bluuebunny/crossref_metadata_2025 huggingface dataset:
The Maximum Number of Dominating Induced Matchings
Authors: Lin Min Chih , Moyano Veronica A. , Rautenbach Dieter , Szwarcfiter Jayme L.
Published: May 2014

A matching M of a graph G is a dominating induced matching (DIM) of G if every edge of G is either in M or adjacent with exactly one edge in M. We prove sharp upper bounds on the number of DIMs of a graph G and characterize all extremal graphs. Our results imply that if G is a graph of order n, then ; provided G is triangle‐free; and provided and G is connected.
Using membrane‐targeted green fluorescent protein to monitor neurotoxic protein‐dependent degeneration of Drosophila eyes
Authors: Burr Aaron A. , Tsou Wei‐Ling , Ristic Gorica , Todi Sokol V.
Published: May 2014

Age‐related neurodegeneration has been studied extensively through the use of model organisms, including the genetically versatile Drosophila melanogaster. Various neurotoxic proteins have been expressed in fly eyes to approximate degeneration occurring in humans, and much has been learned from this heterologous system. Although Drosophila expedites scientific research through rapid generational times and relative inexpensiveness, one factor that can hinder analyses is the examination of milder forms of degeneration caused by some toxic proteins in fly eyes. Whereas several disease proteins cause massive degeneration that is easily observed by examining the external structure of the fly eye, others cause mild degeneration that is difficult to observe externally and requires laborious histological preparation to assess and monitor. Here, we describe a sensitive fluorescence‐based method to observe, monitor, and quantify mild Drosophila eye degeneration caused by various proteins, including the polyglutamine disease proteins ataxin‐3 (spinocerebellar ataxia type 3) and huntingtin (Huntington's disease), mutant α‐synuclein (Parkinson's disease), and Aβ42 (Alzheimer's disease). We show that membrane‐targeted green fluorescent protein reports degeneration robustly and quantitatively. This simple yet powerful technique, which is amenable to large‐scale screens, can help accelerate studies to understand age‐related degeneration and to find factors that suppress it for therapeutic purposes. © 2014 Wiley Periodicals, Inc.
PARK13 regulates PINK1 and subcellular relocation patterns under oxidative stress in neurons
Authors: Patil Ketan S. , Basak Indranil , Lee Sungsu , Abdullah Rashed , Larsen Jan Petter , Møller Simon Geir
Published: May 2014

Parkinson's disease (PD) is a progressive and irreversible neurodegenerative disorder coupled to selective degeneration of dopamine‐producing neurons in the substantia nigra. The majority of PD incidents are sporadic, but monogenic cases account for 5–10% of cases. Mutations in PINK1 cause autosomal recessive forms of early‐onset PD, and PINK1 stimulates Omi/HtrA2/PARK13 protease activity when both proteins act as neuroprotective components in the same stress pathway. Studies on PINK1 and PARK13 have concentrated on phosphorylation‐dependent PINK1‐mediated activation of PARK13 and mitochondrial functions, because both proteins are classically viewed as mitochondrial. Although PARK13‐mediated protective mechanisms are at least in part regulated by PINK1, little is known concerning how these two proteins are regulated in different subcellular compartments or, indeed, the influence of PARK13 on PINK1 characteristics. We show that PARK13 localizes to a variety of subcellular locations in neuronal cells and that PINK1, although more restrictive, also localizes to locations other than those previously reported. We demonstrate that PARK13 accumulation leads to a concomitant accumulation of PINK1 and that the increase in PINK1 levels is compartmental specific, indicating a correlative relationship between the two proteins. Moreover, we show that PARK13 and PINK1 protein levels accumulate in response to H2O2 and L‐DOPA treatments in a subcellular fashion and that both proteins show relocation to the cytoskeleton in response to H2O2. This H2O2‐mediated relocation is abolished by PARK13 overexpression. This study shows that PARK13 and PINK1 are subcellular‐specific, but dynamic, proteins with a reciprocal molecular relationship providing new insight into the complexity of PD. © 2014 Wiley Periodicals, Inc.
Ginsenoside Rd ameliorates experimental autoimmune encephalomyelitis in C57BL/6 mice
Authors: Zhu Dongliang , Liu Mei , Yang Yaowu , Ma Lili , Jiang Ying , Zhou Linli , Huang Qiling , Pi Rongbiao , Chen Xiaohong
Published: May 2014

Multiple sclerosis (MS) is a common disabling autoimmune disease without an effective treatment in young adults. Ginsenoside Rd, extracted from Panax notoginseng, has multiple pharmacological effects and potential therapeutic applications in diseases of the central nervous system. In this study, we explore the efficacy of ginsenoside Rd in experimental autoimmune encephalomyelitis (EAE), an established model of MS. EAE was induced by myelin oligodendrocyte glycoprotein 35–55‐amino‐acid peptide. Ginsenoside Rd (10–80 mg/kg/day) or vehicle was intraperitoneally administered on the disease onset day, and the therapy persisted throughout the experiments. The dose of 40 mg/kg/day of ginsenoside Rd was selected as optimal. Ginsenoside Rd effectively ameliorated the clinical severity in EAE mice, reduced the permeability of the blood–brain barrier, regulated the secretion of interferon‐gamma and interleukin‐4, promoted the Th2 shift in vivo (cerebral cortex) and in vitro (splenocytes culture supernatants), and prevented the reduction in expression of brain‐derived neurotrophic factor and nerve growth factor in both cerebral cortex and lumbar spinal cord of EAE mice. This study establishes the potency of ginsenoside Rd in inhibiting the clinical course of EAE. These findings suggest that ginsenoside Rd could be a promising agent for amelioration of neuroimmune dysfunction diseases such as MS. © 2014 Wiley Periodicals, Inc.
Optimization of extraction conditions and fatty acid characterization of Lactobacillus pentosus cell‐bound biosurfactant/bioemulsifier
Authors: Vecino Xanel , Barbosa‐Pereira Letricia , Devesa‐Rey Rosa , Cruz José M , Moldes Ana B
Published: May 2014

BACKGROUND

There is currently much interest in the use of natural biosurfactants and bioemulsifiers, mainly in the cosmetic, pharmaceutical and food industries. However, there are no studies on the optimization of the extraction conditions of cell‐bound biosurfactants. In this work, a biosurfactant with emulsifier properties was extracted from Lactobacillus pentosus cells, under different extraction conditions, and characterized.

RESULTS

During extraction, the most influential independent variable, concerning the emulsifying capacity of biosurfactant, was the operation time, followed by temperature and salt concentration. Biosurfactant from L. pentosus was evaluated by Fourier transform infrared spectroscopy and the composition of fatty acids was analyzed by gas chromatography–mass spectrometry. The hydrophobic chain of the biosurfactant from L. pentosus comprises 548 g kg−1 linoelaidic acid (C18:2), 221 g kg−1 oleic or elaidic acid (C18:1), 136 g kg−1 palmitic acid (C16) and 95 g kg−1 stearic acid (C18). In addition, emulsions of water and rosemary oil were stabilized with a biosurfactant produced by L. pentosus and compared with emulsions stabilized with polysorbate 20.

CONCLUSION

The optimum extraction conditions of biosurfactant were achieved at 45 °C at 120 min and using 9 g kg−1 of salt. In all the assays biosurfactant from L. pentosus yielded more stable emulsions and higher emulsion volumes than polysorbate 20. © 2014 Society of Chemical Industry
Characterization and complete separation of major cyclolinopeptides in flaxseed oil by reversed‐phase chromatography
Authors: Lao Ying W. , Mackenzie Kim , Vincent William , Krokhin Oleg V.
Published: May 2014

Organoleptic properties of flaxseed oil deteriorate during storage due to methionine oxidation in its major cyclolinopeptides. Cyclolinopeptide E was previously identified as being responsible for the manifestation of bitter taste with flaxseed oil ageing. We developed a chromatographic procedure to monitor the oxidation of major cyclic peptides in flaxseed oil. We also used liquid chromatography with mass spectrometry and high‐efficiency core–shell reversed‐phase sorbents to study the separation of cyclolinopeptides in detail. The KinetexTM family of stationary phases (C8, C18, phenyl‐hexyl) was tested, along with the standard porous LunaTM C18(2) media. We found that only the phenyl‐hexyl stationary phase allows for complete resolution of major cyclolinopeptides, thus permitting direct UV monitoring of degree of conversion for cyclolinopeptide B into C and L into E. We also report, for the first time, a significant effect of peak splitting for some methionine S‐oxide (Mso) containing cyclolinopeptides, which most likely appear due to diastereomerization. This results in poor separation efficiency for cyclolinopeptides F, G, and E, and gives baseline resolution of diastereomeric pairs for cyclolinopeptides I and P. Thus, a single oxidation of cyclolinopeptide N yields three distinct chromatographic peaks corresponding to cyclolinopeptide T (cyclo‐MsoLMPFFWV, reported for the first time) and pair of cyclolinopeptide I (cyclo‐MLMsoPFFWV) diastereomers.
Determination and Fingerprint Analysis of Steroidal Saponins in roots of Liriope muscari (Decne.) L. H. Bailey by ultra high performance liquid chromatography coupled with ion trap time‐of‐flight mass spectrometry
Authors: Li Yong‐Wei , Qi Jin , Wen‐Zhang  , Zhou Shui‐Ping , Yan‐Wu  , Yu Bo‐Yang
Published: May 2014

Liriope muscari (Decne.) L. H. Bailey is a well‐known traditional Chinese medicine used for treating cough and insomnia. There are few reports on the quality evaluation of this herb partly because the major steroid saponins are not readily identified by UV detectors and are not easily isolated due to the existence of many similar isomers. In this study, a qualitative and quantitative method was developed to analyze the major components in L. muscari (Decne.) L. H. Bailey roots. Sixteen components were deduced and identified primarily by the information obtained from ultra high performance liquid chromatography with ion‐trap time‐of‐flight mass spectrometry. The method demonstrated the desired specificity, linearity, stability, precision, and accuracy for simultaneous determination of 15 constituents (13 steroidal glycosides, 25(R)‐ruscogenin, and pentylbenzoate) in 26 samples from different origins. The fingerprint was established, and the evaluation was achieved using similarity analysis and principal component analysis of 15 fingerprint peaks from 26 samples by ultra high performance liquid chromatography. The results from similarity analysis were consistent with those of principal component analysis. All results suggest that the established method could be applied effectively to the determination of multi‐ingredients and fingerprint analysis of steroid saponins for quality assessment and control of L. muscari (Decne.) L. H. Bailey.
Geometric two‐dimensional idèles with cycle module coefficients
Authors: Braunling Oliver
Published: May 2014

We give a theory of idèles with coefficients for smooth surfaces over a field. It is an analogue of Beilinson/Huber's theory of higher adèles, but handling cycle module sheaves instead of quasi‐coherent ones. We prove that they give a flasque resolution of the cycle module sheaves in the Zariski topology. As a technical ingredient we show the Gersten property for cycle modules on equicharacteristic complete regular local rings, which might be of independent interest.
Nonlinear differential identities for cnoidal waves
Authors: Leitner Michael , Mikikits‐Leitner Alice
Published: May 2014

This article presents a family of nonlinear differential identities for the spatially periodic function , which is essentially the Jacobian elliptic function with one non‐trivial parameter . More precisely, we show that this function fulfills equations of the form

urn:x-wiley:dummy:mana201300233:equation:mana201300233-math-0005for all . We give explicit expressions for the coefficients and for given s.

Moreover, we show that for any s the set of functions constitutes a basis for . By virtue of our formulas the problem of finding a periodic solution to any nonlinear wave equation reduces to a problem in the coefficients. A finite ansatz exactly solves the KdV equation (giving the well‐known cnoidal wave solution) and the Kawahara equation. An infinite ansatz is expected to be especially efficient if the equation to be solved can be considered a perturbation of the KdV equation.
ABC Triblock Terpolymer Self‐Assembled Core–Shell–Corona Nanotubes with High Aspect Ratios
Authors: Wang Lulu , Huang Haiying , He Tianbai
Published: May 2014

Nanotubes have attracted considerable attention due to their unique 1D hollow structure; however, the fabrication of pure nanotubes via block copolymer self‐assembly remains a challenge. In this work, the successful preparation of core–shell–corona (CSC) nanotubular micelles with uniform diameter and high aspect ratio is reported, which is achieved via self‐assembly of a poly (styrene‐b‐4‐vinyl pyridine‐b‐ethylene oxide) triblock terpolymer in binary organic solvents with assistance of solution thermal annealing. Via direct visualization of trapped intermediates, the nanotube is believed to be formed via large sphere—large solid cylinderical aggregates—nanotube transformations, wherein the unique solid to hollow transition accompanied with the unidirectional growth is distinct from conventional pathway. In addition, by virtue of the CSC structure, gold nanoparticles are able to be selectively incorporated into different micellar domains of the nanotubes, which may have potential applications in nanoscience and nanotechnology.

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Microstructure of MgAl5Ca3Sr alloy after creep deformation and high‐temperature heat treatment
Authors: Rzychoń T.
Published: May 2014

The paper presents results of microstructural investigations of MgAl5Ca3Sr magnesium alloys in the as‐cast condition, after creep tests at 180 °C, and after heat treatment at 450 °C for 4.5 hours. The microstructure of MgAl5Ca3Sr alloy is composed of α‐Mg solid solution, irregular shaped (Mg,Al)2Ca phase with C36 crystal structure, bulky (Mg,Al)17(Sr,Ca)2 phase, fine lamellar Mg2Ca phase with C14 structure, needle‐shaped Al2Ca precipitates with the C15 crystal structure. The precipitation of the needle‐shaped Al2Ca phase in the α‐Mg grains and spheroidization of the C14 phase were found after heat treatment at 450 °C in argon atmosphere. The (Mg,Al)2Ca (C36) and (Mg,Al)17(Sr,Ca)2 phases seems to be stable at 450 °C, however, the increasing of aluminum content in C36 compound was observed suggesting the initial stage of C36 → C15 transformation. After creep deformation at 180 °C precipitates of the Al2Ca phase were found in α‐Mg phase. The intermetallic compounds are stable at 180 °C. The MgAl5Ca3Sr alloy exhibits good creep resistance up to 75 MPa. Tensile properties are comparable to those of Mg‐RE‐Zn–Zr alloys.
IDRApegasus: a carbon fiber monocoque vehicle prototype
Authors: Carello M. , Airale A. G. , Messana A.
Published: May 2014

Today, in the design of a new vehicle, one of the most important challenge is the weight reduction. For this reason the use of composite materials is very important, in fact the most important challenge is to apply composite materials in structural applications not only in racing vehicles or supercars, but also in mass‐production vehicles.

For prototypes designed to be used in international low consumption competitions, like the Shell Eco Marathon, the targets are very sophisticated because the total vehicle's weight must be less than 30–35 kg.

In this paper is presented a real case study that it is the monocoque of the IDRApegasus low consumption racing prototype, starting from an existing solution IDRA also made in carbon fiber.

The first step was the definition of the new external shape according to aerodynamics, mechanical packaging, powertrain lay‐out, driver ergonomy and visibility constrains which ergonomy that the prototype has three wheels, two front wheels (inside the body, to reduce the frontal area) and a rear steering driving wheel.

Then the critical working situation was defined: the loads, the target weight and the target stiffness in comparison of the previous monocoque, because it was very important to understand the tensile strains to optimize the thickness in all monocoque locations.

The structural design of the monocoque was done by means of numerical simulations using the finite element techniques and once the external surfaces have been defined, a composite layer thickness and orientation optimization have been made to define the lamination lay‐out.
On a numerical strategy to simulate nanotube‐reinforced composite materials
Authors: Makvandi R. , Öchsner A.
Published: May 2014

The application of carbon nanotubes as the reinforcing phase in composite materials is considered. A literature review in regards to the simulation approaches that have been done in order to study the behavior of nanotube‐reinforced composites from several aspects is provided. After that, a new approach for investigating the mechanical properties of the composites reinforced with randomly oriented fibers using the finite element method is proposed. The main idea is to create regular shaped islands around the distributed fibers and to connect these islands to each other and to the representative volume element. Two application examples show the flexibility and the reliability of the proposed method. It has been shown that this approach can handle both aligned and arbitrary distributions of the nanotubes.
Incentives and Selection in Promotion Contests: Is It Possible to Kill Two Birds with One Stone?
Authors: Stracke Rudi , Höchtl Wolfgang , Kerschbamer Rudolf , Sunde Uwe
Published: May 2014

This paper investigates whether a designer can improve both the incentive provision and the selection performance of a promotion contest by making the competition more (or less) dynamic. A comparison of static (one‐stage) and dynamic (two‐stage) contests reveals that this is not the case. A structural change that improves the performance in one dimension leads to a deterioration in the other dimension. This suggests that modifications of the contest structure are an alternative to strategic handicaps. A key advantage of structural handicaps over participant‐specific ones is that the implementation of the former does not require prior identification of worker types. Copyright © 2014 John Wiley & Sons, Ltd.
The local superconvergence of the quadratic triangular element for the poisson problem in a polygonal domain
Authors: He Wen‐Ming , Cui Jun‐Zhi , Zhu Qi‐Ding
Published: May 2014

It is the first time for us to combine the local symmetric technique and the weak estimates to investigate the local superconvergence of the finite element method for the Poisson equation in a bounded domain with polygonal boundary where a uniform family of partitions is not required or the solution need not have high global smoothness. Combining a uniform family of triangulations in the interior of domain with a quasiuniform family of triangulations at the boundary of domain, we present a special family of triangulations. By the finite element theory of the derivative of the Green's function presented in this article, we combine the local symmetric technique and the weak estimates to obtain the local superconvergence of the derivative for the quadratic elements. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1854–1876, 2014
Rare form of autosomal dominant thalassemia—Hemoglobin Hakkari
Authors: Nair Sushmita , Eldjerou Lamis K , Harris Neil S. , Dunbar Levette N.
Published: May 2014

Autosomal dominant Beta Thalassemias are rare and are due to point or frame shift mutations resulting in production of abnormal unstable beta chains of hemoglobin which precipitate leading to hemolysis and anemia. We describe a case of Hemoglobin Hakkari, a rare variant of dominant Thalassemia arising due to a de novo mutation in the exon 2 of the beta globin gene. Pediatr Blood Cancer 2014;61:2118–2120. © 2014 Wiley Periodicals, Inc.
Treatment of poor placentation and the prevention of associated adverse outcomes – what does the future hold?
Authors: Spencer R. N. , Carr D. J. , David A. L.
Published: May 2014

Poor placentation, which manifests as pre‐eclampsia and fetal growth restriction, is a major pregnancy complication. The underlying cause is a deficiency in normal trophoblast invasion of the spiral arteries, associated with placental inflammation, oxidative stress, and an antiangiogenic state. Peripartum therapies, such as prenatal maternal corticosteroids and magnesium sulphate, can prevent some of the adverse neonatal outcomes, but there is currently no treatment for poor placentation itself. Instead, management relies on identifying the consequences of poor placentation in the mother and fetus, with iatrogenic preterm delivery to minimise mortality and morbidity. Several promising therapies are currently under development to treat poor placentation, to improve fetal growth, and to prevent adverse neonatal outcomes. Interventions such as maternal nitric oxide donors, sildenafil citrate, vascular endothelial growth factor gene therapy, hydrogen sulphide donors, and statins address the underlying pathology, while maternal melatonin administration may provide fetal neuroprotection. In the future, these may provide a range of synergistic therapies for pre‐eclampsia and fetal growth restriction, depending on the severity and gestation of onset. © 2014 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.
MAT‐CAP: a novel medication assessment tool to explore adherence to clinical practice guidelines in community‐acquired pneumonia
Authors: Høgli June Utnes , Småbrekke Lars , Garcia Beate Hennie
Published: May 2014

Background/purpose

Community‐acquired pneumonia (CAP) is a disease with high morbidity and mortality. Adherence to clinical practice guidelines (CPGs) in treatment of CAP is associated with favourable outcome. We aimed to develop and validate a medication assessment tool (MAT) to explore adherence to CPG recommendations in patients with CAP admitted to a Norwegian hospital. The tool is named MAT‐CAP.

Method

Sixteen quality indicators (QIs) based on local and international CPGs were developed. Content validity was explored in an expert panel using a two‐round modified Delphi technique. QIs demonstrating content valdity were reformulated into review criteria forming the MAT‐CAP. Feasibility and adherence to MAT‐CAP were explored in a retrospective study using data from electronic patient records of CAP patients admitted to the University Hospital of North Norway Tromso during 2008. Reliability was explored using Cohen's kappa (ĸ) statistics for inter‐ and intra‐observer agreements.

Results

Content validity was demonstrated for 15 QIs covering areas as initial empirical treatment, microbiological diagnostics, pathogen specific treatment, dose adjustment according to renal function, switch from intravenous to oral treatment and treatment duration. Overall reliability was excellent with ĸ‐values of 0.88 and 0.95 for inter‐observer and intra‐observer agreements, respectively. Overall applicability was 37.2%, and mean application times were 3.1 and 3.8 min for the two observers. Overall adherence to 812 criteria applied was 59% (range 0–100).

Conclusions

We have demonstrated content validity, feasibility and reliability of a 15‐criterion MAT‐CAP. Adherence results from applying MAT‐CAP criteria pinpointed areas with good clinical performance and areas with improvement potentials. Copyright © 2014 John Wiley & Sons, Ltd.
Time‐reparametrization invariance and Hamilton‐Jacobi approach to the cosmological σ‐model
Authors: van Holten J.W. , Kerner R.
Published: May 2014

The construction of physical models with local time‐reparametrization invariance is reviewed. Negative‐energy contributions to the hamiltonian are shown to be crucial for the realization of this reparametrization symmetry. The covariant formulation of the dynamics is used to develop a time and gauge invariant Hamilton‐Jacobi theory. This formalism is applied to solve for the cosmology of a homogeneous universe of the Friedmann‐Lemaître‐Robertson‐Walker type. After a discussion of empty universes, the FLRW theory is extended with homogeneous scalar fields generically described by a σ‐model on some scalar manifold. An explicit gauge‐invariant solution is constructed for the non‐linear O(N)‐models.
Plant strengtheners enhance parasitoid attraction to herbivore‐damaged cotton via qualitative and quantitative changes in induced volatiles
Authors: Sobhy Islam S , Erb Matthias , Turlings Ted CJ
Published: May 2014

BACKGROUND

Herbivore‐damaged plants release a blend of volatile organic compounds (VOCs) that differs from undamaged plants. These induced changes are known to attract the natural enemies of the herbivores and therefore are expected to be important determinants of the effectiveness of biological control in agriculture. One way of boosting this phenomenon is the application of plant strengtheners, which has been shown to enhance parasitoid attraction in maize. It is unclear whether this is also the case for other important crops.

RESULTS

The plant strengtheners BTH [benzo (1,2,3) thiadiazole‐7‐carbothioic acid S‐methyl ester] and laminarin were applied to cotton plants, and the effects on volatile releases and the attraction of three hymenopteran parasitoids, Cotesia marginiventris, Campoletis sonorensis and Microplitis rufiventris, were studied. After treated and untreated plants were induced by real or simulated caterpillar feeding, it was found that BTH treatment increased the attraction of the parasitoids, whereas laminarin had no significant effect. BTH treatment selectively increased the release of two homoterpenes and reduced the emission of indole, the latter of which had been shown to interfere with parasitoid attraction in earlier studies. Canonical variate analyses of the data show that the parasitoid responses were dependent on the quality rather than the quantity of volatile emission in this tritrophic interaction.

CONCLUSION

Overall, these results strengthen the emerging paradigm that induction of plant defences with chemical elicitors such as BTH could provide a sustainable and environmentally friendly strategy for biological control of pests by enhancing the attractiveness of cultivated plants to natural enemies of insect herbivores. © 2014 Society of Chemical Industry
Biodegradable delivery system containing a peptide inhibitor of polyglutamine aggregation: a step toward therapeutic development in Huntington's disease
Authors: Joshi Abhayraj S. , Thakur Ashwani Kumar
Published: May 2014

Huntington's and eight other neurodegenerative diseases occur because of CAG repeat expansion mutation culminating into an expanded polyglutamine tract in respective protein. In Huntington's disease (HD), a number of CAG repeats beyond normal repeat length (>36) lead to the formation of mutant protein, the proteolytic cleavage of which induces aggregation in polyglutamine length‐dependent manner. The neurodegeneration in this disease is linked to aggregation, and its inhibition is a potential approach for therapeutic development. Although peptides and other molecules have been developed for inhibiting aggregation, peptides in general are susceptible to degradation in vivo conditions. To understand their clinical significance, they also need to be delivered through blood–brain barrier. Here, for the first time, we have synthesized poly‐d,l‐lactide‐co‐glycolide nanoparticles containing a polyglutamine aggregation inhibitor peptide PGQ9[P2], by nanoprecipitation method. This process yielded less than 200 nm spherical nanoparticles with uniform distribution. Characterization studies by infrared spectroscopy‐based and HPLC‐based assays show the presence of PGQ9[P2] in nanoparticles. In vitro release kinetics demonstrates that nanoparticles release PGQ9[P2] by erosion and diffusion processes. When the PGQ9[P2]‐loaded nanoparticles are incubated with aggregation‐prone Q35P10 peptide, representing N‐terminal part of Huntingtin protein, it arrests the elongation phase of Q35P10 aggregation. These findings propose the first step toward delivery of a peptide inhibitor against polyglutamine aggregation in HD. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.
Young's modulus extraction of epitaxial heterostructure AlGaN/GaN for MEMS application
Authors: Ben Amar Achraf , Faucher Marc , Brandli Virginie , Cordier Yvon , Théron Didier
Published: May 2014

This paper presents a Young's modulus extraction method for thin film group III‐nitrides materials such as GaN, AlN, and its ternary AlGaN. The AlGaN/GaN heterostructures are grown by molecular beam epitaxy on Si (111) substrate and designed for MEMS applications. Various cantilevers with a width of 10 µm and lengths going from 100 to 310 µm were fabricated. The Young's moduli are determined using the resonance frequencies measured by laser Doppler vibrometry (LDV). Finite element modeling (FEM) is used to consider the under‐etching of the cantilevers at the anchor. In this study, we find that the Young moduli of GaN and AlN layers are respectively 261 ± 60 GPa and 339 ± 78 GPa that compares well with the results found in the literature for bulk materials.
Label‐free electrical detection of DNA with a multi‐spot LAPS: First step towards light‐addressable DNA chips
Authors: Wu Chunsheng , Bronder Thomas , Poghossian Arshak , Werner Carl Frederik , Bäcker Matthias , Schöning Michael J.
Published: May 2014

A multi‐spot (4 × 4 spots) light‐addressable potentiometric sensor (MLAPS) consisting of an Al–p‐Si–SiO2 structure has been applied for the label‐free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge for the first time. Single‐stranded probe ssDNA molecules (20 bases) were covalently immobilized onto the silanized SiO2 gate surface. The unspecific adsorption of mismatch ssDNA on the MLAPS gate surface was blocked by bovine serum albumin molecules. To reduce the screening effect and to achieve a high sensor signal, the measurements were performed in a low ionic‐strength solution. The photocurrent–voltage (I–V) curves were simultaneously recorded on all 16 spots after each surface functionalization step. Large shifts of I–V curves of 25 mV were registered after the DNA immobilization and hybridization event. In contrast, a small potential shift (∼5 mV) was observed in case of mismatch ssDNA, revealing good specificity of the sensor. The obtained results demonstrate the potential of the MLAPS as promising transducer platform for the multi‐spot label‐free electrical detection of DNA molecules by their intrinsic molecular charge.
Current density impact on the emission behavior of GaN‐based blue emitting LEDs in the temperature range of 4.2–400 K
Authors: Hetzel Reinhold , Leising Günther
Published: May 2014

Blue emitting GaN‐based light emitting diodes (LEDs) show a distinct spectral behavior with respect to temperature and injection current density. Operating LEDs with short current pulses of 500 ns provides a steady state situation, which allows investigating the emission behavior of LEDs at a certain device temperature thereby maintaining thermal equilibrium. The LEDs were examined in a temperature range between 4.2 and 400 K and in a current density range between 2 and 50 A cm−2. Low temperature investigations showed a blue shift of the electroluminescence spectra (EL) with respect to junction temperature, which is assigned to the radiative recombination of localized excitons. In the elevated temperature region a distinct red shift due to energy gap shrinkage was observed. Further, we expect an exciton lifetime reduction at 4.2 K. Additionally, the influence of the driving parameters (pulse injection current or direct current (DC)) in the presence of piezoelectric fields is discussed and separated into band filling effect and occurrence of fields, which screen the quantum confined Stark effect. Low temperature investigations indicate that band filling is mainly responsible for the blue shift of the EL spectra with respect to the injection current.
Towards X‐ray in‐situ visualization of ammonothermal crystal growth of nitrides
Authors: Schimmel Saskia , Künecke Ulrike , Baser Hasan , Steigerwald Thomas G. , Hertweck Benjamin , Alt Nicolas S. A. , Schlücker Eberhard , Schwieger Wilhelm , Wellmann Peter
Published: May 2014

In‐situ X‐ray visualization of hydrothermal growth of silicalite‐1 is applied as an intermediate step for developing X‐ray in‐situ visualization techniques for ammonothermal growth of nitride materials. In‐situ X‐ray imaging of silicalite‐1 crystals grown by the bulk material dissolution technique (Shimizu and Hamada, Angew. Chem., Int. Ed. 38, 2725 (1999) [1]) is demonstrated using a stainless steel autoclave equipped with ceramic aluminium oxide windows.

Processes in the reaction medium such as local density changes are also visualized. The transferability of the technique to ammonothermal growth of nitrides is evaluated. Furthermore, the applicability of windowless autoclaves for X‐ray in‐situ monitoring of ammonothermal crystal growth of nitrides is investigated.

(© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
UV detector based on zinc oxide nanorods obtained by the hydrothermal method
Authors: Witkowski Bartlomiej S. , Wachnicki Lukasz , Gieraltowska Sylwia , Sybilski Piotr , Kopalko Krzysztof , Stachowicz Marcin , Godlewski Marek
Published: May 2014

Properties of UV detector based on ZnO nanorods, grown by a hydrothermal method, are discussed. The innovative growth technology was used to produce ZnO nanorods. It is characterized by a much higher growth rate, than reported (till now) in the literature, and a very low costs (both of technology and materials). Importantly, ZnO nanorods grown by this method are free from oxygen vacancies. Despite the fact that detector proposed by us is not based on a single nanorod, but on a whole array of nanorods, it is very sensitive. The detector shows sensitivity of 20 mW/m2 (2 µW/cm2) upon UV illumination. Due to a high energy band gap of zinc oxide and a high purity of the obtained nanorods visible light is not detected. The resistivity/current changes are proportional to illumination intensity, i.e., detector response scales with the intensity of UV light. The observed changes of the detector resistivity relate to surface reactions generated upon an illumination. Importantly, detector does not need annealing or cleaning to reset to an initial state.(© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simultaneous reduction in leakage current and enhancement in magnetic moment in BiFeO3 nanofibers via optimized Sn doping
Authors: Yang Qian , Xu Qiang , Sobhan Mushtaq , Ke Qingqing , Anariba Franklin , Ong Khuong P. , Wu Ping
Published: May 2014

Sn4+‐doped BiFeO3 (BFO) nanofibers have been fabricated by sol–gel based electrospinning method with nanofiber diameter in the range of 30–100 nm in the annealed state. The leakage current density dropped by two orders of magnitude in 3% Sn‐doped BFO nanofibers compared to undoped BFO samples. Our density functional theory (DFT) simulation results indicate that Sn4+ prefers to occupy the Fe3+ site in BFO with a formation energy of 1.89 eV. The impurity Sn acts as a shallow donor with a low transition energy level of 41 meV. Furthermore, an enhancement in the saturation magnetization was simultaneously observed for 3% Sn‐doped nanofibers, which correlated well with our theoretical calculations. In other words, by carefully tailoring the degree of Sn doping in BFO nanofibers, we can reduce the leakage current and concurrently enhance the magnetic moment. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Micropatterned ZnO rod arrays prepared by Au‐catalyzed electroless deposition
Authors: Florica Camelia , Preda Nicoleta , Enculescu Monica , Enculescu Ionut
Published: May 2014

Micropatterned ZnO was synthesized by an electroless deposition process using Au stripes as catalytic surfaces. The Au‐patterned electrodes were prepared on SiO2/Si wafers using photolithography. The site‐selective deposition of patterned ZnO hexagonal rod arrays is confirmed by scanning electron microscopy. The ZnO micropatterned surface revealed a conversion of wettability from hydrophilic to superhydrophobic depending on the deposition reaction param‐ eters. The electrical measurements carried out at room temperature before and after exposure to ammonia vapors of the patterned ZnO arrays show a resistance variation with exposure time. Highly reproducible, easy scalable and low‐cost, photolithography and electroless deposition techniques could provide a facile approach to fabricate functionalized micropatterns, for a wide range of applications. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Data‐driven treatment selection for seamless phase II/III trials incorporating early‐outcome data
Authors: Kunz Cornelia Ursula , Friede Tim , Parsons Nick , Todd Susan , Stallard Nigel
Published: May 2014

Seamless phase II/III clinical trials are conducted in two stages with treatment selection at the first stage. In the first stage, patients are randomized to a control or one of k > 1 experimental treatments. At the end of this stage, interim data are analysed, and a decision is made concerning which experimental treatment should continue to the second stage. If the primary endpoint is observable only after some period of follow‐up, at the interim analysis data may be available on some early outcome on a larger number of patients than those for whom the primary endpoint is available. These early endpoint data can thus be used for treatment selection. For two previously proposed approaches, the power has been shown to be greater for one or other method depending on the true treatment effects and correlations. We propose a new approach that builds on the previously proposed approaches and uses data available at the interim analysis to estimate these parameters and then, on the basis of these estimates, chooses the treatment selection method with the highest probability of correctly selecting the most effective treatment. This method is shown to perform well compared with the two previously described methods for a wide range of true parameter values. In most cases, the performance of the new method is either similar to or, in some cases, better than either of the two previously proposed methods. © 2014 The Authors. Pharmaceutical Statistics published by John Wiley & Sons Ltd.
Electronic structure and stability of binary and ternary aluminum‐bismuth‐nitrogen nanoclusters
Authors: Miralrio Alan , Sansores Luis Enrique
Published: May 2014

The electronic structure and stability in binary and ternary aluminum‐bismuth‐nitrogen nanoclusters up to six atoms are studied using density functional theory (DFT). The lowest energy geometries were obtained by sampling the geometrical space with a Monte Carlo method and geometry optimizations, at DFT level, with M06L functional. The clusters stability is analyzed using formation and fragmentation energies. Our results show that a high concentration of nitrogen presents a tendency to form nitrogen clusters. highest occupied molecular orbital‐lowest unoccupied molecular orbital gaps show the well‐known oscillation as the number of atoms is increased. Bonding between Al, Bi, and N has mainly a π character. Bismuth and aluminum atoms tend to promote high multiplicity states in small clusters. These new binary and ternary materials provide a potential new field in optoelectronics and high energetic material compounds. © 2014 Wiley Periodicals, Inc.
Electrodeposition of nanocrystalline Ni–Cu alloy from environmentally friendly lactate bath
Authors: Kamel M. M. , Anwer Z. M. , Abdel‐Salam I. T. , Ibrahim I. S.
Published: May 2014

A new environmentally friendly electroplating bath for Ni–Cu alloy deposition was developed. Lactic acid was used as a complexing agent. The influence of bath composition, current density, pH and temperature on cathodic polarization, cathodic current efficiency and alloy composition was studied. Different proportions of the two metals were obtained by using different deposition parameters, but at all [Ni2+] / [Cu2+] ratios studied, preferential deposition of Cu occurred and regular co‐deposition took place. The Ni content of the deposit increased with Ni2+ content and current density and decreased with temperature. The surface morphology of the deposited Ni–Cu alloy was investigated using scanning electron microscopy. The crystal structure was examined using the X‐ray diffraction technique. The results showed that the deposits consisted of a single solid solution phase with a face‐centered cubic structure. The crystallite size lies in the range of 12 to 25 nm for as‐plated alloys. Copyright © 2014 John Wiley & Sons, Ltd.
Investigation of interface, microstructure, and mechanical properties of layered thermal barrier coatings of lanthanum zirconate and YSZ deposited by EB‐PVD process
Authors: Mishra S. K. , Shravan Kumar K. , Bysakh S. , Sreemany M. , Pathak L. C.
Published: May 2014

Microstructure of the double‐layered ceramic thermal barrier coatings of lanthanum zirconate (LZ) and yttria‐stabilized zirconia (YSZ) with bond coat on Ni‐based superalloy deposited by electron beam evaporation process has been studied. Two sets of combination of LZ and YSZ were deposited: one LZ over YSZ and the other YSZ over LZ. The interfaces of each layer were studied and were found to be sharp; however, some diffusion of elements from below layer was observed. The detailed selected area diffraction of the phases was carried out from the coating cross‐section specimens. The LZ layer was mostly found to be amorphous, and fine columnar growth was observed. The YSZ layer over LZ showed two different crystal structures at interface and at the top surface, which were cubic and tetragonal, respectively. The YSZ layers showed clear columnar grains with feather‐like intercalated structure Copyright © 2014 John Wiley & Sons, Ltd.
Motivation and sorting of human capital in open innovation
Authors: Belenzon Sharon , Schankerman Mark
Published: May 2014

This paper studies how business models can be designed to tap effectively into open innovation labor markets with heterogeneously motivated workers. Using data on open source software, we show that motivations are diverse, and demonstrate how managers can strategically influence the flow of code contributions and their impact on project performance. Unlike previous literature using survey data, we exploit the observed pattern of project membership and code contributions—the “revealed preference” of developers—to infer the motivations driving their decision to contribute. Developers strongly sort along key dimensions of the business model chosen by project managers, especially the degree of openness of the project license. The results indicate an important role for intrinsic motivation, reputation, and labor market signaling, and a more limited role for reciprocity. Copyright © 2014 John Wiley & Sons, Ltd.
Graphene Oxide and Metal‐Mediated Base Pairs Based “Molecular Beacon” Integrating with Exonuclease I for Fluorescence Turn‐on Detection of Biothiols
Authors: Xing Xiaojing , Zhou Ying , Liu Xueguo , Pang Daiwen , Tang Hongwu
Published: May 2014

A novel fluorescence turn‐on strategy, based on the resistance of metal‐mediated molecular‐beacons (MBs) toward nuclease digestion and the remarkable difference in the affinity of graphene oxide (GO) with MBs and the mononucleotides, is designed for the biothiols assay. Specifically, the metal‐mediated base pairs facilitate the dye labeled MBs to fold into a hairpin structure preventing the digestion by exonuclease I, and thus allow the fluorescence quenching. The competition binding by biothiols removes metal ions from the base pairs, causing the nuclease reaction, and less decrease in the fluorescence is obtained after incubating with GO due to the weak affinity of the product‐mononucleotides to GO. Hg2+‐mediated MBs were firstly designed for the biothiols detection, and glutathione (GSH) was applied as the model target. Under the optimal conditions, the approach exhibits high sensitivity to GSH with a detection limit of 1.53 nM. Ag+‐mediated MBs based sensor was also constructed to demonstrate its versatility, and cysteine was studied as the model target. The satisfactory results in the determination of biothiols in serum demonstrate that the method possesses great potential for detecting thiols in biological fluids. This new approach is expected to promote the exploitation of metal‐mediated base pairs‐based biosensors in biochemical and biomedical studies.
Designing Non‐Native Iron‐Binding Site on a Protein Cage for Biological Synthesis of Nanoparticles
Authors: Peng Tao , Paramelle David , Sana Barindra , Lee Chiu Fan , Lim Sierin
Published: May 2014

In biomineralization processes, a supramolecular organic structure is often used as a template for inorganic nanomaterial synthesis. The E2 protein cage derived from Geobacillus stearothermophilus pyruvate dehydrogenase and formed by the self‐assembly of 60 subunits, has been functionalized with non‐native iron‐mineralization capability by incorporating two types of iron‐binding peptides. The non‐native peptides introduced at the interior surface do not affect the self‐assembly of E2 protein subunits. In contrast to the wild‐type, the engineered E2 protein cages can serve as size‐ and shape‐constrained reactors for the synthesis of iron nanoparticles. Electrostatic interactions between anionic amino acids and cationic iron molecules drive the formation of iron oxide nanoparticles within the engineered E2 protein cages. The work expands the investigations on nanomaterial biosynthesis using engineered host‐guest encapsulation properties of protein cages.
Peptide stabilized Ag@Au Core‐shell Nanoparticles: Synthesis, Variation of Shell Thickness, and Catalysis
Authors: Biswas Abhijit , Roy Subhasish , Banerjee Arindam
Published: May 2014

Ag@Au core‐shell nanoparticles were synthesized by using a fluorescent dipeptide β‐Ala‐Trp in water medium and at a room temperature without using any external reducing and stabilizing agents. The shell thickness of gold in core‐shell Ag@Au nanoparticles has also been varied by changing the concentration of the gold(III) precursor keeping the other conditions same. The optical property of these core‐shell nanoparticles varies with the shell thickness. Interestingly, these core‐shell nanoparticles exhibit good catalytic property for the reduction of nitrophenols to aminophenols and nitroanilines to aminoanilines. A series of nitrophenol and nitroaniline compounds were taken as substrates for reduction. Moreover, this core‐shell nanoparticle displays remarkable difference in catalytic property for reduction of nitro group with the variation of shell thickness. This catalyst (Ag@Au core‐shell nanoparticle) can also be recycled for several times indicating its reusability.