bluuebunny/crossref_metadata_2025 huggingface dataset:
Undulatory microswimming near solid boundaries
Authors: Schulman R. D. , Backholm M. , Ryu W. S. , Dalnoki-Veress K.
Published: October 2014

The hydrodynamic forces involved in the undulatory microswimming of the model organism C. elegans are studied in proximity to solid boundaries. Using a micropipette deflection technique, we attain direct and time-resolved force measurements of the viscous forces acting on the worm near a single planar boundary as well as confined between two planar boundaries. We observe a monotonic increase in the lateral and propulsive forces with increasing proximity to the solid interface. We determine normal and tangential drag coefficients for the worm, and find these to increase with confinement. The measured drag coefficients are compared to existing theoretical models. The ratio of normal to tangential drag coefficients is found to assume a constant value of 1.5 ± 0.1(5) at all distances from a single boundary, but increases significantly as the worm is confined between two boundaries. In response to the increased drag due to confinement, we observe a gait modulation of the nematode, which is primarily characterized by a decrease in the swimming amplitude.
Surface sensitivity of the spin Seebeck effect
Authors: Aqeel A. , Vera-Marun I. J. , van Wees B. J. , Palstra T. T. M.
Published: October 2014

We have investigated the influence of the interface quality on the spin Seebeck effect (SSE) of the bilayer system yttrium iron garnet (YIG)–platinum (Pt). The magnitude and shape of the SSE is strongly influenced by mechanical treatment of the YIG single crystal surface. We observe that the saturation magnetic field (HsatSSE) for the SSE signal increases from 55.3 mT to 72.8 mT with mechanical treatment. The change in the magnitude of HsatSSE can be attributed to the presence of a perpendicular magnetic anisotropy due to the treatment induced surface strain or shape anisotropy in the Pt/YIG system. Our results show that the SSE is a powerful tool to investigate magnetic anisotropy at the interface.
Role of hydrodynamic instability growth in hot-spot mass gain and fusion performance of inertial confinement fusion implosions
Authors: Srinivasan Bhuvana , Tang Xian-Zhu
Published: October 2014

In an inertial confinement fusion target, energy loss due to thermal conduction from the hot-spot will inevitably ablate fuel ice into the hot-spot, resulting in a more massive but cooler hot-spot, which negatively impacts fusion yield. Hydrodynamic mix due to Rayleigh-Taylor instability at the gas-ice interface can aggravate the problem via an increased gas-ice interfacial area across which energy transfer from the hot-spot and ice can be enhanced. Here, this mix-enhanced transport effect on hot-spot fusion-performance degradation is quantified using contrasting 1D and 2D hydrodynamic simulations, and its dependence on effective acceleration, Atwood number, and ablation speed is identified.
Electron scattering and nonlinear trapping by oblique whistler waves: The critical wave intensity for nonlinear effects
Authors: Artemyev A. V. , Vasiliev A. A. , Mourenas D. , Agapitov O. V. , Krasnoselskikh V. V.
Published: October 2014

In this paper, we consider high-energy electron scattering and nonlinear trapping by oblique whistler waves via the Landau resonance. We use recent spacecraft observations in the radiation belts to construct the whistler wave model. The main purpose of the paper is to provide an estimate of the critical wave amplitude for which the nonlinear wave-particle resonant interaction becomes more important than particle scattering. To this aim, we derive an analytical expression describing the particle scattering by large amplitude whistler waves and compare the corresponding effect with the nonlinear particle acceleration due to trapping. The latter is much more rare but the corresponding change of energy is substantially larger than energy jumps due to scattering. We show that for reasonable wave amplitudes ∼10–100 mV/m of strong whistlers, the nonlinear effects are more important than the linear and nonlinear scattering for electrons with energies ∼10–50 keV. We test the dependencies of the critical wave amplitude on system parameters (background plasma density, wave frequency, etc.). We discuss the role of obtained results for the theoretical description of the nonlinear wave amplification in radiation belts.
Dark current mechanism of terahertz quantum-well photodetectors
Authors: Jia J. Y. , Gao J. H. , Hao M. R. , Wang T. M. , Shen W. Z. , Zhang Y. H. , Cao J. C. , Guo X. G. , Schneider H.
Published: October 2014

Dark current mechanisms of terahertz quantum-well photodetectors (THz QWPs) are systematically investigated experimentally and theoretically by measuring two newly designed structures combined with samples reported previously. In contrast to previous investigations, scattering-assisted tunneling dark current is found to cause significant contributions to total dark current. A criterion is also proposed to determine the major dark current mechanism at different peak response frequencies. We further determine background limited performance (BLIP) temperatures, which decrease both experimentally and theoretically as the electric field increases. This work gives good description of dark current mechanism for QWPs in the THz region and is extended to determine the transition fields and BLIP temperatures with response peaks from 3 to 12 THz.
Extraction of infrared optical constants from fringing reflectance spectra
Authors: Chung Pei-Kang , Yen Shun-Tung
Published: October 2014

We propose a simple and reliable method for extracting the optical constants of homogeneous dielectrics which can be pure or impure, and polar or nonpolar. The extraction is made from fringing reflectance spectra of slab samples with and without metal on the backside. The method is demonstrated to work well for polar semiconductors GaAs and InP in the infrared regime. The extracted extinction coefficient spectra exhibit plenty of features which correspond well to those in absorption and Raman spectra.
Weakly relativistic and ponderomotive effects on self-focusing and self-compression of laser pulses in near critical plasmas
Authors: Bokaei B. , Niknam A. R.
Published: October 2014

The spatiotemporal dynamics of high power laser pulses in near critical plasmas are studied taking in to account the effects of relativistic and ponderomotive nonlinearities. First, within one-dimensional analysis, the effects of initial parameters such as laser intensity, plasma density, and plasma electron temperature on the self-compression mechanism are discussed. The results illustrate that the ponderomotive nonlinearity obstructs the relativistic self-compression above a certain intensity value. Moreover, the results indicate the existence of the turning point temperature in which the compression process has its strongest strength. Next, the three-dimensional analysis of laser pulse propagation is investigated by coupling the self-focusing equation with the self-compression one. It is shown that in contrast to the case in which the only relativistic nonlinearity is considered, in the presence of ponderomotive nonlinearity, the self-compression mechanism obstructs the self-focusing and leads to an increase of the laser spot size.
Structural and electronic properties of Si1−xGex alloy nanowires
Authors: Iori Federico , Ossicini Stefano , Rurali Riccardo
Published: October 2014

We present first-principles density-functional calculations of Si1−xGex alloy nanowires. We show that given the composition of the alloy, the structural properties of the nanowires can be predicted with great accuracy by means of Vegard's law, linearly interpolating the values of a pure Si and a pure Ge nanowire of the same diameter. The same holds, to some extent, also for electronic properties such as the band-gap. We also assess to what extend the band-gap varies as a function of disorder, i.e., how it changes for different random realization of a given concentration. These results make possible to tailor the desired properties of SiGe alloy nanowires starting directly from the data relative to the pristine wires.
Spin current generation from sputtered Y3Fe5O12 films
Authors: Lustikova J. , Shiomi Y. , Qiu Z. , Kikkawa T. , Iguchi R. , Uchida K. , Saitoh E.
Published: October 2014

Spin current injection from sputtered yttrium iron garnet (YIG) films into an adjacent platinum layer has been investigated by means of the spin pumping and the spin Seebeck effects. Films with a thickness of 83 and 96 nanometers were fabricated by on-axis magnetron rf sputtering at room temperature and subsequent post-annealing. From the frequency dependence of the ferromagnetic resonance linewidth, the damping constant has been estimated to be (7.0 ± 1.0) × 10−4. Magnitudes of the spin current generated by the spin pumping and the spin Seebeck effect are of the same order as values for YIG films prepared by liquid phase epitaxy. The efficient spin current injection can be ascribed to a good YIG|Pt interface, which is confirmed by the large spin-mixing conductance (2.0 ± 0.2) × 1018 m−2.
Light and phospholipid driven structural transitions in nematic microdroplets
Authors: Dubtsov A. V. , Pasechnik S. V. , Shmeliova D. V. , Kralj Samo
Published: October 2014

We studied the UV-irradiation and phospholipid driven bipolar-radial structural transitions within azoxybenzene nematic liquid crystal (LC) droplets dispersed in water. It was found that the UV-irradiation induced trans-cis isomerisation of LC molecules could enable structural transitions into radial-type configurations at a critical UV-irradiation time tc. In particular, we show that under appropriate conditions, a value of tc could sensitively fingerprint the concentration of phospholipid molecules present in LC-water dispersions. This demonstrated proof-of-principle mechanism could be exploited for development of sensitive detectors for specific nanoparticles (NPs), where value of tc reveals concentration of NPs.
Flow-induced vibrations of two tandem circular cylinders in a parallel-wall channel
Authors: Jiang Ren-Jie , Lin Jian-Zhong , Ku Xiao-Ke
Published: October 2014

Flow-induced vibrations of one and two tandem circular cylinders in the flow around cylinders in a parallel-wall channel are numerically studied by the lattice Boltzmann method. Within a range of Reynolds number Re = [1, 160], the effects of streamwise separation between two cylinders S/D = [1.25, 3], mass ratio M = [0.05, 5], and blockage ratio β = [1/2, 1/8] on the motions of cylinders and fluids are investigated, respectively. For the case of an isolated cylinder, as the mass ratio is 1, no large-amplitude oscillation is observed, and as the mass ratio is 0.1, the cylinder motion translates from the steady regime to the biased periodic vibration with a large oscillation amplitude gradually as Reynolds number is increased from 1 to 160. For the case of two cylinders in tandem, two steady regimes and a variety of distinct oscillation regimes with the corresponding flow structures are observed. The critical mass ratio of the two tandem cylinders in the strong coupling regime is about an order of magnitude larger than that of an isolated cylinder. For blockage ratio is more than 1/5, the vibration type of the cylinders is exclusive, while for blockage ratio is less than 1/6, the cylinder oscillation state is bistable. The mechanisms of the observed phenomena are also discussed.
Mechanical property changes in porous low-k dielectric thin films during processing
Authors: Stan G. , Gates R. S. , Kavuri P. , Torres J. , Michalak D. , Ege C. , Bielefeld J. , King S. W.
Published: October 2014

The design of future generations of Cu-low-k dielectric interconnects with reduced electronic crosstalk often requires engineering materials with an optimal trade off between their dielectric constant and elastic modulus. This is because the benefits associated with the reduction of the dielectric constant by increasing the porosity of materials, for example, can adversely affect their mechanical integrity during processing. By using load-dependent contact-resonance atomic force microscopy, the changes in the elastic modulus of low-k dielectric materials due to processing were accurately measured. These changes were linked to alterations sustained by the structure of low-k dielectric films during processing. A two-phase model was used for quantitative assessments of the elastic modulus changes undergone by the organosilicate skeleton of the structure of porous and pore-filled dielectrics.
Maximum power point tracking of permanent magnet wind turbines equipped with direct matrix converter
Authors: Nateghi Ali reza , Karegar Hossein Kazemi , Bagheri Shahriar
Published: October 2014

This paper presents a novel control method for Maximum Power Point Tracking of wind turbines (WTs) equipped with a Permanent Magnet Synchronous Generator (PMSG) and a Direct Matrix Converter (DMC). The method calculates the optimum wind turbine speed and maximizes the extracted power from wind turbine. This is done by Hill Climb Search method, which is simple and does not need to know the generator parameters and no need to solve the complicated differential equations of generator. WT rotor speed is compared with its optimal value and then DMC controls WT until its rotor speed reaches its optimum value. Under this situation, maximum power is extracted from WT and is injected to the grid with unity power factor. It is implemented by controlling the phase and the amplitude of the DMC output voltage by Venturini switching method. Simulations are done on a 2 MW PMSG WT in MATLAB/SIMULINK to obtain the results, the wind speed was varied both using the Van Der Hoven method and changing the wind step. The obtained results verify the accuracy and simplicity of proposed method.
A new redox flow battery of high energy density with V/Mn hybrid redox couples
Authors: He Zhangxing , Jin Guanhua , Gao Chao , Chen Yong , Han Huiguo , Liu Jianlei
Published: October 2014

Mn3+/Mn2+ redox couple with high reaction potential was successfully introduced into a redox flow battery, and the hybrid V/Mn flow cell with multiple redox couples based on Mn(III)/Mn(II) vs. V(III)/V(II) and V(V)/V(IV) vs. V(III)/V(II) was investigated. The results show that the concentration of sulfuric acid of 4 M is suitable for the viscosity, electrical conductivity, and electrochemical performance. Redox flow battery employing V/Mn and V as positive and negative active species was assembled and the charge-discharge performance was evaluated. The hybrid V/Mn flow cell exhibits good capacity retention and energy efficiency can reach up to 80% over 40 cycles. The energy density of 17.85 W h l−1 is achieved for V/Mn hybrid cell, 25.3% higher than that of all vanadium cell.
Comparative study of polar and semipolar (112¯2) InGaN layers grown by metalorganic vapour phase epitaxy
Authors: Dinh Duc V. , Oehler F. , Zubialevich V. Z. , Kappers M. J. , Alam S. N. , Caliebe M. , Scholtz F. , Humphreys C. J. , Parbrook P. J.
Published: October 2014

InGaN layers were grown simultaneously on (112¯2) GaN and (0001) GaN templates by metalorganic vapour phase epitaxy. At higher growth temperature (≥750 °C), the indium content (<15%) of the (112¯2) and (0001) InGaN layers was similar. However, for temperatures less than 750 °C, the indium content of the (112¯2) InGaN layers (15%–26%) were generally lower than those with (0001) orientation (15%–32%). The compositional deviation was attributed to the different strain relaxations between the (112¯2) and (0001) InGaN layers. Room temperature photoluminescence measurements of the (112¯2) InGaN layers showed an emission wavelength that shifts gradually from 380 nm to 580 nm with decreasing growth temperature (or increasing indium composition). The peak emission wavelength of the (112¯2) InGaN layers with an indium content of more than 10% blue-shifted a constant value of ≈(50–60) nm when using higher excitation power densities. This blue-shift was attributed to band filling effects in the layers.
Critical dimension and pattern size enhancement using pre-strained lithography
Authors: Hong Jian-Wei , Yang Chung-Yuan , Lo Cheng-Yao
Published: October 2014

This paper proposes a non-wavelength-shortening-related critical dimension and pattern size reduction solution for the integrated circuit industry that entails generating strain on the substrate prior to lithography. Pattern size reduction of up to 49% was achieved regardless of shape, location, and size on the xy plane, and complete theoretical calculations and process steps are described in this paper. This technique can be applied to enhance pattern resolution by employing materials and process parameters already in use and, thus, to enhance the capability of outdated lithography facilities, enabling them to particularly support the manufacturing of flexible electronic devices with polymer substrates.
Magnetic anisotropy of Fe1−yXyPt-L1 [X = Cr, Mn, Co, Ni, Cu] bulk alloys
Authors: Cuadrado R. , Klemmer Timothy J. , Chantrell R. W.
Published: October 2014

We demonstrate by means of fully relativistic first principles calculations that, by substitution of Fe by Cr, Mn, Co, Ni, or Cu in FePt-L10 bulk alloys, with fixed Pt content, it is possible to tune the magnetocrystalline anisotropy energy by adjusting the content of the non-magnetic species in the material. The changes in the geometry due to the inclusion of each element induces different values of the tetragonality and hence changes in the magnetic anisotropy and in the net magnetic moment. The site resolved magnetic moments of Fe increase with the X content while those of Pt and X are simultaneously reduced. The calculations are in good quantitative agreement with experimental data and demonstrate that models with fixed band structure but varying numbers of electrons per unit cell are insufficient to describe the experimental data for doped FePt-L10 alloys.
Largely defocused probe scanning transmission electron microscopy for imaging local modulation of strain field in a hetero interface
Authors: Kim Suhyun , Oshima Yoshifumi , Jung Younheum , Kim Joong Jung , Lee Sunyoung , Lee Haebum
Published: October 2014

We present an innovative method for characterizing the strain field in three dimensions in a hetero interface. Largely defocused probe scanning transmission electron microscopy (LDP-STEM) was employed for imaging the inhomogeneous strain field in a germanium (Ge) layer deposited on a silicon (Si) substrate. In the LDP-STEM image, Ge-atomic columns that are relaxed or strained to the Si substrate in the Si/Ge hetero interface were observed to be distinguishable, allowing for the qualitative characterization of the coherency of the crystal growth. Our results revealed that the strain field is locally modulated along the in-plane direction in the Si/Ge hetero interface.
Effects of ferroelectric nanoparticles on ion transport in a liquid crystal
Authors: Basu Rajratan , Garvey Alfred
Published: October 2014

A small quantity of BaTiO3 ferroelectric nanoparticles (FNPs) of 50 nm diameter was doped in a nematic liquid crystal (LC), and the free ion concentration was found to be significantly reduced in the LC + FNP hybrid compared to that of the pure LC. The strong electric fields, due to the permanent dipole moment of the FNPs, trapped some mobile ions, reducing the free ion concentration in the LC media. The reduction of free ions was found to have coherent impacts on the LC's conductivity, rotational viscosity, and electric field-induced nematic switching.
Characteristics of Sn segregation in Ge/GeSn heterostructures
Authors: Li H. , Chang C. , Chen T. P. , Cheng H. H. , Shi Z. W. , Chen H.
Published: October 2014

We report an investigation of Sn segregation in Ge/GeSn heterostructures occurred during the growth by molecular beam epitaxy. The measured Sn profile in the Ge layer shows that: (a) the Sn concentration decreases rapidly near the Ge/GeSn interface, and (b) when moving away from the interface, the Sn concentration reduced with a much slower rate. The 1/e decay lengths of the present system are much longer than those of the conventional group IV system of Ge segregation in the Si overlayer because of the smaller kinetic potential as modeled by a self-limited two-state exchange scheme. The demonstration of the Sn segregation shows the material characteristics of the heterostructure, which are needed for the investigation of its optical properties.
Electrical characteristics of multilayer MoS2 transistors at real operating temperatures with different ambient conditions
Authors: Kwon Hyuk-Jun , Jang Jaewon , Kim Sunkook , Subramanian Vivek , Grigoropoulos Costas P.
Published: October 2014

Atomically thin, two-dimensional (2D) materials with bandgaps have attracted increasing research interest due to their promising electronic properties. Here, we investigate carrier transport and the impact of the operating ambient conditions on back-gated multilayer MoS2 field-effect transistors with a thickness of ∼50 nm at their realistic working temperatures and under different ambient conditions (in air and in a vacuum of ∼10−5 Torr). Increases in temperature cause increases in Imin (likely due to thermionic emission at defects), and result in decreased Ion at high VG (likely due to increased phonon scattering). Thus, the Ion/Imin ratio decreases as the temperature increases. Moreover, the ambient effects with working temperatures on field effect mobilities were investigated. The adsorbed oxygen and water created more defect sites or impurities in the MoS2 channel, which can lead another scattering of the carriers. In air, the adsorbed molecules and phonon scattering caused a reduction of the field effect mobility, significantly. These channel mobility drop-off rates in air and in a vacuum reached 0.12 cm2/V s K and 0.07 cm2/V s K, respectively; the rate of degradation is steeper in air than in a vacuum due to enhanced phonon mode by the adsorbed oxygen and water molecules.
A hole accelerator for InGaN/GaN light-emitting diodes
Authors: Zhang Zi-Hui , Liu Wei , Tan Swee Tiam , Ji Yun , Wang Liancheng , Zhu Binbin , Zhang Yiping , Lu Shunpeng , Zhang Xueliang , Hasanov Namig , Sun Xiao Wei , Demir Hilmi Volkan
Published: October 2014

The quantum efficiency of InGaN/GaN light-emitting diodes (LEDs) has been significantly limited by the insufficient hole injection, and this is caused by the inefficient p-type doping and the low hole mobility. The low hole mobility makes the holes less energetic, which hinders the hole injection into the multiple quantum wells (MQWs) especially when a p-type AlGaN electron blocking layer (EBL) is adopted. In this work, we report a hole accelerator to accelerate the holes so that the holes can obtain adequate kinetic energy, travel across the p-type EBL, and then enter the MQWs more efficiently and smoothly. In addition to the numerical study, the effectiveness of the hole accelerator is experimentally shown through achieving improved optical output power and reduced efficiency droop for the proposed InGaN/GaN LED.
Light absorption enhancement of ∼100 nm thick poly(3-hexylthiophene) thin-film by embedding silver nanoparticles
Authors: Cao Yinghui , Du Peng , Qiao Yanfeng , Liu Zhenyu , Sun Zaicheng
Published: October 2014

In this work, we experimentally and numerically investigate the field enhancement and light absorption enhancement in poly(3-hexylthiophene) (P3HT) thin-film by embedding silver nanoparticles (Ag NPs). Experimental results show that light absorption of ∼100 nm thick P3HT thin-film is enhanced by embedding Ag NPs of diameter 20 ∼ 50 nm in the film. Numerical simulations show that by embedding coupled silver nanospheres (Ag NSs) of diameter 20–40 nm into P3HT, the region of field enhancement can be extended about 100 nm towards the incident light source, due to the interference between the incident field and the scattered field of the coupled Ag NSs. The long-distance field enhancement effect of large-sized Ag NPs can be used to improve the efficiency of organic thin-film solar cell devices.
Nonvolatile memory behavior of nanocrystalline cellulose/graphene oxide composite films
Authors: Valentini L. , Cardinali M. , Fortunati E. , Kenny J. M.
Published: October 2014

With the continuous advance of modern electronics, the demand for nonvolatile memory cells rapidly grows. In order to develop post-silicon electronic devices, it is necessary to find innovative solutions to the eco-sustainability problem of materials for nonvolatile memory cells. In this work, we realized a resistive memory device based on graphene oxide (GO) and GO/cellulose nanocrystals (CNC) thin films. Aqueous solutions of GO and GO with CNC have been prepared and drop cast between two metal electrodes. Such thin-film based devices showed a transition between low and high conductivity states upon the forward and backward sweeping of an external electric field. This reversible current density transition behavior demonstrates a typical memory characteristic. The obtained results open an easy route for electronic information storage based on the integration of nanocrystalline cellulose onto graphene based devices.
Piezoelectric layer embedded-microdiaphragm sensors for the determination of blood viscosity and density
Authors: Kim Hye Jin , Kim Jinsik , Zandieh Omid , Chae Myung-Sic , Kim Tae Song , Lee Jeong Hoon , Park Jung Ho , Kim Seonghwan , Hwang Kyo Seon
Published: October 2014

We introduce a lead zirconate titanate [PZT; Pb(Zr0.52Ti0.48)O3] microdiaphragm resonating sensor packaged in a polydimethylsiloxane chip. The proposed sensor can measure the density and viscosity of a liquid that is within the density and viscosity regime of blood (1.060 × 103 kg/m3, 3–4 cP). To verify the basic characteristics of the sensor, viscous solutions were prepared from glycerol and deionized water with a density in the range from 0.998 to 1.263 × 103 kg/m3 and a viscosity in the range from 1 to 1414 cP. We measured the frequency responses of the sensor before and after injecting the viscosity- and density-controlled liquid under the bottom of the microdiaphragm. The resonant frequencies in the (1,1) and (2,2) modes decreased linearly as a function of the liquid density in the range from 0.998 to 1.146 × 103 kg/m3 with a sensitivity of 28.03 Hz/kg·m−3 and 81.85 Hz/kg·m−3, respectively. The full width at half maximum had a logarithmic relationship with the liquid viscosity in the viscosity range from 1 to 8.4 cP. The quality factor (Q-factor) for the 50% glycerol/water mixture was determined to be greater than 20 for both the (1,1) and the (2,2) modes, indicating that the microdiaphragm resonating sensor is suitable for measuring the density and viscosity of a liquid within a density range from 0.998 to 1.1466 × 103 kg/m3 and a viscosity range from 1 to 8.4 cP. These density and viscosity ranges span the regime of possible changes of blood characteristics. The microdiaphragm resonating sensors were also tested with a real human serum to verify that the sensor is suitable for measuring the viscosity and density of blood. Therefore, the PZT microdiaphragm resonating sensor could be utilized for early diagnosis of diseases associated with changes in the physical properties of blood.
Stable magnetic order and charge induced rotation of magnetization in nano-clusters
Authors: Fhokrul Islam M. , Khanna Shiv N.
Published: October 2014

Efficient control of magnetic anisotropy and the orientation of magnetization are of central importance for the application of nanoparticles in spintronics. Conventionally, magnetization is controlled directly by an external magnetic field or by an electric field via spin-orbit coupling. Here, we demonstrate a different approach to control magnetization in small clusters. We first show that the low magnetic anisotropy of a Co5 cluster can be substantially enhanced by attaching benzene molecules due to the mixing between p states of C and the d states of Co sites. We then show that the direction of magnetization vector of Co5 sandwiched between two benzene molecules rotates by 90° when an electron is added or removed from the system. An experimental set up to realize such effect is also suggested.
Wearable and sensitive heart-rate detectors based on PbS quantum dot and multiwalled carbon nanotube blend film
Authors: Gao Liang , Dong Dongdong , He Jungang , Qiao Keke , Cao Furong , Li Min , Liu Huan , Cheng Yibing , Tang Jiang , Song Haisheng
Published: October 2014

Wearable and sensitive photodetectors (PDs) have been demonstrated based on a blend film of PbS quantum dots (QDs) and QDs modified multiwalled carbon nanotubes (MWCNTs). Owing to the synergetic effect from high light sensitivity of PbS QDs and excellent conductive and mechanical properties of MWCNTs, the blend PDs show high sensitivity and flexibility performance: device responsivity and detectivity reach 583 mA/W and 3.25 × 1012 Jones, respectively, and could stand large number (at least 10 000 cycles) and wide angle (up to 80°) bending. Furthermore, the wearable and sensitive PDs have been applied to measure the heart rate in both red and near infrared (NIR) ranges. The presented PDs are expected to work as sensor candidates in integrated electronic skin.
Efficient CoO nanowire array photocatalysts for H2 generation
Authors: Zhan Xueying , Wang Zhenxing , Wang Fengmei , Cheng Zhongzhou , Xu Kai , Wang Qisheng , Safdar Muhammad , He Jun
Published: October 2014

CoO nanowire arrays for efficient water-splitting were fabricated via a facile hydrothermal and subsequent annealing method. The CoO nanowire is composed of assembled CoO nanoparticles and the particle size can be controlled by annealing temperatures. CoO nanowire array exhibits advantages of easy fabrication, recyclability, and high stability. The origin of the difference of photocatalytic activity among CoO bulk, CoO nanowires annealed under different temperatures, can be contributed to remarkable shift in the position of the band edge due to different CoO particle sizes. Our finding may provide an avenue in design and fabrication of Co-based nanosturctures for practical applications.
Active terahertz plasmonic crystal waveguide based on double-structured Schottky grating arrays
Authors: Fan Fei , Chen Sai , Gu Wen-Hao , Wang Xiang Hui , Chang Sheng-Jiang
Published: October 2014

An electrically controllable terahertz (THz) plasmonic crystal waveguide based on double-structured Schottky grating arrays has been fabricated and investigated. The experiment and simulation show two different resonance behaviors of a discrete jump and a continuous shift when applying positive and negative bias, respectively. THz modulations with a 15 dB modulation depth have been realized in the frequency range of 2.2−3.2 THz. Furthermore, these modulation behaviors have been interpreted as the generation and shift of the plasmonic band structures accompanying with the spatial modulations of the Schottky barriers in this device. This active THz device can be feasibly applied into THz application systems.
Direct writing of flexible bimetallic nanoparticles for hybrid plasmon response
Authors: Zhai Tianrui , Wang Yonglu , Xu Zhiyang , Liu Hongmei , Zhang Xinping
Published: October 2014

Two types of bimetallic nanoparticle are constructed on soft substrates via a laser-induced transfer technique. One particle is a physical mixture with distinct gold and silver nanoparticles, while the other is a gold-silver alloy nanoparticle. Different hybrid plasmon responses can be achieved by these nanoparticles, which can be attributed to electromagnetic interactions between gold and silver. Both nanostructures can be fabricated using one or two ultraviolet laser pulses. Also, the stability of the spectra of these nanoparticles remains robust when the substrate is stretched and bended. These particles may provide an alternative way to investigate plasmonic sensors and random laser devices.
Identification of 14-series sulfido-conjugated mediators that promote resolution of infection and organ protection
Authors: Dalli Jesmond , Chiang Nan , Serhan Charles N.
Published: October 2014

Significance

Inability of the body to contain infections may lead to collateral organ damage resulting from unchecked innate immune responses. Here we investigated the chemical signals produced by immune cells to expedite clearance of bacteria and promote organ repair and tissue regeneration. We identified molecules produced during self-limited infections and in human milk that promote clearance of bacteria as well as accelerate tissue regeneration. In addition, these molecules also protected organs from exuberant inflammatory responses by limiting select white blood cell recruitment and up-regulating the expression of proteins involved in tissue repair. Therefore, these results identify new resolution moduli that regulate phagocytes to clear bacteria and activate the regeneration milieu.
A nontranscriptional role for Oct4 in the regulation of mitotic entry
Authors: Zhao Rui , Deibler Richard W. , Lerou Paul H. , Ballabeni Andrea , Heffner Garrett C. , Cahan Patrick , Unternaehrer Juli J. , Kirschner Marc W. , Daley George Q.
Published: October 2014

Significance

Embryonic stem cells and induced pluripotent stem cells have abbreviated cell cycles. To achieve this rapid proliferation, several molecular safeguards that normally distinguish healthy from transformed cells are altered. Understanding how these pluripotent stem cells balance the demands of their unique cell cycles against the need to maintain a stable genome is critical to unlocking their great promise for regenerative medicine. Here, we demonstrate that Oct4 (octamer-binding transcription factor 4), a transcription factor required to maintain pluripotency, inhibits the activation of cyclin-dependent kinase (Cdk) 1, the master regulator of mitosis, and delays mitotic entry in a nontranscriptional manner. To our knowledge, our study is the first demonstration of a nontranscriptional function of the pluripotency regulator Oct4.
Seleukid Sacred Architecture, Royal Cult and the Transformation of Iranian Culture in the Middle Iranian Period
Authors: Canepa Matthew P.
Published: October 2014

This article proposes a new approach to three of the most persistent problems in the study of Iranian art and religion from the coming of Alexander to the fall of the Sasanians: the development of Iranian sacred architecture, the legacy of the Achaemenids, and the development of the art and ritual of Iranian kingship after Alexander. Canepa explores the ways in which the Seleukids contributed basic and enduring elements of Iranian religious and royal culture that lasted throughout late antiquity. Beyond stressing simple continuities or breaks with the Babylonian, Achaemenid or Macedonian traditions, this article argues that the Seleukids selectively integrated a variety of cultural, architectural and religious traditions to forge what became the architectural vocabularies and religious expressions of the Middle Iranian era.
Hobbes and human irrationality
Authors: Field Sandra Leonie
Published: October 2014

Hobbes's science of politics rests on a dual analysis of human beings: humans as complex material bodies in a network of mechanical forces, prone to passions and irrationality; and humans as subjects of right and obligation, morally exhortable by appeal to the standards of reason. The science of politics proposes an absolutist model of politics. If this proposal is not to be idle utopianism, the enduring functioning of the model needs to be compatible with the materialist analysis of human behaviour. In this article, I argue that Hobbes's attempts to render his science of politics compatible with his materialism are only partly successful; a fuller compatibility is achieved in the political writings of Spinoza.
The Sugen 5416/Hypoxia Mouse Model of Pulmonary Hypertension Revisited: Long‐Term Follow‐Up
Authors: Vitali Sally H. , Hansmann Georg , Rose Chase , Fernandez‐Gonzalez Angeles , Scheid Annette , Mitsialis S. Alex , Kourembanas Stella
Published: October 2014

The combination of a vascular endothelial growth factor receptor antagonist, Sugen 5416 (SU5416), and chronic hypoxia is known to cause pronounced pulmonary hypertension (PH) with angioobliterative lesions in rats and leads to exaggerated PH in mice as well. We sought to determine whether weekly SU5416 injections during 3 weeks of hypoxia leads to long‐term development of angioobliterative lesions and sustained or progressive PH in mice. Male C57BL/6J mice were injected with SU5416 (SuHx) or vehicle (VehHx) weekly during 3 weeks of exposure to 10% oxygen. Echocardiographic and invasive measures of hemodynamics and pulmonary vascular morphometry were performed after the 3‐week hypoxic exposure and after 10 weeks of recovery in normoxia. SuHx led to higher right ventricular (RV) systolic pressure and RV hypertrophy than VehHx after 3 weeks of hypoxia. Ten weeks after hypoxic exposure, RV systolic pressure decreased but remained elevated in SuHx mice compared with VehHx or normoxic control mice, but RV hypertrophy had resolved. After 3 weeks of hypoxia and 10 weeks of follow‐up in normoxia, tricuspid annular plane systolic excursion was significantly decreased, indicating decreased systolic RV function. Very few angioobliterative lesions were found at the 10‐week follow‐up time point in SuHx mouse lungs. In conclusion, SU5416 combined with 3 weeks of hypoxia causes a more profound PH phenotype in mice than hypoxia alone. PH persists over 10 weeks of normoxic follow‐up in SuHx mice, but significant angioobliterative lesions do not occur, and neither PH nor RV dysfunction worsens. The SuHx mouse model is a useful adjunct to other PH models, but the search will continue for a mouse model that better recapitulates the human phenotype.
Rcount: simple and flexible RNA-Seq read counting
Authors: Schmid Marc W. , Grossniklaus Ueli
Published: October 2014

Summary: Analysis of differential gene expression by RNA sequencing (RNA-Seq) is frequently done using feature counts, i.e. the number of reads mapping to a gene. However, commonly used count algorithms (e.g. HTSeq) do not address the problem of reads aligning with multiple locations in the genome (multireads) or reads aligning with positions where two or more genes overlap (ambiguous reads). Rcount specifically addresses these issues. Furthermore, Rcount allows the user to assign priorities to certain feature types (e.g. higher priority for protein-coding genes compared to rRNA-coding genes) or to add flanking regions.

Availability and implementation: Rcount provides a fast and easy-to-use graphical user interface requiring no command line or programming skills. It is implemented in C++ using the SeqAn ( www.seqan.de ) and the Qt libraries (qt-project.org). Source code and 64 bit binaries for (Ubuntu) Linux, Windows (7) and MacOSX are released under the GPLv3 license and are freely available on github.com/MWSchmid/Rcount.

Contact:  marcschmid@gmx.ch

Supplementary information: Test data, genome annotation files, useful Python and R scripts and a step-by-step user guide (including run-time and memory usage tests) are available on github.com/MWSchmid/Rcount.
Voidance: Linguistic Negativism in Maurice Blanchot's Fiction
Authors: Weller Shane
Published: October 2014

This article charts the shifting patterns of linguistic negativism in Maurice Blanchot's fiction, from his early works of the mid-1930s, through the novels of the 1940s, to the major
récits
from
L'Arrêt de mort
(1948) to
L'Instant de ma mort
(1994). Particular attention is paid to Blanchot's deployment of negative affixes and negative modifiers. This stylistic analysis provides the groundwork for my exploration of the ‘voidance’ of the semantic in Blanchot's fiction, achieved through an epanorthotic retraction of the said that becomes ever more prevalent, reaching its most extreme form in
L'Attente, l'oubli
(1962). This voidance serves as a form of resistance to semantic hypostatization and reification, but at the risk of an evacuation of sense. Through a charting of these patterns of linguistic negativism, and an appreciation of their function as a form of voidance, it becomes possible to detect a trajectory away from a prose that recalls Mallarmé, through one that recalls Kafka, to one akin to Beckett's. Analysing this trajectory, this article aims to situate Blanchot's writing of the negative within a broader, language-sceptical tradition that achieves its literary flowering in European late modernism.
Numerical model of optical coherence tomographic vibrography imaging to estimate corneal biomechanical properties
Authors: Kling Sabine , Akca Imran B. , Chang Ernest W. , Scarcelli Giuliano , Bekesi Nandor , Yun Seok-Hyun , Marcos Susana
Published: October 2014

Most techniques measuring corneal biomechanics
in vivo
are biased by side factors. We demonstrate the ability of optical coherence tomographic (OCT) vibrography to determine corneal material parameters, while reducing current prevalent restrictions of other techniques (such as intraocular pressure (IOP) and thickness dependency). Modal analysis was performed in a finite-element (FE) model to study the oscillation response in isolated thin corneal flaps/eye globes and to analyse the dependency of the frequency response function on: corneal elasticity, viscoelasticity, geometry (thickness and curvature), IOP and density. The model was verified experimentally in flaps from three bovine corneas and in two enucleated porcine eyes using sound excitation (100–110 dB) together with a phase-sensitive OCT to measure the frequency response function (range 50–510 Hz). Simulations showed that corneal vibration in flaps is sensitive to both, geometrical and biomechanical parameters, whereas in whole globes it is primarily sensitive to corneal biomechanical parameters only. Calculations based on the natural frequency shift revealed that flaps of the posterior cornea were 0.8 times less stiff than flaps from the anterior cornea and cross-linked corneas were 1.6 times stiffer than virgin corneas. Sensitivity analysis showed that natural vibration frequencies of whole globes were nearly independent from corneal thickness and IOP within the physiological range. OCT vibrography is a promising non-invasive technique to measure corneal elasticity without biases from corneal thickness and IOP.
Ecological variation in wealth–fertility relationships in Mongolia: the ‘central theoretical problem of sociobiology’ not a problem after all?
Authors: Alvergne Alexandra , Lummaa Virpi
Published: October 2014

The negative wealth–fertility relationship brought about by market integration remains a puzzle to classic evolutionary models. Evolutionary ecologists have argued that this phenomenon results from both stronger trade-offs between reproductive and socioeconomic success in the highest social classes and the comparison of groups rather than individuals. Indeed, studies in contemporary low fertility settings have typically used aggregated samples that may mask positive wealth–fertility relationships. Furthermore, while much evidence attests to trade-offs between reproductive and socioeconomic success, few studies have explicitly tested the idea that such constraints are intensified by market integration. Using data from Mongolia, a post-socialist nation that underwent mass privatization, we examine wealth–fertility relationships over time and across a rural–urban gradient. Among post-reproductive women, reproductive fitness is the lowest in urban areas, but increases with wealth in all regions. After liberalization, a demographic–economic paradox emerges in urban areas: while educational attainment negatively impacts female fertility in all regions, education uniquely provides socioeconomic benefits in urban contexts. As market integration progresses, socio-economic returns to education increase and women who limit their reproduction to pursue education get wealthier. The results support the view that selection favoured mechanisms that respond to opportunities for status enhancement rather than fertility maximization.
Revisiting Corynebacterium glyciniphilum (ex Kubota et al., 1972) sp. nov., nom. rev., isolated from putrefied banana
Authors: Al-Dilaimi Arwa , Bednarz Hanna , Lömker Alexander , Niehaus Karsten , Kalinowski Jörn , Rückert Christian
Published: October 2014

A strain of a species of the genusCorynebacterium, designated AJ 3170T, was isolated during the 1980s from putrefied bananas. Since then, there have been no further updates on the description of the strain or its phylogenetic classification. However, phylogenetic analysis of this strain using 16S rRNA andin silicoDNA–DNA hybridization has confirmed that it is a member of the genusCorynebacteriumand that strain AJ 3170Tclusters withCorynebacterium variabileDSM 44702T,Corynebacterium terpenotabidumY-11TandCorynebacterium nurukiS6-4Tin one subgroup. Furthermore, a combination of enzymatic, chemical, and morphological characterization techniques was applied in order to describe strain AJ 3170Tfurther. The strain grew well at pH values of 6–10 and at temperatures of 30–41 °C. The major fatty acids were C16 : 0(42.15 %), C18 : 1ω9c(41.6 %) and C18 : 010-methyl (TBSA) (8.56 %). The whole-cell sugars were determined to comprise galactose, arabinose and ribose. On the basis of this phenotypic, chemotaxonomic and phylogenetic characterization, it is proposed that strain AJ 3170Trepresents a novel species, for which the nameCorynebacterium glyciniphilumsp. nov. is proposed; the type strain is AJ 3170T( = DSM 45795T = ATCC 21341T).
Vulcanisaeta thermophila sp. nov., a hyperthermophilic and acidophilic crenarchaeon isolated from solfataric soil
Authors: Yim Kyung June , Cha In-Tae , Rhee Jin-Kyu , Song Hye Seon , Hyun Dong-Wook , Lee Hae-Won , Kim Daekyung , Kim Kil-Nam , Nam Young-Do , Seo Myung-Ji , Bae Jin-Woo , Roh Seong Woon
Published: October 2014

An anaerobic, rod-shaped, hyperthermophilic and acidophilic crenarchaeon, designated strain CBA1501T, was isolated from solfataric soil of the Mayon volcano in the Republic of the Philippines. Phylogenetic analysis showed that strain CBA1501T is affiliated with the genus

Vulcanisaeta

in the phylum

Crenarchaeota

. DNA sequence similarities between the 16S rRNA gene of strain CBA1501T and those of

Vulcanisaeta distributa

IC-017T and

Vulcanisaeta souniana

IC-059T were 98.5 and 97.4 %, respectively. Strain CBA1501T grew between 75–90 °C, over a pH range of 4.0–6.0 and in the presence of 0–1.0 % (w/v) NaCl, with optimal growth occurring at 85 °C, pH 5.0, and with 0 % (w/v) NaCl. Fumarate, malate, oxidized glutathione, sulfur and thiosulfate were used as final electron acceptors, but FeCl3, nitrate and sulfate were not. The DNA G+C content of strain CBA1501T was 43.1 mol%. On the basis of polyphasic taxonomic analysis, strain CBA1501T represents a novel species of the genus

Vulcanisaeta

in the phylum

Crenarchaeota

, for which we propose the name Vulcanisaeta
thermophila sp. nov. The type strain is CBA1501T ( = ATCC BAA-2415T = JCM 17228T).