bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyanamide is biosynthesized from l-canavanine in plants
Authors: Kamo Tsunashi , Sakurai Sakae , Yamanashi Tatsuya , Todoroki Yasushi
Published: May 2015

Cyanamide had long been recognized as a synthetic compound but more recently has been found as a natural product from several leguminous plants. This compound’s biosynthetic pathway, as yet unelaborated, has attracted attention because of its utility in many domains, such as agriculture, chemistry and medicine. We noticed that the distribution of L-canavanine in the plant kingdom appeared to include that of cyanamide and that the guanidino group structure in L-canavanine contained the cyanamide skeleton. Here, quantification of these compounds in Vicia species suggested that cyanamide was biosynthesized from L-canavanine. Subsequent experiments involving L-[guanidineimino-15N2]canavanine addition to young Vicia villosa seedlings resulted in significant incorporation of 15N-label into cyanamide, verifying its presumed biosynthetic pathway.
Tumor Invasion Optimization by Mesenchymal-Amoeboid Heterogeneity
Authors: Hecht Inbal , Bar-El Yasmin , Balmer Frederic , Natan Sari , Tsarfaty Ilan , Schweitzer Frank , Ben-Jacob Eshel
Published: May 2015

Metastasizing tumor cells migrate through the surrounding tissue and extracellular matrix toward the blood vessels, in order to colonize distant organs. They typically move in a dense environment, filled with other cells. In this work we study cooperative effects between neighboring cells of different types, migrating in a maze-like environment with directional cue. Using a computerized model, we measure the percentage of cells that arrive to the defined target, for different mesenchymal/amoeboid ratios. Wall degradation of mesenchymal cells, as well as motility of both types of cells, are coupled to metabolic energy-like resource level. We find that indirect cooperation emerges in mid-level energy, as mesenchymal cells create paths that are used by amoeboids. Therefore, we expect to see a small population of mesenchymals kept in a mostly-amoeboid population. We also study different forms of direct interaction between the cells and show that energy-dependent interaction strength is optimal for the migration of both mesenchymals and amoeboids. The obtained characteristics of cellular cluster size are in agreement with experimental results. We therefore predict that hybrid states, e.g. epithelial-mesenchymal, should be utilized as a stress-response mechanism.
The prognostic factors and multiple biomarkers in young patients with colorectal cancer
Authors: Wang Mo-Jin , Ping Jie , Li Yuan , Adell Gunnar , Arbman Gunnar , Nodin Bjorn , Meng Wen-Jian , Zhang Hong , Yu Yong-Yang , Wang Cun , Yang Lie , Zhou Zong-Guang , Sun Xiao-Feng
Published: May 2015

The incidence of colorectal cancer (CRC) in young patients (≤50 years of age) appears to be increasing. However, their clinicopathological characteristics and survival are controversial. Likewise, the biomarkers are unclear. We used the West China (2008-2013, China), Surveillance, Epidemiology and End Results program (1973-2011, United States) and Linköping Cancer (1972-2009, Sweden) databases to analyse clinicopathological characteristics, survival and multiple biomarkers of young CRC patients. A total of 509,934 CRC patients were included from the three databases. The young CRC patients tended to have more distal location tumours, fewer tumour numbers, later stage, more mucinous carcinoma and poorer differentiation. The cancer-specific survival (CSS) of young patients was significantly better. The PRL (HR = 12.341, 95% CI = 1.615-94.276, P = 0.010), RBM3 (HR = 0.093, 95% CI = 0.012-0.712, P = 0.018), Wrap53 (HR = 1.952, 95% CI = 0.452-6.342, P = 0.031), p53 (HR = 5.549, 95% CI = 1.176-26.178, P = 0.045) and DNA status (HR = 17.602, 95% CI = 2.551-121.448, P = 0.001) were associated with CSS of the young patients. In conclusion, this study suggests that young CRC patients present advanced tumours and more malignant pathological features, while they have a better prognosis. The PRL, RBM3, Wrap53, p53 and DNA status are potential prognostic biomarkers for the young CRC patients.
Preparation and evaluation of silica-based N-octylimidazolium stationary phases for HPLC
Authors: Tabar Heydar Kourosh , Naghdi Elahe , Sharifi Ali , Mirzaei Mojtaba , Ahmadi Seyyed Hamid
Published: May 2015

In this study, a new silica-based N-octylimidazolium bromide stationary phase, SilprOIm Br, has been synthesized, and then the stationary phase's anion has been converted to tetrafluoroborate to provide a new silica-based N-octylimidazolium tetrafluoroborate stationary phase, SilprOIm BF4.
Determination of o-phenylphenol and p-phenylphenol in aqueous samples using magnetic nanoparticles modified with cetyltrimethylammonium bromide by HPLC-FLD
Authors: Wei Han , Hang Yiping , Zhu Yudan , Song Chenglong
Published: May 2015

An obvious advantage of the method developed here is that magnetic adsorbents can be readily isolated from sample solutions with a magnet.
Simultaneous separation and preconcentration of lead and cadmium from water and vegetable samples using a diethylenetriamine-modified magnetic graphene oxide nanocomposite
Authors: Aliyari Elnaz , Alvand Mahrouz , Shemirani Farzaneh
Published: May 2015

A general procedure for the preconcentration/recovery of lead and cadmium ions using a diethylenetriamine-functionalized magnetic graphene oxide nanocomposite.
Mg2+-assisted low temperature reduction of alloyed AuPd/C: an efficient catalyst for hydrogen generation from formic acid at room temperature
Authors: Wu Shuang , Yang Fan , Wang Hao , Chen Rui , Sun Pingchuan , Chen Tiehong
Published: May 2015

An alloyed AuPd/C nanocatalyst was prepared via Mg2+-assisted low temperature reduction, and exhibited high activity in room temperature decomposition of formic acid.
Formation of porous SnS nanoplate networks from solution and their application in hybrid solar cells
Authors: Rath T. , Gury L. , Sánchez-Molina I. , Martínez L. , Haque S. A.
Published: May 2015

Herein, we present a facile solution-based route towards nanostructured, hybrid absorber layers based on tin mono-sulfide (SnS), an emerging, non-toxic absorber material for low-cost and large-scale PV applications.
Structural differences between the active sites of the Ni-A and Ni-B states of the [NiFe] hydrogenase: an approach by quantum chemistry and single crystal ENDOR spectroscopy
Authors: Barilone Jessica L. , Ogata Hideaki , Lubitz Wolfgang , van Gastel Maurice
Published: May 2015

Combined methods of theory and spectroscopy have been used to determine that the Ni-A and Ni-B states in [NiFe] hydrogenase are constitutional isomers.
Colloidal properties and behaviors of 3 nm primary particles of detonation nanodiamonds in aqueous media
Authors: Mchedlov-Petrossyan N. O. , Kamneva N. N. , Marynin A. I. , Kryshtal A. P. , Ōsawa E.
Published: May 2015

The nanodiamond species coagulate in line with the Schulze–Hardy rule. Application of indicators allows evaluating the positive interfacial electrical potential. The increase in size on dilution from 5.00% up to 0.01% is explained in terms of the periodic colloidal structures.
Inclusion of push–pull N-methylpyridinium salts within surfactant hydrogels: is their excited state intramolecular charge transfer mediated by twisting?
Authors: Cesaretti A. , Carlotti B. , Germani R. , Spalletti A. , Elisei F.
Published: May 2015

By confining two push–pull N-methylpyridinium derivatives within the rigid domains of surfactant hydrogels, the twisted nature of their intramolecular charge transfer state (formed in water upon excitation) was unravelled.
Ultrafast charge carrier relaxation and charge transfer processes in CdS/CdTe thin films
Authors: Pandit Bill , Dharmadasa Ruvini , Dharmadasa I. M. , Druffel Thad , Liu Jinjun
Published: May 2015

Charge transfer processes in CdS/CdTe thin films have been studied by femtosecond transient absorption spectroscopy.
Exploring the comparative binding aspects of benzophenanthridine plant alkaloid chelerythrine with RNA triple and double helices: a spectroscopic and calorimetric approach
Authors: Haque Lucy , Pradhan Ankur Bikash , Bhuiya Sutanwi , Das Suman
Published: May 2015

Comparative study on the interaction of benzophenanthridine alkaloid chelerythrine (CHL) with U.A*U triplex and A.U duplex RNA.
Electronic and magnetic properties of DUT-8(Ni)
Authors: Trepte Kai , Schwalbe Sebastian , Seifert Gotthard
Published: May 2015

Antiferromagnetic ordering in a flexible metal–organic framework DUT-8(Ni).
First principles study on stability and hydrogen adsorption properties of Mg/Ti interface
Authors: Dai J. H. , Xie R. W. , Chen Y. Y. , Song Y.
Published: May 2015

The interface provides an open zone for H atom to accumulate.
Discrete variable representation of the Smoluchowski equation using a sinc basis set
Authors: Piserchia Andrea , Barone Vincenzo
Published: May 2015

We present a new general approach for the solution of the monodimensional Smoluchowski equation using a discrete variable representation (DVR).
Bistable electrical switching and nonvolatile memory effect in carbon nanotube–poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) composite films
Authors: Sun Yanmei , Li Lei , Wen Dianzhong , Bai Xuduo , Li Gang
Published: May 2015

The electrical conductance switching behavior and nonvolatile memory effects in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) PEDOT:PSS and single-wall carbon nanotubes (SWCNTs) composite thin films have been investigated.
Characterization of an abnormal photoluminescence behavior upon crystal-phase transition of perovskite CH3NH3PbI3
Authors: Kong Weiguang , Ye Zhenyu , Qi Zhen , Zhang Bingpo , Wang Miao , Rahimi-Iman Arash , Wu Huizhen
Published: May 2015

Solution-processed hybrid perovskite of CH3NH3PbI3(MAPbI3) exhibits an abnormal luminescence behavior at around the tetragonal–orthorhombic phase transition temperature.
Palladium precatalysts containing meta-terarylphosphine ligands for expedient copper-free Sonogashira cross-coupling reactions
Authors: Yang Yong , Lim Joyce Fen Yan , Chew Xinying , Robins Edward G. , Johannes Charles W. , Lim Yee Hwee , Jong Howard
Published: May 2015

Novel precatalysts containing meta-terarylphosphine ligands have set a new standard for high performance and practicality in copper-free Sonogashira cross-coupling catalysis using simple and reliable protocols.
Enhanced magneto-dielectric coupling in multiferroic Fe and Gd codoped PbTiO3 nanorods synthesized via microwave assisted technique
Authors: Dutta Dimple P. , Mandal Balaji P. , Abdelhamid E. , Naik Ratna , Tyagi Avesh K.
Published: May 2015

Fe and Gd codoped PbTiO3 nanorods synthesized via microwave assisted technique exhibits enhanced room temperature ferromagnetic and ferroelectric properties.
100% clean and renewable wind, water, and sunlight (WWS) all-sector energy roadmaps for the 50 United States
Authors: Jacobson Mark Z. , Delucchi Mark A. , Bazouin Guillaume , Bauer Zack A. F. , Heavey Christa C. , Fisher Emma , Morris Sean B. , Piekutowski Diniana J. Y. , Vencill Taylor A. , Yeskoo Tim W.
Published: May 2015

This paper presents roadmaps for each of the 50 United States to convert their energy infrastructures to 100% wind, water, and sunlight (WWS) for all purposes by 2050.
Compact and modular multicolour fluorescence detector for droplet microfluidics
Authors: Cole Russell H. , de Lange Niek , Gartner Zev J. , Abate Adam R.
Published: May 2015

We present a compact and modular detection system capable of sub-nanomolar sensitivity utilizing an optical fibre array to encode spectral information recorded by a single photodetector.
Detection of links between Ebola nucleocapsid and virulence using disorder analysis
Authors: Goh Gerard Kian-Meng , Dunker A. Keith , Uversky Vladimir N.
Published: May 2015

The underlying reasons for the differences in the virulence of various types of Ebola virus (EBOV) remain unknown.
Synthesis of Bi2Sn2O7 and enhanced photocatalytic activity of Bi2Sn2O7 hybridized with C3N4
Authors: Li Di , Xue Juanqin
Published: May 2015

The enhanced photocatalytic activity of the C3N4/Bi2Sn2O7 photocatalysts could be attributed to the effective separation of the photogenerated e−/h+ pairs.
Kumada catalyst transfer polycondensation for controlled synthesis of polyfluorenes using 1,3-bis(diarylphosphino)propanes as ligands
Authors: Sui Aiguo , Shi Xincui , Wang Yongxia , Geng Yanhou , Wang Fosong
Published: May 2015

The moderately hindered catalyst Ni(acac)2/L2 outperformed other catalysts, affording PF8s with Mn up to 91.1 in a controlled manner.
Modification of the photophysics of 3-hydroxyflavone in aqueous solutions of imidazolium-based room temperature ionic liquids: a comparison between micelle-forming and non micelle-forming ionic liquids
Authors: Ghosh Saptarshi , Chattopadhyay Nitin
Published: May 2015

Fluorometric techniques have been exploited to study the photophysical behaviour of an ESIPT probe, 3HF, in two imidazolium-based room temperature ionic liquids, one micelle-forming and the other non micelle-forming.
Rapid quantification of a chemically synthesized peptide GAP162 in rat plasma by liquid chromatography/triple quadrupole tandem mass spectrometry and application to a pharmacokinetic study
Authors: Zhao Xiaoping , Kang Liping , Zhang Taichang , Chen Jianhua , Ren Xinyi , Bao Yuanwu , Cheng Yuanguo
Published: May 2015

Liquid chromatography/tandem mass spectrometry (LC-MS/MS) is a promising analytical platform for the quantification of therapeutic peptide in biological fluids for pharmacokinetics (PK) studies.
Hollow TS-1 mesocrystals: hydrothermal construction and high catalytic performances in cyclohexanone ammoximation
Authors: Xue Yan , Wen Yiqiang , Wei Huijuan , Liu Meng , Huang Xiaoyan , Ye Xiaoxue , Wang Xiangyu , Li Baojun
Published: May 2015

Hollow TS-1 mesocrystals were obtained by the hydrothermal treatment. The hollow mesocrystalline structure significantly affects their catalytic activity in cyclohexanone ammoximation.
Reverse poly(butylene oxide)–poly(ethylene oxide)–poly(butylene oxide) block copolymers with lengthy hydrophilic blocks as efficient single and dual drug-loaded nanocarriers with synergistic toxic effects on cancer cells
Authors: Villar-Alvarez E. , Figueroa-Ochoa E. , Barbosa S. , Soltero J. F. A. , Taboada P. , Mosquera V.
Published: May 2015

Reverse triblock copolymer micelles with lengthy polyethylene oxide blocks as efficient sustained dual drug-loaded nanocarriers.
A thixotropic polyglycerol sebacate-based supramolecular hydrogel showing UCST behavior
Authors: Ye Hongye , Owh Cally , Loh Xian Jun
Published: May 2015

Polyglycerol sebacate (PGS) is a relatively new biodegradable and elastomeric material that exhibits superior biocompatibility, a modulus that is comparable to human soft tissue, and linear biodegradation.
Correction: Synthesis of cerium oxide particles via polyelectrolyte controlled nonclassical crystallization for catalytic application
Authors: Li Mei , Hu Yanhong , Liu Cuicui , Huang Jinguo , Liu Zhaogang , Wang Mitang , An Zhihua
Published: May 2015

Correction for ‘Synthesis of cerium oxide particles via polyelectrolyte controlled nonclassical crystallization for catalytic application’ by Mei Li et al., RSC Adv., 2014, 4, 992–995.
Self-lubricating organogels (SLUGs) with exceptional syneresis-induced anti-sticking properties against viscous emulsions and ices
Authors: Urata Chihiro , Dunderdale Gary J. , England Matt W. , Hozumi Atsushi
Published: May 2015

“Self-lubricating organogels (SLUGs)”showing exceptional surface properties are preparedviaa crosslinking of polydimethylsiloxanes in the presence of organic liquids.
A market model: uncertainty and reachable sets
Authors: Raczynski Stanislaw
Published: May 2015

Uncertain parameters are always present in models that include human factor. In marketing the uncertain consumer behavior makes it difficult to predict the future events and elaborate good marketing strategies. Sometimes uncertainty is being modeled using stochastic variables. Our approach is quite different. The dynamic market with uncertain parameters is treated using differential inclusions, which permits to determine the corresponding reachable sets. This is not a statistical analysis. We are looking for solutions to the differential inclusions. The purpose of the research is to find the way to obtain and visualise the reachable sets, in order to know the limits for the important marketing variables. The modeling method consists in defining the differential inclusion and find its solution, using the differential inclusion solver developed by the author. As the result we obtain images of the reachable sets where the main control parameter is the share of investment, being a part of the revenue. As an additional result we also can define the optimal investment strategy. The conclusion is that the differential inclusion solver can be a useful tool in market model analysis.
A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors
Authors: Waugh C. J. , Rosenberg M. J. , Zylstra A. B. , Frenje J. A. , Séguin F. H. , Petrasso R. D. , Glebov V. Yu. , Sangster T. C. , Stoeckl C.
Published: May 2015

Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition, comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.
Electric properties and carrier multiplication in breakdown sites in multi-crystalline silicon solar cells
Authors: Schneemann Matthias , Kirchartz Thomas , Carius Reinhard , Rau Uwe
Published: May 2015

This paper studies the effective electrical size and carrier multiplication of breakdown sites in multi-crystalline silicon solar cells. The local series resistance limits the current of each breakdown site and is thereby linearizing the current-voltage characteristic. This fact allows the estimation of the effective electrical diameters to be as low as 100 nm. Using a laser beam induced current (LBIC) measurement with a high spatial resolution, we find carrier multiplication factors on the order of 30 (Zener-type breakdown) and 100 (avalanche breakdown) as new lower limits. Hence, we prove that also the so-called Zener-type breakdown is followed by avalanche multiplication. We explain that previous measurements of the carrier multiplication using thermography yield results higher than unity, only if the spatial defect density is high enough, and the illumination intensity is lower than what was used for the LBIC method. The individual series resistances of the breakdown sites limit the current through these breakdown sites. Therefore, the measured multiplication factors depend on the applied voltage as well as on the injected photocurrent. Both dependencies are successfully simulated using a series-resistance-limited diode model.
Visible wide angle view imaging system of KTM tokamak based on multielement image fiber bundle
Authors: Chektybayev B. , Shapovalov G. , Kolodeshnikov A.
Published: May 2015

In the paper, new visible wide angle view imaging system of KTM tokamak is described. The system has been designed to observe processes inside of plasma and the processes occurring due to plasma-wall interactions through the long equatorial port. Imaging system is designed based on special image fiber bundle and entrance wide angle lens, which provide image of large section of the vacuum chamber, both poloidal half-section and divertor through the sufficiently long equatorial port. The system also consists of two video cameras: slow and fast with image intensifier. Commercial equipment had been used in design of the system that allowed reducing the cost and time for research and development. The paper also discusses advantages and disadvantages of the system in comparison with conventional endoscopes based on a lens system and considers its promising utilization in future tokamaks and future steady state fusion reactors.
Temperature-dependent mechanical deformation of silicon at the nanoscale: Phase transformation versus defect propagation
Authors: Kiran M. S. R. N. , Tran T. T. , Smillie L. A. , Haberl B. , Subianto D. , Williams J. S. , Bradby J. E.
Published: May 2015

This study uses high-temperature nanoindentation coupled with in situ electrical measurements to investigate the temperature dependence (25–200 °C) of the phase transformation behavior of diamond cubic (dc) silicon at the nanoscale. Along with in situ indentation and electrical data, ex situ characterizations, such as Raman and cross-sectional transmission electron microscopy, have been used to reveal the indentation-induced deformation mechanisms. We find that phase transformation and defect propagation within the crystal lattice are not mutually exclusive deformation processes at elevated temperature. Both can occur at temperatures up to 150 °C but to different extents, depending on the temperature and loading conditions. For nanoindentation, we observe that phase transformation is dominant below 100 °C but that deformation by twinning along {111} planes dominates at 150 °C and 200 °C. This work, therefore, provides clear insight into the temperature dependent deformation mechanisms in dc-Si at the nanoscale and helps to clarify previous inconsistencies in the literature.
Davydov Ansatz as an efficient tool for the simulation of nonlinear optical response of molecular aggregates
Authors: Sun Ke-Wei , Gelin Maxim F. , Chernyak Vladimir Y. , Zhao Yang
Published: May 2015

We have developed a variational approach to the description of four-wave-mixing signals of molecular aggregates, in which the third-order response functions are evaluated in terms of the Davydov Ansätze. Our theory treats both singly and doubly excited excitonic states, handling the contributions due to stimulated emission, ground state bleach, and excited state absorption. As an illustration, we simulate a series of optical two-dimensional spectra of model J-aggregates. Our approach may become suitable for the computation of femtosecond optical four-wave-mixing signals of molecular aggregates with intermediate-to-strong exciton-phonon and exciton-exciton coupling strengths.
All-dielectric metamaterial frequency selective surfaces based on high-permittivity ceramic resonators
Authors: Li Liyang , Wang Jun , Wang Jiafu , Du Hongliang , Huang Hao , Zhang Jieqiu , Qu Shaobo , Xu Zhuo
Published: May 2015

In this letter, we propose the design of all-dielectric metamaterial frequency selective surface (FSS) using high-permittivity ceramics. The FSS is composed of 2D arrays of rectangular ceramic resonators. By adjusting the geometrical parameters of the ceramic resonator, the first two resonant modes are merged to achieve broadband band-stop property. As an example, a nearly 1.5 GHz wide stop-band is demonstrated both numerically and experimentally in X band. Since such FSSs are made of low-loss high-permittivity ceramics, they are of important values especially in high-temperature or high-power applications. The method can also be used to design all-dielectric FSS in other frequencies by simply scaling the geometry parameters.
Size control, quantum confinement, and oxidation kinetics of silicon nanocrystals synthesized at a high rate by expanding thermal plasma
Authors: Han Lihao , Zeman Miro , Smets Arno H. M.
Published: May 2015

The growth mechanism of silicon nanocrystals (Si NCs) synthesized at a high rate by means of expanding thermal plasma chemical vapor deposition technique are studied in this letter. A bimodal Gaussian size distribution is revealed from the high-resolution transmission electron microscopy images, and routes to reduce the unwanted large Si NCs are discussed. Photoluminescence and Raman spectroscopies are employed to study the size-dependent quantum confinement effect, from which the average diameters of the small Si NCs are determined. The surface oxidation kinetics of Si NCs are studied using Fourier transform infrared spectroscopy and the importance of post-deposition passivation treatments of hydrogenated crystalline silicon surfaces are demonstrated.
Reduction of magnetic 1/f noise in miniature anisotropic magnetoresistive sensors
Authors: Guo Yue , Wang Junyi , White Robert M. , Wang Shan X.
Published: May 2015

The magnetic 1/f noise in miniature anisotropic magnetoresistive sensors has been studied quantitatively, and a linear correlation between sensitivity and magnetic 1/f noise parameter has been observed. The noise level can be effectively reduced by having an IrMn exchange bias layer adjacent to the permalloy layer, as sensing stripes of 2 μm width exhibit 16 times smaller magnetic 1/f noise parameter upon introduction of an IrMn layer. This simple method energetically stabilizes the magnetization fluctuation in permalloy, and lowers the 1/f noise without degrading the sensitivity. The geometry dependences of both noise and sensitivity have also been investigated to better guide future magnetoresistive sensor design.
Great surface-enhanced Raman scattering in hybrids consisting of graphene and silver nanoparticles with large particle sizes
Authors: Sun Hai-Bin , Wu Jun , Zhu Jie-Jun , Pan Dan-Feng , Wang Guang-Hou , Wan Jian-Guo
Published: May 2015

We have prepared graphene-veiled-nanoparticle hybrids by depositing a bilayer graphene film on silver nanoparticles with large particle sizes, ∼200 nm. The hybrids possess good thermal stability and exhibit great surface-enhanced Raman scattering with enhancement factors of 49- and 21-fold for the G and 2D peaks, respectively. The electrical and optical absorption measurements revealed the occurrence of charge transfer and strong interactions between the silver nanoparticles and graphene. Accordingly, a possible mechanism of Raman enhancement is proposed for the present hybrids. This work demonstrates a well-designed way to improve surface-enhanced Raman scattering in graphene-based materials.
Contact resistance improvement by the modulation of peripheral length to area ratio of graphene contact pattern
Authors: Cho Chunhum , Lee Sang Kyung , Noh Jin Woo , Park Woojin , Lee Sangchul , Lee Young Gon , Hwang Hyeon Jun , Kang Chang Goo , Ham Moon-Ho , Lee Byoung Hun
Published: May 2015

High contact resistance between graphene and metal is a major huddle for high performance electronic device applications of graphene. In this work, a method to improve the contact resistance of graphene is investigated by varying the ratio of peripheral length and area of graphene pattern under a metal contact. The contact resistance decreased to 0.8 kΩ·μm from 2.1 kΩ·μm as the peripheral length increased from 312 to 792 μm. This improvement is attributed to the low resistivity of edge-contacted graphene, which is 8.1 × 105 times lower than that of top-contacted graphene.
The half-metallicity of LiMgPdSn-type quaternary Heusler alloys FeMnScZ (Z=Al, Ga, In): A first-principle study
Authors: Gao Y. C. , Gao X.
Published: May 2015

Based on the first-principles calculations, quaternary Heusler alloys FeMnScZ (Z=Al, Ga, In) including its phase stability, band gap, the electronic structures and magnetic properties has been studied systematically. We have found that, in terms of the equilibrium lattice constants, FeMnScZ (Z=Al, Ga, In) are half-metallic ferrimagnets, which can sustain the high spin polarization under a very large amount of lattice distortions. The half-metallic band gap in FeMnScZ (Z=Al, Ga, In) alloys originates from the t1u-t2g splitting instead of the eu-t1u splitting. The total magnetic moments are 3μB per unit cell for FeMnScZ (Z=Al, Ga, In) alloys following the Slater–Pauling rule with the total number of valence electrons minus 18 rather than 24. According to the study, the conclusion can be drawn that all of these compounds which have a negative formation energy are possible to be synthesized experimentally.
Self-focusing of electromagnetic surface waves on a nonlinear impedance surface
Authors: Luo Zhangjie , Chen Xing , Long Jiang , Quarfoth Ryan , Sievenpiper Daniel
Published: May 2015

The self-focusing effect of optical beams has been a popular topic of study for quite a while, but such a nonlinear phenomenon at microwave frequencies has never been realized, partially due to the underdevelopment of nonlinear material. In this research, self-focused electromagnetic (EM) surface waves are demonstrated on a circuit-based, power-dependent impedance surface. The formation of a self-focused beam is investigated using a series of discrete-time simulations, and the result is further validated in measurement. It is experimentally observed that, in contrast to the normal scattering of low-power surface waves, high-power waves propagate through the surface while maintaining narrow beam width, and even converge extremely tightly to create a hot spot with higher power. The result is essentially a nonlinear effect of the surface that compensates for the natural tendency of surface waves to diffract. This intriguing experiment can be extended to various potential EM applications such as power-dependent beam steering antennas and nonlinear microwave propagation or dissipation.
Synthesis of atomically thin hexagonal boron nitride films on nickel foils by molecular beam epitaxy
Authors: Nakhaie S. , Wofford J. M. , Schumann T. , Jahn U. , Ramsteiner M. , Hanke M. , Lopes J. M. J. , Riechert H.
Published: May 2015

Hexagonal boron nitride (h-BN) is a layered two-dimensional material with properties that make it promising as a dielectric in various applications. We report the growth of h-BN films on Ni foils from elemental B and N using molecular beam epitaxy. The presence of crystalline h-BN over the entire substrate is confirmed by Raman spectroscopy. Atomic force microscopy is used to examine the morphology and continuity of the synthesized films. A scanning electron microscopy study of films obtained using shorter depositions offers insight into the nucleation and growth behavior of h-BN on the Ni substrate. The morphology of h-BN was found to evolve from dendritic, star-shaped islands to larger, smooth triangular ones with increasing growth temperature.
Reconstructing folding energy landscapes from splitting probability analysis of single-molecule trajectories
Authors: Manuel Ajay P. , Lambert John , Woodside Michael T.
Published: May 2015

Significance

Energy landscape theory provides the conceptual foundation for describing how structures self-assemble in proteins and nucleic acids, but energy landscapes are hard to measure experimentally, which has limited quantitative applications of landscape theory. Current methods for measuring landscapes based on single-molecule folding trajectories are strongly influenced by the properties of the instrumental probe, which can confound the results. We present a new approach that avoids these limitations, based on the splitting probability that describes the likelihood of folding proceeding to completion at a given point along the reaction coordinate. We demonstrate the method using measurements of DNA hairpins as a model system, as well as computational simulations, discussing both the advantages of this approach and its limitations.
A refined theory of magnetoelastic buckling matches experiments with ferromagnetic and superparamagnetic rods
Authors: Gerbal Fabien , Wang Yuan , Lyonnet Florian , Bacri Jean-Claude , Hocquet Thierry , Devaud Martin
Published: May 2015

Significance

There are certainly few remaining unsolved physics problems as simple and as fundamental as the magnetoelastic buckling phenomenon. In fact, it is just a little more complex than the Euler instability that describes the buckling transition of an axially compressed rod. Here, the bending energy is provided by the magnetization of the system and is balanced by the mechanical energy that hinders the deformation. It is fundamental in the respect that this mechanism could be realized at many different scales with many types of magnetic materials as soon as they offer the suitable combinations of parameters, mainly involving the magnetic susceptibility and the bending modulus. It could find many applications such as the magnetic remote control of nano- or microcantilevers.
Characterization of cooperative bicarbonate uptake into chloroplast stroma in the green alga
Chlamydomonas reinhardtii
Authors: Yamano Takashi , Sato Emi , Iguchi Hiro , Fukuda Yuri , Fukuzawa Hideya
Published: May 2015

Significance

The entry of inorganic carbon (Ci; CO
2
and HCO
3
–
) into cells involves many biological processes in both animals and plants, and aquaporins as well as bicarbonate transporters play roles in Ci transport. Although transporting external HCO
3
–
into the stroma through the chloroplast envelope is one of the rate-limiting factors for aquatic photosynthetic organisms, specific molecular components in this process have not yet been identified experimentally. Molecular identification of proteins essential for Ci uptake located in the chloroplast envelope and in the plasma membrane documented in this study helps in understanding how aquatic photosynthetic organisms developed machinery to acclimate to CO
2
-limiting environment and to maintain adequate levels of photosynthesis for survival or growth.
Structural, functional, and genetic analyses of the actinobacterial transcription factor RbpA
Authors: Hubin Elizabeth A. , Tabib-Salazar Aline , Humphrey Laurence J. , Flack Joshua E. , Olinares Paul Dominic B. , Darst Seth A. , Campbell Elizabeth A. , Paget Mark S.
Published: May 2015

Significance

Initiation of transcription in bacteria relies on a multisubunit RNA polymerase in concert with a dissociable σ-subunit that confers promoter recognition and opening to reveal the DNA template strand. RbpA, a transcription activator unique to Actinobacteria and essential in
Mycobacterium tuberculosis
, associates tightly with σ and is required for efficient initiation, although its mechanism of action is unclear. Here, we solve the crystal structure of an
M. tuberculosis
σ–RbpA complex and present evidence indicating that RbpA activates transcription through unexpected contacts with promoter DNA. The work sheds light on the mechanism of transcription initiation by
M. tuberculosis
RNA polymerase, which is a proven antibiotic target.
Oxytocin modulates fMRI responses to facial expression in macaques
Authors: Liu Ning , Hadj-Bouziane Fadila , Jones Katherine B. , Turchi Janita N. , Averbeck Bruno B. , Ungerleider Leslie G.
Published: May 2015

Significance

Oxytocin (OT), a mammalian hormone, may serve as a treatment for psychiatric disorders because of its beneficial effect on social behavior. Here, we found that in monkeys, OT selectively altered brain activity within multiple neural systems (visual perception, emotion, attention, and higher cognition function) and functional coupling between the amygdala and areas in the ventral visual pathway evoked by negative emotional expressions. Our findings provide key information for understanding the behavioral consequences of OT administration and indicate homologies between monkeys and humans in the neural circuits mediating the effects of OT. Thus, the monkey may be an ideal animal model to explore the development of OT-based pharmacologic strategies for treating patients with dysfunctional social behavior.
Reduced endogenous Ca
2+
buffering speeds active zone Ca
2+
signaling
Authors: Delvendahl Igor , Jablonski Lukasz , Baade Carolin , Matveev Victor , Neher Erwin , Hallermann Stefan
Published: May 2015

Significance

Calcium influx during action potentials triggers neurotransmitter release at presynaptic active zones. Calcium buffers limit the spread of calcium and restrict neurotransmitter release to the vicinity of calcium channels. To sustain synchronous release during repetitive activity, rapid removal of calcium from the active zone is essential, but the underlying mechanisms are unclear. Therefore, we focused on cerebellar mossy fiber synapses, which are among the fastest synapses in the mammalian brain and found very weak presynaptic calcium buffering. One might assume that strong calcium buffering has the potential to efficiently remove calcium from active zones. In contrast, our results show that weak calcium buffering speeds active zone calcium clearance. Thus, the strength of presynaptic buffering limits the rate of synaptic transmission.
Inflected words in production: Evidence for a morphologically rich lexicon
Authors: Caselli Naomi K. , Caselli Michael K. , Cohen-Goldberg Ariel M.
Published: May 2015

Current evidence suggests that there is a difference between the representations of multimorphemic words in production and perception. In perception, it is widely believed that both whole-word and root representations exist, while in production there is little evidence for whole-word representations. The present investigation demonstrates that whole-word and root frequency independently predict the duration of words suffixed with –ing, –ed, and –s, which reveals that both root and word representations play a role in the production of inflected English words. In a second line of analysis, we find that the number of inflected phonological neighbours independently predicts the duration of monomorphemic words, which extends these results and suggests that whole-word representations exist at the lexical level. Together these results suggest that both root and word representations of inflected words are stored in the lexicon and are relevant for the production of both monomorphemic and multimorphemic words.
There Is No Special Problem of Mindreading in Nonhuman Animals
Authors: Halina Marta
Published: May 2015

There is currently a consensus among comparative psychologists that nonhuman animals are capable of some forms of mindreading. Several philosophers and psychologists have criticized this consensus, however, arguing that there is a “logical problem” with the experimental approach used to test for mindreading in nonhuman animals. I argue that the logical problem is no more than a version of the general skeptical problem known as the theoretician’s dilemma. As such, it is not a problem that comparative psychologists must solve before providing evidence for mindreading.
A Pragmatist Theory of Evidence
Authors: Reiss Julian
Published: May 2015

Two approaches to evidential reasoning compete in the biomedical and social sciences: the experimental and the pragmatist. Whereas experimentalism has received considerable philosophical analysis and support since the times of Bacon and Mill (and continues to enjoy attention and support in very recent work on causation and evidence), pragmatism about evidence has been neither articulated nor defended. The overall aim is to fill this gap and develop a theory that articulates the latter. The main ideas of the theory will be illustrated and supported by a case study on the smoking/lung cancer controversy in the 1950s.
Epistemic Landscapes, Optimal Search, and the Division of Cognitive Labor
Authors: Alexander Jason McKenzie , Himmelreich Johannes , Thompson Christopher
Published: May 2015

This article examines two questions about scientists’ search for knowledge. First, which search strategies generate discoveries effectively? Second, is it advantageous to diversify search strategies? We argue pace Weisberg and Muldoon, “Epistemic Landscapes and the Division of Cognitive Labor” (this journal, 2009), that, on the first question, a search strategy that deliberately seeks novel research approaches need not be optimal. On the second question, we argue they have not shown epistemic reasons exist for the division of cognitive labor, identifying the errors that led to their conclusions. Furthermore, we generalize the epistemic landscape model, showing that one should be skeptical about the benefits of social learning in epistemically complex environments.
The Epistemic Division of Labor Revisited
Authors: Thoma Johanna
Published: May 2015

Some scientists are happy to follow in the footsteps of others; some like to explore novel approaches. It is tempting to think that herein lies an epistemic division of labor conducive to overall scientific progress: the latter point the way to fruitful areas of research, and the former more fully explore those areas. Weisberg and Muldoon’s model, however, suggests that it would be best if all scientists explored novel approaches. I argue that this is due to implausible modeling choices, and I present an alternative ‘epistemic landscape’ model that demonstrates the alleged benefits from division of labor, with one restriction.
The Social Forms and Functions of Bioethics in the United Kingdom
Authors: Ashcroft Richard E. , Dixon-Woods Mary
Published: May 2015

This chapter offers an initial sociology of UK bioethics as a complex and newly emerging social phenomenon, describing its emergence, forms, and purposes as being controlled and shaped by actors and bioethicists. Unlike in France, bioethics in the UK is well established as an academic field. However, UK bioethicists remain insignificant as a resource to solve real-life bioethics problems in clinics and the British polity. UK bioethics is renowned for its medical profession, consultative state, and civil society associations.
Reflections on Bioethics in China
Authors: Renzong Qiu
Published: May 2015

This chapter describes the birth and growth of bioethics in China, a progressive process stimulated by the Chinese government's policy of reform and openness. With increasing cultural valuation of nation-building, development, and international competition in accordance with globalization, Chinese bioethics takes on the social function of speeding up China's modernization. Chinese bioethics is not only a concept adopted from Western scholars, but an idea established in China that responds to urgent local and national needs.
Bioethics in Australia
Authors: Irvine Rob , Kerridge Ian , Komesaroff Paul
Published: May 2015

This chapter talks about Australian bioethics and highlights the argument that bioethics have never been above the political struggle for power and influence in the public marketplace of ideas. It describes the Australasian Bioethics Association, as it purposely moves bioethics discourse beyond philosophical or theological inquiry. The chapter concludes with an analysis of bioethics, as it functions as a political field through which the Christian right competes against secular science, bioethics, and liberal ideology in order to amplify religious doctrines, traditional family values and ethics, and social order in Australian society and politics.
On What Matters
Authors: Parfit Derek
Published: May 2015

This book is an important text in moral philosophy. It follows from the 1984 book Reasons and Persons, one of the landmarks of twentieth-century philosophy. The book presents a new treatment of reasons, rationality, and normativity, and a critical examination of three systematic moral theories — Kant's ethics, contractualism, and consequentialism — leading to a new synthetic conclusion. Along the way the volume discusses a wide range of moral issues, such as the significance of consent, treating people as a means rather than an end, and free will and responsibility. This book consists of four parts. The first part presents critiques of previous work by four of the world's leading moral philosophers. The second part contains responses. The third and longest part is a self-contained work on normativity, and the final part comprises seven chapters on Kant, reasons, irrationality, autonomy — and why the universe exists.
How I Am Not a Kantian
Authors: Scanlon T. M.
Published: May 2015

This chapter talks about the book's vigorous defense of a cognitivist and value-based account of reasons and its ending with the claim of a convergence between Kantian, consequentialist, and contractualist moral theories. This chapter comments on the relation between these two parts of the book. Questions about reasons are fundamental to the book's conclusion because the theories for which convergence is in question characterise right and wrong in terms of what people have reason to want, or could rationally do. The three theories the book considers are: Immanuel Kant's Contractualist Formula, Thomas M. Scanlon's Formula, and Kant's Rule Consequentialism. This chapter examines how the theories laid out by this text differ from Kant's and considers Kant's notions of rationality and morality by focusing on his Formula of Universal Law. It also tackles Kant's discussion of the Formula of Universal Law in his Groundwork of the Metaphysics of Morals.
The Triple Theory
Authors: Parfit Derek
Published: May 2015

This chapter considers Triple Theory, which says everyone ought to follow Rule Consequentialist principles that are UA-optimific because these are the only principles with universal acceptance which everyone could rationally choose, and that no one could reasonably reject. In considering this theory, the chapter addresses four issues: what these optimific principles require us to do; whether these are the only principles the universal acceptance of which everyone could rationally choose; whether these are the only principles that no one could reasonably reject; and whether these are the principles that everyone ought to follow. It also explores the relation between Thomas M. Scanlon's Contractualism and that of Immanuel Kant. It suggests that Kantian Contractualism implies Rule Consequentialism, to which Scanlon has no objection. Finally, it discusses the Convergence Argument and the possibility of combining Kantian Rule Consequentialism with Scanlonian Contractualism.
Analytical Naturalism and Subjectivism
Authors: Parfit Derek
Published: May 2015

This chapter provides a philosophical discussion of Analytical Naturalism and Subjectivism. It first considers several types of metaethical view, namely: Semi-Cognitivism, Cognitivism, Nihilism, Non-Cognitivism, Non-Naturalist Cognitivism, Analytical Naturalism, and Non-Analytical Naturalism. It then argues that we ought to reject Non-Cognitivism and the two forms of Naturalism (Analytical Naturalism and Non-Analytical Naturalism). It also suggests that normativity is either an illusion, or involves irreducibly normative truths. If we used the words ‘reason’, ‘should’, and ‘ought’ in their internal senses, Subjectivism about Reasons would not be a substantive normative view, but a concealed tautology. The chapter concludes by discussing normative beliefs and the concept of internal reason.
Epistemology
Authors: Parfit Derek
Published: May 2015

This chapter looks at epistemology, the Causal Objection, the Validity Argument, and epistemic beliefs. According to the Causal Objection, since non-natural normative properties or truths could not have any effects, we could not have any way of knowing about them. This chapter examines such knowledge from the points of view of Naturalism, Rationalism, and Metaphysical Naturalism. The words ‘probable’, ‘likely’, and ‘certain’ can be used in nonnormative, alethic senses. According to Analytical Naturalism, epistemic normative concepts can be explained in alethic terms, and refer to alethic properties. According to Epistemic Rationalism, these concepts are irreducibly normative, and refer to irreducibly normative properties. According to Non-Analytical Naturalism, although these concepts are irreducibly normative, they refer to alethic properties.