bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of corpus examples for language comprehension and production
Authors: Frankenberg-Garcia Ana
Published: February 2014

One of the many new features of English language learners’ dictionaries derived from the technological developments that have taken place over recent decades is the presence of corpus-based examples to illustrate the use of words in context. However, empirical studies have generally not been able to produce conclusive evidence about their actual worth. In Frankenberg-Garcia (2012a), I argued that these studies – and indeed learners’ dictionaries themselves – do not distinguish sufficiently between examples meant to aid language comprehension and examples that focus on enhancing language production. The present study reports on an experiment with secondary school students carried out to test the usefulness of separate corpus examples for comprehension and production. The results support the need for different types of examples for comprehension and production, and provide evidence in support of data-driven learning, particularly if learners have access to more than one example.
In Situ Cryogenic Transmission Electron Microscopy for Characterizing the Evolution of Solidifying Water Ice in Colloidal Systems
Authors: Tai Kaiping , Liu Yin , Dillon Shen J.
Published: February 2014

The details of ice interface dynamics in complex systems are critical to a variety of natural and commercial processes. A platform for low temperature environmental transmission electron microscopy is developed and applied to characterization of ice crystallization in colloidal solutions. The platform is utilized for studying the phase evolution in ice during crystallization and the dynamic interactions of Au nanoparticles at the crystallization front. The results indicate that models developed to treat ice–particle interactions at the micron scale extend well to the nanoscale.
Effect of Reflux Time on Nanoparticle Shape
Authors: Srivastava Chandan , KVL Sushma
Published: February 2014

In the present work, Pt nanoparticles were produced from a reaction mixture containing a trace amount of cobalt carbonyl salt acting as a shape inducer. Nanoparticle shape evolution during reaction mixture reflux was monitored by characterizing particles extracted from the reaction mixture at different times. It was observed that 5 min of reflux produced spherical nanoparticles, 30 min of reflux produced cube shaped nanoparticles, and 60 min of reflux produced truncated octahedron morphology nanoparticles. It is illustrated that during nanoparticle synthesis the reflux process can provide energy needed for shape transformation from a metastable cube morphology to a truncated octahedron morphology which is thermodynamically the most stable geometry for fcc crystals. An optimization of the reaction reflux is thus needed for isolating metastable shapes.
Combined Scanning Transmission Electron Microscopy Tilt- and Focal Series
Authors: Dahmen Tim , Baudoin Jean-Pierre , Lupini Andrew R. , Kübel Christian , Slusallek Philipp , de Jonge Niels
Published: February 2014

In this study, a combined tilt- and focal series is proposed as a new recording scheme for high-angle annular dark-field scanning transmission electron microscopy (STEM) tomography. Three-dimensional (3D) data were acquired by mechanically tilting the specimen, and recording a through-focal series at each tilt direction. The sample was a whole-mount macrophage cell with embedded gold nanoparticles. The tilt–focal algebraic reconstruction technique (TF-ART) is introduced as a new algorithm to reconstruct tomograms from such combined tilt- and focal series. The feasibility of TF-ART was demonstrated by 3D reconstruction of the experimental 3D data. The results were compared with a conventional STEM tilt series of a similar sample. The combined tilt- and focal series led to smaller “missing wedge” artifacts, and a higher axial resolution than obtained for the STEM tilt series, thus improving on one of the main issues of tilt series-based electron tomography.
Realising the Business Case for Diversity: A Realist Perspective on the British National Health Service
Authors: Powell Martin , Johns Nick
Published: February 2014

This article takes a novel approach to exploring the business case for diversity (BCD) as it has been adopted in the British National Health Service (NHS), principally in terms of ‘race’ and ethnicity for the sake of clarity and manageability. It draws on realist perspectives that consider issues of context, mechanism and outcome. It concludes that transferring policies from other countries and sectors is problematic, and consequently that the application of the BCD to the NHS must be treated with extreme caution.
Conservation agriculture in Southern Africa: Advances in knowledge
Authors: Thierfelder Christian , Rusinamhodzi Leonard , Ngwira Amos R. , Mupangwa Walter , Nyagumbo Isaiah , Kassie Girma T. , Cairns Jill E.
Published: February 2014

The increasing demand for food from limited available land, in light of declining soil fertility and future threats of climate variability and change have increased the need for more sustainable crop management systems. Conservation agriculture (CA) is based on the three principles of minimum soil disturbance, surface crop residue retention and crop rotations, and is one of the available options. In Southern Africa, CA has been intensively promoted for more than a decade to combat declining soil fertility and to stabilize crop yields. The objective of this review is to summarize recent advances in knowledge about the benefits of CA and highlight constraints to its widespread adoption within Southern Africa. Research results from Southern Africa showed that CA generally increased water infiltration, reduced soil erosion and run-off, thereby increasing available soil moisture and deeper drainage. Physical, chemical and biological soil parameters were also improved under CA in the medium to long term. CA increased crop productivity and also reduced on-farm labor, especially when direct seeding techniques and herbicides were used. As with other cropping systems, CA has constraints at both the field and farm level. Challenges to adoption in Southern Africa include the retention of sufficient crop residues, crop rotations, weed control, pest and diseases, farmer perception and economic limitations, including poorly developed markets. It was concluded that CA is not a ‘one-size-fits-all’ solution and often needs significant adaptation and flexibility when implementing it across farming systems. However, CA may potentially reduce future soil fertility decline, the effects of seasonal dry-spells and may have a large impact on food security and farmers’ livelihoods if the challenges can be overcome.
Auto-generation of passive scalable macromodels for microwave components using scattered sequential sampling
Authors: Chemmangat Krishnan , Dhaene Tom , Knockaert Luc
Published: February 2014

This paper presents a method for automatic construction of stable and passive scalable macromodels for parameterized frequency responses. The method requires very little prior knowledge to build the scalable macromodels thereby considerably reducing the burden on the designers. The proposed method uses an efficient scattered sequential sampling strategy with as few expensive simulations as possible to generate accurate macromodels for the system using state-of-the-art scalable macromodeling methods. The scalable macromodels can be used as a replacement model for the actual simulator in overall design processes. Pertinent numerical results validate the proposed sequential sampling strategy.
Cardiovascular diseases in grandparents and the risk of congenital heart diseases in grandchildren
Authors: Wijnands K. P. J. , Obermann-Borst S. A. , Sijbrands E. J. G. , Wildhagen M. F. , Helbing W. A. , Steegers-Theunissen R. P. M.
Published: February 2014

Hyperglycemia, dyslipidemia and hyperhomocysteinemia are associated with both adult cardiovascular disease (CVD) and having a child with a congenital heart disease (CHD). We investigated associations between CVD in grandparents and the risk of CHD in grandchildren. In a case–control family study, we obtained detailed questionnaire information on CVD and CHD in 247 families with a CHD child and 203 families without a CHD child. Grandparents with CVD or intermittent claudication (IC) were significantly associated with an increased risk for CHD in grandchildren [OR 1.39 (95% CI 1.03–1.89) and OR 2.77 (95% CI 1.02–7.56), respectively]. The risk of CHD grandchildren was particularly increased in paternal grandfathers with CVD [OR 1.85 (95% CI 1.01–3.37)]. Overall, having a grandparent with CVD increased the risk for CHD in the grandchild by 1.65 (95% CI 1.12–2.41). After adjustment for potential maternal confounders, this risk was 1.44 (95% CI 0.94–2.21). Having two or more grandparents with CVD was associated with an approximately threefold risk for CHD grandchildren [OR adjusted 2.72 (95% CI 1.08–6.89)]. Our data suggest that CVD and IC in grandparents are associated with an increased risk of having a CHD grandchild. These first findings may be explained by shared causality of derangements in metabolic pathways and are in line with the fetal origins of health and disease.
Macroscopic Fourier transform infrared scanning in reflection mode (MA-rFTIR), a new tool for chemical imaging of cultural heritage artefacts in the mid-infrared range
Authors: Legrand Stijn , Alfeld Matthias , Vanmeert Frederik , De Nolf Wout , Janssens Koen
Published: February 2014

Macroscopic Fourier transform infrared scanning in reflection mode (MA-rFTIR), a new tool for the chemical imaging of cultural heritage artefacts in the extended mid-infrared range (7500–375 cm−1).
Expanding the genetic code for site-specific labelling of tobacco mosaic virus coat protein and building biotin-functionalized virus-like particles
Authors: Wu F. C. , Zhang H. , Zhou Q. , Wu M. , Ballard Z. , Tian Y. , Wang J. Y. , Niu Z. W. , Huang Y.
Published: February 2014

Building biotin-functionalized virus-like particles by combining a genetic code expanding technology and site specific modification of tobacco mosaic virus coat protein.
The hydrothermal synthesis and formation mechanism of single-crystalline perovskite BiFeO3 microplates with dominant (012) facets
Authors: Yang Xin , Xu Gang , Ren Zhaohui , Wei Xiao , Chao Chunying , Gong Siyu , Shen Ge , Han Gaorong
Published: February 2014

Single-crystal BiFeO3 (BFO) microplates with dominant (012) facets were successfully synthesized by a facile one-pot hydrothermal method. The adsorption behaviour of the organic ligands may play a key role in the formation of the BFO microplates.
Ex situ and in situ monitoring of the syntheses of thermochromic Schiff bases
Authors: Zbačnik M. , Kaitner B.
Published: February 2014

This work presents in situ PXRD monitoring of the syntheses of thermochromic Schiff bases and a study of the mechanisms of their formation.
Pressure-induced isostructural phase transition of a metal–organic framework Co2(4,4′-bpy)3(NO3)4·xH2O
Authors: Zhou Mi , Wang Kai , Men Zhiwei , Sun Chenglin , Li Zhanlong , Liu Bingbing , Zou Guangtian , Zou Bo
Published: February 2014

Based on the 4,4′-bipyridine organic linker, metal–organic frameworks of Co2(4,4′-bpy)3(NO3)4·xH2O (CB-MOF) have been prepared.
Spiropyran as a reusable chemosensor for selective colorimetric detection of aromatic thiols
Authors: Shiraishi Yasuhiro , Yamamoto Kohei , Sumiya Shigehiro , Hirai Takayuki
Published: February 2014

A colorless spiropyran dye (1) dissolved in aqueous media containing aromatic thiols is selectively isomerized to the colored merocyanine form, behaving as a colorimetric chemosensor for selective detection of aromatic thiols.
Formation of nickel–carbon heterofullerenes under electron irradiation
Authors: Sinitsa A. S. , Lebedeva I. V. , Knizhnik A. A. , Popov A. M. , Skowron S. T. , Bichoutskaia E.
Published: February 2014

Transformation of a graphene flake with an attached nickel cluster to new metal–carbon nanoobjects under electron irradiation is simulated.
Towards a comprehensive understanding of visible-light photogeneration of hydrogen from water using cobalt(ii) polypyridyl catalysts
Authors: Khnayzer R. S. , Thoi V. S. , Nippe M. , King A. E. , Jurss J. W. , El Roz K. A. , Long J. R. , Chang C. J. , Castellano F. N.
Published: February 2014

Numerous visible-light absorbing homogeneous photocatalytic compositions are shown to produce copious amounts of hydrogen gas from pure water.
Tracking dissolution of silver nanoparticles at environmentally relevant concentrations in laboratory, natural, and processed waters using single particle ICP-MS (spICP-MS)
Authors: Mitrano D. M. , Ranville J. F. , Bednar A. , Kazor K. , Hering A. S. , Higgins C. P.
Published: February 2014

Calculating nanosilver dissolution rates by measuring reduction in nanoparticle mass is more direct than measuring release of ionic silver alone.
The study of reduced versus oxidized glutathione in cancer cell models employing isotopically labelled standards
Authors: Hermann Gerrit , Heffeter Petra , Kryeziu Kushtrim , Berger Walter , Hann Stephan , Koellensperger Gunda
Published: February 2014

LC-MS/MS assays for accurate quantification of underivatized glutathione (GSH) and its oxidized form glutathione disulfide (GSSG), in cancer cell models, based on isotope dilution and its application in pre-clinical metallo-drug research.
Tryptoline-3-hydroxypyridinaldoxime conjugates as efficient reactivators of phosphylated human acetyl and butyrylcholinesterases
Authors: Renou Julien , Loiodice Mélanie , Arboléas Mélanie , Baati Rachid , Jean Ludovic , Nachon Florian , Renard Pierre-Yves
Published: February 2014

Uncharged reactivators able to efficiently reactivate human butyrylcholinesterase and human acetylcholinesterase inhibited by organophosphorus nerve agents.
A paper based self-pumping and self-breathing fuel cell using pencil stroked graphite electrodes
Authors: Arun Ravi Kumar , Halder Saurav , Chanda Nripen , Chakraborty Suman
Published: February 2014

We present a pencil stroked paper fuel cell to generate energy (32 mW cm−2) over a prolonged duration (>1000 minutes) and with low consumption of fuel (~1 mL).
Biological evaluation and molecular modelling of didanosine derivatives
Authors: Ravetti Soledad , De Candia Cristian A. , Gualdesi María S. , Pampuro Sandra , Turk Gabriela , Quevedo Mario A. , Briñón Margarita C.
Published: February 2014

These prodrugs of DDI with increased lipophilicity and good antiviral performance should be of interest in HIV therapy.
Synthesis and antiviral evaluation of 4′-(1,2,3-triazol-1-yl)thymidines
Authors: Vernekar Sanjeev Kumar V. , Qiu Li , Zacharias Jeana , Geraghty Robert J. , Wang Zhengqiang
Published: February 2014

The Cu(i)-catalyzed azide–alkyne cycloaddition (CuAAC) of 4′-azidothymidine (5) generated a series of 1,2,3-triazole analogues (9) with moderate anti-HIV activities, while a similar cycloaddition reaction catalyzed by Ru(ii) failed.
BER analysis of space‐time coded RFID system in Nakagami‐m fading channels
Authors: Maichalernnukul K. , Zheng F. , Kaiser T.
Published: February 2014

The exact bit error rate (BER) analysis of a space‐time coded radio frequency identification (RFID) system is presented, where the tag has multiple antennas and the reader has a single antenna. In the analysis, the forward and backward channels exhibiting independent but not necessarily identically distributed Nakagami‐m fading are considered, and the diversity order that the system can achieve is found to be Nmin(mh, mg), where N is the number of antennas at the tag and mh and mg are the fading parameters corresponding to the forward and backward channels, respectively. The analytical results are verified through comparison with the simulation results.
An all permanent magnet electron cyclotron resonance ion source for heavy ion therapy
Authors: Cao Yun , Li Jia Qing , Sun Liang Ting , Zhang Xue Zhen , Feng Yu Cheng , Wang Hui , Ma Bao Hua , Li Xi Xia
Published: February 2014

A high charge state all permanent Electron Cyclotron Resonance ion source, Lanzhou All Permanent ECR ion source no. 3-LAPECR3, has been successfully built at IMP in 2012, which will serve as the ion injector of the Heavy Ion Medical Machine (HIMM) project. As a commercial device, LAPECR3 features a compact structure, small size, and low cost. According to HIMM scenario more than 100 eμA of C5+ ion beam should be extracted from the ion source, and the beam emittance better than 75 π*mm*mrad. In recent commissioning, about 120 eμA of C5+ ion beam was got when work gas was CH4 while about 262 eμA of C5+ ion beam was obtained when work gas was C2H2 gas. The design and construction of the ion source and its low-energy transportation beam line, and the preliminary commissioning results will be presented in detail in this paper.
Toward tuning the surface functionalization of small ceria nanoparticles
Authors: Huang Xing , Wang Binghui , Grulke Eric A. , Beck Matthew J.
Published: February 2014

Understanding and controlling the performance of ceria nanoparticle (CNP) catalysts requires knowledge of the detailed structure and property of CNP surfaces and any attached functional groups. Here we report thermogravimetric analysis results showing that hydrothermally synthesized ∼30 nm CNPs are decorated with 12.9 hydroxyl groups per nm2 of CNP surface. Quantum mechanical calculations of the density and distribution of bound surface groups imply a scaling relationship for surface group density that balances formal charges in the functionalized CNP system. Computational results for CNPs with only hydroxyl surface groups yield a predicted density of bound hydroxyl groups for ∼30 nm CNPs that is ∼33% higher than measured densities. Quantitative agreement between predicted and measured hydroxyl surface densities is achieved when calculations consider CNPs with both –OH and –Ox surface groups. For this more general treatment of CNP surface functionalizations, quantum mechanical calculations predict a range of stable surface group configurations that depend on the chemical potentials of O and H, and demonstrate the potential to tune CNP surface functionalizations by varying temperature and/or partial pressures of O2 and H2O.
Magnetostructural transition and magnetocaloric effect in MnNiGe1.05 melt-spun ribbons
Authors: Daniel-Pérez Gerardo , Sánchez Llamazares J. L. , Quintana-Nedelcos A. , Álvarez-Alonso P. , Varga R. , Chernenko V.
Published: February 2014

Alloy ribbons of nominal composition MnNiGe1.05 were produced using the melt-spinning technique. As-quenched (aq) polycrystalline ribbons are single-phase showing the hexagonal Ni2In-type crystal structure. After thermal annealing at 1148 K, the formation of the orthorhombic TiNiSi-type crystal structure by martensitic transformation is favored. However, XRD patterns for different temperatures indicate that the phase transition from hexagonal to orthorhombic structure is incomplete. The starting and finishing temperatures for the direct and reverse martensitic transformation for aq (annealed) samples determined by DSC were MS = 264 (268) K Mf = 235 (255) K, AS = 259 (266) K, and Af = 289 (276) K. Across this structural phase transition the annealed sample undergoes a drop in magnetization giving rise to a narrow temperature dependence of the magnetic entropy change with a peak value on heating (cooling) of 5.8 (4.8) Jkg−1K−1 for a field change of 5 T.
The creation of 360° domain walls in ferromagnetic nanorings by circular applied magnetic fields
Authors: Bickel Jessica E. , Smith Spencer A. , Aidala Katherine E.
Published: February 2014

Switching behavior in ferromagnetic nanostructures is often determined by the formation and annihilation of domain walls (DWs). In contrast to the more familiar 180° DWs found in most nanostructures, 360° DWs are the proposed transition state of nanorings. This paper examines the formation of 360° DWs created by the application of a circular magnetic field using micromagnetic simulations. 360° DWs form from pairs of canting moments that are oppositely aligned, which each grow to form rotated domains bounded by two 180° DWs and the 180° DWs combine to form 360° DWs. The resulting 360° DWs occur in pairs of opposite topological winding number due to these domains of opposite canting direction. The final number of DWs formed is greatly impacted by symmetry, both of the ring and of the placement of the circular magnetic field.
Decay of homogeneous, nearly isotropic turbulence behind active fractal grids
Authors: Thormann Adrien , Meneveau Charles
Published: February 2014

The study of decaying isotropic turbulent flow is an important point of reference for turbulence theories and numerical simulations. For the past several decades, most experimental results appear to favor power-law decay with exponents between −1.2 and −1.4, approximately. More recently, studies of fractal-generated turbulence with multi-scale passive grids have shown increased Reynolds numbers and exponential or very fast power-law decays following an increase of kinetic energy close to the grid. Other recent studies have confirmed that such non-classical decay is limited to the region near the grid. In order to generate turbulence with multi-scale injection of kinetic energy at more elevated Reynolds numbers and with more spatially homogeneous distributions than available in prior experiments, we use an active-grid consisting of winglets with fractal shapes. We consider various types of fractal winglets, namely, Sierpinski triangle, space-filling squares, and Apollonian gasket type fractal shapes. Regular non-fractal winglets are also considered. Passive fractal grids are studied by keeping the winglets locked in place. Data are acquired using X-wire thermal anemometry and the decay is analyzed between 15 < x/M < 50 (M is the mesh-size). Results exhibit power-law decay with decay exponent approximately between −1.0 and −1.3. The precise values of the decay exponent and the coefficient \documentclass[12pt]{minimal}\begin{document}$C_{\epsilon }=\epsilon \ell /u_{rms}^3$\end{document}Cε=εℓ/urms3 depend on the geometry of the initial condition, although it is not possible to discern systematic or monotonic trends with respect to Reλ, component anisotropy, grid fractal dimension, or blockage ratio.
Electronic structure of antifluorite Cu2X (X = S, Se, Te) within the modified Becke-Johnson potential plus an on-site Coulomb U
Authors: Zhang Yubo , Wang Youwei , Xi Lili , Qiu Ruihao , Shi Xun , Zhang Peihong , Zhang Wenqing
Published: February 2014

The traditional photon absorbers Cu2−xX (X = S, Se, and Te) have regained significant research attention in the search of earth-abundant photovoltaic materials. These moderate- and narrow-gap materials have also been shown to exhibit excellent thermoelectric properties recently. However, semimetallic band structures with inverted band orderings are predicted for antifluorite structure Cu2X using density functional theory with the local density approximation or the generalized gradient approximation. We find that semiconducting band structures and normal band orderings can be obtained using the modified Becke-Johnson potential plus an on-site Coulomb U (the mBJ+U approach), which is consistent with our earlier finding for diamond-like Cu-based multinary semiconductors [Y. Zhang, J. Zhang, W. Gao, T. A. Abtew, Y. Wang, P. Zhang, and W. Zhang, J. Chem. Phys. 139, 184706 (2013)]. The trend of the chemical bonding of Cu2X is analyzed, which shows that the positions of the valence band maximum and conduction band minimum are strongly affected by the inter-site pd and intra-site sp hybridizations, respectively. The calculated gaps of Cu2S and Cu2Se still seem to be underestimated compared with experimental results. We also discuss the effects of different structural phases and Cu disordering and deficiency on the bandgaps of these materials.
On the zero modes of the Faddeev-Popov operator in the Landau gauge
Authors: Landim R. R. , Vilar L. C. Q. , Ventura O. S. , Lemes V. E. R.
Published: February 2014

Following Henyey procedure [Phys. Rev. D 20, 1460 (1979)], we construct examples of zero modes of the Faddeev-Popov operator in the Landau gauge in Euclidean space in D dimensions, for both SU(2) and SU(3) groups. We obtain gauge field configurations \documentclass[12pt]{minimal}\begin{document}$A^a_\mu$\end{document}Aμa which give rise to a field strength, \documentclass[12pt]{minimal}\begin{document}$F^a_{\mu \nu } =\partial _\mu A^a_\nu -\partial _\nu A^a_\mu + f^{abc}A^b_\mu A^c_\nu$\end{document}Fμνa=∂μAνa−∂νAμa+fabcAμbAνc, whose nonlinear term, \documentclass[12pt]{minimal}\begin{document}$f^{abc}A^b_\mu A^c_\nu$\end{document}fabcAμbAνc, turns out to be non-vanishing. To our knowledge, this is the first time where such a non-abelian configuration is explicitly obtained in the case of SU(3) in 4D.
A nonlinear Bloch model for Coulomb interaction in quantum dots
Authors: Bidegaray-Fesquet Brigitte , Keita Kole
Published: February 2014

In this paper, we first derive a Coulomb Hamiltonian for electron–electron interaction in quantum dots in the Heisenberg picture. Then we use this Hamiltonian to enhance a Bloch model, which happens to be nonlinear in the density matrix. The coupling with Maxwell equations in case of interaction with an electromagnetic field is also considered from the Cauchy problem point of view. The study is completed by numerical results and a discussion about the advisability of neglecting intra-band coherences, as is done in part of the literature.
X-ray nano-diffraction study of Sr intermetallic phase during solidification of Al-Si hypoeutectic alloy
Authors: Manickaraj Jeyakumar , Gorny Anton , Cai Zhonghou , Shankar Sumanth
Published: February 2014

The evolution of strontium (Sr) containing intermetallic phase in the eutectic reaction of Sr-modified Al-Si hypoeutectic alloy was studied with high energy synchrotron beam source for nano-diffraction experiments and x-ray fluorescence elemental mapping. Contrary to popular belief, Sr does not seem to interfere with the Twin Plane Re-entrant Edge (TPRE) growth mechanism of eutectic Si, but evolves as the Al2Si2Sr phase during the eutectic reaction at the boundary between the eutectic Si and Al grains.
Table-like magnetocaloric effect in the Gd-Co-Al alloys with multi-phase structure
Authors: Fu H. , Ma Z. , Zhang X. J. , Wang D. H. , Teng B. H. , Agurgo Balfour E.
Published: February 2014

Two sorts of Gd-Co-Al ternary alloys of multi-phase structure with table-like magnetocaloric effect (MCE) suitable for the ideal Ericsson cycle have been developed. One is prepared by arc-melting Gd53Co19Al28 with the resulting alloy composed of Gd2Al, Gd2Co2Al, and GdCo0.74Al1.26 crystalline phases and the other is synthesized by suck-casting Gd52.5Co16Al31 which has a glassy structure and crystalline phases of Gd2Al and Gd2Co2Al. Metamagnetic transition of antiferromagnetic Gd2Al phase near 50 K and ferromagnetic transitions of Gd2Co2Al, GdCo0.74Al1.26, and the glassy phase near 80 K result in the occurring of table-like magnetocaloric effect with magnitude of ∼7 J/kg K over the temperature range from 47.5 K to 77.5 K for a magnetic field variation of 0 to 50 kOe. The fitting reproduces the temperature dependence of magnetic entropy change of samples and the results suggest that the magnetocaloric response of Gd2Al phase in the ternary alloys have been improved, which is crucial for the composite alloys to obtain table-like magnetocaloric effect.
Impact of interplay between magnetic field, transformation strain, and coarsening on variant selection in L1-type FePd
Authors: Ueshima N. , Yoshiya M. , Yasuda H. , Fukuda T. , Kakeshita T.
Published: February 2014

Variant selection of L10-type ferromagnetic alloys has been numerically investigated using the phase-field modeling, to clarify the phenomena at greater temporal and spatial resolution and to reveal the underlying mechanism. The duration for which the external magnetic field is effective is found to be very short, and variant selection is significantly affected by not only direct response to the external magnetic field but also their interplay between the field, intrinsic transformation strain, and various thermodynamic energy components involved in the course of microstructure evolution. The detailed mechanism of the interplay was quantitatively analyzed in terms of the driving force for the variant selection, by partitioning it into the various energy components. Careful examination of the variant selection at the very early stage revealed that the slight difference in size and configuration of variants during disorder-to-order transition realized by the interplay between transformation strain and external field is essentially needed before proceeding to the latter stage of the variant selection driven by interface energy.
On-chip targeted single cell sonoporation with microbubble destruction excited by surface acoustic waves
Authors: Meng Long , Cai Feiyan , Jiang Peng , Deng Zhiting , Li Fei , Niu Lili , Chen Yan , Wu Junru , Zheng Hairong
Published: February 2014

We demonstrate that a surface acoustic wave at tens of megahertz frequency is capable of inducing microbubble cluster destruction at a desired location to achieve a single cell's reparable sonoporation. By controlling the position of the microbubble cluster relative to the targeted cell precisely, the effective size of the collapsing microbubbles is measured to be less than 0.68 times the diameter of microbubble cluster. Furthermore, the sonoporation efficiency and the cell viability are 82.4% ± 6.5% and 90% ± 8.7%, respectively, when the targeted cell is within the effective microbubble destruction region.
HBr/O2 plasma treatment followed by a bake for photoresist linewidth roughness smoothing
Authors: Fouchier M. , Pargon E.
Published: February 2014

With the decrease of CMOS device dimensions, the linewidth roughness (LWR) of transistor gates is being recognized as a major concern. In integrated circuit manufacturing, an HBr plasma treatment has been used so far to reduce the LWR of photoresist (PR) lines printed by 193 nm lithography before transfer into the gate stack by plasma etching. In this article, a more efficient treatment based on HBr/O2 plasma exposure followed by a bake is developed, and the plasma conditions are optimized. We show that by controlling the dose of vacuum ultra violet (VUV) light emitted by the HBr/O2 plasma, the PR bulk can be either softened (photolysis) or strengthened (crosslinking). Moreover, the PR surface properties can be controlled by the O2 content of the plasma. The surface and bulk properties of the PR line after plasma treatment determine the LWR behavior during the subsequent thermal cure treatment. A soft resist bulk combined with a thin surface carbon layer is the ideal case to get the best LWR smoothing effect during the subsequent bake without reflowing. By optimizing both the plasma oxygen content and the VUV dose, we obtained a 59% LWR decrease (from 7.3 nm to 3.0 nm) using an HBr/O2 plasma treatment followed by a bake. The detailed study on the impact of the VUV dose during the plasma treatment permitted to determine the sidewall smoothing mechanisms involved. During both the plasma and the thermal treatments, the outgassing of the products of photolysis or deprotection reactions followed by the re-densification of the polymer material is shown to be the main sidewall smoothing enabler.
Sub-10 nm nano-gap device for single-cluster transport measurements
Authors: Rousseau J. , Morel R. , Vila L. , Brenac A. , Marty A. , Notin L. , Beigné C.
Published: February 2014

We present a versatile procedure for the fabrication of single electron transistor (SET) devices with nanometer-sized clusters and embedded back gate electrode. The process uses sputtering gas-aggregation for the growth of clusters and e-beam lithography with double angle shadow-edge deposition to obtain electrodes separated by nano-gaps with width below 10 nm. The nano-gap width is easily controlled only by geometrical factors such as deposited thin film thickness and evaporation angles. The usefulness of this technique is demonstrated by measuring the SET behavior of a device with a 4 nm cobalt cluster embedded in alumina, where the Coulomb blockade and incremental cluster charging can be readily identified without resorting to the differential conductivity.
Al2O3 multi-density layer structure as a moisture permeation barrier deposited by radio frequency remote plasma atomic layer deposition
Authors: Jung Hyunsoo , Jeon Heeyoung , Choi Hagyoung , Ham Giyul , Shin Seokyoon , Jeon Hyeongtag
Published: February 2014

Al2O3 films deposited by remote plasma atomic layer deposition have been used for thin film encapsulation of organic light emitting diode. In this study, a multi-density layer structure consisting of two Al2O3 layers with different densities are deposited with different deposition conditions of O2 plasma reactant time. This structure improves moisture permeation barrier characteristics, as confirmed by a water vapor transmission rate (WVTR) test. The lowest WVTR of the multi-density layer structure was 4.7 × 10−5 gm−2 day−1, which is one order of magnitude less than WVTR for the reference single-density Al2O3 layer. This improvement is attributed to the location mismatch of paths for atmospheric gases, such as O2 and H2O, in the film due to different densities in the layers. This mechanism is analyzed by high resolution transmission electron microscopy, elastic recoil detection, and angle resolved X-ray photoelectron spectroscopy. These results confirmed that the multi-density layer structure exhibits very good characteristics as an encapsulation layer via location mismatch of paths for H2O and O2 between the two layers.
The effects of crystallographic orientation and strain of thin Hf0.5Zr0.5O2 film on its ferroelectricity
Authors: Hyuk Park Min , Joon Kim Han , Jin Kim Yu , Moon Taehwan , Seong Hwang Cheol
Published: February 2014

To elucidate the origin of the formation of the ferroelectric phase in Hf0.5Zr0.5O2 films, the effects of film strain and crystallographic orientation on the properties were examined. Using a (111)-textured Pt bottom electrode, Hf0.5Zr0.5O2 films with a (111)-preferred texture inappropriate for transforming their phase from non-ferroelectric tetragonal to ferroelectric orthorhombic phase were deposited. In contrast, randomly oriented Hf0.5Zr0.5O2 films, grown on the TiN electrode, showed feasible ferroelectric properties due to their transformation to the ferroelectric orthorhombic phase. The origin of such transformation is the large in-plane tensile strain for the elongation of the c-axis of the tetragonal phase.
Sensitivity to three Parastagonospora nodorum necrotrophic effectors in current Australian wheat cultivars and the presence of further fungal effectors
Authors: Tan Kar-Chun , Waters Ormonde D. C. , Rybak Kasia , Antoni Eva , Furuki Eiko , Oliver Richard P.
Published: February 2014

Parastagonospora nodorum is a major fungal pathogen of wheat in Australia, causing septoria nodorum blotch (SNB). Virulence of P. nodorum is quantitative and depends largely on multiple effector–host sensitivity gene interactions. The pathogen utilises a series of proteinaceous, necrotrophic effectors to facilitate disease development on wheat cultivars that possess appropriate dominant sensitivity loci. Thus far, three necrotrophic effector genes have been cloned. Proteins derived from these genes were used to identify wheat cultivars that confer effector sensitivity. The goal of this study was to determine whether effector sensitivity could be used to enhance breeding for SNB resistance. We have demonstrated that SnTox1 effector sensitivity is common in current commercial Western Australian wheat cultivars. Thirty-three of 46 cultivars showed evidence of sensitivity to SnTox1. Of these, 19 showed moderate or strong chlorotic/necrotic responses to SnTox1. Thirteen were completely insensitive to SnTox1. Disease susceptibility was most closely associated with SnTox3 sensitivity. We have also identified biochemical evidence of a novel chlorosis-inducing protein or proteins in P. nodorum culture filtrates unmasked in strains that lack expression of ToxA, SnTox1 and SnTox3 activities.
Identification of a conserved branched RNA structure that functions as a factor-independent terminator
Authors: Johnson Christopher M. , Chen Yuqing , Lee Heejin , Ke Ailong , Weaver Keith E. , Dunny Gary M.
Published: February 2014

Significance

All cells regulate which regions of DNA are transcribed to RNA. Controlling where transcription terminates is an essential part of this regulation. In bacterial cells, RNA structures, referred to as factor-independent terminators, can interact with RNA polymerase to direct termination. These structures are typically inverted sequence repeats that form an RNA hairpin followed by several uridine residues. We identified a branched RNA structure that functions as a factor-independent terminator. The terminated product is a functional small RNA, but termination is inefficient, allowing transcription of downstream genes. Additional branched terminators are encoded in bacterial chromosomes, demonstrating that this unusual terminator is not unique. This work reveals an unappreciated structural diversity of factor-independent terminators and will inform annotation of bacterial genomes.
Membrane protein insertion and proton-motive-force-dependent secretion through the bacterial holo-translocon SecYEG–SecDF–YajC–YidC
Authors: Schulze Ryan J. , Komar Joanna , Botte Mathieu , Allen William J. , Whitehouse Sarah , Gold Vicki A. M. , Lycklama a Nijeholt Jelger A. , Huard Karine , Berger Imre , Schaffitzel Christiane , Collinson Ian
Published: February 2014

Significance

In this paper, we describe the biophysical properties, stoichiometry, and activity of the
Escherichia coli
SecYEG–SecDF–YajC–YidC holo-translocon. This multiprotein complex consists of seven membrane protein subunits, including those components responsible for both protein secretion (SecYEG) and membrane protein insertion (YidC). We demonstrate the isolation of a stable complex containing YidC together with the core SecY translocon. The availability of this intact assembly allows us to reconstitute posttranslational protein export and cotranslational membrane protein insertion from purified components of known stoichiometry. The experiments demonstrate that protein secretion and insertion occur through a single complex. The reconstitution of membrane protein insertion from defined components is a novel development, breaking ground for the functional analysis of this largely unknown process.
Osteopontin expression by CD103−dendritic cells drives intestinal inflammation
Authors: Kourepini Evangelia , Aggelakopoulou Maria , Alissafi Themis , Paschalidis Nikolaos , Simoes Davina C. M. , Panoutsakopoulou Vily
Published: February 2014

Significance

Dendritic cells (DCs) are important for the development of intestinal inflammation in humans with inflammatory bowel disease (IBD) and in mice with experimental colitis. We demonstrate that a subset of DCs, CD103−DCs, isolated from murine mesenteric lymph nodes, is highly pathogenic for murine intestinal inflammation and expresses high levels of the cytokine osteopontin (Opn). This Opn expression by CD103−DCs is crucial for their pathogenicity. We define a specific domain of Opn protein significant for inducing pathogenic properties in CD103−DCs. Blockade of the interaction of this Opn domain with integrin α9 expressed on CD103−DCs abrogated their harmful effects. These findings may open new paths in IBD treatment.
Linking toxicity and adaptive responses across the transcriptome, proteome, and phenotype of
Chlamydomonas reinhardtii
exposed to silver
Authors: Pillai Smitha , Behra Renata , Nestler Holger , Suter Marc J.-F. , Sigg Laura , Schirmer Kristin
Published: February 2014

Significance

Comprehending the responses of organisms to pollutants by a systems-based approach allows characterization of molecular events and the cellular pathways that have been perturbed. However, mapping only adverse outcomes of a toxicant in an organism falls short of describing the defense response that is mounted to maintain homeostasis and resistance to the toxic insult. Our study provides the understanding of molecular mechanisms of algae in response to silver, which in turn indicates how the algae might behave in a silver contamination scenario. We have used complementary information obtained from the transcriptome, proteome, and physiology to gain mechanistic insights into the responses of
Chlamydomonas reinhardtii
. We show here the importance of stress and adaptive responses, especially at sublethal concentrations of pollutant.
NF-κB signaling mediates homeostatic maturation of new T cells
Authors: Silva Ana , Cornish Georgina , Ley Steven C. , Seddon Benedict
Published: February 2014

Significance

Interleukin (IL)-7 is critical for the maintenance of the peripheral T-cell compartment of the adaptive immune system. Our study identifies a role for the Nuclear Factor κ-B (NF-κB) signalling pathway in the control of IL-7 receptor expression by T cells. Following thymic selection, new T cells specifically up-regulate IL-7R even as they leave the thymus, and we reveal that this expression is strictly NF-κB dependent. NF-κB signaling was only required transiently, however, and once fully mature, naive T cells did not require NF-κB signaling to maintain IL-7R expression. Therefore, we reveal a developmental role for NF-κB signaling for the normal maturation and function of new T cells.
Ion conduction and conformational flexibility of a bacterial voltage-gated sodium channel
Authors: Boiteux Céline , Vorobyov Igor , Allen Toby W.
Published: February 2014

Significance

Voltage-gated sodium channels are one of the most fundamental electrical components in the nervous system and are key targets for local anesthesia and therapeutics for neurological and cardiac disorders. We have used multimicrosecond simulations to provide molecular-level descriptions of sodium channel function. We describe an almost barrier-less three-ion conduction mechanism involving competing knock-on and “pass-by” processes, intimately linked to signature glutamate ring protonation and structural isomerizations. These simulations have uncovered a high degree of protein flexibility, with conformational fluctuations in the pore domain involving residues central to slow-type inactivation, leading to gate collapse, helix bending, filter disruption, and changes in lipid-facing fenestrations linked to Na
v
drug pathways.
Molecular dynamics reveal BCR-ABL1 polymutants as a unique mechanism of resistance to PAN-BCR-ABL1 kinase inhibitor therapy
Authors: Gibbons Don L. , Pricl Sabrina , Posocco Paola , Laurini Erik , Fermeglia Maurizio , Sun Hanshi , Talpaz Moshe , Donato Nicholas , Quintás-Cardama Alfonso
Published: February 2014

Significance

Mutations within the
BCR-ABL1
kinase domain lead to resistance to tyrosine kinase inhibitor (TKI) therapy in chronic myeloid leukemia. We show a high prevalence of compound BCR-ABL1 mutations (polymutants) in patients failing TKIs. Molecular dynamics analyses of the most frequent polymutants in complex with TKIs unveiled the basis of TKI resistance. Modeling of BCR-ABL1 in complex with ponatinib, a potent pan-BCR-ABL1 TKI, highlighted the presence of complex BCR-ABL1 mutant proteins capable of escaping all available TKI therapy.
Scaffold-mediated lentiviral transduction for functional tissue engineering of cartilage
Authors: Brunger Jonathan M. , Huynh Nguyen P. T. , Guenther Caitlin M. , Perez-Pinera Pablo , Moutos Franklin T. , Sanchez-Adams Johannah , Gersbach Charles A. , Guilak Farshid
Published: February 2014

Significance

Engineered replacements for musculoskeletal tissues generally require extensive ex vivo manipulation of stem cells to achieve controlled differentiation and phenotypic stability. The ability to control cell differentiation using cell-instructive scaffolds that have biomechanical properties approximating those of native tissue would represent a transformative advance in functional tissue engineering. The goal of this study was to develop a bioactive scaffold capable of mediating cell differentiation and formation of an extracellular matrix with the biochemical composition and mechanical features that mimic native tissue properties. By combining innovative gene delivery strategies with advanced biomaterial design, we demonstrate the feasibility of generating constructs capable of restoring biological and mechanical function.
Vesicle capture, not delivery, scales up neuropeptide storage in neuroendocrine terminals
Authors: Bulgari Dinara , Zhou Chaoming , Hewes Randall S. , Deitcher David L. , Levitan Edwin S.
Published: February 2014

Significance

Neuropeptides, which affect mood and behavior, are synthesized in the soma and delivered to nerve terminals for storage and release. Yet, among identified neurons, there is great variation in the abundance of neuropeptides in terminals. Demonstrated transcriptional regulation of neuropeptide synthesis supports the view that presynaptic neuropeptide stores are proportional to synthesis-driven delivery of neuropeptide-containing vesicles to terminals. However, we show that nerve terminals with dramatically different neuropeptide stores are supported by identical vesicle delivery and differ instead in efficiency of vesicle capture. Vesicle capture in the terminal is under transcriptional control and influences vesicle distribution and replacement as well as neuropeptide accumulation for release. Thus, vesicle capture is a major determinant of nerve terminal function.
MS-based cross-linking analysis reveals the location of the PsbQ protein in cyanobacterial photosystem II
Authors: Liu Haijun , Zhang Hao , Weisz Daniel A. , Vidavsky Ilan , Gross Michael L. , Pakrasi Himadri B.
Published: February 2014

Significance

Cyanobacteria, photosynthetic prokaryotes, were primarily responsible to create an oxygen-rich atmosphere on our planet. Photosystem II (PSII), a large membrane-bound pigment protein complex in cyanobacteria, uses light energy to oxidize water to dioxygen. X-ray crystal structures of cyanobacterial PSII have recently been determined. PsbQ, a protein that optimizes PSII-mediated oxygen evolution activity, is ubiquitously present in cyanobacteria. However, PsbQ is absent in the determined structures of PSII. By using protein cross-linking, mutagenesis, and advanced MS techniques, we showed that PsbQ in the model cyanobacterium
Synechocystis
6803 binds to CP47 and PsbO, two known protein components of PSII. These results helped determine the location of PsbQ on the lumenal side, near the water oxidation site, of cyanobacterial PSII.
How force unfolding differs from chemical denaturation
Authors: Stirnemann Guillaume , Kang Seung-gu , Zhou Ruhong , Berne Bruce J.
Published: February 2014

Significance

Proteins can be unfolded either chemically by denaturing agents (such as urea) or by mechanical force (such as optical tweezers). If these two methods produce quite different unfolded structures, the course of the subsequent protein refolding when these agents are removed will be quite different. Our computer simulations show that the respective unfolded states are indeed very different, being fully extended under force, with no contacts, and partially extended in urea with many nonnative contacts. Understanding these differences is crucial because such configurations serve as starting points for different single-molecule experimental studies of protein folding. These differences can affect both the folding mechanism and the kinetics observed, leading to very different interpretations.