bluuebunny/crossref_metadata_2025 huggingface dataset:
Studying the Polarization Switching in Polycrystalline BiFeO3 Films by 2D Piezoresponse Force Microscopy
Authors: Jin Yaming , Lu Xiaomei , Zhang Junting , Kan Yi , Bo Huifeng , Huang Fengzhen , Xu Tingting , Du Yingchao , Xiao Shuyu , Zhu Jinsong
Published: July 2015

For rhombohedral multiferroelectrics, non-180° ferroelectric domain switching may induce ferroelastic and/or (anti-)ferromagnetic effect. So the determination and control of ferroelectric domain switching angles is crucial for nonvolatile information storage and exchange-coupled magnetoelectric devices. We try to study the intrinsic characters of polarization switching in BiFeO3 by introducing a special data processing method to determine the switching angle from 2D PFM (Piezoresponse Force Microscopy) images of randomly oriented samples. The response surface of BiFeO3 is first plotted using the piezoelectric tensor got from first principles calculations. Then from the normalized 2D PFM signals before and after switching, the switching angles of randomly oriented BiFeO3 grains can be determined through numerical calculations. In the polycrystalline BiFeO3 films, up to 34% of all switched area is that with original out-of-plane (OP) polarization parallel to the poling field. 71° polarization switching is more favorable, with the area percentages of 71°, 109° and 180° domain switching being about 42%, 29% and 29%, respectively. Our analysis further reveals that IP stress and charge migration have comparable effect on switching and they are sensitive to the geometric arrangements. This work helps exploring a route to control polarization switching in BiFeO3, so as to realize desirable magnetoelectric coupling.
A Josephson radiation comb generator
Authors: Solinas P. , Gasparinetti S. , Golubev D. , Giazotto F.
Published: July 2015

We propose the implementation of a Josephson Radiation Comb Generator (JRCG) based on a dc superconducting quantum interference device (SQUID) driven by an external magnetic field. When the magnetic flux crosses a diffraction node of the critical current interference pattern, the superconducting phase undergoes a jump of π and a voltage pulse is generated at the extremes of the SQUID. Under periodic drive this allows one to generate a sequence of sharp, evenly spaced voltage pulses. In the frequency domain, this corresponds to a comb-like structure similar to the one exploited in optics and metrology. With this device it is possible to generate up to several hundreds of harmonics of the driving frequency. For example, a chain of 50 identical high-critical-temperature SQUIDs driven at 1 GHz can deliver up to a 0.5 nW at 200 GHz. The availability of a fully solid-state radiation comb generator such as the JRCG, easily integrable on chip, may pave the way to a number of technological applications, from metrology to sub-millimeter wave generation.
Insights into the key interactions between human protein phosphatase 5 and cantharidin using molecular dynamics and site-directed mutagenesis bioassays
Authors: Liu Ji-Yuan , Chen Xi-En , Zhang Ya-Lin
Published: July 2015

Serine/threonine protein phosphatase 5 (PP5) is a promising novel target for anticancer therapies. This work aims to uncover the key interactions at the atomic level between PP5 and three inhibitors (cantharidin, norcantharidin and endothall). We found that, unlike previous report, Arg 100 contributes less to PP5-inhibitor binding and the residues His 69, Asn 128, His 129, Arg 225, His 252 and Arg 250 are of importance to PP5-inhibitor binding. The hydrophobic interactions established between the residues Val 254, Phe 271 and Tyr 276, especially Glu 253, are very important to enhance the inhibitive interaction. We suggested that, to increase the inhibitory activity, the interactions of inhibitor with three negatively charged unfavorable interaction residues, Asp 99, Glu 130 and Asp 213, should be avoided. However, the interactions of inhibitor with favorable interaction residue Arg 250 could enhance the inhibitory activity. The Manganese ion 2 (MN2) unfavorably contribute to the total interaction free energies. The coordination between MN2 and chemical group of inhibitor should be eliminated. This work provides insight into how cantharidin and its analogs bind to PP5c at the atomic level and will facilitate modification of cantharidin-like chemicals to rationally develop more specific and less cytotoxic anti-cancer drugs.
Understanding the cryotolerance of lactic acid bacteria using combined synchrotron infrared and fluorescence microscopies
Authors: Passot Stéphanie , Gautier Julie , Jamme Frédéric , Cenard Stéphanie , Dumas Paul , Fonseca Fernanda
Published: July 2015

Combining synchrotron-FTIR microspectroscopy and fluorescence microscopy made it possible the simultaneous assessment of biochemistry and physiological state of small bacterial cells for better understanding the mechanisms of cell cryotolerance.
Oligonucleotide aptamers: emerging affinity probes for bioanalytical mass spectrometry and biomarker discovery
Authors: Gülbakan Basri
Published: July 2015

Aptamers have great potential in affinity mass spectrometry to improve selectivity, specificity and throughput. This review discusses the bioanalytical mass spectrometry and biomarker discovery applications of aptamers.
An eco-friendly HPTLC method for assay of eszopiclone in pharmaceutical preparation: investigation of its water-induced degradation kinetics
Authors: El-Yazbi Amira F. , Youssef Rasha M.
Published: July 2015

An eco-friendly, sensitive and selective high-performance thin-layer chromatographic method was developed and validated for analysis of eszopiclone in bulk powder and formulation.
Production of ultra-deep sulfur-free diesels using a sustainable catalytic system based on UiO-66(Zr)
Authors: Granadeiro Carlos M. , Ribeiro Susana O. , Karmaoui Mohamed , Valença Rita , Ribeiro Jorge C. , de Castro Baltazar , Cunha-Silva Luís , Balula Salete S.
Published: July 2015

The porous metal–organic framework UiO-66(Zr) is a remarkable and highly efficient heterogeneous catalyst for the production of sulfur-free diesels.
pKa tuning in quadrupolar-type two-photon ratiometric fluorescent membrane probes
Authors: Daniel Jonathan , Mastrodonato Cristiano , Sourdon Aude , Clermont Guillaume , Vabre Jean-Marie , Goudeau Bertrand , Voldoire Hannah , Arbault Stéphane , Mongin Olivier , Blanchard-Desce Mireille
Published: July 2015

Two ratiometric two-photon pH probes were designed, combining pKa values close to physiological pH and large two-photon absorption responses. They are able to stain efficiently GUV and cell membranes.
Preservation of epoxy groups on surfaces in the covalent attachment of butadiene monoxide on Si(111)-(7×7): the effect of a vinyl substituent
Authors: Mao Wei , He Jing Hui , Gu Jia Qiang , Chen Wei , Wu Kai , Tok Eng Soon , Xu Guo Qin
Published: July 2015

A vinyl substituent ensures that butadiene monoxide selectively binds to Si(111)-(7×7) through a [2+2]-like cycloaddition, maintaining an epoxy group in the cycloadduct.
A fluorescent G-quadruplex probe for the assay of base excision repair enzyme activity
Authors: Lee Chang Yeol , Park Ki Soo , Park Hyun Gyu
Published: July 2015

A G-quadruplex probe incorporating 2-AP is utilized to develop a novel strategy to accurately determine UDG activity. The excision reaction promoted by UDG is designed to trigger the formation of G-quadruplex structure with significant fluorescence enhancement of 2-AP within the probe. By employing this strategy, UDG activity can be reliably determined with high sensitivity and specificity.
A simple model of burst nucleation
Authors: Baronov Alexandr , Bufkin Kevin , Shaw Dan W. , Johnson Brad L. , Patrick David L.
Published: July 2015

We introduce a comprehensive quantitative treatment for burst nucleation (BN), a kinetic pathway toward self-assembly or crystallization defined by an extended post-supersaturation induction period, followed by a burst of nucleation, and finally the growth of existing stable assemblages absent the formation of new ones, based on a hybrid mean field rate equation model incorporating thermodynamic treatment of the saturated solvent from classical nucleation theory.
Fluorescence switching of sanguinarine in micellar environments
Authors: Satpathi Sagar , Gavvala Krishna , Hazra Partha
Published: July 2015

Conversion from iminium to alkanolamine form of Sanguinarine, a key member of benzylisoquinoline alkaloid family, is monitored in micellar environments by fluorescence switch.
Novel flexible belt-shaped coaxial microcables with tunable multicolor luminescence, electrical conductivity and magnetism
Authors: Shao Hong , Ma Qianli , Dong Xiangting , Yu Wensheng , Yang Ming , Yang Ying , Wang Jinxian , Liu Guixia
Published: July 2015

Novel flexible belt-shaped coaxial microcables [Fe3O4/PANI/PMMA]@{[Eu(BA)3phen + Tb(BA)3phen]/PMMA} with tunable multicolor luminescence, electrical conductivity and magnetism have been successfully fabricated by one-pot electrospinning.
Isotope-edited FTIR reveals distinct aggregation and structural behaviors of unmodified and pyroglutamylated amyloid β peptides
Authors: Goldblatt Greg , Matos Jason O. , Gornto Jeremy , Tatulian Suren A.
Published: July 2015

Isotope-edited FTIR has been used to structurally characterize the early oligomers of amyloid β peptide Aβ1–42and the pyroglutamylated peptide AβpE3–42.
Negative thermal expansion and anomalies of heat capacity of LuB50 at low temperatures
Authors: Novikov V. V. , Zhemoedov N. A. , Matovnikov A. V. , Mitroshenkov N. V. , Kuznetsov S. V. , Bud'ko S. L.
Published: July 2015

Heat capacity and thermal expansion of LuB50 boride were experimentally studied in the 2–300 K temperature range.
Enhancement of white-light-emission from single-phase Sr5(PO4)3F:Eu2+,Mn2+ phosphors for near-UV white LEDs
Authors: Feng Yaomiao , Huang Jinping , Liu Lili , Liu Jie , Yu Xibin
Published: July 2015

Single-phase Sr5(PO4)3F:Eu2+,Mn2+ phosphors are prepared, showing white-light emission under near UV excitation. The photoluminescence intensity is enhanced by 85% by using KCl as flux. The relationship between photoluminescence and the crystal and electronic structures is studied.
The addition of bromine and iodine to palladacyclopentadienyl complexes bearing bidentate heteroditopic P−N spectator ligands derived from differently substituted quinolinic frames. The unexpected evolution of the reaction
Authors: Canovese Luciano , Visentin Fabiano , Scattolin Thomas , Santo Claudio , Bertolasi Valerio
Published: July 2015

The palladacyclopentadienyl complexes with substituted phosphoquinolines react with halogens giving σ-butadienyl or a zwitterionic derivative depending on the ligand structure.
Synthesis and characterization of a polyborosilazane/Cp2ZrCl2 hybrid precursor for the Si–B–C–N–Zr multinary ceramic
Authors: Long Xin , Shao Changwei , Wang Hao , Wang Jun
Published: July 2015

A Si–B–C–N–Zr multinary ceramic was prepared via pyrolysis of a novel zirconium-contained polyborosilazane.
C–F sp2 bond functionalization mediated by niobium complexes
Authors: Nechayev Michael , Gianetti Thomas L. , Bergman Robert G. , Arnold John
Published: July 2015

The functionalization of fluorobenzene is described via insertion of isocyanide after the oxidative addition of the C–F bond.
Dopant and excitation wavelength dependent color-tunable white light-emitting Ln3+:Y2WO6 materials (Ln3+ = Sm, Eu, Tb, Dy)
Authors: Van Deun Rik , Ndagsi Dorine , Liu Jing , Van Driessche Isabel , Van Hecke Kristof , Kaczmarek Anna M.
Published: July 2015

Color-tunable Y2WO6 microstructures doped or co-doped with Sm3+, Eu3+, Tb3+, and Dy3+ were synthesized in the presence of glycerol both as a solvent and a structure directing agent for obtaining white light emitting materials.
Insights into the growth of bismuth nanoparticles on 2D structured BiOCl photocatalysts: an in situ TEM investigation
Authors: Chang Xiaofeng , Wang Shuangbao , Qi Qi , Gondal Mohammed A. , Rashid Siddique G. , Gao Si , Yang Deyuan , Shen Kai , Xu Qingyu , Wang Peng
Published: July 2015

The formation and growth of bismuth nanoparticles onto BiOCl have been directly observed and characterized using a transmission electron microscope.
Synthesis, structure, and reactivity of iridium perfluorocarbene complexes: regio- and stereo-specific addition of HCl across a metal carbon double bond
Authors: Yuan Jian , Bourgeois Cheryl J. , Rheingold Arnold L. , Hughes Russell P.
Published: July 2015

Addition of HCl to perfluorocarbene complexes of iridium occurs regiospecifically and stereospecifically.
Au-iClick mirrors the mechanism of copper catalyzed azide–alkyne cycloaddition (CuAAC)
Authors: Powers Andrew R. , Ghiviriga Ion , Abboud Khalil A. , Veige Adam S.
Published: July 2015

Isolated digold-triazolate products and first-order kinetic profiles for Au–acetylide/azide reactants in iClick provide compelling support for two copper ions in CuAAC.
Spectroscopically tracking charge separation in polymer : fullerene blends with a three-phase morphology
Authors: Gallaher Joseph K. , Prasad Shyamal K. K. , Uddin Mohammad A. , Kim Taehyo , Kim Jin Young , Woo Han Young , Hodgkiss Justin M.
Published: July 2015

Transient absorption spectroscopy reveals that the superior performance of three-versus two-phase polymer : fullerene blends is associated with hole migration from intermixed to pure polymer phases.
The acute impact of polyphenols from Hibiscus sabdariffa in metabolic homeostasis: an approach combining metabolomics and gene-expression analyses
Authors: Beltrán-Debón Raúl , Rodríguez-Gallego Esther , Fernández-Arroyo Salvador , Senan-Campos Oriol , Massucci Francesco A. , Hernández-Aguilera Anna , Sales-Pardo Marta , Guimerà Roger , Camps Jordi , Menendez Javier A. , Joven Jorge
Published: July 2015

The acute multifunctional effects of polyphenols in humans.
Ni nanoparticles encapsulated into mesoporous single-crystalline HBEA: application for drainage oil hydrodeoxygenation to diesel
Authors: Ma Bing , Hu Jiangbo , Wang Yimeng , Zhao Chen
Published: July 2015

A new and promising strategy for encapsulating Ni nanoclusters (d = 5.6 nm) into the uniform and inter-connected intra-mesopores (7–8 nm) of single-crystalline HBEA, achieving highly dispersive Ni nanoparticles (content: 40 wt%, dispersion: 3.5%) on the stable carrier.
Cell spreading area regulates clathrin-coated pit dynamics on micropatterned substrate
Authors: Tan Xinyu , Heureaux Johanna , Liu Allen P.
Published: July 2015

Clathrin-coated pit dynamics changes with different cell spreading area revealed by microcontact printing and total internal reflection fluorescence microscopy.
Interstitial flows promote amoeboid over mesenchymal motility of breast cancer cells revealed by a three dimensional microfluidic model
Authors: Huang Yu Ling , Tung Chih-kuan , Zheng Anqi , Kim Beum Jun , Wu Mingming
Published: July 2015

A novel microfluidic model reveals roles of interstitial flows in regulating tumor cell morphology and migration within a 3D collagen matrix. This work highlights the importance of biological flows in tumor cell dissemination.
Measurement of the entrainment window of islets of Langerhans by microfluidic delivery of a chirped glucose waveform
Authors: Dhumpa Raghuram , Truong Tuan M. , Wang Xue , Roper Michael G.
Published: July 2015

A microfluidic device was used to deliver chirped glucose waves to find the entrainment regions of islets of Langerhans.
2015 Atomic Spectrometry Update – a review of advances in X-ray fluorescence spectrometry and their applications
Authors: West Margaret , Ellis Andrew T. , Potts Philip J. , Streli Christina , Vanhoof Christine , Wobrauschek Peter
Published: July 2015

This review covers developments in and applications of XRF techniques such as EDXRF, WDXRF, TXRF, XRF microscopy using technologies such as synchrotron sources, X-ray optics, X-ray tubes and detectors in laboratory, mobile and hand-held systems.
Neural probes with multi-drug delivery capability
Authors: Shin Hyogeun , Lee Hyunjoo J. , Chae Uikyu , Kim Huiyoung , Kim Jeongyeon , Choi Nakwon , Woo Jiwan , Cho Yakdol , Lee C. Justin , Yoon Eui-Sung , Cho Il-Joo
Published: July 2015

Multi-functional neural probes are promising platforms to conduct efficient and effective in-depth studies of brain by recording neural signals as well as modulating the signals with various stimuli.
Electrical-field-driven metal–insulator transition tuned with self-aligned atomic defects
Authors: Syrlybekov Askar , Wu Han-Chun , Mauit Ozhet , Wu Ye-Cun , Maguire Pierce , Khalid Abbas , Ó Coileáin Cormac , Farrell Leo , Heng Cheng-Lin , Abid Mohamed , Liu Huajun , Yang Li , Zhang Hong-Zhou , Shvets Igor V.
Published: July 2015

An anisotropic resistance switching behavior has been observed in Fe3O4 thin films on stepped SrTiO3 substrates.
Achieving significantly enhanced visible-light photocatalytic efficiency using a polyelectrolyte: the composites of exfoliated titania nanosheets, graphene, and poly(diallyl-dimethyl-ammonium chloride)
Authors: Zhang Qian , An Qi , Luan Xinglong , Huang Hongwei , Li Xiaowei , Meng Zilin , Tong Wangshu , Chen Xiaodong , Chu Paul K. , Zhang Yihe
Published: July 2015

Using a polyelectrolyte and rGO to boost the photocatalystic performance of titania nanosheet.
Nano-structural characteristics of carbon nanotube–polymer composite films for high-amplitude optoacoustic generation
Authors: Baac Hyoung Won , Ok Jong G. , Lee Taehwa , Jay Guo L.
Published: July 2015

We demonstrate nano-structural characteristics of carbon nanotube (CNT)–polydimethylsiloxane (PDMS) composite films that can be used as highly efficient and robust ultrasound transmitters for diagnostic and therapeutic applications.
Synthesis and inhibitive performance of novel cationic and gemini surfactants on carbon steel corrosion in 0.5 M H2SO4solution
Authors: Hegazy M. A. , El-Tabei A. S. , Bedair A. H. , Sadeq M. A.
Published: July 2015

Novel cationic and gemini surfactants are corrosion inhibitors.
Gold supported on Ti incorporated MCM-36 as efficient catalysts in propylene epoxidation with H2and O2
Authors: Jin Fang , Lin Tsung-Han , Chang Chih-Cheng , Wan Ben-Zu , Lee Jyh-Fu , Cheng Soofin
Published: July 2015

Au NPs supported on titanosilicate pillared MCM-36 with 2 nm mesopores were prepared. The influence of the Ti coordination environment on the particle size of anchored Au NPs and their catalytic performance in propylene epoxidation with H2/O2mixtures were investigated.
NiCo2O4 3 dimensional nanosheet as effective and robust catalyst for oxygen evolution reaction
Authors: Xiao Yao , Feng Ligang , Hu Chaoquan , Fateev Vladimir , Liu Changpeng , Xing Wei
Published: July 2015

3D self-supported NiCo2O4 nanosheet exhibit remarkably enhanced performances for OER due to the enlarged electrochemical surface area and reduced electron transference resistance.
First report of the application of simple molecular complexes as organo-catalysts for Knoevenagel condensation
Authors: Panja Sumit Kumar , Dwivedi Nidhi , Saha Satyen
Published: July 2015

A series of molecular complexes have been designed, synthesized and used as organo-catalysts for the first time for very efficient Knoevenagel condensation.
A reduced graphene oxide modified metallic cobalt composite with superior electrochemical performance for supercapacitors
Authors: Liu Guijing , Wang Lei , Wang Bo , Gao Tiantian , Wang Dianlong
Published: July 2015

The prepared rGO/Co//AC asymmetric supercapacitor displayed good electrochemical performance, and it achieved a maximum energy density of 40.7 W h kg−1 at a power density of 1585.0 W kg−1.
Temperature and pH-dependent swelling and copper(ii) adsorption of poly(N-isopropylacrylamide) copolymer hydrogel
Authors: Cheng Jinjin , Shan Guorong , Pan Pengju
Published: July 2015

Poly(N-isopropylacrylamide-co-acrylamide-co-maleic acid) (PNIPAM-AM-MA) hydrogel, which can make the Cu2+ adsorption process stimuli-responsive under temperature and pH value control, has been synthesized by free radical polymerization.
Effect of a novel compound as dietary supplement on growth of decapod crustaceans
Authors: Shrivastava Sajal , Princy S. Adline
Published: July 2015

The concern over water quality, environmental hazard, human health and food safety has led us to develop a novel alternative growth enhancer, CGE-1 which significantly improve the growth of decapod crustaceans without any harmful effects.
Gas barrier properties of polymer/clay nanocomposites
Authors: Cui Yanbin , Kumar S. , Rao Kona Balakantha , van Houcke Daniel
Published: July 2015

The state-of-the-art progress on the use of clay for the gas barrier properties of polymer nanocomposites have been summarized.
Modification of Rapana thomasiana hemocyanin with choline amino acid salts significantly enhances its antiproliferative activity against MCF-7 human breast cancer cells
Authors: Guncheva Maya , Paunova Krasimira , Ossowicz Paula , Rozwadowski Zbigniew , Janus Ewa , Idakieva Krassimira , Todinova Svetla , Raynova Yuliana , Uzunova Veselina , Apostolova Sonia , Tzoneva Rumiana , Yancheva Denitsa
Published: July 2015

This is the first study on the interactions of ionic liquids with large metalloproteins, in particular hemocyanins (Hcs).
Facile hydrothermal synthesis of tubular kapok fiber/MnO2composites and application in supercapacitors
Authors: Xu Weibing , Mu Bin , Zhang Wenbo , Wang Aiqin
Published: July 2015

Kapok fiber/MnO2(TKF/MnO2) composites with a tubular structure are successfully fabricatedviaa facile hydrothermal process.
Uranium and thorium complexes of the phosphaethynolate ion
Authors: Camp Clément , Settineri Nicholas , Lefèvre Julia , Jupp Andrew R. , Goicoechea José M. , Maron Laurent , Arnold John
Published: July 2015

New tris-amidinate actinide (Th, U) complexes containing a rare O-bound terminal phosphaethynolate (OCP−) ligand were synthesized and fully characterized.
Well-defined silica supported aluminum hydride: another step towards the utopian single site dream?
Authors: Werghi Baraa , Bendjeriou-Sedjerari Anissa , Sofack-Kreutzer Julien , Jedidi Abdesslem , Abou-Hamad Edy , Cavallo Luigi , Basset Jean-Marie
Published: July 2015

Reaction of triisobutylaluminum with SBA15700at room temperature occurs by two parallel pathways involving either silanol or siloxane bridges.
Rheology-modulated contact line dynamics of an immiscible binary system under electrical double layer phenomena
Authors: Mondal Pranab Kumar , DasGupta Debabrata , Chakraborty Suman
Published: July 2015

We investigate the electrically-driven contact line dynamics of a binary fluid system constituted by one Newtonian and another non-Newtonian fluid in a narrow fluidic channel with chemically patched walls.
Acoustic suppression of the coffee-ring effect
Authors: Mampallil Dileep , Reboud Julien , Wilson Rab , Wylie Douglas , Klug David R. , Cooper Jonathan M.
Published: July 2015

We study the influence of acoustic fields on the evaporative self-assembly of solute particles suspended inside sessile droplets of complex fluids and demonstrate the suppression of the coffee-ring effect.
Low activation energies for interstitial oxygen conduction in the layered perovskites La1+xSr1−xInO4+δ
Authors: Troncoso L. , Alonso J. A. , Aguadero A.
Published: July 2015

Interstitial oxygen atoms (δ), identified by difference Fourier maps from NPD data, enhance the conductivity of La1.2Sr0.8InO4.11, with an extremely low activation energy of only 0.51 eV for the conduction mechanism of O2− at low temperatures.
Nitrogen-doped carbon nanorods with excellent capacitive deionization ability
Authors: Liu Yong , Xu Xingtao , Wang Miao , Lu Ting , Sun Zhuo , Pan Likun
Published: July 2015

Nitrogen-doped carbon nanorods were prepared from naturally based nanocrystalline cellulose through a simple thermal treatment under an ammonia atmosphere and used for capacitive deionization.
Growth-controlled NiCo2S4nanosheet arrays with self-decorated nanoneedles for high-performance pseudocapacitors
Authors: Lin Liyang , Liu Jianlin , Liu Tianmo , Hao Jinghua , Ji Kemeng , Sun Rong , Zeng Wen , Wang Zhongchang
Published: July 2015

NiCo2S4nanosheet arrays with self-decorated nanoneedles are synthesized on nickel foams and their electrodes show greatly improved electrochemical performances.
Effects of proton irradiation on Si-nanocrystal/SiO2 multilayers: study of photoluminescence and first-principles calculations
Authors: Jang Seunghun , Joo Beom Soo , Kim Sung , Kong Ki-jeong , Chang Hyunju , Yu Byung Deok , Han Moonsup
Published: July 2015

The investigation of photoluminescence and first-principles calculations clarifies the relationship between the hydrogen passivation of N at the interface and the observed band gap reduction of the embedded Si nanocrystal (NC) for Si NC/SiO2 multilayers containing interfacial nitrogens after proton irradiation.
A direct microcontact printing induced supramolecular interaction for creating shape-tunable patterned polymeric surfaces
Authors: Peng Meiwen , Xiao Peng , Huang Youju , Cai Mujin , Hou Yanshan , Chen Jiaming , Liu Zhenzhong , Xiao Zhidong , Chen Tao
Published: July 2015

Morphologically adjustable patterned PEI surfaces could be achieved by a direct microcontact printing induced supramolecular interaction which further serves as highly active SERS substrates by the deposition of Au NPs.
A flexible high-sensitivity piezoresistive sensor comprising a Au nanoribbon-coated polymer sponge
Authors: Yin Xiuxiu , Vinod T. P. , Jelinek Raz
Published: July 2015

A new piezoresistive sensor comprising a Au nanoribbon-coated elastomeric polymer.
Spiropyran-induced one-dimensional cyclodextrin microcrystals with light-driven fluorescence change
Authors: Lv Baozhong , Wu Zhen , Ji Chendong , Yang Wantai , Yan Dongpeng , Yin Meizhen
Published: July 2015

One-dimensional solid-state microcrystals combining a host molecule cyclodextrin (CD) and UV-responsive guest molecule spiropyran (SP) present a light-driven fluorescence change based on the isomerization of the SP molecule in the CD matrix.
Magnetic interplay between two different lanthanides in a tris-phthalocyaninato complex: a viable synthetic route and detailed investigation in the bulk and on the surface
Authors: Lan Yanhua , Klyatskaya Svetlana , Ruben Mario , Fuhr Olaf , Wernsdorfer Wolfgang , Candini Andrea , Corradini Valdis , Lodi Rizzini Alberto , del Pennino Umberto , Troiani Filippo , Joly Loïc , Klar David , Wende Heiko , Affronte Marco
Published: July 2015

Future applications of molecular units in quantum information technologies require a fine control at the single molecule level.
A new compact solid-state neutral particle analyser at ASDEX Upgrade: Setup and physics modeling
Authors: Schneider P. A. , Blank H. , Geiger B. , Mank K. , Martinov S. , Ryter F. , Weiland M. , Weller A. ,   the ASDEX Upgrade Team
Published: July 2015

At ASDEX Upgrade (AUG), a new compact solid-state detector has been installed to measure the energy spectrum of fast neutrals based on the principle described by Shinohara et al. [Rev. Sci. Instrum. 75, 3640 (2004)]. The diagnostic relies on the usual charge exchange of supra-thermal fast-ions with neutrals in the plasma. Therefore, the measured energy spectra directly correspond to those of confined fast-ions with a pitch angle defined by the line of sight of the detector. Experiments in AUG showed the good signal to noise characteristics of the detector. It is energy calibrated and can measure energies of 40-200 keV with count rates of up to 140 kcps. The detector has an active view on one of the heating beams. The heating beam increases the neutral density locally; thereby, information about the central fast-ion velocity distribution is obtained. The measured fluxes are modeled with a newly developed module for the 3D Monte Carlo code F90FIDASIM [Geiger et al., Plasma Phys. Controlled Fusion 53, 65010 (2011)]. The modeling allows to distinguish between the active (beam) and passive contributions to the signal. Thereby, the birth profile of the measured fast neutrals can be reconstructed. This model reproduces the measured energy spectra with good accuracy when the passive contribution is taken into account.
China-U.S. cooperation on China's subnational low carbon planning toolkit development and application
Authors: Yu Qingchan , Roe Stephen M. , Xu Shengnian , Williamson Scott , Cui Nanying , Jin Jiaman , Peterson Thomas D.
Published: July 2015

In May 2011, the China-based Global Environmental Institute and the US-based Center for Climate Strategies successfully joined the China-U.S. EcoPartnership program. The cooperation aims to adapt a methodology and tools used for making U.S. state climate action plans to China's subnational and municipal contexts, in order to help subnational governments achieve carbon emission targets by making scientific and effective climate and energy policies. To achieve this objective, a China subnational low carbon planning toolkit including a systematic process of selection, design and analysis of climate and energy policies was developed and successfully demonstrated in Chongqing Municipality. Through technical exchange and training, the capabilities of Chinese officials and experts who cooperated with us to quantitatively analyze low carbon development policies have been improved. The cooperation also promoted exchange between Chinese provinces and U.S. states on climate and energy policy.
Measurement of Ampère-class pulsed electron beams via field emission from carbon-nanotube cathodes in a radiofrequency gun
Authors: Mihalcea D. , Faillace L. , Hartzell J. , Panuganti H. , Boucher S. , Murokh A. , Piot P. , Thangaraj J. C. T.
Published: July 2015

Pulsed field emission from cold carbon-nanotube cathodes placed in a radiofrequency resonant cavity was directly measured. The cathodes were located on the backplate of a conventional 1+12-cell resonant cavity operating at 1.3-GHz and resulted in the production of bunch train with maximum average current close to 0.7 Ampère. The measured Fowler-Nordheim characteristic, transverse emittance, and pulse duration are presented and, when possible, compared to numerical simulations. The implications of our results to the promise of high-average-current electron sources are briefly discussed.
Au cylindrical nanocup: A geometrically, tunable optical nanoresonator
Authors: Kovylina M. , Alayo N. , Conde-Rubio A. , Borrisé X. , Hibbard G. , Labarta A. , Batlle X. , Pérez-Murano F.
Published: July 2015

The optical response of Au cylindrical metallic nanostructures (nanocups) with very thin walls is studied by means of finite difference time domain simulations. The simulations predict that, by changing the geometry of the nanocups, they behave as tunable optical nanoresonators with strong near-field enhancement. This opens up the possibility to use them simultaneously as container and field enhancer. Nanocups have been produced by an on-purpose designed fabrication route that combines nanoimprint lithography, definition of an intermediate hard mask, and metal lift-off. The fabrication route offers a manifold of supplementary advantages: thorough control of geometrical parameters; versatility of compositional design, including multishell nanocups; precise positioning of nanocups over the substrate; and low-cost and fast manufacturing of large areas of desirable density without loss of resolution, all processes being compatible with high throughput, low cost production, thus enabling future commercial applications.
High-performance organic thin-film transistor by using LaNbO as gate dielectric
Authors: Han C. Y. , Song J. Q. , Tang W. M. , Leung C. H. , Lai P. T.
Published: July 2015

Pentacene organic thin-film transistors (OTFTs) using LaxNb(1−x)Oy as gate dielectric with different La contents (x = 0.347, 0.648) have been fabricated and compared with those using Nb oxide or La oxide. The OTFT with La0.648Nb0.352Oy as gate dielectric can achieve a high carrier mobility of 1.14 cm2V−1s−1 (about 1000 times and 2 times those of the devices using Nb oxide and La oxide, respectively), and has negligible hysteresis of −0.130 V, small sub-threshold swing of 0.280 V/dec, and low threshold voltage of −1.35 V. AFM and XPS reveal that La can suppress the formation of oxygen vacancies in Nb oxide while Nb can alleviate the hygroscopicity of La oxide, which results in a more passivated and smoother dielectric surface, leading to larger pentacene grains grown and thus higher carrier mobility. The OTFT with Nb oxide has an anticlockwise hysteresis but the device with La oxide shows an opposite direction. This can be explained in terms of donor-like traps due to oxygen vacancies and acceptor-like traps originated from hydroxyl ions formed after La2O3 absorbing water moisture.
Correlation between macro- and nano-scopic measurements of carbon nanostructured paper elastic modulus
Authors: Omar Yamila M. , Al Ghaferi Amal , Chiesa Matteo
Published: July 2015

Extensive work has been done in order to determine the bulk elastic modulus of isotropic samples from force curves acquired with atomic force microscopy. However, new challenges are encountered given the development of new materials constructed of one-dimensional anisotropic building blocks, such as carbon nanostructured paper. In the present work, we establish a reliable framework to correlate the elastic modulus values obtained by amplitude modulation atomic force microscope force curves, a nanoscopic technique, with that determined by traditional macroscopic tensile testing. In order to do so, several techniques involving image processing, statistical analysis, and simulations are used to find the appropriate path to understand how macroscopic properties arise from anisotropic nanoscale components, and ultimately, being able to calculate the value of bulk elastic modulus.
Broadband resonances in indium-tin-oxide nanorod arrays
Authors: Li Shi-Qiang , Sakoda Kazuaki , Ketterson John B. , Chang Robert P. H.
Published: July 2015

There is currently much discussion within the nanophotonics community regarding the origin of wavelength selective absorption/scattering of light by the resonances in nanorod arrays. Here, we report a study of resonances in ordered indium-tin-oxide nanorod arrays resulting from waveguide-like modes. We find that with only a 2.4% geometrical coverage, micron-length nanorod arrays interact strongly with light across a surprisingly wide band from the visible to the mid-infrared, resulting in less than 10% transmission. Simulations show excellent agreement with our experimental observations. The field profile in the vicinity of the rods obtained from simulations shows that the electric field is mainly localized on the surfaces of the nanorods for all resonances. Based on our analysis, the resonances in the visible are different in character from those in the infrared. When light is incident on the array, part of it propagates in the space between the rods and part of it is guided within the rods. The phase difference (interference) at the ends of the rods forms the basis for the resonances in the visible region. The resonances in the infrared are Fabry-Perot-like resonances involving standing surface waves between the opposing ends of the rods. Simple analytical formulae predict the spectral positions of these resonances. It is suggested that these phenomena can be utilized for wavelength-selective photodetectors, modulators, and nanorod-based solar cells.
Ion irradiation induced element-enriched and depleted nanostructures in Zr-Al-Cu-Ni metallic glass
Authors: Chen H. C. , Cao G. Q. , Liu R. D. , Wang G. , Yan L. , Zhou X. T.
Published: July 2015

The microstructural evolution of a Zr-Al-Cu-Ni metallic glass induced by irradiation with Ar ions was investigated. Under ion irradiation, the Cu- and Ni-enriched nanostructures (diameter of 30–50 nm) consisted of crystalline and amorphous structures were formed. Further, Cu- and Ni-depleted nanostructures with diameters of 5–20 nm were also observed. The formation of these nanostructures can be ascribed to the migration of Cu and Ni atoms in the irradiated metallic glass.
Donor-acceptor pair recombination luminescence from monoclinic Cu2SnS3 thin film
Authors: Aihara Naoya , Tanaka Kunihiko , Uchiki Hisao , Kanai Ayaka , Araki Hideaki
Published: July 2015

The defect levels in Cu2SnS3 (CTS) were investigated using photoluminescence (PL) spectroscopy. A CTS thin film was prepared on a soda-lime glass/molybdenum substrate by thermal co-evaporation and sulfurization. The crystal structure was determined to be monoclinic, and the compositional ratios of Cu/Sn and S/Metal were determined to be 1.8 and 1.2, respectively. The photon energy of the PL spectra observed from the CTS thin film was lower than that previously reported. All fitted PL peaks were associated with defect related luminescence. The PL peaks observed at 0.843 and 0.867 eV were assigned to donor-acceptor pair recombination luminescence, the thermal activation energies of which were determined to be 22.9 and 24.8 meV, respectively.
Effect of strain in sputtered AlN buffer layers on the growth of GaN by molecular beam epitaxy
Authors: Kong W. , Jiao W. Y. , Li J. C. , Collar K. , Kim T. H. , Leach J. H. , Brown A. S.
Published: July 2015

The strain dynamic of thin film AlN is investigated before and after the deposition of a GaN epitaxial layer using plasma assisted molecular beam epitaxy. X-ray diffraction ω/2θ-scan and asymmetric reciprocal space mapping analysis show that the deposition of GaN alters the strain state of the underlying AlN template. The in-plane lattice constant of the AlN is found to increase upon growth of GaN, giving rise to a more relaxed GaN epitaxial layer. Hence, the subsequent GaN epitaxial thin film possesses better structural quality especially with lower screw dislocation density and flat surface morphology which is evidenced by the X-ray diffraction ω-scan, room temperature photoluminescence, and atomic force microscopy analysis. Such relaxation of AlN upon GaN deposition is only observed for relatively thin AlN templates with thicknesses of 20 nm–30 nm; this effect is negligible for AlN with thickness of 50 nm and above. As the thicker AlN templates already themselves relax before the GaN deposition, the localized strain fields around the misfit dislocations prohibit further change of lattice parameters.
IQGAP1 promotes CXCR4 chemokine receptor function and trafficking via EEA-1+ endosomes
Authors: Bamidele Adebowale O. , Kremer Kimberly N. , Hirsova Petra , Clift Ian C. , Gores Gregory J. , Billadeau Daniel D. , Hedin Karen E.
Published: July 2015

IQ motif–containing GTPase-activating protein 1 (IQGAP1) is a cytoskeleton-interacting scaffold protein. CXCR4 is a chemokine receptor that binds stromal cell–derived factor-1 (SDF-1; also known as CXCL12). Both IQGAP1 and CXCR4 are overexpressed in cancer cell types, yet it was unclear whether these molecules functionally interact. Here, we show that depleting IQGAP1 in Jurkat T leukemic cells reduced CXCR4 expression, disrupted trafficking of endocytosed CXCR4 via EEA-1+ endosomes, and decreased efficiency of CXCR4 recycling. SDF-1–induced cell migration and activation of extracellular signal-regulated kinases 1 and 2 (ERK) MAPK were strongly inhibited, even when forced overexpression restored CXCR4 levels. Similar results were seen in KMBC and HEK293 cells. Exploring the mechanism, we found that SDF-1 treatment induced IQGAP1 binding to α-tubulin and localization to CXCR4-containing endosomes and that CXCR4-containing EEA-1+ endosomes were abnormally located distal from the microtubule (MT)-organizing center (MTOC) in IQGAP1-deficient cells. Thus, IQGAP1 critically mediates CXCR4 cell surface expression and signaling, evidently by regulating EEA-1+ endosome interactions with MTs during CXCR4 trafficking and recycling. IQGAP1 may similarly promote CXCR4 functions in other cancer cell types.
Myosin 1b functions as an effector of EphB signaling to control cell repulsion
Authors: Prospéri Marie-Thérèse , Lépine Priscilla , Dingli Florent , Paul-Gilloteaux Perrine , Martin René , Loew Damarys , Knölker Hans-Joachim , Coudrier Evelyne
Published: July 2015

Eph receptors and their membrane-tethered ligands, the ephrins, have important functions in embryo morphogenesis and in adult tissue homeostasis. Eph/ephrin signaling is essential for cell segregation and cell repulsion. This process is accompanied by morphological changes and actin remodeling that drives cell segregation and tissue patterning. The actin cortex must be mechanically coupled to the plasma membrane to orchestrate the cell morphology changes. Here, we demonstrate that myosin 1b that can mechanically link the membrane to the actin cytoskeleton interacts with EphB2 receptors via its tail and is tyrosine phosphorylated on its tail in an EphB2-dependent manner. Myosin 1b regulates the redistribution of myosin II in actomyosin fibers and the formation of filopodia at the interface of ephrinB1 and EphB2 cells, which are two processes mediated by EphB2 signaling that contribute to cell repulsion. Together, our results provide the first evidence that a myosin 1 functions as an effector of EphB2/ephrinB signaling, controls cell morphology, and thereby cell repulsion.
Improving fold activation of small transcription activating RNAs (STARs) with rational RNA engineering strategies
Authors: Meyer Sarai , Chappell James , Sankar Sitara , Chew Rebecca , Lucks Julius B.
Published: July 2015

Engineered RNAs have become integral components of the synthetic biology and bioengineering toolbox for controlling gene expression. We recently expanded this toolbox by creating small transcription activating RNAs (STARs) that act by disrupting the formation of a target transcriptional terminator hairpin placed upstream of a gene. While STARs are a promising addition to the repertoire of RNA regulators, much work remains to be done to optimize the fold activation of these systems. Here we apply rational RNA engineering strategies to improve the fold activation of two STAR regulators. We demonstrate that a combination of promoter strength tuning and multiple RNA stabilization strategies can improve fold activation from 5.4-fold to 13.4-fold for a STAR regulator derived from the pbuE riboswitch terminator. We then validate the generality of our approach and show that these same strategies improve fold activation from 2.1-fold to 14.6-fold for an unrelated STAR regulator. We also establish that the optimizations preserve the orthogonality of these STARs between themselves and a set of antisense RNA transcriptional repressors, enabling these optimized STARs to be used in more sophisticated circuits. These optimization strategies open the door for creating a generation of additional STARs to use in a broad array of biotechnologies.
The impact of employees’ positive psychological capital on job satisfaction and organizational citizenship behaviors in the hotel
Authors: Jung Hyo Sun , Yoon Hye Hyun
Published: July 2015

Purpose

– This paper aims to explain the relationships among employees’ positive psychological capital (PPC) (hope, self-efficacy, resilience and optimism), job satisfaction (JS) and organizational citizenship behaviors (OCBs) in deluxe hotels. This study also seeks to analyze the effect of JS on the employees’ OCBs. In an era of global competition when the speed of change is increasing, companies’ competitiveness depends on how well they adapt. To respond flexibly to changes, knowing how to use intangible resources is crucial.

Design/methodology/approach

– This study was administered to 324 deluxe hotel employees using a self-administered questionnaire. Following Anderson and Gerbing’s (1988) two-step approach, confirmatory factor analysis was first undertaken to assess the overall fit of the three-factor model, structural equation model which was used to examine the hypothesized relationships between the constructs.

Findings

– The findings showed that employees’ hope and optimism among PPC have a significant effect on their JS; their hope and resilience affect OCBs. Employees’ satisfaction was positively associated with their OCBs.

Practical implications

– It was verified that PPC was an important performance factor that could improve hotel employees’ attitudes and organization’s effectiveness. Employees with high PPC were high in satisfaction with job, positively helped coworkers or superiors, and had high possibility of doing devotional action for organization. Accordingly, there will be a need of forming favorable working atmosphere so that employees can perform job with positive psychology, and of seeking diverse support programs such as counseling program or leisure activity.

Originality/value

– Most previous studies have examined PPC mainly in general industries; however, this study focused on hotels as a hospitality industry. This study will have significance as the initial research of having considered that the hotel employees’ PPC formation has significant influence upon the JS and OCBs. It is predicted that positive psychology of hotel employees in a job situation leads to various efforts to develop their organization and their own development, thereby creating performance and strengthening management power.
Measuring the effects of quality certification on labour productivity
Authors: Sánchez-Ollero José Luis , García-Pozo Alejandro , Marchante-Lara Macarena
Published: July 2015

Purpose

– The purpose of this study was to evaluate the impact of quality certifications on apparent labour productivity in a sample of hotels in Spain.

Design/methodology/approach

– In line with Mairesse and Kremp (1993), the theoretical model was based on a Cobb–Douglas production function readapted to the goals of the study.

Findings

– The descriptive results show that labour productivity increases only when certifications and quality standards specific to the hospitality industry are implemented and the tourist destination is committed to quality. The econometric analysis shows that the hotel category, belonging to a chain, and outsourcing services have a positive impact on labour productivity. In contrast, the location of the establishment in areas other than the coast or the capital city of a province has a negative effect on labour productivity. Of the quality models and certifications studied, only the Spanish Q-Mark certificate significantly improves hotel productivity (an average increase of 23.27 per cent).

Practical implications

– These results provide support for the Spanish Tourism Quality System implemented by the Spanish Ministry of Tourism, which has not only attempted to increase the quality of tourism hotels by increasing their competitiveness and performance but also by providing them with a quality certificate that can be used as a marketing strategy in international markets.

Originality/value

– The main contribution of this study is to show how the adoption of quality standards and certifications increases or decreases labour productivity in hotels. Given that most of the previous literature has only taken into account quantities, this study adds to the literature by incorporating the concept of quality into productivity issues.