bluuebunny/crossref_metadata_2025 huggingface dataset:
Fibrillar gels via the self-assembly of poly(l-glutamate)-based statistical copolymers
Authors: Vacogne Charlotte D. , Brosnan Sarah M. , Masic Admir , Schlaad Helmut
Published: May 2015

The synthesis of smart polypeptide hydrogels from photo-crosslinked self-assembled poly(γ-benzyl-l-glutamate-co-allylglycine) organogels is described.
Template-free synthesis of nanoporous gadolinium phosphonate as a magnetic resonance imaging (MRI) agent
Authors: Pramanik Malay , Shieh Fa-Kuen , Alshehri Saad M. , Alothman Zeid Abdullah , Wu Kevin C.-W. , Yamauchi Yusuke
Published: May 2015

Organic–inorganic hybrid porous gadolinium phosphonate materials are synthesized using benzene-1,3,5-triphosphonic acid as phosphonic acid linker.
Microgels formed by enzyme-mediated polymerization in reverse micelles with tunable activity and high stability
Authors: Bao Song , Wu Dongbei , Su Teng , Wu Qing , Wang Qigang
Published: May 2015

This communication describes the preparation of microgels via enzyme-triggered inverse emulsion polymerization, which provides an effective method for immobilizing enzymes with tunable catalytic performance and high stability.
Template-free synthesis of mesoporous CeO2powders by integrating bottom-up and top-down routes for acid orange 7 adsorption
Authors: Xu Yaohui , Li Ruixing
Published: May 2015

A combined bottom-up and top-down route was developed for the template-free synthesis of mesoporous CeO2powders.
Contactless bottom-up electrodeposition of nickel for 3D integrated circuits
Authors: Zhao Mingrui , Balachandran Rajesh , Patterson Zach , Gouk Roman , Verhaverbeke Steven , Shadman Farhang , Keswani Manish
Published: May 2015

Electrochemical oxidation of silicon by water generates electrons and subsequent chemical etching of silicon dioxide by fluoride based species regenerates the surface. The electrons are conducted through bulk silicon and accepted by nickel ions.
Chemical vapor deposition growth of few-layer graphene for transparent conductive films
Authors: Pu Jun , Tang Lei , Li Chaowei , Li Taotao , Ling Lin , Zhang Kai , Li Qingwen , Yao Yagang
Published: May 2015

The facile and scalable technique is demonstrated, which grow graphene with controllable layers on copper foil substrates using the etching effect of H2 in atmospheric pressure chemical vapor deposition (APCVD).
Degradation of the azo dye Orange G in a fluidized bed reactor using iron oxide as a heterogeneous photo-Fenton catalyst
Authors: Wang Yan , Priambodo Ricky , Zhang Hui , Huang Yao-Hui
Published: May 2015

Waste iron oxide could activate H2O2efficiently under UVA irradiation to degrade Orange G in a novel fluidized bed reactor.
Photoinduced self-assembly of carboxylic acid-terminated lamellar silsesquioxane: highly functional films for attaching and patterning amino-based ligands
Authors: Ni Lingli , Chemtob Abraham , Croutxé-Barghorn Céline , Dietlin Céline , Brendlé Jocelyne , Rigolet Séverinne , Vidal Loïc , Dieterlen Alain , Maalouf Elie , Haeberlé Olivier
Published: May 2015

A facile procedure for immobilizing and photopatterning amino ligands onto a multilayer cross-linked COOH-functionalized organosilica film is described. Key features include high functionality, robustness and no restriction on the substrate.
Synthesis, DNA/protein binding, molecular docking, DNA cleavage and in vitro anticancer activity of nickel(ii) bis(thiosemicarbazone) complexes
Authors: Haribabu Jebiti , Jeyalakshmi Kumaramangalam , Arun Yuvaraj , Bhuvanesh Nattamai S. P. , Perumal Paramasivan Thirumalai , Karvembu Ramasamy
Published: May 2015

Cytotoxic nickel(ii) complexes with an N-substituted isatin thiosemicarbazone were synthesized and their interaction with CT DNA and BSA protein was investigated, which was supported by molecular docking studies.
Identification of the first surrogate agonists for the G protein-coupled receptor GPR132
Authors: Shehata Mohamed A. , Belcik Christensen Hanna , Isberg Vignir , Sejer Pedersen Daniel , Bender Andreas , Bräuner-Osborne Hans , Gloriam David E.
Published: May 2015

We report the first pharmacological tool agonist for in vitro characterization of the orphan receptor GPR132, preliminary structure–activity relationships based on 32 analogs and a suggested binding mode from docking.
A unique fabrication strategy of hierarchical morphologies: combination of multi-step self-assembling and morphology transition
Authors: Zhang Wen-Jian , Hong Chun-Yan , Pan Cai-Yuan
Published: May 2015

Sea cucumber-like hierarchical microstructures were fabricated, and a multi-step self-assembling process was observed in the RAFT dispersion polymerization.
Engineering a nanostructured “super surface” with superhydrophobic and superkilling properties
Authors: Hasan Jafar , Raj Shammy , Yadav Lavendra , Chatterjee Kaushik
Published: May 2015

A “super surface” with superhydrophobic, self-cleaning and bactericidal properties for use in medical devices, instruments and microfluidics is presented.
Improving the fuel properties of biodiesel via complementary blending with diesel from direct coal liquefaction
Authors: Wang Jieni , Zhao Weina , Ai Yani , Chen Hongyan , Cao Leichang , Han Sheng
Published: May 2015

Complementary blending of biodiesel from waste cooking oil (BWCO) with diesel from direct coal liquefaction (DDCL) was evaluated to improve the fuel properties.
Electrochemical-driven water reduction and oxidation catalyzed by an iron(iii) complex supported by 2,3-bis(2-hydroxybenzylideneimino)-2,3-butenedinitrile
Authors: Fu Ling-Zhi , Zhou Ling-Ling , Zhan Shu-Zhong
Published: May 2015

One electrocatalyst, [FeLCl(H2O)] for both water reduction and oxidation with a TOF of 808.46 moles h−1 and 0.849 s−1, respectively.
Rapid separation and on-line detection by coupling high performance liquid chromatography with surface-enhanced Raman spectroscopy
Authors: Wang Wei , Xu Minmin , Guo Qinghua , Yuan Yaxian , Gu Renao , Yao Jianlin
Published: May 2015

The combined HPLC-SERS system was developed to a powerful tool for rapid separation and structural recognition of complex samples in food science and environmental monitoring.
Aggregated Pt–Pd nanoparticles on Nafion membrane for impulsive decomposition of hydrogen peroxide
Authors: Hasnat Mohammad A. , Rahman Mohammed M. , Siddiquey Iqbal A. , Borhanuddin S. M. , Alam M. Saiful , Rahman M. Hamidur , Asiri Abdullah M.
Published: May 2015

A Pd site initiates hydrogen peroxide decomposition by adsorbing one ‘O’ followed by splitting of O–H bond. Meanwhile, a Pt site finally completes the decomposition process by enabling desorption of the incipient O2species.
A simple and fast method based on new magnetic ion imprinted polymer nanoparticles for the selective extraction of Ni(ii) ions in different food samples
Authors: Asgharinezhad Ali Akbar , Jalilian Niloofar , Ebrahimzadeh Homeira , Panjali Zahra
Published: May 2015

A schematic diagram for the synthesis process of magnetic ion imprinted polymer nanoparticles.
Cross dehydrogenative coupling (CDC) of aldehydes with N-hydroxyimides by visible light photoredox catalysis
Authors: Dinda Milan , Bose Chandan , Ghosh Tridev , Maity Soumitra
Published: May 2015

A visible light mediated cross-dehydrogenative-coupling (CDC) reaction has been developed for the synthesis of N-hydroxyester derivatives from aldehydes and N-hydroxyimides.
Fabrication of a pH responsive DOX conjugated PEGylated palladium nanoparticle mediated drug delivery system: an in vitro and in vivo evaluation
Authors: Shanthi Krishnamurthy , Vimala Karuppaiya , Gopi Dhanaraj , Kannan Soundarapandian
Published: May 2015

Schematic illustration of the possible mechanism of pH based drug delivery system of DOX conjugated PEGylated PdNPs induced apoptosis in HeLa cells.
Effects of residual double bonds on the catalytic activity and stability of Pt/SDB hydrophobic catalysts
Authors: Li Xiuchun , Liu Cailin , Gou Kezhen , Yang Haijun , Ren Xianyan , Peng Bihui
Published: May 2015

With residual double bonds contents increasing, the binding energy of Pt/SDB increased, which made the catalytic activity and stability enhanced.
A new electro-generated o-dianisidine derivative stabilized MWCNT-modified GCE for low potential gallic acid detection
Authors: Sundaram Sornambikai , Jagannathan Madhanagopal , Abdul Kadir Mohammed Rafiq , Palanivel Sathishkumar , Hadibarata Tony , Mohammed Yusoff Abdul Rahim
Published: May 2015

An enone derivative of ao-dianisidine dimer stabilized GCE/MWCNT exhibited low potential gallic acid detection at 0.16 Vvs.Ag/AgCl.
Determination of rice sensory quality with similarity analysis-artificial neural network method in electronic tongue system
Authors: Lu Lin , Tian Shiyi , Deng Shaoping , Zhu Zhiwei , Hu Xianqiao
Published: May 2015

A novel similarity analysis-artificial neural network method was developed in electronic tongue system for predicting rice sensory quality.
Effect of alkali and alkaline earth metal ions on benzyl alcohol oxidation activity of titanate nanotube-supported Au catalysts
Authors: Nepak Devadutta , Srinivas Darbha
Published: May 2015

Au supported on barium titanate nanotubes showed higher catalytic activity for selective oxidation of benzyl alcohol with molecular oxygen.
Borylation of primary and secondary alkyl bromides catalyzed by Cu2O nanoparticles
Authors: Zhou Xin-Feng , Wu Ya-Dong , Dai Jian-Jun , Li Yong-Jia , Huang Yu , Xu Hua-Jian
Published: May 2015

A Cu2O nanoparticle catalyzed borylation of alkylboronic esters is developed, with mild reaction conditions, high yield and in the absence of ligands which otherwise are essential in homogenous catalysis, using bis(pinacolato)diboron as the boron source.
Prediction of novel crystal structures and superconductivity of compressed HBr
Authors: Lu Siyu , Wu Min , Liu Hanyu , Tse John S. , Yang Bai
Published: May 2015

CALYPSO predicts two novel structures of solid HBr with a relatively high superconductivity at sufficiently high pressure.
A continuous-flow droplet-based concentrator using ion concentration polarization
Authors: Phan Dinh-Tuan , Chun Yang , Nguyen Nam-Trung
Published: May 2015

We reports the continuous generation of droplets with concentrated sample conditioned ion concentration polarization.
The low dielectric constant and relaxation dielectric behavior in hydrogen-bonding metal–organic frameworks
Authors: Yu Shan-Shan , Yuan Guo-Jun , Duan Hai-Bao
Published: May 2015

A 3D hydrogen-bonding metal–organic framework shows a low dielectric constant and relaxation dielectric behavior at high temperature.
Ethynylene-linked benzo[1,2-b:4,5-b′]dithiophene-alt-diketopyrrolopyrrole alternating copolymer: optoelectronic properties, film morphology and photovoltaic applications
Authors: Wang Hongyu , Ding Yimin , Lai Yanbang , Sun Zhiwei , Liu Yao , Jiang Bin , Chen Ming , Yao Jian , Liu Feng , Russell Thomas P.
Published: May 2015

An ethynylene-linked copolymer was synthesized for increasing theVocof organic solar cells. And a highVocof 0.88 V was achieved due to the low-lying HOMO level.
Synthesis of hollow and rattle-type mesoporous silica spheres by treating layered mesoporous silica with a basic solution, and using the spheres as microreactors for two-phase reactions
Authors: Okamoto Masaki , Tsukada Hiroyuki , Fukasawa Syun , Sakajiri Aya
Published: May 2015

Adding hollow and rattle-type mesoporous silica spheres as microreactors to two-phase reactions, hydroformylation, halogen exchange reaction and esterification, increased reaction rates.
The migration mechanism of transition metal ions in LiNi0.5Mn1.5O4
Authors: Xu Gui-Liang , Qin Yan , Ren Yang , Cai Lu , An Ke , Amine Khalil , Chen Zonghai
Published: May 2015

In situ high-energy X-ray diffraction and neutron diffraction were deployed to trace the migration of transition metal ions in LiNi0.5Mn1.5O4.
Artificial photosynthesis dendrimers integrating light-harvesting, electron delivery and hydrogen production
Authors: Xun Zhiqing , Yu Tianjun , Zeng Yi , Chen Jinping , Zhang Xiaohui , Yang Guoqiang , Li Yi
Published: May 2015

Artificial photosynthesis dendrimers, which integrate light-harvesting, electron delivery and hydrogen production, were constructed and have demonstrated improved photocatalytic activity due to the dendritic architecture.
Reduced graphene oxide diffraction gratings from duplication of photoinduced azo polymer surface-relief-gratings through soft-lithography
Authors: Xiong Zhiyuan , Liao Cailian , Wang Xiaogong
Published: May 2015

Diffraction gratings made of reduced graphene oxide were fabricated by duplication of photoinduced azo polymer surface-relief-gratings through soft-lithography.
Spin-glass behavior and zero-field-cooled exchange bias in a Cr-based antiperovskite compound PdNCr3
Authors: Lin S. , Shao D. F. , Lin J. C. , Zu L. , Kan X. C. , Wang B. S. , Huang Y. N. , Song W. H. , Lu W. J. , Tong P. , Sun Y. P.
Published: May 2015

The nature of spin-glass behavior and zero-field-cooled exchange bias of antiperovskite PdNCr3has been confirmedviathe combination of experiment measurements and theoretical calculations.
Enhancing the photovoltaic properties of terpolymers containing benzo[1,2-b:4,5-b′]dithiophene, phenanthro[4,5-abc]phenazine and benzo[c][1,2,5]thiadiazole by changing the substituents
Authors: Fan Qunping , Liu Yu , Xiao Manjun , Su Wenyan , Gao Huishan , Chen Jianhua , Tan Hua , Wang Yafei , Yang Renqiang , Zhu Weiguo
Published: May 2015

In this study, three novel D–A-type terpolymers of PBDTT–PPzBT–H, PBDTT–PPzBT–F and PBDTT–PPzBT–O were synthesized by copolymerizing electron-rich BDTT and two electron-deficient PPz and BT units.
Evaluation of semiconducting molecular thin films solution-processed via the photoprecursor approach: the case of hexyl-substituted thienoanthracenes
Authors: Quinton Cassandre , Suzuki Mitsuharu , Kaneshige Yoshitaka , Tatenaka Yuki , Katagiri Chiho , Yamaguchi Yuji , Kuzuhara Daiki , Aratani Naoki , Nakayama Ken-ichi , Yamada Hiroko
Published: May 2015

The photoprecursor approach is superior to direct spin coating in preparing high quality organic semiconducting thin films.
Protein nanowires with conductive properties
Authors: Elfwing Anders , Bäcklund Fredrik G. , Musumeci Chiara , Inganäs Olle , Solin Niclas
Published: May 2015

We have investigated protein fibrils decorated with metallic polymers using conductive AFM.
Input‐to‐state stability of discrete‐time singular systems based on quasi‐min–max model predictive control
Authors: Gao Chan , Liu Xiao‐Hua , Li Wuquan
Published: May 2015

This study is concerned with robust quasi‐min–max model predictive control (MPC) for a class of discrete‐time singular systems with persistent disturbance and input constrains. To deal with the persistent disturbance, the authors introduce the notion of input‐to‐state stability (ISS) of discrete‐time singular system for the first time. The optimal control can be obtained by solving a quasi‐min–max optimal problem of a finite horizon cost function. On the basis of the proposed dual‐mode MPC approach, it can be proved that the closed‐loop discrete‐time singular system is ISS, regular and causal. Finally, a numerical simulation shows the feasibility and effectiveness of the proposed method.
Evaluation of the tactile detection response task in a laboratory test using a surrogate driving set‐up
Authors: Schindhelm Roland , Schmidt Eike
Published: May 2015

This study presents findings of a laboratory experiment which aimed at evaluating the sensitivity and intrusiveness of tactile detection response task (TDRT) methodology. Various single‐task, dual‐task and triple‐task scenarios were compared. The task scenarios included a surrogate of driving (tracking task) and different secondary tasks (N ‐back, surrogate reference task (SuRT)). The results suggest that the TDRT is sensitive to load levels of secondary tasks which primarily demand for cognitive resources (N ‐back). Sensitivity to variations of visual–manual load could not be shown (SuRT). TDRT seems also to be able to differentiate between modes of primary task which varies in terms of cognitive load (visual against auditory tracking task). Results indicated intrusiveness of TDRT on primary task performance and secondary task performance depending on the type of underlying task scenario. As a conclusion, TDRT can be recommended as a method to assess attentional effects of cognitive load of a secondary task, but should be used with caution for secondary tasks with strong motor demands.
Phasor estimation in power systems using a neural network with online training for numerical relays purposes
Authors: da Silva Chrystian Dalla Lana , Cardoso Junior Ghendy , Mariotto Lenois , Marchesan Gustavo
Published: May 2015

There are a few components of the current signal that may lead to inaccurate current measurement in power systems, and therefore, may cause malfunction on numerical protective relays and control devices. Some of these components include harmonics, the decaying DC offset, and noises. In this study, a phasor estimation method based on artificial neural networks is proposed, which will provide fast response time and accuracy. The method uses the multilayer perceptron structure to precisely estimate the amplitude and phase angle of the current waveform by determining its input weights during an online training process. The proposed algorithm is tested and compared with other reliable and well‐known methods for a performance evaluation.
Robust spatial multicasting for randomly distributed sensors
Authors: Sudha Gnanou Florence , Vaikundam Gurusamy
Published: May 2015

Beamforming is used in sensor networks to transfer data to remote stations with enhanced communication. When the position of array nodes and directions are known, it is better to form an approximate uniform linear array (ULA), uniform circular array (UCA) and uniform elliptical array (UEA). Since it is not always possible to find actual sensors matching with the ideal positions of ULA, UCA and UEA, least‐square (LS) estimation is used to calculate weights of the array elements. LS estimation does not give realisable weight values and yields transmission in unintended directions. Also, if many single beams arrays are used to transfer data simultaneously to different users, co‐channel interference occurs. In this study, to overcome these problems, multibeam array with restriction imposed on the weights is proposed and is reformulated as Tikhonov regularised LS (TRLS) method. This proposed spatial multicasting method is found to be robust up to 90% position variation of sensors for the ULA with weights under control improving the power efficiency and hence the spectral efficiency and data rate. Moreover, it is also observed that when a faulty node is substituted by nearby nodes, the weights calculated using TRLS method need not be recalculated.
Synthesis and electrochemical properties of tube‐like nitrogen‐doped graphene/manganese oxide composite for supercapacitors
Authors: Chen Chunnian , Ma Ting
Published: May 2015

A facile and simple method to prepare tube‐like nitrogen‐doped graphene (NG)/manganese oxide (Mn3O4) composite is introduced. The transmission electron microscopy patterns show that the Mn3O4 nanotubes were uniformly dispersed on the surface of the NGs. The composite was further investigated by Raman spectroscopy, X‐ray diffraction and X‐ray photoelectron spectroscopy. The electrochemical properties of NG/Mn3O4 composites were tested by cyclic voltammetry curves and galvanostatic charge–discharge curves. The results of the electrochemical measurement show the high capacitance and good long‐term stability of NG/Mn3O4 composites.
Investigation of structural changes in chiral magnet Cr1∕3NbS2 under application of pressure
Authors: Mito M. , Tajiri T. , Tsuruta K. , Deguchi H. , Kishine J. , Inoue K. , Kousaka Y. , Nakao Y. , Akimitsu J.
Published: May 2015

We perform structural analysis experiments on the chiral magnet Cr1∕3NbS2, in which Cr3+ ions are inserted between hexagonal NbS2 layers. The noncentrosymmetrical nature of the inserted Cr3+ appears as a distorted CrS6 octahedron. Under the application of hydrostatic pressure, the lattice shrinks significantly along the c-axis rather than the a-axis. However, at a pressure P of approximately 3–4 GPa, a kink in the rate of decrease in the lattice parameters is observed, and the slight movement of a Nb atom along the c-axis brings about a decrease in the distortion of the CrS6 octahedron. This structural change qualitatively suggests a decrease in the strength of the Dzyaloshinskii-Moriya (D-M) interaction. Under hydrostatic pressure, the magnetic ordering temperature TC decreases, and dTC/dP exhibits a slight change at around 3 GPa. A series of experiments indicates that the change in the structural symmetry of the CrS6 octahedron influences the exchange network between Cr3+ ions as well as the D-M interaction.
Image segmentation of nanoscale Zernike phase contrast X-ray computed tomography images
Authors: Kumar Arjun S. , Mandal Pratiti , Zhang Yongjie , Litster Shawn
Published: May 2015

Zernike phase contrast is a useful technique for nanoscale X-ray computed tomography (CT) imaging of materials with a low X-ray absorption coefficient. It enhances the image contrast by phase shifting X-ray waves to create changes in amplitude. However, it creates artifacts that hinder the use of traditional image segmentation techniques. We propose an image restoration method that models the X-ray phase contrast optics and the three-dimensional image reconstruction method. We generate artifact-free images through an optimization problem that inverts this model. Though similar approaches have been used for Zernike phase contrast in visible light microscopy, this optimization employs an effective edge detection method tailored to handle Zernike phase contrast artifacts. We characterize this optics-based restoration method by removing the artifacts in and thresholding multiple Zernike phase contrast X-ray CT images to produce segmented results that are consistent with the physical specimens. We quantitatively evaluate and compare our method to other segmentation techniques to demonstrate its high accuracy.
The fundamental downscaling limit of field effect transistors
Authors: Mamaluy Denis , Gao Xujiao
Published: May 2015

We predict that within next 15 years a fundamental down-scaling limit for CMOS technology and other Field-Effect Transistors (FETs) will be reached. Specifically, we show that at room temperatures all FETs, irrespective of their channel material, will start experiencing unacceptable level of thermally induced errors around 5-nm gate lengths. These findings were confirmed by performing quantum mechanical transport simulations for a variety of 6-, 5-, and 4-nm gate length Si devices, optimized to satisfy high-performance logic specifications by ITRS. Different channel materials and wafer/channel orientations have also been studied; it is found that altering channel-source-drain materials achieves only insignificant increase in switching energy, which overall cannot sufficiently delay the approaching downscaling limit. Alternative possibilities are discussed to continue the increase of logic element densities for room temperature operation below the said limit.
Humidity scanning quartz crystal microbalance with dissipation monitoring setup for determination of sorption-desorption isotherms and rheological changes
Authors: Björklund Sebastian , Kocherbitov Vitaly
Published: May 2015

A new method to determine water sorption-desorption isotherms with high resolution in the complete range of water activities (relative humidities) is presented. The method is based on quartz crystal microbalance with dissipation monitoring (QCM-D). The QCM-D is equipped with a humidity module in which the sample film is kept in air with controlled humidity. The experimental setup allows for continuous scanning of the relative humidity from either dry to humid conditions or vice versa. The amount of water sorbed or desorbed from the sample is determined from the resonance frequencies of the coated quartz sensor, via analysis of the overtone dependence. In addition, the method allows for characterization of hydration induced changes of the rheological properties from the dissipation data, which is closely connected to the viscoelasticity of the film. The accuracy of the humidity scanning setup is confirmed in control experiments. Sorption-desorption isotherms of pig gastric mucin and lysozyme, obtained by the new method, show good agreement with previous results. Finally, we show that the deposition technique used to coat the quartz sensor influences the QCM-D data and how this issue can be used to obtain further information on the effect of hydration. In particular, we demonstrate that spin-coating represents an attractive alternative to obtain sorption-desorption isotherms, while drop-coating provides additional information on changes of the rheological properties during hydration.
Detection of nanoscale embedded layers using laboratory specular X-ray diffraction
Authors: Beekman Matt , Rodriguez Gabriel , Atkins Ryan , Kunert James , Moore Daniel B. , Johnson David C.
Published: May 2015

Unusual specular X-ray diffraction patterns have been observed from certain thin film intergrowths of metal monochalcogenide (MX) and transition metal dichalcogenide (TX2) structures. These patterns exhibit selective “splitting” or broadening of selected (00l) diffraction peaks, while other (00l) reflections remain relatively unaffected [Atkins et al., Chem. Mater. 24, 4594 (2012)]. Using a simplified optical model in the kinematic approximation, we illustrate that these peculiar and somewhat counterintuitive diffraction features can be understood in terms of additional layers of one of the intergrowth components, MX or TX2, interleaved between otherwise “ideal” regions of MX-TX2 intergrowth. The interpretation is in agreement with scanning transmission electron microscope imaging, which reveals the presence of such stacking “defects” in films prepared from non-ideal precursors. In principle, the effect can be employed as a simple, non-destructive laboratory probe to detect and characterize ultrathin layers of one material, e.g., 2-dimensional crystals, embedded between two slabs of a second material, effectively using the two slabs as a highly sensitive interferometer of their separation distance.
Lattice dynamics of a mist-chemical vapor deposition-grown corundum-like Ga2O3 single crystal
Authors: Cuscó R. , Domènech-Amador N. , Hatakeyama T. , Yamaguchi T. , Honda T. , Artús L.
Published: May 2015

The lattice dynamical properties of the corundum-like α-phase of Ga2O3 are investigated by means of Raman scattering experiments and ab-initio calculations. A high-quality, single-crystal thick epilayer was grown on sapphire by the mist-chemical vapor deposition method. The phonon frequencies at the Brillouin zone center of all the Raman-active modes are determined by polarized Raman scattering measurements on an α-Ga2O3 single crystal. By performing backscattering measurements from (0001) and (101¯0) faces, all Raman active modes are unambiguously identified. Density functional perturbation theory calculations were carried out to determine the symmetry and the frequency of the α-Ga2O3 lattice modes. We find a good agreement between the theoretical predictions and the Raman spectra. The relative intensity of the different modes and their polarizability are discussed. The Raman spectrum is dominated by a narrow A1g peak which indicates the high crystalline quality of the layers grown by the mist chemical vapor deposition method.
Strain-controlled optical absorption in epitaxial ferroelectric BaTiO3 films
Authors: Chernova E. , Pacherova O. , Chvostova D. , Dejneka A. , Kocourek T. , Jelinek M. , Tyunina M.
Published: May 2015

A lattice strain of 0.3%–1.3% is achieved in epitaxial tetragonal BaTiO3 films grown on (001)-oriented SrTiO3 single-crystal substrates. Our experimental studies of absorption spectra in the range of 0.74–9.0 eV demonstrate that epitaxy produces significant changes in the optical properties of the films compared with those of a reference polydomain BaTiO3 crystal: the absorption edge and the peak at 5 eV strongly blue-shift by 0.2–0.4 eV, the magnitude of the peak at 5 eV drops, and certain spectral features disappear, whereas the absorption peak at 8.5 eV remains unchanged. The observed behavior is attributed to ferroelectric polarization, which is enhanced by epitaxial strain in the films. Our results indicate that epitaxially induced variations of ferroelectric polarization may be used to tailor the optical properties of thin films for photonic and optoelectronic applications.
Multi-strata subsurface laser die singulation to enable defect-free ultra-thin stacked memory dies
Authors: Teh W. H. , Boning D. , Welsch R.
Published: May 2015

We report the extension of multi-strata subsurface infrared (1.342 μm) pulsed laser die singulation to the fabrication of defect-free ultra-thin stacked memory dies. We exploit the multi-strata interactions between generated thermal shockwaves and the preceding high dislocation density layers formed to initiate crack fractures that separate the individual dies from within the interior of the die. We show that optimized inter-strata distances between the high dislocation density layers together with effective laser energy dose can be used to compensate for the high backside reflectance (up to ∼ 82%) wafers. This work has successfully demonstrated defect-free eight die stacks of 25 μm thick mechanically functional and 46 μm thick electrically functional memory dies.
Influence of dislocations on indium diffusion in semi-polar InGaN/GaN heterostructures
Authors: Yin Yao , Sun Huabin , Sang Liwen , Chen Peng , Zheng Youdou , Dierre Benjamin , Sumiya Masatomo , Shi Yi , Sekiguchi Takashi
Published: May 2015

The spatial distribution of indium composition in InGaN/GaN heterostructure is a critical topic for modulating the wavelength of light emitting diodes. In this letter, semi-polar InGaN/GaN heterostructure stripes were fabricated on patterned GaN/Sapphire substrates by epitaxial lateral overgrowth (ELO), and the spatial distribution of indium composition in the InGaN layer was characterized by using cathodoluminescence. It is found that the indium composition is mainly controlled by the diffusion behaviors of metal atoms (In and Ga) on the surface. The diffusivity of metal atoms decreases sharply as migrating to the region with a high density of dislocations and other defects, which influences the distribution of indium composition evidently. Our work is beneficial for the understanding of ELO process and the further development of InGaN/GaN heterostructure based devices.
Facile fabrication of a ultraviolet tunable MoS2/p-Si junction diode
Authors: Serrano William , Pinto Nicholas J. , Naylor Carl H. , Kybert Nicholas J. , Johnson A. T. Charlie
Published: May 2015

Chemical vapor deposition grown MoS2 single crystals were transferred onto the edge of a p-Si/SiO2 wafer, forming an abrupt heterogeneous junction diode at the MoS2/p-Si interface. When electrically characterized as a field effect transistor, MoS2 exhibits an n-type response and can be doped in the presence of ultraviolet (UV) light. As a diode, it operates satisfactorily in air, but has higher currents in vacuum with a turn on voltage of ∼1.3 V and an on/off ratio of 20 at ±2 V. UV irradiation increases the diode on state current, decreases the turn-on voltage, and reduces the ideality parameter below 2. These changes are reversible after annealing in air as desorption of electron trapping species like O2− and H2O− are believed responsible for this effect. A circuit integrating this diode was used to rectify a 1 kHz signal with an efficiency of 12%. Its simple design, coupled with the ability to clip AC signals, sense UV light, and reversibly tune these diodes, makes them inexpensive, multifunctional, and usable as active or passive circuit components in complex electronics.
Impact of elevated atmospheric humidity on anatomical and hydraulic traits of xylem in hybrid aspen
Authors: Jasińska Anna Katarzyna , Alber Meeli , Tullus Arvo , Rahi Märt , Sellin Arne
Published: May 2015

This study was performed on hybrid aspen saplings growing at the Free Air Humidity Manipulation site in Estonia. We investigated changes in wood anatomy and hydraulic conductivity in response to increased air humidity. Two hydraulic traits (specific conductivity and leaf-specific conductivity) and four anatomical traits of stem wood – relative vessel area (VA), vessel density (VD), pit area and pit aperture area – were influenced by the humidity manipulation. Stem hydraulic traits decreased in the apical direction, whereas branch hydraulic characteristics tended to be greatest in mid-canopy, associated with branch size. A reduction in VD due to increasing humidity was accompanied by a decrease in vessel lumen diameter, hydraulically weighted mean diameter (Dh), xylem vulnerability index and theoretical hydraulic conductivity. VA and Dh combined accounted for 87.4% of the total variation in kt of branches and 85.5% of that in stems across the treatments. Characters of branch vessels were more stable, and only the vessel-grouping index (the ratio of the total number of vessels to the total number of vessel groupings) was dependent on the interactive effect of the treatment and canopy position. Our results indicate that the increasing atmospheric humidity predicted for high latitudes will result in moderate changes in the structure and functioning of the hybrid aspen xylem.
Growth and spatiotemporal distribution of juvenile shortfin mako (Isurus oxyrinchus) in the western and central North Pacific
Authors: Kai M. , Shiozaki K. , Ohshimo S. , Yokawa K.
Published: May 2015

This paper presents an estimation of growth curves and spatiotemporal distributions of juvenile shortfin mako shark (Isurus oxyrinchus) in the western and central North Pacific Ocean using port sampling data collected from 2005 to 2013. The monthly length compositions show a clear transition of three modes in the size range of smaller than 150-cm precaudal length (PCL), which were believed to represent the growth of age-0 to age-2 classes, and they were then decomposed into age groups by fitting a Gaussian mixture distribution. Simulation data of lengths at monthly ages were generated from the mean and standard deviation of each distribution, and fit with a von Bertalanffy growth function. Parameters of the estimated growth curves for males and females were 274.4 and 239.4cm PCL for the asymptotic length and 0.19 and 0.25 year–1 for the growth coefficient indicating apparently faster growth than previously reported. Generalised linear models were applied to age-0 to explore the seasonal changes of PCL by area. They were born during late autumn and winter off the coast of north-eastern Japan, an area known to have relatively high productivity compared with other pelagic areas, and gradually expanded their habitat eastward and northward with the seasons as they grew.
Mapping seagrass cost-effectively in the Coral Triangle: Sabah, Malaysia as a case study
Authors: Rajamani Leela , Marsh Helene
Published: May 2015

Knowledge of the distribution and relative abundance of seagrass communities in the Coral Triangle is limited, despite their global significance and the vital ecosystem services they perform for local human populations, threatened species such as dugongs and green turtles, as well as the role of being a globally significant carbon stock. To address this gap and investigate cost-effective methods in data-poor regions, we conducted seagrass mapping near two islands off the coast of Sabah in Malaysia: Banggi Island (7°15′N, 117°12′E) and Mantanani Island (6°43′N, 116°21′E). We used a staged approach that included: (1) interview surveys, (2) manta tow and spot surveys, and (3) comprehensive transect surveys. Approximately 415 ha and 112 ha of seagrass meadows were mapped off Banggi Island and Mantanani Island respectively. We found 10 species of seagrasses from two families: Halophila ovalis, Halodule uninervis (broad and thin leaf varieties), Thalassia hemprichii, Cymodocea rotundata, Halophila decipiens, Halophila spinulosa, Cymodocea serrulata, Syringodium isoetifolium, Enhalus acoroides and Halophila sp. nov. Our methodology proved cost-effective and the resultant information should be relevant to conservation planners.
Range decline and conservation status of Westralunio carteri Iredale, 1934 (Bivalvia:Hyriidae) from south-western Australia
Authors: Klunzinger Michael W. , Beatty Stephen J. , Morgan David L. , Pinder Adrian M. , Lymbery Alan J.
Published: May 2015

Westralunio carteri is the only species of freshwater mussel found in south-western Australia and, owing to a lack of comprehensive information on its ecology, its conservation status has been speculative. To more accurately predict the true conservation status of this species, the historical and contemporary distributional records were modelled with environmental data that identified salinity, perenniality and total nitrogen as variables responsible for limiting the species’ current extent of occurrence, inferring threatening processes. The species was found to have undergone a 49% reduction in extent of occurrence in less than three generations, due primarily to secondary salinisation. Current distribution is bounded by Gingin Brook in the north to the Kent, Goodga and Waychinicup Rivers in the South, within 50–100 km of coastal south-western Australia. Field observations indicated that W. carteri was almost never found at sites where mean salinity was >1.6 g L–1. This was corroborated by laboratory tolerance trials that showed that W. carteri has an acute salinity tolerance (LD50) of 1.6–3.0 g L–1. Application of IUCN Red List criteria indicates that W. carteri qualifies for listing as vulnerable. Conservation management measures should focus on maintaining existing populations.
Early land use and centennial scale changes in lake-water organic carbon prior to contemporary monitoring
Authors: Meyer-Jacob Carsten , Tolu Julie , Bigler Christian , Yang Handong , Bindler Richard
Published: May 2015

Significance

Monitoring programs have recorded increases in organic carbon concentrations in northern lakes, which have important implications for water quality and ecosystem functioning. Current hypotheses interpret this trend in light of recent environmental changes such as acidification and climate but do not include an examination of long-term changes and their causes. We inferred past trends from sediment archives across central Sweden, allowing us to assess recent changes on a millennial scale. Our data demonstrate that a long-term decline beginning already in the 15th century preceded the recent organic carbon increase. This was a response to spatially extensive human–landscape interactions that included forest grazing and mire exploitation, which were common across Europe and altered carbon cycling between terrestrial and aquatic ecosystems.
Imaging metabolite dynamics in living cells using a Spinach-based riboswitch
Authors: You Mingxu , Litke Jacob L. , Jaffrey Samie R.
Published: May 2015

Significance

Developing sensors to image cellular metabolites and signaling molecules in living cells is challenging. Here we describe Spinach riboswitches, a novel class of genetically encoded metabolite sensor based on riboswitches, a group of naturally occurring ligand-binding RNAs. Spinach riboswitches use Spinach, an RNA aptamer that binds and activates the fluorescence of an otherwise nonfluorescent small-molecule fluorophore. Drawing upon structural insights into the mechanism of structural switching in riboswitches, we show that Spinach can be swapped into various riboswitches, allowing metabolite binding to induce Spinach fluorescence directly. Expression of Spinach riboswitches in cells allows metabolite levels to be imaged in real time in live bacterial cells. Spinach riboswitches thus provide a novel approach to image cellular metabolites in living cells.
MYC oncogene overexpression drives renal cell carcinoma in a mouse model through glutamine metabolism
Authors: Shroff Emelyn H. , Eberlin Livia S. , Dang Vanessa M. , Gouw Arvin M. , Gabay Meital , Adam Stacey J. , Bellovin David I. , Tran Phuoc T. , Philbrick William M. , Garcia-Ocana Adolfo , Casey Stephanie C. , Li Yulin , Dang Chi V. , Zare Richard N. , Felsher Dean W.
Published: May 2015

Significance

The absence of appropriate transgenic animal models of renal cell carcinomas (RCCs) has made it difficult to identify and test new therapies for this disease. We developed a new transgenic mouse model of a highly aggressive form of RCC in which tumor growth and regression is conditionally regulated by the MYC oncogene. Using desorption electrospray ionization–mass-spectrometric imaging, we found that certain glycerophosphoglycerols and metabolites of the glutaminolytic pathway were higher in abundance in RCC than in normal kidney tissue. Up-regulation of glutaminolytic genes and proteins was identified by genetic analysis and immunohistochemistry, therefore suggesting that RCC tumors are glutamine addicted. Pharmacological inhibition of glutaminase slowed tumor progression in vivo, which may represent a novel therapeutic route for RCC.
Dynamic phospholipid interaction of β2e subunit regulates the gating of voltage-gated Ca2+ channels
Authors: Kim Dong-Il , Park Yongsoo , Jang Deok-Jin , Suh Byung-Chang
Published: May 2015

High voltage-activated Ca2+ (CaV) channels are protein complexes containing pore-forming α1 and auxiliary β and α2δ subunits. The subcellular localization and membrane interactions of the β subunits play a crucial role in regulating CaV channel inactivation and its lipid sensitivity. Here, we investigated the effects of membrane phosphoinositide (PI) turnover on CaV2.2 channel function. The β2 isoform β2e associates with the membrane through electrostatic and hydrophobic interactions. Using chimeric β subunits and liposome-binding assays, we determined that interaction between the N-terminal 23 amino acids of β2e and anionic phospholipids was sufficient for β2e membrane targeting. Binding of the β2e subunit N terminus to liposomes was significantly increased by inclusion of 1% phosphatidylinositol 4,5-bisphosphate (PIP2) in the liposomes, suggesting that, in addition to phosphatidylserine, PIs are responsible for β2e targeting to the plasma membrane. Membrane binding of the β2e subunit slowed CaV2.2 current inactivation. When membrane phosphatidylinositol 4-phosphate and PIP2 were depleted by rapamycin-induced translocation of pseudojanin to the membrane, however, channel opening was decreased and fast inactivation of CaV2.2(β2e) currents was enhanced. Activation of the M1 muscarinic receptor elicited transient and reversible translocation of β2e subunits from membrane to cytosol, but not that of β2a or β3, resulting in fast inactivation of CaV2.2 channels with β2e. These results suggest that membrane targeting of the β2e subunit, which is mediated by nonspecific electrostatic insertion, is dynamically regulated by receptor stimulation, and that the reversible association of β2e with membrane PIs results in functional changes in CaV channel gating. The phospholipid–protein interaction observed here provides structural insight into mechanisms of membrane–protein association and the role of phospholipids in ion channel regulation.
Superradiant Instability of D-Dimensional Reissner—Nordström Black Hole Mirror System*
Authors: Li Ran , Zhao Jun-Kun , Zhang Yan-Ming
Published: May 2015

We analytically study the superradiant instability of charged massless scalar field in the background of D-dimensional Reissner-Nordström (RN) black hole caused by mirror-like boundary condition. By using the asymptotic matching method to solve the Klein-Gordon equation that governs the dynamics of scalar field, we have derived the expressions of complex parts of boxed quasinormal frequencies, and shown they are positive in the regime of superradiance. This indicates the charged scalar field is unstable in D-dimensional Reissner-Nordström (RN) black hole surrounded by mirror. However, the numerical work to calculate the boxed quasinormal frequencies in this system is still required in the future.
High Efficiency Four-Wave Mixing with Relaxation Coupling of Longitude-Optical Phonons in Semiconductor Quantum Wells*
Authors: She Yan-Chao , Zheng Xue-Jun , Wang Deng-Long , Ding Jian-Wen
Published: May 2015

The time-dependent analysis of four-wave mixing (FWM) has been performed in four-level double semiconductor quantum wells (SQWs) considering the cross-coupling of the longitude-optical phonons (LOP) relaxation. It is shown that both the amplitude and the conversion efficiency of the FWM field enhance greatly with the increasing strength of cross-coupling of LOP relaxation. Interestingly, a double peak value of the conversion efficiency is obtained under a relatively weak single-photon detuning considering the LOP coupling. When the detuning becomes stronger, the double peaks turn into one peak appearing at the line respect to the about equality two control fields. The results can be interpreted by the effect of electromagnetically induced transparency and the indirect transition. Such controlled high efficiency FWM based on the cross-coupling LOP may have potential applications in quantum control and communications.
Structural and Interaction Properties of Porphyrin Layers — A Quantum Chemical Study
Authors: Praveena G. , Abiram A.
Published: May 2015

This paper is proposed to understand the interaction of porphyrin layers with diatomic molecules interacting at their interior regions by applying ab initio and density functional theory (DFT) methods. We have used NO, CO, and O2 diatomic molecules to interact with the porphyrin layers. The most common Fe-centered metalloporphyrin structure with tetra-pyrrlic rings having N4 core is chosen for the study. The optimization of Porphyrin-Porphyrin (PI-PII) and Porphyrin-Diatomic molecule-Porphyrin (PI-AB-PII) (AB = NO, CO, and O2) complexes are performed using HF method. In order to understand the planarity and appropriate stacking size of porphyrins and also to infer the separation of diatomic molecules between porphyrin layers the behavior of PI-AB-PII complexes (where AB = NO, CO, and O2) are analyzed using structural properties and molecular electrostatic potentials (MEP). The MEPs are calculated using hybrid exchange correlation functional B3PW91 of DFT along with 6-31+G* basis set for the PI-PII and PI-AB-PII complexes obtained from HF method.
Cytoskeleton Dynamics: A Continuum Cooperative Hydrolysis Model*
Authors: Xu Jian-Wei , Cheng Bo , Feng Yu-Yu , Wang Zi-Qing , Wang Guo-Dong
Published: May 2015

Cytoskeleton is a network of filamentous proteins, such as actin filaments and microtubules. We propose a continuum cooperative hydrolysis model which possesses exactly analytical solution to describe the dynamics of filament. The results show that the cooperativity leads to non negative-exponential distribution of T (ATP or GTP) subunits. As an application, we investigate the treadmilling phenomenon using our model. It is shown that the cooperativity remarkably affects the length of filament.
Imaging on a sphere with interferometers: the spherical wave harmonic transform
Authors: Carozzi T. D.
Published: May 2015

I present an exact and explicit solution to the scalar (Stokes flux intensity) radio interferometer imaging equation on a spherical surface which is valid also for non-coplanar interferometer configurations. This imaging equation is comparable to w-term imaging algorithms, but by using a spherical rather than a Cartesian formulation this term has no special significance. The solution presented also allows direct identification of the scalar (spin 0 weighted) spherical harmonics on the sky. The method should be of interest for future multispacecraft interferometers, wide-field imaging with non-coplanar arrays, and cosmic microwave background spherical harmonic measurements using interferometers.