bluuebunny/crossref_metadata_2025 huggingface dataset:
Substitution of tryptophan 89 with tyrosine switches the DNA binding mode of PC4
Authors: Huang Jinguang , Zhao Yanxiang , Liu Huaian , Huang Dan , Cheng Xiankun , Zhao Wensheng , Taylor Ian A. , Liu Junfeng , Peng You-Liang
Published: March 2015

PC4, a well-known general transcription cofactor, has multiple functions in transcription and DNA repair. Residue W89, is engaged in stacking interactions with DNA in PC4, but substituted by tyrosine in some PC4 orthologous proteins. In order to understand the consequences and reveal the molecular details of this substitution we have determined the crystal structures of the PC4 orthologue MoSub1 and a PC4 W89Y mutant in complex with DNA. In the structure of MoSub1-DNA complex, Y74 interacts directly with a single nucleotide of oligo DNA. By comparison, the equivalent residue, W89 in wild type PC4 interacts with two nucleotides and the base of the second nucleotide has distinct orientation relative to that of the first one. A hydrophobic patch around W89 that favours interaction with two nucleotides is not formed in the PC4 W89Y mutant. Therefore, the change of the surface hydrophobicity around residue 89 results in a difference between the modes of DNA interaction. These results indicate that the conserved Y74 in MoSub1 or W89 in PC4, are not only key residues in making specific interactions with DNA but also required to determine the DNA binding mode of PC4 proteins.
An experimental investigation of evolutionary dynamics in the Rock-Paper-Scissors game
Authors: Hoffman Moshe , Suetens Sigrid , Gneezy Uri , Nowak Martin A.
Published: March 2015

Game theory describes social behaviors in humans and other biological organisms. By far, the most powerful tool available to game theorists is the concept of a Nash Equilibrium (NE), which is motivated by perfect rationality. NE specifies a strategy for everyone, such that no one would benefit by deviating unilaterally from his/her strategy. Another powerful tool available to game theorists are evolutionary dynamics (ED). Motivated by evolutionary and learning processes, ED specify changes in strategies over time in a population, such that more successful strategies typically become more frequent. A simple game that illustrates interesting ED is the generalized Rock-Paper-Scissors (RPS) game. The RPS game extends the children's game to situations where winning or losing can matter more or less relative to tying. Here we investigate experimentally three RPS games, where the NE is always to randomize with equal probability, but the evolutionary stability of this strategy changes. Consistent with the prediction of ED we find that aggregate behavior is far away from NE when it is evolutionarily unstable. Our findings add to the growing literature that demonstrates the predictive validity of ED in large-scale incentivized laboratory experiments with human subjects.
The formation of electronically excited species in the human multiple myeloma cell suspension
Authors: Rác Marek , Sedlářová Michaela , Pospíšil Pavel
Published: March 2015

In this study, evidence is provided on the formation of electronically excited species in human multiple myeloma cells U266 in the growth medium exposed to hydrogen peroxide (H2O2). Two-dimensional imaging of ultra-weak photon emission using highly sensitive charge coupled device camera revealed that the addition of H2O2 to cell suspension caused the formation of triplet excited carbonyls 3(R = O)*. The kinetics of 3(R = O)* formation in the real time, as measured by one-dimensional ultra-weak photon emission using low-noise photomultiplier, showed immediate enhancement followed by a slow decay. In parallel to the formation of 3(R = O)*, the formation of singlet oxygen (1O2) in U266 cells caused by the addition of H2O2 was visualized by the imaging of 1O2 using the green fluorescence of singlet oxygen sensor green detected by confocal laser scanning microscopy. Additionally, the formation of 1O2 after the addition of H2O2 to cell suspension was detected by electron paramagnetic resonance spin-trapping spectroscopy using 2,2,6,6-tetramethyl-4-piperidone. Presented results indicate that the addition of H2O2 to cell suspension results in the formation of 3(R = O)* and 1O2 in U266 cell suspension. The contribution of the cell-free medium to the formation of electronically excited species was discussed.
Controlled translocation of DNA through nanopores in carbon nano-, silicon-nitride- and lipid-coated membranes
Authors: Sischka Andy , Galla Lukas , Meyer Andreas J. , Spiering Andre , Knust Sebastian , Mayer Michael , Hall Adam R. , Beyer André , Reimann Peter , Gölzhäuser Armin , Anselmetti Dario
Published: March 2015

The DNA threading forces through nanopores in novel carbon nano membranes and other membrane materials and their theory are presented.
Vibrational properties of Ti3C2and Ti3C2T2(T = O, F, OH) monosheets by first-principles calculations: a comparative study
Authors: Hu Tao , Wang Jiemin , Zhang Hui , Li Zhaojin , Hu Minmin , Wang Xiaohui
Published: March 2015

Structural and vibrational properties of emerging Ti3C2and T-terminated Ti3C2T2(T = O, F, OH) monosheets are studied by density functional theory calculations.
The modification of ferroelectric LiNbO3(0001) surfaces using chromium oxide thin films
Authors: Herdiech M. W. , Zhu X. , Morales-Acosta M. D. , Walker F. J. , Altman E. I.
Published: March 2015

Illustration showing non-polar Cr2O3 deposition onto ferroelectric LiNbO3. Characterization of the interface suggests that the charge compensation layer migrates to the chromium oxide surface where it can lead to distinct chemistry on oppositely poled substrates.
The role of peroxyl radicals in polyester degradation – a mass spectrometric product and kinetic study using the distonic radical ion approach
Authors: Gervasoni B. D. , Khairallah G. N. , O'Hair R. A. J. , Wille U.
Published: March 2015

Mass spectrometric techniques were employed to reveal detailed insight into the reaction of peroxyl radicals with structural motifs in polyesters.
Optical probes for the detection of protons, and alkali and alkaline earth metal cations
Authors: Hamilton Graham R. C. , Sahoo Suban K. , Kamila Sukanta , Singh Narinder , Kaur Navneet , Hyland Barry W. , Callan John F.
Published: March 2015

Luminescent sensors and switches continue to play a key role in shaping our understanding of key biochemical processes, assist in the diagnosis of disease and contribute to the design of new drugs and therapies.
Chemistry at the interior atoms of polycyclic aromatic hydrocarbons
Authors: Scott Lawrence T.
Published: March 2015

Reactions that form new σ-bonds to interior carbon atoms of polycyclic aromatic hydrocarbons were unknown before the fullerene era.
A palladium salen complex: an efficient catalyst for the Sonogashira reaction at room temperature
Authors: Gogoi Ankur , Dewan Anindita , Borah Geetika , Bora Utpal
Published: March 2015

A tetradentate Schiff base derived palladium complex works as an efficient catalyst for the room temperature Sonogashira reaction.
Label-free detection of DNA using a light-addressable potentiometric sensor modified with a positively charged polyelectrolyte layer
Authors: Wu Chunsheng , Bronder Thomas , Poghossian Arshak , Werner Carl Frederik , Schöning Michael J.
Published: March 2015

A multi-spot light-addressable potentiometric sensor was applied for a label-free electrical detection of DNA immobilization and hybridization by the intrinsic molecular charge.
Metal complexes of tosyl sulfonamides: design, X-ray structure, biological activities and molecular docking studies
Authors: Hassan Khan Najm Ul , Zaib Sumera , Sultana Kishwar , Khan Imtiaz , Mougang-Soume Berline , Nadeem Humaira , Hassan Mukhtiar , Iqbal Jamshed
Published: March 2015

CompoundNA3bound inside the active site of the enzyme.
Formation of organic–inorganic mixed halide perovskite films by thermal evaporation of PbCl2 and CH3NH3I compounds
Authors: Gao Cheng , Liu Jiang , Liao Cheng , Ye Qinyan , Zhang Yongzheng , He Xulin , Guo Xiaowei , Mei Jun , Lau Woonming
Published: March 2015

The ratio of PbCl2 to CH3NH3I compounds strongly affect the PCE and stability of perovskite solar cell fabricated by co-evaporation.
Copper-mediated ortho C–H sulfonylation of benzoic acid derivatives with sodium sulfinates
Authors: Liu Jidan , Yu Lin , Zhuang Shaobo , Gui Qingwen , Chen Xiang , Wang Wenduo , Tan Ze
Published: March 2015

Copper-mediated direct ortho C–H bond sulfonylation of benzoic acid derivatives with sodium sulfinates was achieved by employing an 8-aminoquinoline moiety as the bidentate directing group. Various aryl sulfones were synthesized in good yields with excellent regioselectivity.
Hydroxylamine-O-sulfonic acid as an efficient coreactant for luminol chemiluminescence for selective and sensitive detection
Authors: Saqib Muhammad , Gao Wenyue , Lai Jianping , Qi Liming , Majeed Saadat , Gilani Muhammad Rehan Hasan Shah , Xu Guobao
Published: March 2015

HOSA, a versatile synthetic reagent, has been explored as an effective chemiluminescence coreactant for the sensitive detection of luminol, HOSA, and Co2+, including selective Co2+detection.
Direct fluorination of styrenes
Authors: Shao Qian , Huang Yong
Published: March 2015

We have developed a practical method to synthesize fluorostyrene compounds.
Au–Rh and Au–Pd nanocatalysts supported on rutile titania nanorods: structure and chemical stability
Authors: Konuspayeva Zere , Afanasiev Pavel , Nguyen Thanh-Son , Di Felice Luca , Morfin Franck , Nguyen Nhat-Tai , Nelayah Jaysen , Ricolleau Christian , Li Z. Y. , Yuan Jun , Berhault Gilles , Piccolo Laurent
Published: March 2015

Au–Rh and Au–Pd nanoalloys synthesized by colloidal methods and immobilized on rutile titania nanorods are more stable than their monometallic counterparts for tetralin hydrogenation in the presence of sulfur.
Poly(norepinephrine) as a functional bio-interface for neuronal differentiation on electrospun fibers
Authors: Taskin Mehmet Berat , Xu Ruodan , Zhao Huiling , Wang Xueqin , Dong Mingdong , Besenbacher Flemming , Chen Menglin
Published: March 2015

A mussel inspired polynorepinephrine (pNE) coating serves as a unique bio-interface integrating multi-functions facilitating PC12 neuronal differentiation.
Nucleation and growth of condensate in nanoporous materials
Authors: Zandavi Seyed Hadi , Ward C. A.
Published: March 2015

The adsorbed clusters are predicted to grow in size, interact, and initiate the pore filling.
The adsorption of thiophenol on gold – a spectroelectrochemical study
Authors: Holze Rudolf
Published: March 2015

The adsorbate formed by adsorption of thiophenol on a polycrystalline gold electrode and brought into contact with aqueous solutions of 1 M HClO4and 0.1 M KClO4has been studied using cyclic voltammetry and surface-enhanced Raman spectroscopy.
Surface-enhanced spectroscopies
Authors: Holze Rudolf , Schlücker Sebastian
Published: March 2015

This themed issue presents a collection of articles on surface-enhanced spectroscopies.
Dimetallaborane analogues of pentaborane
Authors: Brânzanic Adrian M. V. , Lupan Alexandru , King R. Bruce
Published: March 2015

The lowest energy Cp2M2B3H7 (M = Pd, Pt) and Cp2M2B3H7 (M = Rh, Ir) structures are analogous to the isoelectronic B5H11 and B5H9, respectively. Trigonal bipyramidal structures are found for the electron poorer Cp2M2B3H7 (M = Ru, Os, Mo, W, Ta) systems. Low energy Cp2Re2B3H7 structures include Re2B2 tetrahedra with the Re–Re edge capped by the third boron atom.
Neuroprotective effect of loganin against Aβ25–35-induced injury via the NF-κB-dependent signaling pathway in PC12 cells
Authors: Kim Hyeri , Youn Kumju , Ahn Mok-Ryeon , Kim Oh Yoen , Jeong Woo-Sik , Ho Chi-Tang , Jun Mira
Published: March 2015

Aβ25–35-induced neurotoxicity was ameliorated by the inhibition of the NF-κB dependent signaling pathway.
The effect of quercetin and kaempferol aglycones and glucuronides on peroxisome proliferator-activated receptor-gamma (PPAR-γ)
Authors: Beekmann Karsten , Rubió Laura , de Haan Laura H. J. , Actis-Goretta Lucas , van der Burg Bart , van Bladeren Peter J. , Rietjens Ivonne M. C. M.
Published: March 2015

Quercetin and kaempferol increase PPAR-γ mediated gene expression without acting as agonistic ligands; glucuronidation reduces their activity in cell-based assays.
A naphthalimide-based ‘Pourbaix sensor’: a redox and pH driven AND logic gate with photoinduced electron transfer and internal charge transfer mechanisms
Authors: Spiteri Jake C. , Schembri Jonathan S. , Magri David C.
Published: March 2015

A molecular logic gate with a ‘receptor–spacer–fluorophore–spacer–redox-unit’ format emits a fluorescent signal on simultaneous oxidation and protonation in aqueous methanol solution.
Can the thermal expansion be controlled by varying the hydrogen bond dimensionality in polymorphs?
Authors: Saraswatula Viswanadha G. , Bhattacharya Suman , Saha Binoy K.
Published: March 2015

A higher dimensional (1-D) hydrogen bonded form shows smaller thermal expansion than a lower dimensional (0-D) hydrogen bonded form of 2-butynoic acid.
Functionalisation of hollow gold nanospheres for use as stable, red-shifted SERS nanotags
Authors: Moreton Samantha , Faulds Karen , Shand Neil C. , Bedics Matthew A. , Detty Michael R. , Graham Duncan
Published: March 2015

Improved method for stabilising HGNs which simultaneously shifts the SPR to longer wavelengths, for use as effective SERS substrates.
Room temperature N-arylation of amino acids and peptides using copper(i) and β-diketone
Authors: Sharma Krishna K. , Sharma Swagat , Kudwal Anurag , Jain Rahul
Published: March 2015

A mild and efficient Cu-catalyzed procedure for the N-arylation of zwitterionic amino acids, amino acid esters and peptides is described.
Chiral surfactants for dispersing carbon nanotubes
Authors: Lin Pengcheng , Cong Yuehua , Zhang Baoyan
Published: March 2015

Chiral surfactants induce excellent dispersion of CNTs. The dispersed CNTs improve the thermal properties and chiral stability of the dispersion medium.
The impact of thienothiophene isomeric structures on the optoelectronic properties and photovoltaic performance in quinoxaline based donor–acceptor copolymers
Authors: Singh Ranbir , Pagona Georgia , Gregoriou Vasilis G. , Tagmatarchis Nikos , Toliopoulos Dimosthenis , Han Yang , Fei Zhuping , Katsouras Athanasios , Avgeropoulos Apostolos , Anthopoulos Thomas D. , Heeney Martin , Keivanidis Panagiotis E. , Chochos Christos L.
Published: March 2015

The importance of the monomer's isomeric structure in the design of new D–A copolymers for various applications.
Aziridine in polymers: a strategy to functionalize polymers by ring-opening reaction of aziridine
Authors: Jang Hyeon-Jae , Lee Jae Tak , Yoon Hyo Jae
Published: March 2015

Aziridine-containing polymers were synthesized, and post-modification of polymers was demonstrated through ring-opening reaction of aziridine.
Designing breathable superhydrophobic cotton fabrics
Authors: Wu Jingxia , Li Jingye , Wang Ziqiang , Yu Ming , Jiang Haiqing , Li Linfan , Zhang Bowu
Published: March 2015

Superhydrophobic cotton fabrics were prepared through radiation induced graft polymerization by applying a series of alkyl methacrylates as the functional monomers.
Synthesis and characterization on novel fluorescent sensors for Pd2+/Pd0with high selectivity
Authors: Zi You , Meng Hua , Chu Xue-Qiang , Xu Xiao-Ping , Ji Shun-Jun
Published: March 2015

Novel chemosensors based on triaryl 1H-imidazo[4,5-b]pyrazine with high selectivity for palladium (Pd0/Pd2+) detection have been synthesized simply.
Organocatalysed Michael addition on arylmethylidenemalonates involving 4-(2-nitrophenyl)acetoacetate: diversity-oriented access to 8,9-dihydropyrido[1,2-a]indol-6(7H)-one and salicylate scaffolds
Authors: Srivastava Anvita , Biswas Soumen , Singh Shivendra , Mobin Shaikh M. , Samanta Sampak
Published: March 2015

A diversity-oriented synthesis of 8,9-dihydropyrido[1,2-a]indol-6(7H)-one and salicylate scaffolds was achieved in high yields with excellent diastereoselectivities (≤96 : 4 dr)viaan organocatalytic reaction of alkylidene malonates with 4-(2-nitrophenyl) acetoacetate.
Recent progress in quantum dot based sensors
Authors: Cui Lei , He Xiao-Peng , Chen Guo-Rong
Published: March 2015

Recent progress in quantum dot (QD) based chemo- and biosensors for various applications is summarized.
Green synthesis of potassium zinc hexacyanoferrate nanocubes and their potential application in photocatalytic degradation of organic dyes
Authors: Jassal Vidhisha , Shanker Uma , Kaith B. S. , Shankar Shiv
Published: March 2015

The novelty of work lies in the green synthesis of KZnHCF nanocubes using natural surfactant and impact on photocatalytic degradation.
Metal-free dehydrogenation of formic acid to H2and CO2using boron-based catalysts
Authors: Chauvier Clément , Tlili Anis , Das Neves Gomes Christophe , Thuéry Pierre , Cantat Thibault
Published: March 2015

The decomposition of formic acid to H2and CO2under metal-free conditions has been unveiled using dialkylborane derivatives as catalysts.
Structure and growth behavior of centimeter-sized helical oleate assemblies formed with assistance of medium-length carboxylic acids
Authors: Kageyama Yoshiyuki , Ikegami Tomonori , Hiramatsu Natsuko , Takeda Sadamu , Sugawara Tadashi
Published: March 2015

Medium-length aliphatic acids promote the continuous formation of helical self-assembly of oleate.
Ultrasonic-assisted synthesis of carbon nanotube supported bimetallic Pt–Ru nanoparticles for effective methanol oxidation
Authors: Zhou Yazhou , Yang Guohai , Pan Horng-Bin , Zhu Chengzhou , Fu Shaofang , Shi Qiurong , Du Dan , Cheng Xiaonong , Yang Juan , Wai Chien M. , Lin Yuehe
Published: March 2015

We demonstrate a facile and one-step ultrasonic-assisted method to synthesize a Pt–Ru/c-MWNT catalyst with ultrasmall size, uniform distribution, low mass loading of Pt, and high electrocatalytic activity for methanol oxidation.
Amelogenin and enamel biomimetics
Authors: Ruan Qichao , Moradian-Oldak Janet
Published: March 2015

Mature tooth enamel is acellular and does not regenerate itself.
Imidazole-containing triblock copolymers with a synergy of ether and imidazolium sites
Authors: Jangu Chainika , Wang Jing-Han Helen , Wang Dong , Fahs Gregory , Heflin James R. , Moore Robert B. , Colby Ralph H. , Long Timothy E.
Published: March 2015

Reversible addition–fragmentation chain transfer (RAFT) polymerization enabled the synthesis of well-defined A–BC–A triblock copolymers containing a synergy of pendant ether and imidazolium sites.
Platelet Rho GTPases–a focus on novel players, roles and relationships
Authors: Goggs Robert , Williams Christopher M. , Mellor Harry , Poole Alastair W.
Published: March 2015

Rho GTPases are critical for platelet function. Although the roles of RhoA, Rac and Cdc42 are characterized, platelets express other Rho GTPases, whose activities are less well understood. This review summarizes our understanding of the roles of platelet Rho GTPases and focuses particularly on the functions of Rif and RhoG. In human platelets, Rif interacts with cytoskeleton regulators including formins mDia1 and mDia3, whereas RhoG binds SNARE-complex proteins and cytoskeletal regulators ELMO and DOCK1. Knockout mouse studies suggest that Rif plays no critical functions in platelets, likely due to functional overlap with other Rho GTPases. In contrast, RhoG is essential for normal granule secretion downstream of the collagen receptor GPVI. The central defect in RhoG−/− platelets is reduced dense granule secretion, which impedes integrin activation and aggregation and limits platelet recruitment to growing thrombi under shear, translating into reduced thrombus formation in vivo. Potential avenues for future work on Rho GTPases in platelets are also highlighted, including identification of the key regulator for platelet filopodia formation and investigation of the role of the many Rho GTPase regulators in platelet function in both health and disease.
Visual comfort assessment in stereoscopic 3D images using salient object disparity
Authors: Jung Cheolkon , Wang Shuai
Published: March 2015

Visual comfort (VC) assessment in stereoscopic three‐dimensional (S3D) images using salient object disparity (SOD) is proposed. Through careful observations in S3D displays, it has been discovered that SOD is a key factor that influences VC in S3D images. This is because the human visual system controls the eye's lens to focus on the salient object and adjusts the salient object to the zero parallax plane. Thus, if the salient object is not adjusted to the zero parallax, the S3D image causes severe visual discomfort in the human brain. Based on human depth perception, the disparity of salient object is combined with the maximum disparity as the feature for VC prediction. Experimental results show that the proposed method substantially improves the VC prediction performance in S3D images compared with conventional prediction methods.
Enhanced locking range technique for divide‐by‐3 differential injection‐locked frequency divider
Authors: Jang Sheng‐Lyang , Lin Chih‐Yuan , Juang Miin‐Horng
Published: March 2015

A new circuit technique is proposed to enhance the locking range of divide‐by‐3 injection‐locked frequency dividers (ILFDs) implemented using a standard 0.18 μm CMOS process. The ILFD uses a transformer feedback to increase the second harmonic and enhances the conversion efficiency of injection metal–oxide semiconductor field‐effect transistor mixers. The ILFD core consumes 10.8 mW power at the supply voltage of 0.9 V and with a circuit core current of 12 mA. At the incident power of 0 dBm, the measured locking range is 4.2 GHz (37.17%), from the incident frequency 9.2–13.4 GHz.
Fractional order Pareto distributions with application to X‐band maritime radar clutter
Authors: Alexopoulos Aris , Weinberg Graham Victor
Published: March 2015

The theory of fractional order calculus is applied to construct variations of the fundamental Pareto clutter model density, used in X‐band maritime surveillance radar. Such data are characterised, at high resolution, by spiky clutter returns whose density function possesses heavy tails. By an application of fractional calculus to the Pareto distribution function, together with optimisation applied to determine the fractional derivative order, it is possible to obtain a new model for radar clutter. This is shown to fit real radar clutter returns better than a standard Pareto model. Additionally, it accounts for receiver thermal noise without the complexity of an additional noise distribution.
ℓ-oscillators from second-order invariant PDEs of the centrally extended conformal Galilei algebras
Authors: Aizawa N. , Kuznetsova Z. , Toppan F.
Published: March 2015

We construct, for any given ℓ=12+N0, the second-order, linear partial differential equations (PDEs) which are invariant under the centrally extended conformal Galilei algebra. At the given ℓ, two invariant equations in one time and ℓ+12 space coordinates are obtained. The first equation possesses a continuum spectrum and generalizes the free Schrödinger equation (recovered for ℓ=12) in 1 + 1 dimension. The second equation (the “ℓ-oscillator”) possesses a discrete, positive spectrum. It generalizes the 1 + 1-dimensional harmonic oscillator (recovered for ℓ=12). The spectrum of the ℓ-oscillator, derived from a specific osp(1|2ℓ + 1) h.w.r., is explicitly presented. The two sets of invariant PDEs are determined by imposing (representation-dependent) on-shell invariant conditions both for degree 1 operators (those with continuum spectrum) and for degree 0 operators (those with discrete spectrum). The on-shell condition is better understood by enlarging the conformal Galilei algebras with the addition of certain second-order differential operators. Two compatible structures (the algebra/superalgebra duality) are defined for the enlarged set of operators.
Improved carrier mobility of chemical vapor deposition-graphene by counter-doping with hydrazine hydrate
Authors: Chen Zhiying , Zhang Yanhui , Zhang Haoran , Sui Yanping , Zhang Yaqian , Ge Xiaoming , Yu Guanghui , Xie Xiaoming , Li Xiaoliang , Jin Zhi , Liu Xinyu
Published: March 2015

We developed a counter-doping method to tune the electronic properties of chemical vapor deposition (CVD)-grown graphene by varying the concentration and time of graphene exposure to hydrazine hydrate (N2H4·H2O). The shift of G and 2D peaks of Raman spectroscopy is analyzed as a function of N2H4·H2O concentration. The result revealed that N2H4·H2O realized n-type doping on CVD grown graphene. X-ray photoelectron spectroscopy measurement proved the existence of nitrogen, which indicated the adsorption of N2H4 on the surface of graphene. After counter-doping, carrier mobility, which was measured by Hall measurements, increased three fold.
Effects of aluminum substitution on the crystal structure and magnetic properties in Zn2Y-type hexaferrites
Authors: Xu Wenfei , Yang Jing , Bai Wei , Zhang Yuanyuan , Tang Kai , Duan Chun-gang , Tang Xiaodong , Chu Junhao
Published: March 2015

Crystal structure and magnetic properties of multiferroic Y-type hexaferrites Ba0.5Sr1.5Zn2(Fe1−xAlx)12O22 (x = 0, 0.04, 0.08, and 0.12) were investigated. The Z- and M-type impurity phases decrease with increasing Al content, and the pure phase samples can be obtained by modulating Al-doping. Lattice distortion exists in Al-doped samples due to the different radius of Al ion (0.535 Å) and Fe ion (0.645 Å). The microstructural morphologies show that the hexagonal shape grains can be observed in all the samples, and grain size decreases with increasing Al content. As for magnetic properties of Ba0.5Sr1.5Zn2(Fe1−xAlx)12O22, there exist rich thermal- and field-driven magnetic phase transitions. Temperature dependence of zero-field cooling magnetization curves from 5 K to 800 K exhibit three magnetic phase transitions involving conical spin phase, proper-screw spin phase, ferromagnetic phase, and paramagnetic phase, which can be found in all the samples. Furthermore, the phase-transition temperatures can be modulated by varying Al content. In addition, four kinds of typical hysteresis loops are observed in pure phase sample at different temperatures, which reveal different magnetization processes of above-motioned magnetic spin structures. Typically, triple hysteresis loops in low magnetic field range from 0 to 0.5 T can be observed at 5 K, which suggests low-field driven magnetic phase transitions from conical spin order to proper-screw spin order and further to ferrimagnetic spin order occur. Furthermore, the coercive field (HC) and the saturation magnetization (MS) enhance with increasing Al content from x = 0 to 0.08, and drop rapidly at x = 0.12, which could be attribute to that in initial Al-doped process the pitch of spin helix increases and therefore magnetization enhances, but conical spin phase eventually collapses in higher-concentration Al-doping.
Crystalline ZrO2 doping induced columnar structural FePt films with larger coercivity and high aspect ratio
Authors: Dong K. F. , Li H. H. , Deng J. Y. , Peng Y. G. , Ju G. , Chow G. M. , Chen J. S.
Published: March 2015

Columnar (001) FePt-ZrO2-C films with large coercivity, small grain size, and high aspect ratio were obtained. By doping ZrO2 into FePt film at high sputtering temperature, tetragonal (002) textured ZrO2 was formed and distributed at the grain boundaries of FePt grains, resulting in the formation of columnar structured FePt films. The perpendicular anisotropy of FePt films was degraded since some (200) FePt grains were formed directly on the (002) textured ZrO2. With a small amount of carbon doping into FePt-ZrO2 35 vol. % films, the perpendicular anisotropy was improved. However, FePt grains were still interconnected. Upon further increasing concentration of ZrO2, (001) textured FePt-ZrO2 40 vol. %-C 5 vol. % films with well isolated grains in average diameter of 5.5 nm and very good columnar structure were obtained.
Quantitative measurement of radiation pressure on a microcantilever in ambient environment
Authors: Ma Dakang , Garrett Joseph L. , Munday Jeremy N.
Published: March 2015

Light reflected off a material or absorbed within it exerts radiation pressure through the transfer of momentum. Micro/nano-mechanical transducers have become sensitive enough that radiation pressure can influence these systems. However, photothermal effects often accompany and overwhelm the radiation pressure, complicating its measurement. In this letter, we investigate the radiation force on an uncoated silicon nitride microcantilever in ambient conditions. We identify and separate the radiation pressure and photothermal forces through an analysis of the cantilever's frequency response. Further, by working in a regime where radiation pressure is dominant, we are able to accurately measure the radiation pressure. Experimental results are compared to theory and found to agree within the measured and calculated uncertainties.
Aerodynamics and vortical structures in hovering fruitflies
Authors: Meng Xue Guang , Sun Mao
Published: March 2015

We measure the wing kinematics and morphological parameters of seven freely hovering fruitflies and numerically compute the flows of the flapping wings. The computed mean lift approximately equals to the measured weight and the mean horizontal force is approximately zero, validating the computational model. Because of the very small relative velocity of the wing, the mean lift coefficient required to support the weight is rather large, around 1.8, and the Reynolds number of the wing is low, around 100. How such a large lift is produced at such a low Reynolds number is explained by combining the wing motion data, the computed vortical structures, and the theory of vorticity dynamics. It has been shown that two unsteady mechanisms are responsible for the high lift. One is referred as to “fast pitching-up rotation”: at the start of an up- or downstroke when the wing has very small speed, it fast pitches down to a small angle of attack, and then, when its speed is higher, it fast pitches up to the angle it normally uses. When the wing pitches up while moving forward, large vorticity is produced and sheds at the trailing edge, and vorticity of opposite sign is produced near the leading edge and on the upper surface, resulting in a large time rate of change of the first moment of vorticity (or fluid impulse), hence a large aerodynamic force. The other is the well known “delayed stall” mechanism: in the mid-portion of the up- or downstroke the wing moves at large angle of attack (about 45 deg) and the leading-edge-vortex (LEV) moves with the wing; thus, the vortex ring, formed by the LEV, the tip vortices, and the starting vortex, expands in size continuously, producing a large time rate of change of fluid impulse or a large aerodynamic force.
Giant dielectric response and low dielectric loss in Al2O3 grafted CaCu3Ti4O12 ceramics
Authors: Rajabtabar-Darvishi A. , Bayati R. , Sheikhnejad-Bishe O. , Wang L. D. , Li W. L. , Sheng J. , Fei W. D.
Published: March 2015

This study sheds light on the effect of alumina on dielectric constant and dielectric loss of novel CaCu3Ti4O12 composite ceramics. Alumina, at several concentrations, was deposited on the surface of CaCu3Ti4O12 particles via sol-gel technique. The dielectric constant significantly increased for all frequencies and the dielectric loss substantially decreased for low and intermediate frequencies. These observations were attributed to the change in characteristics of grains and grain boundaries. It was found that the insulating properties of the grain boundaries are improved following the addition of Al2O3. The relative density of CaCu3Ti4O12/Al2O3 composite ceramics decreased compared to the pure CaCu3Ti4O12 and the grain size was greatly changed with the alumina content affecting the dielectric properties. With the addition of alumina into CaCu3Ti4O12, tighter interfaces formed. The 6%- and 10%-alumina ceramics showed the minimum dielectric loss and the maximum dielectric constant, respectively. Both the dielectric constant and loss tangent decreased in the 20%-alumina ceramic due to the formation of CuO secondary phase. It was revealed that Al serves as an electron acceptor decreasing the electron concentration, if Al3+ ions substitute for Ti4+ ions, and as an electron donor increasing the electron concentration, if Al3+ ions substitute for Ca2+ ions. We established a processing-microstructure-properties paradigm which opens new avenues for novel applications of CaCu3Ti4O12/Al2O3 composite ceramics.
Large-scale flows in transitional plane Couette flow: A key ingredient of the spot growth mechanism
Authors: Couliou M. , Monchaux R.
Published: March 2015

Using particle image velocimetry in a new experimental plane Couette flow, we investigate the dynamics of turbulent patches invading formerly laminar flows. We evidence experimentally for the first time in this geometry the existence of large scale flows. These flows appear as soon as laminar and turbulent domains coexist. Spectral analysis is used to study the dynamical evolution of these large scales as well as that of the small scales associated with turbulence. We show that large-scale flows grow before turbulent spots develop and we point out the crucial role they play in the growth mechanism and possibly also in the emergence of organised patterns.
Global model analysis of negative ion generation in low-pressure inductively coupled hydrogen plasmas with bi-Maxwellian electron energy distributions
Authors: Huh Sung-Ryul , Kim Nam-Kyun , Jung Bong-Ki , Chung Kyoung-Jae , Hwang Yong-Seok , Kim Gon-Ho
Published: March 2015

A global model was developed to investigate the densities of negative ions and the other species in a low-pressure inductively coupled hydrogen plasma with a bi-Maxwellian electron energy distribution. Compared to a Maxwellian plasma, bi-Maxwellian plasmas have higher populations of low-energy electrons and highly vibrationally excited hydrogen molecules that are generated efficiently by high-energy electrons. This leads to a higher reaction rate of the dissociative electron attachment responsible for negative ion production. The model indicated that the bi-Maxwellian electron energy distribution at low pressures is favorable for the creation of negative ions. In addition, the electron temperature, electron density, and negative ion density calculated using the model were compared with the experimental data. In the low-pressure regime, the model results of the bi-Maxwellian electron energy distributions agreed well quantitatively with the experimental measurements, unlike those of the assumed Maxwellian electron energy distributions that had discrepancies.
Active control of chirality in nonlinear metamaterials
Authors: Zhu Yu , Hu Xiaoyong , Chai Zhen , Yang Hong , Gong Qihuang
Published: March 2015

An all-optical tunabe chirality is realized in a photonic metamaterial, the metamolecule of which consists of a nonlinear nano-Au:polycrystalline indium-tin oxide layer sandwiched between two L-shaped gold nano-antennas twisted 90° with each other. The maximum circular dichroism reached 30%. Under excitation of a 40 kW/cm2 weak pump light, the peak in the circular dichroism shifts 45 nm in the short-wavelength direction. An ultrafast response time of 35 ps is maintained. This work not only opens up the possibility for the realization of ultralow-power and ultrafast all-optical tunable chirality but also offers a way to construct ultrahigh-speed on-chip biochemical sensors.
10 mJ 5-cycle pulses at 1.8 μm through optical parametric amplification
Authors: Thiré Nicolas , Beaulieu Samuel , Cardin Vincent , Laramée Antoine , Wanie Vincent , Schmidt Bruno E. , Légaré François
Published: March 2015

We report the generation of 10 mJ, 5-cycle pulses at 1.8 μm (30 fs) at 100 Hz repetition rate using an optical parametric amplifier pumped by a high energy Titanium-Sapphire laser system (total energy of 23 mJ for Signal and Idler). This is the highest reported peak power (0.33 TW) in the infrared spectral range. This high-energy long wavelength laser source is well suited for driving various nonlinear optical phenomena such as high harmonic generation for high flux ultrafast soft X-ray pulses.
Dramatherapy with Parents and Children in Parallel Groups: Developing an Approach for Healthier Family Dynamics
Authors: Hobeck Jessie
Published: March 2015

This article is based on my inquiry into the use of dramatherapy in parallel groups (parent and child) to explore difficult family dynamics within a child and family psychiatric setting. The aim of this work is to develop a new approach, which synthesizes ideas from attachment theory and systemic-oriented approaches, together with dramatherapeutic core processes as a way for clients to identify, explore and express difficult internal material and processes, to work towards greater self-awareness and healthier family dynamics.
The C-terminus SH3-binding domain of Kv1.3 is required for the actin-mediated immobilization of the channel via cortactin
Authors: Hajdu Peter , Martin Geoffrey V. , Chimote Ameet A. , Szilagyi Orsolya , Takimoto Koichi , Conforti Laura
Published: March 2015

Kv1.3 channels play a pivotal role in the activation and migration of T-lymphocytes. These functions are accompanied by the channels' polarization, which is essential for associated downstream events. However, the mechanisms that govern the membrane movement of Kv1.3 channels remain unclear. F-actin polymerization occurs concomitantly to channel polarization, implicating the actin cytoskeleton in this process. Here we show that cortactin, a factor initiating the actin network, controls the membrane mobilization of Kv1.3 channels. FRAP with EGFP-tagged Kv1.3 channels demonstrates that knocking down cortactin decreases the actin-based immobilization of the channels. Using various deletion and mutation constructs, we show that the SH3 motif of Kv1.3 mediates the channel immobilization. Proximity ligation assays indicate that deletion or mutation of the SH3 motif also disrupts interaction of the channel with cortactin. In T-lymphocytes, the interaction between HS1 (the cortactin homologue) and Kv1.3 occurs at the immune synapse and requires the channel's C-terminal domain. These results show that actin dynamics regulates the membrane motility of Kv1.3 channels. They also provide evidence that the SH3 motif of the channel and cortactin plays key roles in this process.
Low occurrence rates of ubiquitously present leptocephalus larvae in the stomach contents of predatory fish
Authors: Miller Michael J. , Dubosc Jeff , Vourey Elodie , Tsukamoto Katsumi , Allain Valerie
Published: March 2015

Leptocephali, the larvae of eels, grow to large sizes and are widely distributed in tropical and subtropical oceans. Their role in oceanic food webs is poorly known because they are rarely reported as food items in fish stomach content studies. Data from 13 years of research on the trophic dynamics of Pacific Ocean predatory fish indicate that among 8746 fish of 76 species/taxa (33 families) that had been feeding, only 16 fish of 6 species had remains of 34 leptocephali in their stomachs. Only 0.013% of the 256 308 total prey items were leptocephalus larvae, and 0.03% of the total prey items were juvenile or adult eels (mostly snipe eels: Nemichthyidae). There were 10 fish of 2 species of lancetfish (Alepisaurus spp., n = 152), 2 rainbow runners (Elagatis bipinnulata, n = 222), and 2 yellowfin tuna (Thunnus albacares, n = 3103) that had leptocephali in their stomach contents, but all except one T. albacares (contained 15 leptocephali) had each eaten ≤3 leptocephali. A swallower, Pseudoscopelus sp., and a frigate tuna, Auxis thazard, had eaten single leptocephali. Twenty-eight bigeye tuna, Thunnus obesus, had eaten 76 juvenile/adult nemichthyid or serrivomerid eels. A literature survey found that only 15 out of 75 examined publications listed leptocephali in the stomach contents of a total of 6 species out of ∼ 42 300 predatory fish of 40 species. The transparency of leptocephali and their apparent mimicry of gelatinous zooplankton could contribute to lower rates of predation. Their soft bodies likely digest rapidly, so although this study and existing literature indicate that leptocephali sometimes contribute to predatory fish diets, particularly for fish that do not exclude gelatinous prey types, and fish with low digestion rates in their stomachs such as lancetfish, their levels of contribution to fish diets and the impacts of predators on eel recruitment remain uncertain.
Statin Treatment and Mortality: Propensity Score-Matched Analyses of 2007–2008 and 2009–2010 Laboratory-Confirmed Influenza Hospitalizations
Authors: Laidler Matthew R. , Thomas Ann , Baumbach Joan , Kirley Pam Daily , Meek James , Aragon Deborah , Morin Craig , Ryan Patricia A. , Schaffner William , Zansky Shelley M. , Chaves Sandra S.
Published: March 2015

Background.  Annual influenza epidemics are responsible for substantial morbidity and mortality. The use of immunomodulatory agents such as statins to target host inflammatory responses in influenza virus infection has been suggested as an adjunct treatment, especially during pandemics, when antiviral quantities are limited or vaccine production can be delayed.

Methods.  We used population-based, influenza hospitalization surveillance data, propensity score-matched analysis, and Cox regression to determine whether there was an association between mortality (within 30 days of a positive influenza test) and statin treatment among hospitalized cohorts from 2 influenza seasons (October 1, 2007 to April 30, 2008 and September 1, 2009 to April 31, 2010).

Results.  Hazard ratios for death within the 30-day follow-up period were 0.41 (95% confidence interval [CI], .25–.68) for a matched sample from the 2007–2008 season and 0.77 (95% CI, .43–1.36) for a matched sample from the 2009 pandemic.

Conclusions.  The analysis suggests a protective effect against death from influenza among patients hospitalized in 2007–2008 but not during the pandemic. Sensitivity analysis indicates the findings for 2007–2008 may be influenced by unmeasured confounders. This analysis does not support using statins as an adjunct treatment for preventing death among persons hospitalized for influenza.
An obscured narrow-line Seyfert 1 galaxy candidate, Mrk 1388 with nonthermal jets
Authors: Doi Akihiro
Published: March 2015

Mrk 1388 has an unusual Seyfert nucleus that shows narrow emission-line components without broad emission-line ones, but shows a strong featureless continuum and strong iron-forbidden, high-ionization emission lines. The apparent coexistence of type-1/2 characteristics is potentially attributed to a heavily obscured broad-line region or to an intermediate-mass black hole with a broad-line component that is intrinsically narrower than those of typical narrow-line Seyfert 1 (NLS1) galaxies. Our observation carried out by using very-long-baseline interferometry (VLBI) reveals high-brightness radio emission in nonthermal jets emerging from an active galactic nucleus (AGN) with a significant radio luminosity. Furthermore, we investigate the radial profile of the host galaxy using a Hubble Space Telescope (HST) image, which shows a Sérsic index suggestive of a pseudobulge. Using the VLBI and HST results which essentially are not affected by dust extinction, we apply the three individual methods to an estimate of the black hole mass and obtain three similar ones: (0.76–5.4) × 106 M⊙, 1.5 × 106 M⊙, and 4.1 × 106 M⊙. These masses are within a range that is fitted with typical NLS1 galaxies rather than with intermediate-mass black holes. Based on the estimated masses, a full width at half maximum FWHM(Hβ) of approximately 1200–1700 km s−1 should have been seen. The scenario in a heavily absorbed NLS1 nucleus can explain the peculiarities previously observed.
Halorubrum persicum sp. nov., an extremely halophilic archaeon isolated from sediment of a hypersaline lake
Authors: Corral Paulina , de la Haba Rafael R. , Sánchez-Porro Cristina , Amoozegar Mohammad Ali , Papke R. Thane , Ventosa Antonio
Published: March 2015

An extremely halophilic archaeon belonging to the genusHalorubrum, strain C49T, was isolated from sediment of the hypersaline lake Aran-Bidgol in Iran. Phylogenetic analysis based on 16S rRNA gene sequence similarities showed that strain C49Twas closely related toHalorubrum saccharovorumJCM 8865T(99.5 %) and other species of the genusHalorubrum. Studies based on multilocus sequence analysis revealed that strain C49Tis placed among the species ofHalorubrum; the strain constituted a defined branch in comparison with the type strains of species ofHalorubrum, while the 16S rRNA gene sequence divergence could not define the status of the newly isolated strain. For optimum growth, strain C49Trequired 20 % (w/v) salts at pH 7.0 and 37 °C under aerobic conditions. Mg2+was not required. The cells were pleomorphic rods, motile and stained Gram-variable. Colonies of the strain were pink. Hypotonic treatment with <12 % NaCl provoked cell lysis. The polar lipid pattern of strain C49Tconsisted of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester derived from both C20C20and C20C25archaeol, phosphatidylglycerol sulfate and sulfated mannosyl glucosyl diether. The DNA G+C content was 64.2 mol%. DNA–DNA hybridization studies and average nucleotide identity confirmed that strain C49Tconstitutes a distinct genospecies. Data obtained in this study show that strain C49Trepresents a novel species, for which the nameHalorubrum persicumsp. nov. is proposed. The type strain is C49T( = IBRC-M 10232T = JCM 30541T).
Amycolatopsis rhabdoformis sp. nov., an actinomycete isolated from a tropical forest soil
Authors: Souza Wallace Rafael , Silva Rafael Eduardo , Goodfellow Michael , Busarakam Kanungnid , Figueiro Fernanda Sales , Ferreira Douglas , Rodrigues-Filho Edson , Moraes Luiz Alberto Beraldo , Zucchi Tiago Domingues
Published: March 2015

Strain SB026T was isolated from Brazilian rainforest soil and its taxonomic position established using data from a polyphasic study. The organism showed a combination of chemotaxonomic and morphological features consistent with its classification in the genus

Amycolatopsis

and formed a branch in the

Amycolatopsis

16S rRNA gene tree together with

Amycolatopsis bullii

NRRL B-24847T,

Amycolatopsis plumensis

NRRL B-24324T,

Amycolatopsis tolypomycina

DSM 44544T and

Amycolatopsis vancoresmycina

NRRL B-24208T. It was related most closely to

A. bullii

NRRL B-24847T (99.0 % 16S rRNA gene sequence similarity), but was distinguished from this strain by a low level of DNA–DNA relatedness (~46 %) and discriminatory phenotypic properties. Based on the combined genotypic and phenotypic data, it is proposed that the isolate should be classified in the genus

Amycolatopsis

as representing a novel species, Amycolatopsis rhabdoformis sp. nov. The type strain is SB026T ( = CBMAI 1694T = CMAA 1285T = NCIMB 14900T).