by three piezoelectric actuators aligned in parallel and staggered to form a triangular base to provide structural compactness and close drive axes. The mechanical structure and 2D tilt principle of the scanner were analyzed and the architecture was tested. With an asymmetric structure, the scanner has an optical angle of 2.558° and a principle resonance frequency at 1036.8 Hz in the x-axis and 4.495° at 654.0 Hz in the y-axis. Experimental results suggest that, with hysteresis compensation, the nonlinearity of the scanner is reduced to ±0.25% for the x-axis and ±0.3% for the y-axis. With an open-loop controller, the laser scanner can realize linear scanning at several hundred hertz.
Identification of photoluminescence P line in indium doped silicon as InSi-Sii defect
Authors: Lauer Kevin , Möller Christian , Schulze Dirk , Ahrens Carsten
Published: January 2015

Indium and carbon co-implanted silicon was investigated by low-temperature photoluminescence spectroscopy. A photoluminescence peak in indium doped silicon (P line) was found to depend on the position of a silicon interstitial rich region, the existence of a SiNx:H/SiOx stack and on characteristic illumination and annealing steps. These results led to the conclusion that silicon interstitials are involved in the defect and that hydrogen impacts the defect responsible for the P line. By applying an unique illumination and annealing cycle we were able to link the P line defect with a defect responsible for degradation of charge carrier lifetime in indium as well as boron doped silicon. We deduced a defect model consisting of one acceptor and one silicon interstitial atom denoted by ASi-Sii, which is able to explain the experimental data of the P line as well as the light-induced degradation in indium and boron doped silicon. Using this model we identified the defect responsible for the P line as InSi-Sii in neutral charge state and C2v configuration.
Landau superfluids as nonequilibrium stationary states
Authors: Wreszinski Walter F.
Published: January 2015

We define a superfluid state to be a nonequilibrium stationary state (NESS), which, at zero temperature, satisfies certain metastability conditions, which physically express that there should be a sufficiently small energy-momentum transfer between the particles of the fluid and the surroundings (e.g., pipe). It is shown that two models, the Girardeau model and the Huang-Yang-Luttinger (HYL) model, describe superfluids in this sense and, moreover, that, in the case of the HYL model, the metastability condition is directly related to Nozières’ conjecture that, due to the repulsive interaction, the condensate does not suffer fragmentation into two (or more) parts, thereby assuring its quantum coherence. The models are rigorous examples of NESS in which the system is not finite, but rather a many-body system.
Stretched arc discharge in produced water
Authors: Cho Y. I. , Wright K. C. , Kim H. S. , Cho D. J. , Rabinovich A. , Fridman A.
Published: January 2015

The objective of the present study was to investigate the feasibility of stretching an arc discharge in produced water to increase the volume of produced water treated by plasma. Produced water is the wastewater generated by hydraulic fracturing of shale during the production phase in shale-oil or shale-gas exploration. The electric conductivity of produced water is in the range of 50-200 mS/cm, which provides both a challenge and opportunity for the application of plasmas. Stretching of an arc discharge in produced water was accomplished using a ground electrode and two high-voltage electrodes: one positioned close to the ground electrode and the other positioned farther away from the ground. The benefit of stretching the arc is that the contact between the arc and water is significantly increased, resulting in more efficient plasma treatment in both performance and energy cost.
The detrimental effect of flux-induced boron alloying in Pd–Si–Cu bulk metallic glasses
Authors: Granata D. , Fischer E. , Wessels V. , Löffler J. F.
Published: January 2015

We report on advanced insights into the fluxing of Pd–Si–Cu bulk metallic glasses. Flux-induced boron alloying and trapping of oxides are found to be associated with the employed boron oxide fluxing agent, and both influence the attainable glass-forming ability (GFA) in opposite ways. Incorporated boron strongly deteriorates the GFA due to a rising liquidus temperature, while the oxygen reduction improves it. Thus, proper fine-tuning of the fluxing time and overheating characteristics leads to an enhancement of GFA. In the current case, the critical diameter of Pd77.5Si16.5Cu6 bulk metallic glasses can be increased to 15 mm, as compared to 3 mm in the unfluxed case. Based on these results, we illustrate that the development of further fluxing agents is crucial for enhancement of the key properties of bulk metallic glasses.
Investigating the dynamics of laser induced sparks in atmospheric helium using Rayleigh and Thomson scattering
Authors: Nedanovska E. , Nersisyan G. , Morgan T. J. , Hüwel L. , Murakami T. , Lewis C. L. S. , Riley D. , Graham W. G.
Published: January 2015

We have used optical Rayleigh and Thomson scattering to investigate the expansion dynamics of laser induced plasma in atmospheric helium and to map its electron parameters both in time and space. The plasma is created using 9 ns duration, 140 mJ pulses from a Nd:YAG laser operating at 1064 nm, focused with a 10 cm focal length lens, and probed with 7 ns, 80 mJ, and 532 nm Nd:YAG laser pulses. Between 0.4 μs and 22.5 μs after breakdown, the electron density decreases from 3.3 × 1017 cm−3 to 9 × 1013 cm−3, while the temperature drops from 3.2 eV to 0.1 eV. Spatially resolved Thomson scattering data recorded up to 17.5 μs reveal that during this time the laser induced plasma expands at a rate given by R ∼ t0.4 consistent with a non-radiative spherical blast wave. This data also indicate the development of a toroidal structure in the lateral profile of both electron temperature and density. Rayleigh scattering data show that the gas density decreases in the center of the expanding plasma with a central scattering peak reemerging after about 12 μs. We have utilized a zero dimensional kinetic global model to identify the dominant particle species versus delay time and this indicates that metastable helium and the He2+ molecular ion play an important role.
Communication: Kinetics of scavenging of small, nucleating clusters: First nucleation theorem and sum rules
Authors: Malila Jussi , McGraw Robert , Laaksonen Ari , Lehtinen Kari E. J.
Published: January 2015

Despite recent advances in monitoring nucleation from a vapor at close-to-molecular resolution, the identity of the critical cluster, forming the bottleneck for the nucleation process, remains elusive. During past twenty years, the first nucleation theorem has been often used to extract the size of the critical cluster from nucleation rate measurements. However, derivations of the first nucleation theorem invoke certain questionable assumptions that may fail, e.g., in the case of atmospheric new particle formation, including absence of sub-critical cluster losses and heterogeneous nucleation on pre-existing nanoparticles. Here, we extend the kinetic derivation of the first nucleation theorem to give a general framework to include such processes, yielding sum rules connecting the size dependent particle formation and loss rates to the corresponding loss-free nucleation rate and the apparent critical size from a naïve application of the first nucleation theorem that neglects them.
The meaning of the “universal” WLF parameters of glass-forming polymer liquids
Authors: Dudowicz Jacek , Douglas Jack F. , Freed Karl F.
Published: January 2015

Although the Williams-Landell-Ferry (WLF) equation for the segmental relaxation time τ(T) of glass-forming materials is one of the most commonly encountered relations in polymer physics, its molecular basis is not well understood. The WLF equation is often claimed to be equivalent to the Vogel-Fulcher-Tammann (VFT) equation, even though the WLF expression for τ(T) contains no explicit dependence on the fragility parameter D of the VFT equation, while the VFT equation lacks any explicit reference to the glass transition temperature Tg, the traditionally chosen reference temperature in the WLF equation. The observed approximate universality of the WLF parameters C1(g) and C2(g) implies that τ(T) depends only on T–Tg, a conclusion that seems difficult to reconcile with the VFT equation where the fragility parameter D largely governs the magnitude of τ(T). The current paper addresses these apparent inconsistencies by first evaluating the macroscopic WLF parameters C1(g) and C2(g) from the generalized entropy theory of glass-formation and then by determining the dependence of C1(g) and C2(g) on the microscopic molecular parameters (including the strength of the cohesive molecular interactions and the degree of chain stiffness) and on the molar mass of the polymer. Attention in these calculations is restricted to the temperature range (Tg < T < Tg + 100 K), where both the WLF and VFT equations apply.
Modelling of edge localised modes and edge localised mode control
Authors: Huijsmans G. T. A. , Chang C. S. , Ferraro N. , Sugiyama L. , Waelbroeck F. , Xu X. Q. , Loarte A. , Futatani S.
Published: January 2015

Edge Localised Modes (ELMs) in ITER Q = 10 H-mode plasmas are likely to lead to large transient heat loads to the divertor. To avoid an ELM induced reduction of the divertor lifetime, the large ELM energy losses need to be controlled. In ITER, ELM control is foreseen using magnetic field perturbations created by in-vessel coils and the injection of small D2 pellets. ITER plasmas are characterised by low collisionality at a high density (high fraction of the Greenwald density limit). These parameters cannot simultaneously be achieved in current experiments. Therefore, the extrapolation of the ELM properties and the requirements for ELM control in ITER relies on the development of validated physics models and numerical simulations. In this paper, we describe the modelling of ELMs and ELM control methods in ITER. The aim of this paper is not a complete review on the subject of ELM and ELM control modelling but rather to describe the current status and discuss open issues.
Tensile testing of Fe and FeCr nanowires using molecular dynamics simulations
Authors: Byggmästar J. , Granberg F. , Kuronen A. , Nordlund K. , Henriksson K. O. E.
Published: January 2015

Using molecular dynamics, we have studied the behaviour of cylindrical [001]-oriented Fe and FeCr nanowires under uniaxial tensile strain with both an embedded atom method (EAM) and a Tersoff-like bond order potential. The mechanical properties were analysed and the deformation mechanism was studied and compared between the potentials. The effects of chromium content and size of the wire were studied. Both potentials show elongation by deformation twinning in the 〈111〉/{211} system resulting in a significantly stiffer and stronger [110]-axial nanowire. The pure iron nanowires are elastically softer than bulk iron and an addition of chromium has both a softening and weakening effect. The bond order potential shows a strong dependence on chromium concentration, while the dependence is considerably weaker for the EAM potential.
Materials and fabrication sequences for water soluble silicon integrated circuits at the 90 nm node
Authors: Yin Lan , Bozler Carl , Harburg Daniel V. , Omenetto Fiorenzo , Rogers John A.
Published: January 2015

Tungsten interconnects in silicon integrated circuits built at the 90 nm node with releasable configurations on silicon on insulator wafers serve as the basis for advanced forms of water-soluble electronics. These physically transient systems have potential uses in applications that range from temporary biomedical implants to zero-waste environmental sensors. Systematic experimental studies and modeling efforts reveal essential aspects of electrical performance in field effect transistors and complementary ring oscillators with as many as 499 stages. Accelerated tests reveal timescales for dissolution of the various constituent materials, including tungsten, silicon, and silicon dioxide. The results demonstrate that silicon complementary metal-oxide-semiconductor circuits formed with tungsten interconnects in foundry-compatible fabrication processes can serve as a path to high performance, mass-produced transient electronic systems.
Interaction effects enhancing magnetic particle detection based on magneto-relaxometry
Authors: Laslett O. , Ruta S. , Barker J. , Chantrell R. W. , Friedman G. , Hovorka O.
Published: January 2015

We investigated the effects of dipolar interactions on the long-time magnetization decay M(t) in clusters of magnetic nanoparticles. Applying the Néel-Arrhenius thermal activation picture shows that M(t) generally follows stretched exponential behavior, dependent not only on the dipolar interaction strength, geometry of particle arrangement within clusters, but also on the field history applied during the initialization. As demonstrated, combining these factors could serve to enhance the degree of resolution in magnetic particle detection based on magneto-relaxometry.
A microfluidic device enabling high-efficiency single cell trapping
Authors: Jin D. , Deng B. , Li J. X. , Cai W. , Tu L. , Chen J. , Wu Q. , Wang W. H.
Published: January 2015

Single cell trapping increasingly serves as a key manipulation technique in single cell analysis for many cutting-edge cell studies. Due to their inherent advantages, microfluidic devices have been widely used to enable single cell immobilization. To further improve the single cell trapping efficiency, this paper reports on a passive hydrodynamic microfluidic device based on the “least flow resistance path” principle with geometry optimized in line with corresponding cell types. Different from serpentine structure, the core trapping structure of the micro-device consists of a series of concatenated T and inverse T junction pairs which function as bypassing channels and trapping constrictions. This new device enhances the single cell trapping efficiency from three aspects: (1) there is no need to deploy very long or complicated channels to adjust flow resistance, thus saving space for each trapping unit; (2) the trapping works in a “deterministic” manner, thus saving a great deal of cell samples; and (3) the compact configuration allows shorter flowing path of cells in multiple channels, thus increasing the speed and throughput of cell trapping. The mathematical model of the design was proposed and optimization of associated key geometric parameters was conducted based on computational fluid dynamics (CFD) simulation. As a proof demonstration, two types of PDMS microfluidic devices were fabricated to trap HeLa and HEK-293T cells with relatively significant differences in cell sizes. Experimental results showed 100% cell trapping and 90% single cell trapping over 4 × 100 trap sites for these two cell types, respectively. The space saving is estimated to be 2-fold and the cell trapping speed enhancement to be 3-fold compared to previously reported devices. This device can be used for trapping various types of cells and expanded to trap cells in the order of tens of thousands on 1-cm2 scale area, as a promising tool to pattern large-scale single cells on specific substrates and facilitate on-chip cellular assay at the single cell level.
Theoretical investigation on the relationship between the torque correlation and spin correlation models for the Gilbert damping constant
Authors: Sakuma Akimasa
Published: January 2015

To gain insight into the relationship between the spin correlation (SC) and torque correlation (TC) models for the Gilbert damping constant, α, we first make a simple consideration on the physical aspect of these models and calculate α for the Fe50Co50 disordered alloy by the two models using the first principles technique. Electron scattering is introduced through the random arrangement of atoms and is treated with coherent potential approximation. The results indicate that in the TC model, vertex correction (VC) does not have significant contribution and the results are insensitive to the infinitesimal positive value, δ, which is used in Green's function. In the SC model, on the other hand, the VC is indispensable and the obtained values of α are found to be considerably sensitive to δ. We confirm that the value of α in the SC model approaches the value obtained in the TC model in the limit δ→+0.
Different singularities in the functions of extended kinetic theory at the origin of the yield stress in granular flows
Authors: Berzi Diego , Vescovi Dalila
Published: January 2015

We use previous results from discrete element simulations of simple shear flows of rigid, identical spheres in the collisional regime to show that the volume fraction-dependence of the stresses is singular at the shear rigidity. Here, we identify the shear rigidity, which is a decreasing function of the interparticle friction, as the maximum volume fraction beyond which a random collisional assembly of grains cannot be sheared without developing force chains that span the entire domain. In the framework of extended kinetic theory, i.e., kinetic theory that accounts for the decreasing in the collisional dissipation due to the breaking of molecular chaos at volume fractions larger than 0.49, we also show that the volume fraction-dependence of the correlation length (measure of the velocity correlation) is singular at random close packing, independent of the interparticle friction. The difference in the singularities ensures that the ratio of the shear stress to the pressure at shear rigidity is different from zero even in the case of frictionless spheres: we identify that with the yield stress ratio of granular materials, and we show that the theoretical predictions, once the different singularities are inserted into the functions of extended kinetic theory, are in excellent agreement with the results of numerical simulations.
Few-cycle plasmon oscillations controlling photoemission from metal nanoparticles
Authors: Földi Péter , Márton István , Német Nikolett , Ayadi Viktor , Dombi Péter
Published: January 2015

Few-cycle optical excitation of nanosystems holds promise of fundamental discoveries and applications in ultrafast nanoscience, the development of nanostructured photocathodes, and many more. For these, surface plasmon generation on unprecedented timescales needs to be controlled. For this, few-cycle plasmon oscillations on a metal nanoparticle can be generated by keeping considerable electric field enhancement factors. As an initial application of such a high spatiotemporal localization of an ultrashort laser pulse, we numerically demonstrate the control of photoelectrons on a true sub-fs timescale in nanometric spatial domains. We show that it is only off-resonant nanoparticles that can provide few-cycle plasmons and electron control on this timescale.
Rapid preparation and magnetodielectric properties of trirutile Cr2WO6
Authors: Gaultois Michael W. , Kemei Moureen C. , Harada Jaye K. , Seshadri Ram
Published: January 2015

Dense pellets of > 99% purity trirutile Cr2WO6 were prepared in one step from starting oxides using spark plasma sintering, leading to simultaneous reaction and consolidation in 3 min at 1473 K. The reducing environment during processing may be partly responsible for the rapid reaction time in these oxides, with partial reduction of Cr3+ and the associated oxygen vacancies allowing rapid diffusion of cations. The low-temperature physical properties of Cr2WO6 were examined, and a new transition at T = 5.9 K was observed as an anomaly in the temperature-dependent dielectric permittivity and a corresponding anomaly in the specific heat. A strong enhancement of the magnetocapacitance is observed below this transition temperature at T = 5.9 K and may be associated with a change from collinear spin order to more complex spin order.
Defects reduction of Ge epitaxial film in a germanium-on-insulator wafer by annealing in oxygen ambient
Authors: Lee Kwang Hong , Bao Shuyu , Chong Gang Yih , Tan Yew Heng , Fitzgerald Eugene A. , Tan Chuan Seng
Published: January 2015

A method to remove the misfit dislocations and reduce the threading dislocations density (TDD) in the germanium (Ge) epilayer growth on a silicon (Si) substrate is presented. The Ge epitaxial film is grown directly on the Si (001) donor wafer using a “three-step growth” approach in a reduced pressure chemical vapour deposition. The Ge epilayer is then bonded and transferred to another Si (001) handle wafer to form a germanium-on-insulator (GOI) substrate. The misfit dislocations, which are initially hidden along the Ge/Si interface, are now accessible from the top surface. These misfit dislocations are then removed by annealing the GOI substrate. After the annealing, the TDD of the Ge epilayer can be reduced by at least two orders of magnitude to <5 × 106 cm−2.
Photoluminescence studies of shock-recovered Y2O3:Eu3+
Authors: Kishimura Hiroaki , Hamada Sho , Aruga Atsushi , Matsumoto Hitoshi
Published: January 2015

A series of shock-recovery experiments on Y2O3:Eu3+ powder were conducted involving the impact of a flyer plate accelerated by a single-stage powder-propellant gun. The recovered samples were characterized by X-ray diffraction (XRD) analysis and photoluminescence (PL) spectroscopy. The XRD and PL results of samples shocked at pressures of 13 GPa indicated that a phase transition from a cubic phase to a monoclinic phase occurred. The recovered samples shocked at 21 and 25 GPa consisted of Y2O3:Eu3+ with the cubic phase and the monoclinic phase. These results indicated that the shock-induced phase transition was the partial completion of the phase transition.
Characterization of anomalous movements of spherical living cells on a silicon dioxide glassy substrate
Authors: Son Myeonggu , Lee Gyudo , Son Jongsang , Choi Seungyeop , Kim Youngho , Lee Sei-Young , Yoon Young-Ro , Yoon Dae Sung , Lee Sang Woo
Published: January 2015

The random walk of spherical living cells on a silicon dioxide glassy substrate was studied experimentally and numerically. This random walk trajectory exhibited erratic dancing, which seemingly obeyed anomalous diffusion (i.e., Lévy-like walk) rather than normal diffusion. Moreover, the angular distribution (−π to π) of the cells' trajectory followed a “U-shaped pattern” in comparison to the uniform distribution seen in the movements of negatively charged polystyrene microspheres. These effects could be attributable to the homeostasis-driven structural resilient character of cells and physical interactions derived from temporarily retained nonspecific binding due to weak forces between the cells and substrates. Our results provide new insights into the stochastic behavior of mesoscopic biological particles with respect to structural properties and physical interactions.
Defect-band mediated ferromagnetism in Gd-doped ZnO thin films
Authors: Venkatesh S. , Franklin J. B. , Ryan M. P. , Lee J.-S. , Ohldag Hendrik , McLachlan M. A. , Alford N. M. , Roqan I. S.
Published: January 2015

Gd-doped ZnO thin films prepared by pulsed laser deposition with Gd concentrations varying from 0.02–0.45 atomic percent (at. %) showed deposition oxygen pressure controlled ferromagnetism. Thin films prepared with Gd dopant levels (<Gd 0.112 at. %) at low oxygen deposition pressure (<25 mTorr) were ferromagnetic at room temperature. Negative magnetoresistance, electric transport properties showed that the ferromagnetic exchange is mediated by a spin-split defect band formed due to oxygen deficiency related defect complexes. Mott's theory of variable range of hopping conduction confirms the formation of the impurity/defect band near the Fermi level.
Effect of Y2O3 nanoparticles addition on the microstructure and tensile strength of Cu/Sn3.0Ag0.5Cu solder joint
Authors: Yang L. M. , Zhang Z. F.
Published: January 2015

A sort of composite solder was produced by adding Y2O3 nanoparticles in Sn3.0Ag0.5Cu solder. The microstructure and tensile strength of solder joint were investigated. It was found that the size of intermetallic compounds and tensile strength of solder joint were notably influenced by the nanoparticles. The growth behaviors of intermetallic compounds Ag3Sn and Cu6Sn5 were suppressed due to the addition of Y2O3 nanoparticles. The tensile test results revealed that the strength of composite solder joint was higher than that of solder joint without nanoparticles addition. It is indicated that Y2O3 nanoparticles should play important roles in strengthening of joint by hampering dislocation movement.
Ordered domain lateral location, symmetry, and thermal stability in Ge:Si islands
Authors: Richard M.-I. , Malachias A. , Schülli T. U. , Favre-Nicolin V. , Zhong Z. , Metzger T. H. , Renaud G.
Published: January 2015

Compositional atomic ordering is a crucial issue in the epitaxial growth of nanoparticles and thin films. Here, we report on a method based on x-ray diffuse scattering close to basis forbidden Bragg reflections to infer the lateral location, the symmetry, and the thermal stability of ordered domains in GeSi dome-shaped islands on Si(001) after growth and during annealing. We observe that atomic ordering does not disappear after annealing, demonstrating that it is a resilient metastable phenomenon.
Linkages between reach-scale physical habitat and invertebrate assemblages in upland streams
Authors: Milner Victoria S. , Willby Nigel J. , Gilvear David J. , Perfect Charles
Published: January 2015

Determining the influence of physical habitat on biological structure in minimally disturbed settings is important if the effects of alterations to physical habitat are to be understood. This study tested whether reach-scale differences in physical habitat influence macroinvertebrate community composition at 24 sites in the Cairngorm Mountains, Scotland. Stream reaches were classified into channel types based on a geomorphic typology (i.e. step-pool, bedrock, plane-bed and pool-riffle). PERMANOVA indicated an overall significant relationship between the geomorphic typology and macroinvertebrate species-level composition, and among all combinations of channel types (such as step-pool and pool-riffle, step-pool and bedrock). Most channel types were dominated by high abundances of Baetis rhodani, Rhithrogena semicolorata and Leuctra inermis, which are ubiquitous in unpolluted gravel-bedded Scottish streams. However, reflecting significant differences in abundance of commoner taxa between types, indicator value (IndVal) analysis revealed that pool-riffle reaches were characterised by elmids (Limnius sp. and Oulimnius sp.) and Caenis rivulorum, and step-pool reaches by Alainites muticus, B. rhodani, L. inermis and Brachyptera risi. Geomorphic typing of rivers provides a useful basis for the initial assessment of ecological status whereas abundance-based biological data processed at the appropriate taxonomic resolution should be sensitive to physical-habitat modifications.
Increased mRNA expression of selected pro-inflammatory factors in inflamed bovine endometrium in vivo as well as in endometrial epithelial cells exposed to Bacillus pumilus in vitro
Authors: Gärtner Martina A. , Peter Sarah , Jung Markus , Drillich Marc , Einspanier Ralf , Gabler Christoph
Published: January 2015

Endometrial epithelium plays a crucial role in the first immune response to invading bacteria by producing cytokines and chemokines. The aim of this study was to investigate the first inflammatory response of the endometrium in vivo and in vitro. Gene expression of several pro-inflammatory factors and Toll-like receptors (TLR2, -4, -6) was determined in endometrial cytobrush samples obtained from healthy cows and cows with clinical or subclinical endometritis. Endometrial epithelial cells were co-cultured with an isolated autochthonous uterine bacterial strain Bacillus pumilus. Total RNA was extracted from in vivo and in vitro samples and subjected to real-time reverse transcription polymerase chain reaction. CXC ligands (CXCL) 1/2 and CXC chemokine receptor (CXCR) 2 mRNA expression was higher in cows with subclinical endometritis and CXCL3 mRNA expression was higher in cows with clinical endometritis compared with healthy cows. B. pumilus induced cell death of epithelial cells within 24 h of co-culturing. The presence of B. pumilus resulted in significantly higher mRNA expression of interleukin 1α (IL1A), IL6, IL8, CXCL1–3 and prostaglandin–endoperoxide synthase 2 in co-cultured cells compared with untreated controls. The maximum increase was mainly detected after 2 h. These results support the hypothesis that bacterial infection of endometrial cells might induce prompt synthesis of pro-inflammatory cytokines resulting in a local inflammatory reaction.
Shadow enhancers enable Hunchback bifunctionality in the
Drosophila
embryo
Authors: Staller Max V. , Vincent Ben J. , Bragdon Meghan D. J. , Lydiard-Martin Tara , Wunderlich Zeba , Estrada Javier , DePace Angela H.
Published: January 2015

Significance

Enhancers are regions of regulatory DNA that control gene expression and cell fate decisions during development. Enhancers compute the expression pattern of their target gene by reading the concentrations of input regulatory proteins. Many developmental genes contain multiple enhancers that control the same output pattern, but it is unclear whether these enhancers all compute the pattern in the same way. We use measurements in single cells and computational models in
Drosophila
embryos to demonstrate that two enhancers that encode the same gene expression pattern compute differently: the same regulatory protein represses one enhancer and activates the other. Pairs of enhancers that generate the same pattern by performing different computations may impart special properties to developmental systems.
Antimalarial 4(1H)-pyridones bind to the Q
i
site of cytochrome
bc
1
Authors: Capper Michael J. , O’Neill Paul M. , Fisher Nicholas , Strange Richard W. , Moss Darren , Ward Stephen A. , Berry Neil G. , Lawrenson Alexandre S. , Hasnain S. Samar , Biagini Giancarlo A. , Antonyuk Svetlana V.
Published: January 2015

Significance

X-ray crystallography greatly benefits drug discovery work by elucidating information about the binding of drug compounds to their target. Using this information, changes to the compounds can be made in a process known as rational drug design. Cytochrome
bc
1
is a proven drug target in the treatment and prevention of malaria, a disease that kills over half a million people each year and many compounds have been developed to inhibit cytochrome
bc
1
. Here we show the binding of two such compounds in X-ray crystal structures, which reveal an unexpected binding site. This work opens up a new area for antimalarial research and reinforces the need for structural information in drug design.
Genetic dissection of pheromone processing reveals main olfactory system-mediated social behaviors in mice
Authors: Matsuo Tomohiko , Hattori Tatsuya , Asaba Akari , Inoue Naokazu , Kanomata Nobuhiro , Kikusui Takefumi , Kobayakawa Reiko , Kobayakawa Ko
Published: January 2015

Significance

It is now widely accepted that the range of pheromones that control social behaviors are processed by both the vomeronasal system (VNS) and the main olfactory system (MOS). However, the functional contributions of each subsystem in social behavior remain unclear. Here, we showed that mice with loss-of-function confined to the dorsal MOS maintained innate odor recognition and VNS activity, but failed to demonstrate multiple male and female social behaviors. Functional dissociation of the MOS and VNS enabled the identification of an MOS-mediated processing of semiochemical information, independent of the VNS.
Tissue-based metabolic labeling of polysialic acids in living primary hippocampal neurons
Authors: Kang Kyungtae , Joo Sunghoon , Choi Ji Yu , Geum Sujeong , Hong Seok-Pyo , Lee Seung-Yeul , Kim Yong Ho , Kim Seong-Min , Yoon Myung-Han , Nam Yoonkey , Lee Kyung-Bok , Lee Hee-Yoon , Choi Insung S.
Published: January 2015

Significance

The roles of cell-surface glycans remain elusive compared with those of proteins or lipids because of their diverse and dynamic nature. Metabolic incorporation of unnatural monosaccharides in the biochemical synthesis of glycans as a chemical reporter has been a successful method to investigate the functions of cell-surface glycans but has also left an issue of cytotoxicity for certain cells. In this work, we developed a tissue-based strategy for metabolic incorporation of a chemical reporter to primary neurons. We let an unnatural monosaccharide be metabolized by hippocampal tissues before dissociation into individual cells, and thereby, we could eliminate cytotoxicity. We used this method to describe, for the first time to our knowledge, the real-time distribution of polysialic acids on the membranes of neurons.
Calcium waves occur as
Drosophila
oocytes activate
Authors: Kaneuchi Taro , Sartain Caroline V. , Takeo Satomi , Horner Vanessa L. , Buehner Norene A. , Aigaki Toshiro , Wolfner Mariana F.
Published: January 2015

Significance

This paper reports the first visualization of calcium dynamics in
Drosophila
eggs in vivo and in vitro, demonstrating that a calcium wave is a conserved feature of egg activation (the process by which a mature egg becomes able to initiate embryo development). In vertebrates and echinoderms, the fertilizing sperm triggers egg activation by inducing calcium release from the egg’s internal stores, causing wave(s) of increased calcium to sweep across the egg. However, insect eggs activate without fertilization. We show that a wave of increased calcium occurs during activation of
Drosophila
eggs. The wave is induced during ovulation by influx of calcium into the egg through mechanosensitive ion channels. Release of calcium from intracellular stores is required for wave propagation.
Insulin-independent regulation of hepatic triglyceride synthesis by fatty acids
Authors: Vatner Daniel F. , Majumdar Sachin K. , Kumashiro Naoki , Petersen Max C. , Rahimi Yasmeen , Gattu Arijeet K. , Bears Mitchell , Camporez João-Paulo G. , Cline Gary W. , Jurczak Michael J. , Samuel Varman T. , Shulman Gerald I.
Published: January 2015

Significance

The paradox of selective hepatic insulin resistance, wherein the insulin-resistant liver fails to suppress glucose production but continues to produce triglycerides, is central to the pathophysiology of type 2 diabetes. We hypothesized that hepatic triglyceride synthesis is regulated mostly by fatty acid delivery to the liver and independent of changes in hepatic insulin signaling. To examine this hypothesis, we used a novel LC-MS/MS method to measure rates of hepatic fatty acid esterification in vivo. In contrast to hepatic de novo hepatic lipogenesis, rates of hepatic esterification of fatty acids into triglyceride was primarily dependent on fatty acid delivery and independent of hepatic insulin action, providing an explanation for increased hepatic triglyceride synthesis in the presence of hepatic insulin resistance.
Beyond school effectiveness and school improvement: lighting the slow fuse of possibility
Authors: Fielding Michael
Published: January 2015

This paper argues that both school effectiveness and school improvement are importantly flawed and that we should be developing alternative approaches which connect more explicitly and more imaginatively with the dilemmas and possibilities facing education in and for democracy at the end of the twentieth century. The first half of the paper (sections 1–3) begins by expressing a number of dissatisfactions with the school effectiveness movement as a prelude to exploring the positive nature and potential of ‘mapping’ change in the school improvement process. The second half (sections 4–5) articulates a number of reservations about both school effectiveness and school improvement and begins to explore the possibility of an alternative, namely, ‘transformative education’.