bluuebunny/crossref_metadata_2025 huggingface dataset:
Tissue Plasminogen Activator for preclinical stroke research: Neither “rat” nor “human” dose mimics clinical recanalization in a carotid occlusion model
Authors: Tomkins Amelia J. , Hood Rebecca J. , Levi Christopher R. , Spratt Neil J.
Published: November 2015

Tissue plasminogen activator (tPA) is the only approved thrombolytic therapy for acute ischemic stroke, yet many patients do not recanalize. Enhancing thrombolytic efficacy of tPA is a major focus of stroke research. Traditionally, a “rat dose” of 10 mg/kg has been used in rodent models. Recent studies suggested that the clinical “human” dose (0.9 mg/kg) may better mimic clinical recanalization. These studies only compared the rat and clinical doses and so we aimed to test recanalization efficacy of multiple tPA doses ranging from 0.9 to 10 mg/kg in a model of endothelial injury and vessel stenosis. The common carotid artery of rats was crushed and stenosed to allow in-situ occlusive thrombus formation (Folt’s model of ‘physiological’ thrombus). Intravenous tPA was administered 60 minutes post-occlusion (n = 6-7/group). Sustained recanalization rates were 0%, 17%, 67% and 71%, for 0.9, 1.8, 4.5 and 10 mg/kg, respectively. Median time to sustained recanalization onset decreased with increasing dosage. We conclude that 10 mg/kg of tPA is too effective, whereas 0.9 mg/kg is ineffective for lysis of occlusive thrombi formed in situ. Neither dose mimics clinical tPA responses. A dose of 2x the clinical dose is a more appropriate mimic of clinical tPA recanalization in this model.
Production of viable trout offspring derived from frozen whole fish
Authors: Lee Seungki , Seki Shinsuke , Katayama Naoto , Yoshizaki Goro
Published: November 2015

Long-term preservation of fish fertility is essential for the conservation of endangered fishes. However, cryopreservation techniques for fish oocytes and embryos have not yet been developed. In the present study, functional eggs and sperm were derived from whole rainbow trout that had been frozen in a freezer and stored without the aid of exogenous cryoprotectants. Type A spermatogonia retrieved from frozen-thawed whole trout remained viable after freezing duration up to 1,113 days. Long-term-frozen trout spermatogonia that were intraperitoneally transplanted into triploid salmon hatchlings migrated toward the recipient gonads, where they were incorporated and proliferated rapidly. Although all triploid recipients that did not undergo transplantation were functionally sterile, 2 of 12 female recipients and 4 of 13 male recipients reached sexual maturity. Eggs and sperm obtained from the salmon recipients were capable of producing donor-derived trout offspring. This methodology is thus a convenient emergency tool for the preservation of endangered fishes.
High-resolution FTIR imaging of colon tissues for elucidation of individual cellular and histopathological features
Authors: Nallala Jayakrupakar , Lloyd Gavin Rhys , Shepherd Neil , Stone Nick
Published: November 2015

Comparison of spectral-histopathological features of a colon tissue measured using a conventional (5.5 μm × 5.5 μm, left) and a high-magnification (1.1 μm × 1.1 μm, right) FTIR imaging system with respect to HE stained tissue (middle).
Theranostics for hepatocellular carcinoma with Fe3O4@ZnO nanocomposites
Authors: Zhang Haijun , Patel Nishant , Ding Shuang , Xiong Jian , Wu Pingping
Published: November 2015

An Fe3O4@ZnO/Dox/TfR Ab was designed and synthesized as a theranostic agent for hepatocellular carcinoma, allowing for a targeted drug delivery with concurrent chemoradiotherapy and visual MRI evaluation of the therapeutic effect.
Conversion of nitroalkanes into carboxylic acids via iodide catalysis in water
Authors: Marcé Patricia , Lynch James , Blacker A. John , Williams Jonathan M. J.
Published: November 2015

Carboxylic acids are prepared in good yields from nitroalkanes catalysed by a combination of a Lewis acid with iodide.
Parent and trisubstituted triazacoronenes: synthesis, crystal structure and physicochemical properties
Authors: Tan Qitao , Chen Huanhuan , Xia Huaida , Liu Bingxin , Xu Bin
Published: November 2015

The parent 1,5,9-triazacoronene and its derivatives bearing various substituents were concisely synthesized, which are promising candidates for emissive and electron-transport materials.
Molecular salts of propranolol with dicarboxylic acids: diversity of stoichiometry, supramolecular structures and physicochemical properties
Authors: Stepanovs D. , Jure M. , Yanichev A. , Belyakov S. , Mishnev A.
Published: November 2015

Crystallization of the drug propranolol with dicarboxylic acids yielded molecular salts with oxalic and fumaric acids in molar ratios of 1 : 1 and 2 : 1, with maleic acid in a molar ratio of 1 : 1.
Coupled phase field, heat conduction, and elastodynamic simulations of kinetic superheating and nanoscale melting of aluminum nanolayer irradiated by picosecond laser
Authors: Hwang Yong Seok , Levitas Valery I.
Published: November 2015

Developed model coupling phase field, heat conduction, and elastodynamics reveals temperature drop of maximum 500 K due to collision of two solid–melt interfaces during ultrafast heating of Al nanolayer under laser-irradiation.
A new look at oxide formation at the copper/electrolyte interface by in situ spectroscopies
Authors: Toparli Cigdem , Sarfraz Adnan , Erbe Andreas
Published: November 2015

The oxide layer passivating copper consists mainly of a complex, defect-rich oxide on the basis of copper mixed oxide, Cu4O3.
Polymers and the p-block elements
Authors: Priegert Andrew M. , Rawe Benjamin W. , Serin Spencer C. , Gates Derek P.
Published: November 2015

A survey of the state-of-the-art in the development of synthetic methods to incorporate p-block elements into polymers is given.
Identification of the reaction pathway and reactive species for the selective catalytic reduction of NO with NH3 over cerium–niobium oxide catalysts
Authors: Qu Ruiyang , Peng Yue , Sun Xiaoxu , Li Junhua , Gao Xiang , Cen Kefa
Published: November 2015

A series of Ce–Nb oxide catalysts were synthesized at different calcination temperatures for the selective catalytic reduction (SCR) of NO with NH3 and the reaction pathway and reactive species were investigated in detail.
Novel direct amination of glycerol over heteropolyacid-based catalysts
Authors: Safariamin M. , Paul S. , Moonen K. , Ulrichts D. , Dumeignil F. , Katryniok B.
Published: November 2015

The direct amination of glycerol with dimethylamine (DMA) was studied over catalysts based on salts of phosphomolybdic acid.
Phosphorus-doped ordered mesoporous carbons embedded with Pd/Fe bimetal nanoparticles for the dechlorination of 2,4-dichlorophenol
Authors: Zhou Yaoyu , Tang Lin , Yang Guide , Zeng Guangming , Deng Yaocheng , Huang Bingbing , Cai Ye , Tang Jing , Wang Jingjing , Wu Yanan
Published: November 2015

Pd–Fe bimetal nanoparticles embedded within phosphorus-doped ordered mesoporous carbons as highly active and stable catalysts for the degradation of 2,4-dichlorophenol.
Polyphosphazenes for the Stille reaction: a new type of recyclable stannyl reagent
Authors: Martínez-Arranz Sheila , Presa-Soto David , Carriedo Gabino A. , Presa Soto Alejandro , Albéniz Ana C.
Published: November 2015

Random and block phosphazene copolymers with stannyl groups have been used as recyclable tin reagents in the Stille reaction. The block copolymer can be recycled without significant release of tin, but its efficiency decreased after three cycles, an effect related to the self-assembly of the polymer.
Surface induces different crystal structures in a room temperature switchable spin crossover compound
Authors: Gentili Denis , Liscio Fabiola , Demitri Nicola , Schäfer Bernhard , Borgatti Francesco , Torelli Piero , Gobaut Benoit , Panaccione Giancarlo , Rossi Giorgio , Degli Esposti Alessandra , Gazzano Massimo , Milita Silvia , Bergenti Ilaria , Ruani Giampiero , Šalitroš Ivan , Ruben Mario , Cavallini Massimiliano
Published: November 2015

We investigated the influence of surfaces in the formation of different crystal structures (polymorphs) of a room temperature switchable spin crossover compound.
1,1′-Bis(di-tert-butylphosphino)ferrocene copper(i) complex catalyzed C–H activation and carboxylation of terminal alkynes
Authors: Trivedi Manoj , Singh Gurmeet , Kumar Abhinav , Rath Nigam P.
Published: November 2015

Reaction of CuX (X = Br, I) and 1,1′-bis(di-tert-butylphosphino) ferrocene (dtbpf) in 1 : 1, 2 : 1 and 6 : 1 molar ratio in DCM–MeOH (50 : 50 V/V) afforded copper(i) complexes. These complexes were shown to be efficient catalysts in comparison with CuI for the conversion of terminal alkynes into propiolic acids with CO2 at room temperature.
Superior performance of borocarbonitrides, BxCyNz, as stable, low-cost metal-free electrocatalysts for the hydrogen evolution reaction
Authors: Chhetri Manjeet , Maitra Somak , Chakraborty Himanshu , Waghmare Umesh V. , Rao C. N. R.
Published: November 2015

We report superior hydrogen evolution activity of metal-free borocarbonitride (BCN) catalysts.
Photosystem I-polyaniline/TiO2solid-state solar cells: simple devices for biohybrid solar energy conversion
Authors: Gizzie Evan A. , Scott Niezgoda J. , Robinson Maxwell T. , Harris Andrew G. , Kane Jennings G. , Rosenthal Sandra J. , Cliffel David E.
Published: November 2015

Novel biophotovoltaic devices were prepared by electrochemically entrapping Photosystem I in a conductive polyaniline film, grownin situon TiO2anodes.
Ru catalysts for levulinic acid hydrogenation with formic acid as a hydrogen source
Authors: Ruppert Agnieszka M. , Jędrzejczyk Marcin , Sneka-Płatek Olga , Keller Nicolas , Dumon Alexandre S. , Michel Carine , Sautet Philippe , Grams Jacek
Published: November 2015

Experimental and theoretical approaches are combined for optimizing Ru catalysts for hydrogenation of levulinic acid (LA) with formic acid (FA) as a hydrogen source into γ-valerolactone (GVL). Particle size and influence of Ru precursor are considered as crucial parameters.
An integrative C. elegans protein–protein interaction network with reliability assessment based on a probabilistic graphical model
Authors: Huang Xiao-Tai , Zhu Yuan , Chan Leanne Lai Hang , Zhao Zhongying , Yan Hong
Published: November 2015

We construct an integrative protein–protein interaction (PPI) network in Caenorhabditis elegans, which is weighted by our proposed reliability score based on a probability graphical model (RSPGM) method.
Real-time label-free quantitative fluorescence microscopy-based detection of ATP using a tunable fluorescent nano-aptasensor platform
Authors: Shrivastava Sajal , Sohn Il-Yung , Son Young-Min , Lee Won-Il , Lee Nae-Eung
Published: November 2015

Although real-time label-free fluorescent aptasensors based on nanomaterials are increasingly recognized as a useful strategy for the detection of target biomolecules with high fidelity, the lack of an imaging-based quantitative measurement platform limits their implementation with biological samples.
Hydrogen storage in a chemical bond stabilized Co9S8–graphene layered structure
Authors: Qin Wei , Han Lu , Bi Hai , Jian Jiahuang , Wu Xiaohong , Gao Peng
Published: November 2015

With the high energy ball milling method, a Co9S8-decorated reduced graphene oxide (RGO) composite, which shows excellent hydrogen storage capacity, has been successfully fabricated with a well-organized layered structure.
Fluorescence enhancement on silver nanoplates at the single- and sub-nanoparticle level
Authors: Shen Yangbin , He Ting , Wang Wenhui , Zhan Yulu , Hu Xin , Yuan Binfang , Zhou Xiaochun
Published: November 2015

Super-resolution microscopy is used to image the diverse patterns of fluorescence enhancement on single triangular silver nanoplates.
Synthesis of (E)-oxindolylidene acetate using tandem palladium-catalyzed Heck and alkoxycarbonylation reactions
Authors: Lin Wei-Jen , Shia Kak-Shan , Song Jen-Shin , Wu Ming-Hsien , Li Wen-Tai
Published: November 2015

One-pot tandem Pd-catalyzed Heck and alkoxycarbonylation reactions for the production of new anticancer agents were established based on (E)-oxindolylidene acetates.
Direct synthesis of C-glycosides from unprotected 2-N-acyl-aldohexoses via aldol condensation–oxa-Michael reactions with unactivated ketones
Authors: Johnson Sherida , Tanaka Fujie
Published: November 2015

C-glycosides were synthesized from unprotected 2-N-acyl-aldohexoses and unactivated ketones in one pot via aldol condensation–oxa-Michael reactions.
Dicyclopenta[cd,jk]pyrene based acceptors in conjugated polymers
Authors: Bheemireddy Sambasiva R. , Plunkett Kyle N.
Published: November 2015

Reduced band gap materials via cyclopenta-fused polycyclic aromatic hydrocarbon inclusion in donor–acceptor copolymers.
Water adsorption properties of a Sc(iii) porous coordination polymer for CO2 capture applications
Authors: Álvarez J. Raziel , Peralta Ricardo A. , Balmaseda Jorge , González-Zamora Eduardo , Ibarra Ilich A.
Published: November 2015

Water adsorption was investigated in the hydrostable Sc(iii) coordination polymer NOTT-400. This material performed CO2 capture under relative humidity (RH) conditions (20 and 10% RH). The maximum CO2 capture was obtained at 20% RH and 30 °C with a total amount of ∼10.2 wt%, representing a 2.5-fold increase in comparison with anhydrous conditions.
Intermolecular OHN hydrogen bond with a proton moving in 3-methylpyridinium 2,6-dichloro-4-nitrophenolate
Authors: Majerz Irena , Gutmann Matthias J.
Published: November 2015

Temperature-dependent changes in the strong OHN hydrogen bond in 3-methylpyridinium 2,6-dichloro-4-nitrophenolate are used to discuss the proton transfer mechanism.
An acid functionalized MWCNT/PVP nanocomposite as a new additive for fabrication of an ultrafiltration membrane with improved anti-fouling resistance
Authors: Irfan Masooma , Basri Hatijah , Irfan Muhammad , Lau Woei-Jye
Published: November 2015

Membrane fouling is one of the main challenges encountered in ultrafiltration (UF) processes and the use of nanoparticles for the improvement of UF performance is a recent trend in membrane technology.
Syntheses and biological evaluation of99mTc-HYNIC-fatty acid complexes for myocardial imaging
Authors: Mathur Anupam , Sharma Abhishek K. , Murhekar V. V. , Mallia Madhava B. , Pawade Shital , Sarma H. D. , Chaudhari Pradip , Sachdev S. S. , Banerjee Sharmila
Published: November 2015

The aim of the present study is to identify a99mTc-labeled fatty acid tracer which could be a possible substitute of the widely used123I-labeled fatty acids in studying myocardial metabolism and in detection of myocardial abnormalities.
Oregonator generalization as a minimal model of quorum sensing in Belousov–Zhabotinsky reaction with catalyst confinement in large populations of particles
Authors: Szabo E.
Published: November 2015

The Oregonator demonstrates that quorum sensing in populations of Belousov–Zhabotinsky oscillators arises from modification of the stoichiometry by catalyst confinement.
One-pot synthesis of grafted brush copolymers via a chain-growth radical/oxidative dual polymerization system
Authors: Govindaiah Patakamuri , Kim Yong Seok , Hong Jae Keun , Kim Jung Hyun , Cheong In Woo
Published: November 2015

Grafted brush copolymers via one-step metal-catalyzed chain-growth radical/oxidative dual polymerization.
Preparation and characterization of a thrombin inhibitor grafted polyethersulfone blending membrane with improved antithrombotic property
Authors: Fu Shuang-Shuang , Ning Jian-Ping , Liao Xiao-Hua , Fu Xiao , Yang Zheng-Bo
Published: November 2015

A thrombin inhibitor grafted polyethersulfone membrane with improved antithrombotic property.
Hyperbranched pyridylphenylene polymers based on the first-generation dendrimer as a multifunctional monomer
Authors: Kuchkina N. V. , Zinatullina M. S. , Serkova E. S. , Vlasov P. S. , Peregudov A. S. , Shifrina Z. B.
Published: November 2015

The A6 + B2 approach to hyperbranched polymers based on the dendrimer (A6) as a multifunctional monomer and bis(cyclopentadienone)s (B2) holds promise for the one-pot synthesis of well-defined polymers with perfect dendritic fragments in the backbone.
Amphiphilic short peptide modulated wormlike micelle formation with pH and metal ion dual-responsive properties
Authors: Wang Dong , Sun Yawei , Cao Meiwen , Wang Jiqian , Hao Jingcheng
Published: November 2015

Amphiphilic short peptides (ASPs) and surfactants (C14DMAO) were employed to prepare dual-responsive wormlike micelles.
Band offset at TiO2/MDMO PPV and TiO2/PEDOT PSS interfaces studied using photoelectron spectroscopy
Authors: Ajimsha R. S. , Joshi M. P. , Mohan S. Raj , Das Amit. K. , Misra P. , Kukreja L. M. , Phase D. M.
Published: November 2015

We report band alignment and band offset studies across the interfaces of hetero-structures of TiO2 with MDMO PPV and PEDOT PSS using photoelectron spectroscopy.
Lack of a unique kinetic pathway in the growth and decay of Pluronic micelles
Authors: Arranja Alexandra , Waton Gilles , Schosseler François , Mendes Eduardo
Published: November 2015

Several concurrent mechanisms control the growth of copolymer micelles and their final morphology.
Novel CO2-tolerant Al-containing membranes for high-temperature oxygen separation
Authors: Partovi Kaveh , Bittner Michael , Caro Jürgen
Published: November 2015

Two novel CO2-stable dual-phase oxygen-transporting membranes were successfully developed by Al-doping of the perovskite phase Nd0.6Sr0.4FeO3. Enhanced oxygen fluxes were achieved, due to increased oxygen non-stoichiometry and the modified cubic crystal symmetry of the perovskite.
Omniphobic nanocomposite fiber mats with peel-away self similarity
Authors: Davis Alexander , Mele Elisa , Heredia-Guerrero José Alejandro , Bayer Ilker S. , Athanassiou Athanassia
Published: November 2015

Self-similar omniphobic electrospun nanofibers peel away when subject to liquid impact, while uncovered layers of nanofibers maintain omniphobicity.
NiO nanosheets as efficient top hole transporters for carbon counter electrode based perovskite solar cells
Authors: Liu Zonghao , Zhang Meng , Xu Xiaobao , Cai Fensha , Yuan Huailiang , Bu Lingling , Li Wenhui , Zhu Aili , Zhao Zhixin , Wang Mingkui , Cheng Yi-Bing , He Hongshan
Published: November 2015

Herein, highly crystalline NiO nanosheets are reported as top hole transporters in fully printable carbon electrode based perovskite solar cells to enhance device performance.
Mesoporous scaffolds based on TiO2 nanorods and nanoparticles for efficient hybrid perovskite solar cells
Authors: Islam Nazifah , Yang Mengjin , Zhu Kai , Fan Zhaoyang
Published: November 2015

Using TiO2 nanorods mixed with nanoparticles as a mesoporous structure, the efficiency of perovskite solar cells is improved by 27%.
Hierarchical architecture of WS2nanosheets on graphene frameworks with enhanced electrochemical properties for lithium storage and hydrogen evolution
Authors: Huang Guowei , Liu Hao , Wang Shengping , Yang Xi , Liu Binhong , Chen Hongzheng , Xu Mingsheng
Published: November 2015

Three-dimensional interlayer-expanded WS2/3DG architecture exhibits enhanced electrochemical properties for lithium storage and hydrogen evolution due to synergistic effects between the components.
Self-assembled hybrid supraparticles that proteolytically degrade tumor necrosis factor-α
Authors: Park Won Min , Yee Christine M. , Champion Julie A.
Published: November 2015

The strategies of pathogens to evade the human immune system are highly sophisticated and modulate a variety of inflammatory pathways.
3-D conformal graphene for stretchable and bendable transparent conductive film
Authors: Song Xuefen , Yang Jun , Ran Qincui , Wei Dapeng , Fang Liang , Shi Haofei , Du Chunlei
Published: November 2015

This paper demonstrates the preparation of conformal 3D graphene films on a flexible substrate by chemical vapor deposition (CVD).
Online phase margin compensation strategy for a grid‐tied inverter to improve its robustness to grid impedance variation
Authors: Zheng Chen , Zhou Lin , Yu Xirui , Li Bin , Liu Jinhong
Published: November 2015

According to studies on active damping and the stability margin, grid impedance variation does not make active damping ineffective; instead, it attenuates the stability margin. The harmonic resonance mechanism of grid‐tied inverters has been revealed by researching the influence of stability margin reduction on harmonic current amplification coefficients around the cut‐off and phase crossover frequencies. With the stability margin decreasing, amplification to harmonics around relevant frequencies is strengthened. The harmonic resonance around the cut‐off frequency is triggered as the stability margin decreases to zero. An online phase margin (PM) compensation strategy is proposed in this study to improve system robustness to grid impedance variation. The strategy is implemented by the lead network to enhance the phase and the proportional component to regulate the cut‐off frequency according to the grid impedance measured online. Hence, the system can be maintained with a sufficient PM to mitigate the harmonic resonance caused by grid impedance. Simulation and experimental results validate the theoretical analysis presented in this study. Comparisons show that the proposed strategy is superior to the zero compensation strategy in suppressing the harmonic resonance.
THz generation mechanisms in the semiconductor alloy, GaAs1−xBix
Authors: Vaisakh C. P. , Mascarenhas A. , Kini R. N.
Published: November 2015

We present measurements of the THz emission from GaAs1−xBix epilayers excited with femtosecond laser pulses (λ ∼ 800 nm). We observed an increase in the peak-to-peak amplitude of the THz electric field with increasing Bi concentration. We also observed a polarity reversal of the THz transient in the epilayers with higher Bi concentration (x ≳ 1.4%). Taking into account the band gap reduction due to Bi incorporation and the excess energy of the carriers, our measurements suggest that there is a cross-over from a predominantly surface field emitter at low Bi concentrations (x ≲ 0.5%) to a predominantly photo-Dember field emitter at higher concentrations (x ≳ 1.4%).
A multilayer sonic film
Authors: Munteanu L. , Chiroiu V. , Sireteanu T. , Dumitriu D.
Published: November 2015

A non-periodic multilayer film was analyzed to show that, despite its non-periodicity, the film exhibits full band-gaps and localized modes at its interfaces, as well as in the sonic composites. The film consists of alternating layers of two different materials that follow a triadic Cantor sequence. The Cantor structure shows extremely low thresholds for subharmonic generation of ultrasonic waves, compared with homogeneous and periodic structures. The coupling between the extended-mode (phonon) and the localized-mode (fracton) vibration regimes explains the generation of full band-gaps, for which there are no propagating Lamb waves. The large enhancement of the nonlinear interaction results from a more favorable frequency and spatial matching of coupled modes. A full band-gap that excludes Love waves is also analyzed.
Tunable two-dimensional acoustic meta-structure composed of funnel-shaped unit cells with multi-band negative acoustic property
Authors: Cho Sungjin , Kim Boseung , Min Dongki , Park Junhong
Published: November 2015

This paper presents a two-dimensional heat-exhaust and sound-proof acoustic meta-structure exhibiting tunable multi-band negative effective mass density. The meta-structure was composed of periodic funnel-shaped units in a square lattice. Each unit cell operates simultaneously as a Helmholtz resonator (HR) and an extended pipe chamber resonator (EPCR), leading to a negative effective mass density creating bandgaps for incident sound energy dissipation without transmission. This structure allowed large heat-flow through the cross-sectional area of the extended pipe since the resonance was generated by acoustic elements without using solid membranes. The pipes were horizontally directed to a flow source to enable small flow resistance for cooling. Measurements of the sound transmission were performed using a two-load, four-microphone method for a unit cell and small reverberation chamber for two-dimensional panel to characterize the acoustic performance. The effective mass density showed significant frequency dependent variation exhibiting negative values at the specific bandgaps, while the effective bulk modulus was not affected by the resonator. Theoretical models incorporating local resonances in the multiple resonator units were proposed to analyze the noise reduction mechanism. The acoustic meta-structure parameters to create broader frequency bandgaps were investigated using the theoretical model. The negative effective mass density was calculated to investigate the creation of the bandgaps. The effects of design parameters such as length, cross-sectional area, and volume of the HR; length and cross-sectional area of the EPCR were analyzed. To maximize the frequency band gap, the suggested acoustic meta-structure panel, small neck length, and cross-sectional area of the HR, large EPCR length was advantageous. The bandgaps became broader when the two resonant frequencies were similar.
Production of multicharged metal ion beams on the first stage of tandem-type ECRIS
Authors: Hagino Shogo , Nagaya Tomoki , Nishiokada Takuya , Otsuka Takuro , Muramatsu Masayuki , Kitagawa Atsushi , Sato Fuminobu , Kato Yushi
Published: November 2015

Multicharged metal ion beams are required to be applied in a wide range of fields. We aim at synthesizing iron-endohedral fullerene by transporting iron ion beams from the first stage into the fullerene plasma in the second stage of the tandem-type electron cyclotron resonance ion source (ECRIS). We developed new evaporators by using a direct ohmic heating method and a radiation heating method from solid state pure metal materials. We investigate their properties in the test chamber and produce iron ions on the first stage of the tandem-type ECRIS. As a result, we were successful in extracting Fe+ ion beams from the first stage and introducing Fe+ ion beams to the second stage. We will try synthesizing iron-endohedral fullerene on the tandem-type ECRIS by using these evaporators.
Thermal stress vs. thermal transpiration: A competition in thermally driven cavity flows
Authors: Mohammadzadeh Alireza , Rana Anirudh Singh , Struchtrup Henning
Published: November 2015

The velocity dependent Maxwell (VDM) model for the boundary condition of a rarefied gas, recently presented by Struchtrup [“Maxwell boundary condition and velocity dependent accommodation coefficient,” Phys. Fluids 25, 112001 (2013)], provides the opportunity to control the strength of the thermal transpiration force at a wall with temperature gradient. Molecular simulations of a heated cavity with varying parameters show intricate flow patterns for weak, or inverted transpiration force. Microscopic and macroscopic transport equations for rarefied gases are solved to study the flow patterns and identify the main driving forces for the flow. It turns out that the patterns arise from a competition between thermal transpiration force at the boundary and thermal stresses in the bulk.
Quantum tunneling between bent semiconductor nanowires
Authors: Sousa A. A. , Chaves Andrey , Pereira T. A. S. , Farias G. A. , Peeters F. M.
Published: November 2015

We theoretically investigate the electronic transport properties of two closely spaced L-shaped semiconductor quantum wires, for different configurations of the output channel widths as well as the distance between the wires. Within the effective-mass approximation, we solve the time-dependent Schrödinger equation using the split-operator technique that allows us to calculate the transmission probability, the total probability current, the conductance, and the wave function scattering between the energy subbands. We determine the maximum distance between the quantum wires below which a relevant non-zero transmission is still found. The transmission probability and the conductance show a strong dependence on the width of the output channel for small distances between the wires.
Patterns due to an interplay between viscous and precipitation-driven fingering
Authors: Haudin F. , De Wit A.
Published: November 2015

Dynamics related to the interplay of viscous fingering with precipitation-driven patterns are studied experimentally in a horizontal Hele-Shaw cell with radial injection. The precipitation reaction, known to produce chemical gardens, involves a cobalt chloride metallic salt solution and a more viscous sodium silicate one. The properties of the fingering precipitation patterns are studied as a function of the flow rate of injection, of the viscosity ratio between the two solutions and of the concentration of the reactants. We show that, for the viscous silicate solution used here, viscous fingering shapes flower-like patterns at low metallic salt concentrations but is not the driving mechanism in the development of spirals and filaments at larger cobalt chloride concentrations. In some cases, enhanced convective motions induced by viscous fingering also increase the amount of precipitate by increasing the mixing between the two reactants.
Biased diffusion in tubes of alternating diameter: Numerical study over a wide range of biasing force
Authors: Makhnovskii Yurii A. , Berezhkovskii Alexander M. , Antipov Anatoly E. , Zitserman Vladimir Yu.
Published: November 2015

This paper is devoted to particle transport in a tube formed by alternating wide and narrow sections, in the presence of an external biasing force. The focus is on the effective transport coefficients—mobility and diffusivity, as functions of the biasing force and the geometric parameters of the tube. Dependences of the effective mobility and diffusivity on the tube geometric parameters are known in the limiting cases of no bias and strong bias. The approximations used to obtain these results are inapplicable at intermediate values of the biasing force. To bridge the two limits Brownian dynamics simulations were run to determine the transport coefficients at intermediate values of the force. The simulations were performed for a representative set of tube geometries over a wide range of the biasing force. They revealed that there is a range of the narrow section length, where the force dependence of the mobility has a maximum. In contrast, the diffusivity is a monotonically increasing function of the force. A simple formula is proposed, which reduces to the known dependences of the diffusivity on the tube geometric parameters in both limits of zero and strong bias. At intermediate values of the biasing force, the formula catches the diffusivity dependence on the narrow section length, if the radius of these sections is not too small.
Experimental and theoretical investigations of the electronic band structure of metal-organic frameworks of HKUST-1 type
Authors: Gu Zhi-Gang , Heinke Lars , Wöll Christof , Neumann Tobias , Wenzel Wolfgang , Li Qiang , Fink Karin , Gordan Ovidiu D. , Zahn Dietrich R. T.
Published: November 2015

The electronic properties of metal-organic frameworks (MOFs) are increasingly attracting the attention due to potential applications in sensor techniques and (micro-) electronic engineering, for instance, as low-k-dielectric in semiconductor technology. Here, the band gap and the band structure of MOFs of type HKUST-1 are studied in detail by means of spectroscopic ellipsometry applied to thin surface-mounted MOF films and by means of quantum chemical calculations. The analysis of the density of states, the band structure, and the excitation spectrum reveal the importance of the empty Cu-3d orbitals for the electronic properties of HKUST-1. This study shows that, in contrast to common belief, even in the case of this fairly “simple” MOF, the excitation spectra cannot be explained by a superposition of “intra-unit” excitations within the individual building blocks. Instead, “inter-unit” excitations also have to be considered.
Diamond synthesis at atmospheric pressure by microwave capillary plasma chemical vapor deposition
Authors: Hemawan Kadek W. , Gou Huiyang , Hemley Russell J.
Published: November 2015

Polycrystalline diamond has been synthesized on silicon substrates at atmospheric pressure, using a microwave capillary plasma chemical vapor deposition technique. The CH4/Ar plasma was generated inside of quartz capillary tubes using 2.45 GHz microwave excitation without adding H2 into the deposition gas chemistry. Electronically excited species of CN, C2, Ar, N2, CH, Hβ, and Hα were observed in the emission spectra. Raman measurements of deposited material indicate the formation of well-crystallized diamond, as evidenced by the sharp T2g phonon at 1333 cm−1 peak relative to the Raman features of graphitic carbon. Field emission scanning electron microscopy images reveal that, depending on the growth conditions, the carbon microstructures of grown films exhibit “coral” and “cauliflower-like” morphologies or well-facetted diamond crystals with grain sizes ranging from 100 nm to 10 μm.
Bidirectional voltage biased implication operations using SiOx based unipolar memristors
Authors: Zhou Fei , Guckert Lauren , Chang Yao-Feng , Swartzlander Earl E. , Lee Jack
Published: November 2015

This work presents a material implication implementation using SiOx based unipolar memristors. SiOx memristors with TaN/SiOx/Si structures have been fabricated, characterized, and used in the implication operation. The implication function and its truth table were well implemented using both positive and negative voltages for load resistor bias. The voltage range for the implication operation is reduced due to bidirectional bias. The key factors for the operation of material implication, such as load resistance, characteristics of the memristor, and design tradeoffs were investigated. This work demonstrates that unipolar SiOx based memristors are suitable for logic operations.
A synchrotron study of defect and strain inhomogeneity in laser-assisted three-dimensionally-printed Ni-based superalloy
Authors: Li Yao , Qian Dan , Xue Jiawei , Wan Jingchun , Zhang Anfeng , Tamura Nobumichi , Song Zhongxiao , Chen Kai
Published: November 2015

Synchrotron X-ray microdiffraction was employed to investigate the inhomogeneous distribution of defect and residual strain in the transitional region between the dendritic and stray grains in a laser-assisted 3D printed Ni-based superalloy. The dendritic region was found to be under tensile strain transversely to the primary dendrite arm directions. The dendrite edges, where high level of strains and geometrically necessary dislocations were detected, were discerned as low angle grain boundaries. High angle grain boundaries were observed in the stray grain region, and the orientation of the strain tensor in this region varied dramatically at the micron scale, in contrast with the more or less homogeneous distribution in the dendritic region.
Imaging outside the box: Resolution enhancement in X-ray coherent diffraction imaging by extrapolation of diffraction patterns
Authors: Latychevskaia Tatiana , Chushkin Yuriy , Zontone Federico , Fink Hans-Werner
Published: November 2015

Coherent diffraction imaging is a high-resolution imaging technique whose potential can be greatly enhanced by applying the extrapolation method presented here. We demonstrate the enhancement in resolution of a non-periodical object reconstructed from an experimental X-ray diffraction record which contains about 10% missing information, including the pixels in the center of the diffraction pattern. A diffraction pattern is extrapolated beyond the detector area and as a result, the object is reconstructed at an enhanced resolution and better agreement with experimental amplitudes is achieved. The optimal parameters for the iterative routine and the limits of the extrapolation procedure are discussed.
Note: Device for obtaining volumetric, three-component velocity fields inside cylindrical cavities
Authors: Ramírez G. , Núñez J. , Hernández G. N. , Hernández-Cruz G. , Ramos E.
Published: November 2015

We describe a device designed and built to obtain the three-component, steady state velocity field in the whole volume occupied by a fluid in motion contained in a cavity with cylindrical walls. The prototype comprises a two-camera stereoscopic particle image velocimetry system mounted on a platform that rotates around the volume under analysis and a slip ring arrangement that transmits data from the rotating sensors to the data storage elements. Sample observations are presented for natural convection in a cylindrical container but other flows can be analyzed.
Volmer-Weber growth stages of polycrystalline metal films probed by in situ and real-time optical diagnostics
Authors: Abadias G. , Simonot L. , Colin J. J. , Michel A. , Camelio S. , Babonneau D.
Published: November 2015

The Volmer-Weber growth of high-mobility metal films is associated with the development of a complex compressive-tensile-compressive stress behavior as the film deposition proceeds through nucleation of islands, coalescence, and formation of a continuous layer. The tensile force maximum has been attributed to the end of the islands coalescence stage, based on ex situ morphological observations. However, microstructural rearrangements are likely to occur in such films during post-deposition, somewhat biasing interpretations solely based on ex situ analysis. Here, by combining two simultaneous in situ and real-time optical sensing techniques, based on surface differential reflectance spectroscopy (SDRS) and change in wafer curvature probed by multibeam optical stress sensor (MOSS), we provide direct evidence that film continuity does coincide with tensile stress maximum during sputter deposition of a series of metal (Ag, Au, and Pd) films on amorphous SiOx. Stress relaxation after growth interruption was testified from MOSS, whose magnitude scaled with adatom mobility, while no change in SDRS signal could be revealed, ruling out possible changes of the surface roughness at the micron scale.
Effect of cubic Dresselhaus spin-orbit interaction in a persistent spin helix state including phonon scattering in semiconductor quantum wells
Authors: Kurosawa R. , Morita K. , Kohda M. , Ishitani Y.
Published: November 2015

We performed a numerical simulation of the spatial behavior of spin precession in a persistent spin helix (PSH) state at high temperatures (>150 K) in a two-dimensional electron gas of GaAs and InGaAs (001)-semiconductor quantum wells (QWs). To describe the spin dynamics of the PSH state at high temperatures, the effect of a cubic Dresselhaus spin-orbit interaction (SOI) that destroys the PSH state was added to the balanced Rashba and linear Dresselhaus SOI. Furthermore, longitudinal optical and acoustic phonon scattering were taken into account in the momentum scattering calculations. The simulation results indicate that the PSH state in the InGaAs QW persists for over 500 ps because of the small effective mass of the electron, even at room temperature. We also reveal that it is closer to the ideal PSH state when the Rashba strength (α) is controlled to the renormalized linear Dresselhaus SOI strength (−β̃) rather than the linear Dresselhaus SOI strength (−β).
Magnetic modulation doping in topological insulators toward higher-temperature quantum anomalous Hall effect
Authors: Mogi M. , Yoshimi R. , Tsukazaki A. , Yasuda K. , Kozuka Y. , Takahashi K. S. , Kawasaki M. , Tokura Y.
Published: November 2015

Quantum anomalous Hall effect (QAHE), which generates dissipation-less edge current without external magnetic field, is observed in magnetic-ion doped topological insulators (TIs) such as Cr- and V-doped (Bi,Sb)2Te3. The QAHE emerges when the Fermi level is inside the magnetically induced gap around the original Dirac point of the TI surface state. Although the size of gap is reported to be about 50 meV, the observable temperature of QAHE has been limited below 300 mK. We attempt magnetic-Cr modulation doping into topological insulator (Bi,Sb)2Te3 films to increase the observable temperature of QAHE. By introducing the rich-Cr-doped thin (1 nm) layers at the vicinity of both the surfaces based on non-Cr-doped (Bi,Sb)2Te3 films, we have succeeded in observing the QAHE up to 2 K. The improvement in the observable temperature achieved by this modulation-doping appears to be originating from the suppression of the disorder in the surface state interacting with the rich magnetic moments. Such a superlattice designing of the stabilized QAHE may pave a way to dissipation-less electronics based on the higher-temperature and zero magnetic-field quantum conduction.
Nuclear Cardiology
Authors: Zaret Barry L.
Published: November 2015

Nuclear cardiology is generally considered a clinical phenomenon of the past four decades. However, the field has its roots in earlier times. This chapter focuses on these historical roots as they have evolved into the present era. The initial application of radioisotopes to cardiac studies occurred in the mid-1920s. Ventricular function was evaluated in the 1960s and 1970s by first pass and equilibrium techniques. Myocardial stress perfusion imaging was first performed using potassium-43 and exercise in 1973. Stress imaging rapidly evolved thereafter with new tracers (thallium-201 and technetium-labeled agents) and from planar to SPECT approaches. Perfusion imaging rapidly proved its value diagnostically and in assessing prognosis. Infarct imaging reached its peak use in the 1970s but is now no longer employed. Advances in hybrid imaging, combining CT with radionuclide imaging has recently allowed attenuation correction as well as providing the combination of anatomic and physiologic data. PET myocardial perfusion studies have recently become a standard approach for evaluating perfusion, absolute coronary blood flow and coronary reserve. PET FDG studies of cardiac sarcoidosis have recently been established as a new approach for defining myocardial inflammation. New SPECT systems provide high sensitivity, high resolution studies, allowing for radiation dose reduction and high quality imaging studies.
Radionuclide Angiography
Authors: Sanghani Rupa Mehta , Williams Kim Allan
Published: November 2015

This chapter discusses the technique and use of radionuclide angiography with planar and tomographic imaging. Planar techniques have given way to tomographic imaging in recent years. An overview of RNA is given, including technical issues such as radiopharmaceutical administration, and performance aspects including image acquisition and data interpretation. First-pass RNA (FPRNA), gated planar equilibrium RNA (ERNA) and gated tomographic equilibrium blood pool imaging (GBP-SPECT) are discussed in detail. The use of RNA in select patient populations, including coronary artery disease, valvular disease and for monitoring chemotherapy is discussed. In addition, the use of RNA for the assessment of dyssynchrony is discussed.
Gated SPECT MPI
Authors: Cerqueira Manuel D.
Published: November 2015

Protocols for SPECT MPI have evolved over the last 40-years based on the following factors: available radiotracers and gamma camera imaging systems, alternative methods of stress, the needs and demands of patients and referring physicians, the need for radiation dose reduction and optimization of laboratory efficiency. Initially studies were performed using dynamic exercise planar multi-day Thallium-201 (Tl-201) studies. Pharmacologic stress agents were not available and novel methods of stress included swallowed esophageal pacing leads, cold presser limb emersion, direct atrial pacing, crushed dipyridamole tablets and even the use of intravenous ergonovine maleate. Eventually intravenous dobutamine, dipyridamole, adenosine and regadenoson became available to allow reliable and safe pharmacologic stress for patients unable to exercise. Tomographic SPECT camera systems replaced planar units and Tc-99m agents offered better imaging characteristics over Tl-201. These gamma camera systems, radiopharmaceutical agents and pharmacologic stress agents were all available by the mid-1990s and still represent the majority of MPI being performed today.
Myocardial Perfusion Imaging Before and After Cardiac Revascularization
Authors: AlJaroudi Wael
Published: November 2015

Coronary artery disease (CAD) remains the leading cause of morbidity and mortality worldwide. While the burden of the disease remains high, the rates of death attributable to CAD have declined by almost a third between 1998 and 2008. In patients with stable ischemic heart disease (SIHD), data supporting survival benefit from coronary artery bypass graft surgery (CABG) or percutaneous coronary intervention (PCI) versus no revascularization are outdated with the recent advancement in medical therapy. Over the years, myocardial perfusion imaging (MPI) has played a significant role in detecting ischemic burden, risk stratifying patients and guiding physicians to the best treatment strategy. Contrary to data from other trials, the role of stress MPI has been downplayed in more contemporary randomized clinical trial that failed to show that ischemic burden identifies the ideal candidate for revascularization or carries incremental prognostic value. Hence, there is an equipoise on the role of MPI in the management of patients prior to revascularization. The role of stress MPI post-revascularization has also been evaluated in multiple studies, mostly done in the last decade or prior. The guidelines advocate against routine stress MPI in asymptomatic patients (unless 5 years or more post-CABG), but allows it in the presence or recurrence of symptoms. The current chapter will review the data on survival benefit from revascularization, complementary role of stress MPI in selecting the appropriate candidate for revascularization, prognostic value of ischemic versus atherosclerotic burden, role of MPI post revascularization, updated guidelines and proposed algorithms to guide the treating physicians.
Screening Asymptomatic Subjects
Authors: Hage Fadi G. , Farag Ayman , Zoghbi Gilbert J.
Published: November 2015

Cardiovascular disease is the leading cause of death in the United States and accounts for more deaths than all cancers combined. Many apparently healthy adults first present to the health system with a myocardial infarction or sudden cardiac death. It is therefore imperative to assess the risk of cardiovascular events among currently asymptomatic individuals to try and intervene early in the disease process to prevent future events. Risk factors for the development of coronary artery disease in particular, and cardiovascular disease in general, have been identified from epidemiological studies and used to develop global risk scores to risk stratify populations. Although these scores work well at the level of the population, unfortunately they are imperfect at estimating risk at the level of the individual. In this Chapter we will discuss the use of exercise stress testing and other imaging modalities as screening methods for the detection of coronary disease and predicting risk in asymptomatic adults. The hope is to develop a screening program to identify cardiovascular disease early in the disease process to introduce interventions that will favorably impact outcomes in a manner similar to the current screening programs available for several cancers.
Role of Imaging in Chronic Kidney Disease
Authors: Ather Sameer , Farag Ayman , Bhatia Vikas , Hage Fadi G.
Published: November 2015

Cardiovascular disease is highly prevalent in patients with chronic kidney disease (CKD) and is the biggest contributor of death in these patients. Myocardial perfusion imaging (MPI) is a validated tool for diagnosing coronary artery disease (CAD) and for predicting short and long term prognosis in this patient population. Non-invasive stress imaging, with MPI or other imaging modalities, is widely used for risk stratification in patients with end-stage renal disease (ESRD) being evaluated for kidney transplantation due to the paucity of donor organs and the high cardiovascular risk of patients on the transplant waiting list. In this Chapter we will review the data on diagnostic accuracy and risk stratification using MPI in patients with CKD and ESRD highlighting the special challenges that are unique to this population. We will also discuss novel indicators that have been used in these patients to improve risk stratification.