bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetostriction in grain‐oriented electrical steels under AC magnetisation at angles to the rolling direction
Authors: Somkun Sakda , Moses Anthony J. , Anderson Philip I.
Published: July 2016

Magnetostriction is an important source of vibration and acoustic noise in electromagnetic cores. This study reports magnetostriction components along the rolling, transverse and magnetisation directions (MDs) of grain‐oriented (GO) electrical steels, used for transformer and large rotating machine cores, under magnetisation at angles to the rolling direction (RD). Magnetostriction components in the sheet plane were simultaneously measured using a two‐dimensional magnetisation system. Results from the measurements agreed with the magnetostriction calculated from a simplified model of magnetic domain patterns in a 3% SiFe single crystal. It is shown that the magnetostrictive strain along the RD is always the highest component in the sheet plane irrespective of MD. This is expected to cause both additional vibration at the corners of transformer cores where flux deviates from the RD and high radial vibration in the back‐iron regions of rotating machine stator cores assembled from segmented GO steel laminations.
Nickel enhanced graphene growth directly on dielectric substrates by molecular beam epitaxy
Authors: Wofford Joseph M. , Speck Florian , Seyller Thomas , Lopes Joao Marcelo J. , Riechert Henning
Published: July 2016

The efficacy of Ni as a surfactant to improve the crystalline quality of graphene grown directly on dielectric Al2O3(0001) substrates by molecular beam epitaxy is examined. Simultaneously exposing the substrate to a Ni flux throughout C deposition at 950 °C led to improved charge carrier mobility and a Raman spectrum indicating less structural disorder in the resulting nanocrystalline graphene film. X-ray photoelectron spectroscopy confirmed that no residual Ni could be detected in the film and showed a decrease in the intensity of the defect-related component of the C1s level. Similar improvements were not observed when a lower substrate temperature (850 °C) was used. A close examination of the Raman spectra suggests that Ni reduces the concentration of lattice vacancies in the film, possibly by catalytically assisting adatom incorporation.
Modeling of the photodetector based on the multilayer graphene nanoribbons
Authors: Liu Haiyue , Niu Yanxiong , Yin Yiheng , Liu Shuai
Published: July 2016

Graphene nanoribbon (GNR), which has unique properties and advantages, is a crucial component of nanoelectornic devices, especially in the development of photoelectric detectors. In this work, an infrared photodetector based on the structure of stacked multiple-GNRs, which is separated by a little thick barrier layers (made of tungsten disulfide or related materials) to prevent tunneling current, is proposed and modeled. Operation of photoelectric detector is related to the electron cascaded radiative transition in the adjacent GNRs strengthened by the electrons heated due to the incident light. With a developed model, the working principle is analyzed and the relationships for the photocurrent and dark current as functions of the intensity of the incident radiation are derived. The spectral dependence of the responsivity and detectivity for graphene nanoribbons photodetector (GNRs-PT) with different Fermi energy, band gaps and numbers of GNRs layers are analyzed as well. The results demonstrate that the spectral characteristics depend on the GNRs band gap, which shows a potential on GNRs-PT application in the multi-wavelength systems. In addition, GNRs-PT has a better spectrum property and higher responsivity compared to photodetectors based on InxGaxAs in room temperature.
First spectroscopic observation of gold(i) butadiynylide: Photodetachment velocity map imaging of the AuC4H anion
Authors: Visser Bradley R. , Addicoat Matthew A. , Gascooke Jason R. , Lawrance Warren D. , Metha Gregory F.
Published: August 2016

The velocity map imaging technique was used in the investigation of gold(i) butadiynylide, AuC4H−, with images recorded at two excitation wavelengths. The resultant photodetachment spectra show a well defined vibrational progression in the neutral with an energy spacing of 343 ± 3 cm−1. The adiabatic electron affinity was determined to be 1.775 ± 0.005 eV and assigned to the X1Σ+←X2Σ+ transition between the anionic and neutral ground states. Franck-Condon simulations performed on density functional theory optimized geometries assisted the assignment of linear geometries to the neutral and anion and the observed vibrational progression to that of the Au–C4H stretch.
A many-body states picture of electronic friction: The case of multiple orbitals and multiple electronic states
Authors: Dou Wenjie , Subotnik Joseph E.
Published: August 2016

We present a very general form of electronic friction as present when a molecule with multiple orbitals hybridizes with a metal electrode. To develop this picture of friction, we embed the quantum-classical Liouville equation (QCLE) within a classical master equation (CME). Thus, this article extends our previous work analyzing the case of one electronic level, as we may now treat the case of multiple levels and many electronic molecular states. We show that, in the adiabatic limit, where electron transitions are much faster than nuclear motion, the QCLE-CME reduces to a Fokker-Planck equation, such that nuclei feel an average force as well as friction and a random force—as caused by their interaction with the metallic electrons. Finally, we show numerically and analytically that our frictional results agree with other published results calculated using non-equilibrium Green’s functions. Numerical recipes for solving this QCLE-CME will be provided in a subsequent paper.
The effects of nanoparticles and organic additives with controlled dispersion on dielectric properties of polymers: Charge trapping and impact excitation
Authors: Huang Yanhui , Wu Ke , Bell Michael , Oakes Andrew , Ratcliff Tyree , Lanzillo Nicholas A. , Breneman Curt , Benicewicz Brian C. , Schadler Linda S.
Published: August 2016

This work presents a comprehensive investigation into the effects of nanoparticles and organic additives on the dielectric properties of insulating polymers using reinforced silicone rubber as a model system. TiO2 and ZrO2 nanoparticles (d = 5 nm) were well dispersed into the polymer via a bimodal surface modification approach. Organic molecules with the potential of voltage stabilization were further grafted to the nanoparticle to ensure their dispersion. These extrinsic species were found to provide deep traps for charge carriers and exhibited effective charge trapping properties at a rather small concentration (∼1017 cm−3). The charge trapping is found to have the most significant effect on breakdown strength when the electrical stressing time is long enough that most charges are trapped in the deep states. To establish a quantitative correlation between the trap depth and the molecular properties, the electron affinity and ionization energy of each species were calculated by an ab initio method and were compared with the experimentally measured values. The correlation however remains elusive and is possibly complicated by the field effect and the electronic interactions between different species that are not considered in this computation. At high field, a super-linear increase of current density was observed for TiO2 filled composites and is likely caused by impact excitation due to the low excitation energy of TiO2 compared to ZrO2. It is reasoned that the hot charge carriers with energies greater than the excitation energy of TiO2 may excite an electron-hole pair upon collision with the NP, which later will be dissociated and contribute to free charge carriers. This mechanism can enhance the energy dissipation and may account for the retarded electrical degradation and breakdown of TiO2 composites.
Size consistent formulations of the perturb-then-diagonalize Møller-Plesset perturbation theory correction to non-orthogonal configuration interaction
Authors: Yost Shane R. , Head-Gordon Martin
Published: August 2016

In this paper we introduce two size consistent forms of the non-orthogonal configuration interaction with second-order Møller-Plesset perturbation theory method, NOCI-MP2. We show that the original NOCI-MP2 formulation [S. R. Yost, T. Kowalczyk, and T. VanVoorh, J. Chem. Phys. 193, 174104 (2013)], which is a perturb-then-diagonalize multi-reference method, is not size consistent. We also show that this causes significant errors in large systems like the linear acenes. By contrast, the size consistent versions of the method give satisfactory results for singlet and triplet excited states when compared to other multi-reference methods that include dynamic correlation. For NOCI-MP2 however, the number of required determinants to yield similar levels of accuracy is significantly smaller. These results show the promise of the NOCI-MP2 method, though work still needs to be done in creating a more consistent black-box approach to computing the determinants that comprise the many-electron NOCI basis.
Aging kinetics of levoglucosan orientational glass as a rate dispersion process and consequences for the heterogeneous dynamics view
Authors: Righetti Maria Cristina , Tombari Elpidio , Johari G. P.
Published: August 2016

Aging kinetics of a glass is currently modeled in terms of slowing of its α-relaxation dynamics, whose features are interpreted in terms of dynamic heterogeneity, i.e., formation and decay of spatially and temporally distinct nm-size regions. To test the merits of this view, we studied the calorimetric effects of aging an orientational glass of levoglucosan crystal in which such regions would not form in the same way as they form in liquids, and persist in structural glasses, because there is no liquid-like molecular diffusion in the crystal. By measuring the heat capacity, Cp, we determined the change in the enthalpy, H, and the entropy, S, during two aging-protocols: (a) keeping the samples isothermally at temperature, Ta, and measuring the changes after different aging times, ta, and (b) keeping the samples at different Tas and measuring the changes after the same ta. A model-free analysis of the data shows that as ta is increased (procedure (a)), H and S decrease according to a dispersive rate kinetics, and as Ta is increased (procedure (b)), H and S first increase, reach a local maximum at a certain Ta, and then decrease. Even though there is no translational diffusion to produce (liquid-like) free volume, and no translational-rotational decoupling, the aging features are indistinguishable from those of structural glasses. We also find that the Kohlrausch parameter, originally fitted to the glass-aging data, decreases with decrease in Ta, which is incompatible with the current use of the aging data for estimating the α-relaxation time. We argue that the vibrational state of a glass is naturally incompatible with its configurational state, and both change on aging until they are compatible, in the equilibrium liquid. So, dipolar fluctuations seen as the α-relaxation would not be the same motions that cause aging. We suggest that aging kinetics is intrinsically dispersive with its own characteristic rate constant and it does not yield the α-relaxation rate. In this view, thermodynamic and other properties define the fictive temperature; the real or imaginary components of a dynamic property do not define it. While particles’ overall motions may still play a crucial role in (structural) glass physics, we conclude that translational diffusion alone is not a requirement for structure stabilization on aging of a kinetically frozen state.
Comment on “Ion distribution function in a plasma with uniform electric field” [Phys. Plasmas 19, 113703 (2012)].
Authors: Mustafaev Alex , Sukhomlinov Vladimir , Timofeev Nikolay
Published: August 2016

The comparison between experimental data of ion distribution function at the parent gas plasma obtained by the authors and results of calculations presented by Lampe et al. are considered. It is shown that the experimental and calculated angular distributions of ions in the case at least of argon differ considerably. The analysis of Lampe et al. assumptions showed that the main reasons of these discrepancies were the assumptions of ion distribution function independence on field orientation and independence of charge exchange cross-section on the relative velocity of ion and atom.
Terahertz radiation generation by beating of two super Gaussian lasers in plasma having static dc electric field
Authors: Hussain Saba , Singh Ram Kishor , Sharma R. P.
Published: July 2016

This paper presents a scheme for the generation of high power terahertz radiation by the beating of two femtosecond super Gaussian lasers in plasma having dc electric field in the transverse direction. In this mechanism, a strong nonlinear ponderomotive force acts on the plasma electrons at the frequency difference of the two lasers (ω1−ω2) that imparts a nonlinear oscillatory velocity to plasma electrons which further result in the generation of a nonlinear current at this difference frequency (lying in THz domain). The dynamical equations governing the generation of THz waves have been solved semi-analytically; the result shows that the amplitude of the generated waves is considerably enhanced in the presence of dc electric field, and the index of super Gaussian beams also plays a keen role in governing the yield of THz waves.
Communication: The origin of many-particle signals in nonlinear optical spectroscopy of non-interacting particles
Authors: Mukamel Shaul
Published: July 2016

Nonlinear spectroscopy signals detected by fluorescence from dilute samples of N non-interacting molecules are usually adequately described by simply multiplying the single molecule response by N. We show that signals that scale with higher powers of N are generated by the joint detection of several particles. This can be accomplished by phase sensitive detection such as phase cycling, photo-acoustic modulation, or by Hanbury-Brown Twiss photon coincidence. Such measurements can dissect the ensemble according to the number of excited particles.
Direct and real time probe of photoinduced structure transition in colossal magnetoresistive material
Authors: Li Junjie , Wang Xuan , Zhou Haidong , Zhou Jun , Cheng J. G. , Cao Jianming
Published: July 2016

We report a direct and real time measurement of photoinduced structure phase transition in single crystal La0.84Sr0.16MnO3 using femtosecond electron diffraction. The melting of orthorhombic lattice ordering under femtosecond optical excitation is found involving two distinct processes with different time scales, an initial fast melting of orthorhombic phase in about 4 ps and a subsequent slower transformation in 90 ps and longer timescales. The fast process is designated as the initial melting of orthorhombic phase induced by the Mn-O bond change that is most likely driven by the quenching of the dynamic Jahn-Teller distortion following the photo-excitation. The slow process is attributed to the growing of newly formed structure domain from the photo-excited sites to the neighboring non-excited orthorhombic sites.
Predictable surface ablation of dielectrics with few-cycle laser pulse even beyond air ionization
Authors: Pasquier C. , Sentis M. , Utéza O. , Sanner N.
Published: August 2016

We study surface ablation of dielectrics with single-shot few-cycle optical pulse (∼10 fs) in air, at intensities below and above the onset of air ionization. We perform 3D analysis and careful calibration of the fluence distribution at the laser focus, spanning from linear– to nonlinear– focusing regimes, enabling to thoroughly characterize the severe limitation of the fluence delivered onto the sample surface upon increase of incident pulse energy. Despite significant beam reshaping taking place at high fluence, we demonstrate that it is nevertheless possible to confidently predict the resulting crater profiles on fused silica surface, even in the regime of filamentation.
The charge transport mechanism and electron trap nature in thermal oxide on silicon
Authors: Islamov Damir R. , Gritsenko Vladimir A. , Perevalov Timofey V. , Orlov Oleg M. , Krasnikov Gennady Ya.
Published: August 2016

The charge transport mechanism of electron via traps in amorphous SiO2 has been studied. Electron transport is limited by phonon-assisted tunneling between traps. Thermal and optical trap energies Wt=1.6 eV, Wopt=3.2 eV, respectively, were determined. Charge flowing leads to oxygen vacancies generation, and the leakage current increases due to the increase of charge trap density. Long-time annealing at high temperatures decreased the leakage current to initial values due to oxygen vacancies recombination with interstitial oxygen. It is found that the oxygen vacancies act as electron traps in SiO2.
Ultra-wideband and high-efficiency polarization rotator based on metasurface
Authors: Jia Yongtao , Liu Ying , Zhang Wenbo , Gong Shuxi
Published: August 2016

An ultra-wideband and high-efficiency polarization rotator based on a metasurface is proposed in this paper. The unit cell of the proposed polarization rotator consists of two pairs of L-shaped metallic patches printed on a substrate, which is backed by a metallic ground and covered by a superstrate. The superstrate is composed of a dielectric layer and a pair of L-shaped metallic patches printed on the dielectric layer. The proposed polarization rotator can rotate the polarization of linearly polarized electromagnetic (EM) wave to its orthogonal counterpart after reflection when the incident EM wave is y-/x-polarized. Simulated results show that the polarization rotator can perform 90° polarization rotation with very high efficiency at seven different frequencies and achieve a polarization conversion ratio higher than 0.9 in the frequency range of 7.8–34.7 GHz at normal incidence. Good agreement between the experimental results and simulated ones has been obtained.
Tuning the heat transfer medium and operating conditions in magnetic refrigeration
Authors: Ghahremani Mohammadreza , Aslani Amir , Siddique Abid , Bennett Lawrence H. , Della Torre Edward
Published: July 2016

A new experimental test bed has been designed, built, and tested to evaluate the effect of the system’s parameters on a reciprocating Active Magnetic Regenerator (AMR) near room temperature. Bulk gadolinium was used as the refrigerant, silicon oil as the heat transfer medium, and a magnetic field of 1.3 T was cycled. This study focuses on the methodology of single stage AMR operation conditions to get a high temperature span near room temperature. Herein, the main objective is not to report the absolute maximum attainable temperature span seen in an AMR system, but rather to find the system’s optimal operating conditions to reach that maximum span. The results of this research show that there is a optimal operating frequency, heat transfer fluid flow rate, flow duration, and displaced volume ratio in any AMR system. By optimizing these parameters in our AMR apparatus the temperature span between the hot and cold ends increased by 24%. The optimized values are system dependent and need to be determined and measured for any AMR system by following the procedures that are introduced in this research. It is expected that such optimization will permit the design of a more efficient magnetic refrigeration system.
Electronegativity-dependent tin etching from thin films
Authors: Pachecka M. , Sturm J. M. , van de Kruijs R. W. E. , Lee C. J. , Bijkerk F.
Published: July 2016

The influence of a thin film substrate material on the etching of a thin layer of deposited tin (Sn) by hydrogen radicals was studied. The amount of remaining Sn was quantified for materials that cover a range of electronegativities. We show that, for metals, etching depends on the relative electronegativity of the surface material and Sn. Tin is chemically etched from surfaces with an electronegativity smaller than Sn, while incomplete Sn etching is observed for materials with an electronegativity larger than Sn. Furthermore, the amount of remaining Sn increases as the electronegativity of the surface material increases. We speculate, that, due to Fermi level differences in the material’s electronic structure, the energy of the two conduction bands shift such that the availability of electrons for binding with hydrogen is significantly reduced.
Scanning nuclear electric resonance microscopy using quantum-Hall-effect breakdown
Authors: Hashimoto K. , Tomimatsu T. , Shirai S. , Taninaka S. , Nagase K. , Sato K. , Hirayama Y.
Published: July 2016

We present a scanning nuclear-spin resonance (NSR) method that incorporates resistive detection with electric-field induced NSR locally excited by a scanning metallic probe. In the quantum-Hall effect breakdown regime, NSR intensity mapping at both the fundamental NSR frequency f75As and twice the frequency 2f75As demonstrates the capability to probe the distribution of nuclear polarization, particularly in a semiconductor quantum well. We find that f75As NSR excitation drives not only local NSR but also spatially overlapped nonlocal NSR, which suppresses the maximum intensity of local NSR, while the 2f75As NSR yields purely local excitation conferring a larger intensity.
Study on the effects of electrical stunning parameters for broilers on biochemical and histological markers of stress and meat quality
Authors: Mercogliano Raffaelina , Santonicola Serena , Murru Nicoletta , Paciello Orlando , Pagano Teresa Bruna , Peruzy Maria Francesca , Pepe Tiziana , Anastasio Aniello , Cortesi Maria Luisa
Published: August 2016

This study was designed to investigate physicochemical (pH, peroxides) and histological parameters (glycogen reserve, muscle damages), as pre-slaughter stress markers and quality meat evaluators. Ross commercial broilers was processed, either without stunning (NS Lot), or by combining two current levels of 200 mA, 67 V (HV Lot), and 200 mA, 53 V (MV Lot); with two frequencies of 1000 Hz and 800 Hz, using sinusoidal alternating current. The use of high frequency (800 and 1000 Hz) induced the fastest pH decline, already at 3 h postmortem, in Pectoralis major and Quadriceps femoris of MV and HV Lot carcasses (P < 0.05). Moreover HV carcasses showed a lesser production of superoxide free radicals than the NS Lot and MV Lot carcasses (P < 0.05). Changes in the glycogen reserve and the histological muscle damages did not show significant differences in the analysed Lots. The incidence of individual carcass defects, sufficient to cause downgrading or rejection was generally low in each Lot. To assess animal welfare and quality poultry meat the pH monitoring and measurement of superoxide radical production, as additional and feasible parameters, might be markers easier to use in practice at abattoir.
Fire regime and vegetation change in the transition from Aboriginal to European land management in a Tasmanian eucalypt savanna
Authors: Romanin Louise M. , Hopf Feli , Haberle Simon G. , Bowman David M. J. S.
Published: August 2016

Using pollen and charcoal analysis we examined how vegetation and fire regimes have changed over the last 600 years in the Midlands of Tasmania. Sediment cores from seven lagoons were sampled, with a chronology developed at one site (Diprose Lagoon) using 210Pb and 14C dating. Statistical contrasts of six cores where Pinus served as a marker of European settlement in the early 19th Century and showed significant changes in pollen composition following settlement with (a) influx of ruderal exotic taxa including Plantago lanceolata L., Brassicaceae, Asteraceae (Liguliflorae) and Rumex, (b) increase in pollen of the aquatics Myriophyllum spp. and Cyperaceae, (c) a decline in native herbaceous pollen taxa, including Chenopodiaceae and Asteraceae (Tubuliflorae) and (d) a decline in Allocasuarina and an initial decline and then increase of Poaceae. The presence of Asteraceae (Liguliflorae) in the pre-European period suggests that an important root vegetable Microseris lanceolata (Walp.) Sch.Bip. may have been abundant. Charcoal deposition was low in the pre-European period and significantly increased immediately after European arrival. Collectively, these changes suggest substantial ecological impacts following European settlement including cessation of Aboriginal traditions of fire management, a shift in hydrological conditions from open water lagoons to more ephemeral herb covered lagoons, and increased diversity of alien herbaceous species following pasture establishment.
Neural mechanisms of transient neocortical beta rhythms: Converging evidence from humans, computational modeling, monkeys, and mice
Authors: Sherman Maxwell A. , Lee Shane , Law Robert , Haegens Saskia , Thorn Catherine A. , Hämäläinen Matti S. , Moore Christopher I. , Jones Stephanie R.
Published: July 2016

Significance

Neocortical beta is one of the most prominent signatures of neural activity measured noninvasively in humans. Beta expression is a strong predictor of healthy and pathological perceptual and motor performance. However, there is considerable debate as to whether beta itself is causally important in information and disease processes. Key to resolving this debate is understanding the neural mechanisms inducing beta. Here, building on prior work, we combined human magnetoencephalography, computational modeling, and laminar recordings in mice and monkeys to establish and test a new theory explaining the emergence of spontaneous transient neocortical beta events in somatosensory and frontal cortex. Our results enable a principled understanding of neocortical beta and can help guide studies seeking to understand its relation to function.
Structure and genome release of Twort-like Myoviridae phage with a double-layered baseplate
Authors: Nováček Jiří , Šiborová Marta , Benešík Martin , Pantůček Roman , Doškař Jiří , Plevka Pavel
Published: July 2016

Significance

Resistance to antibiotics is widespread among pathogenic bacteria, including
Staphylococcus aureus
, which cause serious human diseases. Bacteriophages from the Twort-like genus of the family Myoviridae infect and kill pathogenic bacteria, and therefore are used to treat bacterial diseases. Detailed knowledge of the interactions of phages with bacterial cells is a prerequisite for the effective and safe use of phages for medical purposes. However, the molecular details of the processes regulating infections by these phages are not well understood. We used cryo-electron microscopy and tomography to describe the series of structural changes of a bacteriophage phi812 virion required to deliver its genome into the
S. aureus
cell.
GPR91 senses extracellular succinate released from inflammatory macrophages and exacerbates rheumatoid arthritis
Authors: Littlewood-Evans Amanda , Sarret Sophie , Apfel Verena , Loesle Perrine , Dawson Janet , Zhang Juan , Muller Alban , Tigani Bruno , Kneuer Rainer , Patel Saijel , Valeaux Stephanie , Gommermann Nina , Rubic-Schneider Tina , Junt Tobias , Carballido José M.
Published: August 2016

When SUCNR1/GPR91-expressing macrophages are activated by inflammatory signals, they change their metabolism and accumulate succinate. In this study, we show that during this activation, macrophages release succinate into the extracellular milieu. They simultaneously up-regulate GPR91, which functions as an autocrine and paracrine sensor for extracellular succinate to enhance IL-1β production. GPR91-deficient mice lack this metabolic sensor and show reduced macrophage activation and production of IL-1β during antigen-induced arthritis. Succinate is abundant in synovial fluids from rheumatoid arthritis (RA) patients, and these fluids elicit IL-1β release from macrophages in a GPR91-dependent manner. Together, we reveal a GPR91/succinate-dependent feed-forward loop of macrophage activation and propose GPR91 antagonists as novel therapeutic principles to treat RA.
The α2δ-1 subunit remodels CaV1.2 voltage sensors and allows Ca2+ influx at physiological membrane potentials
Authors: Savalli Nicoletta , Pantazis Antonios , Sigg Daniel , Weiss James N. , Neely Alan , Olcese Riccardo
Published: August 2016

Excitation-evoked calcium influx across cellular membranes is strictly controlled by voltage-gated calcium channels (CaV), which possess four distinct voltage-sensing domains (VSDs) that direct the opening of a central pore. The energetic interactions between the VSDs and the pore are critical for tuning the channel’s voltage dependence. The accessory α2δ-1 subunit is known to facilitate CaV1.2 voltage-dependent activation, but the underlying mechanism is unknown. In this study, using voltage clamp fluorometry, we track the activation of the four individual VSDs in a human L-type CaV1.2 channel consisting of α1C and β3 subunits. We find that, without α2δ-1, the channel complex displays a right-shifted voltage dependence such that currents mainly develop at nonphysiological membrane potentials because of very weak VSD–pore interactions. The presence of α2δ-1 facilitates channel activation by increasing the voltage sensitivity (i.e., the effective charge) of VSDs I–III. Moreover, the α2δ-1 subunit also makes VSDs I–III more efficient at opening the channel by increasing the coupling energy between VSDs II and III and the pore, thus allowing Ca influx within the range of physiological membrane potentials.
An Advanced Protocol‐Driven Transition from Parenteral Prostanoids to Inhaled Trepostinil in Pulmonary Arterial Hypertension
Authors: Oudiz Ronald , Agarwal Manyoo , Rischard Franz , De Marco Teresa
Published: August 2016

Patients with pulmonary arterial hypertension (PAH) often require parenteral prostanoids to improve symptoms and signs of PAH. Complications of parenteral prostanoids—such as catheter‐related infections and intolerable adverse effects—may develop, prompting transition to inhaled prostanoids. We report a prospective, protocol‐driven transition from parenteral prostanoids to inhaled prostanoids with monitoring of exercise gas exchange and acute hemodynamics. Three PAH centers recruited patients transitioning from parenteral prostanoids to inhaled trepostinil. Rigid inclusion criteria were used, including parenteral prostanoid dose < 30 ng/kg/min, New York Heart Association functional class (FC) < 3, and pulmonary vascular resistance (PVR) < 6 Wood units. Of the 9 patients meeting initial inclusion criteria, 3 were excluded. In the remaining patients, the parenteral prostanoid was reduced and the inhaled prostanoid was increased over 24–36 hours with continuous hemodynamic monitoring. Exercise capacity and FC were measured at baseline and weeks 1, 4, and 12. All patients were successfully weaned from parenteral prostanoids. An acute PVR decrease was seen with most inhaled prostanoid doses, but PVR varied throughout the transition. Patients tolerated inhaled prostanoids for 9–12 breaths 4 times a day with no treatment‐limiting adverse events. At week 12, FC was unchanged, and all patients continued to receive inhaled prostanoids without serious adverse events or additional PAH therapy. In 5 of 6 patients, 6‐minute walk distance and peak V̇O2 were within 10% of baseline. Using a strict transition protocol and rigid patient selection criteria, the parenteral prostanoid to inhaled prostanoid transition appeared safe and well tolerated and did not result in clinical deterioration over 12 weeks. Hemodynamic variability noted acutely during transition in our study did not adversely affect successful transition. (Trial registration: ClinicalTrials.gov identifier: NCT01268553)
miR-423-5p contributes to a malignant phenotype and temozolomide chemoresistance in glioblastomas
Authors: Li Shouwei , Zeng Ailiang , Hu Qi , Yan Wei , Liu Yanwei , You Yongping
Published: July 2016

Background

Gliomas are based on a genetic abnormality and present with a dismal prognosis. MicroRNAs (miRNAs) are considered to be important mediators of gene expression in glioma tissues.

Methods

Real-time PCR was used to analyze the expression of microRNA-423-5p (miR-423-5p) in human glioma samples and normal brain tissue. Apoptosis, cell cycle, proliferation, immunostaining, transwell, in vitro 2D and 3D migration, and chemosensitivity assays were performed to assess the phenotypic changes in glioma cells overexpressing miRNA-423-5p. Western blotting was used to determine the expression of inhibitor of growth 4 (ING-4)in glioma tissues, and a luciferase reporter assay was conducted to confirm whether ING-4 is a direct target of miR-423-5p. Western blotting was used to identify the potential signaling pathways that are affected in glioma cell growth by miR-423-5p. Xenograft tumors were examined in vivo for the carcinogenic effects of miR-423-5p in glioma tissues.

Results

We first reported that miR-423-5p expression was increased in gliomas and was a potential tumor promoter via targeting ING-4. The overexpression of miR-423-5p resulted in upregulation of important signaling molecules such as p-AKT and p-ERK1/2. In clinical samples, miR-423-5p was dysregulated, and a corresponding alteration in ING-4 expression was observed (P = .0207). Furthermore, the overexpression of miR-423-5p strengthened glioma cell proliferation, angiogenesis, and invasion. Finally, miR-423-5p overexpression also strengthened GBM neurosphere formation and rendered glioma cells resistant to temozolomide (TMZ).

Conclusion

This study establishes that miR-423-5p functions as an oncogene in glioma tissues by suppressing ING-4 and suggests that it has therapeutic potential for glioma.
Patient Safety
Authors: Donaldson Liam
Published: July 2016

As a unified field of scholarship, patient safety dates to the late 20th century. It has its origins in several developmental strands: observational studies demonstrating that the level of avoidable adverse outcomes of care in hospitals was higher than previously realized; the pressure to do something about the high cost of medical litigation; the recognition that the concepts and methods used to assure and improve safety in other high-risk industries were applicable to healthcare but not being used; and the growing public concern that regular media reports of egregious errors suggested that history was repeating itself with no learning taking place. More than many other areas in health, the direction taken by those publishing on, and researching in, patient safety has closely followed the agenda of policy makers, healthcare system leaders, and managers of health organizations who have aimed to reduce the risks of care for patients. The emphasis has been on assessing the burden of unsafe care; establishing effective incident-reporting systems and other ways of assessing harm; understanding why things go wrong; finding effective solutions and interventions to reduce risk; engaging with patients and families; designing models for improvement; and evaluating the potential application of methods developed in other high-risk industries. Much published work expresses ideas, puts forward opinions, describes practical experiences, and makes calls for action. Official reports and other gray literature are an important part of the body of work on patient safety. Studies involving data gathering are generally observational, rather than experimental, in design. They really belong to the family of health-services research. The major journals accept relatively few studies of this genre. Moreover, some of those authors active in patient safety research are from a clinical research background and not formally trained in health-services research. As a result, studies are of variable quality and many are insufficiently interdisciplinary.
Knowledge network dynamics in clusters: past performance and absorptive capacity
Authors: Belso-Martínez José-Antonio , Expósito-Langa Manuel , Tomás-Miquel José-Vicente
Published: July 2016

Purpose

– The purpose of this paper is to explore the degree to which absorptive capacity and previous innovative performance affect network dynamics, specifically in the creation or destruction of inter-business relationships.

Design/methodology/approach

– The empirical study has drawn on the data collected in an industrial cluster located in the Valencian Community in Spain. This population of firms allowed us to test various roles played by network endogenous forces, absorptive capacity and former performance in the creation and dissolution of inter-organisational linkages. The authors followed an evolutionary approach and applied network analysis techniques.

Findings

– Empirical evidences suggest that absorptive capacity and previous innovative performance are predictors of inter-business relationships. Absorptive capacity affects the emergence of linkages in the technological network, due to the tacit nature of technological knowledge. On the other hand, previous innovative performance is an indicator to identify leaders companies. These companies tend to increase the reception of request for advice from local firms. Moreover, prestigious companies tend to be more selective in choosing collaborators.

Practical implications

– This study helps researchers and managers better understand network dynamics. The generation of inter-organisational relationships in clusters can be determined by cognitive proximity and prestigious status in the network. These evidences are relevant in a mature cluster where knowledge is asymmetrically distributed.

Originality/value

– Over the last few decades, studies on industrial clusters have evolved from the “canonical” standpoint. Nowadays, researchers usually take a more sophisticated and richer view of this reality, mainly as a consequence of the inclusion the proximity concept, intra-cluster heterogeneity and advanced analysis of overlapping between networks and territory. Thus, the authors try to add some empirical evidence along these lines.
Numerical simulation and experiment validation of level-pour direct-chill casting of A390 alloy hollow billets under different feeding schemes
Authors: Zuo Kesheng , Zhang Haitao , Qin Ke , Cui Jianzhong
Published: August 2016

Purpose

– The purpose of this paper is to study the effect of feeding scheme on melt flow and temperature field during the steady-state of level-pour direct-chill (DC) casting of A390 alloy hollow billet and optimize the design of feeding scheme.

Design/methodology/approach

– Melt flow and temperature field are investigated by numerical simulation, which is based on a three-dimensional mathematical model and well verified by experiments.

Findings

– The numerical results reveal that both melt flow and temperature field are obviously affected by the feeding scheme. The homogeneity of melt flow and temperature field in hollow billet with the feeding scheme of modified four inlets are better than the other feeding schemes. Experimental results show that crack can be eliminated by increasing the number of feeding inlets. The primary Si size appears unaffected while the distribution of primary Si particles is highly affected by the change of feeding scheme. Only with the feeding scheme of modified four inlets can fine and uniformly distributed primary Si particles be achieved.

Practical implications

– The paper includes implications for the design of feeding scheme in level-pour DC casting of hollow billet for practical use.

Originality/value

– This paper develops different feeding schemes for level-pour DC casting of hollow billet and optimizes the design of feeding scheme.
Numerical analysis of combined buoyancy-induced and pressure-driven smoke flow in complex vertical shafts during building fires
Authors: Chen Yanqiu , Zhou Xiaodong , Zhang Taolin , Fu Zhijian , Hu Yuqi , Yang Lizhong
Published: August 2016

Purpose

– The purpose of this paper is to study the behavior of smoke flow in building fires and optimize the design of smoke control systems.

Design/methodology/approach

– A total of 435 3-D fire simulations were conducted through NIST fire dynamics simulator to analyze thermal behavior of combined buoyancy-induced and pressure-driven smoke flow in complex vertical shafts, under consideration of influence of heat release rate (HRR) and locations of heat sources. This influence was evaluated through neutral pressure plane (NPP), which is a critical plane depicting the flow velocity distributions. Hot smoke flows out of shafts beyond the NPP and cold air flows into shafts below the NPP.

Findings

– Numerical simulation results show that HRR of heat source has little influence on NPP, while location of heat source can make a significant difference to NPP, particularly in cases of multi-heat source. Identifying the location of NPP helps to develop a more effective way to control the smoke with less energy consumption. Through putting an emphasis on smoke exhausting beyond the NPP and air supplying below the NPP, the smoke control systems can make the best use of energy.

Research limitations/implications

– Because of the chosen research approach, the research results may need to be tested by further experiments.

Practical implications

– The paper includes implications for the optimization of smoke control systems design in buildings.

Originality/value

– This paper fulfills an identified need to research the behavior of hot smoke in building fires and optimize the design of smoke control systems.
Simultaneous geometry and cross-section optimization of aluminum trusses
Authors: Kripka Moacir , Pravia Zacarias Chamberlain , Medeiros Guilherme Fleith , Dias Maiga Marques
Published: August 2016

Purpose

– Trusses constitute a fertile field to demonstrate the application of optimization techniques because of the possibility of several different configurations. Using such techniques allows the search for designs that minimize the use of material to safely comply with the imposed loads. Truss optimization can be classified into three categories: cross-section, shape, and topology. The purpose of this paper is to present a numerical and experimental study developed to minimize the weight of aluminum trusses, taking both the cross-sectional dimensions of the elements and the nodal coordinates as design variables.

Design/methodology/approach

– Initially, several numerical computer simulations were performed with an optimization program developed by combining the displacement method and a simulated annealing optimization method. Subsequently, two aluminum trusses were selected and built in order to validate the numerical results obtained.

Findings

– Experimental tests verified the excellent performance of the optimized model.

Originality/value

– In addition, it was concluded that significant savings could be obtained from the application of the proposed formulation.
Managing celebrity via impression management on social network sites
Authors: Agyemang Kwame J.A. , S. Williams Antonio
Published: July 2016

Purpose

Central to the celebrity creation process is mass media communication and impression management (IM) behaviors of social actors. The emergence of social network sites (SNSs) such as Twitter offers a platform for social actors to engage both of these means in efforts to manage their celebrity. The purpose of this paper is to contribute to the understanding of how celebrity athletes manage their celebrity status by investigating IM tactics employed by National Basketball Association (NBA) celebrities on Twitter.

Design/methodology/approach

A content analytic design was employed to examine the Twitter posts of the top ten most popular and influential NBA celebrity athletes (past and present) at the time of tweet acquisition.

Findings

The findings revealed the celebrity athletes used a variety of IM tactics to manage their celebrity. Defensive IM tactics (i.e. reactive measures taken) were used sparingly when compared to offensive IM tactics (i.e. proactive measures taken). Also, consistent with extant IM literature, the celebrity athletes utilized IM tactics in isolation as well as in combination.

Practical implications

The extant literature suggests that celebrities cultivate their relationships with the various media outlets with the potential to create (or even damage) one’s celebrity. This study offers celebrity athletes and their managers with useful insight on celebrity management.

Originality/value

This study is the first to examine IM in a sport business context, particularly the use of IM of athletes on SNSs.
Passive time-domain numerical models of viscothermal wave propagation in acoustic tubes of variable cross section
Authors: Bilbao Stefan , Harrison Reginald
Published: July 2016

Numerical modeling of wave propagation in acoustic tubes is a subject of longstanding interest, particularly for enclosures of varying cross section, and especially when viscothermal losses due to boundary layer effects are taken into consideration. Though steady-state, or frequency domain methods, are a common avenue of approach, recursive time domain methods are an alternative, allowing for the generation of wideband responses, and offer a point of departure for more general modeling of nonlinear wave propagation. The design of time-domain methods is complicated by numerical stability considerations, and to this end, a passive representation is a useful design principle leading to simple stable and explicit numerical schemes, particularly in the case of viscothermal loss modeling. Such schemes and the accompanying energy and stability analysis are presented here. Numerical examples are presented for a variety of duct profiles, illustrating strict energy dissipation, and for comparison of computed input impedances against frequency-domain results.
On the completeness and the linear dependence of the Cartesian multipole series in representing the solution to the Helmholtz equation
Authors: Liu Yangfan , Bolton J. Stuart
Published: August 2016

The (Cartesian) multipole series, i.e., the series comprising monopole, dipoles, quadrupoles, etc., can be used, as an alternative to the spherical or cylindrical wave series, in representing sound fields in a wide range of problems, such as source radiation, sound scattering, etc. The proofs of the completeness of the spherical and cylindrical wave series in these problems are classical results, and it is also generally agreed that the Cartesian multipole series spans the same space as the spherical waves: a rigorous mathematical proof of that statement has, however, not been presented. In the present work, such a proof of the completeness of the Cartesian multipole series, both in two and three dimensions, is given, and the linear dependence relations among different orders of multipoles are discussed, which then allows one to easily extract a basis from the multipole series. In particular, it is concluded that the multipoles comprising the two highest orders in the series form a basis of the whole series, since the multipoles of all the lower source orders can be expressed as a linear combination of that basis.
Draft Genome Sequences of the Antimicrobial Producers
Pseudomonas
sp. TAA207 and
Pseudomonas
sp. TAD18 Isolated from Antarctic Sediments
Authors: Presta Luana , Inzucchi Ilaria , Bosi Emanuele , Fondi Marco , Perrin Elena , Maida Isabel , Miceli Elisangela , Tutino Maria Luisa , Lo Giudice Angelina , de Pascale Donatella , Fani Renato
Published: July 2016

We report here the draft genome sequence of the
Pseudomonas
sp. TAA207 and
Pseudomonas
sp. TAD18 strains, isolated from Antarctic sediments during a summer campaign near coastal areas of Terra Nova Bay (Antarctica). Genome sequence knowledge allowed the identification of genes associated with the production of bioactive compounds and antibiotic resistance. Furthermore, it will be instrumental for comparative genomics and the fulfillment of both basic and application-oriented investigations.
Whole-Genome Draft Sequences of Six Commensal Fecal and Six Mastitis-Associated
Escherichia coli
Strains of Bovine Origin
Authors: Leimbach Andreas , Poehlein Anja , Witten Anika , Wellnitz Olga , Shpigel Nahum , Petzl Wolfram , Zerbe Holm , Daniel Rolf , Dobrindt Ulrich
Published: July 2016

The bovine gastrointestinal tract is a natural reservoir for commensal and pathogenic
Escherichia coli
strains with the ability to cause mastitis. Here, we report the whole-genome sequences of six
E. coli
isolates from acute mastitis cases and six
E. coli
isolates from the feces of udder-healthy cows.