bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxide-supported Rh catalysts for H2 generation from low-temperature ethanol steam reforming: effects of support, Rh precursor and Rh loading on catalytic performance
Authors: Huang Lin , Choong Catherine , Chen Luwei , Wang Zhan , Zhong Ziyi , Chng Kee Ann , Lin Jianyi
Published: November 2015

Rh4(CO)12-derived Rh/CeO2 is superior to the other oxide-supported Rh catalysts. Coking is the only cause of catalyst deactivation which affects the catalytic stability of Rh/CeO2. Both CeO2-supported Rh0 and Rh+ may participate in catalysis for ESR.
Fabrication of dual-mesoporous silica by triblock copolymers and metal-based ionic liquid: efficient and durable catalyst for oxidative desulfurization in fuel
Authors: Yang Lei , Xiong Jun , Li Hongping , Zhang Ming , Jiang Wei , Liu Hui , Zhu Wenshuai , Li Huaming
Published: November 2015

The D-MoO3–SiO2 material with two uniform sets of mesopores exhibited a very high efficiency and excellent stability in the oxidative desulfurization of model oil.
Selective extraction of metallic arc-discharged single-walled carbon nanotubes by a water soluble polymethylsilane derivative
Authors: Gao Jinling , Huang Yao , Lian Yongfu
Published: November 2015

Arc-discharged metallic SWNTs are selectively extracted with an aqueous solution of polymethyl(1-undecylic acidyl)silane by the formation of a charge donor–acceptor complex.
Synthesis and performance of hollow LiNi0.5Mn1.5O4 with different particle sizes for lithium-ion batteries
Authors: Xue Yuan , Wang Zhen-Bo , Zheng Li-Li , Yu Fu-Da , Liu Bao-Sheng , Zhang Yin , Zhou Yu-Xiang
Published: November 2015

Hollow LiNi0.5Mn1.5O4 with different particle sizes was synthesized using MnCO3 as the manganese resource, and the effects of particle size were investigated.
Direct transformation of metallic copper to copper nanostructures by simple alcohol thermal treatment and their photoactivity
Authors: Xiong Liangbin , Xiao Huaqing , Zeng Qingdong , Wang Boyun , Wen Sheng , Li Bihui , Ding Yaoming , Yu Huaqing
Published: November 2015

Evolution scheme for the morphology of Cu sheets with ATT for different times (left). Inactivation of E. coli by untreated Cu sheet and Cu nanobelts, nanowires and nanoparticles in the dark and under light irradiation (right).
Controllable dye adsorption behavior on amorphous tungsten oxide nanosheet surfaces
Authors: Luo Jian Yi , Lin Yu Rong , Liang Bao Wen , Li Yu Dong , Mo Xi Wei , Zeng Qing Guang
Published: November 2015

In this study, the surface interactions between different dyes and amorphous WO3 nanosheets in water were investigated.
Stable nanoporous thin films through one-step UV treatment of a block copolymer precursor
Authors: Ma Xia , Sui Xin , Zhang Zhenyu , Li Chao , Zhang Naifu , Chen Aihua , Xie Qiong , Gao Longcheng
Published: November 2015

Stable nanoporous structures was fabricated from a self-assembled block copolymer precursor by one-step UV treatment.
Preparation, physicochemical properties and in vitro bioactivity of hierarchically porous bioactive glass scaffolds
Authors: Wang Xiaocheng , Shi Mengchao , Zhai Dong , Wu Chengtie
Published: November 2015

Bioactive glass scaffolds with macropores (300–500 μm), midpores (20 nm to 2 μm) and mesopores (around 5 nm) were prepared using P123, yeast cells and polyurethane sponges as templates.
Photocatalytic O2 production using WO3 nanoparticles prepared by annealing ethylenediamine tungstate/CxNy gel
Authors: Mao Fang , Zhang Yifeng , Wu Jiagang , Xiao Dingquan , Liu Kewei , Cao Hongmei , Yan Hongjian
Published: November 2015

WO3 nanoparticles have extraordinary potential applications in water oxidation and degradation of organic pollutes.
A greener procedure for the synthesis of α-ureidophosphonates under ultrasound irradiation. An X-ray crystallographic study
Authors: Bouzina Abdeslem , Berredjem Malika , Bouacida Sofiane , Merazig Hocine , Aouf Nour-eddine
Published: November 2015

The synthesis of α-ureidophosphonates via a one-pot three-component reaction using ultrasonic irradiation under solvent- and catalyst-free conditions at 75° is developed. The products were obtained in excellent yields within short reaction times.
Poly(ethylene oxide)-based block copolymers with very high molecular weights for biomimetic calcium phosphate mineralization
Authors: Mai Tobias , Boye Susanne , Yuan Jiayin , Völkel Antje , Gräwert Marlies , Günter Christina , Lederer Albena , Taubert Andreas
Published: November 2015

Ampholytic and betaine-type block copolymers are excellent growth modifiers for calcium phosphate in biologically inspired calcium phosphate mineralization.
Non-classical CH⋯O hydrogen-bond determining the regio- and stereoselectivity in the [3 + 2] cycloaddition reaction of (Z)-C-phenyl-N-methylnitrone with dimethyl 2-benzylidenecyclopropane-1,1-dicarboxylate. A topological electron-density study
Authors: Nacereddine Abdelmalek Khorief , Sobhi Chafia , Djerourou Abdelhafid , Ríos-Gutiérrez Mar , Domingo Luis R.
Published: November 2015

Formation of a non-classical CH⋯O hydrogen-bond involving the nitrone C–H hydrogen is responsible for the selectivity experimentally found in this non-polar zw-type 32CA reaction.
Efficient microwave synthesis of novel aromatic esters catalyzed by zirconia and its modified forms: a kinetic study
Authors: Thimmaraju N. , Mohamed Shamshuddin S. Z. , Pratap S. R. , Raja K.
Published: November 2015

A series of solid acids such as ZrO2, 5%Mo(vi)/ZrO2, 10%Mo(vi)/ZrO2, 20%Mo(vi)/ZrO2 and SO42−/ZrO2 were prepared, characterised and used as catalysts in the synthesis of novel esters under microwave irradiation condition.
The influence of replacing Se by Te on electronic structure and optical properties of Tl4PbX3(X = Se or Te): experimental and theoretical investigations
Authors: Reshak A. H. , Alahmed Z. A. , Barchij I. E. , Sabov M. Yu. , Plucinski K. J. , Kityk I. V. , Fedorchuk A. O.
Published: November 2015

The energy band structure, electronic charge density and optical features of Tl4PbSe3and Tl4PbTe3single crystals were studied within a framework of the recently modified Becke–Johnson potential (mBJ).
Enhancement of the mechanical properties at the macro and nanoscale of thermosetting systems modified with a polystyrene-block-polymethyl methacrylate block copolymer
Authors: Cano Laida , Gutierrez Junkal , Tercjak Agnieszka
Published: November 2015

An epoxy-based thermosetting system was modified with varying contents of polystyrene-block-polymethyl methacrylate (PS-b-PMMA) block copolymer by two methods and cured with a 4,4′-methylenebis(3-chloro-2,6-diethylaniline) (MCDEA) curing agent.
Core–shell zeolite@aqueous miscible organic-layered double hydroxides
Authors: Chen Chunping , Byles Coral F. H. , Buffet Jean-Charles , Rees Nicholas H. , Wu Yue , O'Hare Dermot
Published: November 2015

We report a general method for the synthesis of core–shell hybrid materials containing a microporous zeolite core with an aqueous miscible organic-layered double hydroxide (AMO-LDH) shell using a simplein situcoprecipitation method.
A quantitative proteomic approach for unveiling novel mechanisms associated with MeHg-induced toxicity: effects on the methylation cycle
Authors: Cabezas-Sanchez Pablo , Garcia-Calvo Estefania , Camara Carmen , Luque-Garcia Jose L.
Published: November 2015

Methylmercury (MeHg) is still a major threat for human health and the environment due to its extremely high toxicity that mainly affects the nervous system. Despite the great efforts made during the last few decades, the specific molecular mechanisms involved in MeHg-induced toxicity are still not completely unveiled. In this work we explored such mechanisms using neuroblastoma cells (Neuro-2a) and SILAC as a quantitative proteomic approach. We found that exposure of Neuro-2a cells to 2 mg L−1 MeHg for 8 h decreased the cell viability to 70% and caused significant changes in the morphology of the cells, specially regarding neurite development. Our proteomic results showed different proteins altered upon MeHg exposure that helped to identify pathways related to the toxicity exerted by MeHg. Specifically, we have found that MeHg affects the methylation cycle by inhibiting the expression of key enzymes including MTHFD1 and MTR. Moreover, we demonstrate that inhibition of MTHFD1 is not observed when exposing the cells to inorganic Hg and other heavy metals such as Pb or Cu. Thus, this work sets the stage for dissecting a specific molecular mechanism for MeHg-induced toxicity.
Metabolomics screening identifies reducedL-carnitine to be associated with progressive emphysema
Authors: Conlon Thomas M. , Bartel Jörg , Ballweg Korbinian , Günter Stefanie , Prehn Cornelia , Krumsiek Jan , Meiners Silke , Theis Fabian J. , Adamski Jerzy , Eickelberg Oliver , Yildirim Ali Önder
Published: November 2015

Chronic obstructive pulmonary disease (COPD) is characterized by chronic bronchitis, small airway remodelling and emphysema. Emphysema is the destruction of alveolar structures, leading to enlarged airspaces and reduced surface area impairing the ability for gaseous exchange. To further understand the pathological mechanisms underlying progressive emphysema, we used MS-based approaches to quantify the lung, bronchoalveolar lavage fluid (BALF) and serum metabolome during emphysema progression in the established murine porcine pancreatic elastase (PPE) model on days 28, 56 and 161, compared with PBS controls. Partial least squares (PLS) analysis revealed greater changes in the metabolome of lung followed by BALF rather than serum during emphysema progression. Furthermore, we demonstrate for the first time that emphysema progression is associated with a reduction in lung-specific L-carnitine, a metabolite critical for transporting long-chain fatty acids into the mitochondria for their subsequent β-oxidation. In vitro, stimulation of the alveolar epithelial type II (ATII)-like LA4 cell line with L-carnitine diminished apoptosis induced by both PPE and H2O2. Moreover, PPE-treated mice demonstrated impaired lung function compared with PBS-treated controls (lung compliance; 0.067±0.008 ml/cmH20 compared with 0.035±0.005 ml/cmH20, P<0.0001), which improved following supplementation with L-carnitine (0.051±0.006, P<0.01) and was associated with a reduction in apoptosis. In summary, our results provide a new insight into the role of L-carnitine and, importantly, suggest therapeutic avenues for COPD.
Multi‐mode noise parameters for multi‐port networks
Authors: Prinsloo David S. , Meyer Petrie
Published: November 2015

This study derives an equation set by which the equivalent multi‐mode noise parameters of a general multi‐port receiver can be solved in terms of the noise parameters of the constituent single‐ended (SE) low‐noise amplifiers (LNAs). The expressions are used to derive equivalent differential‐ and common‐mode noise parameters for a pair of balanced LNAs as well as the equivalent multi‐mode noise parameters of four SE LNAs excited through a quadraxial transmission line.
Recent developments of ion sources for life-science studies at the Heavy Ion Medical Accelerator in Chiba (invited)
Authors: Kitagawa A. , Drentje A. G. , Fujita T. , Muramatsu M. , Fukushima K. , Shiraishi N. , Suzuki T. , Takahashi K. , Takasugi W. , Biri S. , Rácz R. , Kato Y. , Uchida T. , Yoshida Y.
Published: November 2015

With about 1000-h of relativistic high-energy ion beams provided by Heavy Ion Medical Accelerator in Chiba, about 70 users are performing various biology experiments every year. A rich variety of ion species from hydrogen to xenon ions with a dose rate of several Gy/min is available. Carbon, iron, silicon, helium, neon, argon, hydrogen, and oxygen ions were utilized between 2012 and 2014. Presently, three electron cyclotron resonance ion sources (ECRISs) and one Penning ion source are available. Especially, the two frequency heating techniques have improved the performance of an 18 GHz ECRIS. The results have satisfied most requirements for life-science studies. In addition, this improved performance has realized a feasible solution for similar biology experiments with a hospital-specified accelerator complex.
Controlling electroosmotic flows by polymer coatings: A joint experimental-theoretical investigation
Authors: Monteferrante Michele , Sola Laura , Cretich Marina , Chiari Marcella , Marini Bettolo Marconi Umberto , Melchionna Simone
Published: November 2015

We analyze the electroosmotic flow (EOF) of an electrolytic solution in a polymer coated capillary electrophoresis tube. The polymeric density, charge, thickness, and the capillary tube charge vary as a function of pH and produce a non-trivial modulation of the EOF, including a flow reversal at acid pH conditions. By means of a theoretical argument and numerical simulations, we recover the experimental curve for the EOF, providing a firm approach for predictive analysis of electroosmosis under different polymeric coating conditions. A proposed application of the approach is to determine the near-wall charge of the coating to be used for further quantitative analysis of the electroosmotic flow and mobility.
Solvation free-energy pressure corrections in the three dimensional reference interaction site model
Authors: Sergiievskyi Volodymyr , Jeanmairet Guillaume , Levesque Maximilien , Borgis Daniel
Published: November 2015

Solvation free energies are efficiently predicted by molecular density functional theory if one corrects the overpressure introduced by the usual homogeneous reference fluid approximation. Sergiievskyi et al. [J. Phys. Chem. Lett. 5, 1935–1942 (2014)] recently derived the rigorous compensation of this excess of pressure (referred as “pressure correction” or PC) and proposed an empirical “ideal gas” supplementary correction (referred as “advanced pressure correction” or PC+) that further enhances the calculated solvation free energies. In a recent paper [M. Misin, M. V. Fedorov, and D. S. Palmer, J. Chem. Phys. 142, 091105 (2015)], those corrections were applied to solvation free energy calculations using the three-dimensional reference interaction site model (3D-RISM). As for classical DFT, PC and PC+ improve greatly the predictions of 3D-RISM, but PC+ is described as decreasing the accuracy. In this article, we derive rigorously the expression of the pressure in 3D-RISM as well as the associated PC and PC+. This provides a consistent way to correct the solvation free-energies calculated by 3D-RISM method.
Effect of solute transfer and interfacial instabilities on scalar and velocity field around a drop rising in quiescent liquid channel
Authors: Khanwale Makrand A. , Khadamkar Hrushikesh P. , Mathpati Channamallikarjun S.
Published: November 2015

Physics of development of flow structures around the drop rising with solute transfer is highly influenced by the interfacial behaviour and is remarkably different than a particle rising under the same conditions. We report on the use of simultaneous particle image velocimetry-planar laser induced fluorescence technique to measure scalar and velocity fields around a drop rising in a quiescent liquid channel. The selected continuous phase is glycerol, and the drop consists of a mixture of toluene, acetone, and a dye rhodamine-6G, with acetone working as a interfacial tension depressant. The drop lies in the spherical region with Eötvös number, Eo = 1.95, Morton number, M = 78.20 and the particle Reynolds number being, Rep = 0.053. With Rep approaching that of creeping flow, we analyse the effect of interfacial instabilities solely, contrary to other investigations [M. Wegener et al., “Impact of Marangoni instabilities on the fluid dynamic behaviour of organic droplets,” Int. J. Heat Mass Transfer 52, 2543-2551 (2009); S. Burghoff and E. Y. Kenig, “A CFD model for mass transfer and interfacial phenomena on single droplets,” AIChE J. 52, 4071-4078 (2006); J. Wang et al., “Numerical simulation of the Marangoni effect on transient mass transfer from single moving deformable drops,” AIChE J. 57, 2670-2683 (2011); R. F. Engberg, M. Wegener, and E. Y. Kenig, “The impact of Marangoni convection on fluid dynamics and mass transfer at deformable single rising droplets—A numerical study,” Chem. Eng. Sci. 116, 208-222 (2014)] which account for turbulence as well as interfacial instabilities with Rep in the turbulent range. The velocity and concentration fields obtained are subjected to scale-wise energy decomposition using continuous wavelet transform. Scale-wise probability distribution functions of wavelet coefficients are calculated to check intermittent non-Gaussian behaviour for simultaneous velocity and scalar statistics. Multi-fractal singularity spectra for scalar and velocity fields are calculated using wavelet transform modulus maxima methodology to analyse the distribution of non-Gaussian flow structures and their effect on scalar transport. Further, Fourier spectra based on velocity and concentration are also reported. We found that vorticity and concentration fields became progressively non-Gaussian, as one moved from large scales to small scales. This turbulence like behaviour is attributed to interfacial instabilities developed because of the non-uniform shear at the interface. The multi-fractal singularity spectra had their Hurst exponent H > 0.5, which showed high correlation in the hierarchy of the flow structures. A strong correlation between concentration and velocity multi-fractal spectra was also seen.
Effects of bursting dynamic features on the generation of multi-clustered structure of neural network with symmetric spike-timing-dependent plasticity learning rule
Authors: Liu Hui , Song Yongduan , Xue Fangzheng , Li Xiumin
Published: November 2015

In this paper, the generation of multi-clustered structure of self-organized neural network with different neuronal firing patterns, i.e., bursting or spiking, has been investigated. The initially all-to-all-connected spiking neural network or bursting neural network can be self-organized into clustered structure through the symmetric spike-timing-dependent plasticity learning for both bursting and spiking neurons. However, the time consumption of this clustering procedure of the burst-based self-organized neural network (BSON) is much shorter than the spike-based self-organized neural network (SSON). Our results show that the BSON network has more obvious small-world properties, i.e., higher clustering coefficient and smaller shortest path length than the SSON network. Also, the results of larger structure entropy and activity entropy of the BSON network demonstrate that this network has higher topological complexity and dynamical diversity, which benefits for enhancing information transmission of neural circuits. Hence, we conclude that the burst firing can significantly enhance the efficiency of clustering procedure and the emergent clustered structure renders the whole network more synchronous and therefore more sensitive to weak input. This result is further confirmed from its improved performance on stochastic resonance. Therefore, we believe that the multi-clustered neural network which self-organized from the bursting dynamics has high efficiency in information processing.
Predicting channel bed topography in hydraulic falls
Authors: Tam Alexander , Yu Zheng , Kelso Richard M. , Binder Benjamin J.
Published: November 2015

We consider inverse methods for predicting the channel bed topography in experiments of hydraulic falls. Nonlinear solutions and weakly nonlinear approximations from Euler-based models are compared to experimental observations. Accurate predictions are obtained for the maximum height of the topography and its constant horizontal level far downstream using the nonlinear method. The weakly nonlinear approximation is shown only to be a good predictor of the maximum height of the topography. The error in the inverse predictions is examined and discussed.
Recirculation areas underneath solitary waves on gravity-driven film flows
Authors: Reck Daniel , Aksel Nuri
Published: November 2015

Our experimental study proves the existence of recirculation areas underneath sufficiently large solitary waves that run over gravity-driven film flows. This evidence was obtained by setting up a measurement system that moved with the wave’s speed and displayed the streamlines underneath the wave. Solitary waves of different height, length, and speed, which ran over basic flows of different Reynolds numbers and inclination angles were examined systematically. We found that recirculation areas appear underneath waves, whose height exceeds a critical value. This value depends on the basic flow’s Reynolds number, irrespective of the inclination angle and the distance from the inlet. Furthermore, the size of the recirculation area grows with the height of the wave.
Effect of thickness on dielectric, ferroelectric, and optical properties of Ni substituted Pb(Zr0.2Ti0.8)O3 thin films
Authors: Kumari Shalini , Ortega Nora , Pradhan Dhiren K. , Kumar Ashok , Scott J. F. , Katiyar Ram S.
Published: November 2015

We report thickness dependent dielectric, ferroelectric, and optical properties of Ni substituted Pb(Zr0.2Ti0.8)O3 thin films. The Pb(Zr0.2Ti0.8)0.70Ni0.30O3−δ (PZTNi30) thin films for various thicknesses, ranging from 5 nm to 400 nm, were fabricated by pulsed laser deposition technique. Giant dielectric dispersion, low dielectric loss, large dielectric constant ∼1000–1500 from 100 Hz to 100 kHz, and diffused dielectric anomaly near 570–630 K were observed in PZTNi30 thin films. These films show well saturated ferroelectric hysteresis, with large remanent polarization. It also illustrated excellent optical transparency which decreased from 82 to 72% with increasing film thickness from 5 nm to 400 nm for the probe wavelengths ranging from 200 to 1100 nm. A decrease in direct bandgap (Eg) values from 4 eV to 3.4 eV and indirect-Eg values from 3.5 eV to 2.9 eV were observed for PZTNi30 thin films with increase in film thickness from 5 nm to 400 nm, respectively. The direct and indirect bandgaps were discussed in context of film thickness and grain size effects. Our investigations on optical properties of PZTNi30 thin films suggest that bandgap can be modified as a function of film thickness which may be useful for readers working to develop novel candidates for ferroelectric photovoltaic.
Folding and insertion thermodynamics of the transmembrane WALP peptide
Authors: Bereau Tristan , Bennett W. F. Drew , Pfaendtner Jim , Deserno Markus , Karttunen Mikko
Published: November 2015

The anchor of most integral membrane proteins consists of one or several helices spanning the lipid bilayer. The WALP peptide, GWW(LA)n (L)WWA, is a common model helix to study the fundamentals of protein insertion and folding, as well as helix-helix association in the membrane. Its structural properties have been illuminated in a large number of experimental and simulation studies. In this combined coarse-grained and atomistic simulation study, we probe the thermodynamics of a single WALP peptide, focusing on both the insertion across the water-membrane interface, as well as folding in both water and a membrane. The potential of mean force characterizing the peptide’s insertion into the membrane shows qualitatively similar behavior across peptides and three force fields. However, the Martini force field exhibits a pronounced secondary minimum for an adsorbed interfacial state, which may even become the global minimum—in contrast to both atomistic simulations and the alternative PLUM force field. Even though the two coarse-grained models reproduce the free energy of insertion of individual amino acids side chains, they both underestimate its corresponding value for the full peptide (as compared with atomistic simulations), hinting at cooperative physics beyond the residue level. Folding of WALP in the two environments indicates the helix as the most stable structure, though with different relative stabilities and chain-length dependence.
Accurate structural and spectroscopic characterization of prebiotic molecules: The neutral and cationic acetyl cyanide and their related species
Authors: Bellili A. , Linguerri R. , Hochlaf M. , Puzzarini C.
Published: November 2015

In an effort to provide an accurate structural and spectroscopic characterization of acetyl cyanide, its two enolic isomers and the corresponding cationic species, state-of-the-art computational methods, and approaches have been employed. The coupled-cluster theory including single and double excitations together with a perturbative treatment of triples has been used as starting point in composite schemes accounting for extrapolation to the complete basis-set limit as well as core-valence correlation effects to determine highly accurate molecular structures, fundamental vibrational frequencies, and rotational parameters. The available experimental data for acetyl cyanide allowed us to assess the reliability of our computations: structural, energetic, and spectroscopic properties have been obtained with an overall accuracy of about, or better than, 0.001 Å, 2 kcal/mol, 1-10 MHz, and 11 cm−1 for bond distances, adiabatic ionization potentials, rotational constants, and fundamental vibrational frequencies, respectively. We are therefore confident that the highly accurate spectroscopic data provided herein can be useful for guiding future experimental investigations and/or astronomical observations.
Carbon dioxide is tightly bound in the [Co(Pyridine)(CO2)]− anionic complex
Authors: Graham Jacob D. , Buytendyk Allyson M. , Zhang Xinxing , Kim Seong K. , Bowen Kit H.
Published: November 2015

The [Co(Pyridine)(CO2)]− anionic complex was studied through the combination of photoelectron spectroscopy and density functional theory calculations. This complex was envisioned as a primitive model system for studying CO2 binding to negatively charged sites in metal organic frameworks. The vertical detachment energy (VDE) measured via the photoelectron spectrum is 2.7 eV. Our calculations imply a structure for [Co(Pyridine)(CO2)]− in which a central cobalt atom is bound to pyridine and CO2 moieties on either sides. This structure was validated by acceptable agreement between the calculated and measured VDE values. Based on our calculations, we found CO2 to be bound within the anionic complex by 1.4 eV.
Improving the efficiency of harvesting electricity from living trees
Authors: Ying Qin , Yuan Weifeng , Hu Ning
Published: November 2015

The harvesting of environmental energy has been attracting more and more attention. In this study, it was observed that there exists electrical potential difference between the phloem of a living tree and the surrounding soil. This kind of bioelectricity is sustained and it can be harvested by charging a capacitor. However, the charging efficiency is greatly dependent on the shape of the electrodes which affects the contact resistance between the electrodes and the phloem significantly. Based on an equivalent circuit model, a method to improve the efficiency of electricity harvesting is proposed. The experimental data demonstrate that this method is feasible and effective.
Analysis of bulk and interface defects in hydrogenated amorphous silicon solar cells by Fourier transform photocurrent spectroscopy
Authors: Bidiville A. , Matsui T. , Matsubara K.
Published: November 2015

A series of hydrogenated amorphous silicon (a-Si:H) p-i-n solar cells with varying absorber thicknesses (ti = 10–500 nm) were investigated by Fourier transform photocurrent spectroscopy to determine the sub-bandgap absorption originating from the native and metastable defects. Differences between annealed and degraded states of a-Si:H solar cells, as well as between diode and triode plasma-enhanced chemical vapor deposition methods for the absorber layer depositions were analyzed. Despite having a comparable annealed state performance to diode-deposited cells, the triode-deposited a-Si:H solar cells exhibit notably less light-induced metastable defects over the whole range of absorber thickness. Furthermore, the analysis of thin solar cells (ti < 100 nm) suggests that defects are not preferentially present at the interfaces of the intrinsic layer, but that there are regions with a higher absorption coefficient than the bulk of the absorber near the doped layers. Finally, we show that the solar cell performance, particularly the fill factor, is directly governed by the total amount of sub-gap defects, regardless of the thickness, state (annealed or degraded), and deposition method.
Forming compliance dominated memristive switching through interfacial reaction in Ti/TiO2/Au structure
Authors: Tang Zhensen , Fang Liang , Xu Nuo , Liu Rulin
Published: November 2015

The effects of the forming compliance current (CC) on bipolar resistive switching (BRS) characteristics in Au/Ti/TiO2/Au memristive switches were investigated. After forming with a low CC, a typical BRS with an abrupt SET and negative differential resistance RESET behaviors were observed. In comparison, the sample formed with a high CC exhibited an abnormal BRS with stepwise SET and abrupt RESET transitions. The conduction mechanisms at a high resistance state and a low resistance state were analyzed, respectively. The impact of the forming compliance on the interfacial reaction between Ti and TiO2 was discussed. The Ti-induced interfacial layer played an important role of manipulating the oxygen vacancies, thus providing the possibility of affecting the switching behavior. A physical model based on a combination of the bulk and interfacial effects was proposed to explain our observations.
Micromachined magnetoflexoelastic resonator based magnetometer
Authors: Hatipoglu Gokhan , Tadigadapa Srinivas
Published: November 2015

In this paper, we demonstrate the performance of a magnetoflexoelastic magnetometer consisting of a micromachined ultra-thin (7.5 μm) quartz bulk acoustic resonator on which 500 nm thick magnetostrictive Metglas® (Fe85B5Si10) film is deposited. The resonance frequency of the unimorph resonator structure is sensitively affected by the magnetostrictively induced flexoelastic effect in quartz and is exploited to detect low frequency (<100 Hz) and nanoTesla magnetic fields. The resonance frequency shift is measured by tracking the at-resonance admittance of the resonator as a function of the applied magnetic field. The frequency shifts are linearly correlated to the magnetic field strength. A minimum detectable magnetic flux density of ∼79 nT has been measured for 10 Hz modulated magnetic field input signals which corresponds to a frequency sensitivity of 0.883 Hz/μT.
Norman Alan Walker 1929–2013
Authors: Smith Andrew , Beilby Mary
Published: November 2015

Alan Walker (he never used ‘Norman') developed pioneering electrophysiological methods to make major contributions to our understanding of mechanisms and energetics of transport of solutes across plant cell membranes. He used giant cells of characean algae to measure membrane electrical potential differences and conductances that were combined with measurements of fluxes of inorganic ions and organic nutrients obtained with radioactive tracers. Alan built up a strong research group at the University of Sydney and had many external collaborations that considerably widened the scope of his research in relation to membrane biology of characean cells and well beyond. His considerable skills in mathematical modelling contributed significantly to research led by others on plant-fungal (mycorrhizal) symbiosis, movement of solutes through the cytoplasmic connections between plant cells (plasmodesmata), the membrane transport mechanisms that regulate the release of nutrients from coats of developing legume seeds, and even nutrient cycling in Arctic ecosystems. Alan had strong political views and definite aesthetic tastes that included aspects of visual arts (ceramics and impressionist paintings) and music. He was very interested in good food and wine, and other interests included vertebrate palaeontology and bird-watching. He had many friends with similar tastes, who share fond memories of him.
Bruce Godfrey Hyde 1925–2014
Authors: Withers Ray , Sellar Jeffrey , O'Keeffe Michael , Hyde Stephen
Published: November 2015

Bruce Hyde made seminal contributions to modern solid state chemistry, in particular to the understanding and characterization of non-stoichiometry and structural complexity in the solid state. His work showed unequivocally that non-stoichiometric crystalline materialswere often much more highly ordered than previously believed, that the ‘point defects' of conventional wisdom were in fact ordered into extended defects and that these defects were themselves ordered into structures of complexities hitherto unimagined. His deep understanding of crystal chemistry and structural relationships is apparent in his two co-authored books with his closest colleagues, Sten Andersson and Michael O'Keeffe. It also led to his mentoring an entire generation of younger Australian (and international) solid state chemists.
Karyosystematics of the Australasian stipoid grass Austrostipa and related genera: chromosome sizes, ploidy, chromosome base numbers and phylogeny
Authors: Winterfeld Grit , Schneider Julia , Becher Hannes , Dickie John , Röser Martin
Published: November 2015

Mitotic metaphase chromosomes were counted in 29 taxa, representing 11 subgenera of Austrostipa, and in 11 species from nine related genera of the grass subfamily Pooideae. Karyotype features were also measured. The cytogenetic data were mapped on molecular phylogenetic trees based on nuclear ITS and plastid 3ʹtrnK DNA sequence data. The trees showed four different main lineages within Austrostipa, but supported only two of the 13 acknowledged subgenera. The phylogenetic positions of the genera Anemanthele, Achnatherum, Nassella and Oloptum indicated paraphyly of the genus Austrostipa. In nuclear-sequence data, Anemanthele was nested within Austrostipa; however, in plastid-sequence data, both were sisters. The newly obtained chromosome counts in Austrostipa showed that most species have 2n = 44, the other 2n = 66. Presuming a chromosome base number of x = 11, the counts corresponded with ploidy levels of 4x and 6x respectively. Karyotype data of Austrostipa and Anemanthele were very similar. Chromosome counting in further genera suggested chromosome base numbers of x = 9, 10, 11, 12 and 13. Chromosome sizes of the phylogenetically derived tribe Stipeae were smaller than those of the earliest diverging Pooideae lineages Nardeae, Meliceae and Phaenospermateae. The mechanisms of chromosome evolution and the origin of the considerable variation in chromosome base numbers in the subfamily Pooideae are discussed in the context of chromosome evolution and biosystematics.
Comparative wood anatomy of Taxaceae
Authors: Ghimire Balkrishna , Lee Chunghee , Heo Kweon
Published: November 2015

Comparative wood anatomy of Taxaceae s.l. was examined to elucidate the differences in wood features among genera. In total, 25 samples, comprising three varieties and seven species from five genera (Pseudotaxus was not included), were examined. Sliding microtome, wood maceration and scanning electron microscopy methods were used for the study. The growth rings are well developed and early and late wood are distinguishable in a cross-section. In general, there is remarkable uniformity in the characteristics of the five genera of Taxaceae, although some differences in quantitative traits were found. Wood of Taxaceae s.l. differs from that of most conifers by having helical thickening in the tracheid inner walls, with the exception of Austrotaxus spicata R.H.Compton. All genera are characterised by the absence of resin canals, predominantly uniseriate pits on the radial wall of the axial tracheids, and the presence of pits on the tangential walls of the axial tracheids. The rays are composed solely of parenchyma cells and are uniseriate (occasionally biseriate in Torreya nucifera (L.) Siebold et Zucc.), with a height of 1–22 cells. The genus Taxus shares more characteristics with Torreya than with Amentotaxus, Austrotaxus and Cephalotaxus. Correspondingly, Amentotaxus and Cephalotaxus resemble each other, marked by the presence of either diffuse or sparse axial parenchyma with nodulated transverse walls. Austrotaxus spicata is the sole species that lacks helical thickenings in the tracheid walls and has sparse axial parenchyma with smooth transverse walls. These two features, namely, the absence of helical thickenings and axial parenchyma with smooth transverse walls, are plesiomorphic and might be considered a more primitive character in wood anatomy. Among the other four genera, Amentotaxus appears to have an annular type of wall thickening that could be considered plesiomorphic to the spiral thickenings found in Taxus, Torreya and Cephalotaxus.
Systematic significance of cypsela morphology in Lessingianthus (Vernonieae, Asteraceae)
Authors: Angulo María B. , Sosa María M. , Dematteis Massimiliano
Published: November 2015

The taxonomic significance of cypsela features of South American species of Lessingianthus (Vernonieae, Asteraceae) is analysed for the first time and discussed in relation to other genera of the tribe Vernonieae. The morphology of the cypselae of 112 species of the genus were analysed using stereo-, light and scanning electron microscopy (SEM) to evaluate the infrageneric relationships and their reliability as taxonomic markers at a generic level. Characters such as cypsela pubescence, carpopodium structure, crystals and idioblasts on the fruit wall were examined. We established three types of cypsela on the basis of the presence or absence, and type of trichomes. Carpopodium is present in all species of the genus. Crystals are very variable in shape and size, with prismatic (rectangular and hexagonal) and styloid shapes. Idioblasts are present in all of the species, except for two. Cypsela features of Lessingianthus are often widespread in other related genera of Vernonieae. Therefore, these characters are not good taxonomic markers at the genus level, but they are valuable within genera to differentiate related species from one another.
Identification and characterization of the zosA gene involved in copper uptake in Bacillus subtilis 168
Authors: Fukuhara Takahiro , Kobayashi Kazuo , Kanayama Yousuke , Enomoto Shu-ichi , Kondo Taeko , Tsunekawa Naoki , Nemoto Michiko , Ogasawara Naotake , Inagaki Kenji , Tamura Takashi
Published: November 2015

dl-Penicillamine, a copper-specific metal chelator, remarkably suppressed the growth of Bacillus subtilis 168 when added to a synthetic medium under Cu2+ limitation. DNA microarray and screening of 2,602 knockout mutants showed that the zosA gene was de-repressed in the presence of 0.1% dl-penicillamine, and that the zosA mutant was sensitive to dl-penicillamine medium. The zosA mutant delayed the growth under Cu-limitation even without the chelator, and the sensitivity to dl-penicillamine was reversed by induction using 0.3 mM IPTG and the Pspac promoter inserted directly upstream of the zosA gene. Furthermore, the zosA mutant showed elevated tolerance of excessive Cu2+ but not of excessive Zn2+ added to LB and synthetic media. Homology modeling of the ZosA protein suggested that the protein can fold itself into essential domains for constituting a metal transporting ATPase. Our study suggests that zosA is a candidate gene involved in copper uptake.
Chromatin binding of RCC1 during mitosis is important for its nuclear localization in interphase
Authors: Furuta Maiko , Hori Tetsuya , Fukagawa Tatsuo
Published: November 2015

RCC1, a guanine nucleotide exchange factor of the small GTPase Ran, plays various roles throughout the cell cycle. However, the functions of RCC1 in biological processes in vivo are still unclear. In particular, although RCC1 has multifunctional domains, the biological significance of each domain is unclear. To examine each domain of RCC1, we established an RCC1 conditional knockout chicken DT40 cell line and introduced various RCC1 mutants into the knockout cells. We found that nuclear reformation did not occur properly in RCC1-deficient cells and examined whether specific RCC1 mutants could rescue this phenotype. Surprisingly, we found that neither the nuclear localization signal nor the chromatin-binding domain of RCC1 is essential for its function. However, codisruption of these domains resulted in defective nuclear reformation, which was rescued by artificial nuclear localization of RCC1. Our data indicate that chromatin association of RCC1 during mitosis is crucial for its proper nuclear localization in the next interphase. Moreover, proper nuclear localization of RCC1 in interphase is essential for its function through its nucleotide exchange activity.
Epigenetic engineering shows that a human centromere resists silencing mediated by H3K27me3/K9me3
Authors: Martins Nuno M. C. , Bergmann Jan H. , Shono Nobuaki , Kimura Hiroshi , Larionov Vladimir , Masumoto Hiroshi , Earnshaw William C.
Published: November 2015

Centromeres are characterized by the centromere-specific H3 variant CENP-A, which is embedded in chromatin with a pattern characteristic of active transcription that is required for centromere identity. It is unclear how centromeres remain transcriptionally active despite being flanked by repressive pericentric heterochromatin. To further understand centrochromatin’s response to repressive signals, we nucleated a Polycomb-like chromatin state within the centromere of a human artificial chromosome (HAC) by tethering the methyltransferase EZH2. This led to deposition of the H3K27me3 mark and PRC1 repressor binding. Surprisingly, this state did not abolish HAC centromere function or transcription, and this apparent resistance was not observed on a noncentromeric locus, where transcription was silenced. Directly tethering the reader/repressor PRC1 bypassed this resistance, inactivating the centromere. We observed analogous responses when tethering the heterochromatin Editor Suv39h1-methyltransferase domain (centromere resistance) or reader HP1α (centromere inactivation), respectively. Our results reveal that the HAC centromere can resist repressive pathways driven by H3K9me3/H3K27me3 and may help to explain how centromeres are able to resist inactivation by flanking heterochromatin.
Sequential posttranslational modifications regulate PKC degradation
Authors: Wang Yan , Wang Yangbo , Zhang Huijun , Gao Yingwei , Huang Chao , Zhou Aiwu , Zhou Yi , Li Yong
Published: November 2015

Cross-talk among different types of posttranslational modifications (PTMs) has emerged as an important regulatory mechanism for protein function. Here we elucidate a mechanism that controls PKCα stability via a sequential cascade of PTMs. We demonstrate that PKCα dephosphorylation decreases its sumoylation, which in turn promotes its ubiquitination and ultimately enhances its degradation via the ubiquitin-proteasome pathway. These findings provide a molecular explanation for the activation-induced down-regulation of PKC proteins.
Lovastatin for the Treatment of Adult Patients With Dengue: A Randomized, Double-Blind, Placebo-Controlled Trial
Authors: Whitehorn James , Nguyen Chau Van Vinh , Khanh Lam Phung , Kien Duong Thi Hue , Quyen Nguyen Than Ha , Tran Nguyen Thi Thanh , Hang Nguyen Thuy , Truong Nguyen Thanh , Hue Tai Luong Thi , Cam Huong Nguyen Thi , Nhon Vo Thanh , Van Tram Ta , Farrar Jeremy , Wolbers Marcel , Simmons Cameron P. , Wills Bridget
Published: November 2015

Background.  Dengue endangers billions of people in the tropical world, yet no therapeutic is currently available. In part, the severe manifestations of dengue reflect inflammatory processes affecting the vascular endothelium. In addition to lipid lowering, statins have pleiotropic effects that improve endothelial function, and epidemiological studies suggest that outcomes from a range of acute inflammatory syndromes are improved in patients already on statin therapy.

Methods.  Following satisfactory review of a short pilot phase (40 mg lovastatin vs placebo in 30 cases), we performed a randomized, double-blind, placebo-controlled trial of 5 days of 80 mg lovastatin vs placebo in 300 Vietnamese adults with a positive dengue NS1 rapid test presenting within 72 hours of fever onset. The primary outcome was safety. Secondary outcomes included comparisons of disease progression rates, fever clearance times, and measures of plasma viremia and quality of life between the treatment arms.

Results.  Adverse events occurred with similar frequency in both groups (97/151 [64%] placebo vs 82/149 [55%] lovastatin; P = .13), and were in keeping with the characteristic clinical and laboratory features of acute dengue. We also observed no difference in serious adverse events or any of the secondary outcome measures.

Conclusions.  We found lovastatin to be safe and well tolerated in adults with dengue. However, although the study was not powered to address efficacy, we found no evidence of a beneficial effect on any of the clinical manifestations or on dengue viremia. Continuing established statin therapy in patients who develop dengue is safe.

Chinese Clinical Trials Registration.  ISRCTN03147572.
ID Learning Unit—Diagnostics Update: Current Laboratory Methods for Rapid Pathogen Identification in Patients With Bloodstream Infections
Authors: Rubach Matthew P. , Hanson Kimberly E.
Published: November 2015

Diagnostic assays that rapidly identify bloodstream pathogens have the potential to improve patient outcomes and antibiotic stewardship efforts. Current tests are based on the detection of nucleic acids that are specific to a targeted pathogen or based on organism identification using mass spectrometry. Most rapid assays require a positive blood culture as their sample input and expedite pathogen identification by 24–72 hours. For those assays that also report detection of drug resistance markers, information on antimicrobial resistance is expedited by 48–96 hours. This learning unit reviews the basic principles of rapid microorganism identification assays for bloodstream infections with the aim of assisting clinicians in the interpretation and optimal utilization of test results.
Influence of Myelography and Postmyelographic CT on Therapeutic Decisions in Degenerative Diseases of the Cervical Spine
Authors: Westermaier Thomas , Doerr Christina , Stetter Christian , Linsenmann Thomas , Koehler Stefan , Eriskat Joerg , Solymosi Laszlo , Ernestus Ralf-Ingo
Published: November 2015

Study Design:

A retrospective analysis of clinical records and radiologic imaging by 3 independent reviewers to assess the indication for surgical treatment with and without myelography and postmyelographic computed tomography (MCT).

Objective:

To evaluate whether myelography and MCT obtained in addition to magnetic resonance imaging (MRI) influence therapeutic decisions in degenerative diseases of the cervical spine.

Summary of Background Data:

MRI has become the standard examination in spinal diseases. The role of myelography and MCT is not clearly defined in the modern diagnostic setup. In many departments, they are used if MRI leaves some diagnostic uncertainty. It has not been examined yet whether additional myelography and MCT change therapeutic strategies.

Materials and Methods:

Three investigators independently reviewed the anonymized clinical data and image files of 105 patients who had all undergone MRI, myelography, and MCT. They determined their treatment decisions after each of 2 assessment rounds based on the following: (1) MRI and, if available, native CT, and plain radiographs. (2) Additional myelography and MCT. The intraobserver variability was the primary endpoint.

Results:

Myelography and MCT had been performed in multilevel disease, recurrent complaints after surgery, or if MRI had not revealed a clear finding. The intraobserver variability was 26.3% and varied markedly between the 3 investigators (17%–41 %). It was the highest in cases of multilevel disease. If noninvasive imaging included native CT and plain radiographs, the intraobserver variability was significantly reduced to 10.3%.

Conclusions:

In unclear cases of degenerative disorders of the cervical spine, particularly multilevel stenosis, myelography and MCT add relevant information for therapeutic decisions in more than a quarter of the patients in comparison with MRI as the sole diagnostic modality, and changes therapeutic strategies. However, a significant part of the information drawn out of myelography and MCT can be obtained by a completion of noninvasive examinations (native CT and radiographs).