bluuebunny/crossref_metadata_2025 huggingface dataset:
Renal Allograft Implantation on Prosthetic Vascular Grafts: Short‐ and Long‐term Results
Authors: Patrono Damiano , Verhelst Robert , Buemi Antoine , Goffette Pierre , De Pauw Luc , Kanaan Nada , Goffin Eric , De Meyer Martine , Mourad Michel
Published: April 2013

Background

Arterial anastomosis in transplant patients with severe aortic and iliac atheromatosis is technically challenging and may jeopardize the success of the transplantation procedure. The aim of this retrospective study was to report short‐ and long‐term results of a consecutive series of kidney transplant patients in whom the renal artery was implanted on a prosthetic vascular graft.

Materials and methods

Medical charts and outpatient clinical records of patients who had undergone renal artery implantation on a prosthetic graft were reviewed. Data on patient characteristics, indications for transplantation, prior vascular procedures, surgical technique, and postoperative and long‐term outcome were collected.

Results

The renal artery was implanted on a prosthetic graft in the course of 27 kidney transplantation procedures. Patients were divided into three groups according to the timing of the vascular intervention in relation to the transplantation. In group A (n = 22), the vascular prosthesis was implanted before kidney transplantation, in group B (n = 2), prosthetic iliac artery replacement and kidney transplantation were performed simultaneously, while in group C (n = 3), the vascular prosthesis was implanted after kidney transplantation. After a median follow‐up of 50.5 months, one case of early arterial thrombosis was observed (3.7 %). Infectious complications occurred in two patients (7.4 %) related to mycotic pseudoaneurysms. One hematoma and one evisceration were also encountered, but no late arterial thrombosis nor stenosis were noted. Mean creatinine levels at 1 and 5 years of follow‐up were 1.32 ± 0.36 and 1.27 ± 0.56 mg/dl, respectively. Five‐year patient and graft survival rates were 85.2 and 74 %, respectively.

Conclusions

Grafting of the renal artery to a vascular prosthesis is feasible and yields good results, despite the technical difficulties involved. We stress the importance of good teamwork.
How to Attain Ultralow Interfacial Tension and Three‐Phase Behavior with Surfactant Formulation for Enhanced Oil Recovery: A Review. Part 1. Optimum Formulation for Simple Surfactant–Oil–Water Ternary Systems
Authors: Salager Jean‐Louis , Forgiarini Ana M. , Bullón Johnny
Published: April 2013

Enhanced recovery of crude oil by surfactant flooding requires the attainment of an ultralow interfacial tension. Since Winsor's work in the 1950s it has been known that a minimum interfacial tension and a concomitant three‐phase behavior of a surfactant–oil–water system occurs when the interactions of the surfactant and the oil and water phases are exactly equal. It has been known since the 1970s that these conditions are attained when a linear correlation is satisfied between the formulation variables, which are characteristic parameters of the substances as well as the temperature. This first part of our review on how to attain ultralow interfacial tension for enhanced oil recovery shows how formulation scan techniques using these correlations are used to determine an optimum formulation and to characterize unknown surfactants and oils. The physicochemical significance of the original empirical correlation is reported as the surfactant affinity difference or hydrophilic–lipophilic deviation model. We report the range of accurate validity of, and how to test, this simple model with four variables.
NMR characterization of the interaction of GroEL with amyloid β as a model ligand
Authors: Yagi-Utsumi Maho , Kunihara Tomoko , Nakamura Takashi , Uekusa Yoshinori , Makabe Koki , Kuwajima Kunihiro , Kato Koichi
Published: April 2013

Here we report an NMR study on the substrate interaction modes of GroEL using amyloid β (Aβ) as a model ligand. We found that GroEL could suppress Aβ(1–40) amyloid formation by interacting with its two hydrophobic segments Leu17‐Ala21 and Ala30‐Val36, which involve key residues in fibril formation. The binding site of Aβ(1–40) was mapped on a pair of α‐helices located in the GroEL apical domain. These results provide insights into chaperonin recognition of amyloidogenic proteins of pathological interest.
Semaphorin 3F forms an anti‐angiogenic barrier in outer retina
Authors: Buehler Anima , Sitaras Nicholas , Favret Sandra , Bucher Felicitas , Berger Stefanie , Pielen Amelie , Joyal Jean-Sebastian , Juan Aimee M. , Martin Gottfried , Schlunck Guenther , Agostini Hansjürgen T. , Klagsbrun Michael , Smith Lois E.H. , Sapieha Przemyslaw , Stahl Andreas
Published: April 2013

Semaphorins are known modulators of axonal sprouting and angiogenesis. In the retina, we identified a distinct and almost exclusive expression of Semaphorin 3F in the outer layers. Interestingly, these outer retinal layers are physiologically avascular. Using functional in vitro models, we report potent anti‐angiogenic effects of Semaphorin 3F on both retinal and choroidal vessels. In addition, human retinal pigment epithelium isolates from patients with pathologic neovascularization of the outer retina displayed reduced Semaphorin 3F expression in 10 out of 15 patients. Combined, these results elucidate a functional role for Semaphorin 3F in the outer retina where it acts as a vasorepulsive cue to maintain physiologic avascularity.
Anti-influenza virus effects of both live and non-liveLactobacillus acidophilusL-92 accompanied by the activation of innate immunity
Authors: Goto Hiroaki , Sagitani Atsuhiro , Ashida Nobuhisa , Kato Shinji , Hirota Tatsuhiko , Shinoda Tadashi , Yamamoto Naoyuki
Published: April 2013

The antiviral effects of both a live and non-liveLactobacillus acidophilusstrain L-92 (L-92) were investigated by oral administration (10 mg/mouse per d) daily for 21 d in a mouse model infected intranasally with influenza virus (H1N1). Virus titres in the lung of mice administered either live or non-live L-92 cells daily for 15 d were repressed 6 d after virus infection compared with the control group. Natural killer (NK) activity in the orally administered non-live L-92 group was higher compared with that of the control group before virus infection and on day 6. In contrast, NK activity in the live L-92 group compared with the control group was not significantly changed on both days, but was significantly higher on day 1. In contrast, live L-92 showed a greater repression of virus proliferation compared with non-live L-92, 6 d after the infection. Live L-92 decreased the number of neutrophils in the lung and suppressed lung weight, leading to the consequent deterioration of consolidation scores of the lung. These results indicated that pretreatment of live or non-live L-92 cells had protective effects against influenza virus infection. Among the measured cytokines and chemokines, eotaxin, macrophage colony-stimulating factor, IL-1β, RANTES (regulated on activation, normal T cell expressed and secreted) and interferon-α were significantly increased in the lung: IL-17 was significantly increased in Peyer's patch of the live L-92 group compared with the control group. A mechanistic study suggested that the enhancement of NK activity in the lung caused by stimulating various antiviral cytokines and chemokines after the oral administration of L-92 cells might be important in protecting against virus infection.
A 250 μg/week dose of vitamin D was as effective as a 50 μg/d dose in healthy adults, but a regimen of four weekly followed by monthly doses of 1250 μg raised the risk of hypercalciuria
Authors: Zwart Sara R. , Parsons Howard , Kimlin Michael , Innis Sheila M. , Locke James P. , Smith Scott M.
Published: April 2013

The risk of vitamin D insufficiency is increased in persons having limited sunlight exposure and dietary vitamin D. Supplementation compliance might be improved with larger doses taken less often, but this may increase the potential for side effects. The objective of the present study was to determine whether a weekly or weekly/monthly regimen of vitamin D supplementation is as effective as daily supplementation without increasing the risk of side effects. Participants were forty-eight healthy adults who were randomly assigned for 3 months to placebo or one of three supplementation regimens: 50 μg/d (2000 IU/d, analysed dose 70 μg/d), 250 μg/week (10 000 IU/week, analysed dose 331 μg/week) or 1250 μg/week (50 000 IU/week, analysed dose 1544 μg/week) for 4 weeks and then 1250 μg/month for 2 months. Daily and weekly doses were equally effective at increasing serum 25-hydroxyvitamin D, which was significantly greater than baseline in all the supplemented groups after 30 d of treatment. Subjects in the 1250 μg treatment group, who had a BMI >26 kg/m2, had a steady increase in urinary Ca in the first 3 weeks of supplementation, and, overall, the relative risk of hypercalciuria was higher in the 1250 μg group than in the placebo group (P= 0·01). Although vitamin D supplementation remains a controversial issue, these data document that supplementing with ≤ 250 μg/week ( ≤ 10 000 IU/week) can improve or maintain vitamin D status in healthy populations without the risk of hypercalciuria, but 24 h urinary Ca excretion should be evaluated in healthy persons receiving vitamin D3 supplementation in weekly single doses of 1250 μg (50 000 IU).
Sigmoid sinus dehiscence resurfacing as treatment for pulsatile tinnitus
Authors: Santa Maria P L
Published: April 2013

Aim:

To report a case of sigmoid sinus dehiscence presenting with pulsatile tinnitus and treated successfully with resurfacing.

Case report:

This patient presented with pulsatile tinnitus due to sigmoid sinus dehiscence. This was successfully treated using only soft tissue resurfacing.

Conclusion:

Sigmoid sinus dehiscence is a rare but treatable cause of pulsatile tinnitus. It can occur in the absence of a diverticulum, and is not necessarily limited to the transverse sigmoid junction. When resurfacing, care must be taken not to significantly alter the extraluminal diameter of the sigmoid in a dominant sinus, as this raises the risk of post-operative hydrocephalus.
‘The last duty of an officer’: Lieutenant de vaisseau Joseph-René Bellot, 1826–1853, in the Franklin Search
Authors: Barr William , Forestier-Blazart Nadine , Forestier-Blazart Jean-Claude
Published: April 2013

Lieutenant de vaisseau Joseph René Bellot, (1826–1853) participated, as second-in command, in Lady Franklin's private expedition in search of her missing husband on boardPrince Albert, under the command of Captain William Kennedy in 1851–1852. Having wintered at Batty Bay on the east coast of Somerset Island, Kennedy and Bellot sledged south in the spring of 1852, to Bellot Strait, which they discovered. Having passed through the strait, they crossed Peel Sound, and continued west across Prince of Wales Island to Ommanney Bay, then back across Prince of Wales Island, north to Cape Walker, and back to Batty Bay via the north coast of Somerset Island and Prince Leopold Harbour. They discovered no trace of the missing Franklin expedition. In 1853 Bellot again volunteered to go to the Arctic, this time as supernumerary on board the supply shipPhoenix, Captain Edward Inglefield. From Beechey Island, Bellot volunteered to carry dispatches north up Wellington Channel to Captain Sir Edward Belcher who was in that vicinity. Having been driven out of sea on an ice-floe, Bellot disappeared during a gale, and it is assumed that he was blown off the ice into the water and was drowned. Memorials to Bellot may be found on Beechey Island, at Greenwich, England and at Rochefort, France, but probably the most enduring memorial to him is the name ‘Bellot Strait’, applied by Kennedy to the narrow strait between Somerset Island and Boothia Peninsula which represents an integral component of one variant of the northwest passage.
Multi length scale characterization of austenite in TRIP steels using high-energy X-ray diffraction
Authors: Blondé R. , Jimenez-Melero E. , Zhao L. , Wright J.P. , Brück E. , van der Zwaag S. , van Dijk N.H.
Published: April 2013

The martensitic transformation behavior of the meta-stable austenite phase in low alloyed TRIP steels has been studied in situ using high-energy X-ray diffraction during deformation. The stability of austenite has been studied at different length scales during tensile tests and at variable temperatures down to 153 K. A powder diffraction analysis has been performed to correlate the macroscopic behavior of the material to the observed changes in the volume fraction of the phases. Our results show that at lower temperatures the deformation induced austenite transformation is significantly enhanced and extends over a wider deformation range, resulting in a higher elongation at fracture. To monitor the austenite behavior at the level of an individual grain a high-resolution far-field detector was used. Sub-grains have been observed in austenite prior to transformation.
Scaffolds for design communication: Research through design of shared understanding in design meetings
Authors: van Dijk Jelle , van der Lugt Remko
Published: April 2013

In this paper we explore the influence of the physical and social environment (the design space) son the formation of shared understanding in multidisciplinary design teams. We concentrate on the creative design meeting as a microenvironment for studying processes of design communication. Our applied research context entails the design of mixed physical–digital interactive systems supporting design meetings. Informed by theories of embodiment that have recently gained interest in cognitive science, we focus on the role of interactive “traces,” representational artifacts both created and used by participants as scaffolds for creating shared understanding. Our research through design approach resulted in two prototypes that form two concrete proposals of how the environment may scaffold shared understanding in design meetings. In several user studies we observed users working with our systems in natural contexts. Our analysis reveals how an ensemble of ongoing social as well as physical interactions, scaffolded by the interactive environment, grounds the formation of shared understanding in teams. We discuss implications for designing collaborative tools and for design communication theory in general.
Inverse spectral problems for compact Hankel operators
Authors: Gérard Patrick , Grellier Sandrine
Published: April 2013

Given two arbitrary sequences $({\lambda }_{j} )_{j\geq 1} $ and $({\mu }_{j} )_{j\geq 1} $ of real numbers satisfying $$\begin{eqnarray*}\displaystyle \vert {\lambda }_{1} \vert \gt \vert {\mu }_{1} \vert \gt \vert {\lambda }_{2} \vert \gt \vert {\mu }_{2} \vert \gt \cdots \gt \vert {\lambda }_{j} \vert \gt \vert {\mu }_{j} \vert \rightarrow 0, &&\displaystyle\end{eqnarray*}$$ we prove that there exists a unique sequence $c= ({c}_{n} )_{n\in { \mathbb{Z} }_{+ } } $, real valued, such that the Hankel operators ${\Gamma }_{c} $ and ${\Gamma }_{\tilde {c} } $ of symbols $c= ({c}_{n} )_{n\geq 0} $ and $\tilde {c} = ({c}_{n+ 1} )_{n\geq 0} $, respectively, are selfadjoint compact operators on ${\ell }^{2} ({ \mathbb{Z} }_{+ } )$ and have the sequences $({\lambda }_{j} )_{j\geq 1} $ and $({\mu }_{j} )_{j\geq 1} $, respectively, as non-zero eigenvalues. Moreover, we give an
explicit formula for $c$ and we describe the kernel of ${\Gamma }_{c} $ and of ${\Gamma }_{\tilde {c} } $ in terms of the sequences $({\lambda }_{j} )_{j\geq 1} $ and $({\mu }_{j} )_{j\geq 1} $. More generally, given two arbitrary sequences $({\rho }_{j} )_{j\geq 1} $ and $({\sigma }_{j} )_{j\geq 1} $ of positive numbers satisfying $$\begin{eqnarray*}\displaystyle {\rho }_{1} \gt {\sigma }_{1} \gt {\rho }_{2} \gt {\sigma }_{2} \gt \cdots \gt {\rho }_{j} \gt {\sigma }_{j} \rightarrow 0, &&\displaystyle\end{eqnarray*}$$ we describe the set of sequences $c= ({c}_{n} )_{n\in { \mathbb{Z} }_{+ } } $ of complex numbers such that the Hankel operators ${\Gamma }_{c} $ and ${\Gamma }_{\tilde {c} } $ are compact on ${\ell }^{2} ({ \mathbb{Z} }_{+ } )$ and have sequences $({\rho }_{j} )_{j\geq 1} $ and $({\sigma }_{j} )_{j\geq 1} $, respectively, as non-zero singular values.
Developmental programming of cardiovascular disease by prenatal hypoxia
Authors: Giussani D. A. , Davidge S. T.
Published: April 2013

It is now recognized that the quality of the fetal environment during early development is important in programming cardiovascular health and disease in later life. Fetal hypoxia is one of the most common consequences of complicated pregnancies worldwide. However, in contrast to the extensive research effort on pregnancy affected by maternal nutrition or maternal stress, the contribution of pregnancy affected by fetal chronic hypoxia to developmental programming is only recently becoming delineated and established. This review discusses the increasing body of evidence supporting the programming of cardiac susceptibility to ischaemia and reperfusion (I/R) injury, of endothelial dysfunction in peripheral resistance circulations, and of indices of the metabolic syndrome in adult offspring of hypoxic pregnancy. An additional focus of the review is the identification of plausible mechanisms and the implementation of maternal and early life interventions to protect against adverse programming.
The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF
Authors: Casey D. T. , Frenje J. A. , Gatu Johnson M. , Séguin F. H. , Li C. K. , Petrasso R. D. , Glebov V. Yu. , Katz J. , Magoon J. , Meyerhofer D. D. , Sangster T. C. , Shoup M. , Ulreich J. , Ashabranner R. C. , Bionta R. M. , Carpenter A. C. , Felker B. , Khater H. Y. , LePape S. , MacKinnon A. , McKernan M. A. , Moran M. , Rygg J. R. , Yeoman M. F. , Zacharias R. , Leeper R. J. , Fletcher K. , Farrell M. , Jasion D. , Kilkenny J. , Paguio R.
Published: April 2013

The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.
α-helix to β-hairpin transition of human amylin monomer
Authors: Singh Sadanand , Chiu Chi-cheng , Reddy Allam S. , de Pablo Juan J.
Published: April 2013

The human islet amylin polypeptide is produced along with insulin by pancreatic islets. Under some circumstances, amylin can aggregate to form amyloid fibrils, whose presence in pancreatic cells is a common pathological feature of Type II diabetes. A growing body of evidence indicates that small, early stage aggregates of amylin are cytotoxic. A better understanding of the early stages of the amylin aggregation process and, in particular, of the nucleation events leading to fibril growth could help identify therapeutic strategies. Recent studies have shown that, in dilute solution, human amylin can adopt an α-helical conformation, a β-hairpin conformation, or an unstructured coil conformation. While such states have comparable free energies, the β-hairpin state exhibits a large propensity towards aggregation. In this work, we present a detailed computational analysis of the folding pathways that arise between the various conformational states of human amylin in water. A free energy surface for amylin in explicit water is first constructed by resorting to advanced sampling techniques. Extensive transition path sampling simulations are then employed to identify the preferred folding mechanisms between distinct minima on that surface. Our results reveal that the α-helical conformer of amylin undergoes a transformation into the β-hairpin monomer through one of two mechanisms. In the first, misfolding begins through formation of specific contacts near the turn region, and proceeds via a zipping mechanism. In the second, misfolding occurs through an unstructured coil intermediate. The transition states for these processes are identified. Taken together, the findings presented in this work suggest that the inter-conversion of amylin between an α-helix and a β-hairpin is an activated process and could constitute the nucleation event for fibril growth.
Elliptic (N, N′)-soliton solutions of the lattice Kadomtsev-Petviashvili equation
Authors: Yoo-Kong Sikarin , Nijhoff Frank
Published: April 2013

Elliptic soliton solutions, comprising a soliton-type hierarchy of functions based on an elliptic seed solution, are constructed using elliptic Cauchy matrices, for a family of integrable lattice equations of Kadomtsev-Petviashvili (KP) type. This family consists of the lattice KP, modified KP, and Schwarzian KP equations as well as Hirota's bilinear KP equation, and their successive continuum limits. The reduction to the elliptic soliton solutions of KdV type lattice equations is also discussed.
Nonlinear femtosecond laser induced scanning tunneling microscopy
Authors: Dey Shirshendu , Mirell Daniel , Perez Alejandro Rodriguez , Lee Joonhee , Apkarian V. Ara
Published: April 2013

We demonstrate ultrafast laser driven nonlinear scanning tunneling microscopy (STM), under ambient conditions. The design is an adaptation of the recently introduced cross-polarized double beat method, whereby z-polarized phase modulated fields are tightly focused at a tunneling junction consisting of a sharp tungsten tip and an optically transparent gold film as substrate. We demonstrate the prerequisites for ultrafast time-resolved STM through an operative mechanism of nonlinear laser field-driven tunneling. The spatial resolution of the nonlinear laser driven STM is determined by the local field intensity. Resolution of 0.3 nm–10 nm is demonstrated for the intensity dependent, exponential tunneling range. The demonstration is carried out on a junction consisting of tungsten tip and gold substrate. Nano-structured gold is used for imaging purposes, to highlight junction plasmon controlled tunneling in the conductivity limit.
Calculation of non-adiabatic coupling vectors in a local-orbital basis set
Authors: Abad Enrique , Lewis James P. , Zobač Vladmír , Hapala Prokop , Jelínek Pavel , Ortega José
Published: April 2013

Most of today's molecular-dynamics simulations of materials are based on the Born-Oppenheimer approximation. There are many cases, however, in which the coupling of the electrons and nuclei is important and it is necessary to go beyond the Born-Oppenheimer approximation. In these methods, the non-adiabatic coupling vectors are fundamental since they represent the link between the classical atomic motion of the nuclei and the time evolution of the quantum electronic state. In this paper we analyze the calculation of non-adiabatic coupling vectors in a basis set of local orbitals and derive an expression to calculate them in a practical and computationally efficient way. Some examples of the application of this expression using a local-orbital density functional theory approach are presented for a few simple molecules: H3, formaldimine, and azobenzene. These results show that the approach presented here, using the Slater transition-state density, is a very promising way for the practical calculation of non-adiabatic coupling vectors for large systems.
A novel technique for measurement of thermal rate constants and temperature dependences of dissociative recombination: CO2+, CF3+, N2O+, C7H8+, C7H7+, C6H6+, C6H5+, C5H6+, C4H4+, and C3H3+
Authors: Fournier Joseph A. , Shuman Nicholas S. , Melko Joshua J. , Ard Shaun G. , Viggiano Albert A.
Published: April 2013

A novel technique using a flowing afterglow-Langmuir probe apparatus for measurement of temperature dependences of rate constants for dissociative recombination (DR) is presented. Low (∼1011 cm−3) concentrations of a neutral precursor are added to a noble gas/electron afterglow plasma thermalized at 300–500 K. Charge exchange yields one or many cation species, each of which may undergo DR. Relative ion concentrations are monitored at a fixed reaction time while the initial plasma density is varied between 109 and 1010 cm−3. Modeling of the decrease in concentration of each cation relative to the non-recombining noble gas cation yields the rate constant for DR. The technique is applied to several species (O2+, CO2+, CF3+, N2O+) with previously determined 300 K values, showing excellent agreement. The measurements of those species are extended to 500 K, with good agreement to literature values where they exist. Measurements are also made for a range of CnHm+ (C7H7+, C7H8+, C5H6+, C4H4+, C6H5+, C3H3+, and C6H6+) derived from benzene and toluene neutral precursors. CnHm+ DR rate constants vary from 8–12 × 10−7 cm3 s−1 at 300 K with temperature dependences of approximately T−0.7. Where prior measurements exist these results are in agreement, with the exception of C3H3+ where the present results disagree with a previously reported flat temperature dependence.
Hydrodynamically enforced entropic Brownian pump
Authors: Ai Bao-quan , He Ya-feng , Li Feng-guo , Zhong Wei-rong
Published: April 2013

Transport of overdamped Brownian particles in a finite hydrodynamical channel is investigated in the presence of the ac driving force and the pressure-driven flow. The system is bounded by two particle reservoirs. With the help of the Fick-Jacobs method, we obtain the directed current of Brownian particles and the pumping capacity of the system. The directed transport is determined by the competitions among the asymmetry of the channel, the ac driving force, the pressure-driven flow, and the concentration difference. Their interplays can exhibit the peculiar properties. Remarkably, the particles can be pumped through the channel from the lower concentration reservoir to the higher concentration one, or from the lower pressure side to the higher pressure one. In addition, due to the existence of the pressure drop, ac driving force still plays the significant role on directed transport even in a completely symmetric channel. Our results could be implemented in constrained structures with narrow channels or pores where the particles are suspended in a solvent.
Effects of the TiO2 buffer thickness on SrTiO3 (111) epitaxial films grown on GaN (0002)
Authors: Luo W. B. , Zhu J. , Wu C. G. , Shuai Y. , Zhang W. L. , Zhang Y. , Zhou S. , Gemming S. , Schmidt H.
Published: April 2013

SrTiO3 (STO) films have been grown on TiO2-buffered GaN(0002) substrates. The deposition process was in situ monitored by reflective high energy electron diffraction (RHEED). The deposition rate and in-plane lattice parameter of TiO2 were calculated from the oscillation curve and RHEED patterns, respectively. It was found that the TiO2 lattice parameter changed as the thickness increased, which indicated a strain relaxation process of TiO2 buffer layers during the deposition. We show that the thickness of TiO2 can significantly influence the STO growth mode, surface morphology, and crystalline quality. As the TiO2 thickness increased, the STO growth mode is changed from 3D island to 2D growth mode and finally to SK mode as revealed by RHEED. The growth mode evolution shows close relation with the surface morphology and crystalline quality of STO. STO films deposited on 2 nm thick TiO2 film show 2D growth mode and have smoothest surface and smallest full width at half maximum of the STO rocking curve. Our investigation hints towards to a general approach to optimize the crystalline quality of STO, which can be optimized by adjusting the strain state of TiO2 buffer layer.
Electro-hydrodynamics and kinetic modelling of polluted air flow activated by multi-tip-to-plane corona discharge
Authors: Meziane M. , Eichwald O. , Sarrette J. P. , Ducasse O. , Yousfi M. , Marchal F.
Published: April 2013

The present paper is devoted to the 2D simulation of an Atmospheric Corona Discharge Reactor (ACDR) involving 10 pins powered by a DC high voltage and positioned 7 mm above a grounded metallic plane. The corona reactor is periodically crossed by thin mono filamentary streamers with a natural repetition frequency of some tens of kHz. The simulation involves the electro-dynamic, chemical kinetic, and neutral gas hydrodynamic phenomena that influence the kinetics of the chemical species transformation. Each discharge stage (including the primary and the secondary streamers development and the resulting thermal shock) lasts about one hundred nanoseconds while the post-discharge stages occurring between two successive discharge phases last one hundred microseconds. The ACDR is crossed by a lateral air flow including 400 ppm of NO. During the considered time scale of 10 ms, one hundred discharge/post-discharge cycles are simulated. The simulation involves the radical formation and thermal exchange between the discharges and the background gas. The results show how the successive discharges activate the flow gas and how the induced turbulence phenomena affect the redistribution of the thermal energy and the chemical kinetics inside the ACDR.
Thickness dependence of current-induced domain wall motion in a Co/Ni multi-layer with out-of-plane anisotropy
Authors: Tanigawa Hironobu , Suzuki Tetsuhiro , Fukami Shunsuke , Suemitsu Katsumi , Ohshima Norikazu , Kariyada Eiji
Published: April 2013

Thickness dependence of current-induced domain wall (DW) motion in a perpendicularly magnetized [Co/Ni]N multilayered wire containing Ta/Pt capping and Pt/Ta seed layers has been studied. The thickness of the magnetic layer was controlled by the stacking number, N. The threshold current density for driving DW had a local minimum at N = 3 and the velocity of DW motion decreased with N. Estimation of carrier spin polarization from measurements of DW velocity revealed that a thinner Co/Ni stack adjacent to the Pt layers reduced the carrier spin polarization and the strength of adiabatic spin transfer torque.
Photoinduced inverse spin Hall effect in Pt/Ge(001) at room temperature
Authors: Bottegoni F. , Ferrari A. , Cecchi S. , Finazzi M. , Ciccacci F. , Isella G.
Published: April 2013

We performed photoinduced inverse spin Hall effect (ISHE) measurements on a Pt/Ge(001) junction at room temperature. The spin-oriented electrons, photogenerated at the direct gap of Ge using circularly polarized light, provide a net spin current, which yields an electromotive field EISHE in the Pt layer. Such a signal is clearly detected at room temperature despite the strong Γ to L scattering, which electrons undergo in the Ge conduction band. The ISHE signal dependence on the exciting photon energy is in good agreement with the electron spin polarization expected for optical orientation at the direct gap of Ge.
Ultrawide-band photon routing based on chirped plasmonic gratings
Authors: Fu Yulan , Hu Xiaoyong , Yang Hong , Gong Qihuang
Published: April 2013

We report an ultrawide-band photon routing based on a chirped plasmonic grating, which consists of a gold film coated with a chirped dielectric grating made of organic polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]. The photon routing is realized based on rainbow-trapping like effect. An ultrawide operating bandwidth of 200 nm is reached through scanning near-field optical microscopy measurement. The tunable photon routing is reached through adjusting structural parameters of chirped plasmonic grating or using a pump light. A shift of 0.5 μm in the terminal channel is achieved for the 850-nm incident laser when the groove width changes from 150 to 180 nm.
Selective lateral electrochemical etching of a GaN-based superlattice layer for thin film device application
Authors: Kim Dong-Uk , Chang Hojun , Cha Hyungrae , Jeon Heonsu , Jeon Seong-Ran
Published: April 2013

We propose and demonstrate a selective lateral electrochemical etching using a superlattice as the etch-sacrificial layer. Differing from the previous methods that require a special etch-sacrificial layer and therefore deteriorate the epilayer grown atop, our method simplifies the epi-growth without compromising the epi-quality. At the reverse bias voltage of 20 V in 0.3 M oxalic acid electrolyte, a 50-nm-thick InGaN/AlGaN superlattice was etched laterally at the rate of ∼0.8 μm/min. Our method is efficient enough for the epitaxial lift-off process: an array of 80 μm × 80 μm square platelets is completely detached from substrate, with quantum-well emission properties preserved intact.
Influence of manganese substitution on the microstructure and magnetostrictive properties of Co1−xMnxFe2O4 (x = 0.0–0.4) ferrite
Authors: Atif M. , Sato Turtelli R. , Grossinger R. , Kubel F.
Published: April 2013

Manganese substituted cobalt ferrite, Co1−xMnxFe2O4 (x = 0.0–0.4), was prepared by a ceramic method. The heat-treated powders were pressed at hydrostatic pressure of 167 MPa, and were annealed at 1350 °C for 24 h. These samples present a single-phase cubic spinel structure and the compositional mass ratios are close to the empirical formula. The lattice constant determined from XRD increases with the increase of Mn content, whereas SEM study reveals that Mn substitution changes the microstructure and cause pores within the grains, which reduces the bulk density of the samples. The magnetocrystalline anisotropy constant, coercive field, and magnetostriction were observed to decrease with increasing Mn substitution; however, the strain derivative (dλ/dH) reaches a maximum value for x = 0.3. The observed variation in strain derivative in the Mn substituted cobalt ferrite is correlated to the microstructure whereas the reduced anisotropy of the system plays only a minor role.
Quantitative magneto-optical characterization of diffusive reflected light from rough steel samples
Authors: González-Díaz J. B. , Arregi J. A. , Martínez-de-Guerenu A. , Arizti F. , Berger A.
Published: April 2013

We obtain angular-resolved quantitative magneto-optical measurements with good signal-to-noise ratio from very diffusive reflection patterns of industrial steel samples, which are a consequence of their large surface roughness. For the diffuse spots generated by these samples, we observe that while the overall shape of the magnetic hysteresis loop is nearly independent, a monotonous increase of the magneto-optical polarization change occurs as a function of the scattering angle. We demonstrate that this observation can be explained by considering the diffuse spot as a superposition of independent reflections from planar surfaces with varying incidence angles. This main finding can be ultimately used to facilitate an efficient non-invasive analysis of industrial magnetic samples by means of magneto-optical methods despite their elevated level of roughness.
Growth and texture of spark plasma sintered Al2O3 ceramics: A combined analysis of X-rays and electron back scatter diffraction
Authors: Pravarthana D. , Chateigner D. , Lutterotti L. , Lacotte M. , Marinel S. , Dubos P. A. , Hervas I. , Hug E. , Salvador P. A. , Prellier W.
Published: April 2013

Textured alumina ceramics were obtained by Spark Plasma Sintering of undoped commercial α-Al2O3 powders. Various parameters (density, grain growth, grain size distribution) of the alumina ceramics, sintered at two typical temperatures 1400 °C and 1700 °C, are investigated. Quantitative textural and structural analysis, carried out using a combination of Electron Back Scattering Diffraction and X-ray diffraction, are represented in the form of mapping and pole figures. The mechanical properties of these textured alumina ceramics include high elastic modulus and hardness values with high anisotropic nature, opening the door for a large range of applications.
First-principles study of graphene-lithium structures for battery applications
Authors: Buldum Alper , Tetiker Gulcin
Published: April 2013

In order to identify the best and most promising graphene-lithium structures for battery applications, we performed a systematic study of different multilayer graphene-lithium structures using first-principles density-functional theory. The most promising structure identified is a few layer compound which contains a single graphene layer and four lithium layers. In this structure, lithium density is six times higher than that of intercalated graphite, and high lithium density observed in recent experiments can be due to this structure. In addition, we show that electron density distribution around the positive Li ions is very important to design new advanced materials for battery applications.
Improved light trapping in microcrystalline silicon solar cells by plasmonic back reflector with broad angular scattering and low parasitic absorption
Authors: Tan Hairen , Sivec Laura , Yan Baojie , Santbergen Rudi , Zeman Miro , Smets Arno H. M.
Published: April 2013

We show experimentally that the photocurrent of thin-film hydrogenated microcrystalline silicon (μc-Si:H) solar cells can be enhanced by 4.5 mA/cm2 with a plasmonic back reflector (BR). The light trapping performance is improved using plasmonic BR with broader angular scattering and lower parasitic absorption loss through tuning the size of silver nanoparticles. The μc-Si:H solar cells deposited on the improved plasmonic BR demonstrate a high photocurrent of 26.3 mA/cm2 which is comparable to the state-of-the-art textured Ag/ZnO BR. The commonly observed deterioration of fill factor is avoided by using μc-SiOx:H as the n-layer for solar cells deposited on plasmonic BR.
On the measurement of the thermal impedance in vertical-external-cavity surface-emitting lasers
Authors: Hader J. , Wang T.-L. , Moloney J. V. , Heinen B. , Koch M. , Koch S. W. , Kunert B. , Stolz W.
Published: April 2013

A detailed and systematic analysis of the loss mechanisms in vertical-external-cavity surface-emitting lasers is presented with the goal to correctly determine the amount of pump power that is converted to heat. With this input, the accuracy of a recently proposed method for measuring the thermal impedance based on roll-over characteristics is shown to be very high for devices with and without dielectric coating. Potential errors arising from non-heating losses can be determined by performing experiments with different out-coupling mirrors.
In-situ observation of electric-field-induced acceleration in crystal growth of tetrathiafulvalene-tetracyanoquinodimethane
Authors: Sakai Masatoshi , Kuniyoshi Shigekazu , Yamauchi Hiroshi , Iizuka Masaaki , Nakamura Masakazu , Kudo Kazuhiro
Published: April 2013

In-situ observations of vapor-phase growth of tetrathiafulvalene (TTF)-tetracyanoquinodimethane (TCNQ) crystals under an electric field were conducted without influencing the actual crystal growth process. The shortest incubation time of TTF-TCNQ nuclei and the highest initial growth rate of the crystals are obtained on the anode side and in high electric field regions. It is demonstrated that the distribution of molecules thermally diffusing on the substrate surface is controlled by an external electric field. These results indicate the potential for selective growth of highly conductive organic wires for micro- and nanoscale wiring in organic nanodevices.
Accurate measurement of the jitter time of GaAs photoconductive semiconductor switches triggered by a one-to-two optical fiber
Authors: Shi Wei , Zhang Lin , Gui Huaimeng , Hou Lei , Xu Ming , Qu Guanghui
Published: April 2013

An improved method is proposed to measure the jitter time of the photoconductive semiconductor switches (PCSSs). A one-to-two fiber is utilized to separate and guide the 1053 nm laser beam to trigger two identical 3-mm-gap GaAs PCSSs synchronously. The jitter time is derived from the time lags of two switches turn-on by the error transfer theory. At a bias voltage of 1 kV, the jitter time is measured as 14.41 ps, which is the lowest jitter of GaAs PCSS that has been reported so far.
Communication: Collective dynamics of room-temperature ionic liquids and their Li ion solutions studied by high-resolution inelastic X-ray scattering
Authors: Fujii Kenta , Shibayama Mitsuhiro , Yamaguchi Tsuyoshi , Yoshida Koji , Yamaguchi Toshio , Seki Shiro , Uchiyama Hiroshi , Baron Alfred Q. R. , Umebayashi Yasuhiro
Published: April 2013

High-resolution inelastic X-ray scattering (IXS) measurements were performed for room-temperature ionic liquids (ILs) of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide and bis(fluorosulfonyl)amide, [C2mIm+][TFSA−] and [C2mIm+][FSA−], respectively, at ambient temperature. The observed spectra as a function of Q of 1.4–6 nm−1 can be ascribed to quasi-elastic and inelastic scatterings, so that they are well represented with the fitting by using the Lorentz and the damped harmonic oscillator model functions to yield the dynamic structure factors. It was found in the intermediate scattering function, F(Q, t) that both ILs show the relaxation at t < 10 ps. The IXS measurements were also made on [C2mIm+][TFSA−] and [C2mIm+][FSA−] solutions dissolving Li salt. It is suggested that the adding of Li salt to IL significantly prolongs the relaxation time.
Determinants of the Performance of Business Associations in Rural Settlements in the United Kingdom: An Analysis of Members' Satisfaction and Willingness-to-Pay for Association Survival
Authors: Newbery Robert , Sauer Johannes , Gorton Matthew , Phillipson Jeremy , Atterton Jane
Published: April 2013

Research into business associations indicates that many associations suffer from very high levels of inactive members and fail to deliver significant benefits to members. In order to improve provision, the objective of this paper is to understand the determinants that drive or limit performance of rural business associations. Previous research has focused on the ratio of perceived costs to benefits as informing the decision to remain a member. However, in small associations, membership may be more influenced by social norms than the logic of rational choice. Using measures of satisfaction and willingness to pay for association survival as in-group measures of performance this paper finds that (1) for small associations, group size is critical, (2) associations are valued higher in communities where trust is lower, (3) funding by public bodies may be counterproductive to long-term development aims, and (4) the degree of rurality is insignificant in explaining association performance.
Catching Up, Leapfrogging, or Forging Ahead? Exploring the Effects of Integration and History on Spatial Technological Adoptions
Authors: Giovannetti Emanuele
Published: April 2013

This paper introduces a model of localised competition and technological adoption that produces interesting geographical adoption patterns: persistent asymmetry, where nobody adopts; leapfrogging where only followers adopt; forging ahead, where only leaders adopt; and catching up, where everybody adopts a new technology. I study the conditions leading to the emergence of these adoption patters to interpret the rich and growing empirical literature on intradistribution mobility across and within regions. I consider a set of linked markets characterised by asymmetric initial technological conditions. I show that these different spatial adoption patterns may provide an interesting reference for the debate on regional convergence, as adoption is an essential engine of growth. I also assess both the impact of integration policy and of historical asymmetries on these spatial adoption choices and find some counterintuitive results: for example, that integration policies may increase regional asymmetries instead of reducing them, depending on the relevance of the initial technology gap between neighbouring firms. The model does not assume different learning abilities or adoption costs between leaders and followers. Indeed, they can all adopt, for the same cost, a new technology leading to global catching up and convergence. Notwithstanding this possibility, the emerging spatial adoption patterns may still be asymmetric. The main parameters driving the results of the model are the relevance of the innovation; adoption costs; consumers' preferences for quality; the initial, historically inherited, technology quality asymmetries; and transport costs, expressing the degree of within-market competitiveness and differentiation.
Mass Transportation in the Neoliberal City: The Mobilizing Myths of the Grand Paris Express
Authors: Enright Theresa Erin
Published: April 2013

This paper examines the discourses of transportation and mobility surrounding the Grand Paris Express mass transit network announced in January 2011 as part of the broader Grand Paris urban renewal and agglomeration initiative. It argues that though Grand Paris Express has the potential to symbolically unify the Île-de-France region, and may provide much needed infrastructure to the peripheral suburbs of Paris, because of the neoliberal political rationality upon which it is based, it may likely entrench rather than relieve the problems of territorial inequality it sets out to address. An important tool of gentrification, mass transit is being used in metropolitan Paris to lead urban development in the creation of a polycentric region with functionally differentiated clusters of industry, finance, and technology around proposed transit stations. Following four main ‘mobilizing myths’ that dominate public policy debates, the proposed Grand Paris Express system fails to consider the broad social, economic, and political conditions upon which urban mobility is based, instead orienting transit toward a marketized logic of real estate development, urban rent production, and territorial competition.
The Butler Affair and the Geopolitics of Identity
Authors: Kearns Gerry
Published: April 2013

In the wake of the Global War on Terror, Judith Butler has written of the ‘precarity’ of life, of the inevitable vulnerability of one's life in the face of the actions of strangers. Refusing to accept this, the United States has developed a form of nationalism that claims invulnerability for its citizens while treating as expendable the lives of distant others who even unwittingly associate with those who threaten the US homeland. Butler has extended this set of criticisms to Israel's policy towards Palestinian people and in doing so has been criticised as anti-Semitic. She has engaged with these questions about Jewish identity, nationalism, and toleration through an engagement with writers of the Jewish diaspora, developing what we may describe as a geopolitical perspective on identity. The value of such a perspective was given ironic point by the public controversy over the award to Butler of the Adorno Prize in 2012. This paper argues also that in responding to the biopolitics of the Global War on Terror, Butler has elaborated on some of the geopolitical bases of identity and in doing so has illuminated the academic politics of the current Boycott, Divestment, and Sanctions campaign called for by many institutions of Palestinian civil society.