bluuebunny/crossref_metadata_2025 huggingface dataset:
Friedelin Synthase from Maytenus ilicifolia: Leucine 482 Plays an Essential Role in the Production of the Most Rearranged Pentacyclic Triterpene
Authors: Souza-Moreira Tatiana M. , Alves Thaís B. , Pinheiro Karina A. , Felippe Lidiane G. , De Lima Gustavo M. A. , Watanabe Tatiana F. , Barbosa Cristina C. , Santos Vânia A. F. F. M. , Lopes Norberto P. , Valentini Sandro R. , Guido Rafael V. C. , Furlan Maysa , Zanelli Cleslei F.
Published: November 2016

Among the biologically active triterpenes, friedelin has the most-rearranged structure produced by the oxidosqualene cyclases and is the only one containing a cetonic group. In this study, we cloned and functionally characterized friedelin synthase and one cycloartenol synthase fromMaytenus ilicifolia(Celastraceae). The complete coding sequences of these 2 genes were cloned from leaf mRNA, and their functions were characterized by heterologous expression in yeast. The cycloartenol synthase sequence is very similar to other known OSCs of this type (approximately 80% identity), although theM. ilicifoliafriedelin synthase amino acid sequence is more related to β-amyrin synthases (65–74% identity), which is similar to the friedelin synthase cloned fromKalanchoe daigremontiana. Multiple sequence alignments demonstrated the presence of a leucine residue two positions upstream of the friedelin synthase Asp-Cys-Thr-Ala-Glu (DCTAE) active site motif, while the vast majority of OSCs identified so far have a valine or isoleucine residue at the same position. The substitution of the leucine residue with valine, threonine or isoleucine inM. ilicifoliafriedelin synthase interfered with substrate recognition and lead to the production of different pentacyclic triterpenes. Hence, our data indicate a key role for the leucine residue in the structure and function of this oxidosqualene cyclase.
Competition Between Resonant Plasmonic Coupling and Electrostatic Interaction in Reduced Graphene Oxide Quantum Dots
Authors: Karna Sanjay , Mahat Meg , Choi Tae-Youl , Shimada Ryoko , Wang Zhiming , Neogi Arup
Published: November 2016

The light emission from reduced graphene oxide quantum dots (rGO-QDs) exhibit a significant enhancement in photoluminescence (PL) due to localized surface plasmon (LSP) interactions. Silver and gold nanoparticles (NPs) coupled to rGO nanoparticles exhibit the effect of resonant LSP coupling on the emission processes. Enhancement of the radiative recombination rate in the presence of Ag-NPs induced LSP tuned to the emission energy results in a four-fold increase in PL intensity. The localized field due to the resonantly coupled LSP modes induces n-π* transitions that are not observed in the absence of the resonant interaction of the plasmons with the excitons. An increase in the density of the Ag-NPs result in a detuning of the LSP energy from the emission energy of the nanoparticles. The detuning is due to the cumulative effect of the red-shift in the LSP energy and the electrostatic field induced blue shift in the PL energy of the rGO-QDs. The detuning
quenches the PL emission from rGO-QDs at higher concentration of Ag NPs due to non-dissipative effects unlike plasmon induced Joule heating that occurs under resonance conditions. An increase in Au nanoparticles concentration results in an enhancement of PL emission due to electrostatic image charge effect.
Energetics of vacancy segregation to [100] symmetric tilt grain boundaries in bcc tungsten
Authors: Chen Nanjun , Niu Liang-Liang , Zhang Ying , Shu Xiaolin , Zhou Hong-Bo , Jin Shuo , Ran Guang , Lu Guang-Hong , Gao Fei
Published: November 2016

The harsh irradiation environment poses serious threat to the structural integrity of leading candidate for plasma-facing materials, tungsten (W), in future nuclear fusion reactors. It is thus essential to understand the radiation-induced segregation of native defects and impurities to defect sinks, such as grain boundaries (GBs), by quantifying the segregation energetics. In this work, molecular statics simulations of a range of equilibrium and metastable [100] symmetric tilt GBs are carried out to explore the energetics of vacancy segregation. We show that the low-angle GBs have larger absorption length scales over their high-angle counterparts. Vacancy sites that are energetically unfavorable for segregation are found in all GBs. The magnitudes of minimum segregation energies for the equilibrium GBs vary from −2.61 eV to −0.76 eV depending on the GB character, while those for the metastable GB states tend to be much lower. The significance of vacancy delocalization in decreasing the vacancy segregation energies and facilitating GB migration has been discussed. Metrics such as GB energy and local stress are used to interpret the simulation results, and correlations between them have been established. This study contributes to the possible application of polycrystalline W under irradiation in advanced nuclear fusion reactors.
PLD1 regulates adipogenic differentiation through mTOR - IRS-1 phosphorylation at serine 636/639
Authors: Song Hae-In , Yoon Mee-Sup
Published: November 2016

Phospholipase D1 (PLD1) plays a known role in several differentiation processes, but its role in adipogenic differentiation remains unknown. In the present study, we identified PLD1 as a negative regulator of adipogenic differentiation. We showed that PLD activity was downregulated by both 3-Isobutyl-1-methylxanthine (IBMX) and insulin upon induction of differentiation in 3T3-L1 adipogenic cells. In line with this observation, PLD activity decreased in both high fat diet (HFD)-fed mice and ob/ob mice. We also found that differentiation of 3T3-L1 preadipocytes was enhanced by the depletion of PLD1 levels or inhibition of PLD1 activity by VU0155069, a PLD1-specific inhibitor. Conversely, treatment with phosphatidic acid (PA), a PLD product, and overexpression of PLD1 both caused a decrease in adipogenic differentiation. Moreover, the elevated differentiation in PLD1-knockdown 3T3-L1 cells was reduced by either PA treatment or PLD1 expression, confirming negative roles of PLD1 and PA in adipogenic differentiation. Further investigation revealed that PA displaces DEP domain-containing mTOR-interacting protein (DEPTOR) from mTORC1, which subsequently phosphorylates insulin receptor substrate-1 (IRS-1) at serine 636/639 in 3T3-L1 cells. Taken together, our findings provide convincing evidence for a direct role of PLD1 in adipogenic differentiation by regulating IRS-1 phosphorylation at serine 636/639 through DEPTOR displacement and mTOR activation.
Erratum: Symmetry Breaking by Surface Blocking: Synthesis of Bimorphic Silver Nanoparticles, Nanoscale Fishes and Apples
Authors: Cathcart Nicole , Kitaev Vladimir
Published: November 2016

Scientific Reports 6: Article number: 32561; published online: 08 September 2016; updated: 22 November 2016
Coherent control of double deflected anomalous modes in ultrathin trapezoid-shaped slit metasurface
Authors: Zhu Z. , Liu H. , Wang D. , Li Y. X. , Guan C. Y. , Zhang H. , Shi J. H.
Published: November 2016

Coherent light-matter interaction in ultrathin metamaterials has been demonstrated to dynamically modulate intensity, polarization and propagation direction of light. The gradient metasurface with a transverse phase variation usually exhibits an anomalous refracted beam of light dictated by so-called generalized Snell’s law. However, less attention has been paid to coherent control of the metasurface with multiple anomalous refracted beams. Here we propose an ultrathin gradient metasurface with single trapezoid-shaped slot antenna as its building block that allows one normal and two deflected transmitted beams. It is numerically demonstrated that such metasurface with multiple scattering modes can be coherently controlled to modulate output intensities by changing the relative phase difference between two counterpropagating coherent beams. Each mode can be coherently switched on/off and two deflected anomalous beams can be synchronously dictated by the phase difference. The coherent control effect in the trapezoid-shaped slit metasurface will offer a promising opportunity for multichannel signals modulation, multichannel sensing and wave front shaping.
Identification of inhibitors that dually target the new permeability pathway and dihydroorotate dehydrogenase in the blood stage of Plasmodium falciparum
Authors: Dickerman Benjamin K. , Elsworth Brendan , Cobbold Simon A. , Nie Catherine Q. , McConville Malcolm J. , Crabb Brendan S. , Gilson Paul R.
Published: November 2016

Plasmodium parasites are responsible for the devastating disease malaria that affects hundreds of millions of people each year. Blood stage parasites establish new permeability pathways (NPPs) in infected red blood cell membranes to facilitate the uptake of nutrients and removal of parasite waste products. Pharmacological inhibition of the NPPs is expected to lead to nutrient starvation and accumulation of toxic metabolites resulting in parasite death. Here, we have screened a curated library of antimalarial compounds, the MMV Malaria Box, identifying two compounds that inhibit NPP function. Unexpectedly, metabolic profiling suggested that both compounds also inhibit dihydroorotate dehydrogense (DHODH), which is required for pyrimidine synthesis and is a validated drug target in its own right. Expression of yeast DHODH, which bypasses the need for the parasite DHODH, increased parasite resistance to these compounds. These studies identify two potential candidates for therapeutic development that simultaneously target two essential pathways in Plasmodium, NPP and DHODH.
CL316,243, a β3-adrenergic receptor agonist, induces muscle hypertrophy and increased strength
Authors: Puzzo Daniela , Raiteri Roberto , Castaldo Clotilde , Capasso Raffaele , Pagano Ester , Tedesco Mariateresa , Gulisano Walter , Drozd Lisaveta , Lippiello Pellegrino , Palmeri Agostino , Scotto Pietro , Miniaci Maria Concetta
Published: November 2016

Studies in vitro have demonstrated that β3-adrenergic receptors (β3-ARs) regulate protein metabolism in skeletal muscle by promoting protein synthesis and inhibiting protein degradation. In this study, we evaluated whether activation of β3-ARs by the selective agonist CL316,243 modifies the functional and structural properties of skeletal muscles of healthy mice. Daily injections of CL316,243 for 15 days resulted in a significant improvement in muscle force production, assessed by grip strength and weight tests and an increased myofiber cross-sectional area, indicative of muscle hypertrophy. In addition, atomic force microscopy revealed a significant effect of CL316,243 on the transversal stiffness of isolated muscle fibers. Interestingly, the expression level of mammalian target of rapamycin (mTOR) downstream targets and neuronal nitric oxide synthase (NOS) was also found to be enhanced in tibialis anterior and soleus muscles of CL316,243 treated mice, in accordance with previous data linking β3-ARs to mTOR and NOS signaling pathways. In conclusion, our data suggest that CL316,243 systemic administration might be a novel therapeutic strategy worthy of further investigations in conditions of muscle wasting and weakness associated with aging and muscular diseases.
Control on Surface Plasmon Polaritons Propagation Properties by Continuously Moving a Nanoparticle along a Silver Nanowire Waveguide
Authors: Wu Fan , Wang Wenhui , Hua Jiaojiao , Xu Zhongfeng , Li Fuli
Published: November 2016

Surface plasmon polaritons (SPPs)-based nanowire waveguides possess potential applications for nanophotonic circuits. Precise control on the propagation of SPPs in metal nanowires is thus of significant importance. In this work, we report the control on SPPs propagation properties by moving a silver nanoparticle (Ag NP) along a silver nanowire (Ag NW). The emission intensity at NP can be attenuated to about 25% of the maximum emission value with increasing the distance between excitation end and NP. When NP is gradually moved away from excitation end, the intensity of emission light at Ag NP shows an exponential decay with a superposition of wavy appearance, while the emission at NW end is almost a constant value. It is found that the former is related to the local SPPs field distribution in NW, and the latter is dependent on the distance between excitation end and NW terminal. Moreover, the propagation loss in Ag NP-NW structure has been investigated. Our experiments demonstrate the important role of NP location in NW-based waveguides and provide an effective method of tuning scattering light in NW, which is instructive to design the future specialized function of SPPs-based nanophotonic circuits and devices.
G9a participates in nerve injury-induced Kcna2 downregulation in primary sensory neurons
Authors: Liang Lingli , Gu Xiyao , Zhao Jian-Yuan , Wu Shaogen , Miao Xuerong , Xiao Jifang , Mo Kai , Zhang Jun , Lutz Brianna Marie , Bekker Alex , Tao Yuan-Xiang
Published: November 2016

Nerve injury-induced downregulation of voltage-gated potassium channel subunit Kcna2 in the dorsal root ganglion (DRG) is critical for DRG neuronal excitability and neuropathic pain genesis. However, how nerve injury causes this downregulation is still elusive. Euchromatic histone-lysine N-methyltransferase 2, also known as G9a, methylates histone H3 on lysine residue 9 to predominantly produce a dynamic histone dimethylation, resulting in condensed chromatin and gene transcriptional repression. We showed here that blocking nerve injury-induced increase in G9a rescued Kcna2 mRNA and protein expression in the axotomized DRG and attenuated the development of nerve injury-induced pain hypersensitivity. Mimicking this increase decreased Kcna2 mRNA and protein expression, reduced Kv current, and increased excitability in the DRG neurons and led to spinal cord central sensitization and neuropathic pain-like symptoms. G9a mRNA is co-localized with Kcna2 mRNA in the DRG neurons. These findings indicate that G9a contributes to neuropathic pain development through epigenetic silencing of Kcna2 in the axotomized DRG.
Quantification of prospective type 2 diabetes mellitus biomarkers by stable isotope dilution with bi-labeled standard glycated peptides
Authors: Soboleva Alena , Modzel Maciej , Didio Anna , Płóciennik Halina , Kijewska Monika , Grischina Tatiana , Karonova Tatiana , Bilova Tatiana , Stefanov Vasily , Stefanowicz Piotr , Frolov Andrej
Published: November 2016

A new analytical approach is proposed for quantification of multiple glycated peptides in human plasma tryptic digests.
Evaluation of energy dispersive scanning electron microscopy and X-ray fluorescence techniques for analysis of compost quality
Authors: B. Manohara , S. L. Belagali
Published: November 2016

The ED-XRF and SEM-EDS techniques are significant in analysis of compost quality and can be used as an alternative for AAS.
Thermodynamics and kinetics of graphene chemistry: a graphene hydrogenation prototype study
Authors: Pham Buu Q. , Gordon Mark S.
Published: November 2016

The thermodynamic and kinetic controls of graphene chemistry are studied computationally using a graphene hydrogenation reaction and polyaromatic hydrocarbons to represent the graphene surface.
Energy transduction and signal averaging of fluctuating electric fields by a single protein ion channel
Authors: Verdia-Baguena C. , Gomez V. , Cervera J. , Ramirez P. , Mafe S.
Published: November 2016

A biological ion channel is used to charge a conventional capacitor from an external fluctuating electrical noise.
Self-assembly of partially fluorinated hexabenzocoronene derivatives in the solid state
Authors: Breuer Tobias , Klues Michael , Liesfeld Pauline , Viertel Andreas , Conrad Matthias , Hecht Stefan , Witte Gregor
Published: November 2016

We provide a detailed understanding on a successful route to control the molecular packing motif within novel fluorinated hexabenzocoronenes.
Conformational equilibrium and internal dynamics in the iso-propanol–water dimer
Authors: Evangelisti Luca , Gou Qian , Feng Gang , Caminati Walther , Mead Griffin J. , Finneran Ian A. , Carroll P. Brandon , Blake Geoffrey A.
Published: November 2016

Using rotational spectroscopy, we report characterization of two iso-propanol–water dimers. We further characterize the dynamics of one isomer.
The conformational landscape of 2-(4-fluoro-phenyl)-ethylamine: consequences of fluorine substitution at the para position
Authors: Shachar Afik , Mayorkas Nitzan , Sachs Hanan , Bar Ilana
Published: November 2016

The effect of fluorine substitution on the conformational properties of gas phase 2-(4-fluoro-phenyl)-ethylamine was revealed by unique spectroscopic methods.
Electrochemical polypyrrole formation from pyrrole ‘adlayer’
Authors: Plausinaitis Deivis , Sinkevicius Linas , Mikoliunaite Lina , Plausinaitiene Valentina , Ramanaviciene Almira , Ramanavicius Arunas
Published: November 2016

In this research study, we investigated the morphology of polypyrrole nanostructures, which were formed during the electrochemical deposition of conducting polymer.
Time-resolved photoelectron imaging of iodide–nitromethane (I−·CH3NO2) photodissociation dynamics
Authors: Kunin Alice , Li Wei-Li , Neumark Daniel M.
Published: November 2016

Dissociation to reform iodide was found to be non-statistical and is predicted to be limited by intramolecular vibrational energy redistribution.
Pathological levels of glucosylceramide change the biophysical properties of artificial and cell membranes
Authors: Varela Ana R. P. , Ventura Ana E. , Carreira Ana C. , Fedorov Aleksander , Futerman Anthony H. , Prieto Manuel , Silva Liana C.
Published: November 2016

Accumulation of glucosylceramide decreases membrane fluidity in artificial membranes and in cell models of Gaucher disease.
Enzyme-immobilized clay nanotube–chitosan membranes with sustainable biocatalytic activities
Authors: Sun Jiajia , Yendluri Raghuvara , Liu Kai , Guo Ying , Lvov Yuri , Yan Xuehai
Published: November 2016

We have developed a simple and effective strategy to prepare an enzymatic membrane by the admixing of a halloysite clay nanotube–lipase complex and a chitosan solution.
Electrode–particle impacts: a users guide
Authors: Sokolov Stanislav V. , Eloul Shaltiel , Kätelhön Enno , Batchelor-McAuley Christopher , Compton Richard G.
Published: November 2016

We present a comprehensive guide to nano-impact experiments, in which we introduce newcomers to this rapidly-developing field of research.
A multicomponent assembly approach for the design of deep desulfurization heterogeneous catalysts
Authors: Xu Yanqi , Xuan Weimin , Zhang Mengmeng , Miras Haralampos N. , Song Yu-Fei
Published: November 2016

An assembly approach has been employed for the preparation of a multi-component heterogeneous catalyst showing high efficiency in deep desulfurization processes.
Correction: Characteristics and reactivity of ruthenium–oxo complexes
Authors: Ishizuka Tomoya , Kotani Hiroaki , Kojima Takahiko
Published: November 2016

Correction for ‘Characteristics and reactivity of ruthenium–oxo complexes’ by Tomoya Ishizuka et al., Dalton Trans., 2016, 45, 16727–16750.
Characterization of chemical composition and bacterial community of corrosion scales in different drinking water distribution systems
Authors: Wang Haibo , Hu Chun , Yin Lang , Zhang Sujia , Liu Lizhong
Published: November 2016

There is a relationship between biochemical function and chemical composition of corrosion scales, and Fe3O4formation reduced iron release.
A comparison of RS4-type resistant starch to RS2-type resistant starch in suppressing oxidative stress in high-fat-diet-induced obese rats
Authors: Si Xu , Zhou Zhongkai , Strappe Padraig , Blanchard Chris
Published: November 2016

The anti-obesity effects of two types of resistant starch (RS) in high-fat-diet-induced obese rats were investigated.
PVP-Pd nanoparticles as efficient catalyst for nitroarene reduction under mild conditions in aqueous media
Authors: Uberman Paula M. , García Carolina S. , Rodríguez Julieta R. , Martín Sandra E.
Published: November 2016

Towards an efficient, mild and sustainable approach for nitroarene hydrogenation by Pd nanoparticles in aqueous medium.
Microanalysis of arsenic in solid samples by laser ablation-atomic fluorescence spectrometry
Authors: Šlejkovec Zdenka , van Elteren Johannes T. , Šelih Vid S. , Šala Martin , Corns Warren T.
Published: November 2016

A spot mode-LA-AFS method has been developed for localised microanalysis of arsenic in biological tissues.
A novel nano-sized binuclear nickel(ii) Schiff base complex as a precursor for NiO nanoparticles: synthesis, characterization, DFT study and antibacterial activity
Authors: Parsaee Zohreh , Mohammadi Khosro , Ghahramaninezhad Mahboube , Hosseinzadeh Behzad
Published: November 2016

We prepared a new nano-hexadentate Schiff base and its nickel(ii) complex using an ultrasonic method, which produced NiO with an average size of 53 nm.
Fabrication of porous magnetic nanocomposites for bone tissue engineering
Authors: Bhowmick Arundhati , Pramanik Nilkamal , Mitra Tapas , Gnanamani Arumugam , Das Manas , Kundu Patit Paban
Published: November 2016

Porous superparamagnetic chitosan/polyethylene glycol/hydroxyapatite–Fe3O4 nanocomposites were developed for bone tissue engineering.
Elemental steps of the thermodynamics of dihydropyrimidine: a new class of organic hydride donors
Authors: Meng Fan-kun , Zhu Xiao-qing
Published: November 2016

Elemental steps of the thermodynamics of dihydropyrimidine derivatives (a new class of organo-hydrides) to release a hydride have been determined in acetonitrile.
A gold microarray electrode on a poly(methylmethacrylate) substrate to improve the performance of microbial fuel cells by modifying biofilm formation
Authors: Chen Shan , Chen Xiangyu , Hou Shuangyue , Xiong Penghui , Xiong Ying , Zhang Feng , Yu Hanqing , Liu Gang , Tian Yangchao
Published: November 2016

A gold line microarray anode deposited on PMMA substrate could significantly form effective biofilm to improve the performance of MFCs.
In vitro concentration dependent detection of creatinine: a surface enhanced Raman scattering and fluorescence study
Authors: Gangopadhyay Debraj , Sharma Poornima , Nandi Rajib , Das Moumita , Ghosh Surajit , Singh Ranjan K.
Published: November 2016

(a) SERS spectra and (b) fluorescence spectra of Jaffe complex showing consistent variation relatable to the concentration of CRN.
The effect of tunable graphene oxide sheet size on the structures and catalytic properties of three-dimensional reduced graphene oxide sponge
Authors: Wang Meisong , Huang Yanli , Wang Yuanyuan , Dai Liyi
Published: November 2016

The relationship was established between tunable and uniform GOSs and the structures and catalytic properties of 3D rGO sponge.
Correction: Designed multi-stranded heme binding β-sheet peptides in membrane
Authors: D'Souza Areetha , Mahajan Mukesh , Bhattacharjya Surajit
Published: November 2016

Correction for ‘Designed multi-stranded heme binding β-sheet peptides in membrane’ by Areetha D'Souza et al., Chem. Sci., 2016, 7, 2563–2571.
Coherent oscillations in word-use data from 1700 to 2008
Authors: Montemurro Marcelo A , Zanette Damián H
Published: November 2016

In written language, the choice of specific words is constrained by both grammatical requirements and the specific semantic context of the message to be transmitted. To a significant degree, the semantic context is in turn affected by a broad cultural and historical environment, which also influences matters of style and manners. Over time, those environmental factors leave an imprint in the statistics of language use, with some words becoming more common and other words being preferred less. Here we characterize the patterns of language use over time based on word statistics extracted from more than 4.5 million books written over a period of 308 years. We find evidence of novel systematic oscillatory patterns in word use with a consistent period narrowly distributed around 14 years. The specific phase relationships between different words show structure at two independent levels: first, there is a weak global phase modulation that is primarily linked to overall shifts in the vocabulary across time; and second, a stronger component dependent on well defined semantic relationships between words. In particular, complex network analysis reveals that semantically related words show strong phase coherence. Ultimately, these previously unknown patterns in the statistics of language may be a consequence of changes in the cultural framework that influences the thematic focus of writers.
Effect of germanium doping on electrical properties of n-type 4H-SiC homoepitaxial layers grown by chemical vapor deposition
Authors: Sledziewski T. , Vivona M. , Alassaad K. , Kwasnicki P. , Arvinte R. , Beljakowa S. , Weber H. B. , Giannazzo F. , Peyre H. , Souliere V. , Chassagne T. , Zielinski M. , Juillaguet S. , Ferro G. , Roccaforte F. , Krieger M.
Published: November 2016

The effect of germanium (Ge) on n-type 4H-SiC is experimentally studied by electrical characterization of homoepitaxial layers grown by chemical vapor deposition (CVD). Measurements show that electrical properties of epitaxial layers can be changed by intentional incorporation of germane (GeH4) gas during the deposition process. On the nanoscale, two-dimensional mappings acquired with conductive atomic force microscopy show preferential conductive paths on the surface of Ge-doped samples, which are related to the presence of this isoelectronic impurity. Hall effect measurements confirm that also macroscopic electrical properties of n-type 4H-SiC are improved due to incorporation of Ge into SiC during CVD growth. In particular, despite equal free electron concentration, enhanced mobility in a wide temperature range is measured in Ge-doped samples as compared to a pure 4H-SiC layer. Based on our results from Hall effect measurements as well as admittance spectroscopy and deep level transient spectroscopy, it is speculated that Ge influences the generation and annealing of other point defects and thus helps to reduce the total concentration of defects.
Jet delivery system for Raman scattering on bio-inorganic compounds
Authors: Wetzel A. , Biebl F. , Beyerlein K. R. , Stanek J. , Gumprecht L. , Hoffmann A. , Herres-Pawlis S. , Bajt S. , Chapman H. N. , Grimm-Lebsanft B. , Rukser D. , Rübhausen M.
Published: November 2016

We present a micro-jet sample delivery system for Raman measurements. Compared to cuvette measurements, the observed Raman signal is enhanced by more than one order of magnitude and does not contain signal distortions from the liquid-glass interface. Furthermore, the signal stability of repeated measurements is enhanced due to reduced sample damage effects by constantly replenishing the sample. This allows the study of sensitive samples that can only be produced in low concentrations. Our setup consists of a controlled sample environment that can be either under vacuum or an exchange gas, which allows the study of samples that are unstable in air. Finally, by matching the effective source point of the Raman instrument with the diameter of the jet, controlled experiments using laser beams of different wavelengths are possible. We see future applications of our setup for resonance Raman and time-resolved Raman measurements of bioinorganic samples.
Elemental redistributions at structural defects in Cu(In,Ga)Se2 thin films for solar cells
Authors: Simsek Sanli E. , Ramasse Q. M. , Sigle W. , Abou-Ras D. , Mainz R. , Weber A. , Kleebe H.-J. , van Aken P. A.
Published: November 2016

The microstructural evolution of Cu(In,Ga)Se2 absorber layers during a three-stage-type co-evaporation process was studied to elucidate the effect of a Cu-rich stage on the formation of extended structural defects. Defect densities for two Cu-poor samples, one interrupted before and one after this crucial Cu-rich composition stage, were investigated by scanning transmission electron microscopy (STEM) imaging. The structure and chemical nature of individual defects were investigated by aberration-corrected high-resolution STEM in combination with electron energy-loss spectroscopy on the atomic-scale. In spite of the different defect densities between the two samples, most of the individual defects exhibited similar chemistry. In particular, the elemental distributions of atomic columns at {112} twin planes, which are very frequent in Cu(In,Ga)Se2 thin films, were found to be the same as in the defect-free grain interiors. In contrast, within grain boundaries, dislocation cores, and other structurally more complex defects, elemental redistributions of Cu and In were observed.
Principal dynamic mode analysis of neural mass model for the identification of epileptic states
Authors: Cao Yuzhen , Jin Liu , Su Fei , Wang Jiang , Deng Bin
Published: November 2016

The detection of epileptic seizures in Electroencephalography (EEG) signals is significant for the diagnosis and treatment of epilepsy. In this paper, in order to obtain characteristics of various epileptiform EEGs that may differentiate different states of epilepsy, the concept of Principal Dynamic Modes (PDMs) was incorporated to an autoregressive model framework. First, the neural mass model was used to simulate the required intracerebral EEG signals of various epileptiform activities. Then, the PDMs estimated from the nonlinear autoregressive Volterra models, as well as the corresponding Associated Nonlinear Functions (ANFs), were used for the modeling of epileptic EEGs. The efficient PDM modeling approach provided physiological interpretation of the system. Results revealed that the ANFs of the 1st and 2nd PDMs for the auto-regressive input exhibited evident differences among different states of epilepsy, where the ANFs of the sustained spikes' activity encountered at seizure onset or during a seizure were the most differentiable from that of the normal state. Therefore, the ANFs may be characteristics for the classification of normal and seizure states in the clinical detection of seizures and thus provide assistance for the diagnosis of epilepsy.
Dynamics of a pulsed inductively coupled oxygen plasma
Authors: Zaka-ul-Islam Mujahid
Published: November 2016

Inductively coupled plasma system (ICPs) is extensively used for a wide range of nanofabrication applications. The ICPs operated in a pulsed or power modulated mode has shown several advantages compared to the continuous discharge. In this work, the plasma dynamics in a planar coil pulsed inductively coupled plasma system (ICPs) operated in oxygen has been investigated, using phase and space resolved optical emission spectroscopy. It is well-known that the ICPs operates in two distinct operational modes as a function of power known as E and H modes, generated dominantly by capacitive and inductive couplings, respectively. The measurements show that the discharge ignites due a capacitive coupling (in the E-mode) and later transits to the H-mode as a function of time. The inductive coupling, however, starts during the E-mode along with capacitive coupling. The relative contribution of inductive coupling increases until the discharge reaches the E-H transition where the growth rate of inductive coupling becomes much faster. It is found that the time to reach E-H transition decreases with the pressure. At the E-H transition, the total emission has a spike-like feature (i.e., it first achieves a peak emission which later decreases and finally settles to a lower value). The 2D images of the discharge show that at the time of peak total-emission, the discharge structure is sharp and bright, which later decreases in brightness and becomes diffusive.
Electrolyte decomposition on Li-metal surfaces from first-principles theory
Authors: Ebadi Mahsa , Brandell Daniel , Araujo C. Moyses
Published: November 2016

An important feature in Li batteries is the formation of a solid electrolyte interphase (SEI) on the surface of the anode. This film can have a profound effect on the stability and the performance of the device. In this work, we have employed density functional theory combined with implicit solvation models to study the inner layer of SEI formation from the reduction of common organic carbonate electrolyte solvents (ethylene carbonate, propylene carbonate, dimethyl carbonate, and diethyl carbonate) on a Li metal anode surface. Their stability and electronic structure on the Li surface have been investigated. It is found that the CO producing route is energetically more favorable for ethylene and propylene carbonate decomposition. For the two linear solvents, dimethyl and diethyl carbonates, no significant differences are observed between the two considered reduction pathways. Bader charge analyses indicate that 2 e− reductions take place in the decomposition of all studied solvents. The density of states calculations demonstrate correlations between the degrees of hybridization between the oxygen of adsorbed solvents and the upper Li atoms on the surface with the trend of the solvent adsorption energies.
Understanding inherent substrate selectivity during atomic layer deposition: Effect of surface preparation, hydroxyl density, and metal oxide composition on nucleation mechanisms during tungsten ALD
Authors: Lemaire Paul C. , King Mariah , Parsons Gregory N.
Published: November 2016

Area-selective thin film deposition is expected to be important for advanced sub-10 nanometer semiconductor devices, enabling feature patterning, alignment to underlying structures, and edge definition. Several atomic layer deposition (ALD) processes show inherent propensity for substrate-dependent nucleation. This includes tungsten ALD (W-ALD) which is more energetically favorable on Si than on SiO2. However, the selectivity is often lost after several ALD cycles. We investigated the causes of tungsten nucleation on SiO2 and other “non-growth” surfaces during the WF6/SiH4 W-ALD process to determine how to expand the “selectivity window.” We propose that hydroxyls, generated during the piranha clean, act as nucleation sites for non-selective deposition and show that by excluding the piranha clean or heating the samples, following the piranha clean, extends the tungsten selectivity window. We also assessed how the W-ALD precursors interact with different oxide substrates though individual WF6 and SiH4 pre-exposures prior to W-ALD deposition. We conclude that repeated SiH4 pre-exposures reduce the tungsten nucleation delay, which is attributed to SiH4 adsorption on hydroxyl sites. In addition, oxide surfaces were repeatedly exposed to WF6, which appears to form metal fluoride species. We attribute the different tungsten nucleation delay on Al2O3 and TiO2 to the formation of nonvolatile and volatile metal fluoride species, respectively. Through this study, we have increased the understanding of ALD nucleation and substrate selectivity, which are pivotal to improving the selectivity window for W-ALD and other ALD processes.
Effect of different dust flow velocities on combined Kelvin-Helmholtz and Rayleigh-Taylor instabilities in magnetized incompressible dusty fluids
Authors: Dolai Bivash , Prajapati R. P. , Chhajlani R. K.
Published: November 2016

We investigate the effect of different dust flow velocities and two dimensional magnetic fields on the combined Kelvin-Helmholtz instability (KHI) and Rayleigh-Taylor instability (RTI) of two superimposed incompressible dusty fluids. A single fluid reduced dusty magnetohydrodynamic model is obtained for the three component magnetized incompressible dusty plasma, and it is assumed that a plane interface of infinite boundaries separates heavy and light dusty fluids at z = 0. The general dispersion relations for RT and KH configurations are obtained using appropriate boundary conditions and discussed in the case of equal and different dust fluid flow velocities. In the case of the stable RT configuration, we find that the condition of RTI depends upon both longitudinal and transverse magnetic field components and relative dust flow velocity. In the case of the KH configuration, the effect of magnetic field and relative dust flow velocity is observed and it is shown that dust flow velocity must be larger than a particular value of Alfven speed in order to excite KHI. Numerical calculations have been performed to illustrate the linear growth rates of RTI and KHI in both magnetized and unmagnetized dusty plasmas. We observe that the magnetic field has stabilizing whereas the dust Atwood number has destabilizing influence on the growth rate of RTI. The different dust flow velocities have destabilizing whereas magnetic field has stabilizing influence on the growth rate of KHI in dusty plasmas. The dust Mach number yields a stabilizing influence on the linear growth rate of KHI.
Energetic and entropic components of the Tolman length for mW and TIP4P/2005 water nanodroplets
Authors: Joswiak Mark N. , Do Ryan , Doherty Michael F. , Peters Baron
Published: November 2016

The surface free energy of a droplet is approximately γ(R)=γ(∞)(1−2δ/R), with R being the droplet radius and δ being the Tolman length. Here we use the mitosis method to compute δ=−0.56±0.1Å at 300 K for mW water, indicating that γ(R) increases as the droplet size decreases. The computed Tolman length agrees quite well with a previous study of TIP4P/2005 water. We also decompose the size-dependent surface free energy into energetic and entropic contributions for the mW and TIP4P/2005 force fields. Despite having similar Tolman lengths, the energy-entropy decompositions are very different for the two force fields. We discuss critical assumptions which lead to these findings and their relation to experiments on the nucleation of water droplets. We also discuss surface broken bonds and structural correlations as possible explanations for the energetic and entropic contributions.
Wideband long wave infrared metamaterial absorbers based on silicon nitride
Authors: Üstün Kadir , Turhan-Sayan Gönül
Published: November 2016

In this paper, we present silicon nitride metamaterial absorber designs that accomplish large bandwidth and high absorption in the long wave infrared (LWIR) region. These designs are based on the metal-insulator-metal topology, insulator (silicon nitride), and the top metal (aluminum) layers are optimized to obtain high absorptance values in large bandwidths, for three different silicon nitride based absorber structures. The absorption spectrum of the final design reaches absorptance values above 90% in the wavelength interval between 8.07 μm and 11.97 μm, and above 80% in the wavelength interval between 7.9 μm and 14 μm, in the case of normal incidence. The difficulty in the design process of such absorbers stems from the highly dispersive behavior of silicon nitride in the LWIR region. On the other hand, silicon nitride is a widely used material in microbolometers, and accomplishing wide band absorption in silicon nitride is crucial in this regard. Therefore, this study will pave the way for more efficient infrared imaging devices, which are crucial for defense and security systems. Additionally, such designs may also find applications in thermal emitters.
Continuous and discontinuous transitions to synchronization
Authors: Wang Chaoqing , Garnier Nicolas B.
Published: November 2016

We describe how the transition to synchronization in a system of globally coupled Stuart-Landau oscillators changes from continuous to discontinuous when the nature of the coupling is moved from diffusive to reactive. We explain this drastic qualitative change as resulting from the co-existence of a particular synchronized macrostate together with the trivial incoherent macrostate, in a range of parameter values for which the latter is linearly stable. In contrast to the paradigmatic Kuramoto model, this particular state observed at the synchronization transition contains a finite, non-vanishing number of synchronized oscillators, which results in a discontinuous transition. We consider successively two situations where either a fully synchronized state or a partially synchronized state exists at the transition. Thermodynamic limit and finite size effects are briefly discussed, as well as connections with recently observed discontinuous transitions.
Laser-enhanced high-intensity focused ultrasound heating in an in vivo small animal model
Authors: Jo Janggun , Yang Xinmai
Published: November 2016

The enhanced heating effect during the combination of high-intensity focused ultrasound (HIFU) and low-optical-fluence laser illumination was investigated by using an in vivo murine animal model. The thighs of murine animals were synergistically irradiated by HIFU and pulsed nano-second laser light. The temperature increases in the target region were measured by a thermocouple under different HIFU pressures, which were 6.2, 7.9, and 9.8 MPa, in combination with 20 mJ/cm2 laser exposures at 532 nm wavelength. In comparison with conventional laser therapies, the laser fluence used here is at least one order of magnitude lower. The results showed that laser illumination could enhance temperature during HIFU applications. Additionally, cavitation activity was enhanced when laser and HIFU irradiation were concurrently used. Further, a theoretical simulation showed that the inertial cavitation threshold was indeed decreased when laser and HIFU irradiation were utilized concurrently.
Fluorescence based imaging for M-band drive symmetry measurement in hohlraum
Authors: Li Qi , Yao Li , Jing Longfei , Hu Zhimin , Huang Chengwu , Yuan Zheng , Zhao Yang , Xiong Gang , Qing Bo , Lv Min , Zhu Tuo , Deng Bo , Li Jin , Wei Minxi , Zhan Xiayu , Li Jun , Yang Yimeng , Su Chunxiao , Yang Guohong , Zhang Jiyan , Li Sanwei , Yang Jiamin , Ding Yongkun
Published: November 2016

We describe an experimental technique to measure the drive symmetry of M-band radiation on the capsule in hohlraum. M-band radiation from the corona of the laser-produced gold plasma, especially the laser spot regions in the cavity, was used to pump x-ray fluorescence of a thin layer of Si-tracer coated on a solid CH-ball. The fluorescence images were time resolvedly recorded by an x-ray framing camera and the drive asymmetry due to M-band radiation was deduced from these fluorescence images. Moreover, a Si-doped gold cavity was used with the initial purpose of maximizing the fluorescence signal through resonance transitions. Since the Si-plasma expands more rapidly than the gold-plasma, the evolution of drive asymmetry was accelerated in Si-doped hohlraum.
Rectification magnetoresistance device: Experimental realization and theoretical simulation
Authors: Zhang Kun , Huang Qikun , Yan Yi , Wang Xiaolin , Wang Jing , Kang Shishou , Tian Yufeng
Published: November 2016

A unique technique has been proposed to realize rectification magnetoresistance (RMR) by combining a commercial diode and a magnetoresistance component in parallel. The observed RMR could be greatly tuned in a wide range by applying direct current and alternating current simultaneously to the device. Moreover, a quantitative theoretical model has been established, which well explained both the observed RMR and the electrical manipulation behavior. The highly tunable RMR and the correlated magnetoelectric functionalities provide an alternative route for developing multi-functional spintronics devices.
US daily temperature records past, present, and future
Authors: Meehl Gerald A. , Tebaldi Claudia , Adams-Smith Dennis
Published: November 2016

Significance

Future changes in temperature extremes over the continental United States are represented by the ratio of daily record high maximum temperatures to daily record low minimum temperatures and computed as a function of mean temperature increase that does not depend on scenario. A nonlinear empirical fit of the relation between this ratio and average temperature, using observations from 1930 to 2015, is extended to 2100 and compared with the climate model projections. The projections of the ratio are somewhat higher than the empirical projection from observations, continuing a positively biased trend in daily record high temperatures in the 20th century in the models, which we link to less-than-observed summer precipitation and evapotranspiration.
Mechanism of gating by calcium in connexin hemichannels
Authors: Lopez William , Ramachandran Jayalakshmi , Alsamarah Abdelaziz , Luo Yun , Harris Andrew L. , Contreras Jorge E.
Published: November 2016

Significance

Connexin channels are ubiquitous, providing pathways for movement of molecules between cells (junctional channels) and for release of molecular effectors into the extracellular environment (plasma membrane hemichannels). To maintain an adequate permeability barrier, hemichannels are tightly regulated by normal extracellular Ca
2+
to be closed under most conditions. Connexin mutations that disrupt hemichannel regulation by Ca
2+
cause human pathologies due to aberrantly open hemichannels. Here we elucidate molecular mechanisms of gating by Ca
2+
in hemichannels: Ca
2+
binding causes a reorganization of specific interactions within the connexin protein that lead to a closed channel. Further, we show that the actual “gate” is deeper into the pore from where Ca
2+
binds. The interactions involved are conserved across connexins, pointing to a general mechanism.
Efficient replacement of plasma membrane outer leaflet phospholipids and sphingolipids in cells with exogenous lipids
Authors: Li Guangtao , Kim JiHyun , Huang Zhen , St. Clair Johnna R. , Brown Deborah A. , London Erwin
Published: November 2016

Significance

The use of methyl-α-cyclodextrin to fully replace endogenous sphingolipids and phospholipids in plasma membrane outer leaflets of living mammalian cells with exogenous natural and unnatural lipids is introduced in this paper. Outer leaflet lipid species were evaluated, with lipids exchanged out of the plasma membrane outer leaflet matching expected lipid asymmetry. The method will make possible a range of membrane structure/function studies.
The emergence of longevous populations
Authors: Colchero Fernando , Rau Roland , Jones Owen R. , Barthold Julia A. , Conde Dalia A. , Lenart Adam , Nemeth Laszlo , Scheuerlein Alexander , Schoeley Jonas , Torres Catalina , Zarulli Virginia , Altmann Jeanne , Brockman Diane K. , Bronikowski Anne M. , Fedigan Linda M. , Pusey Anne E. , Stoinski Tara S. , Strier Karen B. , Baudisch Annette , Alberts Susan C. , Vaupel James W.
Published: November 2016

Significance

Public interest in social and economic equality is burgeoning. We examine a related phenomenon, lifespan equality, using data from charismatic primate populations and diverse human populations. Our study reveals three key findings. First, lifespan equality rises in lockstep with life expectancy, across primate species separated by millions of years of evolution and over hundreds of years of human social progress. Second, industrial humans differ more from nonindustrial humans in these measures than nonindustrial humans do from other primates. Third, in spite of the astonishing progress humans have made in lengthening the lifespan, a male disadvantage in lifespan measures has remained substantial—a result that will resonate with enduring public interest in male–female differences in many facets of life.
Direct bulk-sensitive probe of 5
f
symmetry in URu
2
Si
2
Authors: Sundermann Martin , Haverkort Maurits W. , Agrestini Stefano , Al-Zein Ali , Moretti Sala Marco , Huang Yingkai , Golden Mark , de Visser Anne , Thalmeier Peter , Tjeng Liu Hao , Severing Andrea
Published: November 2016

Significance

The hidden order problem in URu
2
Si
2
is an unanswered question in the field of strongly correlated electron materials. Although it has been studied for several decades, there is still no consensus about how this new phase forms. Understanding the hidden order phase formation is not only an intellectual problem, it will also advance concepts for designing quantum materials with new exotic properties. Many hidden order scenarios are based on the assumption of certain ground-state symmetries and the present study addresses this aspect. A spectroscopic technique, nonresonant inelastic X-ray scattering, that has become available through the use of high-brilliance synchrotrons, allows us to measure directly in a bulk-sensitive experiment the symmetry of the 5

f

ground-state wave function in URu
2
Si
2
.