bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatitis A infection in patients with chronic viral liver disease: a cross-sectional study in Jahrom, Iran
Authors: AHMADI VASMEHJANI A. , JAVESHGHANI D. , BAHARLOU R. , SHAYESTEHPOUR M. , MOUSAVINASAB S. D. , JOHARINIA N. , ENDERAMI S. E.
Published: April 2014

Infection with hepatitis A virus (HAV) in patient with chronic liver disease (CLD; due to hepatitis B or hepatitis C) may cause severe disease and fulminant liver failure. This study aimed to determine the seroprevalence of HAV antibodies in patients infected with HCV or HBV in Iran (Jahrom city). A total of 159 patients with underlying CLD were recruited between September 2012 and February 2013. Serum samples were collected from each patient and tested for anti-HAV using enzyme-linked immunosorbent assay (ELISA). The overall seroprevalence of total anti-HAV was 79·2%. Patients aged 20–30 years had the lowest (28·3%) anti-HAV seropositivity and those aged >50 years had the highest (95%) seropositivity. The overall prevalence of anti-HAV in patients with chronic HCV and HBV infection was 93·7% and 77·1%, respectively. The anti-HAV seropositivity in liver cirrhosis patients was 100% compared to CLD patients. Because of low HAV immunity in younger CLD patients, vaccination against HAV should be considered.
Choosing whom to betray: populist right-wing parties, welfare state reforms and the trade-off between office and votes
Authors: Afonso Alexandre
Published: April 2014

This article analyses the impact of populist right-wing parties (PRWPs) on welfare state reforms in Western Europe in the light of the trade-off that they face between office and votes. On the one hand, PRWPs appeal to traditionally left-leaning blue-collar ‘insiders’ supportive of social insurance schemes. On the other hand, they have only been able to take part in government as junior coalition partners with liberal or conservative parties who are more likely to retrench these very same welfare programmes. In this context, the article argues that these parties have to choose between betraying their electorate (and losing votes), and betraying their coalition partners (and losing office). When they choose office, it enables welfare state retrenchment by allowing their coalition partners to curtail left-wing opposition, but entails high electoral costs for PRWPs. When they choose votes, it generates deadlock and potentially jeopardizes their participation in government. The paper draws on a comparative analysis of pension reforms during three periods of government participation of PRWPs: the Schüssel I and II cabinets in Austria (2000–06), the Rutte I cabinet in the Netherlands (2010–12) and three pension reforms in Switzerland between 1995 and 2010. The analysis draws on original primary material and interviews.
Deterministic processes guide long-term synchronised population dynamics in replicate anaerobic digesters
Authors: Vanwonterghem Inka , Jensen Paul D , Dennis Paul G , Hugenholtz Philip , Rabaey Korneel , Tyson Gene W
Published: April 2014

A replicate long-term experiment was conducted using anaerobic digestion (AD) as a model process to determine the relative role of niche and neutral theory on microbial community assembly, and to link community dynamics to system performance. AD is performed by a complex network of microorganisms and process stability relies entirely on the synergistic interactions between populations belonging to different functional guilds. In this study, three independent replicate anaerobic digesters were seeded with the same diverse inoculum, supplied with a model substrate, α-cellulose, and operated for 362 days at a 10-day hydraulic residence time under mesophilic conditions. Selective pressure imposed by the operational conditions and model substrate caused large reproducible changes in community composition including an overall decrease in richness in the first month of operation, followed by synchronised population dynamics that correlated with changes in reactor performance. This included the synchronised emergence and decline of distinct Ruminococcus phylotypes at day 148, and emergence of a Clostridium and Methanosaeta phylotype at day 178, when performance became stable in all reactors. These data suggest that many dynamic functional niches are predictably filled by phylogenetically coherent populations over long time scales. Neutral theory would predict that a complex community with a high degree of recognised functional redundancy would lead to stochastic changes in populations and community divergence over time. We conclude that deterministic processes may play a larger role in microbial community dynamics than currently appreciated, and under controlled conditions it may be possible to reliably predict community structural and functional changes over time.
Interspecies competition triggers virulence and mutability in Candida albicans–Pseudomonas aeruginosa mixed biofilms
Authors: Trejo-Hernández Abigail , Andrade-Domínguez Andrés , Hernández Magdalena , Encarnación Sergio
Published: April 2014

Inter-kingdom and interspecies interactions are ubiquitous in nature and are important for the survival of species and ecological balance. The investigation of microbe-microbe interactions is essential for understanding the in vivo activities of commensal and pathogenic microorganisms. Candida albicans, a polymorphic fungus, and Pseudomonas aeruginosa, a Gram-negative bacterium, are two opportunistic pathogens that interact in various polymicrobial infections in humans. To determine how P. aeruginosa affects the physiology of C. albicans and vice versa, we compared the proteomes of each species in mixed biofilms versus single-species biofilms. In addition, extracellular proteins were analyzed. We observed that, in mixed biofilms, both species showed differential expression of virulence proteins, multidrug resistance-associated proteins, proteases and cell defense, stress and iron-regulated proteins. Furthermore, in mixed biofilms, both species displayed an increase in mutability compared with monospecific biofilms. This characteristic was correlated with the downregulation of enzymes conferring protection against DNA oxidation. In mixed biofilms, P. aeruginosa regulates its production of various molecules involved in quorum sensing and induces the production of virulence factors (pyoverdine, rhamnolipids and pyocyanin), which are major contributors to the ability of this bacterium to cause disease. Overall, our results indicate that interspecies competition between these opportunistic pathogens enhances the production of virulence factors and increases mutability and thus can alter the course of host-pathogen interactions in polymicrobial infections.
Molecular and biogeochemical evidence for methane cycling beneath the western margin of the Greenland Ice Sheet
Authors: Dieser Markus , Broemsen Erik L J E , Cameron Karen A , King Gary M , Achberger Amanda , Choquette Kyla , Hagedorn Birgit , Sletten Ron , Junge Karen , Christner Brent C
Published: April 2014

Microbial processes that mineralize organic carbon and enhance solute production at the bed of polar ice sheets could be of a magnitude sufficient to affect global elemental cycles. To investigate the biogeochemistry of a polar subglacial microbial ecosystem, we analyzed water discharged during the summer of 2012 and 2013 from Russell Glacier, a land-terminating outlet glacier at the western margin of the Greenland Ice Sheet. The molecular data implied that the most abundant and active component of the subglacial microbial community at these marginal locations were bacteria within the order Methylococcales (59–100% of reverse transcribed (RT)-rRNA sequences). mRNA transcripts of the particulate methane monooxygenase (pmoA) from these taxa were also detected, confirming that methanotrophic bacteria were functional members of this subglacial ecosystem. Dissolved methane ranged between 2.7 and 83 μm in the subglacial waters analyzed, and the concentration was inversely correlated with dissolved oxygen while positively correlated with electrical conductivity. Subglacial microbial methane production was supported by δ13C-CH4 values between −64‰ and −62‰ together with the recovery of RT-rRNA sequences that classified within the Methanosarcinales and Methanomicrobiales. Under aerobic conditions, >98% of the methane in the subglacial water was consumed over ∼30 days incubation at ∼4 °C and rates of methane oxidation were estimated at 0.32 μm per day. Our results support the occurrence of active methane cycling beneath this region of the Greenland Ice Sheet, where microbial communities poised in oxygenated subglacial drainage channels could serve as significant methane sinks.
Implications of streamlining theory for microbial ecology
Authors: Giovannoni Stephen J , Cameron Thrash J , Temperton Ben
Published: April 2014

Whether a small cell, a small genome or a minimal set of chemical reactions with self-replicating properties, simplicity is beguiling. As Leonardo da Vinci reportedly said, ‘simplicity is the ultimate sophistication’. Two diverging views of simplicity have emerged in accounts of symbiotic and commensal bacteria and cosmopolitan free-living bacteria with small genomes. The small genomes of obligate insect endosymbionts have been attributed to genetic drift caused by small effective population sizes (Ne). In contrast, streamlining theory attributes small cells and genomes to selection for efficient use of nutrients in populations where Ne is large and nutrients limit growth. Regardless of the cause of genome reduction, lost coding potential eventually dictates loss of function. Consequences of reductive evolution in streamlined organisms include atypical patterns of prototrophy and the absence of common regulatory systems, which have been linked to difficulty in culturing these cells. Recent evidence from metagenomics suggests that streamlining is commonplace, may broadly explain the phenomenon of the uncultured microbial majority, and might also explain the highly interdependent (connected) behavior of many microbial ecosystems. Streamlining theory is belied by the observation that many successful bacteria are large cells with complex genomes. To fully appreciate streamlining, we must look to the life histories and adaptive strategies of cells, which impose minimum requirements for complexity that vary with niche.
Prenatal development is linked to bronchial reactivity: epidemiological and animal model evidence
Authors: Pike Katharine C. , Davis Shelley A. , Collins Samuel A. , Lucas Jane S. A. , Inskip Hazel M. , Wilson Susan J. , Thomas Elin R. , Wain Harris A. , Keskiväli-Bond Piia H. M. , Cooper Cyrus , Godfrey Keith M. , Torrens Christopher , Roberts Graham , Holloway John W.
Published: April 2014

Chronic cardiorespiratory disease is associated with low birthweight suggesting the importance of the developmental environment. Prenatal factors affecting fetal growth are believed important, but the underlying mechanisms are unknown. The influence of developmental programming on bronchial hyperreactivity is investigated in an animal model and evidence for comparable associations is sought in humans. Pregnant Wistar rats were fed either control or protein-restricted diets throughout pregnancy. Bronchoconstrictor responses were recorded from offspring bronchial segments. Morphometric analysis of paraffin-embedded lung sections was conducted. In a human mother-child cohort ultrasound measurements of fetal growth were related to bronchial hyperreactivity, measured at age six years using methacholine. Protein-restricted rats' offspring demonstrated greater bronchoconstriction than controls. Airway structure was not altered. Children with lesser abdominal circumference growth during 11–19 weeks' gestation had greater bronchial hyperreactivity than those with more rapid abdominal growth. Imbalanced maternal nutrition during pregnancy results in offspring bronchial hyperreactivity. Prenatal environmental influences might play a comparable role in humans.
Integrating reductive and synthetic approaches in biology using man-made cell-like compartments
Authors: Aoki Wataru , Saito Masato , Manabe Ri-ichiroh , Mori Hirotada , Yamaguchi Yoshinori , Tamiya Eiichi
Published: April 2014

We propose ‘integrated synthetic genetics’ as a novel methodology that integrates reductive and synthetic approaches used in life science research. Integrated synthetic genetics enables determinations of sets of genes required for the functioning of any biological subsystem. This method utilizes artificial cell-like compartments, including a randomly introduced whole gene library, strictly defined components for in vitro transcription and translation and a reporter that fluoresces ‘only when a particular function of a target biological subsystem is active.’ The set of genes necessary for the target biological subsystem can be identified by isolating fluorescent artificial cells and multiplex next-generation sequencing of genes included in these cells. The importance of this methodology is that screening for the set of genes involved in a subsystem and reconstructing the entire subsystem can be done simultaneously. This methodology can be applied to any biological subsystem of any species and may remarkably accelerate life science research.
Highly efficient conversion of biomass-derived glycolide to ethylene glycol over CuO in water
Authors: Xu Lingli , Huo Zhibao , Fu Jun , Jin Fangming
Published: April 2014

The efficient conversion of biomass-derived glycolide into ethylene glycol over CuO in water was investigated.
Simple sample processing enhances malaria rapid diagnostic test performance
Authors: Davis K. M. , Gibson L. E. , Haselton F. R. , Wright D. W.
Published: April 2014

Several brands of malaria RDTs were analyzed and their signals quantitated. It was found that a simple sample processing step enhanced the limits of detection by at least 4-fold.
Determination of P, S and Si in biodiesel, diesel and lubricating oil using ICP-MS/MS
Authors: Amais Renata S. , Amaral Clarice D. B. , Fialho Lucimar L. , Schiavo Daniela , Nóbrega Joaquim A.
Published: April 2014

The feasibility of inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) to overcome polyatomic interferents in severely affected isotope determination is demonstrated here.
Controllable morphology and tunable colors of Mg and Eu ion co-doped ZnO by thermal annealing
Authors: Yang S. , Han D. L. , Gao M. , Yang J. H. , Bayanheshig Bayanheshig
Published: April 2014

Controllable morphology and tunable colors of Mg and Eu ion co-doped ZnO by thermal annealing.
Two novel mixed Eu3+/Y3+ Ln MOFs: influence of pH on the topology, Eu/Y ratio and energy transfer
Authors: Zhang Yu , Ju Weiwei , Xu Xiao , Lv Yun , Zhu Dunru , Xu Yan
Published: April 2014

Two mixed europium–yttrium MOFs with different interesting structures and doping proportions have been successfully synthesized by adjusting the pH values. The pH value largely affects the topologies and Eu/Y ratios of the two compounds.
Engineering short, strong hydrogen bonds in urea di-carboxylic acid complexes
Authors: Jones Andrew O. F. , Leech Charlotte K. , McIntyre Garry J. , Wilson Chick C. , Thomas Lynne H.
Published: April 2014

The persistence of the acid⋯amide heterodimer and the effect of methyl substitution on the short strong O–H⋯O hydrogen bond is investigated in urea and methylurea di-carboxylic acid molecular complexes. Temperature dependent structural changes are also reported utilising X-ray and neutron diffraction in tandem.
A study on the photophysics of 9-amino-10-cyanoanthracene: probing its dual absorption and emission behavior
Authors: Choudhury Sharmistha Dutta , Muralidharan Sukumaran , Pal Haridas
Published: April 2014

This study explores the photophysics of an interesting donor–acceptor substituted molecule, 9-amino-10-cyanoanthracene, that shows unusual dual absorption and emission behavior.
Combined excitatory and inhibitory coupling in a 1-D array of Belousov–Zhabotinsky droplets
Authors: Li Ning , Delgado Jorge , González-Ochoa Hector O. , Epstein Irving R. , Fraden Seth
Published: April 2014

Experimental and theoretical studies of the coupling between Belousov–Zhabotinsky droplets in oil as a function of malonic acid, drop size, drop spacing, and time.
Catalytic olefin epoxidation over cobalt(ii)-containing mesoporous silica by molecular oxygen in dimethylformamide medium
Authors: Bhunia Susmita , Jana Sreyashi , Saha Debraj , Dutta Buddhadeb , Koner Subratanath
Published: April 2014

A cobalt(ii) Schiff base complex has been anchored onto the surface of Si–MCM-41 to prepare a new catalyst. The catalyst is capable of catalyzing epoxidation reactions of olefinic compounds, including styrene and allyl alcohol, with molecular oxygen at atmospheric pressure in DMF medium.
Coupling ZnxCd1−xS nanoparticles with graphene-like MoS2: superior interfacial contact, low overpotential and enhanced photocatalytic activity under visible-light irradiation
Authors: Lu Yongtao , Wang Dandan , Yang Ping , Du Yukou , Lu Cheng
Published: April 2014

A novel nanocomposite composed of graphene-like MoS2 sheets and ZnxCd1−xS nanoparticles was used for photocatalytic hydrogen generation under visible light irradiation.
Synthesis, photovoltaic performances and TD-DFT modeling of push–pull diacetylide platinum complexes in TiO2 based dye-sensitized solar cells
Authors: Gauthier Sébastien , Caro Bertrand , Robin-Le Guen Françoise , Bhuvanesh Nattamai , Gladysz John A. , Wojcik Laurianne , Le Poul Nicolas , Planchat Aurélien , Pellegrin Yann , Blart Errol , Jacquemin Denis , Odobel Fabrice
Published: April 2014

Five new Pt-containing dyes have been synthesised and characterised in the framework of DSSC applications.
Zeolite and mesoporous silica nanomaterials: greener syntheses, environmental applications and biological toxicity
Authors: Lehman Sean E. , Larsen Sarah C.
Published: April 2014

Zeolites and mesoporous silica nanoparticles are silicate or aluminosilicate nanomaterials with well-defined pore networks.
Coherent dynamics of the charge density wave gap in tritellurides
Authors: Rettig L. , Chu J.-H. , Fisher I. R. , Bovensiepen U. , Wolf M.
Published: April 2014

The dynamics of the transient electronic structure in the charge density wave (CDW) system RTe3 (R = rare-earth element) is studied using time- and angle-resolved photoemission spectroscopy (trARPES). Employing a three-pulse pump–probe scheme we investigate the effect of the amplitude mode oscillations on the electronic band structure and, in particular, on the CDW energy gap. We observe coherent oscillations in both lower and upper CDW band with opposite phases, whereby two dominating frequencies are modulating the CDW order parameter. This demonstrates the existence of more than one collective amplitude mode, in contrast to a simple Peierls model. Coherent control experiments of the two amplitude modes, which are strongly coupled in equilibrium, demonstrate independent control of the modes suggesting a decoupling of both modes in the transient photoexcited state.
Synthesis and characterization of an extractive-based bio-epoxy resin from beetle infested Pinus contorta bark
Authors: Kuo Pei-Yu , Sain Mohini , Yan Ning
Published: April 2014

The cured bio-epoxy resins synthesized from low molecular weight tree bark extractives displayed good mechanical and thermal properties.
Pump-free multi-well-based microfluidic system for high-throughput analysis of size-control relative genes in budding yeast
Authors: Kang Xianjie , Jiang Lingli , Chen Xi , Yuan Haiyu , Luo Chunxiong , Ouyang Qi
Published: April 2014

With a simple but robust well-based microfluidic device, we can high-throughput load and trace dozens of different budding yeast strains at single cell level simultaneously, providing precise cell information such as cell size, cell cycle, protein localization and protein expression level.
High-speed scanning thermal lithography for nanostructuring of electronic devices
Authors: Shaw Joseph E. , Stavrinou Paul N. , Anthopoulos Thomas D.
Published: April 2014

A high-speed nanopatterning method is developed for the rapid prototyping of nanostructured active and passive components as well as fully functional organic electronic devices.
Raman identification of edge alignment of bilayer graphene down to the nanometer scale
Authors: Zhang Xin , Li Qiao-Qiao , Han Wen-Peng , Lu Yan , Shi Wei , Wu Jiang-Bin , Mikhaylushkin Arkady S. , Tan Ping-Heng
Published: April 2014

Raman spectroscopy can acquire the alignment distance between two edges of top and bottom graphene layers of bilayer graphene as small as the nanometer scale.
A nano-frost array technique to prepare nanoporous PVDF membranes
Authors: Lee Min Kyung , Lee Jonghwi
Published: April 2014

We demonstrate a simple but novel approach to fabricate nanoporous polymer membranes using a nano-frost array technique.
Microwave-assisted synthesis of potent PDE7 inhibitors containing a thienopyrimidin-4-amine scaffold
Authors: Sánchez Ana I. , Meneses Ricardo , Mínguez José M. , Núñez Araceli , Castillo Rafael R. , Filace Fabiana , Burgos Carolina , Vaquero Juan J. , Álvarez-Builla Julio , Cortés-Cabrera Alvaro , Gago Federico , Terricabras Emma , Segarra Víctor
Published: April 2014

Thienopyrimidin-4-amines have been synthesized, evaluated and modelled as phosphodiesterase inhibitors.
First total syntheses of chrestifoline-B and (±)-chrestifoline-C, and improved synthetic routes to bismurrayafoline-A, bismurrayafolinol and chrestifoline-D
Authors: Börger Carsten , Schmidt Arndt W. , Knölker Hans-Joachim
Published: April 2014

We describe an efficient synthesis of the methylene-bridged biscarbazole alkaloids bismurrayafoline-A, bismurrayafolinol and chrestifoline B–D using an Ullmann-type coupling at the benzylic position.
Magnetic core–shell nanoprobe for sensitive killing of cancer cells via induction with a strong external magnetic field
Authors: Mandal Samir , Chatterjee Nabanita , Das Subhadip , Saha Krishna Das , Chaudhuri Keya
Published: April 2014

The title system, composed of a highly magnetic core surrounded by a thin arsenite shell, has been synthesized and applied to the magnetically facilitated targeting of anticancer agent (sodium arsenite) at lower dose with minimal side effects and higher efficacy in a biocompatible manner.
Recent advances in the synthesis of quinolines: a review
Authors: Prajapati Shraddha M. , Patel Kinjal D. , Vekariya Rajesh H. , Panchal Shyamali N. , Patel Hitesh D.
Published: April 2014

This review article gives information about the recent advances in the synthesis of quinoline derivatives by various eco-friendly, green and clean protocols.
Lanthanum nickel alloy catalyzed growth of nitrogen-doped carbon nanotubes by chemical vapor deposition
Authors: Rajesh John Anthuvan , Pandurangan Arumugam
Published: April 2014

CNTs doped with large amounts of nitrogen were produced on a LaNi5 alloy catalyst by CVD and its growth mechanism discussed on the basis of dissolution and precipitation mechanisms.
A Ru-catalyzed one-pot synthesis of homopropargylic amines from alkyl azides under photolytic conditions
Authors: Jeong Wook , Lee Ji Hyung , Kim Jungjoon , Lee Won Jong , Seong Ju-Hwa , Park Jaiwook , Rhee Young Ho
Published: April 2014

A new synthetic method for homopropargylic amines from alkyl azides is presented.
Free energy of a long semiflexible polymer confined in a spherical cavity
Authors: Gao Jie , Tang Ping , Yang Yuliang , Chen Jeff Z. Y.
Published: April 2014

The free energy and conformational properties of a wormlike chain confined inside a spherical surface are investigated in this article.
Surfactant or block copolymer micelles? Structural properties of a series of well-defined n-alkyl–PEO micelles in water studied by SANS
Authors: Zinn Thomas , Willner Lutz , Lund Reidar , Pipich Vitaliy , Appavou Marie-Sousai , Richter Dieter
Published: April 2014

By investigating the detailed structure of a series of n-Alkyl-poly(ethylene oxide), Cn-PEOs, we reveal scaling laws that indicate a hybrid behavior between surfactant and block copolymer micelles.
Precise adjustment of structural anisotropy and crystallinity on metal–Fe3O4 hybrid nanoparticles and its influence on magnetic and catalytic properties
Authors: Kim Mijong , Song Hyunjoon
Published: April 2014

Precise control of the growth kinetics achieves symmetry alteration from concentric yolk-shell to dumbbell-like morphologies in a metal-iron oxide hybrid system, which directly affects the magnetic and catalytic properties.
Interface control and modification of band alignment and electrical properties of HfTiO/GaAs gate stacks by nitrogen incorporation
Authors: He Gang , Liu Jiangwei , Chen Hanshuang , Liu Yanmei , Sun Zhaoqi , Chen Xiaoshuang , Liu Mao , Zhang Lide
Published: April 2014

Effects of nitrogen incorporation on the interface chemical bonding states, optical dielectric function, band alignment, and electrical properties of sputtering-derived HfTiO high-kgate dielectrics on GaAs substrates have been studied by angle resolved X-ray photoemission spectroscopy (ARXPS), spectroscopy ellipsometry (SE), and electrical measurements.
Ceramide synthase 4 deficiency in mice causes lipid alterations in sebum and results in alopecia
Authors: Ebel Philipp , Imgrund Silke , vom Dorp Katharina , Hofmann Kristina , Maier Helena , Drake Helena , Degen Joachim , Dörmann Peter , Eckhardt Matthias , Franz Thomas , Willecke Klaus
Published: April 2014

Five ceramide synthases (CerS2–CerS6) are expressed in mouse skin. Although CerS3 has been shown to fulfill an essential function during skin development, neither CerS6- nor CerS2-deficient mice show an obvious skin phenotype. In order to study the role of CerS4, we generated CerS4-deficient mice (Cers4−/−) and CerS4-specific antibodies. With these biological tools we analysed the tissue distribution and determined the cell-type specific expression of CerS4 in suprabasal epidermal layers of footpads as well as in sebaceous glands of the dorsal skin. Loss of CerS4 protein leads to an altered lipid composition of the sebum, which is more solidified and therefore might cause progressive hair loss due to physical blocking of the hair canal. We also noticed a strong decrease in C20 1,2-alkane diols consistent with the decrease of wax diesters in the sebum of Cers4−/− mice. Cers4−/− mice at 12 months old display additional epidermal tissue destruction due to dilated and obstructed pilary canals. Mass spectrometric analyses additionally show a strong decrease in C20-containing sphingolipids.
A new method for determining the plasma electron density using optical frequency comb interferometer
Authors: Arakawa Hiroyuki , Tojo Hiroshi , Sasao Hajime , Kawano Yasunori , Itami Kiyoshi
Published: April 2014

A new method of plasma electron density measurement using interferometric phases (fractional fringes) of an optical frequency comb interferometer is proposed. Using the characteristics of the optical frequency comb laser, high density measurement can be achieved without fringe counting errors. Simulations show that the short wavelength and wide wavelength range of the laser source and low noise in interferometric phases measurements are effective to reduce ambiguity of measured density.
Inverting microwell array chip for the cultivation of human induced pluripotent stem cells with controlled aggregate size and geometrical arrangement
Authors: Satoh Taku , Sugiura Shinji , Sumaru Kimio , Ozaki Shigenori , Gomi Shinichi , Kurakazu Tomoaki , Oshima Yasuhiro , Kanamori Toshiyuki
Published: April 2014

We present a novel cell culture chip, namely, “inverting microwell array chip,” for cultivation of human induced pluripotent stem cells. The chip comprises a lower hydrogel microwell array and an upper polystyrene culture surface. We demonstrate the formation of uniform cellular aggregates in the microwell array, and after inversion, a culture with controlled aggregate size and geometrical arrangement on the polystyrene surface. Here, we report effects of cell concentrations on a cultivation sequence in the chip.
Ballooning modes localized near the null point of a divertor
Authors: Farmer W. A.
Published: April 2014

The stability of ballooning modes localized to the null point in both the standard and snowflake divertors is considered. Ideal magnetohydrodynamics is used. A series expansion of the flux function is performed in the vicinity of the null point with the lowest, non-vanishing term retained for each divertor configuration. The energy principle is used with a trial function to determine a sufficient instability threshold. It is shown that this threshold depends on the orientation of the flux surfaces with respect to the major radius with a critical angle appearing due to the convergence of the field lines away from the null point. When the angle the major radius forms with respect to the flux surfaces exceeds this critical angle, the system is stabilized. Further, the scaling of the instability threshold with the aspect ratio and the ratio of the scrape-off-layer width to the major radius is shown. It is concluded that ballooning modes are not a likely candidate for driving convection in the vicinity of the null for parameters relevant to existing machines. However, the results place a lower bound on the width of the heat flux in the private flux region. To explain convective mixing in the vicinity of the null point, new consideration should be given to an axisymmetric mixing mode [W. A. Farmer and D. D. Ryutov, Phys. Plasmas 20, 092117 (2013)] as a possible candidate to explain current experimental results.
A Hamiltonian fluid-kinetic model for a two-species non-neutral plasma
Authors: Tassi E. , Romé M. , Chandre C.
Published: April 2014

A model for describing the dynamics of a pure electron plasma in the presence of a population of massive charged particles is presented. The model couples the fluid dynamics of the pure electron plasma with the dynamics of the massive particle population, the latter being treated kinetically. The model is shown to possess a noncanonical Hamiltonian structure and to preserve invariants analogous to those of the two-dimensional (2D) Euler equation for an incompressible inviscid fluid, and of the Vlasov equation. The Hamiltonian structure of the model is used to derive a set of stability conditions for rotating coherent structures of the two-species system, in the case of negatively charged massive particles. According to these conditions, stability is attained if both the equilibrium distribution function of the kinetic species and the equilibrium density of the electron fluid are monotonically decreasing functions of the corresponding single-particle energies in the rotating frame. For radially confined equilibria near the axis, the stability condition corresponds to the existence of a finite interval of rotation frequencies for the reference frame, with the upper bound determined by the presence of the kinetic population.
Transition from gas to plasma kinetic equilibria in gravitating axisymmetric structures
Authors: Cremaschini Claudio , Stuchlík Zdeněk
Published: April 2014

The problem of the transition from gas to plasma in gravitating axisymmetric structures is addressed under the assumption of having initial and final states realized by kinetic Maxwellian-like equilibria. In astrophysics, the theory applies to accretion-disc scenarios around compact objects. A formulation based on non-relativistic kinetic theory for collisionless systems is adopted. Equilibrium solutions for the kinetic distribution functions describing the initial neutral matter and the resulting plasma state are constructed in terms of single-particle invariants and expressed by generalized Maxwellian distributions. The final plasma configuration is related to the initial gas distribution by the introduction of appropriate functional constraints. Qualitative aspects of the solution are investigated and physical properties of the system are pointed out. In particular, the admitted functional dependences of the fluid fields carried by the corresponding equilibrium distributions are determined. Then, the plasma is proved to violate the condition of quasi-neutrality, implying a net charge separation between ions and electrons. This result is shown to be independent of the precise realization of the plasma distribution function, while a physical mechanism able to support a non-neutral equilibrium state is proposed.
Tailoring the surface plasmon resonance of embedded silver nanoparticles by combining nano- and femtosecond laser pulses
Authors: Doster J. , Baraldi G. , Gonzalo J. , Solis J. , Hernandez-Rueda J. , Siegel J.
Published: April 2014

We demonstrate that the broad surface plasmon resonance (SPR) of a single layer of near-coalescence silver nanoparticles (NPs), embedded in a dielectric matrix can be tailored by irradiation with a single nanosecond laser pulse into a distribution featuring a sharp resonance at 435 nm. Scanning electron microscopy studies reveal the underlying mechanism to be a transformation into a distribution of well-separated spherical particles. Additional exposure to multiple femtosecond laser pulses at 400 nm or 800 nm wavelength induces polarization anisotropy of the SPR, with a peak shift that increases with laser wavelength. The spectral changes are measured in-situ, employing reflection and transmission micro-spectroscopy with a lateral resolution of 4 μm. Spectral maps as a continuous function of local fluence can be readily produced from a single spot. The results open exciting perspectives for dynamically tuning and switching the optical response of NP systems, paving the way for next-generation applications.
On the reliable analysis of indium mole fraction within InxGa1−xN quantum wells using atom probe tomography
Authors: Riley James R. , Detchprohm Theeradetch , Wetzel Christian , Lauhon Lincoln J.
Published: April 2014

Surface crystallography and polarity are shown to influence the detection probability of In, Ga, and N ions during atom probe tomography analysis of InxGa1−xN m-plane, c-plane, and (202¯1¯) quantum wells. A N deficit is observed in regions of the reconstruction generated from Ga-polar surfaces, and the probability of detecting group-III atoms is lower in InxGa1−xN quantum wells than in GaN barrier layers. Despite these artifacts, the detected In mole fraction is consistent throughout a given quantum well regardless of the crystal orientation of the quantum well or the evaporation surface from which the reconstruction was generated.
Stacking faults and interface roughening in semipolar (202¯1¯) single InGaN quantum wells for long wavelength emission
Authors: Wu Feng , Zhao Yuji , Romanov Alexey , DenBaars Steven P. , Nakamura Shuji , Speck James S.
Published: April 2014

The microstructure of InGaN single quantum wells (QWs) grown in semipolar (202¯1¯) orientation on GaN substrates was studied by transmission electron microscopy. Stress relaxation in the lattice mismatch InxGa1−xN layer was realized by forming partial misfit dislocations associated with basal plane stacking faults (BPSFs). For given composition x = 0.24, BPSFs formation was observed when the QW thickness exceeded 4 nm. The high density of partial threading dislocations that bound the BPSFs is detrimental to light-emitting device performance. Interface roughening (faceting) was observed for both upper and lower QW interfaces (more pronounced for upper interface) and was found to increase with the thickness of the QW. BPSFs had a tendency to nucleate at roughened interface valleys.
Temperature dependent photoexcited carrier dynamics in multiferroic BiFeO3 film: A hidden phase transition
Authors: Zhang Zeyu , Jin Zuanming , Pan Qunfeng , Xu Yue , Lin Xian , Ma Guohong , Cheng Zhenxiang
Published: April 2014

The ultrafast carrier dynamics of the multiferroic BiFeO3 film in a broad temperature range is investigated using optical pump-probe spectroscopy. The photoexcited electrons release their energy with optical phonons emission through electron-phonon coupling in about 1 ps. The following intermediate process is identified as dynamical spin-lattice coupling in several picoseconds. Furthermore, the peak values of the optical reflectivity and the time constants of carrier relaxation channels show significant changes while the temperature varies from 137.5 K to around 195 K, this aligns with the previously reported hidden phase transition. Our study demonstrates that ultrafast spectroscopy is a sensitive method to look into the dynamical interactions among the on-site high-energy electrons accumulated in the p conduction band of Bi, coherent optical phonon, as well as the spin degree of freedom. These features play crucial roles in the characterization of phase transitions.
Electrical conduction mechanisms of Au/NiO/heavily doped p-type Si memory devices
Authors: Su Ting-Hong , Lin Yow-Jon
Published: April 2014

The fabrication of memory devices based on the Au/NiO/heavily doped p-type Si (p+-Si) structures and their current-voltage characteristics were reported. The Au/NiO/p+-Si devices show hysteresis behavior. The fitting data of the temperature-dependent off-state current–voltage curves demonstrated that the carrier transport mechanism of the Au/NiO/p+-Si device was attributed to the space change limited conduction. However, the difference between the temperature-dependent on-state currents in the forward-bias and reverse-bias regions was found. The different electrical conduction mechanisms (hopping conduction and Ohmic conduction with metal-like behaviors) were discussed. This phenomenon is related to the different interfacial characteristics between Au/NiO and NiO/p+-Si.
Laser pulse amplitude changes induced by terahertz waves under linear electro-optic effect
Authors: Ilyakov I. E. , Kitaeva G. Kh. , Shishkin B. V. , Akhmedzhanov R. A.
Published: April 2014

Changes in the amplitude of femtosecond laser pulses and in the energy of terahertz wave radiation induced during their co-propagation in ZnTe and GaP crystals are studied theoretically and experimentally. The results show that variation of the optical field amplitude leads to changes in the laser pulse energy and spectrum shift. We investigate the quantitative correlations between variations of the optical pulse energy, spectrum, phase and terahertz radiation energy. The values of laser pulse energy change and spectrum shift are proportional to the first time derivative of the magnitude of terahertz electric field, which enables coherent electro-optic detection. A simple and convenient calibration technique for terahertz energy detectors based on the correlation between laser and terahertz energy changes is proposed and tested.
Interfacial magnetic coupling in ultrathin all-manganite La0.7Sr0.3MnO3-TbMnO3 superlattices
Authors: Tian Y. F. , Lebedev O. I. , Roddatis V. V. , Lin W. N. , Ding J. F. , Hu S. J. , Yan S. S. , Wu T.
Published: April 2014

We report the growth and magnetic properties of all-manganite superlattices composed of ultrathin double-exchange ferromagnetic La0.7Sr0.3MnO3 and noncollinear multiferroic TbMnO3 layers. Spontaneous magnetization and hysteresis loops are observed in such superlattices with individual La0.7Sr0.3MnO3 layers as thin as two unit cells, which are accompanied by pronounced exchange bias and enhanced coercivity. Our results indicate substantial interfacial magnetic coupling between spin sublattices in such superlattices, providing a powerful approach towards tailoring the properties of artificial magnetic heterostructures.
Single- and bi-layer memristive devices with tunable properties using TiOx switching layers deposited by reactive sputtering
Authors: Jiang Hao , Xia Qiangfei
Published: April 2014

The authors systematically studied reactive sputtering deposition of TiOx thin films using a mixture of Ar and O2 gases under different ratios of O2 flow. As directly revealed by X-ray photoelectron spectroscopy, the deposition changed from a metallic Ti target mode to an oxide target mode when the O2 flow ratio was beyond 40%, resulting in TiOx thin films with different chemical compositions. Consequently, metal/oxide/metal devices with a single TiOx layer exhibited a broad spectrum of electrical characteristics such as Ohmic, rectifying, and memristive behavior. The reactive sputtering deposited TiOx thin films were also used in a bilayer memristive device structure, and a transition from bipolar to unipolar switching behavior was observed for devices based on thin films prepared with different oxygen flow.
Fabrication of high-performance graphene field-effect transistor with solution-processed Al2O3 sensing membrane
Authors: Bae Tae-Eon , Kim Hyeji , Jung Jongwan , Cho Won-Ju
Published: April 2014

High performance graphene field-effect transistors (FETs) with a solution-processed Al2O3 sensing membrane were fabricated. The solution-processed deposition technique offers a lot of advantages in terms of low cost, simplicity, high throughput, and large-area devices. Especially, the solution-deposition process is well-suited for membrane formation of graphene FETs, which is vulnerable to plasma or thermal processes for insulator growth on surface. The graphene FETs with a solution-deposited Al2O3 sensing membrane exhibited a higher pH sensitivity as well as good chemical stability. Therefore, the graphene FETs with solution-deposited Al2O3 sensing membrane are very promising to biological sensors application.
Health promotion: an ethical analysis
Authors: Carter Stacy M.
Published: April 2014

Thinking and practising ethically requires reasoning systematically about the right thing to do. Health promotion ethics – a form of applied ethics – includes analysis of health promotion practice and how this can be ethically justified. Existing frameworks can assist in such evaluation. These acknowledge the moral value of delivering benefits. But benefits need to be weighed against burdens, harms or wrongs, and these should be minimised: they include invading privacy, breaking confidentiality, restraining liberty, undermining self‐determination or people's own values, or perpetuating injustice. Thinking about the ethics of health promotion also means recognising health promotion as a normative ideal: a vision of the good society. This ideal society values health, sees citizens as active and includes them in decisions that affect them, and makes the state responsible for providing all of its citizens, no matter how advantaged or disadvantaged, with the conditions and resources they need to be healthy. Ethicists writing about health promotion have focused on this relationship between the citizen and the state. Comparing existing frameworks, theories and the expressed values of practitioners themselves, we can see common patterns. All oppose pursuing an instrumental, individualistic, health‐at‐all‐costs vision of health promotion. And all defend the moral significance of just processes: those that engage with citizens in a transparent, inclusive and open way. In recent years, some Australian governments have sought to delegitimise health promotion, defining it as extraneous to the role of the state. Good evidence is not enough to counter this trend, because it is founded in competing visions of a good society. For this reason, the most pressing agenda for health promotion ethics is to engage with communities, in a procedurally just way, about the role and responsibilities of the citizen and the state in promoting and maintaining good health.
Getting Australia more active: challenges and opportunities for health promotion
Authors: Hills A. P. , Street S. J. , Harris N.
Published: April 2014

A growing body of evidence demonstrates that regular physical activity promotes health and assists in the prevention of noncommunicable diseases but this is presently curtailed by low and unhealthy participation rates in Australia and comparable industrialised countries. Compounding the problem is knowledge that physical inactivity is independently associated with poor health outcomes. Despite physical activity being described as public health's ‘best bet’ or ‘best buy’, motivating individuals and groups to adopt and maintain physical activity continues to be a major challenge for health professionals. Global advocacy for prevention efforts must be operationalised through national to local strategies to promote and support physical activity in multiple settings including the home, schools and workplace. The Australian health promotion community has and continues to play a leadership role in physical activity promotion. However, there is an urgent need to continue to promote the importance of physical activity, along with its pivotal role in the prevention of non‐communicable diseases, alongside related agendas including healthy diets, tobacco control and environmental sustainability. This commentary overviews the contemporary status of physical activity promotion in Australia and identifies key challenges and opportunities moving forward.
Knowledge, attitudes and beliefs about lung cancer in three culturally and linguistically diverse communities living in Australia: a qualitative study
Authors: Scott Nicola , Donato‐Hunt Connie , Crane Melanie , Lafontaine Mayanne , Varlow Megan , Seale Holly , Currow David
Published: April 2014

Issue addressed

Knowledge, attitudes and beliefs about lung cancer among Chinese, Vietnamese and Arabic‐speaking communities in Sydney, New South Wales (NSW) are explored.

Methods

Seven focus groups were completed with a total of 51 participants (smokers and non‐smokers) from three culturally and linguistically diverse communities (CALD). Five topics were discussed and translated summaries from focus groups were thematically analysed.

Results

There were variations in perceived susceptibility to lung cancer between the CALD groups and between smokers and non‐smokers. Fatalistic views towards lung cancer were apparent across all three CALD communities. There were low levels of awareness of lung cancer signs and symptoms, with the exception of haemoptysis. Differences in help‐seeking behaviour and levels of trust of general practitioners (GP) were apparent.

Conclusion

Limited awareness of the signs and symptoms of lung cancer, combined with cultural perceptions about cancer, impacted on attitudes towards help‐seeking behaviour in these three CALD communities.

So what?

The prevalence of smoking among Chinese men, Vietnamese men and Arabic‐speaking communities in NSW puts them at increased risk of lung cancer. Health promotion initiatives for lung cancer should be tailored for CALD communities and could focus on increasing knowledge of key symptoms, awareness that ex‐smokers are at risk and awareness of the diagnostic pathway including the importance of avoiding delays in help‐seeking.
Characterization of a yam class IV chitinase produced by recombinant Pichia pastoris X-33
Authors: Akond Muhammad Ali , Matsuda Yusuke , Ishimaru Takayuki , Iwai Ken , Saito Akira , Kato Akio , Tanaka Shuhei , Kobayashi Jun , Koga Daizo
Published: April 2014

A yam (Dioscorea opposita Thunb) class IV chitinase, whose genomic DNA was cloned by Mitsunaga et al. (2004), was produced by the recombinant Pichia pastoris X-33 in high yields such as 66 mg/L of culture medium. The chitinase was purified by column chromatography after Endoglycosidase H treatment and then characterized. It showed properties similar to the original chitinase E purified from the yam tuber reported by Arakane et al. (2000). This Pichia-produced chitinase also showed strong lytic activity against Fusarium oxysporum and Phytophthora nicotianae, wide pH and thermal stability, optimum activity at higher temperature such as 70 °C, and high substrate affinity, indicating that one can use this Pichia-produced yam chitinase as a bio-control agent.