bluuebunny/crossref_metadata_2025 huggingface dataset:
High glucose environment inhibits cranial neural crest survival by activating excessive autophagy in the chick embryo
Authors: Wang Xiao-Yu , Li Shuai , Wang Guang , Ma Zheng-Lai , Chuai Manli , Cao Liu , Yang Xuesong
Published: December 2015

High glucose levels induced by maternal diabetes could lead to defects in neural crest development during embryogenesis, but the cellular mechanism is still not understood. In this study, we observed a defect in chick cranial skeleton, especially parietal bone development in the presence of high glucose levels, which is derived from cranial neural crest cells (CNCC). In early chick embryo, we found that inducing high glucose levels could inhibit the development of CNCC, however, cell proliferation was not significantly involved. Nevertheless, apoptotic CNCC increased in the presence of high levels of glucose. In addition, the expression of apoptosis and autophagy relevant genes were elevated by high glucose treatment. Next, the application of beads soaked in either an autophagy stimulator (Tunicamycin) or inhibitor (Hydroxychloroquine) functionally proved that autophagy was involved in regulating the production of CNCC in the presence of high glucose levels. Our observations suggest that the ERK pathway, rather than the mTOR pathway, most likely participates in mediating the autophagy induced by high glucose. Taken together, our observations indicated that exposure to high levels of glucose could inhibit the survival of CNCC by affecting cell apoptosis, which might result from the dysregulation of the autophagic process.
GFP-complementation assay to detect functional CPP and protein delivery into living cells
Authors: Milech Nadia , Longville Brooke AC , Cunningham Paula T , Scobie Marie N , Bogdawa Heique M , Winslow Scott , Anastasas Mark , Connor Theresa , Ong Ferrer , Stone Shane R , Kerfoot Maria , Heinrich Tatjana , Kroeger Karen M , Tan Yew-Foon , Hoffmann Katrin , Thomas Wayne R , Watt Paul M , Hopkins Richard M
Published: December 2015

Efficient cargo uptake is essential for cell-penetrating peptide (CPP) therapeutics, which deliver widely diverse cargoes by exploiting natural cell processes to penetrate the cell’s membranes. Yet most current CPP activity assays are hampered by limitations in assessing uptake, including confounding effects of conjugated fluorophores or ligands, indirect read-outs requiring secondary processing and difficulty in discriminating internalization from endosomally trapped cargo. Split-complementation Endosomal Escape (SEE) provides the first direct assay visualizing true cytoplasmic-delivery of proteins at biologically relevant concentrations. The SEE assay has minimal background, is amenable to high-throughput processes and adaptable to different transient and stable cell lines. This split-GFP-based platform can be useful to study transduction mechanisms, cellular imaging and characterizing novel CPPs as pharmaceutical delivery agents in the treatment of disease.
Development of a pneumatically driven active cover lid for multi-well microplates for use in perfusion three-dimensional cell culture
Authors: Huang Song-Bin , Chou Dean , Chang Yu-Han , Li Ke-Cing , Chiu Tzu-Keng , Ventikos Yiannis , Wu Min-Hsien
Published: December 2015

Before microfluidic-based cell culture models can be practically utilized for bioassays, there is a need for a transitional cell culture technique that can improve conventional cell culture models. To address this, a hybrid cell culture system integrating an active cover lid and a multi-well microplate was proposed to achieve perfusion 3-D cell culture. In this system, a microfluidic-based pneumatically-driven liquid transport mechanism was integrated into the active cover lid to realize 6-unit culture medium perfusion. Experimental results revealed that the flow of culture medium could be pneumatically driven in a flow-rate uniform manner. We used the system to successfully perform a perfusion 3-D cell culture of mesenchymal stem cells (MSCs) for up to 16 days. Moreover, we investigated the effects of various cell culture models on the physiology of MSCs. The physiological nature of MSCs can vary with respect to the cell culture model used. Using the perfusion 3-D cell culture format might affect the proliferation and osteogenic differentiation of MSCs. Overall, we have developed a cell culture system that can achieve multi-well microplate-based perfusion 3-D cell culture in an efficient, cost-effective and user-friendly manner. These features could facilitate the widespread application of perfusion cell culture models for cell-based assays.
Characterisation of radioiodinated flavonoid derivatives for SPECT imaging of cerebral prion deposits
Authors: Fuchigami Takeshi , Yamashita Yuki , Kawasaki Masao , Ogawa Ayaka , Haratake Mamoru , Atarashi Ryuichiro , Sano Kazunori , Nakagaki Takehiro , Ubagai Kaori , Ono Masahiro , Yoshida Sakura , Nishida Noriyuki , Nakayama Morio
Published: December 2015

Prion diseases are fatal neurodegenerative diseases characterised by deposition of amyloid plaques containing abnormal prion protein aggregates (PrPSc). This study aimed to evaluate the potential of radioiodinated flavonoid derivatives for single photon emission computed tomography (SPECT) imaging of PrPSc. In vitro binding assays using recombinant mouse PrP (rMoPrP) aggregates revealed that the 4-dimethylamino-substituted styrylchromone derivative (SC-NMe2) had higher in vitro binding affinity (Kd = 24.5 nM) and capacity (Bmax = 36.3 pmol/nmol protein) than three other flavonoid derivatives (flavone, chalcone and aurone). Fluorescent imaging using brain sections from mouse-adapted bovine spongiform encephalopathy (mBSE)-infected mice demonstrated that SC-NMe2 clearly labelled PrPSc-positive prion deposits in the mice brain. Two methoxy SC derivatives, SC-OMe and SC-(OMe)2, also showed high binding affinity for rMoPrP aggregates with Ki values of 20.8 and 26.6 nM, respectively. In vitro fluorescence and autoradiography experiments demonstrated high accumulation of [125I]SC-OMe and [125I]SC-(OMe)2 in prion deposit-rich regions of the mBSE-infected mouse brain. SPECT/computed tomography (CT) imaging and ex vivo autoradiography demonstrated that [123I]SC-OMe showed consistent brain distribution with the presence of PrPSc deposits in the mBSE-infected mice brain. In conclusion, [123I]SC-OMe appears a promising SPECT radioligand for monitoring prion deposit levels in the living brain.
MCO Membranes: Enhanced Selectivity in High-Flux Class
Authors: Boschetti-de-Fierro Adriana , Voigt Manuel , Storr Markus , Krause Bernd
Published: December 2015

Novel MCO high-flux membranes for hemodialysis have been developed with optimized permeability, allowing for filtration close to that of the natural kidney. A comprehensive in vitro characterization of the membrane properties by dextran filtration is presented. The sieving profile of pristine membranes, as well as that of membranes exposed to blood for 40 minutes, are described. The effective pore size (Stokes-Einstein radius) was estimated from filtration experiments before and after blood exposure and results were compared to hydrodynamic radii of middle and large uremic toxins and essential proteins. The results indicate that the tailored pore sizes of the MCO membranes promote removal of large toxins while ensuring the retention of albumin.
TALENs-mediated gene disruption of FLT3 in leukemia cells: Using genome-editing approach for exploring the molecular basis of gene abnormality
Authors: Wang Jue , Li Tongjuan , Zhou Mi , Hu Zheng , Zhou Xiaoxi , Zhou Shiqiu , Wang Na , Huang Liang , Zhao Lei , Cao Yang , Xiao Min , Ma Ding , Zhou Pengfei , Shang Zhen , Zhou Jianfeng
Published: December 2015

Novel analytic tools are needed to elucidate the molecular basis of leukemia-relevant gene mutations in the post-genome era. We generated isogenic leukemia cell clones in which the FLT3 gene was disrupted in a single allele using TALENs. Isogenic clones with mono-allelic disrupted FLT3 were compared to an isogenic wild-type control clone and parental leukemia cells for transcriptional expression, downstream FLT3 signaling and proliferation capacity. The global gene expression profiles of mutant K562 clones and corresponding wild-type controls were compared using RNA-seq. The transcriptional levels and the ligand-dependent autophosphorylation of FLT3 were decreased in the mutant clones. TALENs-mediated FLT3 haplo-insufficiency impaired cell proliferation and colony formation in vitro. These inhibitory effects were maintained in vivo, improving the survival of NOD/SCID mice transplanted with mutant K562 clones. Cluster analysis revealed that the gene expression pattern of isogenic clones was determined by the FLT3 mutant status rather than the deviation among individual isogenic clones. Differentially expressed genes between the mutant and wild-type clones revealed an activation of nonsense-mediated decay pathway in mutant K562 clones as well as an inhibited FLT3 signaling. Our data support that this genome-editing approach is a robust and generally applicable platform to explore the molecular bases of gene mutations.
A sequential bioorthogonal dual strategy: ManNAl and SiaNAl as distinct tools to unravel sialic acid metabolic pathways
Authors: Gilormini P. A. , Lion C. , Vicogne D. , Levade T. , Potelle S. , Mariller C. , Guérardel Y. , Biot C. , Foulquier F.
Published: December 2015

A new sequential orthogonal dual strategy to unravel the intracellular trafficking and cellular uptake mechanism of sialic acid.
Plasmonic MoO3−x@MoO3 nanosheets for highly sensitive SERS detection through nanoshell-isolated electromagnetic enhancement
Authors: Tan Xianjun , Wang Lingzhi , Cheng Chen , Yan Xuefeng , Shen Bin , Zhang Jinlong
Published: December 2015

Nanoshell-isolated electromagnetic enhancing for highly sensitive sers detection.
Uptake and release of gaseous species accompanying the reactions of isoprene photo-oxidation products with sulfate particles
Authors: Liu Yingjun , Kuwata Mikinori , McKinney Karena A. , Martin Scot T.
Published: December 2015

Uptake and release of gaseous species was observed for the reactions of isoprene photo-oxidation products and sulfate particles.
Mechanistic studies of pyridinium electrochemistry: alternative chemical pathways in the presence of CO2
Authors: Peroff A. G. , Weitz E. , Van Duyne R. P.
Published: December 2015

Pyridinium has been described as a catalyst for CO2 reduction, however with low faradaic efficiency. This article discusses a series of electrochemistry experiments to study other chemical processes occurring during pyridinium electrochemistry which might provide insight into the low faradaic efficiency.
Liquid–liquid equilibria of binary mixtures of a lipidic ionic liquid with hydrocarbons
Authors: Green Blane D. , Badini Alexander J. , O'Brien Richard A. , Davis James H. , West Kevin N.
Published: December 2015

A lipidic ionic liquid is described with very high alkane solubility that is virtually immiscible in the alkane phase.
Experimental evidence for the influence of charge on the adsorption capacity of carbon dioxide on charged fullerenes
Authors: Ralser Stefan , Kaiser Alexander , Probst Michael , Postler Johannes , Renzler Michael , Bohme Diethard K. , Scheier Paul
Published: December 2015

The adsorption of CO2 is sensitive to charge on a capturing model carbonaceous surface, such as C60 fullerenes.
Using photo-initiated polymerization reactions to detect molecular recognition
Authors: Kaastrup K. , Sikes H. D.
Published: December 2015

Radical polymerization reactions initiated by light can be used to provide signal amplification in molecular binding assays.
Iron-catalyzed photoreduction of carbon dioxide to synthesis gas
Authors: Alsabeh Pamela G. , Rosas-Hernández Alonso , Barsch Enrico , Junge Henrik , Ludwig Ralf , Beller Matthias
Published: December 2015

Photocatalytic processes to convert CO2 to useful products including CO and HCOOH are of particular interest as a means to harvest the power of the sun for sustainable energy applications. Herein, we report the photocatalytic reduction of CO2 using iron-based catalysts and visible light generating varying ratios of synthesis gas.
Novel phenazine crystals enable direct electron transfer to methanogens in anaerobic digestion by redox potential modulation
Authors: Beckmann Sabrina , Welte Cornelia , Li Xiaomin , Oo Yee M. , Kroeninger Lena , Heo Yooun , Zhang Miaomiao , Ribeiro Daniela , Lee Matthew , Bhadbhade Mohan , Marjo Christopher E. , Seidel Jan , Deppenmeier Uwe , Manefield Mike
Published: December 2015

Phenazine crystals enhance methanogenesis by electron delivery to respiratory heterodisulfide reductase enzyme.
Towards improved membrane production: using low-toxicity solvents for the preparation of PEEK nanofiltration membranes
Authors: da Silva Burgal João , Peeva Ludmila , Livingston Andrew
Published: December 2015

In this work it is shown that PEEK membranes are “green” from the production point of view when compared with commercial polyimide (PI) based organic solvent nanofiltration (OSN) membranes.
“Happy silver anniversary”: Green Chemistry at 25
Authors: Anastas Paul , Han Buxing , Leitner Walter , Poliakoff Martyn
Published: December 2015

Editorial article celebrating 25 years of the field of Green Chemistry.
Synthesis of Ti, Zr, and Hf complexes with a new tetra-azane ligand by one-pot HCl-elimination and their properties as catalysts for production of UHMWPE
Authors: Ji Xiangdong , Yao Wei , Luo Xuyang , Gao Wei , Mu Ying
Published: December 2015

The first example for the HCl-elimination reaction being applied in the attachment of an amido-containing ligand to Zr and Hf.
Synthesis, electrochemical and spectroscopic properties of ruthenium(ii) complexes containing 2,6-di(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)aryl ligands
Authors: Goudy Violaine , Maynadié Jérôme , Goff Xavier Le , Meyer Daniel , Fontecave Marc
Published: December 2015

Five mono and dinuclear ruthenium complexes containing various symmetrical 2,6-di(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)aryl ligands were synthetized and their physical–chemical properties were studied.
New sterically encumbered arylimido hexamolybdates for organic oxidation reactions
Authors: Jangir Ritambhara , Antony Rajendran , Murugavel Ramaswamy
Published: December 2015

Surface modification of the parent hexamolybdate by aryl amines results in useful catalysts for the oxidation of cyclohexene to cyclohexene epoxide and benzyl alcohol to benzaldehyde and benzoic acid.
A facile and fast synthetic approach to create selenium nanoparticles with diverse shapes and their antioxidation ability
Authors: Yu Bo , You Pengtao , Song Meifang , Zhou Yang , Yu Faquan , Zheng Wenjie
Published: December 2015

A facile microwave-assisted method was developed to synthesize multi-morphology selenium nanoparticles with better antioxidation properties as their size decreased.
Magnetically recoverable Fe3O4-implanted Ag-loaded ZnO nanoflakes for bacteria-inactivation and photocatalytic degradation of organic pollutants
Authors: Karunakaran Chockalingam , Vinayagamoorthy Pazhamalai
Published: December 2015

Tri-functional Ag-loaded ZnO nanoflakes with the Fe3O4 core were synthesized by the hydrothermal method followed by photodeposition.
Two potential self-activated orthoborates Cd4NdO(BO3)3 and Ca3Nd3(BO3)5: growth, crystal structures and optical properties
Authors: Wang Xing , Xia Mingjun , Li R. K.
Published: December 2015

Different arrangements of NdOn polyhedra in the two crystal structures can result in a huge difference of their fluorescence lifetime.
Isolation of gravimetrically quantifiable alkali metal arenides using 18-crown-6
Authors: Castillo Maximiliano , Metta-Magaña Alejandro J. , Fortier Skye
Published: December 2015

A simple and general procedure, using 18-crown-6, is presented for the isolation of arene radical monoanions in the solid-state.
Weak antilocalization and electron–electron interaction in coupled multiple-channel transport in a Bi2Se3 thin film
Authors: Jing Yumei , Huang Shaoyun , Zhang Kai , Wu Jinxiong , Guo Yunfan , Peng Hailin , Liu Zhongfan , Xu H. Q.
Published: December 2015

High crystalline quality topological insulator Bi2Se3 thin films are grown by van der Waals epitaxy on fluorophlogopite mica substrates and the excellent transport properties of the as-grown films are extracted from the magnetotransport measurements.
Smart nanogels at the air/water interface: structural studies by neutron reflectivity
Authors: Zielińska Katarzyna , Sun Huihui , Campbell Richard A. , Zarbakhsh Ali , Resmini Marina
Published: December 2015

Structure of the NIPAM-based nanogels at the air/water interface. Nanogel interfacial behaviour was correlated with and their morphology determined mostly by the amount of cross-linker.
Trace metal profiles in mosses and lichens from the high-altitude Tibetan Plateau
Authors: Shao Jun-juan , Shi Jian-bo , Duo Bu , Liu Cheng-bin , Gao Yan , Fu Jian-jie , Yang Rui-qiang , Cai Yong , Jiang Gui-bin
Published: December 2015

Mosses and lichens showed different abilities to accumulate trace metals, which was influenced by altitude.
Inorganic salt templated porous TiO2 photoelectrode for solid-state dye-sensitized solar cells
Authors: Li Hao , Li Shichao , Zhang Ye , Yan Feng
Published: December 2015

Salt template induced TiO2 photoelectrodes with channels (or pores) were applied to improve the photoelectric conversion efficiency of solid-state dye-sensitized solar cells.
One-pot synthesis of monodispersed porous CoFe2O4nanospheres on graphene as an efficient electrocatalyst for oxygen reduction and evolution reactions
Authors: Yan Wenning , Cao Xuecheng , Ke Ke , Tian Jinghua , Jin Chao , Yang Ruizhi
Published: December 2015

Monodispersed porous CoFe2O4nanospheres grown on graphene with high ORR/OER activities are fabricated by a simple one-pot solvothermal method.
Mixed guanidinato-amido Ge(iv) and Sn(iv) complexes with GeE (E = S, Se) double bond and SnS4, Sn2Se2 rings
Authors: Barman Milan Kr. , Nembenna Sharanappa
Published: December 2015

The oxidative addition of chalcogens (S and Se) to the guanidinate supported Ge(ii) and Sn(ii) amide complexes.
‘Donor-free’ oligo(3-hexylthiophene) dyes for efficient dye-sensitized solar cells
Authors: Hu Yue , Ivaturi Aruna , Planells Miquel , Boldrini Chiara L. , Biroli Alessio Orbelli , Robertson Neil
Published: December 2015

Easily synthesized ‘donor-free’ dyes work as efficient sensitisers for dye-sensitised solar cells.
Influence of habitat quantity, quality and isolation on the distribution and abundance of two epiphytic lichens
Authors: Johansson Per , Ehrlén Johan
Published: December 2015

We assessed the relative importance of habitat quantity, quality and isolation for the distribution and local abundance of two epiphytic lichens,Parmelina tiliacea, which is red‐listed in Sweden, and the commonPleurosticta acetabulum. We predicted that habitat isolation should constrain the distribution of the mainly vegetatively dispersedP. tiliaceamore than the sexually dispersedP. acetabulum.

All patches of habitat containing suitable host trees for the study species were mapped from aerial, infra‐red photographs. Presence and abundance of the lichens were recorded for a total of 3237 trees in 94 patches.

Patch identity had strong influence on presence of both species on individual trees. Within patches, presence was positively correlated with tree size and was also influenced by tree species.

At patch‐level, species presence was positively correlated with tree number and negatively correlated with the proportion of the boundary that bordered coniferous forest and with isolation. Abundance was mostly correlated with tree size or with the number of large trees at tree‐ and patch‐levels, respectively. ForP. acetabulum, within‐patch abundance was also influenced by isolation from other patches.

Presence at patch‐level was affected by isolation for both species, but this effect differed between the three isolation measures used. There was no clear evidence that the distribution ofP. tiliaceawas more constrained by isolation than that ofP. acetabulum.

Whilst this study emphasizes the importance of habitat quantity for species occupancy and local abundance, it shows that explanations of species occurrence in fragmented landscapes must also involve variables describing habitat quality and spatial configuration. Moreover it illustrates the difficulties in predicting species’ occupancy from general knowledge about their dispersal traits.
Computation reduction for turbo decoding through window skipping
Authors: Martina M. , Condo C. , Roch M.R. , Masera G.
Published: December 2015

A simple and effective technique to skip the computation of reliable portions of a frame (windows) for turbo code decoding is proposed. The proposed criterion relies on a very simple approximation of cross‐entropy measure by means of thresholding. This criterion features negligible complexity and low‐memory requirements. Simulation results show that, in the best case, up to 20% of windows can be skipped with no error‐rate degradation. Such a significant computation reduction can be exploited to directly reduce the power consumption as well.
Design of switching hyperplanes for multi‐inputs multi‐outputs discrete‐time linear systems
Authors: Darío Luis‐Delgado José , Mohammed Al‐Hadithi Basil , Jiménez Agustín
Published: December 2015

The design of sliding switching surfaces consist in finding a manifold where the controlled system dynamics are asymptotically stable. This problem has been studied for a long time, during which a wide range of designing approaches has been proposed, which can be classified into two research methodologies; the first one corresponding to eigenvalues designing approaches and the second one is based on optimal approaches. In addition, some research approaches only can be applied to specific type of systems, e.g. single‐input single‐output systems or continuous time systems. Finally, the performance or the level of the achieved accuracy among the different approaches varies significantly. The proposed approach facilitates the task of designing sliding surfaces applied to multi‐input multi‐output (MIMO) linear systems. The presented methodology introduces a switching surface for MIMO linear systems through a simple equation that allows both eigenvalues placement design or optimal methods without any coordinate system representation transformation. In addition, a design parameter is also included for the adjustment of the non‐ideal dynamics. Moreover, this approach guarantees high accuracy of the system dynamics, either for arbitrary eigenvalues assignment or for optimal switching surface definitions. In addition, these benefits are attained using a single switching surface equation. An illustrative example is included to show the advantages of the proposed design methodology.
Laser surface modification of medical grade alloys for reduced heating in a magnetic resonance imaging environment
Authors: Benafan O. , Chen S.-Y. , Kar A. , Vaidyanathan R.
Published: December 2015

Nanoscale surface modification of medical grade metallic alloys was conducted using a neodymium-doped yttrium aluminum garnet laser-based dopant diffusion technique. The objective of this approach was to minimize the induction heating by reducing the absorbed radio frequency field. Such an approach is advantageous in that the dopant is diffused into the alloy and is not susceptible to detachment or spallation as would an externally applied coating, and is expected to not deteriorate the mechanical and electrical properties of the base alloy or device. Experiments were conducted using a controlled environment laser system with the ability to control laser properties (i.e., laser power, spot size, and irradiation time) and dopant characteristics (i.e., temperature, concentration, and pressure). The reflective and transmissive properties of both the doped and untreated samples were measured in a radio frequency (63.86 MHz) magnetic field using a system comprising a high power signal generator, a localized magnetic field source and sensor, and a signal analyzer. The results indicate an increase in the reflectivity of the laser-treated samples compared to untreated samples. The effect of reflectivity on the heating of the alloys is investigated through a mathematical model incorporating Maxwell’s equations and heat conduction.
Synthesis of LaF3 nanosheets with high fluorine mobility investigated by NMR relaxometry and diffusometry
Authors: Gulina L. B. , Schäfer M. , Privalov A. F. , Tolstoy V. P. , Murin I. V.
Published: December 2015

Ionically conducting lanthanum fluoride (LaF3), displaying a nanoscopic lamellar structure, has been synthesized at the surface of an aqueous solution of LaCl3 and HF. The structure and the chemical composition of the conductor have been analyzed by SEM, electron probe microanalysis, X-ray powder diffraction, FTIR, and 19F magic angle spinning nuclear magnetic resonance (NMR) spectroscopy. The fluorine dynamics have been studied by NMR diffusometry and relaxometry in a temperature range from room temperature up to 875 K. The fluorine self-diffusion coefficient of the nanostructured LaF3 is about two orders of magnitude larger than that of bulk LaF3. This novel material is highly promising for many typical applications of fluorine ionic systems.
The Lennard-Jones melting line and isomorphism
Authors: Heyes D. M. , Brańka A. C.
Published: December 2015

The location of the melting line (ML) of the Lennard-Jones (LJ) system and its associated physical properties are investigated using molecular dynamics computer simulation. The radial distribution function and the behavior of the repulsive and attractive parts of the potential energy indicate that the ML is not a single isomorph, but the isomorphic state evolves gradually with temperature, i.e., it is only “locally isomorphic.” The state point dependence of the unitless isomorphic number, X̃, for a range of static and dynamical properties of the LJ system in the solid and fluid states, and for fluid argon, are also reported. The quantity X̃ typically varies most with state point in the vicinity of the triple point and approaches a plateau in the high density (temperature) limit along the ML.
Wave packet dynamics for a system with position and time-dependent effective mass in an infinite square well
Authors: Vubangsi M. , Tchoffo M. , Fai L. C. , Pisma’k Yu. M.
Published: December 2015

The problem of a particle with position and time-dependent effective mass in a one-dimensional infinite square well is treated by means of a quantum canonical formalism. The dynamics of a launched wave packet of the system reveals a peculiar revival pattern that is discussed.
Magneto-induced tunability of thermo-spin current in deformed zigzag graphene nanoribbons
Authors: Adinehloo Davoud , Fathipour Morteza
Published: December 2015

The aim of this report is to unfold how the thermo-electric spin-polarized current in a transverse-biased zigzag graphene nanoribbon changes in the presence of uniaxial deformations and uniform perpendicular magnetic field. Employing the two-parameter Hubbard model along with the non-equilibrium Green's function formalism, we found that both uniaxial strain and magnetic field can significantly modulate the bandgap, local distribution of edge states, and the critical transverse electric field needed to achieve the half-metallic phase in the ribbon. Our analysis shows a significant enhancement of the maximum attainable spin-polarized current as functions of both source temperature and contacts temperature difference, with increasing the magnetic field or applying any magnitude of compressive strain. Furthermore, it is shown that the magneto-resistance ratio of the device, can be drastically tuned via strain engineering, reaching values as high as 2 × 104% for compressive strains of 5% magnitude.
Melting curves and structural properties of tantalum from the modified-Z method
Authors: Liu C. M. , Xu C. , Cheng Y. , Chen X. R. , Cai L. C.
Published: December 2015

The melting curves and structural properties of tantalum (Ta) are investigated by molecular dynamics simulations combining with potential model developed by Ravelo et al. [Phys. Rev. B 88, 134101 (2013)]. Before calculations, five potentials are systematically compared with their abilities of producing reasonable compressional and equilibrium mechanical properties of Ta. We have improved the modified-Z method introduced by Wang et al. [J. Appl. Phys. 114, 163514 (2013)] by increasing the sizes in Lx and Ly of the rectangular parallelepiped box (Lx = Ly ≪ Lz). The influences of size and aspect ratio of the simulation box to melting curves are also fully tested. The structural differences between solid and liquid are detected by number density and local-order parameters Q6. Moreover, the atoms' diffusion with simulation time, defects, and vacancies formations in the sample are all studied by comparing situations in solid, solid-liquid coexistence, and liquid state.
Insight into the epitaxial growth of high optical quality GaAs1–xBix
Authors: Beaton D. A. , Mascarenhas A. , Alberi K.
Published: December 2015

The ternary alloy GaAs1–xBix is a potentially important material for infrared light emitting devices, but its use has been limited by poor optical quality. We report on the synthesis of GaAs1–xBix epi-layers that exhibit narrow, band edge photoluminescence similar to other ternary GaAs based alloys, e.g., InyGa1–yAs. The measured spectral linewidths are as low as 14 meV and 37 meV at low temperature (6 K) and room temperature, respectively, and are less than half of previously reported values. The improved optical quality is attributed to the use of incident UV irradiation of the epitaxial surface and the presence of a partial surface coverage of bismuth in a surfactant layer during epitaxy. Comparisons of samples grown under illuminated and dark conditions provide insight into possible surface processes that may be altered by the incident UV light. The improved optical quality now opens up possibilities for the practical use of GaAs1–xBix in optoelectronic devices.
Quantification of the sensitivity range in neutron dark-field imaging
Authors: Betz B. , Harti R. P. , Strobl M. , Hovind J. , Kaestner A. , Lehmann E. , Van Swygenhoven H. , Grünzweig C.
Published: December 2015

In neutron grating interferometry, the dark-field image visualizes the scattering properties of samples in the small-angle and ultra-small-angle scattering range. These angles correspond to correlation lengths from several hundred nanometers up to several tens of micrometers. In this article, we present an experimental study that demonstrates the potential of quantitative neutron dark-field imaging. The dark-field signal for scattering from different particle sizes and concentrations of mono-dispersive polystyrene particles in aqueous solution is compared to theoretical predictions and the good agreement between measurements and calculations underlines the quantitative nature of the measured values and reliability of the technique with neutrons.
Dynamic actuation of single-crystal diamond nanobeams
Authors: Sohn Young-Ik , Burek Michael J. , Kara Vural , Kearns Ryan , Lončar Marko
Published: December 2015

We show the dielectrophoretic actuation of single-crystal diamond nanomechanical devices. Gradient radio-frequency electromagnetic forces are used to achieve actuation of both cantilever and doubly clamped beam structures, with operation frequencies ranging from a few MHz to ∼50 MHz. Frequency tuning and parametric actuation are also studied.
Preliminary research on overmoded high-power millimeter-wave Cerenkov generator with dual-cavity reflector in low guiding magnetic field
Authors: Ye Hu , Chen Changhua , Ning Hui , Tan Weibing , Teng Yan , Shi Yanchao , Wu Ping , Song Zhimin , Cao Yibing , Du Zhaoyu
Published: December 2015

This paper presents preliminary research on a V-band overmoded Cerenkov generator with dual-cavity reflector operating in a low guiding magnetic field. It is found that the fluctuation of the electron envelope in the low guiding magnetic field can be predicted using an equivalent coaxial model of a foilless diode, and a dual-cavity reflector based on the model matching method can provide strong reflection at the front end of the overmoded structures so that any microwave power that leaks into the diode region can be effectively suppressed. Numerical simulations indicate that the control of the beam envelope and the use of the dual-cavity reflector ease generator operation in the low guiding magnetic field. In the experimental research, the fluctuation of the annular electron beam with the outer radius of 7.5 mm measures approximately 0.7 mm, which is in good agreement with the theoretical results. The disturbance caused by power leaking from the overmoded slow wave structure is eliminated by the dual-cavity reflector. With accurate fabrication and assembly processes, an operating frequency of 61.6 GHz is attained by the fifth harmonic heterodyne method, and the output power is measured to be approximately 123 MW by the far-field measurement method at a diode voltage of 445 kV, a beam current of 4.45 kA, and under a guiding magnetic field of 1.45 T. The output mode is measured using an array of neon flash bulbs, and the pulse shortening phenomenon is both observed and analyzed.
Generation of anomalously energetic suprathermal electrons by an electron beam interacting with a nonuniform plasma
Authors: Sydorenko D. , Kaganovich I. D. , Chen L. , Ventzek P. L. G.
Published: December 2015

Generation of anomalously energetic suprathermal electrons was observed in simulation of a high-voltage dc discharge with electron emission from the cathode. An electron beam produced by the emission interacts with the nonuniform plasma in the discharge via a two-stream instability. The energy transfer from the beam to the plasma electrons is ensured by the plasma nonuniformity. The electron beam excites plasma waves whose wavelength and phase speed gradually decrease towards anode. The waves with short wavelength near the anode accelerate plasma bulk electrons to suprathermal energies. The sheath near the anode reflects some of the accelerated electrons back into the plasma. These electrons travel through the plasma, reflect near the cathode, and enter the accelerating area again but with a higher energy than before. Such particles are accelerated to energies much higher than after the first acceleration. This mechanism plays a role in explaining earlier experimental observations of energetic suprathermal electrons in similar discharges.
Experimental investigation of inhomogeneities, nanoscopic phase separation, and magnetism in arc melted Fe-Cu metals with equal atomic ratio of the constituents
Authors: Hassnain Jaffari G. , Aftab M. , Anjum D. H. , Cha Dongkyu , Poirier Gerald , Ismat Shah S.
Published: December 2015

Composition gradient and phase separation at the nanoscale have been investigated for arc-melted and solidified with equiatomic Fe-Cu. Diffraction studies revealed that Fe and Cu exhibited phase separation with no trace of any mixing. Microscopy studies revealed that immiscible Fe-Cu form dense bulk nanocomposite. The spatial distribution of Fe and Cu showed existence of two distinct regions, i.e., Fe-rich and Cu-rich regions. Fe-rich regions have Cu precipitates of various sizes and different shapes, with Fe forming meshes or channels greater than 100 nm in size. On the other hand, the matrix of Cu-rich regions formed strips with fine strands of nanosized Fe. Macromagnetic response of the system showed ferromagnetic behavior with a magnetic moment being equal to about 2.13 μB/Fe atom and a bulk like negligible value of coercivity over the temperature range of 5–300 K. Anisotropy constant has been calculated from various laws of approach to saturation, and its value is extracted to be equal to 1350 J/m3. Inhomogeneous strain within the Cu and Fe crystallites has been calculated for the (unannealed) sample solidified after arc-melting. Annealed sample also exhibited local inhomogeneity with removal of inhomogeneous strain and no appreciable change in magnetic character. However, for the annealed sample phase separated Fe exhibited homogenous strain.
Polarization-dependent optics using gauge-field metamaterials
Authors: Liu Fu , Wang Saisai , Xiao Shiyi , Hang Zhi Hong , Li Jensen
Published: December 2015

We show that effective gauge field for photons with polarization-split dispersion surfaces, being realized using uniaxial metamaterials, can be used for polarization control with unique opportunities. The metamaterials with the proposed gauge field correspond to a special choice of eigenpolarizations on the Poincaré sphere as pseudo-spins, in contrary to those from either conventional birefringent crystals or optical active media. It gives rise to all-angle polarization control and a generic route to manipulate photon trajectories or polarizations in the pseudo-spin domain. As demonstrations, we show beam splitting (birefringent polarizer), all-angle polarization control, unidirectional polarization filter, and interferometer as various polarization control devices in the pseudo-spin domain. We expect that more polarization-dependent devices can be designed under the same framework.
Bending self-collimated one-way light by using gyromagnetic photonic crystals
Authors: Li Qing-Bo , Li Zhen , Wu Rui-xin
Published: December 2015

We theoretically demonstrate that electromagnetic waves can self-collimate and propagate unidirectionally in photonic crystals fabricated using semicylindrical ferrite rods in magnetized states. The parity and time-reversal symmetries of such photonic crystals are broken, resulting in a self-collimated one-way body wave within the photonic crystals. By applying the bias magnetic field in a complex configuration, the self-collimated one-way wave beam can be bent into arbitrary trajectories within the photonic crystal, providing an avenue for controlling wave beams.
A SDD1-like subtilase is exuded by tobacco roots
Authors: Wendlandt Tim , Moche Martin , Becher Dörte , Stöhr Christine
Published: December 2015

Hydroponically grown tobacco (Nicotiana tabacum L. cv. Samsun) roots exude proteases under non-stressed conditions. Ten different proteases could be distinguished by 2D-zymography of root exudate. The majority of the gelatinolytic activity was susceptible to serine protease inhibitors. One of the proteases could be assigned to an EST (SGN-P361478) by mass spectrometry of immune-purified root exudate. The sequence was completed by RACE-PCR and shows typical serine protease features of subtilase family S8A. Thermostability and SDS-insensitivity indicate a kinetically stable enzyme. Phylogenetic classification of this highly gelatinolytic subtilase showed SDD1 to be the closest relative in Arabidopsis thaliana (L. Heynh.). Even closer related protein sequences could be found in other distant plant genera indicating a high conservation of the subtilase. A 5-methyltetrahydropteroyltriglutamate-homocysteine methyltransferase-like protein and suberisation-associated anionic peroxidase-like protein were co-immune-purified and identified by mass spectrometry and may constitute potential interaction partners.
CD11b regulates obesity-induced insulin resistance via limiting alternative activation and proliferation of adipose tissue macrophages
Authors: Zheng Chunxing , Yang Qian , Xu Chunliang , Shou Peishun , Cao Jianchang , Jiang Menghui , Chen Qing , Cao Gang , Han Yanyan , Li Fengying , Cao Wei , Zhang Liying , Zhang Li , Shi Yufang , Wang Ying
Published: December 2015

Significance

Obesity is associated with long-term low-grade inflammation characterized by the accumulation of adipose tissue macrophages (ATMs). One important molecule that regulates the migration of monocytes/macrophages is CD11b (integrin αM). Here we show an unexpected role of CD11b in modulating the IL-4/STAT6 signaling in macrophages, thereby limiting IL-4/STAT6–mediated proliferation and alternative activation of ATMs. In the absence of CD11b, there is an increase in ATM in situ proliferation and an enhancement of alternatively polarized phenotypes. Importantly, the alternatively activated ATMs attenuate obesity-related insulin resistance in CD11b-deficient mice. These results reveal a previously unidentified physiological function of CD11b, which could be a therapeutic target for insulin resistance.
Casein kinase II promotes target silencing by miRISC through direct phosphorylation of the DEAD-box RNA helicase CGH-1
Authors: Alessi Amelia F. , Khivansara Vishal , Han Ting , Freeberg Mallory A. , Moresco James J. , Tu Patricia G. , Montoye Eric , Yates John R. , Karp Xantha , Kim John K.
Published: December 2015

Significance

MicroRNAs (miRNAs) are critical regulators of diverse biological processes. Despite rapid advances in understanding miRNA biogenesis and function, a gap remains in our knowledge of how miRNA effector complex activity [miRNA-induced silencing complex (miRISC)] is modulated. Specifically, the importance of posttranslational protein modifications in controlling miRISC activity remains largely unexplored. Here, we characterize a previously unidentified role for the conserved serine/threonine kinase, casein kinase II (CK2), in promoting the miRNA pathway in
Caenorhabditis elegans
. Notably, we establish the requirement of CK2 for miRNA function and provide mechanistic evidence that loss of CK2 compromises miRISC binding to mRNA targets. Furthermore, we identify that the miRISC cofactor and DEAD-box RNA helicase, CGH-1/DDX6, is phosphorylated by CK2 at a conserved residue, which is required for CGH-1–mediated miRNA function.
Effects of DNA replication on mRNA noise
Authors: Peterson Joseph R. , Cole John A. , Fei Jingyi , Ha Taekjip , Luthey-Schulten Zaida A.
Published: December 2015

Significance

Gene expression noise affects a cell’s biological state and contributes to such phenomena as phenotype switching and cell fate determination. By examining chromosome replication—which is tightly controlled and thus exhibits little noise—we show that variability in mRNA levels across a population is less than previously expected. This noise is due to the transient relaxation of the mRNA from a low- to a high-copy steady state after a gene replication event. Gene location, mRNA degradation rate, and cell doubling time all contribute to observed noise. Our results demonstrate that it is essential to account for gene replication when modelling gene expression or when interpreting experimental results.
The future of reform in Oman
Authors: Said Basma Mubarak
Published: December 2015

Oman is currently experiencing a social and political crisis pemanating from issues created by the declining health of Sultan pQaboos, as well as fundamental problems with the nature of the pstate’s regime. Oman is a country renowned for its progressive pand modern outlook, but in the last decade it has become pincreasingly alienated from its ruling authority. During the Omani pSpring of 2011 popular protests took place demanding political pchange and greater rights, freedoms and improved living pstandards. Sultan Qaboos wisely responded to these protests with pa package of reforms including some to the constitution and pjudicial institutions, but these have been thwarted by repressive pmeasures by the security services and other agencies. More than pfour years on, Oman faces many challenges in launching a process pof comprehensive reform that would lead to a transition to pdemocracy and limited constitutional rule.
Updated Maturity Estimates for Flatfishes (Pleuronectidae) in the Eastern Bering Sea, with Implications for Fisheries Management
Authors: TenBrink Todd T. , Wilderbuer Thomas K.
Published: December 2015

Female Yellowfin Sole Limanda aspera, Alaska Plaice Pleuronectes quadrituberculatus, and Flathead Sole Hippoglossoides elassodon were collected from the eastern Bering Sea during known prespawning, spawning, and postspawning periods in 2012 and 2013, and their ovaries and otoliths were sampled for use in histological analysis to update historical maturity estimates. For fisheries management, new information on maturity at age can lead to possible changes in estimated reproduction potential (measured as female spawning stock biomass [SSB]) and values of fishing mortality reference points. Our analysis indicated that Yellowfin Sole currently mature at an age similar to that estimated in a study conducted 20 years ago. An evaluation of impacts on the stock assessment indicated that updated estimates of Yellowfin Sole SSB were over 7% higher, but the reference points only changed slightly. The first histologically derived maturity estimates for Alaska Plaice were close to the anatomically derived estimates (visual assessments from 1987), resulting in a marginal decrease (5%) in SSB, but changes in reference points were near 10%. Based on the new maturity estimates for Flathead Sole, SSB estimates increased by 7% compared with estimates currently used in the stock assessment, which relied on maturity data collected in 1999 and 2000. The change in Flathead Sole SSB was concomitant with changes of 16–18% in fishing mortality reference points. Our results indicated minimal differences from historical maturity estimates after re-examination, but in some cases those differences led to relatively large changes in the respective reference points, underscoring the reference points' sensitivity to changes in maturity. Incorporation of these new maturity estimates into the stock assessment process provides valuable updated information for fisheries managers. However, a more comprehensive sampling program is needed to investigate the spatial and temporal aspects of reproduction for each species.

Received November 13, 2014; accepted September 3, 2015
JM25-1, a Lidocaine Analog Combining Airway Relaxant and Antiinflammatory Properties
Authors: Serra Magda F. , Neves Josiane S. , Couto Gina C. , Cotias Amanda C. , Pão Camila R. , Olsen Priscilla C. , de Carvalho Katharinne I. Moraes , Anjos-Valotta Edna A. , Faria Robson X. , Costa Jorge C. S. , Cordeiro Renato S. B. , Silva Patricia M. R. , Martins Marco A.
Published: December 2015

AbstractAbstract

In comparison to lidocaine, JM25-1 was more effective in reducing bronchial smooth muscle constriction, airway hyperreactivity, lung inflammation, and peribronchial fibrosis. These data lend support for further investigation of the therapeutic potential of JM25-1 for the treatment of bronchospasm.

Background

Inhaled lidocaine antagonized bronchospasm in animal models and patients, but adverse effects limited its efficacy. This study evaluated the antibronchospasm potential of the analog JM25-1, exploring in vitro mechanisms and translation to an animal model.

Methods

The effectiveness of JM25-1 was assessed in GH3 cells, rat tracheal rings, mouse lymphocytes, and human eosinophil systems in vitro, assessing changes in Na+ current, contraction, proliferation, and survival, respectively. Lung function and inflammatory changes were studied in ovalbumin-sensitized mice.

Results

The efficacy of JM25-1 was higher than lidocaine in inhibiting carbachol-induced and calcium-induced tracheal contractions (maximum effect inhibition at 1 mM [%]: 67 ± 10 [JM25-1] vs. 41 ± 11 [lidocaine] [P < 0.001] for carbachol; 100 ± 3 [JM25-1] vs. 36 ± 26 [lidocaine] [P < 0.001] for Ca2+; mean ± SD; n = 9 each) but lower in Na+ current (50% inhibitory concentration = 151.5, n = 8 vs. 0.2 mM; n = 5; P < 0.001). JM25-1 also inhibited eosinophil survival (dead cells [%]: 65 ± 6; n = 4; P < 0.001 at 1 mM) and lymphocyte proliferation (cells in phase S + G2 [%]: 94 ± 10; n = 6; P < 0.001) at 0.6 mM. Aerosolized JM25-1 (1%) decreased lung eosinophil numbers from 13.2 ± 2.4 to 1.7 ± 0.7 × 104/μm2 (n = 6; P < 0.001) and neutrophils from 1.9 ± 0.4 to 0.2 ± 0.1 × 104/μm2 (n = 7; P < 0.001). Other parameters, including airway hyperreactivity, cytokines, mucus, and extracellular matrix deposition, were also sensitive to aerosolized JM25-1.

Conclusion

These findings highlight the potential of JM25-1, emphasizing its putative value in drug development for clinical conditions where there is bronchospasm.