bluuebunny/crossref_metadata_2025 huggingface dataset:
Instantaneous signal loss simulation (InSiL): An improved algorithm for myocardial T1 mapping using the MOLLI sequence
Authors: Shao Jiaxin , Nguyen Kim‐Lien , Natsuaki Yutaka , Spottiswoode Bruce , Hu Peng
Published: February 2014

Purpose

To propose a T1 mapping algorithm for the modified Look‐Locker inversion‐recovery (MOLLI) sequence that can improve T1 estimation accuracy.

Materials and Methods

The modified T1 mapping algorithm (InSiL) is based on the simulation of MOLLI signal evolution and simulates the longitudinal magnetization signal perturbation by each single‐shot image acquisition in MOLLI as an instantaneous signal loss. InSiL was evaluated against original MOLLI using Bloch simulations, phantom studies, and in 15 healthy volunteers at 1.5T.

Results

In phantom studies, the maximum absolute error by InSiL is less than 2%, while that by MOLLI is more than 20% for T1 values from 221 msec to 1539 msec. The benefit of InSiL is greatest at heart rate (HR) >80 bpm and T1 >1000 msec, and InSiL reduced MOLLI T1 error from 14.9 ± 4.5% to 0.4 ± 0.3%. Average InSiL‐derived native myocardial T1 values at 1.5T in healthy volunteers were significantly higher than MOLLI‐derived values by 236.9 ± 11.7 msec (1160.3 ± 25.1 msec vs. 923.4 ± 22.3 msec, P < 0.001) at an average HR of 65.1 ± 14.7 bpm.

Conclusion

The proposed InSiL approach yields better T1 mapping accuracy than MOLLI, and is less sensitive to HR variation in tissues with longer T1 values. J. Magn. Reson. Imaging 2015;41:721–729. © 2014 Wiley Periodicals, Inc.
Antagonism of antifungal metabolites from Streptomyces griseus H7602 against Phytophthora capsici
Authors: Nguyen Xuan Hoa , Naing Kyaw Wai , Lee Young Seong , Kim Yong Hwan , Moon Jae Hak , Kim Kil Yong
Published: February 2014

In this study, evidences for antagonism were established by production of antifungal metabolites from Streptomyces griseus H7602, which were active to inhibit mycelial growth of Phytophthora capsici in the in vitro assays. Mycelial growth and zoosporangia formation of P. capsici was strongly inhibited in the medium containing the cell free culture filtrate of S. griseus H7602. Antifungal metabolites from the cell free culture filtrate of S. griseus H7602 showed substantial antagonistic effects on P. capsici. In addition, a purified antifungal compound was separated from the antifungal metabolites of S. griseus H7602 and identified to be 1H‐pyrrole‐2‐carboxylic acid (PCA) by spectra analyses. PCA showed strong antifungal activity and was evaluated for the first time for its antagonism against P. capsici under in vitro conditions. Minimum inhibitory concentration (MIC) value of PCA was low (4 µg ml−1), and the mycelial growth of P. capsici was almost inhibited at concentration of 64 µg ml−1. This study suggests that the PCA may be useful as biofungicides against P. capsici, and the prominent antagonism of antifungal metabolites from S. griseus H7602 highlights it as a candidate for biocontrol of P. capsici.
β‐NaYF4:Yb3+, Er3+ upconversion microcrystals with both high emission intensity and controlled morphology
Authors: Suli Wu , Ye Liu , Jie Chang , Yanhui Ning , Shufen Zhang
Published: February 2014

Upconversion emission intensity and morphology are both important features of NaYF4:Yb3+, Er3+ microcrystals. In this paper, myristic acid (MA) is selected as a novel stabilizing ligand to synthesize NaYF4:Yb3+, Er3+ through a facile hydrothermal method. Upconversion fluorescence spectra indicate that the emission intensity of product prepared with MA as ligand has increased dramatically compared with the sample prepared using commonly used oleic acid (OA) as ligand. Field emission scanning electron microscopy (FE‐SEM) results display that the morphology of NaYF4:Yb3+, Er3+ obtained using MA as ligand can be tuned from nanodisk, nanorod to nanotube. Especially, nanotube with clear caves can be prepared directly with proper concentration of base (NaOH). And powder X‐ray diffraction (XRD) analysis reveals a relationship between the phase transformation process and the amount of NaOH. With increasing the amount of NaOH, the transition process of cubic phase to hexagonal phase is accelerated. The effect of F− and OH− on the fluorescence properties of NaYF4:Yb3+, Er3+ are studied systematically. A gradual increase of the amount of NaF results in a regular increase of the emission intensity. On the contrary, the emission intensity decreases with increasing the amount of NaOH. In addition, reasonable explanations of the influence of F− and OH− on emission intensity are given as well.
Nucleophilic Substitution of Tetrachloroperylene Diimide in Fluorescent Polyvinylpyrrolidone Film
Authors: Sun Mengmeng , He Yong , Ye Yong , Yang Wantai , Yin Meizhen
Published: February 2014

A stable fluorescent polyvinylpyrrolidone (PVP) film is successfully prepared in one pot by using N,N′‐bis‐(2,6‐diisopropylphenyl)‐1,6,7,12‐tetrachloroperylene‐3,4,9,10‐tetracarboxyldi­imide (4Cl‐PDI) as the fluorophore. Aromatic nucleophilic substitution between the chlorine atom in 4Cl‐PDI and the secondary amine in ring‐opened PVP is proposed and demonstrated by a small‐molecule model reaction. In contrast, N,N′‐bis(2,6‐diisopropylphenyl)‐perylene‐3,4,9,10‐tetracarboxyl diimide (PDI), which does not possess any chlorine atoms, has no such functions and can be easily disassociated from the produced PVP film. The chlorine atom is essential for the covalent bonding of the 4Cl‐PDI molecules in the fluorescent PVP film, thus leading to stable optical properties. The facile synthesis approach is especially suitable for the preparation of fluorescent PVP film, by using perylene species as the fluorophore, which usually contains a halogen element in the bay region.

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A spectral element method using the modal basis and its application in solving second‐order nonlinear partial differential equations
Authors: Fakhar–Izadi Farhad , Dehghan Mehdi
Published: February 2014

We present a high‐order spectral element method (SEM) using modal (or hierarchical) basis for modeling of some nonlinear second‐order partial differential equations in two‐dimensional spatial space. The discretization is based on the conforming spectral element technique in space and the semi‐implicit or the explicit finite difference formula in time. Unlike the nodal SEM, which is based on the Lagrange polynomials associated with the Gauss–Lobatto–Legendre or Chebyshev quadrature nodes, the Lobatto polynomials are used in this paper as modal basis. Using modal bases due to their orthogonal properties enables us to exactly obtain the elemental matrices provided that the element‐wise mapping has the constant Jacobian. The difficulty of implementation of modal approximations for nonlinear problems is treated in this paper by expanding the nonlinear terms in the weak form of differential equations in terms of the Lobatto polynomials on each element using the fast Fourier transform (FFT). Utilization of the Fourier interpolation on equidistant points in the FFT algorithm and the enough polynomial order of approximation of the nonlinear terms can lead to minimize the aliasing error. Also, this approach leads to finding numerical solution of a nonlinear differential equation through solving a system of linear algebraic equations. Numerical results for some famous nonlinear equations illustrate efficiency, stability and convergence properties of the approximation scheme, which is exponential in space and up to third‐order in time. Copyright © 2014 John Wiley & Sons, Ltd.
Nonexistence and existence results for a class of fourth‐order difference Dirichlet boundary value problems
Authors: Liu Xia , Zhang Yuanbiao , Shi Haiping
Published: February 2014

This paper is concerned with a class of fourth‐order nonlinear difference equations. By using the critical point theory, we establish various sets of sufficient conditions of the nonexistence and existence of solutions for Dirichlet boundary value problems and give some new results. Our results successfully complement the existing ones. Copyright © 2014 John Wiley & Sons, Ltd.
Scaled boundary polygons with application to fracture analysis of functionally graded materials
Authors: Chiong Irene , Ooi Ean Tat , Song Chongmin , Tin‐Loi Francis
Published: February 2014

This study presents a framework for the development of polygon elements based on the scaled boundary FEM. Underpinning this study is the development of generalized scaled boundary shape functions valid for any n‐sided polygon. These shape functions are continuous inside each polygon and across adjacent polygons. For uncracked polygons, the shape functions are linearly complete. For cracked polygons, the shape functions reproduce the square‐root singularity and the higher‐order terms in the Williams eigenfunction expansion. This allows the singular stress field in the vicinity of the crack tip to be represented accurately. Using these shape functions, a novel‐scaled boundary polygon formulation that captures the heterogeneous material response observed in functionally graded materials is developed. The stiffness matrix in each polygon is derived from the principle of virtual work using the scaled boundary shape functions. The material heterogeneity is approximated in each polygon by a polynomial surface in scaled boundary coordinates. The intrinsic properties of the scaled boundary shape functions enable accurate computation of stress intensity factors in cracked functionally graded materials directly from their definitions. The new formulation is validated, and its salient features are demonstrated, using five numerical benchmarks. Copyright © 2014 John Wiley & Sons, Ltd.
Convergence analysis of a new mixed finite element method for Biot's consolidation model
Authors: Yi Son‐Young
Published: February 2014

In this article, we propose a mixed finite element method for the two‐dimensional Biot's consolidation model of poroelasticity. The new mixed formulation presented herein uses the total stress tensor and fluid flux as primary unknown variables as well as the displacement and pore pressure. This method is based on coupling two mixed finite element methods for each subproblem: the standard mixed finite element method for the flow subproblem and the Hellinger–Reissner formulation for the mechanical subproblem. Optimal a‐priori error estimates are proved for both semidiscrete and fully discrete problems when the Raviart–Thomas space for the flow problem and the Arnold–Winther space for the elasticity problem are used. In particular, optimality in the stress, displacement, and pressure has been proved in when the constrained‐specific storage coefficient is strictly positive and in the weaker norm when is nonnegative. We also present some of our numerical results.Copyright © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1189–1210, 2014
Coupling of mixed finite element and stabilized boundary element methods for a fluid–solid interaction problem in 3D
Authors: Gatica Gabriel N. , Heuer Norbert , Meddahi Salim
Published: February 2014

We introduce and analyze the coupling of a mixed finite element and a boundary element for a three‐dimensional time‐harmonic fluid–solid interaction problem. We consider a formulation in which the Cauchy stress tensor and the rotation are the main variables in the elastic structure and use the usual pressure formulation in the acoustic fluid. The mixed variational formulation in the solid is completed with boundary integral equations relating the Cauchy data of the acoustic problem on the coupling interface. A crucial point in our formulation is the stabilization technique introduced by Hiptmair and coworkers to avoid the well‐known instability issue appearing in the boundary element method treatment of the exterior Helmholtz problem. The main novelty of this formulation, with respect to a previous approach, consists in reducing the computational domain to the solid media and providing a more accurate treatment of the far field effect. We show that the continuous problem is well‐posed and propose a conforming Galerkin method based on the lowest‐order Arnold–Falk–Winther mixed finite element. Finally, we prove that the numerical scheme is convergent with optimal order.Copyright © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1211–1233, 2014
Parallel 2D Axisymmetric Fluid Modeling of CF4 Discharge in an Inductively Coupled Plasma Source During SiO2 Etching
Authors: Chiu Yuan‐Ming , Chiang Chung‐Hua , Hung Chieh‐Tsan , Hu Meng‐Hua , Wu Jong‐Shinn , Hwang Feng‐Nan
Published: February 2014

A parallel 2D axisymmetric plasma fluid modeling for an inductively coupled plasma source with tetrafluoromethane precursor is reported. In total, 32 species with 96 gas‐phase and 27 surface reactions with site‐balance equations are considered. The predicted results of major species densities are in reasonable agreement with reported experiments. The etching products, e.g. SiFx and O2, are found to be appreciable (∼10%) compared to the precursor near the substrate. The predicted density trends, such as CFx+ and CFx (x = 1–3), are also consistent with reported experiments. Finally, the predicted etching rate on the SiO2 substrate is presented and discussed in detail.
Convergence of the bipolar expansion for the coulomb potential
Authors: Silverstone Harris J.
Published: February 2014

The bipolar expansion of the Coulomb potential, which underlies the multipole moment expansion for interacting charge distributions, converges like a geometric series for separated charges, but converges at best only conditionally when the charges interpenetrate. This article shows how the order of summation affects the sum. Evidence is presented for simpler series when the geometry is linear. © 2014 Wiley Periodicals, Inc.
Fault Tolerant Control of Power Grids
Authors: Odgaard P.F. , Aubrun C. , Majanne Y.
Published: February 2014

This special issue contains article on fault detection and isolation and fault tolerant control methods applied to different aspects of modern power grids, both for detection, isolation and accommodating faults in the power grid, and for detection, isolation and accommodation of faults in power generating units. Copyright © 2014 John Wiley & Sons, Ltd.
Proximal and time‐varying effects of cigarette, alcohol, marijuana and other hard drug use on adolescent dating aggression
Authors: McNaughton Reyes H. Luz , Foshee Vangie A. , Bauer Daniel J. , Ennett Susan T.
Published: February 2014

Although numerous studies have established a link between substance use and adult partner violence, little research has examined the relationship during adolescence and most extant research has not examined multiple substance use types. The current study used hierarchical growth modeling to simultaneously examine proximal (between‐person) and time‐varying (within‐person) relations between cigarette, alcohol, marijuana and hard drug use and physical dating aggression across grades 8 through 12 while controlling for demographic covariates and shared risk factors. Proximal effects of marijuana use on dating aggression were found for girls and proximal effects of hard drug use on dating aggression were found for boys. Time‐varying effects were found for alcohol for both boys and girls and for hard drug use for boys only. Overall, findings suggest that alcohol, marijuana and hard drug use predict whether and when adolescents engage in dating aggression and should be targeted by prevention interventions.
CTCF‐mediated reduction of vigilin binding affects the binding of HP1α to the satellite 2 locus
Authors: Shen Wen-Yan , Liu Qiu-Ying , Wei Ling , Yu Xiao-Qin , Li Ran , Yang Wen-Li , Xie Xiao-Yan , Liu Wen-Quan , Huang Yuan , Qin Yang
Published: February 2014

CCCTC‐binding factor (CTCF) has been implicated in numerous aspects of chromosome biology, and vigilin, a multi‐KH‐domain protein, participates in heterochromatin formation and chromosome segregation. We previously showed that CTCF interacts with vigilin. Here, we show that human vigilin, but not CTCF, colocalizes with HP1α on heterochromatic satellite 2 and β‐satellite repeats. CTCF up‐regulates the transcription of satellite 2, while vigilin down‐regulates it. Vigilin depletion or CTCF overexpression reduces the binding of HP1α on the satellite 2 locus. Furthermore, overexpression of CTCF resists the loading of vigilin onto the satellite 2 locus. Thus CTCF may regulate vigilin behavior and thus indirectly influence the binding of HP1α to the satellite 2 locus.
Acylation and cholesterol binding are not required for targeting of influenza A virus M2 protein to the hemagglutinin‐defined budozone
Authors: Thaa Bastian , Siche Stefanie , Herrmann Andreas , Veit Michael
Published: February 2014

Influenza virus assembles in the budozone, a cholesterol‐/sphingolipid‐enriched (“raft”) domain at the apical plasma membrane, organized by hemagglutinin (HA). The viral protein M2 localizes to the budozone edge for virus particle scission. This was proposed to depend on acylation and cholesterol binding. We show that M2–GFP without these motifs is still transported apically in polarized cells. Employing FRET, we determined that clustering between HA and M2 is reduced upon disruption of HA's raft‐association features (acylation, transmembranous VIL motif), but remains unchanged with M2 lacking acylation and/or cholesterol‐binding sites. The motifs are thus irrelevant for M2 targeting in cells.
The MultiTEP platform–based Alzheimer's disease epitope vaccine activates a broad repertoire of T helper cells in nonhuman primates
Authors: Davtyan Hayk , Ghochikyan Anahit , Petrushina Irina , Hovakimyan Armine , Davtyan Arpine , Cribbs David H. , Agadjanyan Michael G.
Published: February 2014

Background

As a prelude to clinical trials we have characterized B‐ and T‐cell immune responses in macaques to AD vaccine candidates: AV‐1955 and its slightly modified version, AV‐1959 (with 3 additional promiscuous Th epitopes).

Methods

T‐ and B‐cell epitope mapping was performed using the ELISPOT assay and competition ELISA, respectively.

Results

AV‐1955 and AV‐1959 did not stimulate potentially harmful autoreactive T cells, but instead activated a broad but individualized repertoire of Th cells specific to the MultiTEP platform in macaques. Although both vaccines induced robust anti‐Aβ antibody responses without producing antibodies specific to Th epitopes of MultiTEP platforms, analyses of cellular immune responses in macaques demonstrated that the addition of Th epitopes in the case of AV‐1959 created a more potent, superior vaccine.

Conclusion

AV‐1959 is a promising vaccine candidate capable of producing therapeutically potent anti‐amyloid antibody in a broader population of vaccinated subjects with high MHC class II gene polymorphisms.
“How I Had Liked This Villain! How I Had Admired Him!”: A. J. Raffles and the Burglar as British Icon, 1898–1939
Authors: Moss Eloise
Published: February 2014

This article analyzes the literary, theatrical, and film versions of E. W. Hornung's fictional “gentleman” burglar Raffles produced between 1898 and 1939. It argues that the character functioned as a nexus for the articulation of a pleasure culture surrounding burglary, highlighting how approbatory and sexualized versions of burglars pervaded popular and official discourse in Britain and, through the character's commercial success, throughout Europe and America. Depictions of Raffles's triumphs over law and order invited successive audiences to vicariously test, and transgress, the legal, social, cultural, political, gendered, and economic constraints of everyday life. As newspapers labelled real-life burglars “Raffles,” both criminologists and criminals around the globe appropriated this title to refashion burglars as glamorous celebrity personae through academic texts and autobiographies. This article thus demonstrates how notions of respectable masculinity were challenged by sympathetic portrayals of burglars fostered under the “new” journalism, human interest journalism, and the true-crime genre of entertainment.
Challenges involved in measuring intake in early life: focus on methods
Authors: Foster Emma , Adamson Ashley
Published: February 2014

Assessing dietary intake in people of any age is challenging but measuring the diet of infants and children can be particularly problematic. Young children may lack the cognitive skills, writing skills and food knowledge to record their own food intake. Multiple people may be responsible for the care of the child and to collect an accurate picture of intake it may be necessary to combine parental reports with observation in school or nursery. Where interviews are conducted with the child themselves questions may need to focus on aspects of the diet which children are likely to attend to. For example, children may not be familiar with food names or brands but may be able to describe their texture, colour and images on packaging. Adolescents are likely to be more aware of the foods they consume and have the cognitive and writing skills to record their own food intake but may lack the interest or motivation. Research has focused on reducing the burden of recording intake on the participant. Developments include food photographs for assessment of portion size which remove the need for weighing each food item, and, in recent years, computer-based methods have been developed for self-completion by young people with the aim of motivating them to participate in studies by making dietary reporting more engaging. The present paper discusses methods and challenges in assessing food intake in children followed by details of two such tools developed at Newcastle University, UK, the Young Person's Food Atlas and INTAKE24.
Copulation order, density cues and variance in fertilization success in a cestode
Authors: ANDREOU D. , BENESH D. P.
Published: February 2014

Simultaneous hermaphrodites maximize their fitness by optimizing their investment into male or female functions. Allocation of resources to male function (tissues, traits, and/or behaviours increasing paternity) is predicted to increase as density, and the associated level of sperm competition, increases. We tested whether the simultaneous hermaphroditic cestodeSchistocephalus solidususes cues of potential partner densities in its fish intermediate host to improve its male reproductive success in the final host. We had two worms, one originating from a multiple infection in the fish intermediate host and one from a single infection, sequentially compete to fertilize the eggs of a third worm. The fertilization rates of the two competitors nearly always differed from the 50–50 null expectation, sometimes considerably, implying there was a ‘winner’ in each experimental competition. However, we did not find a significant effect of density in the fish host (singlevsmultiple) or mating order on paternity. Additional work will be needed to identify the traits and environmental conditions that explain the high variance in male reproductive success observed in this experiment.
Children with SLI exhibit delays resolving ambiguous reference
Authors: ESTIS JULIE M. , BEVERLY BRENDA L.
Published: February 2014

Fast mapping weaknesses in children with specific language impairment (SLI) may be explained by differences in disambiguation, mapping an unknown word to an unnamed object. The impact of language ability and linguistic stimulus on disambiguation was investigated. Sixteen children with SLI (8 preschool, 8 school-age) and sixteen typically developing age-matched children selected referents given familiar and unfamiliar object pairs in three ambiguous conditions: phonologically distinct word (PD), phonologically similar word (PS), no word (NW). Preschoolers with SLI did not disambiguate, unlike typically developing age-matched participants, who consistently selected unfamiliar objects given PD. School-age children with SLI disambiguated given PD. Delays in disambiguation for young children with SLI suggest limitations in processes that facilitate word learning for typically developing children. School-age children with SLI consistently selected familiar objects for PS, unlike typically developing children, suggesting differences in phonological activation for word learning.
Reduced tillage in temperate organic farming: Effects on soil nutrients, nutrient content and yield of barley, rye and associated weeds
Authors: Vakali Christina , Zaller Johann G. , Köpke Ulrich
Published: February 2014

In temperate regions, reduced tillage is still not broadly accepted in organic farming although the guidelines often recommend the reduction of tillage intensity. During the years 5–7 of a long-term experiment, we studied the effects of the three tillage systems moldboard plowing (MP, soil inversion to 30 cm depth), two-layer plowing (TP, inversion to 15 cm, loosening to 30 cm) and layer cultivation (LC, loosening to 30 cm) on soil nutrients, nutrient content of barley, rye and associated weeds, and yield on a clay loam soil. Crops were cultivated within a five-course crop rotation consisting of green fallow, winter wheat, field peas, winter rye and spring barley; no additional fertilizers were applied. Tillage affected only soil nitrate under barley, which decreased with decreasing tillage intensity. Soil humus, phosphorus (P) and potassium (K) were unaffected by tillage under both crops. Barley shoot nitrogen content was significantly influenced by tillage, with, across years, 38 and 83% higher values under MP than under TP or LC, respectively. Weeds in barley had a higher P and K content at LC than at MP or TP. This resulted, across years, in 73% higher barley yields in MP than in LC. The TP showed a 29% higher barley yield than the LC. Tillage methods had no effect on rye nutrient contents, rye yields or on weeds associated with rye. The significant interaction between tillage and year for rye yield suggests that weather conditions in a given year (e.g., amount of rainfall) can considerably alter the effect of reduced tillage.
Cell differentiation versus cell death: extracellular glucose is a key determinant of cell fate following oxidative stress exposure
Authors: Poulsen R C , Knowles H J , Carr A J , Hulley P A
Published: February 2014

Cells, particularly mechano-sensitive musculoskeletal cells such as tenocytes, routinely encounter oxidative stress. Oxidative stress can not only stimulate tissue repair, but also cause damage leading to tissue degeneration. As diabetes is associated with increased oxidative damage as well as increased risk of tendon degeneration, the aim of this study was to determine if extracellular glucose levels alter the response of tendon cells to oxidative stress. Primary human tenocytes were cultured in either high (17.5 mM) or low (5 mM) glucose and treated with 100 μM hydrogen peroxide. In low glucose, peroxide-treated cells remained fully viable and collagen synthesis was increased, suggesting an anabolic response. In high glucose, however, peroxide treatment led to increased bim-mediated apoptosis. The activities of both forkhead box O (FOXO1) and p53 were required for upregulation of bim RNA expression in high glucose. We found that both p53-mediated inhibition of the bim repressor micro RNA (miR17-92) and FOXO1-mediated upregulation of bim transcription were required to permit accumulation of bim RNA. High glucose coupled with oxidative stress resulted in upregulation of miR28-5p, which directly inhibited expression of the p53 deacetylase sirtuin 3, resulting in increased levels of acetylated p53. In peroxide-treated cells in both high and low glucose, protein levels of acetylated FOXO1 as well as HIF1α (hypoxia-inducible factor 1α) were increased. However, under low-glucose conditions, peroxide treatment resulted in activation of p38, which inhibited FOXO1-mediated but promoted HIF1α-mediated transcriptional activity. In low glucose, HIF1α upregulated expression of sox9 and scleraxis, two critical transcription factors involved in establishing the tenocyte phenotype, and increased collagen synthesis. The switch from FOXO1-mediated (proapoptosis) to HIF1α-mediated (prodifferentiation) transcription occurred at an extracellular glucose concentration of 7 mM, a concentration equivalent to the maximum normal blood glucose concentration. Extracellular glucose has a profound effect on the cellular response to oxidative stress. A level of oxidative stress normally anabolic may be pathological in high glucose.
Phagotrophy by the picoeukaryotic green alga Micromonas: implications for Arctic Oceans
Authors: McKie-Krisberg Zaid M , Sanders Robert W
Published: February 2014

Photosynthetic picoeukaryotes (PPE) are recognized as major primary producers and contributors to phytoplankton biomass in oceanic and coastal environments. Molecular surveys indicate a large phylogenetic diversity in the picoeukaryotes, with members of the Prymnesiophyceae and Chrysophyseae tending to be more common in open ocean waters and Prasinophyceae dominating coastal and Arctic waters. In addition to their role as primary producers, PPE have been identified in several studies as mixotrophic and major predators of prokaryotes. Mixotrophy, the combination of photosynthesis and phagotrophy in a single organism, is well established for most photosynthetic lineages. However, green algae, including prasinophytes, were widely considered as a purely photosynthetic group. The prasinophyte Micromonas is perhaps the most common picoeukaryote in coastal and Arctic waters and is one of the relatively few cultured representatives of the picoeukaryotes available for physiological investigations. In this study, we demonstrate phagotrophy by a strain of Micromonas (CCMP2099) isolated from Arctic waters and show that environmental factors (light and nutrient concentration) affect ingestion rates in this mixotroph. In addition, we show size-selective feeding with a preference for smaller particles, and determine P vs I (photosynthesis vs irradiance) responses in different nutrient conditions. If other strains have mixotrophic abilities similar to Micromonas CCMP2099, the widespread distribution and frequently high abundances of Micromonas suggest that these green algae may have significant impact on prokaryote populations in several oceanic regimes.
Impact of better and worse eye damage on quality of life in advanced glaucoma
Authors: Okamoto Mizu , Sugisaki Kenji , Murata Hiroshi , Hirasawa Hiroyo , Mayama Chihiro , Asaoka Ryo
Published: February 2014

The purpose of the study was to investigate the influence of VF and the VA on vision related quality of life (VRQoL) in advanced glaucoma. Subjects consist of 50 glaucoma patients with mean deviation (MD) less than −20 dB in at least one eye. Patients' VRQoL was assessed using the ‘Sumi questionnaire’. The impact of seven visual measures on VRQoL were compared using principal component regression: MDs of better and worse eyes with 10-2 and 24-2 Humphrey VFs, LogMAR VAs of better and worse eyes and the Esterman score. The root mean of the squared prediction error (RMSE) was calculated using leave-one-out cross validation. Better eye summary measurements were much more influential on VRQoL than corresponding worse eye measurements and Esterman score in every VRQoL task. In conclusion, in advanced glaucoma, VF parameters of the better eye are important for the VRQoL of the patient.
Enhanced chemiluminescence of the luminol-hydrogen peroxide system by BSA-stabilized Au nanoclusters as a peroxidase mimic and its application
Authors: Deng Mao , Xu Shuangjiao , Chen Funan
Published: February 2014

Water-soluble Au nanoclusters capped with BSA enhance the CL emission from the luminol-hydrogen peroxide system in alkaline medium.
An aptamer-functionalized gold nanoparticle biosensor for the detection of prion protein
Authors: Zhang Hai-Jie , Lu Yi-Hui , Long Yi-Juan , Wang Qin-Long , Huang Xiao-Xiao , Zhu Rui , Wang Xi-Liang , Liang Li-Ping , Teng Ping , Zheng Hu-Zhi
Published: February 2014

The resonance light scattering intensity of gold nanoparticles which modified a prion protein (rPrP) aptamer increased after addition of rPrP.
A second-order advantage achieved with the aid of gold nanoparticle catalytic activity. Determination of nitrophenol isomers in binary mixtures
Authors: Rabbani Faride , Abdollahi Hamid , Hormozi-Nezhad M. Reza
Published: February 2014

A novel, simple and rapid spectrophotometric method for the determination of nitrophenol (NP) isomer mixtures based on the catalytic activity of gold nanoparticles is described.
Orientation dependence of electrical properties of large-sized sodium potassium niobate lead-free single crystals
Authors: Deng Hao , Zhao Xiangyong , Zhang Haiwu , Chen Chao , Li Xiaobing , Lin Di , Ren Bo , Jiao Jie , Luo Haosu
Published: February 2014

Large-sized sodium potassium niobate lead-free single crystals were successfully grown by a top seeded solution growth technique (TSSG).
Functional group directed C–H borylation
Authors: Ros A. , Fernández R. , Lassaletta J. M.
Published: February 2014

Different strategies designed to enable directing group effects have been applied to achieve regioselective borylation of C(sp2)–H and C(sp3)–H bonds.
Blending remote sensing data products to estimate photochemical production of hydrogen peroxide and superoxide in the surface ocean
Authors: Powers Leanne C. , Miller William L.
Published: February 2014

A novel combination of remote sensing products is used to estimate photochemical production rates of hydrogen peroxide and superoxide in the global surface ocean.
Stereoselective synthesis of Z-acrylonitrile derivatives: catalytic and acetylcholinesterase inhibition studies
Authors: Parveen Mehtab , Malla Ali Mohammed , Alam Mahboob , Ahmad Musheer , Rather Shahnawaz R.
Published: February 2014

Catalyst-assisted, efficient and eco-friendly synthesis of Z-acrylonitrile derivatives 2a–i and 4a–c.
Preparation and pore structure stability at high temperature of silicon-doped ordered mesoporous alumina
Authors: Zhao Xiaoliang , Zheng Ying , Zheng Yong , Zhan Yingying , Zheng Xuelin
Published: February 2014

Ordered mesoporous γ-Al2O3 with high thermal stability and low-level residual chlorine is obtained by optimizing sol–gel parameters and silicon content.
Intermolecular interaction influenced energy and sensitivity of highly energetic salts: structure and physicochemical properties
Authors: Su Zhiyong , Liu Xiangyu , Yang Qi , Zhang Sheng , Wei Qing , Xie Gang , Chen Sanping , Gao Shengli
Published: February 2014

Based on supramolecular interactions, three stable energetic compounds (TATA+)·(TZA−)·H2O, (AT+)2·(OX2−) and (DAT2+)·(NO3−)2 were synthesized and structurally characterized and their physicochemical properties theoretically and experimentally studied.
Wavelength and temperature-dependent apparent quantum yields for photochemical formation of hydrogen peroxide in seawater
Authors: Kieber David J. , Miller Gary W. , Neale Patrick J. , Mopper Kenneth
Published: February 2014

Wavelength, temperature and light-dose dependent hydrogen peroxide photoproduction quantum yields were determined in subtropical, temperate and polar marine waters.
Tuning the pore size of ZnO nano-grids via time-dependent solvent annealing
Authors: Sarkar Kuhu , Schaffer Christoph J. , González Daniel Moseguí , Naumann Anna , Perlich Jan , Müller-Buschbaum Peter
Published: February 2014

Via a block copolymer-assisted sol–gel synthesis route, zinc oxide (ZnO) thin films are obtained with a nanogrid-like morphology.
Low temperature and high frequency effects on polymer-stabilized blue phase liquid crystals with large dielectric anisotropy
Authors: Peng Fenglin , Chen Yuan , Yuan Jiamin , Chen Haiwei , Wu Shin-Tson , Haseba Yasuhiro
Published: February 2014

Debye relaxation limits the low temperature and high frequency operations of a polymer-stabilized blue phase liquid crystal.
High boost ratio DC–DC converter with ripple‐free input current
Authors: Chen Zhangyong , Xu Jianping
Published: February 2014

A high boost ratio non‐isolated converter with a ripple‐free input current is proposed, which combines a zero‐ripple boost cell and a coupled inductor to achieve a high output voltage step‐up. A passive snubber is utilised to suppress voltage spike of the switch caused by the resonance of the leakage inductance of the coupled inductor and the parasitic capacitance of the switch. Therefore, a low‐voltage‐rated metal oxide semiconductor field effect transistor (MOSFET) with low rDS(ON) can be used to improve the efficiency of the converter. In addition, a ripple‐free input current can be achieved, making the electromagnetic interference (EMI) filter simple. Experimental results of a 100 W (40 V/200 V) prototype are presented to verify the analysis results of the proposed converter.
Parallel operation of photovoltaic power conditioning system modules for large‐scale photovoltaic power generation
Authors: Kim Kyu‐Tae , Kwon Jung‐Min , Kwon Bong‐Hwan
Published: February 2014

In this study, parallel operation of photovoltaic (PV) power conditioning system (PCS) modules for large‐scale PV power generation is proposed. This system consists of PCS modules that are connected in parallel and share the dc‐link voltage. PCS modules can be easily connected in parallel for high‐power extension and independent control of the PCS module is achieved. Since this system does not use communication lines among the PCS modules, sensing signal noise and the mutual interference can be neglected. In addition, the number of PCS modules operating simultaneously can be controlled in accordance with the irradiance. Thus, system efficiency can be maximised and PCS module life time is extended. Further, the system has high availability since it has N + 1 redundancy that is achieved by increasing the power capacity of PCS modules through the use of an additional PCS module. A prototype of the proposed system is implemented at a rated power of 500 kW. Experimental results for parallel operation of PCS modules show the feasibility of the proposed control.
Carbon nanotube‐supported bimetallic Pt–Fe catalysts for nitrobenzene hydrogenation
Authors: Hao Liang , Jiao Qingze , Hu Yanting , Li Hansheng , Zhao Yun
Published: February 2014

Carbon nanotube (CNT)‐supported Pt–Fe catalysts were prepared by a chemical reduction method using chloroplatinic acid and ferric nitrate as starting materials. The structure and the morphology of the catalysts were characterised by an X‐ray diffractometer, transmission electron microscopy and inductively coupled plasma atomic emission spectrometry. The catalytic performance for nitrobenzene hydrogenation was evaluated under atmospheric pressure at an ambient temperature. The bimetallic Pt–Fe/CNT catalysts showed much higher activity than Pt/CNTs with a similar Pt content for nitrobenzene hydrogenation.
Generalizing the self-healing diffusion Monte Carlo approach to finite temperature: A path for the optimization of low-energy many-body bases
Authors: Reboredo Fernando A. , Kim Jeongnim
Published: February 2014

A statistical method is derived for the calculation of thermodynamic properties of many-body systems at low temperatures. This method is based on the self-healing diffusion Monte Carlo method for complex functions [F. A. Reboredo, J. Chem. Phys. 136, 204101 (2012)] and some ideas of the correlation function Monte Carlo approach [D. M. Ceperley and B. Bernu, J. Chem. Phys. 89, 6316 (1988)]. In order to allow the evolution in imaginary time to describe the density matrix, we remove the fixed-node restriction using complex antisymmetric guiding wave functions. In the process we obtain a parallel algorithm that optimizes a small subspace of the many-body Hilbert space to provide maximum overlap with the subspace spanned by the lowest-energy eigenstates of a many-body Hamiltonian. We show in a model system that the partition function is progressively maximized within this subspace. We show that the subspace spanned by the small basis systematically converges towards the subspace spanned by the lowest energy eigenstates. Possible applications of this method for calculating the thermodynamic properties of many-body systems near the ground state are discussed. The resulting basis can also be used to accelerate the calculation of the ground or excited states with quantum Monte Carlo.
Effect of doubly layered Ru intermediate layers in perpendicular magnetic recording tape media
Authors: Sakai Hidetada , Saemma Gaku , Nakagawa Shigeki
Published: February 2014

Si/NiFe bilayer structures are very effective to obtain c-axis orientation in both a Ru intermediate layer and a CoPtCr-SiO2 recording layer when they successively deposited on the Si/NiFe bilayer. Doubly layered Ru which consists of two Ru layers prepared at low and high sputtering gas pressures promoted c-axis orientation and well-isolated grains of the CoPtCr even when the Ru intermediate layer was very thin. Doubly layered Ru intermediate layers deposited on Si/NiFe seed layers attained suitable c-axis orientation and well-isolated grains of the CoPtCr recording layer, even though the Ru double-layer was as thin as 5 nm.
Equilibrium shapes of polycrystalline silicon nanodots
Authors: Korzec M. D. , Roczen M. , Schade M. , Wagner B. , Rech B.
Published: February 2014

This study is concerned with the topography of nanostructures consisting of arrays of polycrystalline nanodots. Guided by transmission electron microscopy (TEM) measurements of crystalline Si (c-Si) nanodots that evolved from a “dewetting” process of an amorphous Si (a-Si) layer from a SiO2 coated substrate, we investigate appropriate formulations for the surface energy density and transitions of energy density states at grain boundaries. We introduce a new numerical minimization formulation that allows to account for adhesion energy from an underlying substrate. We demonstrate our approach first for the free standing case, where the solutions can be compared to well-known Wulff constructions, before we treat the general case for interfacial energy settings that support “partial wetting” and grain boundaries for the polycrystalline case. We then use our method to predict the morphologies of silicon nanodots.
Multispectral guided fluorescence diffuse optical tomography using upconverting nanoparticles
Authors: Svenmarker Pontus , Xu Can T. , Liu Haichun , Wu Xia , Andersson-Engels Stefan
Published: February 2014

We report on improved image detectability for fluorescence diffuse optical tomography using upconverting nanoparticles doped with rare-earth elements. Core-shell NaYF4:Yb3+/Er3+@NaYF4 upconverting nanoparticles were synthesized through a stoichiometric method. The Yb3+/Er3+ sensitizer-activator pair yielded two anti-Stokes shifted fluorescence emission bands at 540 nm and 660 nm, here used to a priori estimate the fluorescence source depth with sub-millimeter precision. A spatially varying regularization incorporated the a priori fluorescence source depth estimation into the tomography reconstruction scheme. Tissue phantom experiments showed both an improved resolution and contrast in the reconstructed images as compared to not using any a priori information.
Generation of linear frequency modulation signal with reduced round-off error using pulse-output direct digital synthesis technique
Authors: Peng Cheng Y. , Ma Xiao C. , Yan She F. , Yang Li.
Published: February 2014

The pulse-output Direct Digital Synthesis (DDS), in which the overflow signal of the phase accumulator is used for the pulse output, can be easily implemented due to its simple hardware architecture and low algorithm complexity. This paper introduces the fundamentals for generating Linear Frequency Modulation (LFM) pulse using pulse-output DDS technique. Error introducing mechanisms that affect the accuracy of signal's duration, initial phase, and frequency are studied. Extensive analysis of round-off error is given. A modified hardware architecture for LFM pulse generation with reduced round-off error is proposed. Experiment results are given, which shows that the proposed generator is promising in applications such as sonar transmitters.
Direct observation of adsorption geometry for the van der Waals adsorption of a single π-conjugated hydrocarbon molecule on Au(111)
Authors: Kim Ju-Hyung , Jung Jaehoon , Tahara Kazukuni , Tobe Yoshito , Kim Yousoo , Kawai Maki
Published: February 2014

Weak van der Waals adsorption of π-conjugated hydrocarbon molecules onto the gold surface, Au(111), is one of the essential processes in constructing organic-metal interfaces in organic electronics. Here we provide a first direct observation of adsorption geometry of a single π-conjugated hydrocarbon molecule on Au(111) using an atomically resolved scanning tunneling microscopy study combined with van der Waals density functional methodology. For the purpose, we utilized a highly symmetric π-conjugated hydrocarbon molecule, dehydrobenzo[12]annulene (DBA), which has a definite three-fold symmetry, the same as the Au(111) surface. Interestingly, our observations on an atomically resolved scale clearly indicate that the DBA molecule has only one adsorption configuration on Au(111) in spite of the weak van der Waals adsorption system. Based on the precisely determined adsorption geometry of DBA/Au(111), our calculation results imply that even a very small contribution of the interfacial orbital interaction at the organic-metal interface can play a decisive role in constraining the adsorption geometry even in the van der Waals adsorption system of a π-conjugated hydrocarbon molecule on the noblest Au(111) surface. Our observations provide not only deeper insight into the weak adsorption process, but also new perspectives to organic electronics using π-conjugated hydrocarbon molecules on the Au surface.
Oxygen diffusion and reactivity at low temperature on bare amorphous olivine-type silicate
Authors: Minissale M. , Congiu E. , Dulieu F.
Published: February 2014

The mobility of O atoms at very low temperatures is not generally taken into account, despite O diffusion would add to a series of processes leading to the observed rich molecular diversity in space. We present a study of the mobility and reactivity of O atoms on an amorphous silicate surface. Our results are in the form of reflection absorption infrared spectroscopy and temperature-programmed desorption spectra of O2 and O3 produced via two pathways: O + O and O2 + O, investigated in a submonolayer regime and in the range of temperature between 6.5 and 30 K. All the experiments show that ozone is formed efficiently on silicate at any surface temperature between 6.5 and 30 K. The derived upper limit for the activation barriers of O + O and O2 + O reactions is ∼150 K/kb. Ozone formation at low temperatures indicates that fast diffusion of O atoms is at play even at 6.5 K. Through a series of rate equations included in our model, we also address the reaction mechanisms and show that neither the Eley–Rideal nor the hot atom mechanisms alone can explain the experimental values. The rate of diffusion of O atoms, based on modeling results, is much higher than the one generally expected, and the diffusive process proceeds via the Langmuir-Hinshelwood mechanism enhanced by tunnelling. In fact, quantum effects turn out to be a key factor that cannot be neglected in our simulations. Astrophysically, efficient O3 formation on interstellar dust grains would imply the presence of huge reservoirs of oxygen atoms. Since O3 is a reservoir of elementary oxygen, and also of OH via its hydrogenation, it could explain the observed concomitance of CO2 and H2O in the ices.