bluuebunny/crossref_metadata_2025 huggingface dataset:
On-chip Fabrication of High Performance Nanostructured ZnO UV Detectors
Authors: Alenezi Mohammad R. , Henley Simon J. , Silva S. R. P.
Published: February 2015

Developing rationally controlled bottom-up device fabrication processes is essential for the achievement of high performance optimal devices. We report a controlled, seedless and site-selective hydrothermal technique to fabricate high-performance nanostructured ZnO UV-detectors directly on-chip. We demonstrate that by controlling the nanowire growth process, via tuning the experimental parameters such as the concentration of reactants and the growth time and by introducing a refresh of the growth solution, the device structure efficiency can be enhanced to significantly improve its performance. The on-chip fabricated bridging nanosyringe ultraviolet detector demonstrates improved sensitivity (~105), nanowatts detectability and ultrafast response-time (90 ms) and recovery-time (210 ms). The improvement in response-time and recovery-time is attributed to the unique nanowire-nanowire junction barrier dominated resistance and the direct contact between ZnO and Au electrodes. Furthermore, the enhanced sensitivity and nanowatts detectability of the bridging nanosyringe device are due to the reduction in dimensionality and ultrahigh surface-to-volume ratio. This work paves the way toward low cost, large scale, low temperature, seedless and site-selective fabrication of high performance ZnO nanowire sensors on flexible and transparent substrates.
Structural basis for PPARγ transactivation by endocrine-disrupting organotin compounds
Authors: Harada Shusaku , Hiromori Youhei , Nakamura Shota , Kawahara Kazuki , Fukakusa Shunsuke , Maruno Takahiro , Noda Masanori , Uchiyama Susumu , Fukui Kiichi , Nishikawa Jun-ichi , Nagase Hisamitsu , Kobayashi Yuji , Yoshida Takuya , Ohkubo Tadayasu , Nakanishi Tsuyoshi
Published: February 2015

Organotin compounds such as triphenyltin (TPT) and tributyltin (TBT) act as endocrine disruptors through the peroxisome proliferator–activated receptor γ (PPARγ) signaling pathway. We recently found that TPT is a particularly strong agonist of PPARγ. To elucidate the mechanism underlying organotin-dependent PPARγ activation, we here analyzed the interactions of PPARγ ligand-binding domain (LBD) with TPT and TBT by using X-ray crystallography and mass spectroscopy in conjunction with cell-based activity assays. Crystal structures of PPARγ-LBD/TBT and PPARγ-LBD/TPT complexes were determined at 1.95 Å and 1.89 Å, respectively. Specific binding of organotins is achieved through non-covalent ionic interactions between the sulfur atom of Cys285 and the tin atom. Comparisons of the determined structures suggest that the strong activity of TPT arises through interactions with helix 12 of LBD primarily via π-π interactions. Our findings elucidate the structural basis of PPARγ activation by TPT.
Untreated and dried sample analysis by solid probe assisted nanoelectrospray ionization mass spectrometry
Authors: Mandal Mridul Kanti , Saha Subhrakanti , Yu Zhan , Yoshimura Kentaro , Takeda Sen , Hiraoka Kenzo
Published: February 2015

The present paper describes the application of solid probe assisted nanoelectrospray ionization mass spectrometry (SPA-nanoESI-MS) for the direct analysis of samples in solid or dried form.
A chitosan–polypyrrole@Fe3O4nanocomposite for magnetic solid-phase extraction of macrolides from swine urine samples
Authors: Liao Qie Gen , Hu Li Fang , Luo Lin Guang
Published: February 2015

An effective MSPE procedure with the CS–PPy@Fe3O4nanocomposite has been developed for extraction of four macrolides. An effective MSPE-LC-MS/MS method for determination of macrolides in swine urine samples has been developed.
A new tactic to achieve Y2O2S:Yb3+/Er3+ up-conversion luminescent hollow nanofibers
Authors: Han Lei , Hu Yanhua , Pan Mengmeng , Xie Yangfan , Liu Yangyang , Li Dan , Dong Xiangting
Published: February 2015

Y2O2S:Yb3+/Er3+ hollow nanofibers were synthesized via inheriting the morphology of electrospinning-derived precursors and exhibited excellent up-conversion luminescence properties.
DNA spontaneous mutation and its role in the evolution of GC-content: assessing the impact of the genetic sequence
Authors: Cerón-Carrasco José P. , Jacquemin Denis
Published: February 2015

We use theoretical tools to investigate the possible role played by a DNA sequence in the base pair tautomerization phenomena.
Comparison of photocatalytic and transport properties of TiO2 and ZnO nanostructures for solar-driven water splitting
Authors: Hernández Simelys , Hidalgo Diana , Sacco Adriano , Chiodoni Angelica , Lamberti Andrea , Cauda Valentina , Tresso Elena , Saracco Guido
Published: February 2015

Water splitting interfacial reaction kinetics and charge transport of four TiO2- and ZnO-based nanostructures with similar thickness are investigated.
Structure, function, self-assembly, and applications of bottlebrush copolymers
Authors: Verduzco Rafael , Li Xianyu , Pesek Stacy L. , Stein Gila E.
Published: February 2015

The architectures of bottlebrushes produce novel self-assembly behavior and useful properties for applications. We review research into bottlebrush copolymers, including their self-assembly and functionality.
Specific light-up bioprobes based on AIEgen conjugates
Authors: Liang Jing , Tang Ben Zhong , Liu Bin
Published: February 2015

This review summarizes the synthesis, the operation mechanism and design principles of specific AIE light-up bioprobes with applications in bio-analyte sensing, cell imaging and cancer therapy.
A heteropoly acid ionic crystal containing Cr as an active catalyst for dehydration of monosaccharides to produce 5-HMF in water
Authors: Yi Xiaohu , Delidovich Irina , Sun Zhong , Wang Shengtian , Wang Xiaohong , Palkovits Regina
Published: February 2015

Cs2[Cr3O(OOCC2H5)6(H2O)3]2[α-SiW12O40], a chromium-based heteropoly acid (HPA) ionic crystal, was demonstrated to be an active heterogeneous catalyst for production of 5-hydroxymethylfurfural (HMF) from fructose or glucose.
Hierarchical cupric oxide nanostructures on copper substrate for cold cathode emission: an experimental venture with theoretical correlation
Authors: Das Swati , Saha Subhajit , Sen Dipayan , Ghorai Uttam Kumar , Chattopadhyay Kalyan Kumar
Published: February 2015

Wet chemically developed CuO nanoneedles show lower turn-on value along with heightened enhancement factor. Structural anisotropy mediated better field enhancement characteristics is also reflected from the simulated data.
A mechanistic model for oxide growth and dissolution during corrosion of Cr-containing alloys
Authors: Momeni M. , Wren J. C.
Published: February 2015

We have developed a corrosion model that can predict metal oxide growth and dissolution rates as a function of time for a range of solution conditions. Our model considers electrochemical reactions at the metal/oxide and oxide/solution interfaces, and the metal cation flux from the metal to the solution phase through a growing oxide layer, and formulates the key processes using classical chemical reaction rate or flux equations. The model imposes mass and charge balance and hence, is labeled as the Mass Charge Balance (MCB) model. Mass and charge balance dictate that at any given time the oxidation (or metal cation) flux must be equal to the sum of the oxide growth flux and the dissolution flux. For each redox reaction leading to the formation of a specific oxide, the metal oxidation flux is formulated using a modified Butler–Volmer equation with an oxide-thickness-dependent effective overpotential. The oxide growth and dissolution fluxes have a first-order dependence on the metal cation flux. The rate constant for oxide formation also follows an Arrhenius dependence on the potential drop across the oxide layer and hence decreases exponentially with oxide thickness. This model is able to predict the time-dependent potentiostatic corrosion behaviour of both pure iron, and Co–Cr and Fe–Ni–Cr alloys.
Evaluation of a conducting interpenetrating network based on gum ghatti-g-poly(acrylic acid-aniline) as a colon-specific delivery system for amoxicillin trihydrate and paracetamol
Authors: Sharma Kashma , Kumar Vijay , Kaith Balbir Singh , Kumar Vinod , Som Sudipta , Pandey Anurag , Kalia Susheel , Swart Hendrik C.
Published: February 2015

Development of colon-specific drug delivery systems for amoxicillin trihydrate and paracetamol using gum ghatti based crosslinked hydrogels.
Insight into luminescent bisazoaromatic CNN pincer palladacycle: synthesis, structure, electrochemistry and some catalytic applications in C–C coupling
Authors: Roy Sima , Pramanik Shuvam , Ghorui Tapas , Pramanik Kausikisankar
Published: February 2015

The 2-(phenylazo)azobenzene furnished novel palladacycles in excellent yield, which showed luminescence at rt and catalytic activity. The optoelectronic and electrochemical responses were substantiated with DFT and TDDFT.
One-step synthesis of α-Gal epitope and globotriose derivatives by an engineered α-galactosidase
Authors: Zhang Lili , Lu Lili , Fan Shuquan , Jin Lan , Gu Guofeng , Xu Li , Xiao Min
Published: February 2015

A novel method for synthesis of α-Gal epitope and globotriose derivatives by an engineered α-galactosidase through a one-enzyme one-step reaction.
Electrospun NiO nanofibers as cathode materials for high performance asymmetric supercapacitors
Authors: Kolathodi Muhamed Shareef , Palei Milan , Natarajan Tirupattur Srinivasan
Published: February 2015

Highly granulated NiO nanofibers were prepared by electrospinning and their electrochemical properties as cathode materials were investigated for asymmetrical supercapacitors.
Synthesis and characterization of new Cd-doped ZnO/ZnS core–shell quantum dots with tunable and highly visible photoluminescence
Authors: Luo Jian , Zhao Suqing , Wu Panpan , Zhang Kun , Peng Chao , Zheng Shengwu
Published: February 2015

Novel Cd-doped ZnO/ZnS core–shell quantum dots with tunable and highly visible photoluminescence were successfully synthesized via a simple two-step chemical solution method.
A polyimide anode with high capacity and superior cyclability for aqueous Na-ion batteries
Authors: Deng Wenwen , Shen Yifei , Qian Jiangfeng , Yang Hanxi
Published: February 2015

A redox-active and water-insoluble polyimide can reversibly bind 2 Na+ ions per molecular unit, demonstrating a high capacity of 130 mA h g−1, a strong rate capability at 10 C rate and excellent capacity retention of 91.2% over 1000 cycles, offering a low cost and environmentally benign anode for aqueous Na-ion batteries.
Remarkably selective, non-linear allosteric regulation of anion binding by a tetracationic calix[4]pyrrole homodimer
Authors: Saha Indrajit , Lee Ji Hye , Hwang Hyonseok , Kim Tae Sun , Lee Chang-Hee
Published: February 2015

A covalently coupled, dimeric tetra-cationic calix[4]pyrrole homodimer bearing anthracene linkers displayed distinctive cooperativity and fluoride selectivity with large positive allosterism.
Multi-responsive metal–organic lantern cages in solution
Authors: Brega Valentina , Zeller Matthias , He Yufan , Peter Lu H. , Klosterman Jeremy K.
Published: February 2015

Multi-responsive metal–organic cages bearing internal amines groups formed 1D supramolecular coordination polymers or covalent host–guest complexes from solutions of pre-assembled cages.
Iodine-catalyzed ammoxidation of methyl arenes
Authors: Guo Songjin , Wan Gen , Sun Song , Jiang Yan , Yu Jin-Tao , Cheng Jiang
Published: February 2015

A metal-free direct ammoxidation of readily available methyl arenes leading to nitriles was established under mild conditions.
Synthesis of Z-scheme g-C3N4–Ti3+/TiO2 material: an efficient visible light photoelectrocatalyst for degradation of phenol
Authors: Liao Wenjuan , Murugananthan Muthu , Zhang Yanrong
Published: February 2015

Schematic illustration of Z-scheme g-C3N4–Ti3+/TiO2 photocatalysts.
Enantioselectivity and catalysis improvements of Pseudomonas cepacia lipase with Tyr and Asp modification
Authors: Li Jing , Yue Lei , Li Chang , Pan Yuanjiang , Yang Lirong
Published: February 2015

A concise strategy to improve thep-nitrophenyl palmitate catalytic activity and enantioselectivity towards secondary alcohols ofPcL is described.
Slow magnetic relaxation in a lanthanide helix chain compound [Dy(HNA)(NA)2(NO3)]n (HNA = nicotinic acid)
Authors: Liu Shuang , Li Lei-Lei , Li Han , Gao Hong-Ling , Cui Jian-Zhong , Cheng Peng
Published: February 2015

A racemic helix chain Dy3+ compound 1 bridged by μ1,3-COO groups was synthesized, which showed slow magnetic relaxation behaviour.
Controlled synthesis of graphene–Gd(OH)3 nanocomposites and their application for detection of ascorbic acid
Authors: Ruan Hong , Liu Baoyong , Li Hongguang
Published: February 2015

Graphene–Gd(OH)3 nanocomposites have been synthesized by hydrothermal method, which show superior activity towards ascorbic acid detection.
Preparation, characterization and antifouling properties of polyacrylonitrile/polyurethane blend membranes for water purification
Authors: Panda Swapna Rekha , De Sirshendu
Published: February 2015

70% PAN and 30% PU blend membrane shows the maximum antifowling characteristics during filtration of turbed surface water.
p-Aminophenol sensor based on tetra-β-[3-(dimethylamine)phenoxy] phthalocyanine cobalt(ii)/multiwalled carbon nanotube hybrid
Authors: Guo Liangxiao , Chen Zhimin , Zhang Jialin , Wu Hao , Wu Feng , He Chunying , Wang Bin , Wu Yiqun
Published: February 2015

The hybrid tetra-β-[3-(dimethylamine)phenoxy] phthalocyanine cobalt(ii)/multiwalled carbon nanotube was designed and synthesized, which can serve as an efficient catalyst for sensitive p-aminophenol detection due to synergistic effects between phthalocyanine and the carbon.
Highly conductive, twistable and bendable polypyrrole–carbon nanotube fiber for efficient supercapacitor electrodes
Authors: Xu Ruiqiao , Wei Jinquan , Guo Fengmei , Cui Xian , Zhang Tianyi , Zhu Hongwei , Wang Kunlin , Wu Dehai
Published: February 2015

Carbon nanotubes (CNTs) are a promising candidate for flexible and wearable electronic applications.
Green mechanical activation-assisted solid phase synthesis of cellulose esters using a co-reactant: effect of chain length of fatty acids on reaction efficiency and structure properties of products
Authors: Hu Huayu , Li Haixia , Zhang Yanjuan , Chen Yanmeng , Huang Zuqiang , Huang Aimin , Zhu Yuanqin , Qin Xingzhen , Lin Baofeng
Published: February 2015

A green, simple, and efficient technology for direct production of cellulose mixed esters with acetyl and long chain acyl substituents.
Metallic Ni nanocatalyst in situ formed from a metal–organic-framework by mechanochemical reaction for hydrogen storage in magnesium
Authors: Jia Yi , Sun Chenghua , Peng Ye , Fang Wenqi , Yan Xuecheng , Yang Dongjiang , Zou Jin , Mao Samuel S. , Yao Xiangdong
Published: February 2015

The facile and scalable fabrication of ultrafine (<5 nm) nanoparticles (NPs) as effective catalysts is the key for enhancing the kinetics of most hydrogen storage materials (HSMs).
Quantitative relationship between crystallite size and adhesion strength of the electroforming layer during microelectroforming process
Authors: Zhao Zhong , Du Liqun
Published: February 2015

Many micrometal devices are fabricated by microelectroforming technology in microelectromechanical systems. Micrometal devices usually suffer from poor interfacial adhesion strength, which restricts the application of microelectroforming technology. To solve this problem, in this reported work the influence of the electroforming crystallite size on practical adhesion energy is investigated. Furthermore, based on the energy balance criterion of fracture mechanics, the Miedema model of experimental electron theory (Miedema model) and the surface stress model, the equations between the crystallite size and the practical adhesion energy are established originally. Concerning the equations, the results show that the practical adhesion energy keeps an increasing trend and approaches basic adhesion energy as the crystallite size increases. To prove the equations, microelectroforming experiments were performed. The practical adhesion energy was measured by a scratch test. The crystallite size of the electroforming layer was tested by X‐ray diffraction technology. The results of the experiments show that, within the range of the crystallite size, the practical adhesion energy keeps an increasing trend and approaches 15 J/m2. The theoretical and the experimental results show the same trend. The equations are verified by the experiments and this work may guide the microelectroforming process.
Stability analysis of separated flows subject to control by zero-net-mass-flux jet
Authors: Marxen Olaf , Kotapati Rupesh B. , Mittal Rajat , Zaki Tamer
Published: February 2015

The control of flow around a canonical airfoil-like geometry with laminar separation bubble is analyzed using linear stability theory. The theoretical predictions are compared to data from Navier-Stokes simulations [Kotapati et al., “Nonlinear dynamics and synthetic-jet-based control of a canonical separated flow,” J. Fluid Mech. 654, 65-97 (2010)], in which the flow was controlled through a zero-net-mass-flux actuator. Very good agreement between the two approaches is found for a range of frequencies from low to high relative to the most dominant frequency for convective instability. The uncontrolled case exhibits periodic vortex shedding from the separation bubble due to an absolute instability. Linear modes with intermediate frequencies are found to exhibit strongest convective amplification, and forcing at these frequencies is most effective in order to reduce the size and extent of the separation bubble. The corresponding physical mechanism relies on a Kelvin-Helmholtz instability of the separated shear layer in conjunction with the non-linear effect of the mean flow deformation. For low frequencies, the front part of the bubble still diminishes due to the interaction of a vortex that starts from the actuator with the wall. This vortex transiently amplifies downstream due to the Orr mechanism. Actuation at high frequencies leads to visible, amplified instability waves in the shear layer, but is not effective in reducing the size of the bubble.
Excited state non-adiabatic dynamics of pyrrole: A time-resolved photoelectron spectroscopy and quantum dynamics study
Authors: Wu Guorong , Neville Simon P. , Schalk Oliver , Sekikawa Taro , Ashfold Michael N. R. , Worth Graham A. , Stolow Albert
Published: February 2015

The dynamics of pyrrole excited at wavelengths in the range 242-217 nm are studied using a combination of time-resolved photoelectron spectroscopy and wavepacket propagations performed using the multi-configurational time-dependent Hartree method. Excitation close to the origin of pyrrole’s electronic spectrum, at 242 and 236 nm, is found to result in an ultrafast decay of the system from the ionization window on a single timescale of less than 20 fs. This behaviour is explained fully by assuming the system to be excited to the A2(πσ∗) state, in accord with previous experimental and theoretical studies. Excitation at shorter wavelengths has previously been assumed to result predominantly in population of the bright A1(ππ∗) and B2(ππ∗) states. We here present time-resolved photoelectron spectra at a pump wavelength of 217 nm alongside detailed quantum dynamics calculations that, together with a recent reinterpretation of pyrrole’s electronic spectrum [S. P. Neville and G. A. Worth, J. Chem. Phys. 140, 034317 (2014)], suggest that population of the B1(πσ∗) state (hitherto assumed to be optically dark) may occur directly when pyrrole is excited at energies in the near UV part of its electronic spectrum. The B1(πσ∗) state is found to decay on a timescale of less than 20 fs by both N-H dissociation and internal conversion to the A2(πσ∗) state.
A novel device based on a fluorescent cross-responsive sensor array for detecting lung cancer related volatile organic compounds
Authors: Lei Jin-can , Hou Chang-jun , Huo Dan-qun , Luo Xiao-gang , Bao Ming-ze , Li Xian , Yang Mei , Fa Huan-bao
Published: February 2015

In this paper, a novel, simple, rapid, and low-cost detection device for lung cancer related Volatile Organic Compounds (VOCs) was constructed. For this task, a sensor array based on cross-responsive mechanism was designed. A special gas chamber was made to insure sensor array exposed to VOCs sufficiently and evenly, and FLUENT software was used to simulate the performance of the gas chamber. The data collection and processing system was used to detect fluorescent changes of the sensor arrays before and after reaction, and to extract unique patterns of the tested VOCs. Four selected VOCs, p-xylene, styrene, isoprene, and hexanal, were detected by the proposed device. Unsupervised pattern recognition methods, hierarchical cluster analysis and principal component analysis, were used to analyze data. The results showed that the methods could 100% discriminate the four VOCs. What is more, combined with artificial neural network, the correct rate of quantitative detection was up to 100%, and the device obtained responses at concentrations below 50 ppb. In conclusion, the proposed detection device showed excellent selectivity and discrimination ability for the VOCs related to lung cancer. Furthermore, our preliminary study demonstrated that the proposed detection device has brilliant potential application for early clinical diagnosis of lung cancer.
Solitary pulse-on-demand production by optical injection locking of passively Q-switched InGaN diode laser near lasing threshold
Authors: Zeng X. , Sulmoni L. , Lamy J.-M. , Stadelmann T. , Grossmann S. , Hoogerwerf A. C. , Grandjean N. , Boïko D. L.
Published: February 2015

In this letter, we investigate the behavior of a Q-switched InGaN multi-section laser diode (MSLD) under optical injection from a continuous wave external cavity diode laser. We obtain solitary optical pulse generation when the slave MSLD is driven near free running threshold, and the peak output power is significantly enhanced with respect to free running configuration. When the slave laser is driven well above threshold, optical injection reduces the peak power. Using standard semiconductor laser rate equation model, we find that both power enhancement and suppression effects are the result of partial bleaching of the saturable absorber by externally injected photons.
Liquid drops on a surface: Using density functional theory to calculate the binding potential and drop profiles and comparing with results from mesoscopic modelling
Authors: Hughes Adam P. , Thiele Uwe , Archer Andrew J.
Published: February 2015

The contribution to the free energy for a film of liquid of thickness h on a solid surface due to the interactions between the solid-liquid and liquid-gas interfaces is given by the binding potential, g(h). The precise form of g(h) determines whether or not the liquid wets the surface. Note that differentiating g(h) gives the Derjaguin or disjoining pressure. We develop a microscopic density functional theory (DFT) based method for calculating g(h), allowing us to relate the form of g(h) to the nature of the molecular interactions in the system. We present results based on using a simple lattice gas model, to demonstrate the procedure. In order to describe the static and dynamic behaviour of non-uniform liquid films and drops on surfaces, a mesoscopic free energy based on g(h) is often used. We calculate such equilibrium film height profiles and also directly calculate using DFT the corresponding density profiles for liquid drops on surfaces. Comparing quantities such as the contact angle and also the shape of the drops, we find good agreement between the two methods. We also study in detail the effect on g(h) of truncating the range of the dispersion forces, both those between the fluid molecules and those between the fluid and wall. We find that truncating can have a significant effect on g(h) and the associated wetting behaviour of the fluid.
Suspension of solid particles in a density stratified fluid
Authors: Doostmohammadi A. , Ardekani A. M.
Published: February 2015

Widespread implications of settling particles in stratified fluids call for accurate assessment of a suspension of particles at pycnoclines. We perform direct numerical simulations of the motion of particles based on a distributed Lagrange multiplier technique to quantify the effect of density stratification on the settling velocity and microstructure of a suspension of rigid particles. The flow field around particles is fully resolved, and a statistically steady-state condition is obtained after a transient acceleration of particles. Based on the simulation results, we propose a correlation for the mean settling velocity of the suspension as a function of solid volume fraction and background density gradient in a fluid column. The correlation follows a power-law dependence on the solid volume fraction of the suspension. The effect of the stratification on the microstructure of the suspension is also investigated by direct comparison of the pair correlation function between homogeneous and stratified fluids. It is shown that the presence of the background density gradient enhances the formation of horizontally aligned clusters in the fluid column.
Grafted nanoparticles as soft patchy colloids: Self-assembly versus phase separation
Authors: Mahynski Nathan A. , Panagiotopoulos Athanassios Z.
Published: February 2015

We investigate the thermodynamic behavior of a model polymer-grafted nanoparticle (GNP) system on a fine lattice, using grand canonical Monte Carlo simulations, to compare and contrast the validity of two different models for GNPs: “nanoparticle amphiphiles” versus “patchy particles.” In the former model, continuous self-assembly processes are expected to dominate the system, whereas the latter are characterized by first-order phase separation into novel equilibrium phases such as “empty liquids.” We find that, in general, considering GNPs as amphiphiles within the framework of a recent mean-field theory [Pryamtisyn et al., J. Chem. Phys. 131, 221102 (2009)] provides a qualitatively accurate description of the thermodynamics of GNP systems, revealing either first-order phase separation into two isotropic phases or continuous self-assembly. Our model GNPs display no signs of empty liquid formation, suggesting that these nanoparticles do not provide a route to such phases.
Tandem photo-electrode of InGaN with two Si p-n junctions for CO2 conversion to HCOOH with the efficiency greater than biological photosynthesis
Authors: Sekimoto Takeyuki , Shinagawa Shuichi , Uetake Yusuke , Noda Keiichi , Deguchi Masahiro , Yotsuhashi Satoshi , Ohkawa Kazuhiro
Published: February 2015

We report on a highly improved CO2 to HCOOH conversion system using a tandem photo-electrode (TPE) of InGaN and two Si p-n junctions. To improve its efficiency, narrow-band-gap InGaN was applied as the photo-absorption layer. In the TPE structure, the current matching between GaN-based photo-absorption layer and two Si p-n junctions is crucial for the improvement of the efficiency. The energy conversion efficiency for HCOOH production reached 0.97%, which is greater than average of global biological photosynthetic one.
Direct band gap electroluminescence from bulk germanium at room temperature using an asymmetric fin type metal/germanium/metal structure
Authors: Wang Dong , Maekura Takayuki , Kamezawa Sho , Yamamoto Keisuke , Nakashima Hiroshi
Published: February 2015

We demonstrated direct band gap (DBG) electroluminescence (EL) at room temperature from n-type bulk germanium (Ge) using a fin type asymmetric lateral metal/Ge/metal structure with TiN/Ge and HfGe/Ge contacts, which was fabricated using a low temperature (<400 °C) process. Small electron and hole barrier heights were obtained for TiN/Ge and HfGe/Ge contacts, respectively. DBG EL spectrum peaked at 1.55 μm was clearly observed even at a small current density of 2.2 μA/μm. Superlinear increase in EL intensity was also observed with increasing current density, due to superlinear increase in population of elections in direct conduction band. The efficiency of hole injection was also clarified.
Influence of compositionally induced defects on the vibrational properties of device grade Cu2ZnSnSe4 absorbers for kesterite based solar cells
Authors: Dimitrievska Mirjana , Fairbrother Andrew , Saucedo Edgardo , Pérez-Rodríguez Alejandro , Izquierdo-Roca Victor
Published: February 2015

This work presents a detailed analysis of the impact of compositionally induced defects on the vibrational properties of Cu2ZnSnSe4 absorbers for kesterite based solar cells. Systematic changes in the intensity of the E and B modes located around the 170, 220, and 250 cm−1 frequency regions, which involve mostly cation vibrations, were observed and analyzed in relation to the occurrence of different kinds of defect clusters involving VCu, ZnCu, ZnSn, CuZn, and SnZn point defects. Additional changes are also interpreted in terms of the appearance of SnSe, ZnSe, and CuSe-like contributions at the 185 and 250 cm−1 spectral regions, respectively. The sensitivity of the Raman measurements to the presence of these kinds of defects corroborates the potential of Raman scattering for point defect assessment in these systems.
Detection, Identification, and Significance of Phytoplasmas in Wild Grasses in East Africa
Authors: Asudi George O. , Van den Berg Johnnie , Midega Charles A. O. , Schneider Bernd , Seemüller Erich , Pickett John A. , Khan Zeyaur R.
Published: February 2015

Plant-pathogenic phytoplasmas found in wild grasses in East Africa could pose a serious threat to the cultivation of Napier grass, Pennisetum purpureum, the most important livestock fodder in the region. To asses this threat, leaves from plants of 33 grass species were sampled from Mbita, Bungoma, and Busia districts in western Kenya; Tarime district in northern Tanzania; and Busia and Bugiri districts in the eastern Uganda to determine which species host phytoplasmas, the identity of the phytoplasmas, and their relationship with disease symptoms. Phytoplasmas were detected using universal primers based on conserved phytoplasma-specific 16S rDNA sequences from 11 grass species collected. Sequence and phylogenetic analysis revealed the presence of Napier grass stunt-related phytoplasmas in 11 grass species, ‘Candidatus Phytoplasma cynodontis’ in three, and goosegrass white leaf phytoplasma in 2 wild grass species. This study showed that the geographical distribution, diversity of phytoplasmas, and their grass host species in East Africa is greater than antecedently thought and that typical disease symptoms, including white leaf or stunting alone, are not reliable indicators of the presence of phytoplasma. It also shows the need to identify insect vectors responsible for phytoplasma transmission from native grasses to Napier grass or other cereals present in the region.
Characterization of a Gene Identified in Pathotype 5 of the Clubroot PathogenPlasmodiophora brassicae
Authors: Zhang H. , Feng J. , Manolii V. P. , Strelkov S. E. , Hwang S.-F.
Published: February 2015

Clubroot caused by Plasmodiophora brassicae is an important disease of crucifers worldwide. Isolates of the pathogen can be classified into pathotypes according to their pathogenicity on differential hosts. In this study, the presence or absence of all database-available nonhousekeeping P. brassicae genes (118 in total) were assessed by polymerase chain reaction (PCR) analysis in isolates belonging to five P. brassicae pathotypes (2, 3, 5, 6, and 8 according to Williams’ differential set). One gene, designated Cr811, was present exclusively in the isolate of pathotype 5. This was further confirmed by dot blot hybridization and by PCR using alternative DNA preparations and primers. Reverse transcription quantitative PCR analysis indicated that in planta expression of Cr811 was up-regulated during canola infection, especially in the stage of secondary plasmodia. Primers specific to Cr811 could distinguish a field isolate of P. brassicae belonging to pathotype 5 from two other field isolates representing pathotypes 3 and 8. These findings suggest that Cr811 is a gene that is potentially involved in clubroot pathogenesis and that it also might serve as a molecular marker for differentiation of pathotype 5 from other pathotypes.
Climate, environmental and socio-economic change: weighing up the balance in vector-borne disease transmission
Authors: Parham Paul E. , Waldock Joanna , Christophides George K. , Hemming Deborah , Agusto Folashade , Evans Katherine J. , Fefferman Nina , Gaff Holly , Gumel Abba , LaDeau Shannon , Lenhart Suzanne , Mickens Ronald E. , Naumova Elena N. , Ostfeld Richard S. , Ready Paul D. , Thomas Matthew B. , Velasco-Hernandez Jorge , Michael Edwin
Published: February 2015

Arguably one of the most important effects of climate change is the potential impact on human health. While this is likely to take many forms, the implications for future transmission of vector-borne diseases (VBDs), given their ongoing contribution to global disease burden, are both extremely important and highly uncertain. In part, this is owing not only to data limitations and methodological challenges when integrating climate-driven VBD models and climate change projections, but also, perhaps most crucially, to the multitude of epidemiological, ecological and socio-economic factors that drive VBD transmission, and this complexity has generated considerable debate over the past 10–15 years. In this review, we seek to elucidate current knowledge around this topic, identify key themes and uncertainties, evaluate ongoing challenges and open research questions and, crucially, offer some solutions for the field. Although many of these challenges are ubiquitous across multiple VBDs, more specific issues also arise in different vector–pathogen systems.
Potential effects of warmer worms and vectors on onchocerciasis transmission in West Africa
Authors: Cheke Robert A. , Basáñez Maria-Gloria , Perry Malorie , White Michael T. , Garms Rolf , Obuobie Emmanuel , Lamberton Poppy H. L. , Young Stephen , Osei-Atweneboana Mike Y. , Intsiful Joseph , Shen Mingwang , Boakye Daniel A. , Wilson Michael D.
Published: February 2015

Development times of eggs, larvae and pupae of vectors of onchocerciasis (
Simulium
spp.) and of
Onchocerca volvulus
larvae within the adult females of the vectors decrease with increasing temperature. At and above 25°C, the parasite could reach its infective stage in less than 7 days when vectors could transmit after only two gonotrophic cycles. After incorporating exponential functions for vector development into a novel blackfly population model, it was predicted that fly numbers in Liberia and Ghana would peak at air temperatures of 29°C and 34°C, about 3°C and 7°C above current monthly averages, respectively; parous rates of forest flies (Liberia) would peak at 29°C and of savannah flies (Ghana) at 30°C. Small temperature increases (less than 2°C) might lead to changes in geographical distributions of different vector taxa. When the new model was linked to an existing framework for the population dynamics of onchocerciasis in humans and vectors, transmission rates and worm loads were projected to increase with temperature to at least 33°C. By contrast, analyses of field data on forest flies in Liberia and savannah flies in Ghana, in relation to regional climate change predictions, suggested, on the basis of simple regressions, that 13–41% decreases in fly numbers would be expected between the present and before 2040. Further research is needed to reconcile these conflicting conclusions.
Dengue: recent past and future threats
Authors: Rogers David J.
Published: February 2015

This article explores four key questions about statistical models developed to describe the recent past and future of vector-borne diseases, with special emphasis on dengue:

(1) How many variables should be used to make predictions about the future of vector-borne diseases?

(2) Is the spatial resolution of a climate dataset an important determinant of model accuracy?

(3) Does inclusion of the future distributions of vectors affect predictions of the futures of the diseases they transmit?

(4) Which are the key predictor variables involved in determining the distributions of vector-borne diseases in the present and future?

Examples are given of dengue models using one, five or 10 meteorological variables and at spatial resolutions of from one-sixth to two degrees. Model accuracy is improved with a greater number of descriptor variables, but is surprisingly unaffected by the spatial resolution of the data. Dengue models with a reduced set of climate variables derived from the HadCM3 global circulation model predictions for the 1980s are improved when risk maps for dengue's two main vectors (Aedes aegyptiandAedes albopictus) are also included as predictor variables; disease and vector models are projected into the future using the global circulation model predictions for the 2020s, 2040s and 2080s. The Garthwaite–Koch corr-max transformation is presented as a novel way of showing the relative contribution of each of the input predictor variables to the map predictions.
Spike sorting for large, dense electrode arrays
Authors: Rossant Cyrille , Kadir Shabnam , Goodman Dan F. M. , Schulman John , Belluscio Mariano , Buzsaki Gyorgy , Harris Kenneth D.
Published: February 2015

Developments in microfabrication technology have enabled the production of neural electrode arrays with hundreds of closely-spaced recording sites, and electrodes with thousands of sites are currently under development. These probes will in principle allow the simultaneous recording of very large numbers of neurons. However, use of this technology requires the development of techniques for decoding the spike times of the recorded neurons, from the raw data captured from the probes. There currently exists no practical solution to this problem of “spike sorting” for large, dense electrode arrays. Here, we present a set of novel tools to solve this problem, implemented in a suite of practical, user-friendly, open-source software. We validate these methods on data from rat cortex, demonstrating error rates as low as 5%.
Improving staff morale through authentic appreciation
Authors: White Paul
Published: February 2015

Purpose

– This paper aims to address the increasingly low levels of staff morale found in workplaces and the challenges managers have. Employees tend to view employee recognition programs cynically and the reasons for these reactions are explained, along with the negative results which follow. The concept of authentic appreciation is discussed, and the core components necessary for employees to feel truly valued and practical steps that can be taken are outlined.

Design/methodology/approach

– The paper reports lessons learned through the author’s experiences of applying the concepts to workplaces over the past several years.

Findings

– Job satisfaction and employee engagement are declining in spite of the proliferation of employee recognition programs. Employees perceive much employee recognition activity as being disingenuous, leading to apathy and sarcasm. There are structural issues that need to be corrected for employee recognition to be perceived as authentic – making recognition less generic, more individualized and communicated regularly in the manner that is valued by the recipients.

Practical implications

– Traditional approaches to employee recognition (awards and rewards) need to be re-evaluated. Continuing these activities may actually increase the negativity within a work environment. Learning what each individual employee values and then communicating appreciation to them in ways that are perceived as authentic is critical to having a positive result.

Originality/value

– The paper challenges the current (and growing) trend of impersonal employee recognition programs and examines the factors that contribute to recognition being perceived as inauthentic. The author then provides an alternative approach and methodology that facilitates the ability to communicate authentic appreciation.
Ownership concentration, ownership composition and the performance of the Kuwaiti listed non-financial firms
Authors: Al-Saidi Mejbel , Al-Shammari Bader
Published: February 2015

Purpose

– This paper aims to investigate the relationship between ownership structure (ownership concentration and ownership composition) and firm performance in Kuwaiti non-financial firms. To this end, it examines the relationship between firm performance and ownership concentration to determine whether the impact of this relationship is conditional on the nature of the large shareholders.

Design/methodology/approach

– First, the relationship between ownership concentration and firm performance was tested using ordinary least squares regressions on 618 observations (103 listed firms) from 2005 to 2010; next, the ownership compositions were classified as institutional, government and individuals (families) and their impact on firm performance examined.

Findings

– The overall concentration ownership by large shareholders showed no impact on firm performance. However, when the type of shareholders was introduced, only the government and individuals (families) ownership categories influenced firm performance. Therefore, certain types of shareholders are better at monitoring, and not all concentration by large shareholders is beneficial to Kuwaiti firms.

Research limitations/implications

– This study examined only one important aspect of the corporate governance mechanisms, namely, ownership concentration. Thus, further study may include other mechanisms such as board variables, role of debt and shareholders rights in examining the firm performance. This study is limited to the Kuwaiti environment, and thus, next step can be very useful in case of comparing ownership concentration in the Gulf Cooperation Council (Kuwait, Bahrain, Qatar, Oman, United Arab Emirates and Saudi Arabia) or across different Arab countries.

Practical implications

– The results of this study have important implications for the regulators in Kuwait in their efforts to increase the efficiency of the rapidly developing capital markets and in protecting investors and keeping confidence in the economy. They may mandate a corporate governance code to protect minority shareholders. Investors may use the findings to understand Kuwaiti companies. Such findings may assist them to diversify their investment portfolios.

Originality/value

– This paper extends literature review by investigating the role of large shareholders in the context of a developing country that is characterized by high level of ownership concentration and weak legal protection for investors as well as the absence of code that organized the corporate governance practices.
How SMEs use trade shows to enter global value chains
Authors: Measson Nadège , Campbell-Hunt Colin
Published: February 2015

Purpose

– By examining SMEs’ participation in trade fairs as a way to establish network relationships within a global value chain (GVC), the purpose of this paper is to offer one example of the steps used to reach this goal.

Design/methodology/approach

– The study uses a priori deductions derived from prior literature and case analysis of a purposive sample of six New Zealand SMEs to develop propositions on the use of trade fairs to enter a GVC network. The authors use the typology of GVC governance developed by Gereffi et al. (2005) to investigate how the use of trade fairs varies for each governance type.

Findings

– The study concludes that international trade fairs offer great network-building possibilities for SMEs, as well as selling, promotion and information gathering benefits. Both theoretical argument and experiential evidence suggest that these benefits are contingent on the GVC’s governance type.

Originality/value

– Although there is extensive work on the importance of networks to SME internationalisation, less has been done on the detailed steps used to build these networks.
Member perceptions of ESG investing through superannuation
Authors: de Zwaan Laura , Brimble Mark , Stewart Jenny
Published: February 2015

Purpose

– Environmental, social and governance (ESG) risks have the potential to negatively impact financial returns, yet few superannuation funds integrate these considerations into their investment selection. The Cooper Review (2010) identified a lack of member demand as a key impediment to ESG investing by superannuation funds. Given this problem, the aim of this study is to explore superannuation fund members’ perceptions of ESG investing by their funds in order to identify reasons for the lack of demand.

Design/methodology/approach

– An on-line survey was developed and distributed to assess possible reasons why members do not select ESG investment options. In total, 549 Australian superannuation fund members responded to the survey.

Findings

– Results indicate that the majority of superannuation fund members are interested in ESG investing. Members lack awareness of their fund’s approach to ESG investing, and they do not perceive there to be a financial penalty from ESG investing. Finally, members show a preference for consideration of governance issues over both social and environmental issues.

Research limitations/implications

– Respondents are well educated and the majority did not choose their superannuation fund. There was no measure of financial literacy included in the research instrument. There is also a general limitation in surveying superannuation fund members when they lack knowledge about superannuation.

Practical implications

– The results indicate that superannuation members are interested in both superannuation and ESG investing. Given the low take-up of ESG investment options, this finding raises the question of how effectively funds are engaging their members.

Social implications

– The results should be of interest to superannuation funds and may lead to renewed interest in promoting ESG products.

Originality/value

– This is the first study to examine superannuation members’ attitudes and behaviours towards ESG investing in the context of superannuation. The study also adds to our understanding of member decision-making in the $1.8 trillion superannuation industry.