bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of heterologous expression of human cyclic nucleotide phosphodiesterase 3A (hPDE3A) on redox regulation in yeast
Authors: Rhee Dong Keun , Lim Jung Chae , Hockman Steven C. , Ahmad Faiyaz , Woo Dong Ho , Chung Youn Wook , Liu Shiwei , Hockman Allison L. , Manganiello Vincent C.
Published: September 2016

Oxidative stress plays a pivotal role in pathogenesis of cardiovascular diseases and diabetes; however, the roles of protein kinase A (PKA) and human phosphodiesterase 3A (hPDE3A) remain unknown. Here, we show that yeast expressing wild-type (WT) hPDE3A or K13R hPDE3A (putative ubiquitinylation site mutant) exhibited resistance or sensitivity to exogenous hydrogen peroxide (H2O2), respectively. H2O2-stimulated ROS production was markedly increased in yeast expressing K13R hPDE3A (Oxidative stress Sensitive 1, OxiS1), compared with yeast expressing WT hPDE3A (Oxidative stress Resistant 1, OxiR1). In OxiR1, YAP1 and YAP1-dependent antioxidant genes were up-regulated, accompanied by a reduction in thioredoxin peroxidase. In OxiS1, expression of YAP1 and YAP1-dependent genes was impaired, and the thioredoxin system malfunctioned. H2O2 increased cyclic adenosine monophosphate (cAMP)-hydrolyzing activity of WT hPDE3A, but not K13R hPDE3A, through PKA-dependent phosphorylation of hPDE3A, which was correlated with its ubiquitinylation. The changes in antioxidant gene expression did not directly correlate with differences in cAMP–PKA signaling. Despite differences in their capacities to hydrolyze cAMP, total cAMP levels among OxiR1, OxiS1, and mock were similar; PKA activity, however, was lower in OxiS1 than in OxiR1 or mock. During exposure to H2O2, however, Sch9p activity, a target of Rapamycin complex 1-regulated Rps6 kinase and negative-regulator of PKA, was rapidly reduced in OxiR1, and Tpk1p, a PKA catalytic subunit, was diffusely spread throughout the cytosol, with PKA activation. In OxiS1, Sch9p activity was unchanged during exposure to H2O2, consistent with reduced activation of PKA. These results suggest that, during oxidative stress, TOR-Sch9 signaling might regulate PKA activity, and that post-translational modifications of hPDE3A are critical in its regulation of cellular recovery from oxidative stress.
Identification of keratan sulfate disaccharide at C-3 position of glucuronate of chondroitin sulfate from Mactra chinensis
Authors: Higashi Kyohei , Takeda Keita , Mukuno Ann , Okamoto Yusuke , Masuko Sayaka , Linhardt Robert J. , Toida Toshihiko
Published: September 2016

Glycosaminoglycans (GAGs), including chondroitin sulfate (CS), dermatan sulfate, heparin, heparan sulfate and keratan sulfate (KS) are linear sulfated repeating disaccharide sequences containing hexosamine and uronic acid [or galactose (Gal) in the case of KS]. Among the GAGs, CS shows structural variations, such as sulfation patterns and fucosylation, which are responsible for their physiological functions through CS interaction with CS-binding proteins. Here, we solved the structure of KS-branched CS-E derived from a clam, Mactra chinensis. KS disaccharide [d-GlcNAc6S-(1→3)-β-d-Gal-(1→] was attached to the C-3 position of GlcA, and consecutive KS-branched disaccharide sequences were found in a CS chain. KS-branched polysaccharides clearly exhibited resistance to degradation by chondroitinase ABC or ACII (at low concentrations) compared with typical CS structures. Furthermore, KS-branched polysaccharides stimulated neurite outgrowth of hippocampal neurons. These results strongly suggest that M. chinensis is a rich source of KS-branched CS, and it has important biological activities.
Image quality assessment based on complementary local feature extraction and quantification
Authors: Zhao Yang , Ding Yong , Zhao XinYu
Published: September 2016

A novel full reference image quality assessment method based on statistical local representation from two complementary sources: log‐Gabor wavelet representation and local derivative pattern is presented. The dissimilarity of these extracted features between distorted and reference images is quantified and mapped into an objective quality score. Experimental results on large‐scale database show that the proposed method not only outperforms the state‐of‐the‐art methods in terms of high accuracy of image quality prediction, but also is robust across different distortion types with high computation efficient.
Efficiency optimising strategy for dual‐coupled transmitters based WPT systems
Authors: Li Yong , Mai Ruikun , Liu Yeran , He Zhengyou
Published: September 2016

The wireless power transfer (WPT) system based on dual‐coupled transmitters has been proved to be a good alternative for high‐power applications. However, the efficiency of the WPT system is various with different loads. An active rectifier (H‐bridge) is equipped in the secondary side to replace the passive rectifier (diode rectifier). By controlling the conduction angle and the output voltage of the active rectifier, the equivalent optimal load of the secondary side can be achieved. Owing to the equivalent optimal load, the WPT system with dual‐coupled transmitters can achieve optimising power efficiency. The experimental results agree well with the theoretical analysis. The results show the proposed efficiency optimising strategy is a good candidate for a WPT system with dual‐coupled transmitters.
Progress in and prospects for electrical insulating materials
Authors: Li Shengtao , Yu Shihu , Feng Yang
Published: September 2016

The performance of electrical equipment and devices is determined to a great extent by the properties of their insulating materials. In power systems and electrical devices, insulating materials have to work in extreme circumstances that can include high temperature differences, intense radiation, and strong electric fields. Such conditions demand high‐quality insulating materials with superior electrical, thermal, and mechanical properties as well as resilience to other environmental stresses. This study focuses on advances in insulating materials since the early 20th century and reviews the many developments in their properties and applications, including electric breakdown strength, thermal conductivity, temperature resistance, corona resistance, and specific energy storage in dielectrics. Some research progress on other properties is also covered, such as non‐linearity and radiation resistance. Investigations into the properties of insulating materials can greatly assist in understanding their interface effects and composite structures, which in turn is helpful for discovering methods to improve the performance of electrical devices. Future directions for research are proposed to guide new investigations and support the development of even better insulating materials.
Measurement and simulation of the response function of time of flight enhanced diagnostics neutron spectrometer for beam ion studies at EAST tokamak
Authors: Peng X. Y. , Chen Z. J. , Zhang X. , Du T. F. , Hu Z. M. , Ge L. J. , Zhang Y. M. , Sun J. Q. , Gorini G. , Nocente M. , Tardocchi M. , Hu L. Q. , Zhong G. Q. , Pu N. , Lin S. Y. , Wan B. N. , Li X. Q. , Zhang G. H. , Chen J. X. , Fan T. S.
Published: September 2016

The 2.5 MeV TOFED (Time-Of-Flight Enhanced Diagnostics) neutron spectrometer with a double-ring structure has been installed at Experimental Advanced Superconducting Tokamak (EAST) to perform advanced neutron emission spectroscopy diagnosis of deuterium plasmas. This work describes the response function of the TOFED spectrometer, which is evaluated for the fully assembled instrument in its final layout. Results from Monte Carlo simulations and dedicated experiments with pulsed light sources are presented and used to determine properties of light transport from the scintillator. A GEANT4 model of the TOFED spectrometer was developed to calculate the instrument response matrix. The simulated TOFED response function was successfully benchmarked against measurements of the time-of-flight spectra for quasi-monoenergetic neutrons in the energy range of 1-4 MeV. The results are discussed in relation to the capability of TOFED to perform beam ion studies on EAST.
Research Update: Hybrid organic-inorganic perovskite (HOIP) thin films and solar cells by vapor phase reaction
Authors: Shen Po-Shen , Chiang Yu-Hsien , Li Ming-Hsien , Guo Tzung-Fang , Chen Peter
Published: September 2016

With the rapid progress in deposition techniques for hybrid organic-inorganic perovskite (HOIP) thin films, this new class of photovoltaic (PV) technology has achieved material quality and power conversion efficiency comparable to those established technologies. Among the various techniques for HOIP thin films preparation, vapor based deposition technique is considered as a promising alternative process to substitute solution spin-coating method for large-area or scale-up preparation. This technique provides some unique benefits for high-quality perovskite crystallization, which are discussed in this research update.
Excited state dynamics of acrylonitrile: Substituent effects at conical intersections interrogated via time-resolved photoelectron spectroscopy and ab initio simulation
Authors: MacDonell Ryan J. , Schalk Oliver , Geng Ting , Thomas Richard D. , Feifel Raimund , Hansson Tony , Schuurman Michael S.
Published: September 2016

We report a joint experimental and theoretical study on the photoinitiated ultrafast dynamics of acrylonitrile (AN) and two methylated analogs: crotonitrile (CrN) and methacrylonitrile (MeAN). Time-resolved photoelectron spectroscopy (TRPES) and ab initio simulation are employed to discern the conical intersection mediated vibronic dynamics leading to relaxation to the ground electronic state. Each molecule is pumped with a femtosecond pulse at 200 nm and the ensuing wavepackets are probed by means of one and two photon ionization at 267 nm. The predominant vibrational motions involved in the de-excitation process, determined by ab initio trajectory simulations, are an initial twisting about the C=C axis followed by pyramidalization at a carbon atom. The decay of the time-resolved photoelectron signal for each molecule is characterized by exponential decay lifetimes for the passage back to the ground state of 60 ± 10, 86 ± 11, and 97 ± 9 fs for AN, CrN, and MeAN, respectively. As these results show, the excited state dynamics are sensitive to the choice of methylation site and the explanation for the observed trend may be found in the trajectory simulations. Specifically, since the pyramidalization motion leading to the conical intersection with the ground state is accompanied by the development of a partial negative charge at the central atom of the pyramidal group, the electron donation of the cyano group ensures that this occurs exclusively at the medial carbon atom. In this way, the donated electron density from the cyano group “directs” the wavepacket to a particular region of the intersection seam. The excellent agreement between the experimental and simulated TRPES spectra, the latter determined by employing trajectory simulations, demonstrates that this mechanistic picture is consistent with the spectroscopic results.
Multistability and complex basins in a nonlinear duopoly with price competition and relative profit delegation
Authors: Fanti Luciano , Gori Luca , Mammana Cristiana , Michetti Elisabetta
Published: September 2016

In this article, we investigate the local and global dynamics of a nonlinear duopoly model with price-setting firms and managerial delegation contracts (relative profits). Our study aims at clarifying the effects of the interaction between the degree of product differentiation and the weight of manager's bonus on long-term outcomes in two different states: managers behave more aggressively with the rival (competition) under product complementarity and less aggressively with the rival (cooperation) under product substitutability. We combine analytical tools and numerical techniques to reach interesting results such as synchronisation and on-off intermittency of the state variables (in the case of homogeneous attitude of managers) and the existence of chaotic attractors, complex basins of attraction, and multistability (in the case of heterogeneous attitudes of managers). We also give policy insights.
Microwave spectra of the SiH4-H2O complex: A new sort of intermolecular interaction
Authors: Kawashima Yoshiyuki , Suenram Richard D. , Hirota Eizi
Published: September 2016

Microwave spectral patterns observed for the silane-water complex were found much different from those of the methane-water complex. The SiH4-H2O complex is likely to have a tightly bound structure. The effective rotational and centrifugal distortion constants: B = 3621.1193 (45) MHz and DJ = 49.84 (30) kHz led to the distance between the Si and O atoms in the complex to be 3.3 Å, much shorter than the C and O separation in the CH4-H2O of 3.7 Å, and to the silane-water stretching force constant and stretching frequency to be 2.88 N/m and 65 cm−1, respectively, which are to be compared with 1.52 N/m and 55 cm−1 of the CH4-H2O. The characteristic features of the spectra observed for the main species 28SiH4-H2O are common to those of isotopic species: 29SiH4-H2O, 30SiH4-H2O, 28SiH4-H218O, 28SiH4-D2O, 29SiH4-D2O, 30SiH4-D2O, 28SiH4-HDO, 29SiH4-HDO, 30SiH4-HDO, 28SiD4-H2O, 28SiD4-D2O, and 28SiD4-HDO. The observed spectra also indicate that the silane executes a threefold internal rotation about one of its four Si–H bonds, while the C2 symmetry axis of the water is bent away from the internal-rotation axis. An internal axis method analysis yielded an estimate of the internal-rotation potential barrier V3 to be 140 ± 50 cm−1, and those based on diagonalization of a principal axis method Hamiltonian matrix and on the extended internal axis method resulted in V3 ranging from 180 to 100 cm−1, depending on the isotopic species studied. All the measurements were done by using a pulsed nozzle Fourier transform microwave spectrometer, and the spectral assignments were made with the aid of the Stark effect, which yielded the dipole moment to be 1.730 (10) D. Transitions in higher energy states of the SiH4 internal rotation were observed, clearly resolved from the main lines, when the carrier gas was replaced from Ar to Ne.
Nonequilibrium laser plasma of noble gases: Prospects for amplification and guiding of the microwave radiation
Authors: Bogatskaya A. V. , Bin Hou , Popov A. M. , Smetanin I. V.
Published: September 2016

We developed the analytical model of relaxation of a low-density plasma channel produced in noble gases (Xe, Ar) by a femtosecond KrF laser pulse and investigated the temporal evolution of its dielectric permittivity. It was demonstrated that the strong nonequilibrium of the photoelectron energy spectrum and the presence of Ramsauer minimum in transport scattering cross section make such a plasma channel an optically denser medium in comparison with non-ionized gas in the microwave frequency band and consequently such a channel appears to be a waveguide. In xenon this nonequilibrium state of a plasma leads to both transportation and amplification of the microwave signal during the relaxation of the photoelectron energy spectrum. It was also shown that a circular metal waveguide partially filled with such a nonequilibrium Xe plasma provides efficient amplification of the sub-THz microwave signal.
Laser-driven micro-Coulomb charge movement and energy conversion to relativistic electrons
Authors: Cobble J. A. , Palaniyappan S. , Johnson R. P. , Shimada T. , Huang C. , Gautier D. C. , Clark D. D. , Falk K. , Jung D.
Published: September 2016

Development of robust instrumentation has shown evidence for a multi-μC expulsion of relativistic electrons from a sub-μm-thick foil, laser illuminated with 60–70 J on target at 2 × 1020 W/cm2. From previous work and with electron spectroscopy, it is seen that an exponential electron energy distribution is accurate enough to calculate the emitted electron charge and energy content. The 5–10-μC charge for the >100-TW Trident Laser represents the first active measurement of the >50% laser-light-to-electron conversion efficiency. By shorting out the TV/m electric field usually associated with accelerating multi-MeV ions from such targets, one finds that this charge is representative of a multi-MA current of relativistic electrons for diverse applications from electron fast ignition to advanced radiography concepts. Included with the details of the discoveries of this research, shortcomings of the diagnostics and means of improving their fidelity are discussed.
Bernstein wave aided laser third harmonic generation in a plasma
Authors: Tyagi Yachna , Tripathi Deepak , Kumar Ashok
Published: September 2016

The process of Bernstein wave aided resonant third harmonic generation of laser in a magnetized plasma is investigated. The extra-ordinary mode (X-mode) laser of frequency ω0 and wave number k→0, travelling across the magnetic field in a plasma, exerts a second harmonic ponderomotive force on the electrons imparting them an oscillatory velocity v→2ω0,2k→0. This velocity beats with the density perturbation due to the Bernstein wave to produce a density perturbation at cyclotron frequency shifted second harmonic. The density perturbation couples with the oscillatory velocity v→ω0,k→0 of X-mode of the laser to produce the cyclotron frequency shifted third harmonic current density leading to harmonic radiation. The phase matching condition for the up shifted frequency is satisfied when the Bernstein wave is nearly counter-propagating to the laser. As the transverse wave number of the Bernstein wave is large, it is effective in the phase matched third harmonic generation, when the laser frequency is not too far from the upper hybrid frequency.
High order volume-preserving algorithms for relativistic charged particles in general electromagnetic fields
Authors: He Yang , Sun Yajuan , Zhang Ruili , Wang Yulei , Liu Jian , Qin Hong
Published: September 2016

We construct high order symmetric volume-preserving methods for the relativistic dynamics of a charged particle by the splitting technique with processing. By expanding the phase space to include the time t, we give a more general construction of volume-preserving methods that can be applied to systems with time-dependent electromagnetic fields. The newly derived methods provide numerical solutions with good accuracy and conservative properties over long time of simulation. Furthermore, because of the use of an accuracy-enhancing processing technique, the explicit methods obtain high-order accuracy and are more efficient than the methods derived from standard compositions. The results are verified by the numerical experiments. Linear stability analysis of the methods shows that the high order processed method allows larger time step size in numerical integrations.
Plasmakristall-4: New complex (dusty) plasma laboratory on board the International Space Station
Authors: Pustylnik M. Y. , Fink M. A. , Nosenko V. , Antonova T. , Hagl T. , Thomas H. M. , Zobnin A. V. , Lipaev A. M. , Usachev A. D. , Molotkov V. I. , Petrov O. F. , Fortov V. E. , Rau C. , Deysenroth C. , Albrecht S. , Kretschmer M. , Thoma M. H. , Morfill G. E. , Seurig R. , Stettner A. , Alyamovskaya V. A. , Orr A. , Kufner E. , Lavrenko E. G. , Padalka G. I. , Serova E. O. , Samokutyayev A. M. , Christoforetti S.
Published: September 2016

New complex-plasma facility, Plasmakristall-4 (PK-4), has been recently commissioned on board the International Space Station. In complex plasmas, the subsystem of μm-sized microparticles immersed in low-pressure weakly ionized gas-discharge plasmas becomes strongly coupled due to the high (103–104 e) electric charge on the microparticle surface. The microparticle subsystem of complex plasmas is available for the observation at the kinetic level, which makes complex plasmas appropriate for particle-resolved modeling of classical condensed matter phenomena. The main purpose of PK-4 is the investigation of flowing complex plasmas. To generate plasma, PK-4 makes use of a classical dc discharge in a glass tube, whose polarity can be switched with the frequency of the order of 100 Hz. This frequency is high enough not to be felt by the relatively heavy microparticles. The duty cycle of the polarity switching can be also varied allowing to vary the drift velocity of the microparticles and (when necessary) to trap them. The facility is equipped with two videocameras and illumination laser for the microparticle imaging, kaleidoscopic plasma glow observation system and minispectrometer for plasma diagnostics and various microparticle manipulation devices (e.g., powerful manipulation laser). Scientific experiments are programmed in the form of scripts written with the help of specially developed C scripting language libraries. PK-4 is mainly operated from the ground (control center CADMOS in Toulouse, France) with the support of the space station crew. Data recorded during the experiments are later on delivered to the ground on the removable hard disk drives and distributed to participating scientists for the detailed analysis.
Broadband UV-Vis vibrational coherence spectrometer based on a hollow fiber compressor
Authors: Gueye Moussa , Nillon Julien , Crégut Olivier , Léonard Jérémie
Published: September 2016

We describe a broadband transient absorption (TA) spectrometer devised to excite and probe, in the blue to UV range, vibrational coherence dynamics in organic molecules in condensed phase. A 800-nm Ti:Sa amplifier and a hollow fiber compressor are used to generate a 6-fs short pulse at 1 kHz. Broadband sum frequency generation with the fundamental pulse is implemented to produce a 400-nm, 8-fs Fourier limited short pulse. A UV-Vis white-light supercontinuum is implemented as a probe with intensity self-referencing to achieve a shot-noise-limited sensitivity. Rapid scanning of the pump-probe delay is shown very efficient in suppressing the noise resulting from low-frequency pump intensity fluctuations. Using either of the 800-nm or 400-nm broadband pulses as the pump for TA spectroscopy of organic molecules in solution, we resolve oscillatory signals down to the 320 nm probing wavelength with a 3200 cm−1 FWHM bandwidth. Their Fourier transformation reveals the corresponding molecular vibrational spectra. Finally, we demonstrate the use of this setup as a vibrational coherence spectrometer for the investigation of the vibrational dynamics accompanying the sub-ps C=C photoisomerization of a retinal-like molecular switch through a conical intersection.
Moving target detection for frequency agility radar by sparse reconstruction
Authors: Quan Yinghui , Li YaChao , Wu Yaojun , Ran Lei , Xing Mengdao , Liu Mengqi
Published: September 2016

Frequency agility radar, with randomly varied carrier frequency from pulse to pulse, exhibits superior performance compared to the conventional fixed carrier frequency pulse-Doppler radar against the electromagnetic interference. A novel moving target detection (MTD) method is proposed for the estimation of the target’s velocity of frequency agility radar based on pulses within a coherent processing interval by using sparse reconstruction. Hardware implementation of orthogonal matching pursuit algorithm is executed on Xilinx Virtex-7 Field Programmable Gata Array (FPGA) to perform sparse optimization. Finally, a series of experiments are performed to evaluate the performance of proposed MTD method for frequency agility radar systems.
Monotone-short solutions of the Tolman-Oppenheimer-Volkoff-de Sitter equation
Authors: Hsu Cheng-Hsiung , Makino Tetu
Published: September 2016

It is known that spherically symmetric static solutions of the Einstein equations with a positive cosmological constant for the energy-momentum tensor of a barotropic perfect fluid are governed by the Tolman-Oppenheimer-Volkoff-de Sitter equation. Some sufficient conditions for the existence of monotone-short solutions (with finite radii) of the equation are given in this article. Then we show that the interior metric can extend to the exterior Schwarzschild-de Sitter metric on the exterior vacuum region with twice continuous differentiability. In addition, we investigate the analytic property of the solutions at the vacuum boundary. Our result (Theorem 1) can be considered as the de Sitter version of the result by Rendall and Schmidt [Classical Quantum Gravity 8, 985-1000 (1991)]. Furthermore, one can see that there are different properties of the solutions with those of the Tolman-Oppenheimer-Volkoff equation (with zero cosmological constant) in certain situation.
Long-range correlated dynamics in ultra-thin molecular glass films
Authors: Zhang Yue , Glor Ethan C. , Li Mu , Liu Tianyi , Wahid Kareem , Zhang William , Riggleman Robert A. , Fakhraai Zahra
Published: September 2016

It has been previously shown that the free surface of molecular glasses has enhanced surface diffusion compared to the bulk. However, the degree by which the glass dynamics are affected by the free surface remains unexplored. Here, we measure enhanced dynamics in ultra-thin molecular glass films as a function of film thickness. We demonstrate that these films exhibit a sharp transition from glassy solid to liquid-like behavior when the thickness is reduced below 30 nm. This liquid-like behavior persists even at temperatures well below the glass transition temperature, Tg. The enhanced dynamics in these films can produce large scale morphological features during physical vapor deposition and lead to a dewetting instability in films held at temperatures as low as Tg − 35 K. The effective viscosity of these films are measured by monitoring the dewetting kinetics. These measurements combined with cooling-rate dependent Tg measurements show that the apparent activation barrier for rearrangement decreases sharply in films thinner than 30 nm. This sharp transition in the dynamics suggests that long-range correlated dynamics exists in these films such that the enhancement induced by the free surface can strongly affect the dynamics of the film over a length scale that is ten times larger than the size of the molecules.
High purity x-ray polarimetry with single-crystal diamonds
Authors: Bernhardt Hendrik , Marx-Glowna Berit , Schulze Kai S. , Grabiger Benjamin , Haber Johann , Detlefs Carsten , Loetzsch Robert , Kämpfer Tino , Röhlsberger Ralf , Förster Eckhart , Stöhlker Thomas , Uschmann Ingo , Paulus Gerhard G.
Published: September 2016

We report on the use of synthetic single-crystal diamonds for high purity x-ray polarimetry to improve the polarization purity of present-day x-ray polarimeters. The polarimeter setup consists of a polarizer and an analyzer, each based on two parallel diamond crystals used at a Bragg angle close to 45°. The experiment was performed using one (400) Bragg reflection on each diamond crystal and synchrotron undulator radiation at an x-ray energy of 9838.75 eV. A polarization purity of 8.9 × 10−10 was measured at the European Synchrotron Radiation Facility, which is the best value reported for two-reflection polarizer/analyzer setups. This result is encouraging and is a first step to improve the resolution of x-ray polarimeters further by using diamond crystal polarizers and analyzers with four or six consecutive reflections.
Influence of the polarization anisotropy on the electrocaloric effect in epitaxial PMN-PT thin films
Authors: Mietschke M. , Chekhonin P. , Molin C. , Gebhardt S. , Fähler S. , Nielsch K. , Schultz L. , Hühne R.
Published: September 2016

Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) compounds, which are typically used for high performance actuator applications due to their outstanding piezoelectric properties, show, in addition, a pronounced electrocaloric (EC) effect. The study of epitaxial films is a useful tool to analyze the correlation between the microstructure and EC properties in order to optimize the performance of these materials. Therefore, the 0.9PMN-0.1PT films were grown by a pulsed laser deposition on (001) as well as (111) oriented SrTiO3 single crystalline substrates using a La0.7Sr0.3CoO3 buffer as the bottom electrode and additional Au top electrodes. The structural properties determined by a high resolution X-ray and electron microscopy techniques indicated an undisturbed epitaxial growth. The anisotropy of the ferroelectric domain structure was investigated by a vertical and lateral piezoresponse force microscopy showing clear differences between the two orientations. A significant reduction of the thermal hysteresis was observed in the T-dependent polarization measurements for (111) oriented PMN-PT films, whereas the indirectly determined EC properties yield a maximum ΔT of around 15 K at 40 °C for a field of about 400 kV/cm for both film orientations.
Modulation of Pb chemical state of epitaxial lead zirconate titanate thin films under high energy irradiation
Authors: Barala Surendra Singh , Roul Basanta , Banerjee Nirupam , Kumar Mahesh
Published: September 2016

The chemical states of epitaxial PbZrxTi1-xO3 films were investigated by an X-ray photoelectron spectroscopy as a function of the gamma-ray doses. An anomalous behaviour was observed in Pb4f states, and a core level of Pb4f shifts towards a higher binding energy at 50 kGy and towards a lower binding energy at 200 kGy. The behaviour can be explained by a radiation induced reduction of PbO to metallic Pb. The metal-insulator-metal electrodes were fabricated by lithography, and the current-voltage characteristics were measured. A negative differential resistance (NDR) was observed in the leakage currents at room temperature. A higher current and disappearance of NDR characteristics were found in the 200 kGy irradiated samples, which further confirms the presence of metallic Pb.
Second-harmonic generation in quaternary atomically thin layered AgInP2S6 crystals
Authors: Wang Xingzhi , Du Kezhao , Liu Weiwei , Hu Peng , Lu Xin , Xu Weigao , Kloc Christian , Xiong Qihua
Published: September 2016

Nonlinear effects in two-dimensional (2D) atomic layered materials have attracted increasing interest. Here, we report the observation of optical second-harmonic generation (SHG) in two-dimensional atomically thin silver indium phosphorus sulfide (AgInP2S6) crystals, with odd layer thickness. The nonlinear signal facilitates the use of thickness-dependent SHG intensity to investigate the stacking type of this material, while the crystal-orientation dependent SHG intensity of the monolayer sample reveals the rotational symmetry of the AgInP2S6 lattice in plane. Our studies expand the 2D crystal family in nonlinear effect field, which opened considerable promise to the functionalities and potential applications of 2D materials.
Effect of hall current on MHD flow of a nanofluid with variable properties due to a rotating disk with viscous dissipation and nonlinear thermal radiation
Authors: Abdel-Wahed Mohamed , Akl Mohamed
Published: September 2016

Analysis of the MHD Nanofluid boundary layer flow over a rotating disk with a constant velocity in the presence of hall current and non-linear thermal radiation has been covered in this work. The variation of viscosity and thermal conductivity of the fluid due to temperature and nanoparticles concentration and size is considered. The problem described by a system of P.D.E that converted to a system of ordinary differential equations by the similarity transformation technique, the obtained system solved analytically using Optimal Homotopy Asymptotic Method (OHAM) with association of mathematica program. The velocity profiles and temperature profiles of the boundary layer over the disk are plotted and investigated in details. Moreover, the surface shear stress, rate of heat transfer explained in details.
Local protrusions formed on Si(111) surface by surface melting and solidification under applied tensile stress
Authors: Nishimura T. , Tomitori M.
Published: September 2016

The surface structure and composition of Si(111) was modified, by heating it to 1300 °C in ultrahigh vacuum under an external tensile stress. A stress of approximately 1 GPa was applied, by pressing on the center of the rear side of the sample. This process produced two protrusions of approximately 100 μm in height, to the left and right of the center. Scanning Auger electron spectroscopy revealed Fe, Cr, Ni, and C impurities at the top of one protrusion, and C at the top of the other. These impurities likely diffused into the tops of the protrusions during heating, and segregated to the local surface during cooling when the protrusions formed. The protrusion formation mechanism is discussed. Their formation was related to non-uniform surface temperature, electromigration, piezoresistivity, freezing-point depression due to surface alloying with the impurities, and volume expansion during solidification from surface melting. These findings provide a perspective on controlling surface structures and compositions using heat and stress to induce self-assembly.
Metamorphic InAs1-xBix/In0.83Al0.17As quantum well structures on InP for mid-infrared emission
Authors: Gu Y. , Zhang Y. G. , Chen X. Y. , Ma Y. J. , Xi S. P. , Du B. , Ji W. Y. , Shi Y. H.
Published: September 2016

This work reports on InP-based metamorphic quantum well structures with bismuth incorporation for mid-infrared applications. InAs1-xBix quantum well structures have been grown on InP-based metamorphic In0.83Al0.17As buffers and photoluminescence beyond 3.1 μm has been achieved at 300 K, which is longer than the referenced InAs quantum well. X-ray diffraction, cross-sectional transmission electron microscopy, and energy dispersive X-ray spectroscopy measurements reveal clear interfaces of InAsBi quantum well with low bismuth, while more defects and bismuth inhomogeneity were observed as more bismuth was incorporated.
Nano strain-amplifier: Making ultra-sensitive piezoresistance in nanowires possible without the need of quantum and surface charge effects
Authors: Phan Hoang-Phuong , Dinh Toan , Kozeki Takahiro , Nguyen Tuan-Khoa , Qamar Afzaal , Namazu Takahiro , Nguyen Nam-Trung , Dao Dzung Viet
Published: September 2016

This paper presents an innovative nano strain-amplifier employed to significantly enhance the sensitivity of piezoresistive strain sensors. Inspired from the dogbone structure, the nano strain-amplifier consists of a nano thin frame released from the substrate, where nanowires were formed at the centre of the frame. Analytical and numerical results indicated that a nano strain-amplifier significantly increases the strain induced into a free standing nanowire, resulting in a large change in their electrical conductance. The proposed structure was demonstrated in p-type cubic silicon carbide nanowires fabricated using a top down process. The experimental data showed that the nano strain-amplifier can enhance the sensitivity of SiC strain sensors at least 5.4 times larger than that of the conventional structures. This result indicates the potential of the proposed strain-amplifier for ultra-sensitive mechanical sensing applications.
Light extinction of wheat as affected by N fertilisation and plant parameters
Authors: Soleymani A.
Published: September 2016

Light absorption and light extinction of wheat (Triticum aestivum L.) are among the most important parameters affecting wheat growth and yield production. However, these properties are affected by plant and environmental factors. Despite wheat being an important food crop, there is not much information on these light parameters in wheat. Accordingly, light parameters were investigated in wheat plants in the present study in three field experiments under two distinct climatic conditions, a warm arid and semi-arid climate and a cool climate. The aims of the study were to determine how light absorption and light extinction of wheat are affected by: (1) planting date and plant genotype under arid and semi-arid conditions (Experiment I); and (2) N chemical fertilisation and plant genotype under arid and semi-arid conditions (Experiment II) and cool temperate conditions (Experiment III). Light absorption by the canopy was determined using a lightmeter and coefficients of extinction were calculated. Analyses of variance indicated significant effects of experimental treatments on light properties, wheat growth and yield production. There was a high rate of variability in light absorption, with a maximum of 59.27%, and light extinction coefficients were in the range 0.45–0.66. The experimental treatments resulted in high variability in the leaf area index (2.08–7.49), wheat biological yield (7831.1–22515.96 kg ha–1), grain yield (2481.3–9273.57 kg ha–1) and harvest index (32.86–53.90%). The interaction between planting date and plant genotypes indicated that the responses of different wheat genotypes to planting date were highly variable, significantly affecting light absorption and light extinction by wheat. It is possible to make the optimum use of solar light and produce the highest rate of yield if the most efficient genotype (Line 14-C81, Pishvaz and Pishtaz) is planted on the right planting date (15 November) using the optimum rate of N chemical fertilisation (50, 100, 150 kg ha–1).
Selection indices to identify maize (Zea mays L.) hybrids adapted under drought-stress and drought-free conditions in a tropical climate
Authors: Kumar Bhupender , Guleria Satish Kumar , Khanorkar Subhash M. , Dubey Rajender Babu , Patel Jashvantlal , Kumar Vinod , Parihar Chiter Mal , Jat Shankar Lal , Singh Vishal , Yatish K. R. , Das Abhijit , Sekhar Javaji Chandra , Bhati Pradeep , Kaur Harpreet , Kumar Madhvi , Singh Aditya Kumar , Varghese Eldho , Yadav Om Prakash
Published: September 2016

Drought stress is the most important production constraint in maize (Zea mays L.), especially in rainfed agriculture. To improve productivity of rainfed maize, the development of hybrids with tolerance to drought stress is an important objective in maize breeding programs. The present study was undertaken to identify maize hybrids that perform better under drought-stress and drought-free conditions by using various selection indices. These selection indices were calculated on the basis of yield (t ha–1) performance of hybrids measured under drought stress and optimum environments. A set of 38 cultivars was evaluated at 10 environments (representing five each of drought stress and optimum growing conditions). The average reduction in grain yield due to drought stress was 52%. Effects of genotype, environment and their interaction were significant sources of variation in determining grain yield, respectively explaining 5.0–7.4%, 55.0–60.2% and 12.0–15.0% of total variation in yield under drought-stress and drought-free conditions. Of eight selection indices considered for study, three indices such as harmonic mean, geometric mean, and stress tolerance index were identified as suitable for selection of genotypes capable of performing well both under drought-stress and drought-free environments. Drought response index and drought resistance index were found useful in identifying hybrids that performed better under drought stress. Stress susceptibility index was negatively correlated with yield measured under drought stress. Stress susceptibility index could be used as selection index but only in combination with yield performance data under water-deficit conditions in order to identify drought-tolerant hybrids with reasonable productivity. Test weight, shelling percentage, days to maturity, and ear girth were found to be useful traits for improving yield performance across diverse environments. Cultivation of identified drought-tolerant hybrids would be useful to enhance maize productivity in drought-stress environments.
Findings from a clinical audit in regional general practice of management of patients following acute coronary syndrome
Authors: Dronavalli Mithilesh , Bhagwat Manavi M. , Hamilton Sandy , Gilles Marisa , Garton-Smith Jacquie , Thompson Sandra C.
Published: September 2016

Patients with acute coronary syndrome (ACS) require ongoing treatment and support from their primary care provider to modify cardiovascular risk factors (including diet, exercise and mood), to receive evidence-based pharmacotherapies and be properly monitored and to ensure their take-up and completion of cardiac rehabilitation (CR). This study assesses adherence to National Heart Foundation guidelines for ACS in primary care in a regional centre in Western Australia. Patients discharged from hospital after a coronary event (unstable angina or myocardial infarction) or a coronary procedure (stent or coronary artery bypass graft) were identified through general practice electronic medical records. Patient data was extracted using a data form based on National Heart Foundation guidelines. Summary statistics were calculated and reported. Our study included 22 GPs and 44 patients in a regional centre. In total, 90% (n=39) of discharge summaries recorded medications. Assessment of pharmacological management showed that 53% (n=23) of patients received four or more classes of pharmacotherapy and that GPs often augmented medication beyond that prescribed at discharge. Of 15 smokers, 13 (87%) had advice to quit documented. Minimal advice for other risk-factor modification was documented in care plans. Patients with type 2 diabetes (n=20) were 70% more likely to receive allied health referral (P=0.02) and 60% more likely to receive advice regarding diet and exercise (P=0.007). However, overall, only 30% (n=13) of those eligible were referred to a dietician, and only 25% were referred to CR (n=10) with six completing CR. Although most GPs did not use standardised tools for mood assessment, 18 (41%) patients were diagnosed as depressed, of which 88% (n=16) were started on antidepressants and 28% (n=6) were referred to a psychologist. Although pharmacotherapy, mood management and smoking cessation management generally followed recommended guidelines, risk factor management relating to diet and exercise by GPs require improvement. Detailed care plans and referral to CR and allied health staff for patient support is recommended.
Dynamics of
Escherichia coli
’s passive response to a sudden decrease in external osmolarity
Authors: Buda Renata , Liu Yunxiao , Yang Jin , Hegde Smitha , Stevenson Keiran , Bai Fan , Pilizota Teuta
Published: September 2016

Significance

Mechanosensation is central to life. Bacteria, like the majority of walled cells, live and grow under significant osmotic pressure. By relying on mechanosensitive regulation, bacteria can adapt to dramatic changes in osmotic pressure. Studying such mechanical sensing and control is critical for understanding bacterial survival in a complex host and natural environment. Here, we investigate the fundamental design principles of
Escherichia coli
’s passive mechanosensitive response to osmotic downshocks by implementing single-cell high-resolution imaging. We explain the observed cell volume changes by modeling flux of water and solutes across the cell membrane. A better characterization of bacterial mechanosensitive response can help us map their reaction to environmental threats.
Molecular mechanism of Zn
2+
inhibition of a voltage-gated proton channel
Authors: Qiu Feng , Chamberlin Adam , Watkins Briana M. , Ionescu Alina , Perez Marta Elena , Barro-Soria Rene , González Carlos , Noskov Sergei Y. , Larsson H. Peter
Published: September 2016

Significance

Zn
2+
inhibition of voltage-gated proton (Hv1) channels has important physiological roles, such as quiescence of sperm in the male reproductive system. Here, we show that Zn
2+
binds to different states of Hv1, and we propose a possible mechanism for Zn
2+
inhibition of Hv1. Several residues are found to be involved in Zn
2+
binding, and we provide detailed information about how these residues contribute to the functional effect of Zn
2+
binding. This study provides valuable information for future drug development for Hv1 channels.
Functional analysis of molecular interactions in synthetic auxin response circuits
Authors: Pierre-Jerome Edith , Moss Britney L. , Lanctot Amy , Hageman Amber , Nemhauser Jennifer L.
Published: September 2016

Significance

Auxin-regulated transcription plays a role in almost every aspect of plant growth and development. Recent structural studies of domains from auxin-activated transcription factors and auxin-degraded repressors have raised fundamental questions about the protein complexes required for auxin response. Here, we leverage the power of a synthetic yeast system to identify and systematically characterize the simplest auxin response unit in the absence of the potentially confounding influence of other family members and interacting pathways.
Fast revascularization of the injured area is essential to support zebrafish heart regeneration
Authors: Marín-Juez Rubén , Marass Michele , Gauvrit Sebastien , Rossi Andrea , Lai Shih-Lei , Materna Stefan C. , Black Brian L. , Stainier Didier Y. R.
Published: September 2016

Significance

A heart attack occurs when blood flow to part of the heart is blocked, and oxygen and nutrients are unable to reach that tissue, irreversibly damaging cardiac muscle cells. Dead muscle cells are replaced by a noncontractile scar that affects cardiac function. Unlike humans, zebrafish can regenerate their heart after injury, replacing the scarred tissue with new cardiomyocytes. Understanding the mechanisms zebrafish deploy to regenerate their heart may help us design more efficient therapies for human heart disease. In this study, we show that to regenerate their heart, zebrafish quickly revascularize the damaged area, and that this ability to revascularize is temporally restricted.
Ab initio structure determination from prion nanocrystals at atomic resolution by MicroED
Authors: Sawaya Michael R. , Rodriguez Jose , Cascio Duilio , Collazo Michael J. , Shi Dan , Reyes Francis E. , Hattne Johan , Gonen Tamir , Eisenberg David S.
Published: September 2016

Significance

Microelectron diffraction (MicroED) is a cryo-EM method capable of determining atomic resolution macromolecular structures from nanocrystals of dose-sensitive biological macromolecules. To date, MicroED requires a reasonably accurate guess of the positions of atoms in a structure to solve it, a technique known as molecular replacement. We now show that this need for prior knowledge about a structure is eliminated in cases when crystals diffract to atomic resolution, relying only on the accuracy of the MicroED intensity measurements. Our findings provide a basis for solving structures from tiny crystals that diffract to high resolution, but are presently disregarded because of their small size.
Binding of phosphatidic acid by NsD7 mediates the formation of helical defensin–lipid oligomeric assemblies and membrane permeabilization
Authors: Kvansakul Marc , Lay Fung T. , Adda Christopher G. , Veneer Prem K. , Baxter Amy A. , Phan Thanh Kha , Poon Ivan K. H. , Hulett Mark D.
Published: September 2016

Significance

Direct attack of target cell membranes by protein oligomerization is a powerful innate defense mechanism used widely throughout nature. Defensins are ubiquitous innate immunity mediators that are able to recognize certain phospholipids, and subsequently oligomerize to attack target cell membranes. We now show that the plant defensin NsD7 is able to bind the cellular phospholipid, phosphatidic acid (PA), which triggers defensin oligomerization in a unique manner. Our crystal structure of the NsD7–PA oligomer revealed a striking double-helical defensin–lipid oligomer that features a novel phospholipid-binding site mediating PA binding and membrane permeabilization. This demonstrates that defensins use their conserved small fold in a remarkably flexible way to specifically recognize a range of phospholipids during innate defense using different binding sites.
Biophysical comparison of ATP synthesis mechanisms shows a kinetic advantage for the rotary process
Authors: Anandakrishnan Ramu , Zhang Zining , Donovan-Maiye Rory , Zuckerman Daniel M.
Published: September 2016

Significance

All living organisms—archaea, bacteria, and eukarya—use an intricate rotary molecular machine to synthesize ATP, the energy currency of the cell. Why did evolution select such an elaborate machine when a simpler alternating-access mechanism, already present in cells, could be used for ATP synthesis? Our analysis shows that the rotary mechanism is faster than other possible mechanisms, particularly under challenging conditions, suggesting a possible evolutionary advantage.