bluuebunny/crossref_metadata_2025 huggingface dataset:
Dissociative recombination of HCl+, H2Cl+, DCl+, and D2Cl+ in a flowing afterglow
Authors: Wiens Justin P. , Miller Thomas M. , Shuman Nicholas S. , Viggiano Albert A.
Published: December 2016

Dissociative recombination of electrons with HCl+, H2Cl+, DCl+, and D2Cl+ has been measured under thermal conditions at 300, 400, and 500 K using a flowing afterglow–Langmuir probe apparatus. Measurements for HCl+ and DCl+ employed the variable electron and neutral density attachment mass spectrometry (VENDAMS) method, while those for H2Cl+ and D2Cl+ employed both VENDAMS and the more traditional technique of monitoring electron density as a function of reaction time. At 300 K, HCl+ and H2Cl+ recombine with kDR = 7.7±2.14.5 × 10−8 cm3 s−1 and 2.6 ± 0.8 × 10−7 cm3 s−1, respectively, whereas D2Cl+ is roughly half as fast as H2Cl+ with kDR = 1.1 ± 0.3 × 10−7 cm3 s−1 (2σ confidence intervals). DCl+ recombines with a rate coefficient below the approximate detection limit of the method (≲5 × 10−8 cm3 s−1) at all temperatures. Relatively slow dissociative recombination rates have been speculated to be responsible for the large HCl+ and H2Cl+ abundances in interstellar clouds compared to current astrochemical models, but our results imply that the discrepancy must originate elsewhere.
Relocking of intrinsic angular momenta in collisions of diatoms with ions: Capture of H2(j = 0,1) by H2+
Authors: Dashevskaya E. I. , Litvin I. , Nikitin E. E. , Troe J.
Published: December 2016

Rate coefficients for capture of H2(j = 0,1) by H2+ are calculated in perturbed rotor approximation, i.e., at collision energies considerably lower than Bhc (where B denotes the rotational constant of H2). The results are compared with the results from an axially nonadiabatic channel (ANC) approach, the latter providing a very good approximation from the low-temperature Bethe-Wigner to the high temperature Langevin limit. The classical ANC approximation performs satisfactorily at temperatures above 0.1 K. At 0.1 K, the rate coefficient for j=1 is about 25% higher than that for j = 0 while the latter is close to the Langevin rate coefficient. The Bethe-Wigner limit of the rate coefficient for j = 1 is about twice that for j = 0. The analysis of the relocking of the intrinsic angular momentum of H2 during the course of the collision illustrates the significance of relocking in capture dynamics in general.
Observation of enhanced rate coefficients in the H2++H2→H3++H reaction at low collision energies
Authors: Allmendinger Pitt , Deiglmayr Johannes , Höveler Katharina , Schullian Otto , Merkt Frédéric
Published: December 2016

The energy dependence of the rate coefficient of the H2++H2→H3++H reaction has been measured in the range of collision energies between kB⋅10K and kB⋅300mK. A clear deviation of the rate coefficient from the value expected on the basis of the classical Langevin-capture behavior has been observed at collision energies below kB⋅1K, which is attributed to the joint effects of the ion-quadrupole and Coriolis interactions in collisions involving ortho-H2 molecules in the  j = 1 rotational level, which make up 75% of the population of the neutral H2 molecules in the experiments. The experimental results are compared to very recent predictions by Dashevskaya et al. [J. Chem. Phys. 145, 244315 (2016)], with which they are in agreement.
Electron density evolution during a fast, non-diffusive propagation of a magnetic field in a multi-ion-species plasma
Authors: Doron R. , Rubinstein B. , Citrin J. , Arad R. , Maron Y. , Fruchtman A. , Strauss H. R. , Mehlhorn T. A.
Published: December 2016

We present spectroscopic measurements of the electron density evolution during the propagation of a magnetic-field front (peak magnitude ∼8 kG) through low-resistivity, multi-ion species plasma. In the configuration studied, a pulsed current, generating the magnetic field, is driven through a plasma that pre-fills the volume between two electrodes. 3D spatial resolution is achieved by local injection of dopants via an optimized laser blow-off technique. The electron density evolution is inferred from the intensity evolution of Mg II and B II-III dopant line-emission. The Doppler-shifted line-emission of the light boron, accelerated by the magnetic field is also used to determine the electric-potential-hill associated with the propagating magnetic field. Utilizing the same spectral line for the determination of both the density and the electric potential allowed for exploring the precise correlation between these two key parameters. For these measurements, achieving a high spatial resolution (a small fraction of the magnetic-field front) was necessary. The density evolution is found to be consistent with a scenario in which ions with relatively high charge-to-mass ratios are reflected by different potential heights, namely, reflected off the magnetic-field front at different field magnitudes, whereas the plasma of ions with low charge-to-mass ratios is penetrated by the magnetic field.
Effects of a small magnetic field on homoclinic bifurcations in a low-Prandtl-number fluid
Authors: Basak Arnab , Kumar Krishna
Published: December 2016

Effects of a uniform magnetic field on homoclinic bifurcations in Rayleigh-Bénard convection in a fluid of Prandtl number Pr = 0.01 are investigated using direct numerical simulations (DNS). A uniform magnetic field is applied either in the vertical direction or in the horizontal direction. For a weak vertical magnetic field, the possibilities of both forward and backward homoclinic bifurcations are observed leading to a spontaneous gluing of two limit cycles into one as well as a spontaneous breaking of a limit cycle into two for lower values of the Chandrasekhar's number (Q≤5). A slightly stronger magnetic field makes the convective flow time independent giving the possibility of stationary patterns at the secondary instability. For horizontal magnetic field, the x⇋y symmetry is destroyed and neither a homoclinic gluing nor a homoclinic breaking is observed. Two low-dimensional models are also constructed: one for a weak vertical magnetic field and another for a weak horizontal magnetic field. The models qualitatively capture the features observed in DNS and help understanding the unfolding of bifurcations close to the onset of magnetoconvection.
Combined laser ultrasonics, laser heating, and Raman scattering in diamond anvil cell system
Authors: Zinin Pavel V. , Prakapenka Vitali B. , Burgess Katherine , Odake Shoko , Chigarev Nikolay , Sharma Shiv K.
Published: December 2016

We developed a multi-functional in situ measurement system under high pressure equipped with a laser ultrasonics (LU) system, Raman device, and laser heating system (LU-LH) in a diamond anvil cell (DAC). The system consists of four components: (1) a LU-DAC system (probe and pump lasers, photodetector, and oscilloscope) and DAC; (2) a fiber laser, which is designed to allow precise control of the total power in the range from 2 to 100 W by changing the diode current, for heating samples; (3) a spectrometer for measuring the temperature of the sample (using black body radiation), fluorescence spectrum (spectrum of the ruby for pressure measurement), and Raman scattering measurements inside a DAC under high pressure and high temperature (HPHT) conditions; and (4) an optical system to focus laser beams on the sample and image it in the DAC. The system is unique and allows us to do the following: (a) measure the shear and longitudinal velocities of non-transparent materials under HPHT; (b) measure temperature in a DAC under HPHT conditions using Planck’s law; (c) measure pressure in a DAC using a Raman signal; and (d) measure acoustical properties of small flat specimens removed from the DAC after HPHT treatment. In this report, we demonstrate that the LU-LH-DAC system allows measurements of velocities of the skimming waves in iron at 2580 K and 22 GPa.
Radially localized kinetic beta induced Alfven eigenmodes in tokamak plasmas
Authors: Rizvi H. , Panwar A. , Shahzad M. , Ryu C. M.
Published: December 2016

We have studied the kinetic beta induced Alfven eigenmodes (KBAEs) by developing a fast global eigenvalue solving code. Even and odd parity KBAEs radially localized at the rational surface are found with the presence of the kinetic effects, namely, the finite ion Larmor radius effects. The KBAE mode structures become broader in the presence of the parallel equilibrium current. The KBAE frequency increases with the increase in the plasma β and the ion Larmor radius (ρi). Damping of the KBAE increases with the finite Larmor radius and decreases with the plasma beta and mode with a higher radial mode number has a stronger damping. Numerical results reveal that frequency and kinetic damping of KBAEs are independent of the tokamak size, and that kinetic damping in the core region is significantly smaller by an order of magnitude compared to that in the radially outward region of tokamak.
Indirect NMR spin–spin coupling constants in diatomic alkali halides
Authors: Jaszuński Michał , Antušek Andrej , Demissie Taye B. , Komorovsky Stanislav , Repisky Michal , Ruud Kenneth
Published: December 2016

We report the Nuclear Magnetic Resonance (NMR) spin–spin coupling constants for diatomic alkali halides MX, where M = Li, Na, K, Rb, or Cs and X = F, Cl, Br, or I. The coupling constants are determined by supplementing the non-relativistic coupled-cluster singles-and-doubles (CCSD) values with relativistic corrections evaluated at the four-component density-functional theory (DFT) level. These corrections are calculated as the differences between relativistic and non-relativistic values determined using the PBE0 functional with 50% exact-exchange admixture. The total coupling constants obtained in this approach are in much better agreement with experiment than the standard relativistic DFT values with 25% exact-exchange, and are also noticeably better than the relativistic PBE0 results obtained with 50% exact-exchange. Further improvement is achieved by adding rovibrational corrections, estimated using literature data.
Assessing the role of trap-to-band impact ionization and hole transport on the dark currents of 4H-SiC photoconductive switches containing deep defects
Authors: Chowdhury A. R. , Dickens J. C. , Neuber A. A. , Joshi R. P.
Published: December 2016

Simulation studies of the electrical response characteristics of 4H-SiC switches containing traps are reported in the absence of photoexcitation. The focus is on trap-to-band impact ionization and the role of hole injection from the anode. Simulations show that hole-initiated ionization can be more important than the electron-initiated process. The results also underscore the role of hole injection at the high applied voltages. Our one-dimensional, time-dependent model yielded reasonable agreement with measured current-voltage data spanning over three orders of magnitude, but only when impact ionization was taken into account. Finally, the simulations predicted undulations in the device conduction current density with respect to time, due to the dynamic interplay between impact ionization, spatial electric field values, and occupancies of the trap levels.
Basis for calculating cross sections for nuclear magnetic resonance spin-modulated polarized neutron scattering
Authors: Kotlarchyk Michael , Thurston George M.
Published: December 2016

In this work we study the potential for utilizing the scattering of polarized neutrons from nuclei whose spin has been modulated using nuclear magnetic resonance (NMR). From first principles, we present an in-depth development of the differential scattering cross sections that would arise in such measurements from a hypothetical target system containing nuclei with non-zero spins. In particular, we investigate the modulation of the polarized scattering cross sections following the application of radio frequency pulses that impart initial transverse rotations to selected sets of spin-1/2 nuclei. The long-term aim is to provide a foundational treatment of the scattering cross section associated with enhancing scattering signals from selected nuclei using NMR techniques, thus employing minimal chemical or isotopic alterations, so as to advance the knowledge of macromolecular or liquid structure.
Accurate schemes for calculation of thermodynamic properties of liquid mixtures from molecular dynamics simulations
Authors: Caro Miguel A. , Laurila Tomi , Lopez-Acevedo Olga
Published: December 2016

We explore different schemes for improved accuracy of entropy calculations in aqueous liquid mixtures from molecular dynamics (MD) simulations. We build upon the two-phase thermodynamic (2PT) model of Lin et al. [J. Chem. Phys. 119, 11792 (2003)] and explore new ways to obtain the partition between the gas-like and solid-like parts of the density of states, as well as the effect of the chosen ideal “combinatorial” entropy of mixing, both of which have a large impact on the results. We also propose a first-order correction to the issue of kinetic energy transfer between degrees of freedom (DoF). This problem arises when the effective temperatures of translational, rotational, and vibrational DoF are not equal, either due to poor equilibration or reduced system size/time sampling, which are typical problems for ab initio MD. The new scheme enables improved convergence of the results with respect to configurational sampling, by up to one order of magnitude, for short MD runs. To ensure a meaningful assessment, we perform MD simulations of liquid mixtures of water with several other molecules of varying sizes: methanol, acetonitrile, N, N-dimethylformamide, and n-butanol. Our analysis shows that results in excellent agreement with experiment can be obtained with little computational effort for some systems. However, the ability of the 2PT method to succeed in these calculations is strongly influenced by the choice of force field, the fluidicity (hard-sphere) formalism employed to obtain the solid/gas partition, and the assumed combinatorial entropy of mixing. We tested two popular force fields, GAFF and OPLS with SPC/E water. For the mixtures studied, the GAFF force field seems to perform as a slightly better “all-around” force field when compared to OPLS+SPC/E.
Optomechanically tuned electromagnetically induced transparency-like effect in coupled optical microcavities
Authors: Li Guanyu , Jiang Xiaoshun , Hua Shiyue , Qin Yingchun , Xiao Min
Published: December 2016

We experimentally demonstrate the electromagnetically induced transparency (EIT)-like effect using a double-wheel microcavity coupled with a silica microtoroid cavity. To match the resonant modes of the two microcavities, we shift the resonant wavelength of the double-wheel microcavity by 1.5 nm via the optical gradient force. The EIT-like transmission spectrum is precisely controlled by changing the distance and the frequency detuning between the two coupled microcavities.
Inkjet printed silver electrodes on macroporous paper for a paper-based isoelectric focusing device
Authors: Gaspar Cristina , Sikanen Tiina , Franssila Sami , Jokinen Ville
Published: December 2016

We demonstrate a combined printing process utilizing inkjet printing of silver electrodes and solid-ink technology for printing hydrophobic wax barriers for fabricating paper microfluidic devices with integrated electrodes. Optimized printing parameters are given for achieving conducting silver lines on the top of macroporous chromatography paper down to 250 μm–300 μm resolution. Electrical characterization and wicking experiments demonstrate that the printed silver patterns are simultaneously conductive and porous enough to allow reliable capillary wicking across the electrodes. The combined wax and silver printing method is used for fabrication of paper microfluidic isoelectric focusing devices for separation and concentration of proteins.
Piezoresistive strain sensing of carbon black /silicone composites above percolation threshold
Authors: Shang Shuying , Yue Yujuan , Wang Xiaoer
Published: December 2016

A series of flexible composites with a carbon black (CB) filled silicone rubber matrix were made by an improved process in this work. A low percolation threshold with a mass ratio of 2.99% CB was achieved. The piezoresistive behavior of CB/silicone composites above the critical value, with the mass ratio of carbon black to the silicone rubber ranging from 0.01 to 0.2, was studied. The piezoresistive behavior was different from each other for the composites with different CB contents. But, the composites show an excellent repeatability of piezoresistivity under cyclic compression, no matter with low filler content or with high filler content. The most interesting phenomena were that the plots of gauge factor versus strain of the composites with different CB contents constructed a master curve and the curve could be well fitted by a function. It was showed that the gauge factor of the composites was strain-controlled showing a promising prospect of application.
Curved diamond-crystal spectrographs for x-ray free-electron laser noninvasive diagnostics
Authors: Terentyev Sergey , Blank Vladimir , Kolodziej Tomasz , Shvyd’ko Yuri
Published: December 2016

We report on the manufacturing and X-ray tests of bent diamond-crystal X-ray spectrographs, designed for noninvasive diagnostics of the X-ray free-electron laser (XFEL) spectra in the spectral range from 5 to 15 keV. The key component is a curved, 20-μm thin, single crystalline diamond triangular plate in the (110) orientation. The radius of curvature can be varied between R = 0.6 m and R = 0.1 m in a controlled fashion, ensuring imaging in a spectral window of up to 60 eV for ≃8 keV X-rays. All of the components of the bending mechanism (about 10 parts) are manufactured from diamond, thus ensuring safe operations in intense XFEL beams. The spectrograph is transparent to 88% for 5-keV photons and to 98% for 15-keV photons. Therefore, it can be used for noninvasive diagnostics of the X-ray spectra during XFEL operations.
Electric-field-controlled nonvolatile magnetic switching and resistive change in La0.6Sr0.4MnO3/0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (011) heterostructure at room temperature
Authors: Zhao Wenbo , Zhang Dalong , Meng Dechao , Huang Weichuan , Feng Lei , Hou Chuangming , Lu Yalin , Yin Yuewei , Li Xiaoguang
Published: December 2016

Control over nonvolatile magnetization rotation and resistivity change by an electric field in La0.6Sr0.4MnO3 thin films grown on (011) oriented 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 substrates are studied. By utilizing an in-plane strain induced by a side ferroelectric switching with pulsed electric fields from −2.5 kV/cm to +5 kV/cm along [011¯], a nonvolatile and reversible 90°-rotation of the magnetic easy-axis is achieved, corresponding to −69.68% and +174.26% magnetization switching along the [100] and [011¯] directions, respectively. The strain induced nonvolatile resistivity change is approximately 3.6% along the [011¯] direction. These findings highlight potential strategies for electric-field-driven spintronic devices.
Nanoscale guiding and shaping of indium droplets
Authors: Dąbrowski Maciej , Dai Yanan , Hocevar Moïra , Frolov Sergey , Petek Hrvoje
Published: December 2016

We present time-resolved microscopy of motion and shape transformation of liquid indium (In) sessile droplets on InAs(001) surface. For temperatures up to 800 K, the droplets spontaneously move across the crystal undergoing stick-slip motion that is strongly affected by atomic steps and coalescence events. Above a critical temperature of around 800 K, the droplets stop moving and further increase in temperature causes them to change shape progressively from spherical to rectangular. The process of shape transformation is coherent, reversible and associated with temperature dependent wetting of the surface as well as crystalline anisotropy dependent arsenic solvation and evaporation rates. The etched rectangular substrate depressions formed under the droplets, giving them a rectangular shape, reveal unusual rheology with deeper regions at the corners. Our high spatial resolution measurements link the macroscopic behavior of the metallic droplets with the microscopic topography features and can be used for the metallic liquid droplet nano-manipulation.
Advanced germanium layer transfer for ultra thin body on insulator structure
Authors: Maeda Tatsuro , Chang Wen-Hsin , Irisawa Toshifumi , Ishii Hiroyuki , Hattori Hiroyuki , Poborchii Vladimir , Kurashima Yuuichi , Takagi Hideki , Uchida Noriyuki
Published: December 2016

We present the HEtero-Layer Lift-Off (HELLO) technique to obtain ultra thin body (UTB) Ge on insulator (GeOI) substrates. The transferred ultra thin Ge layers are characterized by the Raman spectroscopy measurements down to the thickness of ∼1 nm, observing a strong Raman intensity enhancement for high quality GeOI structure in ultra thin regime due to quantum size effect. This advanced Ge layer transfer technique enabled us to demonstrate UTB-GeOI nMOSFETs with the body thickness of only 4 nm.
Domain wall motions in BST ferroelectric thin films in the microwave frequency range
Authors: Nadaud Kevin , Borderon Caroline , Renoud Raphaël , Ghalem Areski , Crunteanu Aurelian , Huitema Laure , Dumas-Bouchiat Frédéric , Marchet Pascal , Champeaux Corinne , Gundel Hartmut W.
Published: December 2016

The existence of domain wall motion at microwave frequencies and its contribution to the ferroelectric complex permittivity is shown by evaluating the dielectric properties of BaSrTiO3 (BST) thin films as a function of the incident power. Even at low AC field amplitudes, the presence of the domain walls and the correlated motions (vibration and jumps) result in sensitivity of the dielectric properties to the incident field amplitude. Although the contribution of domain wall motion to the real part of the permittivity is not preponderant (less than 10%), it represents more than 50% of the material's global dielectric losses. This illustrates the importance to consider domain wall motion even in the microwave frequency region and the necessity to take into account the applied AC field amplitude (and thus the incident power) when characterizing ferroelectric materials. The present study has been realized on BST thin films, elaborated by pulsed laser deposition on MgO/Ir substrates.
Generation of multiwavelength light in the region of the biological windows in Tm3+-doped fiber excited at 1.064 μm
Authors: Gouveia-Neto A. S. , Silva J. F. , Vermelho M. V. D. , Gomes A. S. L. , Jacinto C.
Published: December 2016

Multiple wavelength infrared light generated within both “optical transmission windows” of biological tissues and blue light triggering photochemical reactions is produced, in Tm3+-doped fiber multi-excited in a single-pass configuration by a single fundamental source at 1.064 μm. In the process, amplified spontaneous emission at 810 nm (∼8 nm bandwidth) and blue emission at 480 nm are generated through frequency upconversion multiwavelength excitation using a single pump source at 1.064 μm and stimulated Raman scattering (SRS) Stokes emissions around 1115 nm, 1173 nm, 1226 nm, 1284 nm, and a continuum up to 1400 nm and beyond. The proposed excitation mechanism for 810 nm and 480 nm thulium emissions is assigned to a multiphonon-assisted multiwavelength excitation from the 3H6 ground-state to the 3H5 excited-state, a rapid relaxation to the 3F4 level followed by a excited-state absorption of the pump and SRS Stokes photons mediated by multiphonons connecting the 3F4 level to the 3H4 and 1G4 main emitting levels.
Ultrafast annular-magnetic-field-driven vortex-core reversals
Authors: Wang Zhenyu , Wang Ruifang
Published: December 2016

By micromagnetic numerical simulations, we investigate the dynamics of vortex-core reversal in a soft magnetic nanodisk under the excitation of annular, perpendicular, resonant magnetic fields. The non-fundamental radial modes of the nanodisk are characterized into alternating radial-phase-regions for which two adjacent regions across a node point are in antiphase. We show that radial spin-waves excited by fields applied in the in-phase regions are in phase, and therefore generate strong magnetization oscillations resulting from constructive spin-wave interference. Such annular magnetic fields can substantially speed up the vortex-core reversal and lower the threshold field amplitude in comparison with the global field. Our work provides an efficient mechanism for spin-wave excitation and ultrafast vortex-core switching.
High photoresponse in room temperature quantum cascade detector based on coupled quantum well design
Authors: Dougakiuchi Tatsuo , Fujita Kazuue , Hirohata Toru , Ito Akio , Hitaka Masahiro , Edamura Tadataka
Published: December 2016

We report high photoresponse measured in a room temperature quantum cascade detector (QCD) based on a coupled quantum well design that operates with a peak response wavelength of 5.4 μm. The coupled quantum well design is expected to produce higher photocurrents when compared with device active regions that use a combination of simple quantum wells. The coupled quantum well QCD demonstrated high responsivity of 22 mA/W at room temperature with a commonly used 45° wedge-based light coupling configuration. Application of a waveguide configuration to the proposed QCD yielded an elevated responsivity of ∼130 mA/W and a specific detectivity (D*) of 1.1 × 108 cm W−1 Hz1/2 at room temperature.
Millimeter wave transmittance/absorption measurements on micro and nano hexaferrites
Authors: Korolev Konstantin A. , Chen Shu , Barua Radhika , Afsar Mohammed N. , Chen Yajie , Harris Vincent G.
Published: December 2016

Millimeter wave transmittance measurements have been successfully performed on commercial samples of micro- and nano-sized particles of BaFe12O19 and SrFe12O19 hexaferrite powders and nano-sized particles of BaFeO2 and SrFeO2 powders. Broadband millimeter wave transmittance measurements have been performed using free space quasi-optical spectrometer, equipped with a set of high power backward wave oscillators covering the frequency range of 30 – 120 GHz. Real and imaginary parts of dielectric permittivity for both types of micro- and nanoferrites have been calculated using analysis of recorded high precision transmittance spectra. Frequency dependences of magnetic permeability of ferrite powders, as well as saturation magnetization and anisotropy field have been determined based on Schlöemann’s theory for partially magnetized ferrites. Micro- and nano-sized ferrite powders have been further investigated by DC magnetization to assess magnetic behavior and compare with millimeter wave data. Consistency of saturation magnetization determined independently by both millimeter wave absorption and DC magnetization have been found for all ferrite powders. These materials seem to be quite promising as tunable millimeter wave absorbers and filters, based on their size-dependent absorption.
Magnetic susceptibility of multiferroics and chemical ordering
Authors: Maryško Miroslav , Laguta Valentin V. , Raevski Igor P. , Kuzian Roman O. , Olekhnovich Nikolai M. , Pushkarev Anatoli V. , Radyush Yuri V. , Raevskaya Svetlana I. , Titov Victor V. , Kubrin Stanislav P.
Published: December 2016

Magnetic susceptibility of two types of perovskite compounds A(Fe0.5M0.5)O3 A=Ba,Sr with M=Nb and Sb differing in the degree of chemical ordering was studied between 2 and 380 K. In the low temperature region, these compounds exhibit antiferromagnetic and spin-glass transition at T = 16−30 K. For the ordered compounds (M = Sb) the inverse susceptibility depends on T linearly up to the highest temperatures used. This enables the determination of the Weiss temperature θ and effective moment of the Fe3+ ion expressed by a number of Bohr magnetons, peff. In contrast to it, the compounds with M = Nb are characterized by a higher degree of the glassines and by a concave character of the inverse susceptibility vs T dependence in the high temperature region. In these cases, the values of peff and θ could be estimated only very roughly by extrapolation to higher temperatures. The observed behavior was qualitatively explained from the Curie-Weiss law taking into account a distribution of the values θ, which reflects the presence of different exchange interactions between the Fe3+ ions. The disordered samples (M = Nb) exhibit a roughly two times larger |θ|/TN ratio values as compared to the ordered (M = Sb) ones.
Transcranial Magnetic Stimulation-coil design with improved focality
Authors: Rastogi P. , Lee E. G. , Hadimani R. L. , Jiles D. C.
Published: December 2016

Transcranial Magnetic Stimulation (TMS) is a technique for neuromodulation that can be used as a non-invasive therapy for various neurological disorders. In TMS, a time varying magnetic field generated from an electromagnetic coil placed on the scalp is used to induce an electric field inside the brain. TMS coil geometry plays an important role in determining the focality and depth of penetration of the induced electric field responsible for stimulation. Clinicians and basic scientists are interested in stimulating a localized area of the brain, while minimizing the stimulation of surrounding neural networks. In this paper, a novel coil has been proposed, namely Quadruple Butterfly Coil (QBC) with an improved focality over the commercial Figure-8 coil. Finite element simulations were conducted with both the QBC and the conventional Figure-8 coil. The two coil’s stimulation profiles were assessed with 50 anatomically realistic MRI derived head models. The coils were positioned on the vertex and the scalp over the dorsolateral prefrontal cortex to stimulate the brain. Computer modeling of the coils has been done to determine the parameters of interest-volume of stimulation, maximum electric field, location of maximum electric field and area of stimulation across all 50 head models for both coils.
Investigation of effects of long-term thermal aging on magnetization process in low-alloy pressure vessel steels using first-order-reversal-curves
Authors: Kobayashi Satoru , Gillemot Ferenc , Horváth Ákos , Horváth Márta , Almásy László , Tian Qiang , Feoktystov Artem
Published: December 2016

We have investigated effects of long-term thermal aging at 550°C up to 10000 h on major-loop coercivity, hysteresis scaling of minor loops, and first-order reversal curves (FORCs) for low-alloy pressure vessel steels with low and high Ni contents. While major-loop coercivity and minor-loop coefficient of the scaling exhibit a gradual decrease with aging for high-Ni steel, those for low-Ni one are very weakly dependent on aging time. On the other hand, we found that FORC distribution becomes steep along both axes of interaction and switching fields and the peak shifts toward a lower switching field for both steels. Considering that there is no significant development of nanoscale precipitates during the aging as revealed with small-angle neutron scattering experiments, a relaxation of lattice strain in a matrix, possibly associated with diffusion of Ni atoms, may dominate magnetic properties at 550°C.
CD74 is a novel transcription regulator
Authors: Gil-Yarom Naama , Radomir Lihi , Sever Lital , Kramer Matthias P. , Lewinsky Hadas , Bornstein Chamutal , Blecher-Gonen Ronnie , Barnett-Itzhaki Zohar , Mirkin Vita , Friedlander Gilgi , Shvidel Lev , Herishanu Yair , Lolis Elias J. , Becker-Herman Shirly , Amit Ido , Shachar Idit
Published: December 2016

Significance

CD74 has been associated with tumor progression and metastasis. Its expression has been suggested to serve as a prognostic factor in many cancers, with higher relative expression behaving as a marker of tumor progression. Our previous studies showed that stimulation of CD74 expressed on chronic lymphocytic cells initiates a signaling cascade leading to chronic lymphocytic survival. The present study demonstrates that CD74’s cytoplasmic domain binds chromatin and regulates transcription and expression of genes involved in immune regulation, cell survival, and hematopoietic cancers. Further analysis of these processes will identify new targets that regulate tumor cell maintenance.
Comprehensive population-based genome sequencing provides insight into hematopoietic regulatory mechanisms
Authors: Guo Michael H. , Nandakumar Satish K. , Ulirsch Jacob C. , Zekavat Seyedeh M. , Buenrostro Jason D. , Natarajan Pradeep , Salem Rany M. , Chiarle Roberto , Mitt Mario , Kals Mart , Pärn Kalle , Fischer Krista , Milani Lili , Mägi Reedik , Palta Priit , Gabriel Stacey B. , Metspalu Andres , Lander Eric S. , Kathiresan Sekar , Hirschhorn Joel N. , Esko Tõnu , Sankaran Vijay G.
Published: December 2016

Significance

Human blood cell production is coordinated to ensure balanced levels of all lineages. The basis of this regulation remains poorly understood. Identification of genetic differences in human populations associated with blood cell measurements can shed light on such regulatory mechanisms. Here, we used whole-genome sequencing data to perform a genetic association study in a population-based biobank from Estonia. We identified a number of potential causal variants and underlying mechanisms. For example, we identified a regulatory element that is necessary for basophil production, which acts specifically during this process to regulate expression of the transcription factor CEBPA. We demonstrate how genome sequencing, genetic fine-mapping, and functional data can be integrated to gain important insight into blood cell production.
Pharma partnering: other people’s science
Authors: Hofmann Christian
Published: December 2016

Partnering is an ideal field if someone is seeking to move from a scientific to a more business-oriented discipline. Partnering’s goal is to identify and acquire external innovation. These discoveries are then included in a company’s pipeline and help bring novel treatments to patients. Advanced scientific training is essential in the identification and evaluation of these external assets. Here I describe how partnering works in a pharmaceutical company and offer advice on how to make a successful transition from a PhD program to a business career.
A Review of Adult and Pediatric Neuropathic Pain Assessment Tools
Authors: Morgan Kyle J. , Anghelescu Doralina L.
Published: December 2016

Objectives:

To identify and summarize the tools currently available for diagnosing and assessing neuropathic pain (NP) in adults and children and to identify areas where further research is required to address deficiencies in the existing tools.

Methods:

A review of journal articles pertaining to the diagnosis and assessment of NP was conducted.

Results:

We identified 11 tools for assessing NP in adults and 4 for assessing NP in pediatric patients.

Conclusions:

This article summarizes the various screening and assessment tools available to clinicians for evaluating NP. Despite the availability of the 15 tools discussed, a deficiency remains, particularly in the pediatric realm. To date, there is no well-validated NP assessment tool for children younger than 5 years, no pediatric NP screening tool that has been validated outside the domain of chemotherapy-induced peripheral neuropathy, and no consistent recommendation regarding the optimal tool to use with pediatric patients who have chronic pain. These areas, as well as others, would benefit from further research and development.
Palisaded Granuloma on the Nose: An Atypical Presentation of Granuloma Annulare
Authors: Rodríguez Amílcar G. , Sánchez Jorge L. , Sánchez Julio E.
Published: December 2016

Granuloma annulare (GA) is a common, asymptomatic dermatosis of unknown etiology. Many variants exist, among them widespread papules, papules in photodistribution, papules marked by tiny crusts (“perforating” GA), patches, plaques, and nodules (subcutaneous GA). The histopathological hallmark is a palisaded histiocytic infiltrate surrounding a central area of degenerated collagen with abundant mucin deposits. We report 2 women who presented with persistent nodules on the nose, which, on histopathological examination, showed a palisaded granuloma. We propose that these cases represent an unusual variant of GA occurring on the nose.
The Effects of Exercise Training on Brachial Artery Flow-Mediated Dilation
Authors: Early Kate S. , Stewart Abigail , Johannsen Neil , Lavie Carl J. , Thomas Jerry R. , Welsch Michael
Published: December 2016

PURPOSE:

Flow-mediated dilation, a barometer of cardiovascular (CV) health, is reported to increase with exercise training (ET); however, the potential moderating factors of ET are not clear to date. The purpose of this study was to determine the effect of ET assessed by brachial artery flow-mediated dilation (BAFMD).

METHODS:

Authors searched PubMed between January 1999 and December 2013, bibliographies, and reviews to identify studies examining ET and BAFMD. Two independent reviewers extracted quality, descriptive, exercise, and outcome data of eligible studies. Data were presented as weighted effect sizes (ESs) and 95% confidence limits.

RESULTS:

Analysis included 66 studies reporting BAFMD data (1865 ET and 635 control subjects). Overall, ET had significant improvements in BAFMD compared with controls (P < .0001). Exercise training at higher ET intensities resulted in a greater increase in BAFMD (9.29; 95% CI, 5.09-13.47) than lower ET intensities (3.63; 95% CI, −0.56 to 7.83) or control (−0.42; 95% CI, −2.06 to 1.21). Subjects whose ET duration was ≥150 min/wk (11.33; 95% CI, 7.15-15.51) had a significant improvement in BAFMD compared with those with <150 min/wk (4.79; 95% CI, 3.08-6.51) or control (−0.30; 95% CI, −1.99 to 1.39). Age (P = .11) and baseline artery diameter (P = .31) did not modify the BAFMD response to ET.

CONCLUSION:

Exercise training contributes to a significant increase in BAFMD. These results provide indirect evidence that ET alters a well-known factor associated with the primary and secondary prevention of CV diseases. Exercise training interventions, including greater intensity and duration, may optimize the increase in BAFMD.
Patient Characteristics Predictive of Cardiac Rehabilitation Adherence
Authors: Gaalema Diann E. , Savage Patrick D. , Rengo Jason L. , Cutler Alex Y. , Elliott Rebecca J. , Priest Jeffrey S. , Higgins Stephen T. , Ades Philip A.
Published: December 2016

PURPOSE:

Cardiac rehabilitation (CR) is a program of structured exercise and interventions for coronary risk factor reduction that reduces morbidity and mortality rates following a major cardiac event. Although a dose-response relationship between the number of CR sessions completed and health outcomes has been demonstrated, adherence with CR is not high. In this study, we examined associations between the number of sessions completed within CR and patient demographics, clinical characteristics, smoking status, and socioeconomic status (SES).

METHODS:

Multiple logistic regression and classification and regression tree (CART) modeling were used to examine associations between participant characteristics measured at CR intake and the number of sessions completed in a prospectively collected CR clinical database (n = 1658).

RESULTS:

Current smoking, lower SES, nonsurgical diagnosis, exercise-limiting comorbidities, and lower age independently predicted fewer sessions completed. The CART analysis illustrates how combinations of these characteristics (ie, risk profiles) predict the number of sessions completed. Those with the highest-risk profile for nonadherence (<65 years old, current smoker, lower SES) completed on average 9 sessions while those with the lowest-risk profile (>72 years old, not current smoker, higher SES, surgical diagnosis) completed 27 sessions on average.

CONCLUSIONS:

Younger individuals, as well as those who report smoking or economic challenges or have a nonsurgical diagnosis, may require additional support to maintain CR session attendance.
Developing an Adapted Cardiac Rehabilitation Training for Home Care Clinicians
Authors: Feinberg Jodi L. , Russell David , Mola Ana , Bowles Kathryn H. , Lipman Terri H.
Published: December 2016

Purpose:

There is limited evidence that home care clinicians receive education on the core competencies of cardiac rehabilitation (CR). This article describes the development and implementation of a CR training program adapted for home care clinicians, which incorporated the viewpoints of homebound patients with cardiovascular disease.

Methods:

Literature and guideline reviews were performed to glean curriculum content, supplemented with themes identified among patients and clinicians. Semistructured interviews were conducted with homebound patients regarding their perspectives on living with cardiovascular disease and focus groups were held with home care clinicians regarding their perspectives on caring for these patients. Transcripts were analyzed with the constant comparative method. A 15-item questionnaire was administered to home care nurses and rehabilitation therapists pre- and posttraining, and responses were analyzed using a paired sample t test.

Results:

Three themes emerged among patients: (1) awareness of heart disease; (2) motivation and caregivers' importance; and (3) barriers to attendance at outpatient CR; and 2 additional themes among clinicians: (4) gaps in care transitions; and (5) educational needs. Questionnaire results demonstrated significantly increased knowledge posttraining compared with pretraining among home care clinicians (pretest mean = 12.81; posttest mean = 14.63, P < .001). There was no significant difference between scores for nurses and rehabilitation therapists.

Conclusions:

Home care clinicians respond well to an adapted CR training to improve care for homebound patients with cardiovascular disease. Clinicians who participated in the training demonstrated an increase in their knowledge and skills of the core competencies for CR.
OUTER RETINAL LAYER CHANGES AFTER DEXAMETHASONE IMPLANT FOR CENTRAL RETINAL VEIN OCCLUSION
Authors: Battaglia Parodi Maurizio , Iacono Pierluigi , Scaramuzzi Matteo , Bandello Francesco
Published: December 2016

Purpose:

To analyze the outer retinal layer changes on spectral-domain optical coherence tomography after dexamethasone implant for the treatment of macular edema secondary to central retinal vein occlusions (CRVO).

Methods:

Thirty patients affected by macular edema related to CRVO (8 patients less than 50 years of age with nonischemic CRVO [<50-niCRVO], 12 patients more than 50 years with niCRVO [>50-niCRVO], and 10 patients with ischemic CRVO [iCRVO]) were included in a prospective study. After a comprehensive ophthalmologic examination, including best-corrected visual acuity, fluorescein angiography, and spectral-domain optical coherence tomography, each patient received a first implant. Further retreatments were performed on the basis of macular edema detection from the fourth month. Main outcome measure was the change in outer retinal layers at the 12-month examination.

Results:

The retinal layers of interest (external limiting membrane; ellipsoid zone; and retinal pigment epithelium) were classified as absent, disrupted, or present. The best baseline optical coherence tomography profile was found in <50-niCRVO group (absent external limiting membrane, ellipsoid zone, and retinal pigment epithelium layers in no patients; present and disrupted external limiting membrane in 25% and 75% of cases, respectively; disrupted ellipsoid zone and retinal pigment epithelium in 100% of cases), whereas the worst was detected in the iCRVO group (absent external limiting membrane, ellipsoid zone, and retinal pigment epithelium in 40%, 40%, and 10% of cases, respectively). A significant recovery of the retinal layers was observed in all CRVO subgroups; the greatest improvement was found in <50-niCRVO group. Median best-corrected visual acuity in the whole group improved from 0.85 to 0.45 (P = 0.0001). It is noteworthy that a significant best-corrected visual acuity gain was achieved only in eyes showing present or disrupted layers at baseline regardless of the CRVO subgroup examined, whereas eyes with absent layers at baseline were unable to attain any improvement.

Conclusion:

Dexamethasone implant can promote the resolution of macular edema in patients affected by any CRVO subform, but a beneficial functional outcome could be achieved by eyes showing no absence of outer retinal layers on spectral-domain optical coherence tomography at baseline.
ASSOCIATIONS BETWEEN MACULAR EDEMA AND CIRCULATORY STATUS IN EYES WITH RETINAL VEIN OCCLUSION
Authors: Iida Yuto , Muraoka Yuki , Uji Akihito , Ooto Sotaro , Murakami Tomoaki , Suzuma Kiyoshi , Tsujikawa Akitaka , Arichika Shigeta , Takahashi Ayako , Miwa Yuko , Yoshimura Nagahisa
Published: December 2016

Purpose:

To investigate associations between parafoveal microcirculatory status and foveal pathomorphology in eyes with macular edema (ME) secondary to retinal vein occlusion (RVO).

Methods:

Ten consecutive patients (10 eyes) with acute retinal vein occlusion were enrolled, 9 eyes of which received intravitreal ranibizumab (IVR) injections. Foveal morphologic changes were examined via optical coherence tomography (OCT), and parafoveal circulatory status was assessed via adaptive optics scanning laser ophthalmoscopy (AO-SLO).

Results:

The mean parafoveal aggregated erythrocyte velocity (AEV) measured by adaptive optics scanning laser ophthalmoscopy in eyes with retinal vein occlusion was 0.99 ± 0.43 mm/second at baseline, which was significantly lower than that of age-matched healthy subjects (1.41 ± 0.28 mm/second, P = 0.042). The longitudinal adaptive optics scanning laser ophthalmoscopy examinations of each patient showed that parafoveal AEV was strongly inversely correlated with optical coherence tomography-measured central foveal thickness (CFT) over the entire observation period. Using parafoveal AEV and central foveal thickness measurements obtained at the first and second examinations, we investigated associations between differences in parafoveal AEV and central foveal thickness, which were significantly and highly correlated (r = −0.84, P = 0.002).

Conclusion:

Using adaptive optics scanning laser ophthalmoscopy in eyes with retinal vein occlusion macular edema, we could quantitatively evaluate the parafoveal AEV. A reduction or an increase in parafoveal AEV may be a clinical marker for the resolution or development/progression of macular edema respectively.
PRIMARY LASER PHOTOCOAGULATION FOR THE TREATMENT OF GIANT RETINAL TEARS
Authors: Ao Jack , Horo Saban , Farmer Lachlan , Chan Weng Onn , Gilhotra Jagjit
Published: December 2016

Purpose:

Laser photocoagulation has typically been used as an adjunctive treatment to pars planar vitrectomy in achieving retinopexy in the treatment of giant retinal tears. We describe three cases where the giant retinal tear was treated with laser photocoagulation alone.

Methods:

A retrospective case report of three patients with giant retinal tears who underwent primary laser photocoagulation.

Results:

Fundus examination up to 18 months after primary laser photocoagulation of all 3 patients revealed a flat attached retina and no significant complications.

Conclusion:

Laser photocoagulation alone is a viable alternative treatment for giant retinal tears in the absence of significant subretinal fluid.