bluuebunny/crossref_metadata_2025 huggingface dataset:
A sensitive microfluidic platform for a high throughput DNA methylation assay
Authors: Ronen Maria , Avrahami Dorit , Gerber Doron
Published: April 2014

A microfluidic-based fluorometric methylation assay for functional regulation of methyltransferase activity compatible with high-throughput screening of chemical and biological libraries.
Small-molecule axon-polarization studies enabled by a shear-free microfluidic gradient generator
Authors: Xu Hui , Ferreira Meghaan M. , Heilshorn Sarah C.
Published: April 2014

Axon polarization and guidance of primary cortical neurons was quantified during multi-day exposure to forskolin using a PDMS/PEG-DA gradient generator.
3D printed microfluidic devices with integrated versatile and reusable electrodes
Authors: Erkal Jayda L. , Selimovic Asmira , Gross Bethany C. , Lockwood Sarah Y. , Walton Eric L. , McNamara Stephen , Martin R. Scott , Spence Dana M.
Published: April 2014

We present two 3D printed fluidic devices capable of 1) flow-based electrochemical determination of dopamine and nitric oxide and 2) electrochemical measurement of oxygen while simultaneously collecting secreted molecules from red blood cells exposed to varying oxygen tensions.
Jak2 inhibitor – a jackpot for pharmaceutical industries: a comprehensive computational method in the discovery of new potent Jak2 inhibitors
Authors: Singh Kh. Dhanachandra , Naveena Queen , Karthikeyan Muthusamy
Published: April 2014

A potent Jak2 inhibitor could solve numerous diseases and so identifying a potent Jak2 inhibitor could be a jackpot for the pharmaceutical industry. Extensive computational analysis was carried out to identify potent Jak2 inhibitors.
On the synthesis of α-amino sulfoxides
Authors: Rayner Peter J. , Gelardi Giacomo , O'Brien Peter , Horan Richard A. J. , Blakemore David C.
Published: April 2014

Six novel α-amino sulfoxides were successfully prepared and isolated and a spectrum of stability for α-amino sulfoxides is presented.
Macromolecular covalently cross-linked quaternary ammonium poly(ether ether ketone) with polybenzimidazole for anhydrous high temperature proton exchange membranes
Authors: Zhang Na , Zhao Chengji , Ma Wenjia , Wang Shuang , Wang Baolong , Zhang Gang , Li Xuefeng , Na Hui
Published: April 2014

The phosphoric acid doped quaternary ammonium poly(ether ether ketone) membranes cross-linked with PBI showed improved performance.
Antifolate-modified iron oxide nanoparticles for targeted cancer therapy: inclusion vs. covalent union
Authors: López K. A. , Piña M. N. , Alemany R. , Vögler O. , Barceló F. , Morey J.
Published: April 2014

In this work four different iron oxide nanoparticles for the delivery of antitumoral drugs into cancer cells were synthesized and characterized.
One-pot aqueous phase synthesis of peptide–CdTe quantum dots
Authors: Zhang Cuiling , Zu Yuanyuan , Ji Xinghu , He Zhike
Published: April 2014

We report the design and synthesis of short peptide (hexapeptide)-capped CdTe quantum dots (peptide–QDs) by a one-pot method with excellent stability in acidic and high salt solutions.
Microwave-synthesized poly(ionic liquid) particles: a new material with high electrorheological activity
Authors: Dong Yuezhen , Yin Jianbo , Zhao Xiaopeng
Published: April 2014

Poly(ionic liquid) particles, which are synthesized by microwave-assisted dispersion polymerization, show high electrorheological activity due to large dielectric polarization of the high-density of cation/anion parts.
BaTiO3 photoelectrodes for CdS quantum dot sensitized solar cells
Authors: Meng Ke , Surolia Praveen K. , Thampi K. Ravindranathan
Published: April 2014

For the first time, perovskite BaTiO3 nanoparticles were applied as photoelectrode materials for quantum dot sensitization in solar cells, yielding a promising power conversion efficiency of 1.51%.
PKC–NF-κB are involved in CCL2-induced Nav1.8 expression and channel function in dorsal root ganglion neurons
Authors: Zhao Rui , Pei Guo-Xian , Cong Rui , Zhang Hang , Zang Cheng-Wu , Tian Tong
Published: April 2014

CCL2 [chemokine (C–C motif) ligand 2] contributes to the inflammation-induced neuropathic pain through activating VGSC (voltage-gated sodium channel)-mediated nerve impulse conduction, but the underlying mechanism is currently unknown. Our study aimed to investigate whether PKC (protein kinase C)–NF-κB (nuclear factor κB) is involved in CCL2-induced regulation of voltage-gated sodium Nav1.8 currents and expression. DRG (dorsal root ganglion) neurons were prepared from adult male Sprague–Dawley rats and incubated with various concentration of CCL2 for 24 h. Whole-cell patch-clamps were performed to record the Nav1.8 currents in response to the induction by CCL2. After being pretreated with 5 and10 nM CCL2 for 16 h, CCR2 [chemokine (C–C motif) receptor 2] and Nav1.8 expression significantly increased and the peak currents of Nav1.8 elevated from the baseline 46.53±4.53 pA/pF to 64.28±3.12 pA/pF following 10 nM CCL2 (P<0.05). Compared with the control, significant change in Nav1.8 current density was observed when the CCR2 inhibitor INCB3344 (10 nM) was applied. Furthermore, inhibition of PKC by AEB071 significantly eliminated CCL2-induced elevated Nav1.8 currents. In vitro PKC kinase assays and autoradiograms suggested that Nav1.8 within DRG neurons was a substrate of PKC and direct phosphorylation of the Nav1.8 channel by PKC regulates its function in these neurons. Moreover, p65 expression was significantly higher in CCL2-induced neurons (P<0.05), and was reversed by treatment with INCB3344 and AEB071. PKC–NF-κB are involved in CCL2-induced elevation of Nav1.8 current density by promoting the phosphorylation of Nav1.8 and its expression.
Effects of folic acid on renal endothelial function in patients with diabetic nephropathy: results from a randomized trial
Authors: Schneider Markus P. , Schneider Andreas , Jumar Agnes , Kistner Iris , Ott Christian , Schmieder Roland E.
Published: April 2014

Endothelial dysfunction has been shown to promote podocyte injury and albuminuria in diabetes, highlighting the importance of the interaction between renal endothelial cells and podocytes. Folic acid (FA) improves nitric oxide synthase (NOS) function and reduces progression of diabetic nephropathy in animal models. We tested whether high-dose FA treatment improves renal endothelial function and albuminuria in human subjects with incipient diabetic nephropathy. Following a double-blind, randomized, cross-over design, 28 patients with Type 2 diabetes and albuminuria were allocated to 4 weeks’ treatment with placebo and high-dose FA (5 mg/day). Renal nitric oxide (NO) production determined as the response of renal plasma flow (RPF) to NOS inhibition with NG-monomethyl-L-arginine (L-NMMA) (4.25 mg/kg intravenously), renal oxidant stress as response of RPF to vitamin C infusion (3 mg/kg) and albuminuria were determined after each treatment phase. Neither the reduction in RPF to L-NMMA nor the increase in RPF to vitamin C infusion differed between treatment phases (ΔRPF to L-NMMA: −74±71 ml/min per m2 during placebo compared with −63±56 ml/min per m2 during FA, P=0.57; ΔRPF to vitamin C: +93±118 ml/min per m2 compared with +94±108 ml/min per m2; P=0.70). In line with the lack of effect on the renal endothelium, albuminuria was not affected by FA treatment (110±179 mg/day during placebo compared with 87±146 mg/day during FA; P=0.12). High-dose FA treatment does not improve renal endothelial function and fails to reduce albuminuria in human subjects with diabetic nephropathy. Novel treatment options for oxidant stress and endothelial dysfunction in patients with diabetes are urgently needed.
Why do drivers change route? effect of graphical route information panels
Authors: Gan Hongcheng
Published: April 2014

Studies that explore drivers’ decision behaviour under the graphical route information panels (GRIPs) via the discrete choice models have rarely been reported. In this paper, drivers’ route choice response to the GRIPs is quantitatively analysed by using the discrete choice models through a case study of a real‐life GRIP in Shanghai, China. A logit model for predicting the route choice probabilities is developed to capture the relationship between the route choice probability, the driver attributes and the GRIP messages, respectively. The modelling results show that the drivers who have a larger annual driving mileage, access the traffic information via the electronic message signs in daily life highly value the GRIPs and drive their car mainly for the commuting purpose are more likely to divert from the original route to the alternate route under the GRIP; a driver's perceived delay of the original route has a positive effect on his diversion decision under the GRIP; there exist differences in the GRIP response behaviour; the drivers are more likely to divert when the GRIP displays ‘red’ to indicate severe congestion on the original route; the female drivers are more sensitive to ‘red’ and more likely to divert.
mBEEF: An accurate semi-local Bayesian error estimation density functional
Authors: Wellendorff Jess , Lundgaard Keld T. , Jacobsen Karsten W. , Bligaard Thomas
Published: April 2014

We present a general-purpose meta-generalized gradient approximation (MGGA) exchange-correlation functional generated within the Bayesian error estimation functional framework [J. Wellendorff, K. T. Lundgaard, A. Møgelhøj, V. Petzold, D. D. Landis, J. K. Nørskov, T. Bligaard, and K. W. Jacobsen, Phys. Rev. B 85, 235149 (2012)]. The functional is designed to give reasonably accurate density functional theory (DFT) predictions of a broad range of properties in materials physics and chemistry, while exhibiting a high degree of transferability. Particularly, it improves upon solid cohesive energies and lattice constants over the BEEF-vdW functional without compromising high performance on adsorption and reaction energies. We thus expect it to be particularly well-suited for studies in surface science and catalysis. An ensemble of functionals for error estimation in DFT is an intrinsic feature of exchange-correlation models designed this way, and we show how the Bayesian ensemble may provide a systematic analysis of the reliability of DFT based simulations.
On the role of long range interactions for the adsorption of sexithiophene on Ag(110) surface
Authors: Matos Jeronimo , Rojas Tomas , Yildirim Handan , Kara Abdelkader
Published: April 2014

The adsorption characteristics of the sexithiophene (6T) molecule on Ag(110) are studied using density functional theory with the inclusion of van der Waals (vdW) interactions. The stable adsorption configurations on 6T on Ag(110) as well as the nature of bonding the Ag substrate are evaluated. We also assess the performance of the vdW-DF method in describing the adsorption, energetics, heights, as well as the interface characteristics with the Ag(110) surface. We find two lowest adsorption energy configurations, at which the 6T molecule aligns with its molecular long axis parallel and perpendicular to the [001] direction, to be energetically close to each other, suggesting that they may coexist. Our findings indicate a significant increase in the 6T adsorption energies upon the inclusion of vdW interactions with the highest increase obtained using the opt-type functionals, in particular with the optB86b-vdW functional. The revPBE-vdW and rPW86-vdW2 functionals lead to less enhancement in adsorption energies that is attributed to the strong repulsive nature of these functionals, in agreement with earlier predictions. Upon adsorption of the 6T molecule, the changes in the atomic and electronic structures of the 6T molecule and Ag surface are found to be negligible; there is no charge transfer, and no interface state is observed. The work function is reduced upon adsorption with the largest change is ∼0.6 eV obtained using the optB88-vdW functional. The results are in good agreement with the available experimental observations of the adsorption configurations and the work function changes. Based on our results, we conclude that the nature of bonding for 6T on Ag(110) can be classified as strong physisorption.
Treating the effect of interface reflections on superdiffusive spin transport in multilayer samples (invited)
Authors: Battiato M. , Maldonado P. , Oppeneer P. M.
Published: April 2014

Femtosecond laser-induced magnetization dynamics has recently been related to superdiffusive spin transport. With the aim to accurately compute spin superdiffusion in the complex geometries of layered heterostructures and free standing layers, we develop here a dedicated numerical scheme. We introduce a discretization technique to solve the superdiffusive equation numerically on a time and space grid. The discretization scheme facilitates an explicit treatment of the total reflection at the vacuum-material surfaces as well as of partial reflections at the interfaces between two different materials. The advantages of the numerical technique are discussed.
Comment on “A study of vertical and in-plane electron mobility due to interface roughness scattering at low temperature in InAs-GaSb superlattices” [J. Appl. Phys. 114, 053712 (2013)]
Authors: Szmulowicz F.
Published: April 2014

The purpose of this comment is to point out that the paper by Safa, Asgari, and Faraone [J. Appl. Phys. 114, 053712 (2013)] (SAF) on electronic transport in superlattices contains a number of errors in physics and execution. By dealing with a finite number of periods and forcing the wave function to be zero at the upper and lower boundaries of the superlattice stack, SAF have turned the system into a quantum well for which the momentum along the growth axis is not a good quantum number, so that the bands in the growth direction are flat and the corresponding carrier velocities and vertical mobilities are zero. A number of other errors allow the authors to get nonzero results and to reach conclusions that qualitatively mirror those of Szmulowicz, Haugan, Elhamri, and Brown [Phys. Rev. B 84, 155307 (2011)].
The Bain library: A Cu-Au buffer template for a continuous variation of lattice parameters in epitaxial films
Authors: Kauffmann-Weiss S. , Hamann S. , Reichel L. , Siegel A. , Alexandrakis V. , Heller R. , Schultz L. , Ludwig A. , Fähler S.
Published: April 2014

Smallest variations of the lattice parameter result in significant changes in material properties. Whereas in bulk, lattice parameters can only be changed by composition or temperature, coherent epitaxial growth of thin films on single crystals allows adjusting the lattice parameters independently. Up to now only discrete values were accessible by using different buffer or substrate materials. We realize a lateral variation of in-plane lattice parameters using combinatorial film deposition of epitaxial Cu-Au on a 4-in. Si wafer. This template gives the possibility to adjust the in-plane lattice parameter over a wide range from 0.365 nm up to 0.382 nm.
14%-efficient flexible CdTe solar cells on ultra-thin glass substrates
Authors: Rance W. L. , Burst J. M. , Meysing D. M. , Wolden C. A. , Reese M. O. , Gessert T. A. , Metzger W. K. , Garner S. , Cimo P. , Barnes T. M.
Published: April 2014

Flexible glass enables high-temperature, roll-to-roll processing of superstrate devices with higher photocurrents than flexible polymer foils because of its higher optical transmission. Using flexible glass in our high-temperature CdTe process, we achieved a certified record conversion efficiency of 14.05% for a flexible CdTe solar cell. Little has been reported on the flexibility of CdTe devices, so we investigated the effects of three different static bending conditions on device performance. We observed a consistent trend of increased short-circuit current and fill factor, whereas the open-circuit voltage consistently dropped. The quantum efficiency under the same static bend condition showed no change in the response. After storage in a flexed state for 24 h, there was very little change in device efficiency relative to its unflexed state. This indicates that flexible glass is a suitable replacement for rigid glass substrates, and that CdTe solar cells can tolerate bending without a decrease in device performance.
Pressure-induced phase coexistence in BaFe1.8Co0.2As2
Authors: Tang Ling-Yun , Tao Qian , Xu Zhu-An , Chen Xiao-Jia
Published: April 2014

We report high-pressure powder synchrotron X-ray diffraction measurements of overdoped BaFe1.8Co0.2As2 under quasi-hydrostatic pressure up to 40.1 GPa. Our results indicate that a tetragonal (T) to collapsed tetragonal (CT) phase transition occurs at 16.8 GPa and the two phase coexist until 30 GPa, which has not been previously observed in iron arsenide compounds. Both the lattice parameters a and c show discontinuous change for the T and CT phases. The decrease of the c lattice parameter is as large as 12.2% owing to the uniaxial pressure effect. The axial ratio c/a of the T phase exhibits similar features to the other 122-type compounds below 16.8 GPa, whereas there is a very small increase with increasing pressure in the two phase coexistence region. Because of the relationship between the axial ratio and superconductivity, the abnormal expansion may be related to the sudden increase of the strength of antiferromagnetic spin fluctuations.
Interface mechanics of adhesiveless microtransfer printing processes
Authors: Kim-Lee H.-J. , Carlson A. , Grierson D. S. , Rogers J. A. , Turner K. T.
Published: April 2014

Microtransfer printing is a versatile process for retrieving, transferring, and placing nanomembranes of various materials on a diverse set of substrates. The process relies on the ability to preferentially propagate a crack along specific interfaces at different stages in the process. Here, we report a mechanics-based model that examines the factors that determine which interface a crack will propagate along in microtransfer printing with a soft elastomer stamp. The model is described and validated through comparison to experimental measurements. The effects of various factors, including interface toughness, stamp geometry, flaw sizes at the interfaces, and nanomembrane thickness, on the effectiveness of transfer printing are investigated using a fracture-mechanics framework and finite element modeling. The modeling results agree with experimental measurements in which the effects of interface toughness and nanomembranes thickness on the transfer printing yield were examined. The models presented can be used to guide the design of transfer printing processes.
The optimization study of textured a-Si:H solar cells
Authors: Lee Chun-Yao , Yeh Chun-Ming , Liu Yung-Tsung , Fan Chia-Ming , Huang Chien-Fu , Wu Yuh-Renn
Published: April 2014

This article studied the a-Si:H solar cell with a randomly rough surface for high-power conversion efficiency. Both experimental result and simulation modeling are presented. A full three dimensional numerical modeling program including finite difference time domain for optics and Poisson and drift-diffusion solver for electronic simulation are used and verified by experimental results. The influences of surface recombination, junction recombination, absorption, influences to Voc, and fill factor are analyzed to find the balanced condition. The simulation results show the optimized absorber thickness is around 150 nm and the major non-radiative loss region is analyzed. The optimized texture condition is also studied in this paper.
Geometric spin manipulation in semiconductor quantum dots
Authors: Prabhakar Sanjay , Melnik Roderick , Inomata Akira
Published: April 2014

We propose a method to flip the spin completely by an adiabatic transport of quantum dots. We show that it is possible to flip the spin by inducing a geometric phase on the spin state of a quantum dot. We estimate the geometric spin flip time (approximately 2 ps) which turned out to be much shorter than the experimentally reported decoherence time (approximately 100 ns) that would provide an alternative means of fliping the spin before reaching decoherence. It is important that both the Rashba coupling and the Dresselhaus coupling are present for inducing a phase necessary for spin flip. If one of them is absent, the induced phase is trivial and irrelevant for spin-flip.
Noble gas excimer scintillation following neutron capture in boron thin films
Authors: McComb Jacob C. , Coplan Michael A. , Al-Sheikhly Mohamad , Thompson Alan K. , Vest Robert E. , Clark Charles W.
Published: April 2014

Far-ultraviolet scintillation signals have been measured in heavy noble gases (argon, krypton, xenon) following boron-neutron capture (10B(n,α)7Li) in 10B thin films. The observed scintillation yields are comparable to the yields from some liquid and solid neutron scintillators. At noble gas pressures of 107 kPa, the number of photons produced per neutron absorbed following irradiation of a 1200 nm thick 10B film was 14 000 for xenon, 11 000 for krypton, and 6000 for argon. The absolute scintillation yields from the experimental configuration were calculated using data from (1) experimental irradiations, (2) thin-film characterizations, (3) photomultiplier tube calibrations, and (4) photon collection modeling. Both the boron films and the photomultiplier tube were characterized at the National Institute of Standards and Technology. Monte Carlo modeling of the reaction cell provided estimates of the photon collection efficiency and the transport behavior of 10B(n,α)7Li reaction products escaping the thin films. Scintillation yields increased with gas pressure due to increased ionization and excitation densities of the gases from the 10B(n,α)7Li reaction products, increased frequency of three-body, excimer-forming collisions, and reduced photon emission volumes (i.e., larger solid angle) at higher pressures. Yields decreased for thicker 10B thin films due to higher average energy loss of the 10B(n,α)7Li reaction products escaping the films. The relative standard uncertainties in the measurements were determined to lie between 14% and 16%. The observed scintillation signal demonstrates that noble gas excimer scintillation is promising for use in practical neutron detectors.
Piezoelectric single crystal and magnetostrictive Metglas composites: Linear and nonlinear magnetoelectric coupling
Authors: Wang Yaojin , Finkel P. , Li Jiefang , Viehland D.
Published: April 2014

Both the linear (αV) and nonlinear (αV,n) magnetoelectric coefficients were systemically studied in laminated composites of Metglas and [001]-orientated piezoelectric single crystals of Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) and Mn-doped PMN-PT. The coefficients were close in value in both cases at quasistatic mode (i.e., 3.8 V/Oe relative to 3.5 V/Oe) and were enhanced by factors of ×18 (Metglas/PMN-PT) and ×32 (Metglas/Mn-doped PMN-PT) at the electromechanical resonance (EMR). The use of Mn-doped PMN-PT crystals results in a higher gain factor due to a larger mechanical quality factor (i.e., 20.9 relative to 40.6). Accordingly, both types of laminates had similar values of αV,n when modulated at 1 kHz, but Mn-doped PMN-PT ones had a higher value when modulated at the EMR.
Hydriding and dehydriding kinetics in magnetocaloric La(Fe,Si)13 compounds
Authors: Wang G. F. , Mu L. J. , Zhang X. F. , Zhao Z. R. , Huang J. H.
Published: April 2014

We report on the kinetics of hydrogen absorption and desorption in magnetocaloric La(Fe,Si)13 materials based on experimental results and model calculations. In the model, the diffusion process is considered to take place dominantly in a hydriding or dehydriding reaction. An important parameter “characteristic absorption/desorption time” is introduced to predict the kinetics of hydriding/dehydriding reaction in a simple way. The application of the model on the La0.9Ce0.1Fe11.44Si1.56 compound gives coincident kinetic results with those determined from experiments. It indicates that the model provides an efficient guidance for measuring and comparing the kinetic property of the magnetocaloric La(Fe,Si)13Hy materials.
A novel information exchange particle swarm optimization for microgrid multi-objective dynamic optimization control
Authors: Yu Lei , Chen Minyou , Yu David C. , Zhang Liang , Yang Fan , Zhai Jinqian
Published: April 2014

Dynamic optimization is likely to play an important role in the reliability, quality, and efficiency of future power system, specifically for microgrid with renewable generation. This paper presents an improved hybrid optimization algorithm, called information exchange particle swarm optimization (IEPSO), to deal with the problem of dynamic optimal control in a microgrid with multiple distributed generations (DGs), such as wind power, small hydro, and energy storage. Based on the actual application of DG in Southwest China, we propose an optimization model for grid-connected microgrid that introduces a contribution rate of energy storage into the model and incorporates practical engineering constraints. The performance of different optimization control strategies for active and reactive power is investigated, and the results indicate that the IEPSO algorithm is efficient for dynamic optimization, and the dynamic contribution rate control strategy for energy storage is more effective than static strategy.
Modulation of physical and photocatalytic properties of (Cr, N) codoped TiO2 nanorods using soft solution processing
Authors: Lu Wen-Chung , Nguyen Hoang-Diem , Wu Chun-Yi , Chang Kao-Shuo , Yoshimura Masahiro
Published: April 2014

Facile polymerized complex reactions together with a hydrothermal reaction were implemented to make single crystalline TiO2 nanorods for the first time. Chromium (Cr) and nitrogen (N2) co-doping was performed to tailor the physical properties. Transmission electron microscopy and x-ray diffraction study illustrated that highly reactive facets of (101), (111), and (001) dominated rutile TiO2 nanorods. A growth model, based on formation of complex species, was proposed to elucidate effectiveness of the soft solution processing in making TiO2 nanorods. X-ray photoelectron spectroscopy analysis and consideration of fundamentals of charge neutrality showed N2 doping could inhibit formation of Cr6+ and oxygen vacancies (VO2+). An investigation of the photocatalytic properties exhibited high efficiency of photodegradation of methylene blue in 15 min under pH = 10, using a nanocomposite of (7% Cr, 0.0021% N) codoped and 3% Cr doped TiO2 nanorods.
Correlation of shape changes of grain surfaces and reversible stress evolution during interruptions of polycrystalline film growth
Authors: Yu Hang Z. , Thompson Carl V.
Published: April 2014

Short interruptions of the growth of polycrystalline films often lead to stress evolution that is reversed when growth is resumed. Correlated in situ stress measurements and ex situ transmission electron microscopy and atomic force microscopy characterizations of grain boundary surface grooves as a function of the interruption time are reported for films deposited at different temperatures and held for different times before quenching to room temperature. These studies suggest that during film deposition surface grooves at grain boundaries are kinetically constrained to be shallow, while during a growth interruption surface diffusion allows grain boundary grooves to deepen and approach their equilibrium depth. The latter relieves a component of the compressive stress associated with trapped atoms in the grain boundaries. When growth is resumed, the non-equilibrium surface morphology is reestablished and the compressive stress increases to its pre-interruption value.
Hybrid stretchable circuits on silicone substrate
Authors: Robinson A. , Aziz A. , Liu Q. , Suo Z. , Lacour S. P.
Published: April 2014

When rigid and stretchable components are integrated onto a single elastic carrier substrate, large strain heterogeneities appear in the vicinity of the deformable-non-deformable interfaces. In this paper, we report on a generic approach to manufacture hybrid stretchable circuits where commercial electronic components can be mounted on a stretchable circuit board. Similar to printed circuit board development, the components are electrically bonded on the elastic substrate and interconnected with stretchable electrical traces. The substrate—a silicone matrix carrying concentric rigid disks—ensures both the circuit elasticity and the mechanical integrity of the most fragile materials.
Super-dense array of Ge quantum dots grown on Si(100) by low-temperature molecular beam epitaxy
Authors: Talochkin A. B. , Shklyaev A. A. , Mashanov V. I.
Published: April 2014

Ge layer grown on Si(100) at the low temperature of ∼100 °C by molecular beam epitaxy is studied using scanning tunneling microscopy and Raman spectroscopy. It is found that crystalline and pseudomorphic to the Si substrate Ge islands are formed at the initial growth stage. The islands acquire the base size of 1.2–2.6 nm and they form arrays with the super-high density of (5–8) × 1012 cm−2 at 1–2 nm Ge coverages. Such a density is at least 10 times higher than that of Ge “hut” clusters grown via the Stranski-Krastanov growth mode. It is shown that areas between the crystalline Ge islands are filled with amorphous Ge, which is suggested to create potential barrier for holes localized within the islands. As a result, crystalline Ge quantum dots appear being isolated from each other.
Thermodynamic analysis and fluids screening for a gasoline engine exhaust heat recovery system
Authors: Li Guanghua , Gao Wenzhi , Bian Qiang
Published: April 2014

This study explores the possibility of increasing the power output and improving the fuel economy of an internal combustion engine by employing a Rankine cycle driven by the engine exhaust. Engine exhaust energy is analyzed based on the brake power output and exhaust temperature of a 2.0DCVVT engine. The quantitative and qualitative analysis of exhaust energy was conducted on the basis of the first and second laws of thermodynamics. The effects on the efficiency of heat recovery of the parameters of various states of the working fluids were also studied. The results of the theoretical studies give a good indication of the overall efficiency of the Rankine cycle. In addition, an appropriate working fluid for the recovery system was also investigated and selected. Among the working fluids investigated, water shows the best work potential when water is heated over 500 °C, the total system efficiency is over 22%, and the system net work (Wnet) is above 13 kW (up to 14.5 kW), all of which can increase the petrol engine output by more than 14.5%.
Self-annihilation of inversion domains by high energy defects in III-Nitrides
Authors: Koukoula T. , Kioseoglou J. , Kehagias Th. , Ajagunna A. O. , Komninou Ph. , Georgakilas A.
Published: April 2014

Low-defect density InN films were grown on Si(111) by molecular beam epitaxy over an ∼1 μm thick GaN/AlN buffer/nucleation layer. Electron microscopy observations revealed the presence of inverse polarity domains propagating across the GaN layer and terminating at the sharp GaN/InN (0001¯) interface, whereas no inversion domains were detected in InN. The systematic annihilation of GaN inversion domains at the GaN/InN interface is explained in terms of indium incorporation on the Ga-terminated inversion domains forming a metal bonded In-Ga bilayer, a structural instability known as the basal inversion domain boundary, during the initial stages of InN growth on GaN.
Influence of the metal-semiconductor contact by energy harvesting from vertically aligned zinc oxide nanowires
Authors: Fattahi Comjani F. , Willer U. , Kontermann S. , Schade W.
Published: April 2014

This work reports the generation of piezoelectric potential in uniaxially strained zinc oxide (ZnO) nanowires with Ohmic-, symmetric diode-, and rectifying Schottky-like silver-ZnO (Ag-ZnO) contacts. By controlling the synthesis process of the ZnO nanowires, one can control the transport properties of metal-ZnO interfaces. The measurements show the influence of the transport properties of the Ag-ZnO contact on the piezoelectric response of ZnO nanowires. Although the rectifying Schottky contact results in more effective energy harvesting, this is no necessity for operation of a ZnO nanogenerator. Uniaxially strained ZnO nanowires with Ohmic-like Ag-ZnO contacts can also generate measurable piezoelectric signals.
Ti2MnZ (Z=Al, Ga, In) compounds: Nearly spin gapless semiconductors
Authors: Jia H. Y. , Dai X. F. , Wang L. Y. , Liu R. , Wang X. T. , Li P. P. , Cui Y. T. , Liu G. D.
Published: April 2014

Ti2MnZ (Z=Al, Ga, In) compounds with CuHg2Ti-type structure are predicted to have the different width of band gap in two spin channels and exhibit a nearly spin gapless semiconductivity. There are different origins of the band gap in spin-up and spin-down channels. The width of the band gap can be adjusted by changing the lattice parameter or doping congeners. These compounds are completely-compensated ferrimagnets with a zero magnetic moment.
Photo-induced tunneling currents in MOS structures with various HfO2/SiO2 stacking dielectrics
Authors: Pang Chin-Sheng , Hwu Jenn-Gwo
Published: April 2014

In this study, the current conduction mechanisms of structures with tandem high-k dielectric in illumination are discussed. Samples of Al/SiO2/Si (S), Al/HfO2/SiO2/Si (H), and Al/3HfO2/SiO2/Si (3H) were examined. The significant observation of electron traps of sample H compares to sample S is found under the double bias capacitance-voltage (C-V) measurements in illumination. Moreover, the photo absorption sensitivity of sample H is higher than S due to the formation of HfO2 dielectric layer, which leads to larger numbers of carriers crowded through the sweep of VG before the domination of tunneling current. Additionally, the HfO2 dielectric layer would block the electrons passing through oxide from valance band, which would result in less electron-hole (e−-h+) pairs recombination effect. Also, it was found that both of the samples S and H show perimeter dependency of positive bias currents due to strong fringing field effect in dark and illumination; while sample 3H shows area dependency of positive bias currents in strong illumination. The non-uniform tunneling current through thin dielectric and through HfO2 stacking layers are importance to MOS(p) tunneling photo diodes.
Trifolium interspecific hybridisation: widening the white clover gene pool
Authors: Williams W. M.
Published: April 2014

White clover (Trifolium repens) is adapted to moist, fertile soils in temperate zones. Despite its heterozygous allotetraploid nature, it lacks useful genetic variation for survival and growth in semi-arid, infertile soils. Although white clover is apparently genetically isolated in nature, 11 other taxa have so far been found that can be artificially hybridised into the wider gene pool. These species range from annuals to long-lived, hardy perennials with adaptations to stress environments, and they potentially provide new traits for the breeding of more resilient varieties of white clover. The delineation of the secondary, tertiary and quaternary gene pools is described, along with a review of interspecific hybrids achieved to date. The results of large breeding programs to integrate traits from T. nigrescens and 4x T. ambiguum are reviewed, and schemes introduced for the use of T. uniflorum, T. occidentale, T. pallescens, 2x T. ambiguum and 6x T. ambiguum. Interspecific hybrid breeding of white clover has the potential to enable the development of resilient perennial clovers for seasonally dry, infertile grassland environments in many parts of the world.
Variability of seed quality traits in a collection of Spanish landraces of confectionery sunflower
Authors: Velasco Leonardo , Fernández-Cuesta Álvaro , Fernández-Martínez José M.
Published: April 2014

Confectionery sunflower (Helianthus annuus L.) has been cultivated in Spain for many years in small vegetable gardens for self-consumption, and this has created a vast genetic diversity of local landraces. The objective of this research was to assess variation in seed quality traits in a germplasm collection of Spanish local landraces of confectionery sunflower. Seed weight, kernel percentage, oil content, fatty acid composition, squalene, tocopherol and phytosterol contents, and tocopherol and phytosterol composition, were analysed in 137 landraces grown for 2 years in Córdoba, Spain. The evaluation was hindered by large differences for flowering time between accessions (>90 days), which made it difficult to separate genetic from environmental effects. The collection contained large variability for all traits evaluated. Of particular relevance were the ranges of variation (2-year averages) for squalene content (12–128 mg kg–1 seed kernel), tocopherol content (114–423 mg kg–1 seed kernel) and Δ7-stigmastenol content (7.1–35.2% of total phytosterols). Some traits were associated with specific locations; for example, all seven accessions collected in Espiel (Córdoba province) had high Δ7-stigmastenol content, although they differed for other traits. Some of the accessions evaluated in this research are valuable genetic sources for breeding programs focusing on seed and oil quality in sunflower.
Molecular characterisation of high molecular weight glutenin allele Glu-B1h encoding 1Bx14+1By15 subunits in bread wheat (Triticum aestivum L.)
Authors: Xiao Lele , Wang Ke , Liu Yanlin , Ye Xingguo , Ma Wujun , Yan Yueming
Published: April 2014

In this study, the authentic high molecular weight glutenin (HMW-GS) allele Glu-B1 h encoding for subunits 1Bx14 and 1By15 from German bread wheat cultivars Hanno and Imbros was identified and cross-verified by a suite of established protein analysis technologies, including sodium dodecyl sulfate-polyacrylamide gel electrophoresis, reversed-phase high-performance liquid chromatography, reversed-phase ultra-performance liquid chromatography, and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS). The complete encoding sequences were isolated by allele-specific PCR, and consist of 2367 bp for 1Bx14 and 2151 bp for 1By15 and encode 789 and 717 amino acid residues, respectively. The deduced molecular masses of two subunit genes were 82 340.13 Da and 74 736.13 Da, corresponding well to those determined by MALDI-TOF-MS. The presence and authenticity of 1Bx14 and 1By15 subunits were further confirmed by liquid chromatography coupled to tandem mass spectrometry and heterologous expression in E. coli. Comparative analysis demonstrated that 1Bx14 possessed one deletion and 20 single-nucleotide polymorphism variations compared with seven other Glu-B1 x-type HMW-GS genes that mainly resulted from C–T substitutions, whereas compared with five other Glu-B1 y-type HMW-GS genes, 1By15 displayed few variations. Phylogenetic analysis based on the complete coding sequences of the published HMW-GS genes showed that 1Bx14 had a high divergence with other 1Bx subunit genes, whereas 1By15 displayed greater similarity with 1By20. A possible evolutionary route for 1Bx14 gene formation is proposed, which might have resulted from an intra-strand illegitimate recombination event that occurred ~1.32 million years ago.
Gender and Text Messaging in an Iranian Context
Authors: Gohardehi Neda , Gheitury Amer
Published: April 2014

Focusing on four linguistic domains, purpose/manner of communication, preferring local dialects, politeness, and volume of use, this study aims to explore how gender is reflected in messages produced by Iranian female and male students. A corpus of 2,116 text messages was analyzed. Participants also filled out a questionnaire on how frequently they used text messaging. Results indicated females to be more prolific users of messaging. As far as function is concerned, while texts produced by females were for the most part relational, involving an emotional language, males frequently employed messages for informative-transactional functions which were less wordy and in more authoritative language. In addition, males were more likely than females to employ their local dialect and forms considered less polite.
Effects of two sulfated triterpene saponins echinoside A and holothurin A on the inhibition of dietary fat absorption and obesity reduction
Authors: Wang Yuming , Wang Jiahui , Yanagita Ryo C , Liu Chunhua , Hu Xiaoqian , Dong Ping , Xue Changhu , Xue Yong
Published: April 2014

Two similarly sulfated triterpene saponins from Pearsonothuria graeffei were prepared to investigate the anti-obesity effects of echinoside A (EA) and holothurin A (HA). The in vitro inhibitory activities of EA and HA toward pancreatic lipase were investigated, and two in vivo studies were performed: (i) Male Wistar rats were orally administered the lipid emulsion with or without a saponin (HA or EA). The serum’s total triglyceride concentration was measured at various times. (ii) C57BL/6 mice were assigned to four groups, high fat (HF), EA (0.03%), HA (0.04%), and orlistat (0.01%), and the weight of adipose tissue and level of fatty acids excreted in the feces were determined. Both EA and HA repressed the pancreatic lipase activity and increased fatty acid excretion in the feces. Treatment with EA and HA significantly decreased the adipose tissue accumulation in mice. EA and HA manifested different inhibitory activities in vitro, but each of them dramatically inhibited lipid absorption in vivo and showed strong anti-obesity activity.
Syntheses of all the stereoisomers of butanol type 1,7-seco-2,7′-cyclolignane
Authors: Yamauchi Satoshi , Tomiyama Chisato , Wukirsari Tuti , Nishiwaki Hisashi
Published: April 2014

All the stereoisomers of butanol type 1,7-seco-2,7′-cyclolignane were stereoselectively synthesized by employing (S)- and (R)-Evans’ auxiliaries to construct the stereochemistry. (+)- and (−)-Kadangustin J and their diastereomers were also prepared. The optical purity of the synthesized butanol type 1,7-seco-2,7′-cyclolignane was more than 99%ee.
Synthesis of biotinylated keratan sulfate repeating disaccharides
Authors: Takeda Naoko , Tamura Jun-ichi
Published: April 2014

We synthesized four types of keratan and keratan sulfate repeating disaccharides containing non-sulfate, Galβ1-4GlcNAcβ, and three types of sulfates, Gal6Sβ1-4GlcNAcβ, Galβ1-4GlcNAc6Sβ, and Gal6Sβ1-4GlcNAc6Sβ in an efficient and stereo-controlled manner. These disaccharides were conjugated with biotin via a hydrophilic linker at the reducing terminal.
The putative stress sensor protein MtlA is required for conidia formation, cell wall stress tolerance, and cell wall integrity in Aspergillus nidulans
Authors: Futagami Taiki , Seto Kazufumi , Kajiwara Yasuhiro , Takashita Hideharu , Omori Toshiro , Takegawa Kaoru , Goto Masatoshi
Published: April 2014

The Mid2-like protein MtlA is a putative sensor of the cell wall integrity (CWI) signaling pathway in Aspergillus nidulans. An MtlA-EGFP fusion protein was localized at the cell surface and septa. The mtlA disruptant (∆mtlA) showed radial colony growth similar to the wild-type (wt) strain, but showed reduced conidia formation. The ∆mtlA mutant showed growth deficiency in the presence of inhibitors of cell wall synthesis. Moreover, mtlA disruption resulted in a reduction in the glucan and chitin content in the cell wall. These results suggest that MtlA plays a significant role in asexual sporulation, cell wall stress tolerance, and the maintenance of CWI in A. nidulans, but transcriptional upregulation of α-1,3-glucan synthase gene agsB induced by micafungin was observed in the ∆mtlA strain as well as the wt strain. Thus, MtlA is not essential for activation of the downstream CWI signaling pathway components identified in previous studies of Saccharomyces cerevisiae.
Lactate production as representative of the fermentation potential of Corynebacterium glutamicum 2262 in a one-step process
Authors: Khuat Hoang Bao Truc , Kaboré Abdoul Karim , Olmos Eric , Fick Michel , Boudrant Joseph , Goergen Jean-Louis , Delaunay Stéphane , Guedon Emmanuel
Published: April 2014

The fermentative properties of thermo-sensitive strain Corynebacterium glutamicum 2262 were investigated in processes coupling aerobic cell growth and the anaerobic fermentation phase. In particular, the influence of two modes of fermentation on the production of lactate, the fermentation product model, was studied. In both processes, lactate was produced in significant amount, 27 g/L in batch culture, and up to 55.8 g/L in fed-batch culture, but the specific production rate in the fed-batch culture was four times lower than that in the batch culture. Compared to other investigated fermentation processes, our strategy resulted in the highest yield of lactic acid from biomass. Lactate production by C. glutamicum 2262 thus revealed the capability of the strain to produce various fermentation products from pyruvate.
Effects of H2 and electrochemical reducing power on metabolite production by Clostridium acetobutylicum KCTC1037
Authors: Jeon Boyoung , Yi Junyeong , Park Doohyun
Published: April 2014

A conventional fermenter (CF), a single-cathode fermenter (SCF), and a double-cathode fermenter (DCF) were employed to evaluate and compare the effects of H2 and electrochemical reducing power on metabolite production by Clostridium acetobutylicum KCTC1037. The source of the external reducing power for CF was H2, for the SCF was electrochemically reduced neutral red-modified graphite felt electrode (NR-GF), and for the DCF was electrochemically reduced combination of NR-GF and platinum plate electrodes (NR-GF/PtP). The metabolites produced from glucose or CO2 by strain KCTC1037 cultivated in the DCF were butyrate, ethanol, and butanol, but ethanol and butanol were not produced from glucose or CO2 by strain KCTC1037 cultivated in the CF and SCF. It is possible that electrochemically reduced NR-GF/PtP is a more effective source of internal and external reducing power than H2 or NR-GF for strain KCTC1037 to produce metabolites from glucose and CO2. This research might prove useful in developing fermentation technology to actualize direct bioalcohol production of fermentation bacteria from CO2.
Determination by UPLC-MS of four dammarane-type saponins from heat-processed Gynostemma pentaphyllum
Authors: Wu Qian , Jang Moonhee , Piao Xiang-Lan
Published: April 2014

Heat-processed Gynostemma pentaphyllum and its main dammaran-type saponins, gypenoside L, gypenoside LI, damulin B, and damulin A, possess non-small cell lung carcinoma A549 cell inhibitory activity. We established in this study a method by ultra-high performance liquid chromatography with tandem mass spectrometry for determination of the saponins and also investigated their content change in heat-processed G. pentaphyllum. The main saponins increased with increasing heating temperature and time. Further investigation showed that they were produced from gypenoside XLVI and gypenoside LVI by undergoing hydrolysis during the heat treatment.
Attenuation by a Vigna nakashimae extract of nonalcoholic fatty liver disease in high-fat diet-fed mice
Authors: Jeon Byeong Tak , Heo Rok Won , Shin Hyun Joo , Yi Chin-ok , Lee Yu Hee , Joung Han-nah , Jung Jung Hwa , Jung Jaehoon , Kim Soo Kyoung , Hahm Jong Ryeal , Lee Byong Won , Ko Jong Min , Baek In Youl , Kang Sang Soo , Roh Gu Seob
Published: April 2014

A Vigna nakashimae (VN) extract has been shown to have antidiabetic and anti-obesity effects. However, the mechanism underlying the effect of a VN extract on hepatic inflammation and endoplasmic reticulum (ER) stress remains unclear. In the present study, we investigated how a VN extract protects against the development of non-alcoholic fatty liver disease (NAFLD). A VN extract for 12 weeks reduced the body weight, serum metabolic parameters, cytokines, and hepatic steatosis in high-fat diet (HFD)-fed mice. A VN extract decreased HFD-induced hepatic acetyl CoA carboxylase and glucose transporter 4 expressions. In addition to the levels of high-mobility group box 1 and receptor for advanced glycation, the hepatic expression of ATF4 and caspase-3 was also reduced by a VN extract. Thus, these data indicate that a chronic VN extract prevented NAFLD through multiple mechanisms, including inflammation, ER stress, and apoptosis in the liver.