bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Triacylglycerols and Free Fatty Acids in Algae Using Ultra‐Performance Liquid Chromatography Mass Spectrometry
Authors: Samburova Vera , Lemos Mark S. , Hiibel Sage , Kent Hoekman S. , Cushman John C. , Zielinska Barbara
Published: September 2012

To assess the suitability of microalgal strains for biodiesel production the lipid content and composition, especially individual triacylglycerols (TAG) and free fatty acids (FFA) must be determined. In this study, the compositions and concentrations of TAG and FFA were analysed in four halophytic algal species, Dunaliella salina, D. tertiolecta, D. bardawil, and D. granulata. These species were selected as part of a larger screen to identify species suitable for biofuel feedstocks. An accelerated solvent extraction instrument was used for lipids and fatty acid extraction using a dichloromethane–hexane solvent system. Ultra‐performance liquid chromatography coupled with mass spectrometry (MS) detection was optimized and applied to the quantitative analysis of TAG and FFA in the different algal extracts. Individual TAG were characterized structurally using direct electrospray ionization (ESI) MS and MS/MS techniques. Cationic adducts (NH4+) of TAG were detected and quantified in the positive ESI MS and MS/MS modes, while the negative ESI mode was used for FFA analysis. Over 20 TAG were identified and quantified in the four Dunaliella strains. Analysis of FFA compositions demonstrated that the most abundant FFA in these four algal species were palmitic, linolenic, linoleic, and oleic acids.
Lipase Immobilized Methacrylate Polymer Monolith Microreactor for Lipid Transformations and Online Analytics
Authors: Mugo Samuel M. , Ayton Karl
Published: September 2012

This communication entails development of a facile continuous flow lipase immobilized poly(glycidyl methacrylate‐co‐ethylene dimethacrylate (poly(GMA‐co‐EDMA)) monolith microreactor for application in lipid transformations. Candida antarctica lipase B was covalently immobilized on poly(GMA‐co‐EDMA) monolith prepared in a 700‐μm (internal diameter) silica capillary. The specific activity of the immobilized lipase was calculated to be 30 ± 0.03 U/mg, where U refers to μg p‐nitrophenol generated/min from 3.5 mM p‐nitrophenyl butyrate solution. The microreactor performance was further tested for synthesis of lauryl laurate via esterification. Conversions of up to 97 % were realized at a flow rate of 10 μL/min of a mixture of 0.1 M in both lauric acid and lauryl alcohol. These microreactors could be reused at least 15 times over a 1 month time period, stored at room temperature, with minimal to no reduction in the activity of the enzyme. We have also demonstrated microreactors to be useful for facile transesterification of castor oil triglycerides with online ESI–MS analytics key in lipidomics applications.
Structural insight into the interaction of ADP‐ribose with the PARP WWE domains
Authors: He Fahu , Tsuda Kengo , Takahashi Mari , Kuwasako Kanako , Terada Takaho , Shirouzu Mikako , Watanabe Satoru , Kigawa Takanori , Kobayashi Naohiro , Güntert Peter , Yokoyama Shigeyuki , Muto Yutaka
Published: September 2012

The WWE domain is often identified in proteins associated with ubiquitination or poly‐ADP‐ribosylation. Structural information about WWE domains has been obtained for the ubiquitination‐related proteins, such as Deltex and RNF146, but not yet for the poly‐ADP‐ribose polymerases (PARPs). Here we determined the solution structures of the WWE domains from PARP11 and PARP14, and compared them with that of the RNF146 WWE domain. NMR perturbation experiments revealed the specific differences in their ADP‐ribose recognition modes that correlated with their individual biological activities. The present structural information sheds light on the ADP‐ribose recognition modes by the PARP WWE domains.
Aminoacylase 3 binds to and cleaves the N‐terminus of the hepatitis C virus core protein
Authors: Tsirulnikov Kirill , Abuladze Natalia , Vahi Ritu , Hasnain Huma , Phillips Martin , Ryan Christopher M. , Atanasov Ivo , Faull Kym F. , Kurtz Ira , Pushkin Alexander
Published: September 2012

AA3
binds to
HCVCP
by surface plasmon resonance (View Interaction:
1,
2,
3,
4,
5)
Physical activity patterns and correlates among adults from a developing country: the Sri Lanka Diabetes and Cardiovascular Study
Authors: Katulanda Prasad , Jayawardana Ranil , Ranasinghe Priyanga , Rezvi Sheriff MH , Matthews David R
Published: September 2012

Objective

To evaluate patterns of physical activity (PA), the prevalence of physical inactivity and the relationships between PA and sociodemographic, clinical and biochemical parameters among Sri Lankan adults.

Design

Descriptive cross-sectional study.

Setting

Nationally representative population-based survey conducted in Sri Lanka.

Subjects

Data on PA and associated details were obtained from 5000 adults. PA was assessed using the International Physical Activity Questionnaire (short-form). A binary logistic regression analysis was performed using the dichotomous variable ‘health-enhancing PA’ (0 = ‘active’, 1 = ‘inactive’).

Results

Sample size was 4485. Mean age was 46·1 (sd 15·1) years, 39·5 % were males. The mean weekly total MET (metabolic equivalents of task) minutes of PA among the study population was 4703 (sd 4369). Males (5464 (sd 5452)) had a significantly higher weekly total MET minutes than females (4205 (sd 3394); P < 0·001). Rural adults (5175 (sd 4583)) were significantly more active than urban adults (2956 (sd 2847); P < 0·001). Tamils had the highest mean weekly total MET minutes among ethnicities. Those with tertiary education had lowest mean weekly total MET minutes. In all adults 60·0 % were in the ‘highly active’ category, while only 11·0 % were ‘inactive’ (males 14·6 %, females 8·7 %; P < 0·001). Of the ‘highly active’ adults, 85·8 % were residing in rural areas. Results of the binary logistic regression analysis indicated that female gender (OR = 2·1), age >70 years (OR = 3·8), urban living (OR = 2·5), Muslim ethnicity (OR = 2·7), tertiary education (OR = 3·6), obesity (OR = 1·8), diabetes (OR = 1·6), hypertension (OR = 1·2) and metabolic syndrome (OR = 1·3) were all associated with significantly increased odds of being physically ‘inactive’.

Conclusions

The majority of Sri Lankan adults were ‘highly active’ physically. Female gender, older age, urban living, Muslim ethnicity and tertiary education were all significant predictors of physical inactivity. Physical inactivity was associated with obesity, diabetes, hypertension and metabolic syndrome.
Toward ‘Generous Love’: Recent Anglican Approaches to World Religions
Authors: Quinn Frederick
Published: September 2012

How should Anglicans regard other religions? The approaches of a number of Anglican writers considered in this article are valuable, both to Anglicans and to others, beginning with F.D. Maurice in the late nineteenth century. Others include Kenneth Cragg, an Arabist and Evangelical; Alan Race, author of the Exclusivist, Inclusivist, and Pluralist paradigm; Kwok Pui-Lan, a contemporary Asian feminist; Ian S. Markham, who proposes a ‘Theology of Engagement’; Rowan Williams, Archbishop of Canterbury and an important writer on the theology of Raimon Panikkar; David F. Ford, proponent of the Cambridge Scriptural Reasoning (SR) program that seeks ‘better quality disagreement’; and Keith Ward, whose systematic theology develops a concept of ‘convergent spirituality’. Moving from the theoretical to the practical, the article discusses the global United Religions Initiative of William E. Swing, former Episcopal Bishop of California. Collectively, these authors provide a range of intersecting Anglican approaches to the evolving question of Anglican relations with other world religions.
A 60 GHz eight-element phased-array receiver front-end in 0.25 µm SiGe BiCMOS technology
Authors: Elkhouly Mohamed , Choi Chang-Soon , Glisic Srdjan , Ellinger Frank , Scheytt J. Christoph
Published: September 2012

This paper presents the design of an eight-element 60 GHz phased-array receiver chip with interference mitigation capability, fabricated in 0.25 μm SiGe BiCMOS technology. Each receiver element contains a low noise amplifier (LNA) and a vector-modulator that supports high-resolution amplitude and phase control. A fully differential power combining network follows the eight elements. The chip also includes an active power divider, a down conversion mixer, and fully integrated 48 GHz PLL to demonstrate the IF down-conversion. With LNA, a phase shifter and hybrid active and passive power combining network, each receiver path achieves 18 dB of gain, 360° phase shift in steps less than 3°, 20 dB amplitude control, and 4 GHz 3 dB-bandwidth and input referred 1 dB compression point P1 dB of each element is of −22 dBm. Each receiver element dissipates in total 132 mW. The phased-array receiver shows more than 25 dB of signal to interference noise ratio, by means of amplitude and phase control.
High resolution 11B NMR of magnesium diboride using cryogenic magic angle spinning
Authors: Beckett Peter , Denning Mark S. , Heinmaa Ivo , Dimri Mukesh C. , Young Edward A. , Stern Raivo , Carravetta Marina
Published: September 2012

Static and magic-angle spinning 11B nuclear magnetic resonance (NMR) data at 4.7 T and 8.5 T have been obtained under cryogenic conditions on a diluted sample of magnesium diboride powder in the normal and superconducting state. The data provide accurate information on the magnetic shift and longitudinal relaxation time down to a temperature of 8 K, with a resolution improvement over the entire temperature range. The onset of superconductivity is unaffected by the sample rotation, as revealed by a steep variation of the magnetic shift just below the critical temperature.
Donor and acceptor levels in ZnO homoepitaxial thin films grown by molecular beam epitaxy and doped with plasma-activated nitrogen
Authors: Muret Pierre , Tainoff Dimitri , Morhain Christian , Chauveau Jean-Michel
Published: September 2012

Deep level transient spectroscopy of both majority and minority carrier traps is performed in a n-type, nitrogen doped homoepitaxial ZnO layer grown on a m-plane by molecular beam epitaxy. Deep levels, most of them being not detected in undoped ZnO, lie close to the band edges with ionization energies in the range 0.12–0.60 eV. The two hole traps with largest capture cross sections are likely acceptors, 0.19 and 0.48 eV from the valence band edge, able to be ionized below room temperature. These results are compared with theoretical predictions and other experimental data.
Three-dimensional modeling and analysis of a high energy density Kelvin-Helmholtz experiment
Authors: Raman K. S. , Hurricane O. A. , Park H.-S. , Remington B. A. , Robey H. , Smalyuk V. A. , Drake R. P. , Krauland C. M. , Kuranz C. C. , Hansen J. F. , Harding E. C.
Published: September 2012

A recent series of experiments on the OMEGA laser provided the first controlled demonstration of the Kelvin–Helmholtz (KH) instability in a high-energy-density physics context [E. C. Harding et al., Phys. Rev. Lett. 103, 045005, (2009); O. A. Hurricane et al., Phys. Plasmas 16, 056305, (2009)]. We present 3D simulations which resolve previously reported discrepancies between those experiments and the 2D simulation used to design them. Our new simulations reveal a three-dimensional mechanism behind the low density “bubble” structures which appeared in the experimental x-ray radiographs at late times but were completely absent in the 2D simulations. We also demonstrate that the three-dimensional expansion of the walls of the target is sufficient to explain the 20% overprediction by 2D simulation of the late-time growth of the KH rollups. The implications of these results for the design of future experiments are discussed.
Roto-flexoelectric coupling impact on the phase diagrams and pyroelectricity of thin SrTiO3 films
Authors: Morozovska Anna N. , Eliseev Eugene A. , Bravina Svetlana L. , Borisevich Albina Y. , Kalinin Sergei V.
Published: September 2012

The influence of the flexoelectric and rotostriction coupling on the phase diagrams of ferroelastic-quantum paraelectric SrTiO3 films was studied using Landau-Ginzburg-Devonshire theory. The phase diagrams in coordinates temperature–film thickness were calculated for different epitaxial misfit strains. Tensile misfit strains stimulate appearance of the spontaneous out-of-plane structural order parameter (displacement vector of an appropriate oxygen atom from its cubic position) in the structural phase. Compressive misfit strains stimulate appearance of the spontaneous in-plane structural order parameter. Gradients of the structural order parameter components, which inevitably exist in the vicinity of film surfaces due to the termination and symmetry breaking, induce improper polarization and pyroelectric response via the flexoelectric and rotostriction coupling mechanism. Flexoelectric and rotostriction coupling results in the roto-flexoelectric field that is antisymmetric inside the film, small in the central part of the film, where the gradients of the structural parameter are small, and maximal near the surfaces, where the gradients of the structural parameter are highest. The field induces improper polarization and pyroelectric response. Penetration depths of the improper phases (both polar and structural) can reach several nm from the film surfaces. An improper pyroelectric response of thin films is high enough to be registered with planar-type electrode configurations by conventional pyroelectric methods.
Magnetism of electrons in atoms and superatoms
Authors: Medel Victor , Reveles J. Ulises , Khanna Shiv N.
Published: September 2012

The quantum states of electrons in small symmetric metallic clusters are grouped into shells similar to the electronic shells in free atoms, leading to the conceptual basis for defining superatoms. The filling of the electronic shells in clusters, however, do not follow Hund's rule and usually result in non-magnetic species. It is shown that by embedding a transition metal in group II atoms, one can stabilize superatoms with unpaired electronic supershells. We demonstrate this intriguing effect through electronic structure studies of MnSrn (n = 6-12) clusters within first principles generalized gradient calculations. The studies identify an unusually stable magnetic MnSr9 species with a large exchange splitting of 1.82 eV of the superatomic D-states. It is shown that the exchange split d-states in the Mn atom induce exchange splitting in S and D superatomic shells because of the hybridization between orbitals of selected parity. The magnetic MnSr9 cluster with 25 valence electrons has filled 1S2, 1P6, 1D10, 2S2 shells, making it highly stable, and an open shell of 5 unpaired D electrons breeding the magnetic moment. The stable cluster is resistant to collapse as two motifs are united to form a supermolecule.
Performance of the NIST goniocolorimeter with a broad-band source and multichannel charged coupled device based spectrometer
Authors: Podobedov V. B. , Miller C. C. , Nadal M. E.
Published: September 2012

The authors describe the NIST high-efficiency instrument for measurements of bidirectional reflectance distribution function of colored materials, including gonioapparent materials such as metallic and pearlescent coatings. The five-axis goniospectrometer measures the spectral reflectance of samples over a wide range of illumination and viewing angles. The implementation of a broad-band source and a multichannel CCD spectrometer corrected for stray light significantly increased the efficiency of the goniometer. In the extended range of 380 nm to 1050 nm, a reduction of measurement time from a few hours to a few minutes was obtained. Shorter measurement time reduces the load on the precise mechanical assembly ensuring high angular accuracy over time. We describe the application of matrix-based correction of stray light and the extension of effective dynamic range of measured fluxes to the values of 106 to 107 needed for the absolute characterization of samples. The measurement uncertainty was determined to be 0.7% (k = 2), which is comparable with similar instruments operating in a single channel configuration. Several examples of reflectance data obtained with the improved instrument indicate a 0.3% agreement compared to data collected with the single channel configuration.
Computational characterization of bulk heterojunction nanomorphology
Authors: Wodo Olga , Tirthapura Srikanta , Chaudhary Sumit , Ganapathysubramanian Baskar
Published: September 2012

The bulk heterojunction (BHJ) nanomorphology in organic solar cells strongly affects the final efficiency of the device. Progress in experimental techniques now allows visualization of the complex 3D BHJ morphology. It is, therefore, important to characterize the topological properties of the morphology in order to quantify the link between morphology features and performance. Here, we introduce a suite of morphology descriptors which encode the complex nature of the multi-stage photovoltaic process in the BHJ. These morphology descriptors are easily determined using an approach based on converting the morphology into an equivalent weighted, labeled, undirected graph. We show how these descriptors can be used to interrogate BHJ morphologies, allow identification of bottlenecks in the photovoltaic process, and conduct quantitative comparison between morphologies with respect to each sub-process in the photovoltaic phenomena. This framework provides a simple and easy-to-use characterization tool that can be used to unravel the impact of morphology on complex transport phenomena.
Assessment of phonon boundary scattering from light scattering standpoint
Authors: Jin Lee Hyun , Sik Jin Jae , Jae Lee Bong
Published: September 2012

In the present study, we have applied the light scattering theory to investigate the phonon boundary scattering from one-dimensional rough surfaces. It has been shown that Ziman's model for the specularity is only applicable to a slightly rough surface at normal incidence. For relatively rougher Gaussian surfaces, the specularity is insufficient to properly describe the phonon scattering characteristics. Instead, the bidirectional reflectance distribution function must be fully incorporated into the analysis. We also showed that the phonon scattering from a sawtooth-like rough surface is quite different from that from a Gaussian rough surface, even though the roughness parameters are comparable. It was revealed that the multiple scattering from sawtooth-like rough surfaces can cause the confinement of phonons, which is responsible for the reduction of the thermal conductivity of rough Si nanowire below the Casimir limit.
Analytical model of surface depletion in GaAs nanowires
Authors: Chia Andrew C. E. , LaPierre Ray R.
Published: September 2012

Poisson's equation is solved to provide a comprehensive model of nanowire (NW) surface depletion as a function of interface state density, NW radius, and doping density. This model improves upon established theory by giving distinct solutions to the cases of full and partial NW depletion while implementing the charge neutrality level and accurate Fermi-Dirac statistics. To explain the underlying physics, key parameters were plotted as a function of both interface state density and NW radius, showing interesting features such as the lowering of the Fermi level in fully depleted NWs and marked increase in surface depletion width and built-in surface potential (relative to a planar film equivalent) in partially depleted NWs. Finally, examination of NW conductivity found that for NWs of radius acrit, the minimum NW radius before which the entire NW is depleted, conductivity can be reduced by up to 95% relative to bulk. Additionally, majority carrier inversion is predicted to occur in thin NWs.
Effect of macroscopic relaxation on residual stress analysis by diffraction methods
Authors: Repper J. , Hofmann M. , Krempaszky C. , Regener B. , Berhuber E. , Petry W. , Werner E.
Published: September 2012

To know the residual stress state within a component is essential for predicting its service life time. Neutron diffraction is a reliable tool for non-destructive determination of macroscopic residual stresses, even deep inside a component. One standard procedure in neutron residual stress analysis is to cut out small macrostress free coupons from the strained component, which serve as reference samples. Redistribution of intergranular stresses due to relaxation when the coupon is cut out, however, may lead to spurious macroscopic stresses. A quantitative study of the change of intergranular stresses shows that, contrary to conventional thought, even the {311} Bragg reflection is affected strongly by this phenomenon. In this case, the use of reference values calculated using boundary conditions of mechanical equilibrium enables to extract reliable macroscopic residual stress values.
Langmuir probe diagnostics of an atmospheric pressure, vortex–stabilized nitrogen plasma jet
Authors: Prevosto L. , Kelly H. , Mancinelli B. R.
Published: September 2012

Langmuir probe measurements in an atmospheric pressure direct current (dc) plasma jet are reported. Sweeping probes were used. The experiment was carried out using a dc non–transferred arc torch with a rod–type cathode and an anode of 5 mm diameter. The torch was operated at a nominal power level of 15 kW with a nitrogen flow rate of 25 Nl min−1. A flat ion saturation region was found in the current–voltage curve of the probe. The ion saturation current to a cylindrical probe in a high–pressure non local thermal equilibrium (LTE) plasma was modeled. Thermal effects and ionization/recombination processes inside the probe perturbed region were taken into account. Averaged radial profiles of the electron and heavy particle temperatures as well as the electron density were obtained. An electron temperature around 11 000 K, a heavy particle temperature around 9500 K and an electron density of about 4 × 1022 m−3, were found at the jet centre at 3.5 mm downstream from the torch exit. Large deviations from kinetic equilibrium were found throughout the plasma jet. The electron and heavy particle temperature profiles showed good agreement with those reported in the literature by using spectroscopic techniques. It was also found that the temperature radial profile based on LTE was very close to that of the electrons. The calculations have shown that this method is particularly useful for studying spraying–type plasma jets characterized by electron temperatures in the range 9000–14 000 K.
Interaction features of different propellants under plasma impingement
Authors: Li Xingwen , Li Rui , Jia Shenli , Zhang Yucheng
Published: September 2012

The development of electrothermal chemical launch technology and the effective ignition of energetic thermoplastic elastomer (ETPE) propellants all call for a thorough understanding of the plasma propellant interaction mechanism. Therefore in this work, a numerical model is developed to study this process. In this model, special attention is paid to deal with the regression of propellant surface, which is caused by plasma ablation, and is assumed to have considerable influence on the interaction process. By this model, interaction features of four propellants, including two ETPE propellants are studied with the aid of experiments, which are carried out to obtain plasma parameters utilized in the model. Surface temperature, ablation rate, and surface regression rate are obtained for different propellants under plasma impingement. Finally, the influence of propellant composition and charging voltage are analyzed.
Vibrational multi-reference coupled cluster theory in bosonic representation
Authors: Banik Subrata , Pal Sourav , Prasad M. Durga
Published: September 2012

The vibrational multi-reference coupled cluster method is developed to calculate the vibrational excitation energies of polyatomic molecules. The method is implemented on ozone and formaldehyde molecules and the results are compared with full vibrational configuration interaction (FVCI) method. A good agreement is found between the vibrational multi-reference coupled cluster method and converged FVCI method for lower lying vibrational states.
Note: A 4 ns hardware photon correlator based on a general-purpose field-programmable gate array development board implemented in a compact setup for fluorescence correlation spectroscopy
Authors: Kalinin Stanislav , Kühnemuth Ralf , Vardanyan Hayk , Seidel Claus A. M.
Published: September 2012

We present a fast hardware photon correlator implemented in a field-programmable gate array (FPGA) combined with a compact confocal fluorescence setup. The correlator has two independent units with a time resolution of 4 ns while utilizing less than 15% of a low-end FPGA. The device directly accepts transistor-transistor logic (TTL) signals from two photon counting detectors and calculates two auto- or cross-correlation curves in real time. Test measurements demonstrate that the performance of our correlator is comparable with the current generation of commercial devices. The sensitivity of the optical setup is identical or even superior to current commercial devices. The FPGA design and the optical setup both allow for a straightforward extension to multi-color applications. This inexpensive and compact solution with a very good performance can serve as a versatile platform for uses in education, applied sciences, and basic research.
Comprehensive studies of the electronic structure of pristine and potassium doped chrysene investigated by electron energy-loss spectroscopy
Authors: Roth Friedrich , Mahns Benjamin , Schönfelder Ronny , Hampel Silke , Nohr Markus , Büchner Bernd , Knupfer Martin
Published: September 2012

We have performed electron energy-loss spectroscopy studies in order to investigate the electronic properties of chrysene molecular solids. The valence band electronic excitation spectra and the C 1s core level excitations have been measured for pristine and potassium doped chrysene. The core level studies show a fine structure which signals the presence of four close lying conduction bands close to the Fermi level. Upon potassium doping, these bands are filled with electrons, and we have reached a doping level of about K2.7chrysene. Furthermore, undoped chrysene is characterized by an optical gap of about 3.3 eV and five, relatively weak, excitonic features following the excitation onset. Doping induces major changes in the electronic excitation spectra, with a new, prominent low energy excitation at about 1.3 eV. The results of a Kramers-Kronig analysis indicate that this new feature can be assigned to a charge carrier plasmon in the doped material, and momentum dependent studies reveal a negative plasmon dispersion.
Linear stability of the tearing mode with two-fluid and curvature effects in tokamaks
Authors: Meshcheriakov Dmytro , Maget Patrick , Lütjens Hinrich , Beyer Peter , Garbet Xavier
Published: September 2012

Curvature and diamagnetic effects are both recognized to have a stabilizing influence on tearing modes in the linear regime. In this paper, we investigate the impact of these effects on the linear stability of a (2, 1) magnetic island using non-linear two-fluid MHD simulations and we apply our results to Tore Supra experiments where its stability is not well understood from the single fluid MHD model. Simulations show an initial increase of the linear growth rate and then its reduction until full stability as diamagnetic frequency increases. This mechanism is therefore a plausible explanation for experimental observations where the (2, 1) mode was not observed although the single fluid model predicted its growth. Our simulations also show the importance of curvature for an efficient stabilization. A simple analytical model is derived to support the numerical results.
Highly tunable electron transport in epitaxial topological insulator (Bi1-xSbx)2Te3 thin films
Authors: He Xiaoyue , Guan Tong , Wang Xiuxia , Feng Baojie , Cheng Peng , Chen Lan , Li Yongqing , Wu Kehui
Published: September 2012

Atomically smooth, single crystalline (Bi1−xSbx)2Te3 films have been grown on SrTiO3(111) substrates by molecular beam epitaxy. A full range of Sb-Bi compositions have been studied in order to obtain the lowest possible bulk conductivity. For the samples with optimized Sb compositions (x=0.5±0.1), the carrier type can be tuned from n-type to p-type across the whole thickness with the help of a back-gate. Linear magnetoresistance has been observed at gate voltages close to the maximum in the longitudinal resistance of a (Bi0.5Sb0.5)2Te3 sample. These highly tunable (Bi1−xSbx)2Te3 thin films provide an excellent platform to explore the intrinsic transport properties of the three-dimensional topological insulators.
A versatile detector for total fluorescence and electron yield experiments
Authors: Thielemann N. , Hoffmann P. , Föhlisch A.
Published: September 2012

The combination of a non-coated silicon photodiode with electron repelling meshes makes a versatile detector for total fluorescence yield and electron yield techniques highly suitable for x-ray absorption spectroscopy. In particular, a copper mesh with a bias voltage allows to suppress or transmit the electron yield signal. The performance of this detection scheme has been characterized by near edge x-ray absorption fine structure studies of thermal oxidized silicon and sapphire. The results show that the new detector probes both electron yield and for a bias voltage exceeding the maximum photon energy the total fluorescence yield.
Transparent p-type AlN:SnO2 and p-AlN:SnO2/n-SnO2:In2O3 p-n junction fabrication
Authors: Liu Y. S. , Hsieh C. I. , Wu Y. J. , Wei Y. S. , Lee P. M. , Liu C. Y.
Published: September 2012

This study produced transparent p-type AlN-doped SnO2 thin films by annealing sputtered sandwich SnO2/AlN/SnO2 thin films. Both Al3+-Sn4+ and N3−O2− substitution reactions—which are the main sources for the hole carriers—were identified by XPS analysis. The hole concentration of the p-type AlN:SnO2 thin films was as high as 1.074 × 1019 cm−3. Using the produced p-AlN:SnO2 thin film, transparent p-AlN:SnO2/n-SnO2:In2O3 p-n junctions were fabricated and characterized as follows: (1) A low leakage current (2.97 × 10−5 A at −5 V); (2) a 2.17 eV turn-on voltage; and (3) a low ideality factor (12.2).
Thermally switchable adhesions of polystyrene-b
lock-poly(n-isopropylacrylamide) copolymer pillar array mimicking climb attitude of geckos
Authors: Chen Jem-Kun , Wang Jing-Hong , Chang Jia-Yaw , Fan Shih-Kang
Published: September 2012

Inspired by the gecko foot pad, we fabricated polystyrene-block-poly(N-isopropylacrylamide) (PS-b-PNIPAAm) copolymer pillar array to mimic climbing attitude of a gecko, alternately attach to and detach from a surface. The pillar array structure of the PS segment significantly enhances both of the hydrophilic and hydrophobic property of PNIPAAm segment tips at 25 and 50 °C, respectively, which could generate alternating adhesive forces of approximately 120 and 11 nN. The dramatic change in adhesive and friction force difference at 25 and 50 °C may guide the design of bio-inspired artificial analogues, which could approach gecko's climbing behavior.
W-Sb-Te phase-change material: A candidate for the trade-off between programming speed and data retention
Authors: Peng Cheng , Wu Liangcai , Rao Feng , Song Zhitang , Yang Pingxiong , Song Hongjia , Ren Kun , Zhou Xilin , Zhu Min , Liu Bo , Chu Junhao
Published: September 2012

W-Sb-Te phase-change material has been proposed to improve the performance of phase-change memory (PCM). Crystallization temperature, crystalline resistance, and 10-year data retention of Sb2Te increase markedly by W doping. The Wx(Sb2Te)1−x films crystallize quickly into a stable hexagonal phase with W uniformly distributing in the crystal lattice, which ensures faster SET speed and better operation stability for the application in practical device. PCM device based on W0.07(Sb2Te)0.93 shows ultrafast SET operation (6 ns) and good endurance (1.8 × 105 cycles). W-Sb-Te material is a promising candidate for the trade-off between programming speed and data retention.
Long-range surface plasmon single-mode laser concepts
Authors: Keshmarzi Elham Karami , Niall Tait R. , Berini Pierre
Published: September 2012

Near infrared single-mode lasers based on long-range surface plasmon-polariton waveguides and step-in-width Bragg gratings implemented with thin Ag stripes are proposed. The gain medium assumed is a polymer (poly(methylmethacrylate)) doped with organic laser dye molecules (IR-140). Three cavity resonator configurations have been investigated based on distributed feedback or distributed Bragg reflectors. Narrow line-width single-mode lasing is guaranteed by appropriately trading-off the length of the active region against the threshold lasing gain and designing gratings of sufficiently narrow bandwidth. Laser wavelength tuning through thermal modulation of the polymer refractive index by injecting current along the Ag gratings is briefly described.
Comparison of measurements and simulations of series-parallel incommensurate area superconducting quantum interference device arrays fabricated from YBa2Cu3O7−
δ
ion damage Josephson junctions
Authors: Cybart Shane A. , Dalichaouch T. N. , Wu S. M. , Anton S. M. , Drisko J. A. , Parker J. M. , Harteneck B. D. , Dynes R. C.
Published: September 2012

We have fabricated series-parallel (two-dimensional) arrays of incommensurate superconducting quantum interference devices (SQUIDs) using YBa2Cu3O7−δ thin film ion damage Josephson junctions. The arrays initially consisted of a grid of Josephson junctions with 28 junctions in parallel and 565 junctions in series, for a total of 15 255 SQUIDs. The 28 junctions in the parallel direction were sequentially decreased by removing them with photolithography and ion milling to allow comparisons of voltage–magnetic field (V–B) characteristics for different parallel dimensions and area distributions. Comparisons of measurements for these different configurations reveal that the maximum voltage modulation with magnetic field is significantly reduced by both the self inductances of the SQUIDs and the mutual inductances between them. Based on these results, we develop a computer simulation model from first principles which simultaneously solves the differential equations of the junctions in the array while considering the effects of self inductance, mutual inductance, and non-uniformity of junction critical currents. We find that our model can accurately predict V–B for all of the array geometries studied. A second experiment is performed where we use photolithography and ion milling to split another 28 × 565 junction array into 6 decoupled arrays to further investigate mutual interactions between adjacent SQUIDs. This work conclusively shows that the magnetic fields generated by self currents in an incommensurate array severely reduce its performance by reducing the maximum obtainable modulation voltage.
Electrical modulation of the edge channel transport in topological insulators coupled to ferromagnetic leads
Authors: Li Yuan , Jalil M. B. A. , Ghee Tan Seng , Zhou GuangHui
Published: September 2012

The counterpropagating edge states of a two-dimensional topological insulator (TI) carry electrons of opposite spins. We investigate the transport properties of edge states in a two-dimensional TI which is contacted to ferromagnetic leads. The application of a side-gate voltage induces a constriction or quantum point contact (QPC) which couples the two edge channels. The transport properties of the system are calculated via the Keldysh nonequilibrium Green's function method. We found that inter-edge spin-flip coupling can significantly enhance (suppress) the charge current when the magnetization of the leads are anti-parallel (parallel) to one another. On the other hand, spin-conserving inter-edge coupling generally reduces the current by backscattering regardless of the magnetization configuration. The charge current and the conductance as a function of the bias voltage, also exhibit similar trends with respect to spin-flip coupling strength, for both parallel and anti-parallel configurations. Hence, gate voltage modulation of edge states via a QPC can provide a means of modulating the spin or charge current flow in TI-based spintronics devices.
Plasma formation in atmospheric pressure helium discharges under different background air pressures
Authors: Liu Yaoge , Hao Yanpeng , Zheng Bin
Published: September 2012

Atmospheric pressure glow discharges generated between parallel-plate electrodes in helium have been characterized using temporally resolved emission spectra. The variation of typical spectral lines over time has been analyzed. In helium with a low concentration of N2, the emission of He at 706.5 nm is dominant and appears 500 ns earlier than N2+ first negative bands, indicating low reaction rates of Penning ionization and charge transfer in the initial stage. During the decay, it is the Penning ionization caused by He metastables with a long lifetime rather than the charge transfer reaction that leads to the long decay of N2+ emissions. When helium contains a higher concentration of N2 molecules, the N2+ first negative bands become the most intense, and emissions from He, N2+, and O exhibit similar behavior as they increase. The emissions last for a shorter time under such conditions because of rapid consumption of He metastables and He2+.
Numerical simulation of current-free double layers created in a helicon plasma device
Authors: Rao Sathyanarayan , Singh Nagendra
Published: September 2012

Two-dimensional simulations reveal that when radially confined source plasma with magnetized electrons and unmagnetized ions expands into diverging magnetic field B, a current-free double layer (CFDL) embedded in a conical density structure forms, as experimentally measured in the Australian helicon plasma device (HPD). The magnetized electrons follow the diverging B while the unmagnetized ions tend to flow directly downstream of the source, resulting in a radial electric field (E⊥) structure, which couples the ion and electron flows. Ions are transversely (radially) accelerated by E⊥ on the high potential side of the double layer in the CFDL. The accelerated ions are trapped near the conical surface, where E⊥ reverses direction. The potential structure of the CFDL is U-shaped and the plasma density is enhanced on the conical surface. The plasma density is severely depleted downstream of the parallel potential drop (φ||o) in the CFDL; the density depletion and the potential drop are related by quasi-neutrality condition, including the divergence in the magnetic field and in the plasma flow in the conical structure. The potential and density structures, the CFDL spatial size, its electric field strengths and the electron and ion velocities and energy distributions in the CFDL are found to be in good agreements with those measured in the Australian experiment. The applicability of our results to measured axial potential profiles in magnetic nozzle experiments in HPDs is discussed.
Local magnetic moment formation and magnetic hyperfine fields at Cd impurity in RAl2 (R = rare earth metal)
Authors: de Oliveira A. L. , de Oliveira N. A. , Chaves C. M. , Troper A.
Published: September 2012

A model to calculate self-consistently the local magnetic moment and the magnetic hyperfine field Bhf at the nuclei of 119Cd in RAl2 (R = rare earth metal), where the impurity occupies the Al site, is proposed. The local magnetic moment and the magnetic hyperfine field Bhf have two contributions each: one arising from the 4f electrons of the R ions and the other arising from the 3p electrons of Al. Our results are in good agreement with the experimental data.
Systematics and biology of the Australian seed bug genus Megadrymus Gross (Insecta:Heteroptera:Rhyparochromidae:Drymini)
Authors: Cassis Gerasimos , Symonds Celia
Published: September 2012

Megadrymus Gross is an endemic seed bug genus that occurs in subtropical and tropical wet and dry rainforest on the eastern and northern coasts of Australia. The genus is revised with the redescription of the type species M. terraereginae Gross, the transfer of Brentiscerus tenuicornis (Gross) to Megadrymus, and the description of five new species: M. aurorae, sp. nov., M. brunneus, sp. nov., M. capeyorkensis, sp. nov., M. kakadu, sp. nov. and M. refugiensis, sp. nov. A key to species is included. A phylogeny, and biological and distributional information, are presented and discussed.
Inhibition of quorum sensing as a novel antimicrobial strategy.
Authors: Brackman G. , Nelis H. J. , Coenye T.
Published: September 2012

This chapter reviews relevant compounds previously tested as inhibitors of quorum sensing in pathogenic bacteria, including discussions on their mechanism of antibacterial action.
Predicting and dissecting high-order molecular complexity by information-driven biomolecular docking.
Authors: Kastritis P. L. , Bonvin A. M. J. J.
Published: September 2012

This chapter describes the successful application of the HADDOCK - high-ambiguity-driven biomolecular docking - program in the evaluation of protein-small ligand docking, which is currently being used for discovering new antimicrobial agents. Key fundamental concepts relevant to data-driven biomolecular docking, both theoretical and technical, are discussed.
Response to cardiac resynchronization therapy in elderly patients (≥70 years) and octogenarians
Authors: Verbrugge Frederik H. , Dupont Matthias , de Vusser Philippe , Rivero‐Ayerza Maximo , Van Herendael Hugo , Vercammen Jan , Jacobs Linda , Verhaert David , Vandervoort Pieter , Tang W.H. Wilson , Mullens Wilfried
Published: September 2012

Aims

Cardiac resynchronization therapy (CRT) leads to reverse ventricular remodelling, improved functional capacity, and better clinical outcome in patients with advanced chronic heart failure, reduced ejection fraction, and evidence of ventricular conduction delay, who are under optimal medical therapy. This study investigated whether these benefits can be extrapolated to older patients, typically not included in randomized clinical trials.

Methods and results

Consecutive patients who received a CRT device between October 2008 and June 2011, including optimization afterwards in a dedicated clinic, were stratified into 3 pre‐specified groups, according to age: <70 years (n = 76); 70–79 years (n = 95); and ≥80 years (n = 49). Left ventricular remodelling, functional capacity, heart failure hospitalization, and mortality data were assessed during follow‐up. Reverse left ventricular remodelling and improvement in New York Heart Association functional class were similar in all groups at 6 months after implantation. During mean follow‐up of 20 months, 32 patients died and 66 were admitted for heart failure. Annualized mortality rates were significantly higher in elderly patients (6% vs. 8% vs. 15% in all groups, respectively; P < 0.001), but time to death or first heart failure admission was similar among age groups (P = 0.531). Progressive pump failure was the major cause of death (50%), with co‐morbidity‐related deaths also being frequent (41%).

Conclusion

Reverse left ventricular remodelling and functional capacity improvement after CRT are sustained at advanced age. Moreover, time to all‐cause mortality or heart failure admission was similar, irrespective of age, in a context of maximized optimization including optimal medical therapy.
When Did Decapods Invade Hydrothermal Vents? Clues from the Western Pacific and Indian Oceans
Authors: Yang Jin-Shu , Lu Bo , Chen Dian-Fu , Yu Yan-Qin , Yang Fan , Nagasawa Hiromichi , Tsuchida Shinji , Fujiwara Yoshihiro , Yang Wei-Jun
Published: September 2012

Hydrothermal vents are typically located in midocean ridges and back-arc basins and are usually generated by the movement of tectonic plates. Life thrives in these environments despite the extreme conditions. In addition to chemoautotrophic bacteria, decapod crustaceans are dominant in many of the hydrothermal vents discovered to date. Contrary to the hypothesis that these species are remnants of relic fauna, increasing evidence supports the notion that hydrothermal vent decapods have diversified in more recent times with previous research attributing the origin of alvinocarid shrimps to the Miocene. This study investigated seven representative decapod species from four hydrothermal vents throughout the Western Pacific and Indian Oceans. A partitioned mix-model phylogenomic analysis of mitochondrial DNA produced a consistent phylogenetic topology of these vent-endemic species. Additionally, molecular dating analysis calibrated using multiple fossils suggested that both bythograeid crabs and alvinocarid shrimps originated in the late Mesozoic and early Cenozoic. Although of limited sampling, our estimates support the extinction/repopulation hypothesis, which postulates recent diversification times for most hydrothermal vent species due to their mass extinction by global deep-water anoxic/dysoxic events during the Late Cretaceous and Early Tertiary. The continental-derived property of the West Pacific province is compatible with the possibility that vent decapods diversified from ancestors from shallow-water regions such as cold seeps. Our results move us a step closer toward understanding the evolutionary origin of hydrothermal vent species and their distribution in the Western Pacific–Indian Ocean Region.
ACUTE MACULAR NEURORETINOPATHY
Authors: Lalezary Maziar , Schoenberger Scott D. , Cherney Edward , Agarwal Anita
Published: September 2012

Purpose:

The purpose of this report is to describe extensive acute macular neuroretinopathy lesions with atypical features.

Methods:

Retrospective case report.

Results:

A patient developed acute macular neuroretinopathy in the setting of multiple previously described associations including a flu-like illness, sympathomimetic exposure, overdose of norepinephrine reuptake inhibitors, anemia, thrombocytopenia, and hypotensive shock. The fundus lesions superficially resembled retinal hemorrhages in color and fluorescein angiography pattern. The lesions could be detected on autofluorescence and infrared imaging. Optical coherence tomography revealed outer plexiform layer opacification and photoreceptor abnormalities.

Conclusion:

This case suggests a compounding effect of factors associated with acute macular neuroretinopathy, possible exacerbating insults and outer plexiform layer abnormalities that may correlate with the temporal course of this condition.
Lactobacillus shenzhenensis sp. nov., isolated from a fermented dairy beverage
Authors: Zou Yuanqiang , Liu Feng , Fang Chengxiang , Wan Daiwei , Yang Rentao , Su Qingqing , Yang Ruifu , Zhao Jiao
Published: September 2012

Two

Lactobacillus

strains, designated LY-73T and LY-30B, were isolated from a dairy beverage, sold in Shenzhen market, China. The two isolates were Gram-positive, non-spore-forming, non-motile, facultatively anaerobic rods that were heterofermentative and did not exhibit catalase activity. Sequencing of the 16S rRNA, pheS and rpoA genes revealed that the two isolates shared 99.5, 99.8 and 99.9 % sequence similarity, which indicates that they belong to the same species. Phylogenetic analysis demonstrated clustering of the two isolates with the genus

Lactobacillus

. Strain LY-73T showed highest 16S rRNA gene sequence similarities with

Lactobacillus harbinensis

KACC 12409T (97.73 %),

Lactobacillus perolens

DSM 12744T (96.96 %) and

Lactobacillus selangorensis

DSM 13344T (93.10 %). Comparative analyses of their rpoA and pheS gene sequences indicated that the novel strains were significantly different from other

Lactobacillus

species. Low DNA–DNA reassociation values (50.5 %) were obtained between strain LY-73T and its phylogenetically closest neighbours. The G+C contents of the DNA of the two novel isolates were 56.1 and 56.5 mol%. Straight-chain unsaturated fatty acids C18 : 1ω9c (78.85 and 74.29 %) were the dominant components, and the cell-wall peptidoglycan was of the l-Lys–d-Asp type. Based on phenotypic characteristics, and chemotaxonomic and genotypic data, the novel strains represent a novel species of the genus

Lactobacillus

, for which the name Lactobacillus shenzhenensis sp. nov. is proposed, with LY-73T ( = CCTCC M 2011481T = KACC 16878T) as the type strain.