bluuebunny/crossref_metadata_2025 huggingface dataset:
Probing Mechanoregulation of Neuronal Differentiation by Plasma Lithography Patterned Elastomeric Substrates
Authors: Nam Ki-Hwan , Jamilpour Nima , Mfoumou Etienne , Wang Fei-Yue , Zhang Donna D. , Wong Pak Kin
Published: November 2014

Cells sense and interpret mechanical cues, including cell-cell and cell-substrate interactions, in the microenvironment to collectively regulate various physiological functions. Understanding the influences of these mechanical factors on cell behavior is critical for fundamental cell biology and for the development of novel strategies in regenerative medicine. Here, we demonstrate plasma lithography patterning on elastomeric substrates for elucidating the influences of mechanical cues on neuronal differentiation and neuritogenesis. The neuroblastoma cells form neuronal spheres on plasma-treated regions, which geometrically confine the cells over two weeks. The elastic modulus of the elastomer is controlled simultaneously by the crosslinker concentration. The cell-substrate mechanical interactions are also investigated by controlling the size of neuronal spheres with different cell seeding densities. These physical cues are shown to modulate with the formation of focal adhesions, neurite outgrowth and the morphology of neuroblastoma. By systematic adjustment of these cues, along with computational biomechanical analysis, we demonstrate the interrelated mechanoregulatory effects of substrate elasticity and cell size. Taken together, our results reveal that the neuronal differentiation and neuritogenesis of neuroblastoma cells are collectively regulated via the cell-substrate mechanical interactions.
Simulations of Morphology and Charge Transport in Supramolecular Organic Materials
Authors: Andrienko Denis
Published: November 2014

In this chapter, we describe the current state of the art of microscopic charge transport simulations in partially ordered and disordered organic semiconductors, including simulations of atomistic morphologies, evaluation of electronic couplings, driving forces, charge transfer rates, and charge carrier mobilities. Special attention is paid to finite-size effects, long-range interactions, and charge localization.
High adsorptive properties of covalent triazine-based frameworks (CTFs) for surfactants from aqueous solution
Authors: Bhunia Asamanjoy , Dey Subarna , Bous Maria , Zhang Chenyang , von Rybinski Wolfgang , Janiak Christoph
Published: November 2014

CTFs can adsorb 20-times the amount of surfactant than common carbon black.
Multiple and configurable optical logic systems based on layered double hydroxides and chromophore assemblies
Authors: Shi Wenying , Fu Yi , Li Zhixiong , Wei Min
Published: November 2014

Multiple and configurable fluorescence logic gates were fabricated through the self-assembly of layered double hydroxide nanosheets and three fluorescence chromophores.
Direct and metal-free arylsulfonylation of alkynes with sulfonylhydrazides for the construction of 3-sulfonated coumarins
Authors: Wei Wei , Wen Jiangwei , Yang Daoshan , Guo Mengyuan , Wang Yingying , You Jinmao , Wang Hua
Published: November 2014

A novel and metal-free procedure has been developed for the construction of sulfonated coumarins via direct arylsulfonylation of alkynes with sulfonylhydrazides.
Simulating preferential sorption of tartrate on prismatic calcite surfaces
Authors: Ukrainczyk Marko , Greiner Maximilian , Elts Ekaterina , Briesen Heiko
Published: November 2014

Calculated binding energies of favorable adsorption configurations emphasize the importance of surface charge/energetics, structural match and water layers in mineral–organic interactions.
Positional isomeric effect on the structural variation of Cd(ii) coordination polymers based on flexible linear/V-shaped bipyridyl benzene ligands
Authors: Liu Lei-Lei , Yu Cai-Xia , Li Ya-Ru , Han Jing-Jing , Ma Feng-Ji , Ma Lu-Fang
Published: November 2014

Solvothermal reactions of Cd(OAc)2·2H2O with 2,2′-azodibenzoic acid and five positional isomeric N-donor bipyridyl benzene ligands in MeOH/H2O at 170 °C gave rise to five coordination polymers. Complexes 1–5 were characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction, and single-crystal X-ray diffraction.
Electronic structures at the interface between Au and CH3NH3PbI3
Authors: Liu Xiaoliang , Wang Chenggong , Lyu Lu , Wang Congcong , Xiao Zhengguo , Bi Cheng , Huang Jinsong , Gao Yongli
Published: November 2014

The electronic properties of the interface formed between Au and organometal triiodide perovskite (CH3NH3PbI3) are investigated using photoemission spectroscopy.
Interaction of gold nanoparticles mediated by captopril and S-nitrosocaptopril: the effect of manganese ions in mild acid medium
Authors: Iglesias Emilia , Prado-Gotor Rafael
Published: November 2014

Small amounts of Mn+2 ions in mild-acid medium accelerate the self-assembly of thiol-capped gold nanoparticles via electrostatic and/or H-bonding interactions.
Cosolvent and crowding effects on the polymerization kinetics of actin
Authors: Rosin Christopher , Schummel Paul Hendrik , Winter Roland
Published: November 2014

Effects of cosolvents and macromolecular crowding agents on the G-to-F-transformation of actin are studied. Drastic and diverse changes in the lag phase and association rates of polymerizing actin are observed under different solvent conditions.
Washcoating of cordierite honeycomb with vanadia–tungsta–titania mixed oxides for selective catalytic reduction of NO with NH3
Authors: Liu Bo , Du Jun , Lv Xiaowei , Qiu Yue , Tao Changyuan
Published: November 2014

The application of monolithic coated catalysts to NOx abatement is a crucial issue for practical applications to enhance the mechanical strength, economize the cost, facilitate recycling etc., compared with the conventional monolithic extrusive catalysts.
Silver coordination polymers with tri- and hexacyanoethyl-functionalized macrocyclic ligands
Authors: Ma Zhen , Shi Huaduan , Deng Xiuqiang , Guedes da Silva M. Fátima C. , Martins Luísa M. D. R. S. , Pombeiro Armando J. L.
Published: November 2014

Three silver(i) complexes, [Ag(L1)](NO3) (1), [Ag2(NO3)2(L1)]n (2) and {[Ag2(L2)](NO3)2}n (3), were obtained by reaction of silver nitrate with the corresponding cyano-functionalized macrocyclic ligands. Their structures and thermal and electrochemical properties were studied.
Optimizing the high-field relaxivity by self-assembling of macrocyclic Gd(iii) complexes
Authors: Lawson Dale , Barge Alessandro , Terreno Enzo , Parker David , Aime Silvio , Botta Mauro
Published: November 2014

The self-assembling of two macrocyclic Gd-chelates results in a small-sized dimeric system characterized by a remarkably high relaxivity, r1.
Enzymatic hydrolysis of lignocellulosic polysaccharides in the presence of ionic liquids
Authors: Wahlström R. M. , Suurnäkki A.
Published: November 2014

This article reviews the recent progress in designing compatible ionic liquid–enzymatic systems for biomass pretreatment and hydrolysis as a step in the production of biofuels and -chemicals from lignocellulosic polysaccharides.
Ammonia-free coprecipitation synthesis of a Ni–Co–Mn hydroxide precursor for high-performance battery cathode materials
Authors: Nam Kyoung-Mo , Kim Hyun-Jin , Kang Dong-Hyun , Kim Yong-Seok , Song Seung-Wan
Published: November 2014

The ammonia-free coprecipitation process using citric acid as a new chelating agent successfully produced a micro-sized spherical Ni0.5Co0.2Mn0.3(OH)2 precursor and a well-performed cathode active material LiNi0.5Co0.2Mn0.3O2 for Li-ion batteries.
Ce–Nd separation by solid-phase micro-extraction and its application to high-precision 142Nd/144Nd measurements using TIMS in geological materials
Authors: Li Chao-Feng , Wang Xuan-Ce , Li You-Lian , Chu Zhu-Yin , Guo Jing-Hui , Li Xiang-Hui
Published: November 2014

A rapid solid-phase micro-extraction (SPME) technique, using HEHEHP resin as sorbent, is established to completely separate Ce from rare earth element (REE) mixtures.
Bis-EDOT end capped by n-hexyl or n-hexylsulfanyl groups: the effect of the substituents on the stability of the oxidized states
Authors: Turbiez Mathieu , Faye Djibril , Leriche Philippe , Frère Pierre
Published: November 2014

Sulfur atoms of hexylsulfanyl groups stabilize the radical cation and dication states and prevent the σ-dimerization of the radical cation.
Design and synthesis of fluorescent 7-deazaadenosine nucleosides containing π-extended diarylacetylene motifs
Authors: De Ornellas Sara , Slattery John M. , Edkins Robert M. , Beeby Andrew , Baumann Christoph G. , Fairlamb Ian J. S.
Published: November 2014

A novel series of C-modified π-extended 7-deazaadenosines exhibit promising fluorescence properties.
Changes in air quality and tropospheric composition due to depletion of stratospheric ozone and interactions with changing climate: implications for human and environmental health
Authors: Madronich S. , Shao M. , Wilson S. R. , Solomon K. R. , Longstreth J. D. , Tang X. Y.
Published: November 2014

UV radiation is an essential driver for the formation of photochemical smog, which includes ground-level ozone and particulate matter (PM). Recent analyses support earlier work showing that poor outdoor air quality is a major environmental hazard as well as quantifying health effects on regional and global scales more accurately. Greater exposure to these pollutants has been linked to increased risks of cardiovascular and respiratory diseases in humans and is associated globally with several million premature deaths per year. Ozone also has adverse effects on yields of crops, leading to loss of billions of US dollars each year. These detrimental effects also may alter biological diversity and affect the function of natural ecosystems. Future air quality will depend mostly on changes in emission of pollutants and their precursors, but changes in UV radiation and climate will contribute as well. Significant reductions in emissions, mainly from the energy and transportation sectors, have already led to improved air quality in many locations. Air quality will continue to improve in those cities/states that can afford controls, and worsen where the regulatory infrastructure is not available. Future changes in UV radiation and climate will alter the rates of formation of ground-level ozone and photochemically-generated particulate matter and must be considered in predictions of air quality. The decrease in UV radiation associated with recovery of stratospheric ozone will, according to recent global atmospheric model simulations, lead to increases in ground-level ozone at most locations. If correct, this will add significantly to future ground-level ozone trends. However, the spatial resolution of these global models is insufficient to inform policy at this time, especially for urban areas. UV radiation affects the atmospheric concentration of hydroxyl radicals, ?OH, which are responsible for the self-cleaning of the atmosphere. Recent measurements confirm that, on a local scale, ?OH radicals respond rapidly to changes in UV radiation. However, on large (global) scales, models differ in their predictions by nearly a factor of two, with consequent uncertainties for estimating the atmospheric lifetime and concentrations of key greenhouse gases and air pollutants. Projections of future climate need to consider these uncertainties. No new negative environmental effects of substitutes for ozone depleting substances or their breakdown-products have been identified. However, some substitutes for the ozone depleting substances will continue to contribute to global climate change if concentrations rise above current levels.
End-group differentiating ozonolysis of furocoumarins
Authors: Malakhov Mikhail V. , Dubinnyi Maxim A. , Vlasova Natalia V. , Zgoda Victor G. , Efremov Roman G. , Boldyrev Ivan A.
Published: November 2014

Ozonolysis of furocoumarins followed by reductive work-up yields not only common symmetrical dialdehydes, but alsoo-formylumbelliferones with moderate-to-high yields.
Waterproof and breathable membranes of waterborne fluorinated polyurethane modified electrospun polyacrylonitrile fibers
Authors: Wang Jiaqi , Li Yang , Tian Haiyang , Sheng Junlu , Yu Jianyong , Ding Bin
Published: November 2014

Novel waterproof and breathable fibrous membranes with superhydrophobic surface, adjustable pore size and adhesion structure were fabricated by modifying electrospun PAN fibers with WFPU emulsion.
Electrochemical synthesis of Fe oxide-based catalysts for the growth of nanocarbons
Authors: Pérez-Villar Sofía , Carretero-González Javier
Published: November 2014

A pulsed electrodeposition technique has been used for the synthesis of iron-based compounds as catalytic precursors for the growth of carbon nanofilaments via chemical vapor deposition (CVD).
Identification of chemicals resulted in selective glycerol conversion as sustainable fuel on Pd-based anode nanocatalysts
Authors: Palma L. M. , Almeida T. S. , Oliveira V. L. , Tremiliosi-Filho G. , Gonzalez E. R. , de Andrade A. R. , Servat K. , Morais C. , Napporn T. W. , Kokoh K. B.
Published: November 2014

Palladium-based nanoparticles were prepared using mild microwave-assisted heating.
Nanosized Pt-containing Al2O3 as an efficient catalyst to avoid coking and sintering in steam reforming of glycerol
Authors: Carvalho Davi C. , Souza Helvio S. A. , Filho Josué M. , Assaf Elisbete M. , Thyssen Vivian V. , Campos Adriana , Hernandez E. Padron , Raudel Ramon , Oliveira Alcineia C.
Published: November 2014

The action of nanosized Pt-containing Al2O3 catalysts to avoid coking and sintering was studied in steam reforming of glycerol.
Insight into the effects of surface oxidation and carbonization on the electronic properties of silicon quantum dots and silicon slabs: a density functional study
Authors: Zeng Yuheng , Chen Liang , Liu Guoqiang , Xu Hua , Song Weijie
Published: November 2014

In this work, we investigated the effects of surface backbond-oxygen oxidation and surface substitute-carbon carbonization on carrier recombination and transportation of 10-, 12- and 14 Å Si quantum dots (QDs).
Semiaromatic polyamides containing ether and different numbers of methylene (2–10) units: synthesis and properties
Authors: Zhang Gang , Zhou Yu-xuan , Kong Yu , Li Zhi-min , Long Sheng-Ru , Yang Jie
Published: November 2014

The resultant semi-aromatic polyamides showed excellent mechanical, processability, thermal and retardant property.
Structural, spectroscopic and magnetic properties of a novel copper(ii)l-tyrosinato complex
Authors: Wojciechowska Agnieszka , Gągor Anna , Jezierska Julia , Duczmal Marek
Published: November 2014

Anl-tyrosinato copper(ii) ion complex of formula [Cu(l-Tyr)2(H2O)]·H2O (1) (l-Tyr =l-tyrosine) was characterized by X-ray and spectroscopic (FT-IR, FT-Raman, NIR-vis-UV, and EPR) and magnetic methods.
SCO@SiO2@Au core–shell nanomaterials: enhanced photo-thermal plasmonic effect and spin-crossover properties
Authors: Qiu Dan , Gu Ling , Sun Xiao-Li , Ren Dong-Hong , Gu Zhi-Guo , Li Zaijun
Published: November 2014

[Fe(Htrz)2(trz)](BF4)@SiO2@Au core–shell spin-crossover nanocomposites have been successfully synthesized, and Au nanoparticles caused an efficient photo-thermal heating in the nanocomposites and influenced the spin-transition behaviors.
Micellar transitions in catanionic ionic liquid–ibuprofen aqueous mixtures; effects of composition and dilution
Authors: Sanan Reshu , Kaur Rajwinder , Mahajan Rakesh Kumar
Published: November 2014

Interactions between 1-dodecyl-3-methylimidazolium chloride and ibuprofen molecules in aqueous solution form catanionic mixtures, with morphologies of mixed micelles dependent on solution composition.
Photocurrent responsive films prepared from a nickel-dithiolate compound with directly bonded pyridyl groups
Authors: Shen Wei-Chun , Huo Peng , Huang Yu-De , Yin Jing-Xue , Zhu Qin-Yu , Dai Jie
Published: November 2014

Photocurrent response behaviours of a nickel dithiolene derivative upon protonation, transition metal coordination and cation exchange by photoactive MV2+are discussed.
Immobilised peroxidases from Asparagus acutifolius L. seeds for olive mill waste water treatment
Authors: Guida Vincenzo , Niro Elisa , Landi Nicola , Chambery Angela , Parente Augusto , Cantarella Laura , Cantarella Maria , Di Maro Antimo
Published: November 2014

AaP-1-4 peroxidase fromA. acutifoliusL. was immobilised on Eupergit® CM; Eup-AaP-1-4 was proved to be able to remove (poly)phenols in olive mill waste water; Eup-AaP-1-4 is an economic source for removal phenols from industrial processes.
dsDNA-templated fluorescent copper nanoparticles: poly(AT-TA)-dependent formation
Authors: Qing Taiping , Qing Zhihe , Mao Zhengui , He Xiaoxiao , Xu Fengzhou , Wen Li , He Dinggeng , Shi Hui , Wang Kemin
Published: November 2014

Poly(AT-TA) DNA is found to be the specific dsDNA sequence which can act as a highly-efficient template for the formation of dsDNA-templated copper nano-fluorophores.
A novel method for the synthesis of benzothiazole heterocycles catalyzed by a copper–DiAmSar complex loaded on SBA-15 in aqueous media
Authors: Mohammadi Marzieh , Bardajee Ghasem Rezanejade , Pesyan Nader Noroozi
Published: November 2014

Cu(ii)–DiAmSar/SBA-15 was prepared and used as an efficient heterogeneous catalyst for the synthesis of benzothiazole heterocycles in aqueous media.
One-pot synthesis of UiO-66@SiO2 shell–core microspheres as stationary phase for high performance liquid chromatography
Authors: Zhang Xiaoqiong , Han Qiang , Ding Mingyu
Published: November 2014

A facile one-pot synthesis of UiO-66@SiO2 shell–core microspheres as HPLC stationary phase was reported.
Asymmetric Lewis acid catalysis directed by octahedral rhodium centrochirality
Authors: Wang Chuanyong , Chen Liang-An , Huo Haohua , Shen Xiaodong , Harms Klaus , Gong Lei , Meggers Eric
Published: November 2014

A chiral-at-metal octahedral rhodium(iii) complex serves as an effective asymmetric catalyst for Michael additions (electrophile activation) and α-aminations (nucleophile activation).
Examining platelet adhesion via Stokes flow simulations and microfluidic experiments
Authors: Fitzgibbon Sean , Cowman Jonathan , Ricco Antonio J. , Kenny Dermot , Shaqfeh Eric S. G.
Published: November 2014

While critically important, the platelet function at the high shear rates typical of the microcirculation is relatively poorly understood.
One-step synthesis of Pt–NiO nanoplate array/reduced graphene oxide nanocomposites for nonenzymatic glucose sensing
Authors: Wang Li , Lu Xingping , Wen Cunjin , Xie Yingzhen , Miao Longfei , Chen Shouhui , Li Hongbo , Li Ping , Song Yonghai
Published: November 2014

A novel nonenzymatic glucose sensor was constructed based on rGO supported Pt–NiO nanoplate arrays through a simple one-step synthesis.
Vertically oriented MoS2 and WS2 nanosheets directly grown on carbon cloth as efficient and stable 3-dimensional hydrogen-evolving cathodes
Authors: Yan Ya , Xia BaoYu , Li Nan , Xu Zhichuan , Fisher Adrian , Wang Xin
Published: November 2014

Vertically oriented MoS2 and WS2 nanosheet thin films grown on CC have been designed as efficient 3D electrodes for the hydrogen evolution reaction.
Long-living, stress- and pH-tolerant superhydrophobic silica particles via fast and efficient urethane chemistry; facile preparation of self-recoverable SH coatings
Authors: Ramakrishna S. , Kumar K. S. Santhosh , Mathew Dona , Nair C. P. Reghunadhan
Published: November 2014

A facile preparation of long-lived, stress- and pH-tolerant superhydrophobic (SH) particles is presented. The generated coatings are resistant to a wide pH range and display self-recoverable SH behavior after multiple tests.
Construction of Cu@ZnO nanobrushes based on Cu nanowires and their high-performance selective degradation of polycyclic aromatic hydrocarbons
Authors: Chen Hanxing , Wen Ming , Huang Zaidi , Wu Qingsheng , Liu Jiali , Tu Teng
Published: November 2014

Novel Cu@ZnO core–shell nanobrushes exhibit high-performance photocatalytic selective degradation of polycyclic aromatic hydrocarbons (PAHs) under UV irradiation.
Effects of side groups on the kinetics of charge carrier recombination in dye molecule-doped multilayer organic light-emitting diodes
Authors: Shi Shengwei , Gao Feng , Sun Zhengyi , Zhan Yiqiang , Fahlman Mats , Ma Dongge
Published: November 2014

Effects of side groups on the kinetics of charge carrier recombination are investigated in dye molecule-doped multilayer organic light-emitting diodes by transient electroluminescence.
Block Markov superposition transmission of convolutional codes with minimum shift keying signalling
Authors: Liu Xiying , Liang Chulong , Ma Xiao
Published: November 2014

In this study, the authors’ present a scheme, denoted as BMST‐MSK, which combines the block Markov superposition transmission (BMST) with the minimum shift keying (MSK) signalling. The BMST‐MSK can be implemented in two forms – the BMST with recursive MSK (BMST‐RMSK) and the BMST with non‐recursive MSK (BMST‐NRMSK). The BMST‐MSK admits a sliding‐window decoding/demodulation algorithm, where two schedules with or without iterative processing between the BMST and MSK (referred to as outer iteration) are discussed. To analyse the asymptotic performance of BMST‐MSK, the authors’ first assume a genie‐aided decoder and then derive the union bound for the equivalent genie‐aided system. Numerical results show that the performances of the BMST‐MSK match well with the derived lower bounds in the low error rate regions. From simulations, the authors’ found that the outer iterations can provide performance improvement for the BMST‐RMSK, but not for the BMST‐NRMSK. Taking a (2,1,2) convolutional code with input length of 10 000 bits as the basic code, the BMST‐NRMSK achieves a bit‐error‐rate of 10−5 at Eb/N0 = 0.45 dB over additive white Gaussian noise channels, which is away from the Shannon limit about 0.25 dB.
High‐power‐factor electronic ballast zero voltage switching and low dv/dt with combination of charge pump and valley fill based on class DE
Authors: Thongkullaphat Sarayoot , Liutanakul Pisit , Chunkag Viboon
Published: November 2014

In this study, for application of 36 W/220 Vrms/50 Hz fluorescent lamp, a high performance of high‐power‐factor and low line input current harmonics of electronic ballast is proposed. The proposed ballast has a structure based on a combination of charged pump and valley fill circuit. By adding paralleled capacitors to each power switch and setting the circuit parameters, operation modes of the inverter can be modified from single‐stage conventional class D to a class DE. Consequently, duty ratio can be reduced by up to 25% so that the voltage stress at power switch is lower when compared with the conventional class D inverter. Furthermore, switching power loss and dv/dt can also be reduced because of zero voltage switching condition. Details of design and circuit operation are described. The experimental results of prototype circuit, operated around 50 kHz of switching frequency at full power output, show that the proposed ballast has 94.48% of efficiency, 4.30% of THDi, 0.996 of input power factor and 1.38 of lamp current crest factor.
Simple digital current control strategy for single‐phase grid‐connected converters
Authors: Sanatkar‐Chayjani Majid , Monfared Mohammad
Published: November 2014

This study proposes a simple digital current control technique for single‐phase grid‐connected voltage source converters. Unlike conventional strategies, the proposed method does not require any proportional‐integral or proportional‐resonant controller, fictitious phase generation, reference frame transformation and decoupling network; thus, it has the advantages of simplicity and reduced computational efforts. The suggested digital technique only uses a simple proportional controller in its structure and can be directly implemented on available digital signal processors. A digital controller parameter design procedure is proposed which ensures stability and near‐zero steady‐state error under all circumstances. Simulation and experimental results confirm that the proposed technique provides a fast and accurate current tracking with minimum harmonic distortions.
The Effects of Single-Level Instrumented Lumbar Laminectomy on Adjacent Spinal Biomechanics
Authors: Bisschop Arno , Holewijn Roderick M. , Kingma Idsart , Stadhouder Agnita , Vergroesen Pieter-Paul A. , van der Veen Albert J. , van Dieën Jaap H. , van Royen Barend J.
Published: November 2014

Study Design

Biomechanical study.

Objective

Posterior instrumentation is used to stabilize the spine after a lumbar laminectomy. However, the effects on the adjacent segmental stability are unknown. Therefore, we studied the range of motion (ROM) and stiffness of treated lumbar spinal segments and cranial segments after a laminectomy and after posterior instrumentation in flexion and extension (FE), lateral bending (LB), and axial rotation (AR). These outcomes might help to better understand adjacent segment disease (ASD), which is reported cranial to the level on which posterior instrumentation is applied.

Methods

We obtained 12 cadaveric human lumbar spines. Spines were axially loaded with 250 N for 1 hour. Thereafter, 10 consecutive load cycles (4 Nm) were applied in FE, LB, and AR. Subsequently, a laminectomy was performed either at L2 or at L4. Thereafter, load-deformation tests were repeated, after similar preloading. Finally, posterior instrumentation was added to the level treated with a laminectomy before testing was repeated. The ROM and stiffness of the treated, the cranial adjacent, and the control segments were calculated from the load-displacement data. Repeated-measures analyses of variance used the spinal level as the between-subject factor and a laminectomy or instrumentation as the within-subject factors.

Results

After the laminectomy, the ROM increased (+19.4%) and the stiffness decreased (−18.0%) in AR. The ROM in AR of the adjacent segments also increased (+11.0%). The ROM of treated segments after instrumentation decreased in FE (−74.3%), LB (−71.6%), and AR (−59.8%). In the adjacent segments after instrumentation, only the ROM in LB was changed (−12.9%).

Conclusions

The present findings do not substantiate a biomechanical pathway toward or explanation for ASD.
Versatile cold atom source for multi-species experiments
Authors: Paris-Mandoki A. , Jones M. D. , Nute J. , Wu J. , Warriar S. , Hackermüller L.
Published: November 2014

We present a dual-species oven and Zeeman slower setup capable of producing slow, high-flux atomic beams for loading magneto-optical traps. Our compact and versatile system is based on electronic switching between different magnetic field profiles and is applicable to a wide range of multi-species experiments. We give details of the vacuum setup, coils, and simple electronic circuitry. In addition, we demonstrate the performance of our system by optimized, sequential loading of magneto-optical traps of lithium-6 and cesium-133.
On the description of conical intersections—A continuous representation of the local topography of seams of conical intersection of three or more electronic states: A generalization of the two state result
Authors: Zhu Xiaolei , Yarkony David R.
Published: November 2014

For conical intersections of two states (I,J = I + 1) the vectors defining the branching or g-h plane, the energy difference gradient vector gI,J, and the interstate coupling vector hI,J, can be made orthogonal by a one parameter rotation of the degenerate electronic eigenstates. The representation obtained from this rotation is used to construct the parameters that describe the vicinity of the conical intersection seam, the conical parameters, sI,Jx (R), sI,Jy (R), gI,J(R), and hI,J(R). As a result of the orthogonalization these parameters can be made continuous functions of R, the internuclear coordinates. In this work we generalize this notion to construct continuous parametrizations of conical intersection seams of three or more states. The generalization derives from a recently introduced procedure for using non-degenerate electronic states to construct coupled diabatic states that represent adiabatic states coupled by conical intersections. The procedure is illustrated using the seam of conical intersections of three states in parazolyl as an example.
Recognizing molecular patterns by machine learning: An agnostic structural definition of the hydrogen bond
Authors: Gasparotto Piero , Ceriotti Michele
Published: November 2014

The concept of chemical bonding can ultimately be seen as a rationalization of the recurring structural patterns observed in molecules and solids. Chemical intuition is nothing but the ability to recognize and predict such patterns, and how they transform into one another. Here, we discuss how to use a computer to identify atomic patterns automatically, so as to provide an algorithmic definition of a bond based solely on structural information. We concentrate in particular on hydrogen bonding – a central concept to our understanding of the physical chemistry of water, biological systems, and many technologically important materials. Since the hydrogen bond is a somewhat fuzzy entity that covers a broad range of energies and distances, many different criteria have been proposed and used over the years, based either on sophisticate electronic structure calculations followed by an energy decomposition analysis, or on somewhat arbitrary choices of a range of structural parameters that is deemed to correspond to a hydrogen-bonded configuration. We introduce here a definition that is univocal, unbiased, and adaptive, based on our machine-learning analysis of an atomistic simulation. The strategy we propose could be easily adapted to similar scenarios, where one has to recognize or classify structural patterns in a material or chemical compound.
Study of gas-puff Z-pinches on COBRA
Authors: Qi N. , Rosenberg E. W. , Gourdain P. A. , de Grouchy P. W. L. , Kusse B. R. , Hammer D. A. , Bell K. S. , Shelkovenko T. A. , Potter W. M. , Atoyan L. , Cahill A. D. , Evans M. , Greenly J. B. , Hoyt C. L. , Pikuz S. A. , Schrafel P. C. , Kroupp E. , Fisher A. , Maron Y.
Published: November 2014

Gas-puff Z-pinch experiments were conducted on the 1 MA, 200 ns pulse duration Cornell Beam Research Accelerator (COBRA) pulsed power generator in order to achieve an understanding of the dynamics and instability development in the imploding and stagnating plasma. The triple-nozzle gas-puff valve, pre-ionizer, and load hardware are described. Specific diagnostics for the gas-puff experiments, including a Planar Laser Induced Fluorescence system for measuring the radial neutral density profiles along with a Laser Shearing Interferometer and Laser Wavefront Analyzer for electron density measurements, are also described. The results of a series of experiments using two annular argon (Ar) and/or neon (Ne) gas shells (puff-on-puff) with or without an on- (or near-) axis wire are presented. For all of these experiments, plenum pressures were adjusted to hold the radial mass density profile as similar as possible. Initial implosion stability studies were performed using various combinations of the heavier (Ar) and lighter (Ne) gasses. Implosions with Ne in the outer shell and Ar in the inner were more stable than the opposite arrangement. Current waveforms can be adjusted on COBRA and it was found that the particular shape of the 200 ns current pulse affected on the duration and diameter of the stagnated pinched column and the x-ray yield.
Involutive constrained systems and Hamilton-Jacobi formalism
Authors: Bertin M. C. , Pimentel B. M. , Valcárcel C. E.
Published: November 2014

In this paper, we study singular systems with complete sets of involutive constraints. The aim is to establish, within the Hamilton-Jacobi theory, the relationship between the Frobenius’ theorem, the infinitesimal canonical transformations generated by constraints in involution with the Poisson brackets, and the lagrangian point (gauge) transformations of physical systems.
Minimum lattice length and ropelength of 2-bridge knots and links
Authors: Huh Youngsik , Hong Kyungpyo , Kim Hyoungjun , No Sungjong , Oh Seungsang
Published: November 2014

Knots are commonly found in molecular chains such as DNA and proteins, and they have been considered to be useful models for structural analysis of these molecules. One interested quantity is the minimum number of monomers necessary to realize a molecular knot. The minimum lattice length Len(K) of a knot K indicates the minimum length necessary to construct K in the cubic lattice. Another important quantity in physical knot theory is the ropelength which is one of the knot energies measuring the complexity of knot conformation. The minimum ropelength Rop(K) is the minimum length of an ideally flexible rope necessary to tie a given knot K. Much effort has been invested in the research project for finding upper bounds on both quantities in terms of the minimum crossing number c(K) of the knot. It is known that Len(K) and Rop(K) lie between \documentclass[12pt]{minimal}\begin{document}$\mbox{O}(c(K)^{\frac{3}{4}})$\end{document}O(c(K)34) and O(c(K)[ln (c(K))]5), but unknown yet whether any family of knots has superlinear growth. In this paper, we focus on 2-bridge knots and links. Linear growth upper bounds on the minimum lattice length and minimum ropelength for nontrivial 2-bridge knots or links are presented as Len(K) ⩽ 8c(K) + 2 and Rop(K) ⩽ 11.39c(K) + 12.37.
Geometry of flexible filament cohesion: Better contact through twist?
Authors: Cajamarca Luis , Grason Gregory M.
Published: November 2014

Cohesive interactions between filamentous molecules have broad implications for a range of biological and synthetic materials. While long-standing theoretical approaches have addressed the problem of inter-filament forces from the limit of infinitely rigid rods, the ability of flexible filaments to deform intra-filament shape in response to changes in inter-filament geometry has a profound affect on the nature of cohesive interactions. In this paper, we study two theoretical models of inter-filament cohesion in the opposite limit, in which filaments are sufficiently flexible to maintain cohesive contact along their contours, and address, in particular, the role played by helical-interfilament geometry in defining interactions. Specifically, we study models of featureless, tubular filaments interacting via: (1) pair-wise Lennard-Jones (LJ) interactions between surface elements and (2) depletion-induced filament binding stabilized by electrostatic surface repulsion. Analysis of these models reveals a universal preference for cohesive filament interactions for non-zero helical skew, and further, that in the asymptotic limit of vanishing interaction range relative to filament diameter, the skew-dependence of cohesion approaches a geometrically defined limit described purely by the close-packing geometry of twisted tubular filaments. We further analyze non-universal features of the skew-dependence of cohesion at small-twist for both potentials, and argue that in the LJ model the pair-wise surface attraction generically destabilizes parallel filaments, while in the second model, pair-wise electrostatic repulsion in combination with non-pairwise additivity of depletion leads to a meta-stable parallel state.
Electronic structure and crystal phase stability of palladium hydrides
Authors: Houari Abdesalem , Matar Samir F. , Eyert Volker
Published: November 2014

The results of electronic structure calculations for a variety of palladium hydrides are presented. The calculations are based on density functional theory and used different local and semilocal approximations. The thermodynamic stability of all structures as well as the electronic and chemical bonding properties are addressed. For the monohydride, taking into account the zero-point energy is important to identify the octahedral Pd-H arrangement with its larger voids and, hence, softer hydrogen vibrational modes as favorable over the tetrahedral arrangement as found in the zincblende and wurtzite structures. Stabilization of the rocksalt structure is due to strong bonding of the 4d and 1s orbitals, which form a characteristic split-off band separated from the main d-band group. Increased filling of the formerly pure d states of the metal causes strong reduction of the density of states at the Fermi energy, which undermines possible long-range ferromagnetic order otherwise favored by strong magnetovolume effects. For the dihydride, octahedral Pd-H arrangement as realized, e.g., in the pyrite structure turns out to be unstable against tetrahedral arrangement as found in the fluorite structure. Yet, from both heat of formation and chemical bonding considerations, the dihydride turns out to be less favorable than the monohydride. Finally, the vacancy ordered defect phase Pd3H4 follows the general trend of favoring the octahedral arrangement of the rocksalt structure for Pd:H ratios less or equal to one.
Study of the L-mode tokamak plasma “shortfall” with local and global nonlinear gyrokinetic δf particle-in-cell simulation
Authors: Chowdhury J. , Wan Weigang , Chen Yang , Parker Scott E. , Groebner Richard J. , Holland C. , Howard N. T.
Published: November 2014

The δ f particle-in-cell code GEM is used to study the transport “shortfall” problem of gyrokinetic simulations. In local simulations, the GEM results confirm the previously reported simulation results of DIII-D [Holland et al., Phys. Plasmas 16, 052301 (2009)] and Alcator C-Mod [Howard et al., Nucl. Fusion 53, 123011 (2013)] tokamaks with the continuum code GYRO. Namely, for DIII-D the simulations closely predict the ion heat flux at the core, while substantially underpredict transport towards the edge; while for Alcator C-Mod, the simulations show agreement with the experimental values of ion heat flux, at least within the range of experimental error. Global simulations are carried out for DIII-D L-mode plasmas to study the effect of edge turbulence on the outer core ion heat transport. The edge turbulence enhances the outer core ion heat transport through turbulence spreading. However, this edge turbulence spreading effect is not enough to explain the transport underprediction.
Calculation of room temperature conductivity and mobility in tin-based topological insulator nanoribbons
Authors: Vandenberghe William G. , Fischetti Massimo V.
Published: November 2014

Monolayers of tin (stannanane) functionalized with halogens have been shown to be topological insulators. Using density functional theory (DFT), we study the electronic properties and room-temperature transport of nanoribbons of iodine-functionalized stannanane showing that the overlap integral between the wavefunctions associated to edge-states at opposite ends of the ribbons decreases with increasing width of the ribbons. Obtaining the phonon spectra and the deformation potentials also from DFT, we calculate the conductivity of the ribbons using the Kubo-Greenwood formalism and show that their mobility is limited by inter-edge phonon backscattering. We show that wide stannanane ribbons have a mobility exceeding 106 cm2/Vs. Contrary to ordinary semiconductors, two-dimensional topological insulators exhibit a high conductivity at low charge density, decreasing with increasing carrier density. Furthermore, the conductivity of iodine-functionalized stannanane ribbons can be modulated over a range of three orders of magnitude, thus rendering this material extremely interesting for classical computing applications.
The effect of field-orientation on the magnetoelectric coupling in Terfenol-D/PZT/Terfenol-D laminated structure
Authors: Chen Zhengxin , Su Yu , Meguid S. A.
Published: November 2014

The field-orientation dependent magnetoelectric coupling is experimentally studied for a rectangular Terfenol-D/PZT/Terfenol-D laminated structure. The considered magnetic field, namely the dc-bias magnetic field or the ac-excitation magnetic field, is allowed to be spatially re-orientated between two orthogonal geometric dimensions of the composite. In the study, the direction of the excitation can be fixed in the longitudinal (Scheme-I) or thickness (Scheme-II) directions, while considering the bias orientation. Alternatively, the bias field can be restricted to the longitudinal (Scheme-III) or thickness (Scheme-IV) directions, while the excitation orientation is considered. The variation in magnetoelectric coefficient as a function of the bias magnitude is studied with special attention paid to the field-orientation dependency. For the testing schemes of I and II, the direction of the dc-bias field can be re-oriented by forming an angle with the fixed direction of the ac-excitation field. As the angle changes from 0° to 90°, the magnetoelectric coupling evolves from L-T mode to S-T surface shear for Scheme-I, and from T-T mode to S-T thickness shear for Scheme-II. The bias-field-orientation dependence demonstrates a complex pattern due to the varying overall state of anisotropy in Terfenol-D. In Scheme-I with low bias magnitude, the orientation dependence can be represented by the measured effective longitudinal piezomagnetic coefficient. In addition, the optimal bias field for maximum magnetoelectric coefficient is observed to linearly increase with the bias orientation angle. Alternatively, the orientation dependence in Schemes III and IV is more predictable due to the barely changed overall state of anisotropy. In this case, Scheme-III shows that the magnetoelectric coefficient decreases monotonically with the orientation angle and Scheme-IV indicates that the maximum coefficient is attained at around 60°. The dependence of the magnetoelectric coupling on the excitation-filed orientation can be understood via analysis of the resultant magnetostriction in Terfenol-D with assumed effective magnetization, which may depart from the bias field due to the strong demagnetization effect. The analysis is supported by the computed field-orientation dependence of the magnetostriction in Terfenol-D.
Fe ion-implanted TiO2 thin film for efficient visible-light photocatalysis
Authors: Impellizzeri G. , Scuderi V. , Romano L. , Sberna P. M. , Arcadipane E. , Sanz R. , Scuderi M. , Nicotra G. , Bayle M. , Carles R. , Simone F. , Privitera V.
Published: November 2014

This work shows the application of metal ion-implantation to realize an efficient second-generation TiO2 photocatalyst. High fluence Fe+ ions were implanted into thin TiO2 films and subsequently annealed up to 550 °C. The ion-implantation process modified the TiO2 pure film, locally lowering its band-gap energy from 3.2 eV to 1.6–1.9 eV, making the material sensitive to visible light. The measured optical band-gap of 1.6–1.9 eV was associated with the presence of effective energy levels in the energy band structure of the titanium dioxide, due to implantation-induced defects. An accurate structural characterization was performed by Rutherford backscattering spectrometry, transmission electron microscopy, Raman spectroscopy, X-ray diffraction, and UV/VIS spectroscopy. The synthesized materials revealed a remarkable photocatalytic efficiency in the degradation of organic compounds in water under visible light irradiation, without the help of any thermal treatments. The photocatalytic activity has been correlated with the amount of defects induced by the ion-implantation process, clarifying the operative physical mechanism. These results can be fruitfully applied for environmental applications of TiO2.
Suppression of grain growth in nanocrystalline Bi2Te3 through oxide particle dispersions
Authors: Humphry-Baker Samuel A. , Schuh Christopher A.
Published: November 2014

The strategy of suppressing grain growth by dispersing nanoscale particles that pin the grain boundaries is demonstrated in a nanocrystalline thermoelectric compound. Yttria nanoparticles that were incorporated by mechanical alloying enabled nanocrystalline (i.e., d < 100 nm) Bi2Te3 to be retained up to a homologous temperature of 0.94 Tm for durations over which the grain size of the unreinforced compound grew to several microns. The nanostructure appeared to saturate at a grain size that depended on volume fraction (f) according to an f −1/3 relationship, in accordance with theoretical models in the limit of high volume fractions of particles. Interestingly, at low temperatures, the particles stimulate enhanced grain growth over the unreinforced compound, due to particle-stimulated nucleation of recrystallization. To help prevent this effect, in-situ composites formed by internal oxidation of yttrium are compared with those made ex-situ by incorporation of yttria nanoparticles, with the result that the in-situ dispersion eliminates recrystallization at low temperatures and therefore improves nanostructure stabilization. These developments offer a pathway to thermally stabilized bulk nanocrystalline thermoelectrics processed via a powder route.
Communication: Smoothing out excited-state dynamics: Analytical gradients for dynamically weighted complete active space self-consistent field
Authors: Glover W. J.
Published: November 2014

State averaged complete active space self-consistent field (SA-CASSCF) is a workhorse for determining the excited-state electronic structure of molecules, particularly for states with multireference character; however, the method suffers from known issues that have prevented its wider adoption. One issue is the presence of discontinuities in potential energy surfaces when a state that is not included in the state averaging crosses with one that is. In this communication I introduce a new dynamical weight with spline (DWS) scheme that mimics SA-CASSCF while removing energy discontinuities due to unweighted state crossings. In addition, analytical gradients for DWS-CASSCF (and other dynamically weighted schemes) are derived for the first time, enabling energy-conserving excited-state ab initio molecular dynamics in instances where SA-CASSCF fails.
Sphericity and symmetry breaking in the formation of Frank–Kasper phases from one component materials
Authors: Lee Sangwoo , Leighton Chris , Bates Frank S.
Published: November 2014

Significance

Understanding how particles fill space has challenged mathematicians, scientists, and technologists since antiquity. This article rationalizes the spontaneous organization of single-component diblock copolymers into multimolecular nanoscale domains that order into a low-symmetry Frank–Kasper (FK) phase with short-range tetrahedral close packing and a giant unit cell that contains 30 particles. This class of crystal structures bridges conventional periodic crystals and low symmetry aperiodic crystals often termed “quasicrystals.” Surprising analogies are thus drawn between the heretofore unexplained formation of FK structures in soft materials, and in certain elemental metals (including manganese and uranium), alloys, and intermetallic compounds, highlighting opportunities to better understand space filling in hard and soft materials by investigation of block polymers with precisely tuned molecular architectures.
Field-induced superconducting phase of FeSe in the BCS-BEC cross-over
Authors: Kasahara Shigeru , Watashige Tatsuya , Hanaguri Tetsuo , Kohsaka Yuhki , Yamashita Takuya , Shimoyama Yusuke , Mizukami Yuta , Endo Ryota , Ikeda Hiroaki , Aoyama Kazushi , Terashima Taichi , Uji Shinya , Wolf Thomas , von Löhneysen Hilbert , Shibauchi Takasada , Matsuda Yuji
Published: November 2014

Significance

The BCS-BEC (Bardeen–Cooper–Schrieffer––Bose–Einstein-condensate) cross-over bridges the two important theories of bound particles in a unified picture with the ratio of the attractive interaction to the Fermi energy as a tuning parameter. A key issue is to understand the intermediate regime, where new states of matter may emerge. Here, we show that the Fermi energy of FeSe is extremely small, resulting in that this system can be regarded as an extraordinary “high-temperature” superconductor located at the verge of a BCS-BEC cross-over. Most importantly, we discover the emergence of an unexpected superconducting phase in strong magnetic fields, demonstrating that the Zeeman splitting comparable to the Fermi energy leads to a strong modification of the properties of fermionic systems in such a regime.