bluuebunny/crossref_metadata_2025 huggingface dataset:
Superiority of pulmonary administration of mepenzolate bromide over other routes as treatment for chronic obstructive pulmonary disease
Authors: Tanaka Ken-Ichiro , Kurotsu Shota , Asano Teita , Yamakawa Naoki , Kobayashi Daisuke , Yamashita Yasunobu , Yamazaki Hiroshi , Ishihara Tomoaki , Watanabe Hiroshi , Maruyama Toru , Suzuki Hidekazu , Mizushima Tohru
Published: March 2014

We recently proposed that mepenzolate bromide (mepenzolate) would be therapeutically effective against chronic obstructive pulmonary disease (COPD) due to its both anti-inflammatory and bronchodilatory activities. In this study, we examined the benefits and adverse effects associated with different routes of mepenzolate administration in mice. Oral administration of mepenzolate caused not only bronchodilation but also decreased the severity of elastase-induced pulmonary emphysema; however, compared with the intratracheal route of administration, about 5000 times higher dose was required to achieve this effect. Intravenously or intrarectally administered mepenzolate also showed these pharmacological effects. The intratracheal route of mepenzolate administration, but not other routes, resulted in protective effects against elastase-induced pulmonary damage and bronchodilation at a much lower dose than that which affected defecation and heart rate. These results suggest that the pulmonary route of mepenzolate administration may be superior to other routes (oral, intravenous or intrarectal) to treat COPD patients.
A fast and low-cost method for determination of melamine in soil and sediment using high performance liquid chromatography
Authors: Nong Yanfeng , Ma Xiaoguo , Fan Shaofeng , Yu Yumian
Published: March 2014

Ultrasonic-assisted extraction with high performance liquid chromatography was used for rapid and low-cost determination of melamine in soil and sediment.
Step-by-step synthesis of one Fe6 wheel and two Fe10 clusters derived from a multidentate triethanolamine ligand
Authors: Liu Sui-Jun , Han Song-De , Jia Ji-Min , Xue Li , Cui Yu , Zhang Shu-Ming , Chang Ze
Published: March 2014

One Fe6 wheel and two Fe10 clusters based on multidentate triethanolamine have been prepared with step-by-step strategy and structurally characterized. Magnetic analyses indicate that the Fe6 wheel exhibits strong antiferromagnetic behavior with S = 0 ground state.
Highly efficient bimetal synergetic catalysis by a multi-wall carbon nanotube supported palladium and nickel catalyst for the hydrogen storage of magnesium hydride
Authors: Yuan Jianguang , Zhu Yunfeng , Li Liquan
Published: March 2014

PdNi/MWCNTs efficiently catalyze magnesium hydride prepared by HCS + MM with the following excellent properties: hydrogen absorption – 6.44 wt% within 100 s at 373 K and hydrogen desorption – 6.41 wt% within 1800 s at 523 K.
EBNA1-specific luminescent small molecules for the imaging and inhibition of latent EBV-infected tumor cells
Authors: Jiang Lijun , Lui Yin-Lai , Li Hongguang , Chan Chi-Fai , Lan Rongfeng , Chan Wai-Lun , Lau Terrence Chi-Kong , Tsao George Sai-Wah , Mak Nak-Ki , Wong Ka-Leung
Published: March 2014

An EBNA1-specific small molecule (JLP2) has been synthesized and shown selective binding and inhibition of EBNA1in vitroas potential anticancer agent.
Single-crystal to single-crystal guest exchange and phase transformations in a porous metallocycle
Authors: du Plessis Marike , Smith Vincent J. , Barbour Leonard J.
Published: March 2014

The acetonitrile guest molecules in this porous metallocycle can be exchanged for different solvent molecules in a single-crystal to single-crystal manner. These guest exchanges are accompanied by a phase transformation in the solid state.
Incorporating [GaB4O11(OH)]8−clusters to construct luminescent galloborate with open-framework layers
Authors: Deng Ting-Ting , Gao Yan-E , Zhang Li-Xia , Gu Xiang-Yu , Tian Han-Rui , Liu Yi , Feng Yun-Long , Cheng Jian-Wen
Published: March 2014

A luminescent 5-connected galloborate with open-framework layers has been obtained under mild hydrothermal conditions by incorporating [GaB4O11(OH)]8−clusters.
Excited states of protonated DNA/RNA bases
Authors: Berdakin Matias , Féraud Géraldine , Dedonder-Lardeux Claude , Jouvet Christophe , Pino Gustavo A.
Published: March 2014

The excited state lifetime of protonated DNA/RNA bases is strongly dependent on the tautomeric form.
Simultaneous SERS and surface-enhanced fluorescence from dye-embedded metal core–shell nanoparticles
Authors: Zhou Yan , Zhang Peng
Published: March 2014

We demonstrate a methodology to prepare Au-core–Ag-shell nanoparticles displaying both SERS and surface-enhanced fluorescence (SEF) activities simultaneously by embedding dye molecules between the core and the shell.
Enabling practical surface acoustic wave nebulizer drug delivery via amplitude modulation
Authors: Rajapaksa Anushi , Qi Aisha , Yeo Leslie Y. , Coppel Ross , Friend James R.
Published: March 2014

A practical, commercially viable microfluidic device relies upon the miniaturization and integration of all its components—including pumps, circuitry, and power supply—onto a chip-based platform.
The fundamental solution of the unidirectional pulse propagation equation
Authors: Babushkin I. , Bergé L.
Published: March 2014

The fundamental solution of a variant of the three-dimensional wave equation known as “unidirectional pulse propagation equation” (UPPE) and its paraxial approximation is obtained. It is shown that the fundamental solution can be presented as a projection of a fundamental solution of the wave equation to some functional subspace. We discuss the degree of equivalence of the UPPE and the wave equation in this respect. In particular, we show that the UPPE, in contrast to the common belief, describes wave propagation in both longitudinal and temporal directions, and, thereby, its fundamental solution possesses a non-causal character.
Safety concerns towards the biomedical application of PbS nanoparticles: An approach through protein-PbS interaction and corona formation
Authors: Kumar Bhunia Amit , Kanti Samanta Pijus , Saha Satyajit , Kamilya Tapanendu
Published: March 2014

Semiconductor nanoparticles (NPs) with near-infrared (NIR) fluorescence has achieved great interest for early detection of colon tumors/cancer. We have synthesized lead sulphide (PbS) NPs (5–7 nm) having emission in NIR region and investigated its interaction with bovine serum albumin (BSA) to determine the bio-safety of PbS NPs. The interaction of PbS NPs with BSA occurs through formation of “hard” and “soft” protein NPs corona and follows exponential association. The hard corona represents that the core PbS NPs are fully covered by BSA with shell thickness of ∼8 nm, i.e., the dimension of BSA monomer. A large number of PbS NPs with hard corona of BSA forms “colony” with diameters in the range of 200–400 nm. The soft corona grows surrounding this colony. The quenching of fluorescence BSA in the presence of PbS NPs follows dynamic quenching process with tryptophan as major binding sites. Nearest to human body temperature, positive cooperative association between PbS NPs and BSA are found, and affinity of BSA to the PbS NPs gradually increases in superlinear fashion. The electrostatic interaction is the key force in binding of PbS NPs with BSA, and hydrophobic interaction between PbS NPs and BSA is responsible for conformational change of BSA.
Dispersion and damping rates of dispersive Alfvén wave in a nonextensive plasma
Authors: Liu Y. , Liu S. Q. , Dai B. , Xue T. L.
Published: March 2014

The dispersion and landau damping of the dispersive Alfvén waves (DAW) have been studied in the plasma with nonextensive electrons and ions. The conditions for the existence of inertial Alfvén waves (IAW) and kinetic Alfvén waves (KAW) are modified by electrons' nonextensive parameter qe. For IAW, βq ≪ me/mi; for KAW, me/mi ≪ βq ≪ 1, βq is the ratio of the effective thermal pressure to the magnetic pressure. In the plasma with superthermal particles, the frequency of the IAW and KAW will increase with the increase of qe when the effective temperature of the plasma systems keeps invariant. Whereas the damping rates of the IAW and KAW vary inversely with respect to qe for the reason that the phase velocity of KAW is much smaller than the effective thermal velocity, while the phase velocity of IAW is much bigger than the effective thermal velocity.
Computation of generalized and exact dispersion relations for longitudinal plasma waves in nonextensive statistics and the effects of the nonextensivity on the oscillation modes and damps
Authors: Esfandyari-Kalejahi A. , Ebrahimi V.
Published: March 2014

We have derived generalized dispersion relations for longitudinal waves in collisionless thermal plasma using linear Vlasov-Poisson kinetic model and nonextensive distributions for electrons. The Maxwellian limit of the dispersion relations, where the q-nonextensive parameter tends to one, is calculated. The generalized dispersion relations are reduced to polynomials for some specific values of q. The well-known modes of oscillations such as the Langmuir and electron acoustic waves have been obtained by solving the dispersion relations. Some new modes of oscillation are also found. Finally, the dependence of the oscillation modes and damps on q is discussed.
Phase field study of interfacial diffusion-driven spheroidization in a composite comprised of two mutually insoluble phases
Authors: Tian Liang , Russell Alan
Published: March 2014

The phase field approach is a powerful computational technique to simulate morphological and microstructural evolution at the mesoscale. Spheroidization is a frequently observed morphological change of mesoscale heterogeneous structures during annealing. In this study, we used the diffuse interface phase field method to investigate the interfacial diffusion-driven spheroidization of cylindrical rod structures in a composite comprised of two mutually insoluble phases in a two-dimensional case. Perturbation of rod radius along a cylinder's axis has long been known to cause the necessary chemical potential gradient that drives spheroidization of the rod by Lord Rayleigh's instability theory. This theory indicates that a radius perturbation wavelength larger than the initial rod circumference would lead to cylindrical spheroidization. We investigated the effect of perturbation wavelength, interfacial energy, volume diffusion, phase composition, and interfacial percentage on the kinetics of spheroidization. The results match well with both the Rayleigh's instability criterion and experimental observations.
Including screening in van der Waals corrected density functional theory calculations: The case of atoms and small molecules physisorbed on graphene
Authors: Silvestrelli Pier Luigi , Ambrosetti Alberto
Published: March 2014

The Density Functional Theory (DFT)/van der Waals-Quantum Harmonic Oscillator-Wannier function (vdW-QHO-WF) method, recently developed to include the vdW interactions in approximated DFT by combining the quantum harmonic oscillator model with the maximally localized Wannier function technique, is applied to the cases of atoms and small molecules (X=Ar, CO, H2, H2O) weakly interacting with benzene and with the ideal planar graphene surface. Comparison is also presented with the results obtained by other DFT vdW-corrected schemes, including PBE+D, vdW-DF, vdW-DF2, rVV10, and by the simpler Local Density Approximation (LDA) and semilocal generalized gradient approximation approaches. While for the X-benzene systems all the considered vdW-corrected schemes perform reasonably well, it turns out that an accurate description of the X-graphene interaction requires a proper treatment of many-body contributions and of short-range screening effects, as demonstrated by adopting an improved version of the DFT/vdW-QHO-WF method. We also comment on the widespread attitude of relying on LDA to get a rough description of weakly interacting systems.
Glass transition of partially crystallized gelatin-water mixtures studied by broadband dielectric spectroscopy
Authors: Sasaki Kaito , Kita Rio , Shinyashiki Naoki , Yagihara Shin
Published: March 2014

The glass transition of partially crystallized gelatin-water mixtures was investigated for gelatin concentrations of 40 and 20 wt. % by broadband dielectric spectroscopy (BDS) in wide frequency (10 mHz-50 GHz) and temperature (113-298 K) ranges. Three dielectric relaxation processes were clearly observed. The origin of each relaxation process was the same as that observed for partially crystallized bovine serum albumin (BSA)-water mixtures [N. Shinyashiki et al., J. Phys. Chem. B 113, 14448 (2009)]. The relaxation process at the highest frequency is originated from uncrystallized water (UCW) in the hydration shell of gelatin. Its relaxation time is almost the same as that of water in uncrystallized system; water in various binary aqueous mixtures and confined water in nanoscale region. The relaxation process at the intermediate frequency is originated from ice, and its relaxation time and strength were similar to those for the relaxation of pure ice, particularly above 240 K. The glass transition temperature Tg, is defined by BDS measurement as the temperature at which dielectric relaxation time τ, is 100-1000 s. The relaxation process at the lowest frequency, Tg is approximately 200 K, is originated from the cooperative motion of water and gelatin. This relaxation is strong and has a similar relaxation strength to that of hydrated BSA. At Tg for the relaxation process involving the cooperative motion of gelatin and water, the temperature dependence of the relaxation process of UCW crosses over from Vogel-Fulcher behavior to Arrhenius behavior with decreasing temperature. A characteristic property of the gelatin-water mixture is a change in the temperature dependence of the relaxation time of the relaxation processes of hydrated gelatin at approximately 260 K.
Comparative experimental investigation on the actuation mechanisms of ionic polymer–metal composites with different backbones and water contents
Authors: Zhu Zicai , Chang Longfei , Asaka Kinji , Wang Yanjie , Chen Hualing , Zhao Hongxia , Li Dichen
Published: March 2014

Water-based ionic polymer–metal composites (IPMCs) exhibit complex deformation properties, especially when the water content changes. To explore the general actuation mechanisms, both Nafion and Flemion membranes are used as the polymer backbones. IPMC deformation includes three stages: fast anode deformation, relaxation deformation, and slow anode deformation, which is mainly dependent on the water content and the backbone. When the water content decreases from 21 to 14 wt. %, Nafion–IPMC exhibits a large negative relaxation deformation, zero deformation, a positive relaxation deformation, and a positive steady deformation without relaxation in sequence. Despite the slow anode deformation, Flemion–IPMC also shows a slight relaxation deformation, which disappears when the water content is less than 13 wt. %. The different water states are investigated at different water contents using nuclear magnetic resonance spectroscopy. The free water, which decreases rapidly at the beginning through evaporation, is proven to be critical for relaxation deformation. For the backbone, indirect evidence from the steady current response is correlated with the slow anode deformation of Flemion-IPMC. The latter is explained by the secondary dissociation of the weak acid group –COOH. Finally, we thoroughly explain not only the three deformations by swelling but also their evolvement with decreasing water content. A fitting model is also presented based on a multi-diffusion equation to reveal the deformation processes more clearly, the results from which are in good agreement with the experimental results.
Confocal acoustic radiation force optical coherence elastography using a ring ultrasonic transducer
Authors: Qi Wenjuan , Li Rui , Ma Teng , Kirk Shung K. , Zhou Qifa , Chen Zhongping
Published: March 2014

We designed and developed a confocal acoustic radiation force optical coherence elastography system. A ring ultrasound transducer was used to achieve reflection mode excitation and generate an oscillating acoustic radiation force in order to generate displacements within the tissue, which were detected using the phase-resolved optical coherence elastography method. Both phantom and human tissue tests indicate that this system is able to sense the stiffness difference of samples and quantitatively map the elastic property of materials. Our confocal setup promises a great potential for point by point elastic imaging in vivo and differentiation of diseased tissues from normal tissue.
Visible-light electroluminescence in Mn-doped GaAs light-emitting diodes
Authors: Nam Hai Pham , Maruo Daiki , Tanaka Masaaki
Published: March 2014

We observed visible-light electroluminescence (EL) due to d-d transitions in light-emitting diodes with Mn-doped GaAs layers (here, referred to as GaAs:Mn). Besides the band-gap emission of GaAs, the EL spectra show two peaks at 1.89 eV and 2.16 eV, which are exactly the same as 4A2(4F) → 4T1(4G) and 4T1(4G) → 6A1(6S) transitions of Mn atoms doped in ZnS. The temperature dependence and the current-density dependence are consistent with the characteristics of d-d transitions. We explain the observed EL spectra by the p-d hybridized orbitals of the Mn d electrons in GaAs.
Temporal evolution of nanoporous layer in off-normally ion irradiated GaSb
Authors: Datta D. P. , Kanjilal A. , Garg S. K. , Sahoo P. K. , Kanjilal D. , Som T.
Published: March 2014

Room temperature irradiation of GaSb by 60 keV Ar+-ions at an oblique incidence of 60° leads to simultaneous formation of a nanoporous layer and undulations at the interface with the underlying substrate. Interestingly, with increasing ion fluence, a gradual embedding of the dense nanoporous layer takes place below ridge-like structures (up to the fluence of 1 × 1017 ions cm−2), which get extended to form a continuous layer (at fluences ≥4 × 1017 ions cm−2). Systematic compositional analyses reveal the co-existence of Ga2O3 and Sb2O3 in the surface layer. The results are discussed in terms of a competition between ion-induced defect accumulation and re-deposition of sputtered atoms on the surface.
Quantifying electrostatic force contributions in electrically biased nanoscale interactions
Authors: Maragliano C. , Glia A. , Stefancich M. , Chiesa M.
Published: March 2014

A study of the validity of analytical methods for calculating the electrostatic force interaction in alternating current electrostatic force microscopy is presented. Using a simple harmonic oscillator model, two analytical frameworks aimed at relating the electrostatic force between the cantilever tip and the sample with measurable parameters (amplitude and phase of the cantilever) are derived. The validity of the frameworks is examined based on two parameters that define the oscillation amplitude of the cantilever (tip voltage and tip-sample distance). Results are compared with an analytical model of the electrostatic interaction between tip and sample (tip-sample capacitance) and the range of validity of these two frameworks is provided. Our analysis confirms that the commonly used interpretation of the amplitude and the phase as a measure for the electrostatic force and for the derivative of the electrostatic force is only valid for very small oscillation amplitudes and depends on the tip geometry. Furthermore, this study demonstrates that these two techniques suffer from sensitivity limitations at large tip-sample distances. Finally, we compare the two frameworks with an alternative technique for the quantification of the tip-sample electrostatic interaction we have recently proposed and we discuss and experimentally demonstrate its advantages in terms of reliability and sensitivity, providing an example of dielectric constant measurement of a thin insulating film.
Response characteristics of a potentiometric CO2 gas sensor based on Li3PO4 solid electrolyte using Au film as the electrodes
Authors: Sun Guoliang , Wang Hairong , Li Peng , Liu Zhen , Jiang Zhuangde
Published: March 2014

A potentiometric CO2 gas sensor based on Li3PO4 film with the thickness of 0.8 μm prepared by thermal evaporation method was developed. Au thin film with the thickness of 400 nm deposited by sputtering method was used as the metal electrodes of the sensor. Li2CO3 and Li2TiO3 with 10 mol. % TiO2 were used as the sensing and reference electrodes by screen printing the materials on the Au thin film electrodes, respectively. Response characteristics of the sensor to CO2 in the range of 250 ppm to 5000 ppm at different working temperatures were investigated. The electromotive force (EMF) values of the sensor were linearly dependent on logarithm of CO2 partial pressure at the temperatures between 420 °C and 530 °C. Dependence of response and recovery time, initial EMF, ΔEMF/dec on working temperature was presented. It can be found that the response time and recovery time reduced with the enhancement of working temperature and gradually reached to the limit when the temperature is above 500 °C. However, the maximum ΔEMF/dec value was obtained at the temperature of 440 °C. The dependence of ΔEMF/dec on working temperature was newly found and different from previous research. The results suggest potential use of thin film metal electrodes in solid electrolyte gas sensors for lower temperature and miniature applications.
The electronic properties and lattice dynamics of (Na0.5Bi0.5)TiO3: From cubic to tetragonal and rhombohedral phases
Authors: Lü Hongfeng , Wang Shanying , Wang Xiaosu
Published: March 2014

The structural, electronic and dynamical properties of the cubic, tetragonal and rhombohedral phases of a lead-free ferroelectrics, (Na0.5Bi0.5)TiO3 (NBT), have been studied with a density functional formalism. The direct band gap is determined to be 2∼3 eV for three phases, suggesting them to be good optical material. The equilibrium structures were given, and the importance of Bi atom in the low-symmetry ferroelectric phases were investigated with the electron localization functions analysis. The vibration modes at the Γ point were calculated to provide a basis for analyzing the Raman and IR spectra. Soft modes were found in both the cubic and the tetragonal phases, providing a clue in understanding the ferroelectric phase transition in NBT.
Electro-optic switching in iron oxide nanoparticle embedded paramagnetic chiral liquid crystal via magneto-electric coupling
Authors: Goel Puja , Arora Manju , Biradar Ashok M.
Published: March 2014

The variation in optical texture, electro-optic, and dielectric properties of iron oxide nanoparticles (NPs) embedded ferroelectric liquid crystal (FLC) with respect to change in temperature and electrical bias conditions are demonstrated in the current investigations. Improvement in spontaneous polarization and response time in nanocomposites has been attributed to magneto-electric (ME) coupling resulting from the strong interaction among the ferromagnetic nanoparticle's exchange field (due to unpaired e−) and the field of liquid crystal molecular director. Electron paramagnetic resonance spectrum of FLC material gives a broad resonance signal with superimposed components indicating the presence of a source of spin. This paramagnetic behavior of host FLC material had been a major factor in strengthening the guest host interaction by giving an additional possibility of (a) spin-spin interaction and (b) interactions between magnetic-dipole and electric-dipole moments (ME effects) in the composite materials. Furthermore, the phenomenon of dielectric and static memory effect in these composites are also observed which yet again confirms the coupling of magnetic NP's field with FLC's director orientation. We therefore believe that such advanced soft materials holding the optical and electrical properties of conventional LCs with the magnetic and electronic properties of ferromagnetic nanoparticles are going to play a key role in the development of futuristic multifunctional optical devices.
Magnetic and transport properties of Mn0.02Sn0.98O2−δ thin films grown on p-Si varying O2 pressure
Authors: Bhaumik S. , Ray S. K. , Das A. K.
Published: March 2014

Mn0.02Sn0.98O2−δ thin films were fabricated varying oxygen pressure on p-Si (100) substrate by pulsed laser deposition technique. Magnetic moment measurements confirm that the films are ferromagnetic at room temperature. The magnetic moment increases with decrease in oxygen pressure. The Mn0.02Sn0.98O2−δ/p-Si(100) heterojunctions behave well as rectifiers at lower temperature, but not at room temperature. The forward current (I) of the rectifier is drastically reduced at lower temperature on application of a few Oe magnetic field (H), and almost zero current is observed above 0.5 kOe. The I-H curves are symmetric with respect to positive and negative magnetic field. As the temperature increases the dependency of current on magnetic field decreases and becomes null above 70 K.
Breakdown voltage reduction by field emission in multi-walled carbon nanotubes based ionization gas sensor
Authors: Saheed M. Shuaib M. , Muti Mohamed Norani , Arif Burhanudin Zainal
Published: March 2014

Ionization gas sensors using vertically aligned multi-wall carbon nanotubes (MWCNT) are demonstrated. The sharp tips of the nanotubes generate large non-uniform electric fields at relatively low applied voltage. The enhancement of the electric field results in field emission of electrons that dominates the breakdown mechanism in gas sensor with gap spacing below 14 μm. More than 90% reduction in breakdown voltage is observed for sensors with MWCNT and 7 μm gap spacing. Transition of breakdown mechanism, dominated by avalanche electrons to field emission electrons, as decreasing gap spacing is also observed and discussed.
Tailoring of unipolar strain in lead-free piezoelectrics using the ceramic/ceramic composite approach
Authors: Khansur Neamul H. , Groh Claudia , Jo Wook , Reinhard Christina , Kimpton Justin A. , Webber Kyle G. , Daniels John E.
Published: March 2014

The electric-field-induced strain response mechanism in a polycrystalline ceramic/ceramic composite of relaxor and ferroelectric materials has been studied using in situ high-energy x-ray diffraction. The addition of ferroelectric phase material in the relaxor matrix has produced a system where a small volume fraction behaves independently of the bulk under an applied electric field. Inter- and intra-grain models of the strain mechanism in the composite material consistent with the diffraction data have been proposed. The results show that such ceramic/ceramic composite microstructure has the potential for tailoring properties of future piezoelectric materials over a wider range than is possible in uniform compositions.
Real-time measurement of optical anisotropy during film growth using a chemical mist deposition of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)
Authors: Hiate T. , Miyauchi N. , Liu Q. , Ishikawa R. , Ueno K. , Shirai H.
Published: March 2014

Real-time monitoring of optical anisotropy during growth by the chemical mist deposition of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films was carried out using spectroscopic ellipsometry. The microstructure of the grown films was found to be primarily determined by the DC bias applied to the mesh electrode. The ellipsometry results revealed that uniaxial anisotropy appeared for film thicknesses of about 5 nm and above, which corresponds to the average size of PEDOT crystallites. The extraordinary refractive index was found to be strongly correlated with the carrier mobility. Both the degree of optical anisotropy and the carrier mobility could be controlled during film growth by adjusting the DC bias.
Lensless ghost imaging of a phase object with pseudo-thermal light
Authors: Zhang De-Jian , Tang Qiang , Wu Teng-Fei , Qiu Hao-Chuan , Xu De-Qin , Li Hong-Guo , Wang Hai-Bo , Xiong Jun , Wang Kaige
Published: March 2014

We report an experimental realization of lensless ghost imaging for a phase-only object with pseudo-thermal light, which was proposed by W. Gong and S. Han [Phys. Rev. A 82, 023828 (2010)]. In contrast with conventional ghost imaging, the scheme involves the interference of two correlated fields and the phase information of the object can be retrieved. This imaging technique completes the nonlocally lensless spatial reconstruction of both amplitude and phase distributions in ghost imaging with thermal light.
Abnormal electron-heating mode and formation of secondary-energetic electrons in pulsed microwave-frequency atmospheric microplasmas
Authors: Kwon H. C. , Jung S. Y. , Kim H. Y. , Won I. H. , Lee J. K.
Published: March 2014

The formation of secondary energetic electrons induced by an abnormal electron-heating mode in pulsed microwave-frequency atmospheric microplasmas was investigated using particle-in-cell simulation. We found that additional high electron heating only occurs during the first period of the ignition phase after the start of a second pulse at sub-millimeter dimensions. During this period, the electrons are unable to follow the abruptly retreating sheath through diffusion alone. Thus, a self-consistent electric field is induced to drive the electrons toward the electrode. These behaviors result in an abnormal electron-heating mode that produces high-energy electrons at the electrode with energies greater than 50 eV.
Epitaxial Ba2IrO4 thin-films grown on SrTiO3 substrates by pulsed laser deposition
Authors: Nichols J. , Korneta O. B. , Terzic J. , Cao G. , Brill J. W. , Seo S. S. A.
Published: March 2014

We have synthesized epitaxial Ba2IrO4 (BIO) thin-films on SrTiO3 (001) substrates by pulsed laser deposition and studied their electronic structure by dc-transport and optical spectroscopic experiments. We have observed that BIO thin-films are insulating but close to the metal-insulator transition boundary with significantly smaller transport and optical gap energies than its sister compound, Sr2IrO4. Moreover, BIO thin-films have both an enhanced electronic bandwidth and electronic-correlation energy. Our results suggest that BIO thin-films have great potential for realizing the interesting physical properties predicted in layered iridates.
Indirect and direct optical transitions in In0.5Ga0.5As/GaP quantum dots
Authors: Stracke G. , Sala E. M. , Selve S. , Niermann T. , Schliwa A. , Strittmatter A. , Bimberg D.
Published: March 2014

We present a study of self-assembled In0.5Ga0.5As quantum dots on GaP(001) surfaces linking growth parameters with structural, optical, and electronic properties. Quantum dot densities from 5.0 × 107 cm−2 to 1.5 × 1011 cm−2 are achieved. A ripening process during a growth interruption after In0.5Ga0.5As deposition is used to vary the quantum dot size. The main focus of this work lies on the nature of optical transitions which can be switched from low-efficient indirect to high-efficient direct ones through improved strain relief of the quantum dots by different cap layers.
Highly efficient inverted organic solar cells using amino acid modified indium tin oxide as cathode
Authors: Li Aiyuan , Nie Riming , Deng Xianyu , Wei Huaixin , Zheng Shizhao , Li Yanqing , Tang Jianxin , Wong King-Young
Published: March 2014

In this paper, we report that highly efficient inverted organic solar cells were achieved by modifying the surface of indium tin oxide (ITO) using an amino acid, Serine (Ser). With the modification of the ITO surface, device efficiency was significantly enhanced from 0.63% to 4.17%, accompanied with an open circuit voltage (Voc) that was enhanced from 0.30 V to 0.55 V. Ultraviolet and X-ray photoelectron spectroscopy studies indicate that the work function reduction induced by the amino acid modification resulting in the decreased barrier height at the ITO/organic interface played a crucial role in the enhanced performances.
A multidirectional frequency splitter with band-stop plasmonic filters
Authors: Jin Zhou Yong , Yang Xue-Xia , Jun Cui Tie
Published: March 2014

We propose a multidirectional frequency splitter with band-stop plasmonic filters, in which a double-period grating structure is adopted to produce band-stop filtering features. The multidirectional frequency splitter consists of three specially designed metallic gratings with finite thickness. Better isolation between different metallic gratings is achieved at the lower frequencies. The experimental verification of the frequency splitter is implemented at the microwave frequencies with excellent agreements to full-wave simulations. A four-way THz frequency splitter excited by the cylindrical wire is also proposed and simulated to show how the design can be scaled down to the THz frequencies for the potential applications.
Nutrients, chlorophyll and biotic metrics in the Rappahannock River estuary: implications of urbanisation in the Chesapeake Bay watershed, USA
Authors: Prasad M. Bala Krishna , Maddox Michael C. , Sood Aditya , Kaushal Sujay , Murtugudde Raghu
Published: March 2014

In the Chesapeake Bay watershed, various endeavours such as the inter-state agreements and Chesapeake 2000 agreement have been implemented to improve water quality and ecological conditions, and have produced mixed results at best in various tributaries. So as to evaluate the management efforts on ecological conditions in the Rappahannock River watershed, we analysed the long-term variability in land use, nutrient content and ecological biotic metrics. It appears that the inter-annual variability in nutrient loadings and concentrations is largely influenced by changes in urbanisation and climate. Significant increases in urban development (35%) and population growth have exacerbated both point and non-point nutrient pollution in the Rappahannock River. The comparatively low N : P ratio in the tidal zone, with respect to the non-tidal zone, may be due to salinity-induced P leaching from sediments regulating the water quality along the river–estuary continuum. In addition, inter-annual variability in ecological biotic metrics demonstrates degrading ecological conditions in the Rappahannock River watershed, which are primarily due to increasing watershed urbanisation driving high nutrient loadings and altered nutrient stoichiometry.
Combined hydrogels that switch human pluripotent stem cells from self-renewal to differentiation
Authors: Dixon James E. , Shah Disheet A. , Rogers Catherine , Hall Stephen , Weston Nicola , Parmenter Christopher D. J. , McNally Donal , Denning Chris , Shakesheff Kevin M.
Published: March 2014

Significance

Stem-cell microenvironment has been identified as an important modulator of plasticity, self-renewal, and differentiation. This work details the development of a hydrogel system tailored to promote human pluripotent stem cell (HPSC) self-renewal with a simple chemical microenvironmental switch to direct differentiation. Furthermore, the timing of switching post hydrogel fabrication can promote specific lineage differentiation as in vivo. This system highlights the role of microenvironment on fate choices of pluripotent cells and demonstrates that it may be tailored to control differentiation in vitro. Importantly, this approach may improve the generation of fully differentiated tissues, as demonstrated for cardiogenic differentiation. Our combination of hydrogels allows dense tissue structures to be produced from HPSCs by using a single-step process inaccessible to any current methodology.
Generation and confirmation of a (100 × 100)-dimensional entangled quantum system
Authors: Krenn Mario , Huber Marcus , Fickler Robert , Lapkiewicz Radek , Ramelow Sven , Zeilinger Anton
Published: March 2014

Significance

Quantum entanglement is one of the key features of quantum mechanics. Quantum systems are the basis of new paradigms in quantum computation, quantum cryptography, or quantum teleportation. By increasing the size of the entangled quantum system, a wider variety of fundamental tests as well as more realistic applications can be performed. The size of the entangled quantum state can increase with the number of particles or, as in the present paper, with the number of involved dimensions. We explore a quantum system that consists of two photons which are 100-dimensionally entangled. The dimensions investigated are the different spatial modes of photons. The result may have potential applications in quantum cryptography and other quantum information tasks.
Gene-expression analysis of hair cell regeneration in the zebrafish lateral line
Authors: Jiang Linjia , Romero-Carvajal Andres , Haug Jeff S. , Seidel Christopher W. , Piotrowski Tatjana
Published: March 2014

Significance

Deafness is caused largely by the death of sensory hair cells in the inner ear. In contrast to nonmammalian vertebrates, human hair cells do not regenerate. Understanding the mechanisms that regulate hair cell regeneration in zebrafish may shed light on the factors that prevent hair cell regeneration in mammals. RNA-Seq analysis of regenerating sensory organs uncovered dynamic changes in the expression of signaling pathways during zebrafish hair cell regeneration. Unexpectedly, the Wnt/β-catenin, Notch, and Fgf pathways are downregulated following hair cell death, whereas the Jak1/Stat3 pathway and cell cycle are activated. We propose that mimicking the zebrafish activation status of a combination of pathways at the correct time points in mammals may improve the chances of triggering regeneration of functional hair cells.
Thermoflexus hugenholtzii gen. nov., sp. nov., a thermophilic, microaerophilic, filamentous bacterium representing a novel class in the Chloroflexi, Thermoflexia classis nov., and description of Thermoflexaceae fam. nov. and Thermoflexales ord. nov.
Authors: Dodsworth Jeremy A. , Gevorkian Jonathan , Despujos Fairuz , Cole Jessica K. , Murugapiran Senthil K. , Ming Hong , Li Wen-Jun , Zhang Gengxin , Dohnalkova Alice , Hedlund Brian P.
Published: March 2014

A thermophilic, filamentous, heterotrophic bacterium, designated strain JAD2T, a member of an as-yet uncultivated lineage that is present and sometimes abundant in some hot springs worldwide, was isolated from sediment of Great Boiling Spring in Nevada, USA. Cells had a mean diameter of 0.3 µm and length of 4.0 µm, and formed filaments that typically ranged in length from 20 to 200 µm. Filaments were negative for the Gram stain reaction, spores were not formed and motility was not observed. The optimum temperature for growth was 72.5–75 °C, with a range of 67.5–75 °C, and the optimum pH for growth was 6.75, with a range of pH 6.5–7.75. Peptone, tryptone or yeast extract were able to support growth when supplemented with vitamins, but no growth was observed using a variety of defined organic substrates. Strain JAD2T was microaerophilic and facultatively anaerobic, with optimal growth at 1 % (v/v) O2 and an upper limit of 8 % O2. The major cellular fatty acids (>5 %) were C16 : 0, C19 : 0, C18 : 0, C20 : 0 and C19 : 1. The genomic DNA G+C content was 69.3 mol%. Phylogenetic and phylogenomic analyses using sequences of the 16S rRNA gene and other conserved genes placed JAD2T within the phylum

Chloroflexi

, but not within any existing class in this phylum. These results indicate that strain JAD2T is the first cultivated representative of a novel lineage within the phylum

Chloroflexi

, for which we propose the name Thermoflexus hugenholtzii gen. nov., sp. nov., within Thermoflexia classis nov., Thermoflexales ord. nov. and Thermoflexaceae fam. nov. The type strain of Thermoflexus hugenholtzii is JAD2T ( = JCM 19131T = CCTCC AB-2014030T).
Methyloparacoccus murrellii gen. nov., sp. nov., a methanotroph isolated from pond water
Authors: Hoefman Sven , van der Ha David , Iguchi Hiroyuki , Yurimoto Hiroya , Sakai Yasuyoshi , Boon Nico , Vandamme Peter , Heylen Kim , De Vos Paul
Published: March 2014

Two novel methanotrophic strains, R-49797T and OS501, were isolated from pond water in South Africa and Japan, respectively. Strains R-49797T and OS501 shared 99.7 % 16S rRNA gene sequence similarity. Cells were Gram-stain-negative, non-motile cocci with a diplococcoid tendency and contained type I methanotroph intracytoplasmic membranes. The pmoA gene encoding particulate methane monooxygenase was present. Soluble methane monoooxygenase (sMMO) activity, the mmoX gene encoding sMMO and the nifH gene encoding nitrogenase were not detected. Methane and methanol were utilized as sole carbon source. The strains grew optimally at 25–33 °C (range 20–37 °C) and at pH 6.3–6.8 (range 5.8–9.0). The strains did not support growth in media supplemented with 1 % (w/v) NaCl. For both strains, the two major fatty acids were C16 : 1ω7c and C16 : 0 and the DNA G+C content was 65.6 mol%. The isolates belong to the family

Methylococcaceae

of the class

Gammaproteobacteria

and cluster most closely among the genera

Methylocaldum

,

Methylococcus

and

Methylogaea

, with a 16S rRNA gene sequence similarity of 94.2 % between strain R-49797T and its closest related type strain (

Methylocaldum gracile

VKM 14LT). Based on the low 16S rRNA gene sequence similarities with its nearest phylogenetic neighbouring genera, the formation of a separate lineage based on 16S rRNA and pmoA gene phylogenetic analysis, and the unique combination of phenotypic characteristics of the two isolated strains compared with the genera

Methylocaldum

,

Methylococcus

and

Methylogaea

, we propose to classify these strains as representing a novel species of a new genus, Methyloparacoccus murrellii gen. nov., sp. nov., within the family

Methylococcaceae

. The type strain of Methyloparacoccus murrellii is R-49797T ( = LMG 27482T = JCM 19379T).
Thermotoga
profunda sp. nov. and Thermotoga
caldifontis sp. nov., anaerobic thermophilic bacteria isolated from terrestrial hot springs
Authors: Mori Koji , Yamazoe Atsushi , Hosoyama Akira , Ohji Shoko , Fujita Nobuyuki , Ishibashi Jun-ichiro , Kimura Hiroyuki , Suzuki Ken-ichiro
Published: March 2014

Two thermophilic, strictly anaerobic, Gram-negative bacteria, designated strains AZM34c06T and AZM44c09T, were isolated from terrestrial hot springs in Japan. The optimum growth conditions for strain AZM34c06T were 60 °C, pH 7.4 and 0 % additional NaCl, and those for strain AZM44c09T were 70 °C, pH 7.4 and 0 % additional NaCl. Complete genome sequencing was performed for both strains, revealing genome sizes of 2.19 Mbp (AZM34c06T) and 2.01 Mbp (AZM44c09T). Phylogenetic analyses based on 16S rRNA gene sequences and the concatenated predicted amino acid sequences of 33 ribosomal proteins showed that both strains belonged to the genus

Thermotoga

. The closest relatives of strains AZM34c06T and AZM44c09T were the type strains of

Thermotoga lettingae

(96.0 % similarity based on the 16S rRNA gene and 84.1 % similarity based on ribosomal proteins) and

Thermotoga hypogea

(98.6 and 92.7 % similarity), respectively. Using blast, the average nucleotide identity was 70.4–70.5 % when comparing strain AZM34c06T and

T. lettingae

TMOT and 76.6 % when comparing strain AZM44c09T and

T. hypogea

NBRC 106472T. Both values are far below the 95 % threshold value for species delineation. In view of these data, we propose the inclusion of the two isolates in the genus

Thermotoga

within two novel species, Thermotoga profunda sp. nov. (type strain AZM34c06T = NBRC 106115T = DSM 23275T) and Thermotoga caldifontis sp. nov. (type strain AZM44c09T = NBRC 106116T = DSM 23272T).
Indole negatively impacts predation by Bdellovibrio bacteriovorus and its release from the bdelloplast
Authors: Dwidar Mohammed , Nam Dougu , Mitchell Robert J.
Published: March 2014

Bdellovibrio bacteriovorus is a predatory bacterium that attacks a wide range of Gram‐negative bacterial pathogens and is proposed to be a potential living antibiotic. In this study, we evaluated the effects of indole, a bacterial signalling molecule commonly produced within the gut, on the predatory ability of B. bacteriovorus HD100. Indole significantly delayed predation on Escherichia coli MG1655 and Salmonella enterica KACC 11595 at physiological concentrations (0.25 to 1 mM) and completely inhibited predation when present at 2 mM. Microscopic analysis revealed that indole blocked the predator from attacking the prey. Furthermore, indole was not toxic to the predator but slowed down its motility. Microarray and reverse transcription quantitative polymerase chain reaction (RT‐qPCR) analyses confirmed that as the gene group showing the greatest downregulation in the presence of indole was flagellar assembly genes. Indole also caused a wide spectrum changes in gene expression including general downregulation of genes involved in ribosome assembly. Furthermore, indole addition to the predatory culture after the entrance of B. bacteriovorus into the prey periplasm slowed down bdelloplast lysis. In conclusion, indole can have significant impacts on the predation efficiency, which should be taken into consideration especially if B. bacteriovorus is to be applied as a probiotic or living antibiotic.
Fate of arsenate following arsenite oxidation in Agrobacterium tumefaciens GW4
Authors: Wang Qian , Qin Dong , Zhang Shengzhe , Wang Lu , Li Jingxin , Rensing Christopher , McDermott Timothy R. , Wang Gejiao
Published: March 2014

The fate of arsenate (AsV) generated by microbial arsenite (AsIII) oxidation is poorly understood. Agrobacterium tumefaciens wild‐type strain (GW4) was studied to determine how the cell copes with AsV generated in batch culture. GW4 grown heterotrophically with mannitol used AsIII as a supplemental energy supply as reflected by enhanced growth and increased cellular levels of NADH and ATP. Under low phosphate (Pi) conditions and presence of AsIII oxidation, up to ∼ 50% of the resulting AsV was taken up and found associated with the periplasm, membrane or cytoplasm fractions of the cells. Arsenic was found associated with proteins and polar lipids, but not in nucleic acids or sugars. Thin‐layer chromatography and gas chromatography–mass spectrometry analysis suggested the presence of arsenolipids in membranes, presumably as part of the bilayer structure of the cell membrane and replacing Pi under Pi‐limiting conditions. The potential role of a Pi‐binding protein (PstS) for AsV uptake was assessed with the His‐tag purified protein. Intrinsic tryptophan fluorescence spectra analysis suggests that PstS can bind AsV, but with lower affinity as compared with Pi. In early stationary phase cells, the AsV : Pi ratio was approximately 4.3 and accompanied by an altered cell ultrastructure.
Comparison of bacterial communities on limnic versus coastal marine particles reveals profound differences in colonization
Authors: Bižić‐Ionescu Mina , Zeder Michael , Ionescu Danny , Orlić Sandi , Fuchs Bernhard M. , Grossart Hans‐Peter , Amann Rudolf
Published: March 2014

Marine and limnic particles are hotspots of organic matter mineralization significantly affecting biogeochemical element cycling. Fluorescencein‐situhybridization and pyrosequencing of 16SrRNAgenes were combined to investigate bacterial diversity and community composition on limnic and coastal marine particles > 5 and > 10 μm respectively. Limnic particles were more abundant (average: 1 × 107 l−1), smaller in size (average areas: 471 versus 2050 μm2) and more densely colonized (average densities: 7.3 versus 3.6 cells 100 μm−2) than marine ones. Limnic particle‐associated (PA) bacteria harbouredAlphaproteobacteriaandBetaproteobacteria, and unlike previously suggested sizeable populations ofGammaproteobacteria,ActinobacteriaandBacteroidetes. Marine particles were colonized byPlanctomycetesandBetaproteobacteriaadditionally toAlphaproteobacteria,BacteroidetesandGammaproteobacteria. Large differences in individual particle colonization could be detected. High‐throughput sequencing revealed a significant overlap ofPAand free‐living (FL) bacteria highlighting an underestimated connectivity between both fractions.PAbacteria were in 14/21 cases more diverse thanFLbacteria, reflecting a high heterogeneity in the particle microenvironment. We propose that a ratio of Chao 1 indices ofPA/FL < 1 indicates the presence of rather homogeneously colonized particles. The identification of different bacterial families enriched on either limnic or marine particles demonstrates that, despite the seemingly similar ecological niches,PAcommunities of both environments differ substantially.