bluuebunny/crossref_metadata_2025 huggingface dataset:
Basilar Artery Stenosis Mimicking the Lacunar Syndrome of Pure Motor Hemiparesis
Authors: Chan David K. , Silver Frank L.
Published: December 2016

Background:

Stereotyped, repeated transient ischemic attacks manifesting as pure motor hemiparesis are most often attributed to ischemia of the internal capsule or ventral pons resulting from in situ disease of the small penetrating arteries.

Case description:

We report a 61-year-old man presenting with recurrent episodes of left-sided weakness consistent with the lacunar syndrome of pure motor hemiparesis. Subsequent neuroimaging revealed infarction of the right ventral pons and a critical basilar artery stenosis as the inciting lesion. Despite maximal antithrombotic therapy, he continued to have repeated symptoms. Angioplasty and stenting were attempted but both failed due to plaque recoil and technical difficulties. After the procedure, the patient had no further ischemic episodes and remained symptom-free at two months.

Conclusions:

This case illustrates the imprecise and discordant relationship between the mode of presentation of a stroke syndrome and its presumed pathophysiology. The lacunar syndrome of pure motor hemiparesis should be recognized by clinicians as a mode of stroke presentation due not only to small vessel disease, but also to large artery atherosclerotic disease such as basilar artery stenosis. Prompt institution of treatment can lead to a good clinical outcome.
The Codex Mexicanus: Time, Religion, History, and Health in Sixteenth-Century New Spain
Authors: Diel Lori Boornazian
Published: December 2016

About 60 years after the Spanish invasion and conquest of Mexico, a group of Nahua intellectuals gathered in Tenochtitlan. On the very site of the heart of the Aztec empire stood a city of a new name: Mexico City, capital of New Spain. There the Nahuas set about compiling an extensive book of miscellanea, now known as the Codex Mexicanus. Owned by the Bibliothèque National de France, the codex includes records pertaining to the Christian and Aztec calendars, European medical astrology, a genealogy of the Tenochca royal house, and the annals of preconquest and early colonial Mexico City, among other intriguing topics.
Gold nanoparticles stabilized by cationic carbosilane dendrons: synthesis and biological properties
Authors: Peña-González Cornelia E. , Pedziwiatr-Werbicka Elzbieta , Shcharbin Dzmitry , Guerrero-Beltrán Carlos , Abashkin Viktar , Loznikova Svetlana , Jiménez José L. , Muñoz-Fernández M. Ángeles , Bryszewska Maria , Gómez Rafael , Sánchez-Nieves Javier , de la Mata F. Javier
Published: December 2016

Water soluble gold nanoparticles have been isolated with pendant cationic carbosilane dendrons and their biological properties have been evaluated.
Enhanced red upconversion emission and its mechanism in Yb3+–Er3+ codoped α-NaLuF4 nanoparticles
Authors: Lin Hao , Xu Dekang , Li Anming , Qiu Zhiren , Yang Shenghong , Zhang Yueli
Published: December 2016

Red upconversion luminescence is greatly enhanced through manipulation of the initial solution pH.
Further correction: Cobalt co-catalysis for cross-electrophile coupling: diarylmethanes from benzyl mesylates and aryl halides
Authors: Ackerman Laura K. G. , Anka-Lufford Lukiana L. , Naodovic Marina , Weix Daniel J.
Published: December 2016

Further correction for ‘Cobalt co-catalysis for cross-electrophile coupling: diarylmethanes from benzyl mesylates and aryl halides’ by Laura K. G. Ackerman et al., Chem. Sci., 2015, 6, 1115–1119.
Identification of Ly2 members as antimicrobial peptides from zebrafish Danio rerio
Authors: Liu Xuemin , Cao Xuwen , Wang Su , Ji Guangdong , Zhang Shicui , Li Hongyan
Published: December 2016

The emergence of multidrug-resistant (MDR) microbes caused by overuse of antibiotics leads to urgent demands for novel antibiotics exploration. Our recent data showed that Ly2.1–3 (a novel lymphocyte antigen 6 (Ly6) gene cluster) were proteins with cationic nature and rich in cysteine content, that are characteristic of antimicrobial peptides (AMPs) and their expression were all significantly up-regulated after challenge with lipopolysaccharide (LPS). These strongly suggested that Ly2.1–3 are potential AMPs, but firm evidence are lacking. Here, we clearly showed that the recombinant proteins of Ly2.1–3 were capable of killing Gram-negative bacteria Aeromonas hydrophila and Escherichia coli, while they had little bactericidal activity against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis. We also showed that recombinant proteins Ly2.1–3 (rLy2.1–3) were able to bind to the Gram-negative bacteria A. hydrophila, E. coli and the microbial signature molecule LPS, but not to the Gram-positive bacteria S. aureus and B. subtilis as well as the microbial signature molecule LTA. Moreover, the Scatchard analysis revealed that rLy2.1–3 could specifically bind to LPS. Finally, we found that Ly2.1–3 were not cytotoxic to mammalian cells. All these together indicate that Ly2.1–3 can function as AMPs.
Insulinotropic effects of GPR120 agonists are altered in obese diabetic and obese non-diabetic states
Authors: Zhang Dan , So Wing Yan , Wang Yi , Wu Shang Ying , Cheng Qianni , Leung Po Sing
Published: December 2016

G-protein-coupled receptor 120 (GPR120) is a putative target for obesity and diabetes therapies. However, it remains controversial whether resident GPR120 plays a direct regulatory role in islet β-cell insulin secretion. The present study examined this issue in isolated rodent islets and rat β-cell line INS-1E, and assessed the role of GPR120 in islet insulin secretion in obese non-diabetic (OND) and diabetic states. GPR120 expression was detected in rodent islet β-cells. Docosahexaenoic acid (DHA) and synthetic GPR120 agonist GSK137647 (GSK) augmented insulin release from rat/mouse islets and INS-1E; DHA effects were partially mediated by GPR40. GPR120 knockdown and overexpression attenuated and enhanced DHA effects in INS-1E respectively. DHA and GSK improved postprandial hyperglycaemia of diabetic mice. Inhibition of calcium signalling in INS-1E reduced GPR120 activation-induced insulinotropic effects. The insulinotropic effects of DHA/GSK were amplified in OND rat islets, but diminished in diabetic rat islets. GPR120 and peroxisome proliferator-activated receptor γ (PPARγ) expression were elevated in OND islets and palmitic acid (PA)-treated INS-1E, but reduced in diabetic islets and high glucose-treated INS-1E. PPARγ activation increased GPR120 expression in rat islets and INS-1E. DHA and GSK induced protein kinase B (Akt)/extracellular signal-regulated kinase (ERK) phosphorylation in rodent islets and INS-1E, and these effects were altered in OND and diabetic states. Taken together, the present study indicates that (i) GPR120 activation has an insulinotropic influence on β-cells with the involvement of calcium signalling; (ii) GPR120 expression in β-cells and GPR120-mediated insulinotropic effects are altered in OND and diabetic states in distinct ways, and these alterations may be mediated by PPARγ.
MRF model based real‐time traffic flow prediction with support vector regression
Authors: Kim E.Y.
Published: December 2016

A novel statistical model for real‐time traffic flow prediction is proposed. In this study, a 3D Markov random field (MRF) is used to model the temporal dynamics of the traffic flow measured by VDS sensor network. Then, the spatial and temporal relations between roads at a given location are represented by the 3D graph using cliques, then its structure is determined by clique parameters. Here, a support vector regression is adopted for estimating the correlation parameters. The technique is applied to actual traffic flow data from Gyeongbu expressway, South Korea. The experiments demonstrate that the proposed method can predict the traffic flow with an accuracy of 85.6%, which improves 17.3% of the existing state‐of‐the‐art method.
Nitric Oxide: Link between Inflammation and Endothelial Dysfunction in Rheumatoid Arthritis
Authors: Garg Nidhi , Syngle Ashit , Krishan Pawan
Published: December 2016

Nitric oxide (NO) plays an important role in inflammatory joint disease and endothelial function. Endothelial dysfunction has been attributed to a reduction in NO bioactivity in rheumatoid arthritis (RA). However, the relationship of NO with inflammation and endothelial dysfunction in RA has not yet been investigated.

To investigate the relationship of nitrite with inflammation and endothelial dysfunction in RA.

Total 28 patients satisfying 2010 Rheumatoid Arthritis Classification Criteria were recruited for the study. Serum nitrite estimation was performed by Griess reaction. Flow-mediated dilation (FMD) assessed using AngioDefender. Inflammatory disease activity measures included disease activity score of 28 joints (DAS28), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Proinflammatory cytokines (TNF-α, IL-6, and IL-1) measured using standard ELISA kits. Twenty-five healthy controls matched for age and sex were included for comparison.

The serum nitrite level in patients with RA was markedly elevated as compared with controls (p < 0.05). FMD was significantly impaired in RA patients than controls (p < 0.05). DAS28 was significantly higher in RA patients (p < 0.05). Levels of ESR, CRP, TNF-α, IL-1, and IL-6 were significantly higher in RA patients than controls (p < 0.05). Significant positive correlation was observed between nitrite and CRP (r = 0.46, p < 0.05), TNF-α (r = 0.53, p < 0.05), and inverse correlation with FMD (r =0.62, p < 0.05).

Inflammatory disease activity and endothelial dysfunction in RA are associated with increased concentration of proinflammatory cytokines and NO. Inflammatory triggered release of cytokines induced NO production that mediates endothelial dysfunction. These findings suggest a role for NO in inflammation-induced endothelial dysfunction in RA.
Eine neue deutschsprachige Skala zur Erfassung von elterlichem Stress nach Frühgeburtlichkeit (PSS:NICU_German/2-scales)
Authors: Urlesberger P. , Schienle A. , Pichler G. , Baik N. , Schwaberger B. , Urlesberger B. , Pichler-Stachl E.
Published: December 2016

Theoretischer Hintergrund Die Frühgeburt eines Kindes führt bei Eltern zu erhöhtem Stress, Angst und Sorge. Dies kann langfristige Auswirkungen auf die psychische Gesundheit der Mutter haben und potentiell auch die Entwicklung des Kindes beeinflussen.

Fragestellung Der englischsprachige Fragebogen Parental Stressor Scale: Neonatal Intensive Care Unit [1] erhebt elterlichen Stress nach Frühgeburtlichkeit in 3 Subskalen. Das Ziel der vorliegenden Studie war es, eine ins Deutsche übersetzte Fassung des PSS:NICU Fragebogens hinsichtlich ihrer psychometrischen Gütekriterien und Dimensionalität zu überprüfen, um eine reliable deutsche Version zu entwickeln.

Methode Zur Entwicklung (exploratorische Faktorenanalyse) diente eine Stichprobe von 50 Elternpaaren von Frühgeborenen.

Ergebnisse Die Subskala Bilder und Geräusche wurde aufgrund der niedrigen Itemanzahl aus der deutschen Version des PSS:NICU entfernt. Ein PSS:NICU_German/2-scales Fragebogen wurde entwickelt. Dieser besteht nun aus den Subskalen Aussehen und Verhalten des Kindes (7 Items, Cronbachs α=0,82) und Elterliche Rolle (6 Items, Cronbachs α=0,87).

Schlussfolgerung Der PSS:NICU_German/2-scales Fragebogen stellt ein ökonomisches und reliables Instrument zur Erfassung von elterlichem Stress nach Frühgeburtlichkeit dar.
Band offsets and trap-related electron transitions at interfaces of (100)InAs with atomic-layer deposited Al2O3
Authors: Chou H.-Y. , O'Connor E. , O'Mahony A. , Povey I. M. , Hurley P. K. , Dong Lin , Ye P. D. , Afanas'ev V. V. , Houssa M. , Stesmans A.
Published: December 2016

Spectral analysis of optically excited currents in single-crystal (100)InAs/amorphous (a-)Al2O3/metal structures allows one to separate contributions stemming from the internal photoemission (IPE) of electrons into alumina and from the trapping-related displacement currents. IPE spectra suggest that the out-diffusion of In and, possibly, its incorporation in a-Al2O3 lead to the development of ≈0.4 eV wide conduction band (CB) tail states. The top of the InAs valence band is found at 3.45 ± 0.10 eV below the alumina CB bottom, i.e., at the same energy as at the GaAs/a-Al2O3 interface. This corresponds to the CB and the valence band offsets at the InAs/a-Al2O3 interface of 3.1 ± 0.1 eV and 2.5 ± 0.1 eV, respectively. However, atomic-layer deposition of alumina on InAs results in additional low-energy electron transitions with spectral thresholds in the range of 2.0–2.2 eV, which is close to the bandgap of AlAs. The latter suggests the interaction of As with Al, leading to an interlayer containing Al-As bonds providing a lower barrier for electron injection.
Spectral splitting optimization for high-efficiency solar photovoltaic and thermal power generation
Authors: Bierman David M. , Lenert Andrej , Wang Evelyn N.
Published: December 2016

Utilizing the full solar spectrum is desirable to enhance the conversion efficiency of a solar power generator. In practice, this can be achieved through spectral splitting between multiple converters in parallel. However, it is unclear which wavelength bands should be directed to each converter in order to maximize the efficiency. We developed a model of an ideal hybrid solar converter which utilizes both a single-junction photovoltaic cell and a thermal engine. We determined the limiting efficiencies of this hybrid strategy and the corresponding optimum spectral bandwidth directed to the photovoltaic cell. This optimum width is inversely proportional to the thermal engine efficiency and scales with the bandgap of the photovoltaic cell. This bandwidth was also obtained analytically through an entropy minimization scheme and matches well with our model. We show that the maximum efficiency of the system occurs when it minimizes the spectral entropy generation. This concept can be extended to capture generalized non-idealities to increase the usefulness of this technique for a range of full solar spectrum utilization technologies.
Manipulation of the electroluminescence of organic light-emitting diodes via fringe fields from patterned magnetic domains
Authors: Harmon N. J. , Wohlgenannt M. , Flatté M. E.
Published: December 2016

We predict very large changes in the room-temperature electroluminescence of thermally-activated delayed fluorescence organic light emitting diodes near patterned ferromagnetic films. These effects exceed the changes in a uniform magnetic field by as much as a factor of two. We describe optimal ferromagnetic film patterns for enhancing the electroluminescence. A full theory of the spin-mixing processes in exciplex recombination and how they are affected by hyperfine fields, spin-orbit effects, and ferromagnetic fringe field effects is introduced. These spin-mixing processes are used to describe the effect of magnetic domain structures on the luminescence in various regimes. This provides a method of enhancing light emission rates from exciplexes and also a means of efficiently coupling information encoded in the magnetic domains to organic light emitting diode emission.
Molecular dynamics study of flow past an obstacle in strongly coupled Yukawa liquids
Authors: Charan Harish , Ganesh Rajaraman
Published: December 2016

Turbulence is one of the outstanding open problems. Fluid flow past an obstacle is simplest of all paradigms to understand the transition to turbulence. For Navier-Stokes liquids, a transition to turbulence is fully governed by Reynolds number (Re). Using classical molecular dynamics simulation of particles interacting via a Yukawa-type interaction, it is demonstrated unequivocally that for a given Re, the transition from laminar to turbulent flow is controlled by strength and range of inter-particle potential. For a wide range of inter-particle interaction strengths and ranges, our simulation data are seen to collapse onto a universal Strouhal-Reynolds curve with new asymptotic values for a range of Re, 2 ≤ Re ≤ 35. From the emergence of vortex street structures behind the obstacle, it is evident that the onset of turbulence is possible at low Re in Yukawa liquids. Growth rates of the instability are obtained using atomistic calculations and are observed to increase quadratically with low values of Re.
Parameter and state estimation in a Neisseria meningitidis model: A study case of Niger
Authors: Bowong S. , Mountaga L. , Bah A. , Tewa J. J. , Kurths J.
Published: December 2016

Neisseria meningitidis (Nm) is a major cause of bacterial meningitidis outbreaks in Africa and the Middle East. The availability of yearly reported meningitis cases in the African meningitis belt offers the opportunity to analyze the transmission dynamics and the impact of control strategies. In this paper, we propose a method for the estimation of state variables that are not accessible to measurements and an unknown parameter in a Nm model. We suppose that the yearly number of Nm induced mortality and the total population are known inputs, which can be obtained from data, and the yearly number of new Nm cases is the model output. We also suppose that the Nm transmission rate is an unknown parameter. We first show how the recruitment rate into the population can be estimated using real data of the total population and Nm induced mortality. Then, we use an auxiliary system called observer whose solutions converge exponentially to those of the original model. This observer does not use the unknown infection transmission rate but only uses the known inputs and the model output. This allows us to estimate unmeasured state variables such as the number of carriers that play an important role in the transmission of the infection and the total number of infected individuals within a human community. Finally, we also provide a simple method to estimate the unknown Nm transmission rate. In order to validate the estimation results, numerical simulations are conducted using real data of Niger.
Drag-model sensitivity of Kelvin-Helmholtz waves in canopy flows
Authors: Luminari Nicola , Airiau Christophe , Bottaro Alessandro
Published: December 2016

Two models of the flow over and through an immersed, vegetated layer are examined to study the onset of instability waves across the layer and to assess the effect of mild variations in the mean flow and in the drag force exerted by the canopy onto the frequency and growth rate of the monami instability. One of the two models, based on the use of Darcy’s equation, with a tensorial permeability, within the canopy is more robust than the other (which uses a scalar drag coefficient), i.e., it is less sensitive to the inevitable imperfections or approximations in the input data.
Hybrid simulations of solenoidal radio-frequency inductively coupled hydrogen discharges at low pressures
Authors: Yang Wei , Li Hong , Gao Fei , Wang You-Nian
Published: December 2016

In this article, we have described a radio-frequency (RF) inductively coupled H2 plasma using a hybrid computational model, incorporating the Maxwell equations and the linear part of the electron Boltzmann equation into global model equations. This report focuses on the effects of RF frequency, gas pressure, and coil current on the spatial profiles of the induced electric field and plasma absorption power density. The plasma parameters, i.e., plasma density, electron temperature, density of negative ion, electronegativity, densities of neutral species, and dissociation degree of H2, as a function of absorption power, are evaluated at different gas pressures. The simulation results show that the utilization efficiency of the RF source characterized by the coupling efficiency of the RF electric field and power to the plasma can be significantly improved at the low RF frequency, gas pressure, and coil current, due to a low plasma density in these cases. The densities of vibrational states of H2 first rapidly increase with increasing absorption power and then tend to saturate. This is because the rapidly increased dissociation degree of H2 with increasing absorption power somewhat suppresses the increase of the vibrational states of H2, thus inhibiting the increase of the H−. The effects of absorption power on the utilization efficiency of the RF source and the production of the vibrational states of H2 should be considered when setting a value of the coil current. To validate the model simulations, the calculated electron density and temperature are compared with experimental measurements, and a reasonable agreement is achieved.
Absolute distance measurement method without a non-measurable range and directional ambiguity based on the spectral-domain interferometer using the optical comb of the femtosecond pulse laser
Authors: Park J. , Jin J. , Kim J.-A. , Kim J. W.
Published: December 2016

With the help of the optical comb of a femtosecond pulse laser, a spectral-domain interferometer has been utilized for measuring absolute distances. Even if the technique can measure distances at a high speed and with good precision, it has two fundamental problems: non-measurable range and directional ambiguity. First, the non-measurable range arises due to the sampling limit of the interference spectra at very short distances or the integer multiple of a double non-ambiguity range. Second, the peak corresponding to the desired distance in the Fourier domain has a directional ambiguity owing to the repeated property of the optical comb. Therefore, due to these two fundamental problems, most previous works never measure the absolute distances by itself in a single operation. In this letter, an interferometric method for measuring arbitrary absolute distances based on a spectral-domain interferometer operating with two reference mirrors is proposed and demonstrated. The two reference mirrors generate two distinguishable signals, primary and secondary, with a predetermined offset, thus solving these fundamental problems clearly. More importantly, as a practical advantage, the simple layout of the proposed method makes it readily applicable to most previous studies.
Droplet formation in a flow focusing configuration: Effects of viscoelasticity
Authors: Nooranidoost Mohammad , Izbassarov Daulet , Muradoglu Metin
Published: December 2016

We numerically investigate the effects of bulk fluid viscoelasticity on droplet formation and dynamics in an axisymmetric flow focusing configuration. Viscoelasticity is modeled using the finitely extensible nonlinear elastic-Chilcott-Rallison (FENE-CR) model. Extensive simulations are performed to examine droplet formation and breakup dynamics for a wide range of parameters including flow rate ratio, Weissenberg number, polymeric viscosity ratio, and extensibility parameter. It is found that these parameters have a significant influence on the droplet size and size distribution (dispersity). Three different regimes are observed in the sequence of squeezing, dripping, and jetting modes as the flow rate ratio is increased. It is also found that the viscoelasticity has a similar effect as decreasing flow rate ratio and acts to delay transition from squeezing to dripping and from dripping to jetting regimes. The strain-rate hardening occurs at a critical Weissenberg number resulting in an abrupt increase in droplet size and this effect is more pronounced as the polymeric viscosity ratio is increased.
Characterization of electrical noise limits in ultra-stable laser systems
Authors: Zhang J. , Shi X. H. , Zeng X. Y. , Lü X. L. , Deng K. , Lu Z. H.
Published: December 2016

We demonstrate thermal noise limited and shot noise limited performance of ultra-stable diode laser systems. The measured heterodyne beat linewidth between such two independent diode lasers reaches 0.74 Hz. The frequency instability of one single laser approaches 1.0 × 10−15 for averaging time between 0.3 s and 10 s, which is close to the thermal noise limit of the reference cavity. Taking advantage of these two ultra-stable laser systems, we systematically investigate the ultimate electrical noise contributions, and derive expressions for the closed-loop spectral density of laser frequency noise. The measured power spectral density of the beat frequency is compared with the theoretically calculated closed-loop spectral density of the laser frequency noise, and they agree very well. It illustrates the power and generality of the derived closed-loop spectral density formula of the laser frequency noise. Our result demonstrates that a 10−17 level locking in a wide frequency range is feasible with careful design.
Deep ultraviolet emission from ultra-thin GaN/AlN heterostructures
Authors: Bayerl Dylan , Islam SM , Jones Christina M. , Protasenko Vladimir , Jena Debdeep , Kioupakis Emmanouil
Published: December 2016

We present the theoretical and experimental results for the electronic and optical properties of atomically thin (1 and 2 monolayers) GaN quantum wells with AlN barriers. Strong quantum confinement increases the gap of GaN to as high as 5.44 eV and enables light emission in the deep-UV range. Luminescence occurs from the heavy and light hole bands of GaN yielding E ⊥ c polarized light emission. Strong confinement also increases the exciton binding energy up to 230 meV, preventing a thermal dissociation of excitons at room temperature. However, we did not observe excitons experimentally due to high excited free-carrier concentrations. Monolayer-thick GaN wells also exhibit a large electron-hole wave function overlap and negligible Stark shift, which is expected to enhance the radiative recombination efficiency. Our results indicate that atomically thin GaN/AlN heterostructures are promising for efficient deep-UV optoelectronic devices.
Ab initio modeling of steady-state and time-dependent charge transport in hole-only α-NPD devices
Authors: Liu Feilong , Massé Andrea , Friederich Pascal , Symalla Franz , Nitsche Robert , Wenzel Wolfgang , Coehoorn Reinder , Bobbert Peter A.
Published: December 2016

We present an ab initio modeling study of steady-state and time-dependent charge transport in hole-only devices of the amorphous molecular semiconductor α–NPD [N,N′-Di(1–naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine]. The study is based on the microscopic information obtained from atomistic simulations of the morphology and density functional theory calculations of the molecular hole energies, reorganization energies, and transfer integrals. Using stochastic approaches, the microscopic information obtained in simulation boxes at a length scale of ∼10 nm is expanded and employed in one-dimensional (1D) and three-dimensional (3D) master-equation modeling of the charge transport at the device scale of ∼100 nm. Without any fit parameter, predicted current density-voltage and impedance spectroscopy data obtained with the 3D modeling are in very good agreement with measured data on devices with different α-NPD layer thicknesses in a wide range of temperatures, bias voltages, and frequencies. Similarly good results are obtained with the computationally much more efficient 1D modeling after optimizing a hopping prefactor.
Analytic solution of the Ornstein-Zernike relation for inhomogeneous liquids
Authors: He Yan , Rice Stuart A. , Xu Xinliang
Published: December 2016

The properties of a classical simple liquid are strongly affected by the application of an external potential that supports inhomogeneity. To understand the nature of these property changes, the equilibrium particle distribution functions of the liquid have, typically, been calculated directly using either integral equation or density functional based analyses. In this study, we develop a different approach with a focus on two distribution functions that characterize the inhomogeneous liquid: the pair direct correlation function c(r1,r2) and the pair correlation function g(r1,r2). With g(r1,r2) considered to be an experimental observable, we solve the Ornstein-Zernike equation for the inhomogeneous liquid to obtain c(r1,r2), using information about the well studied and resolved g(0)(r1,r2) and c(0)(r1,r2) for the parent homogeneous ((0)) system. In practical cases, where g(r1,r2) is available from experimental data in a discrete form, the resulting c(r1,r2) is expressed as an explicit function of g(r1,r2) in a discrete form. A weaker continuous form of solution is also obtained, in the form of an integral equation with finite integration limits. The result obtained with our formulation is tested against the exact solutions for the correlation and distribution functions of a one-dimensional inhomogeneous hard rod liquid. Following the success of that test, the formalism is extended to higher dimensional systems with explicit consideration of the two-dimensional liquid.
Growth of silicon on tungsten diselenide
Authors: Yao Qirong , van Bremen Rik , Zandvliet Harold J. W.
Published: December 2016

Here, we report a scanning tunneling microscopy and spectroscopy study of the growth of silicon on a tungsten diselenide (WSe2) substrate. We have found convincing experimental evidence that silicon does not remain on the WSe2 substrate but rather intercalates between the top layers of WSe2. Upon silicon deposition, the flat WSe2 surface converts into a surface with a hill-and-valley structure. The lattice constant of the hill-and-valley structure is identical to the lattice constant of WSe2 and the transition from hills to valleys is very gradual, suggesting that the top layer is composed of pristine WSe2. In order to verify this conjecture, we have removed the height information from our scanning tunneling microscopy signal and obtained chemical contrast of the surface by recording dI/dz, rather than the conventional regulation voltage of the z-piezo. The spatially resolved dI/dz maps provide compelling evidence that the deposited silicon does indeed not reside on top of the WSe2 substrate.
Targeting excited states in all-trans polyenes with electron-pair states
Authors: Boguslawski Katharina
Published: December 2016

Wavefunctions restricted to electron pair states are promising models for strongly correlated systems. Specifically, the pair Coupled Cluster Doubles (pCCD) ansatz allows us to accurately describe bond dissociation processes and heavy-element containing compounds with multiple quasi-degenerate single-particle states. Here, we extend the pCCD method to model excited states using the equation of motion (EOM) formalism. As the cluster operator of pCCD is restricted to electron-pair excitations, EOM-pCCD allows us to target excited electron-pair states only. To model singly excited states within EOM-pCCD, we modify the configuration interaction ansatz of EOM-pCCD to contain also single excitations. Our proposed model represents a simple and cost-effective alternative to conventional EOM-CC methods to study singly excited electronic states. The performance of the excited state models is assessed against the lowest-lying excited states of the uranyl cation and the two lowest-lying excited states of all-trans polyenes. Our numerical results suggest that EOM-pCCD including single excitations is a good starting point to target singly excited states.
Effects of both diffuse and collimated incident radiation on phototactic bioconvection
Authors: Panda M. K. , Singh R. , Mishra Amaresh Chandra , Mohanty Sraban Kumar
Published: December 2016

Phototaxis denotes swimming towards (positive) or away (negative) from light. The suspension containing phototactic algae is illuminated by both the diffuse and collimated solar radiation. The algae absorb the incident light and scatter it. We use the phototaxis model of Ghorai et al. [“Bioconvection in a suspension of isotropically scattering phototactic algae,” Phys. Fluids 22, 071901 (2010)] and investigate the onset of bioconvection with particular emphasis on the effects of diffuse irradiation. The basic equilibrium state of the bioconvective governing system is defined by assuming that the bulk velocity of the fluid to be zero and the up and down swimming, caused by the positive and negative phototaxis, is balanced with the diffusion. For some values of the parameters, the bimodal steady-state profile transits to a unimodal equilibrium state as the diffuse irradiation is increased. For a small scattering albedo, at the onset of bioconvective instability, this model differs significantly from the up-swimming model of Vincent and Hill [“Bioconvection in a suspension of phototactic algae,” J. Fluid Mech. 327, 343 (1996)], even for small wavelengths. Furthermore, the solutions show a transition of the most unstable mode from the stationary to oscillatory state, and then back to the stationary state again, as the governing parameters are varied. A significant stabilizing effect on suspension has also been observed due to the effects of diffuse irradiation. The effect of the diffuse irradiation on a dominant bioconvection pattern wavelength at instability is also qualitatively in good agreement with the bioconvection experiments.
Fragmentation dynamics of carbonyl sulfide in collision with 500 eV electron
Authors: Shen Zhenjie , Wang Enliang , Gong Maomao , Shan Xu , Chen Xiangjun
Published: December 2016

The fragmentation dynamics of OCSq+ (q = 2, 3, 4) induced by electron collision at an impact energy of 500 eV is studied. By using the momentum imaging technique, the three dimensional momentum vectors of all the fragments are obtained, which enables us to analyse both the kinetic energy release and the momentum correlations for a certain fragmentation channel. Up to fifteen dissociation channels are analyzed including six, five, and four channels for two-body, and incomplete and complete three-body Coulomb fragmentations. For three-body dissociation, the fragmentation mechanisms are investigated with the help of Dalitz plot and Newton diagram. It is found that the sequential fragmentation involves in OCS2+→O+C++S+ with S+ emitted first and in OCS3+→O++C++S+ with O–C and C–S bonds breaking first. The remaining channels, however, always dissociate through a concerted mechanism. The relative intensities of the channels are also presented in this work.
Investigation of the tunnel magnetoresistance in junctions with a strontium stannate barrier
Authors: Althammer Matthias , Vikam Singh Amit , Keshavarz Sahar , Kenan Yurtisigi Mehmet , Mishra Rohan , Borisevich Albina Y. , LeClair Patrick , Gupta Arunava
Published: December 2016

We experimentally investigate the structural, magnetic, and electrical transport properties of La0.67 Sr0.33MnO3 based magnetic tunnel junctions with a SrSnO3 barrier. Our results show that despite the high density of defects in the strontium stannate barrier, due to the large lattice mismatch, the observed tunnel magnetoresistance (TMR) is comparable to tunnel junctions with a better lattice matched SrTiO3 barrier, reaching values of up to 350% at T=5 K. Further analysis of the current-voltage characteristics of the junction and the bias voltage dependence of the observed tunnel magnetoresistance show a decrease of the TMR with increasing bias voltage. In addition, the observed TMR vanishes for T>200 K. Our results suggest that by employing a better lattice matched ferromagnetic electrode, and thus reducing the structural defects in the strontium stannate barrier, even larger TMR ratios might be possible in the future.
High performance dendrimer functionalized single-walled carbon nanotubes field effect transistor biosensor for protein detection
Authors: Rajesh  , Sharma Vikash , Puri Nitin K. , Mulchandani Ashok , Kotnala Ravinder K.
Published: December 2016

We report a single-walled carbon nanotube (SWNT) field-effect transistor (FET) functionalized with Polyamidoamine (PAMAM) dendrimer with 128 carboxyl groups as anchors for site specific biomolecular immobilization of protein antibody for C-reactive protein (CRP) detection. The FET device was characterized by scanning electron microscopy and current-gate voltage (I-Vg) characteristic studies. A concentration-dependent decrease in the source-drain current was observed in the regime of clinical significance, with a detection limit of ∼85 pM and a high sensitivity of 20% change in current (ΔI/I) per decade CRP concentration, showing SWNT being locally gated by the binding of CRP to antibody (anti-CRP) on the FET device. The low value of the dissociation constant (Kd = 0.31 ± 0.13 μg ml−1) indicated a high affinity of the device towards CRP analyte arising due to high anti-CRP loading with a better probe orientation on the 3-dimensional PAMAM structure.
Theory of molecular conductance using a modular approach
Authors: Hsu Liang-Yan , Rabitz Herschel
Published: December 2016

This study probes the correlation between the conductance of a molecular wire (the property of a whole system) and its constituent backbone units (modules). By using a tight-binding Hamiltonian combined with single-particle Green’s functions, we develop an approach that enables an estimate of a conductance decay constant in terms of the Hamiltonians of molecular backbone units and the couplings between two nearest-neighbor units in the off-resonant tunneling regime. For demonstration, we examine several representative molecular systems in a framework of the Hückel model (the simplest atomistic-level model). The Hückel model can be reduced to a single-orbital-per-site formulation [A. Nitzan, Annu. Rev. Phys. Chem. 52, 681 (2001)], and each energy level in the single-orbital-per-site picture can be expressed in an explicit form including the synergistic effect of all molecular orbitals of a molecular backbone unit. Based on the proposed approach, we show the correspondence between the complete destructive quantum interference and an infinite injection gap and derive the preconditions of the modified Simmons equation and the rule of intramolecular series circuits.
Theoretical investigation of rotationally inelastic collisions of CH(X2Π) with molecular hydrogen
Authors: Dagdigian Paul J.
Published: December 2016

We report calculations of state-to-state cross sections for collision-induced rotational transitions of CH(X2Π) with molecular hydrogen. These calculations employed the diabatic matrix elements of the interaction potential determined by Dagdigian [J. Chem. Phys. 145, 114301 (2016)], which employed the multi-reference configuration-interaction method [MRCISD+Q(Davidson)]. Because of the presence of a deep well on the lower potential energy surface, the scattering calculations were carried out using the quantum statistical method of Manolopoulos and co-workers [Chem. Phys. Lett. 343, 356 (2001)]. The computed cross sections included contributions from direct scattering, as well as from the formation and decay of a collision complex. The magnitude of latter contribution was found to decrease significantly with increasing collision energy. Rotationally energy transfer rate constants were computed for this system since these are required for astrochemical modeling.
Vaporization and recondensation dynamics of indocyanine green-loaded perfluoropentane droplets irradiated by a short pulse laser
Authors: Yu Jaesok , Chen Xucai , Villanueva Flordeliza S. , Kim Kang
Published: December 2016

Phase-transition droplets have been proposed as promising contrast agents for ultrasound and photoacoustic imaging. Short pulse laser activated perfluorocarbon-based droplets, especially when in a medium with a temperature below their boiling point, undergo phase changes of vaporization and recondensation in response to pulsed laser irradiation. Here, we report and discuss the vaporization and recondensation dynamics of perfluoropentane droplets containing indocyanine green in response to a short pulsed laser with optical and acoustic measurements. To investigate the effect of temperature on the vaporization process, an imaging chamber was mounted on a temperature-controlled water reservoir and then the vaporization event was recorded at 5 million frames per second via a high-speed camera. The high-speed movies show that most of the droplets within the laser beam area expanded rapidly as soon as they were exposed to the laser pulse and immediately recondensed within 1–2 μs. The vaporization/recondensation process was consistently reproduced in six consecutive laser pulses to the same area. As the temperature of the media was increased above the boiling point of the perfluoropentane, the droplets were less likely to recondense and remained in a gas phase after the first vaporization. These observations will help to clarify the underlying processes and eventually guide the design of repeatable phase-transition droplets as a photoacoustic imaging contrast agent.
Large coercivity FePt nanoparticles prepared via a one-step method without post-annealing
Authors: Zhang Xinwei , Xiong Fang , Jiang Xiaohong , Hua Zhenghe , Wang Chunlei , Yang Shaoguang
Published: December 2016

L10 FePt nanoparticles were synthesized by a one-step sol-gel autocombustion method, using nontoxic ferric nitrate, hexachloroplatinic acid, and glycine as starting materials. In contrast to common syntheses, high-temperature post-annealing was not required to form the L10 FePt phase. The entire ignition and combustion process lasted no more than one minute. The L10 FePt phase could form in the presence of the high temperature caused by the exothermic combustion reaction. Adjusting the glycine-to-metal ion molar ratio from 0.5 to 6.0 allowed its effects on the phase transformation and magnetic properties of the products to be investigated. X-ray diffraction indicated that pure phase L10 FePt was obtained at a glycine-to-metal ion molar ratio of 1.5. Transmission electron microscopy indicated that the monodisperse L10 FePt nanoparticles had an average particle size of about 20 nm. The reasons why the as-synthesized L10 FePt nanoparticles were not aggregated and sintered could be attributed to the large amount, a gas is being released and the short duration of heat treatment during this combustion. This finding constituted a significant improvement in the synthesis of L10 FePt nanoparticles. Magnetic measurements showed that the L10 FePt nanoparticles had a coercivity of 15.8 kOe at 300 K, and 23.2 kOe at 5 K. Thus, the L10 FePt nanoparticles had a very large coercivity.
Strain-tunable ferroelectricity and its control of Rashba effect in KTaO3
Authors: Tao L. L. , Wang J.
Published: December 2016

The effects of epitaxial strain on the ferroelectric, structural properties of KTaO3 are studied by means of first-principles calculations. We show that the ferroelectric polarization magnitude as well as the orientation can be tuned by an in-plane strain: the c-phase is energetically more stable than the aa-phase at a large compressive strain while a phase transition from c- to aa-phase is observed at a large tensile strain, owing to the significant polarization-strain coupling. More importantly, based on relativistic first-principles calculations, we demonstrate a large Rashba spin splitting in the strained KTaO3. Interestingly, the spin textures in momentum space can be controlled and switched via polarization switching. Our tight-binding analysis indicates that the combination of spin-orbit coupling and ferroelectric distortion plays a key role for the observed Rashba spin splitting. Our results present some fundamental understanding of the interplay between Rashba effect and ferroelectricity in oxides and open avenues for nonvolatile spintronic device applications.
Field-effect transistors with vacuum-deposited organic-inorganic perovskite films as semiconductor channels
Authors: Matsushima Toshinori , Yasuda Takeshi , Fujita Katsuhiko , Adachi Chihaya
Published: December 2016

Films of the organic-inorganic layered perovskite (C6H5C2H4NH3)2SnI4 were vacuum-deposited on substrates heated at various temperatures (Tsub) to investigate the influence of Tsub on their film quality and transistor performance (hole mobilities, threshold voltages, and current on/off ratios). Appropriate substrate heating at Tsub = 60 °C during vacuum deposition led to better-developed perovskite films with larger grains. These films exhibited the best transistor performance in comparison with films fabricated at the other Tsub. The transistor performance was further enhanced by reducing perovskite semiconductor thickness (t) because of a reduction of bulk resistance in a top-contact/bottom-gate transistor structure. By utilizing the optimized Tsub of 60 °C and t of 31 nm, we obtained the most improved hole mobility of 0.78 ± 0.24 cm2/V s, about 5000 times the hole mobilities of our initial transistors fabricated at Tsub = 24 °C and t = 50 nm.
Local conductance mapping of water-intercalated graphene on mica
Authors: Hwang Jin Heui , Lee Hyunsoo , Kwon Sangku , Jeong Jin Hyeok , Song Hee Chan , Choi Joong Il Jake , Park Jeong Young
Published: December 2016

We report that the conductance of graphene is influenced by intercalated water layers using current sensing atomic force microscopy (AFM). We obtained a confined water layer between chemical vapor deposition graphene and mica by transferring graphene onto mica in a liquid water bath. Atomic force microscopy topographic images confirm high coverage by a single water layer, and scanning tunneling microscopy (STM) verifies a clean surface without contamination by measuring the honeycomb lattice structure of the graphene. We show that the surface conductance is perturbed by the presence of a water layer between the graphene and mica, which is not found in the STM topographic image. We found that the graphene on the edge and at pinholes of the water layer exhibits lower conductance, compared with that of graphene on the water terrace. We attribute the perturbation of conductance to structural defects from the water film and a variation of interaction between the edge of the water and graphene.
Colossal negative thermal expansion with an extended temperature interval covering room temperature in fine-powdered Mn0.98CoGe
Authors: Lin Jianchao , Tong Peng , Zhang Kui , Tong Haiyun , Guo Xinge , Yang Cheng , Wu Ying , Wang Meng , Lin Shuai , Chen Li , Song Wenhai , Sun Yuping
Published: December 2016

MnM′X (M′ = Co, Ni; X = Ge, Si, etc.) alloys usually present a large volumetric change during the Martensitic (MA) transformation. This offers a great opportunity for exploring new negative thermal expansion (NTE) materials if the temperature interval of NTE can be extended. Here, we report colossal NTE in fine-powdered Mn0.98CoGe prepared by repeated thermal cycling (TC) through the MA transition or ball milling. Both treatments can expand the MA transformation, and thus broaden the NTE temperature window (ΔT). For the powders that have gone through TC for ten times, ΔT reaches 90 K (309 K–399 K), and the linear expansion coefficient (αL) is about −141 ppm/K, which rank among the largest values of colossal NTE materials. The difference between two kinds of treatments and the possible mechanisms of the extended MA transformation window are discussed based on the introduced strain.
Tunable, omnidirectional structural color on reflection based on metal-SiOx-metal structure
Authors: Yang Chenying , Mao Kening , Shen Weidong , Fang Bo , Fang Xu , Zhang Xing , Zhang Yueguang , Liu Xu
Published: December 2016

An omnidirectional structural color based on the metal-SiOx-metal stack structure is proposed, which can present the same perceived color for a broad range of incidence angles. The tunable structural color can be obtained with adjustable intermediate dielectric layer by simply adjusting the deposition condition, especially the oxygen flow rate during the deposition processes. The resonance condition can be satisfied across the whole visible light region with this special dielectric. The strong absorption caused by the resonance within the metal-SiOx-metal structure accounts for the efficient spectral filtering feature, and the constant phase shift within the dielectric layer leads to angle insensitivity of this color filter. This simple color tuning method for omnidirectional structural colors can have a great potential in various applications such as displaying, imaging, colorful decoration, anti-counterfeiting and so forth.