bluuebunny/crossref_metadata_2025 huggingface dataset:
Medulloblastoma in a patient with the PTPN11 p.Thr468Met mutation
Authors: Rankin Julia , Short John , Turnpenny Peter , Castle Bruce , Hanemann C. Oliver
Published: June 2013

Medulloblastoma is the commonest brain tumor in childhood and in a minority of patients is associated with an underlying genetic disorder such as Gorlin syndrome or familial adenomatous polyposis. Increased susceptibility to certain tumors, including neuroblastoma and some hematological malignancies, is recognized in disorders caused by mutations in genes encoding components of the RAS signaling pathway which include Noonan syndrome, Noonan syndrome with multiple lentigines (NSML; formerly called LEOPARD syndrome), Costello syndrome, Cardiofaciocutaneous syndrome, Legius syndrome, and Neurofibromatosis type 1 (NF1), collectively termed RASopathies. Although an association between medulloblastoma and NF1 has been reported, this tumor has not previously been reported in other RASopathies. We present a patient with NSML caused by the recurrent PTPN11 mutation c.1403C > T (p.Thr468Met) in whom medulloblastoma was diagnosed at age 10 years. Medulloblastoma could therefore be part of the tumor spectrum associated with this disorder. © 2013 Wiley Periodicals, Inc.
Confirmation of GRHL2 as the gene for the DFNA28 locus
Authors: Vona Barbara , Nanda Indrajit , Neuner Cordula , Müller Tobias , Haaf Thomas
Published: June 2013

More than 10 years ago, a c.1609_1610insC mutation in the grainyhead‐like 2 (GRHL2) gene was identified in a large family with nonsyndromic sensorineural hearing loss, so far presenting the only evidence for GRHL2 being an autosomal‐dominant deafness gene (DFNA28). Here, we report on a second large family, in which post‐lingual hearing loss with a highly variable age of onset and progression segregated with a heterozygous non‐classical splice site mutation in GRHL2. The c.1258‐1G>A mutation disrupts the acceptor recognition sequence of intron 9, creating a new AG splice site, which is shifted by only one nucleotide in the 3′ direction. cDNA analysis confirmed a p.Gly420Glufs*111 frameshift mutation in exon 10. © 2013 Wiley Periodicals, Inc.
Dr. Peter Emil Becker and the Third Reich
Authors: Hill Frank
Published: June 2013

In 1985 the physician after whom Becker Muscular Dystrophy is named, German neurologist Dr. Peter Emil Becker (1908−2000), published an autobiographical article in the American Journal of Medical Genetics in which he disavowed any association with the Nazi Party. A closer look at the evidence, however, suggests otherwise. Review of war records and related sources raise concern for Dr. Becker's affiliation with the Nazi Party and his contributions to its ideology. © 2013 Wiley Periodicals, Inc.
Empirical research on the ethics of genomic research
Authors: Middleton Anna , Parker Michael , Wright Caroline F. , Bragin Eugene , Hurles Matthew E. ,   on behalf of the DDD Study
Published: June 2013

© 2013 Wiley Periodicals, Inc.
Corannulene‐Fused Anion‐Responsive π‐Conjugated Molecules that Form Self‐Assemblies with Unique Electronic Properties
Authors: Bando Yuya , Sakurai Tsuneaki , Seki Shu , Maeda Hiromitsu
Published: June 2013

The fusion of bowl‐shaped π‐conjugated corannulene units to anion‐responsive π‐conjugated dipyrrolyldiketone‐boron complexes resulted in new molecular materials with a unique self‐assembly capability. The bowl‐fused receptor with aliphatic tails could form both supramolecular gels and mesophases through π‐stacking interactions and also exhibited anion‐responsive characteristics. The presence of the π‐bowl unit not only afforded enhanced self‐assembly capability both in solution and in the mesophases, as evidenced by gelation experiments and phase‐transition profiles, but also enhanced intrinsic charge‐carrier mobility.
Effects of Environmental Enrichment on Repetitive Behaviors in the BTBR T+tf/J Mouse Model of Autism
Authors: Reynolds Stacey , Urruela Meagan , Devine Darragh P.
Published: June 2013

Lower order and higher order repetitive behaviors have been documented in the BTBR T+tf/J (BTBR) mouse strain, a mouse model that exhibits all three core behavioral domains that define autism. The purpose of this study was to evaluate the effectiveness of environmental enrichment for reducing repetitive behaviors in BTBR mice. Lower order behaviors were captured by assaying the time and sequence of grooming, while higher order behaviors were measured using pattern analysis of an object exploration task from digital recordings. Baseline scores were established at 7 weeks of age, followed by 30 days of housing in either a standard or enriched cage. As expected, BTBR mice spent significantly more time grooming and had a more rigid grooming sequence than control C57BL/6J mice did at baseline. After 30 days of enrichment housing, BTBR mice demonstrated a significant reduction in time spent grooming, resulting in levels that were lower than those exhibited by BTBR mice in standard housing. However, no changes were noted in the rigidity of their grooming sequence. In contrast to previous findings, there was no difference in repetitive patterns of exploration at baseline between BTBR and C57BL/6J mice in the object exploration test. Subsequently, enrichment did not significantly alter the number of repetitive patterns at posttest. Overall, the results suggest that environmental enrichment may be beneficial for reducing the time spent engaging in lower order repetitive behaviors, but may not change the overall quality of the behaviors when they do manifest. Autism Res 2013, ●●: ●●–●●. © 2013 International Society for Autism Research, Wiley Periodicals, Inc.
Sexual Exploitation, Selling and Swapping Sex: Victimhood and Agency
Authors: Dodsworth Jane
Published: June 2013

Drawing on a qualitative study of women involved in sex work in the UK, this paper focuses on the participants who became involved in sexual exploitation or, what some of them saw as, selling or swapping sex for non‐monetary ‘payment’, under the age of 18. A central aim of the study was to develop an understanding of how the meaning ascribed to risk and protective factors influenced perceptions of victimhood and agency. Findings indicate that the key determinants of pathway outcomes were: whether, and how, the search for approval and affection was resolved; whether feeling ‘different’ led to a sense of defeat or strengthened resolve; whether coping strategies were adaptive or maladaptive; and whether individuals experienced the availability of a secure base. The findings suggest the need for policy which acknowledges the expertise and views of the young people involved, recognises the importance of early intervention, and is holistic in service provision not only for young people who are victims of sexual exploitation, but also for those who perceive that they have exercised agency, albeit from limited options, about their involvement in selling or swapping sex. Copyright © 2013 John Wiley & Sons, Ltd.

‘How the meaning ascribed to risk and protective factors influenced perceptions of victimhood and agency’

Key Practitioner Messages

Policy and service provision must acknowledge the agency, expertise and views of the young people involved in sexual exploitation.

We need to build on the good practice already in existence in continuing to develop a model of intervention which promotes security and resilience.

Service interventions with young people involved in or at risk of sexual exploitation, selling and swapping sex must be trust building, respectful, relationship based, solution focused and strengths based.

‘Service interventions must be trust building, respectful, relationship based, solution focused and strengths based’
Euler angles: conversion of arbitrary rotation sequences to specific rotation sequence
Authors: Perumal Logah
Published: June 2013

Euler angles have been used to describe the orientation of objects in two‐dimensional and three‐dimensional spaces since its formulation by Leonhard Euler. Many applications intended to represent the rotation of a body have been developed on the basis of Euler angles. Two‐dimensional rotations are combined in sequence to represent three‐dimensional rotations. Because there are three axes in a three‐dimensional Euclidean space (X, Y and Z), 12 rotation sequences in three dimensions are possible: XYZ, XZY, YXZ, YZX, ZXY, ZYX, XYX, ZYZ, ZXZ, YXY, XZX and YZY. Each rotation sequence yields different results, and different applications implement a different rotation sequence. Thus, conversion between different rotation sequences becomes essential to make applications developed in different rotation sequences compatible with each other. In this paper, a new method is introduced to convert arbitrary rotation sequences to a specific rotation sequence of choice. A sample program is also developed in a MATLAB‐Simulink environment to demonstrate the use of the new method in converting an arbitrary Euler rotation sequence to the specific Euler rotation sequence of XYZ. A six‐degrees‐of‐freedom animation block is used in the program to aid users to graphically see the rotation of a body in three‐dimensional space. Copyright © 2013 John Wiley & Sons, Ltd.
The effect of receipt personalization on tipping behavior
Authors: Kinard Brian R. , Kinard Jerry L.
Published: June 2013

Research has shown that personalizing receipts, such as drawing “smiley faces” and writing “thank you” notes on customer bills to express gratitude, can result in larger tips for restaurant wait staff. Although the practice of receipt personalization has been supported using field experiments, limited research has examined the effectiveness of this technique based on the level of service quality provided by restaurant wait staff. Using a scenario‐based approach, we found from this study that adding a personalized message significantly lowers tip percentages. Moreover, the negative effect is magnified when service quality fails to exceed customer expectations. Implications related to the findings are discussed. Copyright © 2013 John Wiley & Sons, Ltd.
Impact of Hydrostatic Pressure on an Intrinsically Disordered Protein: A High‐Pressure NMR Study of α‐Synuclein
Authors: Roche Julien , Ying Jinfa , Maltsev Alexander S. , Bax Ad
Published: June 2013

The impact of pressure on the backbone 15N, 1H and 13C chemical shifts in N‐terminally acetylated α‐synuclein has been evaluated over a pressure range 1–2500 bar. Even while the chemical shifts fall very close to random coil values, as expected for an intrinsically disordered protein, substantial deviations in the pressure dependence of the chemical shifts are seen relative to those in short model peptides. In particular, the nonlinear pressure response of the 1HN chemical shifts, which commonly is associated with the presence of low‐lying “excited states”, is much larger in α‐synuclein than in model peptides. The linear pressure response of 1HN chemical shift, commonly linked to H‐bond length change, correlates well with those in short model peptides, and is found to be anticorrelated with its temperature dependence. The pressure dependence of 13C chemical shifts shows remarkably large variations, even when accounting for residue type, and do not point to a clear shift in population between different regions of the Ramachandran map. However, a nearly universal decrease in 3JHN–Hα by 0.22±0.05 Hz suggests a slight increase in population of the polyproline II region at 2500 bar. The first six residues of N‐terminally acetylated synuclein show a transient of approximately 15 % population of α‐helix, which slightly diminishes at 2500 bar. The backbone dynamics of the protein is not visibly affected beyond the effect of slight increase in water viscosity at 2500 bar.
Structure and Activity of NADPH‐Dependent Reductase Q1EQE0 from Streptomyces kanamyceticus, which Catalyses the R‐Selective Reduction of an Imine Substrate
Authors: Rodríguez‐Mata María , Frank Annika , Wells Elizabeth , Leipold Friedemann , Turner Nicholas J. , Hart Sam , Turkenburg Johan P. , Grogan Gideon
Published: June 2013

NADPH‐dependent oxidoreductase Q1EQE0 from Streptomyces kanamyceticus catalyzes the asymmetric reduction of the prochiral monocyclic imine 2‐methyl‐1‐pyrroline to the chiral amine (R)‐2‐methylpyrrolidine with >99 % ee, and is thus of interest as a potential biocatalyst for the production of optically active amines. The structures of Q1EQE0 in native form, and in complex with the nicotinamide cofactor NADPH have been solved and refined to a resolution of 2.7 Å. Q1EQE0 functions as a dimer in which the monomer consists of an N‐terminal Rossman‐fold motif attached to a helical C‐terminal domain through a helix of 28 amino acids. The dimer is formed through reciprocal domain sharing in which the C‐terminal domains are swapped, with a substrate‐binding cleft formed between the N‐terminal subunit of monomer A and the C‐terminal subunit of monomer B. The structure is related to those of known β‐hydroxyacid dehydrogenases, except that the essential lysine, which serves as an acid/base in the (de)protonation of the nascent alcohol in those enzymes, is replaced by an aspartate residue, Asp187 in Q1EQE0. Mutation of Asp187 to either asparagine or alanine resulted in an inactive enzyme.
Induction of Supramolecular Chirality in the Self‐Assemblies of Lipophilic Pyrimidine Derivatives by Choice of the Amino Acid‐Based Chiral Spacer
Authors: Datta Sougata , Samanta Suman K. , Bhattacharya Santanu
Published: June 2013

A new family of supramolecular organogelators, based on chiral amino acid derivatives of 2,4,6‐trichloro‐pyrimidine‐5‐carbaldehyde, has been synthesized. L‐alanine was incorporated as a spacer between the pyrimidine core and long hydrocarbon tails to compare the effect of chirality and hydrogen bonding to that of the achiral analogue. The role of aromatic moiety on the chiral spacer was also investigated by introducing L‐phenyl alanine moieties. The presence of intermolecular hydrogen‐bonding leading to the chiral self‐assembly was probed by concentration‐dependent FTIR and UV/Vis spectroscopies, in addition to circular dichroism (CD) studies. Temperature and concentration‐dependent CD spectroscopy ascribed to the formation of β‐sheet‐type H‐bonded networks. The morphology and the arrangements of the molecules in the freeze‐dried gels were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and X‐ray diffraction (XRD) techniques. Calculation of the length of each molecular system by energy minimization in its extended conformation and comparison with the small‐angle XRD pattern reveals that this class of gelator molecules adopts a lamellar organization. Polarized optical microscopy (POM) and differential scanning calorimetry (DSC) indicate that the solid state phase behavior of these molecules is totally dependent on the choice of their amino acid spacers. Structure‐induced aggregation properties based on the H‐bonding motifs and the packing of the molecule in three dimensions leading to gelation was elucidated by rheological studies. However, viscoelasticity was shown to depend only marginally on the H‐bonding interactions; rather it depends on the packing of the gelators to a greater extent.
Preparation of Ordered Mesoporous Alumina‐Doped Titania Films with High Thermal Stability and Their Application to High‐Speed Passive‐Matrix Electrochromic Displays
Authors: Jiang Xiangfen , Bastakoti Bishnu Prasad , Weng Wu , Higuchi Tetsuya , Oveisi Hamid , Suzuki Norihiro , Chen Wei‐Jung , Huang Yu‐Tzu , Yamauchi Yusuke
Published: June 2013

Ordered mesoporous alumina‐doped titania thin films with anatase crystalline structure were prepared by using triblock copolymer Pluronic P123 as structure‐directing agent. Uniform Al doping was realized by using aluminum isopropoxide as a dopant source which can be hydrolyzed together with titanium tetraisopropoxide. Aluminum doping into the titania framework can prevent rapid crystallization to the anatase phase, thereby drastically increasing thermal stability. With increasing Al content, the crystallization temperatures tend to increase gradually. Even when the Al content doped into the framework was increased to 15 mol %, a well‐ordered mesoporous structure was obtained, and the mesostructural ordering was still maintained after calcination at 550 °C. During the calcination process, large uniaxial shrinkage occurred along the direction perpendicular to the substrate with retention of the horizontal mesoscale periodicity, whereby vertically oriented nanopillars were formed in the film. The resulting vertical porosity was successfully exploited to fabricate a high‐speed and high‐quality passive‐matrix electrochromic display by using a leuco dye. The vertical nanospace in the films can effectively prevent drifting of the leuco dye.
Sensing Chiral Drugs by Using CdSe/ZnS Nanoparticles Capped with N‐Acetyl‐L‐Cysteine Methyl Ester
Authors: Delgado‐Pérez Teresa , Bouchet Lydia M. , de la Guardia Miguel , Galian Raquel E. , Pérez‐Prieto Julia
Published: June 2013

Chiral quantum dots (QDs), differing in their core or shell size and, consequently, in their optical properties, were synthesized by the treatment of commercially available amine‐capped quantum dots with methyl ester N‐acetyl‐L‐cysteine (CysP). Interestingly, their colloidal methanol solutions remain stable for several months. Their NMR and IR spectra were in accordance with CysP binding to the QD surface through two anchoring groups; its thiolate (strongly bound) and the carbonyl group of its ester (weaker bound) group, whereas their circular dichroism (CD) spectra showed a new broad redshifted band, suggesting that the attachment to the QD surface modified the conformational equilibrium towards conformer(s) with optical activity in this region. These QDs were sufficiently fluorescent to perform studies of the chiral recognition of drugs, in particular the aryl propionic acids (APAs) ketoprofen (KP), naproxen (NP), flurbiprofen (FP), and ibuprofen (IP). We used different drug concentration ranges, depending on the QD solubility. All the assayed drugs quenched the QD emission in a concentration‐dependent mode. Quenching fluorescence assays with the chiral QDs (CS@CysP) showed their extraordinary capacity for the chiral recognition of KP, NP, and FP, and particularly in the case of KP and FP, a remarkable positive allosteric effect was detected for the R enantiomer. By using a drug/CS@CysP molar ratio of 5000:1 and 2500:1, the changes of intensity and the sign of the CD spectrum of the drug evidenced the dissociation of the drug carboxylic group in the presence of the QD.
Self‐Assembly of Coronene Bisimides: Mechanistic Insight and Chiral Amplification
Authors: Kulkarni Chidambar , Munirathinam Rajesh , George Subi J.
Published: June 2013

The study of the organization of small π‐conjugated molecules is imperative to understanding and controlling its properties for various applications. Coronene bisimides (CBIs) are potential candidates for novel liquid‐crystalline materials and active n‐type semiconductor molecules in organic electronics. To understand the self‐assembly of this seldom‐studied chromophore, we have designed two derivatives of CBIs bearing chiral and achiral 3,4,5‐trialkoxyphenyl groups at the imide position, named as CBI‐GCH and CBI‐GACH, respectively. CBI‐GCH self‐assembles mainly through π‐stacking and van der Waals interactions in nonpolar methylcyclohexane to result in long 1D fibrillar stacks. The mechanism of supramolecular polymerization was probed by using chiroptical studies, which showed an isodesmic pathway for CBI‐GCH. The thermodynamic parameters that govern the self‐assembly are detailed. CBI‐GACH also shows similar self‐assembly behavior as its chiral counterpart. X‐ray diffraction studies of both molecules reveals a 2D hexagonal columnar arrangement. The coassembly of CBI‐GCH and CBI‐GACH shows chiral amplification (sergeant and soldiers experiment) with saturation at 30–50 % of the chiral derivative, which was further used to study the dynamics of the assembly. Thus, this study presents a rare report of chiral amplification in an isodesmic system.
Identification of Hck Inhibitors As Hits for the Development of Antileukemia and Anti‐HIV Agents
Authors: Tintori Cristina , Laurenzana Ilaria , La Rocca Francesco , Falchi Federico , Carraro Fabio , Ruiz Alba , Esté José A. , Kissova Miroslava , Crespan Emmanuele , Maga Giovanni , Biava Mariangela , Brullo Chiara , Schenone Silvia , Botta Maurizio
Published: June 2013

Hematopoietic cell kinase (Hck) is a member of the Src family of non‐receptor protein tyrosine kinases. High levels of Hck are associated with drug resistance in chronic myeloid leukemia. Furthermore, Hck activity has been connected with HIV‐1. Herein, structure‐based drug design efforts were aimed at identifying novel Hck inhibitors. First, an in‐house library of pyrazolo[3,4‐d]pyrimidine derivatives, which were previously shown to be dual Abl and c‐Src inhibitors, was analyzed by docking studies within the ATP binding site of Hck to select the best candidates to be tested in a cell‐free assay. Next, the same computational protocol was applied to screen a database of commercially available compounds. As a result, most of the selected compounds were found active against Hck, with Ki values ranging from 0.14 to 18.4 μM, confirming the suitability of the computational approach adopted. Furthermore, selected compounds showed an interesting antiproliferative activity profile against the human leukemia cell line KU‐812, and one compound was found to block HIV‐1 replication at sub‐toxic concentrations.
An analysis of the contact between the stent and the artery using tube hydroforming simulation
Authors: Araújo Rogério , Guimarães Tobias A. , Oliveira Sônia A.G.
Published: June 2013

Stents for angioplasty have been extensively used to treat coronary diseases. The aim of this study is to analyze the expansion of the stent and the contact with the artery using tube hydroforming simulation. In the simulation, the contact stress and the final shape of the artery after stent expansion process using the Stampack ®; software will be studied. A model of a commercial stent made of 316L stainless steel was modeled by using an elastic–plastic constitutive law with isotropic hardening. The artery was modeled as a cylinder and made of hyperelastic material. The stent model studied in this work presented a good performance according to the results obtained. After expansion, any region of the stent's structure with strong risk of wrinkling, thinning, or buckling was not observed. In the forming limit diagram, all points were far from the Keeler‐Goodwin diagram. Furthermore, the expanded stent model has a good conformability. In conclusion, our data show that the proposed methodology is a useful tool to check if the stent model implanted in the artery may cause restenosis after angioplasty; thus, our tests provided a reliable tool to analyze this risk. Copyright © 2013 John Wiley & Sons, Ltd.
Applying workflow as a service paradigm to application farming
Authors: Cushing Reginald , Koulouzis Spiros , Belloum Adam , Bubak Marian
Published: June 2013

Task farming is often used to enable parameter sweep for exploration of large sets of initial conditions for large scale complex simulations. Such applications occur very often in life sciences. Available solutions enable to perform parameter sweep by creating multiple job submissions with different parameters. This paper presents an approach to farm workflows, employing service oriented paradigms using the WS‐VLAM workflow manager, which provides ways to create, control, and monitor workflow applications and their components. We present two service‐oriented approaches for workflow farming: task level, whereby task harness acts as services by being invoked on which task to load, and data level, where the actual task is invoked as a service with different chunks of data to process. An experimental evaluation of the presented solution is performed with a biomedical application for which 3000 simulations were required to perform a Monte Carlo study. Copyright © 2013 John Wiley & Sons, Ltd.
Stable Aqueous Solutions of Naked Titanate Nanotubes
Authors: Zennaro Lucio , Magro Massimiliano , Vianello Fabio , Rigo Adelio , Mariotto Gino , Giarola Marco , Froner Elena , Scarpa Marina
Published: June 2013

Aqueous solutions of naked nanotubes with Ti concentration up to 10 mM are obtained by hydrothermal synthesis followed by extensive ultrasound treatment. The morphology, surface characteristics, and solution behavior of the solubilized nanotubes are investigated. The time course of the solubilization process driven by ultrasound follows a first‐order kinetic law and is mediated by the competition between Na+ and H+ for surface sites. The dynamics of interaction with small cations (i.e. the sodium ion) is studied by nuclear magnetic resonance spectroscopy and is demonstrated to be a multifaced process, since Na+ is in part free to exchange between the binding sites on nanotubes and the bulk and in part is confined to slowly exchanging nanotube sites. The aqueous titanate nanotube solutions are stable for months, thus opening new perspectives for the use of this material in drug delivery and in homogeneous photocatalysis.
Effect of Non‐Specifically Adsorbed Ions on the Surface Oxidation of Pt(111)
Authors: Nakamura Masashi , Nakajima Yo , Hoshi Nagahiro , Tajiri Hiroo , Sakata Osami
Published: June 2013

The oxidation processes of a Pt(111) electrode in alkaline electrolytes depend on non‐specifically adsorbed ions according to in situ X‐ray diffraction and infrared spectroscopic measurements. In an aqueous solution of LiOH, an OHad adlayer is formed in the first oxidation step of the Pt(111) electrode as a result of the strong interaction between Li+ and OHad, whereas Pt oxidation proceeds without OHad formation in CsOH solution. Structural analysis by X‐ray diffraction indicates that Li+ is strongly protective against surface roughening caused by subsurface oxidation. Although Cs+ is situated near the Pt surface, the weak protective effect of Cs+ results in irreversible surface roughening due to subsurface oxidation.
Synthesis and Characterization of Gold Clusters Ligated with 1,3‐Bis(dicyclohexylphosphino)propane
Authors: Johnson Grant E. , Priest Thomas , Laskin Julia
Published: June 2013

In this multidisciplinary study the chemical reduction synthesis of novel gold clusters in solution was combined with high‐resolution analytical mass spectrometry (MS) to gain insight into the composition of the gold clusters and how their size, ionic charge state, and ligand substitution influences their gas‐phase fragmentation pathways. Ultrasmall cationic gold clusters ligated with 1,3‐bis(dicyclohexylphosphino)propane (dcpp) were synthesized for the first time and introduced into the gas phase using electrospray ionization (ESI). Mass‐selected cluster ions were fragmented by employing collision‐induced dissociation (CID) and the product ions were analyzed using MS. The solutions were found to contain the multiply charged cationic gold clusters Au9L43+, Au13L53+, Au6L32+, Au8L32+, and Au10L42+ (L=dcpp). The gas‐phase fragmentation pathways of these cluster ions were examined systematically by employing CID combined with MS. In addition, CID experiments were performed on related gold clusters of the same size and ionic charge state but capped with 1,3‐bis(diphenylphosphino)propane (dppp) ligands containing phenyl functional groups at the two phosphine centers instead of cyclohexane rings. It is shown that this relatively small change in the molecular substitution of the two phosphine centers in diphosphine ligands (C6H11 versus C6H5) exerts a pronounced influence on the size of the species that are preferentially formed in solution during reduction synthesis as well as the gas‐phase fragmentation channels of otherwise identical gold cluster ions. The mass spectrometry results indicate that in addition to the length of the alkyl chain between the two phosphine centers, the substituents at the phosphine centers also play a crucial role in determining the composition, size, and stability of diphosphine‐ligated gold clusters synthesized in solution.
Facile Size‐Controllable Synthesis of Colorful Quasi‐Cubic α‐Fe2O3 Materials from Nanoscale to Microscale and Their Properties Related to the Size Effect
Authors: He Shuai , Wang Guang‐Sheng , Wang Jia‐Wei , Wei Yun‐Zhao , Wu Yun , Guo Lin , Cao Mao‐Sheng
Published: June 2013

A facile and environmentally friendly hydrothermal approach has been employed to synthesize size‐controllable quasi‐cubic α‐Fe2O3 nanocrystals by using an aqueous solution of FeCl3 without any alkaline materials and stabilizing agent. The as‐prepared products were carefully characterized and the growth mechanism is also discussed. This hydrothermal synthesis of such quasi‐cubic structures implies a simple and low‐cost route to prepare monodisperse nanomaterials on a large scale. The size‐controllable synthesis of α‐Fe2O3 is the first achieved successfully from 80 nm to 2 μm with constant structures. The synthesized α‐Fe2O3 materials have different optical properties and stabilities in water, which are caused by the change of their band‐gap energy and specific surface areas. Finally, the dielectric properties of synthesized α‐Fe2O3 cubes were also investigated, and the differences caused by the particle sizes are discussed.
A general SPICE compatible circuit model for single‐electron devices and application to bit‐error‐rate calculations
Authors: Sharifi M. J. , Jamshidnezhad K.
Published: June 2013

The main purpose of this paper is study of the single‐electron devices (SEDs) behavior, having metal islands, in the time domain. On this basis, some new conceptions, such as division of islands in independent type and dependent type and introduction of multi‐dimensional state space for a SED, have been presented. Then, a new circuit model is introduced for SEDs in general N‐dimensional case. This model is based on the orthodox theory and the solution of the time‐dependent master equation with the capability of installation in the HSPICE software. Hence, one can simulate behavior of the compound circuits including SEDs and other circuit elements by help of this model. Another interesting characteristic of the introduced circuit model is the possibility of using it in calculation of bit error rate in single‐electron logical gates considering both the time and the temperature effects. The behavior of various SEDs in low frequencies is studied, and the results are compared with the results of SIMON, often used as a reference. Furthermore, the time‐dependent results of these devices in high frequencies are calculated and compared with the analytic results for step inputs. These comparisons indicate accuracy and validity of the model. Finally, the model is used for simulating time‐dependent behavior of some single‐electron logic gates, and their total error rate are calculated. Copyright © 2013 John Wiley & Sons, Ltd.
Reconfigurable narrowband microwave band‐pass filter
Authors: Yuceer Mehmet
Published: June 2013

A method is proposed for the design of band‐pass filters with tunable centre frequency and bandwidth without the need for adjusting the inter‐resonator couplings. This is achieved by cascading a quasi low‐pass filter and a quasi high‐pass filter, while minimizing interaction between the filters without the need for an isolator between the filters. Simulated results are presented. Copyright © 2013 John Wiley & Sons, Ltd.
Performance evaluation of sequential spectrum handoff in cognitive radio networks: a single‐user case
Authors: Sayyadi Soheil , Nourinia Javad
Published: June 2013

Powerful spectrum handover schemes enable cognitive radios to exploit transmission opportunities in primary users’ channels appropriately. In this paper, modeling and performance evaluation of sequential spectrum sensing strategy are addressed. To this end, the average number of handovers required for finding a transmission opportunity is evaluated assuming that a prior knowledge of the presence and absence probabilities of the primary users is available. Moreover, the average throughput maximization of a secondary user by optimizing its spectrum sensing time is formulated, and a set of illustrative numerical results is then presented to validate the analytical analysis.Copyright © 2013 John Wiley & Sons, Ltd.
Paracetamol Sensor Based on Molecular Imprinting by Photosensitive Polymers
Authors: Wang Xiaohong , Luo Jing , Yi Chenglin , Liu Xiaoya
Published: June 2013

A voltammetric paracetamol sensor based on molecularly imprinted polymeric (MIP) micelles was prepared by direct electrodeposition. The MIP micelles were prepared via macromolecule self‐assembly of an amphiphilic photocrosslinkable copolymer using paracetamol as the template molecule. The resultant molecularly imprinted polymeric micelles swelled with increasing pH, and the disassociation of the micelles occurred at pH above approximately 7.4. A robust MIP film with good solvent resistance was formed on the electrode surface by anodic electrodeposition of the MIP micelles and subsequent photocrosslinking, resulting in the fabrication of a MIP electrochemical sensor for detecting paracetamol. The resultant sensor showed good response and selectivity towards paracetamol. In addition, a wide linear range from 0.01 mmol/L to 8 mmol/L and a low detection limit of 1×10−6 mol/L for paracetamol detection was demonstrated based on this sensor. The MIP sensor also showed good stability and reversibility which was applied to determine paracetamol commercial tablets.
Indirect Speciation Analysis of Thallium in Plant Extracts by Anodic Stripping Voltammetry
Authors: Pałdyna Joanna , Krasnodębska‐Ostręga Beata , Sadowska Monika , Gołębiewska Justyna
Published: June 2013

A sensitive voltammetric method (DPASV) was developed for the determination of Tl(I) and Tl(III) in plant extracts. To limit the influence of the organic matrix on the measurements, UV irradiation and addition of Amberlite XAD‐7 resin was studied. The application of 0.5 g of the resin allowed defining thallium speciation in 10.0 mL of a solution containing 0.20 mL of Sinapis alba extract. The quantification limit of 0.5 ng mL−1 Tl(I) was found for only 10 min of preconcentration, and is low enough to allow dilution of the sample before thallium determination. The procedure was validated using the recovery study and intermethod comparison with HPLC ICP MS.
Electrochemical Aptasensor for the Determination of Ochratoxin A at the Au Electrode Modified with Ag Nanoparticles Decorated with Macrocyclic Ligand
Authors: Evtugyn Gennady , Porfireva Anna , Sitdikov Rusal , Evtugyn Vladimir , Stoikov Ivan , Antipin Igor , Hianik Tibor
Published: June 2013

An electrochemical aptasensor for ochratoxin A (OTA) detection has been developed on the base of a gold electrode covered with electropolymerized neutral red and silver nanoparticles obtained by chemical reduction with macrocyclic ligands bearing catechol fragments. Thiolated aptamers against OTA were covalently attached to silver nanoparticles via AgS bonding. The interaction with OTA induced the conformational switch of the aptamer, which caused increase of the charge transfer resistance measured by EIS in the presence of ferricyanide ions. The LOD achieved (0.05 nM) was comparable to other electrochemical aptasensors employing sophisticated assembling technique and enzyme amplification of the signal. The aptasensor was validated in spiked beer samples. The recovery of the OTA determination was found to be 66.3±14.1 % for light beer and 64.3±1.8 % for dark beer.
Volatility Discovery Across Stock Limit Order Book and Options Markets
Authors: Wang Qin
Published: June 2013

Foucault [Journal of Financial Markets, 2, 99–134, 1999] provides a theoretical basis for how stock price volatility influences the aggressiveness of limit order traders. I investigate volatility discovery across stock limit order book and options markets using a broad panel of NYSE‐listed stocks from November 2007 to January 2008 and find strong evidence that, as predicted, the aggressiveness of the stock limit order book and option volatility trading Granger‐cause each other. Further, I find that the aggressiveness of the stock limit order book and option volatility trading are inversely related, which is both statistically and economically significant. © 2013 Wiley Periodicals, Inc. Jrl Fut Mark 34:934–956, 2014
DISCOUNT RATES AND THE EDUCATION GRADIENT IN MAMMOGRAPHY IN THE UK
Authors: Bíró Anikó
Published: June 2013

I analyse intertemporal decisions on undertaking breast cancer screening by women aged 50–64 years in the UK and provide estimates of the rate of discounting potential future benefits of screening. I also analyse education differences in mammography decisions and examine the underlying mechanisms by which education influences breast cancer screening attendance. I estimate a structural model, which reveals that although there are differences in the disutility of breast cancer screening between education groups, there is no difference in the estimated discount factor. These results suggest that the observed education gradient is mainly due to differences in health behaviours and healthcare attitudes. Copyright © 2013 John Wiley & Sons, Ltd.
High-fat and high-sucrose (western) diet induces steatohepatitis that is dependent on fructokinase
Authors: Ishimoto Takuji , Lanaspa Miguel A. , Rivard Christopher J. , Roncal-Jimenez Carlos A. , Orlicky David J. , Cicerchi Christina , McMahan Rachel H. , Abdelmalek Manal F. , Rosen Hugo R. , Jackman Matthew R. , MacLean Paul S. , Diggle Christine P. , Asipu Aruna , Inaba Shinichiro , Kosugi Tomoki , Sato Waichi , Maruyama Shoichi , Sánchez-Lozada Laura G. , Sautin Yuri Y. , Hill James O. , Bonthron David T. , Johnson Richard J.
Published: June 2013

Fructose intake from added sugars has been implicated as a cause of nonalcoholic fatty liver disease. Here we tested the hypothesis that fructose may interact with a high-fat diet to induce fatty liver, and to determine if this was dependent on a key enzyme in fructose metabolism, fructokinase. Wild-type or fructokinase knockout mice were fed a low-fat (11%), high-fat (36%), or high-fat (36%) and high-sucrose (30%) diet for 15 weeks. Both wild-type and fructokinase knockout mice developed obesity with mild hepatic steatosis and no evidence of hepatic inflammation on a high-fat diet compared to a low-fat diet. In contrast, wild-type mice fed a high-fat and high-sucrose diet developed more severe hepatic steatosis with low-grade inflammation and fibrosis, as noted by increased CD68, tumor necrosis factor alpha, monocyte chemoattractant protein-1, alpha-smooth muscle actin, and collagen I and TIMP1 expression. These changes were prevented in the fructokinase knockout mice.

Conclusion:

An additive effect of high-fat and high-sucrose diet on the development of hepatic steatosis exists. Further, the combination of sucrose with high-fat diet may induce steatohepatitis. The protection in fructokinase knockout mice suggests a key role for fructose (from sucrose) in this development of steatohepatitis. These studies emphasize the important role of fructose in the development of fatty liver and nonalcoholic steatohepatitis. (Hepatology 2013;58:1632–1643)
First experience of high-intensity focused ultrasound combined with transcatheter arterial embolization as local control for hepatoblastoma
Authors: Wang Shan , Yang Chao , Zhang Jun , Kong Xiang-ru , Zhu Hui , Wu Feng , Wang Zhibiao
Published: June 2013

The purpose of this study was to assess the effectiveness of high-intensity focused ultrasound (HIFU) combined with transarterial chemoembolization (TACE) in treating pediatric hepatoblastoma. Twelve patients with initially unresectable hepatoblastoma were enrolled in the study. All patients received chemotherapy, TACE, and HIFU ablation. Follow-up materials were obtained in all patients. The tumor response, survival rate, and complications were analyzed. Complete ablation was achieved in 10 patients (83.3%), and the alpha-fetoprotein level was also decreased to normal in these patients. The mean follow-up time was 13.3 ± 1.8 months (range, 2-25 months). At the end of follow-up, two patients died from tumor progression, the other 10 patients were alive. One patient was found to have lung metastasis after HIFU and had an operation to remove the lesion. The median survival time was 14 months, and the 1- and 2-year survival rates were 91.7% and 83.3%, respectively. Complications included fever, transient impairment of hepatic function, and mild malformation of ribs.

Conclusion :

HIFU combined with TACE is a safe and promising method with a low rate of severe complications. As a noninvasive approach, it may provide a novel local therapy for patients with unresectable hepatoblastoma.
A case study of postmidnight enhancement in F‐layer electron density over Sanya of China
Authors: Liu Libo , Chen Yiding , Le Huijun , Ning Baiqi , Wan Weixing , Liu Jing , Hu Lianhuan
Published: June 2013

The electron density in the ionospheric F region occasionally stops its decay and rises pronouncedly during night hours, which are termed ionospheric nighttime enhancements. In this case study, we analyzed the manually scaled ionogram records measured by a Lowell DPS‐4D ionosonde operated at Sanya (18.3°N, 109.6°E), China, to explore postmidnight enhancement events occurred in 2012, a year of moderate solar activities. Common features in these cases illustrate that, accompanying nighttime rises in peak electron density of F2 layer (NmF2), the height of F2 layer is depressed significantly, and the ionogram‐derived electron density height profiles become thinner. There are time shifts in the development of electron density enhancements in the F layer; that is, enhancement develops earlier and reaches peaks earlier at higher altitudes than at lower altitudes. Meanwhile, plasma drift is detected downward under such events, revealing the essential role of the westward electric field in forming the postmidnight enhancements in electron density of ionospheric F layer at such low latitudes.
Comparison of thermal structure and evolution between neighboring subarctic glaciers
Authors: Wilson Nat J. , Flowers Gwenn E. , Mingo Laurent
Published: June 2013

The distribution of cold and temperate ice within glaciers and ice sheets affects processes relevant to englacial and basal hydrology, sliding, and material rheology. Thermal regimes, in turn, are shaped by glacier and ice sheet dynamics, as well as environmental setting. We investigate the thermal structures of two small (<7 km2) neighboring glaciers in the St. Elias Mountains of southwestern Yukon, Canada, using ice‐penetrating radar and borehole temperature measurements. Our data reveal polythermal regimes in both glaciers that are strongly influenced by accumulation zone meltwater entrapment, suggesting a climatic control on thermal structure. Differences in hypsometry and glacier dynamics nevertheless result in observed variations in the distribution of temperate ice between the two sites. Experiments with a thermomechanically coupled flow band model corroborate the strong control of meltwater entrapment on thermal structure and suggest a generally minimal role for strain heating. An exception to this occurs where localized basal sliding produces lateral shearing and thus enhanced heat generation. Time‐dependent model simulations suggest that the future thermal evolution of the two glaciers may differ, and therefore simple parameterizations of thermal response based on regional climate may not capture realistic variability between individual glaciers. Despite these differences, both glaciers are ultimately expected to become fully cold prior to disappearing under negative mass balance conditions.
Effects of bubbles, cracks, and volcanic tephra on the spectral albedo of bare ice near the Transantarctic Mountains: Implications for sea glaciers on Snowball Earth
Authors: Dadic Ruzica , Mullen Peter C. , Schneebeli Martin , Brandt Richard E. , Warren Stephen G.
Published: June 2013

Spectral albedo was measured along a 6 km transect near the Allan Hills in East Antarctica. The transect traversed the sequence from new snow through old snow, firn, and white ice, to blue ice, showing a systematic progression of decreasing albedo at all wavelengths, as well as decreasing specific surface area (SSA) and increasing density. Broadband albedos under clear‐sky range from 0.80 for snow to 0.57 for blue ice, and from 0.87 to 0.65 under cloud. Both air bubbles and cracks scatter sunlight; their contributions to SSA were determined by microcomputed tomography on core samples of the ice. Although albedo is governed primarily by the SSA (and secondarily by the shape) of bubbles or snow grains, albedo also correlates highly with porosity, which, as a proxy variable, would be easier for ice sheet models to predict than bubble sizes. Albedo parameterizations are therefore developed as a function of density for three broad wavelength bands commonly used in general circulation models: visible, near‐infrared, and total solar. Relevance to Snowball Earth events derives from the likelihood that sublimation of equatorward‐flowing sea glaciers during those events progressively exposed the same sequence of surface materials that we measured at Allan Hills, with our short 6 km transect representing a transect across many degrees of latitude on the Snowball ocean. At the equator of Snowball Earth, climate models predict thick ice, or thin ice, or open water, depending largely on their albedo parameterizations; our measured albedos appear to be within the range that favors ice hundreds of meters thick.
Towards closing the watershed nitrogen budget: Spatial and temporal scaling of denitrification
Authors: Duncan Jonathan M. , Groffman Peter M. , Band Lawrence E.
Published: June 2013

Enhanced consideration of the hydrogeomorphic template of watersheds is critical to understanding watershed nitrogen budgets. We developed a framework to estimate the spatial distribution and temporal dynamics of soil moisture and soil oxygen in surficial soils to scale nitrogen transformations for a forested watershed (Pond Branch) in Maryland, USA. We sampled soil cores in upland, hillslope hollow, riparian hollow, and riparian hummock landscape positions in different seasons for biogeochemical fluxes including measurement of N2gas produced via denitrification. We extrapolated these rates in space and time with information derived from in situ soil oxygen and soil moisture probes to scale fluxes from plots to the catchment level. We addressed three questions: (1) How important are seasonal, daily, and storm event variations in soil oxygen for denitrification? (2) How is denitrification spatially distributed through the watershed? (3) How important is denitrification to the watershed nitrogen budget? We found that microtopography within the riparian zone is a significant influence on soil oxygen dynamics and therefore redox‐sensitive biogeochemical processes such as denitrification. Riparian zone hollows (lower topographic positions) represented 0.5%–1.0% of the catchment area, but accounted for >99% of total denitrification. Interestingly, topography was a much stronger controller of oxygen than rainfall, which had little influence on temporal variation in soil oxygen levels. Spatial and temporal extrapolations of measured rates suggest that a minimum of 16%–27% of atmospheric nitrogen deposition is lost to denitrification. These results suggest that the importance of denitrification in the nitrogen budget of forested watersheds depends fundamentally on the presence of landscape elements, such as riparian hollows that function as “hot spots” of activity.