bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioinspired preparation of thermo-responsive graphene oxide nanocomposites in an aqueous solution
Authors: Shi Yingge , Liu Meiying , Wang Ke , Deng Fengjie , Wan Qing , Huang Qiang , Fu Lihua , Zhang Xiaoyong , Wei Yen
Published: June 2015

Thermo-responsive graphene oxide nanocomposites were fabricated by a facile, efficient and versatile methodviacombination of mussel inspired chemistry and RAFT polymerization.
What causes tumbling of altro-α-CD derivatives? Insight from computer simulations
Authors: Liu Ying , Chipot Christophe , Shao Xueguang , Cai Wensheng
Published: June 2015

Spontaneous tumbling of altro-α-CD derivatives stems from the solvent and the side chain. Simulation results provide a theoretical basis for design of novel rotaxane-based molecular reels.
Fast and facile preparation of PEGylated graphene from graphene oxide by lysosome targeting delivery of photosensitizer to efficiently enhance photodynamic therapy
Authors: Zeng Yiping , Yang Zhangyou , Luo Shenglin , Li Hong , Liu Cong , Hao Yuhui , Liu Jing , Wang Weidong , Li Rong
Published: June 2015

A fast, facile and mass production method was reported to obtain stable and disperse polyethylene glycol (PEG) modified nanographene (NGO-PEG). Branched polyethylenimine (BPEI) was used to modify the NGO-PEG (NGO-PEG-BPEI) for further application.
Kinetic study and peak purity determination of bupropion hydrochloride using RRLC/DAD and HPLC/MWD methods: stability study and application in pharmaceutical preparation and in synthetic mixtures with nicotine
Authors: El-Kosasy Amira M. , Hussein Lobna A. , Salama Nahla N. , Sedki Nehal G.
Published: June 2015

Two validated stability indicating chromatographic methods have been developed and used for the kinetic study and determination of bupropion HCl in presence of its degradation products and nicotine.
A green synthesis of highly substituted 1,5-diketones
Authors: Liu Lei , Feng Suliu , Li Chunbao
Published: June 2015

The advantages of the aqueous reactions over the conventional ones were demonstrated in the synthesis of highly substituted 1,5-diketones.
Synthesis and characterization of glucosulfonic acid supported on Fe3O4 nanoparticles as a novel and magnetically recoverable nanocatalyst and its application in the synthesis of polyhydroquinoline and 2,3-dihydroquinazolin-4(1H)-one derivatives
Authors: Hajjami Maryam , Tahmasbi Bahman
Published: June 2015

Synthesis and characterization of glucosulfonic acid supported on Fe3O4 nanoparticles as novel and magnetically recoverable nanocatalyst and its application in the synthesis of polyhydroquinoline and 2,3-dihydroquinazolin-4(1H)-one derivatives.
Flexible piezoelectric nanogenerator based on Cu2O–ZnO p–n junction for energy harvesting
Authors: Lei Jixue , Yin Bing , Qiu Yu , Zhang Heqiu , Chang Yue , Luo Yingmin , Zhao Yu , Ji Jiuyu , Hu Lizhong
Published: June 2015

A nanogenerator based on Cu2O–ZnO p–n junction has been fabricated on a Cu wire substrate for harvesting mechanical energy from the environment.
Correction: Pattern-based detection of anion pollutants in water with DNA polyfluorophores
Authors: Kwon Hyukin , Jiang Wei , Kool Eric T.
Published: June 2015

Correction for ‘Pattern-based detection of anion pollutants in water with DNA polyfluorophores’ by Hyukin Kwon et al., Chem. Sci., 2015, 6, 2575–2583.
General synthesis of binary PtM and ternary PtM1M2 alloy nanoparticles on graphene as advanced electrocatalysts for methanol oxidation
Authors: Sun Jing , Ma Haifeng , Jiang Hong , Dang Liyun , Lu Qingyi , Gao Feng
Published: June 2015

Different Pt-based binary and ternary alloys with uniform sizes were synthesized orderly on graphene through a general route.
A facile method for preparation of self-healing epoxy composites: using electrospun nanofibers as microchannels
Authors: Vahedi Vahdat , Pasbakhsh Pooria , Piao Chai Siang , Seng Chan Eng
Published: June 2015

Electrospun nanofibrous mats of polyacrylonitrile (PAN) carrying epoxy and amine dual healing solutions were incorporated into an epoxy matrix to impart self-healing functionality.
Efficient fiber-shaped perovskite photovoltaics using silver nanowires as top electrode
Authors: Lee Minoh , Ko Yohan , Jun Yongseok
Published: June 2015

A flexible perovskite solar cell has been developed on a metal substrate using silver nanowires as top electrode.
Synthesis and electrochemical performance of xLiV3O8·yLi3V2(PO4)3/rGO composite cathode materials for lithium ion batteries
Authors: Li Yi , Xie Dong , Zhang Yi-di , Zhou Ding , Niu Xiao-qing , Tong Yue-yu , Wang Dong-huang , Wang Xiu-li , Gu Chang-dong , Tu Jiang-ping
Published: June 2015

A series of xLiV3O8·yLi3V2(PO4)3/rGO (x : y = 2 : 1, 3 : 1, 1 : 1, 1 : 2, 1 : 3) composites are synthesized by simple mechanical mixing of LiV3O8 and Li3V2(PO4)3/rGO.
Charge transfer processes at the semiconductor/electrolyte interface for solar fuel production: insight from impedance spectroscopy
Authors: Bertoluzzi Luca , Lopez-Varo Pilar , Jiménez Tejada Juan Antonio , Bisquert Juan
Published: June 2015

Low frequency capacitance measurements allow decoupling direct hole transfer from the valence band and indirect hole transfer from surface states.
Flexible and porous catalyst electrodes constructed by Co nanoparticles@nitrogen-doped graphene films for highly efficient hydrogen evolution
Authors: Hou Dongman , Zhou Weijia , Zhou Kai , Zhou Yucheng , Zhong Jing , Yang Linjing , Lu Jia , Li Guoqiang , Chen Shaowei
Published: June 2015

A flexible and porous electrode composed of cobalt nanoparticles embedded into a N-doped graphene film exhibits remarkable HER catalytic activity.
Correction: Interaction mechanism between a functionalized protective layer and dissolved polysulfide for extended cycle life of lithium sulfur batteries
Authors: Ahn Wook , Lim Sung Nam , Lee Dong Un , Kim Kwang-Bum , Chen Zhongwei , Yeon Sun-Hwa , Jin Chang-Soo
Published: June 2015

Correction for ‘Interaction mechanism between a functionalized protective layer and dissolved polysulfide for extended cycle life of lithium sulfur batteries’ by Wook Ahn et al., J. Mater. Chem. A, 2015, 3, 9461–9467.
Viral nano-hybrids for innovative energy conversion and storage schemes
Authors: Vilona D. , Di Lorenzo R. , Carraro M. , Licini G. , Trainotti L. , Bonchio M.
Published: June 2015

A tailored design of unique energy materials can take advantage of 1D, mono-dispersed, viral nano-rods evolving to functional hybrids by supramolecular and covalent synthetic strategies.
Design and application of a water-soluble phosphorescent Ru(ii) complex as turn-on sensing material for Hg2+
Authors: Ru Jiaxi , Mi Xiangquan , Guan Liping , Tang Xiaoliang , Ju Zhenghua , Zhang Guolin , Wang Chunming , Liu Weisheng
Published: June 2015

A turn-on Ru(ii)-based phosphorescent chemodosimeter for Hg2+ is designed by introducing Hg2+-promoted desulfurization and intramolecular cyclic guanylation of thiourea reaction into the luminophor.
Antenna polarisation adjustment for microstrip patch antennas using parasitic elements
Authors: Byun Gangil , Choo Hosung
Published: June 2015

A novel and simple approach to adjust the polarisation properties of a microstrip patch antenna in the entire axial ratio (AR) range is proposed. The proposed antenna consists of a radiating patch and a parasitic strip separated into two parts, and the separated strip is placed at the outer perimeter of the patch for capacitive coupling. This structure enables the antenna to induce opposite‐direction currents on the strip, which allows flexible polarisation adjustment by moving the separated positions of the strip. For evaluation, two antennas with linear and circular polarisations are fabricated, and their performance is measured in a full anechoic chamber. The results prove that the proposed approach is suitable for flexible AR adjustment without a significant degradation of the matching characteristics and the design complexity.
Simplified successive‐cancellation decoding using information set reselection for polar codes with arbitrary blocklength
Authors: Zhang Liang , Zhang Zhaoyang , Wang Xianbin , Zhong Caijun , Ping Li
Published: June 2015

The distribution of information bits and frozen bits on the decoder graph can be exploited to simplify the successive‐cancellation (SC) decoding of polar codes. In this study, the authors establish a general simplified SC decoding framework for polar codes with arbitrary block‐length, which is independent of any specific or explicit generator matrices and considerably reduces decoding complexity while retaining the same error performance. Then, based on the fact that the complexity reduction depends on the distribution of information bits, a so‐called m‐radius reselection scheme is proposed to construct multiple feasible information sets which are different from the original one defined by Arıkan. In this way, flexible tradeoffs between performance and complexity could be achieved.
Robust signal‐to‐noise ratio and noise variance estimation for single carrier frequency domain equalisation ultra‐wideband wireless systems
Authors: Wang Dan , Zhao Qing , Yang Lei
Published: June 2015

In block‐mode transmission, single carrier frequency domain equalisation‐based ultra‐wide‐band technique is a promising physical‐layer candidate scheme. Here, the authors address the noise variance estimation problem for signal‐to‐noise ratio estimation in such systems. Our investigations focus on the estimation schemes both robust to the pilot sequence and the channel type. First, the authors, respectively, define the correlated noise samples and the uncorrelated ones, where the difference signals or the sum signals of two adjacent received pilot signals are included. Then, with the help of the Cramer–Rao lower bound (CRLB) theorem, the authors either use the correlated or the uncorrelated samples to estimate the noise variance based on the difference signals and the sum signals, respectively, regardless of the pilot sequences. The corresponding CRLBs are also given and analysed. Finally, under either the correlated or the uncorrelated noise samples, the authors propose to linearly combine the estimator of the difference signals with that of the sum signals where the weight coefficients are optimised. Since the proposed two combined estimators are not only robust to the pilot sequence but also automatically adapt the weights to the channel condition, they can significantly outperform the existing estimators.
Moving visual focus in salient object segmentation
Authors: Chen Zhi‐Hua , Liu Yi , Xiao Xiao‐Long , Ying Fang‐Li , Zhang Jing , Yuan Yu‐Bo
Published: June 2015

Saliency detection plays an important role in image segmentation, object detection and retrieval, which attracts more attention in the field of computer vision recently. Most existing saliency detection algorithms have not considered the influence of visual focus (VF) shifting yet. In this study, a novel algorithm named moving region contrast (MRC) is proposed to analyse image saliency. The algorithm MRC is built on a novel concept of moving VF. The initial VF is defined as the geometric centre of the image. Then the VF is calculated iteratively by focus‐moving technique where a saliency gravitation model is employed to determine the moving direction. The salient region is obtained according to the final VF. The experiments are conducted on the dataset with 1000 images released by Achanta. Experimental results show that the proposed algorithm achieves marked improvements in performance and outperforms other 11 popular algorithms.
Speed pattern recognition technique for short‐term traffic forecasting based on traffic dynamics
Authors: Kehagias Dionysios , Salamanis Athanasios , Tzovaras Dimitrios
Published: June 2015

This study introduces a new short‐term traffic forecasting technique, based on the dynamic features of traffic data derived from vehicles moving in urban networks. The authors goal is to forecast the values of appropriate traffic status indicators such as average travel time or speed, for one or more time steps in the future until the next half hour. The proposed forecasting technique is based on road profiles generated from the application of data clustering techniques on real traffic data. Data clustering is applied after the original feature space is transformed to a new one of a significantly lower dimension. This transformation is based on the dynamic characteristics of current traffic, expressed in the form of the speed derivatives. To evaluate the proposed technique they used two‐week historical data from the city of Berlin, Germany. Extensive evaluation results indicate improvement of the forecasting accuracy after comparison with a set of existing traffic forecasting techniques.
Design of a custom power park for wind turbine system and analysis of the system performance under power quality disturbances
Authors: Agalar Sener , Kaplan Yusuf Alper
Published: June 2015

This study presents an operation of custom power park (CPP) with wind turbine system (WTS). The classical power system stability, changes and challenges in the power system with installation of wind energy sources are given. The CPP is composed by static transfer switch (STS) for WTS. An electromagnetic transient model of a system is composed by WTS and STS in power system computer aided design/electromagnetic transient including DC (PSCAD/EMTDC) programme. The entire model of the proposed system is developed and simulating results are verified in PSCAD/EMTDC programme at different fault types. The system responses of the different fault types are given and obtained results are evaluated in detail for power quality problems. Moreover, of the different type faults are implemented to the WT feeder and the response of the proposed system is observed for all cases. Then, the simulating results are evaluated. The currents and voltages of all systems are investigated during normal, transfer and post‐transfer periods and also these simulating results are evaluated.
Density of states determination in organic donor-acceptor blend layers enabled by molecular doping
Authors: Fischer Janine , Ray Debdutta , Kleemann Hans , Pahner Paul , Schwarze Martin , Koerner Christian , Vandewal Koen , Leo Karl
Published: June 2015

Charge carrier transport is a key parameter determining the efficiency of organic solar cells, and is closely related to the density of free and trapped states. For trap characterization, impedance spectroscopy is a suitable, non-invasive method, applicable to complete organic semiconductor devices. In order to contribute to the capacitive signal, the traps must be filled with charge carriers. Typically, trap filling is achieved by illuminating the device or by injecting charge carriers through application of a forward bias voltage. However, in both cases, the exact number of charge carriers in the device is not known and depends strongly on the measurement conditions. Here, hole trap states of the model blend layer ZnPc:C60 are filled by weak p-doping, enabling trap characterization in a blend layer at a controlled hole density. We evaluate impedance spectra at different temperatures in order to determine the density of occupied states (DOOS) directly from the capacitance-frequency spectra by assuming a simple energy diagram. The reconstructed DOOS distribution is analyzed at different doping concentrations and device thicknesses and compared to thermally stimulated current measurements performed on the same devices. In both methods, a pronounced Gaussian peak at about 0.4 eV below the transport level is found as well as deep, exponential tail states, providing a deeper insight into the density of states distribution of this donor-acceptor blend layer. Additionally, the effect of doping-induced trap filling on the solar cell characteristics is studied in these devices.
Unidirectional rotating coordinate rotation digital computer algorithm based on rotational phase estimation
Authors: Zhang Chaozhu , Han Jinan , Yan Huizhi
Published: June 2015

The improved coordinate rotation digital computer (CORDIC) algorithm gives high precision and resolution phase rotation, but it has some shortages such as high iterations and big system delay. This paper puts forward unidirectional rotating CORDIC algorithm to solve these problems. First, using under-damping theory, a part of unidirectional phase rotations is carried out. Then, the threshold value of angle is determined based on phase rotation estimation method. Finally, rotation phase estimation completes the rest angle iterations. Furthermore, the paper simulates and implements the numerical control oscillator by Quartus II software and Modelsim software. According to the experimental results, the algorithm reduces iterations and judgment of sign bit, so that it decreases system delay and resource utilization and improves the throughput. We always analyze the error brought by this algorithm. It turned out that the algorithm has a good application prospect in global navigation satellite system and channelized receiver.
Stability of micro-Cassie states on rough substrates
Authors: Guo Zhenjiang , Liu Yawei , Lohse Detlef , Zhang Xuehua , Zhang Xianren
Published: June 2015

We numerically study different forms of nanoscale gaseous domains on a model for rough surfaces. Our calculations based on the constrained lattice density functional theory show that the inter-connectivity of pores surrounded by neighboring nanoposts, which model the surface roughness, leads to the formation of stable microscopic Cassie states. We investigate the dependence of the stability of the micro-Cassie states on substrate roughness, fluid-solid interaction, and chemical potential and then address the differences between the origin of the micro-Cassie states and that of surface nanobubbles within similar models. Finally, we show that the micro-Cassie states share some features with experimentally observed micropancakes at solid-water interfaces.
Nonlinear dielectric response of polar liquids
Authors: Matyushov Dmitry V.
Published: June 2015

The dielectric constant of a polar liquid in a strong electric field changes, in the lowest order, proportionally to the squared field magnitude. The proportionality coefficient (dielectric slope) is traditionally analyzed by mean-field models in terms of the saturation of alignment of individual dipoles as prescribed by the Langevin function. Only a decrease of the dielectric constant induced by the field is allowed by this model, in contrast to observations. Here, the dielectric slope is expressed in terms of the fourth-order cumulant of the liquid dipole moment. The cumulant is in turn separated into the two-particle dipolar correlations, expressed in terms of the Kirkwood factor and the liquid compressibility, and higher, triple and four-particle, dipolar correlations. The model allows both positive and negative dielectric slopes. Two-particle and higher-order correlations largely compensate each other. The analysis of experimental data suggests that dielectric slope gives experimental access to non-trivial triple and four-particle orientational correlations in polar liquids.
Improved ferroelectric polarization of V-doped Bi6Fe2Ti3O18 thin films prepared by a chemical solution deposition
Authors: Song D. P. , Yang J. , Yuan B. , Zuo X. Z. , Tang X. W. , Chen L. , Song W. H. , Zhu X. B. , Sun Y. P.
Published: June 2015

We prepared V-doped Bi6Fe2Ti3O18 thin films on Pt/Ti/SiO2/Si (100) substrates by using a chemical solution deposition route and investigated the doping effect on the microstructure, dielectric, leakage, and ferroelectric properties of Bi6Fe2Ti3O18 thin films. The Bi5.97Fe2Ti2.91V0.09O18 thin film exhibits improved dielectric properties, leakage current, and ferroelectric properties. The incorporation of vanadium resulted in a substantially enhanced remnant polarization (2Pr) over 30 μC/cm2 in Bi5.97Fe2Ti2.91V0.09O18 thin film compared with 10 μC/cm2 in Bi6Fe2Ti3O18 thin film. It is demonstrated that the improved properties may stem from the improvement of crystallinity of the films with the contribution of suppressed oxygen vacancies and decreased mobility of oxygen vacancies caused by the V-doping. The results will provide a guidance to optimize the ferroelectric properties in Bi6Fe2Ti3O18 thin films by chemical solution deposition, which is important to further explore single-phase multiferroics in the n = 5 Aurivillius thin films.
Time dependent changes in Schottky barrier mapping of the W/Si(001) interface utilizing ballistic electron emission microscopy
Authors: Durcan Chris A. , Balsano Robert , LaBella Vincent P.
Published: June 2015

The W/Si(001) Schottky barrier height is mapped to nanoscale dimensions using ballistic electron emission microscopy (BEEM) over a period of 21 days to observe changes in the interface electrostatics. Initially, the average spectrum is fit to a Schottky barrier height of 0.71 eV, and the map is uniform with 98% of the spectra able to be fit. After 21 days, the average spectrum is fit to a Schottky barrier height of 0.62 eV, and the spatial map changes dramatically with only 27% of the spectra able to be fit. Transmission electron microscopy shows the formation of an ultra-thin tungsten silicide at the interface, which increases in thickness over the 21 days. This increase is attributed to an increase in electron scattering and the changes are observed in the BEEM measurements. Interestingly, little to no change is observed in the I-V measurements throughout the 21 day period.
An alternative methodology in Schottky diode physics
Authors: Mitra J. , Feng L. , Peñate-Quesada L. , Dawson P.
Published: June 2015

The fabrication and electrical characterization of Schottky junction diodes have been extensively researched for three-quarters of a century since the original work of Schottky in 1938. This study breaks from the highly standardized regime of such research and provides an alternative methodology that prompts novel, more efficient applications of the adroit Schottky junction in areas such as chemical and thermal sensing. The core departure from standard Schottky diode configuration is that the metal electrode is of comparable or higher resistance than the underlying semiconductor. Further, complete electrical characterization is accomplished through recording four-probe resistance-temperature (RD-T) characteristics of the device, where electrical sourcing and sensing is done only via the metal electrode and not directly through the semiconductor. Importantly, this results in probing a nominally unbiased junction while eliminating the need for an Ohmic contact to the semiconductor. The characteristic RD-T plot shows two distinct regions of high (metal) and low (semiconductor) resistances at low and high temperatures, respectively, connected by a cross-over region of width, ΔT, within which there is a large negative temperature coefficient of resistance. The RD-T characteristic is highly sensitive to the Schottky barrier height; consequently, at a fixed temperature, RD responds appreciably to small changes in barrier height such as that induced by absorption of a chemical species (e.g., H2) at the interface. A theoretical model is developed to simulate the RD-T data and applied to Pd/p-Si and Pt/p-Si Schottky diodes with a range of metal electrode resistance. The analysis gives near-perfect fits to the experimental RD-T characteristics, yielding the junction properties as fit parameters. The modelling not only helps elucidate the underlying physics but also helps to comprehend the parameter space essential for the discussed applications. Although the primary regime of application is limited to a relatively narrow range (ΔT) for a given type of diode, the alternative methodology is of universal applicability to all metal-semiconductor combinations forming Schottky contacts.
First-principles study on lattice thermal conductivity of thermoelectrics HgTe in different phases
Authors: Ouyang Tao , Hu Ming
Published: June 2015

Accurate description of thermal conductivity of high pressure phase of materials is a key for predicting the thermoelectric performance. In this paper, by combining first-principle calculation and phonon Boltzmann transport equation, we investigate the lattice thermal conductivity of HgTe in low pressure zinc blende and high pressure cinnabar phases. The results show that the phononic thermal conductivity of high pressure cinnabar phase HgTe is more than an order of magnitude lower than that for the low pressure zinc blende phase. This is mainly originated from the suppressed group velocity and reduced phonon relaxation time due to the nature of mixed phonon branches in the cinnabar phase of HgTe. Based on the new and precise value of the lattice thermal conductivity calculated in this work, the figure of merit of HgTe is re-calculated and the maximum figure of merit is found to approach 1.4 at room temperature. Our first principles study highlights the high pressure HgTe phase as a very promising candidate for thermoelectric applications and provides the insight for exploring other similar materials at high pressure phases in the future.
Study of wetting and spontaneous motion of droplets on microstructured surfaces with the lattice Boltzmann method
Authors: Tang G. H. , Xia H. H. , Shi Y.
Published: June 2015

The influence of arrangement of micro-pillars on wetting and self-motion of droplets is numerically studied via a three-dimensional lattice Boltzmann model for multiphase flow. Substrates textured with identical pillar array density but different arrangements are considered. The results show that the prediction of Cassie-Baxter model can be improved with the modified roughness factors. In addition, transportation of droplets on the stepwise gradient structured substrates is investigated. A simple model, taking account of pillar arrangement, is developed to estimate droplet velocity. The results show that it is critical to restrain droplet spreading in the lateral direction to achieve higher velocity and longer transportation distance.
Propargyloxyproline Regio- and Stereoisomers for Click-Conjugation of Peptides: Synthesis and Application in Linear and Cyclic Peptides
Authors: Northfield Susan E. , Mountford Simon J. , Wielens Jerome , Liu Mengjie , Zhang Lei , Herzog Herbert , Holliday Nicholas D. , Scanlon Martin J. , Parker Michael W. , Chalmers David K. , Thompson Philip E.
Published: June 2015

The use of the click reaction for the introduction of conjugate groups, such as affinity or fluorescent labels, to a peptide for the study of peptide biochemistry and pharmacology is widespread. However, the nature and location of substituted 1,2,3-triazoles in peptide sequences may markedly affect conformation or binding as compared with native sequences. We have examined the preparation and application of propargyloxyproline (Pop) residues as a precursor to such peptide conjugates. Pop residues are available in a range of regio- and stereoisomers from hydroxyproline precursors and are readily prepared in Fmoc-protected form. They can be incorporated routinely in peptide synthesis and broadly retain the conformational properties of the parent proline containing peptides. This is exemplified by the preparation of biotin- and fluorophore-labelled peptides derived from linear and cyclic peptides.
Protein misfolding occurs by slow diffusion across multiple barriers in a rough energy landscape
Authors: Yu Hao , Dee Derek R. , Liu Xia , Brigley Angela M. , Sosova Iveta , Woodside Michael T.
Published: June 2015

Significance

Structural transitions in proteins are characterized by the coefficient for intrachain diffusion,
D
, which determines the transition kinetics and reveals microscopic properties of the interactions governing folding.
D
has been measured for unfolded proteins and for native folding, but never for misfolding and aggregation, despite the importance of kinetics for driving these processes. We used single-molecule force spectroscopy to observe the misfolding of individual prion protein (PrP) molecules into stable, nonnative dimers. By reconstructing the energy landscape for dimer misfolding, we compared
D
for misfolding of PrP to that for native folding. Diffusion was 1,000-fold slower for misfolding, reflecting significant additional roughness in the energy landscape and confirming quantitatively the long-held hypothesis that misfolding landscapes are rougher than native landscapes.
Ongoing dynamics in large-scale functional connectivity predict perception
Authors: Sadaghiani Sepideh , Poline Jean-Baptiste , Kleinschmidt Andreas , D’Esposito Mark
Published: June 2015

Significance

Most brain activity is not directly evoked by specific external events. This ongoing activity is correlated across distant brain regions within large-scale networks. This correlation or functional connectivity may reflect communication across brain regions. Strength and spatial organization of functional connectivity changes dynamically over seconds to minutes. Using functional MRI, we show that these ongoing changes correlate with behavior. The connectivity state before playback of a faint sound predicted whether the participant was going to perceive the sound on that trial. Connectivity states preceding missed sounds showed weakened modular structure, in which connectivity was more random and less organized across brain regions. These findings suggest that ongoing brain connectivity dynamics contribute to explaining behavioral variability.
Structural analysis of a class III preQ
1
riboswitch reveals an aptamer distant from a ribosome-binding site regulated by fast dynamics
Authors: Liberman Joseph A. , Suddala Krishna C. , Aytenfisu Asaminew , Chan Dalen , Belashov Ivan A. , Salim Mohammad , Mathews David H. , Spitale Robert C. , Walter Nils G. , Wedekind Joseph E.
Published: June 2015

Significance

Riboswitches are RNA molecules found mostly in bacteria that control genes by sensing cellular levels of metabolites, such as the simple organic compound preQ
1
. The diversity of riboswitches and their potential as novel antibiotic targets continue to elicit interest in these regulatory sequences. Here we present the crystal structure of a newly discovered bacterial preQ
1
-III riboswitch that senses preQ
1
using an unusual, two-part architecture. A complementary analysis of flexibility and dynamics showed that recognition of preQ
1
induces riboswitch compaction, while concomitantly enhancing formation of a distant double-helix possessing a regulatory signal that zips and unzips rapidly, producing gene “off” and “on” states. These observations expand our knowledge of riboswitch construction and suggest a broader role for dynamics than previously recognized.
Biocatalytic synthesis of starch esters by immobilized lipase on magnetic microparticles
Authors: Prasertpornsakun Nattanun , Raita Marisa , Laosiripojana Navadol , Champreda Verawat
Published: June 2015

Enzymatic esterification is an efficient approach for modifying starch to functionalized biomaterials. In this study, conversion of cassava starch to fatty acid acyl esters using immobilized Thermomyces lanuginosus lipase on Fe3O4 microparticles modified with 3-aminopropyltriethoxysilane and covalently linked by 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide and N-hydroxysuccinimide (Fe3O4-AP-ED-lipase) in a solvent-free system was studied. An optimized reaction containing 5% w/v gelatinized starch, 1% v/v Triton X-100, and 1% w/v biocatalyst with 2.5% w/v of fatty acids (palmitic, oleic, or linoleic acid) resulted in esterified products with a degree of substitution (DS) of 0.12–0.14, while a slightly lower DS was observed using crude palm fatty acid distillate as the acyl donor with 42.9–59.6% recovery yield. Increasing DS led to lower glass transition temperature and higher viscosity of the esterified products. The enzyme showed high operational stability with 85% retaining in activity after recycling in three consecutive batches with simple separation by magnetization, leading to improved process economics.
Characterization of a feruloyl esterase B from Talaromyces cellulolyticus
Authors: Watanabe Masahiro , Yoshida Erika , Fukada Hiroaki , Inoue Hiroyuki , Tokura Mitsunori , Ishikawa Kazuhiko
Published: June 2015

A feruloyl esterase catalyzes the hydrolysis of the 4-hydroxy-3-methoxycinnamoyl (feruloyl) group from esterified sugars in plant cell walls. Talaromyces cellulolyticus is a high cellulolytic-enzyme producing fungus. However, there is no report for feruloyl esterase activity of T. cellulolyticus. Analysis of the genome database of T. cellulolyticus identified a gene encoding a putative feruloyl esterase B. The recombinant enzyme was prepared using a T. cellulolyticus homologous expression system and characterized. The purified enzyme exhibited hydrolytic activity toward p-nitrophenyl acetate, p-nitrophenyl trans-ferulate, methyl ferulate, rice husk, and bagasse. HPLC assays showed that the enzyme released ferulic acid and p-coumaric acid from hydrothermal-treated rice husk and bagasse. Trichoderma sp. is well-known high cellulolytic-enzyme producing fungus useful for the lignocellulosic biomass saccharification. Interestingly, no feruloyl esterase has been reported from Trichoderma sp. The results show that this enzyme is expected to be industrially useful for biomass saccharification.
Constant term identities and Poincaré polynomials
Authors: Károlyi Gyula , Lascoux Alain , Warnaar S.
Published: June 2015

In 1982 Macdonald published his now famous constant term conjectures for classical root systems. This paper begins with the almost trivial observation that Macdonald’s constant term identities admit an extra set of free parameters, thereby linking them to Poincaré polynomials. We then exploit these extra degrees of freedom in the case of typeA\mathrm {A}to give the first proof of Kadell’s orthogonality conjecture—a symmetric function generalisation of theqq-Dyson conjecture or Zeilberger–Bressoud theorem.

Key ingredients in our proof of Kadell’s orthogonality conjecture are multivariable Lagrange interpolation, the scalar product for Demazure characters and(0,1)(0,1)-matrices.
Long-time behavior for a class of Feller processes
Authors: Sandrić Nikola
Published: June 2015

In this paper, as a main result, we derive a Chung-Fuchs type condition for the recurrence of Feller processes associated with pseudo-differential operators. In the Lévy process case, this condition reduces to the classical and well-known Chung-Fuchs condition. Further, we also discuss the recurrence and transience of Feller processes with respect to the dimension of the state space and Pruitt indices and the recurrence and transience of Feller-Dynkin diffusions and stable-like processes. Finally, in the one-dimensional symmetric case, we study perturbations of Feller processes which do not affect their recurrence and transience properties, and we derive sufficient conditions for their recurrence and transience in terms of the corresponding Lévy measure. In addition, some comparison conditions for recurrence and transience also in terms of the Lévy measures are obtained.
RobotReviewer: evaluation of a system for automatically assessing bias in clinical trials
Authors: Marshall Iain J , Kuiper Joël , Wallace Byron C
Published: June 2015

Objective To develop and evaluate RobotReviewer, a machine learning (ML) system that automatically assesses bias in clinical trials. From a (PDF-formatted) trial report, the system should determine risks of bias for the domains defined by the Cochrane Risk of Bias (RoB) tool, and extract supporting text for these judgments.

Methods We algorithmically annotated 12,808 trial PDFs using data from the Cochrane Database of Systematic Reviews (CDSR). Trials were labeled as being at low or high/unclear risk of bias for each domain, and sentences were labeled as being informative or not. This dataset was used to train a multi-task ML model. We estimated the accuracy of ML judgments versus humans by comparing trials with two or more independent RoB assessments in the CDSR. Twenty blinded experienced reviewers rated the relevance of supporting text, comparing ML output with equivalent (human-extracted) text from the CDSR.

Results By retrieving the top 3 candidate sentences per document (top3 recall), the best ML text was rated more relevant than text from the CDSR, but not significantly (60.4% ML text rated ‘highly relevant' v 56.5% of text from reviews; difference +3.9%, [−3.2% to +10.9%]). Model RoB judgments were less accurate than those from published reviews, though the difference was <10% (overall accuracy 71.0% with ML v 78.3% with CDSR).

Conclusion Risk of bias assessment may be automated with reasonable accuracy. Automatically identified text supporting bias assessment is of equal quality to the manually identified text in the CDSR. This technology could substantially reduce reviewer workload and expedite evidence syntheses.
Cross-vendor evaluation of key user-defined clinical decision support capabilities: a scenario-based assessment of certified electronic health records with guidelines for future development
Authors: McCoy Allison B , Wright Adam , Sittig Dean F
Published: June 2015

Objective Clinical decision support (CDS) is essential for delivery of high-quality, cost-effective, and safe healthcare. The authors sought to evaluate the CDS capabilities across electronic health record (EHR) systems.

Methods We evaluated the CDS implementation capabilities of 8 Office of the National Coordinator for Health Information Technology Authorized Certification Body (ONC-ACB)-certified EHRs. Within each EHR, the authors attempted to implement 3 user-defined rules that utilized the various data and logic elements expected of typical EHRs and that represented clinically important evidenced-based care. The rules were: 1) if a patient has amiodarone on his or her active medication list and does not have a thyroid-stimulating hormone (TSH) result recorded in the last 12 months, suggest ordering a TSH; 2) if a patient has a hemoglobin A1c result >7% and does not have diabetes on his or her problem list, suggest adding diabetes to the problem list; and 3) if a patient has coronary artery disease on his or her problem list and does not have aspirin on the active medication list, suggest ordering aspirin.

Results Most evaluated EHRs lacked some CDS capabilities; 5 EHRs were able to implement all 3 rules, and the remaining 3 EHRs were unable to implement any of the rules. One of these did not allow users to customize CDS rules at all. The most frequently found shortcomings included the inability to use laboratory test results in rules, limit rules by time, use advanced Boolean logic, perform actions from the alert interface, and adequately test rules.

Conclusion Significant improvements in the EHR certification and implementation procedures are necessary.
Fine structure above a light bridge in the transition region and corona
Authors: Bharti L.
Published: June 2015

We present the results of multiwavelength, co-spatial and near co-temporal observations of jets above a sunspot light bridge (LB). The data were obtained with the Solar Optical Telescope on board Hinode, the Interface Region Spectrograph (IRIS) and the Atmospheric Imaging Assembly (AIA) on the Solar Dynamic Observatory. Most of the jets in the Ca ii H images show decreasing brightness with height while in the IRIS slit-jaw images at 1330 Å jets show a bright leading edge. These jets show rising and falling motion as evident from the parabolic profile obtained from the time–distance diagram. The rising and falling speeds of the jets are similar. These jets show a coordinated behaviour between neighbouring jets moving jointly up and down. Some of the jets show a plasma ejection from the leading edge which is also hotter at the transition region (TR) and coronal temperatures. A similar behaviour is seen in the AIA wavebands that suggests that jets above the LB reach up to the lower corona and the leading edges are heated up to coronal temperatures. Such jets are important means of transfer mass and energy to the TR and corona above sunspots.
The Subaru FMOS galaxy redshift survey (FastSound). I. Overview of the survey targeting Hα emitters at z ∼ 1.4
Authors: Tonegawa Motonari , Totani Tomonori , Okada Hiroyuki , Akiyama Masayuki , Dalton Gavin , Glazebrook Karl , Iwamuro Fumihide , Maihara Toshinori , Ohta Kouji , Shimizu Ikkoh , Takato Naruhisa , Tamura Naoyuki , Yabe Kiyoto , Bunker Andrew J. , Coupon Jean , Ferreira Pedro G. , Frenk Carlos S. , Goto Tomotsugu , Hikage Chiaki , Ishikawa Takashi , Matsubara Takahiko , More Surhud , Okumura Teppei , Percival Will J. , Spitler Lee R. , Szapudi Istvan
Published: June 2015

FastSound is a galaxy redshift survey that uses the near-infrared Fiber Multi-Object Spectrograph (FMOS) mounted on the Subaru Telescope, targeting Hα emitters at z ∼ 1.18–1.54 down to the sensitivity limit of Hα flux ∼ 2 × 10−16 erg cm−2 s−1. The primary goal of the survey is to detect redshift space distortion (RSD), to test the general theory of relativity by measuring the growth rate of large-scale structure and to constrain modified gravity models for the origin of the accelerated expansion of the universe. The target galaxies were selected based on photometric redshifts and Hα flux estimates calculated by fitting spectral energy distribution (SED) models to the five optical magnitudes of the Canada–France–Hawaii Telescope Legacy Survey (CFHTLS) Wide catalog. The survey started in 2012 March, and all the observations were completed in 2014 July. In total, we achieved 121 pointings of FMOS (each pointing has a 30′ diameter circular footprint) covering 20.6 deg2 by tiling the four fields of the CFHTLS Wide in a hexagonal pattern. Emission lines were detected from ∼ 4000 star-forming galaxies by an automatic line detection algorithm applied to 2D spectral images. This is the first in a series of papers based on FastSound data, and we describe the details of the survey design, target selection, observations, data reduction, and emission line detections.
X-ray measurement of electron and magnetic-field energy densities in the west lobe of the giant radio galaxy 3C 236
Authors: Isobe Naoki , Koyama Shoko
Published: June 2015

X-ray emission associated with the west lobe of the giant radio galaxy 3C 236 was investigated with the Suzaku observatory to evaluate the energetics in the lobe. After removing contamination from point-like X-ray sources detected with Chandra and subtracting the X-ray and non-X-ray backgrounds, the Suzaku spectrum from the lobe was reproduced by a power-law model with a photon index of $\Gamma = 2.23_{-0.38-0.12}^{+0.44+0.14}$, where the first and second errors represent the statistical and systematic ones, respectively. Within the errors, the X-ray index was consistent with the radio synchrotron one, ΓR = 1.74 ± 0.07, estimated in the 326–2695 MHz range. This agreement supports that the X-ray emission is attributed to the inverse-Compton radiation from the synchrotron electrons filling the lobe, where the cosmic microwave background photons are up-scattered. This result made 3C 236 the largest radio galaxy of which the lobe has ever been probed through the inverse-Compton X-ray photons. When the photon index was fixed at ΓR, the X-ray flux density at 1 keV was measured as SX = 12.3 ± 2.0 ± 1.9 nJy. A comparison of the X-ray flux to the radio one (SR = 1.11 ± 0.02 Jy at 608.5 MHz) yields the energy densities of the electrons and magnetic field in the west lobe as $u_{\rm e} = 3.9_{-0.7 -0.9}^{+0.6 +1.0} \times 10^{-14}$ erg cm−3 and $u_{\rm m} = 0.92_{-0.15 -0.35}^{+0.21 +0.52}\times 10^{-14}$ erg cm−3, respectively, indicating a mild electron dominance of $u_{\rm e}/u_{\rm m} = 4.2_{-1.3 -2.3}^{+1.6 +4.1}$. The latter corresponds to the magnetic field strength of $B = 0.48_{-0.04 -0.10}^{+0.05 +0.12}\ \mu$G. These are typical among the lobes of giant radio galaxies. A summary of the ue–size relation for the inverse-Compton-detected radio galaxies implies that the west lobe of 3C 236 is still actively energized by its jet.
BradyrhizobiumBclA Is a Peptide Transporter Required for Bacterial Differentiation in Symbiosis withAeschynomeneLegumes
Authors: Guefrachi Ibtissem , Pierre Olivier , Timchenko Tatiana , Alunni Benoît , Barrière Quentin , Czernic Pierre , Villaécija-Aguilar José-Antonio , Verly Camille , Bourge Mickaël , Fardoux Joël , Mars Mohamed , Kondorosi Eva , Giraud Eric , Mergaert Peter
Published: June 2015

Nodules of legume plants are highly integrated symbiotic systems shaped by millions of years of evolution. They harbor nitrogen-fixing rhizobium bacteria called bacteroids. Several legume species produce peptides called nodule-specific cysteine-rich (NCR) peptides in the symbiotic nodule cells which house the bacteroids. NCR peptides are related to antimicrobial peptides of innate immunity. They induce the endosymbionts into a differentiated, enlarged, and polyploid state. The bacterial symbionts, on their side, evolved functions for the response to the NCR peptides. Here, we identified the bclA gene of Bradyrhizobium sp. strains ORS278 and ORS285, which is required for the formation of differentiated and functional bacteroids in the nodules of the NCR peptide-producing Aeschynomene legumes. The BclA ABC transporter promotes the import of NCR peptides and provides protection against the antimicrobial activity of these peptides. Moreover, BclA can complement the role of the related BacA transporter of Sinorhizobium meliloti, which has a similar symbiotic function in the interaction with Medicago legumes.
Toward the Identification of Two Glycoproteins Involved in the Stomatal Deregulation of Downy Mildew–Infected Grapevine Leaves
Authors: Guillier Christelle , Gamm Magdalena , Lucchi Géraldine , Truntzer Caroline , Pecqueur Delphine , Ducoroy Patrick , Adrian Marielle , Héloir Marie-Claire
Published: June 2015

Stomata remain abnormally opened and unresponsive to abscisic acid in grapevine leaves infected by downy mildew. This deregulation occurs from 3 days postinoculation and increases concomitantly with leaf colonization by the pathogen. Using epidermal peels, we demonstrated that the active compound involved in this deregulation is located in the apoplast. Biochemical assays showed that the active compound present in the apoplastic fluids isolated from Plasmopara viticola–infected grapevine leaves (IAF) is a CysCys bridge-independent, thermostable and glycosylated protein. Fractionation guided assays based on chromatography coupled to stomatal response and proteomic analysis allowed the identification of both plant and pathogen proteins in the active fraction obtained from IAF. Further in silico analysis and discriminant filtrations based on the comparison between predictions and experimental indications lead to the identification of two Vitis vinifera proteins as candidates for the observed stomatal deregulation.