bluuebunny/crossref_metadata_2025 huggingface dataset:
A DFT-D study of hydrogen adsorption on functionalized graphene
Authors: Seydou Mahamadou , Lassoued Karima , Tielens Frederik , Maurel François , Raouafi Faycal , Diawara Boubakar
Published: January 2015

In this paper, we use density functional theory with dispersion correction functional (DFT-D) as implemented in the Vienna ab initio simulation package in order to investigate hydrogen adsorption on graphane (GH) and fluorographene (GF).
Ultrafast spray pyrolysis fabrication of a nanophase ZnMn2O4anode towards high-performance Li-ion batteries
Authors: Zhang Longhai , Zhu Siqi , Cao Hui , Pang Gang , Lin Jingdong , Hou Linrui , Yuan Changzhou
Published: January 2015

Nanophase ZnMn2O4was ultrafast fabricatedviaa green spray pyrolysis strategy, and exhibited large initial specific discharge capacity, good rate capability, and excellent cycling stability at 1 C rate.
Application of basic isoreticular nanoporous metal–organic framework: IRMOF-3 as a suitable and efficient catalyst for the synthesis of chalcone
Authors: Wu Songhai , Ma Xin , Ran Jingyu , Zhang Yanfei , Qin Fengxiang , Liu Yong
Published: January 2015

IRMOF-3 is found to be an effective, reusable and heterogeneous catalyst for the synthesis of chalcones through Claisen–Schmidt reaction.
Partially crystallized TiO2 for microwave absorption
Authors: Dong Junye , Ullal Rohan , Han Jie , Wei Shanghai , Ouyang Xin , Dong Junzhe , Gao Wei
Published: January 2015

Amorphous TiO2 synthesized via Ti anodization is partially crystallized and displays strong microwave absorption ability. Interfacial electric field forms at the boundary of crystalline–amorphous phases due to the uneven oxygen-vacancy distributions in the two phases, amplifying the microwave absorption.
Naturally derived porous carbon with selective metal- and/or nitrogen-doping for efficient CO2 capture and oxygen reduction
Authors: Zhu Bingjun , Qiu Kaipei , Shang Congxiao , Guo Zhengxiao
Published: January 2015

A low-cost, high-performance “green carbon”, derived from London plane leaves, exhibits excellent sorption capacity for CO2 capture and electro-catalytic capability for oxygen reduction, due to naturally doped nitrogen and metallic elements inherited from biomass.
Enhanced visible light photocatalytic properties of TiO2 thin films on the textured multicrystalline silicon wafers
Authors: Li Jianjiang , Zhang Jingjiao , Fang Liang , Wang Junling , Shen Mingrong , Su Xiaodong
Published: January 2015

TiO2 thin films were grown on solar-grade (SoG) multicrystalline silicon (mc-Si) wafers to improve the visible light photocatalytic property.
Recent advances of Li4Ti5O12 as a promising next generation anode material for high power lithium-ion batteries
Authors: Yi Ting-Feng , Yang Shuang-Yuan , Xie Ying
Published: January 2015

This review highlights breakthroughs in the past decade in the synthesis and the modification of both the chemistry and morphology of Li4Ti5O12.
Controlled release and targeted delivery to cancer cells of doxorubicin from polysaccharide-functionalised single-walled carbon nanotubes
Authors: Mo Yunfei , Wang Haowen , Liu Jianghui , Lan Yong , Guo Rui , Zhang Yi , Xue Wei , Zhang Yuanming
Published: January 2015

Carboxyl single-walled carbon nanotubes (SWNTs) were used to construct an innovative drug delivery system by modification with chitosan (CHI) to enhance water solubility and biocompatibility.
Catalytically induced nanographitic phase by a platinum-ion implantation/annealing process to improve the field electron emission properties of ultrananocrystalline diamond films
Authors: Sankaran Kamatchi Jothiramalingam , Kalpataru Panda , Balakrishnan Sundaravel , Tai Nyan-Hwa , Lin I.-Nan
Published: January 2015

Pt nanoparticles catalytically induce nanographitic phases in grain boundaries achieving highly conducting ultrananocrystalline diamond films with enhanced EFE properties.
Photostable trifluoromethyl-substituted platinum(ii) emitters for continuous monitoring of molecular oxygen
Authors: Xing Yang , Liu Chun , Song Xinlong , Li Jiuyan
Published: January 2015

Cyclometalated platinum(ii) complexes with a trifluoromethyl substituent are sensitive to the concentration of molecular oxygen corresponding to potential oxygen-sensitive probes.
Spin-crossover, mesomorphic and thermoelectrical properties of cobalt(ii) complexes with alkylated N3-Schiff bases
Authors: Abdullah Norbani , Noor Nur Linahafizza Md , Nordin Abdul Rahman , Halcrow Malcolm A. , MacFarlane Douglas R. , Lazar Manoj A. , Pringle Jennifer M. , Bruce Duncan W. , Donnio Bertrand , Heinrich Benoît
Published: January 2015

Cobalt complexes of alkylated N3-Schiff bases show mesomorphic and spin-crossover behaviours, and high Se values.
Bioconjugation-induced ionic current rectification in aptamer-modified single cylindrical nanopores
Authors: Ali Mubarak , Nasir Saima , Ensinger Wolfgang
Published: January 2015

Aptamer–protein conjugation inside a confined environment generates a non-homogeneous fixed charge distribution, leading to the emergence of ionic current rectification characteristics in single cylindrical nanopores.
Lanthano phosphomolybdate-decorated silica nanoparticles: novel hybrid materials with photochromic properties
Authors: Pinto Tânia V. , Fernandes Diana M. , Pereira Clara , Guedes Alexandra , Blanco Ginesa , Pintado Jose M. , Pereira Manuel F. R. , Freire Cristina
Published: January 2015

Novel hybrid nanomaterials prepared through the immobilization of phosphomolybdates onto functional silica nanoparticles revealed promising photochromic properties under UV irradiation.
Role of Cys3602 in the function and regulation of the cardiac ryanodine receptor
Authors: Mi Tao , Xiao Zhichao , Guo Wenting , Tang Yijun , Hiess Florian , Xiao Jianmin , Wang Yundi , Zhang Joe Z. , Zhang Lin , Wang Ruiwu , Jones Peter P. , Chen S. R. Wayne
Published: January 2015

The cardiac Ca2+ release channel [ryanodine receptor type 2 (RyR2)] is modulated by thiol reactive agents, but the molecular basis of RyR2 modulation by thiol reagents is poorly understood. Cys3635 in the skeletal muscle RyR1 is one of the most hyper-reactive thiols and is important for the redox and calmodulin (CaM) regulation of the RyR1 channel. However, little is known about the role of the corresponding cysteine residue in RyR2 (Cys3602) in the function and regulation of the RyR2 channel. In the present study, we assessed the impact of mutating Cys3602 (C3602A) on store overload-induced Ca2+ release (SOICR) and the regulation of RyR2 by thiol reagents and CaM. We found that the C3602A mutation suppressed SOICR by raising the activation threshold and delayed the termination of Ca2+ release by reducing the termination threshold. As a result, C3602A markedly increased the fractional Ca2+ release. Furthermore, the C3602A mutation diminished the inhibitory effect of N-ethylmaleimide on Ca2+ release, but it had no effect on the stimulatory action of 4,4′-dithiodipyridine (DTDP) on Ca2+ release. In addition, Cys3602 mutations (C3602A or C3602R) did not abolish the effect of CaM on Ca2+-release termination. Therefore, RyR2–Cys3602 is a major site mediating the action of thiol alkylating agent N-ethylmaleimide, but not the action of the oxidant DTDP. Our data also indicate that residue Cys3602 plays an important role in the activation and termination of Ca2+ release, but it is not essential for CaM regulation of RyR2.
Smad7 regulates compensatory hepatocyte proliferation in damaged mouse liver and positively relates to better clinical outcome in human hepatocellular carcinoma
Authors: Feng Teng , Dzieran Johanna , Gu Xing , Marhenke Silke , Vogel Arndt , Machida Keigo , Weiss Thomas S. , Ruemmele Petra , Kollmar Otto , Hoffmann Patrick , Grässer Friedrich , Allgayer Heike , Fabian Jasmin , Weng Hong Lei , Teufel Andreas , Maass Thorsten , Meyer Christoph , Lehmann Ulrich , Zhu Cheng , Mertens Peter R. , Gao Chun Fang , Dooley Steven , Meindl-Beinker Nadja M.
Published: January 2015

Transforming growth factor β (TGF-β) is cytostatic towards damage-induced compensatory hepatocyte proliferation. This function is frequently lost during hepatocarcinogenesis, thereby switching the TGF-β role from tumour suppressor to tumour promoter. In the present study, we investigate Smad7 overexpression as a pathophysiological mechanism for cytostatic TGF-β inhibition in liver damage and hepatocellular carcinoma (HCC). Transgenic hepatocyte-specific Smad7 overexpression in damaged liver of fumarylacetoacetate hydrolase (FAH)-deficient mice increased compensatory proliferation of hepatocytes. Similarly, modulation of Smad7 expression changed the sensitivity of Huh7, FLC-4, HLE and HLF HCC cell lines for cytostatic TGF-β effects. In our cohort of 140 HCC patients, Smad7 transcripts were elevated in 41.4% of HCC samples as compared with adjacent tissue, with significant positive correlation to tumour size, whereas low Smad7 expression levels were significantly associated with worse clinical outcome. Univariate and multivariate analyses indicate Smad7 levels as an independent predictor for overall (P<0.001) and disease-free survival (P=0.0123). Delineating a mechanism for Smad7 transcriptional regulation in HCC, we identified cold-shock Y-box protein-1 (YB-1), a multifunctional transcription factor. YB-1 RNAi reduced TGF-β-induced and endogenous Smad7 expression in Huh7 and FLC-4 cells respectively. YB-1 and Smad7 mRNA expression levels correlated positively (P<0.0001). Furthermore, nuclear co-localization of Smad7 and YB-1 proteins was present in cancer cells of those patients. In summary, the present study provides a YB-1/Smad7-mediated mechanism that interferes with anti-proliferative/tumour-suppressive TGF-β actions in a subgroup of HCC cells that may facilitate aspects of tumour progression.
Wide‐range adjustable speed control method for dual‐motor drive systems
Authors: Tseng Shao‐Kai , Tseng Chih‐Chien , Liu Tian‐Hua , Chen Jui‐Ling
Published: January 2015

This study proposes a new control method for a dual‐motor drive system to share its output torque and extend its operating speed range. When the drive system is operated below the rated speed, the dual motors are operated in parallel to share the total output torque. By using the proposed parallel dual‐motor, the efficiency of the whole drive system can be effectively increased. On the other hand, when the drive system is operated beyond the rated speed, one motor is operated at a standstill and its stator inductances are used as three‐phase boost inductances. In addition, an interleave control algorithm is used for the boost converter to reduce the input current ripples. The other motor is used as a driving motor fed by the boost converter. As a result, an extended speed, reaching twice the rated speed range with a near constant torque, is obtained. Several experimental results are included to evaluate the theoretical analysis. This study proposes a new control method for the dual‐motor drive system, which can be applied to the electric drive systems in the industrial applications.
Phase‐shift control and harmonics elimination for H‐bridge Z‐source inverter
Authors: Pilehvar Mohsen Shid , Mardaneh Mohammad
Published: January 2015

Phase‐shift control is a common approach to voltage control of traditional H‐bridge inverters, but this method has not been used to voltage control of H‐bridge Z‐source inverter (ZSI) so far. This study proposes a new phase‐shift control method for H‐bridge ZSI, which its main difference with phase‐shift control of traditional H‐bridge inverters is existence of four shoot‐through states (short circuit of the H‐bridge) in each switching cycle. One of the advantages of the proposed method is simultaneous elimination of several harmonics by choosing the appropriate switching angles. Moreover, by using this phase‐shift control method, the amplitude of low‐order harmonics for many values of switching angles is less than the amplitude of low‐order harmonics in traditional H‐bridge voltage source inverter (VSI). Total harmonic distortion and distortion factor, as two important indexes for quantifying the merits of the proposed method, are calculated and compared with their values in traditional H‐bridge VSI. A detailed description of suggested method and comparison with the traditional method are presented in this study. Simulation and experimental results are also given to demonstrate the new features of the proposed method.
Wetting behavior of nonpolar nanotubes in simple dipolar liquids for varying nanotube diameter and solute-solvent interactions
Authors: Rana Malay Kumar , Chandra Amalendu
Published: January 2015

Atomistic simulations of model nonpolar nanotubes in a Stockmayer liquid are carried out for varying nanotube diameter and nanotube-solvent interactions to investigate solvophobic interactions in generic dipolar solvents. We have considered model armchair type single-walled nonpolar nanotubes with increasing radii from (5,5) to (12,12). The interactions between solute and solvent molecules are modeled by the well-known Lennard-Jones and repulsive Weeks-Chandler-Andersen potentials. We have investigated the density profiles and microscopic arrangement of Stockmayer molecules, orientational profiles of their dipole vectors, time dependence of their occupation, and also the translational and rotational motion of solvent molecules in confined environments of the cylindrical nanopores and also in their external peripheral regions. The present results of structural and dynamical properties of Stockmayer molecules inside and near atomistically rough nonpolar surfaces including their wetting and dewetting behavior for varying interactions provide a more generic picture of solvophobic effects experienced by simple dipolar liquids without any specific interactions such as hydrogen bonds.
Interaction of the NO 3pπ (C 2Π) Rydberg state with RG (RG = Ne, Kr, and Xe): Potential energy surfaces and spectroscopy
Authors: Ershova Olga V. , Kłos Jacek , Besley Nicholas A. , Wright Timothy G.
Published: January 2015

We present new potential energy surfaces for the interaction of NO(C 2Π) with each of Ne, Kr, and Xe. The potential energy surfaces have been calculated using second order Møller-Plesset perturbation theory, exploiting a procedure to converge the reference Hartree-Fock wavefunction for the excited states: the maximum overlap method. The bound rovibrational states obtained from the surfaces are used to simulate the electronic spectra and their appearance is in good agreement with available (2+1) REMPI spectra. We discuss the assignment and appearance of these spectra, comparing to that of NO-Ar.
Adhesion of nanoparticles to polymer brushes studied with the ghost tweezers method
Authors: Cheng Jianli , Vishnyakov Aleksey , Neimark Alexander V.
Published: January 2015

Mechanisms of interactions between nanoparticles (NPs) and polymer brushes (PBs) are explored using dissipative particle dynamics simulations and an original “ghost tweezers” method that emulates lab experiments performed with optical or magnetic tweezers. The ghost tweezers method is employed to calculate the free energy of adhesion. Ghost tweezers represents a virtual harmonic potential, which tethers NP with a spring to a given anchor point. The average spring force represents the effective force of NP-PB interaction as a function of the NP coordinate. The free energy landscape of NP-PB interactions is calculated as the mechanical work needed to transfer NP from the solvent bulk to a particular distance from the substrate surface. With this technique, we explore the adhesion of bare and ligand-functionalized spherical NPs to polyisoprene natural rubber brush in acetone-benzene binary solvent. We examine two basic mechanisms of NP-PB interactions, NP adhesion at PB exterior and NP immersion into PB, which are governed by interplay between entropic repulsive forces and enthalpic attractive forces caused by polymer adsorption at the NP surface and ligand adsorption at the substrate. The relative free energies of the equilibrium adhesion states and the potential barriers separating these states are calculated at varying grafting density, NP size, and solvent composition.
Effect of gold subsurface layer on the surface activity and segregation in Pt/Au/Pt3M (where M = 3d transition metals) alloy catalyst from first-principles
Authors: Kim Chang-Eun , Lim Dong-Hee , Jang Jong Hyun , Kim Hyoung Juhn , Yoon Sung Pil , Han Jonghee , Nam Suk Woo , Hong Seong-Ahn , Soon Aloysius , Ham Hyung Chul
Published: January 2015

The effect of a subsurface hetero layer (thin gold) on the activity and stability of Pt skin surface in Pt3M system (M = 3d transition metals) is investigated using the spin-polarized density functional theory calculation. First, we find that the heterometallic interaction between the Pt skin surface and the gold subsurface in Pt/Au/Pt3M system can significantly modify the electronic structure of the Pt skin surface. In particular, the local density of states projected onto the d states of Pt skin surface near the Fermi level is drastically decreased compared to the Pt/Pt/Pt3M case, leading to the reduction of the oxygen binding strength of the Pt skin surface. This modification is related to the increase of surface charge polarization of outmost Pt skin atoms by the electron transfer from the gold subsurface atoms. Furthermore, a subsurface gold layer is found to cast the energetic barrier to the segregation loss of metal atoms from the bulk (inside) region, which can enhance the durability of Pt3M based catalytic system in oxygen reduction condition at fuel cell devices. This study highlights that a gold subsurface hetero layer can provide an additional mean to tune the surface activity toward oxygen species and in turn the oxygen reduction reaction, where the utilization of geometric strain already reaches its practical limit.
High quality broadband spatial reflections of slow Rayleigh surface acoustic waves modulated by a graded grooved surface
Authors: Xu Yanlong , Peng Pai
Published: January 2015

We report high quality broadband spatial reflections of Rayleigh surface acoustic waves (SAWs) through a graded grooved surface. High quality means that no wave is allowed to transmit and the incident wave is nearly all reflected to the input side. The graded grooved surface is structured by drilling one dimensional array of graded grooves with increased depths on a flat surface. We investigate SAW dispersion relations, wave field distribution at several typical SAW wavelengths, and time evolution of a Gaussian pulse through the graded grooved surface. Results show that the input broadband Rayleigh SAWs can be slowed, spatially enhanced and stopped, and finally reflected to the input side. The study suggests that engraving the flat surface can be used as an efficient and economical way to manipulate Rayleigh SAWs, which has potential application in novel SAW devices such as filters, reflectors, sensors, energy harvesters, and diodes.
Characterization of one-dimensional molecular chains of 4,4′-biphenyl diisocyanide on Au(111) by scanning tunneling microscopy
Authors: Zhou Jing , Li Yan , Zahl Percy , Sutter Peter , Stacchiola Dario J. , White Michael G.
Published: January 2015

The morphology and electronic structure of vapor deposited 4,4′-biphenyldiisocyanide (BPDI) on a Au(111) surface were investigated using variable-temperature scanning tunneling microscopy. When deposited at room temperature, BPDI molecules form one-dimensional molecular chains similar to that recently observed for the structurally related 1,4-phenyl diisocyanide (PDI). Compared to PDI, the longer periodicity for the BPDI molecular chains is consistent with the addition of a second phenyl ring and supports a structural model in which the BPDI molecules lie parallel to the surface and interconnected by Au-adatoms. The molecular chains are mostly aligned along the 11̄0 direction of the Au(111) substrate, but exhibit frequent changes in angle that are consistent with directions between fcc and hcp three-fold hollow sites. Dispersion-corrected density functional theory calculations for one-dimensional chains of BPDI molecules bound end-to-end via their isocyanide groups to Au-adatoms reproduce the observed periodicity of the chains and show that this morphology is energetically favored over upright binding with one free —NC group. The spatially resolved conductance (dI/dV) map for BPDI on Au(111) exhibits a feature centered at −0.67 eV below the Fermi level which are delocalized along the chain with maxima at the Au-adatom and biphenyl positions. This occupied resonant feature is close to that previously observed for the PDI in both photoemission and conductance measurements and is attributed to an occupied interfacial state resulting from BPDI-Au interactions.
Classical integrability for beta-ensembles and general Fokker-Planck equations
Authors: Rumanov Igor
Published: January 2015

Beta-ensembles of random matrices are naturally considered as quantum integrable systems, in particular, due to their relation with conformal field theory, and more recently appeared connection with quantized Painlevé Hamiltonians. Here, we demonstrate that, at least for even integer beta, these systems are classically integrable, e.g., there are Lax pairs associated with them, which we explicitly construct. To come to the result, we show that a solution of every Fokker-Planck equation in one space (and one time) dimensions can be considered as a component of an eigenvector of a Lax pair. The explicit finding of the Lax pair depends on finding a solution of a governing system–a closed system of two nonlinear partial differential equations (PDEs) of hydrodynamic type. This result suggests that there must be a solution for all values of beta. We find the solution of this system for even integer beta in the particular case of quantum Painlevé II related to the soft edge of the spectrum for beta-ensembles. The solution is given in terms of Calogero system of β/2 particles in an additional time-dependent potential. Thus, we find another situation where quantum integrability is reduced to classical integrability.
Time-dependent non-equilibrium dielectric response in QM/continuum approaches
Authors: Ding Feizhi , Lingerfelt David B. , Mennucci Benedetta , Li Xiaosong
Published: January 2015

The Polarizable Continuum Models (PCMs) are some of the most inexpensive yet successful methods for including the effects of solvation in quantum-mechanical calculations of molecular systems. However, when applied to the electronic excitation process, these methods are restricted to dichotomously assuming either that the solvent has completely equilibrated with the excited solute charge density (infinite-time limit), or that it retains the configuration that was in equilibrium with the solute prior to excitation (zero-time limit). This renders the traditional PCMs inappropriate for resolving time-dependent solvent effects on non-equilibrium solute electron dynamics like those implicated in the instants following photoexcitation of a solvated molecular species. To extend the existing methods to this non-equilibrium regime, we herein derive and apply a new formalism for a general time-dependent continuum embedding method designed to be propagated alongside the solute’s electronic degrees of freedom in the time domain. Given the frequency-dependent dielectric constant of the solvent, an equation of motion for the dielectric polarization is derived within the PCM framework and numerically integrated simultaneously with the time-dependent Hartree fock/density functional theory equations. Results for small molecular systems show the anticipated dipole quenching and electronic state dephasing/relaxation resulting from out-of-phase charge fluctuations in the dielectric and embedded quantum system.
Generalized nonlinear oscillators with quasi-harmonic behaviour: Classical solutions
Authors: Quesne C.
Published: January 2015

The classical nonlinear oscillator, proposed by Mathews and Lakshmanan [Q. Appl. Math. 32, 215 (1974)] and including a position-dependent mass in the kinetic energy term, is generalized in two different ways by adding an extra term to the potential. The solutions of the Euler-Lagrange equation are shown to exhibit richer behaviour patterns than those of the original nonlinear oscillator.
Anomalous hole injection deterioration of organic light-emitting diodes with a manganese phthalocyanine layer
Authors: Lee Hyunbok , Lee Jeihyun , Yi Yeonjin , Cho Sang Wan , Kim Jeong Won
Published: January 2015

Metal phthalocyanines (MPcs) are well known as an efficient hole injection layer (HIL) in organic devices. They possess a low ionization energy, and so the low-lying highest occupied molecular orbital (HOMO) gives a small hole injection barrier from an anode in organic light-emitting diodes. However, in this study, we show that the hole injection characteristics of MPc are not only determined by the HOMO position but also significantly affected by the wave function distribution of the HOMO. We show that even with the HOMO level of a manganese phthalocyanine (MnPc) HIL located between the Fermi level of an indium tin oxide anode and the HOMO level of a N,N′-bis(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine hole transport layer the device performance with the MnPc HIL is rather deteriorated. This anomalous hole injection deterioration is due to the contracted HOMO wave function, which leads to small intermolecular electronic coupling. The origin of this contraction is the significant contribution of the Mn d-orbital to the MnPc HOMO.
Density and mobility effects of the majority carriers in organic semiconductors under light excitation
Authors: Vagenas N. , Giannopoulou A. , Kounavis P.
Published: January 2015

This study demonstrates that the effect of light excitation on the density and the mobility of the majority carriers can be explored in organic semiconductors by modulated photocurrent spectroscopy. The spectra of phase and amplitude of the modulated photocurrent of pentacene films indicate a significant increase in the density of the photogenerated mobile holes (majority carriers). This increase is accompanied by a comparatively much smaller increase of the steady state photocurrent response which can be reconciled with a decrease in the mobility (μ) of holes. The decrease of μ is supported from an unusual increase of the Y/μ ratio of the out-of-phase modulated photocurrent (Y) signal to the mobility under light excitation. It is proposed that the mobile holes, which are generated from the dissociation of the light-created excitons more likely near the pentacene-substrate interface by electron trapping, populate grain boundaries charging them and producing a downward band bending. As a result, potential energy barriers are build up which limit the transport of holes interacting through trapping-detrapping with deep partially occupied traps in the charged grain boundaries. On the other hand, the transport of holes interacting through trapping-detrapping with empty traps is found unaffected.
Experimental evidence of very long intrinsic phonon mean free path along the c-axis of graphite
Authors: Fu Qiang , Yang Juekuan , Chen Yunfei , Li Deyu , Xu Dongyan
Published: January 2015

We report on experimental studies of the average phonon mean free path in the c-axis direction of graphite. Through systematically measuring the cross-plane thermal conductivity of thin graphite flakes with thickness ranging from 24 nm to 714 nm via a differential three omega method, we demonstrate that the average phonon mean free path in the c-axis direction of graphite is around 200 nm at room temperature, much larger than the commonly believed value of just a few nanometers. This study provides direct experimental evidence for the recently projected very long phonon mean free path along the c-axis of graphite.
Complex refractive index tunability of graphene at 1550 nm wavelength
Authors: Xu F. , Das S. , Gong Y. , Liu Q. , Chien H.-C. , Chiu H.-Y. , Wu J. , Hui R.
Published: January 2015

The complex refractive index of graphene fabricated using chemical vapor deposition is characterized at 1550 nm wavelength through the reflectivity measurement on a SiO2/Si substrate. The observed tunability of the complex reflective index as the function of gate electric voltage is in agreement with the prediction based on the Kubo formula.
Coherent thermal emission near 10.6 μm mediated by localized phonon-polariton modes in microparticle arrays
Authors: D'Aguanno Giuseppe
Published: January 2015

I study the thermal emission properties of periodic multilayer arrays of subwavelength particles made of silicon carbide embedded in a zinc selenide host medium. A unique interplay between the intrinsic phonon-polariton resonance of the single particle and the field thermally emitted from the different arrays of particles gives rise to a comb of highly coherent absorption/emissivity lines around 10.6 μm, ensuing ideal conditions to achieve long-wave infrared coherent sources.
Wall charging of a helicon antenna wrapped plasma filled dielectric tube
Authors: Barada Kshitish K. , Chattopadhyay P. K. , Ghosh J. , Saxena Y. C. , Bora D.
Published: January 2015

Dielectric wall charging of a cylindrical glass wall surrounded by a helicon antenna of 18 cm length is measured in a linear helicon plasma device with a diverging magnetic field. The ions because of their lesser mobility do not respond to the high frequency electric field and the electrons charge the wall to a negative DC potential also known as the DC self-bias. The wall potential in this device is characterized for different neutral pressure, magnetic field, and radio frequency (RF) power. Axial variation of wall potential shows higher self-bias potentials near the antenna rings. Ion magnetization in the source chamber increases both wall charging and plasma potential of the source due to confinement.
Reference-plane-invariant and thickness- and branch-index-independent retrieval of effective parameters of bi-anisotropic metamaterials
Authors: Hasar U. C. , Barroso J. J. , Karacali T. , Ertugrul M.
Published: January 2015

We propose a retrieval method for reference-plane-invariant electromagnetic parameter measurements of bi-anisotropic metamaterial slabs without resorting to accurate information of the slab thickness and the branch index. To extract reference-plane distances, the slab thickness, and the branch index, we first approximate wave impedances and refractive index away from the slab resonance frequency and then use scattering parameters to calculate the refractive index and the branch index. Once these quantities are determined, they are used as inputs for the retrieval of electromagnetic properties of slabs over the whole band. Different approximations for refractive index and wave impedances are applied to demonstrate the applicability and accuracy of our proposed method. We tested our method for electromagnetic parameter extraction of bi-anisotropic split-ring-resonator and Omega-shaped MM slabs with different number of unit cells. From our analysis, we note that inaccurate information of reference-plane distances, the slab length, and the branch index not only changes the amplitude but also shifts the response of the electromagnetic properties. We show that the presented method can be applied for accurate electromagnetic parameter extraction of bi-anisotropic MM slabs.
Rigorous theory of molecular orientational nonlinear optics
Authors: Kwak Chong Hoon , Kim Gun Yeup
Published: January 2015

Classical statistical mechanics of the molecular optics theory proposed by Buckingham [A. D. Buckingham and J. A. Pople, Proc. Phys. Soc. A 68, 905 (1955)] has been extended to describe the field induced molecular orientational polarization effects on nonlinear optics. In this paper, we present the generalized molecular orientational nonlinear optical processes (MONLO) through the calculation of the classical orientational averaging using the Boltzmann type time-averaged orientational interaction energy in the randomly oriented molecular system under the influence of applied electric fields. The focal points of the calculation are (1) the derivation of rigorous tensorial components of the effective molecular hyperpolarizabilities, (2) the molecular orientational polarizations and the electronic polarizations including the well-known third-order dc polarization, dc electric field induced Kerr effect (dc Kerr effect), optical Kerr effect (OKE), dc electric field induced second harmonic generation (EFISH), degenerate four wave mixing (DFWM) and third harmonic generation (THG). We also present some of the new predictive MONLO processes. For second-order MONLO, second-order optical rectification (SOR), Pockels effect and difference frequency generation (DFG) are described in terms of the anisotropic coefficients of first hyperpolarizability. And, for third-order MONLO, third-order optical rectification (TOR), dc electric field induced difference frequency generation (EFIDFG) and pump-probe transmission are presented.
Advance care planning in palliative care: a national survey of health professionals and service managers
Authors: Sellars Marcus , Silvester William , Masso Malcolm , Johnson Claire E.
Published: January 2015

Objective To identify the attitudes, knowledge and practices regarding advance care planning (ACP) in palliative care. Methods A nationwide online survey was distributed to Australian palliative care services associated with the Palliative Care Outcomes Collaboration (n = 105). Seventy-three health professionals (HPs) and 59 service managers completed the survey. Results Regarding ACP, 51% of service managers reported relevant policies and procedures were in place in their service and 44% included ACP in job descriptions. Most HPs were confident in undertaking ACP, including initiating discussions with patients and complying with documents; however, only 44% reported receiving ACP specific training. Although 58% of HPs reported having conversations about ACP with more than 11 patients in the past 6 months, only 44% of managers report that it is offered to most patients. Thirty per cent of HPs were aware of others not adhering to patient wishes in the past 6 months and only 43% of HPs (and 37% of managers) believed ACP is done well within their service. Conclusions This first national survey examining ACP in palliative care services demonstrates there is a need to improve systems to support ACP and to understand circumstances in which ACP wishes are not followed. What is known about the topic? ACP is increasingly recognised as an important part of care of people in hospital and community settings. However, currently there is no empirical evidence about the national uptake and quality of ACP in palliative care settings specifically. What does this paper add? This nationwide survey shows improvements on past small-scale research showing that ACP is supported by palliative care health professionals; however, the organisational ACP processes and systems did not support best practice in this regard. What are the implications for practitioners? Palliative care organisations should incorporate ACP systems (including greater access to ACP policies and guidelines) that support health professionals to complete ACP with clients who want to. Greater access to support, such as ACP training and resources, would assist with development of ACP documentation and adherence.
Increasing trends of syphilis among men who have sex with men in high income countries
Authors: Read Phillip , Fairley Christopher K. , Chow Eric P. F.
Published: January 2015

Background The epidemiology of syphilis, and therefore the population most impacted, differs between countries. Many developed countries have reported an increase in syphilis notifications among men who have sex with men (MSM) over the past decade. Methods: The rates of syphilis notifications between 2000 and 2013 in the 31 countries categorised by the Organisation for Economic Co-operation and Development (OECD) as high income were investigated. Data was taken primarily from published national surveillance reports, and a male-to-female ratio substantially greater than two in syphilis notifications was taken as a proxy for the infection being disproportionately diagnosed in MSM. Results: Data was available for 27 high-income countries. The male-to-female ratio exceeded two in all but four countries. This ratio significantly increased across all geographical areas over time. Globally, the male-to-female ratio in these countries increased from 4.1 in 2000 to 7.9 in 2013 (P = 0.001). Furthermore, the proportion of male cases reported as being among MSM increased over time from 26.8% to 55.0% between 2000 and 2013 (P < 0.001). Conclusion: These data show that in countries with high income, there is a near universal finding of increasing rates of syphilis in MSM. It is therefore clear that no country has identified an effective method to control syphilis in this population.
Asymmetrical effects of unilateral right or left amygdala damage on auditory cortical processing of vocal emotions
Authors: Frühholz Sascha , Hofstetter Christoph , Cristinzio Chiara , Saj Arnaud , Seeck Margitta , Vuilleumier Patrik , Grandjean Didier
Published: January 2015

Significance

The human voice is a major source for auditorily communicated social signals. The voice in general, and emotional cues embedded in vocalizations in particular, receive enhanced decoding in sensory cortical areas of the auditory system. This enhanced cortical decoding is assumed to be remotely driven by the amygdala, which responds to socially and emotionally meaningful stimuli. Here, we tested for the first time, to our knowledge, how damage to either the left or right amygdala impairs the cortical processing of human voices and vocal affect. Amygdala damage generally leads to reduced cortical processing of human voices in the hemisphere corresponding to the side of the amygdala damage, whereas only left amygdala damage impaired the cortical processing of vocal affect.
Pharmacological activation of myosin II paralogs to correct cell mechanics defects
Authors: Surcel Alexandra , Ng Win Pin , West-Foyle Hoku , Zhu Qingfeng , Ren Yixin , Avery Lindsay B. , Krenc Agata K. , Meyers David J. , Rock Ronald S. , Anders Robert A. , Freel Meyers Caren L. , Robinson Douglas N.
Published: January 2015

Significance

Despite the integral role of cell mechanics, efforts to target mechanics for drug development have lagged. Here, we present an approach to identifying small molecules capable of modulating mechanics. We characterize 4-hydroxyacetophenone (4-HAP), isolated as a breakdown product of a hit from our pilot screen of over 22,000 compounds. We show that 4-HAP specifically alters the localization of the mechanoenzyme myosin II, increasing the stiffness of cells. The effect of 4-HAP on myosin II, whose specificity we have defined, occurs across phylogeny. In particular, we have demonstrated 4-HAP’s ability to convert the mechanical profile of metastasis-derived pancreatic cancer cells toward a normal WT-like state. Invasion and migration of these cells, which are hallmarks of the invasive capacity of malignant lesions, are decreased by 4-HAP.
Selective inactivation of USP18 isopeptidase activity in vivo enhances ISG15 conjugation and viral resistance
Authors: Ketscher Lars , Hannß Ronny , Morales David J. , Basters Anja , Guerra Susana , Goldmann Tobias , Hausmann Annika , Prinz Marco , Naumann Ronald , Pekosz Andrew , Utermöhlen Olaf , Lenschow Deborah J. , Knobeloch Klaus-Peter
Published: January 2015

Significance

Viral infections still constitute a major health issue. Upon viral infection, interferon (IFN) elicits an antiviral response by activating multiple effector systems. The ubiquitin-like protein ISG15 is strongly induced by IFN and mediates its antiviral effect by being covalently conjugated to cellular and viral proteins. The protease USP18, which is also an important negative regulator of the IFN response, counteracts ISG15 conjugation. Within this study, we have generated knock-in mice expressing USP18, which selectively lacks protease activity. ISG15 modification was enhanced in these animals, but the IFN response was unaltered. This clearly shows that USP18 has enzymatic and nonenzymatic properties in vivo. Elevated ISGylation increased resistance to influenza B infections, qualifying USP18 protease inhibition as a potential antiviral strategy.
Identification of hydroxyapatite spherules provides new insight into subretinal pigment epithelial deposit formation in the aging eye
Authors: Thompson Richard B. , Reffatto Valentina , Bundy Jacob G. , Kortvely Elod , Flinn Jane M. , Lanzirotti Antonio , Jones Emrys A. , McPhail David S. , Fearn Sarah , Boldt Karsten , Ueffing Marius , Ratu Savanjeet Guy Singh , Pauleikhoff Laurenz , Bird Alan C. , Lengyel Imre
Published: January 2015

Significance

Proteins and lipids accumulating in deposits external to the retinal pigment epithelium (RPE) represent a barrier to metabolic exchange between the retina and the choroidal capillaries. With time, these deposits can lead to age-related macular degeneration (AMD), the most common cause of blindness in the elderly in the developed world. It remains unclear how sub-RPE deposits are initiated and grow to clinically relevant features. Using a combination of high-resolution analytical techniques, we found that tiny hydroxyapatite (bone mineral) spherules with cholesterol-containing cores are present in all examined sub-RPE deposits, providing a scaffold to which proteins adhere. If the spherules are important in initiating sub-RPE deposit formation, this finding may provide attractive new approaches for early identification and treatment of AMD.
Ghrelin receptor conformational dynamics regulate the transition from a preassembled to an active receptor:Gq complex
Authors: Damian Marjorie , Mary Sophie , Maingot Mathieu , M'Kadmi Céline , Gagne Didier , Leyris Jean-Philippe , Denoyelle Séverine , Gaibelet Gérald , Gavara Laurent , Garcia de Souza Costa Mauricio , Perahia David , Trinquet Eric , Mouillac Bernard , Galandrin Ségolène , Galès Céline , Fehrentz Jean-Alain , Floquet Nicolas , Martinez Jean , Marie Jacky , Banères Jean-Louis
Published: January 2015

Significance

G protein-coupled receptors (GPCRs), one of the largest cell surface receptor families, transmit their signals through the coupling of intracellular partners, such as the G proteins. Knowing how this coupling occurs is essential, because it governs the entire signaling process. To address this open question, we used a purified GPCR as a model to which we applied various state-of-the-art biochemical and biophysical approaches. By doing so, we provide direct experimental evidence of a signaling mechanism in which receptor conformational changes are directly linked to a rearrangement of a preassembled complex between the receptor and its cognate Gq protein. This sheds light on the way in which a GPCR interacts with G proteins to trigger signaling.
Microtubule-targeting agents augment the toxicity of DNA-damaging agents by disrupting intracellular trafficking of DNA repair proteins
Authors: Poruchynsky Marianne S. , Komlodi-Pasztor Edina , Trostel Shana , Wilkerson Julia , Regairaz Marie , Pommier Yves , Zhang Xu , Kumar Maity Tapan , Robey Robert , Burotto Mauricio , Sackett Dan , Guha Udayan , Fojo Antonio Tito
Published: January 2015

Significance

Drugs targeting microtubules are among the most active anticancer agents. In vitro and in preclinical models, these agents are said to interfere with mitosis. However human tumors divide too slowly for this paradigm to apply, evidenced by the failure of over a dozen well-designed antimitotic agents targeting the aurora kinases and kinesin spindle protein that had minimal antitumor activity but caused severe bone marrow suppression. We have proposed that microtubule-targeting agents interfere with the trafficking of critical proteins in interphase microtubules. If true, then one must identify critical proteins whose traffic on microtubules is impacted. We identify nine DNA repair proteins that traffic on microtubules, explaining why combinations of a microtubule-targeting agent and a DNA-damaging agent are frequently used in cancer therapy.
NAD kinase controls animal NADP biosynthesis and is modulated via evolutionarily divergent calmodulin-dependent mechanisms
Authors: Love Nick R. , Pollak Nadine , Dölle Christian , Niere Marc , Chen Yaoyao , Oliveri Paola , Amaya Enrique , Patel Sandip , Ziegler Mathias
Published: January 2015

Significance

Metabolism relies on a set of molecules that provide the chemical framework for all cellular activities. Among these molecules is NADP, a metabolite synthesized from vitamin B3 that is critical for basic metabolism, calcium signaling, and antiinflammatory processes. Despite NADP’s fundamental importance, very little is known about how animal cells regulate their NADP pool. This study shows that the enzyme NAD kinase is required for maintaining NADP levels in animals, is essential for embryonic development, and exhibits conserved regulatory mechanisms among evolutionarily diverse animals such as humans and sea urchins. Together, these results reveal new insights into why vitamin B3 is essential and how it is converted to NADP, and suggests new therapeutic avenues to improve human and animal metabolism.
Climate, vocal folds, and tonal languages: Connecting the physiological and geographic dots
Authors: Everett Caleb , Blasi Damián E. , Roberts Seán G.
Published: January 2015

Significance

The sound systems of human languages are not generally thought to be ecologically adaptive. We offer the most extensive evidence to date that such systems are in fact adaptive and can be influenced, at least in some respects, by climatic factors. Based on a survey of laryngology data demonstrating the deleterious effects of aridity on vocal cord movement, we predict that complex tone patterns should be relatively unlikely to evolve in arid climates. This prediction is supported by careful statistical sampling of climatic and phonological data pertaining to over half of the world’s languages. We conclude that human sound systems, like those of some other species, are influenced by environmental variables.
Flagellin-induced NLRC4 phosphorylation primes the inflammasome for activation by NAIP5
Authors: Matusiak Magdalena , Van Opdenbosch Nina , Vande Walle Lieselotte , Sirard Jean-Claude , Kanneganti Thirumala-Devi , Lamkanfi Mohamed
Published: January 2015

Significance

The Nlrc4 inflammasome is critical for clearing bacterial infections and activating mutations in NLRC4 cause autoinflammation in patients. Here, we used genetic and biochemical approaches to show that Nlrc4 Ser533 phosphorylation by flagellin of
Salmonella
Typhimurium and
Yersinia enterocolitica
occurs upstream of Naip5 detection of flagellin, ASC speck formation and caspase-1 activation. We further showed that
Helicobacter pylori
flagellin triggered robust Nlrc4 phosphorylation but failed to elicit caspase-1 activation in agreement with the differential requirement for the
Salmonella
Typhimurium flagellin D0 domain and the carboxy-terminus for Ser533 phosphorylation and caspase-1 activation, respectively. Collectively, this work suggests a biphasic mechanism for Nlrc4 inflammasome activation in which Ser533 phosphorylation primes Nlrc4 for subsequent activation by Naip5.
Purinosome formation as a function of the cell cycle
Authors: Chan Chung Yu , Zhao Hong , Pugh Raymond J. , Pedley Anthony M. , French Jarrod , Jones Sara A. , Zhuang Xiaowei , Jinnah Hyder , Huang Tony Jun , Benkovic Stephen J.
Published: January 2015

Significance

We show that the assembly/disassembly of the purinosome is cell cycle-dependent and correlates with cellular demands for purine biosynthesis encountered during the cell cycle. The number of purinosome-containing cells fluctuates: it peaks in G
1
phase in HeLa cells cultured under purine-depleted conditions, but remains high across G
1
, S, and G
2
/M phases in fibroblasts incapable of purine salvage owing to a deficiency in hypoxanthine-guanine phosphoribosyltransferase. Thus, purinosome function is a cellular biomarker for increased metabolic flux through the de novo purine biosynthetic pathway in response to cellular purine requirements.